caif_socket.c revision 3bffc475f9995843fa23a4978a4c112d8c8f4a6e
1/* 2 * Copyright (C) ST-Ericsson AB 2010 3 * Author: Sjur Brendeland sjur.brandeland@stericsson.com 4 * License terms: GNU General Public License (GPL) version 2 5 */ 6 7#define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__ 8 9#include <linux/fs.h> 10#include <linux/init.h> 11#include <linux/module.h> 12#include <linux/sched.h> 13#include <linux/spinlock.h> 14#include <linux/mutex.h> 15#include <linux/list.h> 16#include <linux/wait.h> 17#include <linux/poll.h> 18#include <linux/tcp.h> 19#include <linux/uaccess.h> 20#include <linux/debugfs.h> 21#include <linux/caif/caif_socket.h> 22#include <linux/pkt_sched.h> 23#include <net/sock.h> 24#include <net/tcp_states.h> 25#include <net/caif/caif_layer.h> 26#include <net/caif/caif_dev.h> 27#include <net/caif/cfpkt.h> 28 29MODULE_LICENSE("GPL"); 30MODULE_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 */ 37enum 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 46struct 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 56static 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 62static 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 68static 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 74static 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 80static 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 86static 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 92static 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 99static 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 106static 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 112static 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 */ 124static 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 */ 170static 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 186static 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 192static 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 */ 199static 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 259static 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 */ 276static 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; 303out_free: 304 skb_free_datagram(sk, skb); 305 caif_check_flow_release(sk); 306 return ret; 307 308read_error: 309 return ret; 310} 311 312 313/* Copied from unix_stream_wait_data, identical except for lock call. */ 314static 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 */ 348static 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 msg->msg_namelen = 0; 363 364 /* 365 * Lock the socket to prevent queue disordering 366 * while sleeps in memcpy_tomsg 367 */ 368 err = -EAGAIN; 369 if (sk->sk_state == CAIF_CONNECTING) 370 goto out; 371 372 caif_read_lock(sk); 373 target = sock_rcvlowat(sk, flags&MSG_WAITALL, size); 374 timeo = sock_rcvtimeo(sk, flags&MSG_DONTWAIT); 375 376 do { 377 int chunk; 378 struct sk_buff *skb; 379 380 lock_sock(sk); 381 skb = skb_dequeue(&sk->sk_receive_queue); 382 caif_check_flow_release(sk); 383 384 if (skb == NULL) { 385 if (copied >= target) 386 goto unlock; 387 /* 388 * POSIX 1003.1g mandates this order. 389 */ 390 err = sock_error(sk); 391 if (err) 392 goto unlock; 393 err = -ECONNRESET; 394 if (sk->sk_shutdown & RCV_SHUTDOWN) 395 goto unlock; 396 397 err = -EPIPE; 398 if (sk->sk_state != CAIF_CONNECTED) 399 goto unlock; 400 if (sock_flag(sk, SOCK_DEAD)) 401 goto unlock; 402 403 release_sock(sk); 404 405 err = -EAGAIN; 406 if (!timeo) 407 break; 408 409 caif_read_unlock(sk); 410 411 timeo = caif_stream_data_wait(sk, timeo); 412 413 if (signal_pending(current)) { 414 err = sock_intr_errno(timeo); 415 goto out; 416 } 417 caif_read_lock(sk); 418 continue; 419unlock: 420 release_sock(sk); 421 break; 422 } 423 release_sock(sk); 424 chunk = min_t(unsigned int, skb->len, size); 425 if (memcpy_toiovec(msg->msg_iov, skb->data, chunk)) { 426 skb_queue_head(&sk->sk_receive_queue, skb); 427 if (copied == 0) 428 copied = -EFAULT; 429 break; 430 } 431 copied += chunk; 432 size -= chunk; 433 434 /* Mark read part of skb as used */ 435 if (!(flags & MSG_PEEK)) { 436 skb_pull(skb, chunk); 437 438 /* put the skb back if we didn't use it up. */ 439 if (skb->len) { 440 skb_queue_head(&sk->sk_receive_queue, skb); 441 break; 442 } 443 kfree_skb(skb); 444 445 } else { 446 /* 447 * It is questionable, see note in unix_dgram_recvmsg. 448 */ 449 /* put message back and return */ 450 skb_queue_head(&sk->sk_receive_queue, skb); 451 break; 452 } 453 } while (size); 454 caif_read_unlock(sk); 455 456out: 457 return copied ? : err; 458} 459 460/* 461 * Copied from sock.c:sock_wait_for_wmem, but change to wait for 462 * CAIF flow-on and sock_writable. 463 */ 464static long caif_wait_for_flow_on(struct caifsock *cf_sk, 465 int wait_writeable, long timeo, int *err) 466{ 467 struct sock *sk = &cf_sk->sk; 468 DEFINE_WAIT(wait); 469 for (;;) { 470 *err = 0; 471 if (tx_flow_is_on(cf_sk) && 472 (!wait_writeable || sock_writeable(&cf_sk->sk))) 473 break; 474 *err = -ETIMEDOUT; 475 if (!timeo) 476 break; 477 *err = -ERESTARTSYS; 478 if (signal_pending(current)) 479 break; 480 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE); 481 *err = -ECONNRESET; 482 if (sk->sk_shutdown & SHUTDOWN_MASK) 483 break; 484 *err = -sk->sk_err; 485 if (sk->sk_err) 486 break; 487 *err = -EPIPE; 488 if (cf_sk->sk.sk_state != CAIF_CONNECTED) 489 break; 490 timeo = schedule_timeout(timeo); 491 } 492 finish_wait(sk_sleep(sk), &wait); 493 return timeo; 494} 495 496/* 497 * Transmit a SKB. The device may temporarily request re-transmission 498 * by returning EAGAIN. 499 */ 500static int transmit_skb(struct sk_buff *skb, struct caifsock *cf_sk, 501 int noblock, long timeo) 502{ 503 struct cfpkt *pkt; 504 505 pkt = cfpkt_fromnative(CAIF_DIR_OUT, skb); 506 memset(skb->cb, 0, sizeof(struct caif_payload_info)); 507 cfpkt_set_prio(pkt, cf_sk->sk.sk_priority); 508 509 if (cf_sk->layer.dn == NULL) { 510 kfree_skb(skb); 511 return -EINVAL; 512 } 513 514 return cf_sk->layer.dn->transmit(cf_sk->layer.dn, pkt); 515} 516 517/* Copied from af_unix:unix_dgram_sendmsg, and adapted to CAIF */ 518static int caif_seqpkt_sendmsg(struct kiocb *kiocb, struct socket *sock, 519 struct msghdr *msg, size_t len) 520{ 521 struct sock *sk = sock->sk; 522 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); 523 int buffer_size; 524 int ret = 0; 525 struct sk_buff *skb = NULL; 526 int noblock; 527 long timeo; 528 caif_assert(cf_sk); 529 ret = sock_error(sk); 530 if (ret) 531 goto err; 532 533 ret = -EOPNOTSUPP; 534 if (msg->msg_flags&MSG_OOB) 535 goto err; 536 537 ret = -EOPNOTSUPP; 538 if (msg->msg_namelen) 539 goto err; 540 541 ret = -EINVAL; 542 if (unlikely(msg->msg_iov->iov_base == NULL)) 543 goto err; 544 noblock = msg->msg_flags & MSG_DONTWAIT; 545 546 timeo = sock_sndtimeo(sk, noblock); 547 timeo = caif_wait_for_flow_on(container_of(sk, struct caifsock, sk), 548 1, timeo, &ret); 549 550 if (ret) 551 goto err; 552 ret = -EPIPE; 553 if (cf_sk->sk.sk_state != CAIF_CONNECTED || 554 sock_flag(sk, SOCK_DEAD) || 555 (sk->sk_shutdown & RCV_SHUTDOWN)) 556 goto err; 557 558 /* Error if trying to write more than maximum frame size. */ 559 ret = -EMSGSIZE; 560 if (len > cf_sk->maxframe && cf_sk->sk.sk_protocol != CAIFPROTO_RFM) 561 goto err; 562 563 buffer_size = len + cf_sk->headroom + cf_sk->tailroom; 564 565 ret = -ENOMEM; 566 skb = sock_alloc_send_skb(sk, buffer_size, noblock, &ret); 567 568 if (!skb || skb_tailroom(skb) < buffer_size) 569 goto err; 570 571 skb_reserve(skb, cf_sk->headroom); 572 573 ret = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len); 574 575 if (ret) 576 goto err; 577 ret = transmit_skb(skb, cf_sk, noblock, timeo); 578 if (ret < 0) 579 /* skb is already freed */ 580 return ret; 581 582 return len; 583err: 584 kfree_skb(skb); 585 return ret; 586} 587 588/* 589 * Copied from unix_stream_sendmsg and adapted to CAIF: 590 * Changed removed permission handling and added waiting for flow on 591 * and other minor adaptations. 592 */ 593static int caif_stream_sendmsg(struct kiocb *kiocb, struct socket *sock, 594 struct msghdr *msg, size_t len) 595{ 596 struct sock *sk = sock->sk; 597 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); 598 int err, size; 599 struct sk_buff *skb; 600 int sent = 0; 601 long timeo; 602 603 err = -EOPNOTSUPP; 604 if (unlikely(msg->msg_flags&MSG_OOB)) 605 goto out_err; 606 607 if (unlikely(msg->msg_namelen)) 608 goto out_err; 609 610 timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT); 611 timeo = caif_wait_for_flow_on(cf_sk, 1, timeo, &err); 612 613 if (unlikely(sk->sk_shutdown & SEND_SHUTDOWN)) 614 goto pipe_err; 615 616 while (sent < len) { 617 618 size = len-sent; 619 620 if (size > cf_sk->maxframe) 621 size = cf_sk->maxframe; 622 623 /* If size is more than half of sndbuf, chop up message */ 624 if (size > ((sk->sk_sndbuf >> 1) - 64)) 625 size = (sk->sk_sndbuf >> 1) - 64; 626 627 if (size > SKB_MAX_ALLOC) 628 size = SKB_MAX_ALLOC; 629 630 skb = sock_alloc_send_skb(sk, 631 size + cf_sk->headroom + 632 cf_sk->tailroom, 633 msg->msg_flags&MSG_DONTWAIT, 634 &err); 635 if (skb == NULL) 636 goto out_err; 637 638 skb_reserve(skb, cf_sk->headroom); 639 /* 640 * If you pass two values to the sock_alloc_send_skb 641 * it tries to grab the large buffer with GFP_NOFS 642 * (which can fail easily), and if it fails grab the 643 * fallback size buffer which is under a page and will 644 * succeed. [Alan] 645 */ 646 size = min_t(int, size, skb_tailroom(skb)); 647 648 err = memcpy_fromiovec(skb_put(skb, size), msg->msg_iov, size); 649 if (err) { 650 kfree_skb(skb); 651 goto out_err; 652 } 653 err = transmit_skb(skb, cf_sk, 654 msg->msg_flags&MSG_DONTWAIT, timeo); 655 if (err < 0) 656 /* skb is already freed */ 657 goto pipe_err; 658 659 sent += size; 660 } 661 662 return sent; 663 664pipe_err: 665 if (sent == 0 && !(msg->msg_flags&MSG_NOSIGNAL)) 666 send_sig(SIGPIPE, current, 0); 667 err = -EPIPE; 668out_err: 669 return sent ? : err; 670} 671 672static int setsockopt(struct socket *sock, 673 int lvl, int opt, char __user *ov, unsigned int ol) 674{ 675 struct sock *sk = sock->sk; 676 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); 677 int linksel; 678 679 if (cf_sk->sk.sk_socket->state != SS_UNCONNECTED) 680 return -ENOPROTOOPT; 681 682 switch (opt) { 683 case CAIFSO_LINK_SELECT: 684 if (ol < sizeof(int)) 685 return -EINVAL; 686 if (lvl != SOL_CAIF) 687 goto bad_sol; 688 if (copy_from_user(&linksel, ov, sizeof(int))) 689 return -EINVAL; 690 lock_sock(&(cf_sk->sk)); 691 cf_sk->conn_req.link_selector = linksel; 692 release_sock(&cf_sk->sk); 693 return 0; 694 695 case CAIFSO_REQ_PARAM: 696 if (lvl != SOL_CAIF) 697 goto bad_sol; 698 if (cf_sk->sk.sk_protocol != CAIFPROTO_UTIL) 699 return -ENOPROTOOPT; 700 lock_sock(&(cf_sk->sk)); 701 if (ol > sizeof(cf_sk->conn_req.param.data) || 702 copy_from_user(&cf_sk->conn_req.param.data, ov, ol)) { 703 release_sock(&cf_sk->sk); 704 return -EINVAL; 705 } 706 cf_sk->conn_req.param.size = ol; 707 release_sock(&cf_sk->sk); 708 return 0; 709 710 default: 711 return -ENOPROTOOPT; 712 } 713 714 return 0; 715bad_sol: 716 return -ENOPROTOOPT; 717 718} 719 720/* 721 * caif_connect() - Connect a CAIF Socket 722 * Copied and modified af_irda.c:irda_connect(). 723 * 724 * Note : by consulting "errno", the user space caller may learn the cause 725 * of the failure. Most of them are visible in the function, others may come 726 * from subroutines called and are listed here : 727 * o -EAFNOSUPPORT: bad socket family or type. 728 * o -ESOCKTNOSUPPORT: bad socket type or protocol 729 * o -EINVAL: bad socket address, or CAIF link type 730 * o -ECONNREFUSED: remote end refused the connection. 731 * o -EINPROGRESS: connect request sent but timed out (or non-blocking) 732 * o -EISCONN: already connected. 733 * o -ETIMEDOUT: Connection timed out (send timeout) 734 * o -ENODEV: No link layer to send request 735 * o -ECONNRESET: Received Shutdown indication or lost link layer 736 * o -ENOMEM: Out of memory 737 * 738 * State Strategy: 739 * o sk_state: holds the CAIF_* protocol state, it's updated by 740 * caif_ctrl_cb. 741 * o sock->state: holds the SS_* socket state and is updated by connect and 742 * disconnect. 743 */ 744static int caif_connect(struct socket *sock, struct sockaddr *uaddr, 745 int addr_len, int flags) 746{ 747 struct sock *sk = sock->sk; 748 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); 749 long timeo; 750 int err; 751 int ifindex, headroom, tailroom; 752 unsigned int mtu; 753 struct net_device *dev; 754 755 lock_sock(sk); 756 757 err = -EAFNOSUPPORT; 758 if (uaddr->sa_family != AF_CAIF) 759 goto out; 760 761 switch (sock->state) { 762 case SS_UNCONNECTED: 763 /* Normal case, a fresh connect */ 764 caif_assert(sk->sk_state == CAIF_DISCONNECTED); 765 break; 766 case SS_CONNECTING: 767 switch (sk->sk_state) { 768 case CAIF_CONNECTED: 769 sock->state = SS_CONNECTED; 770 err = -EISCONN; 771 goto out; 772 case CAIF_DISCONNECTED: 773 /* Reconnect allowed */ 774 break; 775 case CAIF_CONNECTING: 776 err = -EALREADY; 777 if (flags & O_NONBLOCK) 778 goto out; 779 goto wait_connect; 780 } 781 break; 782 case SS_CONNECTED: 783 caif_assert(sk->sk_state == CAIF_CONNECTED || 784 sk->sk_state == CAIF_DISCONNECTED); 785 if (sk->sk_shutdown & SHUTDOWN_MASK) { 786 /* Allow re-connect after SHUTDOWN_IND */ 787 caif_disconnect_client(sock_net(sk), &cf_sk->layer); 788 caif_free_client(&cf_sk->layer); 789 break; 790 } 791 /* No reconnect on a seqpacket socket */ 792 err = -EISCONN; 793 goto out; 794 case SS_DISCONNECTING: 795 case SS_FREE: 796 caif_assert(1); /*Should never happen */ 797 break; 798 } 799 sk->sk_state = CAIF_DISCONNECTED; 800 sock->state = SS_UNCONNECTED; 801 sk_stream_kill_queues(&cf_sk->sk); 802 803 err = -EINVAL; 804 if (addr_len != sizeof(struct sockaddr_caif)) 805 goto out; 806 807 memcpy(&cf_sk->conn_req.sockaddr, uaddr, 808 sizeof(struct sockaddr_caif)); 809 810 /* Move to connecting socket, start sending Connect Requests */ 811 sock->state = SS_CONNECTING; 812 sk->sk_state = CAIF_CONNECTING; 813 814 /* Check priority value comming from socket */ 815 /* if priority value is out of range it will be ajusted */ 816 if (cf_sk->sk.sk_priority > CAIF_PRIO_MAX) 817 cf_sk->conn_req.priority = CAIF_PRIO_MAX; 818 else if (cf_sk->sk.sk_priority < CAIF_PRIO_MIN) 819 cf_sk->conn_req.priority = CAIF_PRIO_MIN; 820 else 821 cf_sk->conn_req.priority = cf_sk->sk.sk_priority; 822 823 /*ifindex = id of the interface.*/ 824 cf_sk->conn_req.ifindex = cf_sk->sk.sk_bound_dev_if; 825 826 cf_sk->layer.receive = caif_sktrecv_cb; 827 828 err = caif_connect_client(sock_net(sk), &cf_sk->conn_req, 829 &cf_sk->layer, &ifindex, &headroom, &tailroom); 830 831 if (err < 0) { 832 cf_sk->sk.sk_socket->state = SS_UNCONNECTED; 833 cf_sk->sk.sk_state = CAIF_DISCONNECTED; 834 goto out; 835 } 836 837 err = -ENODEV; 838 rcu_read_lock(); 839 dev = dev_get_by_index_rcu(sock_net(sk), ifindex); 840 if (!dev) { 841 rcu_read_unlock(); 842 goto out; 843 } 844 cf_sk->headroom = LL_RESERVED_SPACE_EXTRA(dev, headroom); 845 mtu = dev->mtu; 846 rcu_read_unlock(); 847 848 cf_sk->tailroom = tailroom; 849 cf_sk->maxframe = mtu - (headroom + tailroom); 850 if (cf_sk->maxframe < 1) { 851 pr_warn("CAIF Interface MTU too small (%d)\n", dev->mtu); 852 err = -ENODEV; 853 goto out; 854 } 855 856 err = -EINPROGRESS; 857wait_connect: 858 859 if (sk->sk_state != CAIF_CONNECTED && (flags & O_NONBLOCK)) 860 goto out; 861 862 timeo = sock_sndtimeo(sk, flags & O_NONBLOCK); 863 864 release_sock(sk); 865 err = -ERESTARTSYS; 866 timeo = wait_event_interruptible_timeout(*sk_sleep(sk), 867 sk->sk_state != CAIF_CONNECTING, 868 timeo); 869 lock_sock(sk); 870 if (timeo < 0) 871 goto out; /* -ERESTARTSYS */ 872 873 err = -ETIMEDOUT; 874 if (timeo == 0 && sk->sk_state != CAIF_CONNECTED) 875 goto out; 876 if (sk->sk_state != CAIF_CONNECTED) { 877 sock->state = SS_UNCONNECTED; 878 err = sock_error(sk); 879 if (!err) 880 err = -ECONNREFUSED; 881 goto out; 882 } 883 sock->state = SS_CONNECTED; 884 err = 0; 885out: 886 release_sock(sk); 887 return err; 888} 889 890/* 891 * caif_release() - Disconnect a CAIF Socket 892 * Copied and modified af_irda.c:irda_release(). 893 */ 894static int caif_release(struct socket *sock) 895{ 896 struct sock *sk = sock->sk; 897 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); 898 899 if (!sk) 900 return 0; 901 902 set_tx_flow_off(cf_sk); 903 904 /* 905 * Ensure that packets are not queued after this point in time. 906 * caif_queue_rcv_skb checks SOCK_DEAD holding the queue lock, 907 * this ensures no packets when sock is dead. 908 */ 909 spin_lock_bh(&sk->sk_receive_queue.lock); 910 sock_set_flag(sk, SOCK_DEAD); 911 spin_unlock_bh(&sk->sk_receive_queue.lock); 912 sock->sk = NULL; 913 914 WARN_ON(IS_ERR(cf_sk->debugfs_socket_dir)); 915 if (cf_sk->debugfs_socket_dir != NULL) 916 debugfs_remove_recursive(cf_sk->debugfs_socket_dir); 917 918 lock_sock(&(cf_sk->sk)); 919 sk->sk_state = CAIF_DISCONNECTED; 920 sk->sk_shutdown = SHUTDOWN_MASK; 921 922 caif_disconnect_client(sock_net(sk), &cf_sk->layer); 923 cf_sk->sk.sk_socket->state = SS_DISCONNECTING; 924 wake_up_interruptible_poll(sk_sleep(sk), POLLERR|POLLHUP); 925 926 sock_orphan(sk); 927 sk_stream_kill_queues(&cf_sk->sk); 928 release_sock(sk); 929 sock_put(sk); 930 return 0; 931} 932 933/* Copied from af_unix.c:unix_poll(), added CAIF tx_flow handling */ 934static unsigned int caif_poll(struct file *file, 935 struct socket *sock, poll_table *wait) 936{ 937 struct sock *sk = sock->sk; 938 unsigned int mask; 939 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); 940 941 sock_poll_wait(file, sk_sleep(sk), wait); 942 mask = 0; 943 944 /* exceptional events? */ 945 if (sk->sk_err) 946 mask |= POLLERR; 947 if (sk->sk_shutdown == SHUTDOWN_MASK) 948 mask |= POLLHUP; 949 if (sk->sk_shutdown & RCV_SHUTDOWN) 950 mask |= POLLRDHUP; 951 952 /* readable? */ 953 if (!skb_queue_empty(&sk->sk_receive_queue) || 954 (sk->sk_shutdown & RCV_SHUTDOWN)) 955 mask |= POLLIN | POLLRDNORM; 956 957 /* 958 * we set writable also when the other side has shut down the 959 * connection. This prevents stuck sockets. 960 */ 961 if (sock_writeable(sk) && tx_flow_is_on(cf_sk)) 962 mask |= POLLOUT | POLLWRNORM | POLLWRBAND; 963 964 return mask; 965} 966 967static const struct proto_ops caif_seqpacket_ops = { 968 .family = PF_CAIF, 969 .owner = THIS_MODULE, 970 .release = caif_release, 971 .bind = sock_no_bind, 972 .connect = caif_connect, 973 .socketpair = sock_no_socketpair, 974 .accept = sock_no_accept, 975 .getname = sock_no_getname, 976 .poll = caif_poll, 977 .ioctl = sock_no_ioctl, 978 .listen = sock_no_listen, 979 .shutdown = sock_no_shutdown, 980 .setsockopt = setsockopt, 981 .getsockopt = sock_no_getsockopt, 982 .sendmsg = caif_seqpkt_sendmsg, 983 .recvmsg = caif_seqpkt_recvmsg, 984 .mmap = sock_no_mmap, 985 .sendpage = sock_no_sendpage, 986}; 987 988static const struct proto_ops caif_stream_ops = { 989 .family = PF_CAIF, 990 .owner = THIS_MODULE, 991 .release = caif_release, 992 .bind = sock_no_bind, 993 .connect = caif_connect, 994 .socketpair = sock_no_socketpair, 995 .accept = sock_no_accept, 996 .getname = sock_no_getname, 997 .poll = caif_poll, 998 .ioctl = sock_no_ioctl, 999 .listen = sock_no_listen, 1000 .shutdown = sock_no_shutdown, 1001 .setsockopt = setsockopt, 1002 .getsockopt = sock_no_getsockopt, 1003 .sendmsg = caif_stream_sendmsg, 1004 .recvmsg = caif_stream_recvmsg, 1005 .mmap = sock_no_mmap, 1006 .sendpage = sock_no_sendpage, 1007}; 1008 1009/* This function is called when a socket is finally destroyed. */ 1010static void caif_sock_destructor(struct sock *sk) 1011{ 1012 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); 1013 caif_assert(!atomic_read(&sk->sk_wmem_alloc)); 1014 caif_assert(sk_unhashed(sk)); 1015 caif_assert(!sk->sk_socket); 1016 if (!sock_flag(sk, SOCK_DEAD)) { 1017 pr_debug("Attempt to release alive CAIF socket: %p\n", sk); 1018 return; 1019 } 1020 sk_stream_kill_queues(&cf_sk->sk); 1021 caif_free_client(&cf_sk->layer); 1022} 1023 1024static int caif_create(struct net *net, struct socket *sock, int protocol, 1025 int kern) 1026{ 1027 struct sock *sk = NULL; 1028 struct caifsock *cf_sk = NULL; 1029 static struct proto prot = {.name = "PF_CAIF", 1030 .owner = THIS_MODULE, 1031 .obj_size = sizeof(struct caifsock), 1032 }; 1033 1034 if (!capable(CAP_SYS_ADMIN) && !capable(CAP_NET_ADMIN)) 1035 return -EPERM; 1036 /* 1037 * The sock->type specifies the socket type to use. 1038 * The CAIF socket is a packet stream in the sense 1039 * that it is packet based. CAIF trusts the reliability 1040 * of the link, no resending is implemented. 1041 */ 1042 if (sock->type == SOCK_SEQPACKET) 1043 sock->ops = &caif_seqpacket_ops; 1044 else if (sock->type == SOCK_STREAM) 1045 sock->ops = &caif_stream_ops; 1046 else 1047 return -ESOCKTNOSUPPORT; 1048 1049 if (protocol < 0 || protocol >= CAIFPROTO_MAX) 1050 return -EPROTONOSUPPORT; 1051 /* 1052 * Set the socket state to unconnected. The socket state 1053 * is really not used at all in the net/core or socket.c but the 1054 * initialization makes sure that sock->state is not uninitialized. 1055 */ 1056 sk = sk_alloc(net, PF_CAIF, GFP_KERNEL, &prot); 1057 if (!sk) 1058 return -ENOMEM; 1059 1060 cf_sk = container_of(sk, struct caifsock, sk); 1061 1062 /* Store the protocol */ 1063 sk->sk_protocol = (unsigned char) protocol; 1064 1065 /* Initialize default priority for well-known cases */ 1066 switch (protocol) { 1067 case CAIFPROTO_AT: 1068 sk->sk_priority = TC_PRIO_CONTROL; 1069 break; 1070 case CAIFPROTO_RFM: 1071 sk->sk_priority = TC_PRIO_INTERACTIVE_BULK; 1072 break; 1073 default: 1074 sk->sk_priority = TC_PRIO_BESTEFFORT; 1075 } 1076 1077 /* 1078 * Lock in order to try to stop someone from opening the socket 1079 * too early. 1080 */ 1081 lock_sock(&(cf_sk->sk)); 1082 1083 /* Initialize the nozero default sock structure data. */ 1084 sock_init_data(sock, sk); 1085 sk->sk_destruct = caif_sock_destructor; 1086 1087 mutex_init(&cf_sk->readlock); /* single task reading lock */ 1088 cf_sk->layer.ctrlcmd = caif_ctrl_cb; 1089 cf_sk->sk.sk_socket->state = SS_UNCONNECTED; 1090 cf_sk->sk.sk_state = CAIF_DISCONNECTED; 1091 1092 set_tx_flow_off(cf_sk); 1093 set_rx_flow_on(cf_sk); 1094 1095 /* Set default options on configuration */ 1096 cf_sk->conn_req.link_selector = CAIF_LINK_LOW_LATENCY; 1097 cf_sk->conn_req.protocol = protocol; 1098 release_sock(&cf_sk->sk); 1099 return 0; 1100} 1101 1102 1103static struct net_proto_family caif_family_ops = { 1104 .family = PF_CAIF, 1105 .create = caif_create, 1106 .owner = THIS_MODULE, 1107}; 1108 1109static int __init caif_sktinit_module(void) 1110{ 1111 int err = sock_register(&caif_family_ops); 1112 if (!err) 1113 return err; 1114 return 0; 1115} 1116 1117static void __exit caif_sktexit_module(void) 1118{ 1119 sock_unregister(PF_CAIF); 1120} 1121module_init(caif_sktinit_module); 1122module_exit(caif_sktexit_module); 1123