1/*
2 * wpa_supplicant - Temporary BSSID blacklist
3 * Copyright (c) 2003-2007, Jouni Malinen <j@w1.fi>
4 *
5 * This software may be distributed under the terms of the BSD license.
6 * See README for more details.
7 */
8
9#include "includes.h"
10
11#include "common.h"
12#include "wpa_supplicant_i.h"
13#include "blacklist.h"
14
15/**
16 * wpa_blacklist_get - Get the blacklist entry for a BSSID
17 * @wpa_s: Pointer to wpa_supplicant data
18 * @bssid: BSSID
19 * Returns: Matching blacklist entry for the BSSID or %NULL if not found
20 */
21struct wpa_blacklist * wpa_blacklist_get(struct wpa_supplicant *wpa_s,
22					 const u8 *bssid)
23{
24	struct wpa_blacklist *e;
25
26	if (wpa_s == NULL || bssid == NULL)
27		return NULL;
28
29	e = wpa_s->blacklist;
30	while (e) {
31		if (os_memcmp(e->bssid, bssid, ETH_ALEN) == 0)
32			return e;
33		e = e->next;
34	}
35
36	return NULL;
37}
38
39
40/**
41 * wpa_blacklist_add - Add an BSSID to the blacklist
42 * @wpa_s: Pointer to wpa_supplicant data
43 * @bssid: BSSID to be added to the blacklist
44 * Returns: Current blacklist count on success, -1 on failure
45 *
46 * This function adds the specified BSSID to the blacklist or increases the
47 * blacklist count if the BSSID was already listed. It should be called when
48 * an association attempt fails either due to the selected BSS rejecting
49 * association or due to timeout.
50 *
51 * This blacklist is used to force %wpa_supplicant to go through all available
52 * BSSes before retrying to associate with an BSS that rejected or timed out
53 * association. It does not prevent the listed BSS from being used; it only
54 * changes the order in which they are tried.
55 */
56int wpa_blacklist_add(struct wpa_supplicant *wpa_s, const u8 *bssid)
57{
58	struct wpa_blacklist *e;
59
60	if (wpa_s == NULL || bssid == NULL)
61		return -1;
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 e->count;
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 e->count;
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	if (wpa_s == NULL || bssid == NULL)
97		return -1;
98
99	e = wpa_s->blacklist;
100	while (e) {
101		if (os_memcmp(e->bssid, bssid, ETH_ALEN) == 0) {
102			if (prev == NULL) {
103				wpa_s->blacklist = e->next;
104			} else {
105				prev->next = e->next;
106			}
107			wpa_printf(MSG_DEBUG, "Removed BSSID " MACSTR " from "
108				   "blacklist", MAC2STR(bssid));
109			os_free(e);
110			return 0;
111		}
112		prev = e;
113		e = e->next;
114	}
115	return -1;
116}
117
118
119/**
120 * wpa_blacklist_clear - Clear the blacklist of all entries
121 * @wpa_s: Pointer to wpa_supplicant data
122 */
123void wpa_blacklist_clear(struct wpa_supplicant *wpa_s)
124{
125	struct wpa_blacklist *e, *prev;
126	int max_count = 0;
127
128	e = wpa_s->blacklist;
129	wpa_s->blacklist = NULL;
130	while (e) {
131		if (e->count > max_count)
132			max_count = e->count;
133		prev = e;
134		e = e->next;
135		wpa_printf(MSG_DEBUG, "Removed BSSID " MACSTR " from "
136			   "blacklist (clear)", MAC2STR(prev->bssid));
137		os_free(prev);
138	}
139
140	wpa_s->extra_blacklist_count += max_count;
141}
142