fixes #6 Security attributes support

fixes #382 Permissions support for IPC on POSIX

This adds support for permission management on Windows and
POSIX systems.  There are two different properties, and they
are very different.

Tests and documentation are included.

1 files changed, 47 insertions, 0 deletions

diff --git a/src/transport/ipc/ipc.c b/src/transport/ipc/ipc.c
index 61b89f20..3dbccb50 100644
--- a/src/transport/ipc/ipc.c
+++ b/src/transport/ipc/ipc.c
@@ -13,6 +13,7 @@
 #include <string.h>
 
 #include "core/nng_impl.h"
+#include "ipc.h"
 
 // IPC transport.   Platform specific IPC operations must be
 // supplied as well.  Normally the IPC is UNIX domain sockets or
@@ -739,6 +740,40 @@ nni_ipc_ep_get_addr(void *arg, void *data, size_t *szp, int typ)
 	return (nni_copyout_sockaddr(&ep->sa, data, szp, typ));
 }
 
+static int
+nni_ipc_ep_setopt_permissions(void *arg, const void *data, size_t sz, int typ)
+{
+	nni_ipc_ep *ep = arg;
+	int         val;
+	int         rv;
+
+	// Probably we could further limit this -- most systems don't have
+	// meaningful chmod beyond the lower 9 bits.
+	rv = nni_copyin_int(&val, data, sz, 0, 0x7FFFFFFF, typ);
+	if ((rv == 0) && (ep != NULL)) {
+		rv = nni_plat_ipc_ep_set_permissions(ep->iep, val);
+	}
+	return (rv);
+}
+
+static int
+nni_ipc_ep_setopt_security_desc(
+    void *arg, const void *data, size_t sz, int typ)
+{
+	nni_ipc_ep *ep = arg;
+	void *      ptr;
+	int         rv;
+
+	if ((rv = nni_copyin_ptr((void **) &ptr, data, sz, typ)) != 0) {
+		return (rv);
+	}
+
+	if (ep == NULL) {
+		return (0);
+	}
+	return (nni_plat_ipc_ep_set_security_descriptor(ep->iep, ptr));
+}
+
 static nni_tran_pipe_option nni_ipc_pipe_options[] = {
 	{
 	    .po_name   = NNG_OPT_REMADDR,
@@ -779,6 +814,18 @@ static nni_tran_ep_option nni_ipc_ep_options[] = {
 	    .eo_getopt = nni_ipc_ep_get_addr,
 	    .eo_setopt = NULL,
 	},
+	{
+	    .eo_name   = NNG_OPT_IPC_SECURITY_DESCRIPTOR,
+	    .eo_type   = NNI_TYPE_POINTER,
+	    .eo_getopt = NULL,
+	    .eo_setopt = nni_ipc_ep_setopt_security_desc,
+	},
+	{
+	    .eo_name   = NNG_OPT_IPC_PERMISSIONS,
+	    .eo_type   = NNI_TYPE_INT32,
+	    .eo_getopt = NULL,
+	    .eo_setopt = nni_ipc_ep_setopt_permissions,
+	},
 	// terminate list
 	{
 	    .eo_name = NULL,