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(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                 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->abort_code);
 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 {
 140         struct rxrpc_call *call;
 141         int i;
 142
 143         _enter("{%d},%x", conn->debug_id, conn->abort_code);
 144
 145         spin_lock(&conn->channel_lock);
 146
 147         for (i = 0; i < RXRPC_MAXCALLS; i++) {
 148                 call = rcu_dereference_protected(
 149                         conn->channels[i].call,
 150                         lockdep_is_held(&conn->channel_lock));
 151                 if (call) {
 152                         if (compl == RXRPC_CALL_LOCALLY_ABORTED)
 153                                 trace_rxrpc_abort("CON", call->cid,
 154                                                   call->call_id, 0,
 155                                                   conn->abort_code,
 156                                                   conn->error);
 157                         if (rxrpc_set_call_completion(call, compl,
 158                                                       conn->abort_code,
 159                                                       conn->error))
 160                                 rxrpc_notify_socket(call);
 161                 }
 162         }
 163
 164         spin_unlock(&conn->channel_lock);
 165         _leave("");
 166 }
 167
 168 /*
 169  * generate a connection-level abort
 170  */
 171 static int rxrpc_abort_connection(struct rxrpc_connection *conn,
 172                                   int error, u32 abort_code)
 173 {
 174         struct rxrpc_wire_header whdr;
 175         struct msghdr msg;
 176         struct kvec iov[2];
 177         __be32 word;
 178         size_t len;
 179         u32 serial;
 180         int ret;
 181
 182         _enter("%d,,%u,%u", conn->debug_id, error, abort_code);
 183
 184         /* generate a connection-level abort */
 185         spin_lock_bh(&conn->state_lock);
 186         if (conn->state >= RXRPC_CONN_REMOTELY_ABORTED) {
 187                 spin_unlock_bh(&conn->state_lock);
 188                 _leave(" = 0 [already dead]");
 189                 return 0;
 190         }
 191
 192         conn->error = error;
 193         conn->abort_code = abort_code;
 194         conn->state = RXRPC_CONN_LOCALLY_ABORTED;
 195         spin_unlock_bh(&conn->state_lock);
 196
 197         rxrpc_abort_calls(conn, RXRPC_CALL_LOCALLY_ABORTED);
 198
 199         msg.msg_name    = &conn->params.peer->srx.transport;
 200         msg.msg_namelen = conn->params.peer->srx.transport_len;
 201         msg.msg_control = NULL;
 202         msg.msg_controllen = 0;
 203         msg.msg_flags   = 0;
 204
 205         whdr.epoch      = htonl(conn->proto.epoch);
 206         whdr.cid        = htonl(conn->proto.cid);
 207         whdr.callNumber = 0;
 208         whdr.seq        = 0;
 209         whdr.type       = RXRPC_PACKET_TYPE_ABORT;
 210         whdr.flags      = conn->out_clientflag;
 211         whdr.userStatus = 0;
 212         whdr.securityIndex = conn->security_ix;
 213         whdr._rsvd      = 0;
 214         whdr.serviceId  = htons(conn->service_id);
 215
 216         word            = htonl(conn->abort_code);
 217
 218         iov[0].iov_base = &whdr;
 219         iov[0].iov_len  = sizeof(whdr);
 220         iov[1].iov_base = &word;
 221         iov[1].iov_len  = sizeof(word);
 222
 223         len = iov[0].iov_len + iov[1].iov_len;
 224
 225         serial = atomic_inc_return(&conn->serial);
 226         whdr.serial = htonl(serial);
 227         _proto("Tx CONN ABORT %%%u { %d }", serial, conn->abort_code);
 228
 229         ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 2, len);
 230         if (ret < 0) {
 231                 _debug("sendmsg failed: %d", ret);
 232                 return -EAGAIN;
 233         }
 234
 235         _leave(" = 0");
 236         return 0;
 237 }
 238
 239 /*
 240  * mark a call as being on a now-secured channel
 241  * - must be called with BH's disabled.
 242  */
 243 static void rxrpc_call_is_secure(struct rxrpc_call *call)
 244 {
 245         _enter("%p", call);
 246         if (call) {
 247                 write_lock_bh(&call->state_lock);
 248                 if (call->state == RXRPC_CALL_SERVER_SECURING) {
 249                         call->state = RXRPC_CALL_SERVER_ACCEPTING;
 250                         rxrpc_notify_socket(call);
 251                 }
 252                 write_unlock_bh(&call->state_lock);
 253         }
 254 }
 255
 256 /*
 257  * connection-level Rx packet processor
 258  */
 259 static int rxrpc_process_event(struct rxrpc_connection *conn,
 260                                struct sk_buff *skb,
 261                                u32 *_abort_code)
 262 {
 263         struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 264         __be32 wtmp;
 265         u32 abort_code;
 266         int loop, ret;
 267
 268         if (conn->state >= RXRPC_CONN_REMOTELY_ABORTED) {
 269                 _leave(" = -ECONNABORTED [%u]", conn->state);
 270                 return -ECONNABORTED;
 271         }
 272
 273         _enter("{%d},{%u,%%%u},", conn->debug_id, sp->hdr.type, sp->hdr.serial);
 274
 275         switch (sp->hdr.type) {
 276         case RXRPC_PACKET_TYPE_DATA:
 277         case RXRPC_PACKET_TYPE_ACK:
 278                 rxrpc_conn_retransmit_call(conn, skb);
 279                 return 0;
 280
 281         case RXRPC_PACKET_TYPE_BUSY:
 282                 /* Just ignore BUSY packets for now. */
 283                 return 0;
 284
 285         case RXRPC_PACKET_TYPE_ABORT:
 286                 if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
 287                                   &wtmp, sizeof(wtmp)) < 0) {
 288                         trace_rxrpc_rx_eproto(NULL, sp->hdr.serial,
 289                                               tracepoint_string("bad_abort"));
 290                         return -EPROTO;
 291                 }
 292                 abort_code = ntohl(wtmp);
 293                 _proto("Rx ABORT %%%u { ac=%d }", sp->hdr.serial, abort_code);
 294
 295                 conn->error = -ECONNABORTED;
 296                 conn->abort_code = abort_code;
 297                 conn->state = RXRPC_CONN_REMOTELY_ABORTED;
 298                 rxrpc_abort_calls(conn, RXRPC_CALL_REMOTELY_ABORTED);
 299                 return -ECONNABORTED;
 300
 301         case RXRPC_PACKET_TYPE_CHALLENGE:
 302                 return conn->security->respond_to_challenge(conn, skb,
 303                                                             _abort_code);
 304
 305         case RXRPC_PACKET_TYPE_RESPONSE:
 306                 ret = conn->security->verify_response(conn, skb, _abort_code);
 307                 if (ret < 0)
 308                         return ret;
 309
 310                 ret = conn->security->init_connection_security(conn);
 311                 if (ret < 0)
 312                         return ret;
 313
 314                 ret = conn->security->prime_packet_security(conn);
 315                 if (ret < 0)
 316                         return ret;
 317
 318                 spin_lock(&conn->channel_lock);
 319                 spin_lock_bh(&conn->state_lock);
 320
 321                 if (conn->state == RXRPC_CONN_SERVICE_CHALLENGING) {
 322                         conn->state = RXRPC_CONN_SERVICE;
 323                         spin_unlock_bh(&conn->state_lock);
 324                         for (loop = 0; loop < RXRPC_MAXCALLS; loop++)
 325                                 rxrpc_call_is_secure(
 326                                         rcu_dereference_protected(
 327                                                 conn->channels[loop].call,
 328                                                 lockdep_is_held(&conn->channel_lock)));
 329                 } else {
 330                         spin_unlock_bh(&conn->state_lock);
 331                 }
 332
 333                 spin_unlock(&conn->channel_lock);
 334                 return 0;
 335
 336         default:
 337                 trace_rxrpc_rx_eproto(NULL, sp->hdr.serial,
 338                                       tracepoint_string("bad_conn_pkt"));
 339                 return -EPROTO;
 340         }
 341 }
 342
 343 /*
 344  * set up security and issue a challenge
 345  */
 346 static void rxrpc_secure_connection(struct rxrpc_connection *conn)
 347 {
 348         u32 abort_code;
 349         int ret;
 350
 351         _enter("{%d}", conn->debug_id);
 352
 353         ASSERT(conn->security_ix != 0);
 354
 355         if (!conn->params.key) {
 356                 _debug("set up security");
 357                 ret = rxrpc_init_server_conn_security(conn);
 358                 switch (ret) {
 359                 case 0:
 360                         break;
 361                 case -ENOENT:
 362                         abort_code = RX_CALL_DEAD;
 363                         goto abort;
 364                 default:
 365                         abort_code = RXKADNOAUTH;
 366                         goto abort;
 367                 }
 368         }
 369
 370         if (conn->security->issue_challenge(conn) < 0) {
 371                 abort_code = RX_CALL_DEAD;
 372                 ret = -ENOMEM;
 373                 goto abort;
 374         }
 375
 376         _leave("");
 377         return;
 378
 379 abort:
 380         _debug("abort %d, %d", ret, abort_code);
 381         rxrpc_abort_connection(conn, ret, abort_code);
 382         _leave(" [aborted]");
 383 }
 384
 385 /*
 386  * connection-level event processor
 387  */
 388 void rxrpc_process_connection(struct work_struct *work)
 389 {
 390         struct rxrpc_connection *conn =
 391                 container_of(work, struct rxrpc_connection, processor);
 392         struct sk_buff *skb;
 393         u32 abort_code = RX_PROTOCOL_ERROR;
 394         int ret;
 395
 396         rxrpc_see_connection(conn);
 397
 398         if (test_and_clear_bit(RXRPC_CONN_EV_CHALLENGE, &conn->events))
 399                 rxrpc_secure_connection(conn);
 400
 401         /* go through the conn-level event packets, releasing the ref on this
 402          * connection that each one has when we've finished with it */
 403         while ((skb = skb_dequeue(&conn->rx_queue))) {
 404                 rxrpc_see_skb(skb, rxrpc_skb_rx_seen);
 405                 ret = rxrpc_process_event(conn, skb, &abort_code);
 406                 switch (ret) {
 407                 case -EPROTO:
 408                 case -EKEYEXPIRED:
 409                 case -EKEYREJECTED:
 410                         goto protocol_error;
 411                 case -ENOMEM:
 412                 case -EAGAIN:
 413                         goto requeue_and_leave;
 414                 case -ECONNABORTED:
 415                 default:
 416                         rxrpc_free_skb(skb, rxrpc_skb_rx_freed);
 417                         break;
 418                 }
 419         }
 420
 421 out:
 422         rxrpc_put_connection(conn);
 423         _leave("");
 424         return;
 425
 426 requeue_and_leave:
 427         skb_queue_head(&conn->rx_queue, skb);
 428         goto out;
 429
 430 protocol_error:
 431         if (rxrpc_abort_connection(conn, ret, abort_code) < 0)
 432                 goto requeue_and_leave;
 433         rxrpc_free_skb(skb, rxrpc_skb_rx_freed);
 434         goto out;
 435 }