wireless (linux): switch from libiw to libnl

Based on http://cr.i3wm.org/patch/692/ by Alexander Monakov

fixes #32
fixes #52
This commit is contained in:
Michael Stapelberg 2015-09-24 21:47:02 +02:00
parent 51c1dbdba2
commit 668bf2079f
3 changed files with 225 additions and 113 deletions

View File

@ -30,7 +30,8 @@ OS:=$(shell uname)
ifeq ($(OS),Linux)
CPPFLAGS+=-DLINUX
CPPFLAGS+=-D_GNU_SOURCE
LIBS+=-liw
CFLAGS += $(shell pkg-config --cflags libnl-genl-3.0)
LIBS += $(shell pkg-config --libs libnl-genl-3.0)
LIBS+=-lasound
endif

View File

@ -15,7 +15,7 @@ i3status has the following dependencies:
* libconfuse-dev
* libyajl-dev
* libasound2-dev
* libiw-dev
* libnl-genl-3-dev
* libcap2-bin (for getting network status without root permissions)
* asciidoc (only for the documentation)
* libpulse-dev (for getting the current volume using PulseAudio)

View File

@ -5,12 +5,15 @@
#include <yajl/yajl_version.h>
#ifdef LINUX
#include <iwlib.h>
#else
#ifndef __FreeBSD__
#include <errno.h>
#include <net/if.h>
#include <netlink/netlink.h>
#include <netlink/genl/genl.h>
#include <netlink/genl/ctrl.h>
#include <linux/nl80211.h>
#include <linux/if_ether.h>
#define IW_ESSID_MAX_SIZE 32
#endif
#endif
#ifdef __FreeBSD__
#include <sys/param.h>
@ -62,6 +65,7 @@
typedef struct {
int flags;
char essid[IW_ESSID_MAX_SIZE + 1];
uint8_t bssid[ETH_ALEN];
int quality;
int quality_max;
int quality_average;
@ -73,128 +77,235 @@ typedef struct {
double frequency;
} wireless_info_t;
// Like iw_print_bitrate, but without the dependency on libiw.
static void print_bitrate(char *buffer, int buflen, int bitrate) {
const int kilo = 1e3;
const int mega = 1e6;
const int giga = 1e9;
const double rate = bitrate;
char scale;
int divisor;
if (rate >= giga) {
scale = 'G';
divisor = giga;
} else if (rate >= mega) {
scale = 'M';
divisor = mega;
} else {
scale = 'k';
divisor = kilo;
}
snprintf(buffer, buflen, "%g %cb/s", rate / divisor, scale);
}
static uint32_t nl80211_xbm_to_percent(int32_t xbm, uint32_t divisor) {
#define NOISE_FLOOR_DBM -90
#define SIGNAL_MAX_DBM -20
xbm /= divisor;
if (xbm < NOISE_FLOOR_DBM)
xbm = NOISE_FLOOR_DBM;
if (xbm > SIGNAL_MAX_DBM)
xbm = SIGNAL_MAX_DBM;
return 100 - 70 * (((float)SIGNAL_MAX_DBM - (float)xbm) / ((float)SIGNAL_MAX_DBM - (float)NOISE_FLOOR_DBM));
}
#define WLAN_EID_SSID 0
static void find_ssid(uint8_t *ies, uint32_t ies_len, uint8_t **ssid, uint32_t *ssid_len) {
*ssid = NULL;
*ssid_len = 0;
while (ies_len > 2 && ies[0] != WLAN_EID_SSID) {
ies_len -= ies[1] + 2;
ies += ies[1] + 2;
}
if (ies_len < 2)
return;
if (ies_len < 2 + ies[1])
return;
*ssid_len = ies[1];
*ssid = ies + 2;
}
static int gwi_sta_cb(struct nl_msg *msg, void *data) {
wireless_info_t *info = data;
struct nlattr *tb[NL80211_ATTR_MAX + 1];
struct genlmsghdr *gnlh = nlmsg_data(nlmsg_hdr(msg));
struct nlattr *sinfo[NL80211_STA_INFO_MAX + 1];
struct nlattr *rinfo[NL80211_RATE_INFO_MAX + 1];
static struct nla_policy stats_policy[NL80211_STA_INFO_MAX + 1] = {
[NL80211_STA_INFO_RX_BITRATE] = {.type = NLA_NESTED},
};
static struct nla_policy rate_policy[NL80211_RATE_INFO_MAX + 1] = {
[NL80211_RATE_INFO_BITRATE32] = {.type = NLA_U32},
};
if (nla_parse(tb, NL80211_ATTR_MAX, genlmsg_attrdata(gnlh, 0), genlmsg_attrlen(gnlh, 0), NULL) < 0)
return NL_SKIP;
if (tb[NL80211_ATTR_STA_INFO] == NULL)
return NL_SKIP;
if (nla_parse_nested(sinfo, NL80211_STA_INFO_MAX, tb[NL80211_ATTR_STA_INFO], stats_policy))
return NL_SKIP;
if (sinfo[NL80211_STA_INFO_RX_BITRATE] == NULL)
return NL_SKIP;
if (nla_parse_nested(rinfo, NL80211_RATE_INFO_MAX, sinfo[NL80211_STA_INFO_RX_BITRATE], rate_policy))
return NL_SKIP;
if (rinfo[NL80211_RATE_INFO_BITRATE32] == NULL)
return NL_SKIP;
// NL80211_RATE_INFO_BITRATE32 is specified in units of 100 kbit/s, but iw
// used to specify bit/s, so we convert to use the same code path.
info->bitrate = nla_get_u32(rinfo[NL80211_RATE_INFO_BITRATE32]) * 100 * 1000;
return NL_SKIP;
}
static int gwi_scan_cb(struct nl_msg *msg, void *data) {
wireless_info_t *info = data;
struct genlmsghdr *gnlh = genlmsg_hdr(nlmsg_hdr(msg));
struct nlattr *tb[NL80211_ATTR_MAX + 1];
struct nlattr *bss[NL80211_BSS_MAX + 1];
struct nla_policy bss_policy[NL80211_BSS_MAX + 1] = {
[NL80211_BSS_FREQUENCY] = {.type = NLA_U32},
[NL80211_BSS_BSSID] = {.type = NLA_UNSPEC},
[NL80211_BSS_INFORMATION_ELEMENTS] = {.type = NLA_UNSPEC},
[NL80211_BSS_SIGNAL_MBM] = {.type = NLA_U32},
[NL80211_BSS_SIGNAL_UNSPEC] = {.type = NLA_U8},
[NL80211_BSS_STATUS] = {.type = NLA_U32},
};
if (nla_parse(tb, NL80211_ATTR_MAX, genlmsg_attrdata(gnlh, 0), genlmsg_attrlen(gnlh, 0), NULL) < 0)
return NL_SKIP;
if (tb[NL80211_ATTR_BSS] == NULL)
return NL_SKIP;
if (nla_parse_nested(bss, NL80211_BSS_MAX, tb[NL80211_ATTR_BSS], bss_policy))
return NL_SKIP;
if (bss[NL80211_BSS_STATUS] == NULL)
return NL_SKIP;
const uint32_t status = nla_get_u32(bss[NL80211_BSS_STATUS]);
if (status != NL80211_BSS_STATUS_ASSOCIATED &&
status != NL80211_BSS_STATUS_IBSS_JOINED)
return NL_SKIP;
if (bss[NL80211_BSS_BSSID] == NULL)
return NL_SKIP;
memcpy(info->bssid, nla_data(bss[NL80211_BSS_BSSID]), ETH_ALEN);
if (bss[NL80211_BSS_FREQUENCY]) {
info->flags |= WIRELESS_INFO_FLAG_HAS_FREQUENCY;
info->frequency = (double)nla_get_u32(bss[NL80211_BSS_FREQUENCY]) * 1e6;
}
if (bss[NL80211_BSS_SIGNAL_UNSPEC]) {
info->flags |= WIRELESS_INFO_FLAG_HAS_SIGNAL;
info->signal_level = nla_get_u8(bss[NL80211_BSS_SIGNAL_UNSPEC]);
info->signal_level_max = 100;
info->flags |= WIRELESS_INFO_FLAG_HAS_QUALITY;
info->quality = info->signal_level;
info->quality_max = 100;
info->quality_average = 50;
}
if (bss[NL80211_BSS_SIGNAL_MBM]) {
info->flags |= WIRELESS_INFO_FLAG_HAS_SIGNAL;
info->signal_level = (int)nla_get_u32(bss[NL80211_BSS_SIGNAL_MBM]) / 100;
info->flags |= WIRELESS_INFO_FLAG_HAS_QUALITY;
info->quality = nl80211_xbm_to_percent(nla_get_u32(bss[NL80211_BSS_SIGNAL_MBM]), 100);
info->quality_max = 100;
info->quality_average = 50;
}
if (bss[NL80211_BSS_INFORMATION_ELEMENTS]) {
uint8_t *ssid;
uint32_t ssid_len;
find_ssid(nla_data(bss[NL80211_BSS_INFORMATION_ELEMENTS]),
nla_len(bss[NL80211_BSS_INFORMATION_ELEMENTS]),
&ssid, &ssid_len);
if (ssid && ssid_len) {
info->flags |= WIRELESS_INFO_FLAG_HAS_ESSID;
snprintf(info->essid, sizeof(info->essid), "%.*s", ssid_len, ssid);
}
}
return NL_SKIP;
}
static int get_wireless_info(const char *interface, wireless_info_t *info) {
memset(info, 0, sizeof(wireless_info_t));
#ifdef LINUX
int skfd = iw_sockets_open();
if (skfd < 0) {
perror("iw_sockets_open");
return 0;
}
struct nl_sock *sk = nl_socket_alloc();
if (genl_connect(sk) != 0)
goto error1;
wireless_config wcfg;
if (iw_get_basic_config(skfd, interface, &wcfg) < 0) {
close(skfd);
return 0;
}
if (nl_socket_modify_cb(sk, NL_CB_VALID, NL_CB_CUSTOM, gwi_scan_cb, info) < 0)
goto error1;
if (wcfg.has_essid && wcfg.essid_on) {
info->flags |= WIRELESS_INFO_FLAG_HAS_ESSID;
strncpy(&info->essid[0], wcfg.essid, IW_ESSID_MAX_SIZE);
info->essid[IW_ESSID_MAX_SIZE] = '\0';
}
const int nl80211_id = genl_ctrl_resolve(sk, "nl80211");
if (nl80211_id < 0)
goto error1;
if (wcfg.has_freq) {
info->frequency = wcfg.freq;
info->flags |= WIRELESS_INFO_FLAG_HAS_FREQUENCY;
}
const unsigned int ifidx = if_nametoindex(interface);
if (ifidx == 0)
goto error1;
/* If the function iw_get_stats does not return proper stats, the
* wifi is considered as down.
* Since ad-hoc network does not have theses stats, we need to return
* here for this mode. */
if (wcfg.mode == 1) {
close(skfd);
return 1;
}
struct nl_msg *msg = NULL;
if ((msg = nlmsg_alloc()) == NULL)
goto error1;
/* Wireless quality is a relative value in a driver-specific range.
* Signal and noise level can be either relative or absolute values
* in dBm. Furthermore, noise and quality can be expressed directly
* in dBm or in RCPI (802.11k), which we convert to dBm. When those
* values are expressed directly in dBm, they range from -192 to 63,
* and since the values are packed into 8 bits, we need to perform
* 8-bit arithmetic on them. Assume absolute values if everything
* else fails (driver bug). */
if (!genlmsg_put(msg, NL_AUTO_PORT, NL_AUTO_SEQ, nl80211_id, 0, NLM_F_DUMP, NL80211_CMD_GET_SCAN, 0) ||
nla_put_u32(msg, NL80211_ATTR_IFINDEX, ifidx) < 0)
goto error2;
iwrange range;
if (iw_get_range_info(skfd, interface, &range) < 0) {
close(skfd);
return 0;
}
if (nl_send_sync(sk, msg) < 0)
// nl_send_sync calls nlmsg_free()
goto error1;
msg = NULL;
iwstats stats;
if (iw_get_stats(skfd, interface, &stats, &range, 1) < 0) {
close(skfd);
return 0;
}
if (nl_socket_modify_cb(sk, NL_CB_VALID, NL_CB_CUSTOM, gwi_sta_cb, info) < 0)
goto error1;
if (stats.qual.level != 0 || (stats.qual.updated & (IW_QUAL_DBM | IW_QUAL_RCPI))) {
if (!(stats.qual.updated & IW_QUAL_QUAL_INVALID)) {
info->quality = stats.qual.qual;
info->quality_max = range.max_qual.qual;
info->quality_average = range.avg_qual.qual;
info->flags |= WIRELESS_INFO_FLAG_HAS_QUALITY;
}
if ((msg = nlmsg_alloc()) == NULL)
goto error1;
if (stats.qual.updated & IW_QUAL_RCPI) {
if (!(stats.qual.updated & IW_QUAL_LEVEL_INVALID)) {
info->signal_level = stats.qual.level / 2.0 - 110 + 0.5;
info->flags |= WIRELESS_INFO_FLAG_HAS_SIGNAL;
}
if (!(stats.qual.updated & IW_QUAL_NOISE_INVALID)) {
info->noise_level = stats.qual.noise / 2.0 - 110 + 0.5;
info->flags |= WIRELESS_INFO_FLAG_HAS_NOISE;
}
} else {
if ((stats.qual.updated & IW_QUAL_DBM) || stats.qual.level > range.max_qual.level) {
if (!(stats.qual.updated & IW_QUAL_LEVEL_INVALID)) {
info->signal_level = stats.qual.level;
if (info->signal_level > 63)
info->signal_level -= 256;
info->flags |= WIRELESS_INFO_FLAG_HAS_SIGNAL;
}
if (!(stats.qual.updated & IW_QUAL_NOISE_INVALID)) {
info->noise_level = stats.qual.noise;
if (info->noise_level > 63)
info->noise_level -= 256;
info->flags |= WIRELESS_INFO_FLAG_HAS_NOISE;
}
} else {
if (!(stats.qual.updated & IW_QUAL_LEVEL_INVALID)) {
info->signal_level = stats.qual.level;
info->signal_level_max = range.max_qual.level;
info->flags |= WIRELESS_INFO_FLAG_HAS_SIGNAL;
}
if (!(stats.qual.updated & IW_QUAL_NOISE_INVALID)) {
info->noise_level = stats.qual.noise;
info->noise_level_max = range.max_qual.noise;
info->flags |= WIRELESS_INFO_FLAG_HAS_NOISE;
}
}
}
} else {
if (!(stats.qual.updated & IW_QUAL_QUAL_INVALID)) {
info->quality = stats.qual.qual;
info->flags |= WIRELESS_INFO_FLAG_HAS_QUALITY;
}
if (!(stats.qual.updated & IW_QUAL_LEVEL_INVALID)) {
info->quality = stats.qual.level;
info->flags |= WIRELESS_INFO_FLAG_HAS_SIGNAL;
}
if (!(stats.qual.updated & IW_QUAL_NOISE_INVALID)) {
info->quality = stats.qual.noise;
info->flags |= WIRELESS_INFO_FLAG_HAS_NOISE;
}
}
if (!genlmsg_put(msg, NL_AUTO_PORT, NL_AUTO_SEQ, nl80211_id, 0, NLM_F_DUMP, NL80211_CMD_GET_STATION, 0) || nla_put_u32(msg, NL80211_ATTR_IFINDEX, ifidx) < 0 || nla_put(msg, NL80211_ATTR_MAC, 6, info->bssid) < 0)
goto error2;
struct iwreq wrq;
if (iw_get_ext(skfd, interface, SIOCGIWRATE, &wrq) >= 0)
info->bitrate = wrq.u.bitrate.value;
if (nl_send_sync(sk, msg) < 0)
// nl_send_sync calls nlmsg_free()
goto error1;
msg = NULL;
close(skfd);
nl_socket_free(sk);
return 1;
error2:
nlmsg_free(msg);
error1:
nl_socket_free(sk);
return 0;
#endif
#if defined(__FreeBSD__) || defined(__DragonFly__)
int s, inwid;
@ -426,7 +537,7 @@ void print_wireless_info(yajl_gen json_gen, char *buffer, const char *interface,
if (BEGINS_WITH(walk + 1, "bitrate")) {
char br_buffer[128];
iw_print_bitrate(br_buffer, sizeof(br_buffer), info.bitrate);
print_bitrate(br_buffer, sizeof(br_buffer), info.bitrate);
outwalk += sprintf(outwalk, "%s", br_buffer);
walk += strlen("bitrate");