2fd35d9857
Within wpas_connection_failed(), the 'count' value of wpa_blacklist is erroneously used as a tally of the number times the device has failed to associate to a given BSSID without making a successful connection. This is not accurate because there are a variety of ways a BSS can be added to the blacklist beyond failed association such as interference or deauthentication. This 'count' is lost whenever the blacklist is cleared, so the wpa_supplicant stores an additional value 'extra_blacklist_count' which helps persist the 'count' through clears. These count values are used to determine how long to wait to rescan after a failed connection attempt. While this logic was already slightly wrong, it would have been completely broken by the upcoming change which adds time-based blacklisting functionality. With the upcoming change, 'count' values are not cleared on association, and thus do not necessarily even approximate the "consecutive connection failures" which they were being used for. This change seeks to remove this unnecessary overloading of the blacklist 'count' by directly tracking consecutive connection failures within the wpa_supplicant struct, independent of the blacklist. This new 'consecutive_conn_failures' is iterated with every connection failure and cleared when any successful connection is made. This change also removes the now unused 'extra_blacklist_count' value. Signed-off-by: Kevin Lund <kglund@google.com> Signed-off-by: Brian Norris <briannorris@chromium.org>
136 lines
3.3 KiB
C
136 lines
3.3 KiB
C
/*
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* wpa_supplicant - Temporary BSSID blacklist
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* Copyright (c) 2003-2007, Jouni Malinen <j@w1.fi>
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*
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* This software may be distributed under the terms of the BSD license.
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* See README for more details.
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*/
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#include "includes.h"
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#include "common.h"
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#include "wpa_supplicant_i.h"
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#include "blacklist.h"
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/**
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* wpa_blacklist_get - Get the blacklist entry for a BSSID
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* @wpa_s: Pointer to wpa_supplicant data
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* @bssid: BSSID
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* Returns: Matching blacklist entry for the BSSID or %NULL if not found
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*/
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struct wpa_blacklist * wpa_blacklist_get(struct wpa_supplicant *wpa_s,
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const u8 *bssid)
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{
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struct wpa_blacklist *e;
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if (wpa_s == NULL || bssid == NULL)
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return NULL;
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e = wpa_s->blacklist;
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while (e) {
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if (os_memcmp(e->bssid, bssid, ETH_ALEN) == 0)
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return e;
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e = e->next;
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}
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return NULL;
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}
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/**
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* wpa_blacklist_add - Add an BSSID to the blacklist
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* @wpa_s: Pointer to wpa_supplicant data
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* @bssid: BSSID to be added to the blacklist
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* Returns: Current blacklist count on success, -1 on failure
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*
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* This function adds the specified BSSID to the blacklist or increases the
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* blacklist count if the BSSID was already listed. It should be called when
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* an association attempt fails either due to the selected BSS rejecting
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* association or due to timeout.
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*
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* This blacklist is used to force %wpa_supplicant to go through all available
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* BSSes before retrying to associate with an BSS that rejected or timed out
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* association. It does not prevent the listed BSS from being used; it only
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* changes the order in which they are tried.
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*/
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int wpa_blacklist_add(struct wpa_supplicant *wpa_s, const u8 *bssid)
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{
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struct wpa_blacklist *e;
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if (wpa_s == NULL || bssid == NULL)
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return -1;
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e = wpa_blacklist_get(wpa_s, bssid);
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if (e) {
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e->count++;
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wpa_printf(MSG_DEBUG, "BSSID " MACSTR " blacklist count "
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"incremented to %d",
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MAC2STR(bssid), e->count);
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return e->count;
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}
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e = os_zalloc(sizeof(*e));
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if (e == NULL)
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return -1;
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os_memcpy(e->bssid, bssid, ETH_ALEN);
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e->count = 1;
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e->next = wpa_s->blacklist;
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wpa_s->blacklist = e;
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wpa_printf(MSG_DEBUG, "Added BSSID " MACSTR " into blacklist",
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MAC2STR(bssid));
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return e->count;
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}
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/**
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* wpa_blacklist_del - Remove an BSSID from the blacklist
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* @wpa_s: Pointer to wpa_supplicant data
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* @bssid: BSSID to be removed from the blacklist
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* Returns: 0 on success, -1 on failure
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*/
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int wpa_blacklist_del(struct wpa_supplicant *wpa_s, const u8 *bssid)
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{
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struct wpa_blacklist *e, *prev = NULL;
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if (wpa_s == NULL || bssid == NULL)
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return -1;
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e = wpa_s->blacklist;
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while (e) {
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if (os_memcmp(e->bssid, bssid, ETH_ALEN) == 0) {
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if (prev == NULL) {
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wpa_s->blacklist = e->next;
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} else {
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prev->next = e->next;
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}
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wpa_printf(MSG_DEBUG, "Removed BSSID " MACSTR " from "
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"blacklist", MAC2STR(bssid));
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os_free(e);
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return 0;
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}
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prev = e;
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e = e->next;
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}
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return -1;
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}
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/**
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* wpa_blacklist_clear - Clear the blacklist of all entries
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* @wpa_s: Pointer to wpa_supplicant data
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*/
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void wpa_blacklist_clear(struct wpa_supplicant *wpa_s)
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{
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struct wpa_blacklist *e, *prev;
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e = wpa_s->blacklist;
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wpa_s->blacklist = NULL;
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while (e) {
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prev = e;
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e = e->next;
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wpa_printf(MSG_DEBUG, "Removed BSSID " MACSTR " from "
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"blacklist (clear)", MAC2STR(prev->bssid));
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os_free(prev);
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}
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}
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