cregit-Linux how code gets into the kernel

Release 4.11 net/bluetooth/sco.c

Directory: net/bluetooth
/*
   BlueZ - Bluetooth protocol stack for Linux
   Copyright (C) 2000-2001 Qualcomm Incorporated

   Written 2000,2001 by Maxim Krasnyansky <maxk@qualcomm.com>

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License version 2 as
   published by the Free Software Foundation;

   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
   OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS.
   IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) AND AUTHOR(S) BE LIABLE FOR ANY
   CLAIM, OR ANY SPECIAL INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES
   WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
   ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
   OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

   ALL LIABILITY, INCLUDING LIABILITY FOR INFRINGEMENT OF ANY PATENTS,
   COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS, RELATING TO USE OF THIS
   SOFTWARE IS DISCLAIMED.
*/

/* Bluetooth SCO sockets. */

#include <linux/module.h>
#include <linux/debugfs.h>
#include <linux/seq_file.h>
#include <linux/sched/signal.h>

#include <net/bluetooth/bluetooth.h>
#include <net/bluetooth/hci_core.h>
#include <net/bluetooth/sco.h>


static bool disable_esco;


static const struct proto_ops sco_sock_ops;


static struct bt_sock_list sco_sk_list = {
	.lock = __RW_LOCK_UNLOCKED(sco_sk_list.lock)
};

/* ---- SCO connections ---- */

struct sco_conn {
	
struct hci_conn	*hcon;

	
spinlock_t	lock;
	
struct sock	*sk;

	
unsigned int    mtu;
};


#define sco_conn_lock(c)	spin_lock(&c->lock);

#define sco_conn_unlock(c)	spin_unlock(&c->lock);

static void sco_sock_close(struct sock *sk);
static void sco_sock_kill(struct sock *sk);

/* ----- SCO socket info ----- */

#define sco_pi(sk) ((struct sco_pinfo *) sk)


struct sco_pinfo {
	
struct bt_sock	bt;
	
bdaddr_t	src;
	
bdaddr_t	dst;
	
__u32		flags;
	
__u16		setting;
	
struct sco_conn	*conn;
};

/* ---- SCO timers ---- */

#define SCO_CONN_TIMEOUT	(HZ * 40)

#define SCO_DISCONN_TIMEOUT	(HZ * 2)


static void sco_sock_timeout(unsigned long arg) { struct sock *sk = (struct sock *)arg; BT_DBG("sock %p state %d", sk, sk->sk_state); bh_lock_sock(sk); sk->sk_err = ETIMEDOUT; sk->sk_state_change(sk); bh_unlock_sock(sk); sco_sock_kill(sk); sock_put(sk); }

Contributors

PersonTokensPropCommitsCommitProp
Maksim Krasnyanskiy6395.45%150.00%
Arnaldo Carvalho de Melo34.55%150.00%
Total66100.00%2100.00%


static void sco_sock_set_timer(struct sock *sk, long timeout) { BT_DBG("sock %p state %d timeout %ld", sk, sk->sk_state, timeout); sk_reset_timer(sk, &sk->sk_timer, jiffies + timeout); }

Contributors

PersonTokensPropCommitsCommitProp
Maksim Krasnyanskiy3687.80%133.33%
Arnaldo Carvalho de Melo512.20%266.67%
Total41100.00%3100.00%


static void sco_sock_clear_timer(struct sock *sk) { BT_DBG("sock %p state %d", sk, sk->sk_state); sk_stop_timer(sk, &sk->sk_timer); }

Contributors

PersonTokensPropCommitsCommitProp
Maksim Krasnyanskiy2887.50%133.33%
Arnaldo Carvalho de Melo412.50%266.67%
Total32100.00%3100.00%

/* ---- SCO connections ---- */
static struct sco_conn *sco_conn_add(struct hci_conn *hcon) { struct hci_dev *hdev = hcon->hdev; struct sco_conn *conn = hcon->sco_data; if (conn) return conn; conn = kzalloc(sizeof(struct sco_conn), GFP_KERNEL); if (!conn) return NULL; spin_lock_init(&conn->lock); hcon->sco_data = conn; conn->hcon = hcon; if (hdev->sco_mtu > 0) conn->mtu = hdev->sco_mtu; else conn->mtu = 60; BT_DBG("hcon %p conn %p", hcon, conn); return conn; }

Contributors

PersonTokensPropCommitsCommitProp
Maksim Krasnyanskiy10491.23%133.33%
Marcel Holtmann97.89%133.33%
Claudio Takahasi10.88%133.33%
Total114100.00%3100.00%

/* Delete channel. * Must be called on the locked socket. */
static void sco_chan_del(struct sock *sk, int err) { struct sco_conn *conn; conn = sco_pi(sk)->conn; BT_DBG("sk %p, conn %p, err %d", sk, conn, err); if (conn) { sco_conn_lock(conn); conn->sk = NULL; sco_pi(sk)->conn = NULL; sco_conn_unlock(conn); if (conn->hcon) hci_conn_drop(conn->hcon); } sk->sk_state = BT_CLOSED; sk->sk_err = err; sk->sk_state_change(sk); sock_set_flag(sk, SOCK_ZAPPED); }

Contributors

PersonTokensPropCommitsCommitProp
Marcel Holtmann109100.00%1100.00%
Total109100.00%1100.00%


static void sco_conn_del(struct hci_conn *hcon, int err) { struct sco_conn *conn = hcon->sco_data; struct sock *sk; if (!conn) return; BT_DBG("hcon %p conn %p, err %d", hcon, conn, err); /* Kill socket */ sco_conn_lock(conn); sk = conn->sk; sco_conn_unlock(conn); if (sk) { sock_hold(sk); bh_lock_sock(sk); sco_sock_clear_timer(sk); sco_chan_del(sk, err); bh_unlock_sock(sk); sco_sock_kill(sk); sock_put(sk); } hcon->sco_data = NULL; kfree(conn); }

Contributors

PersonTokensPropCommitsCommitProp
Maksim Krasnyanskiy8674.14%120.00%
Kuba Pawlak108.62%120.00%
Marcel Holtmann108.62%120.00%
Andrei Emeltchenko86.90%120.00%
Nicholas Krause21.72%120.00%
Total116100.00%5100.00%


static void __sco_chan_add(struct sco_conn *conn, struct sock *sk, struct sock *parent) { BT_DBG("conn %p", conn); sco_pi(sk)->conn = conn; conn->sk = sk; if (parent) bt_accept_enqueue(parent, sk); }

Contributors

PersonTokensPropCommitsCommitProp
Marcel Holtmann54100.00%1100.00%
Total54100.00%1100.00%


static int sco_chan_add(struct sco_conn *conn, struct sock *sk, struct sock *parent) { int err = 0; sco_conn_lock(conn); if (conn->sk) err = -EBUSY; else __sco_chan_add(conn, sk, parent); sco_conn_unlock(conn); return err; }

Contributors

PersonTokensPropCommitsCommitProp
Maxim Krasnyansky60100.00%1100.00%
Total60100.00%1100.00%


static int sco_connect(struct sock *sk) { struct sco_conn *conn; struct hci_conn *hcon; struct hci_dev *hdev; int err, type; BT_DBG("%pMR -> %pMR", &sco_pi(sk)->src, &sco_pi(sk)->dst); hdev = hci_get_route(&sco_pi(sk)->dst, &sco_pi(sk)->src, BDADDR_BREDR); if (!hdev) return -EHOSTUNREACH; hci_dev_lock(hdev); if (lmp_esco_capable(hdev) && !disable_esco) type = ESCO_LINK; else type = SCO_LINK; if (sco_pi(sk)->setting == BT_VOICE_TRANSPARENT && (!lmp_transp_capable(hdev) || !lmp_esco_capable(hdev))) { err = -EOPNOTSUPP; goto done; } hcon = hci_connect_sco(hdev, type, &sco_pi(sk)->dst, sco_pi(sk)->setting); if (IS_ERR(hcon)) { err = PTR_ERR(hcon); goto done; } conn = sco_conn_add(hcon); if (!conn) { hci_conn_drop(hcon); err = -ENOMEM; goto done; } /* Update source addr of the socket */ bacpy(&sco_pi(sk)->src, &hcon->src); err = sco_chan_add(conn, sk, NULL); if (err) goto done; if (hcon->state == BT_CONNECTED) { sco_sock_clear_timer(sk); sk->sk_state = BT_CONNECTED; } else { sk->sk_state = BT_CONNECT; sco_sock_set_timer(sk, sk->sk_sndtimeo); } done: hci_dev_unlock(hdev); hci_dev_put(hdev); return err; }

Contributors

PersonTokensPropCommitsCommitProp
Maksim Krasnyanskiy16755.30%16.25%
Marcel Holtmann6120.20%531.25%
Frédéric Dalleau4314.24%318.75%
Ville Tervo175.63%16.25%
Andrei Emeltchenko61.99%212.50%
Arnaldo Carvalho de Melo30.99%16.25%
Gustavo Fernando Padovan20.66%16.25%
Johan Hedberg20.66%16.25%
David Herrmann10.33%16.25%
Total302100.00%16100.00%


static int sco_send_frame(struct sock *sk, struct msghdr *msg, int len) { struct sco_conn *conn = sco_pi(sk)->conn; struct sk_buff *skb; int err; /* Check outgoing MTU */ if (len > conn->mtu) return -EINVAL; BT_DBG("sk %p len %d", sk, len); skb = bt_skb_send_alloc(sk, len, msg->msg_flags & MSG_DONTWAIT, &err); if (!skb) return err; if (memcpy_from_msg(skb_put(skb, len), msg, len)) { kfree_skb(skb); return -EFAULT; } hci_send_sco(conn->hcon, skb); return len; }

Contributors

PersonTokensPropCommitsCommitProp
Maksim Krasnyanskiy10885.71%233.33%
Gustavo Fernando Padovan1310.32%233.33%
Mikel Astiz43.17%116.67%
Al Viro10.79%116.67%
Total126100.00%6100.00%


static void sco_recv_frame(struct sco_conn *conn, struct sk_buff *skb) { struct sock *sk; sco_conn_lock(conn); sk = conn->sk; sco_conn_unlock(conn); if (!sk) goto drop; BT_DBG("sk %p len %d", sk, skb->len); if (sk->sk_state != BT_CONNECTED) goto drop; if (!sock_queue_rcv_skb(sk, skb)) return; drop: kfree_skb(skb); }

Contributors

PersonTokensPropCommitsCommitProp
Maksim Krasnyanskiy7082.35%133.33%
Marcel Holtmann1416.47%133.33%
Arnaldo Carvalho de Melo11.18%133.33%
Total85100.00%3100.00%

/* -------- Socket interface ---------- */
static struct sock *__sco_get_sock_listen_by_addr(bdaddr_t *ba) { struct sock *sk; sk_for_each(sk, &sco_sk_list.head) { if (sk->sk_state != BT_LISTEN) continue; if (!bacmp(&sco_pi(sk)->src, ba)) return sk; } return NULL; }

Contributors

PersonTokensPropCommitsCommitProp
Maksim Krasnyanskiy3053.57%125.00%
Marcel Holtmann1832.14%250.00%
Arnaldo Carvalho de Melo814.29%125.00%
Total56100.00%4100.00%

/* Find socket listening on source bdaddr. * Returns closest match. */
static struct sock *sco_get_sock_listen(bdaddr_t *src) { struct sock *sk = NULL, *sk1 = NULL; read_lock(&sco_sk_list.lock); sk_for_each(sk, &sco_sk_list.head) { if (sk->sk_state != BT_LISTEN) continue; /* Exact match. */ if (!bacmp(&sco_pi(sk)->src, src)) break; /* Closest match */ if (!bacmp(&sco_pi(sk)->src, BDADDR_ANY)) sk1 = sk; } read_unlock(&sco_sk_list.lock); return sk ? sk : sk1; }

Contributors

PersonTokensPropCommitsCommitProp
Maksim Krasnyanskiy9188.35%120.00%
Arnaldo Carvalho de Melo98.74%240.00%
Marcel Holtmann21.94%120.00%
Sasha Levin10.97%120.00%
Total103100.00%5100.00%


static void sco_sock_destruct(struct sock *sk) { BT_DBG("sk %p", sk); skb_queue_purge(&sk->sk_receive_queue); skb_queue_purge(&sk->sk_write_queue); }

Contributors

PersonTokensPropCommitsCommitProp
Maksim Krasnyanskiy3294.12%150.00%
Arnaldo Carvalho de Melo25.88%150.00%
Total34100.00%2100.00%


static void sco_sock_cleanup_listen(struct sock *parent) { struct sock *sk; BT_DBG("parent %p", parent); /* Close not yet accepted channels */ while ((sk = bt_accept_dequeue(parent, NULL))) { sco_sock_close(sk); sco_sock_kill(sk); } parent->sk_state = BT_CLOSED; sock_set_flag(parent, SOCK_ZAPPED); }

Contributors

PersonTokensPropCommitsCommitProp
Maksim Krasnyanskiy5588.71%350.00%
Thomas Graf58.06%116.67%
Arnaldo Carvalho de Melo11.61%116.67%
David Woodhouse11.61%116.67%
Total62100.00%6100.00%

/* Kill socket (only if zapped and orphan) * Must be called on unlocked socket. */
static void sco_sock_kill(struct sock *sk) { if (!sock_flag(sk, SOCK_ZAPPED) || sk->sk_socket) return; BT_DBG("sk %p state %d", sk, sk->sk_state); /* Kill poor orphan */ bt_sock_unlink(&sco_sk_list, sk); sock_set_flag(sk, SOCK_DEAD); sock_put(sk); }

Contributors

PersonTokensPropCommitsCommitProp
Maksim Krasnyanskiy4679.31%233.33%
Arnaldo Carvalho de Melo58.62%233.33%
Thomas Graf58.62%116.67%
James Morris23.45%116.67%
Total58100.00%6100.00%


static void __sco_sock_close(struct sock *sk) { BT_DBG("sk %p state %d socket %p", sk, sk->sk_state, sk->sk_socket); switch (sk->sk_state) { case BT_LISTEN: sco_sock_cleanup_listen(sk); break; case BT_CONNECTED: case BT_CONFIG: if (sco_pi(sk)->conn->hcon) { sk->sk_state = BT_DISCONN; sco_sock_set_timer(sk, SCO_DISCONN_TIMEOUT); sco_conn_lock(sco_pi(sk)->conn); hci_conn_drop(sco_pi(sk)->conn->hcon); sco_pi(sk)->conn->hcon = NULL; sco_conn_unlock(sco_pi(sk)->conn); } else sco_chan_del(sk, ECONNRESET); break; case BT_CONNECT2: case BT_CONNECT: case BT_DISCONN: sco_chan_del(sk, ECONNRESET); break; default: sock_set_flag(sk, SOCK_ZAPPED); break; } }

Contributors

PersonTokensPropCommitsCommitProp
Maksim Krasnyanskiy6139.87%111.11%
Luiz Augusto von Dentz5535.95%111.11%
Kuba Pawlak2013.07%111.11%
Thomas Graf53.27%111.11%
Marcel Holtmann31.96%111.11%
Vinicius Costa Gomes31.96%111.11%
Arnaldo Carvalho de Melo31.96%111.11%
Gustavo Fernando Padovan21.31%111.11%
David Herrmann10.65%111.11%
Total153100.00%9100.00%

/* Must be called on unlocked socket. */
static void sco_sock_close(struct sock *sk) { sco_sock_clear_timer(sk); lock_sock(sk); __sco_sock_close(sk); release_sock(sk); sco_sock_kill(sk); }

Contributors

PersonTokensPropCommitsCommitProp
Marcel Holtmann2569.44%150.00%
Maksim Krasnyanskiy1130.56%150.00%
Total36100.00%2100.00%


static void sco_sock_init(struct sock *sk, struct sock *parent) { BT_DBG("sk %p", sk); if (parent) { sk->sk_type = parent->sk_type; bt_sk(sk)->flags = bt_sk(parent)->flags; security_sk_clone(parent, sk); } }

Contributors

PersonTokensPropCommitsCommitProp
Maksim Krasnyanskiy3356.90%125.00%
Frédéric Dalleau1424.14%125.00%
Paul Moore915.52%125.00%
Arnaldo Carvalho de Melo23.45%125.00%
Total58100.00%4100.00%

static struct proto sco_proto = { .name = "SCO", .owner = THIS_MODULE, .obj_size = sizeof(struct sco_pinfo) };
static struct sock *sco_sock_alloc(struct net *net, struct socket *sock, int proto, gfp_t prio, int kern) { struct sock *sk; sk = sk_alloc(net, PF_BLUETOOTH, prio, &sco_proto, kern); if (!sk) return NULL; sock_init_data(sock, sk); INIT_LIST_HEAD(&bt_sk(sk)->accept_q); sk->sk_destruct = sco_sock_destruct; sk->sk_sndtimeo = SCO_CONN_TIMEOUT; sock_reset_flag(sk, SOCK_ZAPPED); sk->sk_protocol = proto; sk->sk_state = BT_OPEN; sco_pi(sk)->setting = BT_VOICE_CVSD_16BIT; setup_timer(&sk->sk_timer, sco_sock_timeout, (unsigned long)sk); bt_sock_link(&sco_sk_list, sk); return sk; }

Contributors

PersonTokensPropCommitsCommitProp
Maksim Krasnyanskiy6848.23%220.00%
Marcel Holtmann3424.11%110.00%
Pavel Emelyanov128.51%110.00%
Eric W. Biedermann128.51%220.00%
Frédéric Dalleau96.38%110.00%
Arnaldo Carvalho de Melo53.55%220.00%
Al Viro10.71%110.00%
Total141100.00%10100.00%


static int sco_sock_create(struct net *net, struct socket *sock, int protocol, int kern) { struct sock *sk; BT_DBG("sock %p", sock); sock->state = SS_UNCONNECTED; if (sock->type != SOCK_SEQPACKET) return -ESOCKTNOSUPPORT; sock->ops = &sco_sock_ops; sk = sco_sock_alloc(net, sock, protocol, GFP_ATOMIC, kern); if (!sk) return -ENOMEM; sco_sock_init(sk, NULL); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Maksim Krasnyanskiy7580.65%120.00%
Eric W. Biedermann99.68%240.00%
Marcel Holtmann66.45%120.00%
Eric Paris33.23%120.00%
Total93100.00%5100.00%


static int sco_sock_bind(struct socket *sock, struct sockaddr *addr, int addr_len) { struct sockaddr_sco *sa = (struct sockaddr_sco *) addr; struct sock *sk = sock->sk; int err = 0; BT_DBG("sk %p %pMR", sk, &sa->sco_bdaddr); if (!addr || addr->sa_family != AF_BLUETOOTH) return -EINVAL; if (addr_len < sizeof(struct sockaddr_sco)) return -EINVAL; lock_sock(sk); if (sk->sk_state != BT_OPEN) { err = -EBADFD; goto done; } if (sk->sk_type != SOCK_SEQPACKET) { err = -EINVAL; goto done; } bacpy(&sco_pi(sk)->src, &sa->sco_bdaddr); sk->sk_state = BT_BOUND; done: release_sock(sk); return err; }

Contributors

PersonTokensPropCommitsCommitProp
Maksim Krasnyanskiy13283.02%116.67%
David S. Miller148.81%116.67%
Marcel Holtmann106.29%233.33%
Arnaldo Carvalho de Melo21.26%116.67%
Andrei Emeltchenko10.63%116.67%
Total159100.00%6100.00%


static int sco_sock_connect(struct socket *sock, struct sockaddr *addr, int alen, int flags) { struct sockaddr_sco *sa = (struct sockaddr_sco *) addr; struct sock *sk = sock->sk; int err; BT_DBG("sk %p", sk); if (alen < sizeof(struct sockaddr_sco) || addr->sa_family != AF_BLUETOOTH) return -EINVAL; if (sk->sk_state != BT_OPEN && sk->sk_state != BT_BOUND) return -EBADFD; if (sk->sk_type != SOCK_SEQPACKET) return -EINVAL; lock_sock(sk); /* Set destination address and psm */ bacpy(&sco_pi(sk)->dst, &sa->sco_bdaddr); err = sco_connect(sk); if (err) goto done; err = bt_sock_wait_state(sk, BT_CONNECTED, sock_sndtimeo(sk, flags & O_NONBLOCK)); done: release_sock(sk); return err; }

Contributors

PersonTokensPropCommitsCommitProp
Maksim Krasnyanskiy15391.62%233.33%
Changli Gao63.59%116.67%
Andrei Emeltchenko42.40%116.67%
Arnaldo Carvalho de Melo31.80%116.67%
Marcel Holtmann10.60%116.67%
Total167100.00%6100.00%


static int sco_sock_listen(struct socket *sock, int backlog) { struct sock *sk = sock->sk; bdaddr_t *src = &sco_pi(sk)->src; int err = 0; BT_DBG("sk %p backlog %d", sk, backlog); lock_sock(sk); if (sk->sk_state != BT_BOUND) { err = -EBADFD; goto done; } if (sk->sk_type != SOCK_SEQPACKET) { err = -EINVAL; goto done; } write_lock(&sco_sk_list.lock); if (__sco_get_sock_listen_by_addr(src)) { err = -EADDRINUSE; goto unlock; } sk->sk_max_ack_backlog = backlog; sk->sk_ack_backlog = 0; sk->sk_state = BT_LISTEN; unlock: write_unlock(&sco_sk_list.lock); done: release_sock(sk); return err; }

Contributors

PersonTokensPropCommitsCommitProp
Maksim Krasnyanskiy8555.56%116.67%
Marcel Holtmann6441.83%466.67%
Arnaldo Carvalho de Melo42.61%116.67%
Total153100.00%6100.00%


static int sco_sock_accept(struct socket *sock, struct socket *newsock, int flags, bool kern) { DEFINE_WAIT_FUNC(wait, woken_wake_function); struct sock *sk = sock->sk, *ch; long timeo; int err = 0; lock_sock(sk); timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK); BT_DBG("sk %p timeo %ld", sk, timeo); /* Wait for an incoming connection. (wake-one). */ add_wait_queue_exclusive(sk_sleep(sk), &wait); while (1) { if (sk->sk_state != BT_LISTEN) { err = -EBADFD; break; } ch = bt_accept_dequeue(sk, newsock); if (ch) break; if (!timeo) { err = -EAGAIN; break; } if (signal_pending(current)) { err = sock_intr_errno(timeo); break; } release_sock(sk); timeo = wait_woken(&wait, TASK_INTERRUPTIBLE, timeo); lock_sock(sk); } remove_wait_queue(sk_sleep(sk), &wait); if (err) goto done; newsock->state = SS_CONNECTED; BT_DBG("new socket %p", ch); done: release_sock(sk); return err; }

Contributors

PersonTokensPropCommitsCommitProp
Maksim Krasnyanskiy16074.42%114.29%
Peter Hurley4320.00%228.57%
Eric Dumazet62.79%114.29%
David Howells31.40%114.29%
Arnaldo Carvalho de Melo20.93%114.29%
Marcel Holtmann10.47%114.29%
Total215100.00%7100.00%


static int sco_sock_getname(struct socket *sock, struct sockaddr *addr, int *len, int peer) { struct sockaddr_sco *sa = (struct sockaddr_sco *) addr; struct sock *sk = sock->sk; BT_DBG("sock %p, sk %p", sock, sk); addr->sa_family = AF_BLUETOOTH; *len = sizeof(struct sockaddr_sco); if (peer) bacpy(&sa->sco_bdaddr, &sco_pi(sk)->dst); else bacpy(&sa->sco_bdaddr, &sco_pi(sk)->src); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Maksim Krasnyanskiy10698.15%150.00%
Marcel Holtmann21.85%150.00%
Total108100.00%2100.00%


static int sco_sock_sendmsg(struct socket *sock, struct msghdr *msg, size_t len) { struct sock *sk = sock->sk; int