batctl update to use the sys framework for VLAN

Hello list,

The following is a small patch proposal to allow the batctl tool to use the sys framework for VLAN recently added to batman-adv, so that commands can be applied in a per VLAN fashion at user discretion. Comments and suggestions are extremely welcome.

If no directory entry corresponding to the user-selected device is found at the standard location for non VLAN interfaces (/sys/class/net/${base_device}), 'batctl' now looks into directory:

     /sys/devices/virtual/net/${base_device}/mesh/vlan${vid}
Where:
    -${base_device}: the batman device on top of which the VLAN is sitting
    -${device}: the device interface for the VLAN,
    -${vid}: the identifier assigned to the VLAN.

Information on VLAN devices (base device, vid) is acquired by parsing /proc/net/vlan/${device}.

If the user-selected command is not supported by the VLAN, an appropriate error is shown.

---
 functions.c |  7 ++++++-
 sys.c       | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 60 insertions(+), 1 deletion(-)

index cc05a48..973b6f8 100644
@@ -135,8 +135,13 @@ static void file_open_problem_dbg(char *dir, char *fname, char *full_path)
             fprintf(stderr, "Error - the folder '/sys/' was not found 

on the system\n");
fprintf(stderr, "Please make sure that the sys filesystem

is properly mounted\n");
             return;
+        } else if (strstr(dir, "/sys/devices/virtual/")) {
+            fprintf(stderr, "The selected feature '%s' is not supported for vlans\n", fname);
+            return;
         }

- }
+ }
+
+

if (!file_exists(module_ver_path)) {
fprintf(stderr, "Error - batman-adv module has not been
loaded\n");

index b1d7ea8..799f275 100644
@@ -371,6 +371,39 @@ static void settings_usage(int setting)
     fprintf(stderr, " \t -h print this help\n");
 }
 
+int get_basedev_vid(char *mesh_iface, char **base_dev, unsigned short *vid)
+{
+    char *vdev;
+    char line[100];
+    const char path[]="/proc/net/vlan/";
+    int size=sizeof(path)+sizeof(mesh_iface);
+    FILE *fp = NULL;
+
+    char *fpath=malloc(size);
+    strcpy(fpath, path);
+    /* prepare path file path: /proc/net/vlan/$mesh_iface*/
+    strcat(fpath, mesh_iface);
+
+    fp = fopen(fpath, "r");
+    if (fp == NULL) {
+        return 1;
+    }
+
+    if (fscanf(fp, "%ms %*s %hu %*s %*d %*s %*d", &vdev, vid)==0) {
+        return 0;
+    }
+    while (fgets(line, sizeof(line), fp) != NULL) {
+        if (sscanf(line, "Device: %ms", base_dev) == 1) {
+            break;
+        }
+    }
+    // handle base device not found case
+    if (*base_dev==NULL) {
+        return 0;
+    }
+    return 1;
+}
+
 int handle_sys_setting(char *mesh_iface, int setting, int argc, char 

**argv)

 {
     int optchar, res = EXIT_FAILURE;
@@ -392,6 +425,27 @@ int handle_sys_setting(char *mesh_iface, int setting, int argc, char **argv)
     snprintf(path_buff, PATH_BUFF_LEN, SYS_BATIF_PATH_FMT, mesh_iface);
     path_buff[PATH_BUFF_LEN - 1] = '\0';

+ if (access(path_buff, F_OK) != 0) {
+ if (errno == ENOENT) {

+            // does not exist, no lan interface: check vlan
+            unsigned short vid=0;
+            char *base_dev=NULL;
+            if (get_basedev_vid(mesh_iface, &base_dev, &vid) == 1) {
+                free(path_buff);
+                char sys_vlan_path[]="/sys/devices/virtual/net/%s/mesh/vlan%d/";
+                int size=sizeof(sys_vlan_path)+sizeof(base_dev);
+                path_buff=malloc(size);
+                sprintf(path_buff, sys_vlan_path, base_dev, vid);

+ }
+ }
+ if (errno == ENOTDIR) {
+ // not a directory, something wrong here
+ fprintf(stderr, "Error - expected directory at '%s'\n",
+ path_buff);
+ return EXIT_FAILURE;
+ }
+ }
+
if (argc == 1) {
res = read_file(path_buff, (char
*)batctl_settings[setting].sysfs_name,

                 NO_FLAGS, 0, 0, 0);

1.8.3.2

Next patch version will hopefully take care of the coding style issues. Thanks Antonio for pointing that out.

Marco