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