net/rxrpc/conn_event.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /* connection-level event handling
   3  *
   4  * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
   5  * Written by David Howells (dhowells@redhat.com)
   6  */
   7
   8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
   9
  10 #include <linux/module.h>
  11 #include <linux/net.h>
  12 #include <linux/skbuff.h>
  13 #include <linux/errqueue.h>
  14 #include <net/sock.h>
  15 #include <net/af_rxrpc.h>
  16 #include <net/ip.h>
  17 #include "ar-internal.h"
  18
  19 /*
  20  * Retransmit terminal ACK or ABORT of the previous call.
  21  */
  22 static void rxrpc_conn_retransmit_call(struct rxrpc_connection *conn,
  23                                        struct sk_buff *skb,
  24                                        unsigned int channel)
  25 {
  26         struct rxrpc_skb_priv *sp = skb ? rxrpc_skb(skb) : NULL;
  27         struct rxrpc_channel *chan;
  28         struct msghdr msg;
  29         struct kvec iov[3];
  30         struct {
  31                 struct rxrpc_wire_header whdr;
  32                 union {
  33                         __be32 abort_code;
  34                         struct rxrpc_ackpacket ack;
  35                 };
  36         } __attribute__((packed)) pkt;
  37         struct rxrpc_ackinfo ack_info;
  38         size_t len;
  39         int ret, ioc;
  40         u32 serial, mtu, call_id, padding;
  41
  42         _enter("%d", conn->debug_id);
  43
  44         chan = &conn->channels[channel];
  45
  46         /* If the last call got moved on whilst we were waiting to run, just
  47          * ignore this packet.
  48          */
  49         call_id = READ_ONCE(chan->last_call);
  50         /* Sync with __rxrpc_disconnect_call() */
  51         smp_rmb();
  52         if (skb && call_id != sp->hdr.callNumber)
  53                 return;
  54
  55         msg.msg_name    = &conn->peer->srx.transport;
  56         msg.msg_namelen = conn->peer->srx.transport_len;
  57         msg.msg_control = NULL;
  58         msg.msg_controllen = 0;
  59         msg.msg_flags   = 0;
  60
  61         iov[0].iov_base = &pkt;
  62         iov[0].iov_len  = sizeof(pkt.whdr);
  63         iov[1].iov_base = &padding;
  64         iov[1].iov_len  = 3;
  65         iov[2].iov_base = &ack_info;
  66         iov[2].iov_len  = sizeof(ack_info);
  67
  68         pkt.whdr.epoch          = htonl(conn->proto.epoch);
  69         pkt.whdr.cid            = htonl(conn->proto.cid | channel);
  70         pkt.whdr.callNumber     = htonl(call_id);
  71         pkt.whdr.seq            = 0;
  72         pkt.whdr.type           = chan->last_type;
  73         pkt.whdr.flags          = conn->out_clientflag;
  74         pkt.whdr.userStatus     = 0;
  75         pkt.whdr.securityIndex  = conn->security_ix;
  76         pkt.whdr._rsvd          = 0;
  77         pkt.whdr.serviceId      = htons(conn->service_id);
  78
  79         len = sizeof(pkt.whdr);
  80         switch (chan->last_type) {
  81         case RXRPC_PACKET_TYPE_ABORT:
  82                 pkt.abort_code  = htonl(chan->last_abort);
  83                 iov[0].iov_len += sizeof(pkt.abort_code);
  84                 len += sizeof(pkt.abort_code);
  85                 ioc = 1;
  86                 break;
  87
  88         case RXRPC_PACKET_TYPE_ACK:
  89                 mtu = conn->peer->if_mtu;
  90                 mtu -= conn->peer->hdrsize;
  91                 pkt.ack.bufferSpace     = 0;
  92                 pkt.ack.maxSkew         = htons(skb ? skb->priority : 0);
  93                 pkt.ack.firstPacket     = htonl(chan->last_seq + 1);
  94                 pkt.ack.previousPacket  = htonl(chan->last_seq);
  95                 pkt.ack.serial          = htonl(skb ? sp->hdr.serial : 0);
  96                 pkt.ack.reason          = skb ? RXRPC_ACK_DUPLICATE : RXRPC_ACK_IDLE;
  97                 pkt.ack.nAcks           = 0;
  98                 ack_info.rxMTU          = htonl(rxrpc_rx_mtu);
  99                 ack_info.maxMTU         = htonl(mtu);
 100                 ack_info.rwind          = htonl(rxrpc_rx_window_size);
 101                 ack_info.jumbo_max      = htonl(rxrpc_rx_jumbo_max);
 102                 pkt.whdr.flags          |= RXRPC_SLOW_START_OK;
 103                 padding                 = 0;
 104                 iov[0].iov_len += sizeof(pkt.ack);
 105                 len += sizeof(pkt.ack) + 3 + sizeof(ack_info);
 106                 ioc = 3;
 107                 break;
 108
 109         default:
 110                 return;
 111         }
 112
 113         /* Resync with __rxrpc_disconnect_call() and check that the last call
 114          * didn't get advanced whilst we were filling out the packets.
 115          */
 116         smp_rmb();
 117         if (READ_ONCE(chan->last_call) != call_id)
 118                 return;
 119
 120         serial = atomic_inc_return(&conn->serial);
 121         pkt.whdr.serial = htonl(serial);
 122
 123         switch (chan->last_type) {
 124         case RXRPC_PACKET_TYPE_ABORT:
 125                 break;
 126         case RXRPC_PACKET_TYPE_ACK:
 127                 trace_rxrpc_tx_ack(chan->call_debug_id, serial,
 128                                    ntohl(pkt.ack.firstPacket),
 129                                    ntohl(pkt.ack.serial),
 130                                    pkt.ack.reason, 0);
 131                 break;
 132         }
 133
 134         ret = kernel_sendmsg(conn->local->socket, &msg, iov, ioc, len);
 135         conn->peer->last_tx_at = ktime_get_seconds();
 136         if (ret < 0)
 137                 trace_rxrpc_tx_fail(chan->call_debug_id, serial, ret,
 138                                     rxrpc_tx_point_call_final_resend);
 139         else
 140                 trace_rxrpc_tx_packet(chan->call_debug_id, &pkt.whdr,
 141                                       rxrpc_tx_point_call_final_resend);
 142
 143         _leave("");
 144 }
 145
 146 /*
 147  * pass a connection-level abort onto all calls on that connection
 148  */
 149 static void rxrpc_abort_calls(struct rxrpc_connection *conn,
 150                               enum rxrpc_call_completion compl,
 151                               rxrpc_serial_t serial)
 152 {
 153         struct rxrpc_call *call;
 154         int i;
 155
 156         _enter("{%d},%x", conn->debug_id, conn->abort_code);
 157
 158         spin_lock(&conn->bundle->channel_lock);
 159
 160         for (i = 0; i < RXRPC_MAXCALLS; i++) {
 161                 call = rcu_dereference_protected(
 162                         conn->channels[i].call,
 163                         lockdep_is_held(&conn->bundle->channel_lock));
 164                 if (call) {
 165                         if (compl == RXRPC_CALL_LOCALLY_ABORTED)
 166                                 trace_rxrpc_abort(call->debug_id,
 167                                                   "CON", call->cid,
 168                                                   call->call_id, 0,
 169                                                   conn->abort_code,
 170                                                   conn->error);
 171                         else
 172                                 trace_rxrpc_rx_abort(call, serial,
 173                                                      conn->abort_code);
 174                         rxrpc_set_call_completion(call, compl,
 175                                                   conn->abort_code,
 176                                                   conn->error);
 177                 }
 178         }
 179
 180         spin_unlock(&conn->bundle->channel_lock);
 181         _leave("");
 182 }
 183
 184 /*
 185  * generate a connection-level abort
 186  */
 187 static int rxrpc_abort_connection(struct rxrpc_connection *conn,
 188                                   int error, u32 abort_code)
 189 {
 190         struct rxrpc_wire_header whdr;
 191         struct msghdr msg;
 192         struct kvec iov[2];
 193         __be32 word;
 194         size_t len;
 195         u32 serial;
 196         int ret;
 197
 198         _enter("%d,,%u,%u", conn->debug_id, error, abort_code);
 199
 200         /* generate a connection-level abort */
 201         spin_lock_bh(&conn->state_lock);
 202         if (conn->state >= RXRPC_CONN_REMOTELY_ABORTED) {
 203                 spin_unlock_bh(&conn->state_lock);
 204                 _leave(" = 0 [already dead]");
 205                 return 0;
 206         }
 207
 208         conn->error = error;
 209         conn->abort_code = abort_code;
 210         conn->state = RXRPC_CONN_LOCALLY_ABORTED;
 211         set_bit(RXRPC_CONN_DONT_REUSE, &conn->flags);
 212         spin_unlock_bh(&conn->state_lock);
 213
 214         msg.msg_name    = &conn->peer->srx.transport;
 215         msg.msg_namelen = conn->peer->srx.transport_len;
 216         msg.msg_control = NULL;
 217         msg.msg_controllen = 0;
 218         msg.msg_flags   = 0;
 219
 220         whdr.epoch      = htonl(conn->proto.epoch);
 221         whdr.cid        = htonl(conn->proto.cid);
 222         whdr.callNumber = 0;
 223         whdr.seq        = 0;
 224         whdr.type       = RXRPC_PACKET_TYPE_ABORT;
 225         whdr.flags      = conn->out_clientflag;
 226         whdr.userStatus = 0;
 227         whdr.securityIndex = conn->security_ix;
 228         whdr._rsvd      = 0;
 229         whdr.serviceId  = htons(conn->service_id);
 230
 231         word            = htonl(conn->abort_code);
 232
 233         iov[0].iov_base = &whdr;
 234         iov[0].iov_len  = sizeof(whdr);
 235         iov[1].iov_base = &word;
 236         iov[1].iov_len  = sizeof(word);
 237
 238         len = iov[0].iov_len + iov[1].iov_len;
 239
 240         serial = atomic_inc_return(&conn->serial);
 241         rxrpc_abort_calls(conn, RXRPC_CALL_LOCALLY_ABORTED, serial);
 242         whdr.serial = htonl(serial);
 243
 244         ret = kernel_sendmsg(conn->local->socket, &msg, iov, 2, len);
 245         if (ret < 0) {
 246                 trace_rxrpc_tx_fail(conn->debug_id, serial, ret,
 247                                     rxrpc_tx_point_conn_abort);
 248                 _debug("sendmsg failed: %d", ret);
 249                 return -EAGAIN;
 250         }
 251
 252         trace_rxrpc_tx_packet(conn->debug_id, &whdr, rxrpc_tx_point_conn_abort);
 253
 254         conn->peer->last_tx_at = ktime_get_seconds();
 255
 256         _leave(" = 0");
 257         return 0;
 258 }
 259
 260 /*
 261  * mark a call as being on a now-secured channel
 262  * - must be called with BH's disabled.
 263  */
 264 static void rxrpc_call_is_secure(struct rxrpc_call *call)
 265 {
 266         _enter("%p", call);
 267         if (call) {
 268                 write_lock_bh(&call->state_lock);
 269                 if (call->state == RXRPC_CALL_SERVER_SECURING) {
 270                         call->state = RXRPC_CALL_SERVER_RECV_REQUEST;
 271                         rxrpc_notify_socket(call);
 272                 }
 273                 write_unlock_bh(&call->state_lock);
 274         }
 275 }
 276
 277 /*
 278  * connection-level Rx packet processor
 279  */
 280 static int rxrpc_process_event(struct rxrpc_connection *conn,
 281                                struct sk_buff *skb,
 282                                u32 *_abort_code)
 283 {
 284         struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 285         int loop, ret;
 286
 287         if (conn->state >= RXRPC_CONN_REMOTELY_ABORTED) {
 288                 _leave(" = -ECONNABORTED [%u]", conn->state);
 289                 return -ECONNABORTED;
 290         }
 291
 292         _enter("{%d},{%u,%%%u},", conn->debug_id, sp->hdr.type, sp->hdr.serial);
 293
 294         switch (sp->hdr.type) {
 295         case RXRPC_PACKET_TYPE_DATA:
 296         case RXRPC_PACKET_TYPE_ACK:
 297                 rxrpc_conn_retransmit_call(conn, skb,
 298                                            sp->hdr.cid & RXRPC_CHANNELMASK);
 299                 return 0;
 300
 301         case RXRPC_PACKET_TYPE_BUSY:
 302                 /* Just ignore BUSY packets for now. */
 303                 return 0;
 304
 305         case RXRPC_PACKET_TYPE_ABORT:
 306                 conn->error = -ECONNABORTED;
 307                 conn->abort_code = skb->priority;
 308                 conn->state = RXRPC_CONN_REMOTELY_ABORTED;
 309                 set_bit(RXRPC_CONN_DONT_REUSE, &conn->flags);
 310                 rxrpc_abort_calls(conn, RXRPC_CALL_REMOTELY_ABORTED, sp->hdr.serial);
 311                 return -ECONNABORTED;
 312
 313         case RXRPC_PACKET_TYPE_CHALLENGE:
 314                 return conn->security->respond_to_challenge(conn, skb,
 315                                                             _abort_code);
 316
 317         case RXRPC_PACKET_TYPE_RESPONSE:
 318                 ret = conn->security->verify_response(conn, skb, _abort_code);
 319                 if (ret < 0)
 320                         return ret;
 321
 322                 ret = conn->security->init_connection_security(
 323                         conn, conn->key->payload.data[0]);
 324                 if (ret < 0)
 325                         return ret;
 326
 327                 spin_lock(&conn->bundle->channel_lock);
 328                 spin_lock_bh(&conn->state_lock);
 329
 330                 if (conn->state == RXRPC_CONN_SERVICE_CHALLENGING) {
 331                         conn->state = RXRPC_CONN_SERVICE;
 332                         spin_unlock_bh(&conn->state_lock);
 333                         for (loop = 0; loop < RXRPC_MAXCALLS; loop++)
 334                                 rxrpc_call_is_secure(
 335                                         rcu_dereference_protected(
 336                                                 conn->channels[loop].call,
 337                                                 lockdep_is_held(&conn->bundle->channel_lock)));
 338                 } else {
 339                         spin_unlock_bh(&conn->state_lock);
 340                 }
 341
 342                 spin_unlock(&conn->bundle->channel_lock);
 343                 return 0;
 344
 345         default:
 346                 trace_rxrpc_rx_eproto(NULL, sp->hdr.serial,
 347                                       tracepoint_string("bad_conn_pkt"));
 348                 return -EPROTO;
 349         }
 350 }
 351
 352 /*
 353  * set up security and issue a challenge
 354  */
 355 static void rxrpc_secure_connection(struct rxrpc_connection *conn)
 356 {
 357         u32 abort_code;
 358         int ret;
 359
 360         _enter("{%d}", conn->debug_id);
 361
 362         ASSERT(conn->security_ix != 0);
 363
 364         if (conn->security->issue_challenge(conn) < 0) {
 365                 abort_code = RX_CALL_DEAD;
 366                 ret = -ENOMEM;
 367                 goto abort;
 368         }
 369
 370         _leave("");
 371         return;
 372
 373 abort:
 374         _debug("abort %d, %d", ret, abort_code);
 375         rxrpc_abort_connection(conn, ret, abort_code);
 376         _leave(" [aborted]");
 377 }
 378
 379 /*
 380  * Process delayed final ACKs that we haven't subsumed into a subsequent call.
 381  */
 382 void rxrpc_process_delayed_final_acks(struct rxrpc_connection *conn, bool force)
 383 {
 384         unsigned long j = jiffies, next_j;
 385         unsigned int channel;
 386         bool set;
 387
 388 again:
 389         next_j = j + LONG_MAX;
 390         set = false;
 391         for (channel = 0; channel < RXRPC_MAXCALLS; channel++) {
 392                 struct rxrpc_channel *chan = &conn->channels[channel];
 393                 unsigned long ack_at;
 394
 395                 if (!test_bit(RXRPC_CONN_FINAL_ACK_0 + channel, &conn->flags))
 396                         continue;
 397
 398                 smp_rmb(); /* vs rxrpc_disconnect_client_call */
 399                 ack_at = READ_ONCE(chan->final_ack_at);
 400
 401                 if (time_before(j, ack_at) && !force) {
 402                         if (time_before(ack_at, next_j)) {
 403                                 next_j = ack_at;
 404                                 set = true;
 405                         }
 406                         continue;
 407                 }
 408
 409                 if (test_and_clear_bit(RXRPC_CONN_FINAL_ACK_0 + channel,
 410                                        &conn->flags))
 411                         rxrpc_conn_retransmit_call(conn, NULL, channel);
 412         }
 413
 414         j = jiffies;
 415         if (time_before_eq(next_j, j))
 416                 goto again;
 417         if (set)
 418                 rxrpc_reduce_conn_timer(conn, next_j);
 419 }
 420
 421 /*
 422  * connection-level event processor
 423  */
 424 static void rxrpc_do_process_connection(struct rxrpc_connection *conn)
 425 {
 426         struct sk_buff *skb;
 427         u32 abort_code = RX_PROTOCOL_ERROR;
 428         int ret;
 429
 430         if (test_and_clear_bit(RXRPC_CONN_EV_CHALLENGE, &conn->events))
 431                 rxrpc_secure_connection(conn);
 432
 433         /* Process delayed ACKs whose time has come. */
 434         if (conn->flags & RXRPC_CONN_FINAL_ACK_MASK)
 435                 rxrpc_process_delayed_final_acks(conn, false);
 436
 437         /* go through the conn-level event packets, releasing the ref on this
 438          * connection that each one has when we've finished with it */
 439         while ((skb = skb_dequeue(&conn->rx_queue))) {
 440                 rxrpc_see_skb(skb, rxrpc_skb_see_conn_work);
 441                 ret = rxrpc_process_event(conn, skb, &abort_code);
 442                 switch (ret) {
 443                 case -EPROTO:
 444                 case -EKEYEXPIRED:
 445                 case -EKEYREJECTED:
 446                         goto protocol_error;
 447                 case -ENOMEM:
 448                 case -EAGAIN:
 449                         goto requeue_and_leave;
 450                 case -ECONNABORTED:
 451                 default:
 452                         rxrpc_free_skb(skb, rxrpc_skb_put_conn_work);
 453                         break;
 454                 }
 455         }
 456
 457         return;
 458
 459 requeue_and_leave:
 460         skb_queue_head(&conn->rx_queue, skb);
 461         return;
 462
 463 protocol_error:
 464         if (rxrpc_abort_connection(conn, ret, abort_code) < 0)
 465                 goto requeue_and_leave;
 466         rxrpc_free_skb(skb, rxrpc_skb_put_conn_work);
 467         return;
 468 }
 469
 470 void rxrpc_process_connection(struct work_struct *work)
 471 {
 472         struct rxrpc_connection *conn =
 473                 container_of(work, struct rxrpc_connection, processor);
 474
 475         rxrpc_see_connection(conn, rxrpc_conn_see_work);
 476
 477         if (__rxrpc_use_local(conn->local, rxrpc_local_use_conn_work)) {
 478                 rxrpc_do_process_connection(conn);
 479                 rxrpc_unuse_local(conn->local, rxrpc_local_unuse_conn_work);
 480         }
 481
 482         rxrpc_put_connection(conn, rxrpc_conn_put_work);
 483         _leave("");
 484         return;
 485 }