Kyle Swenson | 8d8f654 | 2021-03-15 11:02:55 -0600 | [diff] [blame] | 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 | #include <linux/module.h> |
| 13 | #include <linux/net.h> |
| 14 | #include <linux/skbuff.h> |
| 15 | #include <linux/errqueue.h> |
| 16 | #include <linux/udp.h> |
| 17 | #include <linux/in.h> |
| 18 | #include <linux/in6.h> |
| 19 | #include <linux/icmp.h> |
| 20 | #include <linux/gfp.h> |
| 21 | #include <net/sock.h> |
| 22 | #include <net/af_rxrpc.h> |
| 23 | #include <net/ip.h> |
| 24 | #include "ar-internal.h" |
| 25 | |
| 26 | /* |
| 27 | * generate a connection-level abort |
| 28 | */ |
| 29 | static int rxrpc_busy(struct rxrpc_local *local, struct sockaddr_rxrpc *srx, |
| 30 | struct rxrpc_header *hdr) |
| 31 | { |
| 32 | struct msghdr msg; |
| 33 | struct kvec iov[1]; |
| 34 | size_t len; |
| 35 | int ret; |
| 36 | |
| 37 | _enter("%d,,", local->debug_id); |
| 38 | |
| 39 | msg.msg_name = &srx->transport.sin; |
| 40 | msg.msg_namelen = sizeof(srx->transport.sin); |
| 41 | msg.msg_control = NULL; |
| 42 | msg.msg_controllen = 0; |
| 43 | msg.msg_flags = 0; |
| 44 | |
| 45 | hdr->seq = 0; |
| 46 | hdr->type = RXRPC_PACKET_TYPE_BUSY; |
| 47 | hdr->flags = 0; |
| 48 | hdr->userStatus = 0; |
| 49 | hdr->_rsvd = 0; |
| 50 | |
| 51 | iov[0].iov_base = hdr; |
| 52 | iov[0].iov_len = sizeof(*hdr); |
| 53 | |
| 54 | len = iov[0].iov_len; |
| 55 | |
| 56 | hdr->serial = htonl(1); |
| 57 | _proto("Tx BUSY %%%u", ntohl(hdr->serial)); |
| 58 | |
| 59 | ret = kernel_sendmsg(local->socket, &msg, iov, 1, len); |
| 60 | if (ret < 0) { |
| 61 | _leave(" = -EAGAIN [sendmsg failed: %d]", ret); |
| 62 | return -EAGAIN; |
| 63 | } |
| 64 | |
| 65 | _leave(" = 0"); |
| 66 | return 0; |
| 67 | } |
| 68 | |
| 69 | /* |
| 70 | * accept an incoming call that needs peer, transport and/or connection setting |
| 71 | * up |
| 72 | */ |
| 73 | static int rxrpc_accept_incoming_call(struct rxrpc_local *local, |
| 74 | struct rxrpc_sock *rx, |
| 75 | struct sk_buff *skb, |
| 76 | struct sockaddr_rxrpc *srx) |
| 77 | { |
| 78 | struct rxrpc_connection *conn; |
| 79 | struct rxrpc_transport *trans; |
| 80 | struct rxrpc_skb_priv *sp, *nsp; |
| 81 | struct rxrpc_peer *peer; |
| 82 | struct rxrpc_call *call; |
| 83 | struct sk_buff *notification; |
| 84 | int ret; |
| 85 | |
| 86 | _enter(""); |
| 87 | |
| 88 | sp = rxrpc_skb(skb); |
| 89 | |
| 90 | /* get a notification message to send to the server app */ |
| 91 | notification = alloc_skb(0, GFP_NOFS); |
| 92 | if (!notification) { |
| 93 | _debug("no memory"); |
| 94 | ret = -ENOMEM; |
| 95 | goto error_nofree; |
| 96 | } |
| 97 | rxrpc_new_skb(notification); |
| 98 | notification->mark = RXRPC_SKB_MARK_NEW_CALL; |
| 99 | |
| 100 | peer = rxrpc_get_peer(srx, GFP_NOIO); |
| 101 | if (IS_ERR(peer)) { |
| 102 | _debug("no peer"); |
| 103 | ret = -EBUSY; |
| 104 | goto error; |
| 105 | } |
| 106 | |
| 107 | trans = rxrpc_get_transport(local, peer, GFP_NOIO); |
| 108 | rxrpc_put_peer(peer); |
| 109 | if (IS_ERR(trans)) { |
| 110 | _debug("no trans"); |
| 111 | ret = -EBUSY; |
| 112 | goto error; |
| 113 | } |
| 114 | |
| 115 | conn = rxrpc_incoming_connection(trans, &sp->hdr, GFP_NOIO); |
| 116 | rxrpc_put_transport(trans); |
| 117 | if (IS_ERR(conn)) { |
| 118 | _debug("no conn"); |
| 119 | ret = PTR_ERR(conn); |
| 120 | goto error; |
| 121 | } |
| 122 | |
| 123 | call = rxrpc_incoming_call(rx, conn, &sp->hdr, GFP_NOIO); |
| 124 | rxrpc_put_connection(conn); |
| 125 | if (IS_ERR(call)) { |
| 126 | _debug("no call"); |
| 127 | ret = PTR_ERR(call); |
| 128 | goto error; |
| 129 | } |
| 130 | |
| 131 | /* attach the call to the socket */ |
| 132 | read_lock_bh(&local->services_lock); |
| 133 | if (rx->sk.sk_state == RXRPC_CLOSE) |
| 134 | goto invalid_service; |
| 135 | |
| 136 | write_lock(&rx->call_lock); |
| 137 | if (!test_and_set_bit(RXRPC_CALL_INIT_ACCEPT, &call->flags)) { |
| 138 | rxrpc_get_call(call); |
| 139 | |
| 140 | spin_lock(&call->conn->state_lock); |
| 141 | if (sp->hdr.securityIndex > 0 && |
| 142 | call->conn->state == RXRPC_CONN_SERVER_UNSECURED) { |
| 143 | _debug("await conn sec"); |
| 144 | list_add_tail(&call->accept_link, &rx->secureq); |
| 145 | call->conn->state = RXRPC_CONN_SERVER_CHALLENGING; |
| 146 | atomic_inc(&call->conn->usage); |
| 147 | set_bit(RXRPC_CONN_CHALLENGE, &call->conn->events); |
| 148 | rxrpc_queue_conn(call->conn); |
| 149 | } else { |
| 150 | _debug("conn ready"); |
| 151 | call->state = RXRPC_CALL_SERVER_ACCEPTING; |
| 152 | list_add_tail(&call->accept_link, &rx->acceptq); |
| 153 | rxrpc_get_call(call); |
| 154 | nsp = rxrpc_skb(notification); |
| 155 | nsp->call = call; |
| 156 | |
| 157 | ASSERTCMP(atomic_read(&call->usage), >=, 3); |
| 158 | |
| 159 | _debug("notify"); |
| 160 | spin_lock(&call->lock); |
| 161 | ret = rxrpc_queue_rcv_skb(call, notification, true, |
| 162 | false); |
| 163 | spin_unlock(&call->lock); |
| 164 | notification = NULL; |
| 165 | BUG_ON(ret < 0); |
| 166 | } |
| 167 | spin_unlock(&call->conn->state_lock); |
| 168 | |
| 169 | _debug("queued"); |
| 170 | } |
| 171 | write_unlock(&rx->call_lock); |
| 172 | |
| 173 | _debug("process"); |
| 174 | rxrpc_fast_process_packet(call, skb); |
| 175 | |
| 176 | _debug("done"); |
| 177 | read_unlock_bh(&local->services_lock); |
| 178 | rxrpc_free_skb(notification); |
| 179 | rxrpc_put_call(call); |
| 180 | _leave(" = 0"); |
| 181 | return 0; |
| 182 | |
| 183 | invalid_service: |
| 184 | _debug("invalid"); |
| 185 | read_unlock_bh(&local->services_lock); |
| 186 | |
| 187 | read_lock_bh(&call->state_lock); |
| 188 | if (!test_bit(RXRPC_CALL_RELEASE, &call->flags) && |
| 189 | !test_and_set_bit(RXRPC_CALL_RELEASE, &call->events)) { |
| 190 | rxrpc_get_call(call); |
| 191 | rxrpc_queue_call(call); |
| 192 | } |
| 193 | read_unlock_bh(&call->state_lock); |
| 194 | rxrpc_put_call(call); |
| 195 | ret = -ECONNREFUSED; |
| 196 | error: |
| 197 | rxrpc_free_skb(notification); |
| 198 | error_nofree: |
| 199 | _leave(" = %d", ret); |
| 200 | return ret; |
| 201 | } |
| 202 | |
| 203 | /* |
| 204 | * accept incoming calls that need peer, transport and/or connection setting up |
| 205 | * - the packets we get are all incoming client DATA packets that have seq == 1 |
| 206 | */ |
| 207 | void rxrpc_accept_incoming_calls(struct work_struct *work) |
| 208 | { |
| 209 | struct rxrpc_local *local = |
| 210 | container_of(work, struct rxrpc_local, acceptor); |
| 211 | struct rxrpc_skb_priv *sp; |
| 212 | struct sockaddr_rxrpc srx; |
| 213 | struct rxrpc_sock *rx; |
| 214 | struct sk_buff *skb; |
| 215 | __be16 service_id; |
| 216 | int ret; |
| 217 | |
| 218 | _enter("%d", local->debug_id); |
| 219 | |
| 220 | read_lock_bh(&rxrpc_local_lock); |
| 221 | if (atomic_read(&local->usage) > 0) |
| 222 | rxrpc_get_local(local); |
| 223 | else |
| 224 | local = NULL; |
| 225 | read_unlock_bh(&rxrpc_local_lock); |
| 226 | if (!local) { |
| 227 | _leave(" [local dead]"); |
| 228 | return; |
| 229 | } |
| 230 | |
| 231 | process_next_packet: |
| 232 | skb = skb_dequeue(&local->accept_queue); |
| 233 | if (!skb) { |
| 234 | rxrpc_put_local(local); |
| 235 | _leave("\n"); |
| 236 | return; |
| 237 | } |
| 238 | |
| 239 | _net("incoming call skb %p", skb); |
| 240 | |
| 241 | sp = rxrpc_skb(skb); |
| 242 | |
| 243 | /* determine the remote address */ |
| 244 | memset(&srx, 0, sizeof(srx)); |
| 245 | srx.srx_family = AF_RXRPC; |
| 246 | srx.transport.family = local->srx.transport.family; |
| 247 | srx.transport_type = local->srx.transport_type; |
| 248 | switch (srx.transport.family) { |
| 249 | case AF_INET: |
| 250 | srx.transport_len = sizeof(struct sockaddr_in); |
| 251 | srx.transport.sin.sin_port = udp_hdr(skb)->source; |
| 252 | srx.transport.sin.sin_addr.s_addr = ip_hdr(skb)->saddr; |
| 253 | break; |
| 254 | default: |
| 255 | goto busy; |
| 256 | } |
| 257 | |
| 258 | /* get the socket providing the service */ |
| 259 | service_id = sp->hdr.serviceId; |
| 260 | read_lock_bh(&local->services_lock); |
| 261 | list_for_each_entry(rx, &local->services, listen_link) { |
| 262 | if (rx->service_id == service_id && |
| 263 | rx->sk.sk_state != RXRPC_CLOSE) |
| 264 | goto found_service; |
| 265 | } |
| 266 | read_unlock_bh(&local->services_lock); |
| 267 | goto invalid_service; |
| 268 | |
| 269 | found_service: |
| 270 | _debug("found service %hd", ntohs(rx->service_id)); |
| 271 | if (sk_acceptq_is_full(&rx->sk)) |
| 272 | goto backlog_full; |
| 273 | sk_acceptq_added(&rx->sk); |
| 274 | sock_hold(&rx->sk); |
| 275 | read_unlock_bh(&local->services_lock); |
| 276 | |
| 277 | ret = rxrpc_accept_incoming_call(local, rx, skb, &srx); |
| 278 | if (ret < 0) |
| 279 | sk_acceptq_removed(&rx->sk); |
| 280 | sock_put(&rx->sk); |
| 281 | switch (ret) { |
| 282 | case -ECONNRESET: /* old calls are ignored */ |
| 283 | case -ECONNABORTED: /* aborted calls are reaborted or ignored */ |
| 284 | case 0: |
| 285 | goto process_next_packet; |
| 286 | case -ECONNREFUSED: |
| 287 | goto invalid_service; |
| 288 | case -EBUSY: |
| 289 | goto busy; |
| 290 | case -EKEYREJECTED: |
| 291 | goto security_mismatch; |
| 292 | default: |
| 293 | BUG(); |
| 294 | } |
| 295 | |
| 296 | backlog_full: |
| 297 | read_unlock_bh(&local->services_lock); |
| 298 | busy: |
| 299 | rxrpc_busy(local, &srx, &sp->hdr); |
| 300 | rxrpc_free_skb(skb); |
| 301 | goto process_next_packet; |
| 302 | |
| 303 | invalid_service: |
| 304 | skb->priority = RX_INVALID_OPERATION; |
| 305 | rxrpc_reject_packet(local, skb); |
| 306 | goto process_next_packet; |
| 307 | |
| 308 | /* can't change connection security type mid-flow */ |
| 309 | security_mismatch: |
| 310 | skb->priority = RX_PROTOCOL_ERROR; |
| 311 | rxrpc_reject_packet(local, skb); |
| 312 | goto process_next_packet; |
| 313 | } |
| 314 | |
| 315 | /* |
| 316 | * handle acceptance of a call by userspace |
| 317 | * - assign the user call ID to the call at the front of the queue |
| 318 | */ |
| 319 | struct rxrpc_call *rxrpc_accept_call(struct rxrpc_sock *rx, |
| 320 | unsigned long user_call_ID) |
| 321 | { |
| 322 | struct rxrpc_call *call; |
| 323 | struct rb_node *parent, **pp; |
| 324 | int ret; |
| 325 | |
| 326 | _enter(",%lx", user_call_ID); |
| 327 | |
| 328 | ASSERT(!irqs_disabled()); |
| 329 | |
| 330 | write_lock(&rx->call_lock); |
| 331 | |
| 332 | ret = -ENODATA; |
| 333 | if (list_empty(&rx->acceptq)) |
| 334 | goto out; |
| 335 | |
| 336 | /* check the user ID isn't already in use */ |
| 337 | ret = -EBADSLT; |
| 338 | pp = &rx->calls.rb_node; |
| 339 | parent = NULL; |
| 340 | while (*pp) { |
| 341 | parent = *pp; |
| 342 | call = rb_entry(parent, struct rxrpc_call, sock_node); |
| 343 | |
| 344 | if (user_call_ID < call->user_call_ID) |
| 345 | pp = &(*pp)->rb_left; |
| 346 | else if (user_call_ID > call->user_call_ID) |
| 347 | pp = &(*pp)->rb_right; |
| 348 | else |
| 349 | goto out; |
| 350 | } |
| 351 | |
| 352 | /* dequeue the first call and check it's still valid */ |
| 353 | call = list_entry(rx->acceptq.next, struct rxrpc_call, accept_link); |
| 354 | list_del_init(&call->accept_link); |
| 355 | sk_acceptq_removed(&rx->sk); |
| 356 | |
| 357 | write_lock_bh(&call->state_lock); |
| 358 | switch (call->state) { |
| 359 | case RXRPC_CALL_SERVER_ACCEPTING: |
| 360 | call->state = RXRPC_CALL_SERVER_RECV_REQUEST; |
| 361 | break; |
| 362 | case RXRPC_CALL_REMOTELY_ABORTED: |
| 363 | case RXRPC_CALL_LOCALLY_ABORTED: |
| 364 | ret = -ECONNABORTED; |
| 365 | goto out_release; |
| 366 | case RXRPC_CALL_NETWORK_ERROR: |
| 367 | ret = call->conn->error; |
| 368 | goto out_release; |
| 369 | case RXRPC_CALL_DEAD: |
| 370 | ret = -ETIME; |
| 371 | goto out_discard; |
| 372 | default: |
| 373 | BUG(); |
| 374 | } |
| 375 | |
| 376 | /* formalise the acceptance */ |
| 377 | call->user_call_ID = user_call_ID; |
| 378 | rb_link_node(&call->sock_node, parent, pp); |
| 379 | rb_insert_color(&call->sock_node, &rx->calls); |
| 380 | if (test_and_set_bit(RXRPC_CALL_HAS_USERID, &call->flags)) |
| 381 | BUG(); |
| 382 | if (test_and_set_bit(RXRPC_CALL_ACCEPTED, &call->events)) |
| 383 | BUG(); |
| 384 | rxrpc_queue_call(call); |
| 385 | |
| 386 | rxrpc_get_call(call); |
| 387 | write_unlock_bh(&call->state_lock); |
| 388 | write_unlock(&rx->call_lock); |
| 389 | _leave(" = %p{%d}", call, call->debug_id); |
| 390 | return call; |
| 391 | |
| 392 | /* if the call is already dying or dead, then we leave the socket's ref |
| 393 | * on it to be released by rxrpc_dead_call_expired() as induced by |
| 394 | * rxrpc_release_call() */ |
| 395 | out_release: |
| 396 | _debug("release %p", call); |
| 397 | if (!test_bit(RXRPC_CALL_RELEASED, &call->flags) && |
| 398 | !test_and_set_bit(RXRPC_CALL_RELEASE, &call->events)) |
| 399 | rxrpc_queue_call(call); |
| 400 | out_discard: |
| 401 | write_unlock_bh(&call->state_lock); |
| 402 | _debug("discard %p", call); |
| 403 | out: |
| 404 | write_unlock(&rx->call_lock); |
| 405 | _leave(" = %d", ret); |
| 406 | return ERR_PTR(ret); |
| 407 | } |
| 408 | |
| 409 | /* |
| 410 | * handle rejectance of a call by userspace |
| 411 | * - reject the call at the front of the queue |
| 412 | */ |
| 413 | int rxrpc_reject_call(struct rxrpc_sock *rx) |
| 414 | { |
| 415 | struct rxrpc_call *call; |
| 416 | int ret; |
| 417 | |
| 418 | _enter(""); |
| 419 | |
| 420 | ASSERT(!irqs_disabled()); |
| 421 | |
| 422 | write_lock(&rx->call_lock); |
| 423 | |
| 424 | ret = -ENODATA; |
| 425 | if (list_empty(&rx->acceptq)) |
| 426 | goto out; |
| 427 | |
| 428 | /* dequeue the first call and check it's still valid */ |
| 429 | call = list_entry(rx->acceptq.next, struct rxrpc_call, accept_link); |
| 430 | list_del_init(&call->accept_link); |
| 431 | sk_acceptq_removed(&rx->sk); |
| 432 | |
| 433 | write_lock_bh(&call->state_lock); |
| 434 | switch (call->state) { |
| 435 | case RXRPC_CALL_SERVER_ACCEPTING: |
| 436 | call->state = RXRPC_CALL_SERVER_BUSY; |
| 437 | if (test_and_set_bit(RXRPC_CALL_REJECT_BUSY, &call->events)) |
| 438 | rxrpc_queue_call(call); |
| 439 | ret = 0; |
| 440 | goto out_release; |
| 441 | case RXRPC_CALL_REMOTELY_ABORTED: |
| 442 | case RXRPC_CALL_LOCALLY_ABORTED: |
| 443 | ret = -ECONNABORTED; |
| 444 | goto out_release; |
| 445 | case RXRPC_CALL_NETWORK_ERROR: |
| 446 | ret = call->conn->error; |
| 447 | goto out_release; |
| 448 | case RXRPC_CALL_DEAD: |
| 449 | ret = -ETIME; |
| 450 | goto out_discard; |
| 451 | default: |
| 452 | BUG(); |
| 453 | } |
| 454 | |
| 455 | /* if the call is already dying or dead, then we leave the socket's ref |
| 456 | * on it to be released by rxrpc_dead_call_expired() as induced by |
| 457 | * rxrpc_release_call() */ |
| 458 | out_release: |
| 459 | _debug("release %p", call); |
| 460 | if (!test_bit(RXRPC_CALL_RELEASED, &call->flags) && |
| 461 | !test_and_set_bit(RXRPC_CALL_RELEASE, &call->events)) |
| 462 | rxrpc_queue_call(call); |
| 463 | out_discard: |
| 464 | write_unlock_bh(&call->state_lock); |
| 465 | _debug("discard %p", call); |
| 466 | out: |
| 467 | write_unlock(&rx->call_lock); |
| 468 | _leave(" = %d", ret); |
| 469 | return ret; |
| 470 | } |
| 471 | |
| 472 | /** |
| 473 | * rxrpc_kernel_accept_call - Allow a kernel service to accept an incoming call |
| 474 | * @sock: The socket on which the impending call is waiting |
| 475 | * @user_call_ID: The tag to attach to the call |
| 476 | * |
| 477 | * Allow a kernel service to accept an incoming call, assuming the incoming |
| 478 | * call is still valid. |
| 479 | */ |
| 480 | struct rxrpc_call *rxrpc_kernel_accept_call(struct socket *sock, |
| 481 | unsigned long user_call_ID) |
| 482 | { |
| 483 | struct rxrpc_call *call; |
| 484 | |
| 485 | _enter(",%lx", user_call_ID); |
| 486 | call = rxrpc_accept_call(rxrpc_sk(sock->sk), user_call_ID); |
| 487 | _leave(" = %p", call); |
| 488 | return call; |
| 489 | } |
| 490 | |
| 491 | EXPORT_SYMBOL(rxrpc_kernel_accept_call); |
| 492 | |
| 493 | /** |
| 494 | * rxrpc_kernel_reject_call - Allow a kernel service to reject an incoming call |
| 495 | * @sock: The socket on which the impending call is waiting |
| 496 | * |
| 497 | * Allow a kernel service to reject an incoming call with a BUSY message, |
| 498 | * assuming the incoming call is still valid. |
| 499 | */ |
| 500 | int rxrpc_kernel_reject_call(struct socket *sock) |
| 501 | { |
| 502 | int ret; |
| 503 | |
| 504 | _enter(""); |
| 505 | ret = rxrpc_reject_call(rxrpc_sk(sock->sk)); |
| 506 | _leave(" = %d", ret); |
| 507 | return ret; |
| 508 | } |
| 509 | |
| 510 | EXPORT_SYMBOL(rxrpc_kernel_reject_call); |