blob: 6b117ca2b9076709d3840d06924b363908ce6612 [file] [log] [blame] [edit]
/*
* 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) {
perror("L2: sendmsg(cmd)");
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) {
perror("L2: sendmsg(packet_send)");
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) {
perror("l2_packet_receive - recvfrom");
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) {
perror("socket(PF_UNIX)");
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) {
perror("l2-pkt-privsep: bind(PF_UNIX)");
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) {
perror("select");
goto fail;
}
if (FD_ISSET(l2->fd, &rfds)) {
res = recv(l2->fd, reply, sizeof(reply), 0);
if (res < 0) {
perror("recv");
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);
}