[PATCH RFC 1/2] skbuff: Function to send an skbuf on a socket
From: Tom Herbert <hidden>
Date: 2017-06-29 18:27:53
Subsystem:
networking [general], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
Add skb_send_sock to send an skbuff on a socket within the kernel. Arguments include and offset so that an skbuf might be sent in mulitple calls (e.g. send buffer limit is hit). --- include/linux/skbuff.h | 2 ++ net/core/skbuff.c | 66 ++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 68 insertions(+)
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index a17e235..83849e3 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h@@ -3115,6 +3115,8 @@ __wsum skb_copy_and_csum_bits(const struct sk_buff *skb, int offset, u8 *to, int skb_splice_bits(struct sk_buff *skb, struct sock *sk, unsigned int offset, struct pipe_inode_info *pipe, unsigned int len, unsigned int flags); +int skb_send_sock(struct sk_buff *skb, struct socket *sock, + unsigned int offset); 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 f75897a..ff9f88d 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c@@ -2005,6 +2005,72 @@ 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. */ +int skb_send_sock(struct sk_buff *skb, struct socket *sock, unsigned int offset) +{ + unsigned int sent = 0; + unsigned int ret; + unsigned short fragidx; + + /* Deal with head data */ + while (offset < skb_headlen(skb)) { + size_t len = skb_headlen(skb) - offset; + struct kvec kv; + struct msghdr msg; + + kv.iov_base = skb->data + offset; + kv.iov_len = len; + memset(&msg, 0, sizeof(msg)); + + ret = kernel_sendmsg(sock, &msg, &kv, 1, len); + if (ret < 0) + goto error; + + offset += ret; + sent += ret; + } + + offset -= skb_headlen(skb); + + /* Are there frags? */ + if (!skb_shinfo(skb)->nr_frags) + goto out; + + /* Find where we are in frag list */ + for (fragidx = 0; fragidx < skb_shinfo(skb)->nr_frags; fragidx++) { + skb_frag_t *frag = &skb_shinfo(skb)->frags[fragidx]; + + if (offset < frag->size) + break; + + offset -= frag->size; + } + + for (; fragidx < skb_shinfo(skb)->nr_frags; fragidx++) { + skb_frag_t *frag = &skb_shinfo(skb)->frags[fragidx]; + + ret = kernel_sendpage(sock, frag->page.p, + frag->page_offset + offset, + frag->size - offset, + MSG_DONTWAIT); + if (ret < 0) + goto error; + + sent += ret; + offset = 0; + } + +out: + return sent; + +error: + if (sent) + return sent; + else + return ret; +} +EXPORT_SYMBOL_GPL(skb_send_sock); + /** * skb_store_bits - store bits from kernel buffer to skb * @skb: destination buffer
--
2.7.4