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00016 #include "includes.h"
00017 #if defined(__APPLE__) || defined(__GLIBC__)
00018 #include <net/bpf.h>
00019 #endif
00020 #include <pcap.h>
00021
00022 #include <sys/ioctl.h>
00023 #include <sys/sysctl.h>
00024
00025 #include <net/if.h>
00026 #include <net/if_dl.h>
00027 #include <net/route.h>
00028 #include <netinet/in.h>
00029
00030 #include "common.h"
00031 #include "eloop.h"
00032 #include "l2_packet.h"
00033
00034
00035 static const u8 pae_group_addr[ETH_ALEN] =
00036 { 0x01, 0x80, 0xc2, 0x00, 0x00, 0x03 };
00037
00038 struct l2_packet_data {
00039 pcap_t *pcap;
00040 char ifname[100];
00041 u8 own_addr[ETH_ALEN];
00042 void (*rx_callback)(void *ctx, const u8 *src_addr,
00043 const u8 *buf, size_t len);
00044 void *rx_callback_ctx;
00045 int l2_hdr;
00046
00047 };
00048
00049
00050 int l2_packet_get_own_addr(struct l2_packet_data *l2, u8 *addr)
00051 {
00052 os_memcpy(addr, l2->own_addr, ETH_ALEN);
00053 return 0;
00054 }
00055
00056
00057 int l2_packet_send(struct l2_packet_data *l2, const u8 *dst_addr, u16 proto,
00058 const u8 *buf, size_t len)
00059 {
00060 if (!l2->l2_hdr) {
00061 int ret;
00062 struct l2_ethhdr *eth = os_malloc(sizeof(*eth) + len);
00063 if (eth == NULL)
00064 return -1;
00065 os_memcpy(eth->h_dest, dst_addr, ETH_ALEN);
00066 os_memcpy(eth->h_source, l2->own_addr, ETH_ALEN);
00067 eth->h_proto = htons(proto);
00068 os_memcpy(eth + 1, buf, len);
00069 ret = pcap_inject(l2->pcap, (u8 *) eth, len + sizeof(*eth));
00070 os_free(eth);
00071 return ret;
00072 } else
00073 return pcap_inject(l2->pcap, buf, len);
00074 }
00075
00076
00077 static void l2_packet_receive(int sock, void *eloop_ctx, void *sock_ctx)
00078 {
00079 struct l2_packet_data *l2 = eloop_ctx;
00080 pcap_t *pcap = sock_ctx;
00081 struct pcap_pkthdr hdr;
00082 const u_char *packet;
00083 struct l2_ethhdr *ethhdr;
00084 unsigned char *buf;
00085 size_t len;
00086
00087 packet = pcap_next(pcap, &hdr);
00088
00089 if (packet == NULL || hdr.caplen < sizeof(*ethhdr))
00090 return;
00091
00092 ethhdr = (struct l2_ethhdr *) packet;
00093 if (l2->l2_hdr) {
00094 buf = (unsigned char *) ethhdr;
00095 len = hdr.caplen;
00096 } else {
00097 buf = (unsigned char *) (ethhdr + 1);
00098 len = hdr.caplen - sizeof(*ethhdr);
00099 }
00100 l2->rx_callback(l2->rx_callback_ctx, ethhdr->h_source, buf, len);
00101 }
00102
00103
00104 static int l2_packet_init_libpcap(struct l2_packet_data *l2,
00105 unsigned short protocol)
00106 {
00107 bpf_u_int32 pcap_maskp, pcap_netp;
00108 char pcap_filter[200], pcap_err[PCAP_ERRBUF_SIZE];
00109 struct bpf_program pcap_fp;
00110
00111 pcap_lookupnet(l2->ifname, &pcap_netp, &pcap_maskp, pcap_err);
00112 l2->pcap = pcap_open_live(l2->ifname, 2500, 0, 10, pcap_err);
00113 if (l2->pcap == NULL) {
00114 fprintf(stderr, "pcap_open_live: %s\n", pcap_err);
00115 fprintf(stderr, "ifname='%s'\n", l2->ifname);
00116 return -1;
00117 }
00118 if (pcap_datalink(l2->pcap) != DLT_EN10MB &&
00119 pcap_set_datalink(l2->pcap, DLT_EN10MB) < 0) {
00120 fprintf(stderr, "pcap_set_datalink(DLT_EN10MB): %s\n",
00121 pcap_geterr(l2->pcap));
00122 return -1;
00123 }
00124 os_snprintf(pcap_filter, sizeof(pcap_filter),
00125 "not ether src " MACSTR " and "
00126 "( ether dst " MACSTR " or ether dst " MACSTR " ) and "
00127 "ether proto 0x%x",
00128 MAC2STR(l2->own_addr),
00129 MAC2STR(l2->own_addr), MAC2STR(pae_group_addr),
00130 protocol);
00131 if (pcap_compile(l2->pcap, &pcap_fp, pcap_filter, 1, pcap_netp) < 0) {
00132 fprintf(stderr, "pcap_compile: %s\n", pcap_geterr(l2->pcap));
00133 return -1;
00134 }
00135
00136 if (pcap_setfilter(l2->pcap, &pcap_fp) < 0) {
00137 fprintf(stderr, "pcap_setfilter: %s\n", pcap_geterr(l2->pcap));
00138 return -1;
00139 }
00140
00141 pcap_freecode(&pcap_fp);
00142
00143
00144
00145
00146
00147 {
00148 unsigned int on = 1;
00149 if (ioctl(pcap_fileno(l2->pcap), BIOCIMMEDIATE, &on) < 0) {
00150 fprintf(stderr, "%s: cannot enable immediate mode on "
00151 "interface %s: %s\n",
00152 __func__, l2->ifname, strerror(errno));
00153
00154 }
00155 }
00156
00157 eloop_register_read_sock(pcap_get_selectable_fd(l2->pcap),
00158 l2_packet_receive, l2, l2->pcap);
00159
00160 return 0;
00161 }
00162
00163
00164 static int eth_get(const char *device, u8 ea[ETH_ALEN])
00165 {
00166 struct if_msghdr *ifm;
00167 struct sockaddr_dl *sdl;
00168 u_char *p, *buf;
00169 size_t len;
00170 int mib[] = { CTL_NET, AF_ROUTE, 0, AF_LINK, NET_RT_IFLIST, 0 };
00171
00172 if (sysctl(mib, 6, NULL, &len, NULL, 0) < 0)
00173 return -1;
00174 if ((buf = os_malloc(len)) == NULL)
00175 return -1;
00176 if (sysctl(mib, 6, buf, &len, NULL, 0) < 0) {
00177 os_free(buf);
00178 return -1;
00179 }
00180 for (p = buf; p < buf + len; p += ifm->ifm_msglen) {
00181 ifm = (struct if_msghdr *)p;
00182 sdl = (struct sockaddr_dl *)(ifm + 1);
00183 if (ifm->ifm_type != RTM_IFINFO ||
00184 (ifm->ifm_addrs & RTA_IFP) == 0)
00185 continue;
00186 if (sdl->sdl_family != AF_LINK || sdl->sdl_nlen == 0 ||
00187 os_memcmp(sdl->sdl_data, device, sdl->sdl_nlen) != 0)
00188 continue;
00189 os_memcpy(ea, LLADDR(sdl), sdl->sdl_alen);
00190 break;
00191 }
00192 os_free(buf);
00193
00194 if (p >= buf + len) {
00195 errno = ESRCH;
00196 return -1;
00197 }
00198 return 0;
00199 }
00200
00201
00202 struct l2_packet_data * l2_packet_init(
00203 const char *ifname, const u8 *own_addr, unsigned short protocol,
00204 void (*rx_callback)(void *ctx, const u8 *src_addr,
00205 const u8 *buf, size_t len),
00206 void *rx_callback_ctx, int l2_hdr)
00207 {
00208 struct l2_packet_data *l2;
00209
00210 l2 = os_zalloc(sizeof(struct l2_packet_data));
00211 if (l2 == NULL)
00212 return NULL;
00213 os_strlcpy(l2->ifname, ifname, sizeof(l2->ifname));
00214 l2->rx_callback = rx_callback;
00215 l2->rx_callback_ctx = rx_callback_ctx;
00216 l2->l2_hdr = l2_hdr;
00217
00218 if (eth_get(l2->ifname, l2->own_addr) < 0) {
00219 fprintf(stderr, "Failed to get link-level address for "
00220 "interface '%s'.\n", l2->ifname);
00221 os_free(l2);
00222 return NULL;
00223 }
00224
00225 if (l2_packet_init_libpcap(l2, protocol)) {
00226 os_free(l2);
00227 return NULL;
00228 }
00229
00230 return l2;
00231 }
00232
00233
00234 void l2_packet_deinit(struct l2_packet_data *l2)
00235 {
00236 if (l2 != NULL) {
00237 if (l2->pcap) {
00238 eloop_unregister_read_sock(
00239 pcap_get_selectable_fd(l2->pcap));
00240 pcap_close(l2->pcap);
00241 }
00242 os_free(l2);
00243 }
00244 }
00245
00246
00247 int l2_packet_get_ip_addr(struct l2_packet_data *l2, char *buf, size_t len)
00248 {
00249 pcap_if_t *devs, *dev;
00250 struct pcap_addr *addr;
00251 struct sockaddr_in *saddr;
00252 int found = 0;
00253 char err[PCAP_ERRBUF_SIZE + 1];
00254
00255 if (pcap_findalldevs(&devs, err) < 0) {
00256 wpa_printf(MSG_DEBUG, "pcap_findalldevs: %s\n", err);
00257 return -1;
00258 }
00259
00260 for (dev = devs; dev && !found; dev = dev->next) {
00261 if (os_strcmp(dev->name, l2->ifname) != 0)
00262 continue;
00263
00264 addr = dev->addresses;
00265 while (addr) {
00266 saddr = (struct sockaddr_in *) addr->addr;
00267 if (saddr && saddr->sin_family == AF_INET) {
00268 os_strlcpy(buf, inet_ntoa(saddr->sin_addr),
00269 len);
00270 found = 1;
00271 break;
00272 }
00273 addr = addr->next;
00274 }
00275 }
00276
00277 pcap_freealldevs(devs);
00278
00279 return found ? 0 : -1;
00280 }
00281
00282
00283 void l2_packet_notify_auth_start(struct l2_packet_data *l2)
00284 {
00285 }