[PATCH net-next 03/10] net/tcp: Move tcp_inbound_hash() from headers

Dmitry Safonov
2024-02-24T09:04:48Z

Two reasons:
1. It's grown up enough
2. In order to not do header spaghetti by including
<trace/events/tcp.h>, which is necessary for TCP tracepoints.

Signed-off-by: Dmitry Safonov <dima@arista.com>
---
include/net/tcp.h | 65 ++++---------------------------------------------
net/ipv4/tcp.c | 72 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 76 insertions(+), 61 deletions(-)

diff --git a/include/net/tcp.h b/include/net/tcp.h
index c1fff9207e2d..c80bdfb5efe5 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -2789,66 +2789,9 @@ static inline bool tcp_ao_required(struct sock *sk, const void *saddr,
return false;
}

-/* Called with rcu_read_lock() */
-static inline enum skb_drop_reason
-tcp_inbound_hash(struct sock *sk, const struct request_sock *req,
- const struct sk_buff *skb,
- const void *saddr, const void *daddr,
- int family, int dif, int sdif)
-{
- const struct tcphdr *th = tcp_hdr(skb);
- const struct tcp_ao_hdr *aoh;
- const __u8 *md5_location;
- int l3index;
-
- /* Invalid option or two times meet any of auth options */
- if (tcp_parse_auth_options(th, &md5_location, &aoh)) {
- tcp_hash_fail("TCP segment has incorrect auth options set",
- family, skb, "");
- return SKB_DROP_REASON_TCP_AUTH_HDR;
- }
-
- if (req) {
- if (tcp_rsk_used_ao(req) != !!aoh) {
- NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAOBAD);
- tcp_hash_fail("TCP connection can't start/end using TCP-AO",
- family, skb, "%s",
- !aoh ? "missing AO" : "AO signed");
- return SKB_DROP_REASON_TCP_AOFAILURE;
- }
- }
-
- /* sdif set, means packet ingressed via a device
- * in an L3 domain and dif is set to the l3mdev
- */
- l3index = sdif ? dif : 0;
-
- /* Fast path: unsigned segments */
- if (likely(!md5_location && !aoh)) {
- /* Drop if there's TCP-MD5 or TCP-AO key with any rcvid/sndid
- * for the remote peer. On TCP-AO established connection
- * the last key is impossible to remove, so there's
- * always at least one current_key.
- */
- if (tcp_ao_required(sk, saddr, family, l3index, true)) {
- tcp_hash_fail("AO hash is required, but not found",
- family, skb, "L3 index %d", l3index);
- return SKB_DROP_REASON_TCP_AONOTFOUND;
- }
- if (unlikely(tcp_md5_do_lookup(sk, l3index, saddr, family))) {
- NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND);
- tcp_hash_fail("MD5 Hash not found",
- family, skb, "L3 index %d", l3index);
- return SKB_DROP_REASON_TCP_MD5NOTFOUND;
- }
- return SKB_NOT_DROPPED_YET;
- }
-
- if (aoh)
- return tcp_inbound_ao_hash(sk, skb, family, req, l3index, aoh);
-
- return tcp_inbound_md5_hash(sk, skb, saddr, daddr, family,
- l3index, md5_location);
-}
+enum skb_drop_reason tcp_inbound_hash(struct sock *sk,
+ const struct request_sock *req, const struct sk_buff *skb,
+ const void *saddr, const void *daddr,
+ int family, int dif, int sdif);

#endif /* _TCP_H */
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index c82dc42f57c6..5fd61ae6bcc9 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -4485,6 +4485,78 @@ EXPORT_SYMBOL(tcp_inbound_md5_hash);

#endif

+/* Called with rcu_read_lock() */
+enum skb_drop_reason
+tcp_inbound_hash(struct sock *sk, const struct request_sock *req,
+ const struct sk_buff *skb,
+ const void *saddr, const void *daddr,
+ int family, int dif, int sdif)
+{
+ const struct tcphdr *th = tcp_hdr(skb);
+ const struct tcp_ao_hdr *aoh;
+ const __u8 *md5_location;
+ int l3index;
+
+ /* Invalid option or two times meet any of auth options */
+ if (tcp_parse_auth_options(th, &md5_location, &aoh)) {
+ tcp_hash_fail("TCP segment has incorrect auth options set",
+ family, skb, "");
+ return SKB_DROP_REASON_TCP_AUTH_HDR;
+ }
+
+ if (req) {
+ if (tcp_rsk_used_ao(req) != !!aoh) {
+ u8 keyid, rnext, maclen;
+
+ if (aoh) {
+ keyid = aoh->keyid;
+ rnext = aoh->rnext_keyid;
+ maclen = tcp_ao_hdr_maclen(aoh);
+ } else {
+ keyid = rnext = maclen = 0;
+ }
+
+ NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAOBAD);
+ tcp_hash_fail("TCP connection can't start/end using TCP-AO",
+ family, skb, "%s",
+ !aoh ? "missing AO" : "AO signed");
+ return SKB_DROP_REASON_TCP_AOFAILURE;
+ }
+ }
+
+ /* sdif set, means packet ingressed via a device
+ * in an L3 domain and dif is set to the l3mdev
+ */
+ l3index = sdif ? dif : 0;
+
+ /* Fast path: unsigned segments */
+ if (likely(!md5_location && !aoh)) {
+ /* Drop if there's TCP-MD5 or TCP-AO key with any rcvid/sndid
+ * for the remote peer. On TCP-AO established connection
+ * the last key is impossible to remove, so there's
+ * always at least one current_key.
+ */
+ if (tcp_ao_required(sk, saddr, family, l3index, true)) {
+ tcp_hash_fail("AO hash is required, but not found",
+ family, skb, "L3 index %d", l3index);
+ return SKB_DROP_REASON_TCP_AONOTFOUND;
+ }
+ if (unlikely(tcp_md5_do_lookup(sk, l3index, saddr, family))) {
+ NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND);
+ tcp_hash_fail("MD5 Hash not found",
+ family, skb, "L3 index %d", l3index);
+ return SKB_DROP_REASON_TCP_MD5NOTFOUND;
+ }
+ return SKB_NOT_DROPPED_YET;
+ }
+
+ if (aoh)
+ return tcp_inbound_ao_hash(sk, skb, family, req, l3index, aoh);
+
+ return tcp_inbound_md5_hash(sk, skb, saddr, daddr, family,
+ l3index, md5_location);
+}
+
void tcp_done(struct sock *sk)
{
struct request_sock *req;

--
2.43.0