af_llc.c revision f4f8720febf0d785a054fc09bde5e3ad09728a58
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 <net/llc.h> 30#include <net/llc_sap.h> 31#include <net/llc_pdu.h> 32#include <net/llc_conn.h> 33#include <net/tcp_states.h> 34 35/* remember: uninitialized global data is zeroed because its in .bss */ 36static u16 llc_ui_sap_last_autoport = LLC_SAP_DYN_START; 37static u16 llc_ui_sap_link_no_max[256]; 38static struct sockaddr_llc llc_ui_addrnull; 39static const struct proto_ops llc_ui_ops; 40 41static int llc_ui_wait_for_conn(struct sock *sk, long timeout); 42static int llc_ui_wait_for_disc(struct sock *sk, long timeout); 43static int llc_ui_wait_for_busy_core(struct sock *sk, long timeout); 44 45#if 0 46#define dprintk(args...) printk(KERN_DEBUG args) 47#else 48#define dprintk(args...) 49#endif 50 51/* Maybe we'll add some more in the future. */ 52#define LLC_CMSG_PKTINFO 1 53 54 55/** 56 * llc_ui_next_link_no - return the next unused link number for a sap 57 * @sap: Address of sap to get link number from. 58 * 59 * Return the next unused link number for a given sap. 60 */ 61static inline u16 llc_ui_next_link_no(int sap) 62{ 63 return llc_ui_sap_link_no_max[sap]++; 64} 65 66/** 67 * llc_proto_type - return eth protocol for ARP header type 68 * @arphrd: ARP header type. 69 * 70 * Given an ARP header type return the corresponding ethernet protocol. 71 */ 72static inline __be16 llc_proto_type(u16 arphrd) 73{ 74 return htons(ETH_P_802_2); 75} 76 77/** 78 * llc_ui_addr_null - determines if a address structure is null 79 * @addr: Address to test if null. 80 */ 81static inline u8 llc_ui_addr_null(struct sockaddr_llc *addr) 82{ 83 return !memcmp(addr, &llc_ui_addrnull, sizeof(*addr)); 84} 85 86/** 87 * llc_ui_header_len - return length of llc header based on operation 88 * @sk: Socket which contains a valid llc socket type. 89 * @addr: Complete sockaddr_llc structure received from the user. 90 * 91 * Provide the length of the llc header depending on what kind of 92 * operation the user would like to perform and the type of socket. 93 * Returns the correct llc header length. 94 */ 95static inline u8 llc_ui_header_len(struct sock *sk, struct sockaddr_llc *addr) 96{ 97 u8 rc = LLC_PDU_LEN_U; 98 99 if (addr->sllc_test || addr->sllc_xid) 100 rc = LLC_PDU_LEN_U; 101 else if (sk->sk_type == SOCK_STREAM) 102 rc = LLC_PDU_LEN_I; 103 return rc; 104} 105 106/** 107 * llc_ui_send_data - send data via reliable llc2 connection 108 * @sk: Connection the socket is using. 109 * @skb: Data the user wishes to send. 110 * @noblock: can we block waiting for data? 111 * 112 * Send data via reliable llc2 connection. 113 * Returns 0 upon success, non-zero if action did not succeed. 114 */ 115static int llc_ui_send_data(struct sock* sk, struct sk_buff *skb, int noblock) 116{ 117 struct llc_sock* llc = llc_sk(sk); 118 int rc = 0; 119 120 if (unlikely(llc_data_accept_state(llc->state) || 121 llc->remote_busy_flag || 122 llc->p_flag)) { 123 long timeout = sock_sndtimeo(sk, noblock); 124 125 rc = llc_ui_wait_for_busy_core(sk, timeout); 126 } 127 if (unlikely(!rc)) 128 rc = llc_build_and_send_pkt(sk, skb); 129 return rc; 130} 131 132static void llc_ui_sk_init(struct socket *sock, struct sock *sk) 133{ 134 sock_graft(sk, sock); 135 sk->sk_type = sock->type; 136 sock->ops = &llc_ui_ops; 137} 138 139static struct proto llc_proto = { 140 .name = "LLC", 141 .owner = THIS_MODULE, 142 .obj_size = sizeof(struct llc_sock), 143 .slab_flags = SLAB_DESTROY_BY_RCU, 144}; 145 146/** 147 * llc_ui_create - alloc and init a new llc_ui socket 148 * @net: network namespace (must be default network) 149 * @sock: Socket to initialize and attach allocated sk to. 150 * @protocol: Unused. 151 * @kern: on behalf of kernel or userspace 152 * 153 * Allocate and initialize a new llc_ui socket, validate the user wants a 154 * socket type we have available. 155 * Returns 0 upon success, negative upon failure. 156 */ 157static int llc_ui_create(struct net *net, struct socket *sock, int protocol, 158 int kern) 159{ 160 struct sock *sk; 161 int rc = -ESOCKTNOSUPPORT; 162 163 if (!capable(CAP_NET_RAW)) 164 return -EPERM; 165 166 if (!net_eq(net, &init_net)) 167 return -EAFNOSUPPORT; 168 169 if (likely(sock->type == SOCK_DGRAM || sock->type == SOCK_STREAM)) { 170 rc = -ENOMEM; 171 sk = llc_sk_alloc(net, PF_LLC, GFP_KERNEL, &llc_proto); 172 if (sk) { 173 rc = 0; 174 llc_ui_sk_init(sock, sk); 175 } 176 } 177 return rc; 178} 179 180/** 181 * llc_ui_release - shutdown socket 182 * @sock: Socket to release. 183 * 184 * Shutdown and deallocate an existing socket. 185 */ 186static int llc_ui_release(struct socket *sock) 187{ 188 struct sock *sk = sock->sk; 189 struct llc_sock *llc; 190 191 if (unlikely(sk == NULL)) 192 goto out; 193 sock_hold(sk); 194 lock_sock(sk); 195 llc = llc_sk(sk); 196 dprintk("%s: closing local(%02X) remote(%02X)\n", __func__, 197 llc->laddr.lsap, llc->daddr.lsap); 198 if (!llc_send_disc(sk)) 199 llc_ui_wait_for_disc(sk, sk->sk_rcvtimeo); 200 if (!sock_flag(sk, SOCK_ZAPPED)) 201 llc_sap_remove_socket(llc->sap, sk); 202 release_sock(sk); 203 if (llc->dev) 204 dev_put(llc->dev); 205 sock_put(sk); 206 llc_sk_free(sk); 207out: 208 return 0; 209} 210 211/** 212 * llc_ui_autoport - provide dynamically allocate SAP number 213 * 214 * Provide the caller with a dynamically allocated SAP number according 215 * to the rules that are set in this function. Returns: 0, upon failure, 216 * SAP number otherwise. 217 */ 218static int llc_ui_autoport(void) 219{ 220 struct llc_sap *sap; 221 int i, tries = 0; 222 223 while (tries < LLC_SAP_DYN_TRIES) { 224 for (i = llc_ui_sap_last_autoport; 225 i < LLC_SAP_DYN_STOP; i += 2) { 226 sap = llc_sap_find(i); 227 if (!sap) { 228 llc_ui_sap_last_autoport = i + 2; 229 goto out; 230 } 231 llc_sap_put(sap); 232 } 233 llc_ui_sap_last_autoport = LLC_SAP_DYN_START; 234 tries++; 235 } 236 i = 0; 237out: 238 return i; 239} 240 241/** 242 * llc_ui_autobind - automatically bind a socket to a sap 243 * @sock: socket to bind 244 * @addr: address to connect to 245 * 246 * Used by llc_ui_connect and llc_ui_sendmsg when the user hasn't 247 * specifically used llc_ui_bind to bind to an specific address/sap 248 * 249 * Returns: 0 upon success, negative otherwise. 250 */ 251static int llc_ui_autobind(struct socket *sock, struct sockaddr_llc *addr) 252{ 253 struct sock *sk = sock->sk; 254 struct llc_sock *llc = llc_sk(sk); 255 struct llc_sap *sap; 256 int rc = -EINVAL; 257 258 if (!sock_flag(sk, SOCK_ZAPPED)) 259 goto out; 260 rc = -ENODEV; 261 if (sk->sk_bound_dev_if) { 262 llc->dev = dev_get_by_index(&init_net, sk->sk_bound_dev_if); 263 if (llc->dev && addr->sllc_arphrd != llc->dev->type) { 264 dev_put(llc->dev); 265 llc->dev = NULL; 266 } 267 } else 268 llc->dev = dev_getfirstbyhwtype(&init_net, addr->sllc_arphrd); 269 if (!llc->dev) 270 goto out; 271 rc = -EUSERS; 272 llc->laddr.lsap = llc_ui_autoport(); 273 if (!llc->laddr.lsap) 274 goto out; 275 rc = -EBUSY; /* some other network layer is using the sap */ 276 sap = llc_sap_open(llc->laddr.lsap, NULL); 277 if (!sap) 278 goto out; 279 memcpy(llc->laddr.mac, llc->dev->dev_addr, IFHWADDRLEN); 280 memcpy(&llc->addr, addr, sizeof(llc->addr)); 281 /* assign new connection to its SAP */ 282 llc_sap_add_socket(sap, sk); 283 sock_reset_flag(sk, SOCK_ZAPPED); 284 rc = 0; 285out: 286 return rc; 287} 288 289/** 290 * llc_ui_bind - bind a socket to a specific address. 291 * @sock: Socket to bind an address to. 292 * @uaddr: Address the user wants the socket bound to. 293 * @addrlen: Length of the uaddr structure. 294 * 295 * Bind a socket to a specific address. For llc a user is able to bind to 296 * a specific sap only or mac + sap. 297 * If the user desires to bind to a specific mac + sap, it is possible to 298 * have multiple sap connections via multiple macs. 299 * Bind and autobind for that matter must enforce the correct sap usage 300 * otherwise all hell will break loose. 301 * Returns: 0 upon success, negative otherwise. 302 */ 303static int llc_ui_bind(struct socket *sock, struct sockaddr *uaddr, int addrlen) 304{ 305 struct sockaddr_llc *addr = (struct sockaddr_llc *)uaddr; 306 struct sock *sk = sock->sk; 307 struct llc_sock *llc = llc_sk(sk); 308 struct llc_sap *sap; 309 int rc = -EINVAL; 310 311 dprintk("%s: binding %02X\n", __func__, addr->sllc_sap); 312 if (unlikely(!sock_flag(sk, SOCK_ZAPPED) || addrlen != sizeof(*addr))) 313 goto out; 314 rc = -EAFNOSUPPORT; 315 if (unlikely(addr->sllc_family != AF_LLC)) 316 goto out; 317 rc = -ENODEV; 318 rcu_read_lock(); 319 if (sk->sk_bound_dev_if) { 320 llc->dev = dev_get_by_index_rcu(&init_net, sk->sk_bound_dev_if); 321 if (llc->dev) { 322 if (!addr->sllc_arphrd) 323 addr->sllc_arphrd = llc->dev->type; 324 if (llc_mac_null(addr->sllc_mac)) 325 memcpy(addr->sllc_mac, llc->dev->dev_addr, 326 IFHWADDRLEN); 327 if (addr->sllc_arphrd != llc->dev->type || 328 !llc_mac_match(addr->sllc_mac, 329 llc->dev->dev_addr)) { 330 rc = -EINVAL; 331 llc->dev = NULL; 332 } 333 } 334 } else 335 llc->dev = dev_getbyhwaddr_rcu(&init_net, addr->sllc_arphrd, 336 addr->sllc_mac); 337 if (llc->dev) 338 dev_hold(llc->dev); 339 rcu_read_unlock(); 340 if (!llc->dev) 341 goto out; 342 if (!addr->sllc_sap) { 343 rc = -EUSERS; 344 addr->sllc_sap = llc_ui_autoport(); 345 if (!addr->sllc_sap) 346 goto out; 347 } 348 sap = llc_sap_find(addr->sllc_sap); 349 if (!sap) { 350 sap = llc_sap_open(addr->sllc_sap, NULL); 351 rc = -EBUSY; /* some other network layer is using the sap */ 352 if (!sap) 353 goto out; 354 } else { 355 struct llc_addr laddr, daddr; 356 struct sock *ask; 357 358 memset(&laddr, 0, sizeof(laddr)); 359 memset(&daddr, 0, sizeof(daddr)); 360 /* 361 * FIXME: check if the address is multicast, 362 * only SOCK_DGRAM can do this. 363 */ 364 memcpy(laddr.mac, addr->sllc_mac, IFHWADDRLEN); 365 laddr.lsap = addr->sllc_sap; 366 rc = -EADDRINUSE; /* mac + sap clash. */ 367 ask = llc_lookup_established(sap, &daddr, &laddr); 368 if (ask) { 369 sock_put(ask); 370 goto out_put; 371 } 372 } 373 llc->laddr.lsap = addr->sllc_sap; 374 memcpy(llc->laddr.mac, addr->sllc_mac, IFHWADDRLEN); 375 memcpy(&llc->addr, addr, sizeof(llc->addr)); 376 /* assign new connection to its SAP */ 377 llc_sap_add_socket(sap, sk); 378 sock_reset_flag(sk, SOCK_ZAPPED); 379 rc = 0; 380out_put: 381 llc_sap_put(sap); 382out: 383 return rc; 384} 385 386/** 387 * llc_ui_shutdown - shutdown a connect llc2 socket. 388 * @sock: Socket to shutdown. 389 * @how: What part of the socket to shutdown. 390 * 391 * Shutdown a connected llc2 socket. Currently this function only supports 392 * shutting down both sends and receives (2), we could probably make this 393 * function such that a user can shutdown only half the connection but not 394 * right now. 395 * Returns: 0 upon success, negative otherwise. 396 */ 397static int llc_ui_shutdown(struct socket *sock, int how) 398{ 399 struct sock *sk = sock->sk; 400 int rc = -ENOTCONN; 401 402 lock_sock(sk); 403 if (unlikely(sk->sk_state != TCP_ESTABLISHED)) 404 goto out; 405 rc = -EINVAL; 406 if (how != 2) 407 goto out; 408 rc = llc_send_disc(sk); 409 if (!rc) 410 rc = llc_ui_wait_for_disc(sk, sk->sk_rcvtimeo); 411 /* Wake up anyone sleeping in poll */ 412 sk->sk_state_change(sk); 413out: 414 release_sock(sk); 415 return rc; 416} 417 418/** 419 * llc_ui_connect - Connect to a remote llc2 mac + sap. 420 * @sock: Socket which will be connected to the remote destination. 421 * @uaddr: Remote and possibly the local address of the new connection. 422 * @addrlen: Size of uaddr structure. 423 * @flags: Operational flags specified by the user. 424 * 425 * Connect to a remote llc2 mac + sap. The caller must specify the 426 * destination mac and address to connect to. If the user hasn't previously 427 * called bind(2) with a smac the address of the first interface of the 428 * specified arp type will be used. 429 * This function will autobind if user did not previously call bind. 430 * Returns: 0 upon success, negative otherwise. 431 */ 432static int llc_ui_connect(struct socket *sock, struct sockaddr *uaddr, 433 int addrlen, int flags) 434{ 435 struct sock *sk = sock->sk; 436 struct llc_sock *llc = llc_sk(sk); 437 struct sockaddr_llc *addr = (struct sockaddr_llc *)uaddr; 438 int rc = -EINVAL; 439 440 lock_sock(sk); 441 if (unlikely(addrlen != sizeof(*addr))) 442 goto out; 443 rc = -EAFNOSUPPORT; 444 if (unlikely(addr->sllc_family != AF_LLC)) 445 goto out; 446 if (unlikely(sk->sk_type != SOCK_STREAM)) 447 goto out; 448 rc = -EALREADY; 449 if (unlikely(sock->state == SS_CONNECTING)) 450 goto out; 451 /* bind connection to sap if user hasn't done it. */ 452 if (sock_flag(sk, SOCK_ZAPPED)) { 453 /* bind to sap with null dev, exclusive */ 454 rc = llc_ui_autobind(sock, addr); 455 if (rc) 456 goto out; 457 } 458 llc->daddr.lsap = addr->sllc_sap; 459 memcpy(llc->daddr.mac, addr->sllc_mac, IFHWADDRLEN); 460 sock->state = SS_CONNECTING; 461 sk->sk_state = TCP_SYN_SENT; 462 llc->link = llc_ui_next_link_no(llc->sap->laddr.lsap); 463 rc = llc_establish_connection(sk, llc->dev->dev_addr, 464 addr->sllc_mac, addr->sllc_sap); 465 if (rc) { 466 dprintk("%s: llc_ui_send_conn failed :-(\n", __func__); 467 sock->state = SS_UNCONNECTED; 468 sk->sk_state = TCP_CLOSE; 469 goto out; 470 } 471 472 if (sk->sk_state == TCP_SYN_SENT) { 473 const long timeo = sock_sndtimeo(sk, flags & O_NONBLOCK); 474 475 if (!timeo || !llc_ui_wait_for_conn(sk, timeo)) 476 goto out; 477 478 rc = sock_intr_errno(timeo); 479 if (signal_pending(current)) 480 goto out; 481 } 482 483 if (sk->sk_state == TCP_CLOSE) 484 goto sock_error; 485 486 sock->state = SS_CONNECTED; 487 rc = 0; 488out: 489 release_sock(sk); 490 return rc; 491sock_error: 492 rc = sock_error(sk) ? : -ECONNABORTED; 493 sock->state = SS_UNCONNECTED; 494 goto out; 495} 496 497/** 498 * llc_ui_listen - allow a normal socket to accept incoming connections 499 * @sock: Socket to allow incoming connections on. 500 * @backlog: Number of connections to queue. 501 * 502 * Allow a normal socket to accept incoming connections. 503 * Returns 0 upon success, negative otherwise. 504 */ 505static int llc_ui_listen(struct socket *sock, int backlog) 506{ 507 struct sock *sk = sock->sk; 508 int rc = -EINVAL; 509 510 lock_sock(sk); 511 if (unlikely(sock->state != SS_UNCONNECTED)) 512 goto out; 513 rc = -EOPNOTSUPP; 514 if (unlikely(sk->sk_type != SOCK_STREAM)) 515 goto out; 516 rc = -EAGAIN; 517 if (sock_flag(sk, SOCK_ZAPPED)) 518 goto out; 519 rc = 0; 520 if (!(unsigned int)backlog) /* BSDism */ 521 backlog = 1; 522 sk->sk_max_ack_backlog = backlog; 523 if (sk->sk_state != TCP_LISTEN) { 524 sk->sk_ack_backlog = 0; 525 sk->sk_state = TCP_LISTEN; 526 } 527 sk->sk_socket->flags |= __SO_ACCEPTCON; 528out: 529 release_sock(sk); 530 return rc; 531} 532 533static int llc_ui_wait_for_disc(struct sock *sk, long timeout) 534{ 535 DEFINE_WAIT(wait); 536 int rc = 0; 537 538 while (1) { 539 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE); 540 if (sk_wait_event(sk, &timeout, sk->sk_state == TCP_CLOSE)) 541 break; 542 rc = -ERESTARTSYS; 543 if (signal_pending(current)) 544 break; 545 rc = -EAGAIN; 546 if (!timeout) 547 break; 548 rc = 0; 549 } 550 finish_wait(sk_sleep(sk), &wait); 551 return rc; 552} 553 554static int llc_ui_wait_for_conn(struct sock *sk, long timeout) 555{ 556 DEFINE_WAIT(wait); 557 558 while (1) { 559 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE); 560 if (sk_wait_event(sk, &timeout, sk->sk_state != TCP_SYN_SENT)) 561 break; 562 if (signal_pending(current) || !timeout) 563 break; 564 } 565 finish_wait(sk_sleep(sk), &wait); 566 return timeout; 567} 568 569static int llc_ui_wait_for_busy_core(struct sock *sk, long timeout) 570{ 571 DEFINE_WAIT(wait); 572 struct llc_sock *llc = llc_sk(sk); 573 int rc; 574 575 while (1) { 576 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE); 577 rc = 0; 578 if (sk_wait_event(sk, &timeout, 579 (sk->sk_shutdown & RCV_SHUTDOWN) || 580 (!llc_data_accept_state(llc->state) && 581 !llc->remote_busy_flag && 582 !llc->p_flag))) 583 break; 584 rc = -ERESTARTSYS; 585 if (signal_pending(current)) 586 break; 587 rc = -EAGAIN; 588 if (!timeout) 589 break; 590 } 591 finish_wait(sk_sleep(sk), &wait); 592 return rc; 593} 594 595static int llc_wait_data(struct sock *sk, long timeo) 596{ 597 int rc; 598 599 while (1) { 600 /* 601 * POSIX 1003.1g mandates this order. 602 */ 603 rc = sock_error(sk); 604 if (rc) 605 break; 606 rc = 0; 607 if (sk->sk_shutdown & RCV_SHUTDOWN) 608 break; 609 rc = -EAGAIN; 610 if (!timeo) 611 break; 612 rc = sock_intr_errno(timeo); 613 if (signal_pending(current)) 614 break; 615 rc = 0; 616 if (sk_wait_data(sk, &timeo)) 617 break; 618 } 619 return rc; 620} 621 622static void llc_cmsg_rcv(struct msghdr *msg, struct sk_buff *skb) 623{ 624 struct llc_sock *llc = llc_sk(skb->sk); 625 626 if (llc->cmsg_flags & LLC_CMSG_PKTINFO) { 627 struct llc_pktinfo info; 628 629 info.lpi_ifindex = llc_sk(skb->sk)->dev->ifindex; 630 llc_pdu_decode_dsap(skb, &info.lpi_sap); 631 llc_pdu_decode_da(skb, info.lpi_mac); 632 put_cmsg(msg, SOL_LLC, LLC_OPT_PKTINFO, sizeof(info), &info); 633 } 634} 635 636/** 637 * llc_ui_accept - accept a new incoming connection. 638 * @sock: Socket which connections arrive on. 639 * @newsock: Socket to move incoming connection to. 640 * @flags: User specified operational flags. 641 * 642 * Accept a new incoming connection. 643 * Returns 0 upon success, negative otherwise. 644 */ 645static int llc_ui_accept(struct socket *sock, struct socket *newsock, int flags) 646{ 647 struct sock *sk = sock->sk, *newsk; 648 struct llc_sock *llc, *newllc; 649 struct sk_buff *skb; 650 int rc = -EOPNOTSUPP; 651 652 dprintk("%s: accepting on %02X\n", __func__, 653 llc_sk(sk)->laddr.lsap); 654 lock_sock(sk); 655 if (unlikely(sk->sk_type != SOCK_STREAM)) 656 goto out; 657 rc = -EINVAL; 658 if (unlikely(sock->state != SS_UNCONNECTED || 659 sk->sk_state != TCP_LISTEN)) 660 goto out; 661 /* wait for a connection to arrive. */ 662 if (skb_queue_empty(&sk->sk_receive_queue)) { 663 rc = llc_wait_data(sk, sk->sk_rcvtimeo); 664 if (rc) 665 goto out; 666 } 667 dprintk("%s: got a new connection on %02X\n", __func__, 668 llc_sk(sk)->laddr.lsap); 669 skb = skb_dequeue(&sk->sk_receive_queue); 670 rc = -EINVAL; 671 if (!skb->sk) 672 goto frees; 673 rc = 0; 674 newsk = skb->sk; 675 /* attach connection to a new socket. */ 676 llc_ui_sk_init(newsock, newsk); 677 sock_reset_flag(newsk, SOCK_ZAPPED); 678 newsk->sk_state = TCP_ESTABLISHED; 679 newsock->state = SS_CONNECTED; 680 llc = llc_sk(sk); 681 newllc = llc_sk(newsk); 682 memcpy(&newllc->addr, &llc->addr, sizeof(newllc->addr)); 683 newllc->link = llc_ui_next_link_no(newllc->laddr.lsap); 684 685 /* put original socket back into a clean listen state. */ 686 sk->sk_state = TCP_LISTEN; 687 sk->sk_ack_backlog--; 688 dprintk("%s: ok success on %02X, client on %02X\n", __func__, 689 llc_sk(sk)->addr.sllc_sap, newllc->daddr.lsap); 690frees: 691 kfree_skb(skb); 692out: 693 release_sock(sk); 694 return rc; 695} 696 697/** 698 * llc_ui_recvmsg - copy received data to the socket user. 699 * @sock: Socket to copy data from. 700 * @msg: Various user space related information. 701 * @len: Size of user buffer. 702 * @flags: User specified flags. 703 * 704 * Copy received data to the socket user. 705 * Returns non-negative upon success, negative otherwise. 706 */ 707static int llc_ui_recvmsg(struct kiocb *iocb, struct socket *sock, 708 struct msghdr *msg, size_t len, int flags) 709{ 710 struct sockaddr_llc *uaddr = (struct sockaddr_llc *)msg->msg_name; 711 const int nonblock = flags & MSG_DONTWAIT; 712 struct sk_buff *skb = NULL; 713 struct sock *sk = sock->sk; 714 struct llc_sock *llc = llc_sk(sk); 715 unsigned long cpu_flags; 716 size_t copied = 0; 717 u32 peek_seq = 0; 718 u32 *seq; 719 unsigned long used; 720 int target; /* Read at least this many bytes */ 721 long timeo; 722 723 lock_sock(sk); 724 copied = -ENOTCONN; 725 if (unlikely(sk->sk_type == SOCK_STREAM && sk->sk_state == TCP_LISTEN)) 726 goto out; 727 728 timeo = sock_rcvtimeo(sk, nonblock); 729 730 seq = &llc->copied_seq; 731 if (flags & MSG_PEEK) { 732 peek_seq = llc->copied_seq; 733 seq = &peek_seq; 734 } 735 736 target = sock_rcvlowat(sk, flags & MSG_WAITALL, len); 737 copied = 0; 738 739 do { 740 u32 offset; 741 742 /* 743 * We need to check signals first, to get correct SIGURG 744 * handling. FIXME: Need to check this doesn't impact 1003.1g 745 * and move it down to the bottom of the loop 746 */ 747 if (signal_pending(current)) { 748 if (copied) 749 break; 750 copied = timeo ? sock_intr_errno(timeo) : -EAGAIN; 751 break; 752 } 753 754 /* Next get a buffer. */ 755 756 skb = skb_peek(&sk->sk_receive_queue); 757 if (skb) { 758 offset = *seq; 759 goto found_ok_skb; 760 } 761 /* Well, if we have backlog, try to process it now yet. */ 762 763 if (copied >= target && !sk->sk_backlog.tail) 764 break; 765 766 if (copied) { 767 if (sk->sk_err || 768 sk->sk_state == TCP_CLOSE || 769 (sk->sk_shutdown & RCV_SHUTDOWN) || 770 !timeo || 771 (flags & MSG_PEEK)) 772 break; 773 } else { 774 if (sock_flag(sk, SOCK_DONE)) 775 break; 776 777 if (sk->sk_err) { 778 copied = sock_error(sk); 779 break; 780 } 781 if (sk->sk_shutdown & RCV_SHUTDOWN) 782 break; 783 784 if (sk->sk_type == SOCK_STREAM && sk->sk_state == TCP_CLOSE) { 785 if (!sock_flag(sk, SOCK_DONE)) { 786 /* 787 * This occurs when user tries to read 788 * from never connected socket. 789 */ 790 copied = -ENOTCONN; 791 break; 792 } 793 break; 794 } 795 if (!timeo) { 796 copied = -EAGAIN; 797 break; 798 } 799 } 800 801 if (copied >= target) { /* Do not sleep, just process backlog. */ 802 release_sock(sk); 803 lock_sock(sk); 804 } else 805 sk_wait_data(sk, &timeo); 806 807 if ((flags & MSG_PEEK) && peek_seq != llc->copied_seq) { 808 net_dbg_ratelimited("LLC(%s:%d): Application bug, race in MSG_PEEK\n", 809 current->comm, 810 task_pid_nr(current)); 811 peek_seq = llc->copied_seq; 812 } 813 continue; 814 found_ok_skb: 815 /* Ok so how much can we use? */ 816 used = skb->len - offset; 817 if (len < used) 818 used = len; 819 820 if (!(flags & MSG_TRUNC)) { 821 int rc = skb_copy_datagram_iovec(skb, offset, 822 msg->msg_iov, used); 823 if (rc) { 824 /* Exception. Bailout! */ 825 if (!copied) 826 copied = -EFAULT; 827 break; 828 } 829 } 830 831 *seq += used; 832 copied += used; 833 len -= used; 834 835 /* For non stream protcols we get one packet per recvmsg call */ 836 if (sk->sk_type != SOCK_STREAM) 837 goto copy_uaddr; 838 839 if (!(flags & MSG_PEEK)) { 840 spin_lock_irqsave(&sk->sk_receive_queue.lock, cpu_flags); 841 sk_eat_skb(sk, skb, false); 842 spin_unlock_irqrestore(&sk->sk_receive_queue.lock, cpu_flags); 843 *seq = 0; 844 } 845 846 /* Partial read */ 847 if (used + offset < skb->len) 848 continue; 849 } while (len > 0); 850 851out: 852 release_sock(sk); 853 return copied; 854copy_uaddr: 855 if (uaddr != NULL && skb != NULL) { 856 memcpy(uaddr, llc_ui_skb_cb(skb), sizeof(*uaddr)); 857 msg->msg_namelen = sizeof(*uaddr); 858 } 859 if (llc_sk(sk)->cmsg_flags) 860 llc_cmsg_rcv(msg, skb); 861 862 if (!(flags & MSG_PEEK)) { 863 spin_lock_irqsave(&sk->sk_receive_queue.lock, cpu_flags); 864 sk_eat_skb(sk, skb, false); 865 spin_unlock_irqrestore(&sk->sk_receive_queue.lock, cpu_flags); 866 *seq = 0; 867 } 868 869 goto out; 870} 871 872/** 873 * llc_ui_sendmsg - Transmit data provided by the socket user. 874 * @sock: Socket to transmit data from. 875 * @msg: Various user related information. 876 * @len: Length of data to transmit. 877 * 878 * Transmit data provided by the socket user. 879 * Returns non-negative upon success, negative otherwise. 880 */ 881static int llc_ui_sendmsg(struct kiocb *iocb, struct socket *sock, 882 struct msghdr *msg, size_t len) 883{ 884 struct sock *sk = sock->sk; 885 struct llc_sock *llc = llc_sk(sk); 886 struct sockaddr_llc *addr = (struct sockaddr_llc *)msg->msg_name; 887 int flags = msg->msg_flags; 888 int noblock = flags & MSG_DONTWAIT; 889 struct sk_buff *skb; 890 size_t size = 0; 891 int rc = -EINVAL, copied = 0, hdrlen; 892 893 dprintk("%s: sending from %02X to %02X\n", __func__, 894 llc->laddr.lsap, llc->daddr.lsap); 895 lock_sock(sk); 896 if (addr) { 897 if (msg->msg_namelen < sizeof(*addr)) 898 goto release; 899 } else { 900 if (llc_ui_addr_null(&llc->addr)) 901 goto release; 902 addr = &llc->addr; 903 } 904 /* must bind connection to sap if user hasn't done it. */ 905 if (sock_flag(sk, SOCK_ZAPPED)) { 906 /* bind to sap with null dev, exclusive. */ 907 rc = llc_ui_autobind(sock, addr); 908 if (rc) 909 goto release; 910 } 911 hdrlen = llc->dev->hard_header_len + llc_ui_header_len(sk, addr); 912 size = hdrlen + len; 913 if (size > llc->dev->mtu) 914 size = llc->dev->mtu; 915 copied = size - hdrlen; 916 release_sock(sk); 917 skb = sock_alloc_send_skb(sk, size, noblock, &rc); 918 lock_sock(sk); 919 if (!skb) 920 goto release; 921 skb->dev = llc->dev; 922 skb->protocol = llc_proto_type(addr->sllc_arphrd); 923 skb_reserve(skb, hdrlen); 924 rc = memcpy_fromiovec(skb_put(skb, copied), msg->msg_iov, copied); 925 if (rc) 926 goto out; 927 if (sk->sk_type == SOCK_DGRAM || addr->sllc_ua) { 928 llc_build_and_send_ui_pkt(llc->sap, skb, addr->sllc_mac, 929 addr->sllc_sap); 930 goto out; 931 } 932 if (addr->sllc_test) { 933 llc_build_and_send_test_pkt(llc->sap, skb, addr->sllc_mac, 934 addr->sllc_sap); 935 goto out; 936 } 937 if (addr->sllc_xid) { 938 llc_build_and_send_xid_pkt(llc->sap, skb, addr->sllc_mac, 939 addr->sllc_sap); 940 goto out; 941 } 942 rc = -ENOPROTOOPT; 943 if (!(sk->sk_type == SOCK_STREAM && !addr->sllc_ua)) 944 goto out; 945 rc = llc_ui_send_data(sk, skb, noblock); 946out: 947 if (rc) { 948 kfree_skb(skb); 949release: 950 dprintk("%s: failed sending from %02X to %02X: %d\n", 951 __func__, llc->laddr.lsap, llc->daddr.lsap, rc); 952 } 953 release_sock(sk); 954 return rc ? : copied; 955} 956 957/** 958 * llc_ui_getname - return the address info of a socket 959 * @sock: Socket to get address of. 960 * @uaddr: Address structure to return information. 961 * @uaddrlen: Length of address structure. 962 * @peer: Does user want local or remote address information. 963 * 964 * Return the address information of a socket. 965 */ 966static int llc_ui_getname(struct socket *sock, struct sockaddr *uaddr, 967 int *uaddrlen, int peer) 968{ 969 struct sockaddr_llc sllc; 970 struct sock *sk = sock->sk; 971 struct llc_sock *llc = llc_sk(sk); 972 int rc = 0; 973 974 memset(&sllc, 0, sizeof(sllc)); 975 lock_sock(sk); 976 if (sock_flag(sk, SOCK_ZAPPED)) 977 goto out; 978 *uaddrlen = sizeof(sllc); 979 memset(uaddr, 0, *uaddrlen); 980 if (peer) { 981 rc = -ENOTCONN; 982 if (sk->sk_state != TCP_ESTABLISHED) 983 goto out; 984 if(llc->dev) 985 sllc.sllc_arphrd = llc->dev->type; 986 sllc.sllc_sap = llc->daddr.lsap; 987 memcpy(&sllc.sllc_mac, &llc->daddr.mac, IFHWADDRLEN); 988 } else { 989 rc = -EINVAL; 990 if (!llc->sap) 991 goto out; 992 sllc.sllc_sap = llc->sap->laddr.lsap; 993 994 if (llc->dev) { 995 sllc.sllc_arphrd = llc->dev->type; 996 memcpy(&sllc.sllc_mac, llc->dev->dev_addr, 997 IFHWADDRLEN); 998 } 999 } 1000 rc = 0; 1001 sllc.sllc_family = AF_LLC; 1002 memcpy(uaddr, &sllc, sizeof(sllc)); 1003out: 1004 release_sock(sk); 1005 return rc; 1006} 1007 1008/** 1009 * llc_ui_ioctl - io controls for PF_LLC 1010 * @sock: Socket to get/set info 1011 * @cmd: command 1012 * @arg: optional argument for cmd 1013 * 1014 * get/set info on llc sockets 1015 */ 1016static int llc_ui_ioctl(struct socket *sock, unsigned int cmd, 1017 unsigned long arg) 1018{ 1019 return -ENOIOCTLCMD; 1020} 1021 1022/** 1023 * llc_ui_setsockopt - set various connection specific parameters. 1024 * @sock: Socket to set options on. 1025 * @level: Socket level user is requesting operations on. 1026 * @optname: Operation name. 1027 * @optval: User provided operation data. 1028 * @optlen: Length of optval. 1029 * 1030 * Set various connection specific parameters. 1031 */ 1032static int llc_ui_setsockopt(struct socket *sock, int level, int optname, 1033 char __user *optval, unsigned int optlen) 1034{ 1035 struct sock *sk = sock->sk; 1036 struct llc_sock *llc = llc_sk(sk); 1037 unsigned int opt; 1038 int rc = -EINVAL; 1039 1040 lock_sock(sk); 1041 if (unlikely(level != SOL_LLC || optlen != sizeof(int))) 1042 goto out; 1043 rc = get_user(opt, (int __user *)optval); 1044 if (rc) 1045 goto out; 1046 rc = -EINVAL; 1047 switch (optname) { 1048 case LLC_OPT_RETRY: 1049 if (opt > LLC_OPT_MAX_RETRY) 1050 goto out; 1051 llc->n2 = opt; 1052 break; 1053 case LLC_OPT_SIZE: 1054 if (opt > LLC_OPT_MAX_SIZE) 1055 goto out; 1056 llc->n1 = opt; 1057 break; 1058 case LLC_OPT_ACK_TMR_EXP: 1059 if (opt > LLC_OPT_MAX_ACK_TMR_EXP) 1060 goto out; 1061 llc->ack_timer.expire = opt * HZ; 1062 break; 1063 case LLC_OPT_P_TMR_EXP: 1064 if (opt > LLC_OPT_MAX_P_TMR_EXP) 1065 goto out; 1066 llc->pf_cycle_timer.expire = opt * HZ; 1067 break; 1068 case LLC_OPT_REJ_TMR_EXP: 1069 if (opt > LLC_OPT_MAX_REJ_TMR_EXP) 1070 goto out; 1071 llc->rej_sent_timer.expire = opt * HZ; 1072 break; 1073 case LLC_OPT_BUSY_TMR_EXP: 1074 if (opt > LLC_OPT_MAX_BUSY_TMR_EXP) 1075 goto out; 1076 llc->busy_state_timer.expire = opt * HZ; 1077 break; 1078 case LLC_OPT_TX_WIN: 1079 if (opt > LLC_OPT_MAX_WIN) 1080 goto out; 1081 llc->k = opt; 1082 break; 1083 case LLC_OPT_RX_WIN: 1084 if (opt > LLC_OPT_MAX_WIN) 1085 goto out; 1086 llc->rw = opt; 1087 break; 1088 case LLC_OPT_PKTINFO: 1089 if (opt) 1090 llc->cmsg_flags |= LLC_CMSG_PKTINFO; 1091 else 1092 llc->cmsg_flags &= ~LLC_CMSG_PKTINFO; 1093 break; 1094 default: 1095 rc = -ENOPROTOOPT; 1096 goto out; 1097 } 1098 rc = 0; 1099out: 1100 release_sock(sk); 1101 return rc; 1102} 1103 1104/** 1105 * llc_ui_getsockopt - get connection specific socket info 1106 * @sock: Socket to get information from. 1107 * @level: Socket level user is requesting operations on. 1108 * @optname: Operation name. 1109 * @optval: Variable to return operation data in. 1110 * @optlen: Length of optval. 1111 * 1112 * Get connection specific socket information. 1113 */ 1114static int llc_ui_getsockopt(struct socket *sock, int level, int optname, 1115 char __user *optval, int __user *optlen) 1116{ 1117 struct sock *sk = sock->sk; 1118 struct llc_sock *llc = llc_sk(sk); 1119 int val = 0, len = 0, rc = -EINVAL; 1120 1121 lock_sock(sk); 1122 if (unlikely(level != SOL_LLC)) 1123 goto out; 1124 rc = get_user(len, optlen); 1125 if (rc) 1126 goto out; 1127 rc = -EINVAL; 1128 if (len != sizeof(int)) 1129 goto out; 1130 switch (optname) { 1131 case LLC_OPT_RETRY: 1132 val = llc->n2; break; 1133 case LLC_OPT_SIZE: 1134 val = llc->n1; break; 1135 case LLC_OPT_ACK_TMR_EXP: 1136 val = llc->ack_timer.expire / HZ; break; 1137 case LLC_OPT_P_TMR_EXP: 1138 val = llc->pf_cycle_timer.expire / HZ; break; 1139 case LLC_OPT_REJ_TMR_EXP: 1140 val = llc->rej_sent_timer.expire / HZ; break; 1141 case LLC_OPT_BUSY_TMR_EXP: 1142 val = llc->busy_state_timer.expire / HZ; break; 1143 case LLC_OPT_TX_WIN: 1144 val = llc->k; break; 1145 case LLC_OPT_RX_WIN: 1146 val = llc->rw; break; 1147 case LLC_OPT_PKTINFO: 1148 val = (llc->cmsg_flags & LLC_CMSG_PKTINFO) != 0; 1149 break; 1150 default: 1151 rc = -ENOPROTOOPT; 1152 goto out; 1153 } 1154 rc = 0; 1155 if (put_user(len, optlen) || copy_to_user(optval, &val, len)) 1156 rc = -EFAULT; 1157out: 1158 release_sock(sk); 1159 return rc; 1160} 1161 1162static const struct net_proto_family llc_ui_family_ops = { 1163 .family = PF_LLC, 1164 .create = llc_ui_create, 1165 .owner = THIS_MODULE, 1166}; 1167 1168static const struct proto_ops llc_ui_ops = { 1169 .family = PF_LLC, 1170 .owner = THIS_MODULE, 1171 .release = llc_ui_release, 1172 .bind = llc_ui_bind, 1173 .connect = llc_ui_connect, 1174 .socketpair = sock_no_socketpair, 1175 .accept = llc_ui_accept, 1176 .getname = llc_ui_getname, 1177 .poll = datagram_poll, 1178 .ioctl = llc_ui_ioctl, 1179 .listen = llc_ui_listen, 1180 .shutdown = llc_ui_shutdown, 1181 .setsockopt = llc_ui_setsockopt, 1182 .getsockopt = llc_ui_getsockopt, 1183 .sendmsg = llc_ui_sendmsg, 1184 .recvmsg = llc_ui_recvmsg, 1185 .mmap = sock_no_mmap, 1186 .sendpage = sock_no_sendpage, 1187}; 1188 1189static const char llc_proc_err_msg[] __initconst = 1190 KERN_CRIT "LLC: Unable to register the proc_fs entries\n"; 1191static const char llc_sysctl_err_msg[] __initconst = 1192 KERN_CRIT "LLC: Unable to register the sysctl entries\n"; 1193static const char llc_sock_err_msg[] __initconst = 1194 KERN_CRIT "LLC: Unable to register the network family\n"; 1195 1196static int __init llc2_init(void) 1197{ 1198 int rc = proto_register(&llc_proto, 0); 1199 1200 if (rc != 0) 1201 goto out; 1202 1203 llc_build_offset_table(); 1204 llc_station_init(); 1205 llc_ui_sap_last_autoport = LLC_SAP_DYN_START; 1206 rc = llc_proc_init(); 1207 if (rc != 0) { 1208 printk(llc_proc_err_msg); 1209 goto out_station; 1210 } 1211 rc = llc_sysctl_init(); 1212 if (rc) { 1213 printk(llc_sysctl_err_msg); 1214 goto out_proc; 1215 } 1216 rc = sock_register(&llc_ui_family_ops); 1217 if (rc) { 1218 printk(llc_sock_err_msg); 1219 goto out_sysctl; 1220 } 1221 llc_add_pack(LLC_DEST_SAP, llc_sap_handler); 1222 llc_add_pack(LLC_DEST_CONN, llc_conn_handler); 1223out: 1224 return rc; 1225out_sysctl: 1226 llc_sysctl_exit(); 1227out_proc: 1228 llc_proc_exit(); 1229out_station: 1230 llc_station_exit(); 1231 proto_unregister(&llc_proto); 1232 goto out; 1233} 1234 1235static void __exit llc2_exit(void) 1236{ 1237 llc_station_exit(); 1238 llc_remove_pack(LLC_DEST_SAP); 1239 llc_remove_pack(LLC_DEST_CONN); 1240 sock_unregister(PF_LLC); 1241 llc_proc_exit(); 1242 llc_sysctl_exit(); 1243 proto_unregister(&llc_proto); 1244} 1245 1246module_init(llc2_init); 1247module_exit(llc2_exit); 1248 1249MODULE_LICENSE("GPL"); 1250MODULE_AUTHOR("Procom 1997, Jay Schullist 2001, Arnaldo C. Melo 2001-2003"); 1251MODULE_DESCRIPTION("IEEE 802.2 PF_LLC support"); 1252MODULE_ALIAS_NETPROTO(PF_LLC); 1253