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 */ 38static u16 llc_ui_sap_last_autoport = LLC_SAP_DYN_START; 39static u16 llc_ui_sap_link_no_max[256]; 40static struct sockaddr_llc llc_ui_addrnull; 41static const struct proto_ops llc_ui_ops; 42 43static bool llc_ui_wait_for_conn(struct sock *sk, long timeout); 44static int llc_ui_wait_for_disc(struct sock *sk, long timeout); 45static 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 */ 63static 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 */ 74static 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 */ 83static 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 */ 97static 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) 102 rc = LLC_PDU_LEN_U; 103 else if (addr->sllc_xid) 104 /* We need to expand header to sizeof(struct llc_xid_info) 105 * since llc_pdu_init_as_xid_cmd() sets 4,5,6 bytes of LLC header 106 * as XID PDU. In llc_ui_sendmsg() we reserved header size and then 107 * filled all other space with user data. If we won't reserve this 108 * bytes, llc_pdu_init_as_xid_cmd() will overwrite user data 109 */ 110 rc = LLC_PDU_LEN_U_XID; 111 else if (sk->sk_type == SOCK_STREAM) 112 rc = LLC_PDU_LEN_I; 113 return rc; 114} 115 116/** 117 * llc_ui_send_data - send data via reliable llc2 connection 118 * @sk: Connection the socket is using. 119 * @skb: Data the user wishes to send. 120 * @noblock: can we block waiting for data? 121 * 122 * Send data via reliable llc2 connection. 123 * Returns 0 upon success, non-zero if action did not succeed. 124 * 125 * This function always consumes a reference to the skb. 126 */ 127static int llc_ui_send_data(struct sock* sk, struct sk_buff *skb, int noblock) 128{ 129 struct llc_sock* llc = llc_sk(sk); 130 131 if (unlikely(llc_data_accept_state(llc->state) || 132 llc->remote_busy_flag || 133 llc->p_flag)) { 134 long timeout = sock_sndtimeo(sk, noblock); 135 int rc; 136 137 rc = llc_ui_wait_for_busy_core(sk, timeout); 138 if (rc) { 139 kfree_skb(skb); 140 return rc; 141 } 142 } 143 return llc_build_and_send_pkt(sk, skb); 144} 145 146static void llc_ui_sk_init(struct socket *sock, struct sock *sk) 147{ 148 sock_graft(sk, sock); 149 sk->sk_type = sock->type; 150 sock->ops = &llc_ui_ops; 151} 152 153static struct proto llc_proto = { 154 .name = "LLC", 155 .owner = THIS_MODULE, 156 .obj_size = sizeof(struct llc_sock), 157 .slab_flags = SLAB_TYPESAFE_BY_RCU, 158}; 159 160/** 161 * llc_ui_create - alloc and init a new llc_ui socket 162 * @net: network namespace (must be default network) 163 * @sock: Socket to initialize and attach allocated sk to. 164 * @protocol: Unused. 165 * @kern: on behalf of kernel or userspace 166 * 167 * Allocate and initialize a new llc_ui socket, validate the user wants a 168 * socket type we have available. 169 * Returns 0 upon success, negative upon failure. 170 */ 171static int llc_ui_create(struct net *net, struct socket *sock, int protocol, 172 int kern) 173{ 174 struct sock *sk; 175 int rc = -ESOCKTNOSUPPORT; 176 177 if (!ns_capable(net->user_ns, CAP_NET_RAW)) 178 return -EPERM; 179 180 if (!net_eq(net, &init_net)) 181 return -EAFNOSUPPORT; 182 183 if (likely(sock->type == SOCK_DGRAM || sock->type == SOCK_STREAM)) { 184 rc = -ENOMEM; 185 sk = llc_sk_alloc(net, PF_LLC, GFP_KERNEL, &llc_proto, kern); 186 if (sk) { 187 rc = 0; 188 llc_ui_sk_init(sock, sk); 189 } 190 } 191 return rc; 192} 193 194/** 195 * llc_ui_release - shutdown socket 196 * @sock: Socket to release. 197 * 198 * Shutdown and deallocate an existing socket. 199 */ 200static int llc_ui_release(struct socket *sock) 201{ 202 struct sock *sk = sock->sk; 203 struct llc_sock *llc; 204 205 if (unlikely(sk == NULL)) 206 goto out; 207 sock_hold(sk); 208 lock_sock(sk); 209 llc = llc_sk(sk); 210 dprintk("%s: closing local(%02X) remote(%02X)\n", __func__, 211 llc->laddr.lsap, llc->daddr.lsap); 212 if (!llc_send_disc(sk)) 213 llc_ui_wait_for_disc(sk, sk->sk_rcvtimeo); 214 if (!sock_flag(sk, SOCK_ZAPPED)) { 215 struct llc_sap *sap = llc->sap; 216 217 /* Hold this for release_sock(), so that llc_backlog_rcv() 218 * could still use it. 219 */ 220 llc_sap_hold(sap); 221 llc_sap_remove_socket(llc->sap, sk); 222 release_sock(sk); 223 llc_sap_put(sap); 224 } else { 225 release_sock(sk); 226 } 227 if (llc->dev) 228 dev_put(llc->dev); 229 sock_put(sk); 230 sock_orphan(sk); 231 sock->sk = NULL; 232 llc_sk_free(sk); 233out: 234 return 0; 235} 236 237/** 238 * llc_ui_autoport - provide dynamically allocate SAP number 239 * 240 * Provide the caller with a dynamically allocated SAP number according 241 * to the rules that are set in this function. Returns: 0, upon failure, 242 * SAP number otherwise. 243 */ 244static int llc_ui_autoport(void) 245{ 246 struct llc_sap *sap; 247 int i, tries = 0; 248 249 while (tries < LLC_SAP_DYN_TRIES) { 250 for (i = llc_ui_sap_last_autoport; 251 i < LLC_SAP_DYN_STOP; i += 2) { 252 sap = llc_sap_find(i); 253 if (!sap) { 254 llc_ui_sap_last_autoport = i + 2; 255 goto out; 256 } 257 llc_sap_put(sap); 258 } 259 llc_ui_sap_last_autoport = LLC_SAP_DYN_START; 260 tries++; 261 } 262 i = 0; 263out: 264 return i; 265} 266 267/** 268 * llc_ui_autobind - automatically bind a socket to a sap 269 * @sock: socket to bind 270 * @addr: address to connect to 271 * 272 * Used by llc_ui_connect and llc_ui_sendmsg when the user hasn't 273 * specifically used llc_ui_bind to bind to an specific address/sap 274 * 275 * Returns: 0 upon success, negative otherwise. 276 */ 277static int llc_ui_autobind(struct socket *sock, struct sockaddr_llc *addr) 278{ 279 struct sock *sk = sock->sk; 280 struct llc_sock *llc = llc_sk(sk); 281 struct net_device *dev = NULL; 282 struct llc_sap *sap; 283 int rc = -EINVAL; 284 285 if (!sock_flag(sk, SOCK_ZAPPED)) 286 goto out; 287 if (!addr->sllc_arphrd) 288 addr->sllc_arphrd = ARPHRD_ETHER; 289 if (addr->sllc_arphrd != ARPHRD_ETHER) 290 goto out; 291 rc = -ENODEV; 292 if (sk->sk_bound_dev_if) { 293 dev = dev_get_by_index(&init_net, sk->sk_bound_dev_if); 294 if (dev && addr->sllc_arphrd != dev->type) { 295 dev_put(dev); 296 dev = NULL; 297 } 298 } else 299 dev = dev_getfirstbyhwtype(&init_net, addr->sllc_arphrd); 300 if (!dev) 301 goto out; 302 rc = -EUSERS; 303 llc->laddr.lsap = llc_ui_autoport(); 304 if (!llc->laddr.lsap) 305 goto out; 306 rc = -EBUSY; /* some other network layer is using the sap */ 307 sap = llc_sap_open(llc->laddr.lsap, NULL); 308 if (!sap) 309 goto out; 310 311 /* Note: We do not expect errors from this point. */ 312 llc->dev = dev; 313 dev = NULL; 314 315 memcpy(llc->laddr.mac, llc->dev->dev_addr, IFHWADDRLEN); 316 memcpy(&llc->addr, addr, sizeof(llc->addr)); 317 /* assign new connection to its SAP */ 318 llc_sap_add_socket(sap, sk); 319 sock_reset_flag(sk, SOCK_ZAPPED); 320 rc = 0; 321out: 322 dev_put(dev); 323 return rc; 324} 325 326/** 327 * llc_ui_bind - bind a socket to a specific address. 328 * @sock: Socket to bind an address to. 329 * @uaddr: Address the user wants the socket bound to. 330 * @addrlen: Length of the uaddr structure. 331 * 332 * Bind a socket to a specific address. For llc a user is able to bind to 333 * a specific sap only or mac + sap. 334 * If the user desires to bind to a specific mac + sap, it is possible to 335 * have multiple sap connections via multiple macs. 336 * Bind and autobind for that matter must enforce the correct sap usage 337 * otherwise all hell will break loose. 338 * Returns: 0 upon success, negative otherwise. 339 */ 340static int llc_ui_bind(struct socket *sock, struct sockaddr *uaddr, int addrlen) 341{ 342 struct sockaddr_llc *addr = (struct sockaddr_llc *)uaddr; 343 struct sock *sk = sock->sk; 344 struct llc_sock *llc = llc_sk(sk); 345 struct net_device *dev = NULL; 346 struct llc_sap *sap; 347 int rc = -EINVAL; 348 349 lock_sock(sk); 350 if (unlikely(!sock_flag(sk, SOCK_ZAPPED) || addrlen != sizeof(*addr))) 351 goto out; 352 rc = -EAFNOSUPPORT; 353 if (!addr->sllc_arphrd) 354 addr->sllc_arphrd = ARPHRD_ETHER; 355 if (unlikely(addr->sllc_family != AF_LLC || addr->sllc_arphrd != ARPHRD_ETHER)) 356 goto out; 357 dprintk("%s: binding %02X\n", __func__, addr->sllc_sap); 358 rc = -ENODEV; 359 rcu_read_lock(); 360 if (sk->sk_bound_dev_if) { 361 dev = dev_get_by_index_rcu(&init_net, sk->sk_bound_dev_if); 362 if (dev) { 363 if (is_zero_ether_addr(addr->sllc_mac)) 364 memcpy(addr->sllc_mac, dev->dev_addr, 365 IFHWADDRLEN); 366 if (addr->sllc_arphrd != dev->type || 367 !ether_addr_equal(addr->sllc_mac, 368 dev->dev_addr)) { 369 rc = -EINVAL; 370 dev = NULL; 371 } 372 } 373 } else { 374 dev = dev_getbyhwaddr_rcu(&init_net, addr->sllc_arphrd, 375 addr->sllc_mac); 376 } 377 if (dev) 378 dev_hold(dev); 379 rcu_read_unlock(); 380 if (!dev) 381 goto out; 382 if (!addr->sllc_sap) { 383 rc = -EUSERS; 384 addr->sllc_sap = llc_ui_autoport(); 385 if (!addr->sllc_sap) 386 goto out; 387 } 388 sap = llc_sap_find(addr->sllc_sap); 389 if (!sap) { 390 sap = llc_sap_open(addr->sllc_sap, NULL); 391 rc = -EBUSY; /* some other network layer is using the sap */ 392 if (!sap) 393 goto out; 394 } else { 395 struct llc_addr laddr, daddr; 396 struct sock *ask; 397 398 memset(&laddr, 0, sizeof(laddr)); 399 memset(&daddr, 0, sizeof(daddr)); 400 /* 401 * FIXME: check if the address is multicast, 402 * only SOCK_DGRAM can do this. 403 */ 404 memcpy(laddr.mac, addr->sllc_mac, IFHWADDRLEN); 405 laddr.lsap = addr->sllc_sap; 406 rc = -EADDRINUSE; /* mac + sap clash. */ 407 ask = llc_lookup_established(sap, &daddr, &laddr); 408 if (ask) { 409 sock_put(ask); 410 goto out_put; 411 } 412 } 413 414 /* Note: We do not expect errors from this point. */ 415 llc->dev = dev; 416 dev = NULL; 417 418 llc->laddr.lsap = addr->sllc_sap; 419 memcpy(llc->laddr.mac, addr->sllc_mac, IFHWADDRLEN); 420 memcpy(&llc->addr, addr, sizeof(llc->addr)); 421 /* assign new connection to its SAP */ 422 llc_sap_add_socket(sap, sk); 423 sock_reset_flag(sk, SOCK_ZAPPED); 424 rc = 0; 425out_put: 426 llc_sap_put(sap); 427out: 428 dev_put(dev); 429 release_sock(sk); 430 return rc; 431} 432 433/** 434 * llc_ui_shutdown - shutdown a connect llc2 socket. 435 * @sock: Socket to shutdown. 436 * @how: What part of the socket to shutdown. 437 * 438 * Shutdown a connected llc2 socket. Currently this function only supports 439 * shutting down both sends and receives (2), we could probably make this 440 * function such that a user can shutdown only half the connection but not 441 * right now. 442 * Returns: 0 upon success, negative otherwise. 443 */ 444static int llc_ui_shutdown(struct socket *sock, int how) 445{ 446 struct sock *sk = sock->sk; 447 int rc = -ENOTCONN; 448 449 lock_sock(sk); 450 if (unlikely(sk->sk_state != TCP_ESTABLISHED)) 451 goto out; 452 rc = -EINVAL; 453 if (how != 2) 454 goto out; 455 rc = llc_send_disc(sk); 456 if (!rc) 457 rc = llc_ui_wait_for_disc(sk, sk->sk_rcvtimeo); 458 /* Wake up anyone sleeping in poll */ 459 sk->sk_state_change(sk); 460out: 461 release_sock(sk); 462 return rc; 463} 464 465/** 466 * llc_ui_connect - Connect to a remote llc2 mac + sap. 467 * @sock: Socket which will be connected to the remote destination. 468 * @uaddr: Remote and possibly the local address of the new connection. 469 * @addrlen: Size of uaddr structure. 470 * @flags: Operational flags specified by the user. 471 * 472 * Connect to a remote llc2 mac + sap. The caller must specify the 473 * destination mac and address to connect to. If the user hasn't previously 474 * called bind(2) with a smac the address of the first interface of the 475 * specified arp type will be used. 476 * This function will autobind if user did not previously call bind. 477 * Returns: 0 upon success, negative otherwise. 478 */ 479static int llc_ui_connect(struct socket *sock, struct sockaddr *uaddr, 480 int addrlen, int flags) 481{ 482 struct sock *sk = sock->sk; 483 struct llc_sock *llc = llc_sk(sk); 484 struct sockaddr_llc *addr = (struct sockaddr_llc *)uaddr; 485 int rc = -EINVAL; 486 487 lock_sock(sk); 488 if (unlikely(addrlen != sizeof(*addr))) 489 goto out; 490 rc = -EAFNOSUPPORT; 491 if (unlikely(addr->sllc_family != AF_LLC)) 492 goto out; 493 if (unlikely(sk->sk_type != SOCK_STREAM)) 494 goto out; 495 rc = -EALREADY; 496 if (unlikely(sock->state == SS_CONNECTING)) 497 goto out; 498 /* bind connection to sap if user hasn't done it. */ 499 if (sock_flag(sk, SOCK_ZAPPED)) { 500 /* bind to sap with null dev, exclusive */ 501 rc = llc_ui_autobind(sock, addr); 502 if (rc) 503 goto out; 504 } 505 llc->daddr.lsap = addr->sllc_sap; 506 memcpy(llc->daddr.mac, addr->sllc_mac, IFHWADDRLEN); 507 sock->state = SS_CONNECTING; 508 sk->sk_state = TCP_SYN_SENT; 509 llc->link = llc_ui_next_link_no(llc->sap->laddr.lsap); 510 rc = llc_establish_connection(sk, llc->dev->dev_addr, 511 addr->sllc_mac, addr->sllc_sap); 512 if (rc) { 513 dprintk("%s: llc_ui_send_conn failed :-(\n", __func__); 514 sock->state = SS_UNCONNECTED; 515 sk->sk_state = TCP_CLOSE; 516 goto out; 517 } 518 519 if (sk->sk_state == TCP_SYN_SENT) { 520 const long timeo = sock_sndtimeo(sk, flags & O_NONBLOCK); 521 522 if (!timeo || !llc_ui_wait_for_conn(sk, timeo)) 523 goto out; 524 525 rc = sock_intr_errno(timeo); 526 if (signal_pending(current)) 527 goto out; 528 } 529 530 if (sk->sk_state == TCP_CLOSE) 531 goto sock_error; 532 533 sock->state = SS_CONNECTED; 534 rc = 0; 535out: 536 release_sock(sk); 537 return rc; 538sock_error: 539 rc = sock_error(sk) ? : -ECONNABORTED; 540 sock->state = SS_UNCONNECTED; 541 goto out; 542} 543 544/** 545 * llc_ui_listen - allow a normal socket to accept incoming connections 546 * @sock: Socket to allow incoming connections on. 547 * @backlog: Number of connections to queue. 548 * 549 * Allow a normal socket to accept incoming connections. 550 * Returns 0 upon success, negative otherwise. 551 */ 552static int llc_ui_listen(struct socket *sock, int backlog) 553{ 554 struct sock *sk = sock->sk; 555 int rc = -EINVAL; 556 557 lock_sock(sk); 558 if (unlikely(sock->state != SS_UNCONNECTED)) 559 goto out; 560 rc = -EOPNOTSUPP; 561 if (unlikely(sk->sk_type != SOCK_STREAM)) 562 goto out; 563 rc = -EAGAIN; 564 if (sock_flag(sk, SOCK_ZAPPED)) 565 goto out; 566 rc = 0; 567 if (!(unsigned int)backlog) /* BSDism */ 568 backlog = 1; 569 sk->sk_max_ack_backlog = backlog; 570 if (sk->sk_state != TCP_LISTEN) { 571 sk->sk_ack_backlog = 0; 572 sk->sk_state = TCP_LISTEN; 573 } 574 sk->sk_socket->flags |= __SO_ACCEPTCON; 575out: 576 release_sock(sk); 577 return rc; 578} 579 580static int llc_ui_wait_for_disc(struct sock *sk, long timeout) 581{ 582 DEFINE_WAIT_FUNC(wait, woken_wake_function); 583 int rc = 0; 584 585 add_wait_queue(sk_sleep(sk), &wait); 586 while (1) { 587 if (sk_wait_event(sk, &timeout, 588 READ_ONCE(sk->sk_state) == TCP_CLOSE, &wait)) 589 break; 590 rc = -ERESTARTSYS; 591 if (signal_pending(current)) 592 break; 593 rc = -EAGAIN; 594 if (!timeout) 595 break; 596 rc = 0; 597 } 598 remove_wait_queue(sk_sleep(sk), &wait); 599 return rc; 600} 601 602static bool llc_ui_wait_for_conn(struct sock *sk, long timeout) 603{ 604 DEFINE_WAIT_FUNC(wait, woken_wake_function); 605 606 add_wait_queue(sk_sleep(sk), &wait); 607 while (1) { 608 if (sk_wait_event(sk, &timeout, 609 READ_ONCE(sk->sk_state) != TCP_SYN_SENT, &wait)) 610 break; 611 if (signal_pending(current) || !timeout) 612 break; 613 } 614 remove_wait_queue(sk_sleep(sk), &wait); 615 return timeout; 616} 617 618static int llc_ui_wait_for_busy_core(struct sock *sk, long timeout) 619{ 620 DEFINE_WAIT_FUNC(wait, woken_wake_function); 621 struct llc_sock *llc = llc_sk(sk); 622 int rc; 623 624 add_wait_queue(sk_sleep(sk), &wait); 625 while (1) { 626 rc = 0; 627 if (sk_wait_event(sk, &timeout, 628 (READ_ONCE(sk->sk_shutdown) & RCV_SHUTDOWN) || 629 (!llc_data_accept_state(llc->state) && 630 !llc->remote_busy_flag && 631 !llc->p_flag), &wait)) 632 break; 633 rc = -ERESTARTSYS; 634 if (signal_pending(current)) 635 break; 636 rc = -EAGAIN; 637 if (!timeout) 638 break; 639 } 640 remove_wait_queue(sk_sleep(sk), &wait); 641 return rc; 642} 643 644static int llc_wait_data(struct sock *sk, long timeo) 645{ 646 int rc; 647 648 while (1) { 649 /* 650 * POSIX 1003.1g mandates this order. 651 */ 652 rc = sock_error(sk); 653 if (rc) 654 break; 655 rc = 0; 656 if (sk->sk_shutdown & RCV_SHUTDOWN) 657 break; 658 rc = -EAGAIN; 659 if (!timeo) 660 break; 661 rc = sock_intr_errno(timeo); 662 if (signal_pending(current)) 663 break; 664 rc = 0; 665 if (sk_wait_data(sk, &timeo, NULL)) 666 break; 667 } 668 return rc; 669} 670 671static void llc_cmsg_rcv(struct msghdr *msg, struct sk_buff *skb) 672{ 673 struct llc_sock *llc = llc_sk(skb->sk); 674 675 if (llc->cmsg_flags & LLC_CMSG_PKTINFO) { 676 struct llc_pktinfo info; 677 678 memset(&info, 0, sizeof(info)); 679 info.lpi_ifindex = llc_sk(skb->sk)->dev->ifindex; 680 llc_pdu_decode_dsap(skb, &info.lpi_sap); 681 llc_pdu_decode_da(skb, info.lpi_mac); 682 put_cmsg(msg, SOL_LLC, LLC_OPT_PKTINFO, sizeof(info), &info); 683 } 684} 685 686/** 687 * llc_ui_accept - accept a new incoming connection. 688 * @sock: Socket which connections arrive on. 689 * @newsock: Socket to move incoming connection to. 690 * @flags: User specified operational flags. 691 * @kern: If the socket is kernel internal 692 * 693 * Accept a new incoming connection. 694 * Returns 0 upon success, negative otherwise. 695 */ 696static int llc_ui_accept(struct socket *sock, struct socket *newsock, int flags, 697 bool kern) 698{ 699 struct sock *sk = sock->sk, *newsk; 700 struct llc_sock *llc, *newllc; 701 struct sk_buff *skb; 702 int rc = -EOPNOTSUPP; 703 704 dprintk("%s: accepting on %02X\n", __func__, 705 llc_sk(sk)->laddr.lsap); 706 lock_sock(sk); 707 if (unlikely(sk->sk_type != SOCK_STREAM)) 708 goto out; 709 rc = -EINVAL; 710 if (unlikely(sock->state != SS_UNCONNECTED || 711 sk->sk_state != TCP_LISTEN)) 712 goto out; 713 /* wait for a connection to arrive. */ 714 if (skb_queue_empty(&sk->sk_receive_queue)) { 715 rc = llc_wait_data(sk, sk->sk_rcvtimeo); 716 if (rc) 717 goto out; 718 } 719 dprintk("%s: got a new connection on %02X\n", __func__, 720 llc_sk(sk)->laddr.lsap); 721 skb = skb_dequeue(&sk->sk_receive_queue); 722 rc = -EINVAL; 723 if (!skb->sk) 724 goto frees; 725 rc = 0; 726 newsk = skb->sk; 727 /* attach connection to a new socket. */ 728 llc_ui_sk_init(newsock, newsk); 729 sock_reset_flag(newsk, SOCK_ZAPPED); 730 newsk->sk_state = TCP_ESTABLISHED; 731 newsock->state = SS_CONNECTED; 732 llc = llc_sk(sk); 733 newllc = llc_sk(newsk); 734 memcpy(&newllc->addr, &llc->addr, sizeof(newllc->addr)); 735 newllc->link = llc_ui_next_link_no(newllc->laddr.lsap); 736 737 /* put original socket back into a clean listen state. */ 738 sk->sk_state = TCP_LISTEN; 739 sk_acceptq_removed(sk); 740 dprintk("%s: ok success on %02X, client on %02X\n", __func__, 741 llc_sk(sk)->addr.sllc_sap, newllc->daddr.lsap); 742frees: 743 kfree_skb(skb); 744out: 745 release_sock(sk); 746 return rc; 747} 748 749/** 750 * llc_ui_recvmsg - copy received data to the socket user. 751 * @sock: Socket to copy data from. 752 * @msg: Various user space related information. 753 * @len: Size of user buffer. 754 * @flags: User specified flags. 755 * 756 * Copy received data to the socket user. 757 * Returns non-negative upon success, negative otherwise. 758 */ 759static int llc_ui_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, 760 int flags) 761{ 762 DECLARE_SOCKADDR(struct sockaddr_llc *, uaddr, msg->msg_name); 763 const int nonblock = flags & MSG_DONTWAIT; 764 struct sk_buff *skb = NULL; 765 struct sock *sk = sock->sk; 766 struct llc_sock *llc = llc_sk(sk); 767 size_t copied = 0; 768 u32 peek_seq = 0; 769 u32 *seq, skb_len; 770 unsigned long used; 771 int target; /* Read at least this many bytes */ 772 long timeo; 773 774 lock_sock(sk); 775 copied = -ENOTCONN; 776 if (unlikely(sk->sk_type == SOCK_STREAM && sk->sk_state == TCP_LISTEN)) 777 goto out; 778 779 timeo = sock_rcvtimeo(sk, nonblock); 780 781 seq = &llc->copied_seq; 782 if (flags & MSG_PEEK) { 783 peek_seq = llc->copied_seq; 784 seq = &peek_seq; 785 } 786 787 target = sock_rcvlowat(sk, flags & MSG_WAITALL, len); 788 copied = 0; 789 790 do { 791 u32 offset; 792 793 /* 794 * We need to check signals first, to get correct SIGURG 795 * handling. FIXME: Need to check this doesn't impact 1003.1g 796 * and move it down to the bottom of the loop 797 */ 798 if (signal_pending(current)) { 799 if (copied) 800 break; 801 copied = timeo ? sock_intr_errno(timeo) : -EAGAIN; 802 break; 803 } 804 805 /* Next get a buffer. */ 806 807 skb = skb_peek(&sk->sk_receive_queue); 808 if (skb) { 809 offset = *seq; 810 goto found_ok_skb; 811 } 812 /* Well, if we have backlog, try to process it now yet. */ 813 814 if (copied >= target && !READ_ONCE(sk->sk_backlog.tail)) 815 break; 816 817 if (copied) { 818 if (sk->sk_err || 819 sk->sk_state == TCP_CLOSE || 820 (sk->sk_shutdown & RCV_SHUTDOWN) || 821 !timeo || 822 (flags & MSG_PEEK)) 823 break; 824 } else { 825 if (sock_flag(sk, SOCK_DONE)) 826 break; 827 828 if (sk->sk_err) { 829 copied = sock_error(sk); 830 break; 831 } 832 if (sk->sk_shutdown & RCV_SHUTDOWN) 833 break; 834 835 if (sk->sk_type == SOCK_STREAM && sk->sk_state == TCP_CLOSE) { 836 if (!sock_flag(sk, SOCK_DONE)) { 837 /* 838 * This occurs when user tries to read 839 * from never connected socket. 840 */ 841 copied = -ENOTCONN; 842 break; 843 } 844 break; 845 } 846 if (!timeo) { 847 copied = -EAGAIN; 848 break; 849 } 850 } 851 852 if (copied >= target) { /* Do not sleep, just process backlog. */ 853 release_sock(sk); 854 lock_sock(sk); 855 } else 856 sk_wait_data(sk, &timeo, NULL); 857 858 if ((flags & MSG_PEEK) && peek_seq != llc->copied_seq) { 859 net_dbg_ratelimited("LLC(%s:%d): Application bug, race in MSG_PEEK\n", 860 current->comm, 861 task_pid_nr(current)); 862 peek_seq = llc->copied_seq; 863 } 864 continue; 865 found_ok_skb: 866 skb_len = skb->len; 867 /* Ok so how much can we use? */ 868 used = skb->len - offset; 869 if (len < used) 870 used = len; 871 872 if (!(flags & MSG_TRUNC)) { 873 int rc = skb_copy_datagram_msg(skb, offset, msg, used); 874 if (rc) { 875 /* Exception. Bailout! */ 876 if (!copied) 877 copied = -EFAULT; 878 break; 879 } 880 } 881 882 *seq += used; 883 copied += used; 884 len -= used; 885 886 /* For non stream protcols we get one packet per recvmsg call */ 887 if (sk->sk_type != SOCK_STREAM) 888 goto copy_uaddr; 889 890 if (!(flags & MSG_PEEK)) { 891 skb_unlink(skb, &sk->sk_receive_queue); 892 kfree_skb(skb); 893 *seq = 0; 894 } 895 896 /* Partial read */ 897 if (used + offset < skb_len) 898 continue; 899 } while (len > 0); 900 901out: 902 release_sock(sk); 903 return copied; 904copy_uaddr: 905 if (uaddr != NULL && skb != NULL) { 906 memcpy(uaddr, llc_ui_skb_cb(skb), sizeof(*uaddr)); 907 msg->msg_namelen = sizeof(*uaddr); 908 } 909 if (llc_sk(sk)->cmsg_flags) 910 llc_cmsg_rcv(msg, skb); 911 912 if (!(flags & MSG_PEEK)) { 913 skb_unlink(skb, &sk->sk_receive_queue); 914 kfree_skb(skb); 915 *seq = 0; 916 } 917 918 goto out; 919} 920 921/** 922 * llc_ui_sendmsg - Transmit data provided by the socket user. 923 * @sock: Socket to transmit data from. 924 * @msg: Various user related information. 925 * @len: Length of data to transmit. 926 * 927 * Transmit data provided by the socket user. 928 * Returns non-negative upon success, negative otherwise. 929 */ 930static int llc_ui_sendmsg(struct socket *sock, struct msghdr *msg, size_t len) 931{ 932 DECLARE_SOCKADDR(struct sockaddr_llc *, addr, msg->msg_name); 933 struct sock *sk = sock->sk; 934 struct llc_sock *llc = llc_sk(sk); 935 int flags = msg->msg_flags; 936 int noblock = flags & MSG_DONTWAIT; 937 int rc = -EINVAL, copied = 0, hdrlen, hh_len; 938 struct sk_buff *skb = NULL; 939 struct net_device *dev; 940 size_t size = 0; 941 942 dprintk("%s: sending from %02X to %02X\n", __func__, 943 llc->laddr.lsap, llc->daddr.lsap); 944 lock_sock(sk); 945 if (addr) { 946 if (msg->msg_namelen < sizeof(*addr)) 947 goto out; 948 } else { 949 if (llc_ui_addr_null(&llc->addr)) 950 goto out; 951 addr = &llc->addr; 952 } 953 /* must bind connection to sap if user hasn't done it. */ 954 if (sock_flag(sk, SOCK_ZAPPED)) { 955 /* bind to sap with null dev, exclusive. */ 956 rc = llc_ui_autobind(sock, addr); 957 if (rc) 958 goto out; 959 } 960 dev = llc->dev; 961 hh_len = LL_RESERVED_SPACE(dev); 962 hdrlen = llc_ui_header_len(sk, addr); 963 size = hdrlen + len; 964 size = min_t(size_t, size, READ_ONCE(dev->mtu)); 965 copied = size - hdrlen; 966 rc = -EINVAL; 967 if (copied < 0) 968 goto out; 969 release_sock(sk); 970 skb = sock_alloc_send_skb(sk, hh_len + size, noblock, &rc); 971 lock_sock(sk); 972 if (!skb) 973 goto out; 974 if (sock_flag(sk, SOCK_ZAPPED) || 975 llc->dev != dev || 976 hdrlen != llc_ui_header_len(sk, addr) || 977 hh_len != LL_RESERVED_SPACE(dev) || 978 size > READ_ONCE(dev->mtu)) 979 goto out; 980 skb->dev = dev; 981 skb->protocol = llc_proto_type(addr->sllc_arphrd); 982 skb_reserve(skb, hh_len + hdrlen); 983 rc = memcpy_from_msg(skb_put(skb, copied), msg, copied); 984 if (rc) 985 goto out; 986 if (sk->sk_type == SOCK_DGRAM || addr->sllc_ua) { 987 llc_build_and_send_ui_pkt(llc->sap, skb, addr->sllc_mac, 988 addr->sllc_sap); 989 skb = NULL; 990 goto out; 991 } 992 if (addr->sllc_test) { 993 llc_build_and_send_test_pkt(llc->sap, skb, addr->sllc_mac, 994 addr->sllc_sap); 995 skb = NULL; 996 goto out; 997 } 998 if (addr->sllc_xid) { 999 llc_build_and_send_xid_pkt(llc->sap, skb, addr->sllc_mac, 1000 addr->sllc_sap); 1001 skb = NULL; 1002 goto out; 1003 } 1004 rc = -ENOPROTOOPT; 1005 if (!(sk->sk_type == SOCK_STREAM && !addr->sllc_ua)) 1006 goto out; 1007 rc = llc_ui_send_data(sk, skb, noblock); 1008 skb = NULL; 1009out: 1010 kfree_skb(skb); 1011 if (rc) 1012 dprintk("%s: failed sending from %02X to %02X: %d\n", 1013 __func__, llc->laddr.lsap, llc->daddr.lsap, rc); 1014 release_sock(sk); 1015 return rc ? : copied; 1016} 1017 1018/** 1019 * llc_ui_getname - return the address info of a socket 1020 * @sock: Socket to get address of. 1021 * @uaddr: Address structure to return information. 1022 * @peer: Does user want local or remote address information. 1023 * 1024 * Return the address information of a socket. 1025 */ 1026static int llc_ui_getname(struct socket *sock, struct sockaddr *uaddr, 1027 int peer) 1028{ 1029 struct sockaddr_llc sllc; 1030 struct sock *sk = sock->sk; 1031 struct llc_sock *llc = llc_sk(sk); 1032 int rc = -EBADF; 1033 1034 memset(&sllc, 0, sizeof(sllc)); 1035 lock_sock(sk); 1036 if (sock_flag(sk, SOCK_ZAPPED)) 1037 goto out; 1038 if (peer) { 1039 rc = -ENOTCONN; 1040 if (sk->sk_state != TCP_ESTABLISHED) 1041 goto out; 1042 if(llc->dev) 1043 sllc.sllc_arphrd = llc->dev->type; 1044 sllc.sllc_sap = llc->daddr.lsap; 1045 memcpy(&sllc.sllc_mac, &llc->daddr.mac, IFHWADDRLEN); 1046 } else { 1047 rc = -EINVAL; 1048 if (!llc->sap) 1049 goto out; 1050 sllc.sllc_sap = llc->sap->laddr.lsap; 1051 1052 if (llc->dev) { 1053 sllc.sllc_arphrd = llc->dev->type; 1054 memcpy(&sllc.sllc_mac, llc->dev->dev_addr, 1055 IFHWADDRLEN); 1056 } 1057 } 1058 sllc.sllc_family = AF_LLC; 1059 memcpy(uaddr, &sllc, sizeof(sllc)); 1060 rc = sizeof(sllc); 1061out: 1062 release_sock(sk); 1063 return rc; 1064} 1065 1066/** 1067 * llc_ui_ioctl - io controls for PF_LLC 1068 * @sock: Socket to get/set info 1069 * @cmd: command 1070 * @arg: optional argument for cmd 1071 * 1072 * get/set info on llc sockets 1073 */ 1074static int llc_ui_ioctl(struct socket *sock, unsigned int cmd, 1075 unsigned long arg) 1076{ 1077 return -ENOIOCTLCMD; 1078} 1079 1080/** 1081 * llc_ui_setsockopt - set various connection specific parameters. 1082 * @sock: Socket to set options on. 1083 * @level: Socket level user is requesting operations on. 1084 * @optname: Operation name. 1085 * @optval: User provided operation data. 1086 * @optlen: Length of optval. 1087 * 1088 * Set various connection specific parameters. 1089 */ 1090static int llc_ui_setsockopt(struct socket *sock, int level, int optname, 1091 sockptr_t optval, unsigned int optlen) 1092{ 1093 struct sock *sk = sock->sk; 1094 struct llc_sock *llc = llc_sk(sk); 1095 unsigned int opt; 1096 int rc = -EINVAL; 1097 1098 lock_sock(sk); 1099 if (unlikely(level != SOL_LLC || optlen != sizeof(int))) 1100 goto out; 1101 rc = copy_from_sockptr(&opt, optval, sizeof(opt)); 1102 if (rc) 1103 goto out; 1104 rc = -EINVAL; 1105 switch (optname) { 1106 case LLC_OPT_RETRY: 1107 if (opt > LLC_OPT_MAX_RETRY) 1108 goto out; 1109 llc->n2 = opt; 1110 break; 1111 case LLC_OPT_SIZE: 1112 if (opt > LLC_OPT_MAX_SIZE) 1113 goto out; 1114 llc->n1 = opt; 1115 break; 1116 case LLC_OPT_ACK_TMR_EXP: 1117 if (opt > LLC_OPT_MAX_ACK_TMR_EXP) 1118 goto out; 1119 llc->ack_timer.expire = opt * HZ; 1120 break; 1121 case LLC_OPT_P_TMR_EXP: 1122 if (opt > LLC_OPT_MAX_P_TMR_EXP) 1123 goto out; 1124 llc->pf_cycle_timer.expire = opt * HZ; 1125 break; 1126 case LLC_OPT_REJ_TMR_EXP: 1127 if (opt > LLC_OPT_MAX_REJ_TMR_EXP) 1128 goto out; 1129 llc->rej_sent_timer.expire = opt * HZ; 1130 break; 1131 case LLC_OPT_BUSY_TMR_EXP: 1132 if (opt > LLC_OPT_MAX_BUSY_TMR_EXP) 1133 goto out; 1134 llc->busy_state_timer.expire = opt * HZ; 1135 break; 1136 case LLC_OPT_TX_WIN: 1137 if (opt > LLC_OPT_MAX_WIN) 1138 goto out; 1139 llc->k = opt; 1140 break; 1141 case LLC_OPT_RX_WIN: 1142 if (opt > LLC_OPT_MAX_WIN) 1143 goto out; 1144 llc->rw = opt; 1145 break; 1146 case LLC_OPT_PKTINFO: 1147 if (opt) 1148 llc->cmsg_flags |= LLC_CMSG_PKTINFO; 1149 else 1150 llc->cmsg_flags &= ~LLC_CMSG_PKTINFO; 1151 break; 1152 default: 1153 rc = -ENOPROTOOPT; 1154 goto out; 1155 } 1156 rc = 0; 1157out: 1158 release_sock(sk); 1159 return rc; 1160} 1161 1162/** 1163 * llc_ui_getsockopt - get connection specific socket info 1164 * @sock: Socket to get information from. 1165 * @level: Socket level user is requesting operations on. 1166 * @optname: Operation name. 1167 * @optval: Variable to return operation data in. 1168 * @optlen: Length of optval. 1169 * 1170 * Get connection specific socket information. 1171 */ 1172static int llc_ui_getsockopt(struct socket *sock, int level, int optname, 1173 char __user *optval, int __user *optlen) 1174{ 1175 struct sock *sk = sock->sk; 1176 struct llc_sock *llc = llc_sk(sk); 1177 int val = 0, len = 0, rc = -EINVAL; 1178 1179 lock_sock(sk); 1180 if (unlikely(level != SOL_LLC)) 1181 goto out; 1182 rc = get_user(len, optlen); 1183 if (rc) 1184 goto out; 1185 rc = -EINVAL; 1186 if (len != sizeof(int)) 1187 goto out; 1188 switch (optname) { 1189 case LLC_OPT_RETRY: 1190 val = llc->n2; break; 1191 case LLC_OPT_SIZE: 1192 val = llc->n1; break; 1193 case LLC_OPT_ACK_TMR_EXP: 1194 val = llc->ack_timer.expire / HZ; break; 1195 case LLC_OPT_P_TMR_EXP: 1196 val = llc->pf_cycle_timer.expire / HZ; break; 1197 case LLC_OPT_REJ_TMR_EXP: 1198 val = llc->rej_sent_timer.expire / HZ; break; 1199 case LLC_OPT_BUSY_TMR_EXP: 1200 val = llc->busy_state_timer.expire / HZ; break; 1201 case LLC_OPT_TX_WIN: 1202 val = llc->k; break; 1203 case LLC_OPT_RX_WIN: 1204 val = llc->rw; break; 1205 case LLC_OPT_PKTINFO: 1206 val = (llc->cmsg_flags & LLC_CMSG_PKTINFO) != 0; 1207 break; 1208 default: 1209 rc = -ENOPROTOOPT; 1210 goto out; 1211 } 1212 rc = 0; 1213 if (put_user(len, optlen) || copy_to_user(optval, &val, len)) 1214 rc = -EFAULT; 1215out: 1216 release_sock(sk); 1217 return rc; 1218} 1219 1220static const struct net_proto_family llc_ui_family_ops = { 1221 .family = PF_LLC, 1222 .create = llc_ui_create, 1223 .owner = THIS_MODULE, 1224}; 1225 1226static const struct proto_ops llc_ui_ops = { 1227 .family = PF_LLC, 1228 .owner = THIS_MODULE, 1229 .release = llc_ui_release, 1230 .bind = llc_ui_bind, 1231 .connect = llc_ui_connect, 1232 .socketpair = sock_no_socketpair, 1233 .accept = llc_ui_accept, 1234 .getname = llc_ui_getname, 1235 .poll = datagram_poll, 1236 .ioctl = llc_ui_ioctl, 1237 .listen = llc_ui_listen, 1238 .shutdown = llc_ui_shutdown, 1239 .setsockopt = llc_ui_setsockopt, 1240 .getsockopt = llc_ui_getsockopt, 1241 .sendmsg = llc_ui_sendmsg, 1242 .recvmsg = llc_ui_recvmsg, 1243 .mmap = sock_no_mmap, 1244 .sendpage = sock_no_sendpage, 1245}; 1246 1247static const char llc_proc_err_msg[] __initconst = 1248 KERN_CRIT "LLC: Unable to register the proc_fs entries\n"; 1249static const char llc_sysctl_err_msg[] __initconst = 1250 KERN_CRIT "LLC: Unable to register the sysctl entries\n"; 1251static const char llc_sock_err_msg[] __initconst = 1252 KERN_CRIT "LLC: Unable to register the network family\n"; 1253 1254static int __init llc2_init(void) 1255{ 1256 int rc = proto_register(&llc_proto, 0); 1257 1258 if (rc != 0) 1259 goto out; 1260 1261 llc_build_offset_table(); 1262 llc_station_init(); 1263 llc_ui_sap_last_autoport = LLC_SAP_DYN_START; 1264 rc = llc_proc_init(); 1265 if (rc != 0) { 1266 printk(llc_proc_err_msg); 1267 goto out_station; 1268 } 1269 rc = llc_sysctl_init(); 1270 if (rc) { 1271 printk(llc_sysctl_err_msg); 1272 goto out_proc; 1273 } 1274 rc = sock_register(&llc_ui_family_ops); 1275 if (rc) { 1276 printk(llc_sock_err_msg); 1277 goto out_sysctl; 1278 } 1279 llc_add_pack(LLC_DEST_SAP, llc_sap_handler); 1280 llc_add_pack(LLC_DEST_CONN, llc_conn_handler); 1281out: 1282 return rc; 1283out_sysctl: 1284 llc_sysctl_exit(); 1285out_proc: 1286 llc_proc_exit(); 1287out_station: 1288 llc_station_exit(); 1289 proto_unregister(&llc_proto); 1290 goto out; 1291} 1292 1293static void __exit llc2_exit(void) 1294{ 1295 llc_station_exit(); 1296 llc_remove_pack(LLC_DEST_SAP); 1297 llc_remove_pack(LLC_DEST_CONN); 1298 sock_unregister(PF_LLC); 1299 llc_proc_exit(); 1300 llc_sysctl_exit(); 1301 proto_unregister(&llc_proto); 1302} 1303 1304module_init(llc2_init); 1305module_exit(llc2_exit); 1306 1307MODULE_LICENSE("GPL"); 1308MODULE_AUTHOR("Procom 1997, Jay Schullist 2001, Arnaldo C. Melo 2001-2003"); 1309MODULE_DESCRIPTION("IEEE 802.2 PF_LLC support"); 1310MODULE_ALIAS_NETPROTO(PF_LLC); 1311