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 <linux/udp.h> 19 #include <linux/in.h> 20 #include <linux/in6.h> 21 #include <linux/icmp.h> 22 #include <net/sock.h> 23 #include <net/af_rxrpc.h> 24 #include <net/ip.h> 25 #include "ar-internal.h" 26 27 /* 28 * Retransmit terminal ACK or ABORT of the previous call. 29 */ 30 static void rxrpc_conn_retransmit(struct rxrpc_connection *conn, 31 struct sk_buff *skb) 32 { 33 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 34 struct rxrpc_channel *chan; 35 struct msghdr msg; 36 struct kvec iov; 37 struct { 38 struct rxrpc_wire_header whdr; 39 union { 40 struct { 41 __be32 code; 42 } abort; 43 struct { 44 struct rxrpc_ackpacket ack; 45 u8 padding[3]; 46 struct rxrpc_ackinfo info; 47 }; 48 }; 49 } __attribute__((packed)) pkt; 50 size_t len; 51 u32 serial, mtu, call_id; 52 53 _enter("%d", conn->debug_id); 54 55 chan = &conn->channels[sp->hdr.cid & RXRPC_CHANNELMASK]; 56 57 /* If the last call got moved on whilst we were waiting to run, just 58 * ignore this packet. 59 */ 60 call_id = READ_ONCE(chan->last_call); 61 /* Sync with __rxrpc_disconnect_call() */ 62 smp_rmb(); 63 if (call_id != sp->hdr.callNumber) 64 return; 65 66 msg.msg_name = &conn->params.peer->srx.transport; 67 msg.msg_namelen = conn->params.peer->srx.transport_len; 68 msg.msg_control = NULL; 69 msg.msg_controllen = 0; 70 msg.msg_flags = 0; 71 72 pkt.whdr.epoch = htonl(sp->hdr.epoch); 73 pkt.whdr.cid = htonl(sp->hdr.cid); 74 pkt.whdr.callNumber = htonl(sp->hdr.callNumber); 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(chan->last_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 len += sizeof(pkt.abort); 88 break; 89 90 case RXRPC_PACKET_TYPE_ACK: 91 mtu = conn->params.peer->if_mtu; 92 mtu -= conn->params.peer->hdrsize; 93 pkt.ack.bufferSpace = 0; 94 pkt.ack.maxSkew = htons(skb->priority); 95 pkt.ack.firstPacket = htonl(chan->last_seq); 96 pkt.ack.previousPacket = htonl(chan->last_seq - 1); 97 pkt.ack.serial = htonl(sp->hdr.serial); 98 pkt.ack.reason = RXRPC_ACK_DUPLICATE; 99 pkt.ack.nAcks = 0; 100 pkt.info.rxMTU = htonl(rxrpc_rx_mtu); 101 pkt.info.maxMTU = htonl(mtu); 102 pkt.info.rwind = htonl(rxrpc_rx_window_size); 103 pkt.info.jumbo_max = htonl(rxrpc_rx_jumbo_max); 104 len += sizeof(pkt.ack) + sizeof(pkt.info); 105 break; 106 } 107 108 /* Resync with __rxrpc_disconnect_call() and check that the last call 109 * didn't get advanced whilst we were filling out the packets. 110 */ 111 smp_rmb(); 112 if (READ_ONCE(chan->last_call) != call_id) 113 return; 114 115 iov.iov_base = &pkt; 116 iov.iov_len = len; 117 118 serial = atomic_inc_return(&conn->serial); 119 pkt.whdr.serial = htonl(serial); 120 121 switch (chan->last_type) { 122 case RXRPC_PACKET_TYPE_ABORT: 123 _proto("Tx ABORT %%%u { %d } [re]", serial, conn->local_abort); 124 break; 125 case RXRPC_PACKET_TYPE_ACK: 126 _proto("Tx ACK %%%u [re]", serial); 127 break; 128 } 129 130 kernel_sendmsg(conn->params.local->socket, &msg, &iov, 1, len); 131 _leave(""); 132 return; 133 } 134 135 /* 136 * pass a connection-level abort onto all calls on that connection 137 */ 138 static void rxrpc_abort_calls(struct rxrpc_connection *conn, int state, 139 u32 abort_code) 140 { 141 struct rxrpc_call *call; 142 int i; 143 144 _enter("{%d},%x", conn->debug_id, abort_code); 145 146 spin_lock(&conn->channel_lock); 147 148 for (i = 0; i < RXRPC_MAXCALLS; i++) { 149 call = rcu_dereference_protected( 150 conn->channels[i].call, 151 lockdep_is_held(&conn->channel_lock)); 152 if (call) { 153 write_lock_bh(&call->state_lock); 154 if (call->state <= RXRPC_CALL_COMPLETE) { 155 call->state = state; 156 if (state == RXRPC_CALL_LOCALLY_ABORTED) { 157 call->local_abort = conn->local_abort; 158 set_bit(RXRPC_CALL_EV_CONN_ABORT, 159 &call->events); 160 } else { 161 call->remote_abort = conn->remote_abort; 162 set_bit(RXRPC_CALL_EV_RCVD_ABORT, 163 &call->events); 164 } 165 rxrpc_queue_call(call); 166 } 167 write_unlock_bh(&call->state_lock); 168 } 169 } 170 171 spin_unlock(&conn->channel_lock); 172 _leave(""); 173 } 174 175 /* 176 * generate a connection-level abort 177 */ 178 static int rxrpc_abort_connection(struct rxrpc_connection *conn, 179 u32 error, u32 abort_code) 180 { 181 struct rxrpc_wire_header whdr; 182 struct msghdr msg; 183 struct kvec iov[2]; 184 __be32 word; 185 size_t len; 186 u32 serial; 187 int ret; 188 189 _enter("%d,,%u,%u", conn->debug_id, error, abort_code); 190 191 /* generate a connection-level abort */ 192 spin_lock_bh(&conn->state_lock); 193 if (conn->state < RXRPC_CONN_REMOTELY_ABORTED) { 194 conn->state = RXRPC_CONN_LOCALLY_ABORTED; 195 conn->error = error; 196 spin_unlock_bh(&conn->state_lock); 197 } else { 198 spin_unlock_bh(&conn->state_lock); 199 _leave(" = 0 [already dead]"); 200 return 0; 201 } 202 203 rxrpc_abort_calls(conn, RXRPC_CALL_LOCALLY_ABORTED, abort_code); 204 205 msg.msg_name = &conn->params.peer->srx.transport; 206 msg.msg_namelen = conn->params.peer->srx.transport_len; 207 msg.msg_control = NULL; 208 msg.msg_controllen = 0; 209 msg.msg_flags = 0; 210 211 whdr.epoch = htonl(conn->proto.epoch); 212 whdr.cid = htonl(conn->proto.cid); 213 whdr.callNumber = 0; 214 whdr.seq = 0; 215 whdr.type = RXRPC_PACKET_TYPE_ABORT; 216 whdr.flags = conn->out_clientflag; 217 whdr.userStatus = 0; 218 whdr.securityIndex = conn->security_ix; 219 whdr._rsvd = 0; 220 whdr.serviceId = htons(conn->params.service_id); 221 222 word = htonl(conn->local_abort); 223 224 iov[0].iov_base = &whdr; 225 iov[0].iov_len = sizeof(whdr); 226 iov[1].iov_base = &word; 227 iov[1].iov_len = sizeof(word); 228 229 len = iov[0].iov_len + iov[1].iov_len; 230 231 serial = atomic_inc_return(&conn->serial); 232 whdr.serial = htonl(serial); 233 _proto("Tx CONN ABORT %%%u { %d }", serial, conn->local_abort); 234 235 ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 2, len); 236 if (ret < 0) { 237 _debug("sendmsg failed: %d", ret); 238 return -EAGAIN; 239 } 240 241 _leave(" = 0"); 242 return 0; 243 } 244 245 /* 246 * mark a call as being on a now-secured channel 247 * - must be called with softirqs disabled 248 */ 249 static void rxrpc_call_is_secure(struct rxrpc_call *call) 250 { 251 _enter("%p", call); 252 if (call) { 253 read_lock(&call->state_lock); 254 if (call->state < RXRPC_CALL_COMPLETE && 255 !test_and_set_bit(RXRPC_CALL_EV_SECURED, &call->events)) 256 rxrpc_queue_call(call); 257 read_unlock(&call->state_lock); 258 } 259 } 260 261 /* 262 * connection-level Rx packet processor 263 */ 264 static int rxrpc_process_event(struct rxrpc_connection *conn, 265 struct sk_buff *skb, 266 u32 *_abort_code) 267 { 268 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 269 __be32 wtmp; 270 u32 abort_code; 271 int loop, ret; 272 273 if (conn->state >= RXRPC_CONN_REMOTELY_ABORTED) { 274 kleave(" = -ECONNABORTED [%u]", conn->state); 275 return -ECONNABORTED; 276 } 277 278 _enter("{%d},{%u,%%%u},", conn->debug_id, sp->hdr.type, sp->hdr.serial); 279 280 switch (sp->hdr.type) { 281 case RXRPC_PACKET_TYPE_DATA: 282 case RXRPC_PACKET_TYPE_ACK: 283 rxrpc_conn_retransmit(conn, skb); 284 rxrpc_free_skb(skb); 285 return 0; 286 287 case RXRPC_PACKET_TYPE_ABORT: 288 if (skb_copy_bits(skb, 0, &wtmp, sizeof(wtmp)) < 0) 289 return -EPROTO; 290 abort_code = ntohl(wtmp); 291 _proto("Rx ABORT %%%u { ac=%d }", sp->hdr.serial, abort_code); 292 293 conn->state = RXRPC_CONN_REMOTELY_ABORTED; 294 rxrpc_abort_calls(conn, RXRPC_CALL_REMOTELY_ABORTED, 295 abort_code); 296 return -ECONNABORTED; 297 298 case RXRPC_PACKET_TYPE_CHALLENGE: 299 return conn->security->respond_to_challenge(conn, skb, 300 _abort_code); 301 302 case RXRPC_PACKET_TYPE_RESPONSE: 303 ret = conn->security->verify_response(conn, skb, _abort_code); 304 if (ret < 0) 305 return ret; 306 307 ret = conn->security->init_connection_security(conn); 308 if (ret < 0) 309 return ret; 310 311 ret = conn->security->prime_packet_security(conn); 312 if (ret < 0) 313 return ret; 314 315 spin_lock(&conn->channel_lock); 316 spin_lock(&conn->state_lock); 317 318 if (conn->state == RXRPC_CONN_SERVICE_CHALLENGING) { 319 conn->state = RXRPC_CONN_SERVICE; 320 for (loop = 0; loop < RXRPC_MAXCALLS; loop++) 321 rxrpc_call_is_secure( 322 rcu_dereference_protected( 323 conn->channels[loop].call, 324 lockdep_is_held(&conn->channel_lock))); 325 } 326 327 spin_unlock(&conn->state_lock); 328 spin_unlock(&conn->channel_lock); 329 return 0; 330 331 default: 332 _leave(" = -EPROTO [%u]", sp->hdr.type); 333 return -EPROTO; 334 } 335 } 336 337 /* 338 * set up security and issue a challenge 339 */ 340 static void rxrpc_secure_connection(struct rxrpc_connection *conn) 341 { 342 u32 abort_code; 343 int ret; 344 345 _enter("{%d}", conn->debug_id); 346 347 ASSERT(conn->security_ix != 0); 348 349 if (!conn->params.key) { 350 _debug("set up security"); 351 ret = rxrpc_init_server_conn_security(conn); 352 switch (ret) { 353 case 0: 354 break; 355 case -ENOENT: 356 abort_code = RX_CALL_DEAD; 357 goto abort; 358 default: 359 abort_code = RXKADNOAUTH; 360 goto abort; 361 } 362 } 363 364 if (conn->security->issue_challenge(conn) < 0) { 365 abort_code = RX_CALL_DEAD; 366 ret = -ENOMEM; 367 goto abort; 368 } 369 370 _leave(""); 371 return; 372 373 abort: 374 _debug("abort %d, %d", ret, abort_code); 375 rxrpc_abort_connection(conn, -ret, abort_code); 376 _leave(" [aborted]"); 377 } 378 379 /* 380 * connection-level event processor 381 */ 382 void rxrpc_process_connection(struct work_struct *work) 383 { 384 struct rxrpc_connection *conn = 385 container_of(work, struct rxrpc_connection, processor); 386 struct sk_buff *skb; 387 u32 abort_code = RX_PROTOCOL_ERROR; 388 int ret; 389 390 _enter("{%d}", conn->debug_id); 391 392 if (test_and_clear_bit(RXRPC_CONN_EV_CHALLENGE, &conn->events)) 393 rxrpc_secure_connection(conn); 394 395 /* go through the conn-level event packets, releasing the ref on this 396 * connection that each one has when we've finished with it */ 397 while ((skb = skb_dequeue(&conn->rx_queue))) { 398 rxrpc_see_skb(skb); 399 ret = rxrpc_process_event(conn, skb, &abort_code); 400 switch (ret) { 401 case -EPROTO: 402 case -EKEYEXPIRED: 403 case -EKEYREJECTED: 404 goto protocol_error; 405 case -EAGAIN: 406 goto requeue_and_leave; 407 case -ECONNABORTED: 408 default: 409 rxrpc_free_skb(skb); 410 break; 411 } 412 } 413 414 out: 415 rxrpc_put_connection(conn); 416 _leave(""); 417 return; 418 419 requeue_and_leave: 420 skb_queue_head(&conn->rx_queue, skb); 421 goto out; 422 423 protocol_error: 424 if (rxrpc_abort_connection(conn, -ret, abort_code) < 0) 425 goto requeue_and_leave; 426 rxrpc_free_skb(skb); 427 _leave(" [EPROTO]"); 428 goto out; 429 } 430 431 /* 432 * put a packet up for transport-level abort 433 */ 434 void rxrpc_reject_packet(struct rxrpc_local *local, struct sk_buff *skb) 435 { 436 CHECK_SLAB_OKAY(&local->usage); 437 438 skb_queue_tail(&local->reject_queue, skb); 439 rxrpc_queue_local(local); 440 } 441 442 /* 443 * reject packets through the local endpoint 444 */ 445 void rxrpc_reject_packets(struct rxrpc_local *local) 446 { 447 union { 448 struct sockaddr sa; 449 struct sockaddr_in sin; 450 } sa; 451 struct rxrpc_skb_priv *sp; 452 struct rxrpc_wire_header whdr; 453 struct sk_buff *skb; 454 struct msghdr msg; 455 struct kvec iov[2]; 456 size_t size; 457 __be32 code; 458 459 _enter("%d", local->debug_id); 460 461 iov[0].iov_base = &whdr; 462 iov[0].iov_len = sizeof(whdr); 463 iov[1].iov_base = &code; 464 iov[1].iov_len = sizeof(code); 465 size = sizeof(whdr) + sizeof(code); 466 467 msg.msg_name = &sa; 468 msg.msg_control = NULL; 469 msg.msg_controllen = 0; 470 msg.msg_flags = 0; 471 472 memset(&sa, 0, sizeof(sa)); 473 sa.sa.sa_family = local->srx.transport.family; 474 switch (sa.sa.sa_family) { 475 case AF_INET: 476 msg.msg_namelen = sizeof(sa.sin); 477 break; 478 default: 479 msg.msg_namelen = 0; 480 break; 481 } 482 483 memset(&whdr, 0, sizeof(whdr)); 484 whdr.type = RXRPC_PACKET_TYPE_ABORT; 485 486 while ((skb = skb_dequeue(&local->reject_queue))) { 487 rxrpc_see_skb(skb); 488 sp = rxrpc_skb(skb); 489 switch (sa.sa.sa_family) { 490 case AF_INET: 491 sa.sin.sin_port = udp_hdr(skb)->source; 492 sa.sin.sin_addr.s_addr = ip_hdr(skb)->saddr; 493 code = htonl(skb->priority); 494 495 whdr.epoch = htonl(sp->hdr.epoch); 496 whdr.cid = htonl(sp->hdr.cid); 497 whdr.callNumber = htonl(sp->hdr.callNumber); 498 whdr.serviceId = htons(sp->hdr.serviceId); 499 whdr.flags = sp->hdr.flags; 500 whdr.flags ^= RXRPC_CLIENT_INITIATED; 501 whdr.flags &= RXRPC_CLIENT_INITIATED; 502 503 kernel_sendmsg(local->socket, &msg, iov, 2, size); 504 break; 505 506 default: 507 break; 508 } 509 510 rxrpc_free_skb(skb); 511 } 512 513 _leave(""); 514 } 515