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[1/2] main: Accept interface names as a parameter

Message ID 1465581866-19411-1-git-send-email-tim.a.kourt@linux.intel.com
State Accepted
Headers show

Commit Message

Tim Kourt June 10, 2016, 6:04 p.m. UTC 
The introduction of a parameter ‘-i’ to override the value of
‘interface’ attribute in hostapd.conf files. This change enables
the reuse of the configuration files for the concurrent instances
of hostapd. An ability to dynamically assign the interface names
simplifies the usages of hostapd service in the automated
emulations of the wireless environments.

Signed-off-by: Tim Kourt <tim.a.kourt@linux.intel.com>
---
 hostapd/main.c | 59 +++++++++++++++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 52 insertions(+), 7 deletions(-)

Comments

Jouni Malinen June 12, 2016, 10:25 p.m. UTC | #1 
On Fri, Jun 10, 2016 at 11:04:25AM -0700, Tim Kourt wrote:
> The introduction of a parameter ‘-i’ to override the value of
> ‘interface’ attribute in hostapd.conf files. This change enables
> the reuse of the configuration files for the concurrent instances
> of hostapd. An ability to dynamically assign the interface names
> simplifies the usages of hostapd service in the automated
> emulations of the wireless environments.

Thanks, both patches applied. I fixed some issues with this first patch:

> +	if (if_name) {
> +		strncpy(iface->conf->bss[0]->iface, if_name, strlen(if_name));
> +		iface->conf->bss[0]->iface[strlen(if_name)] = '\0';
> +	}

Should use os_strlcpy() instead of strncpy() and especially that
strlen(if_name) part would make this not do any bounds checking on the
destination, i.e., this would allow buffer write overflow from the
command line.

> +		*if_names = os_realloc_array(*if_names, ++(*if_names_size),
> +					     sizeof(char *));

realloc functions cannot be used in that manner cleanly, i.e., this
would leak memory if realloc returns NULL. A temporary variable is
needed to allow the original (and still allocated) pointer to be freed
in case of such a failure.
diff mbox

Patch

diff --git a/hostapd/main.c b/hostapd/main.c
index 5f3f83b..35a21b4 100644
--- a/hostapd/main.c
+++ b/hostapd/main.c
@@ -251,7 +251,7 @@  static int hostapd_driver_init(struct hostapd_iface *iface)
  * interfaces. No actiual driver operations are started.
  */
 static struct hostapd_iface *
-hostapd_interface_init(struct hapd_interfaces *interfaces,
+hostapd_interface_init(struct hapd_interfaces *interfaces, const char *if_name,
 		       const char *config_fname, int debug)
 {
 	struct hostapd_iface *iface;
@@ -261,6 +261,12 @@  hostapd_interface_init(struct hapd_interfaces *interfaces,
 	iface = hostapd_init(interfaces, config_fname);
 	if (!iface)
 		return NULL;
+
+	if (if_name) {
+		strncpy(iface->conf->bss[0]->iface, if_name, strlen(if_name));
+		iface->conf->bss[0]->iface[strlen(if_name)] = '\0';
+	}
+
 	iface->interfaces = interfaces;
 
 	for (k = 0; k < debug; k++) {
@@ -270,8 +276,8 @@  hostapd_interface_init(struct hapd_interfaces *interfaces,
 
 	if (iface->conf->bss[0]->iface[0] == '\0' &&
 	    !hostapd_drv_none(iface->bss[0])) {
-		wpa_printf(MSG_ERROR, "Interface name not specified in %s",
-			   config_fname);
+		wpa_printf(MSG_ERROR, "Interface name not specified in %s, nor "
+			   "by '-i' parameter", config_fname);
 		hostapd_interface_deinit_free(iface);
 		return NULL;
 	}
@@ -454,7 +460,8 @@  static void usage(void)
 		"\n"
 		"usage: hostapd [-hdBKtv] [-P <PID file>] [-e <entropy file>] "
 		"\\\n"
-		"         [-g <global ctrl_iface>] [-G <group>] \\\n"
+		"         [-g <global ctrl_iface>] [-G <group>]\\\n"
+		"         [-i <comma-separated list of interface names>]\\\n"
 		"         <configuration file(s)>\n"
 		"\n"
 		"options:\n"
@@ -473,6 +480,7 @@  static void usage(void)
 		"   -T = record to Linux tracing in addition to logging\n"
 		"        (records all messages regardless of debug verbosity)\n"
 #endif /* CONFIG_DEBUG_LINUX_TRACING */
+		"   -i   list of interface names to use\n"
 		"   -S   start all the interfaces synchronously\n"
 		"   -t   include timestamps in some debug messages\n"
 		"   -v   show hostapd version\n");
@@ -535,6 +543,27 @@  static int hostapd_get_ctrl_iface_group(struct hapd_interfaces *interfaces,
 	return 0;
 }
 
+static int hostapd_get_interface_names(char ***if_names,
+				       size_t *if_names_size,
+				       char *optarg)
+{
+	char *if_name;
+
+	if_name = strtok(optarg, ",");
+
+	while (if_name) {
+		*if_names = os_realloc_array(*if_names, ++(*if_names_size),
+					     sizeof(char *));
+		if (!(*if_names))
+			return -1;
+
+		(*if_names)[(*if_names_size) - 1] = os_strdup(if_name);
+		if_name = strtok(NULL, ",");
+	}
+
+	return 0;
+}
+
 
 #ifdef CONFIG_WPS
 static int gen_uuid(const char *txt_addr)
@@ -588,8 +617,8 @@  int main(int argc, char *argv[])
 	char *pid_file = NULL;
 	const char *log_file = NULL;
 	const char *entropy_file = NULL;
-	char **bss_config = NULL, **tmp_bss;
-	size_t num_bss_configs = 0;
+	char **bss_config = NULL, **tmp_bss, **if_names = NULL;
+	size_t num_bss_configs = 0, if_names_size = 0;
 #ifdef CONFIG_DEBUG_LINUX_TRACING
 	int enable_trace_dbg = 0;
 #endif /* CONFIG_DEBUG_LINUX_TRACING */
@@ -611,7 +640,7 @@  int main(int argc, char *argv[])
 	dl_list_init(&interfaces.global_ctrl_dst);
 
 	for (;;) {
-		c = getopt(argc, argv, "b:Bde:f:hKP:STtu:vg:G:");
+		c = getopt(argc, argv, "b:Bde:f:hKP:STtu:vg:G:i:");
 		if (c < 0)
 			break;
 		switch (c) {
@@ -675,6 +704,11 @@  int main(int argc, char *argv[])
 		case 'u':
 			return gen_uuid(optarg);
 #endif /* CONFIG_WPS */
+		case 'i':
+			if (hostapd_get_interface_names(&if_names,
+							&if_names_size, optarg))
+				goto out;
+			break;
 		default:
 			usage();
 			break;
@@ -732,7 +766,13 @@  int main(int argc, char *argv[])
 
 	/* Allocate and parse configuration for full interface files */
 	for (i = 0; i < interfaces.count; i++) {
+		char *if_name = NULL;
+
+		if (i < if_names_size)
+			if_name = if_names[i];
+
 		interfaces.iface[i] = hostapd_interface_init(&interfaces,
+							     if_name,
 							     argv[optind + i],
 							     debug);
 		if (!interfaces.iface[i]) {
@@ -826,6 +866,11 @@  int main(int argc, char *argv[])
 
 	os_free(bss_config);
 
+	for (i = 0; i < if_names_size; i++)
+		os_free(if_names[i]);
+
+	os_free(if_names);
+
 	fst_global_deinit();
 
 	os_program_deinit();