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 (4096*10) 32 #define CAIF_DEF_RCVBUF (4096*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 static 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 int headroom, tailroom, maxframe; 80 }; 81 82 static int rx_flow_is_on(struct caifsock *cf_sk) 83 { 84 return test_bit(RX_FLOW_ON_BIT, 85 (void *) &cf_sk->flow_state); 86 } 87 88 static int tx_flow_is_on(struct caifsock *cf_sk) 89 { 90 return test_bit(TX_FLOW_ON_BIT, 91 (void *) &cf_sk->flow_state); 92 } 93 94 static void set_rx_flow_off(struct caifsock *cf_sk) 95 { 96 clear_bit(RX_FLOW_ON_BIT, 97 (void *) &cf_sk->flow_state); 98 } 99 100 static void set_rx_flow_on(struct caifsock *cf_sk) 101 { 102 set_bit(RX_FLOW_ON_BIT, 103 (void *) &cf_sk->flow_state); 104 } 105 106 static void set_tx_flow_off(struct caifsock *cf_sk) 107 { 108 clear_bit(TX_FLOW_ON_BIT, 109 (void *) &cf_sk->flow_state); 110 } 111 112 static void set_tx_flow_on(struct caifsock *cf_sk) 113 { 114 set_bit(TX_FLOW_ON_BIT, 115 (void *) &cf_sk->flow_state); 116 } 117 118 static void caif_read_lock(struct sock *sk) 119 { 120 struct caifsock *cf_sk; 121 cf_sk = container_of(sk, struct caifsock, sk); 122 mutex_lock(&cf_sk->readlock); 123 } 124 125 static void caif_read_unlock(struct sock *sk) 126 { 127 struct caifsock *cf_sk; 128 cf_sk = container_of(sk, struct caifsock, sk); 129 mutex_unlock(&cf_sk->readlock); 130 } 131 132 static int sk_rcvbuf_lowwater(struct caifsock *cf_sk) 133 { 134 /* A quarter of full buffer is used a low water mark */ 135 return cf_sk->sk.sk_rcvbuf / 4; 136 } 137 138 static void caif_flow_ctrl(struct sock *sk, int mode) 139 { 140 struct caifsock *cf_sk; 141 cf_sk = container_of(sk, struct caifsock, sk); 142 if (cf_sk->layer.dn && cf_sk->layer.dn->modemcmd) 143 cf_sk->layer.dn->modemcmd(cf_sk->layer.dn, mode); 144 } 145 146 /* 147 * Copied from sock.c:sock_queue_rcv_skb(), but changed so packets are 148 * not dropped, but CAIF is sending flow off instead. 149 */ 150 static int caif_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) 151 { 152 int err; 153 int skb_len; 154 unsigned long flags; 155 struct sk_buff_head *list = &sk->sk_receive_queue; 156 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); 157 158 if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >= 159 (unsigned)sk->sk_rcvbuf && rx_flow_is_on(cf_sk)) { 160 trace_printk("CAIF: %s():" 161 " sending flow OFF (queue len = %d %d)\n", 162 __func__, 163 atomic_read(&cf_sk->sk.sk_rmem_alloc), 164 sk_rcvbuf_lowwater(cf_sk)); 165 set_rx_flow_off(cf_sk); 166 dbfs_atomic_inc(&cnt.num_rx_flow_off); 167 caif_flow_ctrl(sk, 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 dbfs_atomic_inc(&cnt.num_rx_flow_off); 179 caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_OFF_REQ); 180 } 181 skb->dev = NULL; 182 skb_set_owner_r(skb, sk); 183 /* Cache the SKB length before we tack it onto the receive 184 * queue. Once it is added it no longer belongs to us and 185 * may be freed by other threads of control pulling packets 186 * from the queue. 187 */ 188 skb_len = skb->len; 189 spin_lock_irqsave(&list->lock, flags); 190 if (!sock_flag(sk, SOCK_DEAD)) 191 __skb_queue_tail(list, skb); 192 spin_unlock_irqrestore(&list->lock, flags); 193 194 if (!sock_flag(sk, SOCK_DEAD)) 195 sk->sk_data_ready(sk, skb_len); 196 else 197 kfree_skb(skb); 198 return 0; 199 } 200 201 /* Packet Receive Callback function called from CAIF Stack */ 202 static int caif_sktrecv_cb(struct cflayer *layr, struct cfpkt *pkt) 203 { 204 struct caifsock *cf_sk; 205 struct sk_buff *skb; 206 207 cf_sk = container_of(layr, struct caifsock, layer); 208 skb = cfpkt_tonative(pkt); 209 210 if (unlikely(cf_sk->sk.sk_state != CAIF_CONNECTED)) { 211 cfpkt_destroy(pkt); 212 return 0; 213 } 214 caif_queue_rcv_skb(&cf_sk->sk, skb); 215 return 0; 216 } 217 218 /* Packet Control Callback function called from CAIF */ 219 static void caif_ctrl_cb(struct cflayer *layr, 220 enum caif_ctrlcmd flow, 221 int phyid) 222 { 223 struct caifsock *cf_sk = container_of(layr, struct caifsock, layer); 224 switch (flow) { 225 case CAIF_CTRLCMD_FLOW_ON_IND: 226 /* OK from modem to start sending again */ 227 dbfs_atomic_inc(&cnt.num_tx_flow_on_ind); 228 set_tx_flow_on(cf_sk); 229 cf_sk->sk.sk_state_change(&cf_sk->sk); 230 break; 231 232 case CAIF_CTRLCMD_FLOW_OFF_IND: 233 /* Modem asks us to shut up */ 234 dbfs_atomic_inc(&cnt.num_tx_flow_off_ind); 235 set_tx_flow_off(cf_sk); 236 cf_sk->sk.sk_state_change(&cf_sk->sk); 237 break; 238 239 case CAIF_CTRLCMD_INIT_RSP: 240 /* We're now connected */ 241 dbfs_atomic_inc(&cnt.num_connect_resp); 242 cf_sk->sk.sk_state = CAIF_CONNECTED; 243 set_tx_flow_on(cf_sk); 244 cf_sk->sk.sk_state_change(&cf_sk->sk); 245 break; 246 247 case CAIF_CTRLCMD_DEINIT_RSP: 248 /* We're now disconnected */ 249 cf_sk->sk.sk_state = CAIF_DISCONNECTED; 250 cf_sk->sk.sk_state_change(&cf_sk->sk); 251 cfcnfg_release_adap_layer(&cf_sk->layer); 252 break; 253 254 case CAIF_CTRLCMD_INIT_FAIL_RSP: 255 /* Connect request failed */ 256 dbfs_atomic_inc(&cnt.num_connect_fail_resp); 257 cf_sk->sk.sk_err = ECONNREFUSED; 258 cf_sk->sk.sk_state = CAIF_DISCONNECTED; 259 cf_sk->sk.sk_shutdown = SHUTDOWN_MASK; 260 /* 261 * Socket "standards" seems to require POLLOUT to 262 * be set at connect failure. 263 */ 264 set_tx_flow_on(cf_sk); 265 cf_sk->sk.sk_state_change(&cf_sk->sk); 266 break; 267 268 case CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND: 269 /* Modem has closed this connection, or device is down. */ 270 dbfs_atomic_inc(&cnt.num_remote_shutdown_ind); 271 cf_sk->sk.sk_shutdown = SHUTDOWN_MASK; 272 cf_sk->sk.sk_err = ECONNRESET; 273 set_rx_flow_on(cf_sk); 274 cf_sk->sk.sk_error_report(&cf_sk->sk); 275 break; 276 277 default: 278 pr_debug("CAIF: %s(): Unexpected flow command %d\n", 279 __func__, flow); 280 } 281 } 282 283 static void caif_check_flow_release(struct sock *sk) 284 { 285 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); 286 287 if (rx_flow_is_on(cf_sk)) 288 return; 289 290 if (atomic_read(&sk->sk_rmem_alloc) <= sk_rcvbuf_lowwater(cf_sk)) { 291 dbfs_atomic_inc(&cnt.num_rx_flow_on); 292 set_rx_flow_on(cf_sk); 293 caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_ON_REQ); 294 } 295 } 296 297 /* 298 * Copied from unix_dgram_recvmsg, but removed credit checks, 299 * changed locking, address handling and added MSG_TRUNC. 300 */ 301 static int caif_seqpkt_recvmsg(struct kiocb *iocb, struct socket *sock, 302 struct msghdr *m, size_t len, int flags) 303 304 { 305 struct sock *sk = sock->sk; 306 struct sk_buff *skb; 307 int ret; 308 int copylen; 309 310 ret = -EOPNOTSUPP; 311 if (m->msg_flags&MSG_OOB) 312 goto read_error; 313 314 skb = skb_recv_datagram(sk, flags, 0 , &ret); 315 if (!skb) 316 goto read_error; 317 copylen = skb->len; 318 if (len < copylen) { 319 m->msg_flags |= MSG_TRUNC; 320 copylen = len; 321 } 322 323 ret = skb_copy_datagram_iovec(skb, 0, m->msg_iov, copylen); 324 if (ret) 325 goto out_free; 326 327 ret = (flags & MSG_TRUNC) ? skb->len : copylen; 328 out_free: 329 skb_free_datagram(sk, skb); 330 caif_check_flow_release(sk); 331 return ret; 332 333 read_error: 334 return ret; 335 } 336 337 338 /* Copied from unix_stream_wait_data, identical except for lock call. */ 339 static long caif_stream_data_wait(struct sock *sk, long timeo) 340 { 341 DEFINE_WAIT(wait); 342 lock_sock(sk); 343 344 for (;;) { 345 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE); 346 347 if (!skb_queue_empty(&sk->sk_receive_queue) || 348 sk->sk_err || 349 sk->sk_state != CAIF_CONNECTED || 350 sock_flag(sk, SOCK_DEAD) || 351 (sk->sk_shutdown & RCV_SHUTDOWN) || 352 signal_pending(current) || 353 !timeo) 354 break; 355 356 set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags); 357 release_sock(sk); 358 timeo = schedule_timeout(timeo); 359 lock_sock(sk); 360 clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags); 361 } 362 363 finish_wait(sk_sleep(sk), &wait); 364 release_sock(sk); 365 return timeo; 366 } 367 368 369 /* 370 * Copied from unix_stream_recvmsg, but removed credit checks, 371 * changed locking calls, changed address handling. 372 */ 373 static int caif_stream_recvmsg(struct kiocb *iocb, struct socket *sock, 374 struct msghdr *msg, size_t size, 375 int flags) 376 { 377 struct sock *sk = sock->sk; 378 int copied = 0; 379 int target; 380 int err = 0; 381 long timeo; 382 383 err = -EOPNOTSUPP; 384 if (flags&MSG_OOB) 385 goto out; 386 387 msg->msg_namelen = 0; 388 389 /* 390 * Lock the socket to prevent queue disordering 391 * while sleeps in memcpy_tomsg 392 */ 393 err = -EAGAIN; 394 if (sk->sk_state == CAIF_CONNECTING) 395 goto out; 396 397 caif_read_lock(sk); 398 target = sock_rcvlowat(sk, flags&MSG_WAITALL, size); 399 timeo = sock_rcvtimeo(sk, flags&MSG_DONTWAIT); 400 401 do { 402 int chunk; 403 struct sk_buff *skb; 404 405 lock_sock(sk); 406 skb = skb_dequeue(&sk->sk_receive_queue); 407 caif_check_flow_release(sk); 408 409 if (skb == NULL) { 410 if (copied >= target) 411 goto unlock; 412 /* 413 * POSIX 1003.1g mandates this order. 414 */ 415 err = sock_error(sk); 416 if (err) 417 goto unlock; 418 err = -ECONNRESET; 419 if (sk->sk_shutdown & RCV_SHUTDOWN) 420 goto unlock; 421 422 err = -EPIPE; 423 if (sk->sk_state != CAIF_CONNECTED) 424 goto unlock; 425 if (sock_flag(sk, SOCK_DEAD)) 426 goto unlock; 427 428 release_sock(sk); 429 430 err = -EAGAIN; 431 if (!timeo) 432 break; 433 434 caif_read_unlock(sk); 435 436 timeo = caif_stream_data_wait(sk, timeo); 437 438 if (signal_pending(current)) { 439 err = sock_intr_errno(timeo); 440 goto out; 441 } 442 caif_read_lock(sk); 443 continue; 444 unlock: 445 release_sock(sk); 446 break; 447 } 448 release_sock(sk); 449 chunk = min_t(unsigned int, skb->len, size); 450 if (memcpy_toiovec(msg->msg_iov, skb->data, chunk)) { 451 skb_queue_head(&sk->sk_receive_queue, skb); 452 if (copied == 0) 453 copied = -EFAULT; 454 break; 455 } 456 copied += chunk; 457 size -= chunk; 458 459 /* Mark read part of skb as used */ 460 if (!(flags & MSG_PEEK)) { 461 skb_pull(skb, chunk); 462 463 /* put the skb back if we didn't use it up. */ 464 if (skb->len) { 465 skb_queue_head(&sk->sk_receive_queue, skb); 466 break; 467 } 468 kfree_skb(skb); 469 470 } else { 471 /* 472 * It is questionable, see note in unix_dgram_recvmsg. 473 */ 474 /* put message back and return */ 475 skb_queue_head(&sk->sk_receive_queue, skb); 476 break; 477 } 478 } while (size); 479 caif_read_unlock(sk); 480 481 out: 482 return copied ? : err; 483 } 484 485 /* 486 * Copied from sock.c:sock_wait_for_wmem, but change to wait for 487 * CAIF flow-on and sock_writable. 488 */ 489 static long caif_wait_for_flow_on(struct caifsock *cf_sk, 490 int wait_writeable, long timeo, int *err) 491 { 492 struct sock *sk = &cf_sk->sk; 493 DEFINE_WAIT(wait); 494 for (;;) { 495 *err = 0; 496 if (tx_flow_is_on(cf_sk) && 497 (!wait_writeable || sock_writeable(&cf_sk->sk))) 498 break; 499 *err = -ETIMEDOUT; 500 if (!timeo) 501 break; 502 *err = -ERESTARTSYS; 503 if (signal_pending(current)) 504 break; 505 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE); 506 *err = -ECONNRESET; 507 if (sk->sk_shutdown & SHUTDOWN_MASK) 508 break; 509 *err = -sk->sk_err; 510 if (sk->sk_err) 511 break; 512 *err = -EPIPE; 513 if (cf_sk->sk.sk_state != CAIF_CONNECTED) 514 break; 515 timeo = schedule_timeout(timeo); 516 } 517 finish_wait(sk_sleep(sk), &wait); 518 return timeo; 519 } 520 521 /* 522 * Transmit a SKB. The device may temporarily request re-transmission 523 * by returning EAGAIN. 524 */ 525 static int transmit_skb(struct sk_buff *skb, struct caifsock *cf_sk, 526 int noblock, long timeo) 527 { 528 struct cfpkt *pkt; 529 int ret, loopcnt = 0; 530 531 pkt = cfpkt_fromnative(CAIF_DIR_OUT, skb); 532 memset(cfpkt_info(pkt), 0, sizeof(struct caif_payload_info)); 533 do { 534 535 ret = -ETIMEDOUT; 536 537 /* Slight paranoia, probably not needed. */ 538 if (unlikely(loopcnt++ > 1000)) { 539 pr_warning("CAIF: %s(): transmit retries failed," 540 " error = %d\n", __func__, ret); 541 break; 542 } 543 544 if (cf_sk->layer.dn != NULL) 545 ret = cf_sk->layer.dn->transmit(cf_sk->layer.dn, pkt); 546 if (likely(ret >= 0)) 547 break; 548 /* if transmit return -EAGAIN, then retry */ 549 if (noblock && ret == -EAGAIN) 550 break; 551 timeo = caif_wait_for_flow_on(cf_sk, 0, timeo, &ret); 552 if (signal_pending(current)) { 553 ret = sock_intr_errno(timeo); 554 break; 555 } 556 if (ret) 557 break; 558 if (cf_sk->sk.sk_state != CAIF_CONNECTED || 559 sock_flag(&cf_sk->sk, SOCK_DEAD) || 560 (cf_sk->sk.sk_shutdown & RCV_SHUTDOWN)) { 561 ret = -EPIPE; 562 cf_sk->sk.sk_err = EPIPE; 563 break; 564 } 565 } while (ret == -EAGAIN); 566 return ret; 567 } 568 569 /* Copied from af_unix:unix_dgram_sendmsg, and adapted to CAIF */ 570 static int caif_seqpkt_sendmsg(struct kiocb *kiocb, struct socket *sock, 571 struct msghdr *msg, size_t len) 572 { 573 struct sock *sk = sock->sk; 574 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); 575 int buffer_size; 576 int ret = 0; 577 struct sk_buff *skb = NULL; 578 int noblock; 579 long timeo; 580 caif_assert(cf_sk); 581 ret = sock_error(sk); 582 if (ret) 583 goto err; 584 585 ret = -EOPNOTSUPP; 586 if (msg->msg_flags&MSG_OOB) 587 goto err; 588 589 ret = -EOPNOTSUPP; 590 if (msg->msg_namelen) 591 goto err; 592 593 ret = -EINVAL; 594 if (unlikely(msg->msg_iov->iov_base == NULL)) 595 goto err; 596 noblock = msg->msg_flags & MSG_DONTWAIT; 597 598 timeo = sock_sndtimeo(sk, noblock); 599 timeo = caif_wait_for_flow_on(container_of(sk, struct caifsock, sk), 600 1, timeo, &ret); 601 602 if (ret) 603 goto err; 604 ret = -EPIPE; 605 if (cf_sk->sk.sk_state != CAIF_CONNECTED || 606 sock_flag(sk, SOCK_DEAD) || 607 (sk->sk_shutdown & RCV_SHUTDOWN)) 608 goto err; 609 610 /* Error if trying to write more than maximum frame size. */ 611 ret = -EMSGSIZE; 612 if (len > cf_sk->maxframe && cf_sk->sk.sk_protocol != CAIFPROTO_RFM) 613 goto err; 614 615 buffer_size = len + cf_sk->headroom + cf_sk->tailroom; 616 617 ret = -ENOMEM; 618 skb = sock_alloc_send_skb(sk, buffer_size, noblock, &ret); 619 620 if (!skb || skb_tailroom(skb) < buffer_size) 621 goto err; 622 623 skb_reserve(skb, cf_sk->headroom); 624 625 ret = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len); 626 627 if (ret) 628 goto err; 629 ret = transmit_skb(skb, cf_sk, noblock, timeo); 630 if (ret < 0) 631 goto err; 632 return len; 633 err: 634 kfree_skb(skb); 635 return ret; 636 } 637 638 /* 639 * Copied from unix_stream_sendmsg and adapted to CAIF: 640 * Changed removed permission handling and added waiting for flow on 641 * and other minor adaptations. 642 */ 643 static int caif_stream_sendmsg(struct kiocb *kiocb, struct socket *sock, 644 struct msghdr *msg, size_t len) 645 { 646 struct sock *sk = sock->sk; 647 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); 648 int err, size; 649 struct sk_buff *skb; 650 int sent = 0; 651 long timeo; 652 653 err = -EOPNOTSUPP; 654 if (unlikely(msg->msg_flags&MSG_OOB)) 655 goto out_err; 656 657 if (unlikely(msg->msg_namelen)) 658 goto out_err; 659 660 timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT); 661 timeo = caif_wait_for_flow_on(cf_sk, 1, timeo, &err); 662 663 if (unlikely(sk->sk_shutdown & SEND_SHUTDOWN)) 664 goto pipe_err; 665 666 while (sent < len) { 667 668 size = len-sent; 669 670 if (size > cf_sk->maxframe) 671 size = cf_sk->maxframe; 672 673 /* If size is more than half of sndbuf, chop up message */ 674 if (size > ((sk->sk_sndbuf >> 1) - 64)) 675 size = (sk->sk_sndbuf >> 1) - 64; 676 677 if (size > SKB_MAX_ALLOC) 678 size = SKB_MAX_ALLOC; 679 680 skb = sock_alloc_send_skb(sk, 681 size + cf_sk->headroom + 682 cf_sk->tailroom, 683 msg->msg_flags&MSG_DONTWAIT, 684 &err); 685 if (skb == NULL) 686 goto out_err; 687 688 skb_reserve(skb, cf_sk->headroom); 689 /* 690 * If you pass two values to the sock_alloc_send_skb 691 * it tries to grab the large buffer with GFP_NOFS 692 * (which can fail easily), and if it fails grab the 693 * fallback size buffer which is under a page and will 694 * succeed. [Alan] 695 */ 696 size = min_t(int, size, skb_tailroom(skb)); 697 698 err = memcpy_fromiovec(skb_put(skb, size), msg->msg_iov, size); 699 if (err) { 700 kfree_skb(skb); 701 goto out_err; 702 } 703 err = transmit_skb(skb, cf_sk, 704 msg->msg_flags&MSG_DONTWAIT, timeo); 705 if (err < 0) { 706 kfree_skb(skb); 707 goto pipe_err; 708 } 709 sent += size; 710 } 711 712 return sent; 713 714 pipe_err: 715 if (sent == 0 && !(msg->msg_flags&MSG_NOSIGNAL)) 716 send_sig(SIGPIPE, current, 0); 717 err = -EPIPE; 718 out_err: 719 return sent ? : err; 720 } 721 722 static int setsockopt(struct socket *sock, 723 int lvl, int opt, char __user *ov, unsigned int ol) 724 { 725 struct sock *sk = sock->sk; 726 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); 727 int prio, linksel; 728 struct ifreq ifreq; 729 730 if (cf_sk->sk.sk_socket->state != SS_UNCONNECTED) 731 return -ENOPROTOOPT; 732 733 switch (opt) { 734 case CAIFSO_LINK_SELECT: 735 if (ol < sizeof(int)) 736 return -EINVAL; 737 if (lvl != SOL_CAIF) 738 goto bad_sol; 739 if (copy_from_user(&linksel, ov, sizeof(int))) 740 return -EINVAL; 741 lock_sock(&(cf_sk->sk)); 742 cf_sk->conn_req.link_selector = linksel; 743 release_sock(&cf_sk->sk); 744 return 0; 745 746 case SO_PRIORITY: 747 if (lvl != SOL_SOCKET) 748 goto bad_sol; 749 if (ol < sizeof(int)) 750 return -EINVAL; 751 if (copy_from_user(&prio, ov, sizeof(int))) 752 return -EINVAL; 753 lock_sock(&(cf_sk->sk)); 754 cf_sk->conn_req.priority = prio; 755 release_sock(&cf_sk->sk); 756 return 0; 757 758 case SO_BINDTODEVICE: 759 if (lvl != SOL_SOCKET) 760 goto bad_sol; 761 if (ol < sizeof(struct ifreq)) 762 return -EINVAL; 763 if (copy_from_user(&ifreq, ov, sizeof(ifreq))) 764 return -EFAULT; 765 lock_sock(&(cf_sk->sk)); 766 strncpy(cf_sk->conn_req.link_name, ifreq.ifr_name, 767 sizeof(cf_sk->conn_req.link_name)); 768 cf_sk->conn_req.link_name 769 [sizeof(cf_sk->conn_req.link_name)-1] = 0; 770 release_sock(&cf_sk->sk); 771 return 0; 772 773 case CAIFSO_REQ_PARAM: 774 if (lvl != SOL_CAIF) 775 goto bad_sol; 776 if (cf_sk->sk.sk_protocol != CAIFPROTO_UTIL) 777 return -ENOPROTOOPT; 778 lock_sock(&(cf_sk->sk)); 779 cf_sk->conn_req.param.size = ol; 780 if (ol > sizeof(cf_sk->conn_req.param.data) || 781 copy_from_user(&cf_sk->conn_req.param.data, ov, ol)) { 782 release_sock(&cf_sk->sk); 783 return -EINVAL; 784 } 785 release_sock(&cf_sk->sk); 786 return 0; 787 788 default: 789 return -ENOPROTOOPT; 790 } 791 792 return 0; 793 bad_sol: 794 return -ENOPROTOOPT; 795 796 } 797 798 /* 799 * caif_connect() - Connect a CAIF Socket 800 * Copied and modified af_irda.c:irda_connect(). 801 * 802 * Note : by consulting "errno", the user space caller may learn the cause 803 * of the failure. Most of them are visible in the function, others may come 804 * from subroutines called and are listed here : 805 * o -EAFNOSUPPORT: bad socket family or type. 806 * o -ESOCKTNOSUPPORT: bad socket type or protocol 807 * o -EINVAL: bad socket address, or CAIF link type 808 * o -ECONNREFUSED: remote end refused the connection. 809 * o -EINPROGRESS: connect request sent but timed out (or non-blocking) 810 * o -EISCONN: already connected. 811 * o -ETIMEDOUT: Connection timed out (send timeout) 812 * o -ENODEV: No link layer to send request 813 * o -ECONNRESET: Received Shutdown indication or lost link layer 814 * o -ENOMEM: Out of memory 815 * 816 * State Strategy: 817 * o sk_state: holds the CAIF_* protocol state, it's updated by 818 * caif_ctrl_cb. 819 * o sock->state: holds the SS_* socket state and is updated by connect and 820 * disconnect. 821 */ 822 static int caif_connect(struct socket *sock, struct sockaddr *uaddr, 823 int addr_len, int flags) 824 { 825 struct sock *sk = sock->sk; 826 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); 827 long timeo; 828 int err; 829 int ifindex, headroom, tailroom; 830 struct net_device *dev; 831 832 lock_sock(sk); 833 834 err = -EAFNOSUPPORT; 835 if (uaddr->sa_family != AF_CAIF) 836 goto out; 837 838 switch (sock->state) { 839 case SS_UNCONNECTED: 840 /* Normal case, a fresh connect */ 841 caif_assert(sk->sk_state == CAIF_DISCONNECTED); 842 break; 843 case SS_CONNECTING: 844 switch (sk->sk_state) { 845 case CAIF_CONNECTED: 846 sock->state = SS_CONNECTED; 847 err = -EISCONN; 848 goto out; 849 case CAIF_DISCONNECTED: 850 /* Reconnect allowed */ 851 break; 852 case CAIF_CONNECTING: 853 err = -EALREADY; 854 if (flags & O_NONBLOCK) 855 goto out; 856 goto wait_connect; 857 } 858 break; 859 case SS_CONNECTED: 860 caif_assert(sk->sk_state == CAIF_CONNECTED || 861 sk->sk_state == CAIF_DISCONNECTED); 862 if (sk->sk_shutdown & SHUTDOWN_MASK) { 863 /* Allow re-connect after SHUTDOWN_IND */ 864 caif_disconnect_client(&cf_sk->layer); 865 break; 866 } 867 /* No reconnect on a seqpacket socket */ 868 err = -EISCONN; 869 goto out; 870 case SS_DISCONNECTING: 871 case SS_FREE: 872 caif_assert(1); /*Should never happen */ 873 break; 874 } 875 sk->sk_state = CAIF_DISCONNECTED; 876 sock->state = SS_UNCONNECTED; 877 sk_stream_kill_queues(&cf_sk->sk); 878 879 err = -EINVAL; 880 if (addr_len != sizeof(struct sockaddr_caif)) 881 goto out; 882 883 memcpy(&cf_sk->conn_req.sockaddr, uaddr, 884 sizeof(struct sockaddr_caif)); 885 886 /* Move to connecting socket, start sending Connect Requests */ 887 sock->state = SS_CONNECTING; 888 sk->sk_state = CAIF_CONNECTING; 889 890 dbfs_atomic_inc(&cnt.num_connect_req); 891 cf_sk->layer.receive = caif_sktrecv_cb; 892 err = caif_connect_client(&cf_sk->conn_req, 893 &cf_sk->layer, &ifindex, &headroom, &tailroom); 894 if (err < 0) { 895 cf_sk->sk.sk_socket->state = SS_UNCONNECTED; 896 cf_sk->sk.sk_state = CAIF_DISCONNECTED; 897 goto out; 898 } 899 dev = dev_get_by_index(sock_net(sk), ifindex); 900 cf_sk->headroom = LL_RESERVED_SPACE_EXTRA(dev, headroom); 901 cf_sk->tailroom = tailroom; 902 cf_sk->maxframe = dev->mtu - (headroom + tailroom); 903 dev_put(dev); 904 if (cf_sk->maxframe < 1) { 905 pr_warning("CAIF: %s(): CAIF Interface MTU too small (%d)\n", 906 __func__, dev->mtu); 907 err = -ENODEV; 908 goto out; 909 } 910 911 err = -EINPROGRESS; 912 wait_connect: 913 914 if (sk->sk_state != CAIF_CONNECTED && (flags & O_NONBLOCK)) 915 goto out; 916 917 timeo = sock_sndtimeo(sk, flags & O_NONBLOCK); 918 919 release_sock(sk); 920 err = -ERESTARTSYS; 921 timeo = wait_event_interruptible_timeout(*sk_sleep(sk), 922 sk->sk_state != CAIF_CONNECTING, 923 timeo); 924 lock_sock(sk); 925 if (timeo < 0) 926 goto out; /* -ERESTARTSYS */ 927 928 err = -ETIMEDOUT; 929 if (timeo == 0 && sk->sk_state != CAIF_CONNECTED) 930 goto out; 931 if (sk->sk_state != CAIF_CONNECTED) { 932 sock->state = SS_UNCONNECTED; 933 err = sock_error(sk); 934 if (!err) 935 err = -ECONNREFUSED; 936 goto out; 937 } 938 sock->state = SS_CONNECTED; 939 err = 0; 940 out: 941 release_sock(sk); 942 return err; 943 } 944 945 /* 946 * caif_release() - Disconnect a CAIF Socket 947 * Copied and modified af_irda.c:irda_release(). 948 */ 949 static int caif_release(struct socket *sock) 950 { 951 struct sock *sk = sock->sk; 952 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); 953 int res = 0; 954 955 if (!sk) 956 return 0; 957 958 set_tx_flow_off(cf_sk); 959 960 /* 961 * Ensure that packets are not queued after this point in time. 962 * caif_queue_rcv_skb checks SOCK_DEAD holding the queue lock, 963 * this ensures no packets when sock is dead. 964 */ 965 spin_lock(&sk->sk_receive_queue.lock); 966 sock_set_flag(sk, SOCK_DEAD); 967 spin_unlock(&sk->sk_receive_queue.lock); 968 sock->sk = NULL; 969 970 dbfs_atomic_inc(&cnt.num_disconnect); 971 972 if (cf_sk->debugfs_socket_dir != NULL) 973 debugfs_remove_recursive(cf_sk->debugfs_socket_dir); 974 975 lock_sock(&(cf_sk->sk)); 976 sk->sk_state = CAIF_DISCONNECTED; 977 sk->sk_shutdown = SHUTDOWN_MASK; 978 979 if (cf_sk->sk.sk_socket->state == SS_CONNECTED || 980 cf_sk->sk.sk_socket->state == SS_CONNECTING) 981 res = caif_disconnect_client(&cf_sk->layer); 982 983 cf_sk->sk.sk_socket->state = SS_DISCONNECTING; 984 wake_up_interruptible_poll(sk_sleep(sk), POLLERR|POLLHUP); 985 986 sock_orphan(sk); 987 cf_sk->layer.dn = NULL; 988 sk_stream_kill_queues(&cf_sk->sk); 989 release_sock(sk); 990 sock_put(sk); 991 return res; 992 } 993 994 /* Copied from af_unix.c:unix_poll(), added CAIF tx_flow handling */ 995 static unsigned int caif_poll(struct file *file, 996 struct socket *sock, poll_table *wait) 997 { 998 struct sock *sk = sock->sk; 999 unsigned int mask; 1000 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); 1001 1002 sock_poll_wait(file, sk_sleep(sk), wait); 1003 mask = 0; 1004 1005 /* exceptional events? */ 1006 if (sk->sk_err) 1007 mask |= POLLERR; 1008 if (sk->sk_shutdown == SHUTDOWN_MASK) 1009 mask |= POLLHUP; 1010 if (sk->sk_shutdown & RCV_SHUTDOWN) 1011 mask |= POLLRDHUP; 1012 1013 /* readable? */ 1014 if (!skb_queue_empty(&sk->sk_receive_queue) || 1015 (sk->sk_shutdown & RCV_SHUTDOWN)) 1016 mask |= POLLIN | POLLRDNORM; 1017 1018 /* 1019 * we set writable also when the other side has shut down the 1020 * connection. This prevents stuck sockets. 1021 */ 1022 if (sock_writeable(sk) && tx_flow_is_on(cf_sk)) 1023 mask |= POLLOUT | POLLWRNORM | POLLWRBAND; 1024 1025 return mask; 1026 } 1027 1028 static const struct proto_ops caif_seqpacket_ops = { 1029 .family = PF_CAIF, 1030 .owner = THIS_MODULE, 1031 .release = caif_release, 1032 .bind = sock_no_bind, 1033 .connect = caif_connect, 1034 .socketpair = sock_no_socketpair, 1035 .accept = sock_no_accept, 1036 .getname = sock_no_getname, 1037 .poll = caif_poll, 1038 .ioctl = sock_no_ioctl, 1039 .listen = sock_no_listen, 1040 .shutdown = sock_no_shutdown, 1041 .setsockopt = setsockopt, 1042 .getsockopt = sock_no_getsockopt, 1043 .sendmsg = caif_seqpkt_sendmsg, 1044 .recvmsg = caif_seqpkt_recvmsg, 1045 .mmap = sock_no_mmap, 1046 .sendpage = sock_no_sendpage, 1047 }; 1048 1049 static const struct proto_ops caif_stream_ops = { 1050 .family = PF_CAIF, 1051 .owner = THIS_MODULE, 1052 .release = caif_release, 1053 .bind = sock_no_bind, 1054 .connect = caif_connect, 1055 .socketpair = sock_no_socketpair, 1056 .accept = sock_no_accept, 1057 .getname = sock_no_getname, 1058 .poll = caif_poll, 1059 .ioctl = sock_no_ioctl, 1060 .listen = sock_no_listen, 1061 .shutdown = sock_no_shutdown, 1062 .setsockopt = setsockopt, 1063 .getsockopt = sock_no_getsockopt, 1064 .sendmsg = caif_stream_sendmsg, 1065 .recvmsg = caif_stream_recvmsg, 1066 .mmap = sock_no_mmap, 1067 .sendpage = sock_no_sendpage, 1068 }; 1069 1070 /* This function is called when a socket is finally destroyed. */ 1071 static void caif_sock_destructor(struct sock *sk) 1072 { 1073 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); 1074 caif_assert(!atomic_read(&sk->sk_wmem_alloc)); 1075 caif_assert(sk_unhashed(sk)); 1076 caif_assert(!sk->sk_socket); 1077 if (!sock_flag(sk, SOCK_DEAD)) { 1078 pr_info("Attempt to release alive CAIF socket: %p\n", sk); 1079 return; 1080 } 1081 sk_stream_kill_queues(&cf_sk->sk); 1082 dbfs_atomic_dec(&cnt.caif_nr_socks); 1083 } 1084 1085 static int caif_create(struct net *net, struct socket *sock, int protocol, 1086 int kern) 1087 { 1088 struct sock *sk = NULL; 1089 struct caifsock *cf_sk = NULL; 1090 static struct proto prot = {.name = "PF_CAIF", 1091 .owner = THIS_MODULE, 1092 .obj_size = sizeof(struct caifsock), 1093 }; 1094 1095 if (!capable(CAP_SYS_ADMIN) && !capable(CAP_NET_ADMIN)) 1096 return -EPERM; 1097 /* 1098 * The sock->type specifies the socket type to use. 1099 * The CAIF socket is a packet stream in the sense 1100 * that it is packet based. CAIF trusts the reliability 1101 * of the link, no resending is implemented. 1102 */ 1103 if (sock->type == SOCK_SEQPACKET) 1104 sock->ops = &caif_seqpacket_ops; 1105 else if (sock->type == SOCK_STREAM) 1106 sock->ops = &caif_stream_ops; 1107 else 1108 return -ESOCKTNOSUPPORT; 1109 1110 if (protocol < 0 || protocol >= CAIFPROTO_MAX) 1111 return -EPROTONOSUPPORT; 1112 /* 1113 * Set the socket state to unconnected. The socket state 1114 * is really not used at all in the net/core or socket.c but the 1115 * initialization makes sure that sock->state is not uninitialized. 1116 */ 1117 sk = sk_alloc(net, PF_CAIF, GFP_KERNEL, &prot); 1118 if (!sk) 1119 return -ENOMEM; 1120 1121 cf_sk = container_of(sk, struct caifsock, sk); 1122 1123 /* Store the protocol */ 1124 sk->sk_protocol = (unsigned char) protocol; 1125 1126 /* Sendbuf dictates the amount of outbound packets not yet sent */ 1127 sk->sk_sndbuf = CAIF_DEF_SNDBUF; 1128 sk->sk_rcvbuf = CAIF_DEF_RCVBUF; 1129 1130 /* 1131 * Lock in order to try to stop someone from opening the socket 1132 * too early. 1133 */ 1134 lock_sock(&(cf_sk->sk)); 1135 1136 /* Initialize the nozero default sock structure data. */ 1137 sock_init_data(sock, sk); 1138 sk->sk_destruct = caif_sock_destructor; 1139 1140 mutex_init(&cf_sk->readlock); /* single task reading lock */ 1141 cf_sk->layer.ctrlcmd = caif_ctrl_cb; 1142 cf_sk->sk.sk_socket->state = SS_UNCONNECTED; 1143 cf_sk->sk.sk_state = CAIF_DISCONNECTED; 1144 1145 set_tx_flow_off(cf_sk); 1146 set_rx_flow_on(cf_sk); 1147 1148 /* Set default options on configuration */ 1149 cf_sk->conn_req.priority = CAIF_PRIO_NORMAL; 1150 cf_sk->conn_req.link_selector = CAIF_LINK_LOW_LATENCY; 1151 cf_sk->conn_req.protocol = protocol; 1152 /* Increase the number of sockets created. */ 1153 dbfs_atomic_inc(&cnt.caif_nr_socks); 1154 #ifdef CONFIG_DEBUG_FS 1155 if (!IS_ERR(debugfsdir)) { 1156 /* Fill in some information concerning the misc socket. */ 1157 snprintf(cf_sk->name, sizeof(cf_sk->name), "cfsk%d", 1158 atomic_read(&cnt.caif_nr_socks)); 1159 1160 cf_sk->debugfs_socket_dir = 1161 debugfs_create_dir(cf_sk->name, debugfsdir); 1162 debugfs_create_u32("sk_state", S_IRUSR | S_IWUSR, 1163 cf_sk->debugfs_socket_dir, 1164 (u32 *) &cf_sk->sk.sk_state); 1165 debugfs_create_u32("flow_state", S_IRUSR | S_IWUSR, 1166 cf_sk->debugfs_socket_dir, &cf_sk->flow_state); 1167 debugfs_create_u32("sk_rmem_alloc", S_IRUSR | S_IWUSR, 1168 cf_sk->debugfs_socket_dir, 1169 (u32 *) &cf_sk->sk.sk_rmem_alloc); 1170 debugfs_create_u32("sk_wmem_alloc", S_IRUSR | S_IWUSR, 1171 cf_sk->debugfs_socket_dir, 1172 (u32 *) &cf_sk->sk.sk_wmem_alloc); 1173 debugfs_create_u32("identity", S_IRUSR | S_IWUSR, 1174 cf_sk->debugfs_socket_dir, 1175 (u32 *) &cf_sk->layer.id); 1176 } 1177 #endif 1178 release_sock(&cf_sk->sk); 1179 return 0; 1180 } 1181 1182 1183 static struct net_proto_family caif_family_ops = { 1184 .family = PF_CAIF, 1185 .create = caif_create, 1186 .owner = THIS_MODULE, 1187 }; 1188 1189 static int af_caif_init(void) 1190 { 1191 int err = sock_register(&caif_family_ops); 1192 if (!err) 1193 return err; 1194 return 0; 1195 } 1196 1197 static int __init caif_sktinit_module(void) 1198 { 1199 #ifdef CONFIG_DEBUG_FS 1200 debugfsdir = debugfs_create_dir("caif_sk", NULL); 1201 if (!IS_ERR(debugfsdir)) { 1202 debugfs_create_u32("num_sockets", S_IRUSR | S_IWUSR, 1203 debugfsdir, 1204 (u32 *) &cnt.caif_nr_socks); 1205 debugfs_create_u32("num_connect_req", S_IRUSR | S_IWUSR, 1206 debugfsdir, 1207 (u32 *) &cnt.num_connect_req); 1208 debugfs_create_u32("num_connect_resp", S_IRUSR | S_IWUSR, 1209 debugfsdir, 1210 (u32 *) &cnt.num_connect_resp); 1211 debugfs_create_u32("num_connect_fail_resp", S_IRUSR | S_IWUSR, 1212 debugfsdir, 1213 (u32 *) &cnt.num_connect_fail_resp); 1214 debugfs_create_u32("num_disconnect", S_IRUSR | S_IWUSR, 1215 debugfsdir, 1216 (u32 *) &cnt.num_disconnect); 1217 debugfs_create_u32("num_remote_shutdown_ind", 1218 S_IRUSR | S_IWUSR, debugfsdir, 1219 (u32 *) &cnt.num_remote_shutdown_ind); 1220 debugfs_create_u32("num_tx_flow_off_ind", S_IRUSR | S_IWUSR, 1221 debugfsdir, 1222 (u32 *) &cnt.num_tx_flow_off_ind); 1223 debugfs_create_u32("num_tx_flow_on_ind", S_IRUSR | S_IWUSR, 1224 debugfsdir, 1225 (u32 *) &cnt.num_tx_flow_on_ind); 1226 debugfs_create_u32("num_rx_flow_off", S_IRUSR | S_IWUSR, 1227 debugfsdir, 1228 (u32 *) &cnt.num_rx_flow_off); 1229 debugfs_create_u32("num_rx_flow_on", S_IRUSR | S_IWUSR, 1230 debugfsdir, 1231 (u32 *) &cnt.num_rx_flow_on); 1232 } 1233 #endif 1234 return af_caif_init(); 1235 } 1236 1237 static void __exit caif_sktexit_module(void) 1238 { 1239 sock_unregister(PF_CAIF); 1240 if (debugfsdir != NULL) 1241 debugfs_remove_recursive(debugfsdir); 1242 } 1243 module_init(caif_sktinit_module); 1244 module_exit(caif_sktexit_module); 1245