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 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 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 */ 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 */ 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)) 152 153 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 } 183 184 static int svc_sock_result_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 */ 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 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 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 */ 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 */ 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 } 308 309 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 */ 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 */ 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 } 349 350 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 } 358 359 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 */ 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 */ 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 */ 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 */ 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 svc_xprt_received(rqstp->rq_xprt); 523 return len; 524 525 out_recv_err: 526 if (err != -EAGAIN) { 527 /* possibly an icmp error */ 528 set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags); 529 } 530 trace_svcsock_udp_recv_err(&svsk->sk_xprt, err); 531 goto out_clear_busy; 532 out_cmsg_err: 533 net_warn_ratelimited("svc: received unknown control message %d/%d; dropping RPC reply datagram\n", 534 cmh->cmsg_level, cmh->cmsg_type); 535 goto out_free; 536 out_bh_enable: 537 local_bh_enable(); 538 out_free: 539 kfree_skb(skb); 540 out_clear_busy: 541 svc_xprt_received(rqstp->rq_xprt); 542 return 0; 543 } 544 545 /** 546 * svc_udp_sendto - Send out a reply on a UDP socket 547 * @rqstp: completed svc_rqst 548 * 549 * xpt_mutex ensures @rqstp's whole message is written to the socket 550 * without interruption. 551 * 552 * Returns the number of bytes sent, or a negative errno. 553 */ 554 static int svc_udp_sendto(struct svc_rqst *rqstp) 555 { 556 struct svc_xprt *xprt = rqstp->rq_xprt; 557 struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt); 558 struct xdr_buf *xdr = &rqstp->rq_res; 559 union { 560 struct cmsghdr hdr; 561 long all[SVC_PKTINFO_SPACE / sizeof(long)]; 562 } buffer; 563 struct cmsghdr *cmh = &buffer.hdr; 564 struct msghdr msg = { 565 .msg_name = &rqstp->rq_addr, 566 .msg_namelen = rqstp->rq_addrlen, 567 .msg_control = cmh, 568 .msg_controllen = sizeof(buffer), 569 }; 570 unsigned int sent; 571 int err; 572 573 svc_udp_release_rqst(rqstp); 574 575 svc_set_cmsg_data(rqstp, cmh); 576 577 mutex_lock(&xprt->xpt_mutex); 578 579 if (svc_xprt_is_dead(xprt)) 580 goto out_notconn; 581 582 err = xdr_alloc_bvec(xdr, GFP_KERNEL); 583 if (err < 0) 584 goto out_unlock; 585 586 err = xprt_sock_sendmsg(svsk->sk_sock, &msg, xdr, 0, 0, &sent); 587 if (err == -ECONNREFUSED) { 588 /* ICMP error on earlier request. */ 589 err = xprt_sock_sendmsg(svsk->sk_sock, &msg, xdr, 0, 0, &sent); 590 } 591 xdr_free_bvec(xdr); 592 trace_svcsock_udp_send(xprt, err); 593 out_unlock: 594 mutex_unlock(&xprt->xpt_mutex); 595 if (err < 0) 596 return err; 597 return sent; 598 599 out_notconn: 600 mutex_unlock(&xprt->xpt_mutex); 601 return -ENOTCONN; 602 } 603 604 static int svc_udp_has_wspace(struct svc_xprt *xprt) 605 { 606 struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt); 607 struct svc_serv *serv = xprt->xpt_server; 608 unsigned long required; 609 610 /* 611 * Set the SOCK_NOSPACE flag before checking the available 612 * sock space. 613 */ 614 set_bit(SOCK_NOSPACE, &svsk->sk_sock->flags); 615 required = atomic_read(&svsk->sk_xprt.xpt_reserved) + serv->sv_max_mesg; 616 if (required*2 > sock_wspace(svsk->sk_sk)) 617 return 0; 618 clear_bit(SOCK_NOSPACE, &svsk->sk_sock->flags); 619 return 1; 620 } 621 622 static struct svc_xprt *svc_udp_accept(struct svc_xprt *xprt) 623 { 624 BUG(); 625 return NULL; 626 } 627 628 static void svc_udp_kill_temp_xprt(struct svc_xprt *xprt) 629 { 630 } 631 632 static struct svc_xprt *svc_udp_create(struct svc_serv *serv, 633 struct net *net, 634 struct sockaddr *sa, int salen, 635 int flags) 636 { 637 return svc_create_socket(serv, IPPROTO_UDP, net, sa, salen, flags); 638 } 639 640 static const struct svc_xprt_ops svc_udp_ops = { 641 .xpo_create = svc_udp_create, 642 .xpo_recvfrom = svc_udp_recvfrom, 643 .xpo_sendto = svc_udp_sendto, 644 .xpo_result_payload = svc_sock_result_payload, 645 .xpo_release_rqst = svc_udp_release_rqst, 646 .xpo_detach = svc_sock_detach, 647 .xpo_free = svc_sock_free, 648 .xpo_has_wspace = svc_udp_has_wspace, 649 .xpo_accept = svc_udp_accept, 650 .xpo_secure_port = svc_sock_secure_port, 651 .xpo_kill_temp_xprt = svc_udp_kill_temp_xprt, 652 }; 653 654 static struct svc_xprt_class svc_udp_class = { 655 .xcl_name = "udp", 656 .xcl_owner = THIS_MODULE, 657 .xcl_ops = &svc_udp_ops, 658 .xcl_max_payload = RPCSVC_MAXPAYLOAD_UDP, 659 .xcl_ident = XPRT_TRANSPORT_UDP, 660 }; 661 662 static void svc_udp_init(struct svc_sock *svsk, struct svc_serv *serv) 663 { 664 svc_xprt_init(sock_net(svsk->sk_sock->sk), &svc_udp_class, 665 &svsk->sk_xprt, serv); 666 clear_bit(XPT_CACHE_AUTH, &svsk->sk_xprt.xpt_flags); 667 svsk->sk_sk->sk_data_ready = svc_data_ready; 668 svsk->sk_sk->sk_write_space = svc_write_space; 669 670 /* initialise setting must have enough space to 671 * receive and respond to one request. 672 * svc_udp_recvfrom will re-adjust if necessary 673 */ 674 svc_sock_setbufsize(svsk, 3); 675 676 /* data might have come in before data_ready set up */ 677 set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags); 678 set_bit(XPT_CHNGBUF, &svsk->sk_xprt.xpt_flags); 679 680 /* make sure we get destination address info */ 681 switch (svsk->sk_sk->sk_family) { 682 case AF_INET: 683 ip_sock_set_pktinfo(svsk->sk_sock->sk); 684 break; 685 case AF_INET6: 686 ip6_sock_set_recvpktinfo(svsk->sk_sock->sk); 687 break; 688 default: 689 BUG(); 690 } 691 } 692 693 /* 694 * A data_ready event on a listening socket means there's a connection 695 * pending. Do not use state_change as a substitute for it. 696 */ 697 static void svc_tcp_listen_data_ready(struct sock *sk) 698 { 699 struct svc_sock *svsk = (struct svc_sock *)sk->sk_user_data; 700 701 if (svsk) { 702 /* Refer to svc_setup_socket() for details. */ 703 rmb(); 704 svsk->sk_odata(sk); 705 } 706 707 /* 708 * This callback may called twice when a new connection 709 * is established as a child socket inherits everything 710 * from a parent LISTEN socket. 711 * 1) data_ready method of the parent socket will be called 712 * when one of child sockets become ESTABLISHED. 713 * 2) data_ready method of the child socket may be called 714 * when it receives data before the socket is accepted. 715 * In case of 2, we should ignore it silently. 716 */ 717 if (sk->sk_state == TCP_LISTEN) { 718 if (svsk) { 719 set_bit(XPT_CONN, &svsk->sk_xprt.xpt_flags); 720 svc_xprt_enqueue(&svsk->sk_xprt); 721 } 722 } 723 } 724 725 /* 726 * A state change on a connected socket means it's dying or dead. 727 */ 728 static void svc_tcp_state_change(struct sock *sk) 729 { 730 struct svc_sock *svsk = (struct svc_sock *)sk->sk_user_data; 731 732 if (svsk) { 733 /* Refer to svc_setup_socket() for details. */ 734 rmb(); 735 svsk->sk_ostate(sk); 736 trace_svcsock_tcp_state(&svsk->sk_xprt, svsk->sk_sock); 737 if (sk->sk_state != TCP_ESTABLISHED) 738 svc_xprt_deferred_close(&svsk->sk_xprt); 739 } 740 } 741 742 /* 743 * Accept a TCP connection 744 */ 745 static struct svc_xprt *svc_tcp_accept(struct svc_xprt *xprt) 746 { 747 struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt); 748 struct sockaddr_storage addr; 749 struct sockaddr *sin = (struct sockaddr *) &addr; 750 struct svc_serv *serv = svsk->sk_xprt.xpt_server; 751 struct socket *sock = svsk->sk_sock; 752 struct socket *newsock; 753 struct svc_sock *newsvsk; 754 int err, slen; 755 756 if (!sock) 757 return NULL; 758 759 clear_bit(XPT_CONN, &svsk->sk_xprt.xpt_flags); 760 err = kernel_accept(sock, &newsock, O_NONBLOCK); 761 if (err < 0) { 762 if (err == -ENOMEM) 763 printk(KERN_WARNING "%s: no more sockets!\n", 764 serv->sv_name); 765 else if (err != -EAGAIN) 766 net_warn_ratelimited("%s: accept failed (err %d)!\n", 767 serv->sv_name, -err); 768 trace_svcsock_accept_err(xprt, serv->sv_name, err); 769 return NULL; 770 } 771 set_bit(XPT_CONN, &svsk->sk_xprt.xpt_flags); 772 773 err = kernel_getpeername(newsock, sin); 774 if (err < 0) { 775 trace_svcsock_getpeername_err(xprt, serv->sv_name, err); 776 goto failed; /* aborted connection or whatever */ 777 } 778 slen = err; 779 780 /* Reset the inherited callbacks before calling svc_setup_socket */ 781 newsock->sk->sk_state_change = svsk->sk_ostate; 782 newsock->sk->sk_data_ready = svsk->sk_odata; 783 newsock->sk->sk_write_space = svsk->sk_owspace; 784 785 /* make sure that a write doesn't block forever when 786 * low on memory 787 */ 788 newsock->sk->sk_sndtimeo = HZ*30; 789 790 newsvsk = svc_setup_socket(serv, newsock, 791 (SVC_SOCK_ANONYMOUS | SVC_SOCK_TEMPORARY)); 792 if (IS_ERR(newsvsk)) 793 goto failed; 794 svc_xprt_set_remote(&newsvsk->sk_xprt, sin, slen); 795 err = kernel_getsockname(newsock, sin); 796 slen = err; 797 if (unlikely(err < 0)) 798 slen = offsetof(struct sockaddr, sa_data); 799 svc_xprt_set_local(&newsvsk->sk_xprt, sin, slen); 800 801 if (sock_is_loopback(newsock->sk)) 802 set_bit(XPT_LOCAL, &newsvsk->sk_xprt.xpt_flags); 803 else 804 clear_bit(XPT_LOCAL, &newsvsk->sk_xprt.xpt_flags); 805 if (serv->sv_stats) 806 serv->sv_stats->nettcpconn++; 807 808 return &newsvsk->sk_xprt; 809 810 failed: 811 sock_release(newsock); 812 return NULL; 813 } 814 815 static size_t svc_tcp_restore_pages(struct svc_sock *svsk, 816 struct svc_rqst *rqstp) 817 { 818 size_t len = svsk->sk_datalen; 819 unsigned int i, npages; 820 821 if (!len) 822 return 0; 823 npages = (len + PAGE_SIZE - 1) >> PAGE_SHIFT; 824 for (i = 0; i < npages; i++) { 825 if (rqstp->rq_pages[i] != NULL) 826 put_page(rqstp->rq_pages[i]); 827 BUG_ON(svsk->sk_pages[i] == NULL); 828 rqstp->rq_pages[i] = svsk->sk_pages[i]; 829 svsk->sk_pages[i] = NULL; 830 } 831 rqstp->rq_arg.head[0].iov_base = page_address(rqstp->rq_pages[0]); 832 return len; 833 } 834 835 static void svc_tcp_save_pages(struct svc_sock *svsk, struct svc_rqst *rqstp) 836 { 837 unsigned int i, len, npages; 838 839 if (svsk->sk_datalen == 0) 840 return; 841 len = svsk->sk_datalen; 842 npages = (len + PAGE_SIZE - 1) >> PAGE_SHIFT; 843 for (i = 0; i < npages; i++) { 844 svsk->sk_pages[i] = rqstp->rq_pages[i]; 845 rqstp->rq_pages[i] = NULL; 846 } 847 } 848 849 static void svc_tcp_clear_pages(struct svc_sock *svsk) 850 { 851 unsigned int i, len, npages; 852 853 if (svsk->sk_datalen == 0) 854 goto out; 855 len = svsk->sk_datalen; 856 npages = (len + PAGE_SIZE - 1) >> PAGE_SHIFT; 857 for (i = 0; i < npages; i++) { 858 if (svsk->sk_pages[i] == NULL) { 859 WARN_ON_ONCE(1); 860 continue; 861 } 862 put_page(svsk->sk_pages[i]); 863 svsk->sk_pages[i] = NULL; 864 } 865 out: 866 svsk->sk_tcplen = 0; 867 svsk->sk_datalen = 0; 868 } 869 870 /* 871 * Receive fragment record header into sk_marker. 872 */ 873 static ssize_t svc_tcp_read_marker(struct svc_sock *svsk, 874 struct svc_rqst *rqstp) 875 { 876 ssize_t want, len; 877 878 /* If we haven't gotten the record length yet, 879 * get the next four bytes. 880 */ 881 if (svsk->sk_tcplen < sizeof(rpc_fraghdr)) { 882 struct msghdr msg = { NULL }; 883 struct kvec iov; 884 885 want = sizeof(rpc_fraghdr) - svsk->sk_tcplen; 886 iov.iov_base = ((char *)&svsk->sk_marker) + svsk->sk_tcplen; 887 iov.iov_len = want; 888 iov_iter_kvec(&msg.msg_iter, READ, &iov, 1, want); 889 len = sock_recvmsg(svsk->sk_sock, &msg, MSG_DONTWAIT); 890 if (len < 0) 891 return len; 892 svsk->sk_tcplen += len; 893 if (len < want) { 894 /* call again to read the remaining bytes */ 895 goto err_short; 896 } 897 trace_svcsock_marker(&svsk->sk_xprt, svsk->sk_marker); 898 if (svc_sock_reclen(svsk) + svsk->sk_datalen > 899 svsk->sk_xprt.xpt_server->sv_max_mesg) 900 goto err_too_large; 901 } 902 return svc_sock_reclen(svsk); 903 904 err_too_large: 905 net_notice_ratelimited("svc: %s %s RPC fragment too large: %d\n", 906 __func__, svsk->sk_xprt.xpt_server->sv_name, 907 svc_sock_reclen(svsk)); 908 svc_xprt_deferred_close(&svsk->sk_xprt); 909 err_short: 910 return -EAGAIN; 911 } 912 913 static int receive_cb_reply(struct svc_sock *svsk, struct svc_rqst *rqstp) 914 { 915 struct rpc_xprt *bc_xprt = svsk->sk_xprt.xpt_bc_xprt; 916 struct rpc_rqst *req = NULL; 917 struct kvec *src, *dst; 918 __be32 *p = (__be32 *)rqstp->rq_arg.head[0].iov_base; 919 __be32 xid; 920 __be32 calldir; 921 922 xid = *p++; 923 calldir = *p; 924 925 if (!bc_xprt) 926 return -EAGAIN; 927 spin_lock(&bc_xprt->queue_lock); 928 req = xprt_lookup_rqst(bc_xprt, xid); 929 if (!req) 930 goto unlock_notfound; 931 932 memcpy(&req->rq_private_buf, &req->rq_rcv_buf, sizeof(struct xdr_buf)); 933 /* 934 * XXX!: cheating for now! Only copying HEAD. 935 * But we know this is good enough for now (in fact, for any 936 * callback reply in the forseeable future). 937 */ 938 dst = &req->rq_private_buf.head[0]; 939 src = &rqstp->rq_arg.head[0]; 940 if (dst->iov_len < src->iov_len) 941 goto unlock_eagain; /* whatever; just giving up. */ 942 memcpy(dst->iov_base, src->iov_base, src->iov_len); 943 xprt_complete_rqst(req->rq_task, rqstp->rq_arg.len); 944 rqstp->rq_arg.len = 0; 945 spin_unlock(&bc_xprt->queue_lock); 946 return 0; 947 unlock_notfound: 948 printk(KERN_NOTICE 949 "%s: Got unrecognized reply: " 950 "calldir 0x%x xpt_bc_xprt %p xid %08x\n", 951 __func__, ntohl(calldir), 952 bc_xprt, ntohl(xid)); 953 unlock_eagain: 954 spin_unlock(&bc_xprt->queue_lock); 955 return -EAGAIN; 956 } 957 958 static void svc_tcp_fragment_received(struct svc_sock *svsk) 959 { 960 /* If we have more data, signal svc_xprt_enqueue() to try again */ 961 svsk->sk_tcplen = 0; 962 svsk->sk_marker = xdr_zero; 963 } 964 965 /** 966 * svc_tcp_recvfrom - Receive data from a TCP socket 967 * @rqstp: request structure into which to receive an RPC Call 968 * 969 * Called in a loop when XPT_DATA has been set. 970 * 971 * Read the 4-byte stream record marker, then use the record length 972 * in that marker to set up exactly the resources needed to receive 973 * the next RPC message into @rqstp. 974 * 975 * Returns: 976 * On success, the number of bytes in a received RPC Call, or 977 * %0 if a complete RPC Call message was not ready to return 978 * 979 * The zero return case handles partial receives and callback Replies. 980 * The state of a partial receive is preserved in the svc_sock for 981 * the next call to svc_tcp_recvfrom. 982 */ 983 static int svc_tcp_recvfrom(struct svc_rqst *rqstp) 984 { 985 struct svc_sock *svsk = 986 container_of(rqstp->rq_xprt, struct svc_sock, sk_xprt); 987 struct svc_serv *serv = svsk->sk_xprt.xpt_server; 988 size_t want, base; 989 ssize_t len; 990 __be32 *p; 991 __be32 calldir; 992 993 clear_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags); 994 len = svc_tcp_read_marker(svsk, rqstp); 995 if (len < 0) 996 goto error; 997 998 base = svc_tcp_restore_pages(svsk, rqstp); 999 want = len - (svsk->sk_tcplen - sizeof(rpc_fraghdr)); 1000 len = svc_tcp_read_msg(rqstp, base + want, base); 1001 if (len >= 0) { 1002 trace_svcsock_tcp_recv(&svsk->sk_xprt, len); 1003 svsk->sk_tcplen += len; 1004 svsk->sk_datalen += len; 1005 } 1006 if (len != want || !svc_sock_final_rec(svsk)) 1007 goto err_incomplete; 1008 if (svsk->sk_datalen < 8) 1009 goto err_nuts; 1010 1011 rqstp->rq_arg.len = svsk->sk_datalen; 1012 rqstp->rq_arg.page_base = 0; 1013 if (rqstp->rq_arg.len <= rqstp->rq_arg.head[0].iov_len) { 1014 rqstp->rq_arg.head[0].iov_len = rqstp->rq_arg.len; 1015 rqstp->rq_arg.page_len = 0; 1016 } else 1017 rqstp->rq_arg.page_len = rqstp->rq_arg.len - rqstp->rq_arg.head[0].iov_len; 1018 1019 rqstp->rq_xprt_ctxt = NULL; 1020 rqstp->rq_prot = IPPROTO_TCP; 1021 if (test_bit(XPT_LOCAL, &svsk->sk_xprt.xpt_flags)) 1022 set_bit(RQ_LOCAL, &rqstp->rq_flags); 1023 else 1024 clear_bit(RQ_LOCAL, &rqstp->rq_flags); 1025 1026 p = (__be32 *)rqstp->rq_arg.head[0].iov_base; 1027 calldir = p[1]; 1028 if (calldir) 1029 len = receive_cb_reply(svsk, rqstp); 1030 1031 /* Reset TCP read info */ 1032 svsk->sk_datalen = 0; 1033 svc_tcp_fragment_received(svsk); 1034 1035 if (len < 0) 1036 goto error; 1037 1038 svc_xprt_copy_addrs(rqstp, &svsk->sk_xprt); 1039 if (serv->sv_stats) 1040 serv->sv_stats->nettcpcnt++; 1041 1042 svc_xprt_received(rqstp->rq_xprt); 1043 return rqstp->rq_arg.len; 1044 1045 err_incomplete: 1046 svc_tcp_save_pages(svsk, rqstp); 1047 if (len < 0 && len != -EAGAIN) 1048 goto err_delete; 1049 if (len == want) 1050 svc_tcp_fragment_received(svsk); 1051 else 1052 trace_svcsock_tcp_recv_short(&svsk->sk_xprt, 1053 svc_sock_reclen(svsk), 1054 svsk->sk_tcplen - sizeof(rpc_fraghdr)); 1055 goto err_noclose; 1056 error: 1057 if (len != -EAGAIN) 1058 goto err_delete; 1059 trace_svcsock_tcp_recv_eagain(&svsk->sk_xprt, 0); 1060 goto err_noclose; 1061 err_nuts: 1062 svsk->sk_datalen = 0; 1063 err_delete: 1064 trace_svcsock_tcp_recv_err(&svsk->sk_xprt, len); 1065 svc_xprt_deferred_close(&svsk->sk_xprt); 1066 err_noclose: 1067 svc_xprt_received(rqstp->rq_xprt); 1068 return 0; /* record not complete */ 1069 } 1070 1071 static int svc_tcp_send_kvec(struct socket *sock, const struct kvec *vec, 1072 int flags) 1073 { 1074 return kernel_sendpage(sock, virt_to_page(vec->iov_base), 1075 offset_in_page(vec->iov_base), 1076 vec->iov_len, flags); 1077 } 1078 1079 /* 1080 * kernel_sendpage() is used exclusively to reduce the number of 1081 * copy operations in this path. Therefore the caller must ensure 1082 * that the pages backing @xdr are unchanging. 1083 * 1084 * In addition, the logic assumes that * .bv_len is never larger 1085 * than PAGE_SIZE. 1086 */ 1087 static int svc_tcp_sendmsg(struct socket *sock, struct xdr_buf *xdr, 1088 rpc_fraghdr marker, unsigned int *sentp) 1089 { 1090 const struct kvec *head = xdr->head; 1091 const struct kvec *tail = xdr->tail; 1092 struct kvec rm = { 1093 .iov_base = &marker, 1094 .iov_len = sizeof(marker), 1095 }; 1096 struct msghdr msg = { 1097 .msg_flags = 0, 1098 }; 1099 int ret; 1100 1101 *sentp = 0; 1102 ret = xdr_alloc_bvec(xdr, GFP_KERNEL); 1103 if (ret < 0) 1104 return ret; 1105 1106 ret = kernel_sendmsg(sock, &msg, &rm, 1, rm.iov_len); 1107 if (ret < 0) 1108 return ret; 1109 *sentp += ret; 1110 if (ret != rm.iov_len) 1111 return -EAGAIN; 1112 1113 ret = svc_tcp_send_kvec(sock, head, 0); 1114 if (ret < 0) 1115 return ret; 1116 *sentp += ret; 1117 if (ret != head->iov_len) 1118 goto out; 1119 1120 if (xdr->page_len) { 1121 unsigned int offset, len, remaining; 1122 struct bio_vec *bvec; 1123 1124 bvec = xdr->bvec + (xdr->page_base >> PAGE_SHIFT); 1125 offset = offset_in_page(xdr->page_base); 1126 remaining = xdr->page_len; 1127 while (remaining > 0) { 1128 len = min(remaining, bvec->bv_len - offset); 1129 ret = kernel_sendpage(sock, bvec->bv_page, 1130 bvec->bv_offset + offset, 1131 len, 0); 1132 if (ret < 0) 1133 return ret; 1134 *sentp += ret; 1135 if (ret != len) 1136 goto out; 1137 remaining -= len; 1138 offset = 0; 1139 bvec++; 1140 } 1141 } 1142 1143 if (tail->iov_len) { 1144 ret = svc_tcp_send_kvec(sock, tail, 0); 1145 if (ret < 0) 1146 return ret; 1147 *sentp += ret; 1148 } 1149 1150 out: 1151 return 0; 1152 } 1153 1154 /** 1155 * svc_tcp_sendto - Send out a reply on a TCP socket 1156 * @rqstp: completed svc_rqst 1157 * 1158 * xpt_mutex ensures @rqstp's whole message is written to the socket 1159 * without interruption. 1160 * 1161 * Returns the number of bytes sent, or a negative errno. 1162 */ 1163 static int svc_tcp_sendto(struct svc_rqst *rqstp) 1164 { 1165 struct svc_xprt *xprt = rqstp->rq_xprt; 1166 struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt); 1167 struct xdr_buf *xdr = &rqstp->rq_res; 1168 rpc_fraghdr marker = cpu_to_be32(RPC_LAST_STREAM_FRAGMENT | 1169 (u32)xdr->len); 1170 unsigned int sent; 1171 int err; 1172 1173 svc_tcp_release_rqst(rqstp); 1174 1175 atomic_inc(&svsk->sk_sendqlen); 1176 mutex_lock(&xprt->xpt_mutex); 1177 if (svc_xprt_is_dead(xprt)) 1178 goto out_notconn; 1179 tcp_sock_set_cork(svsk->sk_sk, true); 1180 err = svc_tcp_sendmsg(svsk->sk_sock, xdr, marker, &sent); 1181 xdr_free_bvec(xdr); 1182 trace_svcsock_tcp_send(xprt, err < 0 ? (long)err : sent); 1183 if (err < 0 || sent != (xdr->len + sizeof(marker))) 1184 goto out_close; 1185 if (atomic_dec_and_test(&svsk->sk_sendqlen)) 1186 tcp_sock_set_cork(svsk->sk_sk, false); 1187 mutex_unlock(&xprt->xpt_mutex); 1188 return sent; 1189 1190 out_notconn: 1191 atomic_dec(&svsk->sk_sendqlen); 1192 mutex_unlock(&xprt->xpt_mutex); 1193 return -ENOTCONN; 1194 out_close: 1195 pr_notice("rpc-srv/tcp: %s: %s %d when sending %d bytes - shutting down socket\n", 1196 xprt->xpt_server->sv_name, 1197 (err < 0) ? "got error" : "sent", 1198 (err < 0) ? err : sent, xdr->len); 1199 svc_xprt_deferred_close(xprt); 1200 atomic_dec(&svsk->sk_sendqlen); 1201 mutex_unlock(&xprt->xpt_mutex); 1202 return -EAGAIN; 1203 } 1204 1205 static struct svc_xprt *svc_tcp_create(struct svc_serv *serv, 1206 struct net *net, 1207 struct sockaddr *sa, int salen, 1208 int flags) 1209 { 1210 return svc_create_socket(serv, IPPROTO_TCP, net, sa, salen, flags); 1211 } 1212 1213 static const struct svc_xprt_ops svc_tcp_ops = { 1214 .xpo_create = svc_tcp_create, 1215 .xpo_recvfrom = svc_tcp_recvfrom, 1216 .xpo_sendto = svc_tcp_sendto, 1217 .xpo_result_payload = svc_sock_result_payload, 1218 .xpo_release_rqst = svc_tcp_release_rqst, 1219 .xpo_detach = svc_tcp_sock_detach, 1220 .xpo_free = svc_sock_free, 1221 .xpo_has_wspace = svc_tcp_has_wspace, 1222 .xpo_accept = svc_tcp_accept, 1223 .xpo_secure_port = svc_sock_secure_port, 1224 .xpo_kill_temp_xprt = svc_tcp_kill_temp_xprt, 1225 }; 1226 1227 static struct svc_xprt_class svc_tcp_class = { 1228 .xcl_name = "tcp", 1229 .xcl_owner = THIS_MODULE, 1230 .xcl_ops = &svc_tcp_ops, 1231 .xcl_max_payload = RPCSVC_MAXPAYLOAD_TCP, 1232 .xcl_ident = XPRT_TRANSPORT_TCP, 1233 }; 1234 1235 void svc_init_xprt_sock(void) 1236 { 1237 svc_reg_xprt_class(&svc_tcp_class); 1238 svc_reg_xprt_class(&svc_udp_class); 1239 } 1240 1241 void svc_cleanup_xprt_sock(void) 1242 { 1243 svc_unreg_xprt_class(&svc_tcp_class); 1244 svc_unreg_xprt_class(&svc_udp_class); 1245 } 1246 1247 static void svc_tcp_init(struct svc_sock *svsk, struct svc_serv *serv) 1248 { 1249 struct sock *sk = svsk->sk_sk; 1250 1251 svc_xprt_init(sock_net(svsk->sk_sock->sk), &svc_tcp_class, 1252 &svsk->sk_xprt, serv); 1253 set_bit(XPT_CACHE_AUTH, &svsk->sk_xprt.xpt_flags); 1254 set_bit(XPT_CONG_CTRL, &svsk->sk_xprt.xpt_flags); 1255 if (sk->sk_state == TCP_LISTEN) { 1256 strcpy(svsk->sk_xprt.xpt_remotebuf, "listener"); 1257 set_bit(XPT_LISTENER, &svsk->sk_xprt.xpt_flags); 1258 sk->sk_data_ready = svc_tcp_listen_data_ready; 1259 set_bit(XPT_CONN, &svsk->sk_xprt.xpt_flags); 1260 } else { 1261 sk->sk_state_change = svc_tcp_state_change; 1262 sk->sk_data_ready = svc_data_ready; 1263 sk->sk_write_space = svc_write_space; 1264 1265 svsk->sk_marker = xdr_zero; 1266 svsk->sk_tcplen = 0; 1267 svsk->sk_datalen = 0; 1268 memset(&svsk->sk_pages[0], 0, sizeof(svsk->sk_pages)); 1269 1270 tcp_sock_set_nodelay(sk); 1271 1272 set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags); 1273 switch (sk->sk_state) { 1274 case TCP_SYN_RECV: 1275 case TCP_ESTABLISHED: 1276 break; 1277 default: 1278 svc_xprt_deferred_close(&svsk->sk_xprt); 1279 } 1280 } 1281 } 1282 1283 void svc_sock_update_bufs(struct svc_serv *serv) 1284 { 1285 /* 1286 * The number of server threads has changed. Update 1287 * rcvbuf and sndbuf accordingly on all sockets 1288 */ 1289 struct svc_sock *svsk; 1290 1291 spin_lock_bh(&serv->sv_lock); 1292 list_for_each_entry(svsk, &serv->sv_permsocks, sk_xprt.xpt_list) 1293 set_bit(XPT_CHNGBUF, &svsk->sk_xprt.xpt_flags); 1294 spin_unlock_bh(&serv->sv_lock); 1295 } 1296 EXPORT_SYMBOL_GPL(svc_sock_update_bufs); 1297 1298 /* 1299 * Initialize socket for RPC use and create svc_sock struct 1300 */ 1301 static struct svc_sock *svc_setup_socket(struct svc_serv *serv, 1302 struct socket *sock, 1303 int flags) 1304 { 1305 struct svc_sock *svsk; 1306 struct sock *inet; 1307 int pmap_register = !(flags & SVC_SOCK_ANONYMOUS); 1308 int err = 0; 1309 1310 svsk = kzalloc(sizeof(*svsk), GFP_KERNEL); 1311 if (!svsk) 1312 return ERR_PTR(-ENOMEM); 1313 1314 inet = sock->sk; 1315 1316 /* Register socket with portmapper */ 1317 if (pmap_register) 1318 err = svc_register(serv, sock_net(sock->sk), inet->sk_family, 1319 inet->sk_protocol, 1320 ntohs(inet_sk(inet)->inet_sport)); 1321 1322 if (err < 0) { 1323 kfree(svsk); 1324 return ERR_PTR(err); 1325 } 1326 1327 svsk->sk_sock = sock; 1328 svsk->sk_sk = inet; 1329 svsk->sk_ostate = inet->sk_state_change; 1330 svsk->sk_odata = inet->sk_data_ready; 1331 svsk->sk_owspace = inet->sk_write_space; 1332 /* 1333 * This barrier is necessary in order to prevent race condition 1334 * with svc_data_ready(), svc_listen_data_ready() and others 1335 * when calling callbacks above. 1336 */ 1337 wmb(); 1338 inet->sk_user_data = svsk; 1339 1340 /* Initialize the socket */ 1341 if (sock->type == SOCK_DGRAM) 1342 svc_udp_init(svsk, serv); 1343 else 1344 svc_tcp_init(svsk, serv); 1345 1346 trace_svcsock_new_socket(sock); 1347 return svsk; 1348 } 1349 1350 bool svc_alien_sock(struct net *net, int fd) 1351 { 1352 int err; 1353 struct socket *sock = sockfd_lookup(fd, &err); 1354 bool ret = false; 1355 1356 if (!sock) 1357 goto out; 1358 if (sock_net(sock->sk) != net) 1359 ret = true; 1360 sockfd_put(sock); 1361 out: 1362 return ret; 1363 } 1364 EXPORT_SYMBOL_GPL(svc_alien_sock); 1365 1366 /** 1367 * svc_addsock - add a listener socket to an RPC service 1368 * @serv: pointer to RPC service to which to add a new listener 1369 * @fd: file descriptor of the new listener 1370 * @name_return: pointer to buffer to fill in with name of listener 1371 * @len: size of the buffer 1372 * @cred: credential 1373 * 1374 * Fills in socket name and returns positive length of name if successful. 1375 * Name is terminated with '\n'. On error, returns a negative errno 1376 * value. 1377 */ 1378 int svc_addsock(struct svc_serv *serv, const int fd, char *name_return, 1379 const size_t len, const struct cred *cred) 1380 { 1381 int err = 0; 1382 struct socket *so = sockfd_lookup(fd, &err); 1383 struct svc_sock *svsk = NULL; 1384 struct sockaddr_storage addr; 1385 struct sockaddr *sin = (struct sockaddr *)&addr; 1386 int salen; 1387 1388 if (!so) 1389 return err; 1390 err = -EAFNOSUPPORT; 1391 if ((so->sk->sk_family != PF_INET) && (so->sk->sk_family != PF_INET6)) 1392 goto out; 1393 err = -EPROTONOSUPPORT; 1394 if (so->sk->sk_protocol != IPPROTO_TCP && 1395 so->sk->sk_protocol != IPPROTO_UDP) 1396 goto out; 1397 err = -EISCONN; 1398 if (so->state > SS_UNCONNECTED) 1399 goto out; 1400 err = -ENOENT; 1401 if (!try_module_get(THIS_MODULE)) 1402 goto out; 1403 svsk = svc_setup_socket(serv, so, SVC_SOCK_DEFAULTS); 1404 if (IS_ERR(svsk)) { 1405 module_put(THIS_MODULE); 1406 err = PTR_ERR(svsk); 1407 goto out; 1408 } 1409 salen = kernel_getsockname(svsk->sk_sock, sin); 1410 if (salen >= 0) 1411 svc_xprt_set_local(&svsk->sk_xprt, sin, salen); 1412 svsk->sk_xprt.xpt_cred = get_cred(cred); 1413 svc_add_new_perm_xprt(serv, &svsk->sk_xprt); 1414 return svc_one_sock_name(svsk, name_return, len); 1415 out: 1416 sockfd_put(so); 1417 return err; 1418 } 1419 EXPORT_SYMBOL_GPL(svc_addsock); 1420 1421 /* 1422 * Create socket for RPC service. 1423 */ 1424 static struct svc_xprt *svc_create_socket(struct svc_serv *serv, 1425 int protocol, 1426 struct net *net, 1427 struct sockaddr *sin, int len, 1428 int flags) 1429 { 1430 struct svc_sock *svsk; 1431 struct socket *sock; 1432 int error; 1433 int type; 1434 struct sockaddr_storage addr; 1435 struct sockaddr *newsin = (struct sockaddr *)&addr; 1436 int newlen; 1437 int family; 1438 1439 if (protocol != IPPROTO_UDP && protocol != IPPROTO_TCP) { 1440 printk(KERN_WARNING "svc: only UDP and TCP " 1441 "sockets supported\n"); 1442 return ERR_PTR(-EINVAL); 1443 } 1444 1445 type = (protocol == IPPROTO_UDP)? SOCK_DGRAM : SOCK_STREAM; 1446 switch (sin->sa_family) { 1447 case AF_INET6: 1448 family = PF_INET6; 1449 break; 1450 case AF_INET: 1451 family = PF_INET; 1452 break; 1453 default: 1454 return ERR_PTR(-EINVAL); 1455 } 1456 1457 error = __sock_create(net, family, type, protocol, &sock, 1); 1458 if (error < 0) 1459 return ERR_PTR(error); 1460 1461 svc_reclassify_socket(sock); 1462 1463 /* 1464 * If this is an PF_INET6 listener, we want to avoid 1465 * getting requests from IPv4 remotes. Those should 1466 * be shunted to a PF_INET listener via rpcbind. 1467 */ 1468 if (family == PF_INET6) 1469 ip6_sock_set_v6only(sock->sk); 1470 if (type == SOCK_STREAM) 1471 sock->sk->sk_reuse = SK_CAN_REUSE; /* allow address reuse */ 1472 error = kernel_bind(sock, sin, len); 1473 if (error < 0) 1474 goto bummer; 1475 1476 error = kernel_getsockname(sock, newsin); 1477 if (error < 0) 1478 goto bummer; 1479 newlen = error; 1480 1481 if (protocol == IPPROTO_TCP) { 1482 if ((error = kernel_listen(sock, 64)) < 0) 1483 goto bummer; 1484 } 1485 1486 svsk = svc_setup_socket(serv, sock, flags); 1487 if (IS_ERR(svsk)) { 1488 error = PTR_ERR(svsk); 1489 goto bummer; 1490 } 1491 svc_xprt_set_local(&svsk->sk_xprt, newsin, newlen); 1492 return (struct svc_xprt *)svsk; 1493 bummer: 1494 sock_release(sock); 1495 return ERR_PTR(error); 1496 } 1497 1498 /* 1499 * Detach the svc_sock from the socket so that no 1500 * more callbacks occur. 1501 */ 1502 static void svc_sock_detach(struct svc_xprt *xprt) 1503 { 1504 struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt); 1505 struct sock *sk = svsk->sk_sk; 1506 1507 /* put back the old socket callbacks */ 1508 lock_sock(sk); 1509 sk->sk_state_change = svsk->sk_ostate; 1510 sk->sk_data_ready = svsk->sk_odata; 1511 sk->sk_write_space = svsk->sk_owspace; 1512 sk->sk_user_data = NULL; 1513 release_sock(sk); 1514 } 1515 1516 /* 1517 * Disconnect the socket, and reset the callbacks 1518 */ 1519 static void svc_tcp_sock_detach(struct svc_xprt *xprt) 1520 { 1521 struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt); 1522 1523 svc_sock_detach(xprt); 1524 1525 if (!test_bit(XPT_LISTENER, &xprt->xpt_flags)) { 1526 svc_tcp_clear_pages(svsk); 1527 kernel_sock_shutdown(svsk->sk_sock, SHUT_RDWR); 1528 } 1529 } 1530 1531 /* 1532 * Free the svc_sock's socket resources and the svc_sock itself. 1533 */ 1534 static void svc_sock_free(struct svc_xprt *xprt) 1535 { 1536 struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt); 1537 1538 if (svsk->sk_sock->file) 1539 sockfd_put(svsk->sk_sock); 1540 else 1541 sock_release(svsk->sk_sock); 1542 kfree(svsk); 1543 } 1544