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 <net/sock.h> 19 #include <net/af_rxrpc.h> 20 #include <net/ip.h> 21 #include "ar-internal.h" 22 23 /* 24 * Retransmit terminal ACK or ABORT of the previous call. 25 */ 26 static void rxrpc_conn_retransmit_call(struct rxrpc_connection *conn, 27 struct sk_buff *skb, 28 unsigned int channel) 29 { 30 struct rxrpc_skb_priv *sp = skb ? rxrpc_skb(skb) : NULL; 31 struct rxrpc_channel *chan; 32 struct msghdr msg; 33 struct kvec iov[3]; 34 struct { 35 struct rxrpc_wire_header whdr; 36 union { 37 __be32 abort_code; 38 struct rxrpc_ackpacket ack; 39 }; 40 } __attribute__((packed)) pkt; 41 struct rxrpc_ackinfo ack_info; 42 size_t len; 43 int ioc; 44 u32 serial, mtu, call_id, padding; 45 46 _enter("%d", conn->debug_id); 47 48 chan = &conn->channels[channel]; 49 50 /* If the last call got moved on whilst we were waiting to run, just 51 * ignore this packet. 52 */ 53 call_id = READ_ONCE(chan->last_call); 54 /* Sync with __rxrpc_disconnect_call() */ 55 smp_rmb(); 56 if (skb && call_id != sp->hdr.callNumber) 57 return; 58 59 msg.msg_name = &conn->params.peer->srx.transport; 60 msg.msg_namelen = conn->params.peer->srx.transport_len; 61 msg.msg_control = NULL; 62 msg.msg_controllen = 0; 63 msg.msg_flags = 0; 64 65 iov[0].iov_base = &pkt; 66 iov[0].iov_len = sizeof(pkt.whdr); 67 iov[1].iov_base = &padding; 68 iov[1].iov_len = 3; 69 iov[2].iov_base = &ack_info; 70 iov[2].iov_len = sizeof(ack_info); 71 72 pkt.whdr.epoch = htonl(conn->proto.epoch); 73 pkt.whdr.cid = htonl(conn->proto.cid); 74 pkt.whdr.callNumber = htonl(call_id); 75 pkt.whdr.seq = 0; 76 pkt.whdr.type = chan->last_type; 77 pkt.whdr.flags = conn->out_clientflag; 78 pkt.whdr.userStatus = 0; 79 pkt.whdr.securityIndex = conn->security_ix; 80 pkt.whdr._rsvd = 0; 81 pkt.whdr.serviceId = htons(conn->service_id); 82 83 len = sizeof(pkt.whdr); 84 switch (chan->last_type) { 85 case RXRPC_PACKET_TYPE_ABORT: 86 pkt.abort_code = htonl(chan->last_abort); 87 iov[0].iov_len += sizeof(pkt.abort_code); 88 len += sizeof(pkt.abort_code); 89 ioc = 1; 90 break; 91 92 case RXRPC_PACKET_TYPE_ACK: 93 mtu = conn->params.peer->if_mtu; 94 mtu -= conn->params.peer->hdrsize; 95 pkt.ack.bufferSpace = 0; 96 pkt.ack.maxSkew = htons(skb ? skb->priority : 0); 97 pkt.ack.firstPacket = htonl(chan->last_seq + 1); 98 pkt.ack.previousPacket = htonl(chan->last_seq); 99 pkt.ack.serial = htonl(skb ? sp->hdr.serial : 0); 100 pkt.ack.reason = skb ? RXRPC_ACK_DUPLICATE : RXRPC_ACK_IDLE; 101 pkt.ack.nAcks = 0; 102 ack_info.rxMTU = htonl(rxrpc_rx_mtu); 103 ack_info.maxMTU = htonl(mtu); 104 ack_info.rwind = htonl(rxrpc_rx_window_size); 105 ack_info.jumbo_max = htonl(rxrpc_rx_jumbo_max); 106 pkt.whdr.flags |= RXRPC_SLOW_START_OK; 107 padding = 0; 108 iov[0].iov_len += sizeof(pkt.ack); 109 len += sizeof(pkt.ack) + 3 + sizeof(ack_info); 110 ioc = 3; 111 break; 112 113 default: 114 return; 115 } 116 117 /* Resync with __rxrpc_disconnect_call() and check that the last call 118 * didn't get advanced whilst we were filling out the packets. 119 */ 120 smp_rmb(); 121 if (READ_ONCE(chan->last_call) != call_id) 122 return; 123 124 serial = atomic_inc_return(&conn->serial); 125 pkt.whdr.serial = htonl(serial); 126 127 switch (chan->last_type) { 128 case RXRPC_PACKET_TYPE_ABORT: 129 _proto("Tx ABORT %%%u { %d } [re]", serial, conn->local_abort); 130 break; 131 case RXRPC_PACKET_TYPE_ACK: 132 trace_rxrpc_tx_ack(NULL, serial, chan->last_seq, 0, 133 RXRPC_ACK_DUPLICATE, 0); 134 _proto("Tx ACK %%%u [re]", serial); 135 break; 136 } 137 138 kernel_sendmsg(conn->params.local->socket, &msg, iov, ioc, len); 139 conn->params.peer->last_tx_at = ktime_get_real(); 140 _leave(""); 141 return; 142 } 143 144 /* 145 * pass a connection-level abort onto all calls on that connection 146 */ 147 static void rxrpc_abort_calls(struct rxrpc_connection *conn, 148 enum rxrpc_call_completion compl, 149 u32 abort_code, int error) 150 { 151 struct rxrpc_call *call; 152 int i; 153 154 _enter("{%d},%x", conn->debug_id, abort_code); 155 156 spin_lock(&conn->channel_lock); 157 158 for (i = 0; i < RXRPC_MAXCALLS; i++) { 159 call = rcu_dereference_protected( 160 conn->channels[i].call, 161 lockdep_is_held(&conn->channel_lock)); 162 if (call) { 163 if (compl == RXRPC_CALL_LOCALLY_ABORTED) 164 trace_rxrpc_abort(call->debug_id, 165 "CON", call->cid, 166 call->call_id, 0, 167 abort_code, error); 168 if (rxrpc_set_call_completion(call, compl, 169 abort_code, error)) 170 rxrpc_notify_socket(call); 171 } 172 } 173 174 spin_unlock(&conn->channel_lock); 175 _leave(""); 176 } 177 178 /* 179 * generate a connection-level abort 180 */ 181 static int rxrpc_abort_connection(struct rxrpc_connection *conn, 182 int error, u32 abort_code) 183 { 184 struct rxrpc_wire_header whdr; 185 struct msghdr msg; 186 struct kvec iov[2]; 187 __be32 word; 188 size_t len; 189 u32 serial; 190 int ret; 191 192 _enter("%d,,%u,%u", conn->debug_id, error, abort_code); 193 194 /* generate a connection-level abort */ 195 spin_lock_bh(&conn->state_lock); 196 if (conn->state >= RXRPC_CONN_REMOTELY_ABORTED) { 197 spin_unlock_bh(&conn->state_lock); 198 _leave(" = 0 [already dead]"); 199 return 0; 200 } 201 202 conn->state = RXRPC_CONN_LOCALLY_ABORTED; 203 spin_unlock_bh(&conn->state_lock); 204 205 rxrpc_abort_calls(conn, RXRPC_CALL_LOCALLY_ABORTED, abort_code, error); 206 207 msg.msg_name = &conn->params.peer->srx.transport; 208 msg.msg_namelen = conn->params.peer->srx.transport_len; 209 msg.msg_control = NULL; 210 msg.msg_controllen = 0; 211 msg.msg_flags = 0; 212 213 whdr.epoch = htonl(conn->proto.epoch); 214 whdr.cid = htonl(conn->proto.cid); 215 whdr.callNumber = 0; 216 whdr.seq = 0; 217 whdr.type = RXRPC_PACKET_TYPE_ABORT; 218 whdr.flags = conn->out_clientflag; 219 whdr.userStatus = 0; 220 whdr.securityIndex = conn->security_ix; 221 whdr._rsvd = 0; 222 whdr.serviceId = htons(conn->service_id); 223 224 word = htonl(conn->local_abort); 225 226 iov[0].iov_base = &whdr; 227 iov[0].iov_len = sizeof(whdr); 228 iov[1].iov_base = &word; 229 iov[1].iov_len = sizeof(word); 230 231 len = iov[0].iov_len + iov[1].iov_len; 232 233 serial = atomic_inc_return(&conn->serial); 234 whdr.serial = htonl(serial); 235 _proto("Tx CONN ABORT %%%u { %d }", serial, conn->local_abort); 236 237 ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 2, len); 238 if (ret < 0) { 239 _debug("sendmsg failed: %d", ret); 240 return -EAGAIN; 241 } 242 243 conn->params.peer->last_tx_at = ktime_get_real(); 244 245 _leave(" = 0"); 246 return 0; 247 } 248 249 /* 250 * mark a call as being on a now-secured channel 251 * - must be called with BH's disabled. 252 */ 253 static void rxrpc_call_is_secure(struct rxrpc_call *call) 254 { 255 _enter("%p", call); 256 if (call) { 257 write_lock_bh(&call->state_lock); 258 if (call->state == RXRPC_CALL_SERVER_SECURING) { 259 call->state = RXRPC_CALL_SERVER_ACCEPTING; 260 rxrpc_notify_socket(call); 261 } 262 write_unlock_bh(&call->state_lock); 263 } 264 } 265 266 /* 267 * connection-level Rx packet processor 268 */ 269 static int rxrpc_process_event(struct rxrpc_connection *conn, 270 struct sk_buff *skb, 271 u32 *_abort_code) 272 { 273 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 274 __be32 wtmp; 275 u32 abort_code; 276 int loop, ret; 277 278 if (conn->state >= RXRPC_CONN_REMOTELY_ABORTED) { 279 _leave(" = -ECONNABORTED [%u]", conn->state); 280 return -ECONNABORTED; 281 } 282 283 _enter("{%d},{%u,%%%u},", conn->debug_id, sp->hdr.type, sp->hdr.serial); 284 285 switch (sp->hdr.type) { 286 case RXRPC_PACKET_TYPE_DATA: 287 case RXRPC_PACKET_TYPE_ACK: 288 rxrpc_conn_retransmit_call(conn, skb, 289 sp->hdr.cid & RXRPC_CHANNELMASK); 290 return 0; 291 292 case RXRPC_PACKET_TYPE_BUSY: 293 /* Just ignore BUSY packets for now. */ 294 return 0; 295 296 case RXRPC_PACKET_TYPE_ABORT: 297 if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header), 298 &wtmp, sizeof(wtmp)) < 0) { 299 trace_rxrpc_rx_eproto(NULL, sp->hdr.serial, 300 tracepoint_string("bad_abort")); 301 return -EPROTO; 302 } 303 abort_code = ntohl(wtmp); 304 _proto("Rx ABORT %%%u { ac=%d }", sp->hdr.serial, abort_code); 305 306 conn->state = RXRPC_CONN_REMOTELY_ABORTED; 307 rxrpc_abort_calls(conn, RXRPC_CALL_REMOTELY_ABORTED, 308 abort_code, -ECONNABORTED); 309 return -ECONNABORTED; 310 311 case RXRPC_PACKET_TYPE_CHALLENGE: 312 return conn->security->respond_to_challenge(conn, skb, 313 _abort_code); 314 315 case RXRPC_PACKET_TYPE_RESPONSE: 316 ret = conn->security->verify_response(conn, skb, _abort_code); 317 if (ret < 0) 318 return ret; 319 320 ret = conn->security->init_connection_security(conn); 321 if (ret < 0) 322 return ret; 323 324 ret = conn->security->prime_packet_security(conn); 325 if (ret < 0) 326 return ret; 327 328 spin_lock(&conn->channel_lock); 329 spin_lock(&conn->state_lock); 330 331 if (conn->state == RXRPC_CONN_SERVICE_CHALLENGING) { 332 conn->state = RXRPC_CONN_SERVICE; 333 spin_unlock(&conn->state_lock); 334 for (loop = 0; loop < RXRPC_MAXCALLS; loop++) 335 rxrpc_call_is_secure( 336 rcu_dereference_protected( 337 conn->channels[loop].call, 338 lockdep_is_held(&conn->channel_lock))); 339 } else { 340 spin_unlock(&conn->state_lock); 341 } 342 343 spin_unlock(&conn->channel_lock); 344 return 0; 345 346 default: 347 trace_rxrpc_rx_eproto(NULL, sp->hdr.serial, 348 tracepoint_string("bad_conn_pkt")); 349 return -EPROTO; 350 } 351 } 352 353 /* 354 * set up security and issue a challenge 355 */ 356 static void rxrpc_secure_connection(struct rxrpc_connection *conn) 357 { 358 u32 abort_code; 359 int ret; 360 361 _enter("{%d}", conn->debug_id); 362 363 ASSERT(conn->security_ix != 0); 364 365 if (!conn->params.key) { 366 _debug("set up security"); 367 ret = rxrpc_init_server_conn_security(conn); 368 switch (ret) { 369 case 0: 370 break; 371 case -ENOENT: 372 abort_code = RX_CALL_DEAD; 373 goto abort; 374 default: 375 abort_code = RXKADNOAUTH; 376 goto abort; 377 } 378 } 379 380 if (conn->security->issue_challenge(conn) < 0) { 381 abort_code = RX_CALL_DEAD; 382 ret = -ENOMEM; 383 goto abort; 384 } 385 386 _leave(""); 387 return; 388 389 abort: 390 _debug("abort %d, %d", ret, abort_code); 391 rxrpc_abort_connection(conn, ret, abort_code); 392 _leave(" [aborted]"); 393 } 394 395 /* 396 * Process delayed final ACKs that we haven't subsumed into a subsequent call. 397 */ 398 static void rxrpc_process_delayed_final_acks(struct rxrpc_connection *conn) 399 { 400 unsigned long j = jiffies, next_j; 401 unsigned int channel; 402 bool set; 403 404 again: 405 next_j = j + LONG_MAX; 406 set = false; 407 for (channel = 0; channel < RXRPC_MAXCALLS; channel++) { 408 struct rxrpc_channel *chan = &conn->channels[channel]; 409 unsigned long ack_at; 410 411 if (!test_bit(RXRPC_CONN_FINAL_ACK_0 + channel, &conn->flags)) 412 continue; 413 414 smp_rmb(); /* vs rxrpc_disconnect_client_call */ 415 ack_at = READ_ONCE(chan->final_ack_at); 416 417 if (time_before(j, ack_at)) { 418 if (time_before(ack_at, next_j)) { 419 next_j = ack_at; 420 set = true; 421 } 422 continue; 423 } 424 425 if (test_and_clear_bit(RXRPC_CONN_FINAL_ACK_0 + channel, 426 &conn->flags)) 427 rxrpc_conn_retransmit_call(conn, NULL, channel); 428 } 429 430 j = jiffies; 431 if (time_before_eq(next_j, j)) 432 goto again; 433 if (set) 434 rxrpc_reduce_conn_timer(conn, next_j); 435 } 436 437 /* 438 * connection-level event processor 439 */ 440 void rxrpc_process_connection(struct work_struct *work) 441 { 442 struct rxrpc_connection *conn = 443 container_of(work, struct rxrpc_connection, processor); 444 struct sk_buff *skb; 445 u32 abort_code = RX_PROTOCOL_ERROR; 446 int ret; 447 448 rxrpc_see_connection(conn); 449 450 if (test_and_clear_bit(RXRPC_CONN_EV_CHALLENGE, &conn->events)) 451 rxrpc_secure_connection(conn); 452 453 /* Process delayed ACKs whose time has come. */ 454 if (conn->flags & RXRPC_CONN_FINAL_ACK_MASK) 455 rxrpc_process_delayed_final_acks(conn); 456 457 /* go through the conn-level event packets, releasing the ref on this 458 * connection that each one has when we've finished with it */ 459 while ((skb = skb_dequeue(&conn->rx_queue))) { 460 rxrpc_see_skb(skb, rxrpc_skb_rx_seen); 461 ret = rxrpc_process_event(conn, skb, &abort_code); 462 switch (ret) { 463 case -EPROTO: 464 case -EKEYEXPIRED: 465 case -EKEYREJECTED: 466 goto protocol_error; 467 case -ENOMEM: 468 case -EAGAIN: 469 goto requeue_and_leave; 470 case -ECONNABORTED: 471 default: 472 rxrpc_free_skb(skb, rxrpc_skb_rx_freed); 473 break; 474 } 475 } 476 477 out: 478 rxrpc_put_connection(conn); 479 _leave(""); 480 return; 481 482 requeue_and_leave: 483 skb_queue_head(&conn->rx_queue, skb); 484 goto out; 485 486 protocol_error: 487 if (rxrpc_abort_connection(conn, ret, abort_code) < 0) 488 goto requeue_and_leave; 489 rxrpc_free_skb(skb, rxrpc_skb_rx_freed); 490 goto out; 491 } 492