l2_packet_linux.c revision 8d520ff1dc2da35cdca849e982051b86468016d8 
1/*
2 * WPA Supplicant - Layer2 packet handling with Linux packet sockets
3 * Copyright (c) 2003-2005, Jouni Malinen <j@w1.fi>
4 *
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.
8 *
9 * Alternatively, this software may be distributed under the terms of BSD
10 * license.
11 *
12 * See README and COPYING for more details.
13 */
14
15#include "includes.h"
16#include <sys/ioctl.h>
17#include <netpacket/packet.h>
18#include <net/if.h>
19
20#include "common.h"
21#include "eloop.h"
22#include "l2_packet.h"
23
24
25struct l2_packet_data {
26	int fd; /* packet socket for EAPOL frames */
27	char ifname[IFNAMSIZ + 1];
28	int ifindex;
29	u8 own_addr[ETH_ALEN];
30	void (*rx_callback)(void *ctx, const u8 *src_addr,
31			    const u8 *buf, size_t len);
32	void *rx_callback_ctx;
33	int l2_hdr; /* whether to include layer 2 (Ethernet) header data
34		     * buffers */
35};
36
37
38int l2_packet_get_own_addr(struct l2_packet_data *l2, u8 *addr)
39{
40	os_memcpy(addr, l2->own_addr, ETH_ALEN);
41	return 0;
42}
43
44
45int l2_packet_send(struct l2_packet_data *l2, const u8 *dst_addr, u16 proto,
46		   const u8 *buf, size_t len)
47{
48	int ret;
49	if (l2 == NULL)
50		return -1;
51	if (l2->l2_hdr) {
52		ret = send(l2->fd, buf, len, 0);
53		if (ret < 0)
54			wpa_printf(MSG_ERROR, "l2_packet_send - send: %s",
55				   strerror(errno));
56	} else {
57		struct sockaddr_ll ll;
58		os_memset(&ll, 0, sizeof(ll));
59		ll.sll_family = AF_PACKET;
60		ll.sll_ifindex = l2->ifindex;
61		ll.sll_protocol = htons(proto);
62		ll.sll_halen = ETH_ALEN;
63		os_memcpy(ll.sll_addr, dst_addr, ETH_ALEN);
64		ret = sendto(l2->fd, buf, len, 0, (struct sockaddr *) &ll,
65			     sizeof(ll));
66		if (ret < 0) {
67			wpa_printf(MSG_ERROR, "l2_packet_send - sendto: %s",
68				   strerror(errno));
69		}
70	}
71	return ret;
72}
73
74
75static void l2_packet_receive(int sock, void *eloop_ctx, void *sock_ctx)
76{
77	struct l2_packet_data *l2 = eloop_ctx;
78	u8 buf[2300];
79	int res;
80	struct sockaddr_ll ll;
81	socklen_t fromlen;
82
83	os_memset(&ll, 0, sizeof(ll));
84	fromlen = sizeof(ll);
85	res = recvfrom(sock, buf, sizeof(buf), 0, (struct sockaddr *) &ll,
86		       &fromlen);
87	if (res < 0) {
88		wpa_printf(MSG_DEBUG, "l2_packet_receive - recvfrom: %s",
89			   strerror(errno));
90		return;
91	}
92
93	l2->rx_callback(l2->rx_callback_ctx, ll.sll_addr, buf, res);
94}
95
96
97struct l2_packet_data * l2_packet_init(
98	const char *ifname, const u8 *own_addr, unsigned short protocol,
99	void (*rx_callback)(void *ctx, const u8 *src_addr,
100			    const u8 *buf, size_t len),
101	void *rx_callback_ctx, int l2_hdr)
102{
103	struct l2_packet_data *l2;
104	struct ifreq ifr;
105	struct sockaddr_ll ll;
106
107	l2 = os_zalloc(sizeof(struct l2_packet_data));
108	if (l2 == NULL)
109		return NULL;
110	os_strlcpy(l2->ifname, ifname, sizeof(l2->ifname));
111	l2->rx_callback = rx_callback;
112	l2->rx_callback_ctx = rx_callback_ctx;
113	l2->l2_hdr = l2_hdr;
114
115	l2->fd = socket(PF_PACKET, l2_hdr ? SOCK_RAW : SOCK_DGRAM,
116			htons(protocol));
117	if (l2->fd < 0) {
118		wpa_printf(MSG_ERROR, "%s: socket(PF_PACKET): %s",
119			   __func__, strerror(errno));
120		os_free(l2);
121		return NULL;
122	}
123	os_memset(&ifr, 0, sizeof(ifr));
124	os_strlcpy(ifr.ifr_name, l2->ifname, sizeof(ifr.ifr_name));
125	if (ioctl(l2->fd, SIOCGIFINDEX, &ifr) < 0) {
126		wpa_printf(MSG_ERROR, "%s: ioctl[SIOCGIFINDEX]: %s",
127			   __func__, strerror(errno));
128		close(l2->fd);
129		os_free(l2);
130		return NULL;
131	}
132	l2->ifindex = ifr.ifr_ifindex;
133
134	os_memset(&ll, 0, sizeof(ll));
135	ll.sll_family = PF_PACKET;
136	ll.sll_ifindex = ifr.ifr_ifindex;
137	ll.sll_protocol = htons(protocol);
138	if (bind(l2->fd, (struct sockaddr *) &ll, sizeof(ll)) < 0) {
139		wpa_printf(MSG_ERROR, "%s: bind[PF_PACKET]: %s",
140			   __func__, strerror(errno));
141		close(l2->fd);
142		os_free(l2);
143		return NULL;
144	}
145
146	if (ioctl(l2->fd, SIOCGIFHWADDR, &ifr) < 0) {
147		wpa_printf(MSG_ERROR, "%s: ioctl[SIOCGIFHWADDR]: %s",
148			   __func__, strerror(errno));
149		close(l2->fd);
150		os_free(l2);
151		return NULL;
152	}
153	os_memcpy(l2->own_addr, ifr.ifr_hwaddr.sa_data, ETH_ALEN);
154
155	eloop_register_read_sock(l2->fd, l2_packet_receive, l2, NULL);
156
157	return l2;
158}
159
160
161void l2_packet_deinit(struct l2_packet_data *l2)
162{
163	if (l2 == NULL)
164		return;
165
166	if (l2->fd >= 0) {
167		eloop_unregister_read_sock(l2->fd);
168		close(l2->fd);
169	}
170
171	os_free(l2);
172}
173
174
175int l2_packet_get_ip_addr(struct l2_packet_data *l2, char *buf, size_t len)
176{
177	int s;
178	struct ifreq ifr;
179	struct sockaddr_in *saddr;
180	size_t res;
181
182	s = socket(PF_INET, SOCK_DGRAM, 0);
183	if (s < 0) {
184		wpa_printf(MSG_ERROR, "%s: socket: %s",
185			   __func__, strerror(errno));
186		return -1;
187	}
188	os_memset(&ifr, 0, sizeof(ifr));
189	os_strlcpy(ifr.ifr_name, l2->ifname, sizeof(ifr.ifr_name));
190	if (ioctl(s, SIOCGIFADDR, &ifr) < 0) {
191		if (errno != EADDRNOTAVAIL)
192			wpa_printf(MSG_ERROR, "%s: ioctl[SIOCGIFADDR]: %s",
193				   __func__, strerror(errno));
194		close(s);
195		return -1;
196	}
197	close(s);
198	saddr = aliasing_hide_typecast(&ifr.ifr_addr, struct sockaddr_in);
199	if (saddr->sin_family != AF_INET)
200		return -1;
201	res = os_strlcpy(buf, inet_ntoa(saddr->sin_addr), len);
202	if (res >= len)
203		return -1;
204	return 0;
205}
206
207
208void l2_packet_notify_auth_start(struct l2_packet_data *l2)
209{
210}
211