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