This patch adds a runtime check to determine if netns are available. Some
systems like OpenWRT have the system call setns() but don't have the kernel
option CONFIG_NET_NS enabled.
Reported-by: Christian Franke <ch...@opensourcerouting.org>
Signed-off-by: Nicolas Dichtel <nicolas.dich...@6wind.com>
---
Christian, could you test this patch?
lib/vrf.c | 95 ++++++++++++++++++++++++++++++++++++++-------------------------
1 file changed, 58 insertions(+), 37 deletions(-)
diff --git a/lib/vrf.c b/lib/vrf.c
index 89653a8bb615..29be02a05387 100644
--- a/lib/vrf.c
+++ b/lib/vrf.c
@@ -38,7 +38,6 @@
#include "command.h"
#include "vty.h"
-#ifdef HAVE_NETNS
#ifndef CLONE_NEWNET
#define CLONE_NEWNET 0x40000000 /* New network namespace (lo, device, names
sockets, etc) */
@@ -57,7 +56,11 @@ static inline int setns(int fd, int nstype)
#endif /* HAVE_SETNS */
#define VRF_RUN_DIR "/var/run/netns"
+
+#ifdef HAVE_NETNS
+
#define VRF_DEFAULT_NAME "/proc/self/ns/net"
+static int have_netns_enabled = -1;
#else /* !HAVE_NETNS */
@@ -65,6 +68,27 @@ static inline int setns(int fd, int nstype)
#endif /* HAVE_NETNS */
+static int have_netns(void)
+{
+#ifdef HAVE_NETNS
+ if (have_netns_enabled < 0)
+ {
+ int fd = open (VRF_DEFAULT_NAME, O_RDONLY);
+
+ if (fd < 0)
+ have_netns_enabled = 0;
+ else
+ {
+ have_netns_enabled = 1;
+ close(fd);
+ }
+ }
+ return have_netns_enabled;
+#else
+ return 0;
+#endif
+}
+
struct vrf
{
/* Identifier, same as the vector index */
@@ -185,11 +209,10 @@ vrf_lookup (vrf_id_t vrf_id)
static int
vrf_is_enabled (struct vrf *vrf)
{
-#ifdef HAVE_NETNS
- return vrf && vrf->fd >= 0;
-#else
- return vrf && vrf->fd == -2 && vrf->vrf_id == VRF_DEFAULT;
-#endif
+ if (have_netns())
+ return vrf && vrf->fd >= 0;
+ else
+ return vrf && vrf->fd == -2 && vrf->vrf_id == VRF_DEFAULT;
}
/*
@@ -205,12 +228,12 @@ vrf_enable (struct vrf *vrf)
if (!vrf_is_enabled (vrf))
{
-#ifdef HAVE_NETNS
- vrf->fd = open (vrf->name, O_RDONLY);
-#else
- vrf->fd = -2; /* Remember that vrf_enable_hook has been called */
- errno = -ENOTSUP;
-#endif
+ if (have_netns()) {
+ vrf->fd = open (vrf->name, O_RDONLY);
+ } else {
+ vrf->fd = -2; /* Remember that vrf_enable_hook has been called */
+ errno = -ENOTSUP;
+ }
if (!vrf_is_enabled (vrf))
{
@@ -219,10 +242,9 @@ vrf_enable (struct vrf *vrf)
return 0;
}
-#ifdef HAVE_NETNS
- zlog_info ("VRF %u is associated with NETNS %s.",
- vrf->vrf_id, vrf->name);
-#endif
+ if (have_netns())
+ zlog_info ("VRF %u is associated with NETNS %s.",
+ vrf->vrf_id, vrf->name);
zlog_info ("VRF %u is enabled.", vrf->vrf_id);
if (vrf_master.vrf_enable_hook)
@@ -247,9 +269,9 @@ vrf_disable (struct vrf *vrf)
if (vrf_master.vrf_disable_hook)
(*vrf_master.vrf_disable_hook) (vrf->vrf_id, &vrf->info);
-#ifdef HAVE_NETNS
- close (vrf->fd);
-#endif
+ if (have_netns())
+ close (vrf->fd);
+
vrf->fd = -1;
}
}
@@ -488,7 +510,6 @@ vrf_bitmap_check (vrf_bitmap_t bmap, vrf_id_t vrf_id)
VRF_BITMAP_FLAG (offset)) ? 1 : 0;
}
-#ifdef HAVE_NETNS
/*
* VRF realization with NETNS
*/
@@ -624,8 +645,6 @@ vrf_config_write (struct vty *vty)
return write;
}
-#endif /* HAVE_NETNS */
-
/* Initialize VRF module. */
void
vrf_init (void)
@@ -653,12 +672,13 @@ vrf_init (void)
exit (1);
}
-#ifdef HAVE_NETNS
- /* Install VRF commands. */
- install_node (&vrf_node, vrf_config_write);
- install_element (CONFIG_NODE, &vrf_netns_cmd);
- install_element (CONFIG_NODE, &no_vrf_netns_cmd);
-#endif
+ if (have_netns())
+ {
+ /* Install VRF commands. */
+ install_node (&vrf_node, vrf_config_write);
+ install_element (CONFIG_NODE, &vrf_netns_cmd);
+ install_element (CONFIG_NODE, &no_vrf_netns_cmd);
+ }
}
/* Terminate VRF module. */
@@ -689,17 +709,18 @@ vrf_socket (int domain, int type, int protocol, vrf_id_t
vrf_id)
return -1;
}
-#ifdef HAVE_NETNS
- ret = (vrf_id != VRF_DEFAULT) ? setns (vrf->fd, CLONE_NEWNET) : 0;
- if (ret >= 0)
+ if (have_netns())
{
- ret = socket (domain, type, protocol);
- if (vrf_id != VRF_DEFAULT)
- setns (vrf_lookup (VRF_DEFAULT)->fd, CLONE_NEWNET);
+ ret = (vrf_id != VRF_DEFAULT) ? setns (vrf->fd, CLONE_NEWNET) : 0;
+ if (ret >= 0)
+ {
+ ret = socket (domain, type, protocol);
+ if (vrf_id != VRF_DEFAULT)
+ setns (vrf_lookup (VRF_DEFAULT)->fd, CLONE_NEWNET);
+ }
}
-#else
- ret = socket (domain, type, protocol);
-#endif
+ else
+ ret = socket (domain, type, protocol);
return ret;
}
--
2.4.2
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