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