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 <net/sock.h>
40 #include <net/checksum.h>
41 #include <net/ip.h>
42 #include <net/ipv6.h>
43 #include <net/udp.h>
44 #include <net/tcp.h>
45 #include <net/tcp_states.h>
46 #include <linux/uaccess.h>
47 #include <linux/highmem.h>
48 #include <asm/ioctls.h>
49
50 #include <linux/sunrpc/types.h>
51 #include <linux/sunrpc/clnt.h>
52 #include <linux/sunrpc/xdr.h>
53 #include <linux/sunrpc/msg_prot.h>
54 #include <linux/sunrpc/svcsock.h>
55 #include <linux/sunrpc/stats.h>
56 #include <linux/sunrpc/xprt.h>
57
58 #include <trace/events/sunrpc.h>
59
60 #include "socklib.h"
61 #include "sunrpc.h"
62
63 #define RPCDBG_FACILITY RPCDBG_SVCXPRT
64
65
66 static struct svc_sock *svc_setup_socket(struct svc_serv *, struct socket *,
67 int flags);
68 static int svc_udp_recvfrom(struct svc_rqst *);
69 static int svc_udp_sendto(struct svc_rqst *);
70 static void svc_sock_detach(struct svc_xprt *);
71 static void svc_tcp_sock_detach(struct svc_xprt *);
72 static void svc_sock_free(struct svc_xprt *);
73
74 static struct svc_xprt *svc_create_socket(struct svc_serv *, int,
75 struct net *, struct sockaddr *,
76 int, int);
77 #ifdef CONFIG_DEBUG_LOCK_ALLOC
78 static struct lock_class_key svc_key[2];
79 static struct lock_class_key svc_slock_key[2];
80
svc_reclassify_socket(struct socket * sock)81 static void svc_reclassify_socket(struct socket *sock)
82 {
83 struct sock *sk = sock->sk;
84
85 if (WARN_ON_ONCE(!sock_allow_reclassification(sk)))
86 return;
87
88 switch (sk->sk_family) {
89 case AF_INET:
90 sock_lock_init_class_and_name(sk, "slock-AF_INET-NFSD",
91 &svc_slock_key[0],
92 "sk_xprt.xpt_lock-AF_INET-NFSD",
93 &svc_key[0]);
94 break;
95
96 case AF_INET6:
97 sock_lock_init_class_and_name(sk, "slock-AF_INET6-NFSD",
98 &svc_slock_key[1],
99 "sk_xprt.xpt_lock-AF_INET6-NFSD",
100 &svc_key[1]);
101 break;
102
103 default:
104 BUG();
105 }
106 }
107 #else
svc_reclassify_socket(struct socket * sock)108 static void svc_reclassify_socket(struct socket *sock)
109 {
110 }
111 #endif
112
113 /**
114 * svc_tcp_release_rqst - Release transport-related resources
115 * @rqstp: request structure with resources to be released
116 *
117 */
svc_tcp_release_rqst(struct svc_rqst * rqstp)118 static void svc_tcp_release_rqst(struct svc_rqst *rqstp)
119 {
120 struct sk_buff *skb = rqstp->rq_xprt_ctxt;
121
122 if (skb) {
123 struct svc_sock *svsk =
124 container_of(rqstp->rq_xprt, struct svc_sock, sk_xprt);
125
126 rqstp->rq_xprt_ctxt = NULL;
127 skb_free_datagram_locked(svsk->sk_sk, skb);
128 }
129 }
130
131 /**
132 * svc_udp_release_rqst - Release transport-related resources
133 * @rqstp: request structure with resources to be released
134 *
135 */
svc_udp_release_rqst(struct svc_rqst * rqstp)136 static void svc_udp_release_rqst(struct svc_rqst *rqstp)
137 {
138 struct sk_buff *skb = rqstp->rq_xprt_ctxt;
139
140 if (skb) {
141 rqstp->rq_xprt_ctxt = NULL;
142 consume_skb(skb);
143 }
144 }
145
146 union svc_pktinfo_u {
147 struct in_pktinfo pkti;
148 struct in6_pktinfo pkti6;
149 };
150 #define SVC_PKTINFO_SPACE \
151 CMSG_SPACE(sizeof(union svc_pktinfo_u))
152
svc_set_cmsg_data(struct svc_rqst * rqstp,struct cmsghdr * cmh)153 static void svc_set_cmsg_data(struct svc_rqst *rqstp, struct cmsghdr *cmh)
154 {
155 struct svc_sock *svsk =
156 container_of(rqstp->rq_xprt, struct svc_sock, sk_xprt);
157 switch (svsk->sk_sk->sk_family) {
158 case AF_INET: {
159 struct in_pktinfo *pki = CMSG_DATA(cmh);
160
161 cmh->cmsg_level = SOL_IP;
162 cmh->cmsg_type = IP_PKTINFO;
163 pki->ipi_ifindex = 0;
164 pki->ipi_spec_dst.s_addr =
165 svc_daddr_in(rqstp)->sin_addr.s_addr;
166 cmh->cmsg_len = CMSG_LEN(sizeof(*pki));
167 }
168 break;
169
170 case AF_INET6: {
171 struct in6_pktinfo *pki = CMSG_DATA(cmh);
172 struct sockaddr_in6 *daddr = svc_daddr_in6(rqstp);
173
174 cmh->cmsg_level = SOL_IPV6;
175 cmh->cmsg_type = IPV6_PKTINFO;
176 pki->ipi6_ifindex = daddr->sin6_scope_id;
177 pki->ipi6_addr = daddr->sin6_addr;
178 cmh->cmsg_len = CMSG_LEN(sizeof(*pki));
179 }
180 break;
181 }
182 }
183
svc_sock_read_payload(struct svc_rqst * rqstp,unsigned int offset,unsigned int length)184 static int svc_sock_read_payload(struct svc_rqst *rqstp, unsigned int offset,
185 unsigned int length)
186 {
187 return 0;
188 }
189
190 /*
191 * Report socket names for nfsdfs
192 */
svc_one_sock_name(struct svc_sock * svsk,char * buf,int remaining)193 static int svc_one_sock_name(struct svc_sock *svsk, char *buf, int remaining)
194 {
195 const struct sock *sk = svsk->sk_sk;
196 const char *proto_name = sk->sk_protocol == IPPROTO_UDP ?
197 "udp" : "tcp";
198 int len;
199
200 switch (sk->sk_family) {
201 case PF_INET:
202 len = snprintf(buf, remaining, "ipv4 %s %pI4 %d\n",
203 proto_name,
204 &inet_sk(sk)->inet_rcv_saddr,
205 inet_sk(sk)->inet_num);
206 break;
207 #if IS_ENABLED(CONFIG_IPV6)
208 case PF_INET6:
209 len = snprintf(buf, remaining, "ipv6 %s %pI6 %d\n",
210 proto_name,
211 &sk->sk_v6_rcv_saddr,
212 inet_sk(sk)->inet_num);
213 break;
214 #endif
215 default:
216 len = snprintf(buf, remaining, "*unknown-%d*\n",
217 sk->sk_family);
218 }
219
220 if (len >= remaining) {
221 *buf = '\0';
222 return -ENAMETOOLONG;
223 }
224 return len;
225 }
226
227 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
svc_flush_bvec(const struct bio_vec * bvec,size_t size,size_t seek)228 static void svc_flush_bvec(const struct bio_vec *bvec, size_t size, size_t seek)
229 {
230 struct bvec_iter bi = {
231 .bi_size = size + seek,
232 };
233 struct bio_vec bv;
234
235 bvec_iter_advance(bvec, &bi, seek & PAGE_MASK);
236 for_each_bvec(bv, bvec, bi, bi)
237 flush_dcache_page(bv.bv_page);
238 }
239 #else
svc_flush_bvec(const struct bio_vec * bvec,size_t size,size_t seek)240 static inline void svc_flush_bvec(const struct bio_vec *bvec, size_t size,
241 size_t seek)
242 {
243 }
244 #endif
245
246 /*
247 * Read from @rqstp's transport socket. The incoming message fills whole
248 * pages in @rqstp's rq_pages array until the last page of the message
249 * has been received into a partial page.
250 */
svc_tcp_read_msg(struct svc_rqst * rqstp,size_t buflen,size_t seek)251 static ssize_t svc_tcp_read_msg(struct svc_rqst *rqstp, size_t buflen,
252 size_t seek)
253 {
254 struct svc_sock *svsk =
255 container_of(rqstp->rq_xprt, struct svc_sock, sk_xprt);
256 struct bio_vec *bvec = rqstp->rq_bvec;
257 struct msghdr msg = { NULL };
258 unsigned int i;
259 ssize_t len;
260 size_t t;
261
262 rqstp->rq_xprt_hlen = 0;
263
264 clear_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
265
266 for (i = 0, t = 0; t < buflen; i++, t += PAGE_SIZE) {
267 bvec[i].bv_page = rqstp->rq_pages[i];
268 bvec[i].bv_len = PAGE_SIZE;
269 bvec[i].bv_offset = 0;
270 }
271 rqstp->rq_respages = &rqstp->rq_pages[i];
272 rqstp->rq_next_page = rqstp->rq_respages + 1;
273
274 iov_iter_bvec(&msg.msg_iter, READ, bvec, i, buflen);
275 if (seek) {
276 iov_iter_advance(&msg.msg_iter, seek);
277 buflen -= seek;
278 }
279 len = sock_recvmsg(svsk->sk_sock, &msg, MSG_DONTWAIT);
280 if (len > 0)
281 svc_flush_bvec(bvec, len, seek);
282
283 /* If we read a full record, then assume there may be more
284 * data to read (stream based sockets only!)
285 */
286 if (len == buflen)
287 set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
288
289 return len;
290 }
291
292 /*
293 * Set socket snd and rcv buffer lengths
294 */
svc_sock_setbufsize(struct svc_sock * svsk,unsigned int nreqs)295 static void svc_sock_setbufsize(struct svc_sock *svsk, unsigned int nreqs)
296 {
297 unsigned int max_mesg = svsk->sk_xprt.xpt_server->sv_max_mesg;
298 struct socket *sock = svsk->sk_sock;
299
300 nreqs = min(nreqs, INT_MAX / 2 / max_mesg);
301
302 lock_sock(sock->sk);
303 sock->sk->sk_sndbuf = nreqs * max_mesg * 2;
304 sock->sk->sk_rcvbuf = nreqs * max_mesg * 2;
305 sock->sk->sk_write_space(sock->sk);
306 release_sock(sock->sk);
307 }
308
svc_sock_secure_port(struct svc_rqst * rqstp)309 static void svc_sock_secure_port(struct svc_rqst *rqstp)
310 {
311 if (svc_port_is_privileged(svc_addr(rqstp)))
312 set_bit(RQ_SECURE, &rqstp->rq_flags);
313 else
314 clear_bit(RQ_SECURE, &rqstp->rq_flags);
315 }
316
317 /*
318 * INET callback when data has been received on the socket.
319 */
svc_data_ready(struct sock * sk)320 static void svc_data_ready(struct sock *sk)
321 {
322 struct svc_sock *svsk = (struct svc_sock *)sk->sk_user_data;
323
324 if (svsk) {
325 /* Refer to svc_setup_socket() for details. */
326 rmb();
327 svsk->sk_odata(sk);
328 trace_svcsock_data_ready(&svsk->sk_xprt, 0);
329 if (!test_and_set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags))
330 svc_xprt_enqueue(&svsk->sk_xprt);
331 }
332 }
333
334 /*
335 * INET callback when space is newly available on the socket.
336 */
svc_write_space(struct sock * sk)337 static void svc_write_space(struct sock *sk)
338 {
339 struct svc_sock *svsk = (struct svc_sock *)(sk->sk_user_data);
340
341 if (svsk) {
342 /* Refer to svc_setup_socket() for details. */
343 rmb();
344 trace_svcsock_write_space(&svsk->sk_xprt, 0);
345 svsk->sk_owspace(sk);
346 svc_xprt_enqueue(&svsk->sk_xprt);
347 }
348 }
349
svc_tcp_has_wspace(struct svc_xprt * xprt)350 static int svc_tcp_has_wspace(struct svc_xprt *xprt)
351 {
352 struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt);
353
354 if (test_bit(XPT_LISTENER, &xprt->xpt_flags))
355 return 1;
356 return !test_bit(SOCK_NOSPACE, &svsk->sk_sock->flags);
357 }
358
svc_tcp_kill_temp_xprt(struct svc_xprt * xprt)359 static void svc_tcp_kill_temp_xprt(struct svc_xprt *xprt)
360 {
361 struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt);
362
363 sock_no_linger(svsk->sk_sock->sk);
364 }
365
366 /*
367 * See net/ipv6/ip_sockglue.c : ip_cmsg_recv_pktinfo
368 */
svc_udp_get_dest_address4(struct svc_rqst * rqstp,struct cmsghdr * cmh)369 static int svc_udp_get_dest_address4(struct svc_rqst *rqstp,
370 struct cmsghdr *cmh)
371 {
372 struct in_pktinfo *pki = CMSG_DATA(cmh);
373 struct sockaddr_in *daddr = svc_daddr_in(rqstp);
374
375 if (cmh->cmsg_type != IP_PKTINFO)
376 return 0;
377
378 daddr->sin_family = AF_INET;
379 daddr->sin_addr.s_addr = pki->ipi_spec_dst.s_addr;
380 return 1;
381 }
382
383 /*
384 * See net/ipv6/datagram.c : ip6_datagram_recv_ctl
385 */
svc_udp_get_dest_address6(struct svc_rqst * rqstp,struct cmsghdr * cmh)386 static int svc_udp_get_dest_address6(struct svc_rqst *rqstp,
387 struct cmsghdr *cmh)
388 {
389 struct in6_pktinfo *pki = CMSG_DATA(cmh);
390 struct sockaddr_in6 *daddr = svc_daddr_in6(rqstp);
391
392 if (cmh->cmsg_type != IPV6_PKTINFO)
393 return 0;
394
395 daddr->sin6_family = AF_INET6;
396 daddr->sin6_addr = pki->ipi6_addr;
397 daddr->sin6_scope_id = pki->ipi6_ifindex;
398 return 1;
399 }
400
401 /*
402 * Copy the UDP datagram's destination address to the rqstp structure.
403 * The 'destination' address in this case is the address to which the
404 * peer sent the datagram, i.e. our local address. For multihomed
405 * hosts, this can change from msg to msg. Note that only the IP
406 * address changes, the port number should remain the same.
407 */
svc_udp_get_dest_address(struct svc_rqst * rqstp,struct cmsghdr * cmh)408 static int svc_udp_get_dest_address(struct svc_rqst *rqstp,
409 struct cmsghdr *cmh)
410 {
411 switch (cmh->cmsg_level) {
412 case SOL_IP:
413 return svc_udp_get_dest_address4(rqstp, cmh);
414 case SOL_IPV6:
415 return svc_udp_get_dest_address6(rqstp, cmh);
416 }
417
418 return 0;
419 }
420
421 /**
422 * svc_udp_recvfrom - Receive a datagram from a UDP socket.
423 * @rqstp: request structure into which to receive an RPC Call
424 *
425 * Called in a loop when XPT_DATA has been set.
426 *
427 * Returns:
428 * On success, the number of bytes in a received RPC Call, or
429 * %0 if a complete RPC Call message was not ready to return
430 */
svc_udp_recvfrom(struct svc_rqst * rqstp)431 static int svc_udp_recvfrom(struct svc_rqst *rqstp)
432 {
433 struct svc_sock *svsk =
434 container_of(rqstp->rq_xprt, struct svc_sock, sk_xprt);
435 struct svc_serv *serv = svsk->sk_xprt.xpt_server;
436 struct sk_buff *skb;
437 union {
438 struct cmsghdr hdr;
439 long all[SVC_PKTINFO_SPACE / sizeof(long)];
440 } buffer;
441 struct cmsghdr *cmh = &buffer.hdr;
442 struct msghdr msg = {
443 .msg_name = svc_addr(rqstp),
444 .msg_control = cmh,
445 .msg_controllen = sizeof(buffer),
446 .msg_flags = MSG_DONTWAIT,
447 };
448 size_t len;
449 int err;
450
451 if (test_and_clear_bit(XPT_CHNGBUF, &svsk->sk_xprt.xpt_flags))
452 /* udp sockets need large rcvbuf as all pending
453 * requests are still in that buffer. sndbuf must
454 * also be large enough that there is enough space
455 * for one reply per thread. We count all threads
456 * rather than threads in a particular pool, which
457 * provides an upper bound on the number of threads
458 * which will access the socket.
459 */
460 svc_sock_setbufsize(svsk, serv->sv_nrthreads + 3);
461
462 clear_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
463 err = kernel_recvmsg(svsk->sk_sock, &msg, NULL,
464 0, 0, MSG_PEEK | MSG_DONTWAIT);
465 if (err < 0)
466 goto out_recv_err;
467 skb = skb_recv_udp(svsk->sk_sk, 0, 1, &err);
468 if (!skb)
469 goto out_recv_err;
470
471 len = svc_addr_len(svc_addr(rqstp));
472 rqstp->rq_addrlen = len;
473 if (skb->tstamp == 0) {
474 skb->tstamp = ktime_get_real();
475 /* Don't enable netstamp, sunrpc doesn't
476 need that much accuracy */
477 }
478 sock_write_timestamp(svsk->sk_sk, skb->tstamp);
479 set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags); /* there may be more data... */
480
481 len = skb->len;
482 rqstp->rq_arg.len = len;
483 trace_svcsock_udp_recv(&svsk->sk_xprt, len);
484
485 rqstp->rq_prot = IPPROTO_UDP;
486
487 if (!svc_udp_get_dest_address(rqstp, cmh))
488 goto out_cmsg_err;
489 rqstp->rq_daddrlen = svc_addr_len(svc_daddr(rqstp));
490
491 if (skb_is_nonlinear(skb)) {
492 /* we have to copy */
493 local_bh_disable();
494 if (csum_partial_copy_to_xdr(&rqstp->rq_arg, skb))
495 goto out_bh_enable;
496 local_bh_enable();
497 consume_skb(skb);
498 } else {
499 /* we can use it in-place */
500 rqstp->rq_arg.head[0].iov_base = skb->data;
501 rqstp->rq_arg.head[0].iov_len = len;
502 if (skb_checksum_complete(skb))
503 goto out_free;
504 rqstp->rq_xprt_ctxt = skb;
505 }
506
507 rqstp->rq_arg.page_base = 0;
508 if (len <= rqstp->rq_arg.head[0].iov_len) {
509 rqstp->rq_arg.head[0].iov_len = len;
510 rqstp->rq_arg.page_len = 0;
511 rqstp->rq_respages = rqstp->rq_pages+1;
512 } else {
513 rqstp->rq_arg.page_len = len - rqstp->rq_arg.head[0].iov_len;
514 rqstp->rq_respages = rqstp->rq_pages + 1 +
515 DIV_ROUND_UP(rqstp->rq_arg.page_len, PAGE_SIZE);
516 }
517 rqstp->rq_next_page = rqstp->rq_respages+1;
518
519 if (serv->sv_stats)
520 serv->sv_stats->netudpcnt++;
521
522 return len;
523
524 out_recv_err:
525 if (err != -EAGAIN) {
526 /* possibly an icmp error */
527 set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
528 }
529 trace_svcsock_udp_recv_err(&svsk->sk_xprt, err);
530 return 0;
531 out_cmsg_err:
532 net_warn_ratelimited("svc: received unknown control message %d/%d; dropping RPC reply datagram\n",
533 cmh->cmsg_level, cmh->cmsg_type);
534 goto out_free;
535 out_bh_enable:
536 local_bh_enable();
537 out_free:
538 kfree_skb(skb);
539 return 0;
540 }
541
542 /**
543 * svc_udp_sendto - Send out a reply on a UDP socket
544 * @rqstp: completed svc_rqst
545 *
546 * xpt_mutex ensures @rqstp's whole message is written to the socket
547 * without interruption.
548 *
549 * Returns the number of bytes sent, or a negative errno.
550 */
svc_udp_sendto(struct svc_rqst * rqstp)551 static int svc_udp_sendto(struct svc_rqst *rqstp)
552 {
553 struct svc_xprt *xprt = rqstp->rq_xprt;
554 struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt);
555 struct xdr_buf *xdr = &rqstp->rq_res;
556 union {
557 struct cmsghdr hdr;
558 long all[SVC_PKTINFO_SPACE / sizeof(long)];
559 } buffer;
560 struct cmsghdr *cmh = &buffer.hdr;
561 struct msghdr msg = {
562 .msg_name = &rqstp->rq_addr,
563 .msg_namelen = rqstp->rq_addrlen,
564 .msg_control = cmh,
565 .msg_controllen = sizeof(buffer),
566 };
567 unsigned int sent;
568 int err;
569
570 svc_udp_release_rqst(rqstp);
571
572 svc_set_cmsg_data(rqstp, cmh);
573
574 mutex_lock(&xprt->xpt_mutex);
575
576 if (svc_xprt_is_dead(xprt))
577 goto out_notconn;
578
579 err = xprt_sock_sendmsg(svsk->sk_sock, &msg, xdr, 0, 0, &sent);
580 xdr_free_bvec(xdr);
581 if (err == -ECONNREFUSED) {
582 /* ICMP error on earlier request. */
583 err = xprt_sock_sendmsg(svsk->sk_sock, &msg, xdr, 0, 0, &sent);
584 xdr_free_bvec(xdr);
585 }
586 trace_svcsock_udp_send(xprt, err);
587
588 mutex_unlock(&xprt->xpt_mutex);
589 if (err < 0)
590 return err;
591 return sent;
592
593 out_notconn:
594 mutex_unlock(&xprt->xpt_mutex);
595 return -ENOTCONN;
596 }
597
svc_udp_has_wspace(struct svc_xprt * xprt)598 static int svc_udp_has_wspace(struct svc_xprt *xprt)
599 {
600 struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt);
601 struct svc_serv *serv = xprt->xpt_server;
602 unsigned long required;
603
604 /*
605 * Set the SOCK_NOSPACE flag before checking the available
606 * sock space.
607 */
608 set_bit(SOCK_NOSPACE, &svsk->sk_sock->flags);
609 required = atomic_read(&svsk->sk_xprt.xpt_reserved) + serv->sv_max_mesg;
610 if (required*2 > sock_wspace(svsk->sk_sk))
611 return 0;
612 clear_bit(SOCK_NOSPACE, &svsk->sk_sock->flags);
613 return 1;
614 }
615
svc_udp_accept(struct svc_xprt * xprt)616 static struct svc_xprt *svc_udp_accept(struct svc_xprt *xprt)
617 {
618 BUG();
619 return NULL;
620 }
621
svc_udp_kill_temp_xprt(struct svc_xprt * xprt)622 static void svc_udp_kill_temp_xprt(struct svc_xprt *xprt)
623 {
624 }
625
svc_udp_create(struct svc_serv * serv,struct net * net,struct sockaddr * sa,int salen,int flags)626 static struct svc_xprt *svc_udp_create(struct svc_serv *serv,
627 struct net *net,
628 struct sockaddr *sa, int salen,
629 int flags)
630 {
631 return svc_create_socket(serv, IPPROTO_UDP, net, sa, salen, flags);
632 }
633
634 static const struct svc_xprt_ops svc_udp_ops = {
635 .xpo_create = svc_udp_create,
636 .xpo_recvfrom = svc_udp_recvfrom,
637 .xpo_sendto = svc_udp_sendto,
638 .xpo_read_payload = svc_sock_read_payload,
639 .xpo_release_rqst = svc_udp_release_rqst,
640 .xpo_detach = svc_sock_detach,
641 .xpo_free = svc_sock_free,
642 .xpo_has_wspace = svc_udp_has_wspace,
643 .xpo_accept = svc_udp_accept,
644 .xpo_secure_port = svc_sock_secure_port,
645 .xpo_kill_temp_xprt = svc_udp_kill_temp_xprt,
646 };
647
648 static struct svc_xprt_class svc_udp_class = {
649 .xcl_name = "udp",
650 .xcl_owner = THIS_MODULE,
651 .xcl_ops = &svc_udp_ops,
652 .xcl_max_payload = RPCSVC_MAXPAYLOAD_UDP,
653 .xcl_ident = XPRT_TRANSPORT_UDP,
654 };
655
svc_udp_init(struct svc_sock * svsk,struct svc_serv * serv)656 static void svc_udp_init(struct svc_sock *svsk, struct svc_serv *serv)
657 {
658 svc_xprt_init(sock_net(svsk->sk_sock->sk), &svc_udp_class,
659 &svsk->sk_xprt, serv);
660 clear_bit(XPT_CACHE_AUTH, &svsk->sk_xprt.xpt_flags);
661 svsk->sk_sk->sk_data_ready = svc_data_ready;
662 svsk->sk_sk->sk_write_space = svc_write_space;
663
664 /* initialise setting must have enough space to
665 * receive and respond to one request.
666 * svc_udp_recvfrom will re-adjust if necessary
667 */
668 svc_sock_setbufsize(svsk, 3);
669
670 /* data might have come in before data_ready set up */
671 set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
672 set_bit(XPT_CHNGBUF, &svsk->sk_xprt.xpt_flags);
673
674 /* make sure we get destination address info */
675 switch (svsk->sk_sk->sk_family) {
676 case AF_INET:
677 ip_sock_set_pktinfo(svsk->sk_sock->sk);
678 break;
679 case AF_INET6:
680 ip6_sock_set_recvpktinfo(svsk->sk_sock->sk);
681 break;
682 default:
683 BUG();
684 }
685 }
686
687 /*
688 * A data_ready event on a listening socket means there's a connection
689 * pending. Do not use state_change as a substitute for it.
690 */
svc_tcp_listen_data_ready(struct sock * sk)691 static void svc_tcp_listen_data_ready(struct sock *sk)
692 {
693 struct svc_sock *svsk = (struct svc_sock *)sk->sk_user_data;
694
695 if (svsk) {
696 /* Refer to svc_setup_socket() for details. */
697 rmb();
698 svsk->sk_odata(sk);
699 }
700
701 /*
702 * This callback may called twice when a new connection
703 * is established as a child socket inherits everything
704 * from a parent LISTEN socket.
705 * 1) data_ready method of the parent socket will be called
706 * when one of child sockets become ESTABLISHED.
707 * 2) data_ready method of the child socket may be called
708 * when it receives data before the socket is accepted.
709 * In case of 2, we should ignore it silently.
710 */
711 if (sk->sk_state == TCP_LISTEN) {
712 if (svsk) {
713 set_bit(XPT_CONN, &svsk->sk_xprt.xpt_flags);
714 svc_xprt_enqueue(&svsk->sk_xprt);
715 }
716 }
717 }
718
719 /*
720 * A state change on a connected socket means it's dying or dead.
721 */
svc_tcp_state_change(struct sock * sk)722 static void svc_tcp_state_change(struct sock *sk)
723 {
724 struct svc_sock *svsk = (struct svc_sock *)sk->sk_user_data;
725
726 if (svsk) {
727 /* Refer to svc_setup_socket() for details. */
728 rmb();
729 svsk->sk_ostate(sk);
730 trace_svcsock_tcp_state(&svsk->sk_xprt, svsk->sk_sock);
731 if (sk->sk_state != TCP_ESTABLISHED) {
732 set_bit(XPT_CLOSE, &svsk->sk_xprt.xpt_flags);
733 svc_xprt_enqueue(&svsk->sk_xprt);
734 }
735 }
736 }
737
738 /*
739 * Accept a TCP connection
740 */
svc_tcp_accept(struct svc_xprt * xprt)741 static struct svc_xprt *svc_tcp_accept(struct svc_xprt *xprt)
742 {
743 struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt);
744 struct sockaddr_storage addr;
745 struct sockaddr *sin = (struct sockaddr *) &addr;
746 struct svc_serv *serv = svsk->sk_xprt.xpt_server;
747 struct socket *sock = svsk->sk_sock;
748 struct socket *newsock;
749 struct svc_sock *newsvsk;
750 int err, slen;
751
752 if (!sock)
753 return NULL;
754
755 clear_bit(XPT_CONN, &svsk->sk_xprt.xpt_flags);
756 err = kernel_accept(sock, &newsock, O_NONBLOCK);
757 if (err < 0) {
758 if (err == -ENOMEM)
759 printk(KERN_WARNING "%s: no more sockets!\n",
760 serv->sv_name);
761 else if (err != -EAGAIN)
762 net_warn_ratelimited("%s: accept failed (err %d)!\n",
763 serv->sv_name, -err);
764 trace_svcsock_accept_err(xprt, serv->sv_name, err);
765 return NULL;
766 }
767 set_bit(XPT_CONN, &svsk->sk_xprt.xpt_flags);
768
769 err = kernel_getpeername(newsock, sin);
770 if (err < 0) {
771 trace_svcsock_getpeername_err(xprt, serv->sv_name, err);
772 goto failed; /* aborted connection or whatever */
773 }
774 slen = err;
775
776 /* Reset the inherited callbacks before calling svc_setup_socket */
777 newsock->sk->sk_state_change = svsk->sk_ostate;
778 newsock->sk->sk_data_ready = svsk->sk_odata;
779 newsock->sk->sk_write_space = svsk->sk_owspace;
780
781 /* make sure that a write doesn't block forever when
782 * low on memory
783 */
784 newsock->sk->sk_sndtimeo = HZ*30;
785
786 newsvsk = svc_setup_socket(serv, newsock,
787 (SVC_SOCK_ANONYMOUS | SVC_SOCK_TEMPORARY));
788 if (IS_ERR(newsvsk))
789 goto failed;
790 svc_xprt_set_remote(&newsvsk->sk_xprt, sin, slen);
791 err = kernel_getsockname(newsock, sin);
792 slen = err;
793 if (unlikely(err < 0))
794 slen = offsetof(struct sockaddr, sa_data);
795 svc_xprt_set_local(&newsvsk->sk_xprt, sin, slen);
796
797 if (sock_is_loopback(newsock->sk))
798 set_bit(XPT_LOCAL, &newsvsk->sk_xprt.xpt_flags);
799 else
800 clear_bit(XPT_LOCAL, &newsvsk->sk_xprt.xpt_flags);
801 if (serv->sv_stats)
802 serv->sv_stats->nettcpconn++;
803
804 return &newsvsk->sk_xprt;
805
806 failed:
807 sock_release(newsock);
808 return NULL;
809 }
810
svc_tcp_restore_pages(struct svc_sock * svsk,struct svc_rqst * rqstp)811 static size_t svc_tcp_restore_pages(struct svc_sock *svsk,
812 struct svc_rqst *rqstp)
813 {
814 size_t len = svsk->sk_datalen;
815 unsigned int i, npages;
816
817 if (!len)
818 return 0;
819 npages = (len + PAGE_SIZE - 1) >> PAGE_SHIFT;
820 for (i = 0; i < npages; i++) {
821 if (rqstp->rq_pages[i] != NULL)
822 put_page(rqstp->rq_pages[i]);
823 BUG_ON(svsk->sk_pages[i] == NULL);
824 rqstp->rq_pages[i] = svsk->sk_pages[i];
825 svsk->sk_pages[i] = NULL;
826 }
827 rqstp->rq_arg.head[0].iov_base = page_address(rqstp->rq_pages[0]);
828 return len;
829 }
830
svc_tcp_save_pages(struct svc_sock * svsk,struct svc_rqst * rqstp)831 static void svc_tcp_save_pages(struct svc_sock *svsk, struct svc_rqst *rqstp)
832 {
833 unsigned int i, len, npages;
834
835 if (svsk->sk_datalen == 0)
836 return;
837 len = svsk->sk_datalen;
838 npages = (len + PAGE_SIZE - 1) >> PAGE_SHIFT;
839 for (i = 0; i < npages; i++) {
840 svsk->sk_pages[i] = rqstp->rq_pages[i];
841 rqstp->rq_pages[i] = NULL;
842 }
843 }
844
svc_tcp_clear_pages(struct svc_sock * svsk)845 static void svc_tcp_clear_pages(struct svc_sock *svsk)
846 {
847 unsigned int i, len, npages;
848
849 if (svsk->sk_datalen == 0)
850 goto out;
851 len = svsk->sk_datalen;
852 npages = (len + PAGE_SIZE - 1) >> PAGE_SHIFT;
853 for (i = 0; i < npages; i++) {
854 if (svsk->sk_pages[i] == NULL) {
855 WARN_ON_ONCE(1);
856 continue;
857 }
858 put_page(svsk->sk_pages[i]);
859 svsk->sk_pages[i] = NULL;
860 }
861 out:
862 svsk->sk_tcplen = 0;
863 svsk->sk_datalen = 0;
864 }
865
866 /*
867 * Receive fragment record header into sk_marker.
868 */
svc_tcp_read_marker(struct svc_sock * svsk,struct svc_rqst * rqstp)869 static ssize_t svc_tcp_read_marker(struct svc_sock *svsk,
870 struct svc_rqst *rqstp)
871 {
872 ssize_t want, len;
873
874 /* If we haven't gotten the record length yet,
875 * get the next four bytes.
876 */
877 if (svsk->sk_tcplen < sizeof(rpc_fraghdr)) {
878 struct msghdr msg = { NULL };
879 struct kvec iov;
880
881 want = sizeof(rpc_fraghdr) - svsk->sk_tcplen;
882 iov.iov_base = ((char *)&svsk->sk_marker) + svsk->sk_tcplen;
883 iov.iov_len = want;
884 iov_iter_kvec(&msg.msg_iter, READ, &iov, 1, want);
885 len = sock_recvmsg(svsk->sk_sock, &msg, MSG_DONTWAIT);
886 if (len < 0)
887 return len;
888 svsk->sk_tcplen += len;
889 if (len < want) {
890 /* call again to read the remaining bytes */
891 goto err_short;
892 }
893 trace_svcsock_marker(&svsk->sk_xprt, svsk->sk_marker);
894 if (svc_sock_reclen(svsk) + svsk->sk_datalen >
895 svsk->sk_xprt.xpt_server->sv_max_mesg)
896 goto err_too_large;
897 }
898 return svc_sock_reclen(svsk);
899
900 err_too_large:
901 net_notice_ratelimited("svc: %s %s RPC fragment too large: %d\n",
902 __func__, svsk->sk_xprt.xpt_server->sv_name,
903 svc_sock_reclen(svsk));
904 set_bit(XPT_CLOSE, &svsk->sk_xprt.xpt_flags);
905 err_short:
906 return -EAGAIN;
907 }
908
receive_cb_reply(struct svc_sock * svsk,struct svc_rqst * rqstp)909 static int receive_cb_reply(struct svc_sock *svsk, struct svc_rqst *rqstp)
910 {
911 struct rpc_xprt *bc_xprt = svsk->sk_xprt.xpt_bc_xprt;
912 struct rpc_rqst *req = NULL;
913 struct kvec *src, *dst;
914 __be32 *p = (__be32 *)rqstp->rq_arg.head[0].iov_base;
915 __be32 xid;
916 __be32 calldir;
917
918 xid = *p++;
919 calldir = *p;
920
921 if (!bc_xprt)
922 return -EAGAIN;
923 spin_lock(&bc_xprt->queue_lock);
924 req = xprt_lookup_rqst(bc_xprt, xid);
925 if (!req)
926 goto unlock_notfound;
927
928 memcpy(&req->rq_private_buf, &req->rq_rcv_buf, sizeof(struct xdr_buf));
929 /*
930 * XXX!: cheating for now! Only copying HEAD.
931 * But we know this is good enough for now (in fact, for any
932 * callback reply in the forseeable future).
933 */
934 dst = &req->rq_private_buf.head[0];
935 src = &rqstp->rq_arg.head[0];
936 if (dst->iov_len < src->iov_len)
937 goto unlock_eagain; /* whatever; just giving up. */
938 memcpy(dst->iov_base, src->iov_base, src->iov_len);
939 xprt_complete_rqst(req->rq_task, rqstp->rq_arg.len);
940 rqstp->rq_arg.len = 0;
941 spin_unlock(&bc_xprt->queue_lock);
942 return 0;
943 unlock_notfound:
944 printk(KERN_NOTICE
945 "%s: Got unrecognized reply: "
946 "calldir 0x%x xpt_bc_xprt %p xid %08x\n",
947 __func__, ntohl(calldir),
948 bc_xprt, ntohl(xid));
949 unlock_eagain:
950 spin_unlock(&bc_xprt->queue_lock);
951 return -EAGAIN;
952 }
953
svc_tcp_fragment_received(struct svc_sock * svsk)954 static void svc_tcp_fragment_received(struct svc_sock *svsk)
955 {
956 /* If we have more data, signal svc_xprt_enqueue() to try again */
957 svsk->sk_tcplen = 0;
958 svsk->sk_marker = xdr_zero;
959 }
960
961 /**
962 * svc_tcp_recvfrom - Receive data from a TCP socket
963 * @rqstp: request structure into which to receive an RPC Call
964 *
965 * Called in a loop when XPT_DATA has been set.
966 *
967 * Read the 4-byte stream record marker, then use the record length
968 * in that marker to set up exactly the resources needed to receive
969 * the next RPC message into @rqstp.
970 *
971 * Returns:
972 * On success, the number of bytes in a received RPC Call, or
973 * %0 if a complete RPC Call message was not ready to return
974 *
975 * The zero return case handles partial receives and callback Replies.
976 * The state of a partial receive is preserved in the svc_sock for
977 * the next call to svc_tcp_recvfrom.
978 */
svc_tcp_recvfrom(struct svc_rqst * rqstp)979 static int svc_tcp_recvfrom(struct svc_rqst *rqstp)
980 {
981 struct svc_sock *svsk =
982 container_of(rqstp->rq_xprt, struct svc_sock, sk_xprt);
983 struct svc_serv *serv = svsk->sk_xprt.xpt_server;
984 size_t want, base;
985 ssize_t len;
986 __be32 *p;
987 __be32 calldir;
988
989 clear_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
990 len = svc_tcp_read_marker(svsk, rqstp);
991 if (len < 0)
992 goto error;
993
994 base = svc_tcp_restore_pages(svsk, rqstp);
995 want = len - (svsk->sk_tcplen - sizeof(rpc_fraghdr));
996 len = svc_tcp_read_msg(rqstp, base + want, base);
997 if (len >= 0) {
998 trace_svcsock_tcp_recv(&svsk->sk_xprt, len);
999 svsk->sk_tcplen += len;
1000 svsk->sk_datalen += len;
1001 }
1002 if (len != want || !svc_sock_final_rec(svsk))
1003 goto err_incomplete;
1004 if (svsk->sk_datalen < 8)
1005 goto err_nuts;
1006
1007 rqstp->rq_arg.len = svsk->sk_datalen;
1008 rqstp->rq_arg.page_base = 0;
1009 if (rqstp->rq_arg.len <= rqstp->rq_arg.head[0].iov_len) {
1010 rqstp->rq_arg.head[0].iov_len = rqstp->rq_arg.len;
1011 rqstp->rq_arg.page_len = 0;
1012 } else
1013 rqstp->rq_arg.page_len = rqstp->rq_arg.len - rqstp->rq_arg.head[0].iov_len;
1014
1015 rqstp->rq_xprt_ctxt = NULL;
1016 rqstp->rq_prot = IPPROTO_TCP;
1017 if (test_bit(XPT_LOCAL, &svsk->sk_xprt.xpt_flags))
1018 set_bit(RQ_LOCAL, &rqstp->rq_flags);
1019 else
1020 clear_bit(RQ_LOCAL, &rqstp->rq_flags);
1021
1022 p = (__be32 *)rqstp->rq_arg.head[0].iov_base;
1023 calldir = p[1];
1024 if (calldir)
1025 len = receive_cb_reply(svsk, rqstp);
1026
1027 /* Reset TCP read info */
1028 svsk->sk_datalen = 0;
1029 svc_tcp_fragment_received(svsk);
1030
1031 if (len < 0)
1032 goto error;
1033
1034 svc_xprt_copy_addrs(rqstp, &svsk->sk_xprt);
1035 if (serv->sv_stats)
1036 serv->sv_stats->nettcpcnt++;
1037
1038 return rqstp->rq_arg.len;
1039
1040 err_incomplete:
1041 svc_tcp_save_pages(svsk, rqstp);
1042 if (len < 0 && len != -EAGAIN)
1043 goto err_delete;
1044 if (len == want)
1045 svc_tcp_fragment_received(svsk);
1046 else
1047 trace_svcsock_tcp_recv_short(&svsk->sk_xprt,
1048 svc_sock_reclen(svsk),
1049 svsk->sk_tcplen - sizeof(rpc_fraghdr));
1050 goto err_noclose;
1051 error:
1052 if (len != -EAGAIN)
1053 goto err_delete;
1054 trace_svcsock_tcp_recv_eagain(&svsk->sk_xprt, 0);
1055 return 0;
1056 err_nuts:
1057 svsk->sk_datalen = 0;
1058 err_delete:
1059 trace_svcsock_tcp_recv_err(&svsk->sk_xprt, len);
1060 set_bit(XPT_CLOSE, &svsk->sk_xprt.xpt_flags);
1061 err_noclose:
1062 return 0; /* record not complete */
1063 }
1064
svc_tcp_send_kvec(struct socket * sock,const struct kvec * vec,int flags)1065 static int svc_tcp_send_kvec(struct socket *sock, const struct kvec *vec,
1066 int flags)
1067 {
1068 return kernel_sendpage(sock, virt_to_page(vec->iov_base),
1069 offset_in_page(vec->iov_base),
1070 vec->iov_len, flags);
1071 }
1072
1073 /*
1074 * kernel_sendpage() is used exclusively to reduce the number of
1075 * copy operations in this path. Therefore the caller must ensure
1076 * that the pages backing @xdr are unchanging.
1077 *
1078 * In addition, the logic assumes that * .bv_len is never larger
1079 * than PAGE_SIZE.
1080 */
svc_tcp_sendmsg(struct socket * sock,struct msghdr * msg,struct xdr_buf * xdr,rpc_fraghdr marker,unsigned int * sentp)1081 static int svc_tcp_sendmsg(struct socket *sock, struct msghdr *msg,
1082 struct xdr_buf *xdr, rpc_fraghdr marker,
1083 unsigned int *sentp)
1084 {
1085 const struct kvec *head = xdr->head;
1086 const struct kvec *tail = xdr->tail;
1087 struct kvec rm = {
1088 .iov_base = &marker,
1089 .iov_len = sizeof(marker),
1090 };
1091 int flags, ret;
1092
1093 *sentp = 0;
1094 xdr_alloc_bvec(xdr, GFP_KERNEL);
1095
1096 msg->msg_flags = MSG_MORE;
1097 ret = kernel_sendmsg(sock, msg, &rm, 1, rm.iov_len);
1098 if (ret < 0)
1099 return ret;
1100 *sentp += ret;
1101 if (ret != rm.iov_len)
1102 return -EAGAIN;
1103
1104 flags = head->iov_len < xdr->len ? MSG_MORE | MSG_SENDPAGE_NOTLAST : 0;
1105 ret = svc_tcp_send_kvec(sock, head, flags);
1106 if (ret < 0)
1107 return ret;
1108 *sentp += ret;
1109 if (ret != head->iov_len)
1110 goto out;
1111
1112 if (xdr->page_len) {
1113 unsigned int offset, len, remaining;
1114 struct bio_vec *bvec;
1115
1116 bvec = xdr->bvec + (xdr->page_base >> PAGE_SHIFT);
1117 offset = offset_in_page(xdr->page_base);
1118 remaining = xdr->page_len;
1119 flags = MSG_MORE | MSG_SENDPAGE_NOTLAST;
1120 while (remaining > 0) {
1121 if (remaining <= PAGE_SIZE && tail->iov_len == 0)
1122 flags = 0;
1123
1124 len = min(remaining, bvec->bv_len - offset);
1125 ret = kernel_sendpage(sock, bvec->bv_page,
1126 bvec->bv_offset + offset,
1127 len, flags);
1128 if (ret < 0)
1129 return ret;
1130 *sentp += ret;
1131 if (ret != len)
1132 goto out;
1133 remaining -= len;
1134 offset = 0;
1135 bvec++;
1136 }
1137 }
1138
1139 if (tail->iov_len) {
1140 ret = svc_tcp_send_kvec(sock, tail, 0);
1141 if (ret < 0)
1142 return ret;
1143 *sentp += ret;
1144 }
1145
1146 out:
1147 return 0;
1148 }
1149
1150 /**
1151 * svc_tcp_sendto - Send out a reply on a TCP socket
1152 * @rqstp: completed svc_rqst
1153 *
1154 * xpt_mutex ensures @rqstp's whole message is written to the socket
1155 * without interruption.
1156 *
1157 * Returns the number of bytes sent, or a negative errno.
1158 */
svc_tcp_sendto(struct svc_rqst * rqstp)1159 static int svc_tcp_sendto(struct svc_rqst *rqstp)
1160 {
1161 struct svc_xprt *xprt = rqstp->rq_xprt;
1162 struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt);
1163 struct xdr_buf *xdr = &rqstp->rq_res;
1164 rpc_fraghdr marker = cpu_to_be32(RPC_LAST_STREAM_FRAGMENT |
1165 (u32)xdr->len);
1166 struct msghdr msg = {
1167 .msg_flags = 0,
1168 };
1169 unsigned int sent;
1170 int err;
1171
1172 svc_tcp_release_rqst(rqstp);
1173
1174 mutex_lock(&xprt->xpt_mutex);
1175 if (svc_xprt_is_dead(xprt))
1176 goto out_notconn;
1177 err = svc_tcp_sendmsg(svsk->sk_sock, &msg, xdr, marker, &sent);
1178 xdr_free_bvec(xdr);
1179 trace_svcsock_tcp_send(xprt, err < 0 ? (long)err : sent);
1180 if (err < 0 || sent != (xdr->len + sizeof(marker)))
1181 goto out_close;
1182 mutex_unlock(&xprt->xpt_mutex);
1183 return sent;
1184
1185 out_notconn:
1186 mutex_unlock(&xprt->xpt_mutex);
1187 return -ENOTCONN;
1188 out_close:
1189 pr_notice("rpc-srv/tcp: %s: %s %d when sending %d bytes - shutting down socket\n",
1190 xprt->xpt_server->sv_name,
1191 (err < 0) ? "got error" : "sent",
1192 (err < 0) ? err : sent, xdr->len);
1193 set_bit(XPT_CLOSE, &xprt->xpt_flags);
1194 svc_xprt_enqueue(xprt);
1195 mutex_unlock(&xprt->xpt_mutex);
1196 return -EAGAIN;
1197 }
1198
svc_tcp_create(struct svc_serv * serv,struct net * net,struct sockaddr * sa,int salen,int flags)1199 static struct svc_xprt *svc_tcp_create(struct svc_serv *serv,
1200 struct net *net,
1201 struct sockaddr *sa, int salen,
1202 int flags)
1203 {
1204 return svc_create_socket(serv, IPPROTO_TCP, net, sa, salen, flags);
1205 }
1206
1207 static const struct svc_xprt_ops svc_tcp_ops = {
1208 .xpo_create = svc_tcp_create,
1209 .xpo_recvfrom = svc_tcp_recvfrom,
1210 .xpo_sendto = svc_tcp_sendto,
1211 .xpo_read_payload = svc_sock_read_payload,
1212 .xpo_release_rqst = svc_tcp_release_rqst,
1213 .xpo_detach = svc_tcp_sock_detach,
1214 .xpo_free = svc_sock_free,
1215 .xpo_has_wspace = svc_tcp_has_wspace,
1216 .xpo_accept = svc_tcp_accept,
1217 .xpo_secure_port = svc_sock_secure_port,
1218 .xpo_kill_temp_xprt = svc_tcp_kill_temp_xprt,
1219 };
1220
1221 static struct svc_xprt_class svc_tcp_class = {
1222 .xcl_name = "tcp",
1223 .xcl_owner = THIS_MODULE,
1224 .xcl_ops = &svc_tcp_ops,
1225 .xcl_max_payload = RPCSVC_MAXPAYLOAD_TCP,
1226 .xcl_ident = XPRT_TRANSPORT_TCP,
1227 };
1228
svc_init_xprt_sock(void)1229 void svc_init_xprt_sock(void)
1230 {
1231 svc_reg_xprt_class(&svc_tcp_class);
1232 svc_reg_xprt_class(&svc_udp_class);
1233 }
1234
svc_cleanup_xprt_sock(void)1235 void svc_cleanup_xprt_sock(void)
1236 {
1237 svc_unreg_xprt_class(&svc_tcp_class);
1238 svc_unreg_xprt_class(&svc_udp_class);
1239 }
1240
svc_tcp_init(struct svc_sock * svsk,struct svc_serv * serv)1241 static void svc_tcp_init(struct svc_sock *svsk, struct svc_serv *serv)
1242 {
1243 struct sock *sk = svsk->sk_sk;
1244
1245 svc_xprt_init(sock_net(svsk->sk_sock->sk), &svc_tcp_class,
1246 &svsk->sk_xprt, serv);
1247 set_bit(XPT_CACHE_AUTH, &svsk->sk_xprt.xpt_flags);
1248 set_bit(XPT_CONG_CTRL, &svsk->sk_xprt.xpt_flags);
1249 if (sk->sk_state == TCP_LISTEN) {
1250 strcpy(svsk->sk_xprt.xpt_remotebuf, "listener");
1251 set_bit(XPT_LISTENER, &svsk->sk_xprt.xpt_flags);
1252 sk->sk_data_ready = svc_tcp_listen_data_ready;
1253 set_bit(XPT_CONN, &svsk->sk_xprt.xpt_flags);
1254 } else {
1255 sk->sk_state_change = svc_tcp_state_change;
1256 sk->sk_data_ready = svc_data_ready;
1257 sk->sk_write_space = svc_write_space;
1258
1259 svsk->sk_marker = xdr_zero;
1260 svsk->sk_tcplen = 0;
1261 svsk->sk_datalen = 0;
1262 memset(&svsk->sk_pages[0], 0, sizeof(svsk->sk_pages));
1263
1264 tcp_sk(sk)->nonagle |= TCP_NAGLE_OFF;
1265
1266 set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
1267 switch (sk->sk_state) {
1268 case TCP_SYN_RECV:
1269 case TCP_ESTABLISHED:
1270 break;
1271 default:
1272 set_bit(XPT_CLOSE, &svsk->sk_xprt.xpt_flags);
1273 }
1274 }
1275 }
1276
svc_sock_update_bufs(struct svc_serv * serv)1277 void svc_sock_update_bufs(struct svc_serv *serv)
1278 {
1279 /*
1280 * The number of server threads has changed. Update
1281 * rcvbuf and sndbuf accordingly on all sockets
1282 */
1283 struct svc_sock *svsk;
1284
1285 spin_lock_bh(&serv->sv_lock);
1286 list_for_each_entry(svsk, &serv->sv_permsocks, sk_xprt.xpt_list)
1287 set_bit(XPT_CHNGBUF, &svsk->sk_xprt.xpt_flags);
1288 spin_unlock_bh(&serv->sv_lock);
1289 }
1290 EXPORT_SYMBOL_GPL(svc_sock_update_bufs);
1291
1292 /*
1293 * Initialize socket for RPC use and create svc_sock struct
1294 */
svc_setup_socket(struct svc_serv * serv,struct socket * sock,int flags)1295 static struct svc_sock *svc_setup_socket(struct svc_serv *serv,
1296 struct socket *sock,
1297 int flags)
1298 {
1299 struct svc_sock *svsk;
1300 struct sock *inet;
1301 int pmap_register = !(flags & SVC_SOCK_ANONYMOUS);
1302 int err = 0;
1303
1304 svsk = kzalloc(sizeof(*svsk), GFP_KERNEL);
1305 if (!svsk)
1306 return ERR_PTR(-ENOMEM);
1307
1308 inet = sock->sk;
1309
1310 /* Register socket with portmapper */
1311 if (pmap_register)
1312 err = svc_register(serv, sock_net(sock->sk), inet->sk_family,
1313 inet->sk_protocol,
1314 ntohs(inet_sk(inet)->inet_sport));
1315
1316 if (err < 0) {
1317 kfree(svsk);
1318 return ERR_PTR(err);
1319 }
1320
1321 svsk->sk_sock = sock;
1322 svsk->sk_sk = inet;
1323 svsk->sk_ostate = inet->sk_state_change;
1324 svsk->sk_odata = inet->sk_data_ready;
1325 svsk->sk_owspace = inet->sk_write_space;
1326 /*
1327 * This barrier is necessary in order to prevent race condition
1328 * with svc_data_ready(), svc_listen_data_ready() and others
1329 * when calling callbacks above.
1330 */
1331 wmb();
1332 inet->sk_user_data = svsk;
1333
1334 /* Initialize the socket */
1335 if (sock->type == SOCK_DGRAM)
1336 svc_udp_init(svsk, serv);
1337 else
1338 svc_tcp_init(svsk, serv);
1339
1340 trace_svcsock_new_socket(sock);
1341 return svsk;
1342 }
1343
svc_alien_sock(struct net * net,int fd)1344 bool svc_alien_sock(struct net *net, int fd)
1345 {
1346 int err;
1347 struct socket *sock = sockfd_lookup(fd, &err);
1348 bool ret = false;
1349
1350 if (!sock)
1351 goto out;
1352 if (sock_net(sock->sk) != net)
1353 ret = true;
1354 sockfd_put(sock);
1355 out:
1356 return ret;
1357 }
1358 EXPORT_SYMBOL_GPL(svc_alien_sock);
1359
1360 /**
1361 * svc_addsock - add a listener socket to an RPC service
1362 * @serv: pointer to RPC service to which to add a new listener
1363 * @fd: file descriptor of the new listener
1364 * @name_return: pointer to buffer to fill in with name of listener
1365 * @len: size of the buffer
1366 * @cred: credential
1367 *
1368 * Fills in socket name and returns positive length of name if successful.
1369 * Name is terminated with '\n'. On error, returns a negative errno
1370 * value.
1371 */
svc_addsock(struct svc_serv * serv,const int fd,char * name_return,const size_t len,const struct cred * cred)1372 int svc_addsock(struct svc_serv *serv, const int fd, char *name_return,
1373 const size_t len, const struct cred *cred)
1374 {
1375 int err = 0;
1376 struct socket *so = sockfd_lookup(fd, &err);
1377 struct svc_sock *svsk = NULL;
1378 struct sockaddr_storage addr;
1379 struct sockaddr *sin = (struct sockaddr *)&addr;
1380 int salen;
1381
1382 if (!so)
1383 return err;
1384 err = -EAFNOSUPPORT;
1385 if ((so->sk->sk_family != PF_INET) && (so->sk->sk_family != PF_INET6))
1386 goto out;
1387 err = -EPROTONOSUPPORT;
1388 if (so->sk->sk_protocol != IPPROTO_TCP &&
1389 so->sk->sk_protocol != IPPROTO_UDP)
1390 goto out;
1391 err = -EISCONN;
1392 if (so->state > SS_UNCONNECTED)
1393 goto out;
1394 err = -ENOENT;
1395 if (!try_module_get(THIS_MODULE))
1396 goto out;
1397 svsk = svc_setup_socket(serv, so, SVC_SOCK_DEFAULTS);
1398 if (IS_ERR(svsk)) {
1399 module_put(THIS_MODULE);
1400 err = PTR_ERR(svsk);
1401 goto out;
1402 }
1403 salen = kernel_getsockname(svsk->sk_sock, sin);
1404 if (salen >= 0)
1405 svc_xprt_set_local(&svsk->sk_xprt, sin, salen);
1406 svsk->sk_xprt.xpt_cred = get_cred(cred);
1407 svc_add_new_perm_xprt(serv, &svsk->sk_xprt);
1408 return svc_one_sock_name(svsk, name_return, len);
1409 out:
1410 sockfd_put(so);
1411 return err;
1412 }
1413 EXPORT_SYMBOL_GPL(svc_addsock);
1414
1415 /*
1416 * Create socket for RPC service.
1417 */
svc_create_socket(struct svc_serv * serv,int protocol,struct net * net,struct sockaddr * sin,int len,int flags)1418 static struct svc_xprt *svc_create_socket(struct svc_serv *serv,
1419 int protocol,
1420 struct net *net,
1421 struct sockaddr *sin, int len,
1422 int flags)
1423 {
1424 struct svc_sock *svsk;
1425 struct socket *sock;
1426 int error;
1427 int type;
1428 struct sockaddr_storage addr;
1429 struct sockaddr *newsin = (struct sockaddr *)&addr;
1430 int newlen;
1431 int family;
1432
1433 if (protocol != IPPROTO_UDP && protocol != IPPROTO_TCP) {
1434 printk(KERN_WARNING "svc: only UDP and TCP "
1435 "sockets supported\n");
1436 return ERR_PTR(-EINVAL);
1437 }
1438
1439 type = (protocol == IPPROTO_UDP)? SOCK_DGRAM : SOCK_STREAM;
1440 switch (sin->sa_family) {
1441 case AF_INET6:
1442 family = PF_INET6;
1443 break;
1444 case AF_INET:
1445 family = PF_INET;
1446 break;
1447 default:
1448 return ERR_PTR(-EINVAL);
1449 }
1450
1451 error = __sock_create(net, family, type, protocol, &sock, 1);
1452 if (error < 0)
1453 return ERR_PTR(error);
1454
1455 svc_reclassify_socket(sock);
1456
1457 /*
1458 * If this is an PF_INET6 listener, we want to avoid
1459 * getting requests from IPv4 remotes. Those should
1460 * be shunted to a PF_INET listener via rpcbind.
1461 */
1462 if (family == PF_INET6)
1463 ip6_sock_set_v6only(sock->sk);
1464 if (type == SOCK_STREAM)
1465 sock->sk->sk_reuse = SK_CAN_REUSE; /* allow address reuse */
1466 error = kernel_bind(sock, sin, len);
1467 if (error < 0)
1468 goto bummer;
1469
1470 error = kernel_getsockname(sock, newsin);
1471 if (error < 0)
1472 goto bummer;
1473 newlen = error;
1474
1475 if (protocol == IPPROTO_TCP) {
1476 if ((error = kernel_listen(sock, 64)) < 0)
1477 goto bummer;
1478 }
1479
1480 svsk = svc_setup_socket(serv, sock, flags);
1481 if (IS_ERR(svsk)) {
1482 error = PTR_ERR(svsk);
1483 goto bummer;
1484 }
1485 svc_xprt_set_local(&svsk->sk_xprt, newsin, newlen);
1486 return (struct svc_xprt *)svsk;
1487 bummer:
1488 sock_release(sock);
1489 return ERR_PTR(error);
1490 }
1491
1492 /*
1493 * Detach the svc_sock from the socket so that no
1494 * more callbacks occur.
1495 */
svc_sock_detach(struct svc_xprt * xprt)1496 static void svc_sock_detach(struct svc_xprt *xprt)
1497 {
1498 struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt);
1499 struct sock *sk = svsk->sk_sk;
1500
1501 /* put back the old socket callbacks */
1502 lock_sock(sk);
1503 sk->sk_state_change = svsk->sk_ostate;
1504 sk->sk_data_ready = svsk->sk_odata;
1505 sk->sk_write_space = svsk->sk_owspace;
1506 sk->sk_user_data = NULL;
1507 release_sock(sk);
1508 }
1509
1510 /*
1511 * Disconnect the socket, and reset the callbacks
1512 */
svc_tcp_sock_detach(struct svc_xprt * xprt)1513 static void svc_tcp_sock_detach(struct svc_xprt *xprt)
1514 {
1515 struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt);
1516
1517 svc_sock_detach(xprt);
1518
1519 if (!test_bit(XPT_LISTENER, &xprt->xpt_flags)) {
1520 svc_tcp_clear_pages(svsk);
1521 kernel_sock_shutdown(svsk->sk_sock, SHUT_RDWR);
1522 }
1523 }
1524
1525 /*
1526 * Free the svc_sock's socket resources and the svc_sock itself.
1527 */
svc_sock_free(struct svc_xprt * xprt)1528 static void svc_sock_free(struct svc_xprt *xprt)
1529 {
1530 struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt);
1531
1532 if (svsk->sk_sock->file)
1533 sockfd_put(svsk->sk_sock);
1534 else
1535 sock_release(svsk->sk_sock);
1536 kfree(svsk);
1537 }
1538