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