src/l2_packet/l2_packet_privsep.c - vendor/opensource/hostap - Git at Google

 /*
  * 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;
 }


 struct l2_packet_data * l2_packet_init_bridge(
 	const char *br_ifname, 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)
 {
 	return l2_packet_init(br_ifname, own_addr, protocol, rx_callback,
 			      rx_callback_ctx, l2_hdr);
 }


 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;
 }
	/*
	* 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;
	}


	struct l2_packet_data * l2_packet_init_bridge(
	const char br_ifname, 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)
	{
	return l2_packet_init(br_ifname, own_addr, protocol, rx_callback,
	rx_callback_ctx, l2_hdr);
	}


	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;
	}