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 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 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 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 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 } 153 154 155 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 } 167 168 169 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 } 200 201 202 void l2_packet_notify_auth_start(struct l2_packet_data *l2) 203 { 204 } 205