ifupdown: add support for source stanza

Since Debian 7 (Wheezy) / Ubuntu 11.04 (Natty Narwhal) ifupdown supports
the source stanza to source in other configuration files from
/etc/network/interfaces.

Add support to the ifupdown plugin to include configuration files via
source.

Patch did not apply cleanly and was slightly modified by Thomas Haller.

https://bugzilla.gnome.org/show_bug.cgi?id=707276

Signed-off-by: Thomas Haller <thaller@redhat.com>
Reviewed-by: Sebastian Harl <tokkee@debian.org>

src/settings/plugins/ifupdown/interface_parser.c

@@ -25,6 +25,8 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <wordexp.h>
+#include <libgen.h>
 #include "nm-utils.h"
 
 if_block* first;
@@ -96,21 +98,33 @@ static char *join_values_with_spaces(char *dst, char **src)
 	return(dst);
 }
 
-void ifparser_init (const char *eni_file, int quiet)
+void _ifparser_source (const char *path, const char *en_dir, int quiet);
+void _recursive_ifparser (const char *eni_file, int quiet);
+
+void _recursive_ifparser (const char *eni_file, int quiet)
 {
-	FILE *inp = fopen (eni_file, "r");
+	FILE *inp;
 	char line[255];
 	int skip_to_block = 1;
 	int skip_long_line = 0;
 	int offs = 0;
 
+	// Check if interfaces file exists and open it
+	if (!g_file_test (eni_file, G_FILE_TEST_EXISTS)) {
+		if (!quiet)
+			g_warning ("Warning: interfaces file %s doesn't exist\n", eni_file);
+		return;
+	}
+	inp = fopen (eni_file, "r");
 	if (inp == NULL) {
 		if (!quiet)
 			g_warning ("Error: Can't open %s\n", eni_file);
 		return;
 	}
+	if (!quiet)
+		g_message ("      interface-parser: parsing file %s\n", eni_file);
+
 
-	first = last = NULL;
 	while (!feof(inp))
 	{
 		char *token[128];	// 255 chars can only be split into 127 tokens
@@ -175,8 +189,9 @@ void ifparser_init (const char *eni_file, int quiet)
 			continue;
 		}
 
-		// There are four different stanzas:
+		// There are five different stanzas:
-		// iface, mapping, auto and allow-*. Create a block for each of them.
+		// iface, mapping, auto, allow-* and source.
+		// Create a block for each of them except source.
 
 		// iface stanza takes at least 3 parameters
 		if (strcmp(token[0], "iface") == 0) {
@@ -211,6 +226,33 @@ void ifparser_init (const char *eni_file, int quiet)
 				add_block(token[0], token[i]);
 			skip_to_block = 0;
 		}
+		// source stanza takes one or more filepaths as parameters
+		else if (strcmp(token[0], "source") == 0) {
+			uint i;
+
+			skip_to_block = 0;
+
+			if (toknum == 1) {
+				if (!quiet)
+					g_warning ("Error: Invalid source line without parameters\n");
+				continue;
+			}
+			for (i = 1; i < toknum; ++i) {
+				char *eni_file_copy;
+				char *en_dir;
+
+				eni_file_copy = strdup (eni_file);
+				if (!eni_file_copy) {
+					if (!quiet)
+						g_warning ("Error: Skipping interfaces file %s because strdup failed\n",
+								eni_file);
+					continue;
+				}
+				en_dir = dirname (eni_file_copy);
+				_ifparser_source (token[i], en_dir, quiet);
+				free (eni_file_copy);
+			}
+		}
 		else {
 			if (skip_to_block) {
 				if (!quiet) {
@@ -222,6 +264,46 @@ void ifparser_init (const char *eni_file, int quiet)
 		}
 	}
 	fclose(inp);
+
+	if (!quiet)
+		g_message ("      interface-parser: finished parsing file %s\n", eni_file);
+}
+
+void _ifparser_source (const char *path, const char *en_dir, int quiet)
+{
+	// abs_path = en_dir + '/' + path + '\0'
+	char abs_path[strlen (en_dir) + strlen (path) + 2];
+	wordexp_t we;
+	uint i;
+
+	if (path[0] == '/') {
+		strncpy (abs_path, path, sizeof (abs_path));
+	}
+	else {
+		// Convert relative path to absolute path
+		snprintf (abs_path, sizeof (abs_path), "%s/%s", en_dir, path);
+	}
+	if (!quiet)
+		g_message ("      interface-parser: source line includes interfaces file(s) %s\n", abs_path);
+
+	// Recursively parse sourced in interfaces files
+	// (ifupdown uses WRDE_NOCMD for wordexp)
+	memset (&we, 0, sizeof (we));
+	if (wordexp (abs_path, &we, WRDE_NOCMD)) {
+		if (!quiet)
+			g_warning ("Error: word expansion for %s failed\n", abs_path);
+		return;
+	}
+	for (i = 0; i < we.we_wordc; i++) {
+		_recursive_ifparser (we.we_wordv[i], quiet);
+	}
+	wordfree (&we);
+}
+
+void ifparser_init (const char *eni_file, int quiet)
+{
+	first = last = NULL;
+	_recursive_ifparser (eni_file, quiet);
 }
 
 void _destroy_data(if_data *ifd)

src/settings/plugins/ifupdown/tests/test-ifupdown.c

@@ -903,6 +903,32 @@ test19_read_static_ipv4_plen (const char *path)
 	g_object_unref (connection);
 }
 
+static void
+test20_source_stanza (const char *path)
+{
+	Expected *e;
+	ExpectedBlock *b;
+
+	e = expected_new ();
+
+	b = expected_block_new ("auto", "eth0");
+	expected_add_block (e, b);
+	b = expected_block_new ("iface", "eth0");
+	expected_add_block (e, b);
+	expected_block_add_key (b, expected_key_new ("inet", "dhcp"));
+
+	b = expected_block_new ("auto", "eth1");
+	expected_add_block (e, b);
+	b = expected_block_new ("iface", "eth1");
+	expected_add_block (e, b);
+	expected_block_add_key (b, expected_key_new ("inet", "dhcp"));
+
+	init_ifparser_with_file (path, "test20-source-stanza");
+	compare_expected_to_ifparser (e);
+
+	ifparser_destroy ();
+	expected_free (e);
+}
 
 int
 main (int argc, char **argv)
@@ -955,6 +981,8 @@ main (int argc, char **argv)
 	                      (GTestDataFunc) test18_read_static_ipv6);
 	g_test_add_data_func ("/ifupdate/read_static_ipv4_plen", TEST_ENI_DIR,
 	                      (GTestDataFunc) test19_read_static_ipv4_plen);
+	g_test_add_data_func ("/ifupdate/source_stanza", TEST_ENI_DIR,
+	                      (GTestDataFunc) test20_source_stanza);
 
 	return g_test_run ();
 }

src/settings/plugins/ifupdown/tests/test20-source-stanza

@@ -0,0 +1 @@
+source test20-source-stanza.eth*

src/settings/plugins/ifupdown/tests/test20-source-stanza.eth0

@@ -0,0 +1,2 @@
+auto eth0
+iface eth0 inet dhcp

src/settings/plugins/ifupdown/tests/test20-source-stanza.eth1

@@ -0,0 +1,2 @@
+auto eth1
+iface eth1 inet dhcp