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_track(llc->dev, &llc->dev_tracker); 228 sock_put(sk); 229 llc_sk_free(sk); 230 out: 231 return 0; 232 } 233 234 /** 235 * llc_ui_autoport - provide dynamically allocate SAP number 236 * 237 * Provide the caller with a dynamically allocated SAP number according 238 * to the rules that are set in this function. Returns: 0, upon failure, 239 * SAP number otherwise. 240 */ 241 static int llc_ui_autoport(void) 242 { 243 struct llc_sap *sap; 244 int i, tries = 0; 245 246 while (tries < LLC_SAP_DYN_TRIES) { 247 for (i = llc_ui_sap_last_autoport; 248 i < LLC_SAP_DYN_STOP; i += 2) { 249 sap = llc_sap_find(i); 250 if (!sap) { 251 llc_ui_sap_last_autoport = i + 2; 252 goto out; 253 } 254 llc_sap_put(sap); 255 } 256 llc_ui_sap_last_autoport = LLC_SAP_DYN_START; 257 tries++; 258 } 259 i = 0; 260 out: 261 return i; 262 } 263 264 /** 265 * llc_ui_autobind - automatically bind a socket to a sap 266 * @sock: socket to bind 267 * @addr: address to connect to 268 * 269 * Used by llc_ui_connect and llc_ui_sendmsg when the user hasn't 270 * specifically used llc_ui_bind to bind to an specific address/sap 271 * 272 * Returns: 0 upon success, negative otherwise. 273 */ 274 static int llc_ui_autobind(struct socket *sock, struct sockaddr_llc *addr) 275 { 276 struct sock *sk = sock->sk; 277 struct llc_sock *llc = llc_sk(sk); 278 struct llc_sap *sap; 279 int rc = -EINVAL; 280 281 if (!sock_flag(sk, SOCK_ZAPPED)) 282 goto out; 283 if (!addr->sllc_arphrd) 284 addr->sllc_arphrd = ARPHRD_ETHER; 285 if (addr->sllc_arphrd != ARPHRD_ETHER) 286 goto out; 287 rc = -ENODEV; 288 if (sk->sk_bound_dev_if) { 289 llc->dev = dev_get_by_index(&init_net, sk->sk_bound_dev_if); 290 if (llc->dev && addr->sllc_arphrd != llc->dev->type) { 291 dev_put(llc->dev); 292 llc->dev = NULL; 293 } 294 } else 295 llc->dev = dev_getfirstbyhwtype(&init_net, addr->sllc_arphrd); 296 if (!llc->dev) 297 goto out; 298 netdev_tracker_alloc(llc->dev, &llc->dev_tracker, GFP_KERNEL); 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 memcpy(llc->laddr.mac, llc->dev->dev_addr, IFHWADDRLEN); 308 memcpy(&llc->addr, addr, sizeof(llc->addr)); 309 /* assign new connection to its SAP */ 310 llc_sap_add_socket(sap, sk); 311 sock_reset_flag(sk, SOCK_ZAPPED); 312 rc = 0; 313 out: 314 return rc; 315 } 316 317 /** 318 * llc_ui_bind - bind a socket to a specific address. 319 * @sock: Socket to bind an address to. 320 * @uaddr: Address the user wants the socket bound to. 321 * @addrlen: Length of the uaddr structure. 322 * 323 * Bind a socket to a specific address. For llc a user is able to bind to 324 * a specific sap only or mac + sap. 325 * If the user desires to bind to a specific mac + sap, it is possible to 326 * have multiple sap connections via multiple macs. 327 * Bind and autobind for that matter must enforce the correct sap usage 328 * otherwise all hell will break loose. 329 * Returns: 0 upon success, negative otherwise. 330 */ 331 static int llc_ui_bind(struct socket *sock, struct sockaddr *uaddr, int addrlen) 332 { 333 struct sockaddr_llc *addr = (struct sockaddr_llc *)uaddr; 334 struct sock *sk = sock->sk; 335 struct llc_sock *llc = llc_sk(sk); 336 struct llc_sap *sap; 337 int rc = -EINVAL; 338 339 lock_sock(sk); 340 if (unlikely(!sock_flag(sk, SOCK_ZAPPED) || addrlen != sizeof(*addr))) 341 goto out; 342 rc = -EAFNOSUPPORT; 343 if (!addr->sllc_arphrd) 344 addr->sllc_arphrd = ARPHRD_ETHER; 345 if (unlikely(addr->sllc_family != AF_LLC || addr->sllc_arphrd != ARPHRD_ETHER)) 346 goto out; 347 dprintk("%s: binding %02X\n", __func__, addr->sllc_sap); 348 rc = -ENODEV; 349 rcu_read_lock(); 350 if (sk->sk_bound_dev_if) { 351 llc->dev = dev_get_by_index_rcu(&init_net, sk->sk_bound_dev_if); 352 if (llc->dev) { 353 if (is_zero_ether_addr(addr->sllc_mac)) 354 memcpy(addr->sllc_mac, llc->dev->dev_addr, 355 IFHWADDRLEN); 356 if (addr->sllc_arphrd != llc->dev->type || 357 !ether_addr_equal(addr->sllc_mac, 358 llc->dev->dev_addr)) { 359 rc = -EINVAL; 360 llc->dev = NULL; 361 } 362 } 363 } else 364 llc->dev = dev_getbyhwaddr_rcu(&init_net, addr->sllc_arphrd, 365 addr->sllc_mac); 366 dev_hold_track(llc->dev, &llc->dev_tracker, GFP_ATOMIC); 367 rcu_read_unlock(); 368 if (!llc->dev) 369 goto out; 370 if (!addr->sllc_sap) { 371 rc = -EUSERS; 372 addr->sllc_sap = llc_ui_autoport(); 373 if (!addr->sllc_sap) 374 goto out; 375 } 376 sap = llc_sap_find(addr->sllc_sap); 377 if (!sap) { 378 sap = llc_sap_open(addr->sllc_sap, NULL); 379 rc = -EBUSY; /* some other network layer is using the sap */ 380 if (!sap) 381 goto out; 382 } else { 383 struct llc_addr laddr, daddr; 384 struct sock *ask; 385 386 memset(&laddr, 0, sizeof(laddr)); 387 memset(&daddr, 0, sizeof(daddr)); 388 /* 389 * FIXME: check if the address is multicast, 390 * only SOCK_DGRAM can do this. 391 */ 392 memcpy(laddr.mac, addr->sllc_mac, IFHWADDRLEN); 393 laddr.lsap = addr->sllc_sap; 394 rc = -EADDRINUSE; /* mac + sap clash. */ 395 ask = llc_lookup_established(sap, &daddr, &laddr); 396 if (ask) { 397 sock_put(ask); 398 goto out_put; 399 } 400 } 401 llc->laddr.lsap = addr->sllc_sap; 402 memcpy(llc->laddr.mac, addr->sllc_mac, IFHWADDRLEN); 403 memcpy(&llc->addr, addr, sizeof(llc->addr)); 404 /* assign new connection to its SAP */ 405 llc_sap_add_socket(sap, sk); 406 sock_reset_flag(sk, SOCK_ZAPPED); 407 rc = 0; 408 out_put: 409 llc_sap_put(sap); 410 out: 411 release_sock(sk); 412 return rc; 413 } 414 415 /** 416 * llc_ui_shutdown - shutdown a connect llc2 socket. 417 * @sock: Socket to shutdown. 418 * @how: What part of the socket to shutdown. 419 * 420 * Shutdown a connected llc2 socket. Currently this function only supports 421 * shutting down both sends and receives (2), we could probably make this 422 * function such that a user can shutdown only half the connection but not 423 * right now. 424 * Returns: 0 upon success, negative otherwise. 425 */ 426 static int llc_ui_shutdown(struct socket *sock, int how) 427 { 428 struct sock *sk = sock->sk; 429 int rc = -ENOTCONN; 430 431 lock_sock(sk); 432 if (unlikely(sk->sk_state != TCP_ESTABLISHED)) 433 goto out; 434 rc = -EINVAL; 435 if (how != 2) 436 goto out; 437 rc = llc_send_disc(sk); 438 if (!rc) 439 rc = llc_ui_wait_for_disc(sk, sk->sk_rcvtimeo); 440 /* Wake up anyone sleeping in poll */ 441 sk->sk_state_change(sk); 442 out: 443 release_sock(sk); 444 return rc; 445 } 446 447 /** 448 * llc_ui_connect - Connect to a remote llc2 mac + sap. 449 * @sock: Socket which will be connected to the remote destination. 450 * @uaddr: Remote and possibly the local address of the new connection. 451 * @addrlen: Size of uaddr structure. 452 * @flags: Operational flags specified by the user. 453 * 454 * Connect to a remote llc2 mac + sap. The caller must specify the 455 * destination mac and address to connect to. If the user hasn't previously 456 * called bind(2) with a smac the address of the first interface of the 457 * specified arp type will be used. 458 * This function will autobind if user did not previously call bind. 459 * Returns: 0 upon success, negative otherwise. 460 */ 461 static int llc_ui_connect(struct socket *sock, struct sockaddr *uaddr, 462 int addrlen, int flags) 463 { 464 struct sock *sk = sock->sk; 465 struct llc_sock *llc = llc_sk(sk); 466 struct sockaddr_llc *addr = (struct sockaddr_llc *)uaddr; 467 int rc = -EINVAL; 468 469 lock_sock(sk); 470 if (unlikely(addrlen != sizeof(*addr))) 471 goto out; 472 rc = -EAFNOSUPPORT; 473 if (unlikely(addr->sllc_family != AF_LLC)) 474 goto out; 475 if (unlikely(sk->sk_type != SOCK_STREAM)) 476 goto out; 477 rc = -EALREADY; 478 if (unlikely(sock->state == SS_CONNECTING)) 479 goto out; 480 /* bind connection to sap if user hasn't done it. */ 481 if (sock_flag(sk, SOCK_ZAPPED)) { 482 /* bind to sap with null dev, exclusive */ 483 rc = llc_ui_autobind(sock, addr); 484 if (rc) 485 goto out; 486 } 487 llc->daddr.lsap = addr->sllc_sap; 488 memcpy(llc->daddr.mac, addr->sllc_mac, IFHWADDRLEN); 489 sock->state = SS_CONNECTING; 490 sk->sk_state = TCP_SYN_SENT; 491 llc->link = llc_ui_next_link_no(llc->sap->laddr.lsap); 492 rc = llc_establish_connection(sk, llc->dev->dev_addr, 493 addr->sllc_mac, addr->sllc_sap); 494 if (rc) { 495 dprintk("%s: llc_ui_send_conn failed :-(\n", __func__); 496 sock->state = SS_UNCONNECTED; 497 sk->sk_state = TCP_CLOSE; 498 goto out; 499 } 500 501 if (sk->sk_state == TCP_SYN_SENT) { 502 const long timeo = sock_sndtimeo(sk, flags & O_NONBLOCK); 503 504 if (!timeo || !llc_ui_wait_for_conn(sk, timeo)) 505 goto out; 506 507 rc = sock_intr_errno(timeo); 508 if (signal_pending(current)) 509 goto out; 510 } 511 512 if (sk->sk_state == TCP_CLOSE) 513 goto sock_error; 514 515 sock->state = SS_CONNECTED; 516 rc = 0; 517 out: 518 release_sock(sk); 519 return rc; 520 sock_error: 521 rc = sock_error(sk) ? : -ECONNABORTED; 522 sock->state = SS_UNCONNECTED; 523 goto out; 524 } 525 526 /** 527 * llc_ui_listen - allow a normal socket to accept incoming connections 528 * @sock: Socket to allow incoming connections on. 529 * @backlog: Number of connections to queue. 530 * 531 * Allow a normal socket to accept incoming connections. 532 * Returns 0 upon success, negative otherwise. 533 */ 534 static int llc_ui_listen(struct socket *sock, int backlog) 535 { 536 struct sock *sk = sock->sk; 537 int rc = -EINVAL; 538 539 lock_sock(sk); 540 if (unlikely(sock->state != SS_UNCONNECTED)) 541 goto out; 542 rc = -EOPNOTSUPP; 543 if (unlikely(sk->sk_type != SOCK_STREAM)) 544 goto out; 545 rc = -EAGAIN; 546 if (sock_flag(sk, SOCK_ZAPPED)) 547 goto out; 548 rc = 0; 549 if (!(unsigned int)backlog) /* BSDism */ 550 backlog = 1; 551 sk->sk_max_ack_backlog = backlog; 552 if (sk->sk_state != TCP_LISTEN) { 553 sk->sk_ack_backlog = 0; 554 sk->sk_state = TCP_LISTEN; 555 } 556 sk->sk_socket->flags |= __SO_ACCEPTCON; 557 out: 558 release_sock(sk); 559 return rc; 560 } 561 562 static int llc_ui_wait_for_disc(struct sock *sk, long timeout) 563 { 564 DEFINE_WAIT_FUNC(wait, woken_wake_function); 565 int rc = 0; 566 567 add_wait_queue(sk_sleep(sk), &wait); 568 while (1) { 569 if (sk_wait_event(sk, &timeout, sk->sk_state == TCP_CLOSE, &wait)) 570 break; 571 rc = -ERESTARTSYS; 572 if (signal_pending(current)) 573 break; 574 rc = -EAGAIN; 575 if (!timeout) 576 break; 577 rc = 0; 578 } 579 remove_wait_queue(sk_sleep(sk), &wait); 580 return rc; 581 } 582 583 static bool llc_ui_wait_for_conn(struct sock *sk, long timeout) 584 { 585 DEFINE_WAIT_FUNC(wait, woken_wake_function); 586 587 add_wait_queue(sk_sleep(sk), &wait); 588 while (1) { 589 if (sk_wait_event(sk, &timeout, sk->sk_state != TCP_SYN_SENT, &wait)) 590 break; 591 if (signal_pending(current) || !timeout) 592 break; 593 } 594 remove_wait_queue(sk_sleep(sk), &wait); 595 return timeout; 596 } 597 598 static int llc_ui_wait_for_busy_core(struct sock *sk, long timeout) 599 { 600 DEFINE_WAIT_FUNC(wait, woken_wake_function); 601 struct llc_sock *llc = llc_sk(sk); 602 int rc; 603 604 add_wait_queue(sk_sleep(sk), &wait); 605 while (1) { 606 rc = 0; 607 if (sk_wait_event(sk, &timeout, 608 (sk->sk_shutdown & RCV_SHUTDOWN) || 609 (!llc_data_accept_state(llc->state) && 610 !llc->remote_busy_flag && 611 !llc->p_flag), &wait)) 612 break; 613 rc = -ERESTARTSYS; 614 if (signal_pending(current)) 615 break; 616 rc = -EAGAIN; 617 if (!timeout) 618 break; 619 } 620 remove_wait_queue(sk_sleep(sk), &wait); 621 return rc; 622 } 623 624 static int llc_wait_data(struct sock *sk, long timeo) 625 { 626 int rc; 627 628 while (1) { 629 /* 630 * POSIX 1003.1g mandates this order. 631 */ 632 rc = sock_error(sk); 633 if (rc) 634 break; 635 rc = 0; 636 if (sk->sk_shutdown & RCV_SHUTDOWN) 637 break; 638 rc = -EAGAIN; 639 if (!timeo) 640 break; 641 rc = sock_intr_errno(timeo); 642 if (signal_pending(current)) 643 break; 644 rc = 0; 645 if (sk_wait_data(sk, &timeo, NULL)) 646 break; 647 } 648 return rc; 649 } 650 651 static void llc_cmsg_rcv(struct msghdr *msg, struct sk_buff *skb) 652 { 653 struct llc_sock *llc = llc_sk(skb->sk); 654 655 if (llc->cmsg_flags & LLC_CMSG_PKTINFO) { 656 struct llc_pktinfo info; 657 658 memset(&info, 0, sizeof(info)); 659 info.lpi_ifindex = llc_sk(skb->sk)->dev->ifindex; 660 llc_pdu_decode_dsap(skb, &info.lpi_sap); 661 llc_pdu_decode_da(skb, info.lpi_mac); 662 put_cmsg(msg, SOL_LLC, LLC_OPT_PKTINFO, sizeof(info), &info); 663 } 664 } 665 666 /** 667 * llc_ui_accept - accept a new incoming connection. 668 * @sock: Socket which connections arrive on. 669 * @newsock: Socket to move incoming connection to. 670 * @flags: User specified operational flags. 671 * @kern: If the socket is kernel internal 672 * 673 * Accept a new incoming connection. 674 * Returns 0 upon success, negative otherwise. 675 */ 676 static int llc_ui_accept(struct socket *sock, struct socket *newsock, int flags, 677 bool kern) 678 { 679 struct sock *sk = sock->sk, *newsk; 680 struct llc_sock *llc, *newllc; 681 struct sk_buff *skb; 682 int rc = -EOPNOTSUPP; 683 684 dprintk("%s: accepting on %02X\n", __func__, 685 llc_sk(sk)->laddr.lsap); 686 lock_sock(sk); 687 if (unlikely(sk->sk_type != SOCK_STREAM)) 688 goto out; 689 rc = -EINVAL; 690 if (unlikely(sock->state != SS_UNCONNECTED || 691 sk->sk_state != TCP_LISTEN)) 692 goto out; 693 /* wait for a connection to arrive. */ 694 if (skb_queue_empty(&sk->sk_receive_queue)) { 695 rc = llc_wait_data(sk, sk->sk_rcvtimeo); 696 if (rc) 697 goto out; 698 } 699 dprintk("%s: got a new connection on %02X\n", __func__, 700 llc_sk(sk)->laddr.lsap); 701 skb = skb_dequeue(&sk->sk_receive_queue); 702 rc = -EINVAL; 703 if (!skb->sk) 704 goto frees; 705 rc = 0; 706 newsk = skb->sk; 707 /* attach connection to a new socket. */ 708 llc_ui_sk_init(newsock, newsk); 709 sock_reset_flag(newsk, SOCK_ZAPPED); 710 newsk->sk_state = TCP_ESTABLISHED; 711 newsock->state = SS_CONNECTED; 712 llc = llc_sk(sk); 713 newllc = llc_sk(newsk); 714 memcpy(&newllc->addr, &llc->addr, sizeof(newllc->addr)); 715 newllc->link = llc_ui_next_link_no(newllc->laddr.lsap); 716 717 /* put original socket back into a clean listen state. */ 718 sk->sk_state = TCP_LISTEN; 719 sk_acceptq_removed(sk); 720 dprintk("%s: ok success on %02X, client on %02X\n", __func__, 721 llc_sk(sk)->addr.sllc_sap, newllc->daddr.lsap); 722 frees: 723 kfree_skb(skb); 724 out: 725 release_sock(sk); 726 return rc; 727 } 728 729 /** 730 * llc_ui_recvmsg - copy received data to the socket user. 731 * @sock: Socket to copy data from. 732 * @msg: Various user space related information. 733 * @len: Size of user buffer. 734 * @flags: User specified flags. 735 * 736 * Copy received data to the socket user. 737 * Returns non-negative upon success, negative otherwise. 738 */ 739 static int llc_ui_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, 740 int flags) 741 { 742 DECLARE_SOCKADDR(struct sockaddr_llc *, uaddr, msg->msg_name); 743 const int nonblock = flags & MSG_DONTWAIT; 744 struct sk_buff *skb = NULL; 745 struct sock *sk = sock->sk; 746 struct llc_sock *llc = llc_sk(sk); 747 size_t copied = 0; 748 u32 peek_seq = 0; 749 u32 *seq, skb_len; 750 unsigned long used; 751 int target; /* Read at least this many bytes */ 752 long timeo; 753 754 lock_sock(sk); 755 copied = -ENOTCONN; 756 if (unlikely(sk->sk_type == SOCK_STREAM && sk->sk_state == TCP_LISTEN)) 757 goto out; 758 759 timeo = sock_rcvtimeo(sk, nonblock); 760 761 seq = &llc->copied_seq; 762 if (flags & MSG_PEEK) { 763 peek_seq = llc->copied_seq; 764 seq = &peek_seq; 765 } 766 767 target = sock_rcvlowat(sk, flags & MSG_WAITALL, len); 768 copied = 0; 769 770 do { 771 u32 offset; 772 773 /* 774 * We need to check signals first, to get correct SIGURG 775 * handling. FIXME: Need to check this doesn't impact 1003.1g 776 * and move it down to the bottom of the loop 777 */ 778 if (signal_pending(current)) { 779 if (copied) 780 break; 781 copied = timeo ? sock_intr_errno(timeo) : -EAGAIN; 782 break; 783 } 784 785 /* Next get a buffer. */ 786 787 skb = skb_peek(&sk->sk_receive_queue); 788 if (skb) { 789 offset = *seq; 790 goto found_ok_skb; 791 } 792 /* Well, if we have backlog, try to process it now yet. */ 793 794 if (copied >= target && !READ_ONCE(sk->sk_backlog.tail)) 795 break; 796 797 if (copied) { 798 if (sk->sk_err || 799 sk->sk_state == TCP_CLOSE || 800 (sk->sk_shutdown & RCV_SHUTDOWN) || 801 !timeo || 802 (flags & MSG_PEEK)) 803 break; 804 } else { 805 if (sock_flag(sk, SOCK_DONE)) 806 break; 807 808 if (sk->sk_err) { 809 copied = sock_error(sk); 810 break; 811 } 812 if (sk->sk_shutdown & RCV_SHUTDOWN) 813 break; 814 815 if (sk->sk_type == SOCK_STREAM && sk->sk_state == TCP_CLOSE) { 816 if (!sock_flag(sk, SOCK_DONE)) { 817 /* 818 * This occurs when user tries to read 819 * from never connected socket. 820 */ 821 copied = -ENOTCONN; 822 break; 823 } 824 break; 825 } 826 if (!timeo) { 827 copied = -EAGAIN; 828 break; 829 } 830 } 831 832 if (copied >= target) { /* Do not sleep, just process backlog. */ 833 release_sock(sk); 834 lock_sock(sk); 835 } else 836 sk_wait_data(sk, &timeo, NULL); 837 838 if ((flags & MSG_PEEK) && peek_seq != llc->copied_seq) { 839 net_dbg_ratelimited("LLC(%s:%d): Application bug, race in MSG_PEEK\n", 840 current->comm, 841 task_pid_nr(current)); 842 peek_seq = llc->copied_seq; 843 } 844 continue; 845 found_ok_skb: 846 skb_len = skb->len; 847 /* Ok so how much can we use? */ 848 used = skb->len - offset; 849 if (len < used) 850 used = len; 851 852 if (!(flags & MSG_TRUNC)) { 853 int rc = skb_copy_datagram_msg(skb, offset, msg, used); 854 if (rc) { 855 /* Exception. Bailout! */ 856 if (!copied) 857 copied = -EFAULT; 858 break; 859 } 860 } 861 862 *seq += used; 863 copied += used; 864 len -= used; 865 866 /* For non stream protcols we get one packet per recvmsg call */ 867 if (sk->sk_type != SOCK_STREAM) 868 goto copy_uaddr; 869 870 if (!(flags & MSG_PEEK)) { 871 skb_unlink(skb, &sk->sk_receive_queue); 872 kfree_skb(skb); 873 *seq = 0; 874 } 875 876 /* Partial read */ 877 if (used + offset < skb_len) 878 continue; 879 } while (len > 0); 880 881 out: 882 release_sock(sk); 883 return copied; 884 copy_uaddr: 885 if (uaddr != NULL && skb != NULL) { 886 memcpy(uaddr, llc_ui_skb_cb(skb), sizeof(*uaddr)); 887 msg->msg_namelen = sizeof(*uaddr); 888 } 889 if (llc_sk(sk)->cmsg_flags) 890 llc_cmsg_rcv(msg, skb); 891 892 if (!(flags & MSG_PEEK)) { 893 skb_unlink(skb, &sk->sk_receive_queue); 894 kfree_skb(skb); 895 *seq = 0; 896 } 897 898 goto out; 899 } 900 901 /** 902 * llc_ui_sendmsg - Transmit data provided by the socket user. 903 * @sock: Socket to transmit data from. 904 * @msg: Various user related information. 905 * @len: Length of data to transmit. 906 * 907 * Transmit data provided by the socket user. 908 * Returns non-negative upon success, negative otherwise. 909 */ 910 static int llc_ui_sendmsg(struct socket *sock, struct msghdr *msg, size_t len) 911 { 912 struct sock *sk = sock->sk; 913 struct llc_sock *llc = llc_sk(sk); 914 DECLARE_SOCKADDR(struct sockaddr_llc *, addr, msg->msg_name); 915 int flags = msg->msg_flags; 916 int noblock = flags & MSG_DONTWAIT; 917 struct sk_buff *skb = NULL; 918 size_t size = 0; 919 int rc = -EINVAL, copied = 0, hdrlen; 920 921 dprintk("%s: sending from %02X to %02X\n", __func__, 922 llc->laddr.lsap, llc->daddr.lsap); 923 lock_sock(sk); 924 if (addr) { 925 if (msg->msg_namelen < sizeof(*addr)) 926 goto out; 927 } else { 928 if (llc_ui_addr_null(&llc->addr)) 929 goto out; 930 addr = &llc->addr; 931 } 932 /* must bind connection to sap if user hasn't done it. */ 933 if (sock_flag(sk, SOCK_ZAPPED)) { 934 /* bind to sap with null dev, exclusive. */ 935 rc = llc_ui_autobind(sock, addr); 936 if (rc) 937 goto out; 938 } 939 hdrlen = llc->dev->hard_header_len + llc_ui_header_len(sk, addr); 940 size = hdrlen + len; 941 if (size > llc->dev->mtu) 942 size = llc->dev->mtu; 943 copied = size - hdrlen; 944 rc = -EINVAL; 945 if (copied < 0) 946 goto out; 947 release_sock(sk); 948 skb = sock_alloc_send_skb(sk, size, noblock, &rc); 949 lock_sock(sk); 950 if (!skb) 951 goto out; 952 skb->dev = llc->dev; 953 skb->protocol = llc_proto_type(addr->sllc_arphrd); 954 skb_reserve(skb, hdrlen); 955 rc = memcpy_from_msg(skb_put(skb, copied), msg, copied); 956 if (rc) 957 goto out; 958 if (sk->sk_type == SOCK_DGRAM || addr->sllc_ua) { 959 llc_build_and_send_ui_pkt(llc->sap, skb, addr->sllc_mac, 960 addr->sllc_sap); 961 skb = NULL; 962 goto out; 963 } 964 if (addr->sllc_test) { 965 llc_build_and_send_test_pkt(llc->sap, skb, addr->sllc_mac, 966 addr->sllc_sap); 967 skb = NULL; 968 goto out; 969 } 970 if (addr->sllc_xid) { 971 llc_build_and_send_xid_pkt(llc->sap, skb, addr->sllc_mac, 972 addr->sllc_sap); 973 skb = NULL; 974 goto out; 975 } 976 rc = -ENOPROTOOPT; 977 if (!(sk->sk_type == SOCK_STREAM && !addr->sllc_ua)) 978 goto out; 979 rc = llc_ui_send_data(sk, skb, noblock); 980 skb = NULL; 981 out: 982 kfree_skb(skb); 983 if (rc) 984 dprintk("%s: failed sending from %02X to %02X: %d\n", 985 __func__, llc->laddr.lsap, llc->daddr.lsap, rc); 986 release_sock(sk); 987 return rc ? : copied; 988 } 989 990 /** 991 * llc_ui_getname - return the address info of a socket 992 * @sock: Socket to get address of. 993 * @uaddr: Address structure to return information. 994 * @peer: Does user want local or remote address information. 995 * 996 * Return the address information of a socket. 997 */ 998 static int llc_ui_getname(struct socket *sock, struct sockaddr *uaddr, 999 int peer) 1000 { 1001 struct sockaddr_llc sllc; 1002 struct sock *sk = sock->sk; 1003 struct llc_sock *llc = llc_sk(sk); 1004 int rc = -EBADF; 1005 1006 memset(&sllc, 0, sizeof(sllc)); 1007 lock_sock(sk); 1008 if (sock_flag(sk, SOCK_ZAPPED)) 1009 goto out; 1010 if (peer) { 1011 rc = -ENOTCONN; 1012 if (sk->sk_state != TCP_ESTABLISHED) 1013 goto out; 1014 if(llc->dev) 1015 sllc.sllc_arphrd = llc->dev->type; 1016 sllc.sllc_sap = llc->daddr.lsap; 1017 memcpy(&sllc.sllc_mac, &llc->daddr.mac, IFHWADDRLEN); 1018 } else { 1019 rc = -EINVAL; 1020 if (!llc->sap) 1021 goto out; 1022 sllc.sllc_sap = llc->sap->laddr.lsap; 1023 1024 if (llc->dev) { 1025 sllc.sllc_arphrd = llc->dev->type; 1026 memcpy(&sllc.sllc_mac, llc->dev->dev_addr, 1027 IFHWADDRLEN); 1028 } 1029 } 1030 sllc.sllc_family = AF_LLC; 1031 memcpy(uaddr, &sllc, sizeof(sllc)); 1032 rc = sizeof(sllc); 1033 out: 1034 release_sock(sk); 1035 return rc; 1036 } 1037 1038 /** 1039 * llc_ui_ioctl - io controls for PF_LLC 1040 * @sock: Socket to get/set info 1041 * @cmd: command 1042 * @arg: optional argument for cmd 1043 * 1044 * get/set info on llc sockets 1045 */ 1046 static int llc_ui_ioctl(struct socket *sock, unsigned int cmd, 1047 unsigned long arg) 1048 { 1049 return -ENOIOCTLCMD; 1050 } 1051 1052 /** 1053 * llc_ui_setsockopt - set various connection specific parameters. 1054 * @sock: Socket to set options on. 1055 * @level: Socket level user is requesting operations on. 1056 * @optname: Operation name. 1057 * @optval: User provided operation data. 1058 * @optlen: Length of optval. 1059 * 1060 * Set various connection specific parameters. 1061 */ 1062 static int llc_ui_setsockopt(struct socket *sock, int level, int optname, 1063 sockptr_t optval, unsigned int optlen) 1064 { 1065 struct sock *sk = sock->sk; 1066 struct llc_sock *llc = llc_sk(sk); 1067 unsigned int opt; 1068 int rc = -EINVAL; 1069 1070 lock_sock(sk); 1071 if (unlikely(level != SOL_LLC || optlen != sizeof(int))) 1072 goto out; 1073 rc = copy_from_sockptr(&opt, optval, sizeof(opt)); 1074 if (rc) 1075 goto out; 1076 rc = -EINVAL; 1077 switch (optname) { 1078 case LLC_OPT_RETRY: 1079 if (opt > LLC_OPT_MAX_RETRY) 1080 goto out; 1081 llc->n2 = opt; 1082 break; 1083 case LLC_OPT_SIZE: 1084 if (opt > LLC_OPT_MAX_SIZE) 1085 goto out; 1086 llc->n1 = opt; 1087 break; 1088 case LLC_OPT_ACK_TMR_EXP: 1089 if (opt > LLC_OPT_MAX_ACK_TMR_EXP) 1090 goto out; 1091 llc->ack_timer.expire = opt * HZ; 1092 break; 1093 case LLC_OPT_P_TMR_EXP: 1094 if (opt > LLC_OPT_MAX_P_TMR_EXP) 1095 goto out; 1096 llc->pf_cycle_timer.expire = opt * HZ; 1097 break; 1098 case LLC_OPT_REJ_TMR_EXP: 1099 if (opt > LLC_OPT_MAX_REJ_TMR_EXP) 1100 goto out; 1101 llc->rej_sent_timer.expire = opt * HZ; 1102 break; 1103 case LLC_OPT_BUSY_TMR_EXP: 1104 if (opt > LLC_OPT_MAX_BUSY_TMR_EXP) 1105 goto out; 1106 llc->busy_state_timer.expire = opt * HZ; 1107 break; 1108 case LLC_OPT_TX_WIN: 1109 if (opt > LLC_OPT_MAX_WIN) 1110 goto out; 1111 llc->k = opt; 1112 break; 1113 case LLC_OPT_RX_WIN: 1114 if (opt > LLC_OPT_MAX_WIN) 1115 goto out; 1116 llc->rw = opt; 1117 break; 1118 case LLC_OPT_PKTINFO: 1119 if (opt) 1120 llc->cmsg_flags |= LLC_CMSG_PKTINFO; 1121 else 1122 llc->cmsg_flags &= ~LLC_CMSG_PKTINFO; 1123 break; 1124 default: 1125 rc = -ENOPROTOOPT; 1126 goto out; 1127 } 1128 rc = 0; 1129 out: 1130 release_sock(sk); 1131 return rc; 1132 } 1133 1134 /** 1135 * llc_ui_getsockopt - get connection specific socket info 1136 * @sock: Socket to get information from. 1137 * @level: Socket level user is requesting operations on. 1138 * @optname: Operation name. 1139 * @optval: Variable to return operation data in. 1140 * @optlen: Length of optval. 1141 * 1142 * Get connection specific socket information. 1143 */ 1144 static int llc_ui_getsockopt(struct socket *sock, int level, int optname, 1145 char __user *optval, int __user *optlen) 1146 { 1147 struct sock *sk = sock->sk; 1148 struct llc_sock *llc = llc_sk(sk); 1149 int val = 0, len = 0, rc = -EINVAL; 1150 1151 lock_sock(sk); 1152 if (unlikely(level != SOL_LLC)) 1153 goto out; 1154 rc = get_user(len, optlen); 1155 if (rc) 1156 goto out; 1157 rc = -EINVAL; 1158 if (len != sizeof(int)) 1159 goto out; 1160 switch (optname) { 1161 case LLC_OPT_RETRY: 1162 val = llc->n2; break; 1163 case LLC_OPT_SIZE: 1164 val = llc->n1; break; 1165 case LLC_OPT_ACK_TMR_EXP: 1166 val = llc->ack_timer.expire / HZ; break; 1167 case LLC_OPT_P_TMR_EXP: 1168 val = llc->pf_cycle_timer.expire / HZ; break; 1169 case LLC_OPT_REJ_TMR_EXP: 1170 val = llc->rej_sent_timer.expire / HZ; break; 1171 case LLC_OPT_BUSY_TMR_EXP: 1172 val = llc->busy_state_timer.expire / HZ; break; 1173 case LLC_OPT_TX_WIN: 1174 val = llc->k; break; 1175 case LLC_OPT_RX_WIN: 1176 val = llc->rw; break; 1177 case LLC_OPT_PKTINFO: 1178 val = (llc->cmsg_flags & LLC_CMSG_PKTINFO) != 0; 1179 break; 1180 default: 1181 rc = -ENOPROTOOPT; 1182 goto out; 1183 } 1184 rc = 0; 1185 if (put_user(len, optlen) || copy_to_user(optval, &val, len)) 1186 rc = -EFAULT; 1187 out: 1188 release_sock(sk); 1189 return rc; 1190 } 1191 1192 static const struct net_proto_family llc_ui_family_ops = { 1193 .family = PF_LLC, 1194 .create = llc_ui_create, 1195 .owner = THIS_MODULE, 1196 }; 1197 1198 static const struct proto_ops llc_ui_ops = { 1199 .family = PF_LLC, 1200 .owner = THIS_MODULE, 1201 .release = llc_ui_release, 1202 .bind = llc_ui_bind, 1203 .connect = llc_ui_connect, 1204 .socketpair = sock_no_socketpair, 1205 .accept = llc_ui_accept, 1206 .getname = llc_ui_getname, 1207 .poll = datagram_poll, 1208 .ioctl = llc_ui_ioctl, 1209 .listen = llc_ui_listen, 1210 .shutdown = llc_ui_shutdown, 1211 .setsockopt = llc_ui_setsockopt, 1212 .getsockopt = llc_ui_getsockopt, 1213 .sendmsg = llc_ui_sendmsg, 1214 .recvmsg = llc_ui_recvmsg, 1215 .mmap = sock_no_mmap, 1216 .sendpage = sock_no_sendpage, 1217 }; 1218 1219 static const char llc_proc_err_msg[] __initconst = 1220 KERN_CRIT "LLC: Unable to register the proc_fs entries\n"; 1221 static const char llc_sysctl_err_msg[] __initconst = 1222 KERN_CRIT "LLC: Unable to register the sysctl entries\n"; 1223 static const char llc_sock_err_msg[] __initconst = 1224 KERN_CRIT "LLC: Unable to register the network family\n"; 1225 1226 static int __init llc2_init(void) 1227 { 1228 int rc = proto_register(&llc_proto, 0); 1229 1230 if (rc != 0) 1231 goto out; 1232 1233 llc_build_offset_table(); 1234 llc_station_init(); 1235 llc_ui_sap_last_autoport = LLC_SAP_DYN_START; 1236 rc = llc_proc_init(); 1237 if (rc != 0) { 1238 printk(llc_proc_err_msg); 1239 goto out_station; 1240 } 1241 rc = llc_sysctl_init(); 1242 if (rc) { 1243 printk(llc_sysctl_err_msg); 1244 goto out_proc; 1245 } 1246 rc = sock_register(&llc_ui_family_ops); 1247 if (rc) { 1248 printk(llc_sock_err_msg); 1249 goto out_sysctl; 1250 } 1251 llc_add_pack(LLC_DEST_SAP, llc_sap_handler); 1252 llc_add_pack(LLC_DEST_CONN, llc_conn_handler); 1253 out: 1254 return rc; 1255 out_sysctl: 1256 llc_sysctl_exit(); 1257 out_proc: 1258 llc_proc_exit(); 1259 out_station: 1260 llc_station_exit(); 1261 proto_unregister(&llc_proto); 1262 goto out; 1263 } 1264 1265 static void __exit llc2_exit(void) 1266 { 1267 llc_station_exit(); 1268 llc_remove_pack(LLC_DEST_SAP); 1269 llc_remove_pack(LLC_DEST_CONN); 1270 sock_unregister(PF_LLC); 1271 llc_proc_exit(); 1272 llc_sysctl_exit(); 1273 proto_unregister(&llc_proto); 1274 } 1275 1276 module_init(llc2_init); 1277 module_exit(llc2_exit); 1278 1279 MODULE_LICENSE("GPL"); 1280 MODULE_AUTHOR("Procom 1997, Jay Schullist 2001, Arnaldo C. Melo 2001-2003"); 1281 MODULE_DESCRIPTION("IEEE 802.2 PF_LLC support"); 1282 MODULE_ALIAS_NETPROTO(PF_LLC); 1283