Add endpoint tuning of maxrcv size. Fix cmsg API.

The CMSG handling was completely borked.  This is fixed now, and
we stash the SP header size (ugh) in the CMSG contents to match what
nanomsg does.  We now pass the cmsg validation test.

We also fixed handling of certain endpoint-related options, so that
endpoints can get options from the socket at initialization time.
This required a minor change to the transport API for endpoints.

Finally, we fixed a critical fault in the REP handling of RAW sockets,
which caused them to always return NNG_ESTATE in all cases.  It should
now honor the actual socket option.

6 files changed, 75 insertions, 5 deletions

diff --git a/src/core/endpt.c b/src/core/endpt.c
index c0890cd3..9411c220 100644
--- a/src/core/endpt.c
+++ b/src/core/endpt.c
@@ -131,7 +131,7 @@ nni_ep_create(nni_ep **epp, nni_sock *sock, const char *addr)
 		return (NNG_ECLOSED);
 	}
 
-	rv = ep->ep_ops.ep_init(&ep->ep_data, addr, nni_sock_proto(sock));
+	rv = ep->ep_ops.ep_init(&ep->ep_data, addr, sock);
 	if (rv != 0) {
 		nni_mtx_unlock(&sock->s_mx);
 		nni_cv_fini(&ep->ep_cv);
diff --git a/src/core/options.c b/src/core/options.c
index a0b74014..cd67e0d0 100644
--- a/src/core/options.c
+++ b/src/core/options.c
@@ -49,6 +49,27 @@ nni_setopt_int(int *ptr, const void *val, size_t size, int minval, int maxval)
 
 
 int
+nni_setopt_size(size_t *ptr, const void *val, size_t size, size_t minval,
+    size_t maxval)
+{
+	int v;
+
+	if (size != sizeof (v)) {
+		return (NNG_EINVAL);
+	}
+	memcpy(&v, val, sizeof (v));
+	if (v > maxval) {
+		return (NNG_EINVAL);
+	}
+	if (v < minval) {
+		return (NNG_EINVAL);
+	}
+	*ptr = v;
+	return (0);
+}
+
+
+int
 nni_getopt_duration(nni_duration *ptr, void *val, size_t *sizep)
 {
 	size_t sz = sizeof (*ptr);
@@ -77,6 +98,20 @@ nni_getopt_int(int *ptr, void *val, size_t *sizep)
 
 
 int
+nni_getopt_size(size_t *ptr, void *val, size_t *sizep)
+{
+	size_t sz = sizeof (*ptr);
+
+	if (sz > *sizep) {
+		sz = *sizep;
+	}
+	*sizep = sizeof (*ptr);
+	memcpy(val, ptr, sz);
+	return (0);
+}
+
+
+int
 nni_setopt_buf(nni_msgq *mq, const void *val, size_t sz)
 {
 	int len;
diff --git a/src/core/options.h b/src/core/options.h
index 2d843a4c..ec5cce90 100644
--- a/src/core/options.h
+++ b/src/core/options.h
@@ -37,6 +37,17 @@ extern int nni_setopt_int(int *, const void *, size_t, int, int);
 // nni_getopt_int gets an integer.
 extern int nni_getopt_int(int *, void *, size_t *);
 
+// nni_setopt_size sets a size_t option.
+extern int nni_setopt_size(size_t *, const void *, size_t, size_t, size_t);
+
+// We limit the maximum size to 4GB.  That's intentional because some of the
+// underlying protocols cannot cope with anything bigger than 32-bits.
+#define NNI_MINSZ	(0)
+#define NNI_MAXSZ	((size_t) 0xffffffff)
+
+// nni_getopt_size obtains a size_t option.
+extern int nni_getopt_size(size_t *, void *, size_t *);
+
 // nni_getopt_fd obtains a notification file descriptor.
 extern int nni_getopt_fd(nni_sock *, nni_notifyfd *, int, void *, size_t *);
 
diff --git a/src/core/socket.c b/src/core/socket.c
index b0ce172f..6ccf3025 100644
--- a/src/core/socket.c
+++ b/src/core/socket.c
@@ -102,9 +102,6 @@ nni_sock_hold_close(nni_sock **sockp, uint32_t id)
 }
 
 
-// XXX: don't expose the upper queues to protocols, because we need to
-// trap on activity in those queues!
-
 // Because we have to call back into the socket, and possibly also the proto,
 // and wait for threads to terminate, we do this in a special thread.  The
 // assumption is that closing is always a "fast" operation.
@@ -276,6 +273,7 @@ nni_sock_open(nni_sock **sockp, uint16_t pnum)
 	sock->s_reconn = NNI_SECOND;
 	sock->s_reconnmax = 0;
 	sock->s_reapexit = 0;
+	sock->s_rcvmaxsz = 1024 * 1024; // 1 MB by default
 	NNI_LIST_INIT(&sock->s_pipes, nni_pipe, p_node);
 	NNI_LIST_INIT(&sock->s_reaps, nni_pipe, p_node);
 	NNI_LIST_INIT(&sock->s_eps, nni_ep, ep_node);
@@ -684,6 +682,20 @@ nni_sock_peer(nni_sock *sock)
 }
 
 
+nni_duration
+nni_sock_linger(nni_sock *sock)
+{
+	return (sock->s_linger);
+}
+
+
+size_t
+nni_sock_rcvmaxsz(nni_sock *sock)
+{
+	return (sock->s_rcvmaxsz);
+}
+
+
 int
 nni_sock_dial(nni_sock *sock, const char *addr, nni_ep **epp, int flags)
 {
@@ -775,6 +787,10 @@ nni_sock_setopt(nni_sock *sock, int opt, const void *val, size_t size)
 	case NNG_OPT_RCVBUF:
 		rv = nni_setopt_buf(sock->s_urq, val, size);
 		break;
+	case NNG_OPT_RCVMAXSZ:
+		rv = nni_setopt_size(&sock->s_rcvmaxsz, val, size, 0,
+			NNI_MAXSZ);
+		break;
 	}
 	nni_mtx_unlock(&sock->s_mx);
 	return (rv);
@@ -818,6 +834,9 @@ nni_sock_getopt(nni_sock *sock, int opt, void *val, size_t *sizep)
 	case NNG_OPT_RCVBUF:
 		rv = nni_getopt_buf(sock->s_urq, val, sizep);
 		break;
+	case NNG_OPT_RCVMAXSZ:
+		rv = nni_getopt_size(&sock->s_rcvmaxsz, val, sizep);
+		break;
 	case NNG_OPT_SNDFD:
 		rv = nni_getopt_fd(sock, &sock->s_send_fd, NNG_EV_CAN_SND,
 			val, sizep);
diff --git a/src/core/socket.h b/src/core/socket.h
index 42f42371..df11ded6 100644
--- a/src/core/socket.h
+++ b/src/core/socket.h
@@ -48,6 +48,8 @@ struct nni_socket {
 	nni_cv			s_notify_cv;    // wakes notify thread
 	nni_mtx			s_notify_mx;    // protects s_notify list
 
+	size_t			s_rcvmaxsz;     // maximum receive size
+
 	nni_list		s_reaps;        // pipes to reap
 	nni_thr			s_reaper;
 	nni_thr			s_notifier;
@@ -112,4 +114,7 @@ extern nni_msgq *nni_sock_recvq(nni_sock *);
 // here so that protocols can use it to initialize condvars.
 extern nni_mtx *nni_sock_mtx(nni_sock *);
 
+extern nni_duration nni_sock_linger(nni_sock *);
+extern size_t nni_sock_rcvmaxsz(nni_sock *);
+
 #endif  // CORE_SOCKET_H
diff --git a/src/core/transport.h b/src/core/transport.h
index 8544f097..c74ec497 100644
--- a/src/core/transport.h
+++ b/src/core/transport.h
@@ -40,7 +40,7 @@ struct nni_tran {
 struct nni_tran_ep {
 	// ep_init creates a vanilla endpoint. The value created is
 	// used for the first argument for all other endpoint functions.
-	int	(*ep_init)(void **, const char *, uint16_t);
+	int	(*ep_init)(void **, const char *, nni_sock *);
 
 	// ep_fini frees the resources associated with the endpoint.
 	// The endpoint will already have been closed.