wpa_supplicant/blacklist.c

   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  */
  21 struct 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  */
  56 int 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  */
  92 int 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  */
 123 void 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 }