1/*
2 * wpa_supplicant - Temporary BSSID blacklist
3 * Copyright (c) 2003-2007, Jouni Malinen <j@w1.fi>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
8 *
9 * Alternatively, this software may be distributed under the terms of BSD
10 * license.
11 *
12 * See README and COPYING for more details.
13 */
14
15#include "includes.h"
16
17#include "common.h"
18#include "wpa_supplicant_i.h"
19#include "blacklist.h"
20
21/**
22 * wpa_blacklist_get - Get the blacklist entry for a BSSID
23 * @wpa_s: Pointer to wpa_supplicant data
24 * @bssid: BSSID
25 * Returns: Matching blacklist entry for the BSSID or %NULL if not found
26 */
27struct wpa_blacklist * wpa_blacklist_get(struct wpa_supplicant *wpa_s,
28					 const u8 *bssid)
29{
30	struct wpa_blacklist *e;
31
32	e = wpa_s->blacklist;
33	while (e) {
34		if (os_memcmp(e->bssid, bssid, ETH_ALEN) == 0)
35			return e;
36		e = e->next;
37	}
38
39	return NULL;
40}
41
42
43/**
44 * wpa_blacklist_add - Add an BSSID to the blacklist
45 * @wpa_s: Pointer to wpa_supplicant data
46 * @bssid: BSSID to be added to the blacklist
47 * Returns: 0 on success, -1 on failure
48 *
49 * This function adds the specified BSSID to the blacklist or increases the
50 * blacklist count if the BSSID was already listed. It should be called when
51 * an association attempt fails either due to the selected BSS rejecting
52 * association or due to timeout.
53 *
54 * This blacklist is used to force %wpa_supplicant to go through all available
55 * BSSes before retrying to associate with an BSS that rejected or timed out
56 * association. It does not prevent the listed BSS from being used; it only
57 * changes the order in which they are tried.
58 */
59int wpa_blacklist_add(struct wpa_supplicant *wpa_s, const u8 *bssid)
60{
61	struct wpa_blacklist *e;
62
63	e = wpa_blacklist_get(wpa_s, bssid);
64	if (e) {
65		e->count++;
66		wpa_printf(MSG_DEBUG, "BSSID " MACSTR " blacklist count "
67			   "incremented to %d",
68			   MAC2STR(bssid), e->count);
69		return 0;
70	}
71
72	e = os_zalloc(sizeof(*e));
73	if (e == NULL)
74		return -1;
75	os_memcpy(e->bssid, bssid, ETH_ALEN);
76	e->count = 1;
77	e->next = wpa_s->blacklist;
78	wpa_s->blacklist = e;
79	wpa_printf(MSG_DEBUG, "Added BSSID " MACSTR " into blacklist",
80		   MAC2STR(bssid));
81
82	return 0;
83}
84
85
86/**
87 * wpa_blacklist_del - Remove an BSSID from the blacklist
88 * @wpa_s: Pointer to wpa_supplicant data
89 * @bssid: BSSID to be removed from the blacklist
90 * Returns: 0 on success, -1 on failure
91 */
92int wpa_blacklist_del(struct wpa_supplicant *wpa_s, const u8 *bssid)
93{
94	struct wpa_blacklist *e, *prev = NULL;
95
96	e = wpa_s->blacklist;
97	while (e) {
98		if (os_memcmp(e->bssid, bssid, ETH_ALEN) == 0) {
99			if (prev == NULL) {
100				wpa_s->blacklist = e->next;
101			} else {
102				prev->next = e->next;
103			}
104			wpa_printf(MSG_DEBUG, "Removed BSSID " MACSTR " from "
105				   "blacklist", MAC2STR(bssid));
106			os_free(e);
107			return 0;
108		}
109		prev = e;
110		e = e->next;
111	}
112	return -1;
113}
114
115
116/**
117 * wpa_blacklist_clear - Clear the blacklist of all entries
118 * @wpa_s: Pointer to wpa_supplicant data
119 */
120void wpa_blacklist_clear(struct wpa_supplicant *wpa_s)
121{
122	struct wpa_blacklist *e, *prev;
123
124	e = wpa_s->blacklist;
125	wpa_s->blacklist = NULL;
126	while (e) {
127		prev = e;
128		e = e->next;
129		wpa_printf(MSG_DEBUG, "Removed BSSID " MACSTR " from "
130			   "blacklist (clear)", MAC2STR(prev->bssid));
131		os_free(prev);
132	}
133}
134