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         if (sp && sp->hdr.type == RXRPC_PACKET_TYPE_ACK) {
  99                 if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
 100                                   &pkt.ack, sizeof(pkt.ack)) < 0)
 101                         return;
 102                 if (pkt.ack.reason == RXRPC_ACK_PING_RESPONSE)
 103                         return;
 104         }
 105
 106         chan = &conn->channels[channel];
 107
 108         /* If the last call got moved on whilst we were waiting to run, just
 109          * ignore this packet.
 110          */
 111         call_id = chan->last_call;
 112         if (skb && call_id != sp->hdr.callNumber)
 113                 return;
 114
 115         msg.msg_name    = &conn->peer->srx.transport;
 116         msg.msg_namelen = conn->peer->srx.transport_len;
 117         msg.msg_control = NULL;
 118         msg.msg_controllen = 0;
 119         msg.msg_flags   = 0;
 120
 121         iov[0].iov_base = &pkt;
 122         iov[0].iov_len  = sizeof(pkt.whdr);
 123         iov[1].iov_base = &padding;
 124         iov[1].iov_len  = 3;
 125         iov[2].iov_base = &ack_info;
 126         iov[2].iov_len  = sizeof(ack_info);
 127
 128         serial = rxrpc_get_next_serial(conn);
 129
 130         pkt.whdr.epoch          = htonl(conn->proto.epoch);
 131         pkt.whdr.cid            = htonl(conn->proto.cid | channel);
 132         pkt.whdr.callNumber     = htonl(call_id);
 133         pkt.whdr.serial         = htonl(serial);
 134         pkt.whdr.seq            = 0;
 135         pkt.whdr.type           = chan->last_type;
 136         pkt.whdr.flags          = conn->out_clientflag;
 137         pkt.whdr.userStatus     = 0;
 138         pkt.whdr.securityIndex  = conn->security_ix;
 139         pkt.whdr._rsvd          = 0;
 140         pkt.whdr.serviceId      = htons(conn->service_id);
 141
 142         len = sizeof(pkt.whdr);
 143         switch (chan->last_type) {
 144         case RXRPC_PACKET_TYPE_ABORT:
 145                 pkt.abort_code  = htonl(chan->last_abort);
 146                 iov[0].iov_len += sizeof(pkt.abort_code);
 147                 len += sizeof(pkt.abort_code);
 148                 ioc = 1;
 149                 break;
 150
 151         case RXRPC_PACKET_TYPE_ACK:
 152                 mtu = conn->peer->if_mtu;
 153                 mtu -= conn->peer->hdrsize;
 154                 pkt.ack.bufferSpace     = 0;
 155                 pkt.ack.maxSkew         = htons(skb ? skb->priority : 0);
 156                 pkt.ack.firstPacket     = htonl(chan->last_seq + 1);
 157                 pkt.ack.previousPacket  = htonl(chan->last_seq);
 158                 pkt.ack.serial          = htonl(skb ? sp->hdr.serial : 0);
 159                 pkt.ack.reason          = skb ? RXRPC_ACK_DUPLICATE : RXRPC_ACK_IDLE;
 160                 pkt.ack.nAcks           = 0;
 161                 ack_info.rxMTU          = htonl(rxrpc_rx_mtu);
 162                 ack_info.maxMTU         = htonl(mtu);
 163                 ack_info.rwind          = htonl(rxrpc_rx_window_size);
 164                 ack_info.jumbo_max      = htonl(rxrpc_rx_jumbo_max);
 165                 pkt.whdr.flags          |= RXRPC_SLOW_START_OK;
 166                 padding                 = 0;
 167                 iov[0].iov_len += sizeof(pkt.ack);
 168                 len += sizeof(pkt.ack) + 3 + sizeof(ack_info);
 169                 ioc = 3;
 170
 171                 trace_rxrpc_tx_ack(chan->call_debug_id, serial,
 172                                    ntohl(pkt.ack.firstPacket),
 173                                    ntohl(pkt.ack.serial),
 174                                    pkt.ack.reason, 0, rxrpc_rx_window_size);
 175                 break;
 176
 177         default:
 178                 return;
 179         }
 180
 181         ret = kernel_sendmsg(conn->local->socket, &msg, iov, ioc, len);
 182         conn->peer->last_tx_at = ktime_get_seconds();
 183         if (ret < 0)
 184                 trace_rxrpc_tx_fail(chan->call_debug_id, serial, ret,
 185                                     rxrpc_tx_point_call_final_resend);
 186         else
 187                 trace_rxrpc_tx_packet(chan->call_debug_id, &pkt.whdr,
 188                                       rxrpc_tx_point_call_final_resend);
 189
 190         _leave("");
 191 }
 192
 193 /*
 194  * pass a connection-level abort onto all calls on that connection
 195  */
 196 static void rxrpc_abort_calls(struct rxrpc_connection *conn)
 197 {
 198         struct rxrpc_call *call;
 199         int i;
 200
 201         _enter("{%d},%x", conn->debug_id, conn->abort_code);
 202
 203         for (i = 0; i < RXRPC_MAXCALLS; i++) {
 204                 call = conn->channels[i].call;
 205                 if (call)
 206                         rxrpc_set_call_completion(call,
 207                                                   conn->completion,
 208                                                   conn->abort_code,
 209                                                   conn->error);
 210         }
 211
 212         _leave("");
 213 }
 214
 215 /*
 216  * mark a call as being on a now-secured channel
 217  * - must be called with BH's disabled.
 218  */
 219 static void rxrpc_call_is_secure(struct rxrpc_call *call)
 220 {
 221         if (call && __rxrpc_call_state(call) == RXRPC_CALL_SERVER_SECURING) {
 222                 rxrpc_set_call_state(call, RXRPC_CALL_SERVER_RECV_REQUEST);
 223                 rxrpc_notify_socket(call);
 224         }
 225 }
 226
 227 /*
 228  * connection-level Rx packet processor
 229  */
 230 static int rxrpc_process_event(struct rxrpc_connection *conn,
 231                                struct sk_buff *skb)
 232 {
 233         struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 234         int ret;
 235
 236         if (conn->state == RXRPC_CONN_ABORTED)
 237                 return -ECONNABORTED;
 238
 239         _enter("{%d},{%u,%%%u},", conn->debug_id, sp->hdr.type, sp->hdr.serial);
 240
 241         switch (sp->hdr.type) {
 242         case RXRPC_PACKET_TYPE_CHALLENGE:
 243                 return conn->security->respond_to_challenge(conn, skb);
 244
 245         case RXRPC_PACKET_TYPE_RESPONSE:
 246                 ret = conn->security->verify_response(conn, skb);
 247                 if (ret < 0)
 248                         return ret;
 249
 250                 ret = conn->security->init_connection_security(
 251                         conn, conn->key->payload.data[0]);
 252                 if (ret < 0)
 253                         return ret;
 254
 255                 spin_lock(&conn->state_lock);
 256                 if (conn->state == RXRPC_CONN_SERVICE_CHALLENGING)
 257                         conn->state = RXRPC_CONN_SERVICE;
 258                 spin_unlock(&conn->state_lock);
 259
 260                 if (conn->state == RXRPC_CONN_SERVICE) {
 261                         /* Offload call state flipping to the I/O thread.  As
 262                          * we've already received the packet, put it on the
 263                          * front of the queue.
 264                          */
 265                         skb->mark = RXRPC_SKB_MARK_SERVICE_CONN_SECURED;
 266                         rxrpc_get_skb(skb, rxrpc_skb_get_conn_secured);
 267                         skb_queue_head(&conn->local->rx_queue, skb);
 268                         rxrpc_wake_up_io_thread(conn->local);
 269                 }
 270                 return 0;
 271
 272         default:
 273                 WARN_ON_ONCE(1);
 274                 return -EPROTO;
 275         }
 276 }
 277
 278 /*
 279  * set up security and issue a challenge
 280  */
 281 static void rxrpc_secure_connection(struct rxrpc_connection *conn)
 282 {
 283         if (conn->security->issue_challenge(conn) < 0)
 284                 rxrpc_abort_conn(conn, NULL, RX_CALL_DEAD, -ENOMEM,
 285                                  rxrpc_abort_nomem);
 286 }
 287
 288 /*
 289  * Process delayed final ACKs that we haven't subsumed into a subsequent call.
 290  */
 291 void rxrpc_process_delayed_final_acks(struct rxrpc_connection *conn, bool force)
 292 {
 293         unsigned long j = jiffies, next_j;
 294         unsigned int channel;
 295         bool set;
 296
 297 again:
 298         next_j = j + LONG_MAX;
 299         set = false;
 300         for (channel = 0; channel < RXRPC_MAXCALLS; channel++) {
 301                 struct rxrpc_channel *chan = &conn->channels[channel];
 302                 unsigned long ack_at;
 303
 304                 if (!test_bit(RXRPC_CONN_FINAL_ACK_0 + channel, &conn->flags))
 305                         continue;
 306
 307                 ack_at = chan->final_ack_at;
 308                 if (time_before(j, ack_at) && !force) {
 309                         if (time_before(ack_at, next_j)) {
 310                                 next_j = ack_at;
 311                                 set = true;
 312                         }
 313                         continue;
 314                 }
 315
 316                 if (test_and_clear_bit(RXRPC_CONN_FINAL_ACK_0 + channel,
 317                                        &conn->flags))
 318                         rxrpc_conn_retransmit_call(conn, NULL, channel);
 319         }
 320
 321         j = jiffies;
 322         if (time_before_eq(next_j, j))
 323                 goto again;
 324         if (set)
 325                 rxrpc_reduce_conn_timer(conn, next_j);
 326 }
 327
 328 /*
 329  * connection-level event processor
 330  */
 331 static void rxrpc_do_process_connection(struct rxrpc_connection *conn)
 332 {
 333         struct sk_buff *skb;
 334         int ret;
 335
 336         if (test_and_clear_bit(RXRPC_CONN_EV_CHALLENGE, &conn->events))
 337                 rxrpc_secure_connection(conn);
 338
 339         /* go through the conn-level event packets, releasing the ref on this
 340          * connection that each one has when we've finished with it */
 341         while ((skb = skb_dequeue(&conn->rx_queue))) {
 342                 rxrpc_see_skb(skb, rxrpc_skb_see_conn_work);
 343                 ret = rxrpc_process_event(conn, skb);
 344                 switch (ret) {
 345                 case -ENOMEM:
 346                 case -EAGAIN:
 347                         skb_queue_head(&conn->rx_queue, skb);
 348                         rxrpc_queue_conn(conn, rxrpc_conn_queue_retry_work);
 349                         break;
 350                 default:
 351                         rxrpc_free_skb(skb, rxrpc_skb_put_conn_work);
 352                         break;
 353                 }
 354         }
 355 }
 356
 357 void rxrpc_process_connection(struct work_struct *work)
 358 {
 359         struct rxrpc_connection *conn =
 360                 container_of(work, struct rxrpc_connection, processor);
 361
 362         rxrpc_see_connection(conn, rxrpc_conn_see_work);
 363
 364         if (__rxrpc_use_local(conn->local, rxrpc_local_use_conn_work)) {
 365                 rxrpc_do_process_connection(conn);
 366                 rxrpc_unuse_local(conn->local, rxrpc_local_unuse_conn_work);
 367         }
 368 }
 369
 370 /*
 371  * post connection-level events to the connection
 372  * - this includes challenges, responses, some aborts and call terminal packet
 373  *   retransmission.
 374  */
 375 static void rxrpc_post_packet_to_conn(struct rxrpc_connection *conn,
 376                                       struct sk_buff *skb)
 377 {
 378         _enter("%p,%p", conn, skb);
 379
 380         rxrpc_get_skb(skb, rxrpc_skb_get_conn_work);
 381         skb_queue_tail(&conn->rx_queue, skb);
 382         rxrpc_queue_conn(conn, rxrpc_conn_queue_rx_work);
 383 }
 384
 385 /*
 386  * Input a connection-level packet.
 387  */
 388 bool rxrpc_input_conn_packet(struct rxrpc_connection *conn, struct sk_buff *skb)
 389 {
 390         struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 391
 392         switch (sp->hdr.type) {
 393         case RXRPC_PACKET_TYPE_BUSY:
 394                 /* Just ignore BUSY packets for now. */
 395                 return true;
 396
 397         case RXRPC_PACKET_TYPE_ABORT:
 398                 if (rxrpc_is_conn_aborted(conn))
 399                         return true;
 400                 rxrpc_input_conn_abort(conn, skb);
 401                 rxrpc_abort_calls(conn);
 402                 return true;
 403
 404         case RXRPC_PACKET_TYPE_CHALLENGE:
 405         case RXRPC_PACKET_TYPE_RESPONSE:
 406                 if (rxrpc_is_conn_aborted(conn)) {
 407                         if (conn->completion == RXRPC_CALL_LOCALLY_ABORTED)
 408                                 rxrpc_send_conn_abort(conn);
 409                         return true;
 410                 }
 411                 rxrpc_post_packet_to_conn(conn, skb);
 412                 return true;
 413
 414         default:
 415                 WARN_ON_ONCE(1);
 416                 return true;
 417         }
 418 }
 419
 420 /*
 421  * Input a connection event.
 422  */
 423 void rxrpc_input_conn_event(struct rxrpc_connection *conn, struct sk_buff *skb)
 424 {
 425         unsigned int loop;
 426
 427         if (test_and_clear_bit(RXRPC_CONN_EV_ABORT_CALLS, &conn->events))
 428                 rxrpc_abort_calls(conn);
 429
 430         switch (skb->mark) {
 431         case RXRPC_SKB_MARK_SERVICE_CONN_SECURED:
 432                 if (conn->state != RXRPC_CONN_SERVICE)
 433                         break;
 434
 435                 for (loop = 0; loop < RXRPC_MAXCALLS; loop++)
 436                         rxrpc_call_is_secure(conn->channels[loop].call);
 437                 break;
 438         }
 439
 440         /* Process delayed ACKs whose time has come. */
 441         if (conn->flags & RXRPC_CONN_FINAL_ACK_MASK)
 442                 rxrpc_process_delayed_final_acks(conn, false);
 443 }