1 /* 2 * af_llc.c - LLC User Interface SAPs 3 * Description: 4 * Functions in this module are implementation of socket based llc 5 * communications for the Linux operating system. Support of llc class 6 * one and class two is provided via SOCK_DGRAM and SOCK_STREAM 7 * respectively. 8 * 9 * An llc2 connection is (mac + sap), only one llc2 sap connection 10 * is allowed per mac. Though one sap may have multiple mac + sap 11 * connections. 12 * 13 * Copyright (c) 2001 by Jay Schulist <jschlst@samba.org> 14 * 2002-2003 by Arnaldo Carvalho de Melo <acme@conectiva.com.br> 15 * 16 * This program can be redistributed or modified under the terms of the 17 * GNU General Public License as published by the Free Software Foundation. 18 * This program is distributed without any warranty or implied warranty 19 * of merchantability or fitness for a particular purpose. 20 * 21 * See the GNU General Public License for more details. 22 */ 23 #include <linux/compiler.h> 24 #include <linux/kernel.h> 25 #include <linux/module.h> 26 #include <linux/rtnetlink.h> 27 #include <linux/init.h> 28 #include <linux/slab.h> 29 #include <linux/sched/signal.h> 30 31 #include <net/llc.h> 32 #include <net/llc_sap.h> 33 #include <net/llc_pdu.h> 34 #include <net/llc_conn.h> 35 #include <net/tcp_states.h> 36 37 /* remember: uninitialized global data is zeroed because its in .bss */ 38 static u16 llc_ui_sap_last_autoport = LLC_SAP_DYN_START; 39 static u16 llc_ui_sap_link_no_max[256]; 40 static struct sockaddr_llc llc_ui_addrnull; 41 static const struct proto_ops llc_ui_ops; 42 43 static bool llc_ui_wait_for_conn(struct sock *sk, long timeout); 44 static int llc_ui_wait_for_disc(struct sock *sk, long timeout); 45 static int llc_ui_wait_for_busy_core(struct sock *sk, long timeout); 46 47 #if 0 48 #define dprintk(args...) printk(KERN_DEBUG args) 49 #else 50 #define dprintk(args...) do {} while (0) 51 #endif 52 53 /* Maybe we'll add some more in the future. */ 54 #define LLC_CMSG_PKTINFO 1 55 56 57 /** 58 * llc_ui_next_link_no - return the next unused link number for a sap 59 * @sap: Address of sap to get link number from. 60 * 61 * Return the next unused link number for a given sap. 62 */ 63 static inline u16 llc_ui_next_link_no(int sap) 64 { 65 return llc_ui_sap_link_no_max[sap]++; 66 } 67 68 /** 69 * llc_proto_type - return eth protocol for ARP header type 70 * @arphrd: ARP header type. 71 * 72 * Given an ARP header type return the corresponding ethernet protocol. 73 */ 74 static inline __be16 llc_proto_type(u16 arphrd) 75 { 76 return htons(ETH_P_802_2); 77 } 78 79 /** 80 * llc_ui_addr_null - determines if a address structure is null 81 * @addr: Address to test if null. 82 */ 83 static inline u8 llc_ui_addr_null(struct sockaddr_llc *addr) 84 { 85 return !memcmp(addr, &llc_ui_addrnull, sizeof(*addr)); 86 } 87 88 /** 89 * llc_ui_header_len - return length of llc header based on operation 90 * @sk: Socket which contains a valid llc socket type. 91 * @addr: Complete sockaddr_llc structure received from the user. 92 * 93 * Provide the length of the llc header depending on what kind of 94 * operation the user would like to perform and the type of socket. 95 * Returns the correct llc header length. 96 */ 97 static inline u8 llc_ui_header_len(struct sock *sk, struct sockaddr_llc *addr) 98 { 99 u8 rc = LLC_PDU_LEN_U; 100 101 if (addr->sllc_test) 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 */ 127 static 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 } 145 146 static 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 } 152 153 static 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 */ 171 static 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 */ 200 static 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); 232 out: 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 */ 243 static 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; 262 out: 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 */ 276 static 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; 321 out: 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 */ 340 static 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; 426 out_put: 427 llc_sap_put(sap); 428 out: 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 */ 445 static 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); 461 out: 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 */ 480 static 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; 536 out: 537 release_sock(sk); 538 return rc; 539 sock_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 */ 553 static 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; 576 out: 577 release_sock(sk); 578 return rc; 579 } 580 581 static 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 } 602 603 static 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 } 618 619 static 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 } 644 645 static 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 } 671 672 static 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 * @arg: User specified arguments 692 * 693 * Accept a new incoming connection. 694 * Returns 0 upon success, negative otherwise. 695 */ 696 static int llc_ui_accept(struct socket *sock, struct socket *newsock, 697 struct proto_accept_arg *arg) 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); 742 frees: 743 kfree_skb(skb); 744 out: 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 */ 759 static 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); 900 901 out: 902 release_sock(sk); 903 return copied; 904 copy_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 */ 930 static 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; 1009 out: 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 */ 1026 static 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); 1061 out: 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 */ 1074 static 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 */ 1090 static 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; 1157 out: 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 */ 1172 static 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; 1215 out: 1216 release_sock(sk); 1217 return rc; 1218 } 1219 1220 static const struct net_proto_family llc_ui_family_ops = { 1221 .family = PF_LLC, 1222 .create = llc_ui_create, 1223 .owner = THIS_MODULE, 1224 }; 1225 1226 static 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 }; 1245 1246 static const char llc_proc_err_msg[] __initconst = 1247 KERN_CRIT "LLC: Unable to register the proc_fs entries\n"; 1248 static const char llc_sysctl_err_msg[] __initconst = 1249 KERN_CRIT "LLC: Unable to register the sysctl entries\n"; 1250 static const char llc_sock_err_msg[] __initconst = 1251 KERN_CRIT "LLC: Unable to register the network family\n"; 1252 1253 static int __init llc2_init(void) 1254 { 1255 int rc = proto_register(&llc_proto, 0); 1256 1257 if (rc != 0) 1258 goto out; 1259 1260 llc_build_offset_table(); 1261 llc_station_init(); 1262 llc_ui_sap_last_autoport = LLC_SAP_DYN_START; 1263 rc = llc_proc_init(); 1264 if (rc != 0) { 1265 printk(llc_proc_err_msg); 1266 goto out_station; 1267 } 1268 rc = llc_sysctl_init(); 1269 if (rc) { 1270 printk(llc_sysctl_err_msg); 1271 goto out_proc; 1272 } 1273 rc = sock_register(&llc_ui_family_ops); 1274 if (rc) { 1275 printk(llc_sock_err_msg); 1276 goto out_sysctl; 1277 } 1278 llc_add_pack(LLC_DEST_SAP, llc_sap_handler); 1279 llc_add_pack(LLC_DEST_CONN, llc_conn_handler); 1280 out: 1281 return rc; 1282 out_sysctl: 1283 llc_sysctl_exit(); 1284 out_proc: 1285 llc_proc_exit(); 1286 out_station: 1287 llc_station_exit(); 1288 proto_unregister(&llc_proto); 1289 goto out; 1290 } 1291 1292 static void __exit llc2_exit(void) 1293 { 1294 llc_station_exit(); 1295 llc_remove_pack(LLC_DEST_SAP); 1296 llc_remove_pack(LLC_DEST_CONN); 1297 sock_unregister(PF_LLC); 1298 llc_proc_exit(); 1299 llc_sysctl_exit(); 1300 proto_unregister(&llc_proto); 1301 } 1302 1303 module_init(llc2_init); 1304 module_exit(llc2_exit); 1305 1306 MODULE_LICENSE("GPL"); 1307 MODULE_AUTHOR("Procom 1997, Jay Schullist 2001, Arnaldo C. Melo 2001-2003"); 1308 MODULE_DESCRIPTION("IEEE 802.2 PF_LLC support"); 1309 MODULE_ALIAS_NETPROTO(PF_LLC); 1310