From ebe73a284f4de8c5d401adeccd9b8fe3183b6e95 Mon Sep 17 00:00:00 2001 From: David Ahern Date: Tue, 12 Jul 2022 21:52:30 +0100 Subject: net: Allow custom iter handler in msghdr Add support for custom iov_iter handling to msghdr. The idea is that in-kernel subsystems want control over how an SG is split. Signed-off-by: David Ahern [pavel: move callback into msghdr] Signed-off-by: Pavel Begunkov Signed-off-by: Jakub Kicinski --- net/core/datagram.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) (limited to 'net/core/datagram.c') diff --git a/net/core/datagram.c b/net/core/datagram.c index 50f4faeea76c..28cdb79df74d 100644 --- a/net/core/datagram.c +++ b/net/core/datagram.c @@ -613,10 +613,16 @@ fault: } EXPORT_SYMBOL(skb_copy_datagram_from_iter); -int __zerocopy_sg_from_iter(struct sock *sk, struct sk_buff *skb, - struct iov_iter *from, size_t length) +int __zerocopy_sg_from_iter(struct msghdr *msg, struct sock *sk, + struct sk_buff *skb, struct iov_iter *from, + size_t length) { - int frag = skb_shinfo(skb)->nr_frags; + int frag; + + if (msg && msg->sg_from_iter) + return msg->sg_from_iter(sk, skb, from, length); + + frag = skb_shinfo(skb)->nr_frags; while (length && iov_iter_count(from)) { struct page *pages[MAX_SKB_FRAGS]; @@ -702,7 +708,7 @@ int zerocopy_sg_from_iter(struct sk_buff *skb, struct iov_iter *from) if (skb_copy_datagram_from_iter(skb, 0, from, copy)) return -EFAULT; - return __zerocopy_sg_from_iter(NULL, skb, from, ~0U); + return __zerocopy_sg_from_iter(NULL, NULL, skb, from, ~0U); } EXPORT_SYMBOL(zerocopy_sg_from_iter); -- cgit v1.2.3-59-g8ed1b