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