[B.A.T.M.A.N.] [PATCHv3] batctl: add sys framework for VLAN support

Marco Dalla Torre
2013-08-29T18:43:34Z

*sorry for messing up format in previous message, re-sending*

Allow the batctl tool to take advantage of changes from commit
e4ff5c153dab054a6cd1c4132f87bc5e77127456 ("add sys framework for VLAN")
recently added to batman-adv, so that users can execute commands in
a per VLAN fashion.

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) necessary to construct the
directory path is acquired by parsing /proc/net/vlan/${device}.

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

Signed-off-by: Marco Dalla Torre <marco.dallato@gmail.com>
---
functions.c | 3 +++
main.c | 2 +-
man/batctl.8 | 2 +-
sys.c | 51 +++++++++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 56 insertions(+), 2 deletions(-)

diff --git a/functions.c b/functions.c
index cc05a48..ed010ea 100644
--- a/functions.c
+++ b/functions.c
@@ -135,6 +135,9 @@ 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;
}
}

diff --git a/main.c b/main.c
index 24d42fb..bac37ca 100644
--- a/main.c
+++ b/main.c
@@ -49,7 +49,7 @@ void print_usage(void)

fprintf(stderr, "Usage: batctl [options] command|debug table [parameters]\n");
fprintf(stderr, "options:\n");
- fprintf(stderr, " \t-m mesh interface (default 'bat0')\n");
+ fprintf(stderr, " \t-m mesh interface or mesh-based VLAN interface (default 'bat0')\n");
fprintf(stderr, " \t-h print this help (or 'batctl <command|debug table> -h' for the parameter help)\n");
fprintf(stderr, " \t-v print version\n");
fprintf(stderr, "\n");
diff --git a/man/batctl.8 b/man/batctl.8
index d04385b..7fd324d 100644
--- a/man/batctl.8
+++ b/man/batctl.8
@@ -42,7 +42,7 @@ behaviour or using the B.A.T.M.A.N. advanced protocol.
.SH OPTIONS
.TP
.I \fBoptions:
-\-m specify mesh interface (default 'bat0')
+\-m specify mesh interface or a mesh-based VLAN interface (default 'bat0')
.br
\-h print general batctl help
.br
diff --git a/sys.c b/sys.c
index b1d7ea8..00d2ed1 100644
--- a/sys.c
+++ b/sys.c
@@ -371,6 +371,37 @@ 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 +423,26 @@ 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) {
+ /* path 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);
+ }
+ } else 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