1 /* 2 * af_llc.c - LLC User Interface SAPs 3 * Description: 4 * Functions in this module are implementation of socket based llc 5 * communications for the Linux operating system. Support of llc class 6 * one and class two is provided via SOCK_DGRAM and SOCK_STREAM 7 * respectively. 8 * 9 * An llc2 connection is (mac + sap), only one llc2 sap connection 10 * is allowed per mac. Though one sap may have multiple mac + sap 11 * connections. 12 * 13 * Copyright (c) 2001 by Jay Schulist <jschlst@samba.org> 14 * 2002-2003 by Arnaldo Carvalho de Melo <acme@conectiva.com.br> 15 * 16 * This program can be redistributed or modified under the terms of the 17 * GNU General Public License as published by the Free Software Foundation. 18 * This program is distributed without any warranty or implied warranty 19 * of merchantability or fitness for a particular purpose. 20 * 21 * See the GNU General Public License for more details. 22 */ 23 #include <linux/compiler.h> 24 #include <linux/kernel.h> 25 #include <linux/module.h> 26 #include <linux/rtnetlink.h> 27 #include <linux/init.h> 28 #include <linux/slab.h> 29 #include <linux/sched/signal.h> 30 31 #include <net/llc.h> 32 #include <net/llc_sap.h> 33 #include <net/llc_pdu.h> 34 #include <net/llc_conn.h> 35 #include <net/tcp_states.h> 36 37 /* remember: uninitialized global data is zeroed because its in .bss */ 38 static u16 llc_ui_sap_last_autoport = LLC_SAP_DYN_START; 39 static u16 llc_ui_sap_link_no_max[256]; 40 static struct sockaddr_llc llc_ui_addrnull; 41 static const struct proto_ops llc_ui_ops; 42 43 static bool llc_ui_wait_for_conn(struct sock *sk, long timeout); 44 static int llc_ui_wait_for_disc(struct sock *sk, long timeout); 45 static int llc_ui_wait_for_busy_core(struct sock *sk, long timeout); 46 47 #if 0 48 #define dprintk(args...) printk(KERN_DEBUG args) 49 #else 50 #define dprintk(args...) do {} while (0) 51 #endif 52 53 /* Maybe we'll add some more in the future. */ 54 #define LLC_CMSG_PKTINFO 1 55 56 57 /** 58 * llc_ui_next_link_no - return the next unused link number for a sap 59 * @sap: Address of sap to get link number from. 60 * 61 * Return the next unused link number for a given sap. 62 */ 63 static inline u16 llc_ui_next_link_no(int sap) 64 { 65 return llc_ui_sap_link_no_max[sap]++; 66 } 67 68 /** 69 * llc_proto_type - return eth protocol for ARP header type 70 * @arphrd: ARP header type. 71 * 72 * Given an ARP header type return the corresponding ethernet protocol. 73 */ 74 static inline __be16 llc_proto_type(u16 arphrd) 75 { 76 return htons(ETH_P_802_2); 77 } 78 79 /** 80 * llc_ui_addr_null - determines if a address structure is null 81 * @addr: Address to test if null. 82 */ 83 static inline u8 llc_ui_addr_null(struct sockaddr_llc *addr) 84 { 85 return !memcmp(addr, &llc_ui_addrnull, sizeof(*addr)); 86 } 87 88 /** 89 * llc_ui_header_len - return length of llc header based on operation 90 * @sk: Socket which contains a valid llc socket type. 91 * @addr: Complete sockaddr_llc structure received from the user. 92 * 93 * Provide the length of the llc header depending on what kind of 94 * operation the user would like to perform and the type of socket. 95 * Returns the correct llc header length. 96 */ 97 static inline u8 llc_ui_header_len(struct sock *sk, struct sockaddr_llc *addr) 98 { 99 u8 rc = LLC_PDU_LEN_U; 100 101 if (addr->sllc_test || addr->sllc_xid) 102 rc = LLC_PDU_LEN_U; 103 else if (sk->sk_type == SOCK_STREAM) 104 rc = LLC_PDU_LEN_I; 105 return rc; 106 } 107 108 /** 109 * llc_ui_send_data - send data via reliable llc2 connection 110 * @sk: Connection the socket is using. 111 * @skb: Data the user wishes to send. 112 * @noblock: can we block waiting for data? 113 * 114 * Send data via reliable llc2 connection. 115 * Returns 0 upon success, non-zero if action did not succeed. 116 * 117 * This function always consumes a reference to the skb. 118 */ 119 static int llc_ui_send_data(struct sock* sk, struct sk_buff *skb, int noblock) 120 { 121 struct llc_sock* llc = llc_sk(sk); 122 123 if (unlikely(llc_data_accept_state(llc->state) || 124 llc->remote_busy_flag || 125 llc->p_flag)) { 126 long timeout = sock_sndtimeo(sk, noblock); 127 int rc; 128 129 rc = llc_ui_wait_for_busy_core(sk, timeout); 130 if (rc) { 131 kfree_skb(skb); 132 return rc; 133 } 134 } 135 return llc_build_and_send_pkt(sk, skb); 136 } 137 138 static void llc_ui_sk_init(struct socket *sock, struct sock *sk) 139 { 140 sock_graft(sk, sock); 141 sk->sk_type = sock->type; 142 sock->ops = &llc_ui_ops; 143 } 144 145 static struct proto llc_proto = { 146 .name = "LLC", 147 .owner = THIS_MODULE, 148 .obj_size = sizeof(struct llc_sock), 149 .slab_flags = SLAB_TYPESAFE_BY_RCU, 150 }; 151 152 /** 153 * llc_ui_create - alloc and init a new llc_ui socket 154 * @net: network namespace (must be default network) 155 * @sock: Socket to initialize and attach allocated sk to. 156 * @protocol: Unused. 157 * @kern: on behalf of kernel or userspace 158 * 159 * Allocate and initialize a new llc_ui socket, validate the user wants a 160 * socket type we have available. 161 * Returns 0 upon success, negative upon failure. 162 */ 163 static int llc_ui_create(struct net *net, struct socket *sock, int protocol, 164 int kern) 165 { 166 struct sock *sk; 167 int rc = -ESOCKTNOSUPPORT; 168 169 if (!ns_capable(net->user_ns, CAP_NET_RAW)) 170 return -EPERM; 171 172 if (!net_eq(net, &init_net)) 173 return -EAFNOSUPPORT; 174 175 if (likely(sock->type == SOCK_DGRAM || sock->type == SOCK_STREAM)) { 176 rc = -ENOMEM; 177 sk = llc_sk_alloc(net, PF_LLC, GFP_KERNEL, &llc_proto, kern); 178 if (sk) { 179 rc = 0; 180 llc_ui_sk_init(sock, sk); 181 } 182 } 183 return rc; 184 } 185 186 /** 187 * llc_ui_release - shutdown socket 188 * @sock: Socket to release. 189 * 190 * Shutdown and deallocate an existing socket. 191 */ 192 static int llc_ui_release(struct socket *sock) 193 { 194 struct sock *sk = sock->sk; 195 struct llc_sock *llc; 196 197 if (unlikely(sk == NULL)) 198 goto out; 199 sock_hold(sk); 200 lock_sock(sk); 201 llc = llc_sk(sk); 202 dprintk("%s: closing local(%02X) remote(%02X)\n", __func__, 203 llc->laddr.lsap, llc->daddr.lsap); 204 if (!llc_send_disc(sk)) 205 llc_ui_wait_for_disc(sk, sk->sk_rcvtimeo); 206 if (!sock_flag(sk, SOCK_ZAPPED)) { 207 struct llc_sap *sap = llc->sap; 208 209 /* Hold this for release_sock(), so that llc_backlog_rcv() 210 * could still use it. 211 */ 212 llc_sap_hold(sap); 213 llc_sap_remove_socket(llc->sap, sk); 214 release_sock(sk); 215 llc_sap_put(sap); 216 } else { 217 release_sock(sk); 218 } 219 if (llc->dev) 220 dev_put(llc->dev); 221 sock_put(sk); 222 llc_sk_free(sk); 223 out: 224 return 0; 225 } 226 227 /** 228 * llc_ui_autoport - provide dynamically allocate SAP number 229 * 230 * Provide the caller with a dynamically allocated SAP number according 231 * to the rules that are set in this function. Returns: 0, upon failure, 232 * SAP number otherwise. 233 */ 234 static int llc_ui_autoport(void) 235 { 236 struct llc_sap *sap; 237 int i, tries = 0; 238 239 while (tries < LLC_SAP_DYN_TRIES) { 240 for (i = llc_ui_sap_last_autoport; 241 i < LLC_SAP_DYN_STOP; i += 2) { 242 sap = llc_sap_find(i); 243 if (!sap) { 244 llc_ui_sap_last_autoport = i + 2; 245 goto out; 246 } 247 llc_sap_put(sap); 248 } 249 llc_ui_sap_last_autoport = LLC_SAP_DYN_START; 250 tries++; 251 } 252 i = 0; 253 out: 254 return i; 255 } 256 257 /** 258 * llc_ui_autobind - automatically bind a socket to a sap 259 * @sock: socket to bind 260 * @addr: address to connect to 261 * 262 * Used by llc_ui_connect and llc_ui_sendmsg when the user hasn't 263 * specifically used llc_ui_bind to bind to an specific address/sap 264 * 265 * Returns: 0 upon success, negative otherwise. 266 */ 267 static int llc_ui_autobind(struct socket *sock, struct sockaddr_llc *addr) 268 { 269 struct sock *sk = sock->sk; 270 struct llc_sock *llc = llc_sk(sk); 271 struct llc_sap *sap; 272 int rc = -EINVAL; 273 274 if (!sock_flag(sk, SOCK_ZAPPED)) 275 goto out; 276 rc = -ENODEV; 277 if (sk->sk_bound_dev_if) { 278 llc->dev = dev_get_by_index(&init_net, sk->sk_bound_dev_if); 279 if (llc->dev && addr->sllc_arphrd != llc->dev->type) { 280 dev_put(llc->dev); 281 llc->dev = NULL; 282 } 283 } else 284 llc->dev = dev_getfirstbyhwtype(&init_net, addr->sllc_arphrd); 285 if (!llc->dev) 286 goto out; 287 rc = -EUSERS; 288 llc->laddr.lsap = llc_ui_autoport(); 289 if (!llc->laddr.lsap) 290 goto out; 291 rc = -EBUSY; /* some other network layer is using the sap */ 292 sap = llc_sap_open(llc->laddr.lsap, NULL); 293 if (!sap) 294 goto out; 295 memcpy(llc->laddr.mac, llc->dev->dev_addr, IFHWADDRLEN); 296 memcpy(&llc->addr, addr, sizeof(llc->addr)); 297 /* assign new connection to its SAP */ 298 llc_sap_add_socket(sap, sk); 299 sock_reset_flag(sk, SOCK_ZAPPED); 300 rc = 0; 301 out: 302 return rc; 303 } 304 305 /** 306 * llc_ui_bind - bind a socket to a specific address. 307 * @sock: Socket to bind an address to. 308 * @uaddr: Address the user wants the socket bound to. 309 * @addrlen: Length of the uaddr structure. 310 * 311 * Bind a socket to a specific address. For llc a user is able to bind to 312 * a specific sap only or mac + sap. 313 * If the user desires to bind to a specific mac + sap, it is possible to 314 * have multiple sap connections via multiple macs. 315 * Bind and autobind for that matter must enforce the correct sap usage 316 * otherwise all hell will break loose. 317 * Returns: 0 upon success, negative otherwise. 318 */ 319 static int llc_ui_bind(struct socket *sock, struct sockaddr *uaddr, int addrlen) 320 { 321 struct sockaddr_llc *addr = (struct sockaddr_llc *)uaddr; 322 struct sock *sk = sock->sk; 323 struct llc_sock *llc = llc_sk(sk); 324 struct llc_sap *sap; 325 int rc = -EINVAL; 326 327 lock_sock(sk); 328 if (unlikely(!sock_flag(sk, SOCK_ZAPPED) || addrlen != sizeof(*addr))) 329 goto out; 330 rc = -EAFNOSUPPORT; 331 if (unlikely(addr->sllc_family != AF_LLC)) 332 goto out; 333 dprintk("%s: binding %02X\n", __func__, addr->sllc_sap); 334 rc = -ENODEV; 335 rcu_read_lock(); 336 if (sk->sk_bound_dev_if) { 337 llc->dev = dev_get_by_index_rcu(&init_net, sk->sk_bound_dev_if); 338 if (llc->dev) { 339 if (!addr->sllc_arphrd) 340 addr->sllc_arphrd = llc->dev->type; 341 if (is_zero_ether_addr(addr->sllc_mac)) 342 memcpy(addr->sllc_mac, llc->dev->dev_addr, 343 IFHWADDRLEN); 344 if (addr->sllc_arphrd != llc->dev->type || 345 !ether_addr_equal(addr->sllc_mac, 346 llc->dev->dev_addr)) { 347 rc = -EINVAL; 348 llc->dev = NULL; 349 } 350 } 351 } else 352 llc->dev = dev_getbyhwaddr_rcu(&init_net, addr->sllc_arphrd, 353 addr->sllc_mac); 354 if (llc->dev) 355 dev_hold(llc->dev); 356 rcu_read_unlock(); 357 if (!llc->dev) 358 goto out; 359 if (!addr->sllc_sap) { 360 rc = -EUSERS; 361 addr->sllc_sap = llc_ui_autoport(); 362 if (!addr->sllc_sap) 363 goto out; 364 } 365 sap = llc_sap_find(addr->sllc_sap); 366 if (!sap) { 367 sap = llc_sap_open(addr->sllc_sap, NULL); 368 rc = -EBUSY; /* some other network layer is using the sap */ 369 if (!sap) 370 goto out; 371 } else { 372 struct llc_addr laddr, daddr; 373 struct sock *ask; 374 375 memset(&laddr, 0, sizeof(laddr)); 376 memset(&daddr, 0, sizeof(daddr)); 377 /* 378 * FIXME: check if the address is multicast, 379 * only SOCK_DGRAM can do this. 380 */ 381 memcpy(laddr.mac, addr->sllc_mac, IFHWADDRLEN); 382 laddr.lsap = addr->sllc_sap; 383 rc = -EADDRINUSE; /* mac + sap clash. */ 384 ask = llc_lookup_established(sap, &daddr, &laddr); 385 if (ask) { 386 sock_put(ask); 387 goto out_put; 388 } 389 } 390 llc->laddr.lsap = addr->sllc_sap; 391 memcpy(llc->laddr.mac, addr->sllc_mac, IFHWADDRLEN); 392 memcpy(&llc->addr, addr, sizeof(llc->addr)); 393 /* assign new connection to its SAP */ 394 llc_sap_add_socket(sap, sk); 395 sock_reset_flag(sk, SOCK_ZAPPED); 396 rc = 0; 397 out_put: 398 llc_sap_put(sap); 399 out: 400 release_sock(sk); 401 return rc; 402 } 403 404 /** 405 * llc_ui_shutdown - shutdown a connect llc2 socket. 406 * @sock: Socket to shutdown. 407 * @how: What part of the socket to shutdown. 408 * 409 * Shutdown a connected llc2 socket. Currently this function only supports 410 * shutting down both sends and receives (2), we could probably make this 411 * function such that a user can shutdown only half the connection but not 412 * right now. 413 * Returns: 0 upon success, negative otherwise. 414 */ 415 static int llc_ui_shutdown(struct socket *sock, int how) 416 { 417 struct sock *sk = sock->sk; 418 int rc = -ENOTCONN; 419 420 lock_sock(sk); 421 if (unlikely(sk->sk_state != TCP_ESTABLISHED)) 422 goto out; 423 rc = -EINVAL; 424 if (how != 2) 425 goto out; 426 rc = llc_send_disc(sk); 427 if (!rc) 428 rc = llc_ui_wait_for_disc(sk, sk->sk_rcvtimeo); 429 /* Wake up anyone sleeping in poll */ 430 sk->sk_state_change(sk); 431 out: 432 release_sock(sk); 433 return rc; 434 } 435 436 /** 437 * llc_ui_connect - Connect to a remote llc2 mac + sap. 438 * @sock: Socket which will be connected to the remote destination. 439 * @uaddr: Remote and possibly the local address of the new connection. 440 * @addrlen: Size of uaddr structure. 441 * @flags: Operational flags specified by the user. 442 * 443 * Connect to a remote llc2 mac + sap. The caller must specify the 444 * destination mac and address to connect to. If the user hasn't previously 445 * called bind(2) with a smac the address of the first interface of the 446 * specified arp type will be used. 447 * This function will autobind if user did not previously call bind. 448 * Returns: 0 upon success, negative otherwise. 449 */ 450 static int llc_ui_connect(struct socket *sock, struct sockaddr *uaddr, 451 int addrlen, int flags) 452 { 453 struct sock *sk = sock->sk; 454 struct llc_sock *llc = llc_sk(sk); 455 struct sockaddr_llc *addr = (struct sockaddr_llc *)uaddr; 456 int rc = -EINVAL; 457 458 lock_sock(sk); 459 if (unlikely(addrlen != sizeof(*addr))) 460 goto out; 461 rc = -EAFNOSUPPORT; 462 if (unlikely(addr->sllc_family != AF_LLC)) 463 goto out; 464 if (unlikely(sk->sk_type != SOCK_STREAM)) 465 goto out; 466 rc = -EALREADY; 467 if (unlikely(sock->state == SS_CONNECTING)) 468 goto out; 469 /* bind connection to sap if user hasn't done it. */ 470 if (sock_flag(sk, SOCK_ZAPPED)) { 471 /* bind to sap with null dev, exclusive */ 472 rc = llc_ui_autobind(sock, addr); 473 if (rc) 474 goto out; 475 } 476 llc->daddr.lsap = addr->sllc_sap; 477 memcpy(llc->daddr.mac, addr->sllc_mac, IFHWADDRLEN); 478 sock->state = SS_CONNECTING; 479 sk->sk_state = TCP_SYN_SENT; 480 llc->link = llc_ui_next_link_no(llc->sap->laddr.lsap); 481 rc = llc_establish_connection(sk, llc->dev->dev_addr, 482 addr->sllc_mac, addr->sllc_sap); 483 if (rc) { 484 dprintk("%s: llc_ui_send_conn failed :-(\n", __func__); 485 sock->state = SS_UNCONNECTED; 486 sk->sk_state = TCP_CLOSE; 487 goto out; 488 } 489 490 if (sk->sk_state == TCP_SYN_SENT) { 491 const long timeo = sock_sndtimeo(sk, flags & O_NONBLOCK); 492 493 if (!timeo || !llc_ui_wait_for_conn(sk, timeo)) 494 goto out; 495 496 rc = sock_intr_errno(timeo); 497 if (signal_pending(current)) 498 goto out; 499 } 500 501 if (sk->sk_state == TCP_CLOSE) 502 goto sock_error; 503 504 sock->state = SS_CONNECTED; 505 rc = 0; 506 out: 507 release_sock(sk); 508 return rc; 509 sock_error: 510 rc = sock_error(sk) ? : -ECONNABORTED; 511 sock->state = SS_UNCONNECTED; 512 goto out; 513 } 514 515 /** 516 * llc_ui_listen - allow a normal socket to accept incoming connections 517 * @sock: Socket to allow incoming connections on. 518 * @backlog: Number of connections to queue. 519 * 520 * Allow a normal socket to accept incoming connections. 521 * Returns 0 upon success, negative otherwise. 522 */ 523 static int llc_ui_listen(struct socket *sock, int backlog) 524 { 525 struct sock *sk = sock->sk; 526 int rc = -EINVAL; 527 528 lock_sock(sk); 529 if (unlikely(sock->state != SS_UNCONNECTED)) 530 goto out; 531 rc = -EOPNOTSUPP; 532 if (unlikely(sk->sk_type != SOCK_STREAM)) 533 goto out; 534 rc = -EAGAIN; 535 if (sock_flag(sk, SOCK_ZAPPED)) 536 goto out; 537 rc = 0; 538 if (!(unsigned int)backlog) /* BSDism */ 539 backlog = 1; 540 sk->sk_max_ack_backlog = backlog; 541 if (sk->sk_state != TCP_LISTEN) { 542 sk->sk_ack_backlog = 0; 543 sk->sk_state = TCP_LISTEN; 544 } 545 sk->sk_socket->flags |= __SO_ACCEPTCON; 546 out: 547 release_sock(sk); 548 return rc; 549 } 550 551 static int llc_ui_wait_for_disc(struct sock *sk, long timeout) 552 { 553 DEFINE_WAIT_FUNC(wait, woken_wake_function); 554 int rc = 0; 555 556 add_wait_queue(sk_sleep(sk), &wait); 557 while (1) { 558 if (sk_wait_event(sk, &timeout, sk->sk_state == TCP_CLOSE, &wait)) 559 break; 560 rc = -ERESTARTSYS; 561 if (signal_pending(current)) 562 break; 563 rc = -EAGAIN; 564 if (!timeout) 565 break; 566 rc = 0; 567 } 568 remove_wait_queue(sk_sleep(sk), &wait); 569 return rc; 570 } 571 572 static bool llc_ui_wait_for_conn(struct sock *sk, long timeout) 573 { 574 DEFINE_WAIT_FUNC(wait, woken_wake_function); 575 576 add_wait_queue(sk_sleep(sk), &wait); 577 while (1) { 578 if (sk_wait_event(sk, &timeout, sk->sk_state != TCP_SYN_SENT, &wait)) 579 break; 580 if (signal_pending(current) || !timeout) 581 break; 582 } 583 remove_wait_queue(sk_sleep(sk), &wait); 584 return timeout; 585 } 586 587 static int llc_ui_wait_for_busy_core(struct sock *sk, long timeout) 588 { 589 DEFINE_WAIT_FUNC(wait, woken_wake_function); 590 struct llc_sock *llc = llc_sk(sk); 591 int rc; 592 593 add_wait_queue(sk_sleep(sk), &wait); 594 while (1) { 595 rc = 0; 596 if (sk_wait_event(sk, &timeout, 597 (sk->sk_shutdown & RCV_SHUTDOWN) || 598 (!llc_data_accept_state(llc->state) && 599 !llc->remote_busy_flag && 600 !llc->p_flag), &wait)) 601 break; 602 rc = -ERESTARTSYS; 603 if (signal_pending(current)) 604 break; 605 rc = -EAGAIN; 606 if (!timeout) 607 break; 608 } 609 remove_wait_queue(sk_sleep(sk), &wait); 610 return rc; 611 } 612 613 static int llc_wait_data(struct sock *sk, long timeo) 614 { 615 int rc; 616 617 while (1) { 618 /* 619 * POSIX 1003.1g mandates this order. 620 */ 621 rc = sock_error(sk); 622 if (rc) 623 break; 624 rc = 0; 625 if (sk->sk_shutdown & RCV_SHUTDOWN) 626 break; 627 rc = -EAGAIN; 628 if (!timeo) 629 break; 630 rc = sock_intr_errno(timeo); 631 if (signal_pending(current)) 632 break; 633 rc = 0; 634 if (sk_wait_data(sk, &timeo, NULL)) 635 break; 636 } 637 return rc; 638 } 639 640 static void llc_cmsg_rcv(struct msghdr *msg, struct sk_buff *skb) 641 { 642 struct llc_sock *llc = llc_sk(skb->sk); 643 644 if (llc->cmsg_flags & LLC_CMSG_PKTINFO) { 645 struct llc_pktinfo info; 646 647 memset(&info, 0, sizeof(info)); 648 info.lpi_ifindex = llc_sk(skb->sk)->dev->ifindex; 649 llc_pdu_decode_dsap(skb, &info.lpi_sap); 650 llc_pdu_decode_da(skb, info.lpi_mac); 651 put_cmsg(msg, SOL_LLC, LLC_OPT_PKTINFO, sizeof(info), &info); 652 } 653 } 654 655 /** 656 * llc_ui_accept - accept a new incoming connection. 657 * @sock: Socket which connections arrive on. 658 * @newsock: Socket to move incoming connection to. 659 * @flags: User specified operational flags. 660 * @kern: If the socket is kernel internal 661 * 662 * Accept a new incoming connection. 663 * Returns 0 upon success, negative otherwise. 664 */ 665 static int llc_ui_accept(struct socket *sock, struct socket *newsock, int flags, 666 bool kern) 667 { 668 struct sock *sk = sock->sk, *newsk; 669 struct llc_sock *llc, *newllc; 670 struct sk_buff *skb; 671 int rc = -EOPNOTSUPP; 672 673 dprintk("%s: accepting on %02X\n", __func__, 674 llc_sk(sk)->laddr.lsap); 675 lock_sock(sk); 676 if (unlikely(sk->sk_type != SOCK_STREAM)) 677 goto out; 678 rc = -EINVAL; 679 if (unlikely(sock->state != SS_UNCONNECTED || 680 sk->sk_state != TCP_LISTEN)) 681 goto out; 682 /* wait for a connection to arrive. */ 683 if (skb_queue_empty(&sk->sk_receive_queue)) { 684 rc = llc_wait_data(sk, sk->sk_rcvtimeo); 685 if (rc) 686 goto out; 687 } 688 dprintk("%s: got a new connection on %02X\n", __func__, 689 llc_sk(sk)->laddr.lsap); 690 skb = skb_dequeue(&sk->sk_receive_queue); 691 rc = -EINVAL; 692 if (!skb->sk) 693 goto frees; 694 rc = 0; 695 newsk = skb->sk; 696 /* attach connection to a new socket. */ 697 llc_ui_sk_init(newsock, newsk); 698 sock_reset_flag(newsk, SOCK_ZAPPED); 699 newsk->sk_state = TCP_ESTABLISHED; 700 newsock->state = SS_CONNECTED; 701 llc = llc_sk(sk); 702 newllc = llc_sk(newsk); 703 memcpy(&newllc->addr, &llc->addr, sizeof(newllc->addr)); 704 newllc->link = llc_ui_next_link_no(newllc->laddr.lsap); 705 706 /* put original socket back into a clean listen state. */ 707 sk->sk_state = TCP_LISTEN; 708 sk_acceptq_removed(sk); 709 dprintk("%s: ok success on %02X, client on %02X\n", __func__, 710 llc_sk(sk)->addr.sllc_sap, newllc->daddr.lsap); 711 frees: 712 kfree_skb(skb); 713 out: 714 release_sock(sk); 715 return rc; 716 } 717 718 /** 719 * llc_ui_recvmsg - copy received data to the socket user. 720 * @sock: Socket to copy data from. 721 * @msg: Various user space related information. 722 * @len: Size of user buffer. 723 * @flags: User specified flags. 724 * 725 * Copy received data to the socket user. 726 * Returns non-negative upon success, negative otherwise. 727 */ 728 static int llc_ui_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, 729 int flags) 730 { 731 DECLARE_SOCKADDR(struct sockaddr_llc *, uaddr, msg->msg_name); 732 const int nonblock = flags & MSG_DONTWAIT; 733 struct sk_buff *skb = NULL; 734 struct sock *sk = sock->sk; 735 struct llc_sock *llc = llc_sk(sk); 736 size_t copied = 0; 737 u32 peek_seq = 0; 738 u32 *seq, skb_len; 739 unsigned long used; 740 int target; /* Read at least this many bytes */ 741 long timeo; 742 743 lock_sock(sk); 744 copied = -ENOTCONN; 745 if (unlikely(sk->sk_type == SOCK_STREAM && sk->sk_state == TCP_LISTEN)) 746 goto out; 747 748 timeo = sock_rcvtimeo(sk, nonblock); 749 750 seq = &llc->copied_seq; 751 if (flags & MSG_PEEK) { 752 peek_seq = llc->copied_seq; 753 seq = &peek_seq; 754 } 755 756 target = sock_rcvlowat(sk, flags & MSG_WAITALL, len); 757 copied = 0; 758 759 do { 760 u32 offset; 761 762 /* 763 * We need to check signals first, to get correct SIGURG 764 * handling. FIXME: Need to check this doesn't impact 1003.1g 765 * and move it down to the bottom of the loop 766 */ 767 if (signal_pending(current)) { 768 if (copied) 769 break; 770 copied = timeo ? sock_intr_errno(timeo) : -EAGAIN; 771 break; 772 } 773 774 /* Next get a buffer. */ 775 776 skb = skb_peek(&sk->sk_receive_queue); 777 if (skb) { 778 offset = *seq; 779 goto found_ok_skb; 780 } 781 /* Well, if we have backlog, try to process it now yet. */ 782 783 if (copied >= target && !READ_ONCE(sk->sk_backlog.tail)) 784 break; 785 786 if (copied) { 787 if (sk->sk_err || 788 sk->sk_state == TCP_CLOSE || 789 (sk->sk_shutdown & RCV_SHUTDOWN) || 790 !timeo || 791 (flags & MSG_PEEK)) 792 break; 793 } else { 794 if (sock_flag(sk, SOCK_DONE)) 795 break; 796 797 if (sk->sk_err) { 798 copied = sock_error(sk); 799 break; 800 } 801 if (sk->sk_shutdown & RCV_SHUTDOWN) 802 break; 803 804 if (sk->sk_type == SOCK_STREAM && sk->sk_state == TCP_CLOSE) { 805 if (!sock_flag(sk, SOCK_DONE)) { 806 /* 807 * This occurs when user tries to read 808 * from never connected socket. 809 */ 810 copied = -ENOTCONN; 811 break; 812 } 813 break; 814 } 815 if (!timeo) { 816 copied = -EAGAIN; 817 break; 818 } 819 } 820 821 if (copied >= target) { /* Do not sleep, just process backlog. */ 822 release_sock(sk); 823 lock_sock(sk); 824 } else 825 sk_wait_data(sk, &timeo, NULL); 826 827 if ((flags & MSG_PEEK) && peek_seq != llc->copied_seq) { 828 net_dbg_ratelimited("LLC(%s:%d): Application bug, race in MSG_PEEK\n", 829 current->comm, 830 task_pid_nr(current)); 831 peek_seq = llc->copied_seq; 832 } 833 continue; 834 found_ok_skb: 835 skb_len = skb->len; 836 /* Ok so how much can we use? */ 837 used = skb->len - offset; 838 if (len < used) 839 used = len; 840 841 if (!(flags & MSG_TRUNC)) { 842 int rc = skb_copy_datagram_msg(skb, offset, msg, used); 843 if (rc) { 844 /* Exception. Bailout! */ 845 if (!copied) 846 copied = -EFAULT; 847 break; 848 } 849 } 850 851 *seq += used; 852 copied += used; 853 len -= used; 854 855 /* For non stream protcols we get one packet per recvmsg call */ 856 if (sk->sk_type != SOCK_STREAM) 857 goto copy_uaddr; 858 859 if (!(flags & MSG_PEEK)) { 860 skb_unlink(skb, &sk->sk_receive_queue); 861 kfree_skb(skb); 862 *seq = 0; 863 } 864 865 /* Partial read */ 866 if (used + offset < skb_len) 867 continue; 868 } while (len > 0); 869 870 out: 871 release_sock(sk); 872 return copied; 873 copy_uaddr: 874 if (uaddr != NULL && skb != NULL) { 875 memcpy(uaddr, llc_ui_skb_cb(skb), sizeof(*uaddr)); 876 msg->msg_namelen = sizeof(*uaddr); 877 } 878 if (llc_sk(sk)->cmsg_flags) 879 llc_cmsg_rcv(msg, skb); 880 881 if (!(flags & MSG_PEEK)) { 882 skb_unlink(skb, &sk->sk_receive_queue); 883 kfree_skb(skb); 884 *seq = 0; 885 } 886 887 goto out; 888 } 889 890 /** 891 * llc_ui_sendmsg - Transmit data provided by the socket user. 892 * @sock: Socket to transmit data from. 893 * @msg: Various user related information. 894 * @len: Length of data to transmit. 895 * 896 * Transmit data provided by the socket user. 897 * Returns non-negative upon success, negative otherwise. 898 */ 899 static int llc_ui_sendmsg(struct socket *sock, struct msghdr *msg, size_t len) 900 { 901 struct sock *sk = sock->sk; 902 struct llc_sock *llc = llc_sk(sk); 903 DECLARE_SOCKADDR(struct sockaddr_llc *, addr, msg->msg_name); 904 int flags = msg->msg_flags; 905 int noblock = flags & MSG_DONTWAIT; 906 struct sk_buff *skb = NULL; 907 size_t size = 0; 908 int rc = -EINVAL, copied = 0, hdrlen; 909 910 dprintk("%s: sending from %02X to %02X\n", __func__, 911 llc->laddr.lsap, llc->daddr.lsap); 912 lock_sock(sk); 913 if (addr) { 914 if (msg->msg_namelen < sizeof(*addr)) 915 goto out; 916 } else { 917 if (llc_ui_addr_null(&llc->addr)) 918 goto out; 919 addr = &llc->addr; 920 } 921 /* must bind connection to sap if user hasn't done it. */ 922 if (sock_flag(sk, SOCK_ZAPPED)) { 923 /* bind to sap with null dev, exclusive. */ 924 rc = llc_ui_autobind(sock, addr); 925 if (rc) 926 goto out; 927 } 928 hdrlen = llc->dev->hard_header_len + llc_ui_header_len(sk, addr); 929 size = hdrlen + len; 930 if (size > llc->dev->mtu) 931 size = llc->dev->mtu; 932 copied = size - hdrlen; 933 rc = -EINVAL; 934 if (copied < 0) 935 goto out; 936 release_sock(sk); 937 skb = sock_alloc_send_skb(sk, size, noblock, &rc); 938 lock_sock(sk); 939 if (!skb) 940 goto out; 941 skb->dev = llc->dev; 942 skb->protocol = llc_proto_type(addr->sllc_arphrd); 943 skb_reserve(skb, hdrlen); 944 rc = memcpy_from_msg(skb_put(skb, copied), msg, copied); 945 if (rc) 946 goto out; 947 if (sk->sk_type == SOCK_DGRAM || addr->sllc_ua) { 948 llc_build_and_send_ui_pkt(llc->sap, skb, addr->sllc_mac, 949 addr->sllc_sap); 950 skb = NULL; 951 goto out; 952 } 953 if (addr->sllc_test) { 954 llc_build_and_send_test_pkt(llc->sap, skb, addr->sllc_mac, 955 addr->sllc_sap); 956 skb = NULL; 957 goto out; 958 } 959 if (addr->sllc_xid) { 960 llc_build_and_send_xid_pkt(llc->sap, skb, addr->sllc_mac, 961 addr->sllc_sap); 962 skb = NULL; 963 goto out; 964 } 965 rc = -ENOPROTOOPT; 966 if (!(sk->sk_type == SOCK_STREAM && !addr->sllc_ua)) 967 goto out; 968 rc = llc_ui_send_data(sk, skb, noblock); 969 skb = NULL; 970 out: 971 kfree_skb(skb); 972 if (rc) 973 dprintk("%s: failed sending from %02X to %02X: %d\n", 974 __func__, llc->laddr.lsap, llc->daddr.lsap, rc); 975 release_sock(sk); 976 return rc ? : copied; 977 } 978 979 /** 980 * llc_ui_getname - return the address info of a socket 981 * @sock: Socket to get address of. 982 * @uaddr: Address structure to return information. 983 * @uaddrlen: Length of address structure. 984 * @peer: Does user want local or remote address information. 985 * 986 * Return the address information of a socket. 987 */ 988 static int llc_ui_getname(struct socket *sock, struct sockaddr *uaddr, 989 int peer) 990 { 991 struct sockaddr_llc sllc; 992 struct sock *sk = sock->sk; 993 struct llc_sock *llc = llc_sk(sk); 994 int rc = -EBADF; 995 996 memset(&sllc, 0, sizeof(sllc)); 997 lock_sock(sk); 998 if (sock_flag(sk, SOCK_ZAPPED)) 999 goto out; 1000 if (peer) { 1001 rc = -ENOTCONN; 1002 if (sk->sk_state != TCP_ESTABLISHED) 1003 goto out; 1004 if(llc->dev) 1005 sllc.sllc_arphrd = llc->dev->type; 1006 sllc.sllc_sap = llc->daddr.lsap; 1007 memcpy(&sllc.sllc_mac, &llc->daddr.mac, IFHWADDRLEN); 1008 } else { 1009 rc = -EINVAL; 1010 if (!llc->sap) 1011 goto out; 1012 sllc.sllc_sap = llc->sap->laddr.lsap; 1013 1014 if (llc->dev) { 1015 sllc.sllc_arphrd = llc->dev->type; 1016 memcpy(&sllc.sllc_mac, llc->dev->dev_addr, 1017 IFHWADDRLEN); 1018 } 1019 } 1020 sllc.sllc_family = AF_LLC; 1021 memcpy(uaddr, &sllc, sizeof(sllc)); 1022 rc = sizeof(sllc); 1023 out: 1024 release_sock(sk); 1025 return rc; 1026 } 1027 1028 /** 1029 * llc_ui_ioctl - io controls for PF_LLC 1030 * @sock: Socket to get/set info 1031 * @cmd: command 1032 * @arg: optional argument for cmd 1033 * 1034 * get/set info on llc sockets 1035 */ 1036 static int llc_ui_ioctl(struct socket *sock, unsigned int cmd, 1037 unsigned long arg) 1038 { 1039 return -ENOIOCTLCMD; 1040 } 1041 1042 /** 1043 * llc_ui_setsockopt - set various connection specific parameters. 1044 * @sock: Socket to set options on. 1045 * @level: Socket level user is requesting operations on. 1046 * @optname: Operation name. 1047 * @optval: User provided operation data. 1048 * @optlen: Length of optval. 1049 * 1050 * Set various connection specific parameters. 1051 */ 1052 static int llc_ui_setsockopt(struct socket *sock, int level, int optname, 1053 char __user *optval, unsigned int optlen) 1054 { 1055 struct sock *sk = sock->sk; 1056 struct llc_sock *llc = llc_sk(sk); 1057 unsigned int opt; 1058 int rc = -EINVAL; 1059 1060 lock_sock(sk); 1061 if (unlikely(level != SOL_LLC || optlen != sizeof(int))) 1062 goto out; 1063 rc = get_user(opt, (int __user *)optval); 1064 if (rc) 1065 goto out; 1066 rc = -EINVAL; 1067 switch (optname) { 1068 case LLC_OPT_RETRY: 1069 if (opt > LLC_OPT_MAX_RETRY) 1070 goto out; 1071 llc->n2 = opt; 1072 break; 1073 case LLC_OPT_SIZE: 1074 if (opt > LLC_OPT_MAX_SIZE) 1075 goto out; 1076 llc->n1 = opt; 1077 break; 1078 case LLC_OPT_ACK_TMR_EXP: 1079 if (opt > LLC_OPT_MAX_ACK_TMR_EXP) 1080 goto out; 1081 llc->ack_timer.expire = opt * HZ; 1082 break; 1083 case LLC_OPT_P_TMR_EXP: 1084 if (opt > LLC_OPT_MAX_P_TMR_EXP) 1085 goto out; 1086 llc->pf_cycle_timer.expire = opt * HZ; 1087 break; 1088 case LLC_OPT_REJ_TMR_EXP: 1089 if (opt > LLC_OPT_MAX_REJ_TMR_EXP) 1090 goto out; 1091 llc->rej_sent_timer.expire = opt * HZ; 1092 break; 1093 case LLC_OPT_BUSY_TMR_EXP: 1094 if (opt > LLC_OPT_MAX_BUSY_TMR_EXP) 1095 goto out; 1096 llc->busy_state_timer.expire = opt * HZ; 1097 break; 1098 case LLC_OPT_TX_WIN: 1099 if (opt > LLC_OPT_MAX_WIN) 1100 goto out; 1101 llc->k = opt; 1102 break; 1103 case LLC_OPT_RX_WIN: 1104 if (opt > LLC_OPT_MAX_WIN) 1105 goto out; 1106 llc->rw = opt; 1107 break; 1108 case LLC_OPT_PKTINFO: 1109 if (opt) 1110 llc->cmsg_flags |= LLC_CMSG_PKTINFO; 1111 else 1112 llc->cmsg_flags &= ~LLC_CMSG_PKTINFO; 1113 break; 1114 default: 1115 rc = -ENOPROTOOPT; 1116 goto out; 1117 } 1118 rc = 0; 1119 out: 1120 release_sock(sk); 1121 return rc; 1122 } 1123 1124 /** 1125 * llc_ui_getsockopt - get connection specific socket info 1126 * @sock: Socket to get information from. 1127 * @level: Socket level user is requesting operations on. 1128 * @optname: Operation name. 1129 * @optval: Variable to return operation data in. 1130 * @optlen: Length of optval. 1131 * 1132 * Get connection specific socket information. 1133 */ 1134 static int llc_ui_getsockopt(struct socket *sock, int level, int optname, 1135 char __user *optval, int __user *optlen) 1136 { 1137 struct sock *sk = sock->sk; 1138 struct llc_sock *llc = llc_sk(sk); 1139 int val = 0, len = 0, rc = -EINVAL; 1140 1141 lock_sock(sk); 1142 if (unlikely(level != SOL_LLC)) 1143 goto out; 1144 rc = get_user(len, optlen); 1145 if (rc) 1146 goto out; 1147 rc = -EINVAL; 1148 if (len != sizeof(int)) 1149 goto out; 1150 switch (optname) { 1151 case LLC_OPT_RETRY: 1152 val = llc->n2; break; 1153 case LLC_OPT_SIZE: 1154 val = llc->n1; break; 1155 case LLC_OPT_ACK_TMR_EXP: 1156 val = llc->ack_timer.expire / HZ; break; 1157 case LLC_OPT_P_TMR_EXP: 1158 val = llc->pf_cycle_timer.expire / HZ; break; 1159 case LLC_OPT_REJ_TMR_EXP: 1160 val = llc->rej_sent_timer.expire / HZ; break; 1161 case LLC_OPT_BUSY_TMR_EXP: 1162 val = llc->busy_state_timer.expire / HZ; break; 1163 case LLC_OPT_TX_WIN: 1164 val = llc->k; break; 1165 case LLC_OPT_RX_WIN: 1166 val = llc->rw; break; 1167 case LLC_OPT_PKTINFO: 1168 val = (llc->cmsg_flags & LLC_CMSG_PKTINFO) != 0; 1169 break; 1170 default: 1171 rc = -ENOPROTOOPT; 1172 goto out; 1173 } 1174 rc = 0; 1175 if (put_user(len, optlen) || copy_to_user(optval, &val, len)) 1176 rc = -EFAULT; 1177 out: 1178 release_sock(sk); 1179 return rc; 1180 } 1181 1182 static const struct net_proto_family llc_ui_family_ops = { 1183 .family = PF_LLC, 1184 .create = llc_ui_create, 1185 .owner = THIS_MODULE, 1186 }; 1187 1188 static const struct proto_ops llc_ui_ops = { 1189 .family = PF_LLC, 1190 .owner = THIS_MODULE, 1191 .release = llc_ui_release, 1192 .bind = llc_ui_bind, 1193 .connect = llc_ui_connect, 1194 .socketpair = sock_no_socketpair, 1195 .accept = llc_ui_accept, 1196 .getname = llc_ui_getname, 1197 .poll = datagram_poll, 1198 .ioctl = llc_ui_ioctl, 1199 .listen = llc_ui_listen, 1200 .shutdown = llc_ui_shutdown, 1201 .setsockopt = llc_ui_setsockopt, 1202 .getsockopt = llc_ui_getsockopt, 1203 .sendmsg = llc_ui_sendmsg, 1204 .recvmsg = llc_ui_recvmsg, 1205 .mmap = sock_no_mmap, 1206 .sendpage = sock_no_sendpage, 1207 }; 1208 1209 static const char llc_proc_err_msg[] __initconst = 1210 KERN_CRIT "LLC: Unable to register the proc_fs entries\n"; 1211 static const char llc_sysctl_err_msg[] __initconst = 1212 KERN_CRIT "LLC: Unable to register the sysctl entries\n"; 1213 static const char llc_sock_err_msg[] __initconst = 1214 KERN_CRIT "LLC: Unable to register the network family\n"; 1215 1216 static int __init llc2_init(void) 1217 { 1218 int rc = proto_register(&llc_proto, 0); 1219 1220 if (rc != 0) 1221 goto out; 1222 1223 llc_build_offset_table(); 1224 llc_station_init(); 1225 llc_ui_sap_last_autoport = LLC_SAP_DYN_START; 1226 rc = llc_proc_init(); 1227 if (rc != 0) { 1228 printk(llc_proc_err_msg); 1229 goto out_station; 1230 } 1231 rc = llc_sysctl_init(); 1232 if (rc) { 1233 printk(llc_sysctl_err_msg); 1234 goto out_proc; 1235 } 1236 rc = sock_register(&llc_ui_family_ops); 1237 if (rc) { 1238 printk(llc_sock_err_msg); 1239 goto out_sysctl; 1240 } 1241 llc_add_pack(LLC_DEST_SAP, llc_sap_handler); 1242 llc_add_pack(LLC_DEST_CONN, llc_conn_handler); 1243 out: 1244 return rc; 1245 out_sysctl: 1246 llc_sysctl_exit(); 1247 out_proc: 1248 llc_proc_exit(); 1249 out_station: 1250 llc_station_exit(); 1251 proto_unregister(&llc_proto); 1252 goto out; 1253 } 1254 1255 static void __exit llc2_exit(void) 1256 { 1257 llc_station_exit(); 1258 llc_remove_pack(LLC_DEST_SAP); 1259 llc_remove_pack(LLC_DEST_CONN); 1260 sock_unregister(PF_LLC); 1261 llc_proc_exit(); 1262 llc_sysctl_exit(); 1263 proto_unregister(&llc_proto); 1264 } 1265 1266 module_init(llc2_init); 1267 module_exit(llc2_exit); 1268 1269 MODULE_LICENSE("GPL"); 1270 MODULE_AUTHOR("Procom 1997, Jay Schullist 2001, Arnaldo C. Melo 2001-2003"); 1271 MODULE_DESCRIPTION("IEEE 802.2 PF_LLC support"); 1272 MODULE_ALIAS_NETPROTO(PF_LLC); 1273