hostapd/src/ap/taxonomy.c
Johannes Berg 30eddf3529 Fix or supress various sparse warnings
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2017-01-29 18:33:10 +02:00

292 lines
7.4 KiB
C

/*
* hostapd / Client taxonomy
* Copyright (c) 2015 Google, Inc.
*
* This software may be distributed under the terms of the BSD license.
* See README for more details.
*
* Parse a series of IEs, as in Probe Request or (Re)Association Request frames,
* and render them to a descriptive string. The tag number of standard options
* is written to the string, while the vendor ID and subtag are written for
* vendor options.
*
* Example strings:
* 0,1,50,45,221(00904c,51)
* 0,1,33,36,48,45,221(00904c,51),221(0050f2,2)
*/
#include "utils/includes.h"
#include "utils/common.h"
#include "common/wpa_ctrl.h"
#include "hostapd.h"
#include "sta_info.h"
#include "taxonomy.h"
/* Copy a string with no funny schtuff allowed; only alphanumerics. */
static void no_mischief_strncpy(char *dst, const char *src, size_t n)
{
size_t i;
for (i = 0; i < n; i++) {
unsigned char s = src[i];
int is_lower = s >= 'a' && s <= 'z';
int is_upper = s >= 'A' && s <= 'Z';
int is_digit = s >= '0' && s <= '9';
if (is_lower || is_upper || is_digit) {
/* TODO: if any manufacturer uses Unicode within the
* WPS header, it will get mangled here. */
dst[i] = s;
} else {
/* Note that even spaces will be transformed to
* underscores, so 'Nexus 7' will turn into 'Nexus_7'.
* This is deliberate, to make the string easier to
* parse. */
dst[i] = '_';
}
}
}
static int get_wps_name(char *name, size_t name_len,
const u8 *data, size_t data_len)
{
/* Inside the WPS IE are a series of attributes, using two byte IDs
* and two byte lengths. We're looking for the model name, if
* present. */
while (data_len >= 4) {
u16 id, elen;
id = WPA_GET_BE16(data);
elen = WPA_GET_BE16(data + 2);
data += 4;
data_len -= 4;
if (elen > data_len)
return 0;
if (id == 0x1023) {
/* Model name, like 'Nexus 7' */
size_t n = (elen < name_len) ? elen : name_len;
no_mischief_strncpy(name, (const char *) data, n);
return n;
}
data += elen;
data_len -= elen;
}
return 0;
}
static void ie_to_string(char *fstr, size_t fstr_len, const struct wpabuf *ies)
{
char *fpos = fstr;
char *fend = fstr + fstr_len;
char htcap[7 + 4 + 1]; /* ",htcap:" + %04hx + trailing NUL */
char htagg[7 + 2 + 1]; /* ",htagg:" + %02hx + trailing NUL */
char htmcs[7 + 8 + 1]; /* ",htmcs:" + %08x + trailing NUL */
char vhtcap[8 + 8 + 1]; /* ",vhtcap:" + %08x + trailing NUL */
char vhtrxmcs[10 + 8 + 1]; /* ",vhtrxmcs:" + %08x + trailing NUL */
char vhttxmcs[10 + 8 + 1]; /* ",vhttxmcs:" + %08x + trailing NUL */
#define MAX_EXTCAP 254
char extcap[8 + 2 * MAX_EXTCAP + 1]; /* ",extcap:" + hex + trailing NUL
*/
char txpow[7 + 4 + 1]; /* ",txpow:" + %04hx + trailing NUL */
#define WPS_NAME_LEN 32
char wps[WPS_NAME_LEN + 5 + 1]; /* room to prepend ",wps:" + trailing
* NUL */
int num = 0;
const u8 *ie;
size_t ie_len;
int ret;
os_memset(htcap, 0, sizeof(htcap));
os_memset(htagg, 0, sizeof(htagg));
os_memset(htmcs, 0, sizeof(htmcs));
os_memset(vhtcap, 0, sizeof(vhtcap));
os_memset(vhtrxmcs, 0, sizeof(vhtrxmcs));
os_memset(vhttxmcs, 0, sizeof(vhttxmcs));
os_memset(extcap, 0, sizeof(extcap));
os_memset(txpow, 0, sizeof(txpow));
os_memset(wps, 0, sizeof(wps));
*fpos = '\0';
if (!ies)
return;
ie = wpabuf_head(ies);
ie_len = wpabuf_len(ies);
while (ie_len >= 2) {
u8 id, elen;
char *sep = (num++ == 0) ? "" : ",";
id = *ie++;
elen = *ie++;
ie_len -= 2;
if (elen > ie_len)
break;
if (id == WLAN_EID_VENDOR_SPECIFIC && elen >= 4) {
/* Vendor specific */
if (WPA_GET_BE32(ie) == WPS_IE_VENDOR_TYPE) {
/* WPS */
char model_name[WPS_NAME_LEN + 1];
const u8 *data = &ie[4];
size_t data_len = elen - 4;
os_memset(model_name, 0, sizeof(model_name));
if (get_wps_name(model_name, WPS_NAME_LEN, data,
data_len)) {
os_snprintf(wps, sizeof(wps),
",wps:%s", model_name);
}
}
ret = os_snprintf(fpos, fend - fpos,
"%s%d(%02x%02x%02x,%d)",
sep, id, ie[0], ie[1], ie[2], ie[3]);
} else {
if (id == WLAN_EID_HT_CAP && elen >= 2) {
/* HT Capabilities (802.11n) */
os_snprintf(htcap, sizeof(htcap),
",htcap:%04hx",
WPA_GET_LE16(ie));
}
if (id == WLAN_EID_HT_CAP && elen >= 3) {
/* HT Capabilities (802.11n), A-MPDU information
*/
os_snprintf(htagg, sizeof(htagg),
",htagg:%02hx", (u16) ie[2]);
}
if (id == WLAN_EID_HT_CAP && elen >= 7) {
/* HT Capabilities (802.11n), MCS information */
os_snprintf(htmcs, sizeof(htmcs),
",htmcs:%08hx",
(u16) WPA_GET_LE32(ie + 3));
}
if (id == WLAN_EID_VHT_CAP && elen >= 4) {
/* VHT Capabilities (802.11ac) */
os_snprintf(vhtcap, sizeof(vhtcap),
",vhtcap:%08x",
WPA_GET_LE32(ie));
}
if (id == WLAN_EID_VHT_CAP && elen >= 8) {
/* VHT Capabilities (802.11ac), RX MCS
* information */
os_snprintf(vhtrxmcs, sizeof(vhtrxmcs),
",vhtrxmcs:%08x",
WPA_GET_LE32(ie + 4));
}
if (id == WLAN_EID_VHT_CAP && elen >= 12) {
/* VHT Capabilities (802.11ac), TX MCS
* information */
os_snprintf(vhttxmcs, sizeof(vhttxmcs),
",vhttxmcs:%08x",
WPA_GET_LE32(ie + 8));
}
if (id == WLAN_EID_EXT_CAPAB) {
/* Extended Capabilities */
int i;
int len = (elen < MAX_EXTCAP) ? elen :
MAX_EXTCAP;
char *p = extcap;
p += os_snprintf(extcap, sizeof(extcap),
",extcap:");
for (i = 0; i < len; i++) {
int lim;
lim = sizeof(extcap) -
os_strlen(extcap);
if (lim <= 0)
break;
p += os_snprintf(p, lim, "%02x",
*(ie + i));
}
}
if (id == WLAN_EID_PWR_CAPABILITY && elen == 2) {
/* TX Power */
os_snprintf(txpow, sizeof(txpow),
",txpow:%04hx",
WPA_GET_LE16(ie));
}
ret = os_snprintf(fpos, fend - fpos, "%s%d", sep, id);
}
if (os_snprintf_error(fend - fpos, ret))
goto fail;
fpos += ret;
ie += elen;
ie_len -= elen;
}
ret = os_snprintf(fpos, fend - fpos, "%s%s%s%s%s%s%s%s%s",
htcap, htagg, htmcs, vhtcap, vhtrxmcs, vhttxmcs,
txpow, extcap, wps);
if (os_snprintf_error(fend - fpos, ret)) {
fail:
fstr[0] = '\0';
}
}
int retrieve_sta_taxonomy(const struct hostapd_data *hapd,
struct sta_info *sta, char *buf, size_t buflen)
{
int ret;
char *pos, *end;
if (!sta->probe_ie_taxonomy || !sta->assoc_ie_taxonomy)
return 0;
ret = os_snprintf(buf, buflen, "wifi4|probe:");
if (os_snprintf_error(buflen, ret))
return 0;
pos = buf + ret;
end = buf + buflen;
ie_to_string(pos, end - pos, sta->probe_ie_taxonomy);
pos = os_strchr(pos, '\0');
if (pos >= end)
return 0;
ret = os_snprintf(pos, end - pos, "|assoc:");
if (os_snprintf_error(end - pos, ret))
return 0;
pos += ret;
ie_to_string(pos, end - pos, sta->assoc_ie_taxonomy);
pos = os_strchr(pos, '\0');
return pos - buf;
}
void taxonomy_sta_info_probe_req(const struct hostapd_data *hapd,
struct sta_info *sta,
const u8 *ie, size_t ie_len)
{
wpabuf_free(sta->probe_ie_taxonomy);
sta->probe_ie_taxonomy = wpabuf_alloc_copy(ie, ie_len);
}
void taxonomy_hostapd_sta_info_probe_req(const struct hostapd_data *hapd,
struct hostapd_sta_info *info,
const u8 *ie, size_t ie_len)
{
wpabuf_free(info->probe_ie_taxonomy);
info->probe_ie_taxonomy = wpabuf_alloc_copy(ie, ie_len);
}
void taxonomy_sta_info_assoc_req(const struct hostapd_data *hapd,
struct sta_info *sta,
const u8 *ie, size_t ie_len)
{
wpabuf_free(sta->assoc_ie_taxonomy);
sta->assoc_ie_taxonomy = wpabuf_alloc_copy(ie, ie_len);
}