1 files changed, 24 insertions, 0 deletions

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 88b62441e7e9..f013ddc191e0 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -2042,6 +2042,30 @@ void tcp_set_state(struct sock *sk, int state)
 {
         int oldstate = sk->sk_state;
 
+        /* We defined a new enum for TCP states that are exported in BPF
+         * so as not force the internal TCP states to be frozen. The
+         * following checks will detect if an internal state value ever
+         * differs from the BPF value. If this ever happens, then we will
+         * need to remap the internal value to the BPF value before calling
+         * tcp_call_bpf_2arg.
+         */
+        BUILD_BUG_ON((int)BPF_TCP_ESTABLISHED != (int)TCP_ESTABLISHED);
+        BUILD_BUG_ON((int)BPF_TCP_SYN_SENT != (int)TCP_SYN_SENT);
+        BUILD_BUG_ON((int)BPF_TCP_SYN_RECV != (int)TCP_SYN_RECV);
+        BUILD_BUG_ON((int)BPF_TCP_FIN_WAIT1 != (int)TCP_FIN_WAIT1);
+        BUILD_BUG_ON((int)BPF_TCP_FIN_WAIT2 != (int)TCP_FIN_WAIT2);
+        BUILD_BUG_ON((int)BPF_TCP_TIME_WAIT != (int)TCP_TIME_WAIT);
+        BUILD_BUG_ON((int)BPF_TCP_CLOSE != (int)TCP_CLOSE);
+        BUILD_BUG_ON((int)BPF_TCP_CLOSE_WAIT != (int)TCP_CLOSE_WAIT);
+        BUILD_BUG_ON((int)BPF_TCP_LAST_ACK != (int)TCP_LAST_ACK);
+        BUILD_BUG_ON((int)BPF_TCP_LISTEN != (int)TCP_LISTEN);
+        BUILD_BUG_ON((int)BPF_TCP_CLOSING != (int)TCP_CLOSING);
+        BUILD_BUG_ON((int)BPF_TCP_NEW_SYN_RECV != (int)TCP_NEW_SYN_RECV);
+        BUILD_BUG_ON((int)BPF_TCP_MAX_STATES != (int)TCP_MAX_STATES);
+
+        if (BPF_SOCK_OPS_TEST_FLAG(tcp_sk(sk), BPF_SOCK_OPS_STATE_CB_FLAG))
+                tcp_call_bpf_2arg(sk, BPF_SOCK_OPS_STATE_CB, oldstate, state);
+
         switch (state) {
         case TCP_ESTABLISHED:
                 if (oldstate != TCP_ESTABLISHED)