driver_wext.c

一个Linux下无线网卡的设置工具

		}

		switch (iwe->cmd) {
		case SIOCGIWAP:
			wpa_printf(MSG_DEBUG, "Wireless event: new AP: "
				   MACSTR,
				   MAC2STR((u8 *) iwe->u.ap_addr.sa_data));
			if (memcmp(iwe->u.ap_addr.sa_data,
				   "\x00\x00\x00\x00\x00\x00", ETH_ALEN) == 0
			    ||
			    memcmp(iwe->u.ap_addr.sa_data,
				   "\x44\x44\x44\x44\x44\x44", ETH_ALEN) == 0)
			{
				free(drv->assoc_req_ies);
				drv->assoc_req_ies = NULL;
				free(drv->assoc_resp_ies);
				drv->assoc_resp_ies = NULL;
				wpa_supplicant_event(ctx, EVENT_DISASSOC,
						     NULL);
			
			} else {
				wpa_driver_wext_event_assoc_ies(drv);
				wpa_supplicant_event(ctx, EVENT_ASSOC, NULL);
			}
			break;
		case IWEVMICHAELMICFAILURE:
			wpa_driver_wext_event_wireless_michaelmicfailure(
				drv, ctx, custom, iwe->u.data.length);
			break;
		case IWEVCUSTOM:
			if (custom + iwe->u.data.length > end)
				return;
			buf = malloc(iwe->u.data.length + 1);
			if (buf == NULL)
				return;
			memcpy(buf, custom, iwe->u.data.length);
			buf[iwe->u.data.length] = '\0';
			wpa_driver_wext_event_wireless_custom(drv, ctx, buf);
			free(buf);
			break;
		case SIOCGIWSCAN:
			eloop_cancel_timeout(wpa_driver_wext_scan_timeout,
					     drv, ctx);
			wpa_supplicant_event(ctx, EVENT_SCAN_RESULTS, NULL);
			break;
		case IWEVASSOCREQIE:
			wpa_driver_wext_event_wireless_assocreqie(
				drv, ctx, custom, iwe->u.data.length);
			break;
		case IWEVASSOCRESPIE:
			wpa_driver_wext_event_wireless_assocrespie(
				drv, ctx, custom, iwe->u.data.length);
			break;
		case IWEVPMKIDCAND:
			wpa_driver_wext_event_wireless_pmkidcand(
				drv, ctx, custom, iwe->u.data.length);
			break;
		}

		pos += iwe->len;
	}
}


static void wpa_driver_wext_event_link(struct wpa_driver_wext_data *drv,
				       void *ctx, char *buf, size_t len,
				       int del)
{
	union wpa_event_data event;

	memset(&event, 0, sizeof(event));
	if (len > sizeof(event.interface_status.ifname))
		len = sizeof(event.interface_status.ifname) - 1;
	memcpy(event.interface_status.ifname, buf, len);
	event.interface_status.ievent = del ? EVENT_INTERFACE_REMOVED :
		EVENT_INTERFACE_ADDED;

	wpa_printf(MSG_DEBUG, "RTM_%sLINK, IFLA_IFNAME: Interface '%s' %s",
		   del ? "DEL" : "NEW",
		   event.interface_status.ifname,
		   del ? "removed" : "added");

	wpa_supplicant_event(ctx, EVENT_INTERFACE_STATUS, &event);
}


static void wpa_driver_wext_event_rtm_newlink(struct wpa_driver_wext_data *drv,
					      void *ctx, struct nlmsghdr *h,
					      int len)
{
	struct ifinfomsg *ifi;
	int attrlen, nlmsg_len, rta_len;
	struct rtattr * attr;

	if (len < sizeof(*ifi))
		return;

	ifi = NLMSG_DATA(h);

	if (drv->ifindex != ifi->ifi_index && drv->ifindex2 != ifi->ifi_index)
	{
		wpa_printf(MSG_DEBUG, "Ignore event for foreign ifindex %d",
			   ifi->ifi_index);
		return;
	}

	nlmsg_len = NLMSG_ALIGN(sizeof(struct ifinfomsg));

	attrlen = h->nlmsg_len - nlmsg_len;
	if (attrlen < 0)
		return;

	attr = (struct rtattr *) (((char *) ifi) + nlmsg_len);

	rta_len = RTA_ALIGN(sizeof(struct rtattr));
	while (RTA_OK(attr, attrlen)) {
		if (attr->rta_type == IFLA_WIRELESS) {
			wpa_driver_wext_event_wireless(
				drv, ctx, ((char *) attr) + rta_len,
				attr->rta_len - rta_len);
		} else if (attr->rta_type == IFLA_IFNAME) {
			wpa_driver_wext_event_link(drv, ctx,
						   ((char *) attr) + rta_len,
						   attr->rta_len - rta_len, 0);
		}
		attr = RTA_NEXT(attr, attrlen);
	}
}


static void wpa_driver_wext_event_rtm_dellink(struct wpa_driver_wext_data *drv,
					      void *ctx, struct nlmsghdr *h,
					      int len)
{
	struct ifinfomsg *ifi;
	int attrlen, nlmsg_len, rta_len;
	struct rtattr * attr;

	if (len < sizeof(*ifi))
		return;

	ifi = NLMSG_DATA(h);

	nlmsg_len = NLMSG_ALIGN(sizeof(struct ifinfomsg));

	attrlen = h->nlmsg_len - nlmsg_len;
	if (attrlen < 0)
		return;

	attr = (struct rtattr *) (((char *) ifi) + nlmsg_len);

	rta_len = RTA_ALIGN(sizeof(struct rtattr));
	while (RTA_OK(attr, attrlen)) {
		if (attr->rta_type == IFLA_IFNAME) {
			wpa_driver_wext_event_link(drv, ctx,
						   ((char *) attr) + rta_len,
						   attr->rta_len - rta_len, 1);
		}
		attr = RTA_NEXT(attr, attrlen);
	}
}


static void wpa_driver_wext_event_receive(int sock, void *eloop_ctx,
					  void *sock_ctx)
{
	char buf[8192];
	int left;
	struct sockaddr_nl from;
	socklen_t fromlen;
	struct nlmsghdr *h;

	fromlen = sizeof(from);
	left = recvfrom(sock, buf, sizeof(buf), MSG_DONTWAIT,
			(struct sockaddr *) &from, &fromlen);
	if (left < 0) {
		if (errno != EINTR && errno != EAGAIN)
			perror("recvfrom(netlink)");
		return;
	}

	h = (struct nlmsghdr *) buf;
	while (left >= sizeof(*h)) {
		int len, plen;

		len = h->nlmsg_len;
		plen = len - sizeof(*h);
		if (len > left || plen < 0) {
			wpa_printf(MSG_DEBUG, "Malformed netlink message: "
				   "len=%d left=%d plen=%d",
				   len, left, plen);
			break;
		}

		switch (h->nlmsg_type) {
		case RTM_NEWLINK:
			wpa_driver_wext_event_rtm_newlink(eloop_ctx, sock_ctx,
							  h, plen);
			break;
		case RTM_DELLINK:
			wpa_driver_wext_event_rtm_dellink(eloop_ctx, sock_ctx,
							  h, plen);
			break;
		}

		len = NLMSG_ALIGN(len);
		left -= len;
		h = (struct nlmsghdr *) ((char *) h + len);
	}

	if (left > 0) {
		wpa_printf(MSG_DEBUG, "%d extra bytes in the end of netlink "
			   "message", left);
	}
}


/**
 * wpa_driver_wext_get_ifflags - Get interface flags (SIOCGIFFLAGS)
 * @drv: driver_wext private data
 * @flags: Pointer to returned flags value
 * Returns: 0 on success, -1 on failure
 */
int wpa_driver_wext_get_ifflags(struct wpa_driver_wext_data *drv, int *flags)
{
	struct ifreq ifr;

	memset(&ifr, 0, sizeof(ifr));
	strncpy(ifr.ifr_name, drv->ifname, IFNAMSIZ);
	if (ioctl(drv->ioctl_sock, SIOCGIFFLAGS, (caddr_t) &ifr) < 0) {
		perror("ioctl[SIOCGIFFLAGS]");
		return -1;
	}
	*flags = ifr.ifr_flags & 0xffff;
	return 0;
}


/**
 * wpa_driver_wext_set_ifflags - Set interface flags (SIOCSIFFLAGS)
 * @drv: driver_wext private data
 * @flags: New value for flags
 * Returns: 0 on success, -1 on failure
 */
int wpa_driver_wext_set_ifflags(struct wpa_driver_wext_data *drv, int flags)
{
	struct ifreq ifr;

	memset(&ifr, 0, sizeof(ifr));
	strncpy(ifr.ifr_name, drv->ifname, IFNAMSIZ);
	ifr.ifr_flags = flags & 0xffff;
	if (ioctl(drv->ioctl_sock, SIOCSIFFLAGS, (caddr_t) &ifr) < 0) {
		perror("SIOCSIFFLAGS");
		return -1;
	}
	return 0;
}


/**
 * wpa_driver_wext_init - Initialize WE driver interface
 * @ctx: context to be used when calling wpa_supplicant functions,
 * e.g., wpa_supplicant_event()
 * @ifname: interface name, e.g., wlan0
 * Returns: Pointer to private data, %NULL on failure
 */
void * wpa_driver_wext_init(void *ctx, const char *ifname)
{
	int s, flags;
	struct sockaddr_nl local;
	struct wpa_driver_wext_data *drv;

	drv = malloc(sizeof(*drv));
	if (drv == NULL)
		return NULL;
	memset(drv, 0, sizeof(*drv));
	drv->ctx = ctx;
	strncpy(drv->ifname, ifname, sizeof(drv->ifname));

	drv->ioctl_sock = socket(PF_INET, SOCK_DGRAM, 0);
	if (drv->ioctl_sock < 0) {
		perror("socket(PF_INET,SOCK_DGRAM)");
		free(drv);
		return NULL;
	}

	s = socket(PF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
	if (s < 0) {
		perror("socket(PF_NETLINK,SOCK_RAW,NETLINK_ROUTE)");
		close(drv->ioctl_sock);
		free(drv);
		return NULL;
	}

	memset(&local, 0, sizeof(local));
	local.nl_family = AF_NETLINK;
	local.nl_groups = RTMGRP_LINK;
	if (bind(s, (struct sockaddr *) &local, sizeof(local)) < 0) {
		perror("bind(netlink)");
		close(s);
		close(drv->ioctl_sock);
		free(drv);
		return NULL;
	}

	eloop_register_read_sock(s, wpa_driver_wext_event_receive, drv, ctx);
	drv->event_sock = s;

	/*
	 * Make sure that the driver does not have any obsolete PMKID entries.
	 */
	wpa_driver_wext_flush_pmkid(drv);

	if (wpa_driver_wext_set_mode(drv, 0) < 0) {
		printf("Could not configure driver to use managed mode\n");
	}

	if (wpa_driver_wext_get_ifflags(drv, &flags) != 0 ||
	    wpa_driver_wext_set_ifflags(drv, flags | IFF_UP) != 0) {
		printf("Could not set interface '%s' UP\n", drv->ifname);
	}

	wpa_driver_wext_get_range(drv);

	drv->ifindex = if_nametoindex(drv->ifname);

	if (strncmp(ifname, "wlan", 4) == 0) {
		/*
		 * Host AP driver may use both wlan# and wifi# interface in
		 * wireless events. Since some of the versions included WE-18
		 * support, let's add the alternative ifindex also from
		 * driver_wext.c for the time being. This may be removed at
		 * some point once it is believed that old versions of the
		 * driver are not in use anymore.
		 */
		char ifname2[IFNAMSIZ + 1];
		strncpy(ifname2, ifname, sizeof(ifname2));
		memcpy(ifname2, "wifi", 4);
		wpa_driver_wext_alternative_ifindex(drv, ifname2);
	}

	return drv;
}


/**
 * wpa_driver_wext_deinit - Deinitialize WE driver interface
 * @priv: Pointer to private wext data from wpa_driver_wext_init()
 *
 * Shut down driver interface and processing of driver events. Free
 * private data buffer if one was allocated in wpa_driver_wext_init().
 */
void wpa_driver_wext_deinit(void *priv)
{
	struct wpa_driver_wext_data *drv = priv;
	int flags;

	/*
	 * Clear possibly configured driver parameters in order to make it
	 * easier to use the driver after wpa_supplicant has been terminated.
	 */
	wpa_driver_wext_set_bssid(drv, (u8 *) "\x00\x00\x00\x00\x00\x00");

	eloop_unregister_read_sock(drv->event_sock);

	if (wpa_driver_wext_get_ifflags(drv, &flags) == 0)
		(void) wpa_driver_wext_set_ifflags(drv, flags & ~IFF_UP);

	close(drv->event_sock);
	close(drv->ioctl_sock);
	free(drv->assoc_req_ies);
	free(drv->assoc_resp_ies);
	free(drv);
}


/**
 * wpa_driver_wext_scan_timeout - Scan timeout to report scan completion
 * @eloop_ctx: Unused
 * @timeout_ctx: ctx argument given to wpa_driver_wext_init()
 *
 * This function can be used as registered timeout when starting a scan to
 * generate a scan completed event if the driver does not report this.
 */
void wpa_driver_wext_scan_timeout(void *eloop_ctx, void *timeout_ctx)
{
	wpa_printf(MSG_DEBUG, "Scan timeout - try to get results");
	wpa_supplicant_event(timeout_ctx, EVENT_SCAN_RESULTS, NULL);
}


/**
 * wpa_driver_wext_scan - Request the driver to initiate scan
 * @priv: Pointer to private wext data from wpa_driver_wext_init()
 * @ssid: Specific SSID to scan for (ProbeReq) or %NULL to scan for
 *	all SSIDs (either active scan with broadcast SSID or passive
 *	scan
 * @ssid_len: Length of the SSID
 * Returns: 0 on success, -1 on failure
 */
int wpa_driver_wext_scan(void *priv, const u8 *ssid, size_t ssid_len)
{
	struct wpa_driver_wext_data *drv = priv;
	struct iwreq iwr;
	int ret = 0;
	struct iw_scan_req req;

	if (ssid_len > IW_ESSID_MAX_SIZE) {
		wpa_printf(MSG_DEBUG, "%s: too long SSID (%lu)",
			   __FUNCTION__, (unsigned long) ssid_len);
		return -1;
	}

	memset(&iwr, 0, sizeof(iwr));
	strncpy(iwr.ifr_name, drv->ifname, IFNAMSIZ);

	if (ssid && ssid_len) {
		memset(&req, 0, sizeof(req));
		req.essid_len = ssid_len;
		req.bssid.sa_family = ARPHRD_ETHER;
		memset(req.bssid.sa_data, 0xff, ETH_ALEN);
		memcpy(req.essid, ssid, ssid_len);
		iwr.u.data.pointer = (caddr_t) &req;
		iwr.u.data.length = sizeof(req);
		iwr.u.data.flags = IW_SCAN_THIS_ESSID;
	}

	if (ioctl(drv->ioctl_sock, SIOCSIWSCAN, &iwr) < 0) {
		perror("ioctl[SIOCSIWSCAN]");
		ret = -1;
	}

	/* Not all drivers generate "scan completed" wireless event, so try to
	 * read results after a timeout. */
	eloop_register_timeout(3, 0, wpa_driver_wext_scan_timeout, drv,
			       drv->ctx);

	return ret;
}


/* Compare function for sorting scan results. Return >0 if @b is considered
 * better. */
static int wpa_scan_result_compar(const void *a, const void *b)
{
	const struct wpa_scan_result *wa = a;
	const struct wpa_scan_result *wb = b;

	/* WPA/WPA2 support preferred */
	if ((wb->wpa_ie_len || wb->rsn_ie_len) &&
	    !(wa->wpa_ie_len || wa->rsn_ie_len))
		return 1;
	if (!(wb->wpa_ie_len || wb->rsn_ie_len) &&
	    (wa->wpa_ie_len || wa->rsn_ie_len))
		return -1;

	/* privacy support preferred */
	if ((wa->caps & IEEE80211_CAP_PRIVACY) == 0 &&
	    (wb->caps & IEEE80211_CAP_PRIVACY))
		return 1;
	if ((wa->caps & IEEE80211_CAP_PRIVACY) &&
	    (wb->caps & IEEE80211_CAP_PRIVACY) == 0)
		return -1;