diff options
Diffstat (limited to 'net/caif/caif_socket.c')
| -rw-r--r-- | net/caif/caif_socket.c | 1124 |
1 files changed, 1124 insertions, 0 deletions
diff --git a/net/caif/caif_socket.c b/net/caif/caif_socket.c new file mode 100644 index 000000000..d35ea927c --- /dev/null +++ b/net/caif/caif_socket.c @@ -0,0 +1,1124 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) ST-Ericsson AB 2010 + * Author: Sjur Brendeland + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__ + +#include <linux/fs.h> +#include <linux/init.h> +#include <linux/module.h> +#include <linux/sched/signal.h> +#include <linux/spinlock.h> +#include <linux/mutex.h> +#include <linux/list.h> +#include <linux/wait.h> +#include <linux/poll.h> +#include <linux/tcp.h> +#include <linux/uaccess.h> +#include <linux/debugfs.h> +#include <linux/caif/caif_socket.h> +#include <linux/pkt_sched.h> +#include <net/sock.h> +#include <net/tcp_states.h> +#include <net/caif/caif_layer.h> +#include <net/caif/caif_dev.h> +#include <net/caif/cfpkt.h> + +MODULE_LICENSE("GPL"); +MODULE_ALIAS_NETPROTO(AF_CAIF); + +/* + * CAIF state is re-using the TCP socket states. + * caif_states stored in sk_state reflect the state as reported by + * the CAIF stack, while sk_socket->state is the state of the socket. + */ +enum caif_states { + CAIF_CONNECTED = TCP_ESTABLISHED, + CAIF_CONNECTING = TCP_SYN_SENT, + CAIF_DISCONNECTED = TCP_CLOSE +}; + +#define TX_FLOW_ON_BIT 1 +#define RX_FLOW_ON_BIT 2 + +struct caifsock { + struct sock sk; /* must be first member */ + struct cflayer layer; + u32 flow_state; + struct caif_connect_request conn_req; + struct mutex readlock; + struct dentry *debugfs_socket_dir; + int headroom, tailroom, maxframe; +}; + +static int rx_flow_is_on(struct caifsock *cf_sk) +{ + return test_bit(RX_FLOW_ON_BIT, + (void *) &cf_sk->flow_state); +} + +static int tx_flow_is_on(struct caifsock *cf_sk) +{ + return test_bit(TX_FLOW_ON_BIT, + (void *) &cf_sk->flow_state); +} + +static void set_rx_flow_off(struct caifsock *cf_sk) +{ + clear_bit(RX_FLOW_ON_BIT, + (void *) &cf_sk->flow_state); +} + +static void set_rx_flow_on(struct caifsock *cf_sk) +{ + set_bit(RX_FLOW_ON_BIT, + (void *) &cf_sk->flow_state); +} + +static void set_tx_flow_off(struct caifsock *cf_sk) +{ + clear_bit(TX_FLOW_ON_BIT, + (void *) &cf_sk->flow_state); +} + +static void set_tx_flow_on(struct caifsock *cf_sk) +{ + set_bit(TX_FLOW_ON_BIT, + (void *) &cf_sk->flow_state); +} + +static void caif_read_lock(struct sock *sk) +{ + struct caifsock *cf_sk; + cf_sk = container_of(sk, struct caifsock, sk); + mutex_lock(&cf_sk->readlock); +} + +static void caif_read_unlock(struct sock *sk) +{ + struct caifsock *cf_sk; + cf_sk = container_of(sk, struct caifsock, sk); + mutex_unlock(&cf_sk->readlock); +} + +static int sk_rcvbuf_lowwater(struct caifsock *cf_sk) +{ + /* A quarter of full buffer is used a low water mark */ + return cf_sk->sk.sk_rcvbuf / 4; +} + +static void caif_flow_ctrl(struct sock *sk, int mode) +{ + struct caifsock *cf_sk; + cf_sk = container_of(sk, struct caifsock, sk); + if (cf_sk->layer.dn && cf_sk->layer.dn->modemcmd) + cf_sk->layer.dn->modemcmd(cf_sk->layer.dn, mode); +} + +/* + * Copied from sock.c:sock_queue_rcv_skb(), but changed so packets are + * not dropped, but CAIF is sending flow off instead. + */ +static void caif_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) +{ + int err; + unsigned long flags; + struct sk_buff_head *list = &sk->sk_receive_queue; + struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); + bool queued = false; + + if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >= + (unsigned int)sk->sk_rcvbuf && rx_flow_is_on(cf_sk)) { + net_dbg_ratelimited("sending flow OFF (queue len = %d %d)\n", + atomic_read(&cf_sk->sk.sk_rmem_alloc), + sk_rcvbuf_lowwater(cf_sk)); + set_rx_flow_off(cf_sk); + caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_OFF_REQ); + } + + err = sk_filter(sk, skb); + if (err) + goto out; + + if (!sk_rmem_schedule(sk, skb, skb->truesize) && rx_flow_is_on(cf_sk)) { + set_rx_flow_off(cf_sk); + net_dbg_ratelimited("sending flow OFF due to rmem_schedule\n"); + caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_OFF_REQ); + } + skb->dev = NULL; + skb_set_owner_r(skb, sk); + spin_lock_irqsave(&list->lock, flags); + queued = !sock_flag(sk, SOCK_DEAD); + if (queued) + __skb_queue_tail(list, skb); + spin_unlock_irqrestore(&list->lock, flags); +out: + if (queued) + sk->sk_data_ready(sk); + else + kfree_skb(skb); +} + +/* Packet Receive Callback function called from CAIF Stack */ +static int caif_sktrecv_cb(struct cflayer *layr, struct cfpkt *pkt) +{ + struct caifsock *cf_sk; + struct sk_buff *skb; + + cf_sk = container_of(layr, struct caifsock, layer); + skb = cfpkt_tonative(pkt); + + if (unlikely(cf_sk->sk.sk_state != CAIF_CONNECTED)) { + kfree_skb(skb); + return 0; + } + caif_queue_rcv_skb(&cf_sk->sk, skb); + return 0; +} + +static void cfsk_hold(struct cflayer *layr) +{ + struct caifsock *cf_sk = container_of(layr, struct caifsock, layer); + sock_hold(&cf_sk->sk); +} + +static void cfsk_put(struct cflayer *layr) +{ + struct caifsock *cf_sk = container_of(layr, struct caifsock, layer); + sock_put(&cf_sk->sk); +} + +/* Packet Control Callback function called from CAIF */ +static void caif_ctrl_cb(struct cflayer *layr, + enum caif_ctrlcmd flow, + int phyid) +{ + struct caifsock *cf_sk = container_of(layr, struct caifsock, layer); + switch (flow) { + case CAIF_CTRLCMD_FLOW_ON_IND: + /* OK from modem to start sending again */ + set_tx_flow_on(cf_sk); + cf_sk->sk.sk_state_change(&cf_sk->sk); + break; + + case CAIF_CTRLCMD_FLOW_OFF_IND: + /* Modem asks us to shut up */ + set_tx_flow_off(cf_sk); + cf_sk->sk.sk_state_change(&cf_sk->sk); + break; + + case CAIF_CTRLCMD_INIT_RSP: + /* We're now connected */ + caif_client_register_refcnt(&cf_sk->layer, + cfsk_hold, cfsk_put); + cf_sk->sk.sk_state = CAIF_CONNECTED; + set_tx_flow_on(cf_sk); + cf_sk->sk.sk_shutdown = 0; + cf_sk->sk.sk_state_change(&cf_sk->sk); + break; + + case CAIF_CTRLCMD_DEINIT_RSP: + /* We're now disconnected */ + cf_sk->sk.sk_state = CAIF_DISCONNECTED; + cf_sk->sk.sk_state_change(&cf_sk->sk); + break; + + case CAIF_CTRLCMD_INIT_FAIL_RSP: + /* Connect request failed */ + cf_sk->sk.sk_err = ECONNREFUSED; + cf_sk->sk.sk_state = CAIF_DISCONNECTED; + cf_sk->sk.sk_shutdown = SHUTDOWN_MASK; + /* + * Socket "standards" seems to require POLLOUT to + * be set at connect failure. + */ + set_tx_flow_on(cf_sk); + cf_sk->sk.sk_state_change(&cf_sk->sk); + break; + + case CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND: + /* Modem has closed this connection, or device is down. */ + cf_sk->sk.sk_shutdown = SHUTDOWN_MASK; + cf_sk->sk.sk_err = ECONNRESET; + set_rx_flow_on(cf_sk); + cf_sk->sk.sk_error_report(&cf_sk->sk); + break; + + default: + pr_debug("Unexpected flow command %d\n", flow); + } +} + +static void caif_check_flow_release(struct sock *sk) +{ + struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); + + if (rx_flow_is_on(cf_sk)) + return; + + if (atomic_read(&sk->sk_rmem_alloc) <= sk_rcvbuf_lowwater(cf_sk)) { + set_rx_flow_on(cf_sk); + caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_ON_REQ); + } +} + +/* + * Copied from unix_dgram_recvmsg, but removed credit checks, + * changed locking, address handling and added MSG_TRUNC. + */ +static int caif_seqpkt_recvmsg(struct socket *sock, struct msghdr *m, + size_t len, int flags) + +{ + struct sock *sk = sock->sk; + struct sk_buff *skb; + int ret; + int copylen; + + ret = -EOPNOTSUPP; + if (flags & MSG_OOB) + goto read_error; + + skb = skb_recv_datagram(sk, flags, 0 , &ret); + if (!skb) + goto read_error; + copylen = skb->len; + if (len < copylen) { + m->msg_flags |= MSG_TRUNC; + copylen = len; + } + + ret = skb_copy_datagram_msg(skb, 0, m, copylen); + if (ret) + goto out_free; + + ret = (flags & MSG_TRUNC) ? skb->len : copylen; +out_free: + skb_free_datagram(sk, skb); + caif_check_flow_release(sk); + return ret; + +read_error: + return ret; +} + + +/* Copied from unix_stream_wait_data, identical except for lock call. */ +static long caif_stream_data_wait(struct sock *sk, long timeo) +{ + DEFINE_WAIT(wait); + lock_sock(sk); + + for (;;) { + prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE); + + if (!skb_queue_empty(&sk->sk_receive_queue) || + sk->sk_err || + sk->sk_state != CAIF_CONNECTED || + sock_flag(sk, SOCK_DEAD) || + (sk->sk_shutdown & RCV_SHUTDOWN) || + signal_pending(current) || + !timeo) + break; + + sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk); + release_sock(sk); + timeo = schedule_timeout(timeo); + lock_sock(sk); + + if (sock_flag(sk, SOCK_DEAD)) + break; + + sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk); + } + + finish_wait(sk_sleep(sk), &wait); + release_sock(sk); + return timeo; +} + + +/* + * Copied from unix_stream_recvmsg, but removed credit checks, + * changed locking calls, changed address handling. + */ +static int caif_stream_recvmsg(struct socket *sock, struct msghdr *msg, + size_t size, int flags) +{ + struct sock *sk = sock->sk; + int copied = 0; + int target; + int err = 0; + long timeo; + + err = -EOPNOTSUPP; + if (flags&MSG_OOB) + goto out; + + /* + * Lock the socket to prevent queue disordering + * while sleeps in memcpy_tomsg + */ + err = -EAGAIN; + if (sk->sk_state == CAIF_CONNECTING) + goto out; + + caif_read_lock(sk); + target = sock_rcvlowat(sk, flags&MSG_WAITALL, size); + timeo = sock_rcvtimeo(sk, flags&MSG_DONTWAIT); + + do { + int chunk; + struct sk_buff *skb; + + lock_sock(sk); + if (sock_flag(sk, SOCK_DEAD)) { + err = -ECONNRESET; + goto unlock; + } + skb = skb_dequeue(&sk->sk_receive_queue); + caif_check_flow_release(sk); + + if (skb == NULL) { + if (copied >= target) + goto unlock; + /* + * POSIX 1003.1g mandates this order. + */ + err = sock_error(sk); + if (err) + goto unlock; + err = -ECONNRESET; + if (sk->sk_shutdown & RCV_SHUTDOWN) + goto unlock; + + err = -EPIPE; + if (sk->sk_state != CAIF_CONNECTED) + goto unlock; + if (sock_flag(sk, SOCK_DEAD)) + goto unlock; + + release_sock(sk); + + err = -EAGAIN; + if (!timeo) + break; + + caif_read_unlock(sk); + + timeo = caif_stream_data_wait(sk, timeo); + + if (signal_pending(current)) { + err = sock_intr_errno(timeo); + goto out; + } + caif_read_lock(sk); + continue; +unlock: + release_sock(sk); + break; + } + release_sock(sk); + chunk = min_t(unsigned int, skb->len, size); + if (memcpy_to_msg(msg, skb->data, chunk)) { + skb_queue_head(&sk->sk_receive_queue, skb); + if (copied == 0) + copied = -EFAULT; + break; + } + copied += chunk; + size -= chunk; + + /* Mark read part of skb as used */ + if (!(flags & MSG_PEEK)) { + skb_pull(skb, chunk); + + /* put the skb back if we didn't use it up. */ + if (skb->len) { + skb_queue_head(&sk->sk_receive_queue, skb); + break; + } + kfree_skb(skb); + + } else { + /* + * It is questionable, see note in unix_dgram_recvmsg. + */ + /* put message back and return */ + skb_queue_head(&sk->sk_receive_queue, skb); + break; + } + } while (size); + caif_read_unlock(sk); + +out: + return copied ? : err; +} + +/* + * Copied from sock.c:sock_wait_for_wmem, but change to wait for + * CAIF flow-on and sock_writable. + */ +static long caif_wait_for_flow_on(struct caifsock *cf_sk, + int wait_writeable, long timeo, int *err) +{ + struct sock *sk = &cf_sk->sk; + DEFINE_WAIT(wait); + for (;;) { + *err = 0; + if (tx_flow_is_on(cf_sk) && + (!wait_writeable || sock_writeable(&cf_sk->sk))) + break; + *err = -ETIMEDOUT; + if (!timeo) + break; + *err = -ERESTARTSYS; + if (signal_pending(current)) + break; + prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE); + *err = -ECONNRESET; + if (sk->sk_shutdown & SHUTDOWN_MASK) + break; + *err = -sk->sk_err; + if (sk->sk_err) + break; + *err = -EPIPE; + if (cf_sk->sk.sk_state != CAIF_CONNECTED) + break; + timeo = schedule_timeout(timeo); + } + finish_wait(sk_sleep(sk), &wait); + return timeo; +} + +/* + * Transmit a SKB. The device may temporarily request re-transmission + * by returning EAGAIN. + */ +static int transmit_skb(struct sk_buff *skb, struct caifsock *cf_sk, + int noblock, long timeo) +{ + struct cfpkt *pkt; + + pkt = cfpkt_fromnative(CAIF_DIR_OUT, skb); + memset(skb->cb, 0, sizeof(struct caif_payload_info)); + cfpkt_set_prio(pkt, cf_sk->sk.sk_priority); + + if (cf_sk->layer.dn == NULL) { + kfree_skb(skb); + return -EINVAL; + } + + return cf_sk->layer.dn->transmit(cf_sk->layer.dn, pkt); +} + +/* Copied from af_unix:unix_dgram_sendmsg, and adapted to CAIF */ +static int caif_seqpkt_sendmsg(struct socket *sock, struct msghdr *msg, + size_t len) +{ + struct sock *sk = sock->sk; + struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); + int buffer_size; + int ret = 0; + struct sk_buff *skb = NULL; + int noblock; + long timeo; + caif_assert(cf_sk); + ret = sock_error(sk); + if (ret) + goto err; + + ret = -EOPNOTSUPP; + if (msg->msg_flags&MSG_OOB) + goto err; + + ret = -EOPNOTSUPP; + if (msg->msg_namelen) + goto err; + + ret = -EINVAL; + if (unlikely(msg->msg_iter.nr_segs == 0) || + unlikely(msg->msg_iter.iov->iov_base == NULL)) + goto err; + noblock = msg->msg_flags & MSG_DONTWAIT; + + timeo = sock_sndtimeo(sk, noblock); + timeo = caif_wait_for_flow_on(container_of(sk, struct caifsock, sk), + 1, timeo, &ret); + + if (ret) + goto err; + ret = -EPIPE; + if (cf_sk->sk.sk_state != CAIF_CONNECTED || + sock_flag(sk, SOCK_DEAD) || + (sk->sk_shutdown & RCV_SHUTDOWN)) + goto err; + + /* Error if trying to write more than maximum frame size. */ + ret = -EMSGSIZE; + if (len > cf_sk->maxframe && cf_sk->sk.sk_protocol != CAIFPROTO_RFM) + goto err; + + buffer_size = len + cf_sk->headroom + cf_sk->tailroom; + + ret = -ENOMEM; + skb = sock_alloc_send_skb(sk, buffer_size, noblock, &ret); + + if (!skb || skb_tailroom(skb) < buffer_size) + goto err; + + skb_reserve(skb, cf_sk->headroom); + + ret = memcpy_from_msg(skb_put(skb, len), msg, len); + + if (ret) + goto err; + ret = transmit_skb(skb, cf_sk, noblock, timeo); + if (ret < 0) + /* skb is already freed */ + return ret; + + return len; +err: + kfree_skb(skb); + return ret; +} + +/* + * Copied from unix_stream_sendmsg and adapted to CAIF: + * Changed removed permission handling and added waiting for flow on + * and other minor adaptations. + */ +static int caif_stream_sendmsg(struct socket *sock, struct msghdr *msg, + size_t len) +{ + struct sock *sk = sock->sk; + struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); + int err, size; + struct sk_buff *skb; + int sent = 0; + long timeo; + + err = -EOPNOTSUPP; + if (unlikely(msg->msg_flags&MSG_OOB)) + goto out_err; + + if (unlikely(msg->msg_namelen)) + goto out_err; + + timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT); + timeo = caif_wait_for_flow_on(cf_sk, 1, timeo, &err); + + if (unlikely(sk->sk_shutdown & SEND_SHUTDOWN)) + goto pipe_err; + + while (sent < len) { + + size = len-sent; + + if (size > cf_sk->maxframe) + size = cf_sk->maxframe; + + /* If size is more than half of sndbuf, chop up message */ + if (size > ((sk->sk_sndbuf >> 1) - 64)) + size = (sk->sk_sndbuf >> 1) - 64; + + if (size > SKB_MAX_ALLOC) + size = SKB_MAX_ALLOC; + + skb = sock_alloc_send_skb(sk, + size + cf_sk->headroom + + cf_sk->tailroom, + msg->msg_flags&MSG_DONTWAIT, + &err); + if (skb == NULL) + goto out_err; + + skb_reserve(skb, cf_sk->headroom); + /* + * If you pass two values to the sock_alloc_send_skb + * it tries to grab the large buffer with GFP_NOFS + * (which can fail easily), and if it fails grab the + * fallback size buffer which is under a page and will + * succeed. [Alan] + */ + size = min_t(int, size, skb_tailroom(skb)); + + err = memcpy_from_msg(skb_put(skb, size), msg, size); + if (err) { + kfree_skb(skb); + goto out_err; + } + err = transmit_skb(skb, cf_sk, + msg->msg_flags&MSG_DONTWAIT, timeo); + if (err < 0) + /* skb is already freed */ + goto pipe_err; + + sent += size; + } + + return sent; + +pipe_err: + if (sent == 0 && !(msg->msg_flags&MSG_NOSIGNAL)) + send_sig(SIGPIPE, current, 0); + err = -EPIPE; +out_err: + return sent ? : err; +} + +static int setsockopt(struct socket *sock, int lvl, int opt, sockptr_t ov, + unsigned int ol) +{ + struct sock *sk = sock->sk; + struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); + int linksel; + + if (cf_sk->sk.sk_socket->state != SS_UNCONNECTED) + return -ENOPROTOOPT; + + switch (opt) { + case CAIFSO_LINK_SELECT: + if (ol < sizeof(int)) + return -EINVAL; + if (lvl != SOL_CAIF) + goto bad_sol; + if (copy_from_sockptr(&linksel, ov, sizeof(int))) + return -EINVAL; + lock_sock(&(cf_sk->sk)); + cf_sk->conn_req.link_selector = linksel; + release_sock(&cf_sk->sk); + return 0; + + case CAIFSO_REQ_PARAM: + if (lvl != SOL_CAIF) + goto bad_sol; + if (cf_sk->sk.sk_protocol != CAIFPROTO_UTIL) + return -ENOPROTOOPT; + lock_sock(&(cf_sk->sk)); + if (ol > sizeof(cf_sk->conn_req.param.data) || + copy_from_sockptr(&cf_sk->conn_req.param.data, ov, ol)) { + release_sock(&cf_sk->sk); + return -EINVAL; + } + cf_sk->conn_req.param.size = ol; + release_sock(&cf_sk->sk); + return 0; + + default: + return -ENOPROTOOPT; + } + + return 0; +bad_sol: + return -ENOPROTOOPT; + +} + +/* + * caif_connect() - Connect a CAIF Socket + * Copied and modified af_irda.c:irda_connect(). + * + * Note : by consulting "errno", the user space caller may learn the cause + * of the failure. Most of them are visible in the function, others may come + * from subroutines called and are listed here : + * o -EAFNOSUPPORT: bad socket family or type. + * o -ESOCKTNOSUPPORT: bad socket type or protocol + * o -EINVAL: bad socket address, or CAIF link type + * o -ECONNREFUSED: remote end refused the connection. + * o -EINPROGRESS: connect request sent but timed out (or non-blocking) + * o -EISCONN: already connected. + * o -ETIMEDOUT: Connection timed out (send timeout) + * o -ENODEV: No link layer to send request + * o -ECONNRESET: Received Shutdown indication or lost link layer + * o -ENOMEM: Out of memory + * + * State Strategy: + * o sk_state: holds the CAIF_* protocol state, it's updated by + * caif_ctrl_cb. + * o sock->state: holds the SS_* socket state and is updated by connect and + * disconnect. + */ +static int caif_connect(struct socket *sock, struct sockaddr *uaddr, + int addr_len, int flags) +{ + struct sock *sk = sock->sk; + struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); + long timeo; + int err; + int ifindex, headroom, tailroom; + unsigned int mtu; + struct net_device *dev; + + lock_sock(sk); + + err = -EINVAL; + if (addr_len < offsetofend(struct sockaddr, sa_family)) + goto out; + + err = -EAFNOSUPPORT; + if (uaddr->sa_family != AF_CAIF) + goto out; + + switch (sock->state) { + case SS_UNCONNECTED: + /* Normal case, a fresh connect */ + caif_assert(sk->sk_state == CAIF_DISCONNECTED); + break; + case SS_CONNECTING: + switch (sk->sk_state) { + case CAIF_CONNECTED: + sock->state = SS_CONNECTED; + err = -EISCONN; + goto out; + case CAIF_DISCONNECTED: + /* Reconnect allowed */ + break; + case CAIF_CONNECTING: + err = -EALREADY; + if (flags & O_NONBLOCK) + goto out; + goto wait_connect; + } + break; + case SS_CONNECTED: + caif_assert(sk->sk_state == CAIF_CONNECTED || + sk->sk_state == CAIF_DISCONNECTED); + if (sk->sk_shutdown & SHUTDOWN_MASK) { + /* Allow re-connect after SHUTDOWN_IND */ + caif_disconnect_client(sock_net(sk), &cf_sk->layer); + caif_free_client(&cf_sk->layer); + break; + } + /* No reconnect on a seqpacket socket */ + err = -EISCONN; + goto out; + case SS_DISCONNECTING: + case SS_FREE: + caif_assert(1); /*Should never happen */ + break; + } + sk->sk_state = CAIF_DISCONNECTED; + sock->state = SS_UNCONNECTED; + sk_stream_kill_queues(&cf_sk->sk); + + err = -EINVAL; + if (addr_len != sizeof(struct sockaddr_caif)) + goto out; + + memcpy(&cf_sk->conn_req.sockaddr, uaddr, + sizeof(struct sockaddr_caif)); + + /* Move to connecting socket, start sending Connect Requests */ + sock->state = SS_CONNECTING; + sk->sk_state = CAIF_CONNECTING; + + /* Check priority value comming from socket */ + /* if priority value is out of range it will be ajusted */ + if (cf_sk->sk.sk_priority > CAIF_PRIO_MAX) + cf_sk->conn_req.priority = CAIF_PRIO_MAX; + else if (cf_sk->sk.sk_priority < CAIF_PRIO_MIN) + cf_sk->conn_req.priority = CAIF_PRIO_MIN; + else + cf_sk->conn_req.priority = cf_sk->sk.sk_priority; + + /*ifindex = id of the interface.*/ + cf_sk->conn_req.ifindex = cf_sk->sk.sk_bound_dev_if; + + cf_sk->layer.receive = caif_sktrecv_cb; + + err = caif_connect_client(sock_net(sk), &cf_sk->conn_req, + &cf_sk->layer, &ifindex, &headroom, &tailroom); + + if (err < 0) { + cf_sk->sk.sk_socket->state = SS_UNCONNECTED; + cf_sk->sk.sk_state = CAIF_DISCONNECTED; + goto out; + } + + err = -ENODEV; + rcu_read_lock(); + dev = dev_get_by_index_rcu(sock_net(sk), ifindex); + if (!dev) { + rcu_read_unlock(); + goto out; + } + cf_sk->headroom = LL_RESERVED_SPACE_EXTRA(dev, headroom); + mtu = dev->mtu; + rcu_read_unlock(); + + cf_sk->tailroom = tailroom; + cf_sk->maxframe = mtu - (headroom + tailroom); + if (cf_sk->maxframe < 1) { + pr_warn("CAIF Interface MTU too small (%d)\n", dev->mtu); + err = -ENODEV; + goto out; + } + + err = -EINPROGRESS; +wait_connect: + + if (sk->sk_state != CAIF_CONNECTED && (flags & O_NONBLOCK)) + goto out; + + timeo = sock_sndtimeo(sk, flags & O_NONBLOCK); + + release_sock(sk); + err = -ERESTARTSYS; + timeo = wait_event_interruptible_timeout(*sk_sleep(sk), + sk->sk_state != CAIF_CONNECTING, + timeo); + lock_sock(sk); + if (timeo < 0) + goto out; /* -ERESTARTSYS */ + + err = -ETIMEDOUT; + if (timeo == 0 && sk->sk_state != CAIF_CONNECTED) + goto out; + if (sk->sk_state != CAIF_CONNECTED) { + sock->state = SS_UNCONNECTED; + err = sock_error(sk); + if (!err) + err = -ECONNREFUSED; + goto out; + } + sock->state = SS_CONNECTED; + err = 0; +out: + release_sock(sk); + return err; +} + +/* + * caif_release() - Disconnect a CAIF Socket + * Copied and modified af_irda.c:irda_release(). + */ +static int caif_release(struct socket *sock) +{ + struct sock *sk = sock->sk; + struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); + + if (!sk) + return 0; + + set_tx_flow_off(cf_sk); + + /* + * Ensure that packets are not queued after this point in time. + * caif_queue_rcv_skb checks SOCK_DEAD holding the queue lock, + * this ensures no packets when sock is dead. + */ + spin_lock_bh(&sk->sk_receive_queue.lock); + sock_set_flag(sk, SOCK_DEAD); + spin_unlock_bh(&sk->sk_receive_queue.lock); + sock->sk = NULL; + + WARN_ON(IS_ERR(cf_sk->debugfs_socket_dir)); + debugfs_remove_recursive(cf_sk->debugfs_socket_dir); + + lock_sock(&(cf_sk->sk)); + sk->sk_state = CAIF_DISCONNECTED; + sk->sk_shutdown = SHUTDOWN_MASK; + + caif_disconnect_client(sock_net(sk), &cf_sk->layer); + cf_sk->sk.sk_socket->state = SS_DISCONNECTING; + wake_up_interruptible_poll(sk_sleep(sk), EPOLLERR|EPOLLHUP); + + sock_orphan(sk); + sk_stream_kill_queues(&cf_sk->sk); + release_sock(sk); + sock_put(sk); + return 0; +} + +/* Copied from af_unix.c:unix_poll(), added CAIF tx_flow handling */ +static __poll_t caif_poll(struct file *file, + struct socket *sock, poll_table *wait) +{ + struct sock *sk = sock->sk; + __poll_t mask; + struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); + + sock_poll_wait(file, sock, wait); + mask = 0; + + /* exceptional events? */ + if (sk->sk_err) + mask |= EPOLLERR; + if (sk->sk_shutdown == SHUTDOWN_MASK) + mask |= EPOLLHUP; + if (sk->sk_shutdown & RCV_SHUTDOWN) + mask |= EPOLLRDHUP; + + /* readable? */ + if (!skb_queue_empty_lockless(&sk->sk_receive_queue) || + (sk->sk_shutdown & RCV_SHUTDOWN)) + mask |= EPOLLIN | EPOLLRDNORM; + + /* + * we set writable also when the other side has shut down the + * connection. This prevents stuck sockets. + */ + if (sock_writeable(sk) && tx_flow_is_on(cf_sk)) + mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND; + + return mask; +} + +static const struct proto_ops caif_seqpacket_ops = { + .family = PF_CAIF, + .owner = THIS_MODULE, + .release = caif_release, + .bind = sock_no_bind, + .connect = caif_connect, + .socketpair = sock_no_socketpair, + .accept = sock_no_accept, + .getname = sock_no_getname, + .poll = caif_poll, + .ioctl = sock_no_ioctl, + .listen = sock_no_listen, + .shutdown = sock_no_shutdown, + .setsockopt = setsockopt, + .sendmsg = caif_seqpkt_sendmsg, + .recvmsg = caif_seqpkt_recvmsg, + .mmap = sock_no_mmap, + .sendpage = sock_no_sendpage, +}; + +static const struct proto_ops caif_stream_ops = { + .family = PF_CAIF, + .owner = THIS_MODULE, + .release = caif_release, + .bind = sock_no_bind, + .connect = caif_connect, + .socketpair = sock_no_socketpair, + .accept = sock_no_accept, + .getname = sock_no_getname, + .poll = caif_poll, + .ioctl = sock_no_ioctl, + .listen = sock_no_listen, + .shutdown = sock_no_shutdown, + .setsockopt = setsockopt, + .sendmsg = caif_stream_sendmsg, + .recvmsg = caif_stream_recvmsg, + .mmap = sock_no_mmap, + .sendpage = sock_no_sendpage, +}; + +/* This function is called when a socket is finally destroyed. */ +static void caif_sock_destructor(struct sock *sk) +{ + struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); + caif_assert(!refcount_read(&sk->sk_wmem_alloc)); + caif_assert(sk_unhashed(sk)); + caif_assert(!sk->sk_socket); + if (!sock_flag(sk, SOCK_DEAD)) { + pr_debug("Attempt to release alive CAIF socket: %p\n", sk); + return; + } + sk_stream_kill_queues(&cf_sk->sk); + WARN_ON(sk->sk_forward_alloc); + caif_free_client(&cf_sk->layer); +} + +static int caif_create(struct net *net, struct socket *sock, int protocol, + int kern) +{ + struct sock *sk = NULL; + struct caifsock *cf_sk = NULL; + static struct proto prot = {.name = "PF_CAIF", + .owner = THIS_MODULE, + .obj_size = sizeof(struct caifsock), + .useroffset = offsetof(struct caifsock, conn_req.param), + .usersize = sizeof_field(struct caifsock, conn_req.param) + }; + + if (!capable(CAP_SYS_ADMIN) && !capable(CAP_NET_ADMIN)) + return -EPERM; + /* + * The sock->type specifies the socket type to use. + * The CAIF socket is a packet stream in the sense + * that it is packet based. CAIF trusts the reliability + * of the link, no resending is implemented. + */ + if (sock->type == SOCK_SEQPACKET) + sock->ops = &caif_seqpacket_ops; + else if (sock->type == SOCK_STREAM) + sock->ops = &caif_stream_ops; + else + return -ESOCKTNOSUPPORT; + + if (protocol < 0 || protocol >= CAIFPROTO_MAX) + return -EPROTONOSUPPORT; + /* + * Set the socket state to unconnected. The socket state + * is really not used at all in the net/core or socket.c but the + * initialization makes sure that sock->state is not uninitialized. + */ + sk = sk_alloc(net, PF_CAIF, GFP_KERNEL, &prot, kern); + if (!sk) + return -ENOMEM; + + cf_sk = container_of(sk, struct caifsock, sk); + + /* Store the protocol */ + sk->sk_protocol = (unsigned char) protocol; + + /* Initialize default priority for well-known cases */ + switch (protocol) { + case CAIFPROTO_AT: + sk->sk_priority = TC_PRIO_CONTROL; + break; + case CAIFPROTO_RFM: + sk->sk_priority = TC_PRIO_INTERACTIVE_BULK; + break; + default: + sk->sk_priority = TC_PRIO_BESTEFFORT; + } + + /* + * Lock in order to try to stop someone from opening the socket + * too early. + */ + lock_sock(&(cf_sk->sk)); + + /* Initialize the nozero default sock structure data. */ + sock_init_data(sock, sk); + sk->sk_destruct = caif_sock_destructor; + + mutex_init(&cf_sk->readlock); /* single task reading lock */ + cf_sk->layer.ctrlcmd = caif_ctrl_cb; + cf_sk->sk.sk_socket->state = SS_UNCONNECTED; + cf_sk->sk.sk_state = CAIF_DISCONNECTED; + + set_tx_flow_off(cf_sk); + set_rx_flow_on(cf_sk); + + /* Set default options on configuration */ + cf_sk->conn_req.link_selector = CAIF_LINK_LOW_LATENCY; + cf_sk->conn_req.protocol = protocol; + release_sock(&cf_sk->sk); + return 0; +} + + +static const struct net_proto_family caif_family_ops = { + .family = PF_CAIF, + .create = caif_create, + .owner = THIS_MODULE, +}; + +static int __init caif_sktinit_module(void) +{ + return sock_register(&caif_family_ops); +} + +static void __exit caif_sktexit_module(void) +{ + sock_unregister(PF_CAIF); +} +module_init(caif_sktinit_module); +module_exit(caif_sktexit_module); |