1 /*
2 * WPA Supplicant - Layer2 packet handling with Linux packet sockets
3 * Copyright (c) 2003-2005, Jouni Malinen <j@w1.fi>
4 *
5 * This software may be distributed under the terms of the BSD license.
6 * See README for more details.
7 */
8
9 #include "includes.h"
10 #include <sys/ioctl.h>
11 #include <netpacket/packet.h>
12 #include <net/if.h>
13
14 #include "common.h"
15 #include "eloop.h"
16 #include "l2_packet.h"
17
18
19 struct l2_packet_data {
20 int fd; /* packet socket for EAPOL frames */
21 char ifname[IFNAMSIZ + 1];
22 int ifindex;
23 u8 own_addr[ETH_ALEN];
24 void (*rx_callback)(void *ctx, const u8 *src_addr,
25 const u8 *buf, size_t len);
26 void *rx_callback_ctx;
27 int l2_hdr; /* whether to include layer 2 (Ethernet) header data
28 * buffers */
29 };
30
31
l2_packet_get_own_addr(struct l2_packet_data * l2,u8 * addr)32 int l2_packet_get_own_addr(struct l2_packet_data *l2, u8 *addr)
33 {
34 os_memcpy(addr, l2->own_addr, ETH_ALEN);
35 return 0;
36 }
37
38
l2_packet_send(struct l2_packet_data * l2,const u8 * dst_addr,u16 proto,const u8 * buf,size_t len)39 int l2_packet_send(struct l2_packet_data *l2, const u8 *dst_addr, u16 proto,
40 const u8 *buf, size_t len)
41 {
42 int ret;
43 if (l2 == NULL)
44 return -1;
45 if (l2->l2_hdr) {
46 ret = send(l2->fd, buf, len, 0);
47 if (ret < 0)
48 wpa_printf(MSG_ERROR, "l2_packet_send - send: %s",
49 strerror(errno));
50 } else {
51 struct sockaddr_ll ll;
52 os_memset(&ll, 0, sizeof(ll));
53 ll.sll_family = AF_PACKET;
54 ll.sll_ifindex = l2->ifindex;
55 ll.sll_protocol = htons(proto);
56 ll.sll_halen = ETH_ALEN;
57 os_memcpy(ll.sll_addr, dst_addr, ETH_ALEN);
58 ret = sendto(l2->fd, buf, len, 0, (struct sockaddr *) &ll,
59 sizeof(ll));
60 if (ret < 0) {
61 wpa_printf(MSG_ERROR, "l2_packet_send - sendto: %s",
62 strerror(errno));
63 }
64 }
65 return ret;
66 }
67
68
l2_packet_receive(int sock,void * eloop_ctx,void * sock_ctx)69 static void l2_packet_receive(int sock, void *eloop_ctx, void *sock_ctx)
70 {
71 struct l2_packet_data *l2 = eloop_ctx;
72 u8 buf[2300];
73 int res;
74 struct sockaddr_ll ll;
75 socklen_t fromlen;
76
77 os_memset(&ll, 0, sizeof(ll));
78 fromlen = sizeof(ll);
79 res = recvfrom(sock, buf, sizeof(buf), 0, (struct sockaddr *) &ll,
80 &fromlen);
81 if (res < 0) {
82 wpa_printf(MSG_DEBUG, "l2_packet_receive - recvfrom: %s",
83 strerror(errno));
84 return;
85 }
86
87 l2->rx_callback(l2->rx_callback_ctx, ll.sll_addr, buf, res);
88 }
89
90
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)91 struct l2_packet_data * l2_packet_init(
92 const char *ifname, const u8 *own_addr, unsigned short protocol,
93 void (*rx_callback)(void *ctx, const u8 *src_addr,
94 const u8 *buf, size_t len),
95 void *rx_callback_ctx, int l2_hdr)
96 {
97 struct l2_packet_data *l2;
98 struct ifreq ifr;
99 struct sockaddr_ll ll;
100
101 l2 = os_zalloc(sizeof(struct l2_packet_data));
102 if (l2 == NULL)
103 return NULL;
104 os_strlcpy(l2->ifname, ifname, sizeof(l2->ifname));
105 l2->rx_callback = rx_callback;
106 l2->rx_callback_ctx = rx_callback_ctx;
107 l2->l2_hdr = l2_hdr;
108
109 l2->fd = socket(PF_PACKET, l2_hdr ? SOCK_RAW : SOCK_DGRAM,
110 htons(protocol));
111 if (l2->fd < 0) {
112 wpa_printf(MSG_ERROR, "%s: socket(PF_PACKET): %s",
113 __func__, strerror(errno));
114 os_free(l2);
115 return NULL;
116 }
117 os_memset(&ifr, 0, sizeof(ifr));
118 os_strlcpy(ifr.ifr_name, l2->ifname, sizeof(ifr.ifr_name));
119 if (ioctl(l2->fd, SIOCGIFINDEX, &ifr) < 0) {
120 wpa_printf(MSG_ERROR, "%s: ioctl[SIOCGIFINDEX]: %s",
121 __func__, strerror(errno));
122 close(l2->fd);
123 os_free(l2);
124 return NULL;
125 }
126 l2->ifindex = ifr.ifr_ifindex;
127
128 os_memset(&ll, 0, sizeof(ll));
129 ll.sll_family = PF_PACKET;
130 ll.sll_ifindex = ifr.ifr_ifindex;
131 ll.sll_protocol = htons(protocol);
132 if (bind(l2->fd, (struct sockaddr *) &ll, sizeof(ll)) < 0) {
133 wpa_printf(MSG_ERROR, "%s: bind[PF_PACKET]: %s",
134 __func__, strerror(errno));
135 close(l2->fd);
136 os_free(l2);
137 return NULL;
138 }
139
140 if (ioctl(l2->fd, SIOCGIFHWADDR, &ifr) < 0) {
141 wpa_printf(MSG_ERROR, "%s: ioctl[SIOCGIFHWADDR]: %s",
142 __func__, strerror(errno));
143 close(l2->fd);
144 os_free(l2);
145 return NULL;
146 }
147 os_memcpy(l2->own_addr, ifr.ifr_hwaddr.sa_data, ETH_ALEN);
148
149 eloop_register_read_sock(l2->fd, l2_packet_receive, l2, NULL);
150
151 return l2;
152 }
153
154
l2_packet_deinit(struct l2_packet_data * l2)155 void l2_packet_deinit(struct l2_packet_data *l2)
156 {
157 if (l2 == NULL)
158 return;
159
160 if (l2->fd >= 0) {
161 eloop_unregister_read_sock(l2->fd);
162 close(l2->fd);
163 }
164
165 os_free(l2);
166 }
167
168
l2_packet_get_ip_addr(struct l2_packet_data * l2,char * buf,size_t len)169 int l2_packet_get_ip_addr(struct l2_packet_data *l2, char *buf, size_t len)
170 {
171 int s;
172 struct ifreq ifr;
173 struct sockaddr_in *saddr;
174 size_t res;
175
176 s = socket(PF_INET, SOCK_DGRAM, 0);
177 if (s < 0) {
178 wpa_printf(MSG_ERROR, "%s: socket: %s",
179 __func__, strerror(errno));
180 return -1;
181 }
182 os_memset(&ifr, 0, sizeof(ifr));
183 os_strlcpy(ifr.ifr_name, l2->ifname, sizeof(ifr.ifr_name));
184 if (ioctl(s, SIOCGIFADDR, &ifr) < 0) {
185 if (errno != EADDRNOTAVAIL)
186 wpa_printf(MSG_ERROR, "%s: ioctl[SIOCGIFADDR]: %s",
187 __func__, strerror(errno));
188 close(s);
189 return -1;
190 }
191 close(s);
192 saddr = aliasing_hide_typecast(&ifr.ifr_addr, struct sockaddr_in);
193 if (saddr->sin_family != AF_INET)
194 return -1;
195 res = os_strlcpy(buf, inet_ntoa(saddr->sin_addr), len);
196 if (res >= len)
197 return -1;
198 return 0;
199 }
200
201
l2_packet_notify_auth_start(struct l2_packet_data * l2)202 void l2_packet_notify_auth_start(struct l2_packet_data *l2)
203 {
204 }
205