contrib/hostapd/src/ap/iapp.c

/*
 * hostapd / IEEE 802.11F-2003 Inter-Access Point Protocol (IAPP)
 * Copyright (c) 2002-2007, Jouni Malinen <j@w1.fi>
 *
 * This software may be distributed under the terms of the BSD license.
 * See README for more details.
 *
 * Note: IEEE 802.11F-2003 was a experimental use specification. It has expired
 * and IEEE has withdrawn it. In other words, it is likely better to look at
 * using some other mechanism for AP-to-AP communication than extending the
 * implementation here.
 */

/* TODO:
 * Level 1: no administrative or security support
 *	(e.g., static BSSID to IP address mapping in each AP)
 * Level 2: support for dynamic mapping of BSSID to IP address
 * Level 3: support for encryption and authentication of IAPP messages
 * - add support for MOVE-notify and MOVE-response (this requires support for
 *   finding out IP address for previous AP using RADIUS)
 * - add support for Send- and ACK-Security-Block to speedup IEEE 802.1X during
 *   reassociation to another AP
 * - implement counters etc. for IAPP MIB
 * - verify endianness of fields in IAPP messages; are they big-endian as
 *   used here?
 * - RADIUS connection for AP registration and BSSID to IP address mapping
 * - TCP connection for IAPP MOVE, CACHE
 * - broadcast ESP for IAPP ADD-notify
 * - ESP for IAPP MOVE messages
 * - security block sending/processing
 * - IEEE 802.11 context transfer
 */

#include "utils/includes.h"
#include <net/if.h>
#include <sys/ioctl.h>
#ifdef USE_KERNEL_HEADERS
#include <linux/if_packet.h>
#else /* USE_KERNEL_HEADERS */
#include <netpacket/packet.h>
#endif /* USE_KERNEL_HEADERS */

#include "utils/common.h"
#include "utils/eloop.h"
#include "common/ieee802_11_defs.h"
#include "hostapd.h"
#include "ap_config.h"
#include "ieee802_11.h"
#include "sta_info.h"
#include "iapp.h"


#define IAPP_MULTICAST "224.0.1.178"
#define IAPP_UDP_PORT 3517
#define IAPP_TCP_PORT 3517

struct iapp_hdr {
	u8 version;
	u8 command;
	be16 identifier;
	be16 length;
	/* followed by length-6 octets of data */
} __attribute__ ((packed));

#define IAPP_VERSION 0

enum IAPP_COMMAND {
	IAPP_CMD_ADD_notify = 0,
	IAPP_CMD_MOVE_notify = 1,
	IAPP_CMD_MOVE_response = 2,
	IAPP_CMD_Send_Security_Block = 3,
	IAPP_CMD_ACK_Security_Block = 4,
	IAPP_CMD_CACHE_notify = 5,
	IAPP_CMD_CACHE_response = 6,
};


/* ADD-notify - multicast UDP on the local LAN */
struct iapp_add_notify {
	u8 addr_len; /* ETH_ALEN */
	u8 reserved;
	u8 mac_addr[ETH_ALEN];
	be16 seq_num;
} __attribute__ ((packed));


/* Layer 2 Update frame (802.2 Type 1 LLC XID Update response) */
struct iapp_layer2_update {
	u8 da[ETH_ALEN]; /* broadcast */
	u8 sa[ETH_ALEN]; /* STA addr */
	be16 len; /* 6 */
	u8 dsap; /* null DSAP address */
	u8 ssap; /* null SSAP address, CR=Response */
	u8 control;
	u8 xid_info[3];
} __attribute__ ((packed));


/* MOVE-notify - unicast TCP */
struct iapp_move_notify {
	u8 addr_len; /* ETH_ALEN */
	u8 reserved;
	u8 mac_addr[ETH_ALEN];
	u16 seq_num;
	u16 ctx_block_len;
	/* followed by ctx_block_len bytes */
} __attribute__ ((packed));


/* MOVE-response - unicast TCP */
struct iapp_move_response {
	u8 addr_len; /* ETH_ALEN */
	u8 status;
	u8 mac_addr[ETH_ALEN];
	u16 seq_num;
	u16 ctx_block_len;
	/* followed by ctx_block_len bytes */
} __attribute__ ((packed));

enum {
	IAPP_MOVE_SUCCESSFUL = 0,
	IAPP_MOVE_DENIED = 1,
	IAPP_MOVE_STALE_MOVE = 2,
};


/* CACHE-notify */
struct iapp_cache_notify {
	u8 addr_len; /* ETH_ALEN */
	u8 reserved;
	u8 mac_addr[ETH_ALEN];
	u16 seq_num;
	u8 current_ap[ETH_ALEN];
	u16 ctx_block_len;
	/* ctx_block_len bytes of context block followed by 16-bit context
	 * timeout */
} __attribute__ ((packed));


/* CACHE-response - unicast TCP */
struct iapp_cache_response {
	u8 addr_len; /* ETH_ALEN */
	u8 status;
	u8 mac_addr[ETH_ALEN];
	u16 seq_num;
} __attribute__ ((packed));

enum {
	IAPP_CACHE_SUCCESSFUL = 0,
	IAPP_CACHE_STALE_CACHE = 1,
};


/* Send-Security-Block - unicast TCP */
struct iapp_send_security_block {
	u8 iv[8];
	u16 sec_block_len;
	/* followed by sec_block_len bytes of security block */
} __attribute__ ((packed));


/* ACK-Security-Block - unicast TCP */
struct iapp_ack_security_block {
	u8 iv[8];
	u8 new_ap_ack_authenticator[48];
} __attribute__ ((packed));


struct iapp_data {
	struct hostapd_data *hapd;
	u16 identifier; /* next IAPP identifier */
	struct in_addr own, multicast;
	int udp_sock;
	int packet_sock;
};


static void iapp_send_add(struct iapp_data *iapp, u8 *mac_addr, u16 seq_num)
{
	char buf[128];
	struct iapp_hdr *hdr;
	struct iapp_add_notify *add;
	struct sockaddr_in addr;

	/* Send IAPP ADD-notify to remove possible association from other APs
	 */

	hdr = (struct iapp_hdr *) buf;
	hdr->version = IAPP_VERSION;
	hdr->command = IAPP_CMD_ADD_notify;
	hdr->identifier = host_to_be16(iapp->identifier++);
	hdr->length = host_to_be16(sizeof(*hdr) + sizeof(*add));

	add = (struct iapp_add_notify *) (hdr + 1);
	add->addr_len = ETH_ALEN;
	add->reserved = 0;
	os_memcpy(add->mac_addr, mac_addr, ETH_ALEN);

	add->seq_num = host_to_be16(seq_num);

	os_memset(&addr, 0, sizeof(addr));
	addr.sin_family = AF_INET;
	addr.sin_addr.s_addr = iapp->multicast.s_addr;
	addr.sin_port = htons(IAPP_UDP_PORT);
	if (sendto(iapp->udp_sock, buf, (char *) (add + 1) - buf, 0,
		   (struct sockaddr *) &addr, sizeof(addr)) < 0)
		wpa_printf(MSG_INFO, "sendto[IAPP-ADD]: %s", strerror(errno));
}


static void iapp_send_layer2_update(struct iapp_data *iapp, u8 *addr)
{
	struct iapp_layer2_update msg;

	/* Send Level 2 Update Frame to update forwarding tables in layer 2
	 * bridge devices */

	/* 802.2 Type 1 Logical Link Control (LLC) Exchange Identifier (XID)
	 * Update response frame; IEEE Std 802.2-1998, 5.4.1.2.1 */

	os_memset(msg.da, 0xff, ETH_ALEN);
	os_memcpy(msg.sa, addr, ETH_ALEN);
	msg.len = host_to_be16(6);
	msg.dsap = 0; /* NULL DSAP address */
	msg.ssap = 0x01; /* NULL SSAP address, CR Bit: Response */
	msg.control = 0xaf; /* XID response lsb.1111F101.
			     * F=0 (no poll command; unsolicited frame) */
	msg.xid_info[0] = 0x81; /* XID format identifier */
	msg.xid_info[1] = 1; /* LLC types/classes: Type 1 LLC */
	msg.xid_info[2] = 1 << 1; /* XID sender's receive window size (RW)
				   * FIX: what is correct RW with 802.11? */

	if (send(iapp->packet_sock, &msg, sizeof(msg), 0) < 0)
		wpa_printf(MSG_INFO, "send[L2 Update]: %s", strerror(errno));
}


/**
 * iapp_new_station - IAPP processing for a new STA
 * @iapp: IAPP data
 * @sta: The associated station
 */
void iapp_new_station(struct iapp_data *iapp, struct sta_info *sta)
{
	struct ieee80211_mgmt *assoc;
	u16 seq;

	if (iapp == NULL)
		return;

	assoc = sta->last_assoc_req;
	seq = assoc ? WLAN_GET_SEQ_SEQ(le_to_host16(assoc->seq_ctrl)) : 0;

	/* IAPP-ADD.request(MAC Address, Sequence Number, Timeout) */
	hostapd_logger(iapp->hapd, sta->addr, HOSTAPD_MODULE_IAPP,
		       HOSTAPD_LEVEL_DEBUG, "IAPP-ADD.request(seq=%d)", seq);
	iapp_send_layer2_update(iapp, sta->addr);
	iapp_send_add(iapp, sta->addr, seq);

	if (assoc && WLAN_FC_GET_STYPE(le_to_host16(assoc->frame_control)) ==
	    WLAN_FC_STYPE_REASSOC_REQ) {
		/* IAPP-MOVE.request(MAC Address, Sequence Number, Old AP,
		 *                   Context Block, Timeout)
		 */
		/* TODO: Send IAPP-MOVE to the old AP; Map Old AP BSSID to
		 * IP address */
	}
}


static void iapp_process_add_notify(struct iapp_data *iapp,
				    struct sockaddr_in *from,
				    struct iapp_hdr *hdr, int len)
{
	struct iapp_add_notify *add = (struct iapp_add_notify *) (hdr + 1);
	struct sta_info *sta;

	if (len != sizeof(*add)) {
		wpa_printf(MSG_INFO, "Invalid IAPP-ADD packet length %d (expected %lu)",
			   len, (unsigned long) sizeof(*add));
		return;
	}

	sta = ap_get_sta(iapp->hapd, add->mac_addr);

	/* IAPP-ADD.indication(MAC Address, Sequence Number) */
	hostapd_logger(iapp->hapd, add->mac_addr, HOSTAPD_MODULE_IAPP,
		       HOSTAPD_LEVEL_INFO,
		       "Received IAPP ADD-notify (seq# %d) from %s:%d%s",
		       be_to_host16(add->seq_num),
		       inet_ntoa(from->sin_addr), ntohs(from->sin_port),
		       sta ? "" : " (STA not found)");

	if (!sta)
		return;

	/* TODO: could use seq_num to try to determine whether last association
	 * to this AP is newer than the one advertised in IAPP-ADD. Although,
	 * this is not really a reliable verification. */

	hostapd_logger(iapp->hapd, add->mac_addr, HOSTAPD_MODULE_IAPP,
		       HOSTAPD_LEVEL_DEBUG,
		       "Removing STA due to IAPP ADD-notify");
	ap_sta_disconnect(iapp->hapd, sta, NULL, 0);
}


/**
 * iapp_receive_udp - Process IAPP UDP frames
 * @sock: File descriptor for the socket
 * @eloop_ctx: IAPP data (struct iapp_data *)
 * @sock_ctx: Not used
 */
static void iapp_receive_udp(int sock, void *eloop_ctx, void *sock_ctx)
{
	struct iapp_data *iapp = eloop_ctx;
	int len, hlen;
	unsigned char buf[128];
	struct sockaddr_in from;
	socklen_t fromlen;
	struct iapp_hdr *hdr;

	/* Handle incoming IAPP frames (over UDP/IP) */

	fromlen = sizeof(from);
	len = recvfrom(iapp->udp_sock, buf, sizeof(buf), 0,
		       (struct sockaddr *) &from, &fromlen);
	if (len < 0) {
		wpa_printf(MSG_INFO, "iapp_receive_udp - recvfrom: %s",
			   strerror(errno));
		return;
	}

	if (from.sin_addr.s_addr == iapp->own.s_addr)
		return; /* ignore own IAPP messages */

	hostapd_logger(iapp->hapd, NULL, HOSTAPD_MODULE_IAPP,
		       HOSTAPD_LEVEL_DEBUG,
		       "Received %d byte IAPP frame from %s%s\n",
		       len, inet_ntoa(from.sin_addr),
		       len < (int) sizeof(*hdr) ? " (too short)" : "");

	if (len < (int) sizeof(*hdr))
		return;

	hdr = (struct iapp_hdr *) buf;
	hlen = be_to_host16(hdr->length);
	hostapd_logger(iapp->hapd, NULL, HOSTAPD_MODULE_IAPP,
		       HOSTAPD_LEVEL_DEBUG,
		       "RX: version=%d command=%d id=%d len=%d\n",
		       hdr->version, hdr->command,
		       be_to_host16(hdr->identifier), hlen);
	if (hdr->version != IAPP_VERSION) {
		wpa_printf(MSG_INFO, "Dropping IAPP frame with unknown version %d",
			   hdr->version);
		return;
	}
	if (hlen > len) {
		wpa_printf(MSG_INFO, "Underflow IAPP frame (hlen=%d len=%d)",
			   hlen, len);
		return;
	}
	if (hlen < len) {
		wpa_printf(MSG_INFO, "Ignoring %d extra bytes from IAPP frame",
			   len - hlen);
		len = hlen;
	}

	switch (hdr->command) {
	case IAPP_CMD_ADD_notify:
		iapp_process_add_notify(iapp, &from, hdr, hlen - sizeof(*hdr));
		break;
	case IAPP_CMD_MOVE_notify:
		/* TODO: MOVE is using TCP; so move this to TCP handler once it
		 * is implemented.. */
		/* IAPP-MOVE.indication(MAC Address, New BSSID,
		 * Sequence Number, AP Address, Context Block) */
		/* TODO: process */
		break;
	default:
		wpa_printf(MSG_INFO, "Unknown IAPP command %d", hdr->command);
		break;
	}
}


struct iapp_data * iapp_init(struct hostapd_data *hapd, const char *iface)
{
	struct ifreq ifr;
	struct sockaddr_ll addr;
	int ifindex;
	struct sockaddr_in *paddr, uaddr;
	struct iapp_data *iapp;
	struct ip_mreqn mreq;

	iapp = os_zalloc(sizeof(*iapp));
	if (iapp == NULL)
		return NULL;
	iapp->hapd = hapd;
	iapp->udp_sock = iapp->packet_sock = -1;

	/* TODO:
	 * open socket for sending and receiving IAPP frames over TCP
	 */

	iapp->udp_sock = socket(PF_INET, SOCK_DGRAM, 0);
	if (iapp->udp_sock < 0) {
		wpa_printf(MSG_INFO, "iapp_init - socket[PF_INET,SOCK_DGRAM]: %s",
			   strerror(errno));
		iapp_deinit(iapp);
		return NULL;
	}

	os_memset(&ifr, 0, sizeof(ifr));
	os_strlcpy(ifr.ifr_name, iface, sizeof(ifr.ifr_name));
	if (ioctl(iapp->udp_sock, SIOCGIFINDEX, &ifr) != 0) {
		wpa_printf(MSG_INFO, "iapp_init - ioctl(SIOCGIFINDEX): %s",
			   strerror(errno));
		iapp_deinit(iapp);
		return NULL;
	}
	ifindex = ifr.ifr_ifindex;

	if (ioctl(iapp->udp_sock, SIOCGIFADDR, &ifr) != 0) {
		wpa_printf(MSG_INFO, "iapp_init - ioctl(SIOCGIFADDR): %s",
			   strerror(errno));
		iapp_deinit(iapp);
		return NULL;
	}
	paddr = (struct sockaddr_in *) &ifr.ifr_addr;
	if (paddr->sin_family != AF_INET) {
		wpa_printf(MSG_INFO, "IAPP: Invalid address family %i (SIOCGIFADDR)",
			   paddr->sin_family);
		iapp_deinit(iapp);
		return NULL;
	}
	iapp->own.s_addr = paddr->sin_addr.s_addr;

	if (ioctl(iapp->udp_sock, SIOCGIFBRDADDR, &ifr) != 0) {
		wpa_printf(MSG_INFO, "iapp_init - ioctl(SIOCGIFBRDADDR): %s",
			   strerror(errno));
		iapp_deinit(iapp);
		return NULL;
	}
	paddr = (struct sockaddr_in *) &ifr.ifr_addr;
	if (paddr->sin_family != AF_INET) {
		wpa_printf(MSG_INFO, "Invalid address family %i (SIOCGIFBRDADDR)",
			   paddr->sin_family);
		iapp_deinit(iapp);
		return NULL;
	}
	inet_aton(IAPP_MULTICAST, &iapp->multicast);

	os_memset(&uaddr, 0, sizeof(uaddr));
	uaddr.sin_family = AF_INET;
	uaddr.sin_port = htons(IAPP_UDP_PORT);
	if (bind(iapp->udp_sock, (struct sockaddr *) &uaddr,
		 sizeof(uaddr)) < 0) {
		wpa_printf(MSG_INFO, "iapp_init - bind[UDP]: %s",
			   strerror(errno));
		iapp_deinit(iapp);
		return NULL;
	}

	os_memset(&mreq, 0, sizeof(mreq));
	mreq.imr_multiaddr = iapp->multicast;
	mreq.imr_address.s_addr = INADDR_ANY;
	mreq.imr_ifindex = 0;
	if (setsockopt(iapp->udp_sock, SOL_IP, IP_ADD_MEMBERSHIP, &mreq,
		       sizeof(mreq)) < 0) {
		wpa_printf(MSG_INFO, "iapp_init - setsockopt[UDP,IP_ADD_MEMBERSHIP]: %s",
			   strerror(errno));
		iapp_deinit(iapp);
		return NULL;
	}

	iapp->packet_sock = socket(PF_PACKET, SOCK_RAW, htons(ETH_P_ALL));
	if (iapp->packet_sock < 0) {
		wpa_printf(MSG_INFO, "iapp_init - socket[PF_PACKET,SOCK_RAW]: %s",
			   strerror(errno));
		iapp_deinit(iapp);
		return NULL;
	}

	os_memset(&addr, 0, sizeof(addr));
	addr.sll_family = AF_PACKET;
	addr.sll_ifindex = ifindex;
	if (bind(iapp->packet_sock, (struct sockaddr *) &addr,
		 sizeof(addr)) < 0) {
		wpa_printf(MSG_INFO, "iapp_init - bind[PACKET]: %s",
			   strerror(errno));
		iapp_deinit(iapp);
		return NULL;
	}

	if (eloop_register_read_sock(iapp->udp_sock, iapp_receive_udp,
				     iapp, NULL)) {
		wpa_printf(MSG_INFO, "Could not register read socket for IAPP");
		iapp_deinit(iapp);
		return NULL;
	}

	wpa_printf(MSG_INFO, "IEEE 802.11F (IAPP) using interface %s", iface);

	/* TODO: For levels 2 and 3: send RADIUS Initiate-Request, receive
	 * RADIUS Initiate-Accept or Initiate-Reject. IAPP port should actually
	 * be openned only after receiving Initiate-Accept. If Initiate-Reject
	 * is received, IAPP is not started. */

	return iapp;
}


void iapp_deinit(struct iapp_data *iapp)
{
	struct ip_mreqn mreq;

	if (iapp == NULL)
		return;

	if (iapp->udp_sock >= 0) {
		os_memset(&mreq, 0, sizeof(mreq));
		mreq.imr_multiaddr = iapp->multicast;
		mreq.imr_address.s_addr = INADDR_ANY;
		mreq.imr_ifindex = 0;
		if (setsockopt(iapp->udp_sock, SOL_IP, IP_DROP_MEMBERSHIP,
			       &mreq, sizeof(mreq)) < 0) {
			wpa_printf(MSG_INFO, "iapp_deinit - setsockopt[UDP,IP_DEL_MEMBERSHIP]: %s",
				   strerror(errno));
		}

		eloop_unregister_read_sock(iapp->udp_sock);
		close(iapp->udp_sock);
	}
	if (iapp->packet_sock >= 0) {
		eloop_unregister_read_sock(iapp->packet_sock);
		close(iapp->packet_sock);
	}
	os_free(iapp);
}
Commit	Line	Data
	1	/*
	2	* hostapd / IEEE 802.11F-2003 Inter-Access Point Protocol (IAPP)
	3	* Copyright (c) 2002-2007, Jouni Malinen <j@w1.fi>
	4	*
	5	* This software may be distributed under the terms of the BSD license.
	6	* See README for more details.
	7	*
	8	* Note: IEEE 802.11F-2003 was a experimental use specification. It has expired
	9	* and IEEE has withdrawn it. In other words, it is likely better to look at
	10	* using some other mechanism for AP-to-AP communication than extending the
	11	* implementation here.
	12	*/
	13
	14	/* TODO:
	15	* Level 1: no administrative or security support
	16	* (e.g., static BSSID to IP address mapping in each AP)
	17	* Level 2: support for dynamic mapping of BSSID to IP address
	18	* Level 3: support for encryption and authentication of IAPP messages
	19	* - add support for MOVE-notify and MOVE-response (this requires support for
	20	* finding out IP address for previous AP using RADIUS)
	21	* - add support for Send- and ACK-Security-Block to speedup IEEE 802.1X during
	22	* reassociation to another AP
	23	* - implement counters etc. for IAPP MIB
	24	* - verify endianness of fields in IAPP messages; are they big-endian as
	25	* used here?
	26	* - RADIUS connection for AP registration and BSSID to IP address mapping
	27	* - TCP connection for IAPP MOVE, CACHE
	28	* - broadcast ESP for IAPP ADD-notify
	29	* - ESP for IAPP MOVE messages
	30	* - security block sending/processing
	31	* - IEEE 802.11 context transfer
	32	*/
	33
	34	#include "utils/includes.h"
	35	#include <net/if.h>
	36	#include <sys/ioctl.h>
	37	#ifdef USE_KERNEL_HEADERS
	38	#include <linux/if_packet.h>
	39	#else /* USE_KERNEL_HEADERS */
	40	#include <netpacket/packet.h>
	41	#endif /* USE_KERNEL_HEADERS */
	42
	43	#include "utils/common.h"
	44	#include "utils/eloop.h"
	45	#include "common/ieee802_11_defs.h"
	46	#include "hostapd.h"
	47	#include "ap_config.h"
	48	#include "ieee802_11.h"
	49	#include "sta_info.h"
	50	#include "iapp.h"
	51
	52
	53	#define IAPP_MULTICAST "224.0.1.178"
	54	#define IAPP_UDP_PORT 3517
	55	#define IAPP_TCP_PORT 3517
	56
	57	struct iapp_hdr {
	58	u8 version;
	59	u8 command;
	60	be16 identifier;
	61	be16 length;
	62	/* followed by length-6 octets of data */
	63	} __attribute__ ((packed));
	64
	65	#define IAPP_VERSION 0
	66
	67	enum IAPP_COMMAND {
	68	IAPP_CMD_ADD_notify = 0,
	69	IAPP_CMD_MOVE_notify = 1,
	70	IAPP_CMD_MOVE_response = 2,
	71	IAPP_CMD_Send_Security_Block = 3,
	72	IAPP_CMD_ACK_Security_Block = 4,
	73	IAPP_CMD_CACHE_notify = 5,
	74	IAPP_CMD_CACHE_response = 6,
	75	};
	76
	77
	78	/* ADD-notify - multicast UDP on the local LAN */
	79	struct iapp_add_notify {
	80	u8 addr_len; /* ETH_ALEN */
	81	u8 reserved;
	82	u8 mac_addr[ETH_ALEN];
	83	be16 seq_num;
	84	} __attribute__ ((packed));
	85
	86
	87	/* Layer 2 Update frame (802.2 Type 1 LLC XID Update response) */
	88	struct iapp_layer2_update {
	89	u8 da[ETH_ALEN]; /* broadcast */
	90	u8 sa[ETH_ALEN]; /* STA addr */
	91	be16 len; /* 6 */
	92	u8 dsap; /* null DSAP address */
	93	u8 ssap; /* null SSAP address, CR=Response */
	94	u8 control;
	95	u8 xid_info[3];
	96	} __attribute__ ((packed));
	97
	98
	99	/* MOVE-notify - unicast TCP */
	100	struct iapp_move_notify {
	101	u8 addr_len; /* ETH_ALEN */
	102	u8 reserved;
	103	u8 mac_addr[ETH_ALEN];
	104	u16 seq_num;
	105	u16 ctx_block_len;
	106	/* followed by ctx_block_len bytes */
	107	} __attribute__ ((packed));
	108
	109
	110	/* MOVE-response - unicast TCP */
	111	struct iapp_move_response {
	112	u8 addr_len; /* ETH_ALEN */
	113	u8 status;
	114	u8 mac_addr[ETH_ALEN];
	115	u16 seq_num;
	116	u16 ctx_block_len;
	117	/* followed by ctx_block_len bytes */
	118	} __attribute__ ((packed));
	119
	120	enum {
	121	IAPP_MOVE_SUCCESSFUL = 0,
	122	IAPP_MOVE_DENIED = 1,
	123	IAPP_MOVE_STALE_MOVE = 2,
	124	};
	125
	126
	127	/* CACHE-notify */
	128	struct iapp_cache_notify {
	129	u8 addr_len; /* ETH_ALEN */
	130	u8 reserved;
	131	u8 mac_addr[ETH_ALEN];
	132	u16 seq_num;
	133	u8 current_ap[ETH_ALEN];
	134	u16 ctx_block_len;
	135	/* ctx_block_len bytes of context block followed by 16-bit context
	136	* timeout */
	137	} __attribute__ ((packed));
	138
	139
	140	/* CACHE-response - unicast TCP */
	141	struct iapp_cache_response {
	142	u8 addr_len; /* ETH_ALEN */
	143	u8 status;
	144	u8 mac_addr[ETH_ALEN];
	145	u16 seq_num;
	146	} __attribute__ ((packed));
	147
	148	enum {
	149	IAPP_CACHE_SUCCESSFUL = 0,
	150	IAPP_CACHE_STALE_CACHE = 1,
	151	};
	152
	153
	154	/* Send-Security-Block - unicast TCP */
	155	struct iapp_send_security_block {
	156	u8 iv[8];
	157	u16 sec_block_len;
	158	/* followed by sec_block_len bytes of security block */
	159	} __attribute__ ((packed));
	160
	161
	162	/* ACK-Security-Block - unicast TCP */
	163	struct iapp_ack_security_block {
	164	u8 iv[8];
	165	u8 new_ap_ack_authenticator[48];
	166	} __attribute__ ((packed));
	167
	168
	169	struct iapp_data {
	170	struct hostapd_data *hapd;
	171	u16 identifier; /* next IAPP identifier */
	172	struct in_addr own, multicast;
	173	int udp_sock;
	174	int packet_sock;
	175	};
	176
	177
	178	static void iapp_send_add(struct iapp_data iapp, u8 mac_addr, u16 seq_num)
	179	{
	180	char buf[128];
	181	struct iapp_hdr *hdr;
	182	struct iapp_add_notify *add;
	183	struct sockaddr_in addr;
	184
	185	/* Send IAPP ADD-notify to remove possible association from other APs
	186	*/
	187
	188	hdr = (struct iapp_hdr *) buf;
	189	hdr->version = IAPP_VERSION;
	190	hdr->command = IAPP_CMD_ADD_notify;
	191	hdr->identifier = host_to_be16(iapp->identifier++);
	192	hdr->length = host_to_be16(sizeof(hdr) + sizeof(add));
	193
	194	add = (struct iapp_add_notify *) (hdr + 1);
	195	add->addr_len = ETH_ALEN;
	196	add->reserved = 0;
	197	os_memcpy(add->mac_addr, mac_addr, ETH_ALEN);
	198
	199	add->seq_num = host_to_be16(seq_num);
	200
	201	os_memset(&addr, 0, sizeof(addr));
	202	addr.sin_family = AF_INET;
	203	addr.sin_addr.s_addr = iapp->multicast.s_addr;
	204	addr.sin_port = htons(IAPP_UDP_PORT);
	205	if (sendto(iapp->udp_sock, buf, (char *) (add + 1) - buf, 0,
	206	(struct sockaddr *) &addr, sizeof(addr)) < 0)
	207	wpa_printf(MSG_INFO, "sendto[IAPP-ADD]: %s", strerror(errno));
	208	}
	209
	210
	211	static void iapp_send_layer2_update(struct iapp_data iapp, u8 addr)
	212	{
	213	struct iapp_layer2_update msg;
	214
	215	/* Send Level 2 Update Frame to update forwarding tables in layer 2
	216	* bridge devices */
	217
	218	/* 802.2 Type 1 Logical Link Control (LLC) Exchange Identifier (XID)
	219	* Update response frame; IEEE Std 802.2-1998, 5.4.1.2.1 */
	220
	221	os_memset(msg.da, 0xff, ETH_ALEN);
	222	os_memcpy(msg.sa, addr, ETH_ALEN);
	223	msg.len = host_to_be16(6);
	224	msg.dsap = 0; /* NULL DSAP address */
	225	msg.ssap = 0x01; /* NULL SSAP address, CR Bit: Response */
	226	msg.control = 0xaf; /* XID response lsb.1111F101.
	227	* F=0 (no poll command; unsolicited frame) */
	228	msg.xid_info[0] = 0x81; /* XID format identifier */
	229	msg.xid_info[1] = 1; /* LLC types/classes: Type 1 LLC */
	230	msg.xid_info[2] = 1 << 1; /* XID sender's receive window size (RW)
	231	* FIX: what is correct RW with 802.11? */
	232
	233	if (send(iapp->packet_sock, &msg, sizeof(msg), 0) < 0)
	234	wpa_printf(MSG_INFO, "send[L2 Update]: %s", strerror(errno));
	235	}
	236
	237
	238	/**
	239	* iapp_new_station - IAPP processing for a new STA
	240	* @iapp: IAPP data
	241	* @sta: The associated station
	242	*/
	243	void iapp_new_station(struct iapp_data iapp, struct sta_info sta)
	244	{
	245	struct ieee80211_mgmt *assoc;
	246	u16 seq;
	247
	248	if (iapp == NULL)
	249	return;
	250
	251	assoc = sta->last_assoc_req;
	252	seq = assoc ? WLAN_GET_SEQ_SEQ(le_to_host16(assoc->seq_ctrl)) : 0;
	253
	254	/* IAPP-ADD.request(MAC Address, Sequence Number, Timeout) */
	255	hostapd_logger(iapp->hapd, sta->addr, HOSTAPD_MODULE_IAPP,
	256	HOSTAPD_LEVEL_DEBUG, "IAPP-ADD.request(seq=%d)", seq);
	257	iapp_send_layer2_update(iapp, sta->addr);
	258	iapp_send_add(iapp, sta->addr, seq);
	259
	260	if (assoc && WLAN_FC_GET_STYPE(le_to_host16(assoc->frame_control)) ==
	261	WLAN_FC_STYPE_REASSOC_REQ) {
	262	/* IAPP-MOVE.request(MAC Address, Sequence Number, Old AP,
	263	* Context Block, Timeout)
	264	*/
	265	/* TODO: Send IAPP-MOVE to the old AP; Map Old AP BSSID to
	266	* IP address */
	267	}
	268	}
	269
	270
	271	static void iapp_process_add_notify(struct iapp_data *iapp,
	272	struct sockaddr_in *from,
	273	struct iapp_hdr *hdr, int len)
	274	{
	275	struct iapp_add_notify add = (struct iapp_add_notify ) (hdr + 1);
	276	struct sta_info *sta;
	277
	278	if (len != sizeof(*add)) {
	279	wpa_printf(MSG_INFO, "Invalid IAPP-ADD packet length %d (expected %lu)",
	280	len, (unsigned long) sizeof(*add));
	281	return;
	282	}
	283
	284	sta = ap_get_sta(iapp->hapd, add->mac_addr);
	285
	286	/* IAPP-ADD.indication(MAC Address, Sequence Number) */
	287	hostapd_logger(iapp->hapd, add->mac_addr, HOSTAPD_MODULE_IAPP,
	288	HOSTAPD_LEVEL_INFO,
	289	"Received IAPP ADD-notify (seq# %d) from %s:%d%s",
	290	be_to_host16(add->seq_num),
	291	inet_ntoa(from->sin_addr), ntohs(from->sin_port),
	292	sta ? "" : " (STA not found)");
	293
	294	if (!sta)
	295	return;
	296
	297	/* TODO: could use seq_num to try to determine whether last association
	298	* to this AP is newer than the one advertised in IAPP-ADD. Although,
	299	* this is not really a reliable verification. */
	300
	301	hostapd_logger(iapp->hapd, add->mac_addr, HOSTAPD_MODULE_IAPP,
	302	HOSTAPD_LEVEL_DEBUG,
	303	"Removing STA due to IAPP ADD-notify");
	304	ap_sta_disconnect(iapp->hapd, sta, NULL, 0);
	305	}
	306
	307
	308	/**
	309	* iapp_receive_udp - Process IAPP UDP frames
	310	* @sock: File descriptor for the socket
	311	* @eloop_ctx: IAPP data (struct iapp_data *)
	312	* @sock_ctx: Not used
	313	*/
	314	static void iapp_receive_udp(int sock, void eloop_ctx, void sock_ctx)
	315	{
	316	struct iapp_data *iapp = eloop_ctx;
	317	int len, hlen;
	318	unsigned char buf[128];
	319	struct sockaddr_in from;
	320	socklen_t fromlen;
	321	struct iapp_hdr *hdr;
	322
	323	/* Handle incoming IAPP frames (over UDP/IP) */
	324
	325	fromlen = sizeof(from);
	326	len = recvfrom(iapp->udp_sock, buf, sizeof(buf), 0,
	327	(struct sockaddr *) &from, &fromlen);
	328	if (len < 0) {
	329	wpa_printf(MSG_INFO, "iapp_receive_udp - recvfrom: %s",
	330	strerror(errno));
	331	return;
	332	}
	333
	334	if (from.sin_addr.s_addr == iapp->own.s_addr)
	335	return; /* ignore own IAPP messages */
	336
	337	hostapd_logger(iapp->hapd, NULL, HOSTAPD_MODULE_IAPP,
	338	HOSTAPD_LEVEL_DEBUG,
	339	"Received %d byte IAPP frame from %s%s\n",
	340	len, inet_ntoa(from.sin_addr),
	341	len < (int) sizeof(*hdr) ? " (too short)" : "");
	342
	343	if (len < (int) sizeof(*hdr))
	344	return;
	345
	346	hdr = (struct iapp_hdr *) buf;
	347	hlen = be_to_host16(hdr->length);
	348	hostapd_logger(iapp->hapd, NULL, HOSTAPD_MODULE_IAPP,
	349	HOSTAPD_LEVEL_DEBUG,
	350	"RX: version=%d command=%d id=%d len=%d\n",
	351	hdr->version, hdr->command,
	352	be_to_host16(hdr->identifier), hlen);
	353	if (hdr->version != IAPP_VERSION) {
	354	wpa_printf(MSG_INFO, "Dropping IAPP frame with unknown version %d",
	355	hdr->version);
	356	return;
	357	}
	358	if (hlen > len) {
	359	wpa_printf(MSG_INFO, "Underflow IAPP frame (hlen=%d len=%d)",
	360	hlen, len);
	361	return;
	362	}
	363	if (hlen < len) {
	364	wpa_printf(MSG_INFO, "Ignoring %d extra bytes from IAPP frame",
	365	len - hlen);
	366	len = hlen;
	367	}
	368
	369	switch (hdr->command) {
	370	case IAPP_CMD_ADD_notify:
	371	iapp_process_add_notify(iapp, &from, hdr, hlen - sizeof(*hdr));
	372	break;
	373	case IAPP_CMD_MOVE_notify:
	374	/* TODO: MOVE is using TCP; so move this to TCP handler once it
	375	* is implemented.. */
	376	/* IAPP-MOVE.indication(MAC Address, New BSSID,
	377	* Sequence Number, AP Address, Context Block) */
	378	/* TODO: process */
	379	break;
	380	default:
	381	wpa_printf(MSG_INFO, "Unknown IAPP command %d", hdr->command);
	382	break;
	383	}
	384	}
	385
	386
	387	struct iapp_data * iapp_init(struct hostapd_data hapd, const char iface)
	388	{
	389	struct ifreq ifr;
	390	struct sockaddr_ll addr;
	391	int ifindex;
	392	struct sockaddr_in *paddr, uaddr;
	393	struct iapp_data *iapp;
	394	struct ip_mreqn mreq;
	395
	396	iapp = os_zalloc(sizeof(*iapp));
	397	if (iapp == NULL)
	398	return NULL;
	399	iapp->hapd = hapd;
	400	iapp->udp_sock = iapp->packet_sock = -1;
	401
	402	/* TODO:
	403	* open socket for sending and receiving IAPP frames over TCP
	404	*/
	405
	406	iapp->udp_sock = socket(PF_INET, SOCK_DGRAM, 0);
	407	if (iapp->udp_sock < 0) {
	408	wpa_printf(MSG_INFO, "iapp_init - socket[PF_INET,SOCK_DGRAM]: %s",
	409	strerror(errno));
	410	iapp_deinit(iapp);
	411	return NULL;
	412	}
	413
	414	os_memset(&ifr, 0, sizeof(ifr));
	415	os_strlcpy(ifr.ifr_name, iface, sizeof(ifr.ifr_name));
	416	if (ioctl(iapp->udp_sock, SIOCGIFINDEX, &ifr) != 0) {
	417	wpa_printf(MSG_INFO, "iapp_init - ioctl(SIOCGIFINDEX): %s",
	418	strerror(errno));
	419	iapp_deinit(iapp);
	420	return NULL;
	421	}
	422	ifindex = ifr.ifr_ifindex;
	423
	424	if (ioctl(iapp->udp_sock, SIOCGIFADDR, &ifr) != 0) {
	425	wpa_printf(MSG_INFO, "iapp_init - ioctl(SIOCGIFADDR): %s",
	426	strerror(errno));
	427	iapp_deinit(iapp);
	428	return NULL;
	429	}
	430	paddr = (struct sockaddr_in *) &ifr.ifr_addr;
	431	if (paddr->sin_family != AF_INET) {
	432	wpa_printf(MSG_INFO, "IAPP: Invalid address family %i (SIOCGIFADDR)",
	433	paddr->sin_family);
	434	iapp_deinit(iapp);
	435	return NULL;
	436	}
	437	iapp->own.s_addr = paddr->sin_addr.s_addr;
	438
	439	if (ioctl(iapp->udp_sock, SIOCGIFBRDADDR, &ifr) != 0) {
	440	wpa_printf(MSG_INFO, "iapp_init - ioctl(SIOCGIFBRDADDR): %s",
	441	strerror(errno));
	442	iapp_deinit(iapp);
	443	return NULL;
	444	}
	445	paddr = (struct sockaddr_in *) &ifr.ifr_addr;
	446	if (paddr->sin_family != AF_INET) {
	447	wpa_printf(MSG_INFO, "Invalid address family %i (SIOCGIFBRDADDR)",
	448	paddr->sin_family);
	449	iapp_deinit(iapp);
	450	return NULL;
	451	}
	452	inet_aton(IAPP_MULTICAST, &iapp->multicast);
	453
	454	os_memset(&uaddr, 0, sizeof(uaddr));
	455	uaddr.sin_family = AF_INET;
	456	uaddr.sin_port = htons(IAPP_UDP_PORT);
	457	if (bind(iapp->udp_sock, (struct sockaddr *) &uaddr,
	458	sizeof(uaddr)) < 0) {
	459	wpa_printf(MSG_INFO, "iapp_init - bind[UDP]: %s",
	460	strerror(errno));
	461	iapp_deinit(iapp);
	462	return NULL;
	463	}
	464
	465	os_memset(&mreq, 0, sizeof(mreq));
	466	mreq.imr_multiaddr = iapp->multicast;
	467	mreq.imr_address.s_addr = INADDR_ANY;
	468	mreq.imr_ifindex = 0;
	469	if (setsockopt(iapp->udp_sock, SOL_IP, IP_ADD_MEMBERSHIP, &mreq,
	470	sizeof(mreq)) < 0) {
	471	wpa_printf(MSG_INFO, "iapp_init - setsockopt[UDP,IP_ADD_MEMBERSHIP]: %s",
	472	strerror(errno));
	473	iapp_deinit(iapp);
	474	return NULL;
	475	}
	476
	477	iapp->packet_sock = socket(PF_PACKET, SOCK_RAW, htons(ETH_P_ALL));
	478	if (iapp->packet_sock < 0) {
	479	wpa_printf(MSG_INFO, "iapp_init - socket[PF_PACKET,SOCK_RAW]: %s",
	480	strerror(errno));
	481	iapp_deinit(iapp);
	482	return NULL;
	483	}
	484
	485	os_memset(&addr, 0, sizeof(addr));
	486	addr.sll_family = AF_PACKET;
	487	addr.sll_ifindex = ifindex;
	488	if (bind(iapp->packet_sock, (struct sockaddr *) &addr,
	489	sizeof(addr)) < 0) {
	490	wpa_printf(MSG_INFO, "iapp_init - bind[PACKET]: %s",
	491	strerror(errno));
	492	iapp_deinit(iapp);
	493	return NULL;
	494	}
	495
	496	if (eloop_register_read_sock(iapp->udp_sock, iapp_receive_udp,
	497	iapp, NULL)) {
	498	wpa_printf(MSG_INFO, "Could not register read socket for IAPP");
	499	iapp_deinit(iapp);
	500	return NULL;
	501	}
	502
	503	wpa_printf(MSG_INFO, "IEEE 802.11F (IAPP) using interface %s", iface);
	504
	505	/* TODO: For levels 2 and 3: send RADIUS Initiate-Request, receive
	506	* RADIUS Initiate-Accept or Initiate-Reject. IAPP port should actually
	507	* be openned only after receiving Initiate-Accept. If Initiate-Reject
	508	* is received, IAPP is not started. */
	509
	510	return iapp;
	511	}
	512
	513
	514	void iapp_deinit(struct iapp_data *iapp)
	515	{
	516	struct ip_mreqn mreq;
	517
	518	if (iapp == NULL)
	519	return;
	520
	521	if (iapp->udp_sock >= 0) {
	522	os_memset(&mreq, 0, sizeof(mreq));
	523	mreq.imr_multiaddr = iapp->multicast;
	524	mreq.imr_address.s_addr = INADDR_ANY;
	525	mreq.imr_ifindex = 0;
	526	if (setsockopt(iapp->udp_sock, SOL_IP, IP_DROP_MEMBERSHIP,
	527	&mreq, sizeof(mreq)) < 0) {
	528	wpa_printf(MSG_INFO, "iapp_deinit - setsockopt[UDP,IP_DEL_MEMBERSHIP]: %s",
	529	strerror(errno));
	530	}
	531
	532	eloop_unregister_read_sock(iapp->udp_sock);
	533	close(iapp->udp_sock);
	534	}
	535	if (iapp->packet_sock >= 0) {
	536	eloop_unregister_read_sock(iapp->packet_sock);
	537	close(iapp->packet_sock);
	538	}
	539	os_free(iapp);
	540	}