wpa_supplicant/blacklist.c

   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  */
  27 struct 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  */
  59 int 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  */
  92 int 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  */
 120 void 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 }