scan-dump.c

#include <stdio.h>
#include <stdlib.h>
#include <net/if.h>
#include <unicode/ustdio.h>

#include "core.h"
#include "iw.h"
#include "list.h"
#include "bss.h"


static int error_handler(struct sockaddr_nl *nla, struct nlmsgerr *err, void *arg)
{
	ERR("%s\n", __func__);
	(void)nla;
	(void)err;
	(void)arg;

	return NL_STOP;
}

static int finish_handler(struct nl_msg *msg, void *arg)
{
	DBG("%s\n", __func__);

	(void)msg;

	int *ret = (int *)arg;
	*ret = 0;
	return NL_SKIP;
}

static int ack_handler(struct nl_msg *msg, void *arg)
{
	DBG("%s\n", __func__);
	(void)msg;

	int *ret = (int*)(arg);
	*ret = 0;
	return NL_STOP;
}


static int valid_handler(struct nl_msg *msg, void *arg)
{
	struct list_head* bss_list = (struct list_head*)arg;
	struct BSS* bss;

	INFO("%s\n", __func__);

	struct nlmsghdr *hdr = nlmsg_hdr(msg);
	struct genlmsghdr* gnlh = (struct genlmsghdr*)nlmsg_data(hdr);

	struct nlattr* tb_msg[NL80211_ATTR_MAX + 1];
	nla_parse(tb_msg, NL80211_ATTR_MAX, genlmsg_attrdata(gnlh, 0),
		  genlmsg_attrlen(gnlh, 0), NULL);

	peek_nla_attr(tb_msg, NL80211_ATTR_MAX);

	int err=0;

	if (!tb_msg[NL80211_ATTR_BSS]) {
		return NL_SKIP;
	}

//	err = 0;
	err = parse_nla_bss(tb_msg[NL80211_ATTR_BSS], &bss);
	printf( "%s %d\n", __func__, __LINE__ );
	if (err != 0) {
		goto fail;
	}
	list_add(&bss->node, bss_list);

	DBG("%s success\n", __func__);
	return NL_OK;
fail:
	return NL_SKIP;
}

int main(int argc, char* argv[])
{
	if (argc != 2) {
		fprintf(stderr, "usage: %s ifname\n", argv[0]);
		exit(1);
	}

	const char* ifname = argv[1];

	LIST_HEAD(bss_list);
	struct nl_cb* cb = nl_cb_alloc(NL_CB_DEFAULT);

	nl_cb_set(cb, NL_CB_VALID, NL_CB_CUSTOM, valid_handler, (void*)&bss_list);
	int cb_err = 1;
	nl_cb_err(cb, NL_CB_CUSTOM, error_handler, &cb_err);
	nl_cb_set(cb, NL_CB_FINISH, NL_CB_CUSTOM, finish_handler, &cb_err);
	nl_cb_set(cb, NL_CB_ACK, NL_CB_CUSTOM, ack_handler, &cb_err);

	struct nl_sock* nl_sock = nl_socket_alloc_cb(cb);
	int err = genl_connect(nl_sock);

	int nl80211_id = genl_ctrl_resolve(nl_sock, NL80211_GENL_NAME);

	int ifidx = if_nametoindex(ifname);

	struct nl_msg* msg = nlmsg_alloc();

	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);
	err = nl_send_auto(nl_sock, msg);
	if (err < 0) {
		ERR("nl_send_auto failed err=%d\n", err);
		goto leave;
	}

	while (cb_err > 0) {
		err = nl_recvmsgs(nl_sock, cb);
		INFO("nl_recvmsgs err=%d\n", err);
	}

	struct BSS* bss;
	list_for_each_entry(bss, &bss_list, node) {
		XASSERT(bss->cookie == BSS_COOKIE, bss->cookie);
		const struct IE* ie = ie_list_find_id(&bss->ie_list, IE_SSID);
		if (ie) {
			const struct IE_SSID *ie_ssid = IE_CAST(ie, const struct IE_SSID);
			if (ie_ssid->ssid_len) {
				u_printf("%s ssid=%S\n", bss->bssid_str, ie_ssid->ssid);
				hex_dump("ssid", ie->buf, ie->len);
			}
			else {
				u_printf("%s ssid=<hidden>\n", bss->bssid_str);
			}
		}
		else {
			INFO("%s <no ssid>\n", bss->bssid_str);
		}
	}

leave:
	bss_free_list(&bss_list);
	nl_cb_put(cb);
	nl_socket_free(nl_sock);
	nlmsg_free(msg);
	return EXIT_SUCCESS;
}