Merge branch 'sctp_csum'

Daniel Borkmann says:

====================
SCTP fix/updates

Please see patch 5 for the main description/motivation, the rest just
brings in the needed functionality for that. Although this is actually
a fix, I've based it against net-next as some additional work for
fixing it was needed.
====================

Acked-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 50 insertions, 3 deletions

diff --git a/include/linux/crc32.h b/include/linux/crc32.h
index 68267b64bb98..7d275c4fc011 100644
--- a/include/linux/crc32.h
+++ b/include/linux/crc32.h
@@ -11,8 +11,48 @@
 extern u32  crc32_le(u32 crc, unsigned char const *p, size_t len);
 extern u32  crc32_be(u32 crc, unsigned char const *p, size_t len);
 
+/**
+ * crc32_le_combine - Combine two crc32 check values into one. For two
+ * 		      sequences of bytes, seq1 and seq2 with lengths len1
+ * 		      and len2, crc32_le() check values were calculated
+ * 		      for each, crc1 and crc2.
+ *
+ * @crc1: crc32 of the first block
+ * @crc2: crc32 of the second block
+ * @len2: length of the second block
+ *
+ * Return: The crc32_le() check value of seq1 and seq2 concatenated,
+ * 	   requiring only crc1, crc2, and len2. Note: If seq_full denotes
+ * 	   the concatenated memory area of seq1 with seq2, and crc_full
+ * 	   the crc32_le() value of seq_full, then crc_full ==
+ * 	   crc32_le_combine(crc1, crc2, len2) when crc_full was seeded
+ * 	   with the same initializer as crc1, and crc2 seed was 0. See
+ * 	   also crc32_combine_test().
+ */
+extern u32  crc32_le_combine(u32 crc1, u32 crc2, size_t len2);
+
 extern u32  __crc32c_le(u32 crc, unsigned char const *p, size_t len);
 
+/**
+ * __crc32c_le_combine - Combine two crc32c check values into one. For two
+ * 			 sequences of bytes, seq1 and seq2 with lengths len1
+ * 			 and len2, __crc32c_le() check values were calculated
+ * 			 for each, crc1 and crc2.
+ *
+ * @crc1: crc32c of the first block
+ * @crc2: crc32c of the second block
+ * @len2: length of the second block
+ *
+ * Return: The __crc32c_le() check value of seq1 and seq2 concatenated,
+ * 	   requiring only crc1, crc2, and len2. Note: If seq_full denotes
+ * 	   the concatenated memory area of seq1 with seq2, and crc_full
+ * 	   the __crc32c_le() value of seq_full, then crc_full ==
+ * 	   __crc32c_le_combine(crc1, crc2, len2) when crc_full was
+ * 	   seeded with the same initializer as crc1, and crc2 seed
+ * 	   was 0. See also crc32c_combine_test().
+ */
+extern u32  __crc32c_le_combine(u32 crc1, u32 crc2, size_t len2);
+
 #define crc32(seed, data, length)  crc32_le(seed, (unsigned char const *)(data), length)
 
 /*
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 2c154976394b..44727b5d4981 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -2360,8 +2360,6 @@ int skb_copy_datagram_const_iovec(const struct sk_buff *from, int offset,
 void skb_free_datagram(struct sock *sk, struct sk_buff *skb);
 void skb_free_datagram_locked(struct sock *sk, struct sk_buff *skb);
 int skb_kill_datagram(struct sock *sk, struct sk_buff *skb, unsigned int flags);
-__wsum skb_checksum(const struct sk_buff *skb, int offset, int len,
-		    __wsum csum);
 int skb_copy_bits(const struct sk_buff *skb, int offset, void *to, int len);
 int skb_store_bits(struct sk_buff *skb, int offset, const void *from, int len);
 __wsum skb_copy_and_csum_bits(const struct sk_buff *skb, int offset, u8 *to,
@@ -2373,9 +2371,18 @@ void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to);
 void skb_split(struct sk_buff *skb, struct sk_buff *skb1, const u32 len);
 int skb_shift(struct sk_buff *tgt, struct sk_buff *skb, int shiftlen);
 void skb_scrub_packet(struct sk_buff *skb, bool xnet);
-
 struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features);
 
+struct skb_checksum_ops {
+	__wsum (*update)(const void *mem, int len, __wsum wsum);
+	__wsum (*combine)(__wsum csum, __wsum csum2, int offset, int len);
+};
+
+__wsum __skb_checksum(const struct sk_buff *skb, int offset, int len,
+		      __wsum csum, const struct skb_checksum_ops *ops);
+__wsum skb_checksum(const struct sk_buff *skb, int offset, int len,
+		    __wsum csum);
+
 static inline void *skb_header_pointer(const struct sk_buff *skb, int offset,
 				       int len, void *buffer)
 {