1 /* 2 * Copyright (C) ST-Ericsson AB 2010 3 * Author: Sjur Brendeland sjur.brandeland@stericsson.com 4 * License terms: GNU General Public License (GPL) version 2 5 */ 6 7 #define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__ 8 9 #include <linux/fs.h> 10 #include <linux/init.h> 11 #include <linux/module.h> 12 #include <linux/sched.h> 13 #include <linux/spinlock.h> 14 #include <linux/mutex.h> 15 #include <linux/list.h> 16 #include <linux/wait.h> 17 #include <linux/poll.h> 18 #include <linux/tcp.h> 19 #include <linux/uaccess.h> 20 #include <linux/debugfs.h> 21 #include <linux/caif/caif_socket.h> 22 #include <linux/pkt_sched.h> 23 #include <net/sock.h> 24 #include <net/tcp_states.h> 25 #include <net/caif/caif_layer.h> 26 #include <net/caif/caif_dev.h> 27 #include <net/caif/cfpkt.h> 28 29 MODULE_LICENSE("GPL"); 30 MODULE_ALIAS_NETPROTO(AF_CAIF); 31 32 /* 33 * CAIF state is re-using the TCP socket states. 34 * caif_states stored in sk_state reflect the state as reported by 35 * the CAIF stack, while sk_socket->state is the state of the socket. 36 */ 37 enum caif_states { 38 CAIF_CONNECTED = TCP_ESTABLISHED, 39 CAIF_CONNECTING = TCP_SYN_SENT, 40 CAIF_DISCONNECTED = TCP_CLOSE 41 }; 42 43 #define TX_FLOW_ON_BIT 1 44 #define RX_FLOW_ON_BIT 2 45 46 struct caifsock { 47 struct sock sk; /* must be first member */ 48 struct cflayer layer; 49 u32 flow_state; 50 struct caif_connect_request conn_req; 51 struct mutex readlock; 52 struct dentry *debugfs_socket_dir; 53 int headroom, tailroom, maxframe; 54 }; 55 56 static int rx_flow_is_on(struct caifsock *cf_sk) 57 { 58 return test_bit(RX_FLOW_ON_BIT, 59 (void *) &cf_sk->flow_state); 60 } 61 62 static int tx_flow_is_on(struct caifsock *cf_sk) 63 { 64 return test_bit(TX_FLOW_ON_BIT, 65 (void *) &cf_sk->flow_state); 66 } 67 68 static void set_rx_flow_off(struct caifsock *cf_sk) 69 { 70 clear_bit(RX_FLOW_ON_BIT, 71 (void *) &cf_sk->flow_state); 72 } 73 74 static void set_rx_flow_on(struct caifsock *cf_sk) 75 { 76 set_bit(RX_FLOW_ON_BIT, 77 (void *) &cf_sk->flow_state); 78 } 79 80 static void set_tx_flow_off(struct caifsock *cf_sk) 81 { 82 clear_bit(TX_FLOW_ON_BIT, 83 (void *) &cf_sk->flow_state); 84 } 85 86 static void set_tx_flow_on(struct caifsock *cf_sk) 87 { 88 set_bit(TX_FLOW_ON_BIT, 89 (void *) &cf_sk->flow_state); 90 } 91 92 static void caif_read_lock(struct sock *sk) 93 { 94 struct caifsock *cf_sk; 95 cf_sk = container_of(sk, struct caifsock, sk); 96 mutex_lock(&cf_sk->readlock); 97 } 98 99 static void caif_read_unlock(struct sock *sk) 100 { 101 struct caifsock *cf_sk; 102 cf_sk = container_of(sk, struct caifsock, sk); 103 mutex_unlock(&cf_sk->readlock); 104 } 105 106 static int sk_rcvbuf_lowwater(struct caifsock *cf_sk) 107 { 108 /* A quarter of full buffer is used a low water mark */ 109 return cf_sk->sk.sk_rcvbuf / 4; 110 } 111 112 static void caif_flow_ctrl(struct sock *sk, int mode) 113 { 114 struct caifsock *cf_sk; 115 cf_sk = container_of(sk, struct caifsock, sk); 116 if (cf_sk->layer.dn && cf_sk->layer.dn->modemcmd) 117 cf_sk->layer.dn->modemcmd(cf_sk->layer.dn, mode); 118 } 119 120 /* 121 * Copied from sock.c:sock_queue_rcv_skb(), but changed so packets are 122 * not dropped, but CAIF is sending flow off instead. 123 */ 124 static int caif_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) 125 { 126 int err; 127 int skb_len; 128 unsigned long flags; 129 struct sk_buff_head *list = &sk->sk_receive_queue; 130 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); 131 132 if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >= 133 (unsigned int)sk->sk_rcvbuf && rx_flow_is_on(cf_sk)) { 134 net_dbg_ratelimited("sending flow OFF (queue len = %d %d)\n", 135 atomic_read(&cf_sk->sk.sk_rmem_alloc), 136 sk_rcvbuf_lowwater(cf_sk)); 137 set_rx_flow_off(cf_sk); 138 caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_OFF_REQ); 139 } 140 141 err = sk_filter(sk, skb); 142 if (err) 143 return err; 144 if (!sk_rmem_schedule(sk, skb->truesize) && rx_flow_is_on(cf_sk)) { 145 set_rx_flow_off(cf_sk); 146 net_dbg_ratelimited("sending flow OFF due to rmem_schedule\n"); 147 caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_OFF_REQ); 148 } 149 skb->dev = NULL; 150 skb_set_owner_r(skb, sk); 151 /* Cache the SKB length before we tack it onto the receive 152 * queue. Once it is added it no longer belongs to us and 153 * may be freed by other threads of control pulling packets 154 * from the queue. 155 */ 156 skb_len = skb->len; 157 spin_lock_irqsave(&list->lock, flags); 158 if (!sock_flag(sk, SOCK_DEAD)) 159 __skb_queue_tail(list, skb); 160 spin_unlock_irqrestore(&list->lock, flags); 161 162 if (!sock_flag(sk, SOCK_DEAD)) 163 sk->sk_data_ready(sk, skb_len); 164 else 165 kfree_skb(skb); 166 return 0; 167 } 168 169 /* Packet Receive Callback function called from CAIF Stack */ 170 static int caif_sktrecv_cb(struct cflayer *layr, struct cfpkt *pkt) 171 { 172 struct caifsock *cf_sk; 173 struct sk_buff *skb; 174 175 cf_sk = container_of(layr, struct caifsock, layer); 176 skb = cfpkt_tonative(pkt); 177 178 if (unlikely(cf_sk->sk.sk_state != CAIF_CONNECTED)) { 179 kfree_skb(skb); 180 return 0; 181 } 182 caif_queue_rcv_skb(&cf_sk->sk, skb); 183 return 0; 184 } 185 186 static void cfsk_hold(struct cflayer *layr) 187 { 188 struct caifsock *cf_sk = container_of(layr, struct caifsock, layer); 189 sock_hold(&cf_sk->sk); 190 } 191 192 static void cfsk_put(struct cflayer *layr) 193 { 194 struct caifsock *cf_sk = container_of(layr, struct caifsock, layer); 195 sock_put(&cf_sk->sk); 196 } 197 198 /* Packet Control Callback function called from CAIF */ 199 static void caif_ctrl_cb(struct cflayer *layr, 200 enum caif_ctrlcmd flow, 201 int phyid) 202 { 203 struct caifsock *cf_sk = container_of(layr, struct caifsock, layer); 204 switch (flow) { 205 case CAIF_CTRLCMD_FLOW_ON_IND: 206 /* OK from modem to start sending again */ 207 set_tx_flow_on(cf_sk); 208 cf_sk->sk.sk_state_change(&cf_sk->sk); 209 break; 210 211 case CAIF_CTRLCMD_FLOW_OFF_IND: 212 /* Modem asks us to shut up */ 213 set_tx_flow_off(cf_sk); 214 cf_sk->sk.sk_state_change(&cf_sk->sk); 215 break; 216 217 case CAIF_CTRLCMD_INIT_RSP: 218 /* We're now connected */ 219 caif_client_register_refcnt(&cf_sk->layer, 220 cfsk_hold, cfsk_put); 221 cf_sk->sk.sk_state = CAIF_CONNECTED; 222 set_tx_flow_on(cf_sk); 223 cf_sk->sk.sk_state_change(&cf_sk->sk); 224 break; 225 226 case CAIF_CTRLCMD_DEINIT_RSP: 227 /* We're now disconnected */ 228 cf_sk->sk.sk_state = CAIF_DISCONNECTED; 229 cf_sk->sk.sk_state_change(&cf_sk->sk); 230 break; 231 232 case CAIF_CTRLCMD_INIT_FAIL_RSP: 233 /* Connect request failed */ 234 cf_sk->sk.sk_err = ECONNREFUSED; 235 cf_sk->sk.sk_state = CAIF_DISCONNECTED; 236 cf_sk->sk.sk_shutdown = SHUTDOWN_MASK; 237 /* 238 * Socket "standards" seems to require POLLOUT to 239 * be set at connect failure. 240 */ 241 set_tx_flow_on(cf_sk); 242 cf_sk->sk.sk_state_change(&cf_sk->sk); 243 break; 244 245 case CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND: 246 /* Modem has closed this connection, or device is down. */ 247 cf_sk->sk.sk_shutdown = SHUTDOWN_MASK; 248 cf_sk->sk.sk_err = ECONNRESET; 249 set_rx_flow_on(cf_sk); 250 cf_sk->sk.sk_error_report(&cf_sk->sk); 251 break; 252 253 default: 254 pr_debug("Unexpected flow command %d\n", flow); 255 } 256 } 257 258 static void caif_check_flow_release(struct sock *sk) 259 { 260 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); 261 262 if (rx_flow_is_on(cf_sk)) 263 return; 264 265 if (atomic_read(&sk->sk_rmem_alloc) <= sk_rcvbuf_lowwater(cf_sk)) { 266 set_rx_flow_on(cf_sk); 267 caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_ON_REQ); 268 } 269 } 270 271 /* 272 * Copied from unix_dgram_recvmsg, but removed credit checks, 273 * changed locking, address handling and added MSG_TRUNC. 274 */ 275 static int caif_seqpkt_recvmsg(struct kiocb *iocb, struct socket *sock, 276 struct msghdr *m, size_t len, int flags) 277 278 { 279 struct sock *sk = sock->sk; 280 struct sk_buff *skb; 281 int ret; 282 int copylen; 283 284 ret = -EOPNOTSUPP; 285 if (m->msg_flags&MSG_OOB) 286 goto read_error; 287 288 skb = skb_recv_datagram(sk, flags, 0 , &ret); 289 if (!skb) 290 goto read_error; 291 copylen = skb->len; 292 if (len < copylen) { 293 m->msg_flags |= MSG_TRUNC; 294 copylen = len; 295 } 296 297 ret = skb_copy_datagram_iovec(skb, 0, m->msg_iov, copylen); 298 if (ret) 299 goto out_free; 300 301 ret = (flags & MSG_TRUNC) ? skb->len : copylen; 302 out_free: 303 skb_free_datagram(sk, skb); 304 caif_check_flow_release(sk); 305 return ret; 306 307 read_error: 308 return ret; 309 } 310 311 312 /* Copied from unix_stream_wait_data, identical except for lock call. */ 313 static long caif_stream_data_wait(struct sock *sk, long timeo) 314 { 315 DEFINE_WAIT(wait); 316 lock_sock(sk); 317 318 for (;;) { 319 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE); 320 321 if (!skb_queue_empty(&sk->sk_receive_queue) || 322 sk->sk_err || 323 sk->sk_state != CAIF_CONNECTED || 324 sock_flag(sk, SOCK_DEAD) || 325 (sk->sk_shutdown & RCV_SHUTDOWN) || 326 signal_pending(current) || 327 !timeo) 328 break; 329 330 set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags); 331 release_sock(sk); 332 timeo = schedule_timeout(timeo); 333 lock_sock(sk); 334 clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags); 335 } 336 337 finish_wait(sk_sleep(sk), &wait); 338 release_sock(sk); 339 return timeo; 340 } 341 342 343 /* 344 * Copied from unix_stream_recvmsg, but removed credit checks, 345 * changed locking calls, changed address handling. 346 */ 347 static int caif_stream_recvmsg(struct kiocb *iocb, struct socket *sock, 348 struct msghdr *msg, size_t size, 349 int flags) 350 { 351 struct sock *sk = sock->sk; 352 int copied = 0; 353 int target; 354 int err = 0; 355 long timeo; 356 357 err = -EOPNOTSUPP; 358 if (flags&MSG_OOB) 359 goto out; 360 361 msg->msg_namelen = 0; 362 363 /* 364 * Lock the socket to prevent queue disordering 365 * while sleeps in memcpy_tomsg 366 */ 367 err = -EAGAIN; 368 if (sk->sk_state == CAIF_CONNECTING) 369 goto out; 370 371 caif_read_lock(sk); 372 target = sock_rcvlowat(sk, flags&MSG_WAITALL, size); 373 timeo = sock_rcvtimeo(sk, flags&MSG_DONTWAIT); 374 375 do { 376 int chunk; 377 struct sk_buff *skb; 378 379 lock_sock(sk); 380 skb = skb_dequeue(&sk->sk_receive_queue); 381 caif_check_flow_release(sk); 382 383 if (skb == NULL) { 384 if (copied >= target) 385 goto unlock; 386 /* 387 * POSIX 1003.1g mandates this order. 388 */ 389 err = sock_error(sk); 390 if (err) 391 goto unlock; 392 err = -ECONNRESET; 393 if (sk->sk_shutdown & RCV_SHUTDOWN) 394 goto unlock; 395 396 err = -EPIPE; 397 if (sk->sk_state != CAIF_CONNECTED) 398 goto unlock; 399 if (sock_flag(sk, SOCK_DEAD)) 400 goto unlock; 401 402 release_sock(sk); 403 404 err = -EAGAIN; 405 if (!timeo) 406 break; 407 408 caif_read_unlock(sk); 409 410 timeo = caif_stream_data_wait(sk, timeo); 411 412 if (signal_pending(current)) { 413 err = sock_intr_errno(timeo); 414 goto out; 415 } 416 caif_read_lock(sk); 417 continue; 418 unlock: 419 release_sock(sk); 420 break; 421 } 422 release_sock(sk); 423 chunk = min_t(unsigned int, skb->len, size); 424 if (memcpy_toiovec(msg->msg_iov, skb->data, chunk)) { 425 skb_queue_head(&sk->sk_receive_queue, skb); 426 if (copied == 0) 427 copied = -EFAULT; 428 break; 429 } 430 copied += chunk; 431 size -= chunk; 432 433 /* Mark read part of skb as used */ 434 if (!(flags & MSG_PEEK)) { 435 skb_pull(skb, chunk); 436 437 /* put the skb back if we didn't use it up. */ 438 if (skb->len) { 439 skb_queue_head(&sk->sk_receive_queue, skb); 440 break; 441 } 442 kfree_skb(skb); 443 444 } else { 445 /* 446 * It is questionable, see note in unix_dgram_recvmsg. 447 */ 448 /* put message back and return */ 449 skb_queue_head(&sk->sk_receive_queue, skb); 450 break; 451 } 452 } while (size); 453 caif_read_unlock(sk); 454 455 out: 456 return copied ? : err; 457 } 458 459 /* 460 * Copied from sock.c:sock_wait_for_wmem, but change to wait for 461 * CAIF flow-on and sock_writable. 462 */ 463 static long caif_wait_for_flow_on(struct caifsock *cf_sk, 464 int wait_writeable, long timeo, int *err) 465 { 466 struct sock *sk = &cf_sk->sk; 467 DEFINE_WAIT(wait); 468 for (;;) { 469 *err = 0; 470 if (tx_flow_is_on(cf_sk) && 471 (!wait_writeable || sock_writeable(&cf_sk->sk))) 472 break; 473 *err = -ETIMEDOUT; 474 if (!timeo) 475 break; 476 *err = -ERESTARTSYS; 477 if (signal_pending(current)) 478 break; 479 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE); 480 *err = -ECONNRESET; 481 if (sk->sk_shutdown & SHUTDOWN_MASK) 482 break; 483 *err = -sk->sk_err; 484 if (sk->sk_err) 485 break; 486 *err = -EPIPE; 487 if (cf_sk->sk.sk_state != CAIF_CONNECTED) 488 break; 489 timeo = schedule_timeout(timeo); 490 } 491 finish_wait(sk_sleep(sk), &wait); 492 return timeo; 493 } 494 495 /* 496 * Transmit a SKB. The device may temporarily request re-transmission 497 * by returning EAGAIN. 498 */ 499 static int transmit_skb(struct sk_buff *skb, struct caifsock *cf_sk, 500 int noblock, long timeo) 501 { 502 struct cfpkt *pkt; 503 504 pkt = cfpkt_fromnative(CAIF_DIR_OUT, skb); 505 memset(skb->cb, 0, sizeof(struct caif_payload_info)); 506 cfpkt_set_prio(pkt, cf_sk->sk.sk_priority); 507 508 if (cf_sk->layer.dn == NULL) { 509 kfree_skb(skb); 510 return -EINVAL; 511 } 512 513 return cf_sk->layer.dn->transmit(cf_sk->layer.dn, pkt); 514 } 515 516 /* Copied from af_unix:unix_dgram_sendmsg, and adapted to CAIF */ 517 static int caif_seqpkt_sendmsg(struct kiocb *kiocb, struct socket *sock, 518 struct msghdr *msg, size_t len) 519 { 520 struct sock *sk = sock->sk; 521 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); 522 int buffer_size; 523 int ret = 0; 524 struct sk_buff *skb = NULL; 525 int noblock; 526 long timeo; 527 caif_assert(cf_sk); 528 ret = sock_error(sk); 529 if (ret) 530 goto err; 531 532 ret = -EOPNOTSUPP; 533 if (msg->msg_flags&MSG_OOB) 534 goto err; 535 536 ret = -EOPNOTSUPP; 537 if (msg->msg_namelen) 538 goto err; 539 540 ret = -EINVAL; 541 if (unlikely(msg->msg_iov->iov_base == NULL)) 542 goto err; 543 noblock = msg->msg_flags & MSG_DONTWAIT; 544 545 timeo = sock_sndtimeo(sk, noblock); 546 timeo = caif_wait_for_flow_on(container_of(sk, struct caifsock, sk), 547 1, timeo, &ret); 548 549 if (ret) 550 goto err; 551 ret = -EPIPE; 552 if (cf_sk->sk.sk_state != CAIF_CONNECTED || 553 sock_flag(sk, SOCK_DEAD) || 554 (sk->sk_shutdown & RCV_SHUTDOWN)) 555 goto err; 556 557 /* Error if trying to write more than maximum frame size. */ 558 ret = -EMSGSIZE; 559 if (len > cf_sk->maxframe && cf_sk->sk.sk_protocol != CAIFPROTO_RFM) 560 goto err; 561 562 buffer_size = len + cf_sk->headroom + cf_sk->tailroom; 563 564 ret = -ENOMEM; 565 skb = sock_alloc_send_skb(sk, buffer_size, noblock, &ret); 566 567 if (!skb || skb_tailroom(skb) < buffer_size) 568 goto err; 569 570 skb_reserve(skb, cf_sk->headroom); 571 572 ret = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len); 573 574 if (ret) 575 goto err; 576 ret = transmit_skb(skb, cf_sk, noblock, timeo); 577 if (ret < 0) 578 /* skb is already freed */ 579 return ret; 580 581 return len; 582 err: 583 kfree_skb(skb); 584 return ret; 585 } 586 587 /* 588 * Copied from unix_stream_sendmsg and adapted to CAIF: 589 * Changed removed permission handling and added waiting for flow on 590 * and other minor adaptations. 591 */ 592 static int caif_stream_sendmsg(struct kiocb *kiocb, struct socket *sock, 593 struct msghdr *msg, size_t len) 594 { 595 struct sock *sk = sock->sk; 596 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); 597 int err, size; 598 struct sk_buff *skb; 599 int sent = 0; 600 long timeo; 601 602 err = -EOPNOTSUPP; 603 if (unlikely(msg->msg_flags&MSG_OOB)) 604 goto out_err; 605 606 if (unlikely(msg->msg_namelen)) 607 goto out_err; 608 609 timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT); 610 timeo = caif_wait_for_flow_on(cf_sk, 1, timeo, &err); 611 612 if (unlikely(sk->sk_shutdown & SEND_SHUTDOWN)) 613 goto pipe_err; 614 615 while (sent < len) { 616 617 size = len-sent; 618 619 if (size > cf_sk->maxframe) 620 size = cf_sk->maxframe; 621 622 /* If size is more than half of sndbuf, chop up message */ 623 if (size > ((sk->sk_sndbuf >> 1) - 64)) 624 size = (sk->sk_sndbuf >> 1) - 64; 625 626 if (size > SKB_MAX_ALLOC) 627 size = SKB_MAX_ALLOC; 628 629 skb = sock_alloc_send_skb(sk, 630 size + cf_sk->headroom + 631 cf_sk->tailroom, 632 msg->msg_flags&MSG_DONTWAIT, 633 &err); 634 if (skb == NULL) 635 goto out_err; 636 637 skb_reserve(skb, cf_sk->headroom); 638 /* 639 * If you pass two values to the sock_alloc_send_skb 640 * it tries to grab the large buffer with GFP_NOFS 641 * (which can fail easily), and if it fails grab the 642 * fallback size buffer which is under a page and will 643 * succeed. [Alan] 644 */ 645 size = min_t(int, size, skb_tailroom(skb)); 646 647 err = memcpy_fromiovec(skb_put(skb, size), msg->msg_iov, size); 648 if (err) { 649 kfree_skb(skb); 650 goto out_err; 651 } 652 err = transmit_skb(skb, cf_sk, 653 msg->msg_flags&MSG_DONTWAIT, timeo); 654 if (err < 0) 655 /* skb is already freed */ 656 goto pipe_err; 657 658 sent += size; 659 } 660 661 return sent; 662 663 pipe_err: 664 if (sent == 0 && !(msg->msg_flags&MSG_NOSIGNAL)) 665 send_sig(SIGPIPE, current, 0); 666 err = -EPIPE; 667 out_err: 668 return sent ? : err; 669 } 670 671 static int setsockopt(struct socket *sock, 672 int lvl, int opt, char __user *ov, unsigned int ol) 673 { 674 struct sock *sk = sock->sk; 675 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); 676 int linksel; 677 678 if (cf_sk->sk.sk_socket->state != SS_UNCONNECTED) 679 return -ENOPROTOOPT; 680 681 switch (opt) { 682 case CAIFSO_LINK_SELECT: 683 if (ol < sizeof(int)) 684 return -EINVAL; 685 if (lvl != SOL_CAIF) 686 goto bad_sol; 687 if (copy_from_user(&linksel, ov, sizeof(int))) 688 return -EINVAL; 689 lock_sock(&(cf_sk->sk)); 690 cf_sk->conn_req.link_selector = linksel; 691 release_sock(&cf_sk->sk); 692 return 0; 693 694 case CAIFSO_REQ_PARAM: 695 if (lvl != SOL_CAIF) 696 goto bad_sol; 697 if (cf_sk->sk.sk_protocol != CAIFPROTO_UTIL) 698 return -ENOPROTOOPT; 699 lock_sock(&(cf_sk->sk)); 700 if (ol > sizeof(cf_sk->conn_req.param.data) || 701 copy_from_user(&cf_sk->conn_req.param.data, ov, ol)) { 702 release_sock(&cf_sk->sk); 703 return -EINVAL; 704 } 705 cf_sk->conn_req.param.size = ol; 706 release_sock(&cf_sk->sk); 707 return 0; 708 709 default: 710 return -ENOPROTOOPT; 711 } 712 713 return 0; 714 bad_sol: 715 return -ENOPROTOOPT; 716 717 } 718 719 /* 720 * caif_connect() - Connect a CAIF Socket 721 * Copied and modified af_irda.c:irda_connect(). 722 * 723 * Note : by consulting "errno", the user space caller may learn the cause 724 * of the failure. Most of them are visible in the function, others may come 725 * from subroutines called and are listed here : 726 * o -EAFNOSUPPORT: bad socket family or type. 727 * o -ESOCKTNOSUPPORT: bad socket type or protocol 728 * o -EINVAL: bad socket address, or CAIF link type 729 * o -ECONNREFUSED: remote end refused the connection. 730 * o -EINPROGRESS: connect request sent but timed out (or non-blocking) 731 * o -EISCONN: already connected. 732 * o -ETIMEDOUT: Connection timed out (send timeout) 733 * o -ENODEV: No link layer to send request 734 * o -ECONNRESET: Received Shutdown indication or lost link layer 735 * o -ENOMEM: Out of memory 736 * 737 * State Strategy: 738 * o sk_state: holds the CAIF_* protocol state, it's updated by 739 * caif_ctrl_cb. 740 * o sock->state: holds the SS_* socket state and is updated by connect and 741 * disconnect. 742 */ 743 static int caif_connect(struct socket *sock, struct sockaddr *uaddr, 744 int addr_len, int flags) 745 { 746 struct sock *sk = sock->sk; 747 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); 748 long timeo; 749 int err; 750 int ifindex, headroom, tailroom; 751 unsigned int mtu; 752 struct net_device *dev; 753 754 lock_sock(sk); 755 756 err = -EAFNOSUPPORT; 757 if (uaddr->sa_family != AF_CAIF) 758 goto out; 759 760 switch (sock->state) { 761 case SS_UNCONNECTED: 762 /* Normal case, a fresh connect */ 763 caif_assert(sk->sk_state == CAIF_DISCONNECTED); 764 break; 765 case SS_CONNECTING: 766 switch (sk->sk_state) { 767 case CAIF_CONNECTED: 768 sock->state = SS_CONNECTED; 769 err = -EISCONN; 770 goto out; 771 case CAIF_DISCONNECTED: 772 /* Reconnect allowed */ 773 break; 774 case CAIF_CONNECTING: 775 err = -EALREADY; 776 if (flags & O_NONBLOCK) 777 goto out; 778 goto wait_connect; 779 } 780 break; 781 case SS_CONNECTED: 782 caif_assert(sk->sk_state == CAIF_CONNECTED || 783 sk->sk_state == CAIF_DISCONNECTED); 784 if (sk->sk_shutdown & SHUTDOWN_MASK) { 785 /* Allow re-connect after SHUTDOWN_IND */ 786 caif_disconnect_client(sock_net(sk), &cf_sk->layer); 787 caif_free_client(&cf_sk->layer); 788 break; 789 } 790 /* No reconnect on a seqpacket socket */ 791 err = -EISCONN; 792 goto out; 793 case SS_DISCONNECTING: 794 case SS_FREE: 795 caif_assert(1); /*Should never happen */ 796 break; 797 } 798 sk->sk_state = CAIF_DISCONNECTED; 799 sock->state = SS_UNCONNECTED; 800 sk_stream_kill_queues(&cf_sk->sk); 801 802 err = -EINVAL; 803 if (addr_len != sizeof(struct sockaddr_caif)) 804 goto out; 805 806 memcpy(&cf_sk->conn_req.sockaddr, uaddr, 807 sizeof(struct sockaddr_caif)); 808 809 /* Move to connecting socket, start sending Connect Requests */ 810 sock->state = SS_CONNECTING; 811 sk->sk_state = CAIF_CONNECTING; 812 813 /* Check priority value comming from socket */ 814 /* if priority value is out of range it will be ajusted */ 815 if (cf_sk->sk.sk_priority > CAIF_PRIO_MAX) 816 cf_sk->conn_req.priority = CAIF_PRIO_MAX; 817 else if (cf_sk->sk.sk_priority < CAIF_PRIO_MIN) 818 cf_sk->conn_req.priority = CAIF_PRIO_MIN; 819 else 820 cf_sk->conn_req.priority = cf_sk->sk.sk_priority; 821 822 /*ifindex = id of the interface.*/ 823 cf_sk->conn_req.ifindex = cf_sk->sk.sk_bound_dev_if; 824 825 cf_sk->layer.receive = caif_sktrecv_cb; 826 827 err = caif_connect_client(sock_net(sk), &cf_sk->conn_req, 828 &cf_sk->layer, &ifindex, &headroom, &tailroom); 829 830 if (err < 0) { 831 cf_sk->sk.sk_socket->state = SS_UNCONNECTED; 832 cf_sk->sk.sk_state = CAIF_DISCONNECTED; 833 goto out; 834 } 835 836 err = -ENODEV; 837 rcu_read_lock(); 838 dev = dev_get_by_index_rcu(sock_net(sk), ifindex); 839 if (!dev) { 840 rcu_read_unlock(); 841 goto out; 842 } 843 cf_sk->headroom = LL_RESERVED_SPACE_EXTRA(dev, headroom); 844 mtu = dev->mtu; 845 rcu_read_unlock(); 846 847 cf_sk->tailroom = tailroom; 848 cf_sk->maxframe = mtu - (headroom + tailroom); 849 if (cf_sk->maxframe < 1) { 850 pr_warn("CAIF Interface MTU too small (%d)\n", dev->mtu); 851 err = -ENODEV; 852 goto out; 853 } 854 855 err = -EINPROGRESS; 856 wait_connect: 857 858 if (sk->sk_state != CAIF_CONNECTED && (flags & O_NONBLOCK)) 859 goto out; 860 861 timeo = sock_sndtimeo(sk, flags & O_NONBLOCK); 862 863 release_sock(sk); 864 err = -ERESTARTSYS; 865 timeo = wait_event_interruptible_timeout(*sk_sleep(sk), 866 sk->sk_state != CAIF_CONNECTING, 867 timeo); 868 lock_sock(sk); 869 if (timeo < 0) 870 goto out; /* -ERESTARTSYS */ 871 872 err = -ETIMEDOUT; 873 if (timeo == 0 && sk->sk_state != CAIF_CONNECTED) 874 goto out; 875 if (sk->sk_state != CAIF_CONNECTED) { 876 sock->state = SS_UNCONNECTED; 877 err = sock_error(sk); 878 if (!err) 879 err = -ECONNREFUSED; 880 goto out; 881 } 882 sock->state = SS_CONNECTED; 883 err = 0; 884 out: 885 release_sock(sk); 886 return err; 887 } 888 889 /* 890 * caif_release() - Disconnect a CAIF Socket 891 * Copied and modified af_irda.c:irda_release(). 892 */ 893 static int caif_release(struct socket *sock) 894 { 895 struct sock *sk = sock->sk; 896 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); 897 898 if (!sk) 899 return 0; 900 901 set_tx_flow_off(cf_sk); 902 903 /* 904 * Ensure that packets are not queued after this point in time. 905 * caif_queue_rcv_skb checks SOCK_DEAD holding the queue lock, 906 * this ensures no packets when sock is dead. 907 */ 908 spin_lock_bh(&sk->sk_receive_queue.lock); 909 sock_set_flag(sk, SOCK_DEAD); 910 spin_unlock_bh(&sk->sk_receive_queue.lock); 911 sock->sk = NULL; 912 913 WARN_ON(IS_ERR(cf_sk->debugfs_socket_dir)); 914 if (cf_sk->debugfs_socket_dir != NULL) 915 debugfs_remove_recursive(cf_sk->debugfs_socket_dir); 916 917 lock_sock(&(cf_sk->sk)); 918 sk->sk_state = CAIF_DISCONNECTED; 919 sk->sk_shutdown = SHUTDOWN_MASK; 920 921 caif_disconnect_client(sock_net(sk), &cf_sk->layer); 922 cf_sk->sk.sk_socket->state = SS_DISCONNECTING; 923 wake_up_interruptible_poll(sk_sleep(sk), POLLERR|POLLHUP); 924 925 sock_orphan(sk); 926 sk_stream_kill_queues(&cf_sk->sk); 927 release_sock(sk); 928 sock_put(sk); 929 return 0; 930 } 931 932 /* Copied from af_unix.c:unix_poll(), added CAIF tx_flow handling */ 933 static unsigned int caif_poll(struct file *file, 934 struct socket *sock, poll_table *wait) 935 { 936 struct sock *sk = sock->sk; 937 unsigned int mask; 938 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); 939 940 sock_poll_wait(file, sk_sleep(sk), wait); 941 mask = 0; 942 943 /* exceptional events? */ 944 if (sk->sk_err) 945 mask |= POLLERR; 946 if (sk->sk_shutdown == SHUTDOWN_MASK) 947 mask |= POLLHUP; 948 if (sk->sk_shutdown & RCV_SHUTDOWN) 949 mask |= POLLRDHUP; 950 951 /* readable? */ 952 if (!skb_queue_empty(&sk->sk_receive_queue) || 953 (sk->sk_shutdown & RCV_SHUTDOWN)) 954 mask |= POLLIN | POLLRDNORM; 955 956 /* 957 * we set writable also when the other side has shut down the 958 * connection. This prevents stuck sockets. 959 */ 960 if (sock_writeable(sk) && tx_flow_is_on(cf_sk)) 961 mask |= POLLOUT | POLLWRNORM | POLLWRBAND; 962 963 return mask; 964 } 965 966 static const struct proto_ops caif_seqpacket_ops = { 967 .family = PF_CAIF, 968 .owner = THIS_MODULE, 969 .release = caif_release, 970 .bind = sock_no_bind, 971 .connect = caif_connect, 972 .socketpair = sock_no_socketpair, 973 .accept = sock_no_accept, 974 .getname = sock_no_getname, 975 .poll = caif_poll, 976 .ioctl = sock_no_ioctl, 977 .listen = sock_no_listen, 978 .shutdown = sock_no_shutdown, 979 .setsockopt = setsockopt, 980 .getsockopt = sock_no_getsockopt, 981 .sendmsg = caif_seqpkt_sendmsg, 982 .recvmsg = caif_seqpkt_recvmsg, 983 .mmap = sock_no_mmap, 984 .sendpage = sock_no_sendpage, 985 }; 986 987 static const struct proto_ops caif_stream_ops = { 988 .family = PF_CAIF, 989 .owner = THIS_MODULE, 990 .release = caif_release, 991 .bind = sock_no_bind, 992 .connect = caif_connect, 993 .socketpair = sock_no_socketpair, 994 .accept = sock_no_accept, 995 .getname = sock_no_getname, 996 .poll = caif_poll, 997 .ioctl = sock_no_ioctl, 998 .listen = sock_no_listen, 999 .shutdown = sock_no_shutdown, 1000 .setsockopt = setsockopt, 1001 .getsockopt = sock_no_getsockopt, 1002 .sendmsg = caif_stream_sendmsg, 1003 .recvmsg = caif_stream_recvmsg, 1004 .mmap = sock_no_mmap, 1005 .sendpage = sock_no_sendpage, 1006 }; 1007 1008 /* This function is called when a socket is finally destroyed. */ 1009 static void caif_sock_destructor(struct sock *sk) 1010 { 1011 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); 1012 caif_assert(!atomic_read(&sk->sk_wmem_alloc)); 1013 caif_assert(sk_unhashed(sk)); 1014 caif_assert(!sk->sk_socket); 1015 if (!sock_flag(sk, SOCK_DEAD)) { 1016 pr_debug("Attempt to release alive CAIF socket: %p\n", sk); 1017 return; 1018 } 1019 sk_stream_kill_queues(&cf_sk->sk); 1020 caif_free_client(&cf_sk->layer); 1021 } 1022 1023 static int caif_create(struct net *net, struct socket *sock, int protocol, 1024 int kern) 1025 { 1026 struct sock *sk = NULL; 1027 struct caifsock *cf_sk = NULL; 1028 static struct proto prot = {.name = "PF_CAIF", 1029 .owner = THIS_MODULE, 1030 .obj_size = sizeof(struct caifsock), 1031 }; 1032 1033 if (!capable(CAP_SYS_ADMIN) && !capable(CAP_NET_ADMIN)) 1034 return -EPERM; 1035 /* 1036 * The sock->type specifies the socket type to use. 1037 * The CAIF socket is a packet stream in the sense 1038 * that it is packet based. CAIF trusts the reliability 1039 * of the link, no resending is implemented. 1040 */ 1041 if (sock->type == SOCK_SEQPACKET) 1042 sock->ops = &caif_seqpacket_ops; 1043 else if (sock->type == SOCK_STREAM) 1044 sock->ops = &caif_stream_ops; 1045 else 1046 return -ESOCKTNOSUPPORT; 1047 1048 if (protocol < 0 || protocol >= CAIFPROTO_MAX) 1049 return -EPROTONOSUPPORT; 1050 /* 1051 * Set the socket state to unconnected. The socket state 1052 * is really not used at all in the net/core or socket.c but the 1053 * initialization makes sure that sock->state is not uninitialized. 1054 */ 1055 sk = sk_alloc(net, PF_CAIF, GFP_KERNEL, &prot); 1056 if (!sk) 1057 return -ENOMEM; 1058 1059 cf_sk = container_of(sk, struct caifsock, sk); 1060 1061 /* Store the protocol */ 1062 sk->sk_protocol = (unsigned char) protocol; 1063 1064 /* Initialize default priority for well-known cases */ 1065 switch (protocol) { 1066 case CAIFPROTO_AT: 1067 sk->sk_priority = TC_PRIO_CONTROL; 1068 break; 1069 case CAIFPROTO_RFM: 1070 sk->sk_priority = TC_PRIO_INTERACTIVE_BULK; 1071 break; 1072 default: 1073 sk->sk_priority = TC_PRIO_BESTEFFORT; 1074 } 1075 1076 /* 1077 * Lock in order to try to stop someone from opening the socket 1078 * too early. 1079 */ 1080 lock_sock(&(cf_sk->sk)); 1081 1082 /* Initialize the nozero default sock structure data. */ 1083 sock_init_data(sock, sk); 1084 sk->sk_destruct = caif_sock_destructor; 1085 1086 mutex_init(&cf_sk->readlock); /* single task reading lock */ 1087 cf_sk->layer.ctrlcmd = caif_ctrl_cb; 1088 cf_sk->sk.sk_socket->state = SS_UNCONNECTED; 1089 cf_sk->sk.sk_state = CAIF_DISCONNECTED; 1090 1091 set_tx_flow_off(cf_sk); 1092 set_rx_flow_on(cf_sk); 1093 1094 /* Set default options on configuration */ 1095 cf_sk->conn_req.link_selector = CAIF_LINK_LOW_LATENCY; 1096 cf_sk->conn_req.protocol = protocol; 1097 release_sock(&cf_sk->sk); 1098 return 0; 1099 } 1100 1101 1102 static struct net_proto_family caif_family_ops = { 1103 .family = PF_CAIF, 1104 .create = caif_create, 1105 .owner = THIS_MODULE, 1106 }; 1107 1108 static int __init caif_sktinit_module(void) 1109 { 1110 int err = sock_register(&caif_family_ops); 1111 if (!err) 1112 return err; 1113 return 0; 1114 } 1115 1116 static void __exit caif_sktexit_module(void) 1117 { 1118 sock_unregister(PF_CAIF); 1119 } 1120 module_init(caif_sktinit_module); 1121 module_exit(caif_sktexit_module); 1122