1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * linux/net/sunrpc/svcsock.c
4 *
5 * These are the RPC server socket internals.
6 *
7 * The server scheduling algorithm does not always distribute the load
8 * evenly when servicing a single client. May need to modify the
9 * svc_xprt_enqueue procedure...
10 *
11 * TCP support is largely untested and may be a little slow. The problem
12 * is that we currently do two separate recvfrom's, one for the 4-byte
13 * record length, and the second for the actual record. This could possibly
14 * be improved by always reading a minimum size of around 100 bytes and
15 * tucking any superfluous bytes away in a temporary store. Still, that
16 * leaves write requests out in the rain. An alternative may be to peek at
17 * the first skb in the queue, and if it matches the next TCP sequence
18 * number, to extract the record marker. Yuck.
19 *
20 * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
21 */
22
23#include <linux/kernel.h>
24#include <linux/sched.h>
25#include <linux/module.h>
26#include <linux/errno.h>
27#include <linux/fcntl.h>
28#include <linux/net.h>
29#include <linux/in.h>
30#include <linux/inet.h>
31#include <linux/udp.h>
32#include <linux/tcp.h>
33#include <linux/unistd.h>
34#include <linux/slab.h>
35#include <linux/netdevice.h>
36#include <linux/skbuff.h>
37#include <linux/file.h>
38#include <linux/freezer.h>
39#include <linux/bvec.h>
40
41#include <net/sock.h>
42#include <net/checksum.h>
43#include <net/ip.h>
44#include <net/ipv6.h>
45#include <net/udp.h>
46#include <net/tcp.h>
47#include <net/tcp_states.h>
48#include <net/tls_prot.h>
49#include <net/handshake.h>
50#include <linux/uaccess.h>
51#include <linux/highmem.h>
52#include <asm/ioctls.h>
53#include <linux/key.h>
54
55#include <linux/sunrpc/types.h>
56#include <linux/sunrpc/clnt.h>
57#include <linux/sunrpc/xdr.h>
58#include <linux/sunrpc/msg_prot.h>
59#include <linux/sunrpc/svcsock.h>
60#include <linux/sunrpc/stats.h>
61#include <linux/sunrpc/xprt.h>
62
63#include <trace/events/sock.h>
64#include <trace/events/sunrpc.h>
65
66#include "socklib.h"
67#include "sunrpc.h"
68
69#define RPCDBG_FACILITY RPCDBG_SVCXPRT
70
71/*
72 * For UDP:
73 * 1 for header page
74 * enough pages for RPCSVC_MAXPAYLOAD_UDP
75 * 1 in case payload is not aligned
76 * 1 for tail page
77 */
78enum {
79 SUNRPC_MAX_UDP_SENDPAGES = 1 + RPCSVC_MAXPAYLOAD_UDP / PAGE_SIZE + 1 + 1
80};
81
82/* To-do: to avoid tying up an nfsd thread while waiting for a
83 * handshake request, the request could instead be deferred.
84 */
85enum {
86 SVC_HANDSHAKE_TO = 5U * HZ
87};
88
89static struct svc_sock *svc_setup_socket(struct svc_serv *, struct socket *,
90 int flags);
91static int svc_udp_recvfrom(struct svc_rqst *);
92static int svc_udp_sendto(struct svc_rqst *);
93static void svc_sock_detach(struct svc_xprt *);
94static void svc_tcp_sock_detach(struct svc_xprt *);
95static void svc_sock_free(struct svc_xprt *);
96
97static struct svc_xprt *svc_create_socket(struct svc_serv *, int,
98 struct net *, struct sockaddr *,
99 int, int);
100#ifdef CONFIG_DEBUG_LOCK_ALLOC
101static struct lock_class_key svc_key[2];
102static struct lock_class_key svc_slock_key[2];
103
104static void svc_reclassify_socket(struct socket *sock)
105{
106 struct sock *sk = sock->sk;
107
108 if (WARN_ON_ONCE(!sock_allow_reclassification(sk)))
109 return;
110
111 switch (sk->sk_family) {
112 case AF_INET:
113 sock_lock_init_class_and_name(sk, "slock-AF_INET-NFSD",
114 &svc_slock_key[0],
115 "sk_xprt.xpt_lock-AF_INET-NFSD",
116 &svc_key[0]);
117 break;
118
119 case AF_INET6:
120 sock_lock_init_class_and_name(sk, "slock-AF_INET6-NFSD",
121 &svc_slock_key[1],
122 "sk_xprt.xpt_lock-AF_INET6-NFSD",
123 &svc_key[1]);
124 break;
125
126 default:
127 BUG();
128 }
129}
130#else
131static void svc_reclassify_socket(struct socket *sock)
132{
133}
134#endif
135
136/**
137 * svc_tcp_release_ctxt - Release transport-related resources
138 * @xprt: the transport which owned the context
139 * @ctxt: the context from rqstp->rq_xprt_ctxt or dr->xprt_ctxt
140 *
141 */
142static void svc_tcp_release_ctxt(struct svc_xprt *xprt, void *ctxt)
143{
144}
145
146/**
147 * svc_udp_release_ctxt - Release transport-related resources
148 * @xprt: the transport which owned the context
149 * @ctxt: the context from rqstp->rq_xprt_ctxt or dr->xprt_ctxt
150 *
151 */
152static void svc_udp_release_ctxt(struct svc_xprt *xprt, void *ctxt)
153{
154 struct sk_buff *skb = ctxt;
155
156 if (skb)
157 consume_skb(skb);
158}
159
160union svc_pktinfo_u {
161 struct in_pktinfo pkti;
162 struct in6_pktinfo pkti6;
163};
164#define SVC_PKTINFO_SPACE \
165 CMSG_SPACE(sizeof(union svc_pktinfo_u))
166
167static void svc_set_cmsg_data(struct svc_rqst *rqstp, struct cmsghdr *cmh)
168{
169 struct svc_sock *svsk =
170 container_of(rqstp->rq_xprt, struct svc_sock, sk_xprt);
171 switch (svsk->sk_sk->sk_family) {
172 case AF_INET: {
173 struct in_pktinfo *pki = CMSG_DATA(cmh);
174
175 cmh->cmsg_level = SOL_IP;
176 cmh->cmsg_type = IP_PKTINFO;
177 pki->ipi_ifindex = 0;
178 pki->ipi_spec_dst.s_addr =
179 svc_daddr_in(rqst: rqstp)->sin_addr.s_addr;
180 cmh->cmsg_len = CMSG_LEN(sizeof(*pki));
181 }
182 break;
183
184 case AF_INET6: {
185 struct in6_pktinfo *pki = CMSG_DATA(cmh);
186 struct sockaddr_in6 *daddr = svc_daddr_in6(rqst: rqstp);
187
188 cmh->cmsg_level = SOL_IPV6;
189 cmh->cmsg_type = IPV6_PKTINFO;
190 pki->ipi6_ifindex = daddr->sin6_scope_id;
191 pki->ipi6_addr = daddr->sin6_addr;
192 cmh->cmsg_len = CMSG_LEN(sizeof(*pki));
193 }
194 break;
195 }
196}
197
198static int svc_sock_result_payload(struct svc_rqst *rqstp, unsigned int offset,
199 unsigned int length)
200{
201 return 0;
202}
203
204/*
205 * Report socket names for nfsdfs
206 */
207static int svc_one_sock_name(struct svc_sock *svsk, char *buf, int remaining)
208{
209 const struct sock *sk = svsk->sk_sk;
210 const char *proto_name = sk->sk_protocol == IPPROTO_UDP ?
211 "udp" : "tcp";
212 int len;
213
214 switch (sk->sk_family) {
215 case PF_INET:
216 len = snprintf(buf, size: remaining, fmt: "ipv4 %s %pI4 %d\n",
217 proto_name,
218 &inet_sk(sk)->inet_rcv_saddr,
219 inet_sk(sk)->inet_num);
220 break;
221#if IS_ENABLED(CONFIG_IPV6)
222 case PF_INET6:
223 len = snprintf(buf, size: remaining, fmt: "ipv6 %s %pI6 %d\n",
224 proto_name,
225 &sk->sk_v6_rcv_saddr,
226 inet_sk(sk)->inet_num);
227 break;
228#endif
229 default:
230 len = snprintf(buf, size: remaining, fmt: "*unknown-%d*\n",
231 sk->sk_family);
232 }
233
234 if (len >= remaining) {
235 *buf = '\0';
236 return -ENAMETOOLONG;
237 }
238 return len;
239}
240
241static int
242svc_tcp_sock_process_cmsg(struct socket *sock, struct msghdr *msg,
243 struct cmsghdr *cmsg, int ret)
244{
245 u8 content_type = tls_get_record_type(sk: sock->sk, msg: cmsg);
246 u8 level, description;
247
248 switch (content_type) {
249 case 0:
250 break;
251 case TLS_RECORD_TYPE_DATA:
252 /* TLS sets EOR at the end of each application data
253 * record, even though there might be more frames
254 * waiting to be decrypted.
255 */
256 msg->msg_flags &= ~MSG_EOR;
257 break;
258 case TLS_RECORD_TYPE_ALERT:
259 tls_alert_recv(sk: sock->sk, msg, level: &level, description: &description);
260 ret = (level == TLS_ALERT_LEVEL_FATAL) ?
261 -ENOTCONN : -EAGAIN;
262 break;
263 default:
264 /* discard this record type */
265 ret = -EAGAIN;
266 }
267 return ret;
268}
269
270static int
271svc_tcp_sock_recv_cmsg(struct socket *sock, unsigned int *msg_flags)
272{
273 union {
274 struct cmsghdr cmsg;
275 u8 buf[CMSG_SPACE(sizeof(u8))];
276 } u;
277 u8 alert[2];
278 struct kvec alert_kvec = {
279 .iov_base = alert,
280 .iov_len = sizeof(alert),
281 };
282 struct msghdr msg = {
283 .msg_flags = *msg_flags,
284 .msg_control = &u,
285 .msg_controllen = sizeof(u),
286 };
287 int ret;
288
289 iov_iter_kvec(i: &msg.msg_iter, ITER_DEST, kvec: &alert_kvec, nr_segs: 1,
290 count: alert_kvec.iov_len);
291 ret = sock_recvmsg(sock, msg: &msg, MSG_DONTWAIT);
292 if (ret > 0 &&
293 tls_get_record_type(sk: sock->sk, msg: &u.cmsg) == TLS_RECORD_TYPE_ALERT) {
294 iov_iter_revert(i: &msg.msg_iter, bytes: ret);
295 ret = svc_tcp_sock_process_cmsg(sock, msg: &msg, cmsg: &u.cmsg, ret: -EAGAIN);
296 }
297 return ret;
298}
299
300static int
301svc_tcp_sock_recvmsg(struct svc_sock *svsk, struct msghdr *msg)
302{
303 int ret;
304 struct socket *sock = svsk->sk_sock;
305
306 ret = sock_recvmsg(sock, msg, MSG_DONTWAIT);
307 if (msg->msg_flags & MSG_CTRUNC) {
308 msg->msg_flags &= ~(MSG_CTRUNC | MSG_EOR);
309 if (ret == 0 || ret == -EIO)
310 ret = svc_tcp_sock_recv_cmsg(sock, msg_flags: &msg->msg_flags);
311 }
312 return ret;
313}
314
315#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
316static void svc_flush_bvec(const struct bio_vec *bvec, size_t size, size_t seek)
317{
318 struct bvec_iter bi = {
319 .bi_size = size + seek,
320 };
321 struct bio_vec bv;
322
323 bvec_iter_advance(bvec, &bi, seek & PAGE_MASK);
324 for_each_bvec(bv, bvec, bi, bi)
325 flush_dcache_page(bv.bv_page);
326}
327#else
328static inline void svc_flush_bvec(const struct bio_vec *bvec, size_t size,
329 size_t seek)
330{
331}
332#endif
333
334/*
335 * Read from @rqstp's transport socket. The incoming message fills whole
336 * pages in @rqstp's rq_pages array until the last page of the message
337 * has been received into a partial page.
338 */
339static ssize_t svc_tcp_read_msg(struct svc_rqst *rqstp, size_t buflen,
340 size_t seek)
341{
342 struct svc_sock *svsk =
343 container_of(rqstp->rq_xprt, struct svc_sock, sk_xprt);
344 struct bio_vec *bvec = rqstp->rq_bvec;
345 struct msghdr msg = { NULL };
346 unsigned int i;
347 ssize_t len;
348 size_t t;
349
350 clear_bit(nr: XPT_DATA, addr: &svsk->sk_xprt.xpt_flags);
351
352 for (i = 0, t = 0; t < buflen; i++, t += PAGE_SIZE)
353 bvec_set_page(bv: &bvec[i], page: rqstp->rq_pages[i], PAGE_SIZE, offset: 0);
354 rqstp->rq_respages = &rqstp->rq_pages[i];
355 rqstp->rq_next_page = rqstp->rq_respages + 1;
356
357 iov_iter_bvec(i: &msg.msg_iter, ITER_DEST, bvec, nr_segs: i, count: buflen);
358 if (seek) {
359 iov_iter_advance(i: &msg.msg_iter, bytes: seek);
360 buflen -= seek;
361 }
362 len = svc_tcp_sock_recvmsg(svsk, msg: &msg);
363 if (len > 0)
364 svc_flush_bvec(bvec, size: len, seek);
365
366 /* If we read a full record, then assume there may be more
367 * data to read (stream based sockets only!)
368 */
369 if (len == buflen)
370 set_bit(nr: XPT_DATA, addr: &svsk->sk_xprt.xpt_flags);
371
372 return len;
373}
374
375/*
376 * Set socket snd and rcv buffer lengths
377 */
378static void svc_sock_setbufsize(struct svc_sock *svsk, unsigned int nreqs)
379{
380 unsigned int max_mesg = svsk->sk_xprt.xpt_server->sv_max_mesg;
381 struct socket *sock = svsk->sk_sock;
382
383 nreqs = min(nreqs, INT_MAX / 2 / max_mesg);
384
385 lock_sock(sk: sock->sk);
386 sock->sk->sk_sndbuf = nreqs * max_mesg * 2;
387 sock->sk->sk_rcvbuf = nreqs * max_mesg * 2;
388 sock->sk->sk_write_space(sock->sk);
389 release_sock(sk: sock->sk);
390}
391
392static void svc_sock_secure_port(struct svc_rqst *rqstp)
393{
394 if (svc_port_is_privileged(sin: svc_addr(rqst: rqstp)))
395 set_bit(nr: RQ_SECURE, addr: &rqstp->rq_flags);
396 else
397 clear_bit(nr: RQ_SECURE, addr: &rqstp->rq_flags);
398}
399
400/*
401 * INET callback when data has been received on the socket.
402 */
403static void svc_data_ready(struct sock *sk)
404{
405 struct svc_sock *svsk = (struct svc_sock *)sk->sk_user_data;
406
407 trace_sk_data_ready(sk);
408
409 if (svsk) {
410 /* Refer to svc_setup_socket() for details. */
411 rmb();
412 svsk->sk_odata(sk);
413 trace_svcsock_data_ready(xprt: &svsk->sk_xprt, result: 0);
414 if (test_bit(XPT_HANDSHAKE, &svsk->sk_xprt.xpt_flags))
415 return;
416 if (!test_and_set_bit(nr: XPT_DATA, addr: &svsk->sk_xprt.xpt_flags))
417 svc_xprt_enqueue(xprt: &svsk->sk_xprt);
418 }
419}
420
421/*
422 * INET callback when space is newly available on the socket.
423 */
424static void svc_write_space(struct sock *sk)
425{
426 struct svc_sock *svsk = (struct svc_sock *)(sk->sk_user_data);
427
428 if (svsk) {
429 /* Refer to svc_setup_socket() for details. */
430 rmb();
431 trace_svcsock_write_space(xprt: &svsk->sk_xprt, result: 0);
432 svsk->sk_owspace(sk);
433 svc_xprt_enqueue(xprt: &svsk->sk_xprt);
434 }
435}
436
437static int svc_tcp_has_wspace(struct svc_xprt *xprt)
438{
439 struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt);
440
441 if (test_bit(XPT_LISTENER, &xprt->xpt_flags))
442 return 1;
443 return !test_bit(SOCK_NOSPACE, &svsk->sk_sock->flags);
444}
445
446static void svc_tcp_kill_temp_xprt(struct svc_xprt *xprt)
447{
448 struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt);
449
450 sock_no_linger(sk: svsk->sk_sock->sk);
451}
452
453/**
454 * svc_tcp_handshake_done - Handshake completion handler
455 * @data: address of xprt to wake
456 * @status: status of handshake
457 * @peerid: serial number of key containing the remote peer's identity
458 *
459 * If a security policy is specified as an export option, we don't
460 * have a specific export here to check. So we set a "TLS session
461 * is present" flag on the xprt and let an upper layer enforce local
462 * security policy.
463 */
464static void svc_tcp_handshake_done(void *data, int status, key_serial_t peerid)
465{
466 struct svc_xprt *xprt = data;
467 struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt);
468
469 if (!status) {
470 if (peerid != TLS_NO_PEERID)
471 set_bit(nr: XPT_PEER_AUTH, addr: &xprt->xpt_flags);
472 set_bit(nr: XPT_TLS_SESSION, addr: &xprt->xpt_flags);
473 }
474 clear_bit(nr: XPT_HANDSHAKE, addr: &xprt->xpt_flags);
475 complete_all(&svsk->sk_handshake_done);
476}
477
478/**
479 * svc_tcp_handshake - Perform a transport-layer security handshake
480 * @xprt: connected transport endpoint
481 *
482 */
483static void svc_tcp_handshake(struct svc_xprt *xprt)
484{
485 struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt);
486 struct sock *sk = svsk->sk_sock->sk;
487 struct tls_handshake_args args = {
488 .ta_sock = svsk->sk_sock,
489 .ta_done = svc_tcp_handshake_done,
490 .ta_data = xprt,
491 };
492 int ret;
493
494 trace_svc_tls_upcall(xprt);
495
496 clear_bit(nr: XPT_TLS_SESSION, addr: &xprt->xpt_flags);
497 init_completion(x: &svsk->sk_handshake_done);
498
499 ret = tls_server_hello_x509(args: &args, GFP_KERNEL);
500 if (ret) {
501 trace_svc_tls_not_started(xprt);
502 goto out_failed;
503 }
504
505 ret = wait_for_completion_interruptible_timeout(x: &svsk->sk_handshake_done,
506 timeout: SVC_HANDSHAKE_TO);
507 if (ret <= 0) {
508 if (tls_handshake_cancel(sk)) {
509 trace_svc_tls_timed_out(xprt);
510 goto out_close;
511 }
512 }
513
514 if (!test_bit(XPT_TLS_SESSION, &xprt->xpt_flags)) {
515 trace_svc_tls_unavailable(xprt);
516 goto out_close;
517 }
518
519 /* Mark the transport ready in case the remote sent RPC
520 * traffic before the kernel received the handshake
521 * completion downcall.
522 */
523 set_bit(nr: XPT_DATA, addr: &xprt->xpt_flags);
524 svc_xprt_enqueue(xprt);
525 return;
526
527out_close:
528 set_bit(nr: XPT_CLOSE, addr: &xprt->xpt_flags);
529out_failed:
530 clear_bit(nr: XPT_HANDSHAKE, addr: &xprt->xpt_flags);
531 set_bit(nr: XPT_DATA, addr: &xprt->xpt_flags);
532 svc_xprt_enqueue(xprt);
533}
534
535/*
536 * See net/ipv6/ip_sockglue.c : ip_cmsg_recv_pktinfo
537 */
538static int svc_udp_get_dest_address4(struct svc_rqst *rqstp,
539 struct cmsghdr *cmh)
540{
541 struct in_pktinfo *pki = CMSG_DATA(cmh);
542 struct sockaddr_in *daddr = svc_daddr_in(rqst: rqstp);
543
544 if (cmh->cmsg_type != IP_PKTINFO)
545 return 0;
546
547 daddr->sin_family = AF_INET;
548 daddr->sin_addr.s_addr = pki->ipi_spec_dst.s_addr;
549 return 1;
550}
551
552/*
553 * See net/ipv6/datagram.c : ip6_datagram_recv_ctl
554 */
555static int svc_udp_get_dest_address6(struct svc_rqst *rqstp,
556 struct cmsghdr *cmh)
557{
558 struct in6_pktinfo *pki = CMSG_DATA(cmh);
559 struct sockaddr_in6 *daddr = svc_daddr_in6(rqst: rqstp);
560
561 if (cmh->cmsg_type != IPV6_PKTINFO)
562 return 0;
563
564 daddr->sin6_family = AF_INET6;
565 daddr->sin6_addr = pki->ipi6_addr;
566 daddr->sin6_scope_id = pki->ipi6_ifindex;
567 return 1;
568}
569
570/*
571 * Copy the UDP datagram's destination address to the rqstp structure.
572 * The 'destination' address in this case is the address to which the
573 * peer sent the datagram, i.e. our local address. For multihomed
574 * hosts, this can change from msg to msg. Note that only the IP
575 * address changes, the port number should remain the same.
576 */
577static int svc_udp_get_dest_address(struct svc_rqst *rqstp,
578 struct cmsghdr *cmh)
579{
580 switch (cmh->cmsg_level) {
581 case SOL_IP:
582 return svc_udp_get_dest_address4(rqstp, cmh);
583 case SOL_IPV6:
584 return svc_udp_get_dest_address6(rqstp, cmh);
585 }
586
587 return 0;
588}
589
590/**
591 * svc_udp_recvfrom - Receive a datagram from a UDP socket.
592 * @rqstp: request structure into which to receive an RPC Call
593 *
594 * Called in a loop when XPT_DATA has been set.
595 *
596 * Returns:
597 * On success, the number of bytes in a received RPC Call, or
598 * %0 if a complete RPC Call message was not ready to return
599 */
600static int svc_udp_recvfrom(struct svc_rqst *rqstp)
601{
602 struct svc_sock *svsk =
603 container_of(rqstp->rq_xprt, struct svc_sock, sk_xprt);
604 struct svc_serv *serv = svsk->sk_xprt.xpt_server;
605 struct sk_buff *skb;
606 union {
607 struct cmsghdr hdr;
608 long all[SVC_PKTINFO_SPACE / sizeof(long)];
609 } buffer;
610 struct cmsghdr *cmh = &buffer.hdr;
611 struct msghdr msg = {
612 .msg_name = svc_addr(rqst: rqstp),
613 .msg_control = cmh,
614 .msg_controllen = sizeof(buffer),
615 .msg_flags = MSG_DONTWAIT,
616 };
617 size_t len;
618 int err;
619
620 if (test_and_clear_bit(nr: XPT_CHNGBUF, addr: &svsk->sk_xprt.xpt_flags))
621 /* udp sockets need large rcvbuf as all pending
622 * requests are still in that buffer. sndbuf must
623 * also be large enough that there is enough space
624 * for one reply per thread. We count all threads
625 * rather than threads in a particular pool, which
626 * provides an upper bound on the number of threads
627 * which will access the socket.
628 */
629 svc_sock_setbufsize(svsk, nreqs: serv->sv_nrthreads + 3);
630
631 clear_bit(nr: XPT_DATA, addr: &svsk->sk_xprt.xpt_flags);
632 err = kernel_recvmsg(sock: svsk->sk_sock, msg: &msg, NULL,
633 num: 0, len: 0, MSG_PEEK | MSG_DONTWAIT);
634 if (err < 0)
635 goto out_recv_err;
636 skb = skb_recv_udp(sk: svsk->sk_sk, MSG_DONTWAIT, err: &err);
637 if (!skb)
638 goto out_recv_err;
639
640 len = svc_addr_len(sa: svc_addr(rqst: rqstp));
641 rqstp->rq_addrlen = len;
642 if (skb->tstamp == 0) {
643 skb->tstamp = ktime_get_real();
644 /* Don't enable netstamp, sunrpc doesn't
645 need that much accuracy */
646 }
647 sock_write_timestamp(sk: svsk->sk_sk, kt: skb->tstamp);
648 set_bit(nr: XPT_DATA, addr: &svsk->sk_xprt.xpt_flags); /* there may be more data... */
649
650 len = skb->len;
651 rqstp->rq_arg.len = len;
652 trace_svcsock_udp_recv(xprt: &svsk->sk_xprt, result: len);
653
654 rqstp->rq_prot = IPPROTO_UDP;
655
656 if (!svc_udp_get_dest_address(rqstp, cmh))
657 goto out_cmsg_err;
658 rqstp->rq_daddrlen = svc_addr_len(sa: svc_daddr(rqst: rqstp));
659
660 if (skb_is_nonlinear(skb)) {
661 /* we have to copy */
662 local_bh_disable();
663 if (csum_partial_copy_to_xdr(xdr: &rqstp->rq_arg, skb))
664 goto out_bh_enable;
665 local_bh_enable();
666 consume_skb(skb);
667 } else {
668 /* we can use it in-place */
669 rqstp->rq_arg.head[0].iov_base = skb->data;
670 rqstp->rq_arg.head[0].iov_len = len;
671 if (skb_checksum_complete(skb))
672 goto out_free;
673 rqstp->rq_xprt_ctxt = skb;
674 }
675
676 rqstp->rq_arg.page_base = 0;
677 if (len <= rqstp->rq_arg.head[0].iov_len) {
678 rqstp->rq_arg.head[0].iov_len = len;
679 rqstp->rq_arg.page_len = 0;
680 rqstp->rq_respages = rqstp->rq_pages+1;
681 } else {
682 rqstp->rq_arg.page_len = len - rqstp->rq_arg.head[0].iov_len;
683 rqstp->rq_respages = rqstp->rq_pages + 1 +
684 DIV_ROUND_UP(rqstp->rq_arg.page_len, PAGE_SIZE);
685 }
686 rqstp->rq_next_page = rqstp->rq_respages+1;
687
688 if (serv->sv_stats)
689 serv->sv_stats->netudpcnt++;
690
691 svc_sock_secure_port(rqstp);
692 svc_xprt_received(xprt: rqstp->rq_xprt);
693 return len;
694
695out_recv_err:
696 if (err != -EAGAIN) {
697 /* possibly an icmp error */
698 set_bit(nr: XPT_DATA, addr: &svsk->sk_xprt.xpt_flags);
699 }
700 trace_svcsock_udp_recv_err(xprt: &svsk->sk_xprt, result: err);
701 goto out_clear_busy;
702out_cmsg_err:
703 net_warn_ratelimited("svc: received unknown control message %d/%d; dropping RPC reply datagram\n",
704 cmh->cmsg_level, cmh->cmsg_type);
705 goto out_free;
706out_bh_enable:
707 local_bh_enable();
708out_free:
709 kfree_skb(skb);
710out_clear_busy:
711 svc_xprt_received(xprt: rqstp->rq_xprt);
712 return 0;
713}
714
715/**
716 * svc_udp_sendto - Send out a reply on a UDP socket
717 * @rqstp: completed svc_rqst
718 *
719 * xpt_mutex ensures @rqstp's whole message is written to the socket
720 * without interruption.
721 *
722 * Returns the number of bytes sent, or a negative errno.
723 */
724static int svc_udp_sendto(struct svc_rqst *rqstp)
725{
726 struct svc_xprt *xprt = rqstp->rq_xprt;
727 struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt);
728 struct xdr_buf *xdr = &rqstp->rq_res;
729 union {
730 struct cmsghdr hdr;
731 long all[SVC_PKTINFO_SPACE / sizeof(long)];
732 } buffer;
733 struct cmsghdr *cmh = &buffer.hdr;
734 struct msghdr msg = {
735 .msg_name = &rqstp->rq_addr,
736 .msg_namelen = rqstp->rq_addrlen,
737 .msg_control = cmh,
738 .msg_flags = MSG_SPLICE_PAGES,
739 .msg_controllen = sizeof(buffer),
740 };
741 unsigned int count;
742 int err;
743
744 svc_udp_release_ctxt(xprt, ctxt: rqstp->rq_xprt_ctxt);
745 rqstp->rq_xprt_ctxt = NULL;
746
747 svc_set_cmsg_data(rqstp, cmh);
748
749 mutex_lock(&xprt->xpt_mutex);
750
751 if (svc_xprt_is_dead(xprt))
752 goto out_notconn;
753
754 count = xdr_buf_to_bvec(bvec: svsk->sk_bvec, bvec_size: SUNRPC_MAX_UDP_SENDPAGES, xdr);
755
756 iov_iter_bvec(i: &msg.msg_iter, ITER_SOURCE, bvec: svsk->sk_bvec,
757 nr_segs: count, count: rqstp->rq_res.len);
758 err = sock_sendmsg(sock: svsk->sk_sock, msg: &msg);
759 if (err == -ECONNREFUSED) {
760 /* ICMP error on earlier request. */
761 iov_iter_bvec(i: &msg.msg_iter, ITER_SOURCE, bvec: svsk->sk_bvec,
762 nr_segs: count, count: rqstp->rq_res.len);
763 err = sock_sendmsg(sock: svsk->sk_sock, msg: &msg);
764 }
765
766 trace_svcsock_udp_send(xprt, result: err);
767
768 mutex_unlock(lock: &xprt->xpt_mutex);
769 return err;
770
771out_notconn:
772 mutex_unlock(lock: &xprt->xpt_mutex);
773 return -ENOTCONN;
774}
775
776static int svc_udp_has_wspace(struct svc_xprt *xprt)
777{
778 struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt);
779 struct svc_serv *serv = xprt->xpt_server;
780 unsigned long required;
781
782 /*
783 * Set the SOCK_NOSPACE flag before checking the available
784 * sock space.
785 */
786 set_bit(nr: SOCK_NOSPACE, addr: &svsk->sk_sock->flags);
787 required = atomic_read(v: &svsk->sk_xprt.xpt_reserved) + serv->sv_max_mesg;
788 if (required*2 > sock_wspace(sk: svsk->sk_sk))
789 return 0;
790 clear_bit(nr: SOCK_NOSPACE, addr: &svsk->sk_sock->flags);
791 return 1;
792}
793
794static struct svc_xprt *svc_udp_accept(struct svc_xprt *xprt)
795{
796 BUG();
797 return NULL;
798}
799
800static void svc_udp_kill_temp_xprt(struct svc_xprt *xprt)
801{
802}
803
804static struct svc_xprt *svc_udp_create(struct svc_serv *serv,
805 struct net *net,
806 struct sockaddr *sa, int salen,
807 int flags)
808{
809 return svc_create_socket(serv, IPPROTO_UDP, net, sa, salen, flags);
810}
811
812static const struct svc_xprt_ops svc_udp_ops = {
813 .xpo_create = svc_udp_create,
814 .xpo_recvfrom = svc_udp_recvfrom,
815 .xpo_sendto = svc_udp_sendto,
816 .xpo_result_payload = svc_sock_result_payload,
817 .xpo_release_ctxt = svc_udp_release_ctxt,
818 .xpo_detach = svc_sock_detach,
819 .xpo_free = svc_sock_free,
820 .xpo_has_wspace = svc_udp_has_wspace,
821 .xpo_accept = svc_udp_accept,
822 .xpo_kill_temp_xprt = svc_udp_kill_temp_xprt,
823};
824
825static struct svc_xprt_class svc_udp_class = {
826 .xcl_name = "udp",
827 .xcl_owner = THIS_MODULE,
828 .xcl_ops = &svc_udp_ops,
829 .xcl_max_payload = RPCSVC_MAXPAYLOAD_UDP,
830 .xcl_ident = XPRT_TRANSPORT_UDP,
831};
832
833static void svc_udp_init(struct svc_sock *svsk, struct svc_serv *serv)
834{
835 svc_xprt_init(sock_net(sk: svsk->sk_sock->sk), &svc_udp_class,
836 &svsk->sk_xprt, serv);
837 clear_bit(nr: XPT_CACHE_AUTH, addr: &svsk->sk_xprt.xpt_flags);
838 svsk->sk_sk->sk_data_ready = svc_data_ready;
839 svsk->sk_sk->sk_write_space = svc_write_space;
840
841 /* initialise setting must have enough space to
842 * receive and respond to one request.
843 * svc_udp_recvfrom will re-adjust if necessary
844 */
845 svc_sock_setbufsize(svsk, nreqs: 3);
846
847 /* data might have come in before data_ready set up */
848 set_bit(nr: XPT_DATA, addr: &svsk->sk_xprt.xpt_flags);
849 set_bit(nr: XPT_CHNGBUF, addr: &svsk->sk_xprt.xpt_flags);
850 set_bit(nr: XPT_RPCB_UNREG, addr: &svsk->sk_xprt.xpt_flags);
851
852 /* make sure we get destination address info */
853 switch (svsk->sk_sk->sk_family) {
854 case AF_INET:
855 ip_sock_set_pktinfo(sk: svsk->sk_sock->sk);
856 break;
857 case AF_INET6:
858 ip6_sock_set_recvpktinfo(sk: svsk->sk_sock->sk);
859 break;
860 default:
861 BUG();
862 }
863}
864
865/*
866 * A data_ready event on a listening socket means there's a connection
867 * pending. Do not use state_change as a substitute for it.
868 */
869static void svc_tcp_listen_data_ready(struct sock *sk)
870{
871 struct svc_sock *svsk = (struct svc_sock *)sk->sk_user_data;
872
873 trace_sk_data_ready(sk);
874
875 /*
876 * This callback may called twice when a new connection
877 * is established as a child socket inherits everything
878 * from a parent LISTEN socket.
879 * 1) data_ready method of the parent socket will be called
880 * when one of child sockets become ESTABLISHED.
881 * 2) data_ready method of the child socket may be called
882 * when it receives data before the socket is accepted.
883 * In case of 2, we should ignore it silently and DO NOT
884 * dereference svsk.
885 */
886 if (sk->sk_state != TCP_LISTEN)
887 return;
888
889 if (svsk) {
890 /* Refer to svc_setup_socket() for details. */
891 rmb();
892 svsk->sk_odata(sk);
893 set_bit(nr: XPT_CONN, addr: &svsk->sk_xprt.xpt_flags);
894 svc_xprt_enqueue(xprt: &svsk->sk_xprt);
895 }
896}
897
898/*
899 * A state change on a connected socket means it's dying or dead.
900 */
901static void svc_tcp_state_change(struct sock *sk)
902{
903 struct svc_sock *svsk = (struct svc_sock *)sk->sk_user_data;
904
905 if (svsk) {
906 /* Refer to svc_setup_socket() for details. */
907 rmb();
908 svsk->sk_ostate(sk);
909 trace_svcsock_tcp_state(xprt: &svsk->sk_xprt, socket: svsk->sk_sock);
910 if (sk->sk_state != TCP_ESTABLISHED)
911 svc_xprt_deferred_close(xprt: &svsk->sk_xprt);
912 }
913}
914
915/*
916 * Accept a TCP connection
917 */
918static struct svc_xprt *svc_tcp_accept(struct svc_xprt *xprt)
919{
920 struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt);
921 struct sockaddr_storage addr;
922 struct sockaddr *sin = (struct sockaddr *) &addr;
923 struct svc_serv *serv = svsk->sk_xprt.xpt_server;
924 struct socket *sock = svsk->sk_sock;
925 struct socket *newsock;
926 struct svc_sock *newsvsk;
927 int err, slen;
928
929 if (!sock)
930 return NULL;
931
932 clear_bit(nr: XPT_CONN, addr: &svsk->sk_xprt.xpt_flags);
933 err = kernel_accept(sock, newsock: &newsock, O_NONBLOCK);
934 if (err < 0) {
935 if (err != -EAGAIN)
936 trace_svcsock_accept_err(xprt, service: serv->sv_name, status: err);
937 return NULL;
938 }
939 if (IS_ERR(ptr: sock_alloc_file(sock: newsock, O_NONBLOCK, NULL)))
940 return NULL;
941
942 set_bit(nr: XPT_CONN, addr: &svsk->sk_xprt.xpt_flags);
943
944 err = kernel_getpeername(sock: newsock, addr: sin);
945 if (err < 0) {
946 trace_svcsock_getpeername_err(xprt, service: serv->sv_name, status: err);
947 goto failed; /* aborted connection or whatever */
948 }
949 slen = err;
950
951 /* Reset the inherited callbacks before calling svc_setup_socket */
952 newsock->sk->sk_state_change = svsk->sk_ostate;
953 newsock->sk->sk_data_ready = svsk->sk_odata;
954 newsock->sk->sk_write_space = svsk->sk_owspace;
955
956 /* make sure that a write doesn't block forever when
957 * low on memory
958 */
959 newsock->sk->sk_sndtimeo = HZ*30;
960
961 newsvsk = svc_setup_socket(serv, newsock,
962 flags: (SVC_SOCK_ANONYMOUS | SVC_SOCK_TEMPORARY));
963 if (IS_ERR(ptr: newsvsk))
964 goto failed;
965 svc_xprt_set_remote(xprt: &newsvsk->sk_xprt, sa: sin, salen: slen);
966 err = kernel_getsockname(sock: newsock, addr: sin);
967 slen = err;
968 if (unlikely(err < 0))
969 slen = offsetof(struct sockaddr, sa_data);
970 svc_xprt_set_local(xprt: &newsvsk->sk_xprt, sa: sin, salen: slen);
971
972 if (sock_is_loopback(sk: newsock->sk))
973 set_bit(nr: XPT_LOCAL, addr: &newsvsk->sk_xprt.xpt_flags);
974 else
975 clear_bit(nr: XPT_LOCAL, addr: &newsvsk->sk_xprt.xpt_flags);
976 if (serv->sv_stats)
977 serv->sv_stats->nettcpconn++;
978
979 return &newsvsk->sk_xprt;
980
981failed:
982 sockfd_put(newsock);
983 return NULL;
984}
985
986static size_t svc_tcp_restore_pages(struct svc_sock *svsk,
987 struct svc_rqst *rqstp)
988{
989 size_t len = svsk->sk_datalen;
990 unsigned int i, npages;
991
992 if (!len)
993 return 0;
994 npages = (len + PAGE_SIZE - 1) >> PAGE_SHIFT;
995 for (i = 0; i < npages; i++) {
996 if (rqstp->rq_pages[i] != NULL)
997 put_page(page: rqstp->rq_pages[i]);
998 BUG_ON(svsk->sk_pages[i] == NULL);
999 rqstp->rq_pages[i] = svsk->sk_pages[i];
1000 svsk->sk_pages[i] = NULL;
1001 }
1002 rqstp->rq_arg.head[0].iov_base = page_address(rqstp->rq_pages[0]);
1003 return len;
1004}
1005
1006static void svc_tcp_save_pages(struct svc_sock *svsk, struct svc_rqst *rqstp)
1007{
1008 unsigned int i, len, npages;
1009
1010 if (svsk->sk_datalen == 0)
1011 return;
1012 len = svsk->sk_datalen;
1013 npages = (len + PAGE_SIZE - 1) >> PAGE_SHIFT;
1014 for (i = 0; i < npages; i++) {
1015 svsk->sk_pages[i] = rqstp->rq_pages[i];
1016 rqstp->rq_pages[i] = NULL;
1017 }
1018}
1019
1020static void svc_tcp_clear_pages(struct svc_sock *svsk)
1021{
1022 unsigned int i, len, npages;
1023
1024 if (svsk->sk_datalen == 0)
1025 goto out;
1026 len = svsk->sk_datalen;
1027 npages = (len + PAGE_SIZE - 1) >> PAGE_SHIFT;
1028 for (i = 0; i < npages; i++) {
1029 if (svsk->sk_pages[i] == NULL) {
1030 WARN_ON_ONCE(1);
1031 continue;
1032 }
1033 put_page(page: svsk->sk_pages[i]);
1034 svsk->sk_pages[i] = NULL;
1035 }
1036out:
1037 svsk->sk_tcplen = 0;
1038 svsk->sk_datalen = 0;
1039}
1040
1041/*
1042 * Receive fragment record header into sk_marker.
1043 */
1044static ssize_t svc_tcp_read_marker(struct svc_sock *svsk,
1045 struct svc_rqst *rqstp)
1046{
1047 ssize_t want, len;
1048
1049 /* If we haven't gotten the record length yet,
1050 * get the next four bytes.
1051 */
1052 if (svsk->sk_tcplen < sizeof(rpc_fraghdr)) {
1053 struct msghdr msg = { NULL };
1054 struct kvec iov;
1055
1056 want = sizeof(rpc_fraghdr) - svsk->sk_tcplen;
1057 iov.iov_base = ((char *)&svsk->sk_marker) + svsk->sk_tcplen;
1058 iov.iov_len = want;
1059 iov_iter_kvec(i: &msg.msg_iter, ITER_DEST, kvec: &iov, nr_segs: 1, count: want);
1060 len = svc_tcp_sock_recvmsg(svsk, msg: &msg);
1061 if (len < 0)
1062 return len;
1063 svsk->sk_tcplen += len;
1064 if (len < want) {
1065 /* call again to read the remaining bytes */
1066 goto err_short;
1067 }
1068 trace_svcsock_marker(xprt: &svsk->sk_xprt, marker: svsk->sk_marker);
1069 if (svc_sock_reclen(svsk) + svsk->sk_datalen >
1070 svsk->sk_xprt.xpt_server->sv_max_mesg)
1071 goto err_too_large;
1072 }
1073 return svc_sock_reclen(svsk);
1074
1075err_too_large:
1076 net_notice_ratelimited("svc: %s oversized RPC fragment (%u octets) from %pISpc\n",
1077 svsk->sk_xprt.xpt_server->sv_name,
1078 svc_sock_reclen(svsk),
1079 (struct sockaddr *)&svsk->sk_xprt.xpt_remote);
1080 svc_xprt_deferred_close(xprt: &svsk->sk_xprt);
1081err_short:
1082 return -EAGAIN;
1083}
1084
1085static int receive_cb_reply(struct svc_sock *svsk, struct svc_rqst *rqstp)
1086{
1087 struct rpc_xprt *bc_xprt = svsk->sk_xprt.xpt_bc_xprt;
1088 struct rpc_rqst *req = NULL;
1089 struct kvec *src, *dst;
1090 __be32 *p = (__be32 *)rqstp->rq_arg.head[0].iov_base;
1091 __be32 xid = *p;
1092
1093 if (!bc_xprt)
1094 return -EAGAIN;
1095 spin_lock(lock: &bc_xprt->queue_lock);
1096 req = xprt_lookup_rqst(xprt: bc_xprt, xid);
1097 if (!req)
1098 goto unlock_eagain;
1099
1100 memcpy(&req->rq_private_buf, &req->rq_rcv_buf, sizeof(struct xdr_buf));
1101 /*
1102 * XXX!: cheating for now! Only copying HEAD.
1103 * But we know this is good enough for now (in fact, for any
1104 * callback reply in the forseeable future).
1105 */
1106 dst = &req->rq_private_buf.head[0];
1107 src = &rqstp->rq_arg.head[0];
1108 if (dst->iov_len < src->iov_len)
1109 goto unlock_eagain; /* whatever; just giving up. */
1110 memcpy(dst->iov_base, src->iov_base, src->iov_len);
1111 xprt_complete_rqst(task: req->rq_task, copied: rqstp->rq_arg.len);
1112 rqstp->rq_arg.len = 0;
1113 spin_unlock(lock: &bc_xprt->queue_lock);
1114 return 0;
1115unlock_eagain:
1116 spin_unlock(lock: &bc_xprt->queue_lock);
1117 return -EAGAIN;
1118}
1119
1120static void svc_tcp_fragment_received(struct svc_sock *svsk)
1121{
1122 /* If we have more data, signal svc_xprt_enqueue() to try again */
1123 svsk->sk_tcplen = 0;
1124 svsk->sk_marker = xdr_zero;
1125}
1126
1127/**
1128 * svc_tcp_recvfrom - Receive data from a TCP socket
1129 * @rqstp: request structure into which to receive an RPC Call
1130 *
1131 * Called in a loop when XPT_DATA has been set.
1132 *
1133 * Read the 4-byte stream record marker, then use the record length
1134 * in that marker to set up exactly the resources needed to receive
1135 * the next RPC message into @rqstp.
1136 *
1137 * Returns:
1138 * On success, the number of bytes in a received RPC Call, or
1139 * %0 if a complete RPC Call message was not ready to return
1140 *
1141 * The zero return case handles partial receives and callback Replies.
1142 * The state of a partial receive is preserved in the svc_sock for
1143 * the next call to svc_tcp_recvfrom.
1144 */
1145static int svc_tcp_recvfrom(struct svc_rqst *rqstp)
1146{
1147 struct svc_sock *svsk =
1148 container_of(rqstp->rq_xprt, struct svc_sock, sk_xprt);
1149 struct svc_serv *serv = svsk->sk_xprt.xpt_server;
1150 size_t want, base;
1151 ssize_t len;
1152 __be32 *p;
1153 __be32 calldir;
1154
1155 clear_bit(nr: XPT_DATA, addr: &svsk->sk_xprt.xpt_flags);
1156 len = svc_tcp_read_marker(svsk, rqstp);
1157 if (len < 0)
1158 goto error;
1159
1160 base = svc_tcp_restore_pages(svsk, rqstp);
1161 want = len - (svsk->sk_tcplen - sizeof(rpc_fraghdr));
1162 len = svc_tcp_read_msg(rqstp, buflen: base + want, seek: base);
1163 if (len >= 0) {
1164 trace_svcsock_tcp_recv(xprt: &svsk->sk_xprt, result: len);
1165 svsk->sk_tcplen += len;
1166 svsk->sk_datalen += len;
1167 }
1168 if (len != want || !svc_sock_final_rec(svsk))
1169 goto err_incomplete;
1170 if (svsk->sk_datalen < 8)
1171 goto err_nuts;
1172
1173 rqstp->rq_arg.len = svsk->sk_datalen;
1174 rqstp->rq_arg.page_base = 0;
1175 if (rqstp->rq_arg.len <= rqstp->rq_arg.head[0].iov_len) {
1176 rqstp->rq_arg.head[0].iov_len = rqstp->rq_arg.len;
1177 rqstp->rq_arg.page_len = 0;
1178 } else
1179 rqstp->rq_arg.page_len = rqstp->rq_arg.len - rqstp->rq_arg.head[0].iov_len;
1180
1181 rqstp->rq_xprt_ctxt = NULL;
1182 rqstp->rq_prot = IPPROTO_TCP;
1183 if (test_bit(XPT_LOCAL, &svsk->sk_xprt.xpt_flags))
1184 set_bit(nr: RQ_LOCAL, addr: &rqstp->rq_flags);
1185 else
1186 clear_bit(nr: RQ_LOCAL, addr: &rqstp->rq_flags);
1187
1188 p = (__be32 *)rqstp->rq_arg.head[0].iov_base;
1189 calldir = p[1];
1190 if (calldir)
1191 len = receive_cb_reply(svsk, rqstp);
1192
1193 /* Reset TCP read info */
1194 svsk->sk_datalen = 0;
1195 svc_tcp_fragment_received(svsk);
1196
1197 if (len < 0)
1198 goto error;
1199
1200 svc_xprt_copy_addrs(rqstp, xprt: &svsk->sk_xprt);
1201 if (serv->sv_stats)
1202 serv->sv_stats->nettcpcnt++;
1203
1204 svc_sock_secure_port(rqstp);
1205 svc_xprt_received(xprt: rqstp->rq_xprt);
1206 return rqstp->rq_arg.len;
1207
1208err_incomplete:
1209 svc_tcp_save_pages(svsk, rqstp);
1210 if (len < 0 && len != -EAGAIN)
1211 goto err_delete;
1212 if (len == want)
1213 svc_tcp_fragment_received(svsk);
1214 else
1215 trace_svcsock_tcp_recv_short(xprt: &svsk->sk_xprt,
1216 expected: svc_sock_reclen(svsk),
1217 received: svsk->sk_tcplen - sizeof(rpc_fraghdr));
1218 goto err_noclose;
1219error:
1220 if (len != -EAGAIN)
1221 goto err_delete;
1222 trace_svcsock_tcp_recv_eagain(xprt: &svsk->sk_xprt, result: 0);
1223 goto err_noclose;
1224err_nuts:
1225 svsk->sk_datalen = 0;
1226err_delete:
1227 trace_svcsock_tcp_recv_err(xprt: &svsk->sk_xprt, result: len);
1228 svc_xprt_deferred_close(xprt: &svsk->sk_xprt);
1229err_noclose:
1230 svc_xprt_received(xprt: rqstp->rq_xprt);
1231 return 0; /* record not complete */
1232}
1233
1234/*
1235 * MSG_SPLICE_PAGES is used exclusively to reduce the number of
1236 * copy operations in this path. Therefore the caller must ensure
1237 * that the pages backing @xdr are unchanging.
1238 */
1239static int svc_tcp_sendmsg(struct svc_sock *svsk, struct svc_rqst *rqstp,
1240 rpc_fraghdr marker)
1241{
1242 struct msghdr msg = {
1243 .msg_flags = MSG_SPLICE_PAGES,
1244 };
1245 unsigned int count;
1246 void *buf;
1247 int ret;
1248
1249 /* The stream record marker is copied into a temporary page
1250 * fragment buffer so that it can be included in sk_bvec.
1251 */
1252 buf = page_frag_alloc(nc: &svsk->sk_frag_cache, fragsz: sizeof(marker),
1253 GFP_KERNEL);
1254 if (!buf)
1255 return -ENOMEM;
1256 memcpy(buf, &marker, sizeof(marker));
1257 bvec_set_virt(bv: svsk->sk_bvec, vaddr: buf, len: sizeof(marker));
1258
1259 count = xdr_buf_to_bvec(bvec: svsk->sk_bvec + 1, bvec_size: rqstp->rq_maxpages,
1260 xdr: &rqstp->rq_res);
1261
1262 iov_iter_bvec(i: &msg.msg_iter, ITER_SOURCE, bvec: svsk->sk_bvec,
1263 nr_segs: 1 + count, count: sizeof(marker) + rqstp->rq_res.len);
1264 ret = sock_sendmsg(sock: svsk->sk_sock, msg: &msg);
1265 page_frag_free(addr: buf);
1266 return ret;
1267}
1268
1269/**
1270 * svc_tcp_sendto - Send out a reply on a TCP socket
1271 * @rqstp: completed svc_rqst
1272 *
1273 * xpt_mutex ensures @rqstp's whole message is written to the socket
1274 * without interruption.
1275 *
1276 * Returns the number of bytes sent, or a negative errno.
1277 */
1278static int svc_tcp_sendto(struct svc_rqst *rqstp)
1279{
1280 struct svc_xprt *xprt = rqstp->rq_xprt;
1281 struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt);
1282 struct xdr_buf *xdr = &rqstp->rq_res;
1283 rpc_fraghdr marker = cpu_to_be32(RPC_LAST_STREAM_FRAGMENT |
1284 (u32)xdr->len);
1285 int sent;
1286
1287 svc_tcp_release_ctxt(xprt, ctxt: rqstp->rq_xprt_ctxt);
1288 rqstp->rq_xprt_ctxt = NULL;
1289
1290 mutex_lock(&xprt->xpt_mutex);
1291 if (svc_xprt_is_dead(xprt))
1292 goto out_notconn;
1293 sent = svc_tcp_sendmsg(svsk, rqstp, marker);
1294 trace_svcsock_tcp_send(xprt, result: sent);
1295 if (sent < 0 || sent != (xdr->len + sizeof(marker)))
1296 goto out_close;
1297 mutex_unlock(lock: &xprt->xpt_mutex);
1298 return sent;
1299
1300out_notconn:
1301 mutex_unlock(lock: &xprt->xpt_mutex);
1302 return -ENOTCONN;
1303out_close:
1304 pr_notice("rpc-srv/tcp: %s: %s %d when sending %zu bytes - shutting down socket\n",
1305 xprt->xpt_server->sv_name,
1306 (sent < 0) ? "got error" : "sent",
1307 sent, xdr->len + sizeof(marker));
1308 svc_xprt_deferred_close(xprt);
1309 mutex_unlock(lock: &xprt->xpt_mutex);
1310 return -EAGAIN;
1311}
1312
1313static struct svc_xprt *svc_tcp_create(struct svc_serv *serv,
1314 struct net *net,
1315 struct sockaddr *sa, int salen,
1316 int flags)
1317{
1318 return svc_create_socket(serv, IPPROTO_TCP, net, sa, salen, flags);
1319}
1320
1321static const struct svc_xprt_ops svc_tcp_ops = {
1322 .xpo_create = svc_tcp_create,
1323 .xpo_recvfrom = svc_tcp_recvfrom,
1324 .xpo_sendto = svc_tcp_sendto,
1325 .xpo_result_payload = svc_sock_result_payload,
1326 .xpo_release_ctxt = svc_tcp_release_ctxt,
1327 .xpo_detach = svc_tcp_sock_detach,
1328 .xpo_free = svc_sock_free,
1329 .xpo_has_wspace = svc_tcp_has_wspace,
1330 .xpo_accept = svc_tcp_accept,
1331 .xpo_kill_temp_xprt = svc_tcp_kill_temp_xprt,
1332 .xpo_handshake = svc_tcp_handshake,
1333};
1334
1335static struct svc_xprt_class svc_tcp_class = {
1336 .xcl_name = "tcp",
1337 .xcl_owner = THIS_MODULE,
1338 .xcl_ops = &svc_tcp_ops,
1339 .xcl_max_payload = RPCSVC_MAXPAYLOAD_TCP,
1340 .xcl_ident = XPRT_TRANSPORT_TCP,
1341};
1342
1343void svc_init_xprt_sock(void)
1344{
1345 svc_reg_xprt_class(&svc_tcp_class);
1346 svc_reg_xprt_class(&svc_udp_class);
1347}
1348
1349void svc_cleanup_xprt_sock(void)
1350{
1351 svc_unreg_xprt_class(&svc_tcp_class);
1352 svc_unreg_xprt_class(&svc_udp_class);
1353}
1354
1355static void svc_tcp_init(struct svc_sock *svsk, struct svc_serv *serv)
1356{
1357 struct sock *sk = svsk->sk_sk;
1358
1359 svc_xprt_init(sock_net(sk: svsk->sk_sock->sk), &svc_tcp_class,
1360 &svsk->sk_xprt, serv);
1361 set_bit(nr: XPT_CACHE_AUTH, addr: &svsk->sk_xprt.xpt_flags);
1362 set_bit(nr: XPT_CONG_CTRL, addr: &svsk->sk_xprt.xpt_flags);
1363 if (sk->sk_state == TCP_LISTEN) {
1364 strcpy(p: svsk->sk_xprt.xpt_remotebuf, q: "listener");
1365 set_bit(nr: XPT_LISTENER, addr: &svsk->sk_xprt.xpt_flags);
1366 set_bit(nr: XPT_RPCB_UNREG, addr: &svsk->sk_xprt.xpt_flags);
1367 sk->sk_data_ready = svc_tcp_listen_data_ready;
1368 set_bit(nr: XPT_CONN, addr: &svsk->sk_xprt.xpt_flags);
1369 } else {
1370 sk->sk_state_change = svc_tcp_state_change;
1371 sk->sk_data_ready = svc_data_ready;
1372 sk->sk_write_space = svc_write_space;
1373
1374 svsk->sk_marker = xdr_zero;
1375 svsk->sk_tcplen = 0;
1376 svsk->sk_datalen = 0;
1377 memset(&svsk->sk_pages[0], 0,
1378 svsk->sk_maxpages * sizeof(struct page *));
1379
1380 tcp_sock_set_nodelay(sk);
1381
1382 set_bit(nr: XPT_DATA, addr: &svsk->sk_xprt.xpt_flags);
1383 switch (sk->sk_state) {
1384 case TCP_SYN_RECV:
1385 case TCP_ESTABLISHED:
1386 break;
1387 default:
1388 svc_xprt_deferred_close(xprt: &svsk->sk_xprt);
1389 }
1390 }
1391}
1392
1393void svc_sock_update_bufs(struct svc_serv *serv)
1394{
1395 /*
1396 * The number of server threads has changed. Update
1397 * rcvbuf and sndbuf accordingly on all sockets
1398 */
1399 struct svc_sock *svsk;
1400
1401 spin_lock_bh(lock: &serv->sv_lock);
1402 list_for_each_entry(svsk, &serv->sv_permsocks, sk_xprt.xpt_list)
1403 set_bit(nr: XPT_CHNGBUF, addr: &svsk->sk_xprt.xpt_flags);
1404 spin_unlock_bh(lock: &serv->sv_lock);
1405}
1406
1407static int svc_sock_sendpages(struct svc_serv *serv, struct socket *sock, int flags)
1408{
1409 switch (sock->type) {
1410 case SOCK_STREAM:
1411 /* +1 for TCP record marker */
1412 if (flags & SVC_SOCK_TEMPORARY)
1413 return svc_serv_maxpages(serv) + 1;
1414 return 0;
1415 case SOCK_DGRAM:
1416 return SUNRPC_MAX_UDP_SENDPAGES;
1417 }
1418 return -EINVAL;
1419}
1420
1421/*
1422 * Initialize socket for RPC use and create svc_sock struct
1423 */
1424static struct svc_sock *svc_setup_socket(struct svc_serv *serv,
1425 struct socket *sock,
1426 int flags)
1427{
1428 struct svc_sock *svsk;
1429 struct sock *inet;
1430 int pmap_register = !(flags & SVC_SOCK_ANONYMOUS);
1431 int sendpages;
1432 unsigned long pages;
1433
1434 sendpages = svc_sock_sendpages(serv, sock, flags);
1435 if (sendpages < 0)
1436 return ERR_PTR(error: sendpages);
1437
1438 pages = svc_serv_maxpages(serv);
1439 svsk = kzalloc(struct_size(svsk, sk_pages, pages), GFP_KERNEL);
1440 if (!svsk)
1441 return ERR_PTR(error: -ENOMEM);
1442
1443 if (sendpages) {
1444 svsk->sk_bvec = kcalloc(sendpages, sizeof(*svsk->sk_bvec), GFP_KERNEL);
1445 if (!svsk->sk_bvec) {
1446 kfree(objp: svsk);
1447 return ERR_PTR(error: -ENOMEM);
1448 }
1449 }
1450
1451 svsk->sk_maxpages = pages;
1452
1453 inet = sock->sk;
1454
1455 if (pmap_register) {
1456 int err;
1457
1458 err = svc_register(serv, sock_net(sk: sock->sk), inet->sk_family,
1459 inet->sk_protocol,
1460 ntohs(inet_sk(inet)->inet_sport));
1461 if (err < 0) {
1462 kfree(objp: svsk->sk_bvec);
1463 kfree(objp: svsk);
1464 return ERR_PTR(error: err);
1465 }
1466 }
1467
1468 svsk->sk_sock = sock;
1469 svsk->sk_sk = inet;
1470 svsk->sk_ostate = inet->sk_state_change;
1471 svsk->sk_odata = inet->sk_data_ready;
1472 svsk->sk_owspace = inet->sk_write_space;
1473 /*
1474 * This barrier is necessary in order to prevent race condition
1475 * with svc_data_ready(), svc_tcp_listen_data_ready(), and others
1476 * when calling callbacks above.
1477 */
1478 wmb();
1479 inet->sk_user_data = svsk;
1480
1481 /* Initialize the socket */
1482 if (sock->type == SOCK_DGRAM)
1483 svc_udp_init(svsk, serv);
1484 else
1485 svc_tcp_init(svsk, serv);
1486
1487 trace_svcsock_new(svsk, socket: sock);
1488 return svsk;
1489}
1490
1491/**
1492 * svc_addsock - add a listener socket to an RPC service
1493 * @serv: pointer to RPC service to which to add a new listener
1494 * @net: caller's network namespace
1495 * @fd: file descriptor of the new listener
1496 * @name_return: pointer to buffer to fill in with name of listener
1497 * @len: size of the buffer
1498 * @cred: credential
1499 *
1500 * Fills in socket name and returns positive length of name if successful.
1501 * Name is terminated with '\n'. On error, returns a negative errno
1502 * value.
1503 */
1504int svc_addsock(struct svc_serv *serv, struct net *net, const int fd,
1505 char *name_return, const size_t len, const struct cred *cred)
1506{
1507 int err = 0;
1508 struct socket *so = sockfd_lookup(fd, err: &err);
1509 struct svc_sock *svsk = NULL;
1510 struct sockaddr_storage addr;
1511 struct sockaddr *sin = (struct sockaddr *)&addr;
1512 int salen;
1513
1514 if (!so)
1515 return err;
1516 err = -EINVAL;
1517 if (sock_net(sk: so->sk) != net)
1518 goto out;
1519 err = -EAFNOSUPPORT;
1520 if ((so->sk->sk_family != PF_INET) && (so->sk->sk_family != PF_INET6))
1521 goto out;
1522 err = -EPROTONOSUPPORT;
1523 if (so->sk->sk_protocol != IPPROTO_TCP &&
1524 so->sk->sk_protocol != IPPROTO_UDP)
1525 goto out;
1526 err = -EISCONN;
1527 if (so->state > SS_UNCONNECTED)
1528 goto out;
1529 err = -ENOENT;
1530 if (!try_module_get(THIS_MODULE))
1531 goto out;
1532 svsk = svc_setup_socket(serv, sock: so, SVC_SOCK_DEFAULTS);
1533 if (IS_ERR(ptr: svsk)) {
1534 module_put(THIS_MODULE);
1535 err = PTR_ERR(ptr: svsk);
1536 goto out;
1537 }
1538 salen = kernel_getsockname(sock: svsk->sk_sock, addr: sin);
1539 if (salen >= 0)
1540 svc_xprt_set_local(xprt: &svsk->sk_xprt, sa: sin, salen);
1541 svsk->sk_xprt.xpt_cred = get_cred(cred);
1542 svc_add_new_perm_xprt(serv, xprt: &svsk->sk_xprt);
1543 return svc_one_sock_name(svsk, buf: name_return, remaining: len);
1544out:
1545 sockfd_put(so);
1546 return err;
1547}
1548EXPORT_SYMBOL_GPL(svc_addsock);
1549
1550/*
1551 * Create socket for RPC service.
1552 */
1553static struct svc_xprt *svc_create_socket(struct svc_serv *serv,
1554 int protocol,
1555 struct net *net,
1556 struct sockaddr *sin, int len,
1557 int flags)
1558{
1559 struct svc_sock *svsk;
1560 struct socket *sock;
1561 int error;
1562 int type;
1563 struct sockaddr_storage addr;
1564 struct sockaddr *newsin = (struct sockaddr *)&addr;
1565 int newlen;
1566 int family;
1567
1568 if (protocol != IPPROTO_UDP && protocol != IPPROTO_TCP) {
1569 printk(KERN_WARNING "svc: only UDP and TCP "
1570 "sockets supported\n");
1571 return ERR_PTR(error: -EINVAL);
1572 }
1573
1574 type = (protocol == IPPROTO_UDP)? SOCK_DGRAM : SOCK_STREAM;
1575 switch (sin->sa_family) {
1576 case AF_INET6:
1577 family = PF_INET6;
1578 break;
1579 case AF_INET:
1580 family = PF_INET;
1581 break;
1582 default:
1583 return ERR_PTR(error: -EINVAL);
1584 }
1585
1586 error = __sock_create(net, family, type, proto: protocol, res: &sock, kern: 1);
1587 if (error < 0)
1588 return ERR_PTR(error);
1589
1590 svc_reclassify_socket(sock);
1591
1592 /*
1593 * If this is an PF_INET6 listener, we want to avoid
1594 * getting requests from IPv4 remotes. Those should
1595 * be shunted to a PF_INET listener via rpcbind.
1596 */
1597 if (family == PF_INET6)
1598 ip6_sock_set_v6only(sk: sock->sk);
1599 if (type == SOCK_STREAM)
1600 sock->sk->sk_reuse = SK_CAN_REUSE; /* allow address reuse */
1601 error = kernel_bind(sock, addr: (struct sockaddr_unsized *)sin, addrlen: len);
1602 if (error < 0)
1603 goto bummer;
1604
1605 error = kernel_getsockname(sock, addr: newsin);
1606 if (error < 0)
1607 goto bummer;
1608 newlen = error;
1609
1610 if (protocol == IPPROTO_TCP) {
1611 sk_net_refcnt_upgrade(sk: sock->sk);
1612 if ((error = kernel_listen(sock, SOMAXCONN)) < 0)
1613 goto bummer;
1614 }
1615
1616 svsk = svc_setup_socket(serv, sock, flags);
1617 if (IS_ERR(ptr: svsk)) {
1618 error = PTR_ERR(ptr: svsk);
1619 goto bummer;
1620 }
1621 svc_xprt_set_local(xprt: &svsk->sk_xprt, sa: newsin, salen: newlen);
1622 return (struct svc_xprt *)svsk;
1623bummer:
1624 sock_release(sock);
1625 return ERR_PTR(error);
1626}
1627
1628/*
1629 * Detach the svc_sock from the socket so that no
1630 * more callbacks occur.
1631 */
1632static void svc_sock_detach(struct svc_xprt *xprt)
1633{
1634 struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt);
1635 struct sock *sk = svsk->sk_sk;
1636
1637 /* put back the old socket callbacks */
1638 lock_sock(sk);
1639 sk->sk_state_change = svsk->sk_ostate;
1640 sk->sk_data_ready = svsk->sk_odata;
1641 sk->sk_write_space = svsk->sk_owspace;
1642 sk->sk_user_data = NULL;
1643 release_sock(sk);
1644}
1645
1646/*
1647 * Disconnect the socket, and reset the callbacks
1648 */
1649static void svc_tcp_sock_detach(struct svc_xprt *xprt)
1650{
1651 struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt);
1652
1653 tls_handshake_close(sock: svsk->sk_sock);
1654
1655 svc_sock_detach(xprt);
1656
1657 if (!test_bit(XPT_LISTENER, &xprt->xpt_flags)) {
1658 svc_tcp_clear_pages(svsk);
1659 kernel_sock_shutdown(sock: svsk->sk_sock, how: SHUT_RDWR);
1660 }
1661}
1662
1663/*
1664 * Free the svc_sock's socket resources and the svc_sock itself.
1665 */
1666static void svc_sock_free(struct svc_xprt *xprt)
1667{
1668 struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt);
1669 struct socket *sock = svsk->sk_sock;
1670
1671 trace_svcsock_free(svsk, socket: sock);
1672
1673 tls_handshake_cancel(sk: sock->sk);
1674 if (sock->file)
1675 sockfd_put(sock);
1676 else
1677 sock_release(sock);
1678
1679 page_frag_cache_drain(nc: &svsk->sk_frag_cache);
1680 kfree(objp: svsk->sk_bvec);
1681 kfree(objp: svsk);
1682}
1683

source code of linux/net/sunrpc/svcsock.c