1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * INET An implementation of the TCP/IP protocol suite for the LINUX
4 * operating system. INET is implemented using the BSD Socket
5 * interface as the means of communication with the user level.
6 *
7 * The User Datagram Protocol (UDP).
8 *
9 * Authors: Ross Biro
10 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
11 * Arnt Gulbrandsen, <agulbra@nvg.unit.no>
12 * Alan Cox, <alan@lxorguk.ukuu.org.uk>
13 * Hirokazu Takahashi, <taka@valinux.co.jp>
14 *
15 * Fixes:
16 * Alan Cox : verify_area() calls
17 * Alan Cox : stopped close while in use off icmp
18 * messages. Not a fix but a botch that
19 * for udp at least is 'valid'.
20 * Alan Cox : Fixed icmp handling properly
21 * Alan Cox : Correct error for oversized datagrams
22 * Alan Cox : Tidied select() semantics.
23 * Alan Cox : udp_err() fixed properly, also now
24 * select and read wake correctly on errors
25 * Alan Cox : udp_send verify_area moved to avoid mem leak
26 * Alan Cox : UDP can count its memory
27 * Alan Cox : send to an unknown connection causes
28 * an ECONNREFUSED off the icmp, but
29 * does NOT close.
30 * Alan Cox : Switched to new sk_buff handlers. No more backlog!
31 * Alan Cox : Using generic datagram code. Even smaller and the PEEK
32 * bug no longer crashes it.
33 * Fred Van Kempen : Net2e support for sk->broadcast.
34 * Alan Cox : Uses skb_free_datagram
35 * Alan Cox : Added get/set sockopt support.
36 * Alan Cox : Broadcasting without option set returns EACCES.
37 * Alan Cox : No wakeup calls. Instead we now use the callbacks.
38 * Alan Cox : Use ip_tos and ip_ttl
39 * Alan Cox : SNMP Mibs
40 * Alan Cox : MSG_DONTROUTE, and 0.0.0.0 support.
41 * Matt Dillon : UDP length checks.
42 * Alan Cox : Smarter af_inet used properly.
43 * Alan Cox : Use new kernel side addressing.
44 * Alan Cox : Incorrect return on truncated datagram receive.
45 * Arnt Gulbrandsen : New udp_send and stuff
46 * Alan Cox : Cache last socket
47 * Alan Cox : Route cache
48 * Jon Peatfield : Minor efficiency fix to sendto().
49 * Mike Shaver : RFC1122 checks.
50 * Alan Cox : Nonblocking error fix.
51 * Willy Konynenberg : Transparent proxying support.
52 * Mike McLagan : Routing by source
53 * David S. Miller : New socket lookup architecture.
54 * Last socket cache retained as it
55 * does have a high hit rate.
56 * Olaf Kirch : Don't linearise iovec on sendmsg.
57 * Andi Kleen : Some cleanups, cache destination entry
58 * for connect.
59 * Vitaly E. Lavrov : Transparent proxy revived after year coma.
60 * Melvin Smith : Check msg_name not msg_namelen in sendto(),
61 * return ENOTCONN for unconnected sockets (POSIX)
62 * Janos Farkas : don't deliver multi/broadcasts to a different
63 * bound-to-device socket
64 * Hirokazu Takahashi : HW checksumming for outgoing UDP
65 * datagrams.
66 * Hirokazu Takahashi : sendfile() on UDP works now.
67 * Arnaldo C. Melo : convert /proc/net/udp to seq_file
68 * YOSHIFUJI Hideaki @USAGI and: Support IPV6_V6ONLY socket option, which
69 * Alexey Kuznetsov: allow both IPv4 and IPv6 sockets to bind
70 * a single port at the same time.
71 * Derek Atkins <derek@ihtfp.com>: Add Encapulation Support
72 * James Chapman : Add L2TP encapsulation type.
73 */
74
75#define pr_fmt(fmt) "UDP: " fmt
76
77#include <linux/bpf-cgroup.h>
78#include <linux/uaccess.h>
79#include <asm/ioctls.h>
80#include <linux/memblock.h>
81#include <linux/highmem.h>
82#include <linux/types.h>
83#include <linux/fcntl.h>
84#include <linux/module.h>
85#include <linux/socket.h>
86#include <linux/sockios.h>
87#include <linux/igmp.h>
88#include <linux/inetdevice.h>
89#include <linux/in.h>
90#include <linux/errno.h>
91#include <linux/timer.h>
92#include <linux/mm.h>
93#include <linux/inet.h>
94#include <linux/netdevice.h>
95#include <linux/slab.h>
96#include <linux/sock_diag.h>
97#include <net/tcp_states.h>
98#include <linux/skbuff.h>
99#include <linux/proc_fs.h>
100#include <linux/seq_file.h>
101#include <net/net_namespace.h>
102#include <net/icmp.h>
103#include <net/inet_hashtables.h>
104#include <net/ip.h>
105#include <net/ip_tunnels.h>
106#include <net/route.h>
107#include <net/checksum.h>
108#include <net/gso.h>
109#include <net/xfrm.h>
110#include <trace/events/udp.h>
111#include <linux/static_key.h>
112#include <linux/btf_ids.h>
113#include <trace/events/skb.h>
114#include <net/busy_poll.h>
115#include "udp_impl.h"
116#include <net/sock_reuseport.h>
117#include <net/addrconf.h>
118#include <net/udp_tunnel.h>
119#include <net/gro.h>
120#if IS_ENABLED(CONFIG_IPV6)
121#include <net/ipv6_stubs.h>
122#endif
123#include <net/rps.h>
124
125struct udp_table udp_table __read_mostly;
126
127long sysctl_udp_mem[3] __read_mostly;
128EXPORT_IPV6_MOD(sysctl_udp_mem);
129
130atomic_long_t udp_memory_allocated ____cacheline_aligned_in_smp;
131EXPORT_IPV6_MOD(udp_memory_allocated);
132DEFINE_PER_CPU(int, udp_memory_per_cpu_fw_alloc);
133EXPORT_PER_CPU_SYMBOL_GPL(udp_memory_per_cpu_fw_alloc);
134
135#define MAX_UDP_PORTS 65536
136#define PORTS_PER_CHAIN (MAX_UDP_PORTS / UDP_HTABLE_SIZE_MIN_PERNET)
137
138static struct udp_table *udp_get_table_prot(struct sock *sk)
139{
140 return sk->sk_prot->h.udp_table ? : sock_net(sk)->ipv4.udp_table;
141}
142
143static int udp_lib_lport_inuse(struct net *net, __u16 num,
144 const struct udp_hslot *hslot,
145 unsigned long *bitmap,
146 struct sock *sk, unsigned int log)
147{
148 struct sock *sk2;
149 kuid_t uid = sock_i_uid(sk);
150
151 sk_for_each(sk2, &hslot->head) {
152 if (net_eq(net1: sock_net(sk: sk2), net2: net) &&
153 sk2 != sk &&
154 (bitmap || udp_sk(sk2)->udp_port_hash == num) &&
155 (!sk2->sk_reuse || !sk->sk_reuse) &&
156 (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if ||
157 sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
158 inet_rcv_saddr_equal(sk, sk2, match_wildcard: true)) {
159 if (sk2->sk_reuseport && sk->sk_reuseport &&
160 !rcu_access_pointer(sk->sk_reuseport_cb) &&
161 uid_eq(left: uid, right: sock_i_uid(sk: sk2))) {
162 if (!bitmap)
163 return 0;
164 } else {
165 if (!bitmap)
166 return 1;
167 __set_bit(udp_sk(sk2)->udp_port_hash >> log,
168 bitmap);
169 }
170 }
171 }
172 return 0;
173}
174
175/*
176 * Note: we still hold spinlock of primary hash chain, so no other writer
177 * can insert/delete a socket with local_port == num
178 */
179static int udp_lib_lport_inuse2(struct net *net, __u16 num,
180 struct udp_hslot *hslot2,
181 struct sock *sk)
182{
183 struct sock *sk2;
184 kuid_t uid = sock_i_uid(sk);
185 int res = 0;
186
187 spin_lock(lock: &hslot2->lock);
188 udp_portaddr_for_each_entry(sk2, &hslot2->head) {
189 if (net_eq(net1: sock_net(sk: sk2), net2: net) &&
190 sk2 != sk &&
191 (udp_sk(sk2)->udp_port_hash == num) &&
192 (!sk2->sk_reuse || !sk->sk_reuse) &&
193 (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if ||
194 sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
195 inet_rcv_saddr_equal(sk, sk2, match_wildcard: true)) {
196 if (sk2->sk_reuseport && sk->sk_reuseport &&
197 !rcu_access_pointer(sk->sk_reuseport_cb) &&
198 uid_eq(left: uid, right: sock_i_uid(sk: sk2))) {
199 res = 0;
200 } else {
201 res = 1;
202 }
203 break;
204 }
205 }
206 spin_unlock(lock: &hslot2->lock);
207 return res;
208}
209
210static int udp_reuseport_add_sock(struct sock *sk, struct udp_hslot *hslot)
211{
212 struct net *net = sock_net(sk);
213 kuid_t uid = sock_i_uid(sk);
214 struct sock *sk2;
215
216 sk_for_each(sk2, &hslot->head) {
217 if (net_eq(net1: sock_net(sk: sk2), net2: net) &&
218 sk2 != sk &&
219 sk2->sk_family == sk->sk_family &&
220 ipv6_only_sock(sk2) == ipv6_only_sock(sk) &&
221 (udp_sk(sk2)->udp_port_hash == udp_sk(sk)->udp_port_hash) &&
222 (sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
223 sk2->sk_reuseport && uid_eq(left: uid, right: sock_i_uid(sk: sk2)) &&
224 inet_rcv_saddr_equal(sk, sk2, match_wildcard: false)) {
225 return reuseport_add_sock(sk, sk2,
226 bind_inany: inet_rcv_saddr_any(sk));
227 }
228 }
229
230 return reuseport_alloc(sk, bind_inany: inet_rcv_saddr_any(sk));
231}
232
233/**
234 * udp_lib_get_port - UDP/-Lite port lookup for IPv4 and IPv6
235 *
236 * @sk: socket struct in question
237 * @snum: port number to look up
238 * @hash2_nulladdr: AF-dependent hash value in secondary hash chains,
239 * with NULL address
240 */
241int udp_lib_get_port(struct sock *sk, unsigned short snum,
242 unsigned int hash2_nulladdr)
243{
244 struct udp_table *udptable = udp_get_table_prot(sk);
245 struct udp_hslot *hslot, *hslot2;
246 struct net *net = sock_net(sk);
247 int error = -EADDRINUSE;
248
249 if (!snum) {
250 DECLARE_BITMAP(bitmap, PORTS_PER_CHAIN);
251 unsigned short first, last;
252 int low, high, remaining;
253 unsigned int rand;
254
255 inet_sk_get_local_port_range(sk, low: &low, high: &high);
256 remaining = (high - low) + 1;
257
258 rand = get_random_u32();
259 first = reciprocal_scale(val: rand, ep_ro: remaining) + low;
260 /*
261 * force rand to be an odd multiple of UDP_HTABLE_SIZE
262 */
263 rand = (rand | 1) * (udptable->mask + 1);
264 last = first + udptable->mask + 1;
265 do {
266 hslot = udp_hashslot(table: udptable, net, num: first);
267 bitmap_zero(dst: bitmap, PORTS_PER_CHAIN);
268 spin_lock_bh(lock: &hslot->lock);
269 udp_lib_lport_inuse(net, num: snum, hslot, bitmap, sk,
270 log: udptable->log);
271
272 snum = first;
273 /*
274 * Iterate on all possible values of snum for this hash.
275 * Using steps of an odd multiple of UDP_HTABLE_SIZE
276 * give us randomization and full range coverage.
277 */
278 do {
279 if (low <= snum && snum <= high &&
280 !test_bit(snum >> udptable->log, bitmap) &&
281 !inet_is_local_reserved_port(net, port: snum))
282 goto found;
283 snum += rand;
284 } while (snum != first);
285 spin_unlock_bh(lock: &hslot->lock);
286 cond_resched();
287 } while (++first != last);
288 goto fail;
289 } else {
290 hslot = udp_hashslot(table: udptable, net, num: snum);
291 spin_lock_bh(lock: &hslot->lock);
292 if (hslot->count > 10) {
293 int exist;
294 unsigned int slot2 = udp_sk(sk)->udp_portaddr_hash ^ snum;
295
296 slot2 &= udptable->mask;
297 hash2_nulladdr &= udptable->mask;
298
299 hslot2 = udp_hashslot2(table: udptable, hash: slot2);
300 if (hslot->count < hslot2->count)
301 goto scan_primary_hash;
302
303 exist = udp_lib_lport_inuse2(net, num: snum, hslot2, sk);
304 if (!exist && (hash2_nulladdr != slot2)) {
305 hslot2 = udp_hashslot2(table: udptable, hash: hash2_nulladdr);
306 exist = udp_lib_lport_inuse2(net, num: snum, hslot2,
307 sk);
308 }
309 if (exist)
310 goto fail_unlock;
311 else
312 goto found;
313 }
314scan_primary_hash:
315 if (udp_lib_lport_inuse(net, num: snum, hslot, NULL, sk, log: 0))
316 goto fail_unlock;
317 }
318found:
319 inet_sk(sk)->inet_num = snum;
320 udp_sk(sk)->udp_port_hash = snum;
321 udp_sk(sk)->udp_portaddr_hash ^= snum;
322 if (sk_unhashed(sk)) {
323 if (sk->sk_reuseport &&
324 udp_reuseport_add_sock(sk, hslot)) {
325 inet_sk(sk)->inet_num = 0;
326 udp_sk(sk)->udp_port_hash = 0;
327 udp_sk(sk)->udp_portaddr_hash ^= snum;
328 goto fail_unlock;
329 }
330
331 sock_set_flag(sk, flag: SOCK_RCU_FREE);
332
333 sk_add_node_rcu(sk, list: &hslot->head);
334 hslot->count++;
335 sock_prot_inuse_add(net: sock_net(sk), prot: sk->sk_prot, val: 1);
336
337 hslot2 = udp_hashslot2(table: udptable, udp_sk(sk)->udp_portaddr_hash);
338 spin_lock(lock: &hslot2->lock);
339 if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport &&
340 sk->sk_family == AF_INET6)
341 hlist_add_tail_rcu(n: &udp_sk(sk)->udp_portaddr_node,
342 h: &hslot2->head);
343 else
344 hlist_add_head_rcu(n: &udp_sk(sk)->udp_portaddr_node,
345 h: &hslot2->head);
346 hslot2->count++;
347 spin_unlock(lock: &hslot2->lock);
348 }
349
350 error = 0;
351fail_unlock:
352 spin_unlock_bh(lock: &hslot->lock);
353fail:
354 return error;
355}
356EXPORT_IPV6_MOD(udp_lib_get_port);
357
358int udp_v4_get_port(struct sock *sk, unsigned short snum)
359{
360 unsigned int hash2_nulladdr =
361 ipv4_portaddr_hash(net: sock_net(sk), htonl(INADDR_ANY), port: snum);
362 unsigned int hash2_partial =
363 ipv4_portaddr_hash(net: sock_net(sk), inet_sk(sk)->inet_rcv_saddr, port: 0);
364
365 /* precompute partial secondary hash */
366 udp_sk(sk)->udp_portaddr_hash = hash2_partial;
367 return udp_lib_get_port(sk, snum, hash2_nulladdr);
368}
369
370static int compute_score(struct sock *sk, const struct net *net,
371 __be32 saddr, __be16 sport,
372 __be32 daddr, unsigned short hnum,
373 int dif, int sdif)
374{
375 int score;
376 struct inet_sock *inet;
377 bool dev_match;
378
379 if (!net_eq(net1: sock_net(sk), net2: net) ||
380 udp_sk(sk)->udp_port_hash != hnum ||
381 ipv6_only_sock(sk))
382 return -1;
383
384 if (sk->sk_rcv_saddr != daddr)
385 return -1;
386
387 score = (sk->sk_family == PF_INET) ? 2 : 1;
388
389 inet = inet_sk(sk);
390 if (inet->inet_daddr) {
391 if (inet->inet_daddr != saddr)
392 return -1;
393 score += 4;
394 }
395
396 if (inet->inet_dport) {
397 if (inet->inet_dport != sport)
398 return -1;
399 score += 4;
400 }
401
402 dev_match = udp_sk_bound_dev_eq(net, bound_dev_if: sk->sk_bound_dev_if,
403 dif, sdif);
404 if (!dev_match)
405 return -1;
406 if (sk->sk_bound_dev_if)
407 score += 4;
408
409 if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id())
410 score++;
411 return score;
412}
413
414u32 udp_ehashfn(const struct net *net, const __be32 laddr, const __u16 lport,
415 const __be32 faddr, const __be16 fport)
416{
417 net_get_random_once(&udp_ehash_secret, sizeof(udp_ehash_secret));
418
419 return __inet_ehashfn(laddr, lport, faddr, fport,
420 udp_ehash_secret + net_hash_mix(net));
421}
422EXPORT_IPV6_MOD(udp_ehashfn);
423
424/**
425 * udp4_lib_lookup1() - Simplified lookup using primary hash (destination port)
426 * @net: Network namespace
427 * @saddr: Source address, network order
428 * @sport: Source port, network order
429 * @daddr: Destination address, network order
430 * @hnum: Destination port, host order
431 * @dif: Destination interface index
432 * @sdif: Destination bridge port index, if relevant
433 * @udptable: Set of UDP hash tables
434 *
435 * Simplified lookup to be used as fallback if no sockets are found due to a
436 * potential race between (receive) address change, and lookup happening before
437 * the rehash operation. This function ignores SO_REUSEPORT groups while scoring
438 * result sockets, because if we have one, we don't need the fallback at all.
439 *
440 * Called under rcu_read_lock().
441 *
442 * Return: socket with highest matching score if any, NULL if none
443 */
444static struct sock *udp4_lib_lookup1(const struct net *net,
445 __be32 saddr, __be16 sport,
446 __be32 daddr, unsigned int hnum,
447 int dif, int sdif,
448 const struct udp_table *udptable)
449{
450 unsigned int slot = udp_hashfn(net, num: hnum, mask: udptable->mask);
451 struct udp_hslot *hslot = &udptable->hash[slot];
452 struct sock *sk, *result = NULL;
453 int score, badness = 0;
454
455 sk_for_each_rcu(sk, &hslot->head) {
456 score = compute_score(sk, net,
457 saddr, sport, daddr, hnum, dif, sdif);
458 if (score > badness) {
459 result = sk;
460 badness = score;
461 }
462 }
463
464 return result;
465}
466
467/* called with rcu_read_lock() */
468static struct sock *udp4_lib_lookup2(const struct net *net,
469 __be32 saddr, __be16 sport,
470 __be32 daddr, unsigned int hnum,
471 int dif, int sdif,
472 struct udp_hslot *hslot2,
473 struct sk_buff *skb)
474{
475 struct sock *sk, *result;
476 int score, badness;
477 bool need_rescore;
478
479 result = NULL;
480 badness = 0;
481 udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {
482 need_rescore = false;
483rescore:
484 score = compute_score(sk: need_rescore ? result : sk, net, saddr,
485 sport, daddr, hnum, dif, sdif);
486 if (score > badness) {
487 badness = score;
488
489 if (need_rescore)
490 continue;
491
492 if (sk->sk_state == TCP_ESTABLISHED) {
493 result = sk;
494 continue;
495 }
496
497 result = inet_lookup_reuseport(net, sk, skb, doff: sizeof(struct udphdr),
498 saddr, sport, daddr, hnum, ehashfn: udp_ehashfn);
499 if (!result) {
500 result = sk;
501 continue;
502 }
503
504 /* Fall back to scoring if group has connections */
505 if (!reuseport_has_conns(sk))
506 return result;
507
508 /* Reuseport logic returned an error, keep original score. */
509 if (IS_ERR(ptr: result))
510 continue;
511
512 /* compute_score is too long of a function to be
513 * inlined, and calling it again here yields
514 * measureable overhead for some
515 * workloads. Work around it by jumping
516 * backwards to rescore 'result'.
517 */
518 need_rescore = true;
519 goto rescore;
520 }
521 }
522 return result;
523}
524
525#if IS_ENABLED(CONFIG_BASE_SMALL)
526static struct sock *udp4_lib_lookup4(const struct net *net,
527 __be32 saddr, __be16 sport,
528 __be32 daddr, unsigned int hnum,
529 int dif, int sdif,
530 struct udp_table *udptable)
531{
532 return NULL;
533}
534
535static void udp_rehash4(struct udp_table *udptable, struct sock *sk,
536 u16 newhash4)
537{
538}
539
540static void udp_unhash4(struct udp_table *udptable, struct sock *sk)
541{
542}
543#else /* !CONFIG_BASE_SMALL */
544static struct sock *udp4_lib_lookup4(const struct net *net,
545 __be32 saddr, __be16 sport,
546 __be32 daddr, unsigned int hnum,
547 int dif, int sdif,
548 struct udp_table *udptable)
549{
550 const __portpair ports = INET_COMBINED_PORTS(sport, hnum);
551 const struct hlist_nulls_node *node;
552 struct udp_hslot *hslot4;
553 unsigned int hash4, slot;
554 struct udp_sock *up;
555 struct sock *sk;
556
557 hash4 = udp_ehashfn(net, daddr, hnum, saddr, sport);
558 slot = hash4 & udptable->mask;
559 hslot4 = &udptable->hash4[slot];
560 INET_ADDR_COOKIE(acookie, saddr, daddr);
561
562begin:
563 /* SLAB_TYPESAFE_BY_RCU not used, so we don't need to touch sk_refcnt */
564 udp_lrpa_for_each_entry_rcu(up, node, &hslot4->nulls_head) {
565 sk = (struct sock *)up;
566 if (inet_match(net, sk, acookie, ports, dif, sdif))
567 return sk;
568 }
569
570 /* if the nulls value we got at the end of this lookup is not the
571 * expected one, we must restart lookup. We probably met an item that
572 * was moved to another chain due to rehash.
573 */
574 if (get_nulls_value(node) != slot)
575 goto begin;
576
577 return NULL;
578}
579
580/* udp_rehash4() only checks hslot4, and hash4_cnt is not processed. */
581static void udp_rehash4(struct udp_table *udptable, struct sock *sk,
582 u16 newhash4)
583{
584 struct udp_hslot *hslot4, *nhslot4;
585
586 hslot4 = udp_hashslot4(udptable, udp_sk(sk)->udp_lrpa_hash);
587 nhslot4 = udp_hashslot4(udptable, newhash4);
588 udp_sk(sk)->udp_lrpa_hash = newhash4;
589
590 if (hslot4 != nhslot4) {
591 spin_lock_bh(&hslot4->lock);
592 hlist_nulls_del_init_rcu(&udp_sk(sk)->udp_lrpa_node);
593 hslot4->count--;
594 spin_unlock_bh(&hslot4->lock);
595
596 spin_lock_bh(&nhslot4->lock);
597 hlist_nulls_add_head_rcu(&udp_sk(sk)->udp_lrpa_node,
598 &nhslot4->nulls_head);
599 nhslot4->count++;
600 spin_unlock_bh(&nhslot4->lock);
601 }
602}
603
604static void udp_unhash4(struct udp_table *udptable, struct sock *sk)
605{
606 struct udp_hslot *hslot2, *hslot4;
607
608 if (udp_hashed4(sk)) {
609 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash);
610 hslot4 = udp_hashslot4(udptable, udp_sk(sk)->udp_lrpa_hash);
611
612 spin_lock(&hslot4->lock);
613 hlist_nulls_del_init_rcu(&udp_sk(sk)->udp_lrpa_node);
614 hslot4->count--;
615 spin_unlock(&hslot4->lock);
616
617 spin_lock(&hslot2->lock);
618 udp_hash4_dec(hslot2);
619 spin_unlock(&hslot2->lock);
620 }
621}
622
623void udp_lib_hash4(struct sock *sk, u16 hash)
624{
625 struct udp_hslot *hslot, *hslot2, *hslot4;
626 struct net *net = sock_net(sk);
627 struct udp_table *udptable;
628
629 /* Connected udp socket can re-connect to another remote address, which
630 * will be handled by rehash. Thus no need to redo hash4 here.
631 */
632 if (udp_hashed4(sk))
633 return;
634
635 udptable = net->ipv4.udp_table;
636 hslot = udp_hashslot(udptable, net, udp_sk(sk)->udp_port_hash);
637 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash);
638 hslot4 = udp_hashslot4(udptable, hash);
639 udp_sk(sk)->udp_lrpa_hash = hash;
640
641 spin_lock_bh(&hslot->lock);
642 if (rcu_access_pointer(sk->sk_reuseport_cb))
643 reuseport_detach_sock(sk);
644
645 spin_lock(&hslot4->lock);
646 hlist_nulls_add_head_rcu(&udp_sk(sk)->udp_lrpa_node,
647 &hslot4->nulls_head);
648 hslot4->count++;
649 spin_unlock(&hslot4->lock);
650
651 spin_lock(&hslot2->lock);
652 udp_hash4_inc(hslot2);
653 spin_unlock(&hslot2->lock);
654
655 spin_unlock_bh(&hslot->lock);
656}
657EXPORT_IPV6_MOD(udp_lib_hash4);
658
659/* call with sock lock */
660void udp4_hash4(struct sock *sk)
661{
662 struct net *net = sock_net(sk);
663 unsigned int hash;
664
665 if (sk_unhashed(sk) || sk->sk_rcv_saddr == htonl(INADDR_ANY))
666 return;
667
668 hash = udp_ehashfn(net, sk->sk_rcv_saddr, sk->sk_num,
669 sk->sk_daddr, sk->sk_dport);
670
671 udp_lib_hash4(sk, hash);
672}
673EXPORT_IPV6_MOD(udp4_hash4);
674#endif /* CONFIG_BASE_SMALL */
675
676/* UDP is nearly always wildcards out the wazoo, it makes no sense to try
677 * harder than this. -DaveM
678 */
679struct sock *__udp4_lib_lookup(const struct net *net, __be32 saddr,
680 __be16 sport, __be32 daddr, __be16 dport, int dif,
681 int sdif, struct udp_table *udptable, struct sk_buff *skb)
682{
683 unsigned short hnum = ntohs(dport);
684 struct udp_hslot *hslot2;
685 struct sock *result, *sk;
686 unsigned int hash2;
687
688 hash2 = ipv4_portaddr_hash(net, saddr: daddr, port: hnum);
689 hslot2 = udp_hashslot2(table: udptable, hash: hash2);
690
691 if (udp_has_hash4(hslot2)) {
692 result = udp4_lib_lookup4(net, saddr, sport, daddr, hnum,
693 dif, sdif, udptable);
694 if (result) /* udp4_lib_lookup4 return sk or NULL */
695 return result;
696 }
697
698 /* Lookup connected or non-wildcard socket */
699 result = udp4_lib_lookup2(net, saddr, sport,
700 daddr, hnum, dif, sdif,
701 hslot2, skb);
702 if (!IS_ERR_OR_NULL(ptr: result) && result->sk_state == TCP_ESTABLISHED)
703 goto done;
704
705 /* Lookup redirect from BPF */
706 if (static_branch_unlikely(&bpf_sk_lookup_enabled) &&
707 udptable == net->ipv4.udp_table) {
708 sk = inet_lookup_run_sk_lookup(net, IPPROTO_UDP, skb, doff: sizeof(struct udphdr),
709 saddr, sport, daddr, hnum, dif,
710 ehashfn: udp_ehashfn);
711 if (sk) {
712 result = sk;
713 goto done;
714 }
715 }
716
717 /* Got non-wildcard socket or error on first lookup */
718 if (result)
719 goto done;
720
721 /* Lookup wildcard sockets */
722 hash2 = ipv4_portaddr_hash(net, htonl(INADDR_ANY), port: hnum);
723 hslot2 = udp_hashslot2(table: udptable, hash: hash2);
724
725 result = udp4_lib_lookup2(net, saddr, sport,
726 htonl(INADDR_ANY), hnum, dif, sdif,
727 hslot2, skb);
728 if (!IS_ERR_OR_NULL(ptr: result))
729 goto done;
730
731 /* Primary hash (destination port) lookup as fallback for this race:
732 * 1. __ip4_datagram_connect() sets sk_rcv_saddr
733 * 2. lookup (this function): new sk_rcv_saddr, hashes not updated yet
734 * 3. rehash operation updating _secondary and four-tuple_ hashes
735 * The primary hash doesn't need an update after 1., so, thanks to this
736 * further step, 1. and 3. don't need to be atomic against the lookup.
737 */
738 result = udp4_lib_lookup1(net, saddr, sport, daddr, hnum, dif, sdif,
739 udptable);
740
741done:
742 if (IS_ERR(ptr: result))
743 return NULL;
744 return result;
745}
746EXPORT_SYMBOL_GPL(__udp4_lib_lookup);
747
748static inline struct sock *__udp4_lib_lookup_skb(struct sk_buff *skb,
749 __be16 sport, __be16 dport,
750 struct udp_table *udptable)
751{
752 const struct iphdr *iph = ip_hdr(skb);
753
754 return __udp4_lib_lookup(dev_net(dev: skb->dev), iph->saddr, sport,
755 iph->daddr, dport, inet_iif(skb),
756 inet_sdif(skb), udptable, skb);
757}
758
759struct sock *udp4_lib_lookup_skb(const struct sk_buff *skb,
760 __be16 sport, __be16 dport)
761{
762 const u16 offset = NAPI_GRO_CB(skb)->network_offsets[skb->encapsulation];
763 const struct iphdr *iph = (struct iphdr *)(skb->data + offset);
764 struct net *net = dev_net(dev: skb->dev);
765 int iif, sdif;
766
767 inet_get_iif_sdif(skb, iif: &iif, sdif: &sdif);
768
769 return __udp4_lib_lookup(net, iph->saddr, sport,
770 iph->daddr, dport, iif,
771 sdif, net->ipv4.udp_table, NULL);
772}
773
774/* Must be called under rcu_read_lock().
775 * Does increment socket refcount.
776 */
777#if IS_ENABLED(CONFIG_NF_TPROXY_IPV4) || IS_ENABLED(CONFIG_NF_SOCKET_IPV4)
778struct sock *udp4_lib_lookup(const struct net *net, __be32 saddr, __be16 sport,
779 __be32 daddr, __be16 dport, int dif)
780{
781 struct sock *sk;
782
783 sk = __udp4_lib_lookup(net, saddr, sport, daddr, dport,
784 dif, 0, net->ipv4.udp_table, NULL);
785 if (sk && !refcount_inc_not_zero(r: &sk->sk_refcnt))
786 sk = NULL;
787 return sk;
788}
789EXPORT_SYMBOL_GPL(udp4_lib_lookup);
790#endif
791
792static inline bool __udp_is_mcast_sock(struct net *net, const struct sock *sk,
793 __be16 loc_port, __be32 loc_addr,
794 __be16 rmt_port, __be32 rmt_addr,
795 int dif, int sdif, unsigned short hnum)
796{
797 const struct inet_sock *inet = inet_sk(sk);
798
799 if (!net_eq(net1: sock_net(sk), net2: net) ||
800 udp_sk(sk)->udp_port_hash != hnum ||
801 (inet->inet_daddr && inet->inet_daddr != rmt_addr) ||
802 (inet->inet_dport != rmt_port && inet->inet_dport) ||
803 (inet->inet_rcv_saddr && inet->inet_rcv_saddr != loc_addr) ||
804 ipv6_only_sock(sk) ||
805 !udp_sk_bound_dev_eq(net, bound_dev_if: sk->sk_bound_dev_if, dif, sdif))
806 return false;
807 if (!ip_mc_sf_allow(sk, local: loc_addr, rmt: rmt_addr, dif, sdif))
808 return false;
809 return true;
810}
811
812DEFINE_STATIC_KEY_FALSE(udp_encap_needed_key);
813EXPORT_IPV6_MOD(udp_encap_needed_key);
814
815#if IS_ENABLED(CONFIG_IPV6)
816DEFINE_STATIC_KEY_FALSE(udpv6_encap_needed_key);
817EXPORT_IPV6_MOD(udpv6_encap_needed_key);
818#endif
819
820void udp_encap_enable(void)
821{
822 static_branch_inc(&udp_encap_needed_key);
823}
824EXPORT_SYMBOL(udp_encap_enable);
825
826void udp_encap_disable(void)
827{
828 static_branch_dec(&udp_encap_needed_key);
829}
830EXPORT_SYMBOL(udp_encap_disable);
831
832/* Handler for tunnels with arbitrary destination ports: no socket lookup, go
833 * through error handlers in encapsulations looking for a match.
834 */
835static int __udp4_lib_err_encap_no_sk(struct sk_buff *skb, u32 info)
836{
837 int i;
838
839 for (i = 0; i < MAX_IPTUN_ENCAP_OPS; i++) {
840 int (*handler)(struct sk_buff *skb, u32 info);
841 const struct ip_tunnel_encap_ops *encap;
842
843 encap = rcu_dereference(iptun_encaps[i]);
844 if (!encap)
845 continue;
846 handler = encap->err_handler;
847 if (handler && !handler(skb, info))
848 return 0;
849 }
850
851 return -ENOENT;
852}
853
854/* Try to match ICMP errors to UDP tunnels by looking up a socket without
855 * reversing source and destination port: this will match tunnels that force the
856 * same destination port on both endpoints (e.g. VXLAN, GENEVE). Note that
857 * lwtunnels might actually break this assumption by being configured with
858 * different destination ports on endpoints, in this case we won't be able to
859 * trace ICMP messages back to them.
860 *
861 * If this doesn't match any socket, probe tunnels with arbitrary destination
862 * ports (e.g. FoU, GUE): there, the receiving socket is useless, as the port
863 * we've sent packets to won't necessarily match the local destination port.
864 *
865 * Then ask the tunnel implementation to match the error against a valid
866 * association.
867 *
868 * Return an error if we can't find a match, the socket if we need further
869 * processing, zero otherwise.
870 */
871static struct sock *__udp4_lib_err_encap(struct net *net,
872 const struct iphdr *iph,
873 struct udphdr *uh,
874 struct udp_table *udptable,
875 struct sock *sk,
876 struct sk_buff *skb, u32 info)
877{
878 int (*lookup)(struct sock *sk, struct sk_buff *skb);
879 int network_offset, transport_offset;
880 struct udp_sock *up;
881
882 network_offset = skb_network_offset(skb);
883 transport_offset = skb_transport_offset(skb);
884
885 /* Network header needs to point to the outer IPv4 header inside ICMP */
886 skb_reset_network_header(skb);
887
888 /* Transport header needs to point to the UDP header */
889 skb_set_transport_header(skb, offset: iph->ihl << 2);
890
891 if (sk) {
892 up = udp_sk(sk);
893
894 lookup = READ_ONCE(up->encap_err_lookup);
895 if (lookup && lookup(sk, skb))
896 sk = NULL;
897
898 goto out;
899 }
900
901 sk = __udp4_lib_lookup(net, iph->daddr, uh->source,
902 iph->saddr, uh->dest, skb->dev->ifindex, 0,
903 udptable, NULL);
904 if (sk) {
905 up = udp_sk(sk);
906
907 lookup = READ_ONCE(up->encap_err_lookup);
908 if (!lookup || lookup(sk, skb))
909 sk = NULL;
910 }
911
912out:
913 if (!sk)
914 sk = ERR_PTR(error: __udp4_lib_err_encap_no_sk(skb, info));
915
916 skb_set_transport_header(skb, offset: transport_offset);
917 skb_set_network_header(skb, offset: network_offset);
918
919 return sk;
920}
921
922/*
923 * This routine is called by the ICMP module when it gets some
924 * sort of error condition. If err < 0 then the socket should
925 * be closed and the error returned to the user. If err > 0
926 * it's just the icmp type << 8 | icmp code.
927 * Header points to the ip header of the error packet. We move
928 * on past this. Then (as it used to claim before adjustment)
929 * header points to the first 8 bytes of the udp header. We need
930 * to find the appropriate port.
931 */
932
933int __udp4_lib_err(struct sk_buff *skb, u32 info, struct udp_table *udptable)
934{
935 struct inet_sock *inet;
936 const struct iphdr *iph = (const struct iphdr *)skb->data;
937 struct udphdr *uh = (struct udphdr *)(skb->data+(iph->ihl<<2));
938 const int type = icmp_hdr(skb)->type;
939 const int code = icmp_hdr(skb)->code;
940 bool tunnel = false;
941 struct sock *sk;
942 int harderr;
943 int err;
944 struct net *net = dev_net(dev: skb->dev);
945
946 sk = __udp4_lib_lookup(net, iph->daddr, uh->dest,
947 iph->saddr, uh->source, skb->dev->ifindex,
948 inet_sdif(skb), udptable, NULL);
949
950 if (!sk || READ_ONCE(udp_sk(sk)->encap_type)) {
951 /* No socket for error: try tunnels before discarding */
952 if (static_branch_unlikely(&udp_encap_needed_key)) {
953 sk = __udp4_lib_err_encap(net, iph, uh, udptable, sk, skb,
954 info);
955 if (!sk)
956 return 0;
957 } else
958 sk = ERR_PTR(error: -ENOENT);
959
960 if (IS_ERR(ptr: sk)) {
961 __ICMP_INC_STATS(net, ICMP_MIB_INERRORS);
962 return PTR_ERR(ptr: sk);
963 }
964
965 tunnel = true;
966 }
967
968 err = 0;
969 harderr = 0;
970 inet = inet_sk(sk);
971
972 switch (type) {
973 default:
974 case ICMP_TIME_EXCEEDED:
975 err = EHOSTUNREACH;
976 break;
977 case ICMP_SOURCE_QUENCH:
978 goto out;
979 case ICMP_PARAMETERPROB:
980 err = EPROTO;
981 harderr = 1;
982 break;
983 case ICMP_DEST_UNREACH:
984 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */
985 ipv4_sk_update_pmtu(skb, sk, mtu: info);
986 if (READ_ONCE(inet->pmtudisc) != IP_PMTUDISC_DONT) {
987 err = EMSGSIZE;
988 harderr = 1;
989 break;
990 }
991 goto out;
992 }
993 err = EHOSTUNREACH;
994 if (code <= NR_ICMP_UNREACH) {
995 harderr = icmp_err_convert[code].fatal;
996 err = icmp_err_convert[code].errno;
997 }
998 break;
999 case ICMP_REDIRECT:
1000 ipv4_sk_redirect(skb, sk);
1001 goto out;
1002 }
1003
1004 /*
1005 * RFC1122: OK. Passes ICMP errors back to application, as per
1006 * 4.1.3.3.
1007 */
1008 if (tunnel) {
1009 /* ...not for tunnels though: we don't have a sending socket */
1010 if (udp_sk(sk)->encap_err_rcv)
1011 udp_sk(sk)->encap_err_rcv(sk, skb, err, uh->dest, info,
1012 (u8 *)(uh+1));
1013 goto out;
1014 }
1015 if (!inet_test_bit(RECVERR, sk)) {
1016 if (!harderr || sk->sk_state != TCP_ESTABLISHED)
1017 goto out;
1018 } else
1019 ip_icmp_error(sk, skb, err, port: uh->dest, info, payload: (u8 *)(uh+1));
1020
1021 sk->sk_err = err;
1022 sk_error_report(sk);
1023out:
1024 return 0;
1025}
1026
1027int udp_err(struct sk_buff *skb, u32 info)
1028{
1029 return __udp4_lib_err(skb, info, udptable: dev_net(dev: skb->dev)->ipv4.udp_table);
1030}
1031
1032/*
1033 * Throw away all pending data and cancel the corking. Socket is locked.
1034 */
1035void udp_flush_pending_frames(struct sock *sk)
1036{
1037 struct udp_sock *up = udp_sk(sk);
1038
1039 if (up->pending) {
1040 up->len = 0;
1041 WRITE_ONCE(up->pending, 0);
1042 ip_flush_pending_frames(sk);
1043 }
1044}
1045EXPORT_IPV6_MOD(udp_flush_pending_frames);
1046
1047/**
1048 * udp4_hwcsum - handle outgoing HW checksumming
1049 * @skb: sk_buff containing the filled-in UDP header
1050 * (checksum field must be zeroed out)
1051 * @src: source IP address
1052 * @dst: destination IP address
1053 */
1054void udp4_hwcsum(struct sk_buff *skb, __be32 src, __be32 dst)
1055{
1056 struct udphdr *uh = udp_hdr(skb);
1057 int offset = skb_transport_offset(skb);
1058 int len = skb->len - offset;
1059 int hlen = len;
1060 __wsum csum = 0;
1061
1062 if (!skb_has_frag_list(skb)) {
1063 /*
1064 * Only one fragment on the socket.
1065 */
1066 skb->csum_start = skb_transport_header(skb) - skb->head;
1067 skb->csum_offset = offsetof(struct udphdr, check);
1068 uh->check = ~csum_tcpudp_magic(saddr: src, daddr: dst, len,
1069 IPPROTO_UDP, sum: 0);
1070 } else {
1071 struct sk_buff *frags;
1072
1073 /*
1074 * HW-checksum won't work as there are two or more
1075 * fragments on the socket so that all csums of sk_buffs
1076 * should be together
1077 */
1078 skb_walk_frags(skb, frags) {
1079 csum = csum_add(csum, addend: frags->csum);
1080 hlen -= frags->len;
1081 }
1082
1083 csum = skb_checksum(skb, offset, len: hlen, csum);
1084 skb->ip_summed = CHECKSUM_NONE;
1085
1086 uh->check = csum_tcpudp_magic(saddr: src, daddr: dst, len, IPPROTO_UDP, sum: csum);
1087 if (uh->check == 0)
1088 uh->check = CSUM_MANGLED_0;
1089 }
1090}
1091EXPORT_SYMBOL_GPL(udp4_hwcsum);
1092
1093/* Function to set UDP checksum for an IPv4 UDP packet. This is intended
1094 * for the simple case like when setting the checksum for a UDP tunnel.
1095 */
1096void udp_set_csum(bool nocheck, struct sk_buff *skb,
1097 __be32 saddr, __be32 daddr, int len)
1098{
1099 struct udphdr *uh = udp_hdr(skb);
1100
1101 if (nocheck) {
1102 uh->check = 0;
1103 } else if (skb_is_gso(skb)) {
1104 uh->check = ~udp_v4_check(len, saddr, daddr, base: 0);
1105 } else if (skb->ip_summed == CHECKSUM_PARTIAL) {
1106 uh->check = 0;
1107 uh->check = udp_v4_check(len, saddr, daddr, base: lco_csum(skb));
1108 if (uh->check == 0)
1109 uh->check = CSUM_MANGLED_0;
1110 } else {
1111 skb->ip_summed = CHECKSUM_PARTIAL;
1112 skb->csum_start = skb_transport_header(skb) - skb->head;
1113 skb->csum_offset = offsetof(struct udphdr, check);
1114 uh->check = ~udp_v4_check(len, saddr, daddr, base: 0);
1115 }
1116}
1117EXPORT_SYMBOL(udp_set_csum);
1118
1119static int udp_send_skb(struct sk_buff *skb, struct flowi4 *fl4,
1120 struct inet_cork *cork)
1121{
1122 struct sock *sk = skb->sk;
1123 struct inet_sock *inet = inet_sk(sk);
1124 struct udphdr *uh;
1125 int err;
1126 int is_udplite = IS_UDPLITE(sk);
1127 int offset = skb_transport_offset(skb);
1128 int len = skb->len - offset;
1129 int datalen = len - sizeof(*uh);
1130 __wsum csum = 0;
1131
1132 /*
1133 * Create a UDP header
1134 */
1135 uh = udp_hdr(skb);
1136 uh->source = inet->inet_sport;
1137 uh->dest = fl4->fl4_dport;
1138 uh->len = htons(len);
1139 uh->check = 0;
1140
1141 if (cork->gso_size) {
1142 const int hlen = skb_network_header_len(skb) +
1143 sizeof(struct udphdr);
1144
1145 if (hlen + min(datalen, cork->gso_size) > cork->fragsize) {
1146 kfree_skb(skb);
1147 return -EMSGSIZE;
1148 }
1149 if (datalen > cork->gso_size * UDP_MAX_SEGMENTS) {
1150 kfree_skb(skb);
1151 return -EINVAL;
1152 }
1153 if (sk->sk_no_check_tx) {
1154 kfree_skb(skb);
1155 return -EINVAL;
1156 }
1157 if (is_udplite || dst_xfrm(dst: skb_dst(skb))) {
1158 kfree_skb(skb);
1159 return -EIO;
1160 }
1161
1162 if (datalen > cork->gso_size) {
1163 skb_shinfo(skb)->gso_size = cork->gso_size;
1164 skb_shinfo(skb)->gso_type = SKB_GSO_UDP_L4;
1165 skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(datalen,
1166 cork->gso_size);
1167
1168 /* Don't checksum the payload, skb will get segmented */
1169 goto csum_partial;
1170 }
1171 }
1172
1173 if (is_udplite) /* UDP-Lite */
1174 csum = udplite_csum(skb);
1175
1176 else if (sk->sk_no_check_tx) { /* UDP csum off */
1177
1178 skb->ip_summed = CHECKSUM_NONE;
1179 goto send;
1180
1181 } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */
1182csum_partial:
1183
1184 udp4_hwcsum(skb, fl4->saddr, fl4->daddr);
1185 goto send;
1186
1187 } else
1188 csum = udp_csum(skb);
1189
1190 /* add protocol-dependent pseudo-header */
1191 uh->check = csum_tcpudp_magic(saddr: fl4->saddr, daddr: fl4->daddr, len,
1192 proto: sk->sk_protocol, sum: csum);
1193 if (uh->check == 0)
1194 uh->check = CSUM_MANGLED_0;
1195
1196send:
1197 err = ip_send_skb(net: sock_net(sk), skb);
1198 if (err) {
1199 if (err == -ENOBUFS &&
1200 !inet_test_bit(RECVERR, sk)) {
1201 UDP_INC_STATS(sock_net(sk),
1202 UDP_MIB_SNDBUFERRORS, is_udplite);
1203 err = 0;
1204 }
1205 } else
1206 UDP_INC_STATS(sock_net(sk),
1207 UDP_MIB_OUTDATAGRAMS, is_udplite);
1208 return err;
1209}
1210
1211/*
1212 * Push out all pending data as one UDP datagram. Socket is locked.
1213 */
1214int udp_push_pending_frames(struct sock *sk)
1215{
1216 struct udp_sock *up = udp_sk(sk);
1217 struct inet_sock *inet = inet_sk(sk);
1218 struct flowi4 *fl4 = &inet->cork.fl.u.ip4;
1219 struct sk_buff *skb;
1220 int err = 0;
1221
1222 skb = ip_finish_skb(sk, fl4);
1223 if (!skb)
1224 goto out;
1225
1226 err = udp_send_skb(skb, fl4, cork: &inet->cork.base);
1227
1228out:
1229 up->len = 0;
1230 WRITE_ONCE(up->pending, 0);
1231 return err;
1232}
1233EXPORT_IPV6_MOD(udp_push_pending_frames);
1234
1235static int __udp_cmsg_send(struct cmsghdr *cmsg, u16 *gso_size)
1236{
1237 switch (cmsg->cmsg_type) {
1238 case UDP_SEGMENT:
1239 if (cmsg->cmsg_len != CMSG_LEN(sizeof(__u16)))
1240 return -EINVAL;
1241 *gso_size = *(__u16 *)CMSG_DATA(cmsg);
1242 return 0;
1243 default:
1244 return -EINVAL;
1245 }
1246}
1247
1248int udp_cmsg_send(struct sock *sk, struct msghdr *msg, u16 *gso_size)
1249{
1250 struct cmsghdr *cmsg;
1251 bool need_ip = false;
1252 int err;
1253
1254 for_each_cmsghdr(cmsg, msg) {
1255 if (!CMSG_OK(msg, cmsg))
1256 return -EINVAL;
1257
1258 if (cmsg->cmsg_level != SOL_UDP) {
1259 need_ip = true;
1260 continue;
1261 }
1262
1263 err = __udp_cmsg_send(cmsg, gso_size);
1264 if (err)
1265 return err;
1266 }
1267
1268 return need_ip;
1269}
1270EXPORT_IPV6_MOD_GPL(udp_cmsg_send);
1271
1272int udp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
1273{
1274 struct inet_sock *inet = inet_sk(sk);
1275 struct udp_sock *up = udp_sk(sk);
1276 DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name);
1277 struct flowi4 fl4_stack;
1278 struct flowi4 *fl4;
1279 int ulen = len;
1280 struct ipcm_cookie ipc;
1281 struct rtable *rt = NULL;
1282 int free = 0;
1283 int connected = 0;
1284 __be32 daddr, faddr, saddr;
1285 u8 scope;
1286 __be16 dport;
1287 int err, is_udplite = IS_UDPLITE(sk);
1288 int corkreq = udp_test_bit(CORK, sk) || msg->msg_flags & MSG_MORE;
1289 int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);
1290 struct sk_buff *skb;
1291 struct ip_options_data opt_copy;
1292 int uc_index;
1293
1294 if (len > 0xFFFF)
1295 return -EMSGSIZE;
1296
1297 /*
1298 * Check the flags.
1299 */
1300
1301 if (msg->msg_flags & MSG_OOB) /* Mirror BSD error message compatibility */
1302 return -EOPNOTSUPP;
1303
1304 getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag;
1305
1306 fl4 = &inet->cork.fl.u.ip4;
1307 if (READ_ONCE(up->pending)) {
1308 /*
1309 * There are pending frames.
1310 * The socket lock must be held while it's corked.
1311 */
1312 lock_sock(sk);
1313 if (likely(up->pending)) {
1314 if (unlikely(up->pending != AF_INET)) {
1315 release_sock(sk);
1316 return -EINVAL;
1317 }
1318 goto do_append_data;
1319 }
1320 release_sock(sk);
1321 }
1322 ulen += sizeof(struct udphdr);
1323
1324 /*
1325 * Get and verify the address.
1326 */
1327 if (usin) {
1328 if (msg->msg_namelen < sizeof(*usin))
1329 return -EINVAL;
1330 if (usin->sin_family != AF_INET) {
1331 if (usin->sin_family != AF_UNSPEC)
1332 return -EAFNOSUPPORT;
1333 }
1334
1335 daddr = usin->sin_addr.s_addr;
1336 dport = usin->sin_port;
1337 if (dport == 0)
1338 return -EINVAL;
1339 } else {
1340 if (sk->sk_state != TCP_ESTABLISHED)
1341 return -EDESTADDRREQ;
1342 daddr = inet->inet_daddr;
1343 dport = inet->inet_dport;
1344 /* Open fast path for connected socket.
1345 Route will not be used, if at least one option is set.
1346 */
1347 connected = 1;
1348 }
1349
1350 ipcm_init_sk(ipcm: &ipc, inet);
1351 ipc.gso_size = READ_ONCE(up->gso_size);
1352
1353 if (msg->msg_controllen) {
1354 err = udp_cmsg_send(sk, msg, gso_size: &ipc.gso_size);
1355 if (err > 0) {
1356 err = ip_cmsg_send(sk, msg, ipc: &ipc,
1357 allow_ipv6: sk->sk_family == AF_INET6);
1358 connected = 0;
1359 }
1360 if (unlikely(err < 0)) {
1361 kfree(objp: ipc.opt);
1362 return err;
1363 }
1364 if (ipc.opt)
1365 free = 1;
1366 }
1367 if (!ipc.opt) {
1368 struct ip_options_rcu *inet_opt;
1369
1370 rcu_read_lock();
1371 inet_opt = rcu_dereference(inet->inet_opt);
1372 if (inet_opt) {
1373 memcpy(&opt_copy, inet_opt,
1374 sizeof(*inet_opt) + inet_opt->opt.optlen);
1375 ipc.opt = &opt_copy.opt;
1376 }
1377 rcu_read_unlock();
1378 }
1379
1380 if (cgroup_bpf_enabled(CGROUP_UDP4_SENDMSG) && !connected) {
1381 err = BPF_CGROUP_RUN_PROG_UDP4_SENDMSG_LOCK(sk,
1382 (struct sockaddr *)usin,
1383 &msg->msg_namelen,
1384 &ipc.addr);
1385 if (err)
1386 goto out_free;
1387 if (usin) {
1388 if (usin->sin_port == 0) {
1389 /* BPF program set invalid port. Reject it. */
1390 err = -EINVAL;
1391 goto out_free;
1392 }
1393 daddr = usin->sin_addr.s_addr;
1394 dport = usin->sin_port;
1395 }
1396 }
1397
1398 saddr = ipc.addr;
1399 ipc.addr = faddr = daddr;
1400
1401 if (ipc.opt && ipc.opt->opt.srr) {
1402 if (!daddr) {
1403 err = -EINVAL;
1404 goto out_free;
1405 }
1406 faddr = ipc.opt->opt.faddr;
1407 connected = 0;
1408 }
1409 scope = ip_sendmsg_scope(inet, ipc: &ipc, msg);
1410 if (scope == RT_SCOPE_LINK)
1411 connected = 0;
1412
1413 uc_index = READ_ONCE(inet->uc_index);
1414 if (ipv4_is_multicast(addr: daddr)) {
1415 if (!ipc.oif || netif_index_is_l3_master(net: sock_net(sk), ifindex: ipc.oif))
1416 ipc.oif = READ_ONCE(inet->mc_index);
1417 if (!saddr)
1418 saddr = READ_ONCE(inet->mc_addr);
1419 connected = 0;
1420 } else if (!ipc.oif) {
1421 ipc.oif = uc_index;
1422 } else if (ipv4_is_lbcast(addr: daddr) && uc_index) {
1423 /* oif is set, packet is to local broadcast and
1424 * uc_index is set. oif is most likely set
1425 * by sk_bound_dev_if. If uc_index != oif check if the
1426 * oif is an L3 master and uc_index is an L3 slave.
1427 * If so, we want to allow the send using the uc_index.
1428 */
1429 if (ipc.oif != uc_index &&
1430 ipc.oif == l3mdev_master_ifindex_by_index(net: sock_net(sk),
1431 ifindex: uc_index)) {
1432 ipc.oif = uc_index;
1433 }
1434 }
1435
1436 if (connected)
1437 rt = dst_rtable(sk_dst_check(sk, 0));
1438
1439 if (!rt) {
1440 struct net *net = sock_net(sk);
1441 __u8 flow_flags = inet_sk_flowi_flags(sk);
1442
1443 fl4 = &fl4_stack;
1444
1445 flowi4_init_output(fl4, oif: ipc.oif, mark: ipc.sockc.mark,
1446 tos: ipc.tos & INET_DSCP_MASK, scope,
1447 proto: sk->sk_protocol, flags: flow_flags, daddr: faddr, saddr,
1448 dport, sport: inet->inet_sport, uid: sk->sk_uid);
1449
1450 security_sk_classify_flow(sk, flic: flowi4_to_flowi_common(fl4));
1451 rt = ip_route_output_flow(net, flp: fl4, sk);
1452 if (IS_ERR(ptr: rt)) {
1453 err = PTR_ERR(ptr: rt);
1454 rt = NULL;
1455 if (err == -ENETUNREACH)
1456 IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES);
1457 goto out;
1458 }
1459
1460 err = -EACCES;
1461 if ((rt->rt_flags & RTCF_BROADCAST) &&
1462 !sock_flag(sk, flag: SOCK_BROADCAST))
1463 goto out;
1464 if (connected)
1465 sk_dst_set(sk, dst: dst_clone(dst: &rt->dst));
1466 }
1467
1468 if (msg->msg_flags&MSG_CONFIRM)
1469 goto do_confirm;
1470back_from_confirm:
1471
1472 saddr = fl4->saddr;
1473 if (!ipc.addr)
1474 daddr = ipc.addr = fl4->daddr;
1475
1476 /* Lockless fast path for the non-corking case. */
1477 if (!corkreq) {
1478 struct inet_cork cork;
1479
1480 skb = ip_make_skb(sk, fl4, getfrag, from: msg, length: ulen,
1481 transhdrlen: sizeof(struct udphdr), ipc: &ipc, rtp: &rt,
1482 cork: &cork, flags: msg->msg_flags);
1483 err = PTR_ERR(ptr: skb);
1484 if (!IS_ERR_OR_NULL(ptr: skb))
1485 err = udp_send_skb(skb, fl4, cork: &cork);
1486 goto out;
1487 }
1488
1489 lock_sock(sk);
1490 if (unlikely(up->pending)) {
1491 /* The socket is already corked while preparing it. */
1492 /* ... which is an evident application bug. --ANK */
1493 release_sock(sk);
1494
1495 net_dbg_ratelimited("socket already corked\n");
1496 err = -EINVAL;
1497 goto out;
1498 }
1499 /*
1500 * Now cork the socket to pend data.
1501 */
1502 fl4 = &inet->cork.fl.u.ip4;
1503 fl4->daddr = daddr;
1504 fl4->saddr = saddr;
1505 fl4->fl4_dport = dport;
1506 fl4->fl4_sport = inet->inet_sport;
1507 WRITE_ONCE(up->pending, AF_INET);
1508
1509do_append_data:
1510 up->len += ulen;
1511 err = ip_append_data(sk, fl4, getfrag, from: msg, len: ulen,
1512 protolen: sizeof(struct udphdr), ipc: &ipc, rt: &rt,
1513 flags: corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags);
1514 if (err)
1515 udp_flush_pending_frames(sk);
1516 else if (!corkreq)
1517 err = udp_push_pending_frames(sk);
1518 else if (unlikely(skb_queue_empty(&sk->sk_write_queue)))
1519 WRITE_ONCE(up->pending, 0);
1520 release_sock(sk);
1521
1522out:
1523 ip_rt_put(rt);
1524out_free:
1525 if (free)
1526 kfree(objp: ipc.opt);
1527 if (!err)
1528 return len;
1529 /*
1530 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space. Reporting
1531 * ENOBUFS might not be good (it's not tunable per se), but otherwise
1532 * we don't have a good statistic (IpOutDiscards but it can be too many
1533 * things). We could add another new stat but at least for now that
1534 * seems like overkill.
1535 */
1536 if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) {
1537 UDP_INC_STATS(sock_net(sk),
1538 UDP_MIB_SNDBUFERRORS, is_udplite);
1539 }
1540 return err;
1541
1542do_confirm:
1543 if (msg->msg_flags & MSG_PROBE)
1544 dst_confirm_neigh(dst: &rt->dst, daddr: &fl4->daddr);
1545 if (!(msg->msg_flags&MSG_PROBE) || len)
1546 goto back_from_confirm;
1547 err = 0;
1548 goto out;
1549}
1550EXPORT_SYMBOL(udp_sendmsg);
1551
1552void udp_splice_eof(struct socket *sock)
1553{
1554 struct sock *sk = sock->sk;
1555 struct udp_sock *up = udp_sk(sk);
1556
1557 if (!READ_ONCE(up->pending) || udp_test_bit(CORK, sk))
1558 return;
1559
1560 lock_sock(sk);
1561 if (up->pending && !udp_test_bit(CORK, sk))
1562 udp_push_pending_frames(sk);
1563 release_sock(sk);
1564}
1565EXPORT_IPV6_MOD_GPL(udp_splice_eof);
1566
1567#define UDP_SKB_IS_STATELESS 0x80000000
1568
1569/* all head states (dst, sk, nf conntrack) except skb extensions are
1570 * cleared by udp_rcv().
1571 *
1572 * We need to preserve secpath, if present, to eventually process
1573 * IP_CMSG_PASSSEC at recvmsg() time.
1574 *
1575 * Other extensions can be cleared.
1576 */
1577static bool udp_try_make_stateless(struct sk_buff *skb)
1578{
1579 if (!skb_has_extensions(skb))
1580 return true;
1581
1582 if (!secpath_exists(skb)) {
1583 skb_ext_reset(skb);
1584 return true;
1585 }
1586
1587 return false;
1588}
1589
1590static void udp_set_dev_scratch(struct sk_buff *skb)
1591{
1592 struct udp_dev_scratch *scratch = udp_skb_scratch(skb);
1593
1594 BUILD_BUG_ON(sizeof(struct udp_dev_scratch) > sizeof(long));
1595 scratch->_tsize_state = skb->truesize;
1596#if BITS_PER_LONG == 64
1597 scratch->len = skb->len;
1598 scratch->csum_unnecessary = !!skb_csum_unnecessary(skb);
1599 scratch->is_linear = !skb_is_nonlinear(skb);
1600#endif
1601 if (udp_try_make_stateless(skb))
1602 scratch->_tsize_state |= UDP_SKB_IS_STATELESS;
1603}
1604
1605static void udp_skb_csum_unnecessary_set(struct sk_buff *skb)
1606{
1607 /* We come here after udp_lib_checksum_complete() returned 0.
1608 * This means that __skb_checksum_complete() might have
1609 * set skb->csum_valid to 1.
1610 * On 64bit platforms, we can set csum_unnecessary
1611 * to true, but only if the skb is not shared.
1612 */
1613#if BITS_PER_LONG == 64
1614 if (!skb_shared(skb))
1615 udp_skb_scratch(skb)->csum_unnecessary = true;
1616#endif
1617}
1618
1619static int udp_skb_truesize(struct sk_buff *skb)
1620{
1621 return udp_skb_scratch(skb)->_tsize_state & ~UDP_SKB_IS_STATELESS;
1622}
1623
1624static bool udp_skb_has_head_state(struct sk_buff *skb)
1625{
1626 return !(udp_skb_scratch(skb)->_tsize_state & UDP_SKB_IS_STATELESS);
1627}
1628
1629/* fully reclaim rmem/fwd memory allocated for skb */
1630static void udp_rmem_release(struct sock *sk, unsigned int size,
1631 int partial, bool rx_queue_lock_held)
1632{
1633 struct udp_sock *up = udp_sk(sk);
1634 struct sk_buff_head *sk_queue;
1635 unsigned int amt;
1636
1637 if (likely(partial)) {
1638 up->forward_deficit += size;
1639 size = up->forward_deficit;
1640 if (size < READ_ONCE(up->forward_threshold) &&
1641 !skb_queue_empty(list: &up->reader_queue))
1642 return;
1643 } else {
1644 size += up->forward_deficit;
1645 }
1646 up->forward_deficit = 0;
1647
1648 /* acquire the sk_receive_queue for fwd allocated memory scheduling,
1649 * if the called don't held it already
1650 */
1651 sk_queue = &sk->sk_receive_queue;
1652 if (!rx_queue_lock_held)
1653 spin_lock(lock: &sk_queue->lock);
1654
1655 amt = (size + sk->sk_forward_alloc - partial) & ~(PAGE_SIZE - 1);
1656 sk_forward_alloc_add(sk, val: size - amt);
1657
1658 if (amt)
1659 __sk_mem_reduce_allocated(sk, amount: amt >> PAGE_SHIFT);
1660
1661 atomic_sub(i: size, v: &sk->sk_rmem_alloc);
1662
1663 /* this can save us from acquiring the rx queue lock on next receive */
1664 skb_queue_splice_tail_init(list: sk_queue, head: &up->reader_queue);
1665
1666 if (!rx_queue_lock_held)
1667 spin_unlock(lock: &sk_queue->lock);
1668}
1669
1670/* Note: called with reader_queue.lock held.
1671 * Instead of using skb->truesize here, find a copy of it in skb->dev_scratch
1672 * This avoids a cache line miss while receive_queue lock is held.
1673 * Look at __udp_enqueue_schedule_skb() to find where this copy is done.
1674 */
1675void udp_skb_destructor(struct sock *sk, struct sk_buff *skb)
1676{
1677 prefetch(&skb->data);
1678 udp_rmem_release(sk, size: udp_skb_truesize(skb), partial: 1, rx_queue_lock_held: false);
1679}
1680EXPORT_IPV6_MOD(udp_skb_destructor);
1681
1682/* as above, but the caller held the rx queue lock, too */
1683static void udp_skb_dtor_locked(struct sock *sk, struct sk_buff *skb)
1684{
1685 prefetch(&skb->data);
1686 udp_rmem_release(sk, size: udp_skb_truesize(skb), partial: 1, rx_queue_lock_held: true);
1687}
1688
1689/* Idea of busylocks is to let producers grab an extra spinlock
1690 * to relieve pressure on the receive_queue spinlock shared by consumer.
1691 * Under flood, this means that only one producer can be in line
1692 * trying to acquire the receive_queue spinlock.
1693 * These busylock can be allocated on a per cpu manner, instead of a
1694 * per socket one (that would consume a cache line per socket)
1695 */
1696static int udp_busylocks_log __read_mostly;
1697static spinlock_t *udp_busylocks __read_mostly;
1698
1699static spinlock_t *busylock_acquire(void *ptr)
1700{
1701 spinlock_t *busy;
1702
1703 busy = udp_busylocks + hash_ptr(ptr, bits: udp_busylocks_log);
1704 spin_lock(lock: busy);
1705 return busy;
1706}
1707
1708static void busylock_release(spinlock_t *busy)
1709{
1710 if (busy)
1711 spin_unlock(lock: busy);
1712}
1713
1714static int udp_rmem_schedule(struct sock *sk, int size)
1715{
1716 int delta;
1717
1718 delta = size - sk->sk_forward_alloc;
1719 if (delta > 0 && !__sk_mem_schedule(sk, size: delta, SK_MEM_RECV))
1720 return -ENOBUFS;
1721
1722 return 0;
1723}
1724
1725int __udp_enqueue_schedule_skb(struct sock *sk, struct sk_buff *skb)
1726{
1727 struct sk_buff_head *list = &sk->sk_receive_queue;
1728 unsigned int rmem, rcvbuf;
1729 spinlock_t *busy = NULL;
1730 int size, err = -ENOMEM;
1731
1732 rmem = atomic_read(v: &sk->sk_rmem_alloc);
1733 rcvbuf = READ_ONCE(sk->sk_rcvbuf);
1734 size = skb->truesize;
1735
1736 /* Immediately drop when the receive queue is full.
1737 * Cast to unsigned int performs the boundary check for INT_MAX.
1738 */
1739 if (rmem + size > rcvbuf) {
1740 if (rcvbuf > INT_MAX >> 1)
1741 goto drop;
1742
1743 /* Always allow at least one packet for small buffer. */
1744 if (rmem > rcvbuf)
1745 goto drop;
1746 }
1747
1748 /* Under mem pressure, it might be helpful to help udp_recvmsg()
1749 * having linear skbs :
1750 * - Reduce memory overhead and thus increase receive queue capacity
1751 * - Less cache line misses at copyout() time
1752 * - Less work at consume_skb() (less alien page frag freeing)
1753 */
1754 if (rmem > (rcvbuf >> 1)) {
1755 skb_condense(skb);
1756 size = skb->truesize;
1757 busy = busylock_acquire(ptr: sk);
1758 }
1759
1760 udp_set_dev_scratch(skb);
1761
1762 atomic_add(i: size, v: &sk->sk_rmem_alloc);
1763
1764 spin_lock(lock: &list->lock);
1765 err = udp_rmem_schedule(sk, size);
1766 if (err) {
1767 spin_unlock(lock: &list->lock);
1768 goto uncharge_drop;
1769 }
1770
1771 sk_forward_alloc_add(sk, val: -size);
1772
1773 /* no need to setup a destructor, we will explicitly release the
1774 * forward allocated memory on dequeue
1775 */
1776 sock_skb_set_dropcount(sk, skb);
1777
1778 __skb_queue_tail(list, newsk: skb);
1779 spin_unlock(lock: &list->lock);
1780
1781 if (!sock_flag(sk, flag: SOCK_DEAD))
1782 INDIRECT_CALL_1(sk->sk_data_ready, sock_def_readable, sk);
1783
1784 busylock_release(busy);
1785 return 0;
1786
1787uncharge_drop:
1788 atomic_sub(i: skb->truesize, v: &sk->sk_rmem_alloc);
1789
1790drop:
1791 atomic_inc(v: &sk->sk_drops);
1792 busylock_release(busy);
1793 return err;
1794}
1795EXPORT_IPV6_MOD_GPL(__udp_enqueue_schedule_skb);
1796
1797void udp_destruct_common(struct sock *sk)
1798{
1799 /* reclaim completely the forward allocated memory */
1800 struct udp_sock *up = udp_sk(sk);
1801 unsigned int total = 0;
1802 struct sk_buff *skb;
1803
1804 skb_queue_splice_tail_init(list: &sk->sk_receive_queue, head: &up->reader_queue);
1805 while ((skb = __skb_dequeue(list: &up->reader_queue)) != NULL) {
1806 total += skb->truesize;
1807 kfree_skb(skb);
1808 }
1809 udp_rmem_release(sk, size: total, partial: 0, rx_queue_lock_held: true);
1810}
1811EXPORT_IPV6_MOD_GPL(udp_destruct_common);
1812
1813static void udp_destruct_sock(struct sock *sk)
1814{
1815 udp_destruct_common(sk);
1816 inet_sock_destruct(sk);
1817}
1818
1819int udp_init_sock(struct sock *sk)
1820{
1821 udp_lib_init_sock(sk);
1822 sk->sk_destruct = udp_destruct_sock;
1823 set_bit(nr: SOCK_SUPPORT_ZC, addr: &sk->sk_socket->flags);
1824 return 0;
1825}
1826
1827void skb_consume_udp(struct sock *sk, struct sk_buff *skb, int len)
1828{
1829 if (unlikely(READ_ONCE(udp_sk(sk)->peeking_with_offset)))
1830 sk_peek_offset_bwd(sk, val: len);
1831
1832 if (!skb_unref(skb))
1833 return;
1834
1835 /* In the more common cases we cleared the head states previously,
1836 * see __udp_queue_rcv_skb().
1837 */
1838 if (unlikely(udp_skb_has_head_state(skb)))
1839 skb_release_head_state(skb);
1840 __consume_stateless_skb(skb);
1841}
1842EXPORT_IPV6_MOD_GPL(skb_consume_udp);
1843
1844static struct sk_buff *__first_packet_length(struct sock *sk,
1845 struct sk_buff_head *rcvq,
1846 unsigned int *total)
1847{
1848 struct sk_buff *skb;
1849
1850 while ((skb = skb_peek(list_: rcvq)) != NULL) {
1851 if (udp_lib_checksum_complete(skb)) {
1852 __UDP_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS,
1853 IS_UDPLITE(sk));
1854 __UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS,
1855 IS_UDPLITE(sk));
1856 atomic_inc(v: &sk->sk_drops);
1857 __skb_unlink(skb, list: rcvq);
1858 *total += skb->truesize;
1859 kfree_skb_reason(skb, reason: SKB_DROP_REASON_UDP_CSUM);
1860 } else {
1861 udp_skb_csum_unnecessary_set(skb);
1862 break;
1863 }
1864 }
1865 return skb;
1866}
1867
1868/**
1869 * first_packet_length - return length of first packet in receive queue
1870 * @sk: socket
1871 *
1872 * Drops all bad checksum frames, until a valid one is found.
1873 * Returns the length of found skb, or -1 if none is found.
1874 */
1875static int first_packet_length(struct sock *sk)
1876{
1877 struct sk_buff_head *rcvq = &udp_sk(sk)->reader_queue;
1878 struct sk_buff_head *sk_queue = &sk->sk_receive_queue;
1879 unsigned int total = 0;
1880 struct sk_buff *skb;
1881 int res;
1882
1883 spin_lock_bh(lock: &rcvq->lock);
1884 skb = __first_packet_length(sk, rcvq, total: &total);
1885 if (!skb && !skb_queue_empty_lockless(list: sk_queue)) {
1886 spin_lock(lock: &sk_queue->lock);
1887 skb_queue_splice_tail_init(list: sk_queue, head: rcvq);
1888 spin_unlock(lock: &sk_queue->lock);
1889
1890 skb = __first_packet_length(sk, rcvq, total: &total);
1891 }
1892 res = skb ? skb->len : -1;
1893 if (total)
1894 udp_rmem_release(sk, size: total, partial: 1, rx_queue_lock_held: false);
1895 spin_unlock_bh(lock: &rcvq->lock);
1896 return res;
1897}
1898
1899/*
1900 * IOCTL requests applicable to the UDP protocol
1901 */
1902
1903int udp_ioctl(struct sock *sk, int cmd, int *karg)
1904{
1905 switch (cmd) {
1906 case SIOCOUTQ:
1907 {
1908 *karg = sk_wmem_alloc_get(sk);
1909 return 0;
1910 }
1911
1912 case SIOCINQ:
1913 {
1914 *karg = max_t(int, 0, first_packet_length(sk));
1915 return 0;
1916 }
1917
1918 default:
1919 return -ENOIOCTLCMD;
1920 }
1921
1922 return 0;
1923}
1924EXPORT_IPV6_MOD(udp_ioctl);
1925
1926struct sk_buff *__skb_recv_udp(struct sock *sk, unsigned int flags,
1927 int *off, int *err)
1928{
1929 struct sk_buff_head *sk_queue = &sk->sk_receive_queue;
1930 struct sk_buff_head *queue;
1931 struct sk_buff *last;
1932 long timeo;
1933 int error;
1934
1935 queue = &udp_sk(sk)->reader_queue;
1936 timeo = sock_rcvtimeo(sk, noblock: flags & MSG_DONTWAIT);
1937 do {
1938 struct sk_buff *skb;
1939
1940 error = sock_error(sk);
1941 if (error)
1942 break;
1943
1944 error = -EAGAIN;
1945 do {
1946 spin_lock_bh(lock: &queue->lock);
1947 skb = __skb_try_recv_from_queue(queue, flags, off, err,
1948 last: &last);
1949 if (skb) {
1950 if (!(flags & MSG_PEEK))
1951 udp_skb_destructor(sk, skb);
1952 spin_unlock_bh(lock: &queue->lock);
1953 return skb;
1954 }
1955
1956 if (skb_queue_empty_lockless(list: sk_queue)) {
1957 spin_unlock_bh(lock: &queue->lock);
1958 goto busy_check;
1959 }
1960
1961 /* refill the reader queue and walk it again
1962 * keep both queues locked to avoid re-acquiring
1963 * the sk_receive_queue lock if fwd memory scheduling
1964 * is needed.
1965 */
1966 spin_lock(lock: &sk_queue->lock);
1967 skb_queue_splice_tail_init(list: sk_queue, head: queue);
1968
1969 skb = __skb_try_recv_from_queue(queue, flags, off, err,
1970 last: &last);
1971 if (skb && !(flags & MSG_PEEK))
1972 udp_skb_dtor_locked(sk, skb);
1973 spin_unlock(lock: &sk_queue->lock);
1974 spin_unlock_bh(lock: &queue->lock);
1975 if (skb)
1976 return skb;
1977
1978busy_check:
1979 if (!sk_can_busy_loop(sk))
1980 break;
1981
1982 sk_busy_loop(sk, nonblock: flags & MSG_DONTWAIT);
1983 } while (!skb_queue_empty_lockless(list: sk_queue));
1984
1985 /* sk_queue is empty, reader_queue may contain peeked packets */
1986 } while (timeo &&
1987 !__skb_wait_for_more_packets(sk, queue: &sk->sk_receive_queue,
1988 err: &error, timeo_p: &timeo,
1989 skb: (struct sk_buff *)sk_queue));
1990
1991 *err = error;
1992 return NULL;
1993}
1994EXPORT_SYMBOL(__skb_recv_udp);
1995
1996int udp_read_skb(struct sock *sk, skb_read_actor_t recv_actor)
1997{
1998 struct sk_buff *skb;
1999 int err;
2000
2001try_again:
2002 skb = skb_recv_udp(sk, MSG_DONTWAIT, err: &err);
2003 if (!skb)
2004 return err;
2005
2006 if (udp_lib_checksum_complete(skb)) {
2007 int is_udplite = IS_UDPLITE(sk);
2008 struct net *net = sock_net(sk);
2009
2010 __UDP_INC_STATS(net, UDP_MIB_CSUMERRORS, is_udplite);
2011 __UDP_INC_STATS(net, UDP_MIB_INERRORS, is_udplite);
2012 atomic_inc(v: &sk->sk_drops);
2013 kfree_skb_reason(skb, reason: SKB_DROP_REASON_UDP_CSUM);
2014 goto try_again;
2015 }
2016
2017 WARN_ON_ONCE(!skb_set_owner_sk_safe(skb, sk));
2018 return recv_actor(sk, skb);
2019}
2020EXPORT_IPV6_MOD(udp_read_skb);
2021
2022/*
2023 * This should be easy, if there is something there we
2024 * return it, otherwise we block.
2025 */
2026
2027int udp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int flags,
2028 int *addr_len)
2029{
2030 struct inet_sock *inet = inet_sk(sk);
2031 DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
2032 struct sk_buff *skb;
2033 unsigned int ulen, copied;
2034 int off, err, peeking = flags & MSG_PEEK;
2035 int is_udplite = IS_UDPLITE(sk);
2036 bool checksum_valid = false;
2037
2038 if (flags & MSG_ERRQUEUE)
2039 return ip_recv_error(sk, msg, len, addr_len);
2040
2041try_again:
2042 off = sk_peek_offset(sk, flags);
2043 skb = __skb_recv_udp(sk, flags, &off, &err);
2044 if (!skb)
2045 return err;
2046
2047 ulen = udp_skb_len(skb);
2048 copied = len;
2049 if (copied > ulen - off)
2050 copied = ulen - off;
2051 else if (copied < ulen)
2052 msg->msg_flags |= MSG_TRUNC;
2053
2054 /*
2055 * If checksum is needed at all, try to do it while copying the
2056 * data. If the data is truncated, or if we only want a partial
2057 * coverage checksum (UDP-Lite), do it before the copy.
2058 */
2059
2060 if (copied < ulen || peeking ||
2061 (is_udplite && UDP_SKB_CB(skb)->partial_cov)) {
2062 checksum_valid = udp_skb_csum_unnecessary(skb) ||
2063 !__udp_lib_checksum_complete(skb);
2064 if (!checksum_valid)
2065 goto csum_copy_err;
2066 }
2067
2068 if (checksum_valid || udp_skb_csum_unnecessary(skb)) {
2069 if (udp_skb_is_linear(skb))
2070 err = copy_linear_skb(skb, len: copied, off, to: &msg->msg_iter);
2071 else
2072 err = skb_copy_datagram_msg(from: skb, offset: off, msg, size: copied);
2073 } else {
2074 err = skb_copy_and_csum_datagram_msg(skb, hlen: off, msg);
2075
2076 if (err == -EINVAL)
2077 goto csum_copy_err;
2078 }
2079
2080 if (unlikely(err)) {
2081 if (!peeking) {
2082 atomic_inc(v: &sk->sk_drops);
2083 UDP_INC_STATS(sock_net(sk),
2084 UDP_MIB_INERRORS, is_udplite);
2085 }
2086 kfree_skb(skb);
2087 return err;
2088 }
2089
2090 if (!peeking)
2091 UDP_INC_STATS(sock_net(sk),
2092 UDP_MIB_INDATAGRAMS, is_udplite);
2093
2094 sock_recv_cmsgs(msg, sk, skb);
2095
2096 /* Copy the address. */
2097 if (sin) {
2098 sin->sin_family = AF_INET;
2099 sin->sin_port = udp_hdr(skb)->source;
2100 sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
2101 memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
2102 *addr_len = sizeof(*sin);
2103
2104 BPF_CGROUP_RUN_PROG_UDP4_RECVMSG_LOCK(sk,
2105 (struct sockaddr *)sin,
2106 addr_len);
2107 }
2108
2109 if (udp_test_bit(GRO_ENABLED, sk))
2110 udp_cmsg_recv(msg, sk, skb);
2111
2112 if (inet_cmsg_flags(inet))
2113 ip_cmsg_recv_offset(msg, sk, skb, tlen: sizeof(struct udphdr), offset: off);
2114
2115 err = copied;
2116 if (flags & MSG_TRUNC)
2117 err = ulen;
2118
2119 skb_consume_udp(sk, skb, len: peeking ? -err : err);
2120 return err;
2121
2122csum_copy_err:
2123 if (!__sk_queue_drop_skb(sk, sk_queue: &udp_sk(sk)->reader_queue, skb, flags,
2124 destructor: udp_skb_destructor)) {
2125 UDP_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite);
2126 UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
2127 }
2128 kfree_skb_reason(skb, reason: SKB_DROP_REASON_UDP_CSUM);
2129
2130 /* starting over for a new packet, but check if we need to yield */
2131 cond_resched();
2132 msg->msg_flags &= ~MSG_TRUNC;
2133 goto try_again;
2134}
2135
2136int udp_pre_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
2137{
2138 /* This check is replicated from __ip4_datagram_connect() and
2139 * intended to prevent BPF program called below from accessing bytes
2140 * that are out of the bound specified by user in addr_len.
2141 */
2142 if (addr_len < sizeof(struct sockaddr_in))
2143 return -EINVAL;
2144
2145 return BPF_CGROUP_RUN_PROG_INET4_CONNECT_LOCK(sk, uaddr, &addr_len);
2146}
2147EXPORT_IPV6_MOD(udp_pre_connect);
2148
2149static int udp_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
2150{
2151 int res;
2152
2153 lock_sock(sk);
2154 res = __ip4_datagram_connect(sk, uaddr, addr_len);
2155 if (!res)
2156 udp4_hash4(sk);
2157 release_sock(sk);
2158 return res;
2159}
2160
2161int __udp_disconnect(struct sock *sk, int flags)
2162{
2163 struct inet_sock *inet = inet_sk(sk);
2164 /*
2165 * 1003.1g - break association.
2166 */
2167
2168 sk->sk_state = TCP_CLOSE;
2169 inet->inet_daddr = 0;
2170 inet->inet_dport = 0;
2171 sock_rps_reset_rxhash(sk);
2172 sk->sk_bound_dev_if = 0;
2173 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) {
2174 inet_reset_saddr(sk);
2175 if (sk->sk_prot->rehash &&
2176 (sk->sk_userlocks & SOCK_BINDPORT_LOCK))
2177 sk->sk_prot->rehash(sk);
2178 }
2179
2180 if (!(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) {
2181 sk->sk_prot->unhash(sk);
2182 inet->inet_sport = 0;
2183 }
2184 sk_dst_reset(sk);
2185 return 0;
2186}
2187EXPORT_SYMBOL(__udp_disconnect);
2188
2189int udp_disconnect(struct sock *sk, int flags)
2190{
2191 lock_sock(sk);
2192 __udp_disconnect(sk, flags);
2193 release_sock(sk);
2194 return 0;
2195}
2196EXPORT_IPV6_MOD(udp_disconnect);
2197
2198void udp_lib_unhash(struct sock *sk)
2199{
2200 if (sk_hashed(sk)) {
2201 struct udp_table *udptable = udp_get_table_prot(sk);
2202 struct udp_hslot *hslot, *hslot2;
2203
2204 sock_rps_delete_flow(sk);
2205 hslot = udp_hashslot(table: udptable, net: sock_net(sk),
2206 udp_sk(sk)->udp_port_hash);
2207 hslot2 = udp_hashslot2(table: udptable, udp_sk(sk)->udp_portaddr_hash);
2208
2209 spin_lock_bh(lock: &hslot->lock);
2210 if (rcu_access_pointer(sk->sk_reuseport_cb))
2211 reuseport_detach_sock(sk);
2212 if (sk_del_node_init_rcu(sk)) {
2213 hslot->count--;
2214 inet_sk(sk)->inet_num = 0;
2215 sock_prot_inuse_add(net: sock_net(sk), prot: sk->sk_prot, val: -1);
2216
2217 spin_lock(lock: &hslot2->lock);
2218 hlist_del_init_rcu(n: &udp_sk(sk)->udp_portaddr_node);
2219 hslot2->count--;
2220 spin_unlock(lock: &hslot2->lock);
2221
2222 udp_unhash4(udptable, sk);
2223 }
2224 spin_unlock_bh(lock: &hslot->lock);
2225 }
2226}
2227EXPORT_IPV6_MOD(udp_lib_unhash);
2228
2229/*
2230 * inet_rcv_saddr was changed, we must rehash secondary hash
2231 */
2232void udp_lib_rehash(struct sock *sk, u16 newhash, u16 newhash4)
2233{
2234 if (sk_hashed(sk)) {
2235 struct udp_table *udptable = udp_get_table_prot(sk);
2236 struct udp_hslot *hslot, *hslot2, *nhslot2;
2237
2238 hslot = udp_hashslot(table: udptable, net: sock_net(sk),
2239 udp_sk(sk)->udp_port_hash);
2240 hslot2 = udp_hashslot2(table: udptable, udp_sk(sk)->udp_portaddr_hash);
2241 nhslot2 = udp_hashslot2(table: udptable, hash: newhash);
2242 udp_sk(sk)->udp_portaddr_hash = newhash;
2243
2244 if (hslot2 != nhslot2 ||
2245 rcu_access_pointer(sk->sk_reuseport_cb)) {
2246 /* we must lock primary chain too */
2247 spin_lock_bh(lock: &hslot->lock);
2248 if (rcu_access_pointer(sk->sk_reuseport_cb))
2249 reuseport_detach_sock(sk);
2250
2251 if (hslot2 != nhslot2) {
2252 spin_lock(lock: &hslot2->lock);
2253 hlist_del_init_rcu(n: &udp_sk(sk)->udp_portaddr_node);
2254 hslot2->count--;
2255 spin_unlock(lock: &hslot2->lock);
2256
2257 spin_lock(lock: &nhslot2->lock);
2258 hlist_add_head_rcu(n: &udp_sk(sk)->udp_portaddr_node,
2259 h: &nhslot2->head);
2260 nhslot2->count++;
2261 spin_unlock(lock: &nhslot2->lock);
2262 }
2263
2264 spin_unlock_bh(lock: &hslot->lock);
2265 }
2266
2267 /* Now process hash4 if necessary:
2268 * (1) update hslot4;
2269 * (2) update hslot2->hash4_cnt.
2270 * Note that hslot2/hslot4 should be checked separately, as
2271 * either of them may change with the other unchanged.
2272 */
2273 if (udp_hashed4(sk)) {
2274 spin_lock_bh(lock: &hslot->lock);
2275
2276 udp_rehash4(udptable, sk, newhash4);
2277 if (hslot2 != nhslot2) {
2278 spin_lock(lock: &hslot2->lock);
2279 udp_hash4_dec(hslot2);
2280 spin_unlock(lock: &hslot2->lock);
2281
2282 spin_lock(lock: &nhslot2->lock);
2283 udp_hash4_inc(hslot2: nhslot2);
2284 spin_unlock(lock: &nhslot2->lock);
2285 }
2286
2287 spin_unlock_bh(lock: &hslot->lock);
2288 }
2289 }
2290}
2291EXPORT_IPV6_MOD(udp_lib_rehash);
2292
2293void udp_v4_rehash(struct sock *sk)
2294{
2295 u16 new_hash = ipv4_portaddr_hash(net: sock_net(sk),
2296 inet_sk(sk)->inet_rcv_saddr,
2297 inet_sk(sk)->inet_num);
2298 u16 new_hash4 = udp_ehashfn(net: sock_net(sk),
2299 laddr: sk->sk_rcv_saddr, lport: sk->sk_num,
2300 faddr: sk->sk_daddr, fport: sk->sk_dport);
2301
2302 udp_lib_rehash(sk, newhash: new_hash, newhash4: new_hash4);
2303}
2304
2305static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
2306{
2307 int rc;
2308
2309 if (inet_sk(sk)->inet_daddr) {
2310 sock_rps_save_rxhash(sk, skb);
2311 sk_mark_napi_id(sk, skb);
2312 sk_incoming_cpu_update(sk);
2313 } else {
2314 sk_mark_napi_id_once(sk, skb);
2315 }
2316
2317 rc = __udp_enqueue_schedule_skb(sk, skb);
2318 if (rc < 0) {
2319 int is_udplite = IS_UDPLITE(sk);
2320 int drop_reason;
2321
2322 /* Note that an ENOMEM error is charged twice */
2323 if (rc == -ENOMEM) {
2324 UDP_INC_STATS(sock_net(sk), UDP_MIB_RCVBUFERRORS,
2325 is_udplite);
2326 drop_reason = SKB_DROP_REASON_SOCKET_RCVBUFF;
2327 } else {
2328 UDP_INC_STATS(sock_net(sk), UDP_MIB_MEMERRORS,
2329 is_udplite);
2330 drop_reason = SKB_DROP_REASON_PROTO_MEM;
2331 }
2332 UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
2333 trace_udp_fail_queue_rcv_skb(rc, sk, skb);
2334 sk_skb_reason_drop(sk, skb, reason: drop_reason);
2335 return -1;
2336 }
2337
2338 return 0;
2339}
2340
2341/* returns:
2342 * -1: error
2343 * 0: success
2344 * >0: "udp encap" protocol resubmission
2345 *
2346 * Note that in the success and error cases, the skb is assumed to
2347 * have either been requeued or freed.
2348 */
2349static int udp_queue_rcv_one_skb(struct sock *sk, struct sk_buff *skb)
2350{
2351 int drop_reason = SKB_DROP_REASON_NOT_SPECIFIED;
2352 struct udp_sock *up = udp_sk(sk);
2353 int is_udplite = IS_UDPLITE(sk);
2354
2355 /*
2356 * Charge it to the socket, dropping if the queue is full.
2357 */
2358 if (!xfrm4_policy_check(sk, dir: XFRM_POLICY_IN, skb)) {
2359 drop_reason = SKB_DROP_REASON_XFRM_POLICY;
2360 goto drop;
2361 }
2362 nf_reset_ct(skb);
2363
2364 if (static_branch_unlikely(&udp_encap_needed_key) &&
2365 READ_ONCE(up->encap_type)) {
2366 int (*encap_rcv)(struct sock *sk, struct sk_buff *skb);
2367
2368 /*
2369 * This is an encapsulation socket so pass the skb to
2370 * the socket's udp_encap_rcv() hook. Otherwise, just
2371 * fall through and pass this up the UDP socket.
2372 * up->encap_rcv() returns the following value:
2373 * =0 if skb was successfully passed to the encap
2374 * handler or was discarded by it.
2375 * >0 if skb should be passed on to UDP.
2376 * <0 if skb should be resubmitted as proto -N
2377 */
2378
2379 /* if we're overly short, let UDP handle it */
2380 encap_rcv = READ_ONCE(up->encap_rcv);
2381 if (encap_rcv) {
2382 int ret;
2383
2384 /* Verify checksum before giving to encap */
2385 if (udp_lib_checksum_complete(skb))
2386 goto csum_error;
2387
2388 ret = encap_rcv(sk, skb);
2389 if (ret <= 0) {
2390 __UDP_INC_STATS(sock_net(sk),
2391 UDP_MIB_INDATAGRAMS,
2392 is_udplite);
2393 return -ret;
2394 }
2395 }
2396
2397 /* FALLTHROUGH -- it's a UDP Packet */
2398 }
2399
2400 /*
2401 * UDP-Lite specific tests, ignored on UDP sockets
2402 */
2403 if (udp_test_bit(UDPLITE_RECV_CC, sk) && UDP_SKB_CB(skb)->partial_cov) {
2404 u16 pcrlen = READ_ONCE(up->pcrlen);
2405
2406 /*
2407 * MIB statistics other than incrementing the error count are
2408 * disabled for the following two types of errors: these depend
2409 * on the application settings, not on the functioning of the
2410 * protocol stack as such.
2411 *
2412 * RFC 3828 here recommends (sec 3.3): "There should also be a
2413 * way ... to ... at least let the receiving application block
2414 * delivery of packets with coverage values less than a value
2415 * provided by the application."
2416 */
2417 if (pcrlen == 0) { /* full coverage was set */
2418 net_dbg_ratelimited("UDPLite: partial coverage %d while full coverage %d requested\n",
2419 UDP_SKB_CB(skb)->cscov, skb->len);
2420 goto drop;
2421 }
2422 /* The next case involves violating the min. coverage requested
2423 * by the receiver. This is subtle: if receiver wants x and x is
2424 * greater than the buffersize/MTU then receiver will complain
2425 * that it wants x while sender emits packets of smaller size y.
2426 * Therefore the above ...()->partial_cov statement is essential.
2427 */
2428 if (UDP_SKB_CB(skb)->cscov < pcrlen) {
2429 net_dbg_ratelimited("UDPLite: coverage %d too small, need min %d\n",
2430 UDP_SKB_CB(skb)->cscov, pcrlen);
2431 goto drop;
2432 }
2433 }
2434
2435 prefetch(&sk->sk_rmem_alloc);
2436 if (rcu_access_pointer(sk->sk_filter) &&
2437 udp_lib_checksum_complete(skb))
2438 goto csum_error;
2439
2440 if (sk_filter_trim_cap(sk, skb, cap: sizeof(struct udphdr))) {
2441 drop_reason = SKB_DROP_REASON_SOCKET_FILTER;
2442 goto drop;
2443 }
2444
2445 udp_csum_pull_header(skb);
2446
2447 ipv4_pktinfo_prepare(sk, skb, drop_dst: true);
2448 return __udp_queue_rcv_skb(sk, skb);
2449
2450csum_error:
2451 drop_reason = SKB_DROP_REASON_UDP_CSUM;
2452 __UDP_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite);
2453drop:
2454 __UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
2455 atomic_inc(v: &sk->sk_drops);
2456 sk_skb_reason_drop(sk, skb, reason: drop_reason);
2457 return -1;
2458}
2459
2460static int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
2461{
2462 struct sk_buff *next, *segs;
2463 int ret;
2464
2465 if (likely(!udp_unexpected_gso(sk, skb)))
2466 return udp_queue_rcv_one_skb(sk, skb);
2467
2468 BUILD_BUG_ON(sizeof(struct udp_skb_cb) > SKB_GSO_CB_OFFSET);
2469 __skb_push(skb, len: -skb_mac_offset(skb));
2470 segs = udp_rcv_segment(sk, skb, ipv4: true);
2471 skb_list_walk_safe(segs, skb, next) {
2472 __skb_pull(skb, len: skb_transport_offset(skb));
2473
2474 udp_post_segment_fix_csum(skb);
2475 ret = udp_queue_rcv_one_skb(sk, skb);
2476 if (ret > 0)
2477 ip_protocol_deliver_rcu(net: dev_net(dev: skb->dev), skb, proto: ret);
2478 }
2479 return 0;
2480}
2481
2482/* For TCP sockets, sk_rx_dst is protected by socket lock
2483 * For UDP, we use xchg() to guard against concurrent changes.
2484 */
2485bool udp_sk_rx_dst_set(struct sock *sk, struct dst_entry *dst)
2486{
2487 struct dst_entry *old;
2488
2489 if (dst_hold_safe(dst)) {
2490 old = unrcu_pointer(xchg(&sk->sk_rx_dst, RCU_INITIALIZER(dst)));
2491 dst_release(dst: old);
2492 return old != dst;
2493 }
2494 return false;
2495}
2496EXPORT_IPV6_MOD(udp_sk_rx_dst_set);
2497
2498/*
2499 * Multicasts and broadcasts go to each listener.
2500 *
2501 * Note: called only from the BH handler context.
2502 */
2503static int __udp4_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
2504 struct udphdr *uh,
2505 __be32 saddr, __be32 daddr,
2506 struct udp_table *udptable,
2507 int proto)
2508{
2509 struct sock *sk, *first = NULL;
2510 unsigned short hnum = ntohs(uh->dest);
2511 struct udp_hslot *hslot = udp_hashslot(table: udptable, net, num: hnum);
2512 unsigned int hash2 = 0, hash2_any = 0, use_hash2 = (hslot->count > 10);
2513 unsigned int offset = offsetof(typeof(*sk), sk_node);
2514 int dif = skb->dev->ifindex;
2515 int sdif = inet_sdif(skb);
2516 struct hlist_node *node;
2517 struct sk_buff *nskb;
2518
2519 if (use_hash2) {
2520 hash2_any = ipv4_portaddr_hash(net, htonl(INADDR_ANY), port: hnum) &
2521 udptable->mask;
2522 hash2 = ipv4_portaddr_hash(net, saddr: daddr, port: hnum) & udptable->mask;
2523start_lookup:
2524 hslot = &udptable->hash2[hash2].hslot;
2525 offset = offsetof(typeof(*sk), __sk_common.skc_portaddr_node);
2526 }
2527
2528 sk_for_each_entry_offset_rcu(sk, node, &hslot->head, offset) {
2529 if (!__udp_is_mcast_sock(net, sk, loc_port: uh->dest, loc_addr: daddr,
2530 rmt_port: uh->source, rmt_addr: saddr, dif, sdif, hnum))
2531 continue;
2532
2533 if (!first) {
2534 first = sk;
2535 continue;
2536 }
2537 nskb = skb_clone(skb, GFP_ATOMIC);
2538
2539 if (unlikely(!nskb)) {
2540 atomic_inc(v: &sk->sk_drops);
2541 __UDP_INC_STATS(net, UDP_MIB_RCVBUFERRORS,
2542 IS_UDPLITE(sk));
2543 __UDP_INC_STATS(net, UDP_MIB_INERRORS,
2544 IS_UDPLITE(sk));
2545 continue;
2546 }
2547 if (udp_queue_rcv_skb(sk, skb: nskb) > 0)
2548 consume_skb(skb: nskb);
2549 }
2550
2551 /* Also lookup *:port if we are using hash2 and haven't done so yet. */
2552 if (use_hash2 && hash2 != hash2_any) {
2553 hash2 = hash2_any;
2554 goto start_lookup;
2555 }
2556
2557 if (first) {
2558 if (udp_queue_rcv_skb(sk: first, skb) > 0)
2559 consume_skb(skb);
2560 } else {
2561 kfree_skb(skb);
2562 __UDP_INC_STATS(net, UDP_MIB_IGNOREDMULTI,
2563 proto == IPPROTO_UDPLITE);
2564 }
2565 return 0;
2566}
2567
2568/* Initialize UDP checksum. If exited with zero value (success),
2569 * CHECKSUM_UNNECESSARY means, that no more checks are required.
2570 * Otherwise, csum completion requires checksumming packet body,
2571 * including udp header and folding it to skb->csum.
2572 */
2573static inline int udp4_csum_init(struct sk_buff *skb, struct udphdr *uh,
2574 int proto)
2575{
2576 int err;
2577
2578 UDP_SKB_CB(skb)->partial_cov = 0;
2579 UDP_SKB_CB(skb)->cscov = skb->len;
2580
2581 if (proto == IPPROTO_UDPLITE) {
2582 err = udplite_checksum_init(skb, uh);
2583 if (err)
2584 return err;
2585
2586 if (UDP_SKB_CB(skb)->partial_cov) {
2587 skb->csum = inet_compute_pseudo(skb, proto);
2588 return 0;
2589 }
2590 }
2591
2592 /* Note, we are only interested in != 0 or == 0, thus the
2593 * force to int.
2594 */
2595 err = (__force int)skb_checksum_init_zero_check(skb, proto, uh->check,
2596 inet_compute_pseudo);
2597 if (err)
2598 return err;
2599
2600 if (skb->ip_summed == CHECKSUM_COMPLETE && !skb->csum_valid) {
2601 /* If SW calculated the value, we know it's bad */
2602 if (skb->csum_complete_sw)
2603 return 1;
2604
2605 /* HW says the value is bad. Let's validate that.
2606 * skb->csum is no longer the full packet checksum,
2607 * so don't treat it as such.
2608 */
2609 skb_checksum_complete_unset(skb);
2610 }
2611
2612 return 0;
2613}
2614
2615/* wrapper for udp_queue_rcv_skb tacking care of csum conversion and
2616 * return code conversion for ip layer consumption
2617 */
2618static int udp_unicast_rcv_skb(struct sock *sk, struct sk_buff *skb,
2619 struct udphdr *uh)
2620{
2621 int ret;
2622
2623 if (inet_get_convert_csum(sk) && uh->check && !IS_UDPLITE(sk))
2624 skb_checksum_try_convert(skb, IPPROTO_UDP, inet_compute_pseudo);
2625
2626 ret = udp_queue_rcv_skb(sk, skb);
2627
2628 /* a return value > 0 means to resubmit the input, but
2629 * it wants the return to be -protocol, or 0
2630 */
2631 if (ret > 0)
2632 return -ret;
2633 return 0;
2634}
2635
2636/*
2637 * All we need to do is get the socket, and then do a checksum.
2638 */
2639
2640int __udp4_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
2641 int proto)
2642{
2643 struct sock *sk = NULL;
2644 struct udphdr *uh;
2645 unsigned short ulen;
2646 struct rtable *rt = skb_rtable(skb);
2647 __be32 saddr, daddr;
2648 struct net *net = dev_net(dev: skb->dev);
2649 bool refcounted;
2650 int drop_reason;
2651
2652 drop_reason = SKB_DROP_REASON_NOT_SPECIFIED;
2653
2654 /*
2655 * Validate the packet.
2656 */
2657 if (!pskb_may_pull(skb, len: sizeof(struct udphdr)))
2658 goto drop; /* No space for header. */
2659
2660 uh = udp_hdr(skb);
2661 ulen = ntohs(uh->len);
2662 saddr = ip_hdr(skb)->saddr;
2663 daddr = ip_hdr(skb)->daddr;
2664
2665 if (ulen > skb->len)
2666 goto short_packet;
2667
2668 if (proto == IPPROTO_UDP) {
2669 /* UDP validates ulen. */
2670 if (ulen < sizeof(*uh) || pskb_trim_rcsum(skb, len: ulen))
2671 goto short_packet;
2672 uh = udp_hdr(skb);
2673 }
2674
2675 if (udp4_csum_init(skb, uh, proto))
2676 goto csum_error;
2677
2678 sk = inet_steal_sock(net, skb, doff: sizeof(struct udphdr), saddr, sport: uh->source, daddr, dport: uh->dest,
2679 refcounted: &refcounted, ehashfn: udp_ehashfn);
2680 if (IS_ERR(ptr: sk))
2681 goto no_sk;
2682
2683 if (sk) {
2684 struct dst_entry *dst = skb_dst(skb);
2685 int ret;
2686
2687 if (unlikely(rcu_dereference(sk->sk_rx_dst) != dst))
2688 udp_sk_rx_dst_set(sk, dst);
2689
2690 ret = udp_unicast_rcv_skb(sk, skb, uh);
2691 if (refcounted)
2692 sock_put(sk);
2693 return ret;
2694 }
2695
2696 if (rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST))
2697 return __udp4_lib_mcast_deliver(net, skb, uh,
2698 saddr, daddr, udptable, proto);
2699
2700 sk = __udp4_lib_lookup_skb(skb, sport: uh->source, dport: uh->dest, udptable);
2701 if (sk)
2702 return udp_unicast_rcv_skb(sk, skb, uh);
2703no_sk:
2704 if (!xfrm4_policy_check(NULL, dir: XFRM_POLICY_IN, skb))
2705 goto drop;
2706 nf_reset_ct(skb);
2707
2708 /* No socket. Drop packet silently, if checksum is wrong */
2709 if (udp_lib_checksum_complete(skb))
2710 goto csum_error;
2711
2712 drop_reason = SKB_DROP_REASON_NO_SOCKET;
2713 __UDP_INC_STATS(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
2714 icmp_send(skb_in: skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, info: 0);
2715
2716 /*
2717 * Hmm. We got an UDP packet to a port to which we
2718 * don't wanna listen. Ignore it.
2719 */
2720 sk_skb_reason_drop(sk, skb, reason: drop_reason);
2721 return 0;
2722
2723short_packet:
2724 drop_reason = SKB_DROP_REASON_PKT_TOO_SMALL;
2725 net_dbg_ratelimited("UDP%s: short packet: From %pI4:%u %d/%d to %pI4:%u\n",
2726 proto == IPPROTO_UDPLITE ? "Lite" : "",
2727 &saddr, ntohs(uh->source),
2728 ulen, skb->len,
2729 &daddr, ntohs(uh->dest));
2730 goto drop;
2731
2732csum_error:
2733 /*
2734 * RFC1122: OK. Discards the bad packet silently (as far as
2735 * the network is concerned, anyway) as per 4.1.3.4 (MUST).
2736 */
2737 drop_reason = SKB_DROP_REASON_UDP_CSUM;
2738 net_dbg_ratelimited("UDP%s: bad checksum. From %pI4:%u to %pI4:%u ulen %d\n",
2739 proto == IPPROTO_UDPLITE ? "Lite" : "",
2740 &saddr, ntohs(uh->source), &daddr, ntohs(uh->dest),
2741 ulen);
2742 __UDP_INC_STATS(net, UDP_MIB_CSUMERRORS, proto == IPPROTO_UDPLITE);
2743drop:
2744 __UDP_INC_STATS(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
2745 sk_skb_reason_drop(sk, skb, reason: drop_reason);
2746 return 0;
2747}
2748
2749/* We can only early demux multicast if there is a single matching socket.
2750 * If more than one socket found returns NULL
2751 */
2752static struct sock *__udp4_lib_mcast_demux_lookup(struct net *net,
2753 __be16 loc_port, __be32 loc_addr,
2754 __be16 rmt_port, __be32 rmt_addr,
2755 int dif, int sdif)
2756{
2757 struct udp_table *udptable = net->ipv4.udp_table;
2758 unsigned short hnum = ntohs(loc_port);
2759 struct sock *sk, *result;
2760 struct udp_hslot *hslot;
2761 unsigned int slot;
2762
2763 slot = udp_hashfn(net, num: hnum, mask: udptable->mask);
2764 hslot = &udptable->hash[slot];
2765
2766 /* Do not bother scanning a too big list */
2767 if (hslot->count > 10)
2768 return NULL;
2769
2770 result = NULL;
2771 sk_for_each_rcu(sk, &hslot->head) {
2772 if (__udp_is_mcast_sock(net, sk, loc_port, loc_addr,
2773 rmt_port, rmt_addr, dif, sdif, hnum)) {
2774 if (result)
2775 return NULL;
2776 result = sk;
2777 }
2778 }
2779
2780 return result;
2781}
2782
2783/* For unicast we should only early demux connected sockets or we can
2784 * break forwarding setups. The chains here can be long so only check
2785 * if the first socket is an exact match and if not move on.
2786 */
2787static struct sock *__udp4_lib_demux_lookup(struct net *net,
2788 __be16 loc_port, __be32 loc_addr,
2789 __be16 rmt_port, __be32 rmt_addr,
2790 int dif, int sdif)
2791{
2792 struct udp_table *udptable = net->ipv4.udp_table;
2793 INET_ADDR_COOKIE(acookie, rmt_addr, loc_addr);
2794 unsigned short hnum = ntohs(loc_port);
2795 struct udp_hslot *hslot2;
2796 unsigned int hash2;
2797 __portpair ports;
2798 struct sock *sk;
2799
2800 hash2 = ipv4_portaddr_hash(net, saddr: loc_addr, port: hnum);
2801 hslot2 = udp_hashslot2(table: udptable, hash: hash2);
2802 ports = INET_COMBINED_PORTS(rmt_port, hnum);
2803
2804 udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {
2805 if (inet_match(net, sk, cookie: acookie, ports, dif, sdif))
2806 return sk;
2807 /* Only check first socket in chain */
2808 break;
2809 }
2810 return NULL;
2811}
2812
2813int udp_v4_early_demux(struct sk_buff *skb)
2814{
2815 struct net *net = dev_net(dev: skb->dev);
2816 struct in_device *in_dev = NULL;
2817 const struct iphdr *iph;
2818 const struct udphdr *uh;
2819 struct sock *sk = NULL;
2820 struct dst_entry *dst;
2821 int dif = skb->dev->ifindex;
2822 int sdif = inet_sdif(skb);
2823 int ours;
2824
2825 /* validate the packet */
2826 if (!pskb_may_pull(skb, len: skb_transport_offset(skb) + sizeof(struct udphdr)))
2827 return 0;
2828
2829 iph = ip_hdr(skb);
2830 uh = udp_hdr(skb);
2831
2832 if (skb->pkt_type == PACKET_MULTICAST) {
2833 in_dev = __in_dev_get_rcu(dev: skb->dev);
2834
2835 if (!in_dev)
2836 return 0;
2837
2838 ours = ip_check_mc_rcu(dev: in_dev, mc_addr: iph->daddr, src_addr: iph->saddr,
2839 proto: iph->protocol);
2840 if (!ours)
2841 return 0;
2842
2843 sk = __udp4_lib_mcast_demux_lookup(net, loc_port: uh->dest, loc_addr: iph->daddr,
2844 rmt_port: uh->source, rmt_addr: iph->saddr,
2845 dif, sdif);
2846 } else if (skb->pkt_type == PACKET_HOST) {
2847 sk = __udp4_lib_demux_lookup(net, loc_port: uh->dest, loc_addr: iph->daddr,
2848 rmt_port: uh->source, rmt_addr: iph->saddr, dif, sdif);
2849 }
2850
2851 if (!sk)
2852 return 0;
2853
2854 skb->sk = sk;
2855 DEBUG_NET_WARN_ON_ONCE(sk_is_refcounted(sk));
2856 skb->destructor = sock_pfree;
2857 dst = rcu_dereference(sk->sk_rx_dst);
2858
2859 if (dst)
2860 dst = dst_check(dst, cookie: 0);
2861 if (dst) {
2862 u32 itag = 0;
2863
2864 /* set noref for now.
2865 * any place which wants to hold dst has to call
2866 * dst_hold_safe()
2867 */
2868 skb_dst_set_noref(skb, dst);
2869
2870 /* for unconnected multicast sockets we need to validate
2871 * the source on each packet
2872 */
2873 if (!inet_sk(sk)->inet_daddr && in_dev)
2874 return ip_mc_validate_source(skb, daddr: iph->daddr,
2875 saddr: iph->saddr,
2876 dscp: ip4h_dscp(ip4h: iph),
2877 dev: skb->dev, in_dev, itag: &itag);
2878 }
2879 return 0;
2880}
2881
2882int udp_rcv(struct sk_buff *skb)
2883{
2884 return __udp4_lib_rcv(skb, udptable: dev_net(dev: skb->dev)->ipv4.udp_table, IPPROTO_UDP);
2885}
2886
2887void udp_destroy_sock(struct sock *sk)
2888{
2889 struct udp_sock *up = udp_sk(sk);
2890 bool slow = lock_sock_fast(sk);
2891
2892 /* protects from races with udp_abort() */
2893 sock_set_flag(sk, flag: SOCK_DEAD);
2894 udp_flush_pending_frames(sk);
2895 unlock_sock_fast(sk, slow);
2896 if (static_branch_unlikely(&udp_encap_needed_key)) {
2897 if (up->encap_type) {
2898 void (*encap_destroy)(struct sock *sk);
2899 encap_destroy = READ_ONCE(up->encap_destroy);
2900 if (encap_destroy)
2901 encap_destroy(sk);
2902 }
2903 if (udp_test_bit(ENCAP_ENABLED, sk)) {
2904 static_branch_dec(&udp_encap_needed_key);
2905 udp_tunnel_cleanup_gro(sk);
2906 }
2907 }
2908}
2909
2910typedef struct sk_buff *(*udp_gro_receive_t)(struct sock *sk,
2911 struct list_head *head,
2912 struct sk_buff *skb);
2913
2914static void set_xfrm_gro_udp_encap_rcv(__u16 encap_type, unsigned short family,
2915 struct sock *sk)
2916{
2917#ifdef CONFIG_XFRM
2918 udp_gro_receive_t new_gro_receive;
2919
2920 if (udp_test_bit(GRO_ENABLED, sk) && encap_type == UDP_ENCAP_ESPINUDP) {
2921 if (IS_ENABLED(CONFIG_IPV6) && family == AF_INET6)
2922 new_gro_receive = ipv6_stub->xfrm6_gro_udp_encap_rcv;
2923 else
2924 new_gro_receive = xfrm4_gro_udp_encap_rcv;
2925
2926 if (udp_sk(sk)->gro_receive != new_gro_receive) {
2927 /*
2928 * With IPV6_ADDRFORM the gro callback could change
2929 * after being set, unregister the old one, if valid.
2930 */
2931 if (udp_sk(sk)->gro_receive)
2932 udp_tunnel_update_gro_rcv(sk, add: false);
2933
2934 WRITE_ONCE(udp_sk(sk)->gro_receive, new_gro_receive);
2935 udp_tunnel_update_gro_rcv(sk, add: true);
2936 }
2937 }
2938#endif
2939}
2940
2941/*
2942 * Socket option code for UDP
2943 */
2944int udp_lib_setsockopt(struct sock *sk, int level, int optname,
2945 sockptr_t optval, unsigned int optlen,
2946 int (*push_pending_frames)(struct sock *))
2947{
2948 struct udp_sock *up = udp_sk(sk);
2949 int val, valbool;
2950 int err = 0;
2951 int is_udplite = IS_UDPLITE(sk);
2952
2953 if (level == SOL_SOCKET) {
2954 err = sk_setsockopt(sk, level, optname, optval, optlen);
2955
2956 if (optname == SO_RCVBUF || optname == SO_RCVBUFFORCE) {
2957 sockopt_lock_sock(sk);
2958 /* paired with READ_ONCE in udp_rmem_release() */
2959 WRITE_ONCE(up->forward_threshold, sk->sk_rcvbuf >> 2);
2960 sockopt_release_sock(sk);
2961 }
2962 return err;
2963 }
2964
2965 if (optlen < sizeof(int))
2966 return -EINVAL;
2967
2968 if (copy_from_sockptr(dst: &val, src: optval, size: sizeof(val)))
2969 return -EFAULT;
2970
2971 valbool = val ? 1 : 0;
2972
2973 switch (optname) {
2974 case UDP_CORK:
2975 if (val != 0) {
2976 udp_set_bit(CORK, sk);
2977 } else {
2978 udp_clear_bit(CORK, sk);
2979 lock_sock(sk);
2980 push_pending_frames(sk);
2981 release_sock(sk);
2982 }
2983 break;
2984
2985 case UDP_ENCAP:
2986 sockopt_lock_sock(sk);
2987 switch (val) {
2988 case 0:
2989#ifdef CONFIG_XFRM
2990 case UDP_ENCAP_ESPINUDP:
2991 set_xfrm_gro_udp_encap_rcv(encap_type: val, family: sk->sk_family, sk);
2992#if IS_ENABLED(CONFIG_IPV6)
2993 if (sk->sk_family == AF_INET6)
2994 WRITE_ONCE(up->encap_rcv,
2995 ipv6_stub->xfrm6_udp_encap_rcv);
2996 else
2997#endif
2998 WRITE_ONCE(up->encap_rcv,
2999 xfrm4_udp_encap_rcv);
3000#endif
3001 fallthrough;
3002 case UDP_ENCAP_L2TPINUDP:
3003 WRITE_ONCE(up->encap_type, val);
3004 udp_tunnel_encap_enable(sk);
3005 break;
3006 default:
3007 err = -ENOPROTOOPT;
3008 break;
3009 }
3010 sockopt_release_sock(sk);
3011 break;
3012
3013 case UDP_NO_CHECK6_TX:
3014 udp_set_no_check6_tx(sk, val: valbool);
3015 break;
3016
3017 case UDP_NO_CHECK6_RX:
3018 udp_set_no_check6_rx(sk, val: valbool);
3019 break;
3020
3021 case UDP_SEGMENT:
3022 if (val < 0 || val > USHRT_MAX)
3023 return -EINVAL;
3024 WRITE_ONCE(up->gso_size, val);
3025 break;
3026
3027 case UDP_GRO:
3028 sockopt_lock_sock(sk);
3029 /* when enabling GRO, accept the related GSO packet type */
3030 if (valbool)
3031 udp_tunnel_encap_enable(sk);
3032 udp_assign_bit(GRO_ENABLED, sk, valbool);
3033 udp_assign_bit(ACCEPT_L4, sk, valbool);
3034 set_xfrm_gro_udp_encap_rcv(encap_type: up->encap_type, family: sk->sk_family, sk);
3035 sockopt_release_sock(sk);
3036 break;
3037
3038 /*
3039 * UDP-Lite's partial checksum coverage (RFC 3828).
3040 */
3041 /* The sender sets actual checksum coverage length via this option.
3042 * The case coverage > packet length is handled by send module. */
3043 case UDPLITE_SEND_CSCOV:
3044 if (!is_udplite) /* Disable the option on UDP sockets */
3045 return -ENOPROTOOPT;
3046 if (val != 0 && val < 8) /* Illegal coverage: use default (8) */
3047 val = 8;
3048 else if (val > USHRT_MAX)
3049 val = USHRT_MAX;
3050 WRITE_ONCE(up->pcslen, val);
3051 udp_set_bit(UDPLITE_SEND_CC, sk);
3052 break;
3053
3054 /* The receiver specifies a minimum checksum coverage value. To make
3055 * sense, this should be set to at least 8 (as done below). If zero is
3056 * used, this again means full checksum coverage. */
3057 case UDPLITE_RECV_CSCOV:
3058 if (!is_udplite) /* Disable the option on UDP sockets */
3059 return -ENOPROTOOPT;
3060 if (val != 0 && val < 8) /* Avoid silly minimal values. */
3061 val = 8;
3062 else if (val > USHRT_MAX)
3063 val = USHRT_MAX;
3064 WRITE_ONCE(up->pcrlen, val);
3065 udp_set_bit(UDPLITE_RECV_CC, sk);
3066 break;
3067
3068 default:
3069 err = -ENOPROTOOPT;
3070 break;
3071 }
3072
3073 return err;
3074}
3075EXPORT_IPV6_MOD(udp_lib_setsockopt);
3076
3077int udp_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval,
3078 unsigned int optlen)
3079{
3080 if (level == SOL_UDP || level == SOL_UDPLITE || level == SOL_SOCKET)
3081 return udp_lib_setsockopt(sk, level, optname,
3082 optval, optlen,
3083 push_pending_frames: udp_push_pending_frames);
3084 return ip_setsockopt(sk, level, optname, optval, optlen);
3085}
3086
3087int udp_lib_getsockopt(struct sock *sk, int level, int optname,
3088 char __user *optval, int __user *optlen)
3089{
3090 struct udp_sock *up = udp_sk(sk);
3091 int val, len;
3092
3093 if (get_user(len, optlen))
3094 return -EFAULT;
3095
3096 if (len < 0)
3097 return -EINVAL;
3098
3099 len = min_t(unsigned int, len, sizeof(int));
3100
3101 switch (optname) {
3102 case UDP_CORK:
3103 val = udp_test_bit(CORK, sk);
3104 break;
3105
3106 case UDP_ENCAP:
3107 val = READ_ONCE(up->encap_type);
3108 break;
3109
3110 case UDP_NO_CHECK6_TX:
3111 val = udp_get_no_check6_tx(sk);
3112 break;
3113
3114 case UDP_NO_CHECK6_RX:
3115 val = udp_get_no_check6_rx(sk);
3116 break;
3117
3118 case UDP_SEGMENT:
3119 val = READ_ONCE(up->gso_size);
3120 break;
3121
3122 case UDP_GRO:
3123 val = udp_test_bit(GRO_ENABLED, sk);
3124 break;
3125
3126 /* The following two cannot be changed on UDP sockets, the return is
3127 * always 0 (which corresponds to the full checksum coverage of UDP). */
3128 case UDPLITE_SEND_CSCOV:
3129 val = READ_ONCE(up->pcslen);
3130 break;
3131
3132 case UDPLITE_RECV_CSCOV:
3133 val = READ_ONCE(up->pcrlen);
3134 break;
3135
3136 default:
3137 return -ENOPROTOOPT;
3138 }
3139
3140 if (put_user(len, optlen))
3141 return -EFAULT;
3142 if (copy_to_user(to: optval, from: &val, n: len))
3143 return -EFAULT;
3144 return 0;
3145}
3146EXPORT_IPV6_MOD(udp_lib_getsockopt);
3147
3148int udp_getsockopt(struct sock *sk, int level, int optname,
3149 char __user *optval, int __user *optlen)
3150{
3151 if (level == SOL_UDP || level == SOL_UDPLITE)
3152 return udp_lib_getsockopt(sk, level, optname, optval, optlen);
3153 return ip_getsockopt(sk, level, optname, optval, optlen);
3154}
3155
3156/**
3157 * udp_poll - wait for a UDP event.
3158 * @file: - file struct
3159 * @sock: - socket
3160 * @wait: - poll table
3161 *
3162 * This is same as datagram poll, except for the special case of
3163 * blocking sockets. If application is using a blocking fd
3164 * and a packet with checksum error is in the queue;
3165 * then it could get return from select indicating data available
3166 * but then block when reading it. Add special case code
3167 * to work around these arguably broken applications.
3168 */
3169__poll_t udp_poll(struct file *file, struct socket *sock, poll_table *wait)
3170{
3171 __poll_t mask = datagram_poll(file, sock, wait);
3172 struct sock *sk = sock->sk;
3173
3174 if (!skb_queue_empty_lockless(list: &udp_sk(sk)->reader_queue))
3175 mask |= EPOLLIN | EPOLLRDNORM;
3176
3177 /* Check for false positives due to checksum errors */
3178 if ((mask & EPOLLRDNORM) && !(file->f_flags & O_NONBLOCK) &&
3179 !(sk->sk_shutdown & RCV_SHUTDOWN) && first_packet_length(sk) == -1)
3180 mask &= ~(EPOLLIN | EPOLLRDNORM);
3181
3182 /* psock ingress_msg queue should not contain any bad checksum frames */
3183 if (sk_is_readable(sk))
3184 mask |= EPOLLIN | EPOLLRDNORM;
3185 return mask;
3186
3187}
3188EXPORT_IPV6_MOD(udp_poll);
3189
3190int udp_abort(struct sock *sk, int err)
3191{
3192 if (!has_current_bpf_ctx())
3193 lock_sock(sk);
3194
3195 /* udp{v6}_destroy_sock() sets it under the sk lock, avoid racing
3196 * with close()
3197 */
3198 if (sock_flag(sk, flag: SOCK_DEAD))
3199 goto out;
3200
3201 sk->sk_err = err;
3202 sk_error_report(sk);
3203 __udp_disconnect(sk, 0);
3204
3205out:
3206 if (!has_current_bpf_ctx())
3207 release_sock(sk);
3208
3209 return 0;
3210}
3211EXPORT_IPV6_MOD_GPL(udp_abort);
3212
3213struct proto udp_prot = {
3214 .name = "UDP",
3215 .owner = THIS_MODULE,
3216 .close = udp_lib_close,
3217 .pre_connect = udp_pre_connect,
3218 .connect = udp_connect,
3219 .disconnect = udp_disconnect,
3220 .ioctl = udp_ioctl,
3221 .init = udp_init_sock,
3222 .destroy = udp_destroy_sock,
3223 .setsockopt = udp_setsockopt,
3224 .getsockopt = udp_getsockopt,
3225 .sendmsg = udp_sendmsg,
3226 .recvmsg = udp_recvmsg,
3227 .splice_eof = udp_splice_eof,
3228 .release_cb = ip4_datagram_release_cb,
3229 .hash = udp_lib_hash,
3230 .unhash = udp_lib_unhash,
3231 .rehash = udp_v4_rehash,
3232 .get_port = udp_v4_get_port,
3233 .put_port = udp_lib_unhash,
3234#ifdef CONFIG_BPF_SYSCALL
3235 .psock_update_sk_prot = udp_bpf_update_proto,
3236#endif
3237 .memory_allocated = &udp_memory_allocated,
3238 .per_cpu_fw_alloc = &udp_memory_per_cpu_fw_alloc,
3239
3240 .sysctl_mem = sysctl_udp_mem,
3241 .sysctl_wmem_offset = offsetof(struct net, ipv4.sysctl_udp_wmem_min),
3242 .sysctl_rmem_offset = offsetof(struct net, ipv4.sysctl_udp_rmem_min),
3243 .obj_size = sizeof(struct udp_sock),
3244 .h.udp_table = NULL,
3245 .diag_destroy = udp_abort,
3246};
3247EXPORT_SYMBOL(udp_prot);
3248
3249/* ------------------------------------------------------------------------ */
3250#ifdef CONFIG_PROC_FS
3251
3252static unsigned short seq_file_family(const struct seq_file *seq);
3253static bool seq_sk_match(struct seq_file *seq, const struct sock *sk)
3254{
3255 unsigned short family = seq_file_family(seq);
3256
3257 /* AF_UNSPEC is used as a match all */
3258 return ((family == AF_UNSPEC || family == sk->sk_family) &&
3259 net_eq(net1: sock_net(sk), net2: seq_file_net(seq)));
3260}
3261
3262#ifdef CONFIG_BPF_SYSCALL
3263static const struct seq_operations bpf_iter_udp_seq_ops;
3264#endif
3265static struct udp_table *udp_get_table_seq(struct seq_file *seq,
3266 struct net *net)
3267{
3268 const struct udp_seq_afinfo *afinfo;
3269
3270#ifdef CONFIG_BPF_SYSCALL
3271 if (seq->op == &bpf_iter_udp_seq_ops)
3272 return net->ipv4.udp_table;
3273#endif
3274
3275 afinfo = pde_data(inode: file_inode(f: seq->file));
3276 return afinfo->udp_table ? : net->ipv4.udp_table;
3277}
3278
3279static struct sock *udp_get_first(struct seq_file *seq, int start)
3280{
3281 struct udp_iter_state *state = seq->private;
3282 struct net *net = seq_file_net(seq);
3283 struct udp_table *udptable;
3284 struct sock *sk;
3285
3286 udptable = udp_get_table_seq(seq, net);
3287
3288 for (state->bucket = start; state->bucket <= udptable->mask;
3289 ++state->bucket) {
3290 struct udp_hslot *hslot = &udptable->hash[state->bucket];
3291
3292 if (hlist_empty(h: &hslot->head))
3293 continue;
3294
3295 spin_lock_bh(lock: &hslot->lock);
3296 sk_for_each(sk, &hslot->head) {
3297 if (seq_sk_match(seq, sk))
3298 goto found;
3299 }
3300 spin_unlock_bh(lock: &hslot->lock);
3301 }
3302 sk = NULL;
3303found:
3304 return sk;
3305}
3306
3307static struct sock *udp_get_next(struct seq_file *seq, struct sock *sk)
3308{
3309 struct udp_iter_state *state = seq->private;
3310 struct net *net = seq_file_net(seq);
3311 struct udp_table *udptable;
3312
3313 do {
3314 sk = sk_next(sk);
3315 } while (sk && !seq_sk_match(seq, sk));
3316
3317 if (!sk) {
3318 udptable = udp_get_table_seq(seq, net);
3319
3320 if (state->bucket <= udptable->mask)
3321 spin_unlock_bh(lock: &udptable->hash[state->bucket].lock);
3322
3323 return udp_get_first(seq, start: state->bucket + 1);
3324 }
3325 return sk;
3326}
3327
3328static struct sock *udp_get_idx(struct seq_file *seq, loff_t pos)
3329{
3330 struct sock *sk = udp_get_first(seq, start: 0);
3331
3332 if (sk)
3333 while (pos && (sk = udp_get_next(seq, sk)) != NULL)
3334 --pos;
3335 return pos ? NULL : sk;
3336}
3337
3338void *udp_seq_start(struct seq_file *seq, loff_t *pos)
3339{
3340 struct udp_iter_state *state = seq->private;
3341 state->bucket = MAX_UDP_PORTS;
3342
3343 return *pos ? udp_get_idx(seq, pos: *pos-1) : SEQ_START_TOKEN;
3344}
3345EXPORT_IPV6_MOD(udp_seq_start);
3346
3347void *udp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
3348{
3349 struct sock *sk;
3350
3351 if (v == SEQ_START_TOKEN)
3352 sk = udp_get_idx(seq, pos: 0);
3353 else
3354 sk = udp_get_next(seq, sk: v);
3355
3356 ++*pos;
3357 return sk;
3358}
3359EXPORT_IPV6_MOD(udp_seq_next);
3360
3361void udp_seq_stop(struct seq_file *seq, void *v)
3362{
3363 struct udp_iter_state *state = seq->private;
3364 struct udp_table *udptable;
3365
3366 udptable = udp_get_table_seq(seq, net: seq_file_net(seq));
3367
3368 if (state->bucket <= udptable->mask)
3369 spin_unlock_bh(lock: &udptable->hash[state->bucket].lock);
3370}
3371EXPORT_IPV6_MOD(udp_seq_stop);
3372
3373/* ------------------------------------------------------------------------ */
3374static void udp4_format_sock(struct sock *sp, struct seq_file *f,
3375 int bucket)
3376{
3377 struct inet_sock *inet = inet_sk(sp);
3378 __be32 dest = inet->inet_daddr;
3379 __be32 src = inet->inet_rcv_saddr;
3380 __u16 destp = ntohs(inet->inet_dport);
3381 __u16 srcp = ntohs(inet->inet_sport);
3382
3383 seq_printf(m: f, fmt: "%5d: %08X:%04X %08X:%04X"
3384 " %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %u",
3385 bucket, src, srcp, dest, destp, sp->sk_state,
3386 sk_wmem_alloc_get(sk: sp),
3387 udp_rqueue_get(sk: sp),
3388 0, 0L, 0,
3389 from_kuid_munged(to: seq_user_ns(seq: f), uid: sock_i_uid(sk: sp)),
3390 0, sock_i_ino(sk: sp),
3391 refcount_read(r: &sp->sk_refcnt), sp,
3392 atomic_read(v: &sp->sk_drops));
3393}
3394
3395int udp4_seq_show(struct seq_file *seq, void *v)
3396{
3397 seq_setwidth(m: seq, size: 127);
3398 if (v == SEQ_START_TOKEN)
3399 seq_puts(m: seq, s: " sl local_address rem_address st tx_queue "
3400 "rx_queue tr tm->when retrnsmt uid timeout "
3401 "inode ref pointer drops");
3402 else {
3403 struct udp_iter_state *state = seq->private;
3404
3405 udp4_format_sock(sp: v, f: seq, bucket: state->bucket);
3406 }
3407 seq_pad(m: seq, c: '\n');
3408 return 0;
3409}
3410
3411#ifdef CONFIG_BPF_SYSCALL
3412struct bpf_iter__udp {
3413 __bpf_md_ptr(struct bpf_iter_meta *, meta);
3414 __bpf_md_ptr(struct udp_sock *, udp_sk);
3415 uid_t uid __aligned(8);
3416 int bucket __aligned(8);
3417};
3418
3419union bpf_udp_iter_batch_item {
3420 struct sock *sk;
3421 __u64 cookie;
3422};
3423
3424struct bpf_udp_iter_state {
3425 struct udp_iter_state state;
3426 unsigned int cur_sk;
3427 unsigned int end_sk;
3428 unsigned int max_sk;
3429 union bpf_udp_iter_batch_item *batch;
3430};
3431
3432static int bpf_iter_udp_realloc_batch(struct bpf_udp_iter_state *iter,
3433 unsigned int new_batch_sz, gfp_t flags);
3434static struct sock *bpf_iter_udp_resume(struct sock *first_sk,
3435 union bpf_udp_iter_batch_item *cookies,
3436 int n_cookies)
3437{
3438 struct sock *sk = NULL;
3439 int i;
3440
3441 for (i = 0; i < n_cookies; i++) {
3442 sk = first_sk;
3443 udp_portaddr_for_each_entry_from(sk)
3444 if (cookies[i].cookie == atomic64_read(v: &sk->sk_cookie))
3445 goto done;
3446 }
3447done:
3448 return sk;
3449}
3450
3451static struct sock *bpf_iter_udp_batch(struct seq_file *seq)
3452{
3453 struct bpf_udp_iter_state *iter = seq->private;
3454 struct udp_iter_state *state = &iter->state;
3455 unsigned int find_cookie, end_cookie;
3456 struct net *net = seq_file_net(seq);
3457 struct udp_table *udptable;
3458 unsigned int batch_sks = 0;
3459 int resume_bucket;
3460 int resizes = 0;
3461 struct sock *sk;
3462 int err = 0;
3463
3464 resume_bucket = state->bucket;
3465
3466 /* The current batch is done, so advance the bucket. */
3467 if (iter->cur_sk == iter->end_sk)
3468 state->bucket++;
3469
3470 udptable = udp_get_table_seq(seq, net);
3471
3472again:
3473 /* New batch for the next bucket.
3474 * Iterate over the hash table to find a bucket with sockets matching
3475 * the iterator attributes, and return the first matching socket from
3476 * the bucket. The remaining matched sockets from the bucket are batched
3477 * before releasing the bucket lock. This allows BPF programs that are
3478 * called in seq_show to acquire the bucket lock if needed.
3479 */
3480 find_cookie = iter->cur_sk;
3481 end_cookie = iter->end_sk;
3482 iter->cur_sk = 0;
3483 iter->end_sk = 0;
3484 batch_sks = 0;
3485
3486 for (; state->bucket <= udptable->mask; state->bucket++) {
3487 struct udp_hslot *hslot2 = &udptable->hash2[state->bucket].hslot;
3488
3489 if (hlist_empty(h: &hslot2->head))
3490 goto next_bucket;
3491
3492 spin_lock_bh(lock: &hslot2->lock);
3493 sk = hlist_entry_safe(hslot2->head.first, struct sock,
3494 __sk_common.skc_portaddr_node);
3495 /* Resume from the first (in iteration order) unseen socket from
3496 * the last batch that still exists in resume_bucket. Most of
3497 * the time this will just be where the last iteration left off
3498 * in resume_bucket unless that socket disappeared between
3499 * reads.
3500 */
3501 if (state->bucket == resume_bucket)
3502 sk = bpf_iter_udp_resume(first_sk: sk, cookies: &iter->batch[find_cookie],
3503 n_cookies: end_cookie - find_cookie);
3504fill_batch:
3505 udp_portaddr_for_each_entry_from(sk) {
3506 if (seq_sk_match(seq, sk)) {
3507 if (iter->end_sk < iter->max_sk) {
3508 sock_hold(sk);
3509 iter->batch[iter->end_sk++].sk = sk;
3510 }
3511 batch_sks++;
3512 }
3513 }
3514
3515 /* Allocate a larger batch and try again. */
3516 if (unlikely(resizes <= 1 && iter->end_sk &&
3517 iter->end_sk != batch_sks)) {
3518 resizes++;
3519
3520 /* First, try with GFP_USER to maximize the chances of
3521 * grabbing more memory.
3522 */
3523 if (resizes == 1) {
3524 spin_unlock_bh(lock: &hslot2->lock);
3525 err = bpf_iter_udp_realloc_batch(iter,
3526 new_batch_sz: batch_sks * 3 / 2,
3527 GFP_USER);
3528 if (err)
3529 return ERR_PTR(error: err);
3530 /* Start over. */
3531 goto again;
3532 }
3533
3534 /* Next, hold onto the lock, so the bucket doesn't
3535 * change while we get the rest of the sockets.
3536 */
3537 err = bpf_iter_udp_realloc_batch(iter, new_batch_sz: batch_sks,
3538 GFP_NOWAIT);
3539 if (err) {
3540 spin_unlock_bh(lock: &hslot2->lock);
3541 return ERR_PTR(error: err);
3542 }
3543
3544 /* Pick up where we left off. */
3545 sk = iter->batch[iter->end_sk - 1].sk;
3546 sk = hlist_entry_safe(sk->__sk_common.skc_portaddr_node.next,
3547 struct sock,
3548 __sk_common.skc_portaddr_node);
3549 batch_sks = iter->end_sk;
3550 goto fill_batch;
3551 }
3552
3553 spin_unlock_bh(lock: &hslot2->lock);
3554
3555 if (iter->end_sk)
3556 break;
3557next_bucket:
3558 resizes = 0;
3559 }
3560
3561 WARN_ON_ONCE(iter->end_sk != batch_sks);
3562 return iter->end_sk ? iter->batch[0].sk : NULL;
3563}
3564
3565static void *bpf_iter_udp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
3566{
3567 struct bpf_udp_iter_state *iter = seq->private;
3568 struct sock *sk;
3569
3570 /* Whenever seq_next() is called, the iter->cur_sk is
3571 * done with seq_show(), so unref the iter->cur_sk.
3572 */
3573 if (iter->cur_sk < iter->end_sk)
3574 sock_put(sk: iter->batch[iter->cur_sk++].sk);
3575
3576 /* After updating iter->cur_sk, check if there are more sockets
3577 * available in the current bucket batch.
3578 */
3579 if (iter->cur_sk < iter->end_sk)
3580 sk = iter->batch[iter->cur_sk].sk;
3581 else
3582 /* Prepare a new batch. */
3583 sk = bpf_iter_udp_batch(seq);
3584
3585 ++*pos;
3586 return sk;
3587}
3588
3589static void *bpf_iter_udp_seq_start(struct seq_file *seq, loff_t *pos)
3590{
3591 /* bpf iter does not support lseek, so it always
3592 * continue from where it was stop()-ped.
3593 */
3594 if (*pos)
3595 return bpf_iter_udp_batch(seq);
3596
3597 return SEQ_START_TOKEN;
3598}
3599
3600static int udp_prog_seq_show(struct bpf_prog *prog, struct bpf_iter_meta *meta,
3601 struct udp_sock *udp_sk, uid_t uid, int bucket)
3602{
3603 struct bpf_iter__udp ctx;
3604
3605 meta->seq_num--; /* skip SEQ_START_TOKEN */
3606 ctx.meta = meta;
3607 ctx.udp_sk = udp_sk;
3608 ctx.uid = uid;
3609 ctx.bucket = bucket;
3610 return bpf_iter_run_prog(prog, ctx: &ctx);
3611}
3612
3613static int bpf_iter_udp_seq_show(struct seq_file *seq, void *v)
3614{
3615 struct udp_iter_state *state = seq->private;
3616 struct bpf_iter_meta meta;
3617 struct bpf_prog *prog;
3618 struct sock *sk = v;
3619 uid_t uid;
3620 int ret;
3621
3622 if (v == SEQ_START_TOKEN)
3623 return 0;
3624
3625 lock_sock(sk);
3626
3627 if (unlikely(sk_unhashed(sk))) {
3628 ret = SEQ_SKIP;
3629 goto unlock;
3630 }
3631
3632 uid = from_kuid_munged(to: seq_user_ns(seq), uid: sock_i_uid(sk));
3633 meta.seq = seq;
3634 prog = bpf_iter_get_info(meta: &meta, in_stop: false);
3635 ret = udp_prog_seq_show(prog, meta: &meta, udp_sk: v, uid, bucket: state->bucket);
3636
3637unlock:
3638 release_sock(sk);
3639 return ret;
3640}
3641
3642static void bpf_iter_udp_put_batch(struct bpf_udp_iter_state *iter)
3643{
3644 union bpf_udp_iter_batch_item *item;
3645 unsigned int cur_sk = iter->cur_sk;
3646 __u64 cookie;
3647
3648 /* Remember the cookies of the sockets we haven't seen yet, so we can
3649 * pick up where we left off next time around.
3650 */
3651 while (cur_sk < iter->end_sk) {
3652 item = &iter->batch[cur_sk++];
3653 cookie = sock_gen_cookie(sk: item->sk);
3654 sock_put(sk: item->sk);
3655 item->cookie = cookie;
3656 }
3657}
3658
3659static void bpf_iter_udp_seq_stop(struct seq_file *seq, void *v)
3660{
3661 struct bpf_udp_iter_state *iter = seq->private;
3662 struct bpf_iter_meta meta;
3663 struct bpf_prog *prog;
3664
3665 if (!v) {
3666 meta.seq = seq;
3667 prog = bpf_iter_get_info(meta: &meta, in_stop: true);
3668 if (prog)
3669 (void)udp_prog_seq_show(prog, meta: &meta, udp_sk: v, uid: 0, bucket: 0);
3670 }
3671
3672 if (iter->cur_sk < iter->end_sk)
3673 bpf_iter_udp_put_batch(iter);
3674}
3675
3676static const struct seq_operations bpf_iter_udp_seq_ops = {
3677 .start = bpf_iter_udp_seq_start,
3678 .next = bpf_iter_udp_seq_next,
3679 .stop = bpf_iter_udp_seq_stop,
3680 .show = bpf_iter_udp_seq_show,
3681};
3682#endif
3683
3684static unsigned short seq_file_family(const struct seq_file *seq)
3685{
3686 const struct udp_seq_afinfo *afinfo;
3687
3688#ifdef CONFIG_BPF_SYSCALL
3689 /* BPF iterator: bpf programs to filter sockets. */
3690 if (seq->op == &bpf_iter_udp_seq_ops)
3691 return AF_UNSPEC;
3692#endif
3693
3694 /* Proc fs iterator */
3695 afinfo = pde_data(inode: file_inode(f: seq->file));
3696 return afinfo->family;
3697}
3698
3699const struct seq_operations udp_seq_ops = {
3700 .start = udp_seq_start,
3701 .next = udp_seq_next,
3702 .stop = udp_seq_stop,
3703 .show = udp4_seq_show,
3704};
3705EXPORT_IPV6_MOD(udp_seq_ops);
3706
3707static struct udp_seq_afinfo udp4_seq_afinfo = {
3708 .family = AF_INET,
3709 .udp_table = NULL,
3710};
3711
3712static int __net_init udp4_proc_init_net(struct net *net)
3713{
3714 if (!proc_create_net_data(name: "udp", mode: 0444, parent: net->proc_net, ops: &udp_seq_ops,
3715 state_size: sizeof(struct udp_iter_state), data: &udp4_seq_afinfo))
3716 return -ENOMEM;
3717 return 0;
3718}
3719
3720static void __net_exit udp4_proc_exit_net(struct net *net)
3721{
3722 remove_proc_entry("udp", net->proc_net);
3723}
3724
3725static struct pernet_operations udp4_net_ops = {
3726 .init = udp4_proc_init_net,
3727 .exit = udp4_proc_exit_net,
3728};
3729
3730int __init udp4_proc_init(void)
3731{
3732 return register_pernet_subsys(&udp4_net_ops);
3733}
3734
3735void udp4_proc_exit(void)
3736{
3737 unregister_pernet_subsys(&udp4_net_ops);
3738}
3739#endif /* CONFIG_PROC_FS */
3740
3741static __initdata unsigned long uhash_entries;
3742static int __init set_uhash_entries(char *str)
3743{
3744 ssize_t ret;
3745
3746 if (!str)
3747 return 0;
3748
3749 ret = kstrtoul(s: str, base: 0, res: &uhash_entries);
3750 if (ret)
3751 return 0;
3752
3753 if (uhash_entries && uhash_entries < UDP_HTABLE_SIZE_MIN)
3754 uhash_entries = UDP_HTABLE_SIZE_MIN;
3755 return 1;
3756}
3757__setup("uhash_entries=", set_uhash_entries);
3758
3759void __init udp_table_init(struct udp_table *table, const char *name)
3760{
3761 unsigned int i, slot_size;
3762
3763 slot_size = sizeof(struct udp_hslot) + sizeof(struct udp_hslot_main) +
3764 udp_hash4_slot_size();
3765 table->hash = alloc_large_system_hash(tablename: name,
3766 bucketsize: slot_size,
3767 numentries: uhash_entries,
3768 scale: 21, /* one slot per 2 MB */
3769 flags: 0,
3770 hash_shift: &table->log,
3771 hash_mask: &table->mask,
3772 UDP_HTABLE_SIZE_MIN,
3773 UDP_HTABLE_SIZE_MAX);
3774
3775 table->hash2 = (void *)(table->hash + (table->mask + 1));
3776 for (i = 0; i <= table->mask; i++) {
3777 INIT_HLIST_HEAD(&table->hash[i].head);
3778 table->hash[i].count = 0;
3779 spin_lock_init(&table->hash[i].lock);
3780 }
3781 for (i = 0; i <= table->mask; i++) {
3782 INIT_HLIST_HEAD(&table->hash2[i].hslot.head);
3783 table->hash2[i].hslot.count = 0;
3784 spin_lock_init(&table->hash2[i].hslot.lock);
3785 }
3786 udp_table_hash4_init(table);
3787}
3788
3789u32 udp_flow_hashrnd(void)
3790{
3791 static u32 hashrnd __read_mostly;
3792
3793 net_get_random_once(&hashrnd, sizeof(hashrnd));
3794
3795 return hashrnd;
3796}
3797EXPORT_SYMBOL(udp_flow_hashrnd);
3798
3799static void __net_init udp_sysctl_init(struct net *net)
3800{
3801 net->ipv4.sysctl_udp_rmem_min = PAGE_SIZE;
3802 net->ipv4.sysctl_udp_wmem_min = PAGE_SIZE;
3803
3804#ifdef CONFIG_NET_L3_MASTER_DEV
3805 net->ipv4.sysctl_udp_l3mdev_accept = 0;
3806#endif
3807}
3808
3809static struct udp_table __net_init *udp_pernet_table_alloc(unsigned int hash_entries)
3810{
3811 struct udp_table *udptable;
3812 unsigned int slot_size;
3813 int i;
3814
3815 udptable = kmalloc(sizeof(*udptable), GFP_KERNEL);
3816 if (!udptable)
3817 goto out;
3818
3819 slot_size = sizeof(struct udp_hslot) + sizeof(struct udp_hslot_main) +
3820 udp_hash4_slot_size();
3821 udptable->hash = vmalloc_huge(size: hash_entries * slot_size,
3822 GFP_KERNEL_ACCOUNT);
3823 if (!udptable->hash)
3824 goto free_table;
3825
3826 udptable->hash2 = (void *)(udptable->hash + hash_entries);
3827 udptable->mask = hash_entries - 1;
3828 udptable->log = ilog2(hash_entries);
3829
3830 for (i = 0; i < hash_entries; i++) {
3831 INIT_HLIST_HEAD(&udptable->hash[i].head);
3832 udptable->hash[i].count = 0;
3833 spin_lock_init(&udptable->hash[i].lock);
3834
3835 INIT_HLIST_HEAD(&udptable->hash2[i].hslot.head);
3836 udptable->hash2[i].hslot.count = 0;
3837 spin_lock_init(&udptable->hash2[i].hslot.lock);
3838 }
3839 udp_table_hash4_init(table: udptable);
3840
3841 return udptable;
3842
3843free_table:
3844 kfree(objp: udptable);
3845out:
3846 return NULL;
3847}
3848
3849static void __net_exit udp_pernet_table_free(struct net *net)
3850{
3851 struct udp_table *udptable = net->ipv4.udp_table;
3852
3853 if (udptable == &udp_table)
3854 return;
3855
3856 kvfree(addr: udptable->hash);
3857 kfree(objp: udptable);
3858}
3859
3860static void __net_init udp_set_table(struct net *net)
3861{
3862 struct udp_table *udptable;
3863 unsigned int hash_entries;
3864 struct net *old_net;
3865
3866 if (net_eq(net1: net, net2: &init_net))
3867 goto fallback;
3868
3869 old_net = current->nsproxy->net_ns;
3870 hash_entries = READ_ONCE(old_net->ipv4.sysctl_udp_child_hash_entries);
3871 if (!hash_entries)
3872 goto fallback;
3873
3874 /* Set min to keep the bitmap on stack in udp_lib_get_port() */
3875 if (hash_entries < UDP_HTABLE_SIZE_MIN_PERNET)
3876 hash_entries = UDP_HTABLE_SIZE_MIN_PERNET;
3877 else
3878 hash_entries = roundup_pow_of_two(hash_entries);
3879
3880 udptable = udp_pernet_table_alloc(hash_entries);
3881 if (udptable) {
3882 net->ipv4.udp_table = udptable;
3883 } else {
3884 pr_warn("Failed to allocate UDP hash table (entries: %u) "
3885 "for a netns, fallback to the global one\n",
3886 hash_entries);
3887fallback:
3888 net->ipv4.udp_table = &udp_table;
3889 }
3890}
3891
3892static int __net_init udp_pernet_init(struct net *net)
3893{
3894#if IS_ENABLED(CONFIG_NET_UDP_TUNNEL)
3895 int i;
3896
3897 /* No tunnel is configured */
3898 for (i = 0; i < ARRAY_SIZE(net->ipv4.udp_tunnel_gro); ++i) {
3899 INIT_HLIST_HEAD(&net->ipv4.udp_tunnel_gro[i].list);
3900 RCU_INIT_POINTER(net->ipv4.udp_tunnel_gro[i].sk, NULL);
3901 }
3902#endif
3903 udp_sysctl_init(net);
3904 udp_set_table(net);
3905
3906 return 0;
3907}
3908
3909static void __net_exit udp_pernet_exit(struct net *net)
3910{
3911 udp_pernet_table_free(net);
3912}
3913
3914static struct pernet_operations __net_initdata udp_sysctl_ops = {
3915 .init = udp_pernet_init,
3916 .exit = udp_pernet_exit,
3917};
3918
3919#if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS)
3920DEFINE_BPF_ITER_FUNC(udp, struct bpf_iter_meta *meta,
3921 struct udp_sock *udp_sk, uid_t uid, int bucket)
3922
3923static int bpf_iter_udp_realloc_batch(struct bpf_udp_iter_state *iter,
3924 unsigned int new_batch_sz, gfp_t flags)
3925{
3926 union bpf_udp_iter_batch_item *new_batch;
3927
3928 new_batch = kvmalloc_array(new_batch_sz, sizeof(*new_batch),
3929 flags | __GFP_NOWARN);
3930 if (!new_batch)
3931 return -ENOMEM;
3932
3933 if (flags != GFP_NOWAIT)
3934 bpf_iter_udp_put_batch(iter);
3935
3936 memcpy(new_batch, iter->batch, sizeof(*iter->batch) * iter->end_sk);
3937 kvfree(addr: iter->batch);
3938 iter->batch = new_batch;
3939 iter->max_sk = new_batch_sz;
3940
3941 return 0;
3942}
3943
3944#define INIT_BATCH_SZ 16
3945
3946static int bpf_iter_init_udp(void *priv_data, struct bpf_iter_aux_info *aux)
3947{
3948 struct bpf_udp_iter_state *iter = priv_data;
3949 int ret;
3950
3951 ret = bpf_iter_init_seq_net(priv_data, aux);
3952 if (ret)
3953 return ret;
3954
3955 ret = bpf_iter_udp_realloc_batch(iter, INIT_BATCH_SZ, GFP_USER);
3956 if (ret)
3957 bpf_iter_fini_seq_net(priv_data);
3958
3959 iter->state.bucket = -1;
3960
3961 return ret;
3962}
3963
3964static void bpf_iter_fini_udp(void *priv_data)
3965{
3966 struct bpf_udp_iter_state *iter = priv_data;
3967
3968 bpf_iter_fini_seq_net(priv_data);
3969 kvfree(addr: iter->batch);
3970}
3971
3972static const struct bpf_iter_seq_info udp_seq_info = {
3973 .seq_ops = &bpf_iter_udp_seq_ops,
3974 .init_seq_private = bpf_iter_init_udp,
3975 .fini_seq_private = bpf_iter_fini_udp,
3976 .seq_priv_size = sizeof(struct bpf_udp_iter_state),
3977};
3978
3979static struct bpf_iter_reg udp_reg_info = {
3980 .target = "udp",
3981 .ctx_arg_info_size = 1,
3982 .ctx_arg_info = {
3983 { offsetof(struct bpf_iter__udp, udp_sk),
3984 PTR_TO_BTF_ID_OR_NULL | PTR_TRUSTED },
3985 },
3986 .seq_info = &udp_seq_info,
3987};
3988
3989static void __init bpf_iter_register(void)
3990{
3991 udp_reg_info.ctx_arg_info[0].btf_id = btf_sock_ids[BTF_SOCK_TYPE_UDP];
3992 if (bpf_iter_reg_target(reg_info: &udp_reg_info))
3993 pr_warn("Warning: could not register bpf iterator udp\n");
3994}
3995#endif
3996
3997void __init udp_init(void)
3998{
3999 unsigned long limit;
4000 unsigned int i;
4001
4002 udp_table_init(table: &udp_table, name: "UDP");
4003 limit = nr_free_buffer_pages() / 8;
4004 limit = max(limit, 128UL);
4005 sysctl_udp_mem[0] = limit / 4 * 3;
4006 sysctl_udp_mem[1] = limit;
4007 sysctl_udp_mem[2] = sysctl_udp_mem[0] * 2;
4008
4009 /* 16 spinlocks per cpu */
4010 udp_busylocks_log = ilog2(nr_cpu_ids) + 4;
4011 udp_busylocks = kmalloc(sizeof(spinlock_t) << udp_busylocks_log,
4012 GFP_KERNEL);
4013 if (!udp_busylocks)
4014 panic(fmt: "UDP: failed to alloc udp_busylocks\n");
4015 for (i = 0; i < (1U << udp_busylocks_log); i++)
4016 spin_lock_init(udp_busylocks + i);
4017
4018 if (register_pernet_subsys(&udp_sysctl_ops))
4019 panic(fmt: "UDP: failed to init sysctl parameters.\n");
4020
4021#if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS)
4022 bpf_iter_register();
4023#endif
4024}
4025

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source code of linux/net/ipv4/udp.c