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