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