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 #include <linux/fs.h> 8 #include <linux/init.h> 9 #include <linux/module.h> 10 #include <linux/sched.h> 11 #include <linux/spinlock.h> 12 #include <linux/mutex.h> 13 #include <linux/list.h> 14 #include <linux/wait.h> 15 #include <linux/poll.h> 16 #include <linux/tcp.h> 17 #include <linux/uaccess.h> 18 #include <linux/mutex.h> 19 #include <linux/debugfs.h> 20 #include <linux/caif/caif_socket.h> 21 #include <asm/atomic.h> 22 #include <net/sock.h> 23 #include <net/tcp_states.h> 24 #include <net/caif/caif_layer.h> 25 #include <net/caif/caif_dev.h> 26 #include <net/caif/cfpkt.h> 27 28 MODULE_LICENSE("GPL"); 29 MODULE_ALIAS_NETPROTO(AF_CAIF); 30 31 #define CAIF_DEF_SNDBUF (CAIF_MAX_PAYLOAD_SIZE*10) 32 #define CAIF_DEF_RCVBUF (CAIF_MAX_PAYLOAD_SIZE*100) 33 34 /* 35 * CAIF state is re-using the TCP socket states. 36 * caif_states stored in sk_state reflect the state as reported by 37 * the CAIF stack, while sk_socket->state is the state of the socket. 38 */ 39 enum caif_states { 40 CAIF_CONNECTED = TCP_ESTABLISHED, 41 CAIF_CONNECTING = TCP_SYN_SENT, 42 CAIF_DISCONNECTED = TCP_CLOSE 43 }; 44 45 #define TX_FLOW_ON_BIT 1 46 #define RX_FLOW_ON_BIT 2 47 48 static struct dentry *debugfsdir; 49 50 #ifdef CONFIG_DEBUG_FS 51 struct debug_fs_counter { 52 atomic_t caif_nr_socks; 53 atomic_t num_connect_req; 54 atomic_t num_connect_resp; 55 atomic_t num_connect_fail_resp; 56 atomic_t num_disconnect; 57 atomic_t num_remote_shutdown_ind; 58 atomic_t num_tx_flow_off_ind; 59 atomic_t num_tx_flow_on_ind; 60 atomic_t num_rx_flow_off; 61 atomic_t num_rx_flow_on; 62 }; 63 struct debug_fs_counter cnt; 64 #define dbfs_atomic_inc(v) atomic_inc(v) 65 #define dbfs_atomic_dec(v) atomic_dec(v) 66 #else 67 #define dbfs_atomic_inc(v) 68 #define dbfs_atomic_dec(v) 69 #endif 70 71 struct caifsock { 72 struct sock sk; /* must be first member */ 73 struct cflayer layer; 74 char name[CAIF_LAYER_NAME_SZ]; /* Used for debugging */ 75 u32 flow_state; 76 struct caif_connect_request conn_req; 77 struct mutex readlock; 78 struct dentry *debugfs_socket_dir; 79 }; 80 81 static int rx_flow_is_on(struct caifsock *cf_sk) 82 { 83 return test_bit(RX_FLOW_ON_BIT, 84 (void *) &cf_sk->flow_state); 85 } 86 87 static int tx_flow_is_on(struct caifsock *cf_sk) 88 { 89 return test_bit(TX_FLOW_ON_BIT, 90 (void *) &cf_sk->flow_state); 91 } 92 93 static void set_rx_flow_off(struct caifsock *cf_sk) 94 { 95 clear_bit(RX_FLOW_ON_BIT, 96 (void *) &cf_sk->flow_state); 97 } 98 99 static void set_rx_flow_on(struct caifsock *cf_sk) 100 { 101 set_bit(RX_FLOW_ON_BIT, 102 (void *) &cf_sk->flow_state); 103 } 104 105 static void set_tx_flow_off(struct caifsock *cf_sk) 106 { 107 clear_bit(TX_FLOW_ON_BIT, 108 (void *) &cf_sk->flow_state); 109 } 110 111 static void set_tx_flow_on(struct caifsock *cf_sk) 112 { 113 set_bit(TX_FLOW_ON_BIT, 114 (void *) &cf_sk->flow_state); 115 } 116 117 static void caif_read_lock(struct sock *sk) 118 { 119 struct caifsock *cf_sk; 120 cf_sk = container_of(sk, struct caifsock, sk); 121 mutex_lock(&cf_sk->readlock); 122 } 123 124 static void caif_read_unlock(struct sock *sk) 125 { 126 struct caifsock *cf_sk; 127 cf_sk = container_of(sk, struct caifsock, sk); 128 mutex_unlock(&cf_sk->readlock); 129 } 130 131 int sk_rcvbuf_lowwater(struct caifsock *cf_sk) 132 { 133 /* A quarter of full buffer is used a low water mark */ 134 return cf_sk->sk.sk_rcvbuf / 4; 135 } 136 137 void caif_flow_ctrl(struct sock *sk, int mode) 138 { 139 struct caifsock *cf_sk; 140 cf_sk = container_of(sk, struct caifsock, sk); 141 if (cf_sk->layer.dn) 142 cf_sk->layer.dn->modemcmd(cf_sk->layer.dn, mode); 143 } 144 145 /* 146 * Copied from sock.c:sock_queue_rcv_skb(), but changed so packets are 147 * not dropped, but CAIF is sending flow off instead. 148 */ 149 int caif_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) 150 { 151 int err; 152 int skb_len; 153 unsigned long flags; 154 struct sk_buff_head *list = &sk->sk_receive_queue; 155 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); 156 157 if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >= 158 (unsigned)sk->sk_rcvbuf && rx_flow_is_on(cf_sk)) { 159 trace_printk("CAIF: %s():" 160 " sending flow OFF (queue len = %d %d)\n", 161 __func__, 162 atomic_read(&cf_sk->sk.sk_rmem_alloc), 163 sk_rcvbuf_lowwater(cf_sk)); 164 set_rx_flow_off(cf_sk); 165 if (cf_sk->layer.dn) 166 cf_sk->layer.dn->modemcmd(cf_sk->layer.dn, 167 CAIF_MODEMCMD_FLOW_OFF_REQ); 168 } 169 170 err = sk_filter(sk, skb); 171 if (err) 172 return err; 173 if (!sk_rmem_schedule(sk, skb->truesize) && rx_flow_is_on(cf_sk)) { 174 set_rx_flow_off(cf_sk); 175 trace_printk("CAIF: %s():" 176 " sending flow OFF due to rmem_schedule\n", 177 __func__); 178 if (cf_sk->layer.dn) 179 cf_sk->layer.dn->modemcmd(cf_sk->layer.dn, 180 CAIF_MODEMCMD_FLOW_OFF_REQ); 181 } 182 skb->dev = NULL; 183 skb_set_owner_r(skb, sk); 184 /* Cache the SKB length before we tack it onto the receive 185 * queue. Once it is added it no longer belongs to us and 186 * may be freed by other threads of control pulling packets 187 * from the queue. 188 */ 189 skb_len = skb->len; 190 spin_lock_irqsave(&list->lock, flags); 191 if (!sock_flag(sk, SOCK_DEAD)) 192 __skb_queue_tail(list, skb); 193 spin_unlock_irqrestore(&list->lock, flags); 194 195 if (!sock_flag(sk, SOCK_DEAD)) 196 sk->sk_data_ready(sk, skb_len); 197 else 198 kfree_skb(skb); 199 return 0; 200 } 201 202 /* Packet Receive Callback function called from CAIF Stack */ 203 static int caif_sktrecv_cb(struct cflayer *layr, struct cfpkt *pkt) 204 { 205 struct caifsock *cf_sk; 206 struct sk_buff *skb; 207 208 cf_sk = container_of(layr, struct caifsock, layer); 209 skb = cfpkt_tonative(pkt); 210 211 if (unlikely(cf_sk->sk.sk_state != CAIF_CONNECTED)) { 212 cfpkt_destroy(pkt); 213 return 0; 214 } 215 caif_queue_rcv_skb(&cf_sk->sk, skb); 216 return 0; 217 } 218 219 /* Packet Control Callback function called from CAIF */ 220 static void caif_ctrl_cb(struct cflayer *layr, 221 enum caif_ctrlcmd flow, 222 int phyid) 223 { 224 struct caifsock *cf_sk = container_of(layr, struct caifsock, layer); 225 switch (flow) { 226 case CAIF_CTRLCMD_FLOW_ON_IND: 227 /* OK from modem to start sending again */ 228 dbfs_atomic_inc(&cnt.num_tx_flow_on_ind); 229 set_tx_flow_on(cf_sk); 230 cf_sk->sk.sk_state_change(&cf_sk->sk); 231 break; 232 233 case CAIF_CTRLCMD_FLOW_OFF_IND: 234 /* Modem asks us to shut up */ 235 dbfs_atomic_inc(&cnt.num_tx_flow_off_ind); 236 set_tx_flow_off(cf_sk); 237 cf_sk->sk.sk_state_change(&cf_sk->sk); 238 break; 239 240 case CAIF_CTRLCMD_INIT_RSP: 241 /* We're now connected */ 242 dbfs_atomic_inc(&cnt.num_connect_resp); 243 cf_sk->sk.sk_state = CAIF_CONNECTED; 244 set_tx_flow_on(cf_sk); 245 cf_sk->sk.sk_state_change(&cf_sk->sk); 246 break; 247 248 case CAIF_CTRLCMD_DEINIT_RSP: 249 /* We're now disconnected */ 250 cf_sk->sk.sk_state = CAIF_DISCONNECTED; 251 cf_sk->sk.sk_state_change(&cf_sk->sk); 252 cfcnfg_release_adap_layer(&cf_sk->layer); 253 break; 254 255 case CAIF_CTRLCMD_INIT_FAIL_RSP: 256 /* Connect request failed */ 257 dbfs_atomic_inc(&cnt.num_connect_fail_resp); 258 cf_sk->sk.sk_err = ECONNREFUSED; 259 cf_sk->sk.sk_state = CAIF_DISCONNECTED; 260 cf_sk->sk.sk_shutdown = SHUTDOWN_MASK; 261 /* 262 * Socket "standards" seems to require POLLOUT to 263 * be set at connect failure. 264 */ 265 set_tx_flow_on(cf_sk); 266 cf_sk->sk.sk_state_change(&cf_sk->sk); 267 break; 268 269 case CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND: 270 /* Modem has closed this connection, or device is down. */ 271 dbfs_atomic_inc(&cnt.num_remote_shutdown_ind); 272 cf_sk->sk.sk_shutdown = SHUTDOWN_MASK; 273 cf_sk->sk.sk_err = ECONNRESET; 274 set_rx_flow_on(cf_sk); 275 cf_sk->sk.sk_error_report(&cf_sk->sk); 276 break; 277 278 default: 279 pr_debug("CAIF: %s(): Unexpected flow command %d\n", 280 __func__, flow); 281 } 282 } 283 284 static void caif_check_flow_release(struct sock *sk) 285 { 286 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); 287 288 if (cf_sk->layer.dn == NULL || cf_sk->layer.dn->modemcmd == NULL) 289 return; 290 if (rx_flow_is_on(cf_sk)) 291 return; 292 293 if (atomic_read(&sk->sk_rmem_alloc) <= sk_rcvbuf_lowwater(cf_sk)) { 294 dbfs_atomic_inc(&cnt.num_rx_flow_on); 295 set_rx_flow_on(cf_sk); 296 cf_sk->layer.dn->modemcmd(cf_sk->layer.dn, 297 CAIF_MODEMCMD_FLOW_ON_REQ); 298 } 299 } 300 /* 301 * Copied from sock.c:sock_queue_rcv_skb(), and added check that user buffer 302 * has sufficient size. 303 */ 304 305 static int caif_seqpkt_recvmsg(struct kiocb *iocb, struct socket *sock, 306 struct msghdr *m, size_t buf_len, int flags) 307 308 { 309 struct sock *sk = sock->sk; 310 struct sk_buff *skb; 311 int ret = 0; 312 int len; 313 314 if (unlikely(!buf_len)) 315 return -EINVAL; 316 317 skb = skb_recv_datagram(sk, flags, 0 , &ret); 318 if (!skb) 319 goto read_error; 320 321 len = skb->len; 322 323 if (skb && skb->len > buf_len && !(flags & MSG_PEEK)) { 324 len = buf_len; 325 /* 326 * Push skb back on receive queue if buffer too small. 327 * This has a built-in race where multi-threaded receive 328 * may get packet in wrong order, but multiple read does 329 * not really guarantee ordered delivery anyway. 330 * Let's optimize for speed without taking locks. 331 */ 332 333 skb_queue_head(&sk->sk_receive_queue, skb); 334 ret = -EMSGSIZE; 335 goto read_error; 336 } 337 338 ret = skb_copy_datagram_iovec(skb, 0, m->msg_iov, len); 339 if (ret) 340 goto read_error; 341 342 skb_free_datagram(sk, skb); 343 344 caif_check_flow_release(sk); 345 346 return len; 347 348 read_error: 349 return ret; 350 } 351 352 353 /* Copied from unix_stream_wait_data, identical except for lock call. */ 354 static long caif_stream_data_wait(struct sock *sk, long timeo) 355 { 356 DEFINE_WAIT(wait); 357 lock_sock(sk); 358 359 for (;;) { 360 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE); 361 362 if (!skb_queue_empty(&sk->sk_receive_queue) || 363 sk->sk_err || 364 sk->sk_state != CAIF_CONNECTED || 365 sock_flag(sk, SOCK_DEAD) || 366 (sk->sk_shutdown & RCV_SHUTDOWN) || 367 signal_pending(current) || 368 !timeo) 369 break; 370 371 set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags); 372 release_sock(sk); 373 timeo = schedule_timeout(timeo); 374 lock_sock(sk); 375 clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags); 376 } 377 378 finish_wait(sk_sleep(sk), &wait); 379 release_sock(sk); 380 return timeo; 381 } 382 383 384 /* 385 * Copied from unix_stream_recvmsg, but removed credit checks, 386 * changed locking calls, changed address handling. 387 */ 388 static int caif_stream_recvmsg(struct kiocb *iocb, struct socket *sock, 389 struct msghdr *msg, size_t size, 390 int flags) 391 { 392 struct sock *sk = sock->sk; 393 int copied = 0; 394 int target; 395 int err = 0; 396 long timeo; 397 398 err = -EOPNOTSUPP; 399 if (flags&MSG_OOB) 400 goto out; 401 402 msg->msg_namelen = 0; 403 404 /* 405 * Lock the socket to prevent queue disordering 406 * while sleeps in memcpy_tomsg 407 */ 408 err = -EAGAIN; 409 if (sk->sk_state == CAIF_CONNECTING) 410 goto out; 411 412 caif_read_lock(sk); 413 target = sock_rcvlowat(sk, flags&MSG_WAITALL, size); 414 timeo = sock_rcvtimeo(sk, flags&MSG_DONTWAIT); 415 416 do { 417 int chunk; 418 struct sk_buff *skb; 419 420 lock_sock(sk); 421 skb = skb_dequeue(&sk->sk_receive_queue); 422 caif_check_flow_release(sk); 423 424 if (skb == NULL) { 425 if (copied >= target) 426 goto unlock; 427 /* 428 * POSIX 1003.1g mandates this order. 429 */ 430 err = sock_error(sk); 431 if (err) 432 goto unlock; 433 err = -ECONNRESET; 434 if (sk->sk_shutdown & RCV_SHUTDOWN) 435 goto unlock; 436 437 err = -EPIPE; 438 if (sk->sk_state != CAIF_CONNECTED) 439 goto unlock; 440 if (sock_flag(sk, SOCK_DEAD)) 441 goto unlock; 442 443 release_sock(sk); 444 445 err = -EAGAIN; 446 if (!timeo) 447 break; 448 449 caif_read_unlock(sk); 450 451 timeo = caif_stream_data_wait(sk, timeo); 452 453 if (signal_pending(current)) { 454 err = sock_intr_errno(timeo); 455 goto out; 456 } 457 caif_read_lock(sk); 458 continue; 459 unlock: 460 release_sock(sk); 461 break; 462 } 463 release_sock(sk); 464 chunk = min_t(unsigned int, skb->len, size); 465 if (memcpy_toiovec(msg->msg_iov, skb->data, chunk)) { 466 skb_queue_head(&sk->sk_receive_queue, skb); 467 if (copied == 0) 468 copied = -EFAULT; 469 break; 470 } 471 copied += chunk; 472 size -= chunk; 473 474 /* Mark read part of skb as used */ 475 if (!(flags & MSG_PEEK)) { 476 skb_pull(skb, chunk); 477 478 /* put the skb back if we didn't use it up. */ 479 if (skb->len) { 480 skb_queue_head(&sk->sk_receive_queue, skb); 481 break; 482 } 483 kfree_skb(skb); 484 485 } else { 486 /* 487 * It is questionable, see note in unix_dgram_recvmsg. 488 */ 489 /* put message back and return */ 490 skb_queue_head(&sk->sk_receive_queue, skb); 491 break; 492 } 493 } while (size); 494 caif_read_unlock(sk); 495 496 out: 497 return copied ? : err; 498 } 499 500 /* 501 * Copied from sock.c:sock_wait_for_wmem, but change to wait for 502 * CAIF flow-on and sock_writable. 503 */ 504 static long caif_wait_for_flow_on(struct caifsock *cf_sk, 505 int wait_writeable, long timeo, int *err) 506 { 507 struct sock *sk = &cf_sk->sk; 508 DEFINE_WAIT(wait); 509 for (;;) { 510 *err = 0; 511 if (tx_flow_is_on(cf_sk) && 512 (!wait_writeable || sock_writeable(&cf_sk->sk))) 513 break; 514 *err = -ETIMEDOUT; 515 if (!timeo) 516 break; 517 *err = -ERESTARTSYS; 518 if (signal_pending(current)) 519 break; 520 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE); 521 *err = -ECONNRESET; 522 if (sk->sk_shutdown & SHUTDOWN_MASK) 523 break; 524 *err = -sk->sk_err; 525 if (sk->sk_err) 526 break; 527 *err = -EPIPE; 528 if (cf_sk->sk.sk_state != CAIF_CONNECTED) 529 break; 530 timeo = schedule_timeout(timeo); 531 } 532 finish_wait(sk_sleep(sk), &wait); 533 return timeo; 534 } 535 536 /* 537 * Transmit a SKB. The device may temporarily request re-transmission 538 * by returning EAGAIN. 539 */ 540 static int transmit_skb(struct sk_buff *skb, struct caifsock *cf_sk, 541 int noblock, long timeo) 542 { 543 struct cfpkt *pkt; 544 int ret, loopcnt = 0; 545 546 pkt = cfpkt_fromnative(CAIF_DIR_OUT, skb); 547 memset(cfpkt_info(pkt), 0, sizeof(struct caif_payload_info)); 548 do { 549 550 ret = -ETIMEDOUT; 551 552 /* Slight paranoia, probably not needed. */ 553 if (unlikely(loopcnt++ > 1000)) { 554 pr_warning("CAIF: %s(): transmit retries failed," 555 " error = %d\n", __func__, ret); 556 break; 557 } 558 559 if (cf_sk->layer.dn != NULL) 560 ret = cf_sk->layer.dn->transmit(cf_sk->layer.dn, pkt); 561 if (likely(ret >= 0)) 562 break; 563 /* if transmit return -EAGAIN, then retry */ 564 if (noblock && ret == -EAGAIN) 565 break; 566 timeo = caif_wait_for_flow_on(cf_sk, 0, timeo, &ret); 567 if (signal_pending(current)) { 568 ret = sock_intr_errno(timeo); 569 break; 570 } 571 if (ret) 572 break; 573 if (cf_sk->sk.sk_state != CAIF_CONNECTED || 574 sock_flag(&cf_sk->sk, SOCK_DEAD) || 575 (cf_sk->sk.sk_shutdown & RCV_SHUTDOWN)) { 576 ret = -EPIPE; 577 cf_sk->sk.sk_err = EPIPE; 578 break; 579 } 580 } while (ret == -EAGAIN); 581 return ret; 582 } 583 584 /* Copied from af_unix:unix_dgram_sendmsg, and adapted to CAIF */ 585 static int caif_seqpkt_sendmsg(struct kiocb *kiocb, struct socket *sock, 586 struct msghdr *msg, size_t len) 587 { 588 struct sock *sk = sock->sk; 589 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); 590 int buffer_size; 591 int ret = 0; 592 struct sk_buff *skb = NULL; 593 int noblock; 594 long timeo; 595 caif_assert(cf_sk); 596 ret = sock_error(sk); 597 if (ret) 598 goto err; 599 600 ret = -EOPNOTSUPP; 601 if (msg->msg_flags&MSG_OOB) 602 goto err; 603 604 ret = -EOPNOTSUPP; 605 if (msg->msg_namelen) 606 goto err; 607 608 ret = -EINVAL; 609 if (unlikely(msg->msg_iov->iov_base == NULL)) 610 goto err; 611 noblock = msg->msg_flags & MSG_DONTWAIT; 612 613 buffer_size = len + CAIF_NEEDED_HEADROOM + CAIF_NEEDED_TAILROOM; 614 615 ret = -EMSGSIZE; 616 if (buffer_size > CAIF_MAX_PAYLOAD_SIZE) 617 goto err; 618 619 timeo = sock_sndtimeo(sk, noblock); 620 timeo = caif_wait_for_flow_on(container_of(sk, struct caifsock, sk), 621 1, timeo, &ret); 622 623 ret = -EPIPE; 624 if (cf_sk->sk.sk_state != CAIF_CONNECTED || 625 sock_flag(sk, SOCK_DEAD) || 626 (sk->sk_shutdown & RCV_SHUTDOWN)) 627 goto err; 628 629 ret = -ENOMEM; 630 skb = sock_alloc_send_skb(sk, buffer_size, noblock, &ret); 631 if (!skb) 632 goto err; 633 skb_reserve(skb, CAIF_NEEDED_HEADROOM); 634 635 ret = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len); 636 637 if (ret) 638 goto err; 639 ret = transmit_skb(skb, cf_sk, noblock, timeo); 640 if (ret < 0) 641 goto err; 642 return len; 643 err: 644 kfree_skb(skb); 645 return ret; 646 } 647 648 /* 649 * Copied from unix_stream_sendmsg and adapted to CAIF: 650 * Changed removed permission handling and added waiting for flow on 651 * and other minor adaptations. 652 */ 653 static int caif_stream_sendmsg(struct kiocb *kiocb, struct socket *sock, 654 struct msghdr *msg, size_t len) 655 { 656 struct sock *sk = sock->sk; 657 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); 658 int err, size; 659 struct sk_buff *skb; 660 int sent = 0; 661 long timeo; 662 663 err = -EOPNOTSUPP; 664 665 if (unlikely(msg->msg_flags&MSG_OOB)) 666 goto out_err; 667 668 if (unlikely(msg->msg_namelen)) 669 goto out_err; 670 671 timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT); 672 timeo = caif_wait_for_flow_on(cf_sk, 1, timeo, &err); 673 674 if (unlikely(sk->sk_shutdown & SEND_SHUTDOWN)) 675 goto pipe_err; 676 677 while (sent < len) { 678 679 size = len-sent; 680 681 if (size > CAIF_MAX_PAYLOAD_SIZE) 682 size = CAIF_MAX_PAYLOAD_SIZE; 683 684 /* If size is more than half of sndbuf, chop up message */ 685 if (size > ((sk->sk_sndbuf >> 1) - 64)) 686 size = (sk->sk_sndbuf >> 1) - 64; 687 688 if (size > SKB_MAX_ALLOC) 689 size = SKB_MAX_ALLOC; 690 691 skb = sock_alloc_send_skb(sk, 692 size + CAIF_NEEDED_HEADROOM 693 + CAIF_NEEDED_TAILROOM, 694 msg->msg_flags&MSG_DONTWAIT, 695 &err); 696 if (skb == NULL) 697 goto out_err; 698 699 skb_reserve(skb, CAIF_NEEDED_HEADROOM); 700 /* 701 * If you pass two values to the sock_alloc_send_skb 702 * it tries to grab the large buffer with GFP_NOFS 703 * (which can fail easily), and if it fails grab the 704 * fallback size buffer which is under a page and will 705 * succeed. [Alan] 706 */ 707 size = min_t(int, size, skb_tailroom(skb)); 708 709 err = memcpy_fromiovec(skb_put(skb, size), msg->msg_iov, size); 710 if (err) { 711 kfree_skb(skb); 712 goto out_err; 713 } 714 err = transmit_skb(skb, cf_sk, 715 msg->msg_flags&MSG_DONTWAIT, timeo); 716 if (err < 0) { 717 kfree_skb(skb); 718 goto pipe_err; 719 } 720 sent += size; 721 } 722 723 return sent; 724 725 pipe_err: 726 if (sent == 0 && !(msg->msg_flags&MSG_NOSIGNAL)) 727 send_sig(SIGPIPE, current, 0); 728 err = -EPIPE; 729 out_err: 730 return sent ? : err; 731 } 732 733 static int setsockopt(struct socket *sock, 734 int lvl, int opt, char __user *ov, unsigned int ol) 735 { 736 struct sock *sk = sock->sk; 737 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); 738 int prio, linksel; 739 struct ifreq ifreq; 740 741 if (cf_sk->sk.sk_socket->state != SS_UNCONNECTED) 742 return -ENOPROTOOPT; 743 744 switch (opt) { 745 case CAIFSO_LINK_SELECT: 746 if (ol < sizeof(int)) 747 return -EINVAL; 748 if (lvl != SOL_CAIF) 749 goto bad_sol; 750 if (copy_from_user(&linksel, ov, sizeof(int))) 751 return -EINVAL; 752 lock_sock(&(cf_sk->sk)); 753 cf_sk->conn_req.link_selector = linksel; 754 release_sock(&cf_sk->sk); 755 return 0; 756 757 case SO_PRIORITY: 758 if (lvl != SOL_SOCKET) 759 goto bad_sol; 760 if (ol < sizeof(int)) 761 return -EINVAL; 762 if (copy_from_user(&prio, ov, sizeof(int))) 763 return -EINVAL; 764 lock_sock(&(cf_sk->sk)); 765 cf_sk->conn_req.priority = prio; 766 release_sock(&cf_sk->sk); 767 return 0; 768 769 case SO_BINDTODEVICE: 770 if (lvl != SOL_SOCKET) 771 goto bad_sol; 772 if (ol < sizeof(struct ifreq)) 773 return -EINVAL; 774 if (copy_from_user(&ifreq, ov, sizeof(ifreq))) 775 return -EFAULT; 776 lock_sock(&(cf_sk->sk)); 777 strncpy(cf_sk->conn_req.link_name, ifreq.ifr_name, 778 sizeof(cf_sk->conn_req.link_name)); 779 cf_sk->conn_req.link_name 780 [sizeof(cf_sk->conn_req.link_name)-1] = 0; 781 release_sock(&cf_sk->sk); 782 return 0; 783 784 case CAIFSO_REQ_PARAM: 785 if (lvl != SOL_CAIF) 786 goto bad_sol; 787 if (cf_sk->sk.sk_protocol != CAIFPROTO_UTIL) 788 return -ENOPROTOOPT; 789 lock_sock(&(cf_sk->sk)); 790 cf_sk->conn_req.param.size = ol; 791 if (ol > sizeof(cf_sk->conn_req.param.data) || 792 copy_from_user(&cf_sk->conn_req.param.data, ov, ol)) { 793 release_sock(&cf_sk->sk); 794 return -EINVAL; 795 } 796 release_sock(&cf_sk->sk); 797 return 0; 798 799 default: 800 return -ENOPROTOOPT; 801 } 802 803 return 0; 804 bad_sol: 805 return -ENOPROTOOPT; 806 807 } 808 809 /* 810 * caif_connect() - Connect a CAIF Socket 811 * Copied and modified af_irda.c:irda_connect(). 812 * 813 * Note : by consulting "errno", the user space caller may learn the cause 814 * of the failure. Most of them are visible in the function, others may come 815 * from subroutines called and are listed here : 816 * o -EAFNOSUPPORT: bad socket family or type. 817 * o -ESOCKTNOSUPPORT: bad socket type or protocol 818 * o -EINVAL: bad socket address, or CAIF link type 819 * o -ECONNREFUSED: remote end refused the connection. 820 * o -EINPROGRESS: connect request sent but timed out (or non-blocking) 821 * o -EISCONN: already connected. 822 * o -ETIMEDOUT: Connection timed out (send timeout) 823 * o -ENODEV: No link layer to send request 824 * o -ECONNRESET: Received Shutdown indication or lost link layer 825 * o -ENOMEM: Out of memory 826 * 827 * State Strategy: 828 * o sk_state: holds the CAIF_* protocol state, it's updated by 829 * caif_ctrl_cb. 830 * o sock->state: holds the SS_* socket state and is updated by connect and 831 * disconnect. 832 */ 833 static int caif_connect(struct socket *sock, struct sockaddr *uaddr, 834 int addr_len, int flags) 835 { 836 struct sock *sk = sock->sk; 837 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); 838 long timeo; 839 int err; 840 lock_sock(sk); 841 842 err = -EAFNOSUPPORT; 843 if (uaddr->sa_family != AF_CAIF) 844 goto out; 845 846 err = -ESOCKTNOSUPPORT; 847 if (unlikely(!(sk->sk_type == SOCK_STREAM && 848 cf_sk->sk.sk_protocol == CAIFPROTO_AT) && 849 sk->sk_type != SOCK_SEQPACKET)) 850 goto out; 851 switch (sock->state) { 852 case SS_UNCONNECTED: 853 /* Normal case, a fresh connect */ 854 caif_assert(sk->sk_state == CAIF_DISCONNECTED); 855 break; 856 case SS_CONNECTING: 857 switch (sk->sk_state) { 858 case CAIF_CONNECTED: 859 sock->state = SS_CONNECTED; 860 err = -EISCONN; 861 goto out; 862 case CAIF_DISCONNECTED: 863 /* Reconnect allowed */ 864 break; 865 case CAIF_CONNECTING: 866 err = -EALREADY; 867 if (flags & O_NONBLOCK) 868 goto out; 869 goto wait_connect; 870 } 871 break; 872 case SS_CONNECTED: 873 caif_assert(sk->sk_state == CAIF_CONNECTED || 874 sk->sk_state == CAIF_DISCONNECTED); 875 if (sk->sk_shutdown & SHUTDOWN_MASK) { 876 /* Allow re-connect after SHUTDOWN_IND */ 877 caif_disconnect_client(&cf_sk->layer); 878 break; 879 } 880 /* No reconnect on a seqpacket socket */ 881 err = -EISCONN; 882 goto out; 883 case SS_DISCONNECTING: 884 case SS_FREE: 885 caif_assert(1); /*Should never happen */ 886 break; 887 } 888 sk->sk_state = CAIF_DISCONNECTED; 889 sock->state = SS_UNCONNECTED; 890 sk_stream_kill_queues(&cf_sk->sk); 891 892 err = -EINVAL; 893 if (addr_len != sizeof(struct sockaddr_caif) || 894 !uaddr) 895 goto out; 896 897 memcpy(&cf_sk->conn_req.sockaddr, uaddr, 898 sizeof(struct sockaddr_caif)); 899 900 /* Move to connecting socket, start sending Connect Requests */ 901 sock->state = SS_CONNECTING; 902 sk->sk_state = CAIF_CONNECTING; 903 904 dbfs_atomic_inc(&cnt.num_connect_req); 905 cf_sk->layer.receive = caif_sktrecv_cb; 906 err = caif_connect_client(&cf_sk->conn_req, 907 &cf_sk->layer); 908 if (err < 0) { 909 cf_sk->sk.sk_socket->state = SS_UNCONNECTED; 910 cf_sk->sk.sk_state = CAIF_DISCONNECTED; 911 goto out; 912 } 913 914 err = -EINPROGRESS; 915 wait_connect: 916 917 if (sk->sk_state != CAIF_CONNECTED && (flags & O_NONBLOCK)) 918 goto out; 919 920 timeo = sock_sndtimeo(sk, flags & O_NONBLOCK); 921 922 release_sock(sk); 923 err = wait_event_interruptible_timeout(*sk_sleep(sk), 924 sk->sk_state != CAIF_CONNECTING, 925 timeo); 926 lock_sock(sk); 927 if (err < 0) 928 goto out; /* -ERESTARTSYS */ 929 if (err == 0 && sk->sk_state != CAIF_CONNECTED) { 930 err = -ETIMEDOUT; 931 goto out; 932 } 933 934 if (sk->sk_state != CAIF_CONNECTED) { 935 sock->state = SS_UNCONNECTED; 936 err = sock_error(sk); 937 if (!err) 938 err = -ECONNREFUSED; 939 goto out; 940 } 941 sock->state = SS_CONNECTED; 942 err = 0; 943 out: 944 release_sock(sk); 945 return err; 946 } 947 948 949 /* 950 * caif_release() - Disconnect a CAIF Socket 951 * Copied and modified af_irda.c:irda_release(). 952 */ 953 static int caif_release(struct socket *sock) 954 { 955 struct sock *sk = sock->sk; 956 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); 957 int res = 0; 958 959 if (!sk) 960 return 0; 961 962 set_tx_flow_off(cf_sk); 963 964 /* 965 * Ensure that packets are not queued after this point in time. 966 * caif_queue_rcv_skb checks SOCK_DEAD holding the queue lock, 967 * this ensures no packets when sock is dead. 968 */ 969 spin_lock(&sk->sk_receive_queue.lock); 970 sock_set_flag(sk, SOCK_DEAD); 971 spin_unlock(&sk->sk_receive_queue.lock); 972 sock->sk = NULL; 973 974 dbfs_atomic_inc(&cnt.num_disconnect); 975 976 if (cf_sk->debugfs_socket_dir != NULL) 977 debugfs_remove_recursive(cf_sk->debugfs_socket_dir); 978 979 lock_sock(&(cf_sk->sk)); 980 sk->sk_state = CAIF_DISCONNECTED; 981 sk->sk_shutdown = SHUTDOWN_MASK; 982 983 if (cf_sk->sk.sk_socket->state == SS_CONNECTED || 984 cf_sk->sk.sk_socket->state == SS_CONNECTING) 985 res = caif_disconnect_client(&cf_sk->layer); 986 987 cf_sk->sk.sk_socket->state = SS_DISCONNECTING; 988 wake_up_interruptible_poll(sk_sleep(sk), POLLERR|POLLHUP); 989 990 sock_orphan(sk); 991 cf_sk->layer.dn = NULL; 992 sk_stream_kill_queues(&cf_sk->sk); 993 release_sock(sk); 994 sock_put(sk); 995 return res; 996 } 997 998 /* Copied from af_unix.c:unix_poll(), added CAIF tx_flow handling */ 999 static unsigned int caif_poll(struct file *file, 1000 struct socket *sock, poll_table *wait) 1001 { 1002 struct sock *sk = sock->sk; 1003 unsigned int mask; 1004 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); 1005 1006 sock_poll_wait(file, sk_sleep(sk), wait); 1007 mask = 0; 1008 1009 /* exceptional events? */ 1010 if (sk->sk_err) 1011 mask |= POLLERR; 1012 if (sk->sk_shutdown == SHUTDOWN_MASK) 1013 mask |= POLLHUP; 1014 if (sk->sk_shutdown & RCV_SHUTDOWN) 1015 mask |= POLLRDHUP; 1016 1017 /* readable? */ 1018 if (!skb_queue_empty(&sk->sk_receive_queue) || 1019 (sk->sk_shutdown & RCV_SHUTDOWN)) 1020 mask |= POLLIN | POLLRDNORM; 1021 1022 /* Connection-based need to check for termination and startup */ 1023 if (sk->sk_state == CAIF_DISCONNECTED) 1024 mask |= POLLHUP; 1025 1026 /* 1027 * we set writable also when the other side has shut down the 1028 * connection. This prevents stuck sockets. 1029 */ 1030 if (sock_writeable(sk) && tx_flow_is_on(cf_sk)) 1031 mask |= POLLOUT | POLLWRNORM | POLLWRBAND; 1032 1033 return mask; 1034 } 1035 1036 static const struct proto_ops caif_seqpacket_ops = { 1037 .family = PF_CAIF, 1038 .owner = THIS_MODULE, 1039 .release = caif_release, 1040 .bind = sock_no_bind, 1041 .connect = caif_connect, 1042 .socketpair = sock_no_socketpair, 1043 .accept = sock_no_accept, 1044 .getname = sock_no_getname, 1045 .poll = caif_poll, 1046 .ioctl = sock_no_ioctl, 1047 .listen = sock_no_listen, 1048 .shutdown = sock_no_shutdown, 1049 .setsockopt = setsockopt, 1050 .getsockopt = sock_no_getsockopt, 1051 .sendmsg = caif_seqpkt_sendmsg, 1052 .recvmsg = caif_seqpkt_recvmsg, 1053 .mmap = sock_no_mmap, 1054 .sendpage = sock_no_sendpage, 1055 }; 1056 1057 static const struct proto_ops caif_stream_ops = { 1058 .family = PF_CAIF, 1059 .owner = THIS_MODULE, 1060 .release = caif_release, 1061 .bind = sock_no_bind, 1062 .connect = caif_connect, 1063 .socketpair = sock_no_socketpair, 1064 .accept = sock_no_accept, 1065 .getname = sock_no_getname, 1066 .poll = caif_poll, 1067 .ioctl = sock_no_ioctl, 1068 .listen = sock_no_listen, 1069 .shutdown = sock_no_shutdown, 1070 .setsockopt = setsockopt, 1071 .getsockopt = sock_no_getsockopt, 1072 .sendmsg = caif_stream_sendmsg, 1073 .recvmsg = caif_stream_recvmsg, 1074 .mmap = sock_no_mmap, 1075 .sendpage = sock_no_sendpage, 1076 }; 1077 1078 /* This function is called when a socket is finally destroyed. */ 1079 static void caif_sock_destructor(struct sock *sk) 1080 { 1081 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); 1082 caif_assert(!atomic_read(&sk->sk_wmem_alloc)); 1083 caif_assert(sk_unhashed(sk)); 1084 caif_assert(!sk->sk_socket); 1085 if (!sock_flag(sk, SOCK_DEAD)) { 1086 pr_info("Attempt to release alive CAIF socket: %p\n", sk); 1087 return; 1088 } 1089 sk_stream_kill_queues(&cf_sk->sk); 1090 dbfs_atomic_dec(&cnt.caif_nr_socks); 1091 } 1092 1093 static int caif_create(struct net *net, struct socket *sock, int protocol, 1094 int kern) 1095 { 1096 struct sock *sk = NULL; 1097 struct caifsock *cf_sk = NULL; 1098 static struct proto prot = {.name = "PF_CAIF", 1099 .owner = THIS_MODULE, 1100 .obj_size = sizeof(struct caifsock), 1101 }; 1102 1103 if (!capable(CAP_SYS_ADMIN) && !capable(CAP_NET_ADMIN)) 1104 return -EPERM; 1105 /* 1106 * The sock->type specifies the socket type to use. 1107 * The CAIF socket is a packet stream in the sense 1108 * that it is packet based. CAIF trusts the reliability 1109 * of the link, no resending is implemented. 1110 */ 1111 if (sock->type == SOCK_SEQPACKET) 1112 sock->ops = &caif_seqpacket_ops; 1113 else if (sock->type == SOCK_STREAM) 1114 sock->ops = &caif_stream_ops; 1115 else 1116 return -ESOCKTNOSUPPORT; 1117 1118 if (protocol < 0 || protocol >= CAIFPROTO_MAX) 1119 return -EPROTONOSUPPORT; 1120 /* 1121 * Set the socket state to unconnected. The socket state 1122 * is really not used at all in the net/core or socket.c but the 1123 * initialization makes sure that sock->state is not uninitialized. 1124 */ 1125 sk = sk_alloc(net, PF_CAIF, GFP_KERNEL, &prot); 1126 if (!sk) 1127 return -ENOMEM; 1128 1129 cf_sk = container_of(sk, struct caifsock, sk); 1130 1131 /* Store the protocol */ 1132 sk->sk_protocol = (unsigned char) protocol; 1133 1134 /* Sendbuf dictates the amount of outbound packets not yet sent */ 1135 sk->sk_sndbuf = CAIF_DEF_SNDBUF; 1136 sk->sk_rcvbuf = CAIF_DEF_RCVBUF; 1137 1138 /* 1139 * Lock in order to try to stop someone from opening the socket 1140 * too early. 1141 */ 1142 lock_sock(&(cf_sk->sk)); 1143 1144 /* Initialize the nozero default sock structure data. */ 1145 sock_init_data(sock, sk); 1146 sk->sk_destruct = caif_sock_destructor; 1147 1148 mutex_init(&cf_sk->readlock); /* single task reading lock */ 1149 cf_sk->layer.ctrlcmd = caif_ctrl_cb; 1150 cf_sk->sk.sk_socket->state = SS_UNCONNECTED; 1151 cf_sk->sk.sk_state = CAIF_DISCONNECTED; 1152 1153 set_tx_flow_off(cf_sk); 1154 set_rx_flow_on(cf_sk); 1155 1156 /* Set default options on configuration */ 1157 cf_sk->conn_req.priority = CAIF_PRIO_NORMAL; 1158 cf_sk->conn_req.link_selector = CAIF_LINK_LOW_LATENCY; 1159 cf_sk->conn_req.protocol = protocol; 1160 /* Increase the number of sockets created. */ 1161 dbfs_atomic_inc(&cnt.caif_nr_socks); 1162 #ifdef CONFIG_DEBUG_FS 1163 if (!IS_ERR(debugfsdir)) { 1164 /* Fill in some information concerning the misc socket. */ 1165 snprintf(cf_sk->name, sizeof(cf_sk->name), "cfsk%d", 1166 atomic_read(&cnt.caif_nr_socks)); 1167 1168 cf_sk->debugfs_socket_dir = 1169 debugfs_create_dir(cf_sk->name, debugfsdir); 1170 debugfs_create_u32("sk_state", S_IRUSR | S_IWUSR, 1171 cf_sk->debugfs_socket_dir, 1172 (u32 *) &cf_sk->sk.sk_state); 1173 debugfs_create_u32("flow_state", S_IRUSR | S_IWUSR, 1174 cf_sk->debugfs_socket_dir, &cf_sk->flow_state); 1175 debugfs_create_u32("sk_rmem_alloc", S_IRUSR | S_IWUSR, 1176 cf_sk->debugfs_socket_dir, 1177 (u32 *) &cf_sk->sk.sk_rmem_alloc); 1178 debugfs_create_u32("sk_wmem_alloc", S_IRUSR | S_IWUSR, 1179 cf_sk->debugfs_socket_dir, 1180 (u32 *) &cf_sk->sk.sk_wmem_alloc); 1181 debugfs_create_u32("identity", S_IRUSR | S_IWUSR, 1182 cf_sk->debugfs_socket_dir, 1183 (u32 *) &cf_sk->layer.id); 1184 } 1185 #endif 1186 release_sock(&cf_sk->sk); 1187 return 0; 1188 } 1189 1190 1191 static struct net_proto_family caif_family_ops = { 1192 .family = PF_CAIF, 1193 .create = caif_create, 1194 .owner = THIS_MODULE, 1195 }; 1196 1197 int af_caif_init(void) 1198 { 1199 int err = sock_register(&caif_family_ops); 1200 if (!err) 1201 return err; 1202 return 0; 1203 } 1204 1205 static int __init caif_sktinit_module(void) 1206 { 1207 #ifdef CONFIG_DEBUG_FS 1208 debugfsdir = debugfs_create_dir("caif_sk", NULL); 1209 if (!IS_ERR(debugfsdir)) { 1210 debugfs_create_u32("num_sockets", S_IRUSR | S_IWUSR, 1211 debugfsdir, 1212 (u32 *) &cnt.caif_nr_socks); 1213 debugfs_create_u32("num_connect_req", S_IRUSR | S_IWUSR, 1214 debugfsdir, 1215 (u32 *) &cnt.num_connect_req); 1216 debugfs_create_u32("num_connect_resp", S_IRUSR | S_IWUSR, 1217 debugfsdir, 1218 (u32 *) &cnt.num_connect_resp); 1219 debugfs_create_u32("num_connect_fail_resp", S_IRUSR | S_IWUSR, 1220 debugfsdir, 1221 (u32 *) &cnt.num_connect_fail_resp); 1222 debugfs_create_u32("num_disconnect", S_IRUSR | S_IWUSR, 1223 debugfsdir, 1224 (u32 *) &cnt.num_disconnect); 1225 debugfs_create_u32("num_remote_shutdown_ind", 1226 S_IRUSR | S_IWUSR, debugfsdir, 1227 (u32 *) &cnt.num_remote_shutdown_ind); 1228 debugfs_create_u32("num_tx_flow_off_ind", S_IRUSR | S_IWUSR, 1229 debugfsdir, 1230 (u32 *) &cnt.num_tx_flow_off_ind); 1231 debugfs_create_u32("num_tx_flow_on_ind", S_IRUSR | S_IWUSR, 1232 debugfsdir, 1233 (u32 *) &cnt.num_tx_flow_on_ind); 1234 debugfs_create_u32("num_rx_flow_off", S_IRUSR | S_IWUSR, 1235 debugfsdir, 1236 (u32 *) &cnt.num_rx_flow_off); 1237 debugfs_create_u32("num_rx_flow_on", S_IRUSR | S_IWUSR, 1238 debugfsdir, 1239 (u32 *) &cnt.num_rx_flow_on); 1240 } 1241 #endif 1242 return af_caif_init(); 1243 } 1244 1245 static void __exit caif_sktexit_module(void) 1246 { 1247 sock_unregister(PF_CAIF); 1248 if (debugfsdir != NULL) 1249 debugfs_remove_recursive(debugfsdir); 1250 } 1251 module_init(caif_sktinit_module); 1252 module_exit(caif_sktexit_module); 1253