1 /* incoming call 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 <linux/gfp.h> 23 #include <net/sock.h> 24 #include <net/af_rxrpc.h> 25 #include <net/ip.h> 26 #include "ar-internal.h" 27 28 /* 29 * generate a connection-level abort 30 */ 31 static int rxrpc_busy(struct rxrpc_local *local, struct sockaddr_rxrpc *srx, 32 struct rxrpc_wire_header *whdr) 33 { 34 struct msghdr msg; 35 struct kvec iov[1]; 36 size_t len; 37 int ret; 38 39 _enter("%d,,", local->debug_id); 40 41 whdr->type = RXRPC_PACKET_TYPE_BUSY; 42 whdr->serial = htonl(1); 43 44 msg.msg_name = &srx->transport.sin; 45 msg.msg_namelen = sizeof(srx->transport.sin); 46 msg.msg_control = NULL; 47 msg.msg_controllen = 0; 48 msg.msg_flags = 0; 49 50 iov[0].iov_base = whdr; 51 iov[0].iov_len = sizeof(*whdr); 52 53 len = iov[0].iov_len; 54 55 _proto("Tx BUSY %%1"); 56 57 ret = kernel_sendmsg(local->socket, &msg, iov, 1, len); 58 if (ret < 0) { 59 _leave(" = -EAGAIN [sendmsg failed: %d]", ret); 60 return -EAGAIN; 61 } 62 63 _leave(" = 0"); 64 return 0; 65 } 66 67 /* 68 * accept an incoming call that needs peer, transport and/or connection setting 69 * up 70 */ 71 static int rxrpc_accept_incoming_call(struct rxrpc_local *local, 72 struct rxrpc_sock *rx, 73 struct sk_buff *skb, 74 struct sockaddr_rxrpc *srx) 75 { 76 struct rxrpc_connection *conn; 77 struct rxrpc_transport *trans; 78 struct rxrpc_skb_priv *sp, *nsp; 79 struct rxrpc_peer *peer; 80 struct rxrpc_call *call; 81 struct sk_buff *notification; 82 int ret; 83 84 _enter(""); 85 86 sp = rxrpc_skb(skb); 87 88 /* get a notification message to send to the server app */ 89 notification = alloc_skb(0, GFP_NOFS); 90 if (!notification) { 91 _debug("no memory"); 92 ret = -ENOMEM; 93 goto error_nofree; 94 } 95 rxrpc_new_skb(notification); 96 notification->mark = RXRPC_SKB_MARK_NEW_CALL; 97 98 peer = rxrpc_lookup_peer(local, srx, GFP_NOIO); 99 if (IS_ERR(peer)) { 100 _debug("no peer"); 101 ret = -EBUSY; 102 goto error; 103 } 104 105 trans = rxrpc_get_transport(local, peer, GFP_NOIO); 106 rxrpc_put_peer(peer); 107 if (IS_ERR(trans)) { 108 _debug("no trans"); 109 ret = -EBUSY; 110 goto error; 111 } 112 113 conn = rxrpc_incoming_connection(trans, &sp->hdr); 114 rxrpc_put_transport(trans); 115 if (IS_ERR(conn)) { 116 _debug("no conn"); 117 ret = PTR_ERR(conn); 118 goto error; 119 } 120 121 call = rxrpc_incoming_call(rx, conn, &sp->hdr); 122 rxrpc_put_connection(conn); 123 if (IS_ERR(call)) { 124 _debug("no call"); 125 ret = PTR_ERR(call); 126 goto error; 127 } 128 129 /* attach the call to the socket */ 130 read_lock_bh(&local->services_lock); 131 if (rx->sk.sk_state == RXRPC_CLOSE) 132 goto invalid_service; 133 134 write_lock(&rx->call_lock); 135 if (!test_and_set_bit(RXRPC_CALL_INIT_ACCEPT, &call->flags)) { 136 rxrpc_get_call(call); 137 138 spin_lock(&call->conn->state_lock); 139 if (sp->hdr.securityIndex > 0 && 140 call->conn->state == RXRPC_CONN_SERVER_UNSECURED) { 141 _debug("await conn sec"); 142 list_add_tail(&call->accept_link, &rx->secureq); 143 call->conn->state = RXRPC_CONN_SERVER_CHALLENGING; 144 atomic_inc(&call->conn->usage); 145 set_bit(RXRPC_CONN_CHALLENGE, &call->conn->events); 146 rxrpc_queue_conn(call->conn); 147 } else { 148 _debug("conn ready"); 149 call->state = RXRPC_CALL_SERVER_ACCEPTING; 150 list_add_tail(&call->accept_link, &rx->acceptq); 151 rxrpc_get_call(call); 152 nsp = rxrpc_skb(notification); 153 nsp->call = call; 154 155 ASSERTCMP(atomic_read(&call->usage), >=, 3); 156 157 _debug("notify"); 158 spin_lock(&call->lock); 159 ret = rxrpc_queue_rcv_skb(call, notification, true, 160 false); 161 spin_unlock(&call->lock); 162 notification = NULL; 163 BUG_ON(ret < 0); 164 } 165 spin_unlock(&call->conn->state_lock); 166 167 _debug("queued"); 168 } 169 write_unlock(&rx->call_lock); 170 171 _debug("process"); 172 rxrpc_fast_process_packet(call, skb); 173 174 _debug("done"); 175 read_unlock_bh(&local->services_lock); 176 rxrpc_free_skb(notification); 177 rxrpc_put_call(call); 178 _leave(" = 0"); 179 return 0; 180 181 invalid_service: 182 _debug("invalid"); 183 read_unlock_bh(&local->services_lock); 184 185 read_lock_bh(&call->state_lock); 186 if (!test_bit(RXRPC_CALL_RELEASED, &call->flags) && 187 !test_and_set_bit(RXRPC_CALL_EV_RELEASE, &call->events)) { 188 rxrpc_get_call(call); 189 rxrpc_queue_call(call); 190 } 191 read_unlock_bh(&call->state_lock); 192 rxrpc_put_call(call); 193 ret = -ECONNREFUSED; 194 error: 195 rxrpc_free_skb(notification); 196 error_nofree: 197 _leave(" = %d", ret); 198 return ret; 199 } 200 201 /* 202 * accept incoming calls that need peer, transport and/or connection setting up 203 * - the packets we get are all incoming client DATA packets that have seq == 1 204 */ 205 void rxrpc_accept_incoming_calls(struct rxrpc_local *local) 206 { 207 struct rxrpc_skb_priv *sp; 208 struct sockaddr_rxrpc srx; 209 struct rxrpc_sock *rx; 210 struct rxrpc_wire_header whdr; 211 struct sk_buff *skb; 212 int ret; 213 214 _enter("%d", local->debug_id); 215 216 skb = skb_dequeue(&local->accept_queue); 217 if (!skb) { 218 _leave("\n"); 219 return; 220 } 221 222 _net("incoming call skb %p", skb); 223 224 sp = rxrpc_skb(skb); 225 226 /* Set up a response packet header in case we need it */ 227 whdr.epoch = htonl(sp->hdr.epoch); 228 whdr.cid = htonl(sp->hdr.cid); 229 whdr.callNumber = htonl(sp->hdr.callNumber); 230 whdr.seq = htonl(sp->hdr.seq); 231 whdr.serial = 0; 232 whdr.flags = 0; 233 whdr.type = 0; 234 whdr.userStatus = 0; 235 whdr.securityIndex = sp->hdr.securityIndex; 236 whdr._rsvd = 0; 237 whdr.serviceId = htons(sp->hdr.serviceId); 238 239 /* determine the remote address */ 240 memset(&srx, 0, sizeof(srx)); 241 srx.srx_family = AF_RXRPC; 242 srx.transport.family = local->srx.transport.family; 243 srx.transport_type = local->srx.transport_type; 244 switch (srx.transport.family) { 245 case AF_INET: 246 srx.transport_len = sizeof(struct sockaddr_in); 247 srx.transport.sin.sin_port = udp_hdr(skb)->source; 248 srx.transport.sin.sin_addr.s_addr = ip_hdr(skb)->saddr; 249 break; 250 default: 251 goto busy; 252 } 253 254 /* get the socket providing the service */ 255 read_lock_bh(&local->services_lock); 256 list_for_each_entry(rx, &local->services, listen_link) { 257 if (rx->srx.srx_service == sp->hdr.serviceId && 258 rx->sk.sk_state != RXRPC_CLOSE) 259 goto found_service; 260 } 261 read_unlock_bh(&local->services_lock); 262 goto invalid_service; 263 264 found_service: 265 _debug("found service %hd", rx->srx.srx_service); 266 if (sk_acceptq_is_full(&rx->sk)) 267 goto backlog_full; 268 sk_acceptq_added(&rx->sk); 269 sock_hold(&rx->sk); 270 read_unlock_bh(&local->services_lock); 271 272 ret = rxrpc_accept_incoming_call(local, rx, skb, &srx); 273 if (ret < 0) 274 sk_acceptq_removed(&rx->sk); 275 sock_put(&rx->sk); 276 switch (ret) { 277 case -ECONNRESET: /* old calls are ignored */ 278 case -ECONNABORTED: /* aborted calls are reaborted or ignored */ 279 case 0: 280 return; 281 case -ECONNREFUSED: 282 goto invalid_service; 283 case -EBUSY: 284 goto busy; 285 case -EKEYREJECTED: 286 goto security_mismatch; 287 default: 288 BUG(); 289 } 290 291 backlog_full: 292 read_unlock_bh(&local->services_lock); 293 busy: 294 rxrpc_busy(local, &srx, &whdr); 295 rxrpc_free_skb(skb); 296 return; 297 298 invalid_service: 299 skb->priority = RX_INVALID_OPERATION; 300 rxrpc_reject_packet(local, skb); 301 return; 302 303 /* can't change connection security type mid-flow */ 304 security_mismatch: 305 skb->priority = RX_PROTOCOL_ERROR; 306 rxrpc_reject_packet(local, skb); 307 return; 308 } 309 310 /* 311 * handle acceptance of a call by userspace 312 * - assign the user call ID to the call at the front of the queue 313 */ 314 struct rxrpc_call *rxrpc_accept_call(struct rxrpc_sock *rx, 315 unsigned long user_call_ID) 316 { 317 struct rxrpc_call *call; 318 struct rb_node *parent, **pp; 319 int ret; 320 321 _enter(",%lx", user_call_ID); 322 323 ASSERT(!irqs_disabled()); 324 325 write_lock(&rx->call_lock); 326 327 ret = -ENODATA; 328 if (list_empty(&rx->acceptq)) 329 goto out; 330 331 /* check the user ID isn't already in use */ 332 ret = -EBADSLT; 333 pp = &rx->calls.rb_node; 334 parent = NULL; 335 while (*pp) { 336 parent = *pp; 337 call = rb_entry(parent, struct rxrpc_call, sock_node); 338 339 if (user_call_ID < call->user_call_ID) 340 pp = &(*pp)->rb_left; 341 else if (user_call_ID > call->user_call_ID) 342 pp = &(*pp)->rb_right; 343 else 344 goto out; 345 } 346 347 /* dequeue the first call and check it's still valid */ 348 call = list_entry(rx->acceptq.next, struct rxrpc_call, accept_link); 349 list_del_init(&call->accept_link); 350 sk_acceptq_removed(&rx->sk); 351 352 write_lock_bh(&call->state_lock); 353 switch (call->state) { 354 case RXRPC_CALL_SERVER_ACCEPTING: 355 call->state = RXRPC_CALL_SERVER_RECV_REQUEST; 356 break; 357 case RXRPC_CALL_REMOTELY_ABORTED: 358 case RXRPC_CALL_LOCALLY_ABORTED: 359 ret = -ECONNABORTED; 360 goto out_release; 361 case RXRPC_CALL_NETWORK_ERROR: 362 ret = call->conn->error; 363 goto out_release; 364 case RXRPC_CALL_DEAD: 365 ret = -ETIME; 366 goto out_discard; 367 default: 368 BUG(); 369 } 370 371 /* formalise the acceptance */ 372 call->user_call_ID = user_call_ID; 373 rb_link_node(&call->sock_node, parent, pp); 374 rb_insert_color(&call->sock_node, &rx->calls); 375 if (test_and_set_bit(RXRPC_CALL_HAS_USERID, &call->flags)) 376 BUG(); 377 if (test_and_set_bit(RXRPC_CALL_EV_ACCEPTED, &call->events)) 378 BUG(); 379 rxrpc_queue_call(call); 380 381 rxrpc_get_call(call); 382 write_unlock_bh(&call->state_lock); 383 write_unlock(&rx->call_lock); 384 _leave(" = %p{%d}", call, call->debug_id); 385 return call; 386 387 /* if the call is already dying or dead, then we leave the socket's ref 388 * on it to be released by rxrpc_dead_call_expired() as induced by 389 * rxrpc_release_call() */ 390 out_release: 391 _debug("release %p", call); 392 if (!test_bit(RXRPC_CALL_RELEASED, &call->flags) && 393 !test_and_set_bit(RXRPC_CALL_EV_RELEASE, &call->events)) 394 rxrpc_queue_call(call); 395 out_discard: 396 write_unlock_bh(&call->state_lock); 397 _debug("discard %p", call); 398 out: 399 write_unlock(&rx->call_lock); 400 _leave(" = %d", ret); 401 return ERR_PTR(ret); 402 } 403 404 /* 405 * Handle rejection of a call by userspace 406 * - reject the call at the front of the queue 407 */ 408 int rxrpc_reject_call(struct rxrpc_sock *rx) 409 { 410 struct rxrpc_call *call; 411 int ret; 412 413 _enter(""); 414 415 ASSERT(!irqs_disabled()); 416 417 write_lock(&rx->call_lock); 418 419 ret = -ENODATA; 420 if (list_empty(&rx->acceptq)) 421 goto out; 422 423 /* dequeue the first call and check it's still valid */ 424 call = list_entry(rx->acceptq.next, struct rxrpc_call, accept_link); 425 list_del_init(&call->accept_link); 426 sk_acceptq_removed(&rx->sk); 427 428 write_lock_bh(&call->state_lock); 429 switch (call->state) { 430 case RXRPC_CALL_SERVER_ACCEPTING: 431 call->state = RXRPC_CALL_SERVER_BUSY; 432 if (test_and_set_bit(RXRPC_CALL_EV_REJECT_BUSY, &call->events)) 433 rxrpc_queue_call(call); 434 ret = 0; 435 goto out_release; 436 case RXRPC_CALL_REMOTELY_ABORTED: 437 case RXRPC_CALL_LOCALLY_ABORTED: 438 ret = -ECONNABORTED; 439 goto out_release; 440 case RXRPC_CALL_NETWORK_ERROR: 441 ret = call->conn->error; 442 goto out_release; 443 case RXRPC_CALL_DEAD: 444 ret = -ETIME; 445 goto out_discard; 446 default: 447 BUG(); 448 } 449 450 /* if the call is already dying or dead, then we leave the socket's ref 451 * on it to be released by rxrpc_dead_call_expired() as induced by 452 * rxrpc_release_call() */ 453 out_release: 454 _debug("release %p", call); 455 if (!test_bit(RXRPC_CALL_RELEASED, &call->flags) && 456 !test_and_set_bit(RXRPC_CALL_EV_RELEASE, &call->events)) 457 rxrpc_queue_call(call); 458 out_discard: 459 write_unlock_bh(&call->state_lock); 460 _debug("discard %p", call); 461 out: 462 write_unlock(&rx->call_lock); 463 _leave(" = %d", ret); 464 return ret; 465 } 466 467 /** 468 * rxrpc_kernel_accept_call - Allow a kernel service to accept an incoming call 469 * @sock: The socket on which the impending call is waiting 470 * @user_call_ID: The tag to attach to the call 471 * 472 * Allow a kernel service to accept an incoming call, assuming the incoming 473 * call is still valid. 474 */ 475 struct rxrpc_call *rxrpc_kernel_accept_call(struct socket *sock, 476 unsigned long user_call_ID) 477 { 478 struct rxrpc_call *call; 479 480 _enter(",%lx", user_call_ID); 481 call = rxrpc_accept_call(rxrpc_sk(sock->sk), user_call_ID); 482 _leave(" = %p", call); 483 return call; 484 } 485 EXPORT_SYMBOL(rxrpc_kernel_accept_call); 486 487 /** 488 * rxrpc_kernel_reject_call - Allow a kernel service to reject an incoming call 489 * @sock: The socket on which the impending call is waiting 490 * 491 * Allow a kernel service to reject an incoming call with a BUSY message, 492 * assuming the incoming call is still valid. 493 */ 494 int rxrpc_kernel_reject_call(struct socket *sock) 495 { 496 int ret; 497 498 _enter(""); 499 ret = rxrpc_reject_call(rxrpc_sk(sock->sk)); 500 _leave(" = %d", ret); 501 return ret; 502 } 503 EXPORT_SYMBOL(rxrpc_kernel_reject_call); 504