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Commit f5ea9120 authored by Johannes Berg's avatar Johannes Berg Committed by John W. Linville
Browse files

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: default avatarJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent f401a6f7

include/linux/nl80211.h

+12 −5
Original line number Original line Diff line number Diff line
@@ -480,10 +480,6 @@ enum nl80211_commands { 
 * @NL80211_ATTR_SCAN_FREQUENCIES: nested attribute with frequencies (in MHz)

 * @NL80211_ATTR_SCAN_FREQUENCIES: nested attribute with frequencies (in MHz)

 * @NL80211_ATTR_SCAN_SSIDS: nested attribute with SSIDs, leave out for passive

 * @NL80211_ATTR_SCAN_SSIDS: nested attribute with SSIDs, leave out for passive

 *	scanning and include a zero-length SSID (wildcard) for wildcard scan

 *	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_BSS: scan result BSS

 *

 *

 * @NL80211_ATTR_REG_INITIATOR: indicates who requested the regulatory domain

 * @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_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_MAX: highest attribute number currently defined

 * @__NL80211_ATTR_AFTER_LAST: internal use

 * @__NL80211_ATTR_AFTER_LAST: internal use

 */

 */
@@ -651,7 +655,7 @@ enum nl80211_attrs { 




	NL80211_ATTR_SCAN_FREQUENCIES,

	NL80211_ATTR_SCAN_FREQUENCIES,

	NL80211_ATTR_SCAN_SSIDS,

	NL80211_ATTR_SCAN_SSIDS,

	NL80211_ATTR_SCAN_GENERATION,

	NL80211_ATTR_GENERATION, /* replaces old SCAN_GENERATION */

	NL80211_ATTR_BSS,

	NL80211_ATTR_BSS,





	NL80211_ATTR_REG_INITIATOR,

	NL80211_ATTR_REG_INITIATOR,
@@ -716,6 +720,9 @@ enum nl80211_attrs { 
	NL80211_ATTR_MAX = __NL80211_ATTR_AFTER_LAST - 1

	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

 * Allow user space programs to use #ifdef on new attributes by defining them

 * here

 * here

include/net/cfg80211.h

+12 −0
Original line number Original line Diff line number Diff line
@@ -372,6 +372,10 @@ struct rate_info { 
 * @txrate: current unicast bitrate to this station

 * @txrate: current unicast bitrate to this station

 * @rx_packets: packets received from this station

 * @rx_packets: packets received from this station

 * @tx_packets: packets transmitted to this station

 * @tx_packets: packets transmitted to this station

 * @generation: generation number for nl80211 dumps.

 *	This number should increase every time the list of stations

 *	changes, i.e. when a station is added or removed, so that

 *	userspace can tell whether it got a consistent snapshot.

 */

 */

struct station_info {

struct station_info {

	u32 filled;

	u32 filled;
@@ -385,6 +389,8 @@ struct station_info { 
	struct rate_info txrate;

	struct rate_info txrate;

	u32 rx_packets;

	u32 rx_packets;

	u32 tx_packets;

	u32 tx_packets;



	int generation;

};

};





/**

/**
@@ -444,6 +450,10 @@ enum mpath_info_flags { 
 * @flags: mesh path flags

 * @flags: mesh path flags

 * @discovery_timeout: total mesh path discovery timeout, in msecs

 * @discovery_timeout: total mesh path discovery timeout, in msecs

 * @discovery_retries: mesh path discovery retries

 * @discovery_retries: mesh path discovery retries

 * @generation: generation number for nl80211 dumps.

 *	This number should increase every time the list of mesh paths

 *	changes, i.e. when a station is added or removed, so that

 *	userspace can tell whether it got a consistent snapshot.

 */

 */

struct mpath_info {

struct mpath_info {

	u32 filled;

	u32 filled;
@@ -454,6 +464,8 @@ struct mpath_info { 
	u32 discovery_timeout;

	u32 discovery_timeout;

	u8 discovery_retries;

	u8 discovery_retries;

	u8 flags;

	u8 flags;



	int generation;

};

};





/**

/**

net/mac80211/cfg.c

+4 −0
Original line number Original line Diff line number Diff line
@@ -323,6 +323,8 @@ static void sta_set_sinfo(struct sta_info *sta, struct station_info *sinfo) 
{

{

	struct ieee80211_sub_if_data *sdata = sta->sdata;

	struct ieee80211_sub_if_data *sdata = sta->sdata;





	sinfo->generation = sdata->local->sta_generation;



	sinfo->filled = STATION_INFO_INACTIVE_TIME |

	sinfo->filled = STATION_INFO_INACTIVE_TIME |

			STATION_INFO_RX_BYTES |

			STATION_INFO_RX_BYTES |

			STATION_INFO_TX_BYTES |

			STATION_INFO_TX_BYTES |
@@ -909,6 +911,8 @@ static void mpath_set_pinfo(struct mesh_path *mpath, u8 *next_hop, 
	else

	else

		memset(next_hop, 0, ETH_ALEN);

		memset(next_hop, 0, ETH_ALEN);





	pinfo->generation = mesh_paths_generation;



	pinfo->filled = MPATH_INFO_FRAME_QLEN |

	pinfo->filled = MPATH_INFO_FRAME_QLEN |

			MPATH_INFO_DSN |

			MPATH_INFO_DSN |

			MPATH_INFO_METRIC |

			MPATH_INFO_METRIC |

net/mac80211/ieee80211_i.h

+1 −0
Original line number Original line Diff line number Diff line
@@ -678,6 +678,7 @@ struct ieee80211_local { 
	struct list_head sta_list;

	struct list_head sta_list;

	struct sta_info *sta_hash[STA_HASH_SIZE];

	struct sta_info *sta_hash[STA_HASH_SIZE];

	struct timer_list sta_cleanup;

	struct timer_list sta_cleanup;

	int sta_generation;





	struct sk_buff_head pending[IEEE80211_MAX_QUEUES];

	struct sk_buff_head pending[IEEE80211_MAX_QUEUES];

	struct tasklet_struct tx_pending_tasklet;

	struct tasklet_struct tx_pending_tasklet;

net/mac80211/mesh.h

+2 −0
Original line number Original line Diff line number Diff line
@@ -265,6 +265,8 @@ void mesh_path_discard_frame(struct sk_buff *skb, 
void mesh_path_quiesce(struct ieee80211_sub_if_data *sdata);

void mesh_path_quiesce(struct ieee80211_sub_if_data *sdata);

void mesh_path_restart(struct ieee80211_sub_if_data *sdata);

void mesh_path_restart(struct ieee80211_sub_if_data *sdata);





extern int mesh_paths_generation;



#ifdef CONFIG_MAC80211_MESH

#ifdef CONFIG_MAC80211_MESH

extern int mesh_allocated;

extern int mesh_allocated;