diff options
Diffstat (limited to 'src/print_wireless_info.c')
| -rw-r--r-- | src/print_wireless_info.c | 327 |
1 files changed, 219 insertions, 108 deletions
diff --git a/src/print_wireless_info.c b/src/print_wireless_info.c index 99b07f8..cd95562 100644 --- a/src/print_wireless_info.c +++ b/src/print_wireless_info.c @@ -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; -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; +// 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); +} - wireless_config wcfg; - if (iw_get_basic_config(skfd, interface, &wcfg) < 0) { - close(skfd); - return 0; - } +static uint32_t nl80211_xbm_to_percent(int32_t xbm, uint32_t divisor) { +#define NOISE_FLOOR_DBM -90 +#define SIGNAL_MAX_DBM -20 - 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'; + 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 (wcfg.has_freq) { - info->frequency = wcfg.freq; + 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 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; - } + 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; - /* 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). */ - - iwrange range; - if (iw_get_range_info(skfd, interface, &range) < 0) { - close(skfd); - return 0; + info->flags |= WIRELESS_INFO_FLAG_HAS_QUALITY; + info->quality = info->signal_level; + info->quality_max = 100; + info->quality_average = 50; } - iwstats stats; - if (iw_get_stats(skfd, interface, &stats, &range, 1) < 0) { - close(skfd); - return 0; + 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 (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 (bss[NL80211_BSS_INFORMATION_ELEMENTS]) { + uint8_t *ssid; + uint32_t ssid_len; - 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; + 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); } } - struct iwreq wrq; - if (iw_get_ext(skfd, interface, SIOCGIWRATE, &wrq) >= 0) - info->bitrate = wrq.u.bitrate.value; + return NL_SKIP; +} + +static int get_wireless_info(const char *interface, wireless_info_t *info) { + memset(info, 0, sizeof(wireless_info_t)); + +#ifdef LINUX + struct nl_sock *sk = nl_socket_alloc(); + if (genl_connect(sk) != 0) + goto error1; + + if (nl_socket_modify_cb(sk, NL_CB_VALID, NL_CB_CUSTOM, gwi_scan_cb, info) < 0) + goto error1; + + const int nl80211_id = genl_ctrl_resolve(sk, "nl80211"); + if (nl80211_id < 0) + goto error1; + + const unsigned int ifidx = if_nametoindex(interface); + if (ifidx == 0) + goto error1; + + struct nl_msg *msg = NULL; + if ((msg = nlmsg_alloc()) == NULL) + goto error1; - close(skfd); + 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; + + if (nl_send_sync(sk, msg) < 0) + // nl_send_sync calls nlmsg_free() + goto error1; + msg = NULL; + + if (nl_socket_modify_cb(sk, NL_CB_VALID, NL_CB_CUSTOM, gwi_sta_cb, info) < 0) + goto error1; + + if ((msg = nlmsg_alloc()) == NULL) + goto error1; + + 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; + + if (nl_send_sync(sk, msg) < 0) + // nl_send_sync calls nlmsg_free() + goto error1; + msg = NULL; + + 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"); |