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 <linux/udp.h>
  19 #include <linux/in.h>
  20 #include <linux/in6.h>
  21 #include <linux/icmp.h>
  22 #include <net/sock.h>
  23 #include <net/af_rxrpc.h>
  24 #include <net/ip.h>
  25 #include "ar-internal.h"
  26
  27 /*
  28  * pass a connection-level abort onto all calls on that connection
  29  */
  30 static void rxrpc_abort_calls(struct rxrpc_connection *conn, int state,
  31                               u32 abort_code)
  32 {
  33         struct rxrpc_call *call;
  34         int i;
  35
  36         _enter("{%d},%x", conn->debug_id, abort_code);
  37
  38         spin_lock(&conn->channel_lock);
  39
  40         for (i = 0; i < RXRPC_MAXCALLS; i++) {
  41                 call = rcu_dereference_protected(
  42                         conn->channels[i].call,
  43                         lockdep_is_held(&conn->channel_lock));
  44                 write_lock_bh(&call->state_lock);
  45                 if (call->state <= RXRPC_CALL_COMPLETE) {
  46                         call->state = state;
  47                         if (state == RXRPC_CALL_LOCALLY_ABORTED) {
  48                                 call->local_abort = conn->local_abort;
  49                                 set_bit(RXRPC_CALL_EV_CONN_ABORT, &call->events);
  50                         } else {
  51                                 call->remote_abort = conn->remote_abort;
  52                                 set_bit(RXRPC_CALL_EV_RCVD_ABORT, &call->events);
  53                         }
  54                         rxrpc_queue_call(call);
  55                 }
  56                 write_unlock_bh(&call->state_lock);
  57         }
  58
  59         spin_unlock(&conn->channel_lock);
  60         _leave("");
  61 }
  62
  63 /*
  64  * generate a connection-level abort
  65  */
  66 static int rxrpc_abort_connection(struct rxrpc_connection *conn,
  67                                   u32 error, u32 abort_code)
  68 {
  69         struct rxrpc_wire_header whdr;
  70         struct msghdr msg;
  71         struct kvec iov[2];
  72         __be32 word;
  73         size_t len;
  74         u32 serial;
  75         int ret;
  76
  77         _enter("%d,,%u,%u", conn->debug_id, error, abort_code);
  78
  79         /* generate a connection-level abort */
  80         spin_lock_bh(&conn->state_lock);
  81         if (conn->state < RXRPC_CONN_REMOTELY_ABORTED) {
  82                 conn->state = RXRPC_CONN_LOCALLY_ABORTED;
  83                 conn->error = error;
  84                 spin_unlock_bh(&conn->state_lock);
  85         } else {
  86                 spin_unlock_bh(&conn->state_lock);
  87                 _leave(" = 0 [already dead]");
  88                 return 0;
  89         }
  90
  91         rxrpc_abort_calls(conn, RXRPC_CALL_LOCALLY_ABORTED, abort_code);
  92
  93         msg.msg_name    = &conn->params.peer->srx.transport;
  94         msg.msg_namelen = conn->params.peer->srx.transport_len;
  95         msg.msg_control = NULL;
  96         msg.msg_controllen = 0;
  97         msg.msg_flags   = 0;
  98
  99         whdr.epoch      = htonl(conn->proto.epoch);
 100         whdr.cid        = htonl(conn->proto.cid);
 101         whdr.callNumber = 0;
 102         whdr.seq        = 0;
 103         whdr.type       = RXRPC_PACKET_TYPE_ABORT;
 104         whdr.flags      = conn->out_clientflag;
 105         whdr.userStatus = 0;
 106         whdr.securityIndex = conn->security_ix;
 107         whdr._rsvd      = 0;
 108         whdr.serviceId  = htons(conn->params.service_id);
 109
 110         word            = htonl(conn->local_abort);
 111
 112         iov[0].iov_base = &whdr;
 113         iov[0].iov_len  = sizeof(whdr);
 114         iov[1].iov_base = &word;
 115         iov[1].iov_len  = sizeof(word);
 116
 117         len = iov[0].iov_len + iov[1].iov_len;
 118
 119         serial = atomic_inc_return(&conn->serial);
 120         whdr.serial = htonl(serial);
 121         _proto("Tx CONN ABORT %%%u { %d }", serial, conn->local_abort);
 122
 123         ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 2, len);
 124         if (ret < 0) {
 125                 _debug("sendmsg failed: %d", ret);
 126                 return -EAGAIN;
 127         }
 128
 129         _leave(" = 0");
 130         return 0;
 131 }
 132
 133 /*
 134  * mark a call as being on a now-secured channel
 135  * - must be called with softirqs disabled
 136  */
 137 static void rxrpc_call_is_secure(struct rxrpc_call *call)
 138 {
 139         _enter("%p", call);
 140         if (call) {
 141                 read_lock(&call->state_lock);
 142                 if (call->state < RXRPC_CALL_COMPLETE &&
 143                     !test_and_set_bit(RXRPC_CALL_EV_SECURED, &call->events))
 144                         rxrpc_queue_call(call);
 145                 read_unlock(&call->state_lock);
 146         }
 147 }
 148
 149 /*
 150  * connection-level Rx packet processor
 151  */
 152 static int rxrpc_process_event(struct rxrpc_connection *conn,
 153                                struct sk_buff *skb,
 154                                u32 *_abort_code)
 155 {
 156         struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 157         __be32 wtmp;
 158         u32 abort_code;
 159         int loop, ret;
 160
 161         if (conn->state >= RXRPC_CONN_REMOTELY_ABORTED) {
 162                 kleave(" = -ECONNABORTED [%u]", conn->state);
 163                 return -ECONNABORTED;
 164         }
 165
 166         _enter("{%d},{%u,%%%u},", conn->debug_id, sp->hdr.type, sp->hdr.serial);
 167
 168         switch (sp->hdr.type) {
 169         case RXRPC_PACKET_TYPE_ABORT:
 170                 if (skb_copy_bits(skb, 0, &wtmp, sizeof(wtmp)) < 0)
 171                         return -EPROTO;
 172                 abort_code = ntohl(wtmp);
 173                 _proto("Rx ABORT %%%u { ac=%d }", sp->hdr.serial, abort_code);
 174
 175                 conn->state = RXRPC_CONN_REMOTELY_ABORTED;
 176                 rxrpc_abort_calls(conn, RXRPC_CALL_REMOTELY_ABORTED,
 177                                   abort_code);
 178                 return -ECONNABORTED;
 179
 180         case RXRPC_PACKET_TYPE_CHALLENGE:
 181                 return conn->security->respond_to_challenge(conn, skb,
 182                                                             _abort_code);
 183
 184         case RXRPC_PACKET_TYPE_RESPONSE:
 185                 ret = conn->security->verify_response(conn, skb, _abort_code);
 186                 if (ret < 0)
 187                         return ret;
 188
 189                 ret = conn->security->init_connection_security(conn);
 190                 if (ret < 0)
 191                         return ret;
 192
 193                 ret = conn->security->prime_packet_security(conn);
 194                 if (ret < 0)
 195                         return ret;
 196
 197                 spin_lock(&conn->channel_lock);
 198                 spin_lock(&conn->state_lock);
 199
 200                 if (conn->state == RXRPC_CONN_SERVICE_CHALLENGING) {
 201                         conn->state = RXRPC_CONN_SERVICE;
 202                         for (loop = 0; loop < RXRPC_MAXCALLS; loop++)
 203                                 rxrpc_call_is_secure(
 204                                         rcu_dereference_protected(
 205                                                 conn->channels[loop].call,
 206                                                 lockdep_is_held(&conn->channel_lock)));
 207                 }
 208
 209                 spin_unlock(&conn->state_lock);
 210                 spin_unlock(&conn->channel_lock);
 211                 return 0;
 212
 213         default:
 214                 _leave(" = -EPROTO [%u]", sp->hdr.type);
 215                 return -EPROTO;
 216         }
 217 }
 218
 219 /*
 220  * set up security and issue a challenge
 221  */
 222 static void rxrpc_secure_connection(struct rxrpc_connection *conn)
 223 {
 224         u32 abort_code;
 225         int ret;
 226
 227         _enter("{%d}", conn->debug_id);
 228
 229         ASSERT(conn->security_ix != 0);
 230
 231         if (!conn->params.key) {
 232                 _debug("set up security");
 233                 ret = rxrpc_init_server_conn_security(conn);
 234                 switch (ret) {
 235                 case 0:
 236                         break;
 237                 case -ENOENT:
 238                         abort_code = RX_CALL_DEAD;
 239                         goto abort;
 240                 default:
 241                         abort_code = RXKADNOAUTH;
 242                         goto abort;
 243                 }
 244         }
 245
 246         if (conn->security->issue_challenge(conn) < 0) {
 247                 abort_code = RX_CALL_DEAD;
 248                 ret = -ENOMEM;
 249                 goto abort;
 250         }
 251
 252         _leave("");
 253         return;
 254
 255 abort:
 256         _debug("abort %d, %d", ret, abort_code);
 257         rxrpc_abort_connection(conn, -ret, abort_code);
 258         _leave(" [aborted]");
 259 }
 260
 261 /*
 262  * connection-level event processor
 263  */
 264 void rxrpc_process_connection(struct work_struct *work)
 265 {
 266         struct rxrpc_connection *conn =
 267                 container_of(work, struct rxrpc_connection, processor);
 268         struct sk_buff *skb;
 269         u32 abort_code = RX_PROTOCOL_ERROR;
 270         int ret;
 271
 272         _enter("{%d}", conn->debug_id);
 273
 274         if (test_and_clear_bit(RXRPC_CONN_EV_CHALLENGE, &conn->events))
 275                 rxrpc_secure_connection(conn);
 276
 277         /* go through the conn-level event packets, releasing the ref on this
 278          * connection that each one has when we've finished with it */
 279         while ((skb = skb_dequeue(&conn->rx_queue))) {
 280                 ret = rxrpc_process_event(conn, skb, &abort_code);
 281                 switch (ret) {
 282                 case -EPROTO:
 283                 case -EKEYEXPIRED:
 284                 case -EKEYREJECTED:
 285                         goto protocol_error;
 286                 case -EAGAIN:
 287                         goto requeue_and_leave;
 288                 case -ECONNABORTED:
 289                 default:
 290                         rxrpc_free_skb(skb);
 291                         break;
 292                 }
 293         }
 294
 295 out:
 296         rxrpc_put_connection(conn);
 297         _leave("");
 298         return;
 299
 300 requeue_and_leave:
 301         skb_queue_head(&conn->rx_queue, skb);
 302         goto out;
 303
 304 protocol_error:
 305         if (rxrpc_abort_connection(conn, -ret, abort_code) < 0)
 306                 goto requeue_and_leave;
 307         rxrpc_free_skb(skb);
 308         _leave(" [EPROTO]");
 309         goto out;
 310 }
 311
 312 /*
 313  * put a packet up for transport-level abort
 314  */
 315 void rxrpc_reject_packet(struct rxrpc_local *local, struct sk_buff *skb)
 316 {
 317         CHECK_SLAB_OKAY(&local->usage);
 318
 319         skb_queue_tail(&local->reject_queue, skb);
 320         rxrpc_queue_local(local);
 321 }
 322
 323 /*
 324  * reject packets through the local endpoint
 325  */
 326 void rxrpc_reject_packets(struct rxrpc_local *local)
 327 {
 328         union {
 329                 struct sockaddr sa;
 330                 struct sockaddr_in sin;
 331         } sa;
 332         struct rxrpc_skb_priv *sp;
 333         struct rxrpc_wire_header whdr;
 334         struct sk_buff *skb;
 335         struct msghdr msg;
 336         struct kvec iov[2];
 337         size_t size;
 338         __be32 code;
 339
 340         _enter("%d", local->debug_id);
 341
 342         iov[0].iov_base = &whdr;
 343         iov[0].iov_len = sizeof(whdr);
 344         iov[1].iov_base = &code;
 345         iov[1].iov_len = sizeof(code);
 346         size = sizeof(whdr) + sizeof(code);
 347
 348         msg.msg_name = &sa;
 349         msg.msg_control = NULL;
 350         msg.msg_controllen = 0;
 351         msg.msg_flags = 0;
 352
 353         memset(&sa, 0, sizeof(sa));
 354         sa.sa.sa_family = local->srx.transport.family;
 355         switch (sa.sa.sa_family) {
 356         case AF_INET:
 357                 msg.msg_namelen = sizeof(sa.sin);
 358                 break;
 359         default:
 360                 msg.msg_namelen = 0;
 361                 break;
 362         }
 363
 364         memset(&whdr, 0, sizeof(whdr));
 365         whdr.type = RXRPC_PACKET_TYPE_ABORT;
 366
 367         while ((skb = skb_dequeue(&local->reject_queue))) {
 368                 sp = rxrpc_skb(skb);
 369                 switch (sa.sa.sa_family) {
 370                 case AF_INET:
 371                         sa.sin.sin_port = udp_hdr(skb)->source;
 372                         sa.sin.sin_addr.s_addr = ip_hdr(skb)->saddr;
 373                         code = htonl(skb->priority);
 374
 375                         whdr.epoch      = htonl(sp->hdr.epoch);
 376                         whdr.cid        = htonl(sp->hdr.cid);
 377                         whdr.callNumber = htonl(sp->hdr.callNumber);
 378                         whdr.serviceId  = htons(sp->hdr.serviceId);
 379                         whdr.flags      = sp->hdr.flags;
 380                         whdr.flags      ^= RXRPC_CLIENT_INITIATED;
 381                         whdr.flags      &= RXRPC_CLIENT_INITIATED;
 382
 383                         kernel_sendmsg(local->socket, &msg, iov, 2, size);
 384                         break;
 385
 386                 default:
 387                         break;
 388                 }
 389
 390                 rxrpc_free_skb(skb);
 391         }
 392
 393         _leave("");
 394 }