diff mbox series

[bpf-next,v4,03/11] skmsg: introduce skb_send_sock() for sock_map

Message ID 20210310053222.41371-4-xiyou.wangcong@gmail.com
State New
Headers show
Series None | expand

Commit Message

Cong Wang March 10, 2021, 5:32 a.m. UTC
From: Cong Wang <cong.wang@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.fastabend@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Jakub Sitnicki <jakub@cloudflare.com>
Cc: Lorenz Bauer <lmb@cloudflare.com>
Signed-off-by: Cong Wang <cong.wang@bytedance.com>
---
 include/linux/skbuff.h |  1 +
 net/core/skbuff.c      | 52 ++++++++++++++++++++++++++++++++++++------
 2 files changed, 46 insertions(+), 7 deletions(-)

Comments

Jakub Sitnicki March 11, 2021, 11:42 a.m. UTC | #1
On Wed, Mar 10, 2021 at 06:32 AM CET, Cong Wang wrote:
> From: Cong Wang <cong.wang@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.fastabend@gmail.com>

> Cc: Daniel Borkmann <daniel@iogearbox.net>

> Cc: Jakub Sitnicki <jakub@cloudflare.com>

> Cc: Lorenz Bauer <lmb@cloudflare.com>

> Signed-off-by: Cong Wang <cong.wang@bytedance.com>

> ---

>  include/linux/skbuff.h |  1 +

>  net/core/skbuff.c      | 52 ++++++++++++++++++++++++++++++++++++------

>  2 files changed, 46 insertions(+), 7 deletions(-)

>

> diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h

> index 0503c917d773..2fc8c3657c53 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 545a472273a5..396586bd6ae3 100644

> --- a/net/core/skbuff.c

> +++ b/net/core/skbuff.c

> @@ -2500,9 +2500,12 @@ 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)

> +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 +2525,7 @@ 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 = sendmsg(sk, &msg, &kv, 1, slen);



Maybe use INDIRECT_CALLABLE_DECLARE() and INDIRECT_CALL_2() since there
are just two possibilities? Same for sendpage below.

>  		if (ret <= 0)

>  			goto error;

>

> @@ -2553,9 +2556,9 @@ 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 = sendpage(sk, skb_frag_page(frag),

> +				       skb_frag_off(frag) + offset,

> +				       slen, MSG_DONTWAIT);

>  			if (ret <= 0)

>  				goto error;

>


[...]
Cong Wang March 12, 2021, 12:47 a.m. UTC | #2
On Thu, Mar 11, 2021 at 3:42 AM Jakub Sitnicki <jakub@cloudflare.com> wrote:
>

> On Wed, Mar 10, 2021 at 06:32 AM CET, Cong Wang wrote:

> > From: Cong Wang <cong.wang@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.fastabend@gmail.com>

> > Cc: Daniel Borkmann <daniel@iogearbox.net>

> > Cc: Jakub Sitnicki <jakub@cloudflare.com>

> > Cc: Lorenz Bauer <lmb@cloudflare.com>

> > Signed-off-by: Cong Wang <cong.wang@bytedance.com>

> > ---

> >  include/linux/skbuff.h |  1 +

> >  net/core/skbuff.c      | 52 ++++++++++++++++++++++++++++++++++++------

> >  2 files changed, 46 insertions(+), 7 deletions(-)

> >

> > diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h

> > index 0503c917d773..2fc8c3657c53 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 545a472273a5..396586bd6ae3 100644

> > --- a/net/core/skbuff.c

> > +++ b/net/core/skbuff.c

> > @@ -2500,9 +2500,12 @@ 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)

> > +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 +2525,7 @@ 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 = sendmsg(sk, &msg, &kv, 1, slen);

>

>

> Maybe use INDIRECT_CALLABLE_DECLARE() and INDIRECT_CALL_2() since there

> are just two possibilities? Same for sendpage below.


Yeah. Actually I wanted to call __skb_send_sock() in espintcp for
tcp_sendmsg(), but it actually could be TCP over IPv6 too, so I decided
not to  touch it.

Thanks.
diff mbox series

Patch

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 0503c917d773..2fc8c3657c53 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 545a472273a5..396586bd6ae3 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -2500,9 +2500,12 @@  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)
+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 +2525,7 @@  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 = sendmsg(sk, &msg, &kv, 1, slen);
 		if (ret <= 0)
 			goto error;
 
@@ -2553,9 +2556,9 @@  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 = sendpage(sk, skb_frag_page(frag),
+				       skb_frag_off(frag) + offset,
+				       slen, MSG_DONTWAIT);
 			if (ret <= 0)
 				goto error;
 
@@ -2587,8 +2590,43 @@  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);
 
+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);
+}
+
+/* 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