From 0739cd28f2645e814586c7536ba5da9825cb8029 Mon Sep 17 00:00:00 2001 From: Cong Wang Date: Tue, 30 Mar 2021 19:32:24 -0700 Subject: [PATCH] net: Introduce skb_send_sock() for sock_map 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. Signed-off-by: Cong Wang Signed-off-by: Alexei Starovoitov Reviewed-by: Jakub Sitnicki Link: https://lore.kernel.org/bpf/20210331023237.41094-4-xiyou.wangcong@gmail.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 c8def85..dbf820a 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 e8320b5..3ad9e84 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 @@ do_frag_list: 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 @@ do_frag_list: 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 @@ out: 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 -- 2.7.4