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| author | Johannes Berg <johannes@sipsolutions.net> | 2009-08-07 16:17:38 +0200 |
|---|---|---|
| committer | John W. Linville <linville@tuxdriver.com> | 2009-08-14 09:13:43 -0400 |
| commit | f5ea9120be2e5d5c846243416cfdce01d02f5836 (patch) | |
| tree | cade27e47a90dde79a523598b96a2ebb50770d2f /include/linux/nl80211.h | |
| parent | f401a6f7ede753e56b84025e7d2db0d5ef560ce6 (diff) | |
| download | lwn-f5ea9120be2e5d5c846243416cfdce01d02f5836.tar.gz lwn-f5ea9120be2e5d5c846243416cfdce01d02f5836.zip | |
nl80211: add generation number to all dumps
In order for userspace to be able to figure out whether
it obtained a consistent snapshot of data or not when
using netlink dumps, we need to have a generation number
in each dump message that indicates whether the list has
changed or not -- its value is arbitrary.
This patch adds such a number to all dumps, this needs
some mac80211 involvement to keep track of a generation
number to start with when adding/removing mesh paths or
stations.
The wiphy and netdev lists can be fully handled within
cfg80211, of course, but generation numbers need to be
stored there as well.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Diffstat (limited to 'include/linux/nl80211.h')
| -rw-r--r-- | include/linux/nl80211.h | 17 |
1 files changed, 12 insertions, 5 deletions
diff --git a/include/linux/nl80211.h b/include/linux/nl80211.h index cb3dc6027fd9..a8d71ed43a0e 100644 --- a/include/linux/nl80211.h +++ b/include/linux/nl80211.h @@ -480,10 +480,6 @@ enum nl80211_commands { * @NL80211_ATTR_SCAN_FREQUENCIES: nested attribute with frequencies (in MHz) * @NL80211_ATTR_SCAN_SSIDS: nested attribute with SSIDs, leave out for passive * scanning and include a zero-length SSID (wildcard) for wildcard scan - * @NL80211_ATTR_SCAN_GENERATION: the scan generation increases whenever the - * scan result list changes (BSS expired or added) so that applications - * can verify that they got a single, consistent snapshot (when all dump - * messages carried the same generation number) * @NL80211_ATTR_BSS: scan result BSS * * @NL80211_ATTR_REG_INITIATOR: indicates who requested the regulatory domain @@ -580,6 +576,14 @@ enum nl80211_commands { * * @NL80211_ATTR_PID: Process ID of a network namespace. * + * @NL80211_ATTR_GENERATION: Used to indicate consistent snapshots for + * dumps. This number increases whenever the object list being + * dumped changes, and as such userspace can verify that it has + * obtained a complete and consistent snapshot by verifying that + * all dump messages contain the same generation number. If it + * changed then the list changed and the dump should be repeated + * completely from scratch. + * * @NL80211_ATTR_MAX: highest attribute number currently defined * @__NL80211_ATTR_AFTER_LAST: internal use */ @@ -651,7 +655,7 @@ enum nl80211_attrs { NL80211_ATTR_SCAN_FREQUENCIES, NL80211_ATTR_SCAN_SSIDS, - NL80211_ATTR_SCAN_GENERATION, + NL80211_ATTR_GENERATION, /* replaces old SCAN_GENERATION */ NL80211_ATTR_BSS, NL80211_ATTR_REG_INITIATOR, @@ -716,6 +720,9 @@ enum nl80211_attrs { NL80211_ATTR_MAX = __NL80211_ATTR_AFTER_LAST - 1 }; +/* source-level API compatibility */ +#define NL80211_ATTR_SCAN_GENERATION NL80211_ATTR_GENERATION + /* * Allow user space programs to use #ifdef on new attributes by defining them * here |