From ac77cfd4258fb8174766a92d118436da7f9dabf1 Mon Sep 17 00:00:00 2001 From: Jason Wang Date: Wed, 17 May 2017 12:14:43 +0800 Subject: [PATCH] tun: support receiving skb through msg_control This patch makes tun_recvmsg() can receive from skb from its caller through msg_control. Vhost_net will be the first user. Signed-off-by: Jason Wang Signed-off-by: David S. Miller --- drivers/net/tun.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) diff --git a/drivers/net/tun.c b/drivers/net/tun.c index 3cbfc5c707e3..f8041f9c7e65 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -1510,9 +1510,8 @@ out: static ssize_t tun_do_read(struct tun_struct *tun, struct tun_file *tfile, struct iov_iter *to, - int noblock) + int noblock, struct sk_buff *skb) { - struct sk_buff *skb; ssize_t ret; int err; @@ -1521,10 +1520,12 @@ static ssize_t tun_do_read(struct tun_struct *tun, struct tun_file *tfile, if (!iov_iter_count(to)) return 0; - /* Read frames from ring */ - skb = tun_ring_recv(tfile, noblock, &err); - if (!skb) - return err; + if (!skb) { + /* Read frames from ring */ + skb = tun_ring_recv(tfile, noblock, &err); + if (!skb) + return err; + } ret = tun_put_user(tun, tfile, skb, to); if (unlikely(ret < 0)) @@ -1544,7 +1545,7 @@ static ssize_t tun_chr_read_iter(struct kiocb *iocb, struct iov_iter *to) if (!tun) return -EBADFD; - ret = tun_do_read(tun, tfile, to, file->f_flags & O_NONBLOCK); + ret = tun_do_read(tun, tfile, to, file->f_flags & O_NONBLOCK, NULL); ret = min_t(ssize_t, ret, len); if (ret > 0) iocb->ki_pos = ret; @@ -1646,7 +1647,8 @@ static int tun_recvmsg(struct socket *sock, struct msghdr *m, size_t total_len, SOL_PACKET, TUN_TX_TIMESTAMP); goto out; } - ret = tun_do_read(tun, tfile, &m->msg_iter, flags & MSG_DONTWAIT); + ret = tun_do_read(tun, tfile, &m->msg_iter, flags & MSG_DONTWAIT, + m->msg_control); if (ret > (ssize_t)total_len) { m->msg_flags |= MSG_TRUNC; ret = flags & MSG_TRUNC ? ret : total_len;