net/rxrpc/ar-connevent.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 #include <linux/module.h>
  13 #include <linux/net.h>
  14 #include <linux/skbuff.h>
  15 #include <linux/errqueue.h>
  16 #include <linux/udp.h>
  17 #include <linux/in.h>
  18 #include <linux/in6.h>
  19 #include <linux/icmp.h>
  20 #include <net/sock.h>
  21 #include <net/af_rxrpc.h>
  22 #include <net/ip.h>
  23 #include "ar-internal.h"
  24
  25 /*
  26  * pass a connection-level abort onto all calls on that connection
  27  */
  28 static void rxrpc_abort_calls(struct rxrpc_connection *conn, int state,
  29                               u32 abort_code)
  30 {
  31         struct rxrpc_call *call;
  32         struct rb_node *p;
  33
  34         _enter("{%d},%x", conn->debug_id, abort_code);
  35
  36         read_lock_bh(&conn->lock);
  37
  38         for (p = rb_first(&conn->calls); p; p = rb_next(p)) {
  39                 call = rb_entry(p, struct rxrpc_call, conn_node);
  40                 write_lock(&call->state_lock);
  41                 if (call->state <= RXRPC_CALL_COMPLETE) {
  42                         call->state = state;
  43                         call->abort_code = abort_code;
  44                         if (state == RXRPC_CALL_LOCALLY_ABORTED)
  45                                 set_bit(RXRPC_CALL_CONN_ABORT, &call->events);
  46                         else
  47                                 set_bit(RXRPC_CALL_RCVD_ABORT, &call->events);
  48                         rxrpc_queue_call(call);
  49                 }
  50                 write_unlock(&call->state_lock);
  51         }
  52
  53         read_unlock_bh(&conn->lock);
  54         _leave("");
  55 }
  56
  57 /*
  58  * generate a connection-level abort
  59  */
  60 static int rxrpc_abort_connection(struct rxrpc_connection *conn,
  61                                   u32 error, u32 abort_code)
  62 {
  63         struct rxrpc_header hdr;
  64         struct msghdr msg;
  65         struct kvec iov[2];
  66         __be32 word;
  67         size_t len;
  68         int ret;
  69
  70         _enter("%d,,%u,%u", conn->debug_id, error, abort_code);
  71
  72         /* generate a connection-level abort */
  73         spin_lock_bh(&conn->state_lock);
  74         if (conn->state < RXRPC_CONN_REMOTELY_ABORTED) {
  75                 conn->state = RXRPC_CONN_LOCALLY_ABORTED;
  76                 conn->error = error;
  77                 spin_unlock_bh(&conn->state_lock);
  78         } else {
  79                 spin_unlock_bh(&conn->state_lock);
  80                 _leave(" = 0 [already dead]");
  81                 return 0;
  82         }
  83
  84         rxrpc_abort_calls(conn, RXRPC_CALL_LOCALLY_ABORTED, abort_code);
  85
  86         msg.msg_name    = &conn->trans->peer->srx.transport.sin;
  87         msg.msg_namelen = sizeof(conn->trans->peer->srx.transport.sin);
  88         msg.msg_control = NULL;
  89         msg.msg_controllen = 0;
  90         msg.msg_flags   = 0;
  91
  92         hdr.epoch       = conn->epoch;
  93         hdr.cid         = conn->cid;
  94         hdr.callNumber  = 0;
  95         hdr.seq         = 0;
  96         hdr.type        = RXRPC_PACKET_TYPE_ABORT;
  97         hdr.flags       = conn->out_clientflag;
  98         hdr.userStatus  = 0;
  99         hdr.securityIndex = conn->security_ix;
 100         hdr._rsvd       = 0;
 101         hdr.serviceId   = conn->service_id;
 102
 103         word = htonl(abort_code);
 104
 105         iov[0].iov_base = &hdr;
 106         iov[0].iov_len  = sizeof(hdr);
 107         iov[1].iov_base = &word;
 108         iov[1].iov_len  = sizeof(word);
 109
 110         len = iov[0].iov_len + iov[1].iov_len;
 111
 112         hdr.serial = htonl(atomic_inc_return(&conn->serial));
 113         _proto("Tx CONN ABORT %%%u { %d }", ntohl(hdr.serial), abort_code);
 114
 115         ret = kernel_sendmsg(conn->trans->local->socket, &msg, iov, 2, len);
 116         if (ret < 0) {
 117                 _debug("sendmsg failed: %d", ret);
 118                 return -EAGAIN;
 119         }
 120
 121         _leave(" = 0");
 122         return 0;
 123 }
 124
 125 /*
 126  * mark a call as being on a now-secured channel
 127  * - must be called with softirqs disabled
 128  */
 129 static void rxrpc_call_is_secure(struct rxrpc_call *call)
 130 {
 131         _enter("%p", call);
 132         if (call) {
 133                 read_lock(&call->state_lock);
 134                 if (call->state < RXRPC_CALL_COMPLETE &&
 135                     !test_and_set_bit(RXRPC_CALL_SECURED, &call->events))
 136                         rxrpc_queue_call(call);
 137                 read_unlock(&call->state_lock);
 138         }
 139 }
 140
 141 /*
 142  * connection-level Rx packet processor
 143  */
 144 static int rxrpc_process_event(struct rxrpc_connection *conn,
 145                                struct sk_buff *skb,
 146                                u32 *_abort_code)
 147 {
 148         struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 149         __be32 tmp;
 150         u32 serial;
 151         int loop, ret;
 152
 153         if (conn->state >= RXRPC_CONN_REMOTELY_ABORTED) {
 154                 kleave(" = -ECONNABORTED [%u]", conn->state);
 155                 return -ECONNABORTED;
 156         }
 157
 158         serial = ntohl(sp->hdr.serial);
 159
 160         _enter("{%d},{%u,%%%u},", conn->debug_id, sp->hdr.type, serial);
 161
 162         switch (sp->hdr.type) {
 163         case RXRPC_PACKET_TYPE_ABORT:
 164                 if (skb_copy_bits(skb, 0, &tmp, sizeof(tmp)) < 0)
 165                         return -EPROTO;
 166                 _proto("Rx ABORT %%%u { ac=%d }", serial, ntohl(tmp));
 167
 168                 conn->state = RXRPC_CONN_REMOTELY_ABORTED;
 169                 rxrpc_abort_calls(conn, RXRPC_CALL_REMOTELY_ABORTED,
 170                                   ntohl(tmp));
 171                 return -ECONNABORTED;
 172
 173         case RXRPC_PACKET_TYPE_CHALLENGE:
 174                 if (conn->security)
 175                         return conn->security->respond_to_challenge(
 176                                 conn, skb, _abort_code);
 177                 return -EPROTO;
 178
 179         case RXRPC_PACKET_TYPE_RESPONSE:
 180                 if (!conn->security)
 181                         return -EPROTO;
 182
 183                 ret = conn->security->verify_response(conn, skb, _abort_code);
 184                 if (ret < 0)
 185                         return ret;
 186
 187                 ret = conn->security->init_connection_security(conn);
 188                 if (ret < 0)
 189                         return ret;
 190
 191                 conn->security->prime_packet_security(conn);
 192                 read_lock_bh(&conn->lock);
 193                 spin_lock(&conn->state_lock);
 194
 195                 if (conn->state == RXRPC_CONN_SERVER_CHALLENGING) {
 196                         conn->state = RXRPC_CONN_SERVER;
 197                         for (loop = 0; loop < RXRPC_MAXCALLS; loop++)
 198                                 rxrpc_call_is_secure(conn->channels[loop]);
 199                 }
 200
 201                 spin_unlock(&conn->state_lock);
 202                 read_unlock_bh(&conn->lock);
 203                 return 0;
 204
 205         default:
 206                 _leave(" = -EPROTO [%u]", sp->hdr.type);
 207                 return -EPROTO;
 208         }
 209 }
 210
 211 /*
 212  * set up security and issue a challenge
 213  */
 214 static void rxrpc_secure_connection(struct rxrpc_connection *conn)
 215 {
 216         u32 abort_code;
 217         int ret;
 218
 219         _enter("{%d}", conn->debug_id);
 220
 221         ASSERT(conn->security_ix != 0);
 222
 223         if (!conn->key) {
 224                 _debug("set up security");
 225                 ret = rxrpc_init_server_conn_security(conn);
 226                 switch (ret) {
 227                 case 0:
 228                         break;
 229                 case -ENOENT:
 230                         abort_code = RX_CALL_DEAD;
 231                         goto abort;
 232                 default:
 233                         abort_code = RXKADNOAUTH;
 234                         goto abort;
 235                 }
 236         }
 237
 238         ASSERT(conn->security != NULL);
 239
 240         if (conn->security->issue_challenge(conn) < 0) {
 241                 abort_code = RX_CALL_DEAD;
 242                 ret = -ENOMEM;
 243                 goto abort;
 244         }
 245
 246         _leave("");
 247         return;
 248
 249 abort:
 250         _debug("abort %d, %d", ret, abort_code);
 251         rxrpc_abort_connection(conn, -ret, abort_code);
 252         _leave(" [aborted]");
 253 }
 254
 255 /*
 256  * connection-level event processor
 257  */
 258 void rxrpc_process_connection(struct work_struct *work)
 259 {
 260         struct rxrpc_connection *conn =
 261                 container_of(work, struct rxrpc_connection, processor);
 262         struct rxrpc_skb_priv *sp;
 263         struct sk_buff *skb;
 264         u32 abort_code = RX_PROTOCOL_ERROR;
 265         int ret;
 266
 267         _enter("{%d}", conn->debug_id);
 268
 269         atomic_inc(&conn->usage);
 270
 271         if (test_and_clear_bit(RXRPC_CONN_CHALLENGE, &conn->events)) {
 272                 rxrpc_secure_connection(conn);
 273                 rxrpc_put_connection(conn);
 274         }
 275
 276         /* go through the conn-level event packets, releasing the ref on this
 277          * connection that each one has when we've finished with it */
 278         while ((skb = skb_dequeue(&conn->rx_queue))) {
 279                 sp = rxrpc_skb(skb);
 280
 281                 ret = rxrpc_process_event(conn, skb, &abort_code);
 282                 switch (ret) {
 283                 case -EPROTO:
 284                 case -EKEYEXPIRED:
 285                 case -EKEYREJECTED:
 286                         goto protocol_error;
 287                 case -EAGAIN:
 288                         goto requeue_and_leave;
 289                 case -ECONNABORTED:
 290                 default:
 291                         rxrpc_put_connection(conn);
 292                         rxrpc_free_skb(skb);
 293                         break;
 294                 }
 295         }
 296
 297 out:
 298         rxrpc_put_connection(conn);
 299         _leave("");
 300         return;
 301
 302 requeue_and_leave:
 303         skb_queue_head(&conn->rx_queue, skb);
 304         goto out;
 305
 306 protocol_error:
 307         if (rxrpc_abort_connection(conn, -ret, abort_code) < 0)
 308                 goto requeue_and_leave;
 309         rxrpc_put_connection(conn);
 310         rxrpc_free_skb(skb);
 311         _leave(" [EPROTO]");
 312         goto out;
 313 }
 314
 315 /*
 316  * put a packet up for transport-level abort
 317  */
 318 void rxrpc_reject_packet(struct rxrpc_local *local, struct sk_buff *skb)
 319 {
 320         CHECK_SLAB_OKAY(&local->usage);
 321
 322         if (!atomic_inc_not_zero(&local->usage)) {
 323                 printk("resurrected on reject\n");
 324                 BUG();
 325         }
 326
 327         skb_queue_tail(&local->reject_queue, skb);
 328         rxrpc_queue_work(&local->rejecter);
 329 }
 330
 331 /*
 332  * reject packets through the local endpoint
 333  */
 334 void rxrpc_reject_packets(struct work_struct *work)
 335 {
 336         union {
 337                 struct sockaddr sa;
 338                 struct sockaddr_in sin;
 339         } sa;
 340         struct rxrpc_skb_priv *sp;
 341         struct rxrpc_header hdr;
 342         struct rxrpc_local *local;
 343         struct sk_buff *skb;
 344         struct msghdr msg;
 345         struct kvec iov[2];
 346         size_t size;
 347         __be32 code;
 348
 349         local = container_of(work, struct rxrpc_local, rejecter);
 350         rxrpc_get_local(local);
 351
 352         _enter("%d", local->debug_id);
 353
 354         iov[0].iov_base = &hdr;
 355         iov[0].iov_len = sizeof(hdr);
 356         iov[1].iov_base = &code;
 357         iov[1].iov_len = sizeof(code);
 358         size = sizeof(hdr) + sizeof(code);
 359
 360         msg.msg_name = &sa;
 361         msg.msg_control = NULL;
 362         msg.msg_controllen = 0;
 363         msg.msg_flags = 0;
 364
 365         memset(&sa, 0, sizeof(sa));
 366         sa.sa.sa_family = local->srx.transport.family;
 367         switch (sa.sa.sa_family) {
 368         case AF_INET:
 369                 msg.msg_namelen = sizeof(sa.sin);
 370                 break;
 371         default:
 372                 msg.msg_namelen = 0;
 373                 break;
 374         }
 375
 376         memset(&hdr, 0, sizeof(hdr));
 377         hdr.type = RXRPC_PACKET_TYPE_ABORT;
 378
 379         while ((skb = skb_dequeue(&local->reject_queue))) {
 380                 sp = rxrpc_skb(skb);
 381                 switch (sa.sa.sa_family) {
 382                 case AF_INET:
 383                         sa.sin.sin_port = udp_hdr(skb)->source;
 384                         sa.sin.sin_addr.s_addr = ip_hdr(skb)->saddr;
 385                         code = htonl(skb->priority);
 386
 387                         hdr.epoch = sp->hdr.epoch;
 388                         hdr.cid = sp->hdr.cid;
 389                         hdr.callNumber = sp->hdr.callNumber;
 390                         hdr.serviceId = sp->hdr.serviceId;
 391                         hdr.flags = sp->hdr.flags;
 392                         hdr.flags ^= RXRPC_CLIENT_INITIATED;
 393                         hdr.flags &= RXRPC_CLIENT_INITIATED;
 394
 395                         kernel_sendmsg(local->socket, &msg, iov, 2, size);
 396                         break;
 397
 398                 default:
 399                         break;
 400                 }
 401
 402                 rxrpc_free_skb(skb);
 403                 rxrpc_put_local(local);
 404         }
 405
 406         rxrpc_put_local(local);
 407         _leave("");
 408 }