Add address masks to BSSID lists

In many applications it is useful not just to enumerate a group of well
known access points, but to use a address/mask notation to match an
entire set of addresses (ca:ff:ee:00:00:00/ff:ff:ff:00:00:00).

This change expands the data structures used by MAC lists to include a
mask indicating the significant (non-masked) portions of an address and
extends the list parser to recognize mask suffixes.

Signed-off-by: Stefan Tomanek <stefan.tomanek@wertarbyte.de>
This commit is contained in:
Stefan Tomanek 2015-01-05 21:10:16 +01:00 committed by Jouni Malinen
parent b83e455451
commit 79cd993a62
6 changed files with 145 additions and 48 deletions

View file

@ -36,6 +36,25 @@ int hex2byte(const char *hex)
}
static const char * hwaddr_parse(const char *txt, u8 *addr)
{
size_t i;
for (i = 0; i < ETH_ALEN; i++) {
int a;
a = hex2byte(txt);
if (a < 0)
return NULL;
txt += 2;
addr[i] = a;
if (i < ETH_ALEN - 1 && *txt++ != ':')
return NULL;
}
return txt;
}
/**
* hwaddr_aton - Convert ASCII string to MAC address (colon-delimited format)
* @txt: MAC address as a string (e.g., "00:11:22:33:44:55")
@ -44,25 +63,46 @@ int hex2byte(const char *hex)
*/
int hwaddr_aton(const char *txt, u8 *addr)
{
int i;
return hwaddr_parse(txt, addr) ? 0 : -1;
}
for (i = 0; i < 6; i++) {
int a, b;
a = hex2num(*txt++);
if (a < 0)
/**
* hwaddr_masked_aton - Convert ASCII string with optional mask to MAC address (colon-delimited format)
* @txt: MAC address with optional mask as a string (e.g., "00:11:22:33:44:55/ff:ff:ff:ff:00:00")
* @addr: Buffer for the MAC address (ETH_ALEN = 6 bytes)
* @mask: Buffer for the MAC address mask (ETH_ALEN = 6 bytes)
* @maskable: Flag to indicate whether a mask is allowed
* Returns: 0 on success, -1 on failure (e.g., string not a MAC address)
*/
int hwaddr_masked_aton(const char *txt, u8 *addr, u8 *mask, u8 maskable)
{
const char *r;
/* parse address part */
r = hwaddr_parse(txt, addr);
if (!r)
return -1;
b = hex2num(*txt++);
if (b < 0)
/* check for optional mask */
if (*r == '\0' || isspace(*r)) {
/* no mask specified, assume default */
os_memset(mask, 0xff, ETH_ALEN);
} else if (maskable && *r == '/') {
/* mask specified and allowed */
r = hwaddr_parse(r + 1, mask);
/* parser error? */
if (!r)
return -1;
*addr++ = (a << 4) | b;
if (i < 5 && *txt++ != ':')
} else {
/* mask specified but not allowed or trailing garbage */
return -1;
}
return 0;
}
/**
* hwaddr_compact_aton - Convert ASCII string to MAC address (no colon delimitors format)
* @txt: MAC address as a string (e.g., "001122334455")
@ -144,6 +184,30 @@ int hexstr2bin(const char *hex, u8 *buf, size_t len)
}
int hwaddr_mask_txt(char *buf, size_t len, const u8 *addr, const u8 *mask)
{
size_t i;
int print_mask = 0;
int res;
for (i = 0; i < ETH_ALEN; i++) {
if (mask[i] != 0xff) {
print_mask = 1;
break;
}
}
if (print_mask)
res = os_snprintf(buf, len, MACSTR "/" MACSTR,
MAC2STR(addr), MAC2STR(mask));
else
res = os_snprintf(buf, len, MACSTR, MAC2STR(addr));
if (os_snprintf_error(len, res))
return -1;
return res;
}
/**
* inc_byte_array - Increment arbitrary length byte array by one
* @counter: Pointer to byte array

View file

@ -471,6 +471,7 @@ typedef u64 __bitwise le64;
#endif /* __must_check */
int hwaddr_aton(const char *txt, u8 *addr);
int hwaddr_masked_aton(const char *txt, u8 *addr, u8 *mask, u8 maskable);
int hwaddr_compact_aton(const char *txt, u8 *addr);
int hwaddr_aton2(const char *txt, u8 *addr);
int hex2byte(const char *hex);
@ -482,6 +483,8 @@ int wpa_snprintf_hex(char *buf, size_t buf_size, const u8 *data, size_t len);
int wpa_snprintf_hex_uppercase(char *buf, size_t buf_size, const u8 *data,
size_t len);
int hwaddr_mask_txt(char *buf, size_t len, const u8 *addr, const u8 *mask);
#ifdef CONFIG_NATIVE_WINDOWS
void wpa_unicode2ascii_inplace(TCHAR *str);
TCHAR * wpa_strdup_tchar(const char *str);

View file

@ -238,10 +238,10 @@ static char * wpa_config_write_int(const struct parse_data *data,
static int wpa_config_parse_addr_list(const struct parse_data *data,
int line, const char *value,
u8 **list, size_t *num, char *name,
u8 abort_on_error)
u8 abort_on_error, u8 masked)
{
const char *pos;
u8 *buf, *n, addr[ETH_ALEN];
u8 *buf, *n, addr[2 * ETH_ALEN];
size_t count;
buf = NULL;
@ -252,7 +252,7 @@ static int wpa_config_parse_addr_list(const struct parse_data *data,
while (*pos == ' ')
pos++;
if (hwaddr_aton(pos, addr)) {
if (hwaddr_masked_aton(pos, addr, &addr[ETH_ALEN], masked)) {
if (abort_on_error || count == 0) {
wpa_printf(MSG_ERROR,
"Line %d: Invalid %s address '%s'",
@ -266,16 +266,20 @@ static int wpa_config_parse_addr_list(const struct parse_data *data,
"Line %d: Ignore likely truncated %s address '%s'",
line, name, pos);
} else {
n = os_realloc_array(buf, count + 1, ETH_ALEN);
n = os_realloc_array(buf, count + 1, 2 * ETH_ALEN);
if (n == NULL) {
os_free(buf);
return -1;
}
buf = n;
os_memmove(buf + ETH_ALEN, buf, count * ETH_ALEN);
os_memcpy(buf, addr, ETH_ALEN);
os_memmove(buf + 2 * ETH_ALEN, buf,
count * 2 * ETH_ALEN);
os_memcpy(buf, addr, 2 * ETH_ALEN);
count++;
wpa_hexdump(MSG_MSGDUMP, name, addr, ETH_ALEN);
wpa_printf(MSG_MSGDUMP,
"%s: addr=" MACSTR " mask=" MACSTR,
name, MAC2STR(addr),
MAC2STR(&addr[ETH_ALEN]));
}
pos = os_strchr(pos, ' ');
@ -300,25 +304,26 @@ static char * wpa_config_write_addr_list(const struct parse_data *data,
if (list == NULL || num == 0)
return NULL;
value = os_malloc(20 * num);
value = os_malloc(2 * 20 * num);
if (value == NULL)
return NULL;
pos = value;
end = value + 20 * num;
end = value + 2 * 20 * num;
for (i = num; i > 0; i--) {
res = os_snprintf(pos, end - pos, MACSTR " ",
MAC2STR(list + (i - 1) * ETH_ALEN));
if (os_snprintf_error(end - pos, res)) {
const u8 *a = list + (i - 1) * 2 * ETH_ALEN;
const u8 *m = a + ETH_ALEN;
if (i < num)
*pos++ = ' ';
res = hwaddr_mask_txt(pos, end - pos, a, m);
if (res < 0) {
os_free(value);
return NULL;
}
pos += res;
}
if (pos > value)
pos[-1] = '\0';
return value;
}
#endif /* NO_CONFIG_WRITE */
@ -375,7 +380,7 @@ static int wpa_config_parse_bssid_blacklist(const struct parse_data *data,
return wpa_config_parse_addr_list(data, line, value,
&ssid->bssid_blacklist,
&ssid->num_bssid_blacklist,
"bssid_blacklist", 1);
"bssid_blacklist", 1, 1);
}
@ -397,7 +402,7 @@ static int wpa_config_parse_bssid_whitelist(const struct parse_data *data,
return wpa_config_parse_addr_list(data, line, value,
&ssid->bssid_whitelist,
&ssid->num_bssid_whitelist,
"bssid_whitelist", 1);
"bssid_whitelist", 1, 1);
}
@ -1588,7 +1593,7 @@ static int wpa_config_parse_p2p_client_list(const struct parse_data *data,
return wpa_config_parse_addr_list(data, line, value,
&ssid->p2p_client_list,
&ssid->num_p2p_clients,
"p2p_client_list", 0);
"p2p_client_list", 0, 0);
}
@ -2101,6 +2106,8 @@ void wpa_config_free_ssid(struct wpa_ssid *ssid)
os_free(ssid->freq_list);
os_free(ssid->bgscan);
os_free(ssid->p2p_client_list);
os_free(ssid->bssid_blacklist);
os_free(ssid->bssid_whitelist);
#ifdef CONFIG_HT_OVERRIDES
os_free(ssid->ht_mcs);
#endif /* CONFIG_HT_OVERRIDES */

View file

@ -698,14 +698,27 @@ static int bss_is_ess(struct wpa_bss *bss)
}
static int match_mac_mask(const u8 *addr_a, const u8 *addr_b, const u8 *mask)
{
size_t i;
for (i = 0; i < ETH_ALEN; i++) {
if ((addr_a[i] & mask[i]) != (addr_b[i] & mask[i]))
return 0;
}
return 1;
}
static int addr_in_list(const u8 *addr, const u8 *list, size_t num)
{
size_t i;
for (i = 0; i < num; i++) {
const u8 *a = list + (i * ETH_ALEN);
const u8 *a = list + i * ETH_ALEN * 2;
const u8 *m = a + ETH_ALEN;
if (os_memcmp(a, addr, ETH_ALEN) == 0)
if (match_mac_mask(a, addr, m))
return 1;
}
return 0;

View file

@ -837,7 +837,7 @@ static void wpas_p2p_add_persistent_group_client(struct wpa_supplicant *wpa_s,
return;
for (i = 0; s->p2p_client_list && i < s->num_p2p_clients; i++) {
if (os_memcmp(s->p2p_client_list + i * ETH_ALEN, addr,
if (os_memcmp(s->p2p_client_list + i * 2 * ETH_ALEN, addr,
ETH_ALEN) != 0)
continue;
@ -845,32 +845,42 @@ static void wpas_p2p_add_persistent_group_client(struct wpa_supplicant *wpa_s,
return; /* already the most recent entry */
/* move the entry to mark it most recent */
os_memmove(s->p2p_client_list + i * ETH_ALEN,
s->p2p_client_list + (i + 1) * ETH_ALEN,
(s->num_p2p_clients - i - 1) * ETH_ALEN);
os_memmove(s->p2p_client_list + i * 2 * ETH_ALEN,
s->p2p_client_list + (i + 1) * 2 * ETH_ALEN,
(s->num_p2p_clients - i - 1) * 2 * ETH_ALEN);
os_memcpy(s->p2p_client_list +
(s->num_p2p_clients - 1) * ETH_ALEN, addr, ETH_ALEN);
(s->num_p2p_clients - 1) * 2 * ETH_ALEN, addr,
ETH_ALEN);
os_memset(s->p2p_client_list +
(s->num_p2p_clients - 1) * 2 * ETH_ALEN + ETH_ALEN,
0xff, ETH_ALEN);
found = 1;
break;
}
if (!found && s->num_p2p_clients < P2P_MAX_STORED_CLIENTS) {
n = os_realloc_array(s->p2p_client_list,
s->num_p2p_clients + 1, ETH_ALEN);
s->num_p2p_clients + 1, 2 * ETH_ALEN);
if (n == NULL)
return;
os_memcpy(n + s->num_p2p_clients * ETH_ALEN, addr, ETH_ALEN);
os_memcpy(n + s->num_p2p_clients * 2 * ETH_ALEN, addr,
ETH_ALEN);
os_memset(n + s->num_p2p_clients * 2 * ETH_ALEN + ETH_ALEN,
0xff, ETH_ALEN);
s->p2p_client_list = n;
s->num_p2p_clients++;
} else if (!found && s->p2p_client_list) {
/* Not enough room for an additional entry - drop the oldest
* entry */
os_memmove(s->p2p_client_list,
s->p2p_client_list + ETH_ALEN,
(s->num_p2p_clients - 1) * ETH_ALEN);
s->p2p_client_list + 2 * ETH_ALEN,
(s->num_p2p_clients - 1) * 2 * ETH_ALEN);
os_memcpy(s->p2p_client_list +
(s->num_p2p_clients - 1) * ETH_ALEN,
(s->num_p2p_clients - 1) * 2 * ETH_ALEN,
addr, ETH_ALEN);
os_memset(s->p2p_client_list +
(s->num_p2p_clients - 1) * 2 * ETH_ALEN + ETH_ALEN,
0xff, ETH_ALEN);
}
if (wpa_s->parent->conf->update_config &&
@ -3348,7 +3358,7 @@ static void wpas_remove_persistent_peer(struct wpa_supplicant *wpa_s,
return;
for (i = 0; ssid->p2p_client_list && i < ssid->num_p2p_clients; i++) {
if (os_memcmp(ssid->p2p_client_list + i * ETH_ALEN, peer,
if (os_memcmp(ssid->p2p_client_list + i * 2 * ETH_ALEN, peer,
ETH_ALEN) == 0)
break;
}
@ -3368,9 +3378,9 @@ static void wpas_remove_persistent_peer(struct wpa_supplicant *wpa_s,
"group %d client list%s",
MAC2STR(peer), ssid->id,
inv ? " due to invitation result" : "");
os_memmove(ssid->p2p_client_list + i * ETH_ALEN,
ssid->p2p_client_list + (i + 1) * ETH_ALEN,
(ssid->num_p2p_clients - i - 1) * ETH_ALEN);
os_memmove(ssid->p2p_client_list + i * 2 * ETH_ALEN,
ssid->p2p_client_list + (i + 1) * 2 * ETH_ALEN,
(ssid->num_p2p_clients - i - 1) * 2 * ETH_ALEN);
ssid->num_p2p_clients--;
if (wpa_s->parent->conf->update_config &&
wpa_config_write(wpa_s->parent->confname, wpa_s->parent->conf))
@ -7047,7 +7057,7 @@ struct wpa_ssid * wpas_p2p_get_persistent(struct wpa_supplicant *wpa_s,
if (s->mode != WPAS_MODE_P2P_GO || s->p2p_client_list == NULL)
continue;
for (i = 0; i < s->num_p2p_clients; i++) {
if (os_memcmp(s->p2p_client_list + i * ETH_ALEN,
if (os_memcmp(s->p2p_client_list + i * 2 * ETH_ALEN,
addr, ETH_ALEN) == 0)
return s; /* peer is P2P client in persistent
* group */

View file

@ -1440,11 +1440,11 @@ network={
}
# Example configuration limiting AP selection to a specific set of APs;
# any other AP will be ignored for this network entry.
# any other AP not matching the masked address will be ignored.
network={
ssid="example"
psk="very secret passphrase"
bssid_whitelist=02:55:ae:bc:de:f0 02:88:77:66:55:44
bssid_whitelist=02:55:ae:bc:00:00/ff:ff:ff:ff:00:00 00:00:77:66:55:44/00:00:ff:ff:ff:ff
}
# Example config file that will only scan on channel 36.