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 = chan->last_call;
 104         if (skb && call_id != sp->hdr.callNumber)
 105                 return;
 106
 107         msg.msg_name    = &conn->peer->srx.transport;
 108         msg.msg_namelen = conn->peer->srx.transport_len;
 109         msg.msg_control = NULL;
 110         msg.msg_controllen = 0;
 111         msg.msg_flags   = 0;
 112
 113         iov[0].iov_base = &pkt;
 114         iov[0].iov_len  = sizeof(pkt.whdr);
 115         iov[1].iov_base = &padding;
 116         iov[1].iov_len  = 3;
 117         iov[2].iov_base = &ack_info;
 118         iov[2].iov_len  = sizeof(ack_info);
 119
 120         serial = atomic_inc_return(&conn->serial);
 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.serial         = htonl(serial);
 126         pkt.whdr.seq            = 0;
 127         pkt.whdr.type           = chan->last_type;
 128         pkt.whdr.flags          = conn->out_clientflag;
 129         pkt.whdr.userStatus     = 0;
 130         pkt.whdr.securityIndex  = conn->security_ix;
 131         pkt.whdr._rsvd          = 0;
 132         pkt.whdr.serviceId      = htons(conn->service_id);
 133
 134         len = sizeof(pkt.whdr);
 135         switch (chan->last_type) {
 136         case RXRPC_PACKET_TYPE_ABORT:
 137                 pkt.abort_code  = htonl(chan->last_abort);
 138                 iov[0].iov_len += sizeof(pkt.abort_code);
 139                 len += sizeof(pkt.abort_code);
 140                 ioc = 1;
 141                 break;
 142
 143         case RXRPC_PACKET_TYPE_ACK:
 144                 mtu = conn->peer->if_mtu;
 145                 mtu -= conn->peer->hdrsize;
 146                 pkt.ack.bufferSpace     = 0;
 147                 pkt.ack.maxSkew         = htons(skb ? skb->priority : 0);
 148                 pkt.ack.firstPacket     = htonl(chan->last_seq + 1);
 149                 pkt.ack.previousPacket  = htonl(chan->last_seq);
 150                 pkt.ack.serial          = htonl(skb ? sp->hdr.serial : 0);
 151                 pkt.ack.reason          = skb ? RXRPC_ACK_DUPLICATE : RXRPC_ACK_IDLE;
 152                 pkt.ack.nAcks           = 0;
 153                 ack_info.rxMTU          = htonl(rxrpc_rx_mtu);
 154                 ack_info.maxMTU         = htonl(mtu);
 155                 ack_info.rwind          = htonl(rxrpc_rx_window_size);
 156                 ack_info.jumbo_max      = htonl(rxrpc_rx_jumbo_max);
 157                 pkt.whdr.flags          |= RXRPC_SLOW_START_OK;
 158                 padding                 = 0;
 159                 iov[0].iov_len += sizeof(pkt.ack);
 160                 len += sizeof(pkt.ack) + 3 + sizeof(ack_info);
 161                 ioc = 3;
 162
 163                 trace_rxrpc_tx_ack(chan->call_debug_id, serial,
 164                                    ntohl(pkt.ack.firstPacket),
 165                                    ntohl(pkt.ack.serial),
 166                                    pkt.ack.reason, 0, rxrpc_rx_window_size);
 167                 break;
 168
 169         default:
 170                 return;
 171         }
 172
 173         ret = kernel_sendmsg(conn->local->socket, &msg, iov, ioc, len);
 174         conn->peer->last_tx_at = ktime_get_seconds();
 175         if (ret < 0)
 176                 trace_rxrpc_tx_fail(chan->call_debug_id, serial, ret,
 177                                     rxrpc_tx_point_call_final_resend);
 178         else
 179                 trace_rxrpc_tx_packet(chan->call_debug_id, &pkt.whdr,
 180                                       rxrpc_tx_point_call_final_resend);
 181
 182         _leave("");
 183 }
 184
 185 /*
 186  * pass a connection-level abort onto all calls on that connection
 187  */
 188 static void rxrpc_abort_calls(struct rxrpc_connection *conn)
 189 {
 190         struct rxrpc_call *call;
 191         int i;
 192
 193         _enter("{%d},%x", conn->debug_id, conn->abort_code);
 194
 195         for (i = 0; i < RXRPC_MAXCALLS; i++) {
 196                 call = conn->channels[i].call;
 197                 if (call)
 198                         rxrpc_set_call_completion(call,
 199                                                   conn->completion,
 200                                                   conn->abort_code,
 201                                                   conn->error);
 202         }
 203
 204         _leave("");
 205 }
 206
 207 /*
 208  * mark a call as being on a now-secured channel
 209  * - must be called with BH's disabled.
 210  */
 211 static void rxrpc_call_is_secure(struct rxrpc_call *call)
 212 {
 213         if (call && __rxrpc_call_state(call) == RXRPC_CALL_SERVER_SECURING) {
 214                 rxrpc_set_call_state(call, RXRPC_CALL_SERVER_RECV_REQUEST);
 215                 rxrpc_notify_socket(call);
 216         }
 217 }
 218
 219 /*
 220  * connection-level Rx packet processor
 221  */
 222 static int rxrpc_process_event(struct rxrpc_connection *conn,
 223                                struct sk_buff *skb)
 224 {
 225         struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 226         int ret;
 227
 228         if (conn->state == RXRPC_CONN_ABORTED)
 229                 return -ECONNABORTED;
 230
 231         _enter("{%d},{%u,%%%u},", conn->debug_id, sp->hdr.type, sp->hdr.serial);
 232
 233         switch (sp->hdr.type) {
 234         case RXRPC_PACKET_TYPE_CHALLENGE:
 235                 return conn->security->respond_to_challenge(conn, skb);
 236
 237         case RXRPC_PACKET_TYPE_RESPONSE:
 238                 ret = conn->security->verify_response(conn, skb);
 239                 if (ret < 0)
 240                         return ret;
 241
 242                 ret = conn->security->init_connection_security(
 243                         conn, conn->key->payload.data[0]);
 244                 if (ret < 0)
 245                         return ret;
 246
 247                 spin_lock(&conn->state_lock);
 248                 if (conn->state == RXRPC_CONN_SERVICE_CHALLENGING)
 249                         conn->state = RXRPC_CONN_SERVICE;
 250                 spin_unlock(&conn->state_lock);
 251
 252                 if (conn->state == RXRPC_CONN_SERVICE) {
 253                         /* Offload call state flipping to the I/O thread.  As
 254                          * we've already received the packet, put it on the
 255                          * front of the queue.
 256                          */
 257                         skb->mark = RXRPC_SKB_MARK_SERVICE_CONN_SECURED;
 258                         rxrpc_get_skb(skb, rxrpc_skb_get_conn_secured);
 259                         skb_queue_head(&conn->local->rx_queue, skb);
 260                         rxrpc_wake_up_io_thread(conn->local);
 261                 }
 262                 return 0;
 263
 264         default:
 265                 WARN_ON_ONCE(1);
 266                 return -EPROTO;
 267         }
 268 }
 269
 270 /*
 271  * set up security and issue a challenge
 272  */
 273 static void rxrpc_secure_connection(struct rxrpc_connection *conn)
 274 {
 275         if (conn->security->issue_challenge(conn) < 0)
 276                 rxrpc_abort_conn(conn, NULL, RX_CALL_DEAD, -ENOMEM,
 277                                  rxrpc_abort_nomem);
 278 }
 279
 280 /*
 281  * Process delayed final ACKs that we haven't subsumed into a subsequent call.
 282  */
 283 void rxrpc_process_delayed_final_acks(struct rxrpc_connection *conn, bool force)
 284 {
 285         unsigned long j = jiffies, next_j;
 286         unsigned int channel;
 287         bool set;
 288
 289 again:
 290         next_j = j + LONG_MAX;
 291         set = false;
 292         for (channel = 0; channel < RXRPC_MAXCALLS; channel++) {
 293                 struct rxrpc_channel *chan = &conn->channels[channel];
 294                 unsigned long ack_at;
 295
 296                 if (!test_bit(RXRPC_CONN_FINAL_ACK_0 + channel, &conn->flags))
 297                         continue;
 298
 299                 ack_at = chan->final_ack_at;
 300                 if (time_before(j, ack_at) && !force) {
 301                         if (time_before(ack_at, next_j)) {
 302                                 next_j = ack_at;
 303                                 set = true;
 304                         }
 305                         continue;
 306                 }
 307
 308                 if (test_and_clear_bit(RXRPC_CONN_FINAL_ACK_0 + channel,
 309                                        &conn->flags))
 310                         rxrpc_conn_retransmit_call(conn, NULL, channel);
 311         }
 312
 313         j = jiffies;
 314         if (time_before_eq(next_j, j))
 315                 goto again;
 316         if (set)
 317                 rxrpc_reduce_conn_timer(conn, next_j);
 318 }
 319
 320 /*
 321  * connection-level event processor
 322  */
 323 static void rxrpc_do_process_connection(struct rxrpc_connection *conn)
 324 {
 325         struct sk_buff *skb;
 326         int ret;
 327
 328         if (test_and_clear_bit(RXRPC_CONN_EV_CHALLENGE, &conn->events))
 329                 rxrpc_secure_connection(conn);
 330
 331         /* go through the conn-level event packets, releasing the ref on this
 332          * connection that each one has when we've finished with it */
 333         while ((skb = skb_dequeue(&conn->rx_queue))) {
 334                 rxrpc_see_skb(skb, rxrpc_skb_see_conn_work);
 335                 ret = rxrpc_process_event(conn, skb);
 336                 switch (ret) {
 337                 case -ENOMEM:
 338                 case -EAGAIN:
 339                         skb_queue_head(&conn->rx_queue, skb);
 340                         rxrpc_queue_conn(conn, rxrpc_conn_queue_retry_work);
 341                         break;
 342                 default:
 343                         rxrpc_free_skb(skb, rxrpc_skb_put_conn_work);
 344                         break;
 345                 }
 346         }
 347 }
 348
 349 void rxrpc_process_connection(struct work_struct *work)
 350 {
 351         struct rxrpc_connection *conn =
 352                 container_of(work, struct rxrpc_connection, processor);
 353
 354         rxrpc_see_connection(conn, rxrpc_conn_see_work);
 355
 356         if (__rxrpc_use_local(conn->local, rxrpc_local_use_conn_work)) {
 357                 rxrpc_do_process_connection(conn);
 358                 rxrpc_unuse_local(conn->local, rxrpc_local_unuse_conn_work);
 359         }
 360 }
 361
 362 /*
 363  * post connection-level events to the connection
 364  * - this includes challenges, responses, some aborts and call terminal packet
 365  *   retransmission.
 366  */
 367 static void rxrpc_post_packet_to_conn(struct rxrpc_connection *conn,
 368                                       struct sk_buff *skb)
 369 {
 370         _enter("%p,%p", conn, skb);
 371
 372         rxrpc_get_skb(skb, rxrpc_skb_get_conn_work);
 373         skb_queue_tail(&conn->rx_queue, skb);
 374         rxrpc_queue_conn(conn, rxrpc_conn_queue_rx_work);
 375 }
 376
 377 /*
 378  * Input a connection-level packet.
 379  */
 380 bool rxrpc_input_conn_packet(struct rxrpc_connection *conn, struct sk_buff *skb)
 381 {
 382         struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 383
 384         switch (sp->hdr.type) {
 385         case RXRPC_PACKET_TYPE_BUSY:
 386                 /* Just ignore BUSY packets for now. */
 387                 return true;
 388
 389         case RXRPC_PACKET_TYPE_ABORT:
 390                 if (rxrpc_is_conn_aborted(conn))
 391                         return true;
 392                 rxrpc_input_conn_abort(conn, skb);
 393                 rxrpc_abort_calls(conn);
 394                 return true;
 395
 396         case RXRPC_PACKET_TYPE_CHALLENGE:
 397         case RXRPC_PACKET_TYPE_RESPONSE:
 398                 if (rxrpc_is_conn_aborted(conn)) {
 399                         if (conn->completion == RXRPC_CALL_LOCALLY_ABORTED)
 400                                 rxrpc_send_conn_abort(conn);
 401                         return true;
 402                 }
 403                 rxrpc_post_packet_to_conn(conn, skb);
 404                 return true;
 405
 406         default:
 407                 WARN_ON_ONCE(1);
 408                 return true;
 409         }
 410 }
 411
 412 /*
 413  * Input a connection event.
 414  */
 415 void rxrpc_input_conn_event(struct rxrpc_connection *conn, struct sk_buff *skb)
 416 {
 417         unsigned int loop;
 418
 419         if (test_and_clear_bit(RXRPC_CONN_EV_ABORT_CALLS, &conn->events))
 420                 rxrpc_abort_calls(conn);
 421
 422         switch (skb->mark) {
 423         case RXRPC_SKB_MARK_SERVICE_CONN_SECURED:
 424                 if (conn->state != RXRPC_CONN_SERVICE)
 425                         break;
 426
 427                 for (loop = 0; loop < RXRPC_MAXCALLS; loop++)
 428                         rxrpc_call_is_secure(conn->channels[loop].call);
 429                 break;
 430         }
 431
 432         /* Process delayed ACKs whose time has come. */
 433         if (conn->flags & RXRPC_CONN_FINAL_ACK_MASK)
 434                 rxrpc_process_delayed_final_acks(conn, false);
 435 }