2 * WPA Supplicant - Layer2 packet handling with privilege separation
3 * Copyright (c) 2007, Jouni Malinen <j@w1.fi>
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
9 * Alternatively, this software may be distributed under the terms of BSD
12 * See README and COPYING for more details.
20 #include "l2_packet.h"
21 #include "privsep_commands.h"
24 struct l2_packet_data {
25 int fd; /* UNIX domain socket for privsep access */
26 void (*rx_callback)(void *ctx, const u8 *src_addr,
27 const u8 *buf, size_t len);
28 void *rx_callback_ctx;
29 u8 own_addr[ETH_ALEN];
30 char *own_socket_path;
31 struct sockaddr_un priv_addr;
35 static int wpa_priv_cmd(struct l2_packet_data *l2, int cmd,
36 const void *data, size_t data_len)
41 io[0].iov_base = &cmd;
42 io[0].iov_len = sizeof(cmd);
43 io[1].iov_base = (u8 *) data;
44 io[1].iov_len = data_len;
46 os_memset(&msg, 0, sizeof(msg));
48 msg.msg_iovlen = data ? 2 : 1;
49 msg.msg_name = &l2->priv_addr;
50 msg.msg_namelen = sizeof(l2->priv_addr);
52 if (sendmsg(l2->fd, &msg, 0) < 0) {
53 perror("L2: sendmsg(cmd)");
61 int l2_packet_get_own_addr(struct l2_packet_data *l2, u8 *addr)
63 os_memcpy(addr, l2->own_addr, ETH_ALEN);
68 int l2_packet_send(struct l2_packet_data *l2, const u8 *dst_addr, u16 proto,
69 const u8 *buf, size_t len)
73 int cmd = PRIVSEP_CMD_L2_SEND;
75 io[0].iov_base = &cmd;
76 io[0].iov_len = sizeof(cmd);
77 io[1].iov_base = &dst_addr;
78 io[1].iov_len = ETH_ALEN;
79 io[2].iov_base = &proto;
81 io[3].iov_base = (u8 *) buf;
84 os_memset(&msg, 0, sizeof(msg));
87 msg.msg_name = &l2->priv_addr;
88 msg.msg_namelen = sizeof(l2->priv_addr);
90 if (sendmsg(l2->fd, &msg, 0) < 0) {
91 perror("L2: sendmsg(packet_send)");
99 static void l2_packet_receive(int sock, void *eloop_ctx, void *sock_ctx)
101 struct l2_packet_data *l2 = eloop_ctx;
104 struct sockaddr_un from;
105 socklen_t fromlen = sizeof(from);
107 os_memset(&from, 0, sizeof(from));
108 res = recvfrom(sock, buf, sizeof(buf), 0, (struct sockaddr *) &from,
111 perror("l2_packet_receive - recvfrom");
114 if (res < ETH_ALEN) {
115 wpa_printf(MSG_DEBUG, "L2: Too show packet received");
119 if (from.sun_family != AF_UNIX ||
120 os_strncmp(from.sun_path, l2->priv_addr.sun_path,
121 sizeof(from.sun_path)) != 0) {
122 wpa_printf(MSG_DEBUG, "L2: Received message from unexpected "
127 l2->rx_callback(l2->rx_callback_ctx, buf, buf + ETH_ALEN,
132 struct l2_packet_data * l2_packet_init(
133 const char *ifname, const u8 *own_addr, unsigned short protocol,
134 void (*rx_callback)(void *ctx, const u8 *src_addr,
135 const u8 *buf, size_t len),
136 void *rx_callback_ctx, int l2_hdr)
138 struct l2_packet_data *l2;
139 char *own_dir = "/tmp";
140 char *priv_dir = "/var/run/wpa_priv";
142 static unsigned int counter = 0;
143 struct sockaddr_un addr;
147 u8 reply[ETH_ALEN + 1];
150 l2 = os_zalloc(sizeof(struct l2_packet_data));
153 l2->rx_callback = rx_callback;
154 l2->rx_callback_ctx = rx_callback_ctx;
156 len = os_strlen(own_dir) + 50;
157 l2->own_socket_path = os_malloc(len);
158 if (l2->own_socket_path == NULL) {
162 os_snprintf(l2->own_socket_path, len, "%s/wpa_privsep-l2-%d-%d",
163 own_dir, getpid(), counter++);
165 l2->priv_addr.sun_family = AF_UNIX;
166 os_snprintf(l2->priv_addr.sun_path, sizeof(l2->priv_addr.sun_path),
167 "%s/%s", priv_dir, ifname);
169 l2->fd = socket(PF_UNIX, SOCK_DGRAM, 0);
171 perror("socket(PF_UNIX)");
172 os_free(l2->own_socket_path);
173 l2->own_socket_path = NULL;
178 os_memset(&addr, 0, sizeof(addr));
179 addr.sun_family = AF_UNIX;
180 os_strlcpy(addr.sun_path, l2->own_socket_path, sizeof(addr.sun_path));
181 if (bind(l2->fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
182 perror("bind(PF_UNIX)");
186 reg_cmd[0] = protocol;
188 if (wpa_priv_cmd(l2, PRIVSEP_CMD_L2_REGISTER, reg_cmd, sizeof(reg_cmd))
190 wpa_printf(MSG_ERROR, "L2: Failed to register with wpa_priv");
195 FD_SET(l2->fd, &rfds);
198 res = select(l2->fd + 1, &rfds, NULL, NULL, &tv);
199 if (res < 0 && errno != EINTR) {
204 if (FD_ISSET(l2->fd, &rfds)) {
205 res = recv(l2->fd, reply, sizeof(reply), 0);
211 wpa_printf(MSG_DEBUG, "L2: Timeout while waiting for "
212 "registration reply");
216 if (res != ETH_ALEN) {
217 wpa_printf(MSG_DEBUG, "L2: Unexpected registration reply "
220 os_memcpy(l2->own_addr, reply, ETH_ALEN);
222 eloop_register_read_sock(l2->fd, l2_packet_receive, l2, NULL);
229 unlink(l2->own_socket_path);
230 os_free(l2->own_socket_path);
231 l2->own_socket_path = NULL;
237 void l2_packet_deinit(struct l2_packet_data *l2)
243 wpa_priv_cmd(l2, PRIVSEP_CMD_L2_UNREGISTER, NULL, 0);
244 eloop_unregister_read_sock(l2->fd);
248 if (l2->own_socket_path) {
249 unlink(l2->own_socket_path);
250 os_free(l2->own_socket_path);
257 int l2_packet_get_ip_addr(struct l2_packet_data *l2, char *buf, size_t len)
264 void l2_packet_notify_auth_start(struct l2_packet_data *l2)
266 wpa_priv_cmd(l2, PRIVSEP_CMD_L2_NOTIFY_AUTH_START, NULL, 0);