[PATCH net-next 5/8] tun: support receiving skb through msg_control
From: Jason Wang <jasowang@redhat.com>
Date: 2017-03-21 04:16:15
Also in:
kvm, lkml, virtualization
Subsystem:
networking drivers, the rest, tun/tap driver · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds, Willem de Bruijn, Jason Wang
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 <jasowang@redhat.com> --- 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 70dd9ec..a82bced 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c@@ -1498,9 +1498,8 @@ static struct sk_buff *tun_ring_recv(struct tun_file *tfile, int noblock, 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;
@@ -1509,10 +1508,12 @@ 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))
@@ -1532,7 +1533,7 @@ 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;
@@ -1634,7 +1635,8 @@ 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;
--
2.7.4