/* * Copyright (C) ST-Ericsson AB 2010 * Author: Sjur Brendeland * License terms: GNU General Public License (GPL) version 2 */ #define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__ #include <linux/fs.h>#include <linux/init.h>#include <linux/module.h>#include <linux/sched.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 int caif_queue_rcv_skb(struct sock *sk, struct sk_buff *skb){ int err; int skb_len; unsigned long flags; struct sk_buff_head *list = &sk->sk_receive_queue; struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); 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) return err; 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); /* Cache the SKB length before we tack it onto the receive * queue. Once it is added it no longer belongs to us and * may be freed by other threads of control pulling packets * from the queue. */ skb_len = skb->len; spin_lock_irqsave(&list->lock, flags); if (!sock_flag(sk, SOCK_DEAD)) __skb_queue_tail(list, skb); spin_unlock_irqrestore(&list->lock, flags); if (!sock_flag(sk, SOCK_DEAD)) sk->sk_data_ready(sk, skb_len); else kfree_skb(skb); return 0;} /* 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 kiocb *iocb, 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 (m->msg_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_iovec(skb, 0, m->msg_iov, 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; set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags); release_sock(sk); timeo = schedule_timeout(timeo); lock_sock(sk); clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags); } 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 kiocb *iocb, 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); 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_toiovec(msg->msg_iov, 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){Lines 1–500 of 1120. Load more
/* * Copyright (C) ST-Ericsson AB 2010 * Author: Sjur Brendeland * License terms: GNU General Public License (GPL) version 2 */ #define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__ #include <linux/fs.h> #include <linux/init.h> #include <linux/module.h> #include <linux/sched.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 int caif_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) { int err; int skb_len; unsigned long flags; struct sk_buff_head *list = &sk->sk_receive_queue; struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); 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) return err; 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); /* Cache the SKB length before we tack it onto the receive * queue. Once it is added it no longer belongs to us and * may be freed by other threads of control pulling packets * from the queue. */ skb_len = skb->len; spin_lock_irqsave(&list->lock, flags); if (!sock_flag(sk, SOCK_DEAD)) __skb_queue_tail(list, skb); spin_unlock_irqrestore(&list->lock, flags); if (!sock_flag(sk, SOCK_DEAD)) sk->sk_data_ready(sk, skb_len); else kfree_skb(skb); return 0; } /* 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 kiocb *iocb, 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 (m->msg_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_iovec(skb, 0, m->msg_iov, 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; set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags); release_sock(sk); timeo = schedule_timeout(timeo); lock_sock(sk); clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags); } 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 kiocb *iocb, 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); 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_toiovec(msg->msg_iov, 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) {