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core/tun: make reading of tun properties more robust

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There seems to be the possibility of a race while reading tun
properties from sysctl. In this case, when being unable to
read the properties at construction of NMDeviceTun, we retry
shortly after.

- let tun_get_properties() not log any errors and it
  does not stop on the first error but tries to read all
  the values. Also, it initializes all fields of the output
  structure with a default value (NULL).

- hard code kernel flag #ifndef in header files. Even if the
  flag IFF_MULTI_QUEUE is not defined at compile time of NM,
  it could still be supported by the kernel (eg. when booting
  a newer kernel then the installed kernel headers). Simply
  hard code the value, this value is not ever going to change
  anyway.

https://bugzilla.redhat.com/show_bug.cgi?id=1034737

Signed-off-by: Thomas Haller <thaller@redhat.com>
This commit is contained in:
Thomas Haller
2014-01-21 11:04:26 +01:00
parent 634e4c99c3
commit 4b2533fc00
2 changed files with 108 additions and 36 deletions
Download Patch File Download Diff File Expand all files Collapse all files

90
src/platform/nm-linux-platform.c
View File

@@ -44,6 +44,8 @@
#include <gudev/gudev.h>
#include "nm-linux-platform.h"
#include "NetworkManagerUtils.h"
#include "nm-utils.h"
#include "nm-logging.h"
#include "wifi/wifi-utils.h"
@@ -619,12 +621,23 @@ link_extract_type (NMPlatform *platform, struct rtnl_link *rtnllink, const char
return_type (NM_LINK_TYPE_MACVTAP, "macvtap");
else if (!strcmp (type, "tun")) {
NMPlatformTunProperties props;
guint flags;
if ( nm_platform_tun_get_properties (rtnl_link_get_ifindex (rtnllink), &props)
&& !strcmp (props.mode, "tap"))
return_type (NM_LINK_TYPE_TAP, "tap");
else
if (nm_platform_tun_get_properties (rtnl_link_get_ifindex (rtnllink), &props)) {
if (!g_strcmp0 (props.mode, "tap"))
return_type (NM_LINK_TYPE_TAP, "tap");
if (!g_strcmp0 (props.mode, "tun"))
return_type (NM_LINK_TYPE_TUN, "tun");
}
flags = rtnl_link_get_flags (rtnllink);
nm_log_dbg (LOGD_PLATFORM, "Failed to read tun properties for interface %d (link flags: %X)",
rtnl_link_get_ifindex (rtnllink), flags);
/* try guessing the type using the link flags instead... */
if (flags & IFF_POINTOPOINT)
return_type (NM_LINK_TYPE_TUN, "tun");
return_type (NM_LINK_TYPE_TAP, "tap");
} else if (!strcmp (type, "veth"))
return_type (NM_LINK_TYPE_VETH, "veth");
else if (!strcmp (type, "vlan"))
@@ -2006,45 +2019,62 @@ tun_get_properties (NMPlatform *platform, int ifindex, NMPlatformTunProperties *
{
const char *ifname;
char *path, *val;
guint32 flags;
gboolean success = TRUE;
g_return_val_if_fail (props, FALSE);
memset (props, 0, sizeof (*props));
props->owner = -1;
props->group = -1;
ifname = nm_platform_link_get_name (ifindex);
if (!ifname)
if (!ifname || !nm_utils_iface_valid_name (ifname))
return FALSE;
path = g_strdup_printf ("/sys/class/net/%s/owner", ifname);
val = nm_platform_sysctl_get (path, FALSE);
val = nm_platform_sysctl_get (path, TRUE);
g_free (path);
if (!val)
return FALSE;
props->owner = strtoll (val, NULL, 10);
g_free (val);
if (val) {
props->owner = nm_utils_ascii_str_to_int64 (val, 10, -1, G_MAXINT64, -1);
if (errno)
success = FALSE;
g_free (val);
} else
success = FALSE;
path = g_strdup_printf ("/sys/class/net/%s/group", ifname);
val = nm_platform_sysctl_get (path, FALSE);
val = nm_platform_sysctl_get (path, TRUE);
g_free (path);
if (!val)
return FALSE;
props->group = strtoll (val, NULL, 10);
g_free (val);
if (val) {
props->group = nm_utils_ascii_str_to_int64 (val, 10, -1, G_MAXINT64, -1);
if (errno)
success = FALSE;
g_free (val);
} else
success = FALSE;
path = g_strdup_printf ("/sys/class/net/%s/tun_flags", ifname);
val = nm_platform_sysctl_get (path, FALSE);
val = nm_platform_sysctl_get (path, TRUE);
g_free (path);
if (!val)
return FALSE;
flags = strtoul (val, NULL, 16);
props->mode = ((flags & TUN_TYPE_MASK) == TUN_TUN_DEV) ? "tun" : "tap";
props->no_pi = !!(flags & IFF_NO_PI);
props->vnet_hdr = !!(flags & IFF_VNET_HDR);
#ifdef IFF_MULTI_QUEUE
props->multi_queue = !!(flags & IFF_MULTI_QUEUE);
#else
props->multi_queue = FALSE;
#endif
g_free (val);
if (val) {
gint64 flags;
return TRUE;
flags = nm_utils_ascii_str_to_int64 (val, 16, 0, G_MAXINT64, 0);
if (!errno) {
#ifndef IFF_MULTI_QUEUE
const int IFF_MULTI_QUEUE = 0x0100;
#endif
props->mode = ((flags & TUN_TYPE_MASK) == TUN_TUN_DEV) ? "tun" : "tap";
props->no_pi = !!(flags & IFF_NO_PI);
props->vnet_hdr = !!(flags & IFF_VNET_HDR);
props->multi_queue = !!(flags & IFF_MULTI_QUEUE);
} else
success = FALSE;
g_free (val);
} else
success = FALSE;
return success;
}
static const struct nla_policy macvlan_info_policy[IFLA_MACVLAN_MAX + 1] = {