From: Cong Wang <cong.w...@bytedance.com>
We only have skb_send_sock_locked() which requires callers
to use lock_sock(). Introduce a variant skb_send_sock()
which locks on its own, callers do not need to lock it
any more. This will save us from adding a ->sendmsg_locked
for each protocol.
To reuse the code, pass function pointers to __skb_send_sock()
and build skb_send_sock() and skb_send_sock_locked() on top.
Cc: John Fastabend <john.fastab...@gmail.com>
Cc: Daniel Borkmann <dan...@iogearbox.net>
Cc: Jakub Sitnicki <ja...@cloudflare.com>
Cc: Lorenz Bauer <l...@cloudflare.com>
Signed-off-by: Cong Wang <cong.w...@bytedance.com>
---
include/linux/skbuff.h | 1 +
net/core/skbuff.c | 55 ++++++++++++++++++++++++++++++++++++------
2 files changed, 49 insertions(+), 7 deletions(-)
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index c8def85fcc22..dbf820a50a39 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -3626,6 +3626,7 @@ int skb_splice_bits(struct sk_buff *skb, struct sock *sk,
unsigned int offset,
unsigned int flags);
int skb_send_sock_locked(struct sock *sk, struct sk_buff *skb, int offset,
int len);
+int skb_send_sock(struct sock *sk, struct sk_buff *skb, int offset, int len);
void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to);
unsigned int skb_zerocopy_headlen(const struct sk_buff *from);
int skb_zerocopy(struct sk_buff *to, struct sk_buff *from,
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index e8320b5d651a..3ad9e8425ab2 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -2500,9 +2500,32 @@ int skb_splice_bits(struct sk_buff *skb, struct sock
*sk, unsigned int offset,
}
EXPORT_SYMBOL_GPL(skb_splice_bits);
-/* Send skb data on a socket. Socket must be locked. */
-int skb_send_sock_locked(struct sock *sk, struct sk_buff *skb, int offset,
- int len)
+static int sendmsg_unlocked(struct sock *sk, struct msghdr *msg,
+ struct kvec *vec, size_t num, size_t size)
+{
+ struct socket *sock = sk->sk_socket;
+
+ if (!sock)
+ return -EINVAL;
+ return kernel_sendmsg(sock, msg, vec, num, size);
+}
+
+static int sendpage_unlocked(struct sock *sk, struct page *page, int offset,
+ size_t size, int flags)
+{
+ struct socket *sock = sk->sk_socket;
+
+ if (!sock)
+ return -EINVAL;
+ return kernel_sendpage(sock, page, offset, size, flags);
+}
+
+typedef int (*sendmsg_func)(struct sock *sk, struct msghdr *msg,
+ struct kvec *vec, size_t num, size_t size);
+typedef int (*sendpage_func)(struct sock *sk, struct page *page, int offset,
+ size_t size, int flags);
+static int __skb_send_sock(struct sock *sk, struct sk_buff *skb, int offset,
+ int len, sendmsg_func sendmsg, sendpage_func
sendpage)
{
unsigned int orig_len = len;
struct sk_buff *head = skb;
@@ -2522,7 +2545,8 @@ int skb_send_sock_locked(struct sock *sk, struct sk_buff
*skb, int offset,
memset(&msg, 0, sizeof(msg));
msg.msg_flags = MSG_DONTWAIT;
- ret = kernel_sendmsg_locked(sk, &msg, &kv, 1, slen);
+ ret = INDIRECT_CALL_2(sendmsg, kernel_sendmsg_locked,
+ sendmsg_unlocked, sk, &msg, &kv, 1, slen);
if (ret <= 0)
goto error;
@@ -2553,9 +2577,11 @@ int skb_send_sock_locked(struct sock *sk, struct sk_buff
*skb, int offset,
slen = min_t(size_t, len, skb_frag_size(frag) - offset);
while (slen) {
- ret = kernel_sendpage_locked(sk, skb_frag_page(frag),
- skb_frag_off(frag) +
offset,
- slen, MSG_DONTWAIT);
+ ret = INDIRECT_CALL_2(sendpage, kernel_sendpage_locked,
+ sendpage_unlocked, sk,
+ skb_frag_page(frag),
+ skb_frag_off(frag) + offset,
+ slen, MSG_DONTWAIT);
if (ret <= 0)
goto error;
@@ -2587,8 +2613,23 @@ int skb_send_sock_locked(struct sock *sk, struct sk_buff
*skb, int offset,
error:
return orig_len == len ? ret : orig_len - len;
}
+
+/* Send skb data on a socket. Socket must be locked. */
+int skb_send_sock_locked(struct sock *sk, struct sk_buff *skb, int offset,
+ int len)
+{
+ return __skb_send_sock(sk, skb, offset, len, kernel_sendmsg_locked,
+ kernel_sendpage_locked);
+}
EXPORT_SYMBOL_GPL(skb_send_sock_locked);
+/* Send skb data on a socket. Socket must be unlocked. */
+int skb_send_sock(struct sock *sk, struct sk_buff *skb, int offset, int len)
+{
+ return __skb_send_sock(sk, skb, offset, len, sendmsg_unlocked,
+ sendpage_unlocked);
+}
+
/**
* skb_store_bits - store bits from kernel buffer to skb
* @skb: destination buffer
--
2.25.1
