[PATCH 2/4] alfred: Allow operating without any interface specified

[Marek Lindner <mareklindner@neomailbox.ch>]

The '-i' commandline parameter to specify interface names
no longer is mandatory. Specifying interface 'none' or
sending a 'none' interface string within the
ALFRED_CHANGE_INTERFACE unix socket command disables
all interfaces operations at runtime.

Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
---
 README.rst   |  6 +++++-
 alfred.h     |  1 -
 man/alfred.8 |  6 +++++-
 netsock.c    | 23 ++++-------------------
 server.c     | 12 ------------
 5 files changed, 14 insertions(+), 34 deletions(-)

diff --git a/README.rst b/README.rst
index 33200e4..7f44db6 100644
--- a/README.rst
+++ b/README.rst
@@ -82,7 +82,8 @@ documentation how to configure alfred in this case. In any event, you can
 still run alfred from the command line. The relevant options are (for a full
 list of options, run alfred -h):
 
-  -i, --interface             specify the interface to listen on
+  -i, --interface             specify the interface to listen on. use 'none'
+                              to disable interface operations
   -b                          specify the batman-adv interface configured on
                               the system (default: bat0). use 'none' to disable
                               the batman-adv based best server selection
@@ -90,6 +91,9 @@ list of options, run alfred -h):
                               accepts data from secondaries and syncs it with
                               other primaries
 
+The interface option '-i' is optional. If interface 'none' is specified, the
+alfred daemon will not communicate with other alfred instances on the
+network unless the interface list is modified at runtime via the unix socket.
 The -b option is optional, and only needed if you run alfred on a batman-adv
 interface not called bat0, or if you don't use batman-adv at all
 (use '-b none'). In this case, alfred will still work but will not be able to
diff --git a/alfred.h b/alfred.h
index d844261..57d7daf 100644
--- a/alfred.h
+++ b/alfred.h
@@ -182,7 +182,6 @@ int unix_sock_req_data_finish(struct globals *globals,
 /* vis.c */
 int vis_update_data(struct globals *globals);
 /* netsock.c */
-int netsock_open_all(struct globals *globals);
 size_t netsocket_count_interfaces(struct globals *globals);
 void netsock_close_all(struct globals *globals);
 int netsock_set_interfaces(struct globals *globals, char *interfaces);
diff --git a/man/alfred.8 b/man/alfred.8
index 18e008e..ff9b315 100644
--- a/man/alfred.8
+++ b/man/alfred.8
@@ -95,12 +95,16 @@ Change the alfred server to use the new \fBinterface\fP(s)
 .SH SERVER OPTIONS
 .TP
 \fB\-i\fP, \fB\-\-interface\fP \fIiface\fP
-Specify the interface (or comma separated list of interfaces) to listen on
+Specify the interface (or comma separated list of interfaces) to listen on.
+Use 'none' to disable interface operations.
 .TP
 \fB\-b\fP \fIbatmanif\fP
 Specify the batman-adv interface configured on the system (default: bat0).
 Use 'none' to disable the batman-adv based best server selection.
 
+The interface option \fB\-i\fP is optional. If interface 'none' is specified, the
+alfred daemon will not communicate with other alfred instances on the
+network unless the interface list is modified at runtime via the unix socket.
 The \fB\-b\fP option is optional, and only needed if you run alfred on a
 batman-adv interface not called bat0, or if you don't use batman-adv at all
 (use '\fB\-b\fP none'). In this case, alfred will still work but will not be
diff --git a/netsock.c b/netsock.c
index 84b0ec3..7bc49b4 100644
--- a/netsock.c
+++ b/netsock.c
@@ -116,6 +116,10 @@ int netsock_set_interfaces(struct globals *globals, char *interfaces)
 
 	netsock_close_all(globals);
 
+	/* interface 'none' disables all interface operations */
+	if (strcmp(interfaces, "none") == 0)
+		return 0;
+
 	input = interfaces;
 	while ((token = strtok_r(input, ",", &saveptr))) {
 		input = NULL;
@@ -452,25 +456,6 @@ err:
 	return -1;
 }
 
-int netsock_open_all(struct globals *globals)
-{
-	int num_socks = 0;
-	int ret;
-	struct interface *interface;
-
-	list_for_each_entry(interface, &globals->interfaces, list) {
-		if (globals->ipv4mode)
-			ret = netsock_open4(interface);
-		else
-			ret = netsock_open(interface);
-
-		if (ret >= 0)
-			num_socks++;
-	}
-
-	return num_socks;
-}
-
 size_t netsocket_count_interfaces(struct globals *globals)
 {
 	struct interface *interface;
diff --git a/server.c b/server.c
index 85bf453..39206bf 100644
--- a/server.c
+++ b/server.c
@@ -372,7 +372,6 @@ int alfred_server(struct globals *globals)
 	struct timespec last_check, now, tv;
 	fd_set fds, errfds;
 	size_t num_interfaces;
-	int num_socks;
 
 	if (create_hashes(globals))
 		return -1;
@@ -380,11 +379,6 @@ int alfred_server(struct globals *globals)
 	if (unix_sock_open_daemon(globals))
 		return -1;
 
-	if (list_empty(&globals->interfaces)) {
-		fprintf(stderr, "Can't start server: interface missing\n");
-		return -1;
-	}
-
 	if (strcmp(globals->mesh_iface, "none") != 0 &&
 	    batadv_interface_check(globals->mesh_iface) < 0 &&
 	    !globals->force) {
@@ -393,12 +387,6 @@ int alfred_server(struct globals *globals)
 		return -1;
 	}
 
-	num_socks = netsock_open_all(globals);
-	if (num_socks <= 0 && !globals->force) {
-		fprintf(stderr, "Failed to open interfaces\n");
-		return -1;
-	}
-
 	num_interfaces = netsocket_count_interfaces(globals);
 	if (num_interfaces > 1 && globals->opmode == OPMODE_SECONDARY) {
 		fprintf(stderr, "More than one interface specified in secondary mode\n");
-- 
2.32.0.rc0