[thirdparty/hostap.git] / src / l2_packet / l2_packet_privsep.c

/*
 * WPA Supplicant - Layer2 packet handling with privilege separation
 * Copyright (c) 2007, Jouni Malinen <j@w1.fi>
 *
 * This software may be distributed under the terms of the BSD license.
 * See README for more details.
 */

#include "includes.h"
#include <sys/un.h>

#include "common.h"
#include "eloop.h"
#include "l2_packet.h"
#include "common/privsep_commands.h"


struct l2_packet_data {
	int fd; /* UNIX domain socket for privsep access */
	void (*rx_callback)(void *ctx, const u8 *src_addr,
			    const u8 *buf, size_t len);
	void *rx_callback_ctx;
	u8 own_addr[ETH_ALEN];
	char *own_socket_path;
	struct sockaddr_un priv_addr;
};


static int wpa_priv_cmd(struct l2_packet_data *l2, int cmd,
			const void *data, size_t data_len)
{
	struct msghdr msg;
	struct iovec io[2];

	io[0].iov_base = &cmd;
	io[0].iov_len = sizeof(cmd);
	io[1].iov_base = (u8 *) data;
	io[1].iov_len = data_len;

	os_memset(&msg, 0, sizeof(msg));
	msg.msg_iov = io;
	msg.msg_iovlen = data ? 2 : 1;
	msg.msg_name = &l2->priv_addr;
	msg.msg_namelen = sizeof(l2->priv_addr);

	if (sendmsg(l2->fd, &msg, 0) < 0) {
		wpa_printf(MSG_ERROR, "L2: sendmsg(cmd): %s", strerror(errno));
		return -1;
	}

	return 0;
}

			     
int l2_packet_get_own_addr(struct l2_packet_data *l2, u8 *addr)
{
	os_memcpy(addr, l2->own_addr, ETH_ALEN);
	return 0;
}


int l2_packet_send(struct l2_packet_data *l2, const u8 *dst_addr, u16 proto,
		   const u8 *buf, size_t len)
{
	struct msghdr msg;
	struct iovec io[4];
	int cmd = PRIVSEP_CMD_L2_SEND;

	io[0].iov_base = &cmd;
	io[0].iov_len = sizeof(cmd);
	io[1].iov_base = &dst_addr;
	io[1].iov_len = ETH_ALEN;
	io[2].iov_base = &proto;
	io[2].iov_len = 2;
	io[3].iov_base = (u8 *) buf;
	io[3].iov_len = len;

	os_memset(&msg, 0, sizeof(msg));
	msg.msg_iov = io;
	msg.msg_iovlen = 4;
	msg.msg_name = &l2->priv_addr;
	msg.msg_namelen = sizeof(l2->priv_addr);

	if (sendmsg(l2->fd, &msg, 0) < 0) {
		wpa_printf(MSG_ERROR, "L2: sendmsg(packet_send): %s",
			   strerror(errno));
		return -1;
	}

	return 0;
}


static void l2_packet_receive(int sock, void *eloop_ctx, void *sock_ctx)
{
	struct l2_packet_data *l2 = eloop_ctx;
	u8 buf[2300];
	int res;
	struct sockaddr_un from;
	socklen_t fromlen = sizeof(from);

	os_memset(&from, 0, sizeof(from));
	res = recvfrom(sock, buf, sizeof(buf), 0, (struct sockaddr *) &from,
		       &fromlen);
	if (res < 0) {
		wpa_printf(MSG_ERROR, "l2_packet_receive - recvfrom: %s",
			   strerror(errno));
		return;
	}
	if (res < ETH_ALEN) {
		wpa_printf(MSG_DEBUG, "L2: Too show packet received");
		return;
	}

	if (from.sun_family != AF_UNIX ||
	    os_strncmp(from.sun_path, l2->priv_addr.sun_path,
		       sizeof(from.sun_path)) != 0) {
		wpa_printf(MSG_DEBUG, "L2: Received message from unexpected "
			   "source");
		return;
	}

	l2->rx_callback(l2->rx_callback_ctx, buf, buf + ETH_ALEN,
			res - ETH_ALEN);
}


struct l2_packet_data * l2_packet_init(
	const char *ifname, const u8 *own_addr, unsigned short protocol,
	void (*rx_callback)(void *ctx, const u8 *src_addr,
			    const u8 *buf, size_t len),
	void *rx_callback_ctx, int l2_hdr)
{
	struct l2_packet_data *l2;
	char *own_dir = "/tmp";
	char *priv_dir = "/var/run/wpa_priv";
	size_t len;
	static unsigned int counter = 0;
	struct sockaddr_un addr;
	fd_set rfds;
	struct timeval tv;
	int res;
	u8 reply[ETH_ALEN + 1];
	int reg_cmd[2];

	l2 = os_zalloc(sizeof(struct l2_packet_data));
	if (l2 == NULL)
		return NULL;
	l2->rx_callback = rx_callback;
	l2->rx_callback_ctx = rx_callback_ctx;

	len = os_strlen(own_dir) + 50;
	l2->own_socket_path = os_malloc(len);
	if (l2->own_socket_path == NULL) {
		os_free(l2);
		return NULL;
	}
	os_snprintf(l2->own_socket_path, len, "%s/wpa_privsep-l2-%d-%d",
		    own_dir, getpid(), counter++);

	l2->priv_addr.sun_family = AF_UNIX;
	os_snprintf(l2->priv_addr.sun_path, sizeof(l2->priv_addr.sun_path),
		    "%s/%s", priv_dir, ifname);

	l2->fd = socket(PF_UNIX, SOCK_DGRAM, 0);
	if (l2->fd < 0) {
		wpa_printf(MSG_ERROR, "socket(PF_UNIX): %s", strerror(errno));
		os_free(l2->own_socket_path);
		l2->own_socket_path = NULL;
		os_free(l2);
		return NULL;
	}

	os_memset(&addr, 0, sizeof(addr));
	addr.sun_family = AF_UNIX;
	os_strlcpy(addr.sun_path, l2->own_socket_path, sizeof(addr.sun_path));
	if (bind(l2->fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
		wpa_printf(MSG_ERROR, "l2-pkt-privsep: bind(PF_UNIX): %s",
			   strerror(errno));
		goto fail;
	}

	reg_cmd[0] = protocol;
	reg_cmd[1] = l2_hdr;
	if (wpa_priv_cmd(l2, PRIVSEP_CMD_L2_REGISTER, reg_cmd, sizeof(reg_cmd))
	    < 0) {
		wpa_printf(MSG_ERROR, "L2: Failed to register with wpa_priv");
		goto fail;
	}

	FD_ZERO(&rfds);
	FD_SET(l2->fd, &rfds);
	tv.tv_sec = 5;
	tv.tv_usec = 0;
	res = select(l2->fd + 1, &rfds, NULL, NULL, &tv);
	if (res < 0 && errno != EINTR) {
		wpa_printf(MSG_ERROR, "select: %s", strerror(errno));
		goto fail;
	}

	if (FD_ISSET(l2->fd, &rfds)) {
		res = recv(l2->fd, reply, sizeof(reply), 0);
		if (res < 0) {
			wpa_printf(MSG_ERROR, "recv: %s", strerror(errno));
			goto fail;
		}
	} else {
		wpa_printf(MSG_DEBUG, "L2: Timeout while waiting for "
			   "registration reply");
		goto fail;
	}

	if (res != ETH_ALEN) {
		wpa_printf(MSG_DEBUG, "L2: Unexpected registration reply "
			   "(len=%d)", res);
	}
	os_memcpy(l2->own_addr, reply, ETH_ALEN);

	eloop_register_read_sock(l2->fd, l2_packet_receive, l2, NULL);

	return l2;

fail:
	close(l2->fd);
	l2->fd = -1;
	unlink(l2->own_socket_path);
	os_free(l2->own_socket_path);
	l2->own_socket_path = NULL;
	os_free(l2);
	return NULL;
}


void l2_packet_deinit(struct l2_packet_data *l2)
{
	if (l2 == NULL)
		return;

	if (l2->fd >= 0) {
		wpa_priv_cmd(l2, PRIVSEP_CMD_L2_UNREGISTER, NULL, 0);
		eloop_unregister_read_sock(l2->fd);
		close(l2->fd);
	}

	if (l2->own_socket_path) {
		unlink(l2->own_socket_path);
		os_free(l2->own_socket_path);
	}
		
	os_free(l2);
}


int l2_packet_get_ip_addr(struct l2_packet_data *l2, char *buf, size_t len)
{
	/* TODO */
	return -1;
}


void l2_packet_notify_auth_start(struct l2_packet_data *l2)
{
	wpa_priv_cmd(l2, PRIVSEP_CMD_L2_NOTIFY_AUTH_START, NULL, 0);
}


int l2_packet_set_packet_filter(struct l2_packet_data *l2,
				enum l2_packet_filter_type type)
{
	return -1;
}
Commit	Line	Data
6fc6879b JM	1	/*
	2	* WPA Supplicant - Layer2 packet handling with privilege separation
	3	* Copyright (c) 2007, Jouni Malinen <j@w1.fi>
	4	*
0f3d578e JM	5	* This software may be distributed under the terms of the BSD license.
0f3d578e JM	6	* See README for more details.
6fc6879b JM	7	*/
	8
	9	#include "includes.h"
	10	#include <sys/un.h>
	11
	12	#include "common.h"
	13	#include "eloop.h"
	14	#include "l2_packet.h"
90973fb2	15	#include "common/privsep_commands.h"
6fc6879b JM	16
	17
	18	struct l2_packet_data {
	19	int fd; /* UNIX domain socket for privsep access */
	20	void (rx_callback)(void ctx, const u8 *src_addr,
	21	const u8 *buf, size_t len);
	22	void *rx_callback_ctx;
	23	u8 own_addr[ETH_ALEN];
	24	char *own_socket_path;
	25	struct sockaddr_un priv_addr;
	26	};
	27
	28
	29	static int wpa_priv_cmd(struct l2_packet_data *l2, int cmd,
	30	const void *data, size_t data_len)
	31	{
	32	struct msghdr msg;
	33	struct iovec io[2];
	34
	35	io[0].iov_base = &cmd;
	36	io[0].iov_len = sizeof(cmd);
	37	io[1].iov_base = (u8 *) data;
	38	io[1].iov_len = data_len;
	39
	40	os_memset(&msg, 0, sizeof(msg));
	41	msg.msg_iov = io;
	42	msg.msg_iovlen = data ? 2 : 1;
	43	msg.msg_name = &l2->priv_addr;
	44	msg.msg_namelen = sizeof(l2->priv_addr);
	45
	46	if (sendmsg(l2->fd, &msg, 0) < 0) {
a193231d	47	wpa_printf(MSG_ERROR, "L2: sendmsg(cmd): %s", strerror(errno));
6fc6879b JM	48	return -1;
	49	}
	50
	51	return 0;
	52	}
	53
	54
	55	int l2_packet_get_own_addr(struct l2_packet_data l2, u8 addr)
	56	{
	57	os_memcpy(addr, l2->own_addr, ETH_ALEN);
	58	return 0;
	59	}
	60
	61
	62	int l2_packet_send(struct l2_packet_data l2, const u8 dst_addr, u16 proto,
	63	const u8 *buf, size_t len)
	64	{
	65	struct msghdr msg;
	66	struct iovec io[4];
	67	int cmd = PRIVSEP_CMD_L2_SEND;
	68
	69	io[0].iov_base = &cmd;
	70	io[0].iov_len = sizeof(cmd);
	71	io[1].iov_base = &dst_addr;
	72	io[1].iov_len = ETH_ALEN;
	73	io[2].iov_base = &proto;
	74	io[2].iov_len = 2;
	75	io[3].iov_base = (u8 *) buf;
	76	io[3].iov_len = len;
	77
	78	os_memset(&msg, 0, sizeof(msg));
	79	msg.msg_iov = io;
	80	msg.msg_iovlen = 4;
	81	msg.msg_name = &l2->priv_addr;
	82	msg.msg_namelen = sizeof(l2->priv_addr);
	83
	84	if (sendmsg(l2->fd, &msg, 0) < 0) {
a193231d JM	85	wpa_printf(MSG_ERROR, "L2: sendmsg(packet_send): %s",
a193231d JM	86	strerror(errno));
6fc6879b JM	87	return -1;
	88	}
	89
	90	return 0;
	91	}
	92
	93
	94	static void l2_packet_receive(int sock, void eloop_ctx, void sock_ctx)
	95	{
	96	struct l2_packet_data *l2 = eloop_ctx;
	97	u8 buf[2300];
	98	int res;
	99	struct sockaddr_un from;
	100	socklen_t fromlen = sizeof(from);
	101
	102	os_memset(&from, 0, sizeof(from));
	103	res = recvfrom(sock, buf, sizeof(buf), 0, (struct sockaddr *) &from,
	104	&fromlen);
	105	if (res < 0) {
a193231d JM	106	wpa_printf(MSG_ERROR, "l2_packet_receive - recvfrom: %s",
a193231d JM	107	strerror(errno));
6fc6879b JM	108	return;
	109	}
	110	if (res < ETH_ALEN) {
	111	wpa_printf(MSG_DEBUG, "L2: Too show packet received");
	112	return;
	113	}
	114
	115	if (from.sun_family != AF_UNIX \|\|
	116	os_strncmp(from.sun_path, l2->priv_addr.sun_path,
	117	sizeof(from.sun_path)) != 0) {
	118	wpa_printf(MSG_DEBUG, "L2: Received message from unexpected "
	119	"source");
	120	return;
	121	}
	122
	123	l2->rx_callback(l2->rx_callback_ctx, buf, buf + ETH_ALEN,
	124	res - ETH_ALEN);
	125	}
	126
	127
	128	struct l2_packet_data * l2_packet_init(
	129	const char ifname, const u8 own_addr, unsigned short protocol,
	130	void (rx_callback)(void ctx, const u8 *src_addr,
	131	const u8 *buf, size_t len),
	132	void *rx_callback_ctx, int l2_hdr)
	133	{
	134	struct l2_packet_data *l2;
	135	char *own_dir = "/tmp";
	136	char *priv_dir = "/var/run/wpa_priv";
	137	size_t len;
	138	static unsigned int counter = 0;
	139	struct sockaddr_un addr;
	140	fd_set rfds;
	141	struct timeval tv;
	142	int res;
	143	u8 reply[ETH_ALEN + 1];
	144	int reg_cmd[2];
	145
	146	l2 = os_zalloc(sizeof(struct l2_packet_data));
	147	if (l2 == NULL)
	148	return NULL;
	149	l2->rx_callback = rx_callback;
	150	l2->rx_callback_ctx = rx_callback_ctx;
	151
	152	len = os_strlen(own_dir) + 50;
	153	l2->own_socket_path = os_malloc(len);
	154	if (l2->own_socket_path == NULL) {
	155	os_free(l2);
	156	return NULL;
	157	}
	158	os_snprintf(l2->own_socket_path, len, "%s/wpa_privsep-l2-%d-%d",
	159	own_dir, getpid(), counter++);
	160
	161	l2->priv_addr.sun_family = AF_UNIX;
	162	os_snprintf(l2->priv_addr.sun_path, sizeof(l2->priv_addr.sun_path),
	163	"%s/%s", priv_dir, ifname);
	164
	165	l2->fd = socket(PF_UNIX, SOCK_DGRAM, 0);
	166	if (l2->fd < 0) {
a193231d	167	wpa_printf(MSG_ERROR, "socket(PF_UNIX): %s", strerror(errno));
6fc6879b JM	168	os_free(l2->own_socket_path);
	169	l2->own_socket_path = NULL;
	170	os_free(l2);
	171	return NULL;
	172	}
	173
	174	os_memset(&addr, 0, sizeof(addr));
	175	addr.sun_family = AF_UNIX;
	176	os_strlcpy(addr.sun_path, l2->own_socket_path, sizeof(addr.sun_path));
	177	if (bind(l2->fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
a193231d JM	178	wpa_printf(MSG_ERROR, "l2-pkt-privsep: bind(PF_UNIX): %s",
a193231d JM	179	strerror(errno));
6fc6879b JM	180	goto fail;
	181	}
	182
	183	reg_cmd[0] = protocol;
	184	reg_cmd[1] = l2_hdr;
	185	if (wpa_priv_cmd(l2, PRIVSEP_CMD_L2_REGISTER, reg_cmd, sizeof(reg_cmd))
	186	< 0) {
	187	wpa_printf(MSG_ERROR, "L2: Failed to register with wpa_priv");
	188	goto fail;
	189	}
	190
	191	FD_ZERO(&rfds);
	192	FD_SET(l2->fd, &rfds);
	193	tv.tv_sec = 5;
	194	tv.tv_usec = 0;
	195	res = select(l2->fd + 1, &rfds, NULL, NULL, &tv);
	196	if (res < 0 && errno != EINTR) {
a193231d	197	wpa_printf(MSG_ERROR, "select: %s", strerror(errno));
6fc6879b JM	198	goto fail;
	199	}
	200
	201	if (FD_ISSET(l2->fd, &rfds)) {
	202	res = recv(l2->fd, reply, sizeof(reply), 0);
	203	if (res < 0) {
a193231d	204	wpa_printf(MSG_ERROR, "recv: %s", strerror(errno));
6fc6879b JM	205	goto fail;
	206	}
	207	} else {
	208	wpa_printf(MSG_DEBUG, "L2: Timeout while waiting for "
	209	"registration reply");
	210	goto fail;
	211	}
	212
	213	if (res != ETH_ALEN) {
	214	wpa_printf(MSG_DEBUG, "L2: Unexpected registration reply "
	215	"(len=%d)", res);
	216	}
	217	os_memcpy(l2->own_addr, reply, ETH_ALEN);
	218
	219	eloop_register_read_sock(l2->fd, l2_packet_receive, l2, NULL);
	220
	221	return l2;
	222
	223	fail:
	224	close(l2->fd);
	225	l2->fd = -1;
	226	unlink(l2->own_socket_path);
	227	os_free(l2->own_socket_path);
	228	l2->own_socket_path = NULL;
	229	os_free(l2);
	230	return NULL;
	231	}
	232
	233
	234	void l2_packet_deinit(struct l2_packet_data *l2)
	235	{
	236	if (l2 == NULL)
	237	return;
	238
	239	if (l2->fd >= 0) {
	240	wpa_priv_cmd(l2, PRIVSEP_CMD_L2_UNREGISTER, NULL, 0);
	241	eloop_unregister_read_sock(l2->fd);
	242	close(l2->fd);
	243	}
	244
	245	if (l2->own_socket_path) {
	246	unlink(l2->own_socket_path);
	247	os_free(l2->own_socket_path);
	248	}
	249
	250	os_free(l2);
	251	}
	252
	253
	254	int l2_packet_get_ip_addr(struct l2_packet_data l2, char buf, size_t len)
	255	{
	256	/* TODO */
	257	return -1;
	258	}
	259
	260
	261	void l2_packet_notify_auth_start(struct l2_packet_data *l2)
	262	{
	263	wpa_priv_cmd(l2, PRIVSEP_CMD_L2_NOTIFY_AUTH_START, NULL, 0);
	264	}
7d20dd66 KP	265
	266
	267	int l2_packet_set_packet_filter(struct l2_packet_data *l2,
	268	enum l2_packet_filter_type type)
	269	{
	270	return -1;
	271	}