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