diff mbox series

[RFC,net-next,4/6] net: Add a struct for managing copy functions

Message ID 1652241268-46732-5-git-send-email-jdamato@fastly.com (mailing list archive)
State RFC
Delegated to: Netdev Maintainers
Headers show
Series Nontemporal copies in unix socket write path | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for net-next, async
netdev/fixes_present success Fixes tag not required for -next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit fail Errors and warnings before: 113 this patch: 7
netdev/cc_maintainers warning 3 maintainers not CCed: arjunroy@google.com willemb@google.com talalahmad@google.com
netdev/build_clang success Errors and warnings before: 9 this patch: 9
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn fail Errors and warnings before: 2 this patch: 3
netdev/checkpatch warning WARNING: line length of 82 exceeds 80 columns WARNING: line length of 85 exceeds 80 columns WARNING: line length of 89 exceeds 80 columns WARNING: line length of 96 exceeds 80 columns
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Joe Damato May 11, 2022, 3:54 a.m. UTC 
Add struct skb_copier which encapsulates two functions for copying data,
and provide a default copier, skb_copier.

Separate skb_copy_datagram_from_iter into a a helper function,
do_skb_copy_datagram, which takes a struct skb_copier.

Signed-off-by: Joe Damato <jdamato@fastly.com>
---
 net/core/datagram.c | 49 ++++++++++++++++++++++++++++++++-----------------
 1 file changed, 32 insertions(+), 17 deletions(-)
diff mbox series

Patch

diff --git a/net/core/datagram.c b/net/core/datagram.c
index 50f4fae..a87c41b 100644
--- a/net/core/datagram.c
+++ b/net/core/datagram.c
@@ -532,18 +532,19 @@  int skb_copy_datagram_iter(const struct sk_buff *skb, int offset,
 }
 EXPORT_SYMBOL(skb_copy_datagram_iter);
 
-/**
- *	skb_copy_datagram_from_iter - Copy a datagram from an iov_iter.
- *	@skb: buffer to copy
- *	@offset: offset in the buffer to start copying to
- *	@from: the copy source
- *	@len: amount of data to copy to buffer from iovec
- *
- *	Returns 0 or -EFAULT.
- */
-int skb_copy_datagram_from_iter(struct sk_buff *skb, int offset,
-				 struct iov_iter *from,
-				 int len)
+struct skb_copier {
+	size_t (*copy_from_iter)(void *addr, size_t bytes, struct iov_iter *i);
+	size_t (*copy_page_from_iter)(struct page *page, size_t offset, size_t bytes,
+				      struct iov_iter *i);
+};
+
+struct skb_copier skb_copier = {
+	.copy_from_iter = copy_from_iter,
+	.copy_page_from_iter = copy_page_from_iter
+};
+
+static int do_skb_copy_datagram(struct sk_buff *skb, int offset,
+				struct iov_iter *from, int len, struct skb_copier copier)
 {
 	int start = skb_headlen(skb);
 	int i, copy = start - offset;
@@ -553,7 +554,7 @@  int skb_copy_datagram_from_iter(struct sk_buff *skb, int offset,
 	if (copy > 0) {
 		if (copy > len)
 			copy = len;
-		if (copy_from_iter(skb->data + offset, copy, from) != copy)
+		if (copier.copy_from_iter(skb->data + offset, copy, from) != copy)
 			goto fault;
 		if ((len -= copy) == 0)
 			return 0;
@@ -573,7 +574,7 @@  int skb_copy_datagram_from_iter(struct sk_buff *skb, int offset,
 
 			if (copy > len)
 				copy = len;
-			copied = copy_page_from_iter(skb_frag_page(frag),
+			copied = copier.copy_page_from_iter(skb_frag_page(frag),
 					  skb_frag_off(frag) + offset - start,
 					  copy, from);
 			if (copied != copy)
@@ -595,9 +596,7 @@  int skb_copy_datagram_from_iter(struct sk_buff *skb, int offset,
 		if ((copy = end - offset) > 0) {
 			if (copy > len)
 				copy = len;
-			if (skb_copy_datagram_from_iter(frag_iter,
-							offset - start,
-							from, copy))
+			if (do_skb_copy_datagram(frag_iter, offset - start, from, copy, copier))
 				goto fault;
 			if ((len -= copy) == 0)
 				return 0;
@@ -611,6 +610,22 @@  int skb_copy_datagram_from_iter(struct sk_buff *skb, int offset,
 fault:
 	return -EFAULT;
 }
+
+/**
+ *	skb_copy_datagram_from_iter - Copy a datagram from an iov_iter.
+ *	@skb: buffer to copy
+ *	@offset: offset in the buffer to start copying to
+ *	@from: the copy source
+ *	@len: amount of data to copy to buffer from iovec
+ *
+ *	Returns 0 or -EFAULT.
+ */
+int skb_copy_datagram_from_iter(struct sk_buff *skb, int offset,
+				struct iov_iter *from,
+				 int len)
+{
+	return do_skb_copy_datagram(skb, offset, from, len, skb_copier);
+}
 EXPORT_SYMBOL(skb_copy_datagram_from_iter);
 
 int __zerocopy_sg_from_iter(struct sock *sk, struct sk_buff *skb,