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 {
  29         struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
  30         struct rxrpc_channel *chan;
  31         struct msghdr msg;
  32         struct kvec iov;
  33         struct {
  34                 struct rxrpc_wire_header whdr;
  35                 union {
  36                         struct {
  37                                 __be32 code;
  38                         } abort;
  39                         struct {
  40                                 struct rxrpc_ackpacket ack;
  41                                 u8 padding[3];
  42                                 struct rxrpc_ackinfo info;
  43                         };
  44                 };
  45         } __attribute__((packed)) pkt;
  46         size_t len;
  47         u32 serial, mtu, call_id;
  48
  49         _enter("%d", conn->debug_id);
  50
  51         chan = &conn->channels[sp->hdr.cid & RXRPC_CHANNELMASK];
  52
  53         /* If the last call got moved on whilst we were waiting to run, just
  54          * ignore this packet.
  55          */
  56         call_id = READ_ONCE(chan->last_call);
  57         /* Sync with __rxrpc_disconnect_call() */
  58         smp_rmb();
  59         if (call_id != sp->hdr.callNumber)
  60                 return;
  61
  62         msg.msg_name    = &conn->params.peer->srx.transport;
  63         msg.msg_namelen = conn->params.peer->srx.transport_len;
  64         msg.msg_control = NULL;
  65         msg.msg_controllen = 0;
  66         msg.msg_flags   = 0;
  67
  68         pkt.whdr.epoch          = htonl(sp->hdr.epoch);
  69         pkt.whdr.cid            = htonl(sp->hdr.cid);
  70         pkt.whdr.callNumber     = htonl(sp->hdr.callNumber);
  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(chan->last_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                 len += sizeof(pkt.abort);
  84                 break;
  85
  86         case RXRPC_PACKET_TYPE_ACK:
  87                 mtu = conn->params.peer->if_mtu;
  88                 mtu -= conn->params.peer->hdrsize;
  89                 pkt.ack.bufferSpace     = 0;
  90                 pkt.ack.maxSkew         = htons(skb->priority);
  91                 pkt.ack.firstPacket     = htonl(chan->last_seq);
  92                 pkt.ack.previousPacket  = htonl(chan->last_seq - 1);
  93                 pkt.ack.serial          = htonl(sp->hdr.serial);
  94                 pkt.ack.reason          = RXRPC_ACK_DUPLICATE;
  95                 pkt.ack.nAcks           = 0;
  96                 pkt.info.rxMTU          = htonl(rxrpc_rx_mtu);
  97                 pkt.info.maxMTU         = htonl(mtu);
  98                 pkt.info.rwind          = htonl(rxrpc_rx_window_size);
  99                 pkt.info.jumbo_max      = htonl(rxrpc_rx_jumbo_max);
 100                 pkt.whdr.flags          |= RXRPC_SLOW_START_OK;
 101                 len += sizeof(pkt.ack) + sizeof(pkt.info);
 102                 break;
 103         }
 104
 105         /* Resync with __rxrpc_disconnect_call() and check that the last call
 106          * didn't get advanced whilst we were filling out the packets.
 107          */
 108         smp_rmb();
 109         if (READ_ONCE(chan->last_call) != call_id)
 110                 return;
 111
 112         iov.iov_base    = &pkt;
 113         iov.iov_len     = len;
 114
 115         serial = atomic_inc_return(&conn->serial);
 116         pkt.whdr.serial = htonl(serial);
 117
 118         switch (chan->last_type) {
 119         case RXRPC_PACKET_TYPE_ABORT:
 120                 _proto("Tx ABORT %%%u { %d } [re]", serial, conn->local_abort);
 121                 break;
 122         case RXRPC_PACKET_TYPE_ACK:
 123                 trace_rxrpc_tx_ack(NULL, serial, chan->last_seq, 0,
 124                                    RXRPC_ACK_DUPLICATE, 0);
 125                 _proto("Tx ACK %%%u [re]", serial);
 126                 break;
 127         }
 128
 129         kernel_sendmsg(conn->params.local->socket, &msg, &iov, 1, len);
 130         _leave("");
 131         return;
 132 }
 133
 134 /*
 135  * pass a connection-level abort onto all calls on that connection
 136  */
 137 static void rxrpc_abort_calls(struct rxrpc_connection *conn,
 138                               enum rxrpc_call_completion compl,
 139                               u32 abort_code, int error)
 140 {
 141         struct rxrpc_call *call;
 142         int i;
 143
 144         _enter("{%d},%x", conn->debug_id, abort_code);
 145
 146         spin_lock(&conn->channel_lock);
 147
 148         for (i = 0; i < RXRPC_MAXCALLS; i++) {
 149                 call = rcu_dereference_protected(
 150                         conn->channels[i].call,
 151                         lockdep_is_held(&conn->channel_lock));
 152                 if (call) {
 153                         if (compl == RXRPC_CALL_LOCALLY_ABORTED)
 154                                 trace_rxrpc_abort("CON", call->cid,
 155                                                   call->call_id, 0,
 156                                                   abort_code, error);
 157                         if (rxrpc_set_call_completion(call, compl,
 158                                                       abort_code, error))
 159                                 rxrpc_notify_socket(call);
 160                 }
 161         }
 162
 163         spin_unlock(&conn->channel_lock);
 164         _leave("");
 165 }
 166
 167 /*
 168  * generate a connection-level abort
 169  */
 170 static int rxrpc_abort_connection(struct rxrpc_connection *conn,
 171                                   u32 error, u32 abort_code)
 172 {
 173         struct rxrpc_wire_header whdr;
 174         struct msghdr msg;
 175         struct kvec iov[2];
 176         __be32 word;
 177         size_t len;
 178         u32 serial;
 179         int ret;
 180
 181         _enter("%d,,%u,%u", conn->debug_id, error, abort_code);
 182
 183         /* generate a connection-level abort */
 184         spin_lock_bh(&conn->state_lock);
 185         if (conn->state >= RXRPC_CONN_REMOTELY_ABORTED) {
 186                 spin_unlock_bh(&conn->state_lock);
 187                 _leave(" = 0 [already dead]");
 188                 return 0;
 189         }
 190
 191         conn->state = RXRPC_CONN_LOCALLY_ABORTED;
 192         spin_unlock_bh(&conn->state_lock);
 193
 194         rxrpc_abort_calls(conn, RXRPC_CALL_LOCALLY_ABORTED, abort_code, error);
 195
 196         msg.msg_name    = &conn->params.peer->srx.transport;
 197         msg.msg_namelen = conn->params.peer->srx.transport_len;
 198         msg.msg_control = NULL;
 199         msg.msg_controllen = 0;
 200         msg.msg_flags   = 0;
 201
 202         whdr.epoch      = htonl(conn->proto.epoch);
 203         whdr.cid        = htonl(conn->proto.cid);
 204         whdr.callNumber = 0;
 205         whdr.seq        = 0;
 206         whdr.type       = RXRPC_PACKET_TYPE_ABORT;
 207         whdr.flags      = conn->out_clientflag;
 208         whdr.userStatus = 0;
 209         whdr.securityIndex = conn->security_ix;
 210         whdr._rsvd      = 0;
 211         whdr.serviceId  = htons(conn->params.service_id);
 212
 213         word            = htonl(conn->local_abort);
 214
 215         iov[0].iov_base = &whdr;
 216         iov[0].iov_len  = sizeof(whdr);
 217         iov[1].iov_base = &word;
 218         iov[1].iov_len  = sizeof(word);
 219
 220         len = iov[0].iov_len + iov[1].iov_len;
 221
 222         serial = atomic_inc_return(&conn->serial);
 223         whdr.serial = htonl(serial);
 224         _proto("Tx CONN ABORT %%%u { %d }", serial, conn->local_abort);
 225
 226         ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 2, len);
 227         if (ret < 0) {
 228                 _debug("sendmsg failed: %d", ret);
 229                 return -EAGAIN;
 230         }
 231
 232         _leave(" = 0");
 233         return 0;
 234 }
 235
 236 /*
 237  * mark a call as being on a now-secured channel
 238  * - must be called with BH's disabled.
 239  */
 240 static void rxrpc_call_is_secure(struct rxrpc_call *call)
 241 {
 242         _enter("%p", call);
 243         if (call) {
 244                 write_lock_bh(&call->state_lock);
 245                 if (call->state == RXRPC_CALL_SERVER_SECURING) {
 246                         call->state = RXRPC_CALL_SERVER_ACCEPTING;
 247                         rxrpc_notify_socket(call);
 248                 }
 249                 write_unlock_bh(&call->state_lock);
 250         }
 251 }
 252
 253 /*
 254  * connection-level Rx packet processor
 255  */
 256 static int rxrpc_process_event(struct rxrpc_connection *conn,
 257                                struct sk_buff *skb,
 258                                u32 *_abort_code)
 259 {
 260         struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 261         __be32 wtmp;
 262         u32 abort_code;
 263         int loop, ret;
 264
 265         if (conn->state >= RXRPC_CONN_REMOTELY_ABORTED) {
 266                 _leave(" = -ECONNABORTED [%u]", conn->state);
 267                 return -ECONNABORTED;
 268         }
 269
 270         _enter("{%d},{%u,%%%u},", conn->debug_id, sp->hdr.type, sp->hdr.serial);
 271
 272         switch (sp->hdr.type) {
 273         case RXRPC_PACKET_TYPE_DATA:
 274         case RXRPC_PACKET_TYPE_ACK:
 275                 rxrpc_conn_retransmit_call(conn, skb);
 276                 return 0;
 277
 278         case RXRPC_PACKET_TYPE_ABORT:
 279                 if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
 280                                   &wtmp, sizeof(wtmp)) < 0)
 281                         return -EPROTO;
 282                 abort_code = ntohl(wtmp);
 283                 _proto("Rx ABORT %%%u { ac=%d }", sp->hdr.serial, abort_code);
 284
 285                 conn->state = RXRPC_CONN_REMOTELY_ABORTED;
 286                 rxrpc_abort_calls(conn, RXRPC_CALL_REMOTELY_ABORTED,
 287                                   abort_code, ECONNABORTED);
 288                 return -ECONNABORTED;
 289
 290         case RXRPC_PACKET_TYPE_CHALLENGE:
 291                 return conn->security->respond_to_challenge(conn, skb,
 292                                                             _abort_code);
 293
 294         case RXRPC_PACKET_TYPE_RESPONSE:
 295                 ret = conn->security->verify_response(conn, skb, _abort_code);
 296                 if (ret < 0)
 297                         return ret;
 298
 299                 ret = conn->security->init_connection_security(conn);
 300                 if (ret < 0)
 301                         return ret;
 302
 303                 ret = conn->security->prime_packet_security(conn);
 304                 if (ret < 0)
 305                         return ret;
 306
 307                 spin_lock(&conn->channel_lock);
 308                 spin_lock(&conn->state_lock);
 309
 310                 if (conn->state == RXRPC_CONN_SERVICE_CHALLENGING) {
 311                         conn->state = RXRPC_CONN_SERVICE;
 312                         spin_unlock(&conn->state_lock);
 313                         for (loop = 0; loop < RXRPC_MAXCALLS; loop++)
 314                                 rxrpc_call_is_secure(
 315                                         rcu_dereference_protected(
 316                                                 conn->channels[loop].call,
 317                                                 lockdep_is_held(&conn->channel_lock)));
 318                 } else {
 319                         spin_unlock(&conn->state_lock);
 320                 }
 321
 322                 spin_unlock(&conn->channel_lock);
 323                 return 0;
 324
 325         default:
 326                 _leave(" = -EPROTO [%u]", sp->hdr.type);
 327                 return -EPROTO;
 328         }
 329 }
 330
 331 /*
 332  * set up security and issue a challenge
 333  */
 334 static void rxrpc_secure_connection(struct rxrpc_connection *conn)
 335 {
 336         u32 abort_code;
 337         int ret;
 338
 339         _enter("{%d}", conn->debug_id);
 340
 341         ASSERT(conn->security_ix != 0);
 342
 343         if (!conn->params.key) {
 344                 _debug("set up security");
 345                 ret = rxrpc_init_server_conn_security(conn);
 346                 switch (ret) {
 347                 case 0:
 348                         break;
 349                 case -ENOENT:
 350                         abort_code = RX_CALL_DEAD;
 351                         goto abort;
 352                 default:
 353                         abort_code = RXKADNOAUTH;
 354                         goto abort;
 355                 }
 356         }
 357
 358         if (conn->security->issue_challenge(conn) < 0) {
 359                 abort_code = RX_CALL_DEAD;
 360                 ret = -ENOMEM;
 361                 goto abort;
 362         }
 363
 364         _leave("");
 365         return;
 366
 367 abort:
 368         _debug("abort %d, %d", ret, abort_code);
 369         rxrpc_abort_connection(conn, -ret, abort_code);
 370         _leave(" [aborted]");
 371 }
 372
 373 /*
 374  * connection-level event processor
 375  */
 376 void rxrpc_process_connection(struct work_struct *work)
 377 {
 378         struct rxrpc_connection *conn =
 379                 container_of(work, struct rxrpc_connection, processor);
 380         struct sk_buff *skb;
 381         u32 abort_code = RX_PROTOCOL_ERROR;
 382         int ret;
 383
 384         rxrpc_see_connection(conn);
 385
 386         if (test_and_clear_bit(RXRPC_CONN_EV_CHALLENGE, &conn->events))
 387                 rxrpc_secure_connection(conn);
 388
 389         /* go through the conn-level event packets, releasing the ref on this
 390          * connection that each one has when we've finished with it */
 391         while ((skb = skb_dequeue(&conn->rx_queue))) {
 392                 rxrpc_see_skb(skb, rxrpc_skb_rx_seen);
 393                 ret = rxrpc_process_event(conn, skb, &abort_code);
 394                 switch (ret) {
 395                 case -EPROTO:
 396                 case -EKEYEXPIRED:
 397                 case -EKEYREJECTED:
 398                         goto protocol_error;
 399                 case -EAGAIN:
 400                         goto requeue_and_leave;
 401                 case -ECONNABORTED:
 402                 default:
 403                         rxrpc_free_skb(skb, rxrpc_skb_rx_freed);
 404                         break;
 405                 }
 406         }
 407
 408 out:
 409         rxrpc_put_connection(conn);
 410         _leave("");
 411         return;
 412
 413 requeue_and_leave:
 414         skb_queue_head(&conn->rx_queue, skb);
 415         goto out;
 416
 417 protocol_error:
 418         if (rxrpc_abort_connection(conn, -ret, abort_code) < 0)
 419                 goto requeue_and_leave;
 420         rxrpc_free_skb(skb, rxrpc_skb_rx_freed);
 421         _leave(" [EPROTO]");
 422         goto out;
 423 }