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 25 struct 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 38 int 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 45 int 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 perror("l2_packet_send - send"); 55 } else { 56 struct sockaddr_ll ll; 57 os_memset(&ll, 0, sizeof(ll)); 58 ll.sll_family = AF_PACKET; 59 ll.sll_ifindex = l2->ifindex; 60 ll.sll_protocol = htons(proto); 61 ll.sll_halen = ETH_ALEN; 62 os_memcpy(ll.sll_addr, dst_addr, ETH_ALEN); 63 ret = sendto(l2->fd, buf, len, 0, (struct sockaddr *) &ll, 64 sizeof(ll)); 65 if (ret < 0) 66 perror("l2_packet_send - sendto"); 67 } 68 return ret; 69 } 70 71 72 static void l2_packet_receive(int sock, void *eloop_ctx, void *sock_ctx) 73 { 74 struct l2_packet_data *l2 = eloop_ctx; 75 u8 buf[2300]; 76 int res; 77 struct sockaddr_ll ll; 78 socklen_t fromlen; 79 80 os_memset(&ll, 0, sizeof(ll)); 81 fromlen = sizeof(ll); 82 res = recvfrom(sock, buf, sizeof(buf), 0, (struct sockaddr *) &ll, 83 &fromlen); 84 if (res < 0) { 85 perror("l2_packet_receive - recvfrom"); 86 return; 87 } 88 89 l2->rx_callback(l2->rx_callback_ctx, ll.sll_addr, buf, res); 90 } 91 92 93 struct l2_packet_data * l2_packet_init( 94 const char *ifname, const u8 *own_addr, unsigned short protocol, 95 void (*rx_callback)(void *ctx, const u8 *src_addr, 96 const u8 *buf, size_t len), 97 void *rx_callback_ctx, int l2_hdr) 98 { 99 struct l2_packet_data *l2; 100 struct ifreq ifr; 101 struct sockaddr_ll ll; 102 103 l2 = os_zalloc(sizeof(struct l2_packet_data)); 104 if (l2 == NULL) 105 return NULL; 106 os_strlcpy(l2->ifname, ifname, sizeof(l2->ifname)); 107 l2->rx_callback = rx_callback; 108 l2->rx_callback_ctx = rx_callback_ctx; 109 l2->l2_hdr = l2_hdr; 110 111 l2->fd = socket(PF_PACKET, l2_hdr ? SOCK_RAW : SOCK_DGRAM, 112 htons(protocol)); 113 if (l2->fd < 0) { 114 perror("socket(PF_PACKET)"); 115 os_free(l2); 116 return NULL; 117 } 118 os_memset(&ifr, 0, sizeof(ifr)); 119 os_strlcpy(ifr.ifr_name, l2->ifname, sizeof(ifr.ifr_name)); 120 if (ioctl(l2->fd, SIOCGIFINDEX, &ifr) < 0) { 121 perror("ioctl[SIOCGIFINDEX]"); 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 perror("bind[PF_PACKET]"); 134 close(l2->fd); 135 os_free(l2); 136 return NULL; 137 } 138 139 if (ioctl(l2->fd, SIOCGIFHWADDR, &ifr) < 0) { 140 perror("ioctl[SIOCGIFHWADDR]"); 141 close(l2->fd); 142 os_free(l2); 143 return NULL; 144 } 145 os_memcpy(l2->own_addr, ifr.ifr_hwaddr.sa_data, ETH_ALEN); 146 147 eloop_register_read_sock(l2->fd, l2_packet_receive, l2, NULL); 148 149 return l2; 150 } 151 152 153 void l2_packet_deinit(struct l2_packet_data *l2) 154 { 155 if (l2 == NULL) 156 return; 157 158 if (l2->fd >= 0) { 159 eloop_unregister_read_sock(l2->fd); 160 close(l2->fd); 161 } 162 163 os_free(l2); 164 } 165 166 167 int l2_packet_get_ip_addr(struct l2_packet_data *l2, char *buf, size_t len) 168 { 169 int s; 170 struct ifreq ifr; 171 struct sockaddr_in *saddr; 172 size_t res; 173 174 s = socket(PF_INET, SOCK_DGRAM, 0); 175 if (s < 0) { 176 perror("socket"); 177 return -1; 178 } 179 os_memset(&ifr, 0, sizeof(ifr)); 180 os_strlcpy(ifr.ifr_name, l2->ifname, sizeof(ifr.ifr_name)); 181 if (ioctl(s, SIOCGIFADDR, &ifr) < 0) { 182 if (errno != EADDRNOTAVAIL) 183 perror("ioctl[SIOCGIFADDR]"); 184 close(s); 185 return -1; 186 } 187 close(s); 188 saddr = aliasing_hide_typecast(&ifr.ifr_addr, struct sockaddr_in); 189 if (saddr->sin_family != AF_INET) 190 return -1; 191 res = os_strlcpy(buf, inet_ntoa(saddr->sin_addr), len); 192 if (res >= len) 193 return -1; 194 return 0; 195 } 196 197 198 void l2_packet_notify_auth_start(struct l2_packet_data *l2) 199 { 200 } 201