Merge branch 'mptcp-refactoring-for-one-selftest-and-csum-validation'

Mat Martineau says:

====================
mptcp: Refactoring for one selftest and csum validation

Patch 1 changes the MPTCP join self tests to depend more on events
rather than delays, so the script runs faster and has more consistent
results.

Patches 2 and 3 get rid of some duplicate code in MPTCP's checksum
validation by modifying and leveraging an existing helper function.
====================

Link: https://lore.kernel.org/r/20220107192524.445137-1-mathew.j.martineau@linux.intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

3 files changed, 11 insertions, 13 deletions

diff --git a/net/mptcp/options.c b/net/mptcp/options.c
index 38e34a1fb2dd..8ed2d9f4a84d 100644
--- a/net/mptcp/options.c
+++ b/net/mptcp/options.c
@@ -1233,7 +1233,7 @@ static void mptcp_set_rwin(const struct tcp_sock *tp)
 		WRITE_ONCE(msk->rcv_wnd_sent, ack_seq);
 }
 
-static u16 __mptcp_make_csum(u64 data_seq, u32 subflow_seq, u16 data_len, __sum16 sum)
+u16 __mptcp_make_csum(u64 data_seq, u32 subflow_seq, u16 data_len, __wsum sum)
 {
 	struct csum_pseudo_header header;
 	__wsum csum;
@@ -1248,14 +1248,14 @@ static u16 __mptcp_make_csum(u64 data_seq, u32 subflow_seq, u16 data_len, __sum1
 	header.data_len = htons(data_len);
 	header.csum = 0;
 
-	csum = csum_partial(&header, sizeof(header), ~csum_unfold(sum));
+	csum = csum_partial(&header, sizeof(header), sum);
 	return (__force u16)csum_fold(csum);
 }
 
 static u16 mptcp_make_csum(const struct mptcp_ext *mpext)
 {
 	return __mptcp_make_csum(mpext->data_seq, mpext->subflow_seq, mpext->data_len,
-				 mpext->csum);
+				 ~csum_unfold(mpext->csum));
 }
 
 void mptcp_write_options(__be32 *ptr, const struct tcp_sock *tp,
@@ -1376,7 +1376,7 @@ void mptcp_write_options(__be32 *ptr, const struct tcp_sock *tp,
 					   __mptcp_make_csum(opts->data_seq,
 							     opts->subflow_seq,
 							     opts->data_len,
-							     opts->csum), ptr);
+							     ~csum_unfold(opts->csum)), ptr);
 		} else {
 			put_unaligned_be32(opts->data_len << 16 |
 					   TCPOPT_NOP << 8 | TCPOPT_NOP, ptr);
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index a77f512d5ad7..0e6b42c76ea0 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -725,6 +725,7 @@ void mptcp_token_destroy(struct mptcp_sock *msk);
 void mptcp_crypto_key_sha(u64 key, u32 *token, u64 *idsn);
 
 void mptcp_crypto_hmac_sha(u64 key1, u64 key2, u8 *msg, int len, void *hmac);
+u16 __mptcp_make_csum(u64 data_seq, u32 subflow_seq, u16 data_len, __wsum sum);
 
 void __init mptcp_pm_init(void);
 void mptcp_pm_data_init(struct mptcp_sock *msk);
diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
index 5bedc7e88977..bea47a1180dc 100644
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -845,9 +845,8 @@ static enum mapping_status validate_data_csum(struct sock *ssk, struct sk_buff *
 					      bool csum_reqd)
 {
 	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
-	struct csum_pseudo_header header;
 	u32 offset, seq, delta;
-	__wsum csum;
+	u16 csum;
 	int len;
 
 	if (!csum_reqd)
@@ -908,13 +907,11 @@ static enum mapping_status validate_data_csum(struct sock *ssk, struct sk_buff *
 	 * while the pseudo header requires the original DSS data len,
 	 * including that
 	 */
-	header.data_seq = cpu_to_be64(subflow->map_seq);
-	header.subflow_seq = htonl(subflow->map_subflow_seq);
-	header.data_len = htons(subflow->map_data_len + subflow->map_data_fin);
-	header.csum = 0;
-
-	csum = csum_partial(&header, sizeof(header), subflow->map_data_csum);
-	if (unlikely(csum_fold(csum))) {
+	csum = __mptcp_make_csum(subflow->map_seq,
+				 subflow->map_subflow_seq,
+				 subflow->map_data_len + subflow->map_data_fin,
+				 subflow->map_data_csum);
+	if (unlikely(csum)) {
 		MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_DATACSUMERR);
 		subflow->send_mp_fail = 1;
 		MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_MPFAILTX);