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 * Definitions for inet_sock
8 *
9 * Authors: Many, reorganised here by
10 * Arnaldo Carvalho de Melo <acme@mandriva.com>
11 */
12#ifndef _INET_SOCK_H
13#define _INET_SOCK_H
14
15#include <linux/bitops.h>
16#include <linux/string.h>
17#include <linux/types.h>
18#include <linux/jhash.h>
19#include <linux/netdevice.h>
20
21#include <net/flow.h>
22#include <net/sock.h>
23#include <net/request_sock.h>
24#include <net/netns/hash.h>
25#include <net/tcp_states.h>
26#include <net/l3mdev.h>
27
28/** struct ip_options - IP Options
29 *
30 * @faddr - Saved first hop address
31 * @nexthop - Saved nexthop address in LSRR and SSRR
32 * @is_strictroute - Strict source route
33 * @srr_is_hit - Packet destination addr was our one
34 * @is_changed - IP checksum more not valid
35 * @rr_needaddr - Need to record addr of outgoing dev
36 * @ts_needtime - Need to record timestamp
37 * @ts_needaddr - Need to record addr of outgoing dev
38 */
39struct ip_options {
40 __be32 faddr;
41 __be32 nexthop;
42 unsigned char optlen;
43 unsigned char srr;
44 unsigned char rr;
45 unsigned char ts;
46 unsigned char is_strictroute:1,
47 srr_is_hit:1,
48 is_changed:1,
49 rr_needaddr:1,
50 ts_needtime:1,
51 ts_needaddr:1;
52 unsigned char router_alert;
53 unsigned char cipso;
54 unsigned char __pad2;
55 unsigned char __data[];
56};
57
58struct ip_options_rcu {
59 struct rcu_head rcu;
60 struct ip_options opt;
61};
62
63struct ip_options_data {
64 struct ip_options_rcu opt;
65 char data[40];
66};
67
68struct inet_request_sock {
69 struct request_sock req;
70#define ir_loc_addr req.__req_common.skc_rcv_saddr
71#define ir_rmt_addr req.__req_common.skc_daddr
72#define ir_num req.__req_common.skc_num
73#define ir_rmt_port req.__req_common.skc_dport
74#define ir_v6_rmt_addr req.__req_common.skc_v6_daddr
75#define ir_v6_loc_addr req.__req_common.skc_v6_rcv_saddr
76#define ir_iif req.__req_common.skc_bound_dev_if
77#define ir_cookie req.__req_common.skc_cookie
78#define ireq_net req.__req_common.skc_net
79#define ireq_state req.__req_common.skc_state
80#define ireq_family req.__req_common.skc_family
81
82 u16 snd_wscale : 4,
83 rcv_wscale : 4,
84 tstamp_ok : 1,
85 sack_ok : 1,
86 wscale_ok : 1,
87 ecn_ok : 1,
88 acked : 1,
89 no_srccheck: 1,
90 smc_ok : 1;
91 u32 ir_mark;
92 union {
93 struct ip_options_rcu __rcu *ireq_opt;
94#if IS_ENABLED(CONFIG_IPV6)
95 struct {
96 struct ipv6_txoptions *ipv6_opt;
97 struct sk_buff *pktopts;
98 };
99#endif
100 };
101};
102
103static inline struct inet_request_sock *inet_rsk(const struct request_sock *sk)
104{
105 return (struct inet_request_sock *)sk;
106}
107
108static inline u32 inet_request_mark(const struct sock *sk, struct sk_buff *skb)
109{
110 if (!sk->sk_mark &&
111 READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_fwmark_accept))
112 return skb->mark;
113
114 return sk->sk_mark;
115}
116
117static inline int inet_request_bound_dev_if(const struct sock *sk,
118 struct sk_buff *skb)
119{
120 int bound_dev_if = READ_ONCE(sk->sk_bound_dev_if);
121#ifdef CONFIG_NET_L3_MASTER_DEV
122 struct net *net = sock_net(sk);
123
124 if (!bound_dev_if && READ_ONCE(net->ipv4.sysctl_tcp_l3mdev_accept))
125 return l3mdev_master_ifindex_by_index(net, skb->skb_iif);
126#endif
127
128 return bound_dev_if;
129}
130
131static inline int inet_sk_bound_l3mdev(const struct sock *sk)
132{
133#ifdef CONFIG_NET_L3_MASTER_DEV
134 struct net *net = sock_net(sk);
135
136 if (!READ_ONCE(net->ipv4.sysctl_tcp_l3mdev_accept))
137 return l3mdev_master_ifindex_by_index(net,
138 sk->sk_bound_dev_if);
139#endif
140
141 return 0;
142}
143
144static inline bool inet_bound_dev_eq(bool l3mdev_accept, int bound_dev_if,
145 int dif, int sdif)
146{
147 if (!bound_dev_if)
148 return !sdif || l3mdev_accept;
149 return bound_dev_if == dif || bound_dev_if == sdif;
150}
151
152static inline bool inet_sk_bound_dev_eq(struct net *net, int bound_dev_if,
153 int dif, int sdif)
154{
155#if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV)
156 return inet_bound_dev_eq(!!READ_ONCE(net->ipv4.sysctl_tcp_l3mdev_accept),
157 bound_dev_if, dif, sdif);
158#else
159 return inet_bound_dev_eq(true, bound_dev_if, dif, sdif);
160#endif
161}
162
163struct inet_cork {
164 unsigned int flags;
165 __be32 addr;
166 struct ip_options *opt;
167 unsigned int fragsize;
168 int length; /* Total length of all frames */
169 struct dst_entry *dst;
170 u8 tx_flags;
171 __u8 ttl;
172 __s16 tos;
173 char priority;
174 __u16 gso_size;
175 u64 transmit_time;
176 u32 mark;
177};
178
179struct inet_cork_full {
180 struct inet_cork base;
181 struct flowi fl;
182};
183
184struct ip_mc_socklist;
185struct ipv6_pinfo;
186struct rtable;
187
188/** struct inet_sock - representation of INET sockets
189 *
190 * @sk - ancestor class
191 * @pinet6 - pointer to IPv6 control block
192 * @inet_daddr - Foreign IPv4 addr
193 * @inet_rcv_saddr - Bound local IPv4 addr
194 * @inet_dport - Destination port
195 * @inet_num - Local port
196 * @inet_saddr - Sending source
197 * @uc_ttl - Unicast TTL
198 * @inet_sport - Source port
199 * @inet_id - ID counter for DF pkts
200 * @tos - TOS
201 * @mc_ttl - Multicasting TTL
202 * @is_icsk - is this an inet_connection_sock?
203 * @uc_index - Unicast outgoing device index
204 * @mc_index - Multicast device index
205 * @mc_list - Group array
206 * @cork - info to build ip hdr on each ip frag while socket is corked
207 */
208struct inet_sock {
209 /* sk and pinet6 has to be the first two members of inet_sock */
210 struct sock sk;
211#if IS_ENABLED(CONFIG_IPV6)
212 struct ipv6_pinfo *pinet6;
213#endif
214 /* Socket demultiplex comparisons on incoming packets. */
215#define inet_daddr sk.__sk_common.skc_daddr
216#define inet_rcv_saddr sk.__sk_common.skc_rcv_saddr
217#define inet_dport sk.__sk_common.skc_dport
218#define inet_num sk.__sk_common.skc_num
219
220 __be32 inet_saddr;
221 __s16 uc_ttl;
222 __u16 cmsg_flags;
223 struct ip_options_rcu __rcu *inet_opt;
224 __be16 inet_sport;
225 __u16 inet_id;
226
227 __u8 tos;
228 __u8 min_ttl;
229 __u8 mc_ttl;
230 __u8 pmtudisc;
231 __u8 recverr:1,
232 is_icsk:1,
233 freebind:1,
234 hdrincl:1,
235 mc_loop:1,
236 transparent:1,
237 mc_all:1,
238 nodefrag:1;
239 __u8 bind_address_no_port:1,
240 recverr_rfc4884:1,
241 defer_connect:1; /* Indicates that fastopen_connect is set
242 * and cookie exists so we defer connect
243 * until first data frame is written
244 */
245 __u8 rcv_tos;
246 __u8 convert_csum;
247 int uc_index;
248 int mc_index;
249 __be32 mc_addr;
250 struct ip_mc_socklist __rcu *mc_list;
251 struct inet_cork_full cork;
252};
253
254#define IPCORK_OPT 1 /* ip-options has been held in ipcork.opt */
255#define IPCORK_ALLFRAG 2 /* always fragment (for ipv6 for now) */
256
257/* cmsg flags for inet */
258#define IP_CMSG_PKTINFO BIT(0)
259#define IP_CMSG_TTL BIT(1)
260#define IP_CMSG_TOS BIT(2)
261#define IP_CMSG_RECVOPTS BIT(3)
262#define IP_CMSG_RETOPTS BIT(4)
263#define IP_CMSG_PASSSEC BIT(5)
264#define IP_CMSG_ORIGDSTADDR BIT(6)
265#define IP_CMSG_CHECKSUM BIT(7)
266#define IP_CMSG_RECVFRAGSIZE BIT(8)
267
268static inline bool sk_is_inet(struct sock *sk)
269{
270 return sk->sk_family == AF_INET || sk->sk_family == AF_INET6;
271}
272
273/**
274 * sk_to_full_sk - Access to a full socket
275 * @sk: pointer to a socket
276 *
277 * SYNACK messages might be attached to request sockets.
278 * Some places want to reach the listener in this case.
279 */
280static inline struct sock *sk_to_full_sk(struct sock *sk)
281{
282#ifdef CONFIG_INET
283 if (sk && sk->sk_state == TCP_NEW_SYN_RECV)
284 sk = inet_reqsk(sk)->rsk_listener;
285#endif
286 return sk;
287}
288
289/* sk_to_full_sk() variant with a const argument */
290static inline const struct sock *sk_const_to_full_sk(const struct sock *sk)
291{
292#ifdef CONFIG_INET
293 if (sk && sk->sk_state == TCP_NEW_SYN_RECV)
294 sk = ((const struct request_sock *)sk)->rsk_listener;
295#endif
296 return sk;
297}
298
299static inline struct sock *skb_to_full_sk(const struct sk_buff *skb)
300{
301 return sk_to_full_sk(skb->sk);
302}
303
304static inline struct inet_sock *inet_sk(const struct sock *sk)
305{
306 return (struct inet_sock *)sk;
307}
308
309static inline void __inet_sk_copy_descendant(struct sock *sk_to,
310 const struct sock *sk_from,
311 const int ancestor_size)
312{
313 memcpy(inet_sk(sk_to) + 1, inet_sk(sk_from) + 1,
314 sk_from->sk_prot->obj_size - ancestor_size);
315}
316
317int inet_sk_rebuild_header(struct sock *sk);
318
319/**
320 * inet_sk_state_load - read sk->sk_state for lockless contexts
321 * @sk: socket pointer
322 *
323 * Paired with inet_sk_state_store(). Used in places we don't hold socket lock:
324 * tcp_diag_get_info(), tcp_get_info(), tcp_poll(), get_tcp4_sock() ...
325 */
326static inline int inet_sk_state_load(const struct sock *sk)
327{
328 /* state change might impact lockless readers. */
329 return smp_load_acquire(&sk->sk_state);
330}
331
332/**
333 * inet_sk_state_store - update sk->sk_state
334 * @sk: socket pointer
335 * @newstate: new state
336 *
337 * Paired with inet_sk_state_load(). Should be used in contexts where
338 * state change might impact lockless readers.
339 */
340void inet_sk_state_store(struct sock *sk, int newstate);
341
342void inet_sk_set_state(struct sock *sk, int state);
343
344static inline unsigned int __inet_ehashfn(const __be32 laddr,
345 const __u16 lport,
346 const __be32 faddr,
347 const __be16 fport,
348 u32 initval)
349{
350 return jhash_3words((__force __u32) laddr,
351 (__force __u32) faddr,
352 ((__u32) lport) << 16 | (__force __u32)fport,
353 initval);
354}
355
356struct request_sock *inet_reqsk_alloc(const struct request_sock_ops *ops,
357 struct sock *sk_listener,
358 bool attach_listener);
359
360static inline __u8 inet_sk_flowi_flags(const struct sock *sk)
361{
362 __u8 flags = 0;
363
364 if (inet_sk(sk)->transparent || inet_sk(sk)->hdrincl)
365 flags |= FLOWI_FLAG_ANYSRC;
366 return flags;
367}
368
369static inline void inet_inc_convert_csum(struct sock *sk)
370{
371 inet_sk(sk)->convert_csum++;
372}
373
374static inline void inet_dec_convert_csum(struct sock *sk)
375{
376 if (inet_sk(sk)->convert_csum > 0)
377 inet_sk(sk)->convert_csum--;
378}
379
380static inline bool inet_get_convert_csum(struct sock *sk)
381{
382 return !!inet_sk(sk)->convert_csum;
383}
384
385
386static inline bool inet_can_nonlocal_bind(struct net *net,
387 struct inet_sock *inet)
388{
389 return READ_ONCE(net->ipv4.sysctl_ip_nonlocal_bind) ||
390 inet->freebind || inet->transparent;
391}
392
393static inline bool inet_addr_valid_or_nonlocal(struct net *net,
394 struct inet_sock *inet,
395 __be32 addr,
396 int addr_type)
397{
398 return inet_can_nonlocal_bind(net, inet) ||
399 addr == htonl(INADDR_ANY) ||
400 addr_type == RTN_LOCAL ||
401 addr_type == RTN_MULTICAST ||
402 addr_type == RTN_BROADCAST;
403}
404
405#endif /* _INET_SOCK_H */
406

source code of linux/include/net/inet_sock.h