diff options
Diffstat (limited to 'net/llc/af_llc.c')
| -rw-r--r-- | net/llc/af_llc.c | 1309 |
1 files changed, 1309 insertions, 0 deletions
diff --git a/net/llc/af_llc.c b/net/llc/af_llc.c new file mode 100644 index 000000000..19c478bd8 --- /dev/null +++ b/net/llc/af_llc.c @@ -0,0 +1,1309 @@ +/* + * 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 <jschlst@samba.org> + * 2002-2003 by Arnaldo Carvalho de Melo <acme@conectiva.com.br> + * + * 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 <linux/compiler.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/rtnetlink.h> +#include <linux/init.h> +#include <linux/slab.h> +#include <linux/sched/signal.h> + +#include <net/llc.h> +#include <net/llc_sap.h> +#include <net/llc_pdu.h> +#include <net/llc_conn.h> +#include <net/tcp_states.h> + +/* 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); + } + netdev_put(llc->dev, &llc->dev_tracker); + sock_put(sk); + 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; + netdev_tracker_alloc(llc->dev, &llc->dev_tracker, GFP_KERNEL); + 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; + netdev_tracker_alloc(llc->dev, &llc->dev_tracker, GFP_KERNEL); + 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); |