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