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

[Marco Dalla Torre <marco.dallato@gmail.com>]

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

@@ -135,7 +135,10 @@

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

@@ -49,8 +49,8 @@

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

@@ -42,8 +42,8 @@

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

@@ -371,7 +371,38 @@

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;

@@ -392,8 +423,27 @@

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)·{
+» » » /*·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