Initial cut at TCP, totally untested beyond compilation.

This also adds checks in the protocols to verify that pipe peers
are of the proper protocol.

3 files changed, 10 insertions, 3 deletions

diff --git a/src/protocol/pair/pair.c b/src/protocol/pair/pair.c
index cc906791..f86a9fa7 100644
--- a/src/protocol/pair/pair.c
+++ b/src/protocol/pair/pair.c
@@ -102,6 +102,9 @@ nni_pair_pipe_add(void *arg)
 	nni_pair_pipe *pp = arg;
 	nni_pair_sock *pair = pp->pair;
 
+	if (nni_pipe_peer(pp->pipe) != NNG_PROTO_PAIR) {
+		return (NNG_EPROTO);
+	}
 	if (pair->pipe != NULL) {
 		return (NNG_EBUSY);      // Already have a peer, denied.
 	}
diff --git a/src/protocol/reqrep/rep.c b/src/protocol/reqrep/rep.c
index ca59d799..8c375b61 100644
--- a/src/protocol/reqrep/rep.c
+++ b/src/protocol/reqrep/rep.c
@@ -137,6 +137,9 @@ nni_rep_pipe_add(void *arg)
 	nni_rep_sock *rep = rp->rep;
 	int rv;
 
+	if (nni_pipe_peer(rp->pipe) != NNG_PROTO_REQ) {
+		return (NNG_EPROTO);
+	}
 	nni_mtx_lock(&rep->mx);
 	rv = nni_idhash_insert(rep->pipes, nni_pipe_id(rp->pipe), rp);
 	nni_mtx_unlock(&rep->mx);
diff --git a/src/protocol/reqrep/req.c b/src/protocol/reqrep/req.c
index 4ce66ab6..b9981c3c 100644
--- a/src/protocol/reqrep/req.c
+++ b/src/protocol/reqrep/req.c
@@ -138,9 +138,10 @@ nni_req_pipe_fini(void *arg)
 static int
 nni_req_pipe_add(void *arg)
 {
-	// We have nothing to do, since we don't need to maintain a global
-	// list of related pipes.
-	NNI_ARG_UNUSED(arg);
+	nni_req_pipe *rp = arg;
+	if (nni_pipe_peer(rp->pipe) != NNG_PROTO_REP) {
+		return (NNG_EPROTO);
+	}
 	return (0);
 }