net/rxrpc/conn_event.c

   1 /* connection-level event handling
   2  *
   3  * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
   4  * Written by David Howells (dhowells@redhat.com)
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License
   8  * as published by the Free Software Foundation; either version
   9  * 2 of the License, or (at your option) any later version.
  10  */
  11
  12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  13
  14 #include <linux/module.h>
  15 #include <linux/net.h>
  16 #include <linux/skbuff.h>
  17 #include <linux/errqueue.h>
  18 #include <net/sock.h>
  19 #include <net/af_rxrpc.h>
  20 #include <net/ip.h>
  21 #include "ar-internal.h"
  22
  23 /*
  24  * Retransmit terminal ACK or ABORT of the previous call.
  25  */
  26 static void rxrpc_conn_retransmit_call(struct rxrpc_connection *conn,
  27                                        struct sk_buff *skb,
  28                                        unsigned int channel)
  29 {
  30         struct rxrpc_skb_priv *sp = skb ? rxrpc_skb(skb) : NULL;
  31         struct rxrpc_channel *chan;
  32         struct msghdr msg;
  33         struct kvec iov[3];
  34         struct {
  35                 struct rxrpc_wire_header whdr;
  36                 union {
  37                         __be32 abort_code;
  38                         struct rxrpc_ackpacket ack;
  39                 };
  40         } __attribute__((packed)) pkt;
  41         struct rxrpc_ackinfo ack_info;
  42         size_t len;
  43         int ioc;
  44         u32 serial, mtu, call_id, padding;
  45
  46         _enter("%d", conn->debug_id);
  47
  48         chan = &conn->channels[channel];
  49
  50         /* If the last call got moved on whilst we were waiting to run, just
  51          * ignore this packet.
  52          */
  53         call_id = READ_ONCE(chan->last_call);
  54         /* Sync with __rxrpc_disconnect_call() */
  55         smp_rmb();
  56         if (skb && call_id != sp->hdr.callNumber)
  57                 return;
  58
  59         msg.msg_name    = &conn->params.peer->srx.transport;
  60         msg.msg_namelen = conn->params.peer->srx.transport_len;
  61         msg.msg_control = NULL;
  62         msg.msg_controllen = 0;
  63         msg.msg_flags   = 0;
  64
  65         iov[0].iov_base = &pkt;
  66         iov[0].iov_len  = sizeof(pkt.whdr);
  67         iov[1].iov_base = &padding;
  68         iov[1].iov_len  = 3;
  69         iov[2].iov_base = &ack_info;
  70         iov[2].iov_len  = sizeof(ack_info);
  71
  72         pkt.whdr.epoch          = htonl(conn->proto.epoch);
  73         pkt.whdr.cid            = htonl(conn->proto.cid);
  74         pkt.whdr.callNumber     = htonl(call_id);
  75         pkt.whdr.seq            = 0;
  76         pkt.whdr.type           = chan->last_type;
  77         pkt.whdr.flags          = conn->out_clientflag;
  78         pkt.whdr.userStatus     = 0;
  79         pkt.whdr.securityIndex  = conn->security_ix;
  80         pkt.whdr._rsvd          = 0;
  81         pkt.whdr.serviceId      = htons(conn->service_id);
  82
  83         len = sizeof(pkt.whdr);
  84         switch (chan->last_type) {
  85         case RXRPC_PACKET_TYPE_ABORT:
  86                 pkt.abort_code  = htonl(chan->last_abort);
  87                 iov[0].iov_len += sizeof(pkt.abort_code);
  88                 len += sizeof(pkt.abort_code);
  89                 ioc = 1;
  90                 break;
  91
  92         case RXRPC_PACKET_TYPE_ACK:
  93                 mtu = conn->params.peer->if_mtu;
  94                 mtu -= conn->params.peer->hdrsize;
  95                 pkt.ack.bufferSpace     = 0;
  96                 pkt.ack.maxSkew         = htons(skb ? skb->priority : 0);
  97                 pkt.ack.firstPacket     = htonl(chan->last_seq + 1);
  98                 pkt.ack.previousPacket  = htonl(chan->last_seq);
  99                 pkt.ack.serial          = htonl(skb ? sp->hdr.serial : 0);
 100                 pkt.ack.reason          = skb ? RXRPC_ACK_DUPLICATE : RXRPC_ACK_IDLE;
 101                 pkt.ack.nAcks           = 0;
 102                 ack_info.rxMTU          = htonl(rxrpc_rx_mtu);
 103                 ack_info.maxMTU         = htonl(mtu);
 104                 ack_info.rwind          = htonl(rxrpc_rx_window_size);
 105                 ack_info.jumbo_max      = htonl(rxrpc_rx_jumbo_max);
 106                 pkt.whdr.flags          |= RXRPC_SLOW_START_OK;
 107                 padding                 = 0;
 108                 iov[0].iov_len += sizeof(pkt.ack);
 109                 len += sizeof(pkt.ack) + 3 + sizeof(ack_info);
 110                 ioc = 3;
 111                 break;
 112
 113         default:
 114                 return;
 115         }
 116
 117         /* Resync with __rxrpc_disconnect_call() and check that the last call
 118          * didn't get advanced whilst we were filling out the packets.
 119          */
 120         smp_rmb();
 121         if (READ_ONCE(chan->last_call) != call_id)
 122                 return;
 123
 124         serial = atomic_inc_return(&conn->serial);
 125         pkt.whdr.serial = htonl(serial);
 126
 127         switch (chan->last_type) {
 128         case RXRPC_PACKET_TYPE_ABORT:
 129                 _proto("Tx ABORT %%%u { %d } [re]", serial, conn->local_abort);
 130                 break;
 131         case RXRPC_PACKET_TYPE_ACK:
 132                 trace_rxrpc_tx_ack(NULL, serial, chan->last_seq, 0,
 133                                    RXRPC_ACK_DUPLICATE, 0);
 134                 _proto("Tx ACK %%%u [re]", serial);
 135                 break;
 136         }
 137
 138         kernel_sendmsg(conn->params.local->socket, &msg, iov, ioc, len);
 139         _leave("");
 140         return;
 141 }
 142
 143 /*
 144  * pass a connection-level abort onto all calls on that connection
 145  */
 146 static void rxrpc_abort_calls(struct rxrpc_connection *conn,
 147                               enum rxrpc_call_completion compl,
 148                               u32 abort_code, int error)
 149 {
 150         struct rxrpc_call *call;
 151         int i;
 152
 153         _enter("{%d},%x", conn->debug_id, abort_code);
 154
 155         spin_lock(&conn->channel_lock);
 156
 157         for (i = 0; i < RXRPC_MAXCALLS; i++) {
 158                 call = rcu_dereference_protected(
 159                         conn->channels[i].call,
 160                         lockdep_is_held(&conn->channel_lock));
 161                 if (call) {
 162                         if (compl == RXRPC_CALL_LOCALLY_ABORTED)
 163                                 trace_rxrpc_abort("CON", call->cid,
 164                                                   call->call_id, 0,
 165                                                   abort_code, error);
 166                         if (rxrpc_set_call_completion(call, compl,
 167                                                       abort_code, error))
 168                                 rxrpc_notify_socket(call);
 169                 }
 170         }
 171
 172         spin_unlock(&conn->channel_lock);
 173         _leave("");
 174 }
 175
 176 /*
 177  * generate a connection-level abort
 178  */
 179 static int rxrpc_abort_connection(struct rxrpc_connection *conn,
 180                                   int error, u32 abort_code)
 181 {
 182         struct rxrpc_wire_header whdr;
 183         struct msghdr msg;
 184         struct kvec iov[2];
 185         __be32 word;
 186         size_t len;
 187         u32 serial;
 188         int ret;
 189
 190         _enter("%d,,%u,%u", conn->debug_id, error, abort_code);
 191
 192         /* generate a connection-level abort */
 193         spin_lock_bh(&conn->state_lock);
 194         if (conn->state >= RXRPC_CONN_REMOTELY_ABORTED) {
 195                 spin_unlock_bh(&conn->state_lock);
 196                 _leave(" = 0 [already dead]");
 197                 return 0;
 198         }
 199
 200         conn->state = RXRPC_CONN_LOCALLY_ABORTED;
 201         spin_unlock_bh(&conn->state_lock);
 202
 203         rxrpc_abort_calls(conn, RXRPC_CALL_LOCALLY_ABORTED, abort_code, error);
 204
 205         msg.msg_name    = &conn->params.peer->srx.transport;
 206         msg.msg_namelen = conn->params.peer->srx.transport_len;
 207         msg.msg_control = NULL;
 208         msg.msg_controllen = 0;
 209         msg.msg_flags   = 0;
 210
 211         whdr.epoch      = htonl(conn->proto.epoch);
 212         whdr.cid        = htonl(conn->proto.cid);
 213         whdr.callNumber = 0;
 214         whdr.seq        = 0;
 215         whdr.type       = RXRPC_PACKET_TYPE_ABORT;
 216         whdr.flags      = conn->out_clientflag;
 217         whdr.userStatus = 0;
 218         whdr.securityIndex = conn->security_ix;
 219         whdr._rsvd      = 0;
 220         whdr.serviceId  = htons(conn->service_id);
 221
 222         word            = htonl(conn->local_abort);
 223
 224         iov[0].iov_base = &whdr;
 225         iov[0].iov_len  = sizeof(whdr);
 226         iov[1].iov_base = &word;
 227         iov[1].iov_len  = sizeof(word);
 228
 229         len = iov[0].iov_len + iov[1].iov_len;
 230
 231         serial = atomic_inc_return(&conn->serial);
 232         whdr.serial = htonl(serial);
 233         _proto("Tx CONN ABORT %%%u { %d }", serial, conn->local_abort);
 234
 235         ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 2, len);
 236         if (ret < 0) {
 237                 _debug("sendmsg failed: %d", ret);
 238                 return -EAGAIN;
 239         }
 240
 241         _leave(" = 0");
 242         return 0;
 243 }
 244
 245 /*
 246  * mark a call as being on a now-secured channel
 247  * - must be called with BH's disabled.
 248  */
 249 static void rxrpc_call_is_secure(struct rxrpc_call *call)
 250 {
 251         _enter("%p", call);
 252         if (call) {
 253                 write_lock_bh(&call->state_lock);
 254                 if (call->state == RXRPC_CALL_SERVER_SECURING) {
 255                         call->state = RXRPC_CALL_SERVER_ACCEPTING;
 256                         rxrpc_notify_socket(call);
 257                 }
 258                 write_unlock_bh(&call->state_lock);
 259         }
 260 }
 261
 262 /*
 263  * connection-level Rx packet processor
 264  */
 265 static int rxrpc_process_event(struct rxrpc_connection *conn,
 266                                struct sk_buff *skb,
 267                                u32 *_abort_code)
 268 {
 269         struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 270         __be32 wtmp;
 271         u32 abort_code;
 272         int loop, ret;
 273
 274         if (conn->state >= RXRPC_CONN_REMOTELY_ABORTED) {
 275                 _leave(" = -ECONNABORTED [%u]", conn->state);
 276                 return -ECONNABORTED;
 277         }
 278
 279         _enter("{%d},{%u,%%%u},", conn->debug_id, sp->hdr.type, sp->hdr.serial);
 280
 281         switch (sp->hdr.type) {
 282         case RXRPC_PACKET_TYPE_DATA:
 283         case RXRPC_PACKET_TYPE_ACK:
 284                 rxrpc_conn_retransmit_call(conn, skb,
 285                                            sp->hdr.cid & RXRPC_CHANNELMASK);
 286                 return 0;
 287
 288         case RXRPC_PACKET_TYPE_BUSY:
 289                 /* Just ignore BUSY packets for now. */
 290                 return 0;
 291
 292         case RXRPC_PACKET_TYPE_ABORT:
 293                 if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
 294                                   &wtmp, sizeof(wtmp)) < 0) {
 295                         trace_rxrpc_rx_eproto(NULL, sp->hdr.serial,
 296                                               tracepoint_string("bad_abort"));
 297                         return -EPROTO;
 298                 }
 299                 abort_code = ntohl(wtmp);
 300                 _proto("Rx ABORT %%%u { ac=%d }", sp->hdr.serial, abort_code);
 301
 302                 conn->state = RXRPC_CONN_REMOTELY_ABORTED;
 303                 rxrpc_abort_calls(conn, RXRPC_CALL_REMOTELY_ABORTED,
 304                                   abort_code, -ECONNABORTED);
 305                 return -ECONNABORTED;
 306
 307         case RXRPC_PACKET_TYPE_CHALLENGE:
 308                 return conn->security->respond_to_challenge(conn, skb,
 309                                                             _abort_code);
 310
 311         case RXRPC_PACKET_TYPE_RESPONSE:
 312                 ret = conn->security->verify_response(conn, skb, _abort_code);
 313                 if (ret < 0)
 314                         return ret;
 315
 316                 ret = conn->security->init_connection_security(conn);
 317                 if (ret < 0)
 318                         return ret;
 319
 320                 ret = conn->security->prime_packet_security(conn);
 321                 if (ret < 0)
 322                         return ret;
 323
 324                 spin_lock(&conn->channel_lock);
 325                 spin_lock(&conn->state_lock);
 326
 327                 if (conn->state == RXRPC_CONN_SERVICE_CHALLENGING) {
 328                         conn->state = RXRPC_CONN_SERVICE;
 329                         spin_unlock(&conn->state_lock);
 330                         for (loop = 0; loop < RXRPC_MAXCALLS; loop++)
 331                                 rxrpc_call_is_secure(
 332                                         rcu_dereference_protected(
 333                                                 conn->channels[loop].call,
 334                                                 lockdep_is_held(&conn->channel_lock)));
 335                 } else {
 336                         spin_unlock(&conn->state_lock);
 337                 }
 338
 339                 spin_unlock(&conn->channel_lock);
 340                 return 0;
 341
 342         default:
 343                 trace_rxrpc_rx_eproto(NULL, sp->hdr.serial,
 344                                       tracepoint_string("bad_conn_pkt"));
 345                 return -EPROTO;
 346         }
 347 }
 348
 349 /*
 350  * set up security and issue a challenge
 351  */
 352 static void rxrpc_secure_connection(struct rxrpc_connection *conn)
 353 {
 354         u32 abort_code;
 355         int ret;
 356
 357         _enter("{%d}", conn->debug_id);
 358
 359         ASSERT(conn->security_ix != 0);
 360
 361         if (!conn->params.key) {
 362                 _debug("set up security");
 363                 ret = rxrpc_init_server_conn_security(conn);
 364                 switch (ret) {
 365                 case 0:
 366                         break;
 367                 case -ENOENT:
 368                         abort_code = RX_CALL_DEAD;
 369                         goto abort;
 370                 default:
 371                         abort_code = RXKADNOAUTH;
 372                         goto abort;
 373                 }
 374         }
 375
 376         if (conn->security->issue_challenge(conn) < 0) {
 377                 abort_code = RX_CALL_DEAD;
 378                 ret = -ENOMEM;
 379                 goto abort;
 380         }
 381
 382         _leave("");
 383         return;
 384
 385 abort:
 386         _debug("abort %d, %d", ret, abort_code);
 387         rxrpc_abort_connection(conn, ret, abort_code);
 388         _leave(" [aborted]");
 389 }
 390
 391 /*
 392  * Process delayed final ACKs that we haven't subsumed into a subsequent call.
 393  */
 394 static void rxrpc_process_delayed_final_acks(struct rxrpc_connection *conn)
 395 {
 396         unsigned long j = jiffies, next_j;
 397         unsigned int channel;
 398         bool set;
 399
 400 again:
 401         next_j = j + LONG_MAX;
 402         set = false;
 403         for (channel = 0; channel < RXRPC_MAXCALLS; channel++) {
 404                 struct rxrpc_channel *chan = &conn->channels[channel];
 405                 unsigned long ack_at;
 406
 407                 if (!test_bit(RXRPC_CONN_FINAL_ACK_0 + channel, &conn->flags))
 408                         continue;
 409
 410                 smp_rmb(); /* vs rxrpc_disconnect_client_call */
 411                 ack_at = READ_ONCE(chan->final_ack_at);
 412
 413                 if (time_before(j, ack_at)) {
 414                         if (time_before(ack_at, next_j)) {
 415                                 next_j = ack_at;
 416                                 set = true;
 417                         }
 418                         continue;
 419                 }
 420
 421                 if (test_and_clear_bit(RXRPC_CONN_FINAL_ACK_0 + channel,
 422                                        &conn->flags))
 423                         rxrpc_conn_retransmit_call(conn, NULL, channel);
 424         }
 425
 426         j = jiffies;
 427         if (time_before_eq(next_j, j))
 428                 goto again;
 429         if (set)
 430                 rxrpc_reduce_conn_timer(conn, next_j);
 431 }
 432
 433 /*
 434  * connection-level event processor
 435  */
 436 void rxrpc_process_connection(struct work_struct *work)
 437 {
 438         struct rxrpc_connection *conn =
 439                 container_of(work, struct rxrpc_connection, processor);
 440         struct sk_buff *skb;
 441         u32 abort_code = RX_PROTOCOL_ERROR;
 442         int ret;
 443
 444         rxrpc_see_connection(conn);
 445
 446         if (test_and_clear_bit(RXRPC_CONN_EV_CHALLENGE, &conn->events))
 447                 rxrpc_secure_connection(conn);
 448
 449         /* Process delayed ACKs whose time has come. */
 450         if (conn->flags & RXRPC_CONN_FINAL_ACK_MASK)
 451                 rxrpc_process_delayed_final_acks(conn);
 452
 453         /* go through the conn-level event packets, releasing the ref on this
 454          * connection that each one has when we've finished with it */
 455         while ((skb = skb_dequeue(&conn->rx_queue))) {
 456                 rxrpc_see_skb(skb, rxrpc_skb_rx_seen);
 457                 ret = rxrpc_process_event(conn, skb, &abort_code);
 458                 switch (ret) {
 459                 case -EPROTO:
 460                 case -EKEYEXPIRED:
 461                 case -EKEYREJECTED:
 462                         goto protocol_error;
 463                 case -EAGAIN:
 464                         goto requeue_and_leave;
 465                 case -ECONNABORTED:
 466                 default:
 467                         rxrpc_free_skb(skb, rxrpc_skb_rx_freed);
 468                         break;
 469                 }
 470         }
 471
 472 out:
 473         rxrpc_put_connection(conn);
 474         _leave("");
 475         return;
 476
 477 requeue_and_leave:
 478         skb_queue_head(&conn->rx_queue, skb);
 479         goto out;
 480
 481 protocol_error:
 482         if (rxrpc_abort_connection(conn, ret, abort_code) < 0)
 483                 goto requeue_and_leave;
 484         rxrpc_free_skb(skb, rxrpc_skb_rx_freed);
 485         goto out;
 486 }