sctp: use skb_crc32c() instead of __skb_checksum()

Make sctp_compute_cksum() just use the new function skb_crc32c(),
instead of calling __skb_checksum() with a skb_checksum_ops struct that
does CRC32C.  This is faster and simpler.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://patch.msgid.link/20250519175012.36581-6-ebiggers@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

7 files changed, 8 insertions, 33 deletions

diff --git a/include/net/sctp/checksum.h b/include/net/sctp/checksum.h
index 291465c25810..654d37ec0402 100644
--- a/include/net/sctp/checksum.h
+++ b/include/net/sctp/checksum.h
@@ -15,8 +15,6 @@
  *    Dinakaran Joseph
  *    Jon Grimm <jgrimm@us.ibm.com>
  *    Sridhar Samudrala <sri@us.ibm.com>
- *
- * Rewritten to use libcrc32c by:
  *    Vlad Yasevich <vladislav.yasevich@hp.com>
  */
 
@@ -25,39 +23,18 @@
 
 #include <linux/types.h>
 #include <linux/sctp.h>
-#include <linux/crc32c.h>
-#include <linux/crc32.h>
-
-static inline __wsum sctp_csum_update(const void *buff, int len, __wsum sum)
-{
-	return (__force __wsum)crc32c((__force __u32)sum, buff, len);
-}
-
-static inline __wsum sctp_csum_combine(__wsum csum, __wsum csum2,
-				       int offset, int len)
-{
-	return (__force __wsum)crc32c_combine((__force __u32)csum,
-					      (__force __u32)csum2, len);
-}
-
-static const struct skb_checksum_ops sctp_csum_ops = {
-	.update  = sctp_csum_update,
-	.combine = sctp_csum_combine,
-};
 
 static inline __le32 sctp_compute_cksum(const struct sk_buff *skb,
 					unsigned int offset)
 {
 	struct sctphdr *sh = (struct sctphdr *)(skb->data + offset);
 	__le32 old = sh->checksum;
-	__wsum new;
+	u32 new;
 
 	sh->checksum = 0;
-	new = ~__skb_checksum(skb, offset, skb->len - offset, ~(__wsum)0,
-			      &sctp_csum_ops);
+	new = ~skb_crc32c(skb, offset, skb->len - offset, ~0);
 	sh->checksum = old;
-
-	return cpu_to_le32((__force __u32)new);
+	return cpu_to_le32(new);
 }
 
 #endif /* __sctp_checksum_h__ */
diff --git a/net/netfilter/Kconfig b/net/netfilter/Kconfig
index 3b2183fc7e56..2560416218d0 100644
--- a/net/netfilter/Kconfig
+++ b/net/netfilter/Kconfig
@@ -212,7 +212,7 @@ config NF_CT_PROTO_SCTP
 	bool 'SCTP protocol connection tracking support'
 	depends on NETFILTER_ADVANCED
 	default y
-	select CRC32
+	select NET_CRC32C
 	help
 	  With this option enabled, the layer 3 independent connection
 	  tracking code will be able to do state tracking on SCTP connections.
@@ -475,7 +475,7 @@ endif # NF_CONNTRACK
 
 config NF_TABLES
 	select NETFILTER_NETLINK
-	select CRC32
+	select NET_CRC32C
 	tristate "Netfilter nf_tables support"
 	help
 	  nftables is the new packet classification framework that intends to
diff --git a/net/netfilter/ipvs/Kconfig b/net/netfilter/ipvs/Kconfig
index 8c5b1fe12d07..c203252e856d 100644
--- a/net/netfilter/ipvs/Kconfig
+++ b/net/netfilter/ipvs/Kconfig
@@ -105,7 +105,7 @@ config	IP_VS_PROTO_AH
 
 config  IP_VS_PROTO_SCTP
 	bool "SCTP load balancing support"
-	select CRC32
+	select NET_CRC32C
 	help
 	  This option enables support for load balancing SCTP transport
 	  protocol. Say Y if unsure.
diff --git a/net/openvswitch/Kconfig b/net/openvswitch/Kconfig
index 5481bd561eb4..e6aaee92dba4 100644
--- a/net/openvswitch/Kconfig
+++ b/net/openvswitch/Kconfig
@@ -11,8 +11,8 @@ config OPENVSWITCH
 				     (!NF_NAT || NF_NAT) && \
 				     (!NETFILTER_CONNCOUNT || NETFILTER_CONNCOUNT)))
 	depends on PSAMPLE || !PSAMPLE
-	select CRC32
 	select MPLS
+	select NET_CRC32C
 	select NET_MPLS_GSO
 	select DST_CACHE
 	select NET_NSH
diff --git a/net/sched/Kconfig b/net/sched/Kconfig
index 9f0b3f943fca..ad914d2b2e22 100644
--- a/net/sched/Kconfig
+++ b/net/sched/Kconfig
@@ -796,7 +796,7 @@ config NET_ACT_SKBEDIT
 config NET_ACT_CSUM
 	tristate "Checksum Updating"
 	depends on NET_CLS_ACT && INET
-	select CRC32
+	select NET_CRC32C
 	help
 	  Say Y here to update some common checksum after some direct
 	  packet alterations.
diff --git a/net/sctp/Kconfig b/net/sctp/Kconfig
index 3669ba351856..24d5a35ce894 100644
--- a/net/sctp/Kconfig
+++ b/net/sctp/Kconfig
@@ -7,7 +7,6 @@ menuconfig IP_SCTP
 	tristate "The SCTP Protocol"
 	depends on INET
 	depends on IPV6 || IPV6=n
-	select CRC32
 	select CRYPTO
 	select CRYPTO_HMAC
 	select CRYPTO_SHA1
diff --git a/net/sctp/offload.c b/net/sctp/offload.c
index 502095173d88..e6f863c031b4 100644
--- a/net/sctp/offload.c
+++ b/net/sctp/offload.c
@@ -111,7 +111,6 @@ int __init sctp_offload_init(void)
 	if (ret)
 		goto ipv4;
 
-	crc32c_csum_stub = &sctp_csum_ops;
 	return ret;
 
 ipv4: