net/rxrpc/conn_event.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /* connection-level event handling
   3  *
   4  * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
   5  * Written by David Howells (dhowells@redhat.com)
   6  */
   7
   8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
   9
  10 #include <linux/module.h>
  11 #include <linux/net.h>
  12 #include <linux/skbuff.h>
  13 #include <linux/errqueue.h>
  14 #include <net/sock.h>
  15 #include <net/af_rxrpc.h>
  16 #include <net/ip.h>
  17 #include "ar-internal.h"
  18
  19 /*
  20  * Set the completion state on an aborted connection.
  21  */
  22 static bool rxrpc_set_conn_aborted(struct rxrpc_connection *conn, struct sk_buff *skb,
  23                                    s32 abort_code, int err,
  24                                    enum rxrpc_call_completion compl)
  25 {
  26         bool aborted = false;
  27
  28         if (conn->state != RXRPC_CONN_ABORTED) {
  29                 spin_lock(&conn->state_lock);
  30                 if (conn->state != RXRPC_CONN_ABORTED) {
  31                         conn->abort_code = abort_code;
  32                         conn->error      = err;
  33                         conn->completion = compl;
  34                         /* Order the abort info before the state change. */
  35                         smp_store_release(&conn->state, RXRPC_CONN_ABORTED);
  36                         set_bit(RXRPC_CONN_DONT_REUSE, &conn->flags);
  37                         set_bit(RXRPC_CONN_EV_ABORT_CALLS, &conn->events);
  38                         aborted = true;
  39                 }
  40                 spin_unlock(&conn->state_lock);
  41         }
  42
  43         return aborted;
  44 }
  45
  46 /*
  47  * Mark a socket buffer to indicate that the connection it's on should be aborted.
  48  */
  49 int rxrpc_abort_conn(struct rxrpc_connection *conn, struct sk_buff *skb,
  50                      s32 abort_code, int err, enum rxrpc_abort_reason why)
  51 {
  52         struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
  53
  54         if (rxrpc_set_conn_aborted(conn, skb, abort_code, err,
  55                                    RXRPC_CALL_LOCALLY_ABORTED)) {
  56                 trace_rxrpc_abort(0, why, sp->hdr.cid, sp->hdr.callNumber,
  57                                   sp->hdr.seq, abort_code, err);
  58                 rxrpc_poke_conn(conn, rxrpc_conn_get_poke_abort);
  59         }
  60         return -EPROTO;
  61 }
  62
  63 /*
  64  * Mark a connection as being remotely aborted.
  65  */
  66 static bool rxrpc_input_conn_abort(struct rxrpc_connection *conn,
  67                                    struct sk_buff *skb)
  68 {
  69         return rxrpc_set_conn_aborted(conn, skb, skb->priority, -ECONNABORTED,
  70                                       RXRPC_CALL_REMOTELY_ABORTED);
  71 }
  72
  73 /*
  74  * Retransmit terminal ACK or ABORT of the previous call.
  75  */
  76 void rxrpc_conn_retransmit_call(struct rxrpc_connection *conn,
  77                                 struct sk_buff *skb,
  78                                 unsigned int channel)
  79 {
  80         struct rxrpc_skb_priv *sp = skb ? rxrpc_skb(skb) : NULL;
  81         struct rxrpc_channel *chan;
  82         struct msghdr msg;
  83         struct kvec iov[3];
  84         struct {
  85                 struct rxrpc_wire_header whdr;
  86                 union {
  87                         __be32 abort_code;
  88                         struct rxrpc_ackpacket ack;
  89                 };
  90         } __attribute__((packed)) pkt;
  91         struct rxrpc_ackinfo ack_info;
  92         size_t len;
  93         int ret, ioc;
  94         u32 serial, mtu, call_id, padding;
  95
  96         _enter("%d", conn->debug_id);
  97
  98         chan = &conn->channels[channel];
  99
 100         /* If the last call got moved on whilst we were waiting to run, just
 101          * ignore this packet.
 102          */
 103         call_id = READ_ONCE(chan->last_call);
 104         /* Sync with __rxrpc_disconnect_call() */
 105         smp_rmb();
 106         if (skb && call_id != sp->hdr.callNumber)
 107                 return;
 108
 109         msg.msg_name    = &conn->peer->srx.transport;
 110         msg.msg_namelen = conn->peer->srx.transport_len;
 111         msg.msg_control = NULL;
 112         msg.msg_controllen = 0;
 113         msg.msg_flags   = 0;
 114
 115         iov[0].iov_base = &pkt;
 116         iov[0].iov_len  = sizeof(pkt.whdr);
 117         iov[1].iov_base = &padding;
 118         iov[1].iov_len  = 3;
 119         iov[2].iov_base = &ack_info;
 120         iov[2].iov_len  = sizeof(ack_info);
 121
 122         pkt.whdr.epoch          = htonl(conn->proto.epoch);
 123         pkt.whdr.cid            = htonl(conn->proto.cid | channel);
 124         pkt.whdr.callNumber     = htonl(call_id);
 125         pkt.whdr.seq            = 0;
 126         pkt.whdr.type           = chan->last_type;
 127         pkt.whdr.flags          = conn->out_clientflag;
 128         pkt.whdr.userStatus     = 0;
 129         pkt.whdr.securityIndex  = conn->security_ix;
 130         pkt.whdr._rsvd          = 0;
 131         pkt.whdr.serviceId      = htons(conn->service_id);
 132
 133         len = sizeof(pkt.whdr);
 134         switch (chan->last_type) {
 135         case RXRPC_PACKET_TYPE_ABORT:
 136                 pkt.abort_code  = htonl(chan->last_abort);
 137                 iov[0].iov_len += sizeof(pkt.abort_code);
 138                 len += sizeof(pkt.abort_code);
 139                 ioc = 1;
 140                 break;
 141
 142         case RXRPC_PACKET_TYPE_ACK:
 143                 mtu = conn->peer->if_mtu;
 144                 mtu -= conn->peer->hdrsize;
 145                 pkt.ack.bufferSpace     = 0;
 146                 pkt.ack.maxSkew         = htons(skb ? skb->priority : 0);
 147                 pkt.ack.firstPacket     = htonl(chan->last_seq + 1);
 148                 pkt.ack.previousPacket  = htonl(chan->last_seq);
 149                 pkt.ack.serial          = htonl(skb ? sp->hdr.serial : 0);
 150                 pkt.ack.reason          = skb ? RXRPC_ACK_DUPLICATE : RXRPC_ACK_IDLE;
 151                 pkt.ack.nAcks           = 0;
 152                 ack_info.rxMTU          = htonl(rxrpc_rx_mtu);
 153                 ack_info.maxMTU         = htonl(mtu);
 154                 ack_info.rwind          = htonl(rxrpc_rx_window_size);
 155                 ack_info.jumbo_max      = htonl(rxrpc_rx_jumbo_max);
 156                 pkt.whdr.flags          |= RXRPC_SLOW_START_OK;
 157                 padding                 = 0;
 158                 iov[0].iov_len += sizeof(pkt.ack);
 159                 len += sizeof(pkt.ack) + 3 + sizeof(ack_info);
 160                 ioc = 3;
 161                 break;
 162
 163         default:
 164                 return;
 165         }
 166
 167         /* Resync with __rxrpc_disconnect_call() and check that the last call
 168          * didn't get advanced whilst we were filling out the packets.
 169          */
 170         smp_rmb();
 171         if (READ_ONCE(chan->last_call) != call_id)
 172                 return;
 173
 174         serial = atomic_inc_return(&conn->serial);
 175         pkt.whdr.serial = htonl(serial);
 176
 177         switch (chan->last_type) {
 178         case RXRPC_PACKET_TYPE_ABORT:
 179                 break;
 180         case RXRPC_PACKET_TYPE_ACK:
 181                 trace_rxrpc_tx_ack(chan->call_debug_id, serial,
 182                                    ntohl(pkt.ack.firstPacket),
 183                                    ntohl(pkt.ack.serial),
 184                                    pkt.ack.reason, 0);
 185                 break;
 186         }
 187
 188         ret = kernel_sendmsg(conn->local->socket, &msg, iov, ioc, len);
 189         conn->peer->last_tx_at = ktime_get_seconds();
 190         if (ret < 0)
 191                 trace_rxrpc_tx_fail(chan->call_debug_id, serial, ret,
 192                                     rxrpc_tx_point_call_final_resend);
 193         else
 194                 trace_rxrpc_tx_packet(chan->call_debug_id, &pkt.whdr,
 195                                       rxrpc_tx_point_call_final_resend);
 196
 197         _leave("");
 198 }
 199
 200 /*
 201  * pass a connection-level abort onto all calls on that connection
 202  */
 203 static void rxrpc_abort_calls(struct rxrpc_connection *conn)
 204 {
 205         struct rxrpc_call *call;
 206         int i;
 207
 208         _enter("{%d},%x", conn->debug_id, conn->abort_code);
 209
 210         spin_lock(&conn->bundle->channel_lock);
 211
 212         for (i = 0; i < RXRPC_MAXCALLS; i++) {
 213                 call = rcu_dereference_protected(
 214                         conn->channels[i].call,
 215                         lockdep_is_held(&conn->bundle->channel_lock));
 216                 if (call)
 217                         rxrpc_set_call_completion(call,
 218                                                   conn->completion,
 219                                                   conn->abort_code,
 220                                                   conn->error);
 221         }
 222
 223         spin_unlock(&conn->bundle->channel_lock);
 224         _leave("");
 225 }
 226
 227 /*
 228  * mark a call as being on a now-secured channel
 229  * - must be called with BH's disabled.
 230  */
 231 static void rxrpc_call_is_secure(struct rxrpc_call *call)
 232 {
 233         _enter("%p", call);
 234         if (call) {
 235                 write_lock(&call->state_lock);
 236                 if (call->state == RXRPC_CALL_SERVER_SECURING) {
 237                         call->state = RXRPC_CALL_SERVER_RECV_REQUEST;
 238                         rxrpc_notify_socket(call);
 239                 }
 240                 write_unlock(&call->state_lock);
 241         }
 242 }
 243
 244 /*
 245  * connection-level Rx packet processor
 246  */
 247 static int rxrpc_process_event(struct rxrpc_connection *conn,
 248                                struct sk_buff *skb)
 249 {
 250         struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 251         int loop, ret;
 252
 253         if (conn->state == RXRPC_CONN_ABORTED)
 254                 return -ECONNABORTED;
 255
 256         _enter("{%d},{%u,%%%u},", conn->debug_id, sp->hdr.type, sp->hdr.serial);
 257
 258         switch (sp->hdr.type) {
 259         case RXRPC_PACKET_TYPE_CHALLENGE:
 260                 return conn->security->respond_to_challenge(conn, skb);
 261
 262         case RXRPC_PACKET_TYPE_RESPONSE:
 263                 ret = conn->security->verify_response(conn, skb);
 264                 if (ret < 0)
 265                         return ret;
 266
 267                 ret = conn->security->init_connection_security(
 268                         conn, conn->key->payload.data[0]);
 269                 if (ret < 0)
 270                         return ret;
 271
 272                 spin_lock(&conn->bundle->channel_lock);
 273                 spin_lock(&conn->state_lock);
 274
 275                 if (conn->state == RXRPC_CONN_SERVICE_CHALLENGING) {
 276                         conn->state = RXRPC_CONN_SERVICE;
 277                         spin_unlock(&conn->state_lock);
 278                         for (loop = 0; loop < RXRPC_MAXCALLS; loop++)
 279                                 rxrpc_call_is_secure(
 280                                         rcu_dereference_protected(
 281                                                 conn->channels[loop].call,
 282                                                 lockdep_is_held(&conn->bundle->channel_lock)));
 283                 } else {
 284                         spin_unlock(&conn->state_lock);
 285                 }
 286
 287                 spin_unlock(&conn->bundle->channel_lock);
 288                 return 0;
 289
 290         default:
 291                 WARN_ON_ONCE(1);
 292                 return -EPROTO;
 293         }
 294 }
 295
 296 /*
 297  * set up security and issue a challenge
 298  */
 299 static void rxrpc_secure_connection(struct rxrpc_connection *conn)
 300 {
 301         if (conn->security->issue_challenge(conn) < 0)
 302                 rxrpc_abort_conn(conn, NULL, RX_CALL_DEAD, -ENOMEM,
 303                                  rxrpc_abort_nomem);
 304 }
 305
 306 /*
 307  * Process delayed final ACKs that we haven't subsumed into a subsequent call.
 308  */
 309 void rxrpc_process_delayed_final_acks(struct rxrpc_connection *conn, bool force)
 310 {
 311         unsigned long j = jiffies, next_j;
 312         unsigned int channel;
 313         bool set;
 314
 315 again:
 316         next_j = j + LONG_MAX;
 317         set = false;
 318         for (channel = 0; channel < RXRPC_MAXCALLS; channel++) {
 319                 struct rxrpc_channel *chan = &conn->channels[channel];
 320                 unsigned long ack_at;
 321
 322                 if (!test_bit(RXRPC_CONN_FINAL_ACK_0 + channel, &conn->flags))
 323                         continue;
 324
 325                 smp_rmb(); /* vs rxrpc_disconnect_client_call */
 326                 ack_at = READ_ONCE(chan->final_ack_at);
 327
 328                 if (time_before(j, ack_at) && !force) {
 329                         if (time_before(ack_at, next_j)) {
 330                                 next_j = ack_at;
 331                                 set = true;
 332                         }
 333                         continue;
 334                 }
 335
 336                 if (test_and_clear_bit(RXRPC_CONN_FINAL_ACK_0 + channel,
 337                                        &conn->flags))
 338                         rxrpc_conn_retransmit_call(conn, NULL, channel);
 339         }
 340
 341         j = jiffies;
 342         if (time_before_eq(next_j, j))
 343                 goto again;
 344         if (set)
 345                 rxrpc_reduce_conn_timer(conn, next_j);
 346 }
 347
 348 /*
 349  * connection-level event processor
 350  */
 351 static void rxrpc_do_process_connection(struct rxrpc_connection *conn)
 352 {
 353         struct sk_buff *skb;
 354         int ret;
 355
 356         if (test_and_clear_bit(RXRPC_CONN_EV_CHALLENGE, &conn->events))
 357                 rxrpc_secure_connection(conn);
 358
 359         /* go through the conn-level event packets, releasing the ref on this
 360          * connection that each one has when we've finished with it */
 361         while ((skb = skb_dequeue(&conn->rx_queue))) {
 362                 rxrpc_see_skb(skb, rxrpc_skb_see_conn_work);
 363                 ret = rxrpc_process_event(conn, skb);
 364                 switch (ret) {
 365                 case -ENOMEM:
 366                 case -EAGAIN:
 367                         skb_queue_head(&conn->rx_queue, skb);
 368                         rxrpc_queue_conn(conn, rxrpc_conn_queue_retry_work);
 369                         break;
 370                 default:
 371                         rxrpc_free_skb(skb, rxrpc_skb_put_conn_work);
 372                         break;
 373                 }
 374         }
 375 }
 376
 377 void rxrpc_process_connection(struct work_struct *work)
 378 {
 379         struct rxrpc_connection *conn =
 380                 container_of(work, struct rxrpc_connection, processor);
 381
 382         rxrpc_see_connection(conn, rxrpc_conn_see_work);
 383
 384         if (__rxrpc_use_local(conn->local, rxrpc_local_use_conn_work)) {
 385                 rxrpc_do_process_connection(conn);
 386                 rxrpc_unuse_local(conn->local, rxrpc_local_unuse_conn_work);
 387         }
 388 }
 389
 390 /*
 391  * post connection-level events to the connection
 392  * - this includes challenges, responses, some aborts and call terminal packet
 393  *   retransmission.
 394  */
 395 static void rxrpc_post_packet_to_conn(struct rxrpc_connection *conn,
 396                                       struct sk_buff *skb)
 397 {
 398         _enter("%p,%p", conn, skb);
 399
 400         rxrpc_get_skb(skb, rxrpc_skb_get_conn_work);
 401         skb_queue_tail(&conn->rx_queue, skb);
 402         rxrpc_queue_conn(conn, rxrpc_conn_queue_rx_work);
 403 }
 404
 405 /*
 406  * Input a connection-level packet.
 407  */
 408 bool rxrpc_input_conn_packet(struct rxrpc_connection *conn, struct sk_buff *skb)
 409 {
 410         struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 411
 412         switch (sp->hdr.type) {
 413         case RXRPC_PACKET_TYPE_BUSY:
 414                 /* Just ignore BUSY packets for now. */
 415                 return true;
 416
 417         case RXRPC_PACKET_TYPE_ABORT:
 418                 if (rxrpc_is_conn_aborted(conn))
 419                         return true;
 420                 rxrpc_input_conn_abort(conn, skb);
 421                 rxrpc_abort_calls(conn);
 422                 return true;
 423
 424         case RXRPC_PACKET_TYPE_CHALLENGE:
 425         case RXRPC_PACKET_TYPE_RESPONSE:
 426                 if (rxrpc_is_conn_aborted(conn)) {
 427                         if (conn->completion == RXRPC_CALL_LOCALLY_ABORTED)
 428                                 rxrpc_send_conn_abort(conn);
 429                         return true;
 430                 }
 431                 rxrpc_post_packet_to_conn(conn, skb);
 432                 return true;
 433
 434         default:
 435                 WARN_ON_ONCE(1);
 436                 return true;
 437         }
 438 }
 439
 440 /*
 441  * Input a connection event.
 442  */
 443 void rxrpc_input_conn_event(struct rxrpc_connection *conn, struct sk_buff *skb)
 444 {
 445         if (test_and_clear_bit(RXRPC_CONN_EV_ABORT_CALLS, &conn->events))
 446                 rxrpc_abort_calls(conn);
 447
 448         /* Process delayed ACKs whose time has come. */
 449         if (conn->flags & RXRPC_CONN_FINAL_ACK_MASK)
 450                 rxrpc_process_delayed_final_acks(conn, false);
 451 }