src/l2_packet/l2_packet_linux.c

   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 }