When running within a network namespace, access to files within debugfs have to take into account the network name space. Each namespace has its own directory under /sys/kernel/debug/batman_adv/netns.
Add example how this can be used in the README.
Signed-off-by: Andrew Lunn andrew@lunn.ch --- v2: README additions --- README | 58 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ debug.h | 2 +- debugfs.c | 49 ++++++++++++++++++++++++++++++++++++++++++++++++- 3 files changed, 107 insertions(+), 2 deletions(-)
diff --git a/README b/README index f87c551..431c62e 100644 --- a/README +++ b/README @@ -520,3 +520,61 @@ where: - IPv4 is the IP address of a client in the mesh network - MAC is the MAC address associated to that IP - last-seen is the amount of time since last refresh of this entry + +batctl and network name spaces +============================== + +The batman-adv kernel module is netns aware. Mesh instances can be +created in name spaces, and interfaces in that name space added to the +mesh. The mesh interface cannot be moved between name spaces, as is +typical for virtual interfaces. + +The following example creates two network namespaces, and uses veth +pairs to connect them together into a mesh of three nodes. + +EMU1="ip netns exec emu1" +EMU2="ip netns exec emu2" + +ip netns add emu1 +ip netns add emu2 + +ip link add emu1-veth1 type veth peer name emu2-veth1 +ip link set emu1-veth1 netns emu1 +ip link set emu2-veth1 netns emu2 + +$EMU1 ip link set emu1-veth1 name veth1 +$EMU2 ip link set emu2-veth1 name veth1 + +$EMU1 ip link set veth1 up +$EMU2 ip link set veth1 up + +ip link add emu1-veth2 type veth peer name veth2 +ip link set emu1-veth2 netns emu1 +$EMU1 ip link set emu1-veth2 name veth2 + +$EMU1 ip link set veth2 up +ip link set veth2 up + +$EMU1 batctl if add veth1 +$EMU1 batctl if add veth2 +$EMU1 ip link set bat0 up + +$EMU2 batctl if add veth1 +$EMU2 ip link set bat0 up + +batctl if add veth2 +ip link set bat0 up + +alfred and batadv-vis can also be used with name spaces. In this +example, only netns has been used, so there are no filesystem name +spaces. Hence the unix domain socket used by alfred needs to be given +a unique name per instance. + +($EMU1 alfred -m -i bat0 -u /var/run/emu1-alfred.soc) & +($EMU2 alfred -m -i bat0 -u /var/run/emu2-alfred.soc) & +alfred -m -i bat0 & + +($EMU1 batadv-vis -s -u /var/run/emu1-alfred.soc) & +($EMU2 batadv-vis -s -u /var/run/emu2-alfred.soc) & +batadv-vis -s & + diff --git a/debug.h b/debug.h index df65f50..ac7a97b 100644 --- a/debug.h +++ b/debug.h @@ -25,7 +25,7 @@ #include <stddef.h> #include "main.h"
-#define DEBUG_BATIF_PATH_FMT "%s/batman_adv/%s" +#define DEBUG_BATIF_PATH_FMT "%s/batman_adv/%s%s" #define DEBUG_TRANSTABLE_GLOBAL "transtable_global" #define DEBUG_LOG "log" #define DEBUG_ROUTING_ALGOS "routing_algos" diff --git a/debugfs.c b/debugfs.c index 3c58195..a66dbdd 100644 --- a/debugfs.c +++ b/debugfs.c @@ -20,11 +20,15 @@
#include "debugfs.h" #include <errno.h> +#include <fcntl.h> +#include <limits.h> #include <stdio.h> #include <string.h> #include <sys/mount.h> #include <sys/stat.h> #include <sys/statfs.h> +#include <sys/types.h> +#include <unistd.h>
#ifndef DEBUGFS_MAGIC #define DEBUGFS_MAGIC 0x64626720 @@ -39,15 +43,58 @@ static const char *debugfs_known_mountpoints[] = { NULL, };
+/* Return the current net namespace number. 0 is never a valid + * namespace, so use it to return that there is no name space + * support. + */ + +static unsigned int debugfs_get_netns_inum(void) +{ + char net_path[] = "/proc/self/ns/net"; + struct stat netst; + int netns; + + netns = open(net_path, O_RDONLY); + if (netns < 0) { + if (errno == ENOENT) + /* Probably means no netns support in the kernel */ + return 0; + + fprintf(stderr, + "Error - can't open /proc/self/ns/net for read: %s\n", + strerror(errno)); + return 0; + } + + if (fstat(netns, &netst) < 0) { + fprintf(stderr, "Stat of netns failed: %s\n", + strerror(errno)); + return 0; + } + close (netns); + + return netst.st_ino; +} + /* construct a full path to a debugfs element */ int debugfs_make_path(const char *fmt, char *mesh_iface, char *buffer, int size) { + unsigned int ns = debugfs_get_netns_inum(); + char ns_dir[PATH_MAX]; + if (strlen(debugfs_mountpoint) == 0) { buffer[0] = '\0'; return -1; }
- return snprintf(buffer, size, fmt, debugfs_mountpoint, mesh_iface); + if (ns) { + snprintf(ns_dir, PATH_MAX, "netns/%u/", ns); + return snprintf(buffer, size, fmt, debugfs_mountpoint, ns_dir, + mesh_iface); + } else { + return snprintf(buffer, size, fmt, debugfs_mountpoint, "", + mesh_iface); + } }
static int debugfs_found;