caif_socket.c revision f2527ec436fd675f08a8e7434f6e940688cb96d0
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 <asm/atomic.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 46static struct dentry *debugfsdir; 47 48#ifdef CONFIG_DEBUG_FS 49struct debug_fs_counter { 50 atomic_t caif_nr_socks; 51 atomic_t num_connect_req; 52 atomic_t num_connect_resp; 53 atomic_t num_connect_fail_resp; 54 atomic_t num_disconnect; 55 atomic_t num_remote_shutdown_ind; 56 atomic_t num_tx_flow_off_ind; 57 atomic_t num_tx_flow_on_ind; 58 atomic_t num_rx_flow_off; 59 atomic_t num_rx_flow_on; 60}; 61static struct debug_fs_counter cnt; 62#define dbfs_atomic_inc(v) atomic_inc(v) 63#define dbfs_atomic_dec(v) atomic_dec(v) 64#else 65#define dbfs_atomic_inc(v) 66#define dbfs_atomic_dec(v) 67#endif 68 69struct caifsock { 70 struct sock sk; /* must be first member */ 71 struct cflayer layer; 72 char name[CAIF_LAYER_NAME_SZ]; /* Used for debugging */ 73 u32 flow_state; 74 struct caif_connect_request conn_req; 75 struct mutex readlock; 76 struct dentry *debugfs_socket_dir; 77 int headroom, tailroom, maxframe; 78}; 79 80static int rx_flow_is_on(struct caifsock *cf_sk) 81{ 82 return test_bit(RX_FLOW_ON_BIT, 83 (void *) &cf_sk->flow_state); 84} 85 86static int tx_flow_is_on(struct caifsock *cf_sk) 87{ 88 return test_bit(TX_FLOW_ON_BIT, 89 (void *) &cf_sk->flow_state); 90} 91 92static void set_rx_flow_off(struct caifsock *cf_sk) 93{ 94 clear_bit(RX_FLOW_ON_BIT, 95 (void *) &cf_sk->flow_state); 96} 97 98static void set_rx_flow_on(struct caifsock *cf_sk) 99{ 100 set_bit(RX_FLOW_ON_BIT, 101 (void *) &cf_sk->flow_state); 102} 103 104static void set_tx_flow_off(struct caifsock *cf_sk) 105{ 106 clear_bit(TX_FLOW_ON_BIT, 107 (void *) &cf_sk->flow_state); 108} 109 110static void set_tx_flow_on(struct caifsock *cf_sk) 111{ 112 set_bit(TX_FLOW_ON_BIT, 113 (void *) &cf_sk->flow_state); 114} 115 116static void caif_read_lock(struct sock *sk) 117{ 118 struct caifsock *cf_sk; 119 cf_sk = container_of(sk, struct caifsock, sk); 120 mutex_lock(&cf_sk->readlock); 121} 122 123static void caif_read_unlock(struct sock *sk) 124{ 125 struct caifsock *cf_sk; 126 cf_sk = container_of(sk, struct caifsock, sk); 127 mutex_unlock(&cf_sk->readlock); 128} 129 130static int sk_rcvbuf_lowwater(struct caifsock *cf_sk) 131{ 132 /* A quarter of full buffer is used a low water mark */ 133 return cf_sk->sk.sk_rcvbuf / 4; 134} 135 136static void caif_flow_ctrl(struct sock *sk, int mode) 137{ 138 struct caifsock *cf_sk; 139 cf_sk = container_of(sk, struct caifsock, sk); 140 if (cf_sk->layer.dn && cf_sk->layer.dn->modemcmd) 141 cf_sk->layer.dn->modemcmd(cf_sk->layer.dn, mode); 142} 143 144/* 145 * Copied from sock.c:sock_queue_rcv_skb(), but changed so packets are 146 * not dropped, but CAIF is sending flow off instead. 147 */ 148static int caif_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) 149{ 150 int err; 151 int skb_len; 152 unsigned long flags; 153 struct sk_buff_head *list = &sk->sk_receive_queue; 154 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); 155 156 if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >= 157 (unsigned)sk->sk_rcvbuf && rx_flow_is_on(cf_sk)) { 158 pr_debug("sending flow OFF (queue len = %d %d)\n", 159 atomic_read(&cf_sk->sk.sk_rmem_alloc), 160 sk_rcvbuf_lowwater(cf_sk)); 161 set_rx_flow_off(cf_sk); 162 dbfs_atomic_inc(&cnt.num_rx_flow_off); 163 caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_OFF_REQ); 164 } 165 166 err = sk_filter(sk, skb); 167 if (err) 168 return err; 169 if (!sk_rmem_schedule(sk, skb->truesize) && rx_flow_is_on(cf_sk)) { 170 set_rx_flow_off(cf_sk); 171 pr_debug("sending flow OFF due to rmem_schedule\n"); 172 dbfs_atomic_inc(&cnt.num_rx_flow_off); 173 caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_OFF_REQ); 174 } 175 skb->dev = NULL; 176 skb_set_owner_r(skb, sk); 177 /* Cache the SKB length before we tack it onto the receive 178 * queue. Once it is added it no longer belongs to us and 179 * may be freed by other threads of control pulling packets 180 * from the queue. 181 */ 182 skb_len = skb->len; 183 spin_lock_irqsave(&list->lock, flags); 184 if (!sock_flag(sk, SOCK_DEAD)) 185 __skb_queue_tail(list, skb); 186 spin_unlock_irqrestore(&list->lock, flags); 187 188 if (!sock_flag(sk, SOCK_DEAD)) 189 sk->sk_data_ready(sk, skb_len); 190 else 191 kfree_skb(skb); 192 return 0; 193} 194 195/* Packet Receive Callback function called from CAIF Stack */ 196static int caif_sktrecv_cb(struct cflayer *layr, struct cfpkt *pkt) 197{ 198 struct caifsock *cf_sk; 199 struct sk_buff *skb; 200 201 cf_sk = container_of(layr, struct caifsock, layer); 202 skb = cfpkt_tonative(pkt); 203 204 if (unlikely(cf_sk->sk.sk_state != CAIF_CONNECTED)) { 205 cfpkt_destroy(pkt); 206 return 0; 207 } 208 caif_queue_rcv_skb(&cf_sk->sk, skb); 209 return 0; 210} 211 212/* Packet Control Callback function called from CAIF */ 213static void caif_ctrl_cb(struct cflayer *layr, 214 enum caif_ctrlcmd flow, 215 int phyid) 216{ 217 struct caifsock *cf_sk = container_of(layr, struct caifsock, layer); 218 switch (flow) { 219 case CAIF_CTRLCMD_FLOW_ON_IND: 220 /* OK from modem to start sending again */ 221 dbfs_atomic_inc(&cnt.num_tx_flow_on_ind); 222 set_tx_flow_on(cf_sk); 223 cf_sk->sk.sk_state_change(&cf_sk->sk); 224 break; 225 226 case CAIF_CTRLCMD_FLOW_OFF_IND: 227 /* Modem asks us to shut up */ 228 dbfs_atomic_inc(&cnt.num_tx_flow_off_ind); 229 set_tx_flow_off(cf_sk); 230 cf_sk->sk.sk_state_change(&cf_sk->sk); 231 break; 232 233 case CAIF_CTRLCMD_INIT_RSP: 234 /* We're now connected */ 235 dbfs_atomic_inc(&cnt.num_connect_resp); 236 cf_sk->sk.sk_state = CAIF_CONNECTED; 237 set_tx_flow_on(cf_sk); 238 cf_sk->sk.sk_state_change(&cf_sk->sk); 239 break; 240 241 case CAIF_CTRLCMD_DEINIT_RSP: 242 /* We're now disconnected */ 243 cf_sk->sk.sk_state = CAIF_DISCONNECTED; 244 cf_sk->sk.sk_state_change(&cf_sk->sk); 245 cfcnfg_release_adap_layer(&cf_sk->layer); 246 break; 247 248 case CAIF_CTRLCMD_INIT_FAIL_RSP: 249 /* Connect request failed */ 250 dbfs_atomic_inc(&cnt.num_connect_fail_resp); 251 cf_sk->sk.sk_err = ECONNREFUSED; 252 cf_sk->sk.sk_state = CAIF_DISCONNECTED; 253 cf_sk->sk.sk_shutdown = SHUTDOWN_MASK; 254 /* 255 * Socket "standards" seems to require POLLOUT to 256 * be set at connect failure. 257 */ 258 set_tx_flow_on(cf_sk); 259 cf_sk->sk.sk_state_change(&cf_sk->sk); 260 break; 261 262 case CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND: 263 /* Modem has closed this connection, or device is down. */ 264 dbfs_atomic_inc(&cnt.num_remote_shutdown_ind); 265 cf_sk->sk.sk_shutdown = SHUTDOWN_MASK; 266 cf_sk->sk.sk_err = ECONNRESET; 267 set_rx_flow_on(cf_sk); 268 cf_sk->sk.sk_error_report(&cf_sk->sk); 269 break; 270 271 default: 272 pr_debug("Unexpected flow command %d\n", flow); 273 } 274} 275 276static void caif_check_flow_release(struct sock *sk) 277{ 278 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); 279 280 if (rx_flow_is_on(cf_sk)) 281 return; 282 283 if (atomic_read(&sk->sk_rmem_alloc) <= sk_rcvbuf_lowwater(cf_sk)) { 284 dbfs_atomic_inc(&cnt.num_rx_flow_on); 285 set_rx_flow_on(cf_sk); 286 caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_ON_REQ); 287 } 288} 289 290/* 291 * Copied from unix_dgram_recvmsg, but removed credit checks, 292 * changed locking, address handling and added MSG_TRUNC. 293 */ 294static int caif_seqpkt_recvmsg(struct kiocb *iocb, struct socket *sock, 295 struct msghdr *m, size_t len, int flags) 296 297{ 298 struct sock *sk = sock->sk; 299 struct sk_buff *skb; 300 int ret; 301 int copylen; 302 303 ret = -EOPNOTSUPP; 304 if (m->msg_flags&MSG_OOB) 305 goto read_error; 306 307 skb = skb_recv_datagram(sk, flags, 0 , &ret); 308 if (!skb) 309 goto read_error; 310 copylen = skb->len; 311 if (len < copylen) { 312 m->msg_flags |= MSG_TRUNC; 313 copylen = len; 314 } 315 316 ret = skb_copy_datagram_iovec(skb, 0, m->msg_iov, copylen); 317 if (ret) 318 goto out_free; 319 320 ret = (flags & MSG_TRUNC) ? skb->len : copylen; 321out_free: 322 skb_free_datagram(sk, skb); 323 caif_check_flow_release(sk); 324 return ret; 325 326read_error: 327 return ret; 328} 329 330 331/* Copied from unix_stream_wait_data, identical except for lock call. */ 332static long caif_stream_data_wait(struct sock *sk, long timeo) 333{ 334 DEFINE_WAIT(wait); 335 lock_sock(sk); 336 337 for (;;) { 338 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE); 339 340 if (!skb_queue_empty(&sk->sk_receive_queue) || 341 sk->sk_err || 342 sk->sk_state != CAIF_CONNECTED || 343 sock_flag(sk, SOCK_DEAD) || 344 (sk->sk_shutdown & RCV_SHUTDOWN) || 345 signal_pending(current) || 346 !timeo) 347 break; 348 349 set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags); 350 release_sock(sk); 351 timeo = schedule_timeout(timeo); 352 lock_sock(sk); 353 clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags); 354 } 355 356 finish_wait(sk_sleep(sk), &wait); 357 release_sock(sk); 358 return timeo; 359} 360 361 362/* 363 * Copied from unix_stream_recvmsg, but removed credit checks, 364 * changed locking calls, changed address handling. 365 */ 366static int caif_stream_recvmsg(struct kiocb *iocb, struct socket *sock, 367 struct msghdr *msg, size_t size, 368 int flags) 369{ 370 struct sock *sk = sock->sk; 371 int copied = 0; 372 int target; 373 int err = 0; 374 long timeo; 375 376 err = -EOPNOTSUPP; 377 if (flags&MSG_OOB) 378 goto out; 379 380 msg->msg_namelen = 0; 381 382 /* 383 * Lock the socket to prevent queue disordering 384 * while sleeps in memcpy_tomsg 385 */ 386 err = -EAGAIN; 387 if (sk->sk_state == CAIF_CONNECTING) 388 goto out; 389 390 caif_read_lock(sk); 391 target = sock_rcvlowat(sk, flags&MSG_WAITALL, size); 392 timeo = sock_rcvtimeo(sk, flags&MSG_DONTWAIT); 393 394 do { 395 int chunk; 396 struct sk_buff *skb; 397 398 lock_sock(sk); 399 skb = skb_dequeue(&sk->sk_receive_queue); 400 caif_check_flow_release(sk); 401 402 if (skb == NULL) { 403 if (copied >= target) 404 goto unlock; 405 /* 406 * POSIX 1003.1g mandates this order. 407 */ 408 err = sock_error(sk); 409 if (err) 410 goto unlock; 411 err = -ECONNRESET; 412 if (sk->sk_shutdown & RCV_SHUTDOWN) 413 goto unlock; 414 415 err = -EPIPE; 416 if (sk->sk_state != CAIF_CONNECTED) 417 goto unlock; 418 if (sock_flag(sk, SOCK_DEAD)) 419 goto unlock; 420 421 release_sock(sk); 422 423 err = -EAGAIN; 424 if (!timeo) 425 break; 426 427 caif_read_unlock(sk); 428 429 timeo = caif_stream_data_wait(sk, timeo); 430 431 if (signal_pending(current)) { 432 err = sock_intr_errno(timeo); 433 goto out; 434 } 435 caif_read_lock(sk); 436 continue; 437unlock: 438 release_sock(sk); 439 break; 440 } 441 release_sock(sk); 442 chunk = min_t(unsigned int, skb->len, size); 443 if (memcpy_toiovec(msg->msg_iov, skb->data, chunk)) { 444 skb_queue_head(&sk->sk_receive_queue, skb); 445 if (copied == 0) 446 copied = -EFAULT; 447 break; 448 } 449 copied += chunk; 450 size -= chunk; 451 452 /* Mark read part of skb as used */ 453 if (!(flags & MSG_PEEK)) { 454 skb_pull(skb, chunk); 455 456 /* put the skb back if we didn't use it up. */ 457 if (skb->len) { 458 skb_queue_head(&sk->sk_receive_queue, skb); 459 break; 460 } 461 kfree_skb(skb); 462 463 } else { 464 /* 465 * It is questionable, see note in unix_dgram_recvmsg. 466 */ 467 /* put message back and return */ 468 skb_queue_head(&sk->sk_receive_queue, skb); 469 break; 470 } 471 } while (size); 472 caif_read_unlock(sk); 473 474out: 475 return copied ? : err; 476} 477 478/* 479 * Copied from sock.c:sock_wait_for_wmem, but change to wait for 480 * CAIF flow-on and sock_writable. 481 */ 482static long caif_wait_for_flow_on(struct caifsock *cf_sk, 483 int wait_writeable, long timeo, int *err) 484{ 485 struct sock *sk = &cf_sk->sk; 486 DEFINE_WAIT(wait); 487 for (;;) { 488 *err = 0; 489 if (tx_flow_is_on(cf_sk) && 490 (!wait_writeable || sock_writeable(&cf_sk->sk))) 491 break; 492 *err = -ETIMEDOUT; 493 if (!timeo) 494 break; 495 *err = -ERESTARTSYS; 496 if (signal_pending(current)) 497 break; 498 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE); 499 *err = -ECONNRESET; 500 if (sk->sk_shutdown & SHUTDOWN_MASK) 501 break; 502 *err = -sk->sk_err; 503 if (sk->sk_err) 504 break; 505 *err = -EPIPE; 506 if (cf_sk->sk.sk_state != CAIF_CONNECTED) 507 break; 508 timeo = schedule_timeout(timeo); 509 } 510 finish_wait(sk_sleep(sk), &wait); 511 return timeo; 512} 513 514/* 515 * Transmit a SKB. The device may temporarily request re-transmission 516 * by returning EAGAIN. 517 */ 518static int transmit_skb(struct sk_buff *skb, struct caifsock *cf_sk, 519 int noblock, long timeo) 520{ 521 struct cfpkt *pkt; 522 int ret, loopcnt = 0; 523 524 pkt = cfpkt_fromnative(CAIF_DIR_OUT, skb); 525 memset(cfpkt_info(pkt), 0, sizeof(struct caif_payload_info)); 526 do { 527 528 ret = -ETIMEDOUT; 529 530 /* Slight paranoia, probably not needed. */ 531 if (unlikely(loopcnt++ > 1000)) { 532 pr_warn("transmit retries failed, error = %d\n", ret); 533 break; 534 } 535 536 if (cf_sk->layer.dn != NULL) 537 ret = cf_sk->layer.dn->transmit(cf_sk->layer.dn, pkt); 538 if (likely(ret >= 0)) 539 break; 540 /* if transmit return -EAGAIN, then retry */ 541 if (noblock && ret == -EAGAIN) 542 break; 543 timeo = caif_wait_for_flow_on(cf_sk, 0, timeo, &ret); 544 if (signal_pending(current)) { 545 ret = sock_intr_errno(timeo); 546 break; 547 } 548 if (ret) 549 break; 550 if (cf_sk->sk.sk_state != CAIF_CONNECTED || 551 sock_flag(&cf_sk->sk, SOCK_DEAD) || 552 (cf_sk->sk.sk_shutdown & RCV_SHUTDOWN)) { 553 ret = -EPIPE; 554 cf_sk->sk.sk_err = EPIPE; 555 break; 556 } 557 } while (ret == -EAGAIN); 558 return ret; 559} 560 561/* Copied from af_unix:unix_dgram_sendmsg, and adapted to CAIF */ 562static int caif_seqpkt_sendmsg(struct kiocb *kiocb, struct socket *sock, 563 struct msghdr *msg, size_t len) 564{ 565 struct sock *sk = sock->sk; 566 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); 567 int buffer_size; 568 int ret = 0; 569 struct sk_buff *skb = NULL; 570 int noblock; 571 long timeo; 572 caif_assert(cf_sk); 573 ret = sock_error(sk); 574 if (ret) 575 goto err; 576 577 ret = -EOPNOTSUPP; 578 if (msg->msg_flags&MSG_OOB) 579 goto err; 580 581 ret = -EOPNOTSUPP; 582 if (msg->msg_namelen) 583 goto err; 584 585 ret = -EINVAL; 586 if (unlikely(msg->msg_iov->iov_base == NULL)) 587 goto err; 588 noblock = msg->msg_flags & MSG_DONTWAIT; 589 590 timeo = sock_sndtimeo(sk, noblock); 591 timeo = caif_wait_for_flow_on(container_of(sk, struct caifsock, sk), 592 1, timeo, &ret); 593 594 if (ret) 595 goto err; 596 ret = -EPIPE; 597 if (cf_sk->sk.sk_state != CAIF_CONNECTED || 598 sock_flag(sk, SOCK_DEAD) || 599 (sk->sk_shutdown & RCV_SHUTDOWN)) 600 goto err; 601 602 /* Error if trying to write more than maximum frame size. */ 603 ret = -EMSGSIZE; 604 if (len > cf_sk->maxframe && cf_sk->sk.sk_protocol != CAIFPROTO_RFM) 605 goto err; 606 607 buffer_size = len + cf_sk->headroom + cf_sk->tailroom; 608 609 ret = -ENOMEM; 610 skb = sock_alloc_send_skb(sk, buffer_size, noblock, &ret); 611 612 if (!skb || skb_tailroom(skb) < buffer_size) 613 goto err; 614 615 skb_reserve(skb, cf_sk->headroom); 616 617 ret = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len); 618 619 if (ret) 620 goto err; 621 ret = transmit_skb(skb, cf_sk, noblock, timeo); 622 if (ret < 0) 623 goto err; 624 return len; 625err: 626 kfree_skb(skb); 627 return ret; 628} 629 630/* 631 * Copied from unix_stream_sendmsg and adapted to CAIF: 632 * Changed removed permission handling and added waiting for flow on 633 * and other minor adaptations. 634 */ 635static int caif_stream_sendmsg(struct kiocb *kiocb, struct socket *sock, 636 struct msghdr *msg, size_t len) 637{ 638 struct sock *sk = sock->sk; 639 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); 640 int err, size; 641 struct sk_buff *skb; 642 int sent = 0; 643 long timeo; 644 645 err = -EOPNOTSUPP; 646 if (unlikely(msg->msg_flags&MSG_OOB)) 647 goto out_err; 648 649 if (unlikely(msg->msg_namelen)) 650 goto out_err; 651 652 timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT); 653 timeo = caif_wait_for_flow_on(cf_sk, 1, timeo, &err); 654 655 if (unlikely(sk->sk_shutdown & SEND_SHUTDOWN)) 656 goto pipe_err; 657 658 while (sent < len) { 659 660 size = len-sent; 661 662 if (size > cf_sk->maxframe) 663 size = cf_sk->maxframe; 664 665 /* If size is more than half of sndbuf, chop up message */ 666 if (size > ((sk->sk_sndbuf >> 1) - 64)) 667 size = (sk->sk_sndbuf >> 1) - 64; 668 669 if (size > SKB_MAX_ALLOC) 670 size = SKB_MAX_ALLOC; 671 672 skb = sock_alloc_send_skb(sk, 673 size + cf_sk->headroom + 674 cf_sk->tailroom, 675 msg->msg_flags&MSG_DONTWAIT, 676 &err); 677 if (skb == NULL) 678 goto out_err; 679 680 skb_reserve(skb, cf_sk->headroom); 681 /* 682 * If you pass two values to the sock_alloc_send_skb 683 * it tries to grab the large buffer with GFP_NOFS 684 * (which can fail easily), and if it fails grab the 685 * fallback size buffer which is under a page and will 686 * succeed. [Alan] 687 */ 688 size = min_t(int, size, skb_tailroom(skb)); 689 690 err = memcpy_fromiovec(skb_put(skb, size), msg->msg_iov, size); 691 if (err) { 692 kfree_skb(skb); 693 goto out_err; 694 } 695 err = transmit_skb(skb, cf_sk, 696 msg->msg_flags&MSG_DONTWAIT, timeo); 697 if (err < 0) { 698 kfree_skb(skb); 699 goto pipe_err; 700 } 701 sent += size; 702 } 703 704 return sent; 705 706pipe_err: 707 if (sent == 0 && !(msg->msg_flags&MSG_NOSIGNAL)) 708 send_sig(SIGPIPE, current, 0); 709 err = -EPIPE; 710out_err: 711 return sent ? : err; 712} 713 714static int setsockopt(struct socket *sock, 715 int lvl, int opt, char __user *ov, unsigned int ol) 716{ 717 struct sock *sk = sock->sk; 718 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); 719 int linksel; 720 721 if (cf_sk->sk.sk_socket->state != SS_UNCONNECTED) 722 return -ENOPROTOOPT; 723 724 switch (opt) { 725 case CAIFSO_LINK_SELECT: 726 if (ol < sizeof(int)) 727 return -EINVAL; 728 if (lvl != SOL_CAIF) 729 goto bad_sol; 730 if (copy_from_user(&linksel, ov, sizeof(int))) 731 return -EINVAL; 732 lock_sock(&(cf_sk->sk)); 733 cf_sk->conn_req.link_selector = linksel; 734 release_sock(&cf_sk->sk); 735 return 0; 736 737 case CAIFSO_REQ_PARAM: 738 if (lvl != SOL_CAIF) 739 goto bad_sol; 740 if (cf_sk->sk.sk_protocol != CAIFPROTO_UTIL) 741 return -ENOPROTOOPT; 742 lock_sock(&(cf_sk->sk)); 743 cf_sk->conn_req.param.size = ol; 744 if (ol > sizeof(cf_sk->conn_req.param.data) || 745 copy_from_user(&cf_sk->conn_req.param.data, ov, ol)) { 746 release_sock(&cf_sk->sk); 747 return -EINVAL; 748 } 749 release_sock(&cf_sk->sk); 750 return 0; 751 752 default: 753 return -ENOPROTOOPT; 754 } 755 756 return 0; 757bad_sol: 758 return -ENOPROTOOPT; 759 760} 761 762/* 763 * caif_connect() - Connect a CAIF Socket 764 * Copied and modified af_irda.c:irda_connect(). 765 * 766 * Note : by consulting "errno", the user space caller may learn the cause 767 * of the failure. Most of them are visible in the function, others may come 768 * from subroutines called and are listed here : 769 * o -EAFNOSUPPORT: bad socket family or type. 770 * o -ESOCKTNOSUPPORT: bad socket type or protocol 771 * o -EINVAL: bad socket address, or CAIF link type 772 * o -ECONNREFUSED: remote end refused the connection. 773 * o -EINPROGRESS: connect request sent but timed out (or non-blocking) 774 * o -EISCONN: already connected. 775 * o -ETIMEDOUT: Connection timed out (send timeout) 776 * o -ENODEV: No link layer to send request 777 * o -ECONNRESET: Received Shutdown indication or lost link layer 778 * o -ENOMEM: Out of memory 779 * 780 * State Strategy: 781 * o sk_state: holds the CAIF_* protocol state, it's updated by 782 * caif_ctrl_cb. 783 * o sock->state: holds the SS_* socket state and is updated by connect and 784 * disconnect. 785 */ 786static int caif_connect(struct socket *sock, struct sockaddr *uaddr, 787 int addr_len, int flags) 788{ 789 struct sock *sk = sock->sk; 790 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); 791 long timeo; 792 int err; 793 int ifindex, headroom, tailroom; 794 unsigned int mtu; 795 struct net_device *dev; 796 797 lock_sock(sk); 798 799 err = -EAFNOSUPPORT; 800 if (uaddr->sa_family != AF_CAIF) 801 goto out; 802 803 switch (sock->state) { 804 case SS_UNCONNECTED: 805 /* Normal case, a fresh connect */ 806 caif_assert(sk->sk_state == CAIF_DISCONNECTED); 807 break; 808 case SS_CONNECTING: 809 switch (sk->sk_state) { 810 case CAIF_CONNECTED: 811 sock->state = SS_CONNECTED; 812 err = -EISCONN; 813 goto out; 814 case CAIF_DISCONNECTED: 815 /* Reconnect allowed */ 816 break; 817 case CAIF_CONNECTING: 818 err = -EALREADY; 819 if (flags & O_NONBLOCK) 820 goto out; 821 goto wait_connect; 822 } 823 break; 824 case SS_CONNECTED: 825 caif_assert(sk->sk_state == CAIF_CONNECTED || 826 sk->sk_state == CAIF_DISCONNECTED); 827 if (sk->sk_shutdown & SHUTDOWN_MASK) { 828 /* Allow re-connect after SHUTDOWN_IND */ 829 caif_disconnect_client(&cf_sk->layer); 830 break; 831 } 832 /* No reconnect on a seqpacket socket */ 833 err = -EISCONN; 834 goto out; 835 case SS_DISCONNECTING: 836 case SS_FREE: 837 caif_assert(1); /*Should never happen */ 838 break; 839 } 840 sk->sk_state = CAIF_DISCONNECTED; 841 sock->state = SS_UNCONNECTED; 842 sk_stream_kill_queues(&cf_sk->sk); 843 844 err = -EINVAL; 845 if (addr_len != sizeof(struct sockaddr_caif)) 846 goto out; 847 848 memcpy(&cf_sk->conn_req.sockaddr, uaddr, 849 sizeof(struct sockaddr_caif)); 850 851 /* Move to connecting socket, start sending Connect Requests */ 852 sock->state = SS_CONNECTING; 853 sk->sk_state = CAIF_CONNECTING; 854 855 /* Check priority value comming from socket */ 856 /* if priority value is out of range it will be ajusted */ 857 if (cf_sk->sk.sk_priority > CAIF_PRIO_MAX) 858 cf_sk->conn_req.priority = CAIF_PRIO_MAX; 859 else if (cf_sk->sk.sk_priority < CAIF_PRIO_MIN) 860 cf_sk->conn_req.priority = CAIF_PRIO_MIN; 861 else 862 cf_sk->conn_req.priority = cf_sk->sk.sk_priority; 863 864 /*ifindex = id of the interface.*/ 865 cf_sk->conn_req.ifindex = cf_sk->sk.sk_bound_dev_if; 866 867 dbfs_atomic_inc(&cnt.num_connect_req); 868 cf_sk->layer.receive = caif_sktrecv_cb; 869 err = caif_connect_client(&cf_sk->conn_req, 870 &cf_sk->layer, &ifindex, &headroom, &tailroom); 871 if (err < 0) { 872 cf_sk->sk.sk_socket->state = SS_UNCONNECTED; 873 cf_sk->sk.sk_state = CAIF_DISCONNECTED; 874 goto out; 875 } 876 877 err = -ENODEV; 878 rcu_read_lock(); 879 dev = dev_get_by_index_rcu(sock_net(sk), ifindex); 880 if (!dev) { 881 rcu_read_unlock(); 882 goto out; 883 } 884 cf_sk->headroom = LL_RESERVED_SPACE_EXTRA(dev, headroom); 885 mtu = dev->mtu; 886 rcu_read_unlock(); 887 888 cf_sk->tailroom = tailroom; 889 cf_sk->maxframe = mtu - (headroom + tailroom); 890 if (cf_sk->maxframe < 1) { 891 pr_warn("CAIF Interface MTU too small (%d)\n", dev->mtu); 892 err = -ENODEV; 893 goto out; 894 } 895 896 err = -EINPROGRESS; 897wait_connect: 898 899 if (sk->sk_state != CAIF_CONNECTED && (flags & O_NONBLOCK)) 900 goto out; 901 902 timeo = sock_sndtimeo(sk, flags & O_NONBLOCK); 903 904 release_sock(sk); 905 err = -ERESTARTSYS; 906 timeo = wait_event_interruptible_timeout(*sk_sleep(sk), 907 sk->sk_state != CAIF_CONNECTING, 908 timeo); 909 lock_sock(sk); 910 if (timeo < 0) 911 goto out; /* -ERESTARTSYS */ 912 913 err = -ETIMEDOUT; 914 if (timeo == 0 && sk->sk_state != CAIF_CONNECTED) 915 goto out; 916 if (sk->sk_state != CAIF_CONNECTED) { 917 sock->state = SS_UNCONNECTED; 918 err = sock_error(sk); 919 if (!err) 920 err = -ECONNREFUSED; 921 goto out; 922 } 923 sock->state = SS_CONNECTED; 924 err = 0; 925out: 926 release_sock(sk); 927 return err; 928} 929 930/* 931 * caif_release() - Disconnect a CAIF Socket 932 * Copied and modified af_irda.c:irda_release(). 933 */ 934static int caif_release(struct socket *sock) 935{ 936 struct sock *sk = sock->sk; 937 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); 938 int res = 0; 939 940 if (!sk) 941 return 0; 942 943 set_tx_flow_off(cf_sk); 944 945 /* 946 * Ensure that packets are not queued after this point in time. 947 * caif_queue_rcv_skb checks SOCK_DEAD holding the queue lock, 948 * this ensures no packets when sock is dead. 949 */ 950 spin_lock(&sk->sk_receive_queue.lock); 951 sock_set_flag(sk, SOCK_DEAD); 952 spin_unlock(&sk->sk_receive_queue.lock); 953 sock->sk = NULL; 954 955 dbfs_atomic_inc(&cnt.num_disconnect); 956 957 if (cf_sk->debugfs_socket_dir != NULL) 958 debugfs_remove_recursive(cf_sk->debugfs_socket_dir); 959 960 lock_sock(&(cf_sk->sk)); 961 sk->sk_state = CAIF_DISCONNECTED; 962 sk->sk_shutdown = SHUTDOWN_MASK; 963 964 if (cf_sk->sk.sk_socket->state == SS_CONNECTED || 965 cf_sk->sk.sk_socket->state == SS_CONNECTING) 966 res = caif_disconnect_client(&cf_sk->layer); 967 968 cf_sk->sk.sk_socket->state = SS_DISCONNECTING; 969 wake_up_interruptible_poll(sk_sleep(sk), POLLERR|POLLHUP); 970 971 sock_orphan(sk); 972 cf_sk->layer.dn = NULL; 973 sk_stream_kill_queues(&cf_sk->sk); 974 release_sock(sk); 975 sock_put(sk); 976 return res; 977} 978 979/* Copied from af_unix.c:unix_poll(), added CAIF tx_flow handling */ 980static unsigned int caif_poll(struct file *file, 981 struct socket *sock, poll_table *wait) 982{ 983 struct sock *sk = sock->sk; 984 unsigned int mask; 985 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); 986 987 sock_poll_wait(file, sk_sleep(sk), wait); 988 mask = 0; 989 990 /* exceptional events? */ 991 if (sk->sk_err) 992 mask |= POLLERR; 993 if (sk->sk_shutdown == SHUTDOWN_MASK) 994 mask |= POLLHUP; 995 if (sk->sk_shutdown & RCV_SHUTDOWN) 996 mask |= POLLRDHUP; 997 998 /* readable? */ 999 if (!skb_queue_empty(&sk->sk_receive_queue) || 1000 (sk->sk_shutdown & RCV_SHUTDOWN)) 1001 mask |= POLLIN | POLLRDNORM; 1002 1003 /* 1004 * we set writable also when the other side has shut down the 1005 * connection. This prevents stuck sockets. 1006 */ 1007 if (sock_writeable(sk) && tx_flow_is_on(cf_sk)) 1008 mask |= POLLOUT | POLLWRNORM | POLLWRBAND; 1009 1010 return mask; 1011} 1012 1013static const struct proto_ops caif_seqpacket_ops = { 1014 .family = PF_CAIF, 1015 .owner = THIS_MODULE, 1016 .release = caif_release, 1017 .bind = sock_no_bind, 1018 .connect = caif_connect, 1019 .socketpair = sock_no_socketpair, 1020 .accept = sock_no_accept, 1021 .getname = sock_no_getname, 1022 .poll = caif_poll, 1023 .ioctl = sock_no_ioctl, 1024 .listen = sock_no_listen, 1025 .shutdown = sock_no_shutdown, 1026 .setsockopt = setsockopt, 1027 .getsockopt = sock_no_getsockopt, 1028 .sendmsg = caif_seqpkt_sendmsg, 1029 .recvmsg = caif_seqpkt_recvmsg, 1030 .mmap = sock_no_mmap, 1031 .sendpage = sock_no_sendpage, 1032}; 1033 1034static const struct proto_ops caif_stream_ops = { 1035 .family = PF_CAIF, 1036 .owner = THIS_MODULE, 1037 .release = caif_release, 1038 .bind = sock_no_bind, 1039 .connect = caif_connect, 1040 .socketpair = sock_no_socketpair, 1041 .accept = sock_no_accept, 1042 .getname = sock_no_getname, 1043 .poll = caif_poll, 1044 .ioctl = sock_no_ioctl, 1045 .listen = sock_no_listen, 1046 .shutdown = sock_no_shutdown, 1047 .setsockopt = setsockopt, 1048 .getsockopt = sock_no_getsockopt, 1049 .sendmsg = caif_stream_sendmsg, 1050 .recvmsg = caif_stream_recvmsg, 1051 .mmap = sock_no_mmap, 1052 .sendpage = sock_no_sendpage, 1053}; 1054 1055/* This function is called when a socket is finally destroyed. */ 1056static void caif_sock_destructor(struct sock *sk) 1057{ 1058 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); 1059 caif_assert(!atomic_read(&sk->sk_wmem_alloc)); 1060 caif_assert(sk_unhashed(sk)); 1061 caif_assert(!sk->sk_socket); 1062 if (!sock_flag(sk, SOCK_DEAD)) { 1063 pr_info("Attempt to release alive CAIF socket: %p\n", sk); 1064 return; 1065 } 1066 sk_stream_kill_queues(&cf_sk->sk); 1067 dbfs_atomic_dec(&cnt.caif_nr_socks); 1068} 1069 1070static int caif_create(struct net *net, struct socket *sock, int protocol, 1071 int kern) 1072{ 1073 struct sock *sk = NULL; 1074 struct caifsock *cf_sk = NULL; 1075 static struct proto prot = {.name = "PF_CAIF", 1076 .owner = THIS_MODULE, 1077 .obj_size = sizeof(struct caifsock), 1078 }; 1079 1080 if (!capable(CAP_SYS_ADMIN) && !capable(CAP_NET_ADMIN)) 1081 return -EPERM; 1082 /* 1083 * The sock->type specifies the socket type to use. 1084 * The CAIF socket is a packet stream in the sense 1085 * that it is packet based. CAIF trusts the reliability 1086 * of the link, no resending is implemented. 1087 */ 1088 if (sock->type == SOCK_SEQPACKET) 1089 sock->ops = &caif_seqpacket_ops; 1090 else if (sock->type == SOCK_STREAM) 1091 sock->ops = &caif_stream_ops; 1092 else 1093 return -ESOCKTNOSUPPORT; 1094 1095 if (protocol < 0 || protocol >= CAIFPROTO_MAX) 1096 return -EPROTONOSUPPORT; 1097 /* 1098 * Set the socket state to unconnected. The socket state 1099 * is really not used at all in the net/core or socket.c but the 1100 * initialization makes sure that sock->state is not uninitialized. 1101 */ 1102 sk = sk_alloc(net, PF_CAIF, GFP_KERNEL, &prot); 1103 if (!sk) 1104 return -ENOMEM; 1105 1106 cf_sk = container_of(sk, struct caifsock, sk); 1107 1108 /* Store the protocol */ 1109 sk->sk_protocol = (unsigned char) protocol; 1110 1111 /* 1112 * Lock in order to try to stop someone from opening the socket 1113 * too early. 1114 */ 1115 lock_sock(&(cf_sk->sk)); 1116 1117 /* Initialize the nozero default sock structure data. */ 1118 sock_init_data(sock, sk); 1119 sk->sk_destruct = caif_sock_destructor; 1120 1121 mutex_init(&cf_sk->readlock); /* single task reading lock */ 1122 cf_sk->layer.ctrlcmd = caif_ctrl_cb; 1123 cf_sk->sk.sk_socket->state = SS_UNCONNECTED; 1124 cf_sk->sk.sk_state = CAIF_DISCONNECTED; 1125 1126 set_tx_flow_off(cf_sk); 1127 set_rx_flow_on(cf_sk); 1128 1129 /* Set default options on configuration */ 1130 cf_sk->sk.sk_priority= CAIF_PRIO_NORMAL; 1131 cf_sk->conn_req.link_selector = CAIF_LINK_LOW_LATENCY; 1132 cf_sk->conn_req.protocol = protocol; 1133 /* Increase the number of sockets created. */ 1134 dbfs_atomic_inc(&cnt.caif_nr_socks); 1135#ifdef CONFIG_DEBUG_FS 1136 if (!IS_ERR(debugfsdir)) { 1137 /* Fill in some information concerning the misc socket. */ 1138 snprintf(cf_sk->name, sizeof(cf_sk->name), "cfsk%d", 1139 atomic_read(&cnt.caif_nr_socks)); 1140 1141 cf_sk->debugfs_socket_dir = 1142 debugfs_create_dir(cf_sk->name, debugfsdir); 1143 debugfs_create_u32("sk_state", S_IRUSR | S_IWUSR, 1144 cf_sk->debugfs_socket_dir, 1145 (u32 *) &cf_sk->sk.sk_state); 1146 debugfs_create_u32("flow_state", S_IRUSR | S_IWUSR, 1147 cf_sk->debugfs_socket_dir, &cf_sk->flow_state); 1148 debugfs_create_u32("sk_rmem_alloc", S_IRUSR | S_IWUSR, 1149 cf_sk->debugfs_socket_dir, 1150 (u32 *) &cf_sk->sk.sk_rmem_alloc); 1151 debugfs_create_u32("sk_wmem_alloc", S_IRUSR | S_IWUSR, 1152 cf_sk->debugfs_socket_dir, 1153 (u32 *) &cf_sk->sk.sk_wmem_alloc); 1154 debugfs_create_u32("identity", S_IRUSR | S_IWUSR, 1155 cf_sk->debugfs_socket_dir, 1156 (u32 *) &cf_sk->layer.id); 1157 } 1158#endif 1159 release_sock(&cf_sk->sk); 1160 return 0; 1161} 1162 1163 1164static struct net_proto_family caif_family_ops = { 1165 .family = PF_CAIF, 1166 .create = caif_create, 1167 .owner = THIS_MODULE, 1168}; 1169 1170static int af_caif_init(void) 1171{ 1172 int err = sock_register(&caif_family_ops); 1173 if (!err) 1174 return err; 1175 return 0; 1176} 1177 1178static int __init caif_sktinit_module(void) 1179{ 1180#ifdef CONFIG_DEBUG_FS 1181 debugfsdir = debugfs_create_dir("caif_sk", NULL); 1182 if (!IS_ERR(debugfsdir)) { 1183 debugfs_create_u32("num_sockets", S_IRUSR | S_IWUSR, 1184 debugfsdir, 1185 (u32 *) &cnt.caif_nr_socks); 1186 debugfs_create_u32("num_connect_req", S_IRUSR | S_IWUSR, 1187 debugfsdir, 1188 (u32 *) &cnt.num_connect_req); 1189 debugfs_create_u32("num_connect_resp", S_IRUSR | S_IWUSR, 1190 debugfsdir, 1191 (u32 *) &cnt.num_connect_resp); 1192 debugfs_create_u32("num_connect_fail_resp", S_IRUSR | S_IWUSR, 1193 debugfsdir, 1194 (u32 *) &cnt.num_connect_fail_resp); 1195 debugfs_create_u32("num_disconnect", S_IRUSR | S_IWUSR, 1196 debugfsdir, 1197 (u32 *) &cnt.num_disconnect); 1198 debugfs_create_u32("num_remote_shutdown_ind", 1199 S_IRUSR | S_IWUSR, debugfsdir, 1200 (u32 *) &cnt.num_remote_shutdown_ind); 1201 debugfs_create_u32("num_tx_flow_off_ind", S_IRUSR | S_IWUSR, 1202 debugfsdir, 1203 (u32 *) &cnt.num_tx_flow_off_ind); 1204 debugfs_create_u32("num_tx_flow_on_ind", S_IRUSR | S_IWUSR, 1205 debugfsdir, 1206 (u32 *) &cnt.num_tx_flow_on_ind); 1207 debugfs_create_u32("num_rx_flow_off", S_IRUSR | S_IWUSR, 1208 debugfsdir, 1209 (u32 *) &cnt.num_rx_flow_off); 1210 debugfs_create_u32("num_rx_flow_on", S_IRUSR | S_IWUSR, 1211 debugfsdir, 1212 (u32 *) &cnt.num_rx_flow_on); 1213 } 1214#endif 1215 return af_caif_init(); 1216} 1217 1218static void __exit caif_sktexit_module(void) 1219{ 1220 sock_unregister(PF_CAIF); 1221 if (debugfsdir != NULL) 1222 debugfs_remove_recursive(debugfsdir); 1223} 1224module_init(caif_sktinit_module); 1225module_exit(caif_sktexit_module); 1226