Squash to "selftests/bpf: Add mptcp_subflow bpf_iter subtest"

IPPROTO_MPTCP is checked in bpf_mptcp_sk(), no need to check it in BPF
program.

bpf_mptcp_sk() and bpf_mptcp_subflow_ctx() may return NULL, need to
check the return values.

Signed-off-by: Geliang Tang <[email protected]>

Author: Geliang Tang

tools/testing/selftests/bpf/progs/mptcp_bpf_iters.c

@@ -21,12 +21,11 @@ int iters_subflow(struct bpf_sockopt *ctx)
 	struct mptcp_sock *msk;
 	int local_ids = 0;
 
-	if (!sk || sk->protocol != IPPROTO_MPTCP ||
-	    ctx->level != SOL_TCP || ctx->optname != TCP_IS_MPTCP)
+	if (ctx->level != SOL_TCP || ctx->optname != TCP_IS_MPTCP)
 		return 1;
 
 	msk = bpf_mptcp_sk((struct sock *)sk);
-	if (msk->pm.server_side || !msk->pm.subflows)
+	if (!msk || msk->pm.server_side || !msk->pm.subflows)
 		return 1;
 
 	msk = bpf_mptcp_sock_acquire(msk);
@@ -53,7 +52,7 @@ int iters_subflow(struct bpf_sockopt *ctx)
 
 	/* only to check the following kfunc works */
 	subflow = bpf_mptcp_subflow_ctx(ssk);
-	if (subflow->token != msk->token)
+	if (!subflow || subflow->token != msk->token)
 		goto out;
 
 	ids = local_ids;