1 /* 2 * Copyright (c) 2006 Oracle. All rights reserved. 3 * 4 * This software is available to you under a choice of one of two 5 * licenses. You may choose to be licensed under the terms of the GNU 6 * General Public License (GPL) Version 2, available from the file 7 * COPYING in the main directory of this source tree, or the 8 * OpenIB.org BSD license below: 9 * 10 * Redistribution and use in source and binary forms, with or 11 * without modification, are permitted provided that the following 12 * conditions are met: 13 * 14 * - Redistributions of source code must retain the above 15 * copyright notice, this list of conditions and the following 16 * disclaimer. 17 * 18 * - Redistributions in binary form must reproduce the above 19 * copyright notice, this list of conditions and the following 20 * disclaimer in the documentation and/or other materials 21 * provided with the distribution. 22 * 23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 24 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 25 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 26 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS 27 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN 28 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN 29 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE 30 * SOFTWARE. 31 * 32 */ 33 #include <linux/kernel.h> 34 #include <linux/slab.h> 35 #include <net/sock.h> 36 #include <linux/in.h> 37 #include <linux/export.h> 38 #include <linux/time.h> 39 #include <linux/rds.h> 40 41 #include "rds.h" 42 43 void rds_inc_init(struct rds_incoming *inc, struct rds_connection *conn, 44 __be32 saddr) 45 { 46 atomic_set(&inc->i_refcount, 1); 47 INIT_LIST_HEAD(&inc->i_item); 48 inc->i_conn = conn; 49 inc->i_saddr = saddr; 50 inc->i_rdma_cookie = 0; 51 inc->i_rx_tstamp.tv_sec = 0; 52 inc->i_rx_tstamp.tv_usec = 0; 53 } 54 EXPORT_SYMBOL_GPL(rds_inc_init); 55 56 static void rds_inc_addref(struct rds_incoming *inc) 57 { 58 rdsdebug("addref inc %p ref %d\n", inc, atomic_read(&inc->i_refcount)); 59 atomic_inc(&inc->i_refcount); 60 } 61 62 void rds_inc_put(struct rds_incoming *inc) 63 { 64 rdsdebug("put inc %p ref %d\n", inc, atomic_read(&inc->i_refcount)); 65 if (atomic_dec_and_test(&inc->i_refcount)) { 66 BUG_ON(!list_empty(&inc->i_item)); 67 68 inc->i_conn->c_trans->inc_free(inc); 69 } 70 } 71 EXPORT_SYMBOL_GPL(rds_inc_put); 72 73 static void rds_recv_rcvbuf_delta(struct rds_sock *rs, struct sock *sk, 74 struct rds_cong_map *map, 75 int delta, __be16 port) 76 { 77 int now_congested; 78 79 if (delta == 0) 80 return; 81 82 rs->rs_rcv_bytes += delta; 83 now_congested = rs->rs_rcv_bytes > rds_sk_rcvbuf(rs); 84 85 rdsdebug("rs %p (%pI4:%u) recv bytes %d buf %d " 86 "now_cong %d delta %d\n", 87 rs, &rs->rs_bound_addr, 88 ntohs(rs->rs_bound_port), rs->rs_rcv_bytes, 89 rds_sk_rcvbuf(rs), now_congested, delta); 90 91 /* wasn't -> am congested */ 92 if (!rs->rs_congested && now_congested) { 93 rs->rs_congested = 1; 94 rds_cong_set_bit(map, port); 95 rds_cong_queue_updates(map); 96 } 97 /* was -> aren't congested */ 98 /* Require more free space before reporting uncongested to prevent 99 bouncing cong/uncong state too often */ 100 else if (rs->rs_congested && (rs->rs_rcv_bytes < (rds_sk_rcvbuf(rs)/2))) { 101 rs->rs_congested = 0; 102 rds_cong_clear_bit(map, port); 103 rds_cong_queue_updates(map); 104 } 105 106 /* do nothing if no change in cong state */ 107 } 108 109 /* 110 * Process all extension headers that come with this message. 111 */ 112 static void rds_recv_incoming_exthdrs(struct rds_incoming *inc, struct rds_sock *rs) 113 { 114 struct rds_header *hdr = &inc->i_hdr; 115 unsigned int pos = 0, type, len; 116 union { 117 struct rds_ext_header_version version; 118 struct rds_ext_header_rdma rdma; 119 struct rds_ext_header_rdma_dest rdma_dest; 120 } buffer; 121 122 while (1) { 123 len = sizeof(buffer); 124 type = rds_message_next_extension(hdr, &pos, &buffer, &len); 125 if (type == RDS_EXTHDR_NONE) 126 break; 127 /* Process extension header here */ 128 switch (type) { 129 case RDS_EXTHDR_RDMA: 130 rds_rdma_unuse(rs, be32_to_cpu(buffer.rdma.h_rdma_rkey), 0); 131 break; 132 133 case RDS_EXTHDR_RDMA_DEST: 134 /* We ignore the size for now. We could stash it 135 * somewhere and use it for error checking. */ 136 inc->i_rdma_cookie = rds_rdma_make_cookie( 137 be32_to_cpu(buffer.rdma_dest.h_rdma_rkey), 138 be32_to_cpu(buffer.rdma_dest.h_rdma_offset)); 139 140 break; 141 } 142 } 143 } 144 145 /* 146 * The transport must make sure that this is serialized against other 147 * rx and conn reset on this specific conn. 148 * 149 * We currently assert that only one fragmented message will be sent 150 * down a connection at a time. This lets us reassemble in the conn 151 * instead of per-flow which means that we don't have to go digging through 152 * flows to tear down partial reassembly progress on conn failure and 153 * we save flow lookup and locking for each frag arrival. It does mean 154 * that small messages will wait behind large ones. Fragmenting at all 155 * is only to reduce the memory consumption of pre-posted buffers. 156 * 157 * The caller passes in saddr and daddr instead of us getting it from the 158 * conn. This lets loopback, who only has one conn for both directions, 159 * tell us which roles the addrs in the conn are playing for this message. 160 */ 161 void rds_recv_incoming(struct rds_connection *conn, __be32 saddr, __be32 daddr, 162 struct rds_incoming *inc, gfp_t gfp) 163 { 164 struct rds_sock *rs = NULL; 165 struct sock *sk; 166 unsigned long flags; 167 168 inc->i_conn = conn; 169 inc->i_rx_jiffies = jiffies; 170 171 rdsdebug("conn %p next %llu inc %p seq %llu len %u sport %u dport %u " 172 "flags 0x%x rx_jiffies %lu\n", conn, 173 (unsigned long long)conn->c_next_rx_seq, 174 inc, 175 (unsigned long long)be64_to_cpu(inc->i_hdr.h_sequence), 176 be32_to_cpu(inc->i_hdr.h_len), 177 be16_to_cpu(inc->i_hdr.h_sport), 178 be16_to_cpu(inc->i_hdr.h_dport), 179 inc->i_hdr.h_flags, 180 inc->i_rx_jiffies); 181 182 /* 183 * Sequence numbers should only increase. Messages get their 184 * sequence number as they're queued in a sending conn. They 185 * can be dropped, though, if the sending socket is closed before 186 * they hit the wire. So sequence numbers can skip forward 187 * under normal operation. They can also drop back in the conn 188 * failover case as previously sent messages are resent down the 189 * new instance of a conn. We drop those, otherwise we have 190 * to assume that the next valid seq does not come after a 191 * hole in the fragment stream. 192 * 193 * The headers don't give us a way to realize if fragments of 194 * a message have been dropped. We assume that frags that arrive 195 * to a flow are part of the current message on the flow that is 196 * being reassembled. This means that senders can't drop messages 197 * from the sending conn until all their frags are sent. 198 * 199 * XXX we could spend more on the wire to get more robust failure 200 * detection, arguably worth it to avoid data corruption. 201 */ 202 if (be64_to_cpu(inc->i_hdr.h_sequence) < conn->c_next_rx_seq && 203 (inc->i_hdr.h_flags & RDS_FLAG_RETRANSMITTED)) { 204 rds_stats_inc(s_recv_drop_old_seq); 205 goto out; 206 } 207 conn->c_next_rx_seq = be64_to_cpu(inc->i_hdr.h_sequence) + 1; 208 209 if (rds_sysctl_ping_enable && inc->i_hdr.h_dport == 0) { 210 rds_stats_inc(s_recv_ping); 211 rds_send_pong(conn, inc->i_hdr.h_sport); 212 goto out; 213 } 214 215 rs = rds_find_bound(daddr, inc->i_hdr.h_dport); 216 if (!rs) { 217 rds_stats_inc(s_recv_drop_no_sock); 218 goto out; 219 } 220 221 /* Process extension headers */ 222 rds_recv_incoming_exthdrs(inc, rs); 223 224 /* We can be racing with rds_release() which marks the socket dead. */ 225 sk = rds_rs_to_sk(rs); 226 227 /* serialize with rds_release -> sock_orphan */ 228 write_lock_irqsave(&rs->rs_recv_lock, flags); 229 if (!sock_flag(sk, SOCK_DEAD)) { 230 rdsdebug("adding inc %p to rs %p's recv queue\n", inc, rs); 231 rds_stats_inc(s_recv_queued); 232 rds_recv_rcvbuf_delta(rs, sk, inc->i_conn->c_lcong, 233 be32_to_cpu(inc->i_hdr.h_len), 234 inc->i_hdr.h_dport); 235 if (sock_flag(sk, SOCK_RCVTSTAMP)) 236 do_gettimeofday(&inc->i_rx_tstamp); 237 rds_inc_addref(inc); 238 list_add_tail(&inc->i_item, &rs->rs_recv_queue); 239 __rds_wake_sk_sleep(sk); 240 } else { 241 rds_stats_inc(s_recv_drop_dead_sock); 242 } 243 write_unlock_irqrestore(&rs->rs_recv_lock, flags); 244 245 out: 246 if (rs) 247 rds_sock_put(rs); 248 } 249 EXPORT_SYMBOL_GPL(rds_recv_incoming); 250 251 /* 252 * be very careful here. This is being called as the condition in 253 * wait_event_*() needs to cope with being called many times. 254 */ 255 static int rds_next_incoming(struct rds_sock *rs, struct rds_incoming **inc) 256 { 257 unsigned long flags; 258 259 if (!*inc) { 260 read_lock_irqsave(&rs->rs_recv_lock, flags); 261 if (!list_empty(&rs->rs_recv_queue)) { 262 *inc = list_entry(rs->rs_recv_queue.next, 263 struct rds_incoming, 264 i_item); 265 rds_inc_addref(*inc); 266 } 267 read_unlock_irqrestore(&rs->rs_recv_lock, flags); 268 } 269 270 return *inc != NULL; 271 } 272 273 static int rds_still_queued(struct rds_sock *rs, struct rds_incoming *inc, 274 int drop) 275 { 276 struct sock *sk = rds_rs_to_sk(rs); 277 int ret = 0; 278 unsigned long flags; 279 280 write_lock_irqsave(&rs->rs_recv_lock, flags); 281 if (!list_empty(&inc->i_item)) { 282 ret = 1; 283 if (drop) { 284 /* XXX make sure this i_conn is reliable */ 285 rds_recv_rcvbuf_delta(rs, sk, inc->i_conn->c_lcong, 286 -be32_to_cpu(inc->i_hdr.h_len), 287 inc->i_hdr.h_dport); 288 list_del_init(&inc->i_item); 289 rds_inc_put(inc); 290 } 291 } 292 write_unlock_irqrestore(&rs->rs_recv_lock, flags); 293 294 rdsdebug("inc %p rs %p still %d dropped %d\n", inc, rs, ret, drop); 295 return ret; 296 } 297 298 /* 299 * Pull errors off the error queue. 300 * If msghdr is NULL, we will just purge the error queue. 301 */ 302 int rds_notify_queue_get(struct rds_sock *rs, struct msghdr *msghdr) 303 { 304 struct rds_notifier *notifier; 305 struct rds_rdma_notify cmsg = { 0 }; /* fill holes with zero */ 306 unsigned int count = 0, max_messages = ~0U; 307 unsigned long flags; 308 LIST_HEAD(copy); 309 int err = 0; 310 311 312 /* put_cmsg copies to user space and thus may sleep. We can't do this 313 * with rs_lock held, so first grab as many notifications as we can stuff 314 * in the user provided cmsg buffer. We don't try to copy more, to avoid 315 * losing notifications - except when the buffer is so small that it wouldn't 316 * even hold a single notification. Then we give him as much of this single 317 * msg as we can squeeze in, and set MSG_CTRUNC. 318 */ 319 if (msghdr) { 320 max_messages = msghdr->msg_controllen / CMSG_SPACE(sizeof(cmsg)); 321 if (!max_messages) 322 max_messages = 1; 323 } 324 325 spin_lock_irqsave(&rs->rs_lock, flags); 326 while (!list_empty(&rs->rs_notify_queue) && count < max_messages) { 327 notifier = list_entry(rs->rs_notify_queue.next, 328 struct rds_notifier, n_list); 329 list_move(¬ifier->n_list, ©); 330 count++; 331 } 332 spin_unlock_irqrestore(&rs->rs_lock, flags); 333 334 if (!count) 335 return 0; 336 337 while (!list_empty(©)) { 338 notifier = list_entry(copy.next, struct rds_notifier, n_list); 339 340 if (msghdr) { 341 cmsg.user_token = notifier->n_user_token; 342 cmsg.status = notifier->n_status; 343 344 err = put_cmsg(msghdr, SOL_RDS, RDS_CMSG_RDMA_STATUS, 345 sizeof(cmsg), &cmsg); 346 if (err) 347 break; 348 } 349 350 list_del_init(¬ifier->n_list); 351 kfree(notifier); 352 } 353 354 /* If we bailed out because of an error in put_cmsg, 355 * we may be left with one or more notifications that we 356 * didn't process. Return them to the head of the list. */ 357 if (!list_empty(©)) { 358 spin_lock_irqsave(&rs->rs_lock, flags); 359 list_splice(©, &rs->rs_notify_queue); 360 spin_unlock_irqrestore(&rs->rs_lock, flags); 361 } 362 363 return err; 364 } 365 366 /* 367 * Queue a congestion notification 368 */ 369 static int rds_notify_cong(struct rds_sock *rs, struct msghdr *msghdr) 370 { 371 uint64_t notify = rs->rs_cong_notify; 372 unsigned long flags; 373 int err; 374 375 err = put_cmsg(msghdr, SOL_RDS, RDS_CMSG_CONG_UPDATE, 376 sizeof(notify), ¬ify); 377 if (err) 378 return err; 379 380 spin_lock_irqsave(&rs->rs_lock, flags); 381 rs->rs_cong_notify &= ~notify; 382 spin_unlock_irqrestore(&rs->rs_lock, flags); 383 384 return 0; 385 } 386 387 /* 388 * Receive any control messages. 389 */ 390 static int rds_cmsg_recv(struct rds_incoming *inc, struct msghdr *msg, 391 struct rds_sock *rs) 392 { 393 int ret = 0; 394 395 if (inc->i_rdma_cookie) { 396 ret = put_cmsg(msg, SOL_RDS, RDS_CMSG_RDMA_DEST, 397 sizeof(inc->i_rdma_cookie), &inc->i_rdma_cookie); 398 if (ret) 399 return ret; 400 } 401 402 if ((inc->i_rx_tstamp.tv_sec != 0) && 403 sock_flag(rds_rs_to_sk(rs), SOCK_RCVTSTAMP)) { 404 ret = put_cmsg(msg, SOL_SOCKET, SCM_TIMESTAMP, 405 sizeof(struct timeval), 406 &inc->i_rx_tstamp); 407 if (ret) 408 return ret; 409 } 410 411 return 0; 412 } 413 414 int rds_recvmsg(struct socket *sock, struct msghdr *msg, size_t size, 415 int msg_flags) 416 { 417 struct sock *sk = sock->sk; 418 struct rds_sock *rs = rds_sk_to_rs(sk); 419 long timeo; 420 int ret = 0, nonblock = msg_flags & MSG_DONTWAIT; 421 DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name); 422 struct rds_incoming *inc = NULL; 423 424 /* udp_recvmsg()->sock_recvtimeo() gets away without locking too.. */ 425 timeo = sock_rcvtimeo(sk, nonblock); 426 427 rdsdebug("size %zu flags 0x%x timeo %ld\n", size, msg_flags, timeo); 428 429 if (msg_flags & MSG_OOB) 430 goto out; 431 432 while (1) { 433 struct iov_iter save; 434 /* If there are pending notifications, do those - and nothing else */ 435 if (!list_empty(&rs->rs_notify_queue)) { 436 ret = rds_notify_queue_get(rs, msg); 437 break; 438 } 439 440 if (rs->rs_cong_notify) { 441 ret = rds_notify_cong(rs, msg); 442 break; 443 } 444 445 if (!rds_next_incoming(rs, &inc)) { 446 if (nonblock) { 447 ret = -EAGAIN; 448 break; 449 } 450 451 timeo = wait_event_interruptible_timeout(*sk_sleep(sk), 452 (!list_empty(&rs->rs_notify_queue) || 453 rs->rs_cong_notify || 454 rds_next_incoming(rs, &inc)), timeo); 455 rdsdebug("recvmsg woke inc %p timeo %ld\n", inc, 456 timeo); 457 if (timeo > 0 || timeo == MAX_SCHEDULE_TIMEOUT) 458 continue; 459 460 ret = timeo; 461 if (ret == 0) 462 ret = -ETIMEDOUT; 463 break; 464 } 465 466 rdsdebug("copying inc %p from %pI4:%u to user\n", inc, 467 &inc->i_conn->c_faddr, 468 ntohs(inc->i_hdr.h_sport)); 469 save = msg->msg_iter; 470 ret = inc->i_conn->c_trans->inc_copy_to_user(inc, &msg->msg_iter); 471 if (ret < 0) 472 break; 473 474 /* 475 * if the message we just copied isn't at the head of the 476 * recv queue then someone else raced us to return it, try 477 * to get the next message. 478 */ 479 if (!rds_still_queued(rs, inc, !(msg_flags & MSG_PEEK))) { 480 rds_inc_put(inc); 481 inc = NULL; 482 rds_stats_inc(s_recv_deliver_raced); 483 msg->msg_iter = save; 484 continue; 485 } 486 487 if (ret < be32_to_cpu(inc->i_hdr.h_len)) { 488 if (msg_flags & MSG_TRUNC) 489 ret = be32_to_cpu(inc->i_hdr.h_len); 490 msg->msg_flags |= MSG_TRUNC; 491 } 492 493 if (rds_cmsg_recv(inc, msg, rs)) { 494 ret = -EFAULT; 495 goto out; 496 } 497 498 rds_stats_inc(s_recv_delivered); 499 500 if (sin) { 501 sin->sin_family = AF_INET; 502 sin->sin_port = inc->i_hdr.h_sport; 503 sin->sin_addr.s_addr = inc->i_saddr; 504 memset(sin->sin_zero, 0, sizeof(sin->sin_zero)); 505 msg->msg_namelen = sizeof(*sin); 506 } 507 break; 508 } 509 510 if (inc) 511 rds_inc_put(inc); 512 513 out: 514 return ret; 515 } 516 517 /* 518 * The socket is being shut down and we're asked to drop messages that were 519 * queued for recvmsg. The caller has unbound the socket so the receive path 520 * won't queue any more incoming fragments or messages on the socket. 521 */ 522 void rds_clear_recv_queue(struct rds_sock *rs) 523 { 524 struct sock *sk = rds_rs_to_sk(rs); 525 struct rds_incoming *inc, *tmp; 526 unsigned long flags; 527 528 write_lock_irqsave(&rs->rs_recv_lock, flags); 529 list_for_each_entry_safe(inc, tmp, &rs->rs_recv_queue, i_item) { 530 rds_recv_rcvbuf_delta(rs, sk, inc->i_conn->c_lcong, 531 -be32_to_cpu(inc->i_hdr.h_len), 532 inc->i_hdr.h_dport); 533 list_del_init(&inc->i_item); 534 rds_inc_put(inc); 535 } 536 write_unlock_irqrestore(&rs->rs_recv_lock, flags); 537 } 538 539 /* 540 * inc->i_saddr isn't used here because it is only set in the receive 541 * path. 542 */ 543 void rds_inc_info_copy(struct rds_incoming *inc, 544 struct rds_info_iterator *iter, 545 __be32 saddr, __be32 daddr, int flip) 546 { 547 struct rds_info_message minfo; 548 549 minfo.seq = be64_to_cpu(inc->i_hdr.h_sequence); 550 minfo.len = be32_to_cpu(inc->i_hdr.h_len); 551 552 if (flip) { 553 minfo.laddr = daddr; 554 minfo.faddr = saddr; 555 minfo.lport = inc->i_hdr.h_dport; 556 minfo.fport = inc->i_hdr.h_sport; 557 } else { 558 minfo.laddr = saddr; 559 minfo.faddr = daddr; 560 minfo.lport = inc->i_hdr.h_sport; 561 minfo.fport = inc->i_hdr.h_dport; 562 } 563 564 minfo.flags = 0; 565 566 rds_info_copy(iter, &minfo, sizeof(minfo)); 567 } 568