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