/* * af_llc.c - LLC User Interface SAPs * Description: * Functions in this module are implementation of socket based llc * communications for the Linux operating system. Support of llc class * one and class two is provided via SOCK_DGRAM and SOCK_STREAM * respectively. * * An llc2 connection is (mac + sap), only one llc2 sap connection * is allowed per mac. Though one sap may have multiple mac + sap * connections. * * Copyright (c) 2001 by Jay Schulist * 2002-2003 by Arnaldo Carvalho de Melo * * This program can be redistributed or modified under the terms of the * GNU General Public License as published by the Free Software Foundation. * This program is distributed without any warranty or implied warranty * of merchantability or fitness for a particular purpose. * * See the GNU General Public License for more details. */ #include #include #include #include #include #include #include #include #include #include #include #include /* remember: uninitialized global data is zeroed because its in .bss */ static u16 llc_ui_sap_last_autoport = LLC_SAP_DYN_START; static u16 llc_ui_sap_link_no_max[256]; static struct sockaddr_llc llc_ui_addrnull; static const struct proto_ops llc_ui_ops; static bool llc_ui_wait_for_conn(struct sock *sk, long timeout); static int llc_ui_wait_for_disc(struct sock *sk, long timeout); static int llc_ui_wait_for_busy_core(struct sock *sk, long timeout); #if 0 #define dprintk(args...) printk(KERN_DEBUG args) #else #define dprintk(args...) do {} while (0) #endif /* Maybe we'll add some more in the future. */ #define LLC_CMSG_PKTINFO 1 /** * llc_ui_next_link_no - return the next unused link number for a sap * @sap: Address of sap to get link number from. * * Return the next unused link number for a given sap. */ static inline u16 llc_ui_next_link_no(int sap) { return llc_ui_sap_link_no_max[sap]++; } /** * llc_proto_type - return eth protocol for ARP header type * @arphrd: ARP header type. * * Given an ARP header type return the corresponding ethernet protocol. */ static inline __be16 llc_proto_type(u16 arphrd) { return htons(ETH_P_802_2); } /** * llc_ui_addr_null - determines if a address structure is null * @addr: Address to test if null. */ static inline u8 llc_ui_addr_null(struct sockaddr_llc *addr) { return !memcmp(addr, &llc_ui_addrnull, sizeof(*addr)); } /** * llc_ui_header_len - return length of llc header based on operation * @sk: Socket which contains a valid llc socket type. * @addr: Complete sockaddr_llc structure received from the user. * * Provide the length of the llc header depending on what kind of * operation the user would like to perform and the type of socket. * Returns the correct llc header length. */ static inline u8 llc_ui_header_len(struct sock *sk, struct sockaddr_llc *addr) { u8 rc = LLC_PDU_LEN_U; if (addr->sllc_test) rc = LLC_PDU_LEN_U; else if (addr->sllc_xid) /* We need to expand header to sizeof(struct llc_xid_info) * since llc_pdu_init_as_xid_cmd() sets 4,5,6 bytes of LLC header * as XID PDU. In llc_ui_sendmsg() we reserved header size and then * filled all other space with user data. If we won't reserve this * bytes, llc_pdu_init_as_xid_cmd() will overwrite user data */ rc = LLC_PDU_LEN_U_XID; else if (sk->sk_type == SOCK_STREAM) rc = LLC_PDU_LEN_I; return rc; } /** * llc_ui_send_data - send data via reliable llc2 connection * @sk: Connection the socket is using. * @skb: Data the user wishes to send. * @noblock: can we block waiting for data? * * Send data via reliable llc2 connection. * Returns 0 upon success, non-zero if action did not succeed. * * This function always consumes a reference to the skb. */ static int llc_ui_send_data(struct sock* sk, struct sk_buff *skb, int noblock) { struct llc_sock* llc = llc_sk(sk); if (unlikely(llc_data_accept_state(llc->state) || llc->remote_busy_flag || llc->p_flag)) { long timeout = sock_sndtimeo(sk, noblock); int rc; rc = llc_ui_wait_for_busy_core(sk, timeout); if (rc) { kfree_skb(skb); return rc; } } return llc_build_and_send_pkt(sk, skb); } static void llc_ui_sk_init(struct socket *sock, struct sock *sk) { sock_graft(sk, sock); sk->sk_type = sock->type; sock->ops = &llc_ui_ops; } static struct proto llc_proto = { .name = "LLC", .owner = THIS_MODULE, .obj_size = sizeof(struct llc_sock), .slab_flags = SLAB_TYPESAFE_BY_RCU, }; /** * llc_ui_create - alloc and init a new llc_ui socket * @net: network namespace (must be default network) * @sock: Socket to initialize and attach allocated sk to. * @protocol: Unused. * @kern: on behalf of kernel or userspace * * Allocate and initialize a new llc_ui socket, validate the user wants a * socket type we have available. * Returns 0 upon success, negative upon failure. */ static int llc_ui_create(struct net *net, struct socket *sock, int protocol, int kern) { struct sock *sk; int rc = -ESOCKTNOSUPPORT; if (!ns_capable(net->user_ns, CAP_NET_RAW)) return -EPERM; if (!net_eq(net, &init_net)) return -EAFNOSUPPORT; if (likely(sock->type == SOCK_DGRAM || sock->type == SOCK_STREAM)) { rc = -ENOMEM; sk = llc_sk_alloc(net, PF_LLC, GFP_KERNEL, &llc_proto, kern); if (sk) { rc = 0; llc_ui_sk_init(sock, sk); } } return rc; } /** * llc_ui_release - shutdown socket * @sock: Socket to release. * * Shutdown and deallocate an existing socket. */ static int llc_ui_release(struct socket *sock) { struct sock *sk = sock->sk; struct llc_sock *llc; if (unlikely(sk == NULL)) goto out; sock_hold(sk); lock_sock(sk); llc = llc_sk(sk); dprintk("%s: closing local(%02X) remote(%02X)\n", __func__, llc->laddr.lsap, llc->daddr.lsap); if (!llc_send_disc(sk)) llc_ui_wait_for_disc(sk, sk->sk_rcvtimeo); if (!sock_flag(sk, SOCK_ZAPPED)) { struct llc_sap *sap = llc->sap; /* Hold this for release_sock(), so that llc_backlog_rcv() * could still use it. */ llc_sap_hold(sap); llc_sap_remove_socket(llc->sap, sk); release_sock(sk); llc_sap_put(sap); } else { release_sock(sk); } dev_put(llc->dev); sock_put(sk); sock_orphan(sk); sock->sk = NULL; llc_sk_free(sk); out: return 0; } /** * llc_ui_autoport - provide dynamically allocate SAP number * * Provide the caller with a dynamically allocated SAP number according * to the rules that are set in this function. Returns: 0, upon failure, * SAP number otherwise. */ static int llc_ui_autoport(void) { struct llc_sap *sap; int i, tries = 0; while (tries < LLC_SAP_DYN_TRIES) { for (i = llc_ui_sap_last_autoport; i < LLC_SAP_DYN_STOP; i += 2) { sap = llc_sap_find(i); if (!sap) { llc_ui_sap_last_autoport = i + 2; goto out; } llc_sap_put(sap); } llc_ui_sap_last_autoport = LLC_SAP_DYN_START; tries++; } i = 0; out: return i; } /** * llc_ui_autobind - automatically bind a socket to a sap * @sock: socket to bind * @addr: address to connect to * * Used by llc_ui_connect and llc_ui_sendmsg when the user hasn't * specifically used llc_ui_bind to bind to an specific address/sap * * Returns: 0 upon success, negative otherwise. */ static int llc_ui_autobind(struct socket *sock, struct sockaddr_llc *addr) { struct sock *sk = sock->sk; struct llc_sock *llc = llc_sk(sk); struct net_device *dev = NULL; struct llc_sap *sap; int rc = -EINVAL; if (!sock_flag(sk, SOCK_ZAPPED)) goto out; if (!addr->sllc_arphrd) addr->sllc_arphrd = ARPHRD_ETHER; if (addr->sllc_arphrd != ARPHRD_ETHER) goto out; rc = -ENODEV; if (sk->sk_bound_dev_if) { dev = dev_get_by_index(&init_net, sk->sk_bound_dev_if); if (dev && addr->sllc_arphrd != dev->type) { dev_put(dev); dev = NULL; } } else dev = dev_getfirstbyhwtype(&init_net, addr->sllc_arphrd); if (!dev) goto out; rc = -EUSERS; llc->laddr.lsap = llc_ui_autoport(); if (!llc->laddr.lsap) goto out; rc = -EBUSY; /* some other network layer is using the sap */ sap = llc_sap_open(llc->laddr.lsap, NULL); if (!sap) goto out; /* Note: We do not expect errors from this point. */ llc->dev = dev; dev = NULL; memcpy(llc->laddr.mac, llc->dev->dev_addr, IFHWADDRLEN); memcpy(&llc->addr, addr, sizeof(llc->addr)); /* assign new connection to its SAP */ llc_sap_add_socket(sap, sk); sock_reset_flag(sk, SOCK_ZAPPED); rc = 0; out: dev_put(dev); return rc; } /** * llc_ui_bind - bind a socket to a specific address. * @sock: Socket to bind an address to. * @uaddr: Address the user wants the socket bound to. * @addrlen: Length of the uaddr structure. * * Bind a socket to a specific address. For llc a user is able to bind to * a specific sap only or mac + sap. * If the user desires to bind to a specific mac + sap, it is possible to * have multiple sap connections via multiple macs. * Bind and autobind for that matter must enforce the correct sap usage * otherwise all hell will break loose. * Returns: 0 upon success, negative otherwise. */ static int llc_ui_bind(struct socket *sock, struct sockaddr *uaddr, int addrlen) { struct sockaddr_llc *addr = (struct sockaddr_llc *)uaddr; struct sock *sk = sock->sk; struct llc_sock *llc = llc_sk(sk); struct net_device *dev = NULL; struct llc_sap *sap; int rc = -EINVAL; lock_sock(sk); if (unlikely(!sock_flag(sk, SOCK_ZAPPED) || addrlen != sizeof(*addr))) goto out; rc = -EAFNOSUPPORT; if (!addr->sllc_arphrd) addr->sllc_arphrd = ARPHRD_ETHER; if (unlikely(addr->sllc_family != AF_LLC || addr->sllc_arphrd != ARPHRD_ETHER)) goto out; dprintk("%s: binding %02X\n", __func__, addr->sllc_sap); rc = -ENODEV; rcu_read_lock(); if (sk->sk_bound_dev_if) { dev = dev_get_by_index_rcu(&init_net, sk->sk_bound_dev_if); if (dev) { if (is_zero_ether_addr(addr->sllc_mac)) memcpy(addr->sllc_mac, dev->dev_addr, IFHWADDRLEN); if (addr->sllc_arphrd != dev->type || !ether_addr_equal(addr->sllc_mac, dev->dev_addr)) { rc = -EINVAL; dev = NULL; } } } else { dev = dev_getbyhwaddr_rcu(&init_net, addr->sllc_arphrd, addr->sllc_mac); } dev_hold(dev); rcu_read_unlock(); if (!dev) goto out; if (!addr->sllc_sap) { rc = -EUSERS; addr->sllc_sap = llc_ui_autoport(); if (!addr->sllc_sap) goto out; } sap = llc_sap_find(addr->sllc_sap); if (!sap) { sap = llc_sap_open(addr->sllc_sap, NULL); rc = -EBUSY; /* some other network layer is using the sap */ if (!sap) goto out; } else { struct llc_addr laddr, daddr; struct sock *ask; memset(&laddr, 0, sizeof(laddr)); memset(&daddr, 0, sizeof(daddr)); /* * FIXME: check if the address is multicast, * only SOCK_DGRAM can do this. */ memcpy(laddr.mac, addr->sllc_mac, IFHWADDRLEN); laddr.lsap = addr->sllc_sap; rc = -EADDRINUSE; /* mac + sap clash. */ ask = llc_lookup_established(sap, &daddr, &laddr); if (ask) { sock_put(ask); goto out_put; } } /* Note: We do not expect errors from this point. */ llc->dev = dev; dev = NULL; llc->laddr.lsap = addr->sllc_sap; memcpy(llc->laddr.mac, addr->sllc_mac, IFHWADDRLEN); memcpy(&llc->addr, addr, sizeof(llc->addr)); /* assign new connection to its SAP */ llc_sap_add_socket(sap, sk); sock_reset_flag(sk, SOCK_ZAPPED); rc = 0; out_put: llc_sap_put(sap); out: dev_put(dev); release_sock(sk); return rc; } /** * llc_ui_shutdown - shutdown a connect llc2 socket. * @sock: Socket to shutdown. * @how: What part of the socket to shutdown. * * Shutdown a connected llc2 socket. Currently this function only supports * shutting down both sends and receives (2), we could probably make this * function such that a user can shutdown only half the connection but not * right now. * Returns: 0 upon success, negative otherwise. */ static int llc_ui_shutdown(struct socket *sock, int how) { struct sock *sk = sock->sk; int rc = -ENOTCONN; lock_sock(sk); if (unlikely(sk->sk_state != TCP_ESTABLISHED)) goto out; rc = -EINVAL; if (how != 2) goto out; rc = llc_send_disc(sk); if (!rc) rc = llc_ui_wait_for_disc(sk, sk->sk_rcvtimeo); /* Wake up anyone sleeping in poll */ sk->sk_state_change(sk); out: release_sock(sk); return rc; } /** * llc_ui_connect - Connect to a remote llc2 mac + sap. * @sock: Socket which will be connected to the remote destination. * @uaddr: Remote and possibly the local address of the new connection. * @addrlen: Size of uaddr structure. * @flags: Operational flags specified by the user. * * Connect to a remote llc2 mac + sap. The caller must specify the * destination mac and address to connect to. If the user hasn't previously * called bind(2) with a smac the address of the first interface of the * specified arp type will be used. * This function will autobind if user did not previously call bind. * Returns: 0 upon success, negative otherwise. */ static int llc_ui_connect(struct socket *sock, struct sockaddr *uaddr, int addrlen, int flags) { struct sock *sk = sock->sk; struct llc_sock *llc = llc_sk(sk); struct sockaddr_llc *addr = (struct sockaddr_llc *)uaddr; int rc = -EINVAL; lock_sock(sk); if (unlikely(addrlen != sizeof(*addr))) goto out; rc = -EAFNOSUPPORT; if (unlikely(addr->sllc_family != AF_LLC)) goto out; if (unlikely(sk->sk_type != SOCK_STREAM)) goto out; rc = -EALREADY; if (unlikely(sock->state == SS_CONNECTING)) goto out; /* bind connection to sap if user hasn't done it. */ if (sock_flag(sk, SOCK_ZAPPED)) { /* bind to sap with null dev, exclusive */ rc = llc_ui_autobind(sock, addr); if (rc) goto out; } llc->daddr.lsap = addr->sllc_sap; memcpy(llc->daddr.mac, addr->sllc_mac, IFHWADDRLEN); sock->state = SS_CONNECTING; sk->sk_state = TCP_SYN_SENT; llc->link = llc_ui_next_link_no(llc->sap->laddr.lsap); rc = llc_establish_connection(sk, llc->dev->dev_addr, addr->sllc_mac, addr->sllc_sap); if (rc) { dprintk("%s: llc_ui_send_conn failed :-(\n", __func__); sock->state = SS_UNCONNECTED; sk->sk_state = TCP_CLOSE; goto out; } if (sk->sk_state == TCP_SYN_SENT) { const long timeo = sock_sndtimeo(sk, flags & O_NONBLOCK); if (!timeo || !llc_ui_wait_for_conn(sk, timeo)) goto out; rc = sock_intr_errno(timeo); if (signal_pending(current)) goto out; } if (sk->sk_state == TCP_CLOSE) goto sock_error; sock->state = SS_CONNECTED; rc = 0; out: release_sock(sk); return rc; sock_error: rc = sock_error(sk) ? : -ECONNABORTED; sock->state = SS_UNCONNECTED; goto out; } /** * llc_ui_listen - allow a normal socket to accept incoming connections * @sock: Socket to allow incoming connections on. * @backlog: Number of connections to queue. * * Allow a normal socket to accept incoming connections. * Returns 0 upon success, negative otherwise. */ static int llc_ui_listen(struct socket *sock, int backlog) { struct sock *sk = sock->sk; int rc = -EINVAL; lock_sock(sk); if (unlikely(sock->state != SS_UNCONNECTED)) goto out; rc = -EOPNOTSUPP; if (unlikely(sk->sk_type != SOCK_STREAM)) goto out; rc = -EAGAIN; if (sock_flag(sk, SOCK_ZAPPED)) goto out; rc = 0; if (!(unsigned int)backlog) /* BSDism */ backlog = 1; sk->sk_max_ack_backlog = backlog; if (sk->sk_state != TCP_LISTEN) { sk->sk_ack_backlog = 0; sk->sk_state = TCP_LISTEN; } sk->sk_socket->flags |= __SO_ACCEPTCON; out: release_sock(sk); return rc; } static int llc_ui_wait_for_disc(struct sock *sk, long timeout) { DEFINE_WAIT_FUNC(wait, woken_wake_function); int rc = 0; add_wait_queue(sk_sleep(sk), &wait); while (1) { if (sk_wait_event(sk, &timeout, READ_ONCE(sk->sk_state) == TCP_CLOSE, &wait)) break; rc = -ERESTARTSYS; if (signal_pending(current)) break; rc = -EAGAIN; if (!timeout) break; rc = 0; } remove_wait_queue(sk_sleep(sk), &wait); return rc; } static bool llc_ui_wait_for_conn(struct sock *sk, long timeout) { DEFINE_WAIT_FUNC(wait, woken_wake_function); add_wait_queue(sk_sleep(sk), &wait); while (1) { if (sk_wait_event(sk, &timeout, READ_ONCE(sk->sk_state) != TCP_SYN_SENT, &wait)) break; if (signal_pending(current) || !timeout) break; } remove_wait_queue(sk_sleep(sk), &wait); return timeout; } static int llc_ui_wait_for_busy_core(struct sock *sk, long timeout) { DEFINE_WAIT_FUNC(wait, woken_wake_function); struct llc_sock *llc = llc_sk(sk); int rc; add_wait_queue(sk_sleep(sk), &wait); while (1) { rc = 0; if (sk_wait_event(sk, &timeout, (READ_ONCE(sk->sk_shutdown) & RCV_SHUTDOWN) || (!llc_data_accept_state(llc->state) && !llc->remote_busy_flag && !llc->p_flag), &wait)) break; rc = -ERESTARTSYS; if (signal_pending(current)) break; rc = -EAGAIN; if (!timeout) break; } remove_wait_queue(sk_sleep(sk), &wait); return rc; } static int llc_wait_data(struct sock *sk, long timeo) { int rc; while (1) { /* * POSIX 1003.1g mandates this order. */ rc = sock_error(sk); if (rc) break; rc = 0; if (sk->sk_shutdown & RCV_SHUTDOWN) break; rc = -EAGAIN; if (!timeo) break; rc = sock_intr_errno(timeo); if (signal_pending(current)) break; rc = 0; if (sk_wait_data(sk, &timeo, NULL)) break; } return rc; } static void llc_cmsg_rcv(struct msghdr *msg, struct sk_buff *skb) { struct llc_sock *llc = llc_sk(skb->sk); if (llc->cmsg_flags & LLC_CMSG_PKTINFO) { struct llc_pktinfo info; memset(&info, 0, sizeof(info)); info.lpi_ifindex = llc_sk(skb->sk)->dev->ifindex; llc_pdu_decode_dsap(skb, &info.lpi_sap); llc_pdu_decode_da(skb, info.lpi_mac); put_cmsg(msg, SOL_LLC, LLC_OPT_PKTINFO, sizeof(info), &info); } } /** * llc_ui_accept - accept a new incoming connection. * @sock: Socket which connections arrive on. * @newsock: Socket to move incoming connection to. * @flags: User specified operational flags. * @kern: If the socket is kernel internal * * Accept a new incoming connection. * Returns 0 upon success, negative otherwise. */ static int llc_ui_accept(struct socket *sock, struct socket *newsock, int flags, bool kern) { struct sock *sk = sock->sk, *newsk; struct llc_sock *llc, *newllc; struct sk_buff *skb; int rc = -EOPNOTSUPP; dprintk("%s: accepting on %02X\n", __func__, llc_sk(sk)->laddr.lsap); lock_sock(sk); if (unlikely(sk->sk_type != SOCK_STREAM)) goto out; rc = -EINVAL; if (unlikely(sock->state != SS_UNCONNECTED || sk->sk_state != TCP_LISTEN)) goto out; /* wait for a connection to arrive. */ if (skb_queue_empty(&sk->sk_receive_queue)) { rc = llc_wait_data(sk, sk->sk_rcvtimeo); if (rc) goto out; } dprintk("%s: got a new connection on %02X\n", __func__, llc_sk(sk)->laddr.lsap); skb = skb_dequeue(&sk->sk_receive_queue); rc = -EINVAL; if (!skb->sk) goto frees; rc = 0; newsk = skb->sk; /* attach connection to a new socket. */ llc_ui_sk_init(newsock, newsk); sock_reset_flag(newsk, SOCK_ZAPPED); newsk->sk_state = TCP_ESTABLISHED; newsock->state = SS_CONNECTED; llc = llc_sk(sk); newllc = llc_sk(newsk); memcpy(&newllc->addr, &llc->addr, sizeof(newllc->addr)); newllc->link = llc_ui_next_link_no(newllc->laddr.lsap); /* put original socket back into a clean listen state. */ sk->sk_state = TCP_LISTEN; sk_acceptq_removed(sk); dprintk("%s: ok success on %02X, client on %02X\n", __func__, llc_sk(sk)->addr.sllc_sap, newllc->daddr.lsap); frees: kfree_skb(skb); out: release_sock(sk); return rc; } /** * llc_ui_recvmsg - copy received data to the socket user. * @sock: Socket to copy data from. * @msg: Various user space related information. * @len: Size of user buffer. * @flags: User specified flags. * * Copy received data to the socket user. * Returns non-negative upon success, negative otherwise. */ static int llc_ui_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, int flags) { DECLARE_SOCKADDR(struct sockaddr_llc *, uaddr, msg->msg_name); const int nonblock = flags & MSG_DONTWAIT; struct sk_buff *skb = NULL; struct sock *sk = sock->sk; struct llc_sock *llc = llc_sk(sk); size_t copied = 0; u32 peek_seq = 0; u32 *seq, skb_len; unsigned long used; int target; /* Read at least this many bytes */ long timeo; lock_sock(sk); copied = -ENOTCONN; if (unlikely(sk->sk_type == SOCK_STREAM && sk->sk_state == TCP_LISTEN)) goto out; timeo = sock_rcvtimeo(sk, nonblock); seq = &llc->copied_seq; if (flags & MSG_PEEK) { peek_seq = llc->copied_seq; seq = &peek_seq; } target = sock_rcvlowat(sk, flags & MSG_WAITALL, len); copied = 0; do { u32 offset; /* * We need to check signals first, to get correct SIGURG * handling. FIXME: Need to check this doesn't impact 1003.1g * and move it down to the bottom of the loop */ if (signal_pending(current)) { if (copied) break; copied = timeo ? sock_intr_errno(timeo) : -EAGAIN; break; } /* Next get a buffer. */ skb = skb_peek(&sk->sk_receive_queue); if (skb) { offset = *seq; goto found_ok_skb; } /* Well, if we have backlog, try to process it now yet. */ if (copied >= target && !READ_ONCE(sk->sk_backlog.tail)) break; if (copied) { if (sk->sk_err || sk->sk_state == TCP_CLOSE || (sk->sk_shutdown & RCV_SHUTDOWN) || !timeo || (flags & MSG_PEEK)) break; } else { if (sock_flag(sk, SOCK_DONE)) break; if (sk->sk_err) { copied = sock_error(sk); break; } if (sk->sk_shutdown & RCV_SHUTDOWN) break; if (sk->sk_type == SOCK_STREAM && sk->sk_state == TCP_CLOSE) { if (!sock_flag(sk, SOCK_DONE)) { /* * This occurs when user tries to read * from never connected socket. */ copied = -ENOTCONN; break; } break; } if (!timeo) { copied = -EAGAIN; break; } } if (copied >= target) { /* Do not sleep, just process backlog. */ release_sock(sk); lock_sock(sk); } else sk_wait_data(sk, &timeo, NULL); if ((flags & MSG_PEEK) && peek_seq != llc->copied_seq) { net_dbg_ratelimited("LLC(%s:%d): Application bug, race in MSG_PEEK\n", current->comm, task_pid_nr(current)); peek_seq = llc->copied_seq; } continue; found_ok_skb: skb_len = skb->len; /* Ok so how much can we use? */ used = skb->len - offset; if (len < used) used = len; if (!(flags & MSG_TRUNC)) { int rc = skb_copy_datagram_msg(skb, offset, msg, used); if (rc) { /* Exception. Bailout! */ if (!copied) copied = -EFAULT; break; } } *seq += used; copied += used; len -= used; /* For non stream protcols we get one packet per recvmsg call */ if (sk->sk_type != SOCK_STREAM) goto copy_uaddr; if (!(flags & MSG_PEEK)) { skb_unlink(skb, &sk->sk_receive_queue); kfree_skb(skb); *seq = 0; } /* Partial read */ if (used + offset < skb_len) continue; } while (len > 0); out: release_sock(sk); return copied; copy_uaddr: if (uaddr != NULL && skb != NULL) { memcpy(uaddr, llc_ui_skb_cb(skb), sizeof(*uaddr)); msg->msg_namelen = sizeof(*uaddr); } if (llc_sk(sk)->cmsg_flags) llc_cmsg_rcv(msg, skb); if (!(flags & MSG_PEEK)) { skb_unlink(skb, &sk->sk_receive_queue); kfree_skb(skb); *seq = 0; } goto out; } /** * llc_ui_sendmsg - Transmit data provided by the socket user. * @sock: Socket to transmit data from. * @msg: Various user related information. * @len: Length of data to transmit. * * Transmit data provided by the socket user. * Returns non-negative upon success, negative otherwise. */ static int llc_ui_sendmsg(struct socket *sock, struct msghdr *msg, size_t len) { DECLARE_SOCKADDR(struct sockaddr_llc *, addr, msg->msg_name); struct sock *sk = sock->sk; struct llc_sock *llc = llc_sk(sk); int flags = msg->msg_flags; int noblock = flags & MSG_DONTWAIT; int rc = -EINVAL, copied = 0, hdrlen, hh_len; struct sk_buff *skb = NULL; struct net_device *dev; size_t size = 0; dprintk("%s: sending from %02X to %02X\n", __func__, llc->laddr.lsap, llc->daddr.lsap); lock_sock(sk); if (addr) { if (msg->msg_namelen < sizeof(*addr)) goto out; } else { if (llc_ui_addr_null(&llc->addr)) goto out; addr = &llc->addr; } /* must bind connection to sap if user hasn't done it. */ if (sock_flag(sk, SOCK_ZAPPED)) { /* bind to sap with null dev, exclusive. */ rc = llc_ui_autobind(sock, addr); if (rc) goto out; } dev = llc->dev; hh_len = LL_RESERVED_SPACE(dev); hdrlen = llc_ui_header_len(sk, addr); size = hdrlen + len; size = min_t(size_t, size, READ_ONCE(dev->mtu)); copied = size - hdrlen; rc = -EINVAL; if (copied < 0) goto out; release_sock(sk); skb = sock_alloc_send_skb(sk, hh_len + size, noblock, &rc); lock_sock(sk); if (!skb) goto out; if (sock_flag(sk, SOCK_ZAPPED) || llc->dev != dev || hdrlen != llc_ui_header_len(sk, addr) || hh_len != LL_RESERVED_SPACE(dev) || size > READ_ONCE(dev->mtu)) goto out; skb->dev = dev; skb->protocol = llc_proto_type(addr->sllc_arphrd); skb_reserve(skb, hh_len + hdrlen); rc = memcpy_from_msg(skb_put(skb, copied), msg, copied); if (rc) goto out; if (sk->sk_type == SOCK_DGRAM || addr->sllc_ua) { llc_build_and_send_ui_pkt(llc->sap, skb, addr->sllc_mac, addr->sllc_sap); skb = NULL; goto out; } if (addr->sllc_test) { llc_build_and_send_test_pkt(llc->sap, skb, addr->sllc_mac, addr->sllc_sap); skb = NULL; goto out; } if (addr->sllc_xid) { llc_build_and_send_xid_pkt(llc->sap, skb, addr->sllc_mac, addr->sllc_sap); skb = NULL; goto out; } rc = -ENOPROTOOPT; if (!(sk->sk_type == SOCK_STREAM && !addr->sllc_ua)) goto out; rc = llc_ui_send_data(sk, skb, noblock); skb = NULL; out: kfree_skb(skb); if (rc) dprintk("%s: failed sending from %02X to %02X: %d\n", __func__, llc->laddr.lsap, llc->daddr.lsap, rc); release_sock(sk); return rc ? : copied; } /** * llc_ui_getname - return the address info of a socket * @sock: Socket to get address of. * @uaddr: Address structure to return information. * @peer: Does user want local or remote address information. * * Return the address information of a socket. */ static int llc_ui_getname(struct socket *sock, struct sockaddr *uaddr, int peer) { struct sockaddr_llc sllc; struct sock *sk = sock->sk; struct llc_sock *llc = llc_sk(sk); int rc = -EBADF; memset(&sllc, 0, sizeof(sllc)); lock_sock(sk); if (sock_flag(sk, SOCK_ZAPPED)) goto out; if (peer) { rc = -ENOTCONN; if (sk->sk_state != TCP_ESTABLISHED) goto out; if(llc->dev) sllc.sllc_arphrd = llc->dev->type; sllc.sllc_sap = llc->daddr.lsap; memcpy(&sllc.sllc_mac, &llc->daddr.mac, IFHWADDRLEN); } else { rc = -EINVAL; if (!llc->sap) goto out; sllc.sllc_sap = llc->sap->laddr.lsap; if (llc->dev) { sllc.sllc_arphrd = llc->dev->type; memcpy(&sllc.sllc_mac, llc->dev->dev_addr, IFHWADDRLEN); } } sllc.sllc_family = AF_LLC; memcpy(uaddr, &sllc, sizeof(sllc)); rc = sizeof(sllc); out: release_sock(sk); return rc; } /** * llc_ui_ioctl - io controls for PF_LLC * @sock: Socket to get/set info * @cmd: command * @arg: optional argument for cmd * * get/set info on llc sockets */ static int llc_ui_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) { return -ENOIOCTLCMD; } /** * llc_ui_setsockopt - set various connection specific parameters. * @sock: Socket to set options on. * @level: Socket level user is requesting operations on. * @optname: Operation name. * @optval: User provided operation data. * @optlen: Length of optval. * * Set various connection specific parameters. */ static int llc_ui_setsockopt(struct socket *sock, int level, int optname, sockptr_t optval, unsigned int optlen) { struct sock *sk = sock->sk; struct llc_sock *llc = llc_sk(sk); unsigned int opt; int rc = -EINVAL; lock_sock(sk); if (unlikely(level != SOL_LLC || optlen != sizeof(int))) goto out; rc = copy_from_sockptr(&opt, optval, sizeof(opt)); if (rc) goto out; rc = -EINVAL; switch (optname) { case LLC_OPT_RETRY: if (opt > LLC_OPT_MAX_RETRY) goto out; llc->n2 = opt; break; case LLC_OPT_SIZE: if (opt > LLC_OPT_MAX_SIZE) goto out; llc->n1 = opt; break; case LLC_OPT_ACK_TMR_EXP: if (opt > LLC_OPT_MAX_ACK_TMR_EXP) goto out; llc->ack_timer.expire = opt * HZ; break; case LLC_OPT_P_TMR_EXP: if (opt > LLC_OPT_MAX_P_TMR_EXP) goto out; llc->pf_cycle_timer.expire = opt * HZ; break; case LLC_OPT_REJ_TMR_EXP: if (opt > LLC_OPT_MAX_REJ_TMR_EXP) goto out; llc->rej_sent_timer.expire = opt * HZ; break; case LLC_OPT_BUSY_TMR_EXP: if (opt > LLC_OPT_MAX_BUSY_TMR_EXP) goto out; llc->busy_state_timer.expire = opt * HZ; break; case LLC_OPT_TX_WIN: if (opt > LLC_OPT_MAX_WIN) goto out; llc->k = opt; break; case LLC_OPT_RX_WIN: if (opt > LLC_OPT_MAX_WIN) goto out; llc->rw = opt; break; case LLC_OPT_PKTINFO: if (opt) llc->cmsg_flags |= LLC_CMSG_PKTINFO; else llc->cmsg_flags &= ~LLC_CMSG_PKTINFO; break; default: rc = -ENOPROTOOPT; goto out; } rc = 0; out: release_sock(sk); return rc; } /** * llc_ui_getsockopt - get connection specific socket info * @sock: Socket to get information from. * @level: Socket level user is requesting operations on. * @optname: Operation name. * @optval: Variable to return operation data in. * @optlen: Length of optval. * * Get connection specific socket information. */ static int llc_ui_getsockopt(struct socket *sock, int level, int optname, char __user *optval, int __user *optlen) { struct sock *sk = sock->sk; struct llc_sock *llc = llc_sk(sk); int val = 0, len = 0, rc = -EINVAL; lock_sock(sk); if (unlikely(level != SOL_LLC)) goto out; rc = get_user(len, optlen); if (rc) goto out; rc = -EINVAL; if (len != sizeof(int)) goto out; switch (optname) { case LLC_OPT_RETRY: val = llc->n2; break; case LLC_OPT_SIZE: val = llc->n1; break; case LLC_OPT_ACK_TMR_EXP: val = llc->ack_timer.expire / HZ; break; case LLC_OPT_P_TMR_EXP: val = llc->pf_cycle_timer.expire / HZ; break; case LLC_OPT_REJ_TMR_EXP: val = llc->rej_sent_timer.expire / HZ; break; case LLC_OPT_BUSY_TMR_EXP: val = llc->busy_state_timer.expire / HZ; break; case LLC_OPT_TX_WIN: val = llc->k; break; case LLC_OPT_RX_WIN: val = llc->rw; break; case LLC_OPT_PKTINFO: val = (llc->cmsg_flags & LLC_CMSG_PKTINFO) != 0; break; default: rc = -ENOPROTOOPT; goto out; } rc = 0; if (put_user(len, optlen) || copy_to_user(optval, &val, len)) rc = -EFAULT; out: release_sock(sk); return rc; } static const struct net_proto_family llc_ui_family_ops = { .family = PF_LLC, .create = llc_ui_create, .owner = THIS_MODULE, }; static const struct proto_ops llc_ui_ops = { .family = PF_LLC, .owner = THIS_MODULE, .release = llc_ui_release, .bind = llc_ui_bind, .connect = llc_ui_connect, .socketpair = sock_no_socketpair, .accept = llc_ui_accept, .getname = llc_ui_getname, .poll = datagram_poll, .ioctl = llc_ui_ioctl, .listen = llc_ui_listen, .shutdown = llc_ui_shutdown, .setsockopt = llc_ui_setsockopt, .getsockopt = llc_ui_getsockopt, .sendmsg = llc_ui_sendmsg, .recvmsg = llc_ui_recvmsg, .mmap = sock_no_mmap, .sendpage = sock_no_sendpage, }; static const char llc_proc_err_msg[] __initconst = KERN_CRIT "LLC: Unable to register the proc_fs entries\n"; static const char llc_sysctl_err_msg[] __initconst = KERN_CRIT "LLC: Unable to register the sysctl entries\n"; static const char llc_sock_err_msg[] __initconst = KERN_CRIT "LLC: Unable to register the network family\n"; static int __init llc2_init(void) { int rc = proto_register(&llc_proto, 0); if (rc != 0) goto out; llc_build_offset_table(); llc_station_init(); llc_ui_sap_last_autoport = LLC_SAP_DYN_START; rc = llc_proc_init(); if (rc != 0) { printk(llc_proc_err_msg); goto out_station; } rc = llc_sysctl_init(); if (rc) { printk(llc_sysctl_err_msg); goto out_proc; } rc = sock_register(&llc_ui_family_ops); if (rc) { printk(llc_sock_err_msg); goto out_sysctl; } llc_add_pack(LLC_DEST_SAP, llc_sap_handler); llc_add_pack(LLC_DEST_CONN, llc_conn_handler); out: return rc; out_sysctl: llc_sysctl_exit(); out_proc: llc_proc_exit(); out_station: llc_station_exit(); proto_unregister(&llc_proto); goto out; } static void __exit llc2_exit(void) { llc_station_exit(); llc_remove_pack(LLC_DEST_SAP); llc_remove_pack(LLC_DEST_CONN); sock_unregister(PF_LLC); llc_proc_exit(); llc_sysctl_exit(); proto_unregister(&llc_proto); } module_init(llc2_init); module_exit(llc2_exit); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Procom 1997, Jay Schullist 2001, Arnaldo C. Melo 2001-2003"); MODULE_DESCRIPTION("IEEE 802.2 PF_LLC support"); MODULE_ALIAS_NETPROTO(PF_LLC);