dist/wpa/src/l2_packet/l2_packet_freebsd.c

   1 /*
   2  * WPA Supplicant - Layer2 packet handling with FreeBSD
   3  * Copyright (c) 2003-2005, Jouni Malinen <j@w1.fi>
   4  * Copyright (c) 2005, Sam Leffler <sam@errno.com>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  *
  10  * Alternatively, this software may be distributed under the terms of BSD
  11  * license.
  12  *
  13  * See README and COPYING for more details.
  14  */
  15
  16 #include "includes.h"
  17 #ifdef __APPLE__
  18 #include <net/bpf.h>
  19 #endif /* __APPLE__ */
  20 #include <pcap.h>
  21
  22 #include <sys/ioctl.h>
  23 #include <sys/sysctl.h>
  24
  25 #include <net/if.h>
  26 #include <net/if_dl.h>
  27 #include <net/route.h>
  28 #include <netinet/in.h>
  29
  30 #include "common.h"
  31 #include "eloop.h"
  32 #include "l2_packet.h"
  33
  34
  35 static const u8 pae_group_addr[ETH_ALEN] =
  36 { 0x01, 0x80, 0xc2, 0x00, 0x00, 0x03 };
  37
  38 struct l2_packet_data {
  39         pcap_t *pcap;
  40         char ifname[100];
  41         u8 own_addr[ETH_ALEN];
  42         void (*rx_callback)(void *ctx, const u8 *src_addr,
  43                             const u8 *buf, size_t len);
  44         void *rx_callback_ctx;
  45         int l2_hdr; /* whether to include layer 2 (Ethernet) header data
  46                      * buffers */
  47 };
  48
  49
  50 int l2_packet_get_own_addr(struct l2_packet_data *l2, u8 *addr)
  51 {
  52         os_memcpy(addr, l2->own_addr, ETH_ALEN);
  53         return 0;
  54 }
  55
  56
  57 int l2_packet_send(struct l2_packet_data *l2, const u8 *dst_addr, u16 proto,
  58                    const u8 *buf, size_t len)
  59 {
  60         if (!l2->l2_hdr) {
  61                 int ret;
  62                 struct l2_ethhdr *eth = os_malloc(sizeof(*eth) + len);
  63                 if (eth == NULL)
  64                         return -1;
  65                 os_memcpy(eth->h_dest, dst_addr, ETH_ALEN);
  66                 os_memcpy(eth->h_source, l2->own_addr, ETH_ALEN);
  67                 eth->h_proto = htons(proto);
  68                 os_memcpy(eth + 1, buf, len);
  69                 ret = pcap_inject(l2->pcap, (u8 *) eth, len + sizeof(*eth));
  70                 os_free(eth);
  71                 return ret;
  72         } else
  73                 return pcap_inject(l2->pcap, buf, len);
  74 }
  75
  76
  77 static void l2_packet_receive(int sock, void *eloop_ctx, void *sock_ctx)
  78 {
  79         struct l2_packet_data *l2 = eloop_ctx;
  80         pcap_t *pcap = sock_ctx;
  81         struct pcap_pkthdr hdr;
  82         const u_char *packet;
  83         struct l2_ethhdr *ethhdr;
  84         unsigned char *buf;
  85         size_t len;
  86
  87         packet = pcap_next(pcap, &hdr);
  88
  89         if (packet == NULL || hdr.caplen < sizeof(*ethhdr))
  90                 return;
  91
  92         ethhdr = (struct l2_ethhdr *) packet;
  93         if (l2->l2_hdr) {
  94                 buf = (unsigned char *) ethhdr;
  95                 len = hdr.caplen;
  96         } else {
  97                 buf = (unsigned char *) (ethhdr + 1);
  98                 len = hdr.caplen - sizeof(*ethhdr);
  99         }
 100         l2->rx_callback(l2->rx_callback_ctx, ethhdr->h_source, buf, len);
 101 }
 102
 103
 104 static int l2_packet_init_libpcap(struct l2_packet_data *l2,
 105                                   unsigned short protocol)
 106 {
 107         bpf_u_int32 pcap_maskp, pcap_netp;
 108         char pcap_filter[200], pcap_err[PCAP_ERRBUF_SIZE];
 109         struct bpf_program pcap_fp;
 110
 111         pcap_lookupnet(l2->ifname, &pcap_netp, &pcap_maskp, pcap_err);
 112         l2->pcap = pcap_open_live(l2->ifname, 2500, 0, 10, pcap_err);
 113         if (l2->pcap == NULL) {
 114                 fprintf(stderr, "pcap_open_live: %s\n", pcap_err);
 115                 fprintf(stderr, "ifname='%s'\n", l2->ifname);
 116                 return -1;
 117         }
 118         if (pcap_datalink(l2->pcap) != DLT_EN10MB &&
 119             pcap_set_datalink(l2->pcap, DLT_EN10MB) < 0) {
 120                 fprintf(stderr, "pcap_set_datalink(DLT_EN10MB): %s\n",
 121                         pcap_geterr(l2->pcap));
 122                 return -1;
 123         }
 124         os_snprintf(pcap_filter, sizeof(pcap_filter),
 125                     "not ether src " MACSTR " and "
 126                     "( ether dst " MACSTR " or ether dst " MACSTR " ) and "
 127                     "ether proto 0x%x",
 128                     MAC2STR(l2->own_addr), /* do not receive own packets */
 129                     MAC2STR(l2->own_addr), MAC2STR(pae_group_addr),
 130                     protocol);
 131         if (pcap_compile(l2->pcap, &pcap_fp, pcap_filter, 1, pcap_netp) < 0) {
 132                 fprintf(stderr, "pcap_compile: %s\n", pcap_geterr(l2->pcap));
 133                 return -1;
 134         }
 135
 136         if (pcap_setfilter(l2->pcap, &pcap_fp) < 0) {
 137                 fprintf(stderr, "pcap_setfilter: %s\n", pcap_geterr(l2->pcap));
 138                 return -1;
 139         }
 140
 141         pcap_freecode(&pcap_fp);
 142         /*
 143          * When libpcap uses BPF we must enable "immediate mode" to
 144          * receive frames right away; otherwise the system may
 145          * buffer them for us.
 146          */
 147         {
 148                 unsigned int on = 1;
 149                 if (ioctl(pcap_fileno(l2->pcap), BIOCIMMEDIATE, &on) < 0) {
 150                         fprintf(stderr, "%s: cannot enable immediate mode on "
 151                                 "interface %s: %s\n",
 152                                 __func__, l2->ifname, strerror(errno));
 153                         /* XXX should we fail? */
 154                 }
 155         }
 156
 157         eloop_register_read_sock(pcap_get_selectable_fd(l2->pcap),
 158                                  l2_packet_receive, l2, l2->pcap);
 159
 160         return 0;
 161 }
 162
 163
 164 static int eth_get(const char *device, u8 ea[ETH_ALEN])
 165 {
 166         struct if_msghdr *ifm;
 167         struct sockaddr_dl *sdl;
 168         u_char *p, *buf;
 169         size_t len;
 170         int mib[] = { CTL_NET, AF_ROUTE, 0, AF_LINK, NET_RT_IFLIST, 0 };
 171
 172         if (sysctl(mib, 6, NULL, &len, NULL, 0) < 0)
 173                 return -1;
 174         if ((buf = os_malloc(len)) == NULL)
 175                 return -1;
 176         if (sysctl(mib, 6, buf, &len, NULL, 0) < 0) {
 177                 os_free(buf);
 178                 return -1;
 179         }
 180         for (p = buf; p < buf + len; p += ifm->ifm_msglen) {
 181                 ifm = (struct if_msghdr *)p;
 182                 sdl = (struct sockaddr_dl *)(ifm + 1);
 183                 if (ifm->ifm_type != RTM_IFINFO ||
 184                     (ifm->ifm_addrs & RTA_IFP) == 0)
 185                         continue;
 186                 if (sdl->sdl_family != AF_LINK || sdl->sdl_nlen == 0 ||
 187                     os_memcmp(sdl->sdl_data, device, sdl->sdl_nlen) != 0)
 188                         continue;
 189                 os_memcpy(ea, LLADDR(sdl), sdl->sdl_alen);
 190                 break;
 191         }
 192         os_free(buf);
 193
 194         if (p >= buf + len) {
 195                 errno = ESRCH;
 196                 return -1;
 197         }
 198         return 0;
 199 }
 200
 201
 202 struct l2_packet_data * l2_packet_init(
 203         const char *ifname, const u8 *own_addr, unsigned short protocol,
 204         void (*rx_callback)(void *ctx, const u8 *src_addr,
 205                             const u8 *buf, size_t len),
 206         void *rx_callback_ctx, int l2_hdr)
 207 {
 208         struct l2_packet_data *l2;
 209
 210         l2 = os_zalloc(sizeof(struct l2_packet_data));
 211         if (l2 == NULL)
 212                 return NULL;
 213         os_strlcpy(l2->ifname, ifname, sizeof(l2->ifname));
 214         l2->rx_callback = rx_callback;
 215         l2->rx_callback_ctx = rx_callback_ctx;
 216         l2->l2_hdr = l2_hdr;
 217
 218         if (eth_get(l2->ifname, l2->own_addr) < 0) {
 219                 fprintf(stderr, "Failed to get link-level address for "
 220                         "interface '%s'.\n", l2->ifname);
 221                 os_free(l2);
 222                 return NULL;
 223         }
 224
 225         if (l2_packet_init_libpcap(l2, protocol)) {
 226                 os_free(l2);
 227                 return NULL;
 228         }
 229
 230         return l2;
 231 }
 232
 233
 234 void l2_packet_deinit(struct l2_packet_data *l2)
 235 {
 236         if (l2 != NULL) {
 237                 if (l2->pcap) {
 238                         eloop_unregister_read_sock(
 239                                 pcap_get_selectable_fd(l2->pcap));
 240                         pcap_close(l2->pcap);
 241                 }
 242                 os_free(l2);
 243         }
 244 }
 245
 246
 247 int l2_packet_get_ip_addr(struct l2_packet_data *l2, char *buf, size_t len)
 248 {
 249         pcap_if_t *devs, *dev;
 250         struct pcap_addr *addr;
 251         struct sockaddr_in *saddr;
 252         int found = 0;
 253         char err[PCAP_ERRBUF_SIZE + 1];
 254
 255         if (pcap_findalldevs(&devs, err) < 0) {
 256                 wpa_printf(MSG_DEBUG, "pcap_findalldevs: %s\n", err);
 257                 return -1;
 258         }
 259
 260         for (dev = devs; dev && !found; dev = dev->next) {
 261                 if (os_strcmp(dev->name, l2->ifname) != 0)
 262                         continue;
 263
 264                 addr = dev->addresses;
 265                 while (addr) {
 266                         saddr = (struct sockaddr_in *) addr->addr;
 267                         if (saddr && saddr->sin_family == AF_INET) {
 268                                 os_strlcpy(buf, inet_ntoa(saddr->sin_addr),
 269                                            len);
 270                                 found = 1;
 271                                 break;
 272                         }
 273                         addr = addr->next;
 274                 }
 275         }
 276
 277         pcap_freealldevs(devs);
 278
 279         return found ? 0 : -1;
 280 }
 281
 282
 283 void l2_packet_notify_auth_start(struct l2_packet_data *l2)
 284 {
 285 }