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