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