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authorJason Wang <jasowang@redhat.com>2018-09-12 06:17:06 +0300
committerDavid S. Miller <davem@davemloft.net>2018-09-13 19:25:40 +0300
commitfe8dd45bb7556246c6b76277b1ba4296c91c2505 (patch)
tree9e31911fda3e7b8ca55238498bf8becead0e3db4 /drivers/net/tap.c
parent1a097910adda6b3328fc235575bba0e9ee408492 (diff)
downloadlinux-fe8dd45bb7556246c6b76277b1ba4296c91c2505.tar.xz
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.c18
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,