nl80211: Replace SIOCGIWSCAN with NL80211_CMD_GET_SCAN

This replaces the WEXT mechanism for fetching scan results with the new
nl80211 mechanism.
This commit is contained in:
Jouni Malinen 2009-02-12 17:12:58 +02:00 committed by Jouni Malinen
parent 0e75527f7e
commit b3db1e1cd3

View file

@ -1552,336 +1552,76 @@ nla_put_failure:
}
static u8 * wpa_driver_nl80211_giwscan(struct wpa_driver_nl80211_data *drv,
size_t *len)
{
struct iwreq iwr;
u8 *res_buf;
size_t res_buf_len;
res_buf_len = IW_SCAN_MAX_DATA;
for (;;) {
res_buf = os_malloc(res_buf_len);
if (res_buf == NULL)
return NULL;
os_memset(&iwr, 0, sizeof(iwr));
os_strlcpy(iwr.ifr_name, drv->ifname, IFNAMSIZ);
iwr.u.data.pointer = res_buf;
iwr.u.data.length = res_buf_len;
if (ioctl(drv->ioctl_sock, SIOCGIWSCAN, &iwr) == 0)
break;
if (errno == E2BIG && res_buf_len < 65535) {
os_free(res_buf);
res_buf = NULL;
res_buf_len *= 2;
if (res_buf_len > 65535)
res_buf_len = 65535; /* 16-bit length field */
wpa_printf(MSG_DEBUG, "Scan results did not fit - "
"trying larger buffer (%lu bytes)",
(unsigned long) res_buf_len);
} else {
perror("ioctl[SIOCGIWSCAN]");
os_free(res_buf);
return NULL;
}
}
if (iwr.u.data.length > res_buf_len) {
os_free(res_buf);
return NULL;
}
*len = iwr.u.data.length;
return res_buf;
}
/*
* Data structure for collecting WEXT scan results. This is needed to allow
* the various methods of reporting IEs to be combined into a single IE buffer.
*/
struct wext_scan_data {
struct wpa_scan_res res;
u8 *ie;
size_t ie_len;
u8 ssid[32];
size_t ssid_len;
int maxrate;
};
static void wext_get_scan_mode(struct iw_event *iwe,
struct wext_scan_data *res)
{
if (iwe->u.mode == IW_MODE_ADHOC)
res->res.caps |= IEEE80211_CAP_IBSS;
else if (iwe->u.mode == IW_MODE_MASTER || iwe->u.mode == IW_MODE_INFRA)
res->res.caps |= IEEE80211_CAP_ESS;
}
static void wext_get_scan_ssid(struct iw_event *iwe,
struct wext_scan_data *res, char *custom,
char *end)
{
int ssid_len = iwe->u.essid.length;
if (custom + ssid_len > end)
return;
if (iwe->u.essid.flags &&
ssid_len > 0 &&
ssid_len <= IW_ESSID_MAX_SIZE) {
os_memcpy(res->ssid, custom, ssid_len);
res->ssid_len = ssid_len;
}
}
static void wext_get_scan_freq(struct iw_event *iwe,
struct wext_scan_data *res)
{
int divi = 1000000, i;
if (iwe->u.freq.e == 0) {
/*
* Some drivers do not report frequency, but a channel.
* Try to map this to frequency by assuming they are using
* IEEE 802.11b/g. But don't overwrite a previously parsed
* frequency if the driver sends both frequency and channel,
* since the driver may be sending an A-band channel that we
* don't handle here.
*/
if (res->res.freq)
return;
if (iwe->u.freq.m >= 1 && iwe->u.freq.m <= 13) {
res->res.freq = 2407 + 5 * iwe->u.freq.m;
return;
} else if (iwe->u.freq.m == 14) {
res->res.freq = 2484;
return;
}
}
if (iwe->u.freq.e > 6) {
wpa_printf(MSG_DEBUG, "Invalid freq in scan results (BSSID="
MACSTR " m=%d e=%d)",
MAC2STR(res->res.bssid), iwe->u.freq.m,
iwe->u.freq.e);
return;
}
for (i = 0; i < iwe->u.freq.e; i++)
divi /= 10;
res->res.freq = iwe->u.freq.m / divi;
}
static void wext_get_scan_qual(struct iw_event *iwe,
struct wext_scan_data *res)
{
res->res.qual = iwe->u.qual.qual;
res->res.noise = iwe->u.qual.noise;
res->res.level = iwe->u.qual.level;
}
static void wext_get_scan_encode(struct iw_event *iwe,
struct wext_scan_data *res)
{
if (!(iwe->u.data.flags & IW_ENCODE_DISABLED))
res->res.caps |= IEEE80211_CAP_PRIVACY;
}
static void wext_get_scan_rate(struct iw_event *iwe,
struct wext_scan_data *res, char *pos,
char *end)
{
int maxrate;
char *custom = pos + IW_EV_LCP_LEN;
struct iw_param p;
size_t clen;
clen = iwe->len;
if (custom + clen > end)
return;
maxrate = 0;
while (((ssize_t) clen) >= (ssize_t) sizeof(struct iw_param)) {
/* Note: may be misaligned, make a local, aligned copy */
os_memcpy(&p, custom, sizeof(struct iw_param));
if (p.value > maxrate)
maxrate = p.value;
clen -= sizeof(struct iw_param);
custom += sizeof(struct iw_param);
}
/* Convert the maxrate from WE-style (b/s units) to
* 802.11 rates (500000 b/s units).
*/
res->maxrate = maxrate / 500000;
}
static void wext_get_scan_iwevgenie(struct iw_event *iwe,
struct wext_scan_data *res, char *custom,
char *end)
{
char *genie, *gpos, *gend;
u8 *tmp;
if (iwe->u.data.length == 0)
return;
gpos = genie = custom;
gend = genie + iwe->u.data.length;
if (gend > end) {
wpa_printf(MSG_INFO, "IWEVGENIE overflow");
return;
}
tmp = os_realloc(res->ie, res->ie_len + gend - gpos);
if (tmp == NULL)
return;
os_memcpy(tmp + res->ie_len, gpos, gend - gpos);
res->ie = tmp;
res->ie_len += gend - gpos;
}
static void wext_get_scan_custom(struct iw_event *iwe,
struct wext_scan_data *res, char *custom,
char *end)
{
size_t clen;
u8 *tmp;
clen = iwe->u.data.length;
if (custom + clen > end)
return;
if (clen > 7 && os_strncmp(custom, "wpa_ie=", 7) == 0) {
char *spos;
int bytes;
spos = custom + 7;
bytes = custom + clen - spos;
if (bytes & 1 || bytes == 0)
return;
bytes /= 2;
tmp = os_realloc(res->ie, res->ie_len + bytes);
if (tmp == NULL)
return;
hexstr2bin(spos, tmp + res->ie_len, bytes);
res->ie = tmp;
res->ie_len += bytes;
} else if (clen > 7 && os_strncmp(custom, "rsn_ie=", 7) == 0) {
char *spos;
int bytes;
spos = custom + 7;
bytes = custom + clen - spos;
if (bytes & 1 || bytes == 0)
return;
bytes /= 2;
tmp = os_realloc(res->ie, res->ie_len + bytes);
if (tmp == NULL)
return;
hexstr2bin(spos, tmp + res->ie_len, bytes);
res->ie = tmp;
res->ie_len += bytes;
} else if (clen > 4 && os_strncmp(custom, "tsf=", 4) == 0) {
char *spos;
int bytes;
u8 bin[8];
spos = custom + 4;
bytes = custom + clen - spos;
if (bytes != 16) {
wpa_printf(MSG_INFO, "Invalid TSF length (%d)", bytes);
return;
}
bytes /= 2;
hexstr2bin(spos, bin, bytes);
res->res.tsf += WPA_GET_BE64(bin);
}
}
static int wext_19_iw_point(struct wpa_driver_nl80211_data *drv, u16 cmd)
{
return drv->we_version_compiled > 18 &&
(cmd == SIOCGIWESSID || cmd == SIOCGIWENCODE ||
cmd == IWEVGENIE || cmd == IWEVCUSTOM);
}
static void wpa_driver_nl80211_add_scan_entry(struct wpa_scan_results *res,
struct wext_scan_data *data)
static int bss_info_handler(struct nl_msg *msg, void *arg)
{
struct nlattr *tb[NL80211_ATTR_MAX + 1];
struct genlmsghdr *gnlh = nlmsg_data(nlmsg_hdr(msg));
struct nlattr *bss[NL80211_BSS_MAX + 1];
static struct nla_policy bss_policy[NL80211_BSS_MAX + 1] = {
[NL80211_BSS_BSSID] = { .type = NLA_UNSPEC },
[NL80211_BSS_FREQUENCY] = { .type = NLA_U32 },
[NL80211_BSS_TSF] = { .type = NLA_U64 },
[NL80211_BSS_BEACON_INTERVAL] = { .type = NLA_U16 },
[NL80211_BSS_CAPABILITY] = { .type = NLA_U16 },
[NL80211_BSS_INFORMATION_ELEMENTS] = { .type = NLA_UNSPEC },
[NL80211_BSS_SIGNAL_MBM] = { .type = NLA_U32 },
[NL80211_BSS_SIGNAL_UNSPEC] = { .type = NLA_U8 },
};
struct wpa_scan_results *res = arg;
struct wpa_scan_res **tmp;
struct wpa_scan_res *r;
size_t extra_len;
u8 *pos, *end, *ssid_ie = NULL, *rate_ie = NULL;
const u8 *ie;
size_t ie_len;
/* Figure out whether we need to fake any IEs */
pos = data->ie;
end = pos + data->ie_len;
while (pos && pos + 1 < end) {
if (pos + 2 + pos[1] > end)
break;
if (pos[0] == WLAN_EID_SSID)
ssid_ie = pos;
else if (pos[0] == WLAN_EID_SUPP_RATES)
rate_ie = pos;
else if (pos[0] == WLAN_EID_EXT_SUPP_RATES)
rate_ie = pos;
pos += 2 + pos[1];
nla_parse(tb, NL80211_ATTR_MAX, genlmsg_attrdata(gnlh, 0),
genlmsg_attrlen(gnlh, 0), NULL);
if (!tb[NL80211_ATTR_BSS])
return NL_SKIP;
if (nla_parse_nested(bss, NL80211_BSS_MAX, tb[NL80211_ATTR_BSS],
bss_policy))
return NL_SKIP;
if (bss[NL80211_BSS_INFORMATION_ELEMENTS]) {
ie = nla_data(bss[NL80211_BSS_INFORMATION_ELEMENTS]);
ie_len = nla_len(bss[NL80211_BSS_INFORMATION_ELEMENTS]);
} else {
ie = NULL;
ie_len = 0;
}
extra_len = 0;
if (ssid_ie == NULL)
extra_len += 2 + data->ssid_len;
if (rate_ie == NULL && data->maxrate)
extra_len += 3;
r = os_zalloc(sizeof(*r) + extra_len + data->ie_len);
r = os_zalloc(sizeof(*r) + ie_len);
if (r == NULL)
return;
os_memcpy(r, &data->res, sizeof(*r));
r->ie_len = extra_len + data->ie_len;
pos = (u8 *) (r + 1);
if (ssid_ie == NULL) {
/*
* Generate a fake SSID IE since the driver did not report
* a full IE list.
*/
*pos++ = WLAN_EID_SSID;
*pos++ = data->ssid_len;
os_memcpy(pos, data->ssid, data->ssid_len);
pos += data->ssid_len;
}
if (rate_ie == NULL && data->maxrate) {
/*
* Generate a fake Supported Rates IE since the driver did not
* report a full IE list.
*/
*pos++ = WLAN_EID_SUPP_RATES;
*pos++ = 1;
*pos++ = data->maxrate;
}
if (data->ie)
os_memcpy(pos, data->ie, data->ie_len);
return NL_SKIP;
if (bss[NL80211_BSS_BSSID])
os_memcpy(r->bssid, nla_data(bss[NL80211_BSS_BSSID]),
ETH_ALEN);
if (bss[NL80211_BSS_FREQUENCY])
r->freq = nla_get_u32(bss[NL80211_BSS_FREQUENCY]);
if (bss[NL80211_BSS_BEACON_INTERVAL])
r->beacon_int = nla_get_u16(bss[NL80211_BSS_BEACON_INTERVAL]);
if (bss[NL80211_BSS_CAPABILITY])
r->caps = nla_get_u16(bss[NL80211_BSS_CAPABILITY]);
if (bss[NL80211_BSS_SIGNAL_UNSPEC])
r->qual = nla_get_u8(bss[NL80211_BSS_SIGNAL_UNSPEC]);
if (bss[NL80211_BSS_SIGNAL_MBM])
r->level = nla_get_u32(bss[NL80211_BSS_SIGNAL_MBM]);
if (bss[NL80211_BSS_TSF])
r->tsf = nla_get_u64(bss[NL80211_BSS_TSF]);
r->ie_len = ie_len;
if (ie)
os_memcpy(r + 1, ie, ie_len);
tmp = os_realloc(res->res,
(res->num + 1) * sizeof(struct wpa_scan_res *));
if (tmp == NULL) {
os_free(r);
return;
return NL_SKIP;
}
tmp[res->num++] = r;
res->res = tmp;
return NL_SKIP;
}
/**
* wpa_driver_nl80211_get_scan_results - Fetch the latest scan results
@ -1892,98 +1632,34 @@ static struct wpa_scan_results *
wpa_driver_nl80211_get_scan_results(void *priv)
{
struct wpa_driver_nl80211_data *drv = priv;
size_t ap_num = 0, len;
int first;
u8 *res_buf;
struct iw_event iwe_buf, *iwe = &iwe_buf;
char *pos, *end, *custom;
struct nl_msg *msg;
struct wpa_scan_results *res;
struct wext_scan_data data;
res_buf = wpa_driver_nl80211_giwscan(drv, &len);
if (res_buf == NULL)
return NULL;
ap_num = 0;
first = 1;
int ret;
res = os_zalloc(sizeof(*res));
if (res == NULL) {
os_free(res_buf);
return NULL;
if (res == NULL)
return 0;
msg = nlmsg_alloc();
if (!msg)
goto nla_put_failure;
genlmsg_put(msg, 0, 0, genl_family_get_id(drv->nl80211), 0, NLM_F_DUMP,
NL80211_CMD_GET_SCAN, 0);
NLA_PUT_U32(msg, NL80211_ATTR_IFINDEX, drv->ifindex);
ret = send_and_recv_msgs(drv, msg, bss_info_handler, res);
msg = NULL;
if (ret == 0) {
wpa_printf(MSG_DEBUG, "Received scan results (%lu BSSes)",
(unsigned long) res->num);
return res;
}
pos = (char *) res_buf;
end = (char *) res_buf + len;
os_memset(&data, 0, sizeof(data));
while (pos + IW_EV_LCP_LEN <= end) {
/* Event data may be unaligned, so make a local, aligned copy
* before processing. */
os_memcpy(&iwe_buf, pos, IW_EV_LCP_LEN);
if (iwe->len <= IW_EV_LCP_LEN)
break;
custom = pos + IW_EV_POINT_LEN;
if (wext_19_iw_point(drv, iwe->cmd)) {
/* WE-19 removed the pointer from struct iw_point */
char *dpos = (char *) &iwe_buf.u.data.length;
int dlen = dpos - (char *) &iwe_buf;
os_memcpy(dpos, pos + IW_EV_LCP_LEN,
sizeof(struct iw_event) - dlen);
} else {
os_memcpy(&iwe_buf, pos, sizeof(struct iw_event));
custom += IW_EV_POINT_OFF;
}
switch (iwe->cmd) {
case SIOCGIWAP:
if (!first)
wpa_driver_nl80211_add_scan_entry(res, &data);
first = 0;
os_free(data.ie);
os_memset(&data, 0, sizeof(data));
os_memcpy(data.res.bssid,
iwe->u.ap_addr.sa_data, ETH_ALEN);
break;
case SIOCGIWMODE:
wext_get_scan_mode(iwe, &data);
break;
case SIOCGIWESSID:
wext_get_scan_ssid(iwe, &data, custom, end);
break;
case SIOCGIWFREQ:
wext_get_scan_freq(iwe, &data);
break;
case IWEVQUAL:
wext_get_scan_qual(iwe, &data);
break;
case SIOCGIWENCODE:
wext_get_scan_encode(iwe, &data);
break;
case SIOCGIWRATE:
wext_get_scan_rate(iwe, &data, pos, end);
break;
case IWEVGENIE:
wext_get_scan_iwevgenie(iwe, &data, custom, end);
break;
case IWEVCUSTOM:
wext_get_scan_custom(iwe, &data, custom, end);
break;
}
pos += iwe->len;
}
os_free(res_buf);
res_buf = NULL;
if (!first)
wpa_driver_nl80211_add_scan_entry(res, &data);
os_free(data.ie);
wpa_printf(MSG_DEBUG, "Received %lu bytes of scan results (%lu BSSes)",
(unsigned long) len, (unsigned long) res->num);
return res;
wpa_printf(MSG_DEBUG, "nl80211: Scan result fetch failed: ret=%d "
"(%s)", ret, strerror(-ret));
nla_put_failure:
nlmsg_free(msg);
wpa_scan_results_free(res);
return NULL;
}