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