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| author | Jason Wang <jasowang@redhat.com> | 2018-09-12 11:17:06 +0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2018-09-13 09:25:40 -0700 |
| commit | fe8dd45bb7556246c6b76277b1ba4296c91c2505 (patch) | |
| tree | 9e31911fda3e7b8ca55238498bf8becead0e3db4 /drivers/net/tap.c | |
| parent | 1a097910adda6b3328fc235575bba0e9ee408492 (diff) | |
| download | lwn-fe8dd45bb7556246c6b76277b1ba4296c91c2505.tar.gz lwn-fe8dd45bb7556246c6b76277b1ba4296c91c2505.zip | |
tun: switch to new type of msg_control
This patch introduces to a new tun/tap specific msg_control:
#define TUN_MSG_UBUF 1
#define TUN_MSG_PTR 2
struct tun_msg_ctl {
int type;
void *ptr;
};
This allows us to pass different kinds of msg_control through
sendmsg(). The first supported type is ubuf (TUN_MSG_UBUF) which will
be used by the existed vhost_net zerocopy code. The second is XDP
buff, which allows vhost_net to pass XDP buff to TUN. This could be
used to implement accepting an array of XDP buffs from vhost_net in
the following patches.
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/tap.c')
| -rw-r--r-- | drivers/net/tap.c | 18 |
1 files changed, 12 insertions, 6 deletions
diff --git a/drivers/net/tap.c b/drivers/net/tap.c index f0f7cd977667..7996ed7cbf18 100644 --- a/drivers/net/tap.c +++ b/drivers/net/tap.c @@ -619,7 +619,7 @@ static inline struct sk_buff *tap_alloc_skb(struct sock *sk, size_t prepad, #define TAP_RESERVE HH_DATA_OFF(ETH_HLEN) /* Get packet from user space buffer */ -static ssize_t tap_get_user(struct tap_queue *q, struct msghdr *m, +static ssize_t tap_get_user(struct tap_queue *q, void *msg_control, struct iov_iter *from, int noblock) { int good_linear = SKB_MAX_HEAD(TAP_RESERVE); @@ -663,7 +663,7 @@ static ssize_t tap_get_user(struct tap_queue *q, struct msghdr *m, if (unlikely(len < ETH_HLEN)) goto err; - if (m && m->msg_control && sock_flag(&q->sk, SOCK_ZEROCOPY)) { + if (msg_control && sock_flag(&q->sk, SOCK_ZEROCOPY)) { struct iov_iter i; copylen = vnet_hdr.hdr_len ? @@ -724,11 +724,11 @@ static ssize_t tap_get_user(struct tap_queue *q, struct msghdr *m, tap = rcu_dereference(q->tap); /* copy skb_ubuf_info for callback when skb has no error */ if (zerocopy) { - skb_shinfo(skb)->destructor_arg = m->msg_control; + skb_shinfo(skb)->destructor_arg = msg_control; skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY; skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG; - } else if (m && m->msg_control) { - struct ubuf_info *uarg = m->msg_control; + } else if (msg_control) { + struct ubuf_info *uarg = msg_control; uarg->callback(uarg, false); } @@ -1150,7 +1150,13 @@ static int tap_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len) { struct tap_queue *q = container_of(sock, struct tap_queue, sock); - return tap_get_user(q, m, &m->msg_iter, m->msg_flags & MSG_DONTWAIT); + struct tun_msg_ctl *ctl = m->msg_control; + + if (ctl && ctl->type != TUN_MSG_UBUF) + return -EINVAL; + + return tap_get_user(q, ctl ? ctl->ptr : NULL, &m->msg_iter, + m->msg_flags & MSG_DONTWAIT); } static int tap_recvmsg(struct socket *sock, struct msghdr *m, |