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 ret, 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 | channel); 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, 133 ntohl(pkt.ack.firstPacket), 134 ntohl(pkt.ack.serial), 135 pkt.ack.reason, 0); 136 _proto("Tx ACK %%%u [re]", serial); 137 break; 138 } 139 140 ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, ioc, len); 141 conn->params.peer->last_tx_at = ktime_get_real(); 142 if (ret < 0) 143 trace_rxrpc_tx_fail(conn->debug_id, serial, ret, 144 rxrpc_tx_fail_call_final_resend); 145 146 _leave(""); 147 } 148 149 /* 150 * pass a connection-level abort onto all calls on that connection 151 */ 152 static void rxrpc_abort_calls(struct rxrpc_connection *conn, 153 enum rxrpc_call_completion compl, 154 u32 abort_code, int error) 155 { 156 struct rxrpc_call *call; 157 int i; 158 159 _enter("{%d},%x", conn->debug_id, abort_code); 160 161 spin_lock(&conn->channel_lock); 162 163 for (i = 0; i < RXRPC_MAXCALLS; i++) { 164 call = rcu_dereference_protected( 165 conn->channels[i].call, 166 lockdep_is_held(&conn->channel_lock)); 167 if (call) { 168 if (compl == RXRPC_CALL_LOCALLY_ABORTED) 169 trace_rxrpc_abort(call->debug_id, 170 "CON", call->cid, 171 call->call_id, 0, 172 abort_code, error); 173 if (rxrpc_set_call_completion(call, compl, 174 abort_code, error)) 175 rxrpc_notify_socket(call); 176 } 177 } 178 179 spin_unlock(&conn->channel_lock); 180 _leave(""); 181 } 182 183 /* 184 * generate a connection-level abort 185 */ 186 static int rxrpc_abort_connection(struct rxrpc_connection *conn, 187 int error, u32 abort_code) 188 { 189 struct rxrpc_wire_header whdr; 190 struct msghdr msg; 191 struct kvec iov[2]; 192 __be32 word; 193 size_t len; 194 u32 serial; 195 int ret; 196 197 _enter("%d,,%u,%u", conn->debug_id, error, abort_code); 198 199 /* generate a connection-level abort */ 200 spin_lock_bh(&conn->state_lock); 201 if (conn->state >= RXRPC_CONN_REMOTELY_ABORTED) { 202 spin_unlock_bh(&conn->state_lock); 203 _leave(" = 0 [already dead]"); 204 return 0; 205 } 206 207 conn->state = RXRPC_CONN_LOCALLY_ABORTED; 208 spin_unlock_bh(&conn->state_lock); 209 210 rxrpc_abort_calls(conn, RXRPC_CALL_LOCALLY_ABORTED, abort_code, error); 211 212 msg.msg_name = &conn->params.peer->srx.transport; 213 msg.msg_namelen = conn->params.peer->srx.transport_len; 214 msg.msg_control = NULL; 215 msg.msg_controllen = 0; 216 msg.msg_flags = 0; 217 218 whdr.epoch = htonl(conn->proto.epoch); 219 whdr.cid = htonl(conn->proto.cid); 220 whdr.callNumber = 0; 221 whdr.seq = 0; 222 whdr.type = RXRPC_PACKET_TYPE_ABORT; 223 whdr.flags = conn->out_clientflag; 224 whdr.userStatus = 0; 225 whdr.securityIndex = conn->security_ix; 226 whdr._rsvd = 0; 227 whdr.serviceId = htons(conn->service_id); 228 229 word = htonl(conn->local_abort); 230 231 iov[0].iov_base = &whdr; 232 iov[0].iov_len = sizeof(whdr); 233 iov[1].iov_base = &word; 234 iov[1].iov_len = sizeof(word); 235 236 len = iov[0].iov_len + iov[1].iov_len; 237 238 serial = atomic_inc_return(&conn->serial); 239 whdr.serial = htonl(serial); 240 _proto("Tx CONN ABORT %%%u { %d }", serial, conn->local_abort); 241 242 ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 2, len); 243 if (ret < 0) { 244 trace_rxrpc_tx_fail(conn->debug_id, serial, ret, 245 rxrpc_tx_fail_conn_abort); 246 _debug("sendmsg failed: %d", ret); 247 return -EAGAIN; 248 } 249 250 conn->params.peer->last_tx_at = ktime_get_real(); 251 252 _leave(" = 0"); 253 return 0; 254 } 255 256 /* 257 * mark a call as being on a now-secured channel 258 * - must be called with BH's disabled. 259 */ 260 static void rxrpc_call_is_secure(struct rxrpc_call *call) 261 { 262 _enter("%p", call); 263 if (call) { 264 write_lock_bh(&call->state_lock); 265 if (call->state == RXRPC_CALL_SERVER_SECURING) { 266 call->state = RXRPC_CALL_SERVER_ACCEPTING; 267 rxrpc_notify_socket(call); 268 } 269 write_unlock_bh(&call->state_lock); 270 } 271 } 272 273 /* 274 * connection-level Rx packet processor 275 */ 276 static int rxrpc_process_event(struct rxrpc_connection *conn, 277 struct sk_buff *skb, 278 u32 *_abort_code) 279 { 280 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 281 __be32 wtmp; 282 u32 abort_code; 283 int loop, ret; 284 285 if (conn->state >= RXRPC_CONN_REMOTELY_ABORTED) { 286 _leave(" = -ECONNABORTED [%u]", conn->state); 287 return -ECONNABORTED; 288 } 289 290 _enter("{%d},{%u,%%%u},", conn->debug_id, sp->hdr.type, sp->hdr.serial); 291 292 switch (sp->hdr.type) { 293 case RXRPC_PACKET_TYPE_DATA: 294 case RXRPC_PACKET_TYPE_ACK: 295 rxrpc_conn_retransmit_call(conn, skb, 296 sp->hdr.cid & RXRPC_CHANNELMASK); 297 return 0; 298 299 case RXRPC_PACKET_TYPE_BUSY: 300 /* Just ignore BUSY packets for now. */ 301 return 0; 302 303 case RXRPC_PACKET_TYPE_ABORT: 304 if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header), 305 &wtmp, sizeof(wtmp)) < 0) { 306 trace_rxrpc_rx_eproto(NULL, sp->hdr.serial, 307 tracepoint_string("bad_abort")); 308 return -EPROTO; 309 } 310 abort_code = ntohl(wtmp); 311 _proto("Rx ABORT %%%u { ac=%d }", sp->hdr.serial, abort_code); 312 313 conn->state = RXRPC_CONN_REMOTELY_ABORTED; 314 rxrpc_abort_calls(conn, RXRPC_CALL_REMOTELY_ABORTED, 315 abort_code, -ECONNABORTED); 316 return -ECONNABORTED; 317 318 case RXRPC_PACKET_TYPE_CHALLENGE: 319 return conn->security->respond_to_challenge(conn, skb, 320 _abort_code); 321 322 case RXRPC_PACKET_TYPE_RESPONSE: 323 ret = conn->security->verify_response(conn, skb, _abort_code); 324 if (ret < 0) 325 return ret; 326 327 ret = conn->security->init_connection_security(conn); 328 if (ret < 0) 329 return ret; 330 331 ret = conn->security->prime_packet_security(conn); 332 if (ret < 0) 333 return ret; 334 335 spin_lock(&conn->channel_lock); 336 spin_lock(&conn->state_lock); 337 338 if (conn->state == RXRPC_CONN_SERVICE_CHALLENGING) { 339 conn->state = RXRPC_CONN_SERVICE; 340 spin_unlock(&conn->state_lock); 341 for (loop = 0; loop < RXRPC_MAXCALLS; loop++) 342 rxrpc_call_is_secure( 343 rcu_dereference_protected( 344 conn->channels[loop].call, 345 lockdep_is_held(&conn->channel_lock))); 346 } else { 347 spin_unlock(&conn->state_lock); 348 } 349 350 spin_unlock(&conn->channel_lock); 351 return 0; 352 353 default: 354 trace_rxrpc_rx_eproto(NULL, sp->hdr.serial, 355 tracepoint_string("bad_conn_pkt")); 356 return -EPROTO; 357 } 358 } 359 360 /* 361 * set up security and issue a challenge 362 */ 363 static void rxrpc_secure_connection(struct rxrpc_connection *conn) 364 { 365 u32 abort_code; 366 int ret; 367 368 _enter("{%d}", conn->debug_id); 369 370 ASSERT(conn->security_ix != 0); 371 372 if (!conn->params.key) { 373 _debug("set up security"); 374 ret = rxrpc_init_server_conn_security(conn); 375 switch (ret) { 376 case 0: 377 break; 378 case -ENOENT: 379 abort_code = RX_CALL_DEAD; 380 goto abort; 381 default: 382 abort_code = RXKADNOAUTH; 383 goto abort; 384 } 385 } 386 387 if (conn->security->issue_challenge(conn) < 0) { 388 abort_code = RX_CALL_DEAD; 389 ret = -ENOMEM; 390 goto abort; 391 } 392 393 _leave(""); 394 return; 395 396 abort: 397 _debug("abort %d, %d", ret, abort_code); 398 rxrpc_abort_connection(conn, ret, abort_code); 399 _leave(" [aborted]"); 400 } 401 402 /* 403 * Process delayed final ACKs that we haven't subsumed into a subsequent call. 404 */ 405 static void rxrpc_process_delayed_final_acks(struct rxrpc_connection *conn) 406 { 407 unsigned long j = jiffies, next_j; 408 unsigned int channel; 409 bool set; 410 411 again: 412 next_j = j + LONG_MAX; 413 set = false; 414 for (channel = 0; channel < RXRPC_MAXCALLS; channel++) { 415 struct rxrpc_channel *chan = &conn->channels[channel]; 416 unsigned long ack_at; 417 418 if (!test_bit(RXRPC_CONN_FINAL_ACK_0 + channel, &conn->flags)) 419 continue; 420 421 smp_rmb(); /* vs rxrpc_disconnect_client_call */ 422 ack_at = READ_ONCE(chan->final_ack_at); 423 424 if (time_before(j, ack_at)) { 425 if (time_before(ack_at, next_j)) { 426 next_j = ack_at; 427 set = true; 428 } 429 continue; 430 } 431 432 if (test_and_clear_bit(RXRPC_CONN_FINAL_ACK_0 + channel, 433 &conn->flags)) 434 rxrpc_conn_retransmit_call(conn, NULL, channel); 435 } 436 437 j = jiffies; 438 if (time_before_eq(next_j, j)) 439 goto again; 440 if (set) 441 rxrpc_reduce_conn_timer(conn, next_j); 442 } 443 444 /* 445 * connection-level event processor 446 */ 447 void rxrpc_process_connection(struct work_struct *work) 448 { 449 struct rxrpc_connection *conn = 450 container_of(work, struct rxrpc_connection, processor); 451 struct sk_buff *skb; 452 u32 abort_code = RX_PROTOCOL_ERROR; 453 int ret; 454 455 rxrpc_see_connection(conn); 456 457 if (test_and_clear_bit(RXRPC_CONN_EV_CHALLENGE, &conn->events)) 458 rxrpc_secure_connection(conn); 459 460 /* Process delayed ACKs whose time has come. */ 461 if (conn->flags & RXRPC_CONN_FINAL_ACK_MASK) 462 rxrpc_process_delayed_final_acks(conn); 463 464 /* go through the conn-level event packets, releasing the ref on this 465 * connection that each one has when we've finished with it */ 466 while ((skb = skb_dequeue(&conn->rx_queue))) { 467 rxrpc_see_skb(skb, rxrpc_skb_rx_seen); 468 ret = rxrpc_process_event(conn, skb, &abort_code); 469 switch (ret) { 470 case -EPROTO: 471 case -EKEYEXPIRED: 472 case -EKEYREJECTED: 473 goto protocol_error; 474 case -ENOMEM: 475 case -EAGAIN: 476 goto requeue_and_leave; 477 case -ECONNABORTED: 478 default: 479 rxrpc_free_skb(skb, rxrpc_skb_rx_freed); 480 break; 481 } 482 } 483 484 out: 485 rxrpc_put_connection(conn); 486 _leave(""); 487 return; 488 489 requeue_and_leave: 490 skb_queue_head(&conn->rx_queue, skb); 491 goto out; 492 493 protocol_error: 494 if (rxrpc_abort_connection(conn, ret, abort_code) < 0) 495 goto requeue_and_leave; 496 rxrpc_free_skb(skb, rxrpc_skb_rx_freed); 497 goto out; 498 } 499