ethsock.c

   1 #include <sys/types.h>
   2 #include <stdbool.h>
   3 #include <string.h>
   4 #include <stdlib.h>
   5 #include <stdio.h>
   6 #include "nmrpd.h"
   7
   8 #if defined(NMRPFLASH_WINDOWS)
   9 #define NMRPFLASH_NETALIAS_PREFIX "net"
  10 #define WPCAP
  11 #include <pcap.h>
  12 #else
  13 #include <pcap.h>
  14 #include <ifaddrs.h>
  15 #if defined(NMRPFLASH_LINUX)
  16 #include <linux/if_packet.h>
  17 #elif defined (NMRPFLASH_OSX)
  18 #include <net/if_dl.h>
  19 #endif
  20 #endif
  21
  22 #ifndef MIN
  23 #define MIN(a, b) ((a) < (b) ? (a) : (b))
  24 #endif
  25
  26
  27 struct ethsock
  28 {
  29         pcap_t *pcap;
  30 #ifndef NMRPFLASH_WINDOWS
  31         int fd;
  32 #else
  33         HANDLE handle;
  34 #endif
  35         unsigned timeout;
  36         uint8_t hwaddr[6];
  37 };
  38
  39 static int x_pcap_findalldevs(pcap_if_t **devs)
  40 {
  41         char errbuf[PCAP_ERRBUF_SIZE];
  42         if (pcap_findalldevs(devs, errbuf) != 0) {
  43                 fprintf(stderr, "%s.\n", errbuf);
  44                 return -1;
  45         }
  46
  47         return 0;
  48 }
  49
  50 #ifndef NMRPFLASH_WINDOWS
  51 static bool get_hwaddr(uint8_t *hwaddr, const char *intf)
  52 {
  53         struct ifaddrs *ifas, *ifa;
  54         void *src;
  55         bool found;
  56
  57         if (getifaddrs(&ifas) != 0) {
  58                 perror("getifaddrs");
  59                 return false;
  60         }
  61
  62         found = false;
  63
  64         for (ifa = ifas; ifa; ifa = ifa->ifa_next) {
  65                 if (!strcmp(ifa->ifa_name, intf)) {
  66 #ifdef NMRPFLASH_LINUX
  67                         if (ifa->ifa_addr->sa_family != AF_PACKET) {
  68                                 continue;
  69                         }
  70                         src = ((struct sockaddr_ll*)ifa->ifa_addr)->sll_addr;
  71 #else
  72                         if (ifa->ifa_addr->sa_family != AF_LINK) {
  73                                 continue;
  74                         }
  75                         src = LLADDR((struct sockaddr_dl*)ifa->ifa_addr);
  76 #endif
  77                         memcpy(hwaddr, src, 6);
  78                         found = true;
  79                         break;
  80                 }
  81         }
  82
  83         freeifaddrs(ifas);
  84         return found;
  85 }
  86 #else
  87
  88 void win_perror2(const char *msg, DWORD err)
  89 {
  90         char *buf = NULL;
  91         FormatMessageA(FORMAT_MESSAGE_ALLOCATE_BUFFER |
  92                         FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
  93                         NULL, err, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
  94                         (LPTSTR)&buf, 0, NULL);
  95
  96         if (buf) {
  97                 /* FormatMessageA terminates buf with CRLF! */
  98                 fprintf(stderr, "%s: %s", msg, buf);
  99                 LocalFree(buf);
 100         } else {
 101                 fprintf(stderr, "%s: error %d\n", msg, (int)err);
 102         }
 103 }
 104
 105 static bool get_hwaddr(uint8_t *hwaddr, const char *intf)
 106 {
 107         PIP_ADAPTER_INFO adapters, adapter;
 108         DWORD ret;
 109         ULONG i, bufLen = 0;
 110         bool found = false;
 111
 112         if ((ret = GetAdaptersInfo(NULL, &bufLen)) != ERROR_BUFFER_OVERFLOW) {
 113                 win_perror2("GetAdaptersInfo", ret);
 114                 return false;
 115         }
 116
 117         adapters = malloc(bufLen);
 118         if (!adapters) {
 119                 perror("malloc");
 120                 return false;
 121         }
 122
 123         if ((ret = GetAdaptersInfo(adapters, &bufLen) == NO_ERROR)) {
 124                 for (adapter = adapters; adapter; adapter = adapter->Next) {
 125                         if (adapter->Type != MIB_IF_TYPE_ETHERNET) {
 126                                 continue;
 127                         }
 128
 129 #ifndef NMRPFLASH_WINDOWS
 130                         if (!strcmp(intf, adapter->AdapterName))
 131 #else
 132                         /* Interface names from WinPcap are "\Device\NPF_{GUID}", while
 133                          * AdapterName from GetAdaptersInfo is just "{GUID}".*/
 134                         if (strstr(intf, adapter->AdapterName))
 135 #endif
 136                         {
 137                                 if (adapter->AddressLength == 6) {
 138                                         for (i = 0; i != 6; ++i) {
 139                                                 hwaddr[i] = adapter->Address[i];
 140                                         }
 141
 142                                         found = true;
 143                                         break;
 144                                 }
 145                         }
 146                 }
 147         } else {
 148                 win_perror2("GetAdaptersInfo", ret);
 149         }
 150
 151         free(adapters);
 152         return found;
 153 }
 154
 155 static const char *intf_alias_to_wpcap(const char *intf)
 156 {
 157         static char buf[128];
 158         pcap_if_t *devs, *dev;
 159         unsigned i = 0, dev_num = 0;
 160
 161         if (intf[0] == '\\') {
 162                 return intf;
 163         } else if (sscanf(intf, NMRPFLASH_NETALIAS_PREFIX "%u", &dev_num) != 1) {
 164                 fprintf(stderr, "Invalid interface alias.\n");
 165                 return NULL;
 166         }
 167
 168         if (x_pcap_findalldevs(&devs) != 0) {
 169                 return NULL;
 170         }
 171
 172         for (dev = devs; dev; dev = dev->next) {
 173                 if (i == dev_num) {
 174                         if (verbosity) {
 175                                 printf("%s%u: %s\n", NMRPFLASH_NETALIAS_PREFIX, i, dev->name);
 176                         }
 177                         strncpy(buf, dev->name, sizeof(buf) - 1);
 178                         buf[sizeof(buf) - 1] = '\0';
 179                         break;
 180                 }
 181         }
 182
 183         pcap_freealldevs(devs);
 184
 185         if (!dev) {
 186                 fprintf(stderr, "Interface alias not found.\n");
 187                 return NULL;
 188         }
 189
 190         return buf;
 191 }
 192
 193 static const char *intf_get_pretty_name(const char *intf)
 194 {
 195         static char buf[512];
 196         char *guid;
 197         HKEY hkey;
 198         LONG err;
 199         DWORD len;
 200
 201         guid = strstr(intf, "NPF_{");
 202         if (!guid) {
 203                 return NULL;
 204         }
 205
 206         guid += 4;
 207
 208         snprintf(buf, sizeof(buf),
 209                         "System\\CurrentControlSet\\Control\\Network\\"
 210                         "{4D36E972-E325-11CE-BFC1-08002BE10318}\\"
 211                         "%s\\Connection", guid);
 212         err = RegOpenKeyExA(HKEY_LOCAL_MACHINE, buf, 0, KEY_READ, &hkey);
 213         if (err != ERROR_SUCCESS) {
 214                 if (verbosity > 1) {
 215                         win_perror2("RegOpenKeyExA", err);
 216                 }
 217                 return NULL;
 218         }
 219
 220         len = sizeof(buf);
 221         err = RegQueryValueExA(hkey, "Name", NULL, NULL, (LPBYTE)buf, &len);
 222         if (err == ERROR_SUCCESS) {
 223                 intf = buf;
 224         } else {
 225                 if (verbosity > 1) {
 226                         win_perror2("RegQueryValueExA", err);
 227                 }
 228                 intf = NULL;
 229         }
 230
 231         RegCloseKey(hkey);
 232         return intf;
 233 }
 234 #endif
 235
 236
 237 inline uint8_t *ethsock_get_hwaddr(struct ethsock *sock)
 238 {
 239         return sock->hwaddr;
 240 }
 241
 242 struct ethsock *ethsock_create(const char *intf, uint16_t protocol)
 243 {
 244         char buf[PCAP_ERRBUF_SIZE];
 245         struct bpf_program fp;
 246         struct ethsock *sock;
 247         int err;
 248
 249         sock = malloc(sizeof(struct ethsock));
 250         if (!sock) {
 251                 perror("malloc");
 252                 return NULL;
 253         }
 254
 255 #ifdef NMRPFLASH_WINDOWS
 256         intf = intf_alias_to_wpcap(intf);
 257         if (!intf) {
 258                 return NULL;
 259         }
 260 #endif
 261
 262         buf[0] = '\0';
 263
 264         sock->pcap = pcap_open_live(intf, BUFSIZ, 1, 1, buf);
 265         if (!sock->pcap) {
 266                 fprintf(stderr, "%s.\n", buf);
 267                 goto cleanup_malloc;
 268         }
 269
 270         if (*buf) {
 271                 fprintf(stderr, "Warning: %s.\n", buf);
 272         }
 273
 274         if (pcap_datalink(sock->pcap) != DLT_EN10MB) {
 275                 fprintf(stderr, "%s is not an ethernet interface.\n",
 276                                 intf);
 277                 goto cleanup_pcap;
 278         }
 279
 280         if (!get_hwaddr(sock->hwaddr, intf)) {
 281                 fprintf(stderr, "Failed to get MAC address of interface.\n");
 282                 goto cleanup_malloc;
 283         }
 284
 285 #ifndef NMRPFLASH_WINDOWS
 286         sock->fd = pcap_get_selectable_fd(sock->pcap);
 287         if (sock->fd == -1) {
 288                 fprintf(stderr, "No selectable file descriptor available.\n");
 289                 goto cleanup_pcap;
 290         }
 291 #else
 292         sock->handle = pcap_getevent(sock->pcap);
 293         if (!sock->handle) {
 294                 fprintf(stderr, "No event handle available.\n");
 295                 goto cleanup_pcap;
 296         }
 297 #endif
 298
 299         snprintf(buf, sizeof(buf), "ether proto 0x%04x", protocol);
 300         err = pcap_compile(sock->pcap, &fp, buf, 0, 0);
 301         if (err) {
 302                 pcap_perror(sock->pcap, "pcap_compile");
 303                 goto cleanup_pcap;
 304         }
 305
 306         if ((err = pcap_setfilter(sock->pcap, &fp))) {
 307                 pcap_perror(sock->pcap, "pcap_setfilter");
 308                 goto cleanup_pcap;
 309         }
 310
 311         return sock;
 312
 313 cleanup_pcap:
 314         pcap_close(sock->pcap);
 315 cleanup_malloc:
 316         free(sock);
 317         return NULL;
 318 }
 319
 320 int select_fd(int fd, unsigned timeout)
 321 {
 322         struct timeval tv;
 323         int status;
 324         fd_set fds;
 325
 326         FD_ZERO(&fds);
 327         FD_SET(fd, &fds);
 328
 329         tv.tv_sec = timeout / 1000;
 330         tv.tv_usec = 1000 * (timeout % 1000);
 331
 332         status = select(fd + 1, &fds, NULL, NULL, &tv);
 333         if (status < 0) {
 334                 sock_perror("select");
 335         }
 336
 337         return status;
 338 }
 339
 340 ssize_t ethsock_recv(struct ethsock *sock, void *buf, size_t len)
 341 {
 342         struct pcap_pkthdr* hdr;
 343         const u_char *capbuf;
 344         int status;
 345 #ifdef NMRPFLASH_WINDOWS
 346         DWORD ret;
 347
 348         if (sock->timeout) {
 349                 ret = WaitForSingleObject(sock->handle, sock->timeout);
 350                 if (ret == WAIT_TIMEOUT) {
 351                         return 0;
 352                 } else if (ret != WAIT_OBJECT_0) {
 353                         win_perror2("WaitForSingleObject", ret);
 354                         return -1;
 355                 }
 356         }
 357 #else
 358         if (sock->timeout) {
 359                 status = select_fd(sock->fd, sock->timeout);
 360                 if (status < 0) {
 361                         return -1;
 362                 } else if (status == 0) {
 363                         return 0;
 364                 }
 365         }
 366 #endif
 367
 368         status = pcap_next_ex(sock->pcap, &hdr, &capbuf);
 369         switch (status) {
 370                 case 1:
 371                         memcpy(buf, capbuf, MIN(len, hdr->caplen));
 372                         return hdr->caplen;
 373                 case 0:
 374                         return 0;
 375                 case -1:
 376                         pcap_perror(sock->pcap, "pcap_next_ex");
 377                         return -1;
 378                 default:
 379                         fprintf(stderr, "pcap_next_ex: returned %d.\n", status);
 380                         return -1;
 381         }
 382 }
 383
 384 int ethsock_send(struct ethsock *sock, void *buf, size_t len)
 385 {
 386 #ifdef NMRPFLASH_WINDOWS
 387         if (pcap_sendpacket(sock->pcap, buf, len) == 0) {
 388                 return 0;
 389         } else {
 390                 pcap_perror(sock->pcap, "pcap_sendpacket");
 391                 return -1;
 392         }
 393 #else
 394         if (pcap_inject(sock->pcap, buf, len) == len) {
 395                 return 0;
 396         } else {
 397                 pcap_perror(sock->pcap, "pcap_inject");
 398                 return -1;
 399         }
 400 #endif
 401 }
 402
 403 int ethsock_close(struct ethsock *sock)
 404 {
 405         pcap_close(sock->pcap);
 406         free(sock);
 407         return 0;
 408 }
 409
 410 inline int ethsock_set_timeout(struct ethsock *sock, unsigned msec)
 411 {
 412         sock->timeout = msec;
 413         return 0;
 414 }
 415
 416 static bool is_ethernet(const char *intf)
 417 {
 418         pcap_t *pcap;
 419         char errbuf[PCAP_ERRBUF_SIZE];
 420         bool ret = false;
 421
 422         if ((pcap = pcap_create(intf, errbuf))) {
 423                 if (pcap_activate(pcap) == 0) {
 424                         ret = (pcap_datalink(pcap) == DLT_EN10MB);
 425                 }
 426                 pcap_close(pcap);
 427         }
 428
 429         return ret;
 430 }
 431
 432 int ethsock_list_all(void)
 433 {
 434         pcap_if_t *devs, *dev;
 435         pcap_addr_t *addr;
 436         uint8_t hwaddr[6];
 437         unsigned dev_num = 0;
 438 #ifdef NMRPFLASH_WINDOWS
 439         const char *pretty;
 440 #endif
 441
 442         if (x_pcap_findalldevs(&devs) != 0) {
 443                 return -1;
 444         }
 445
 446         memset(hwaddr, 0, 6);
 447
 448         for (dev = devs; dev; dev = dev->next) {
 449                 if (dev->flags & PCAP_IF_LOOPBACK) {
 450                         if (verbosity) {
 451                                 printf("%-15s  (loopback device)\n", dev->name);
 452                         }
 453                         continue;
 454                 }
 455
 456                 if (!is_ethernet(dev->name)) {
 457                         if (verbosity) {
 458                                 printf("%-15s  (not an ethernet device)\n",
 459                                                 dev->name);
 460                         }
 461                         continue;
 462                 }
 463
 464                 if (!get_hwaddr(hwaddr, dev->name)) {
 465                         if (verbosity) {
 466                                 printf("%-15s  (failed to get hardware address)\n",
 467                                                 dev->name);
 468                         }
 469                         continue;
 470                 }
 471
 472 #ifndef NMRPFLASH_WINDOWS
 473                 printf("%-15s", dev->name);
 474 #else
 475                 /* Call this here so *_perror() calls don't happen within a line */
 476                 pretty = intf_get_pretty_name(dev->name);
 477
 478                 if (!verbosity) {
 479                         printf("%s%u", NMRPFLASH_NETALIAS_PREFIX, dev_num);
 480                 } else {
 481                         printf("%s", dev->name);
 482                 }
 483 #endif
 484
 485                 for (addr = dev->addresses; addr; addr = addr->next) {
 486                         if (addr->addr->sa_family == AF_INET) {
 487                                 printf("  %-15s",
 488                                                 inet_ntoa(((struct sockaddr_in*)addr->addr)->sin_addr));
 489                                 break;
 490                         }
 491                 }
 492
 493                 if (!addr) {
 494                         printf("  %-15s", "0.0.0.0");
 495                 }
 496
 497                 printf("  %02x:%02x:%02x:%02x:%02x:%02x", hwaddr[0], hwaddr[1],
 498                                 hwaddr[2], hwaddr[3], hwaddr[4], hwaddr[5]);
 499
 500 #ifdef NMRPFLASH_WINDOWS
 501                 if (pretty) {
 502                         printf("  (%s)", pretty);
 503                 } else if (dev->description) {
 504                         printf("  (%s)", dev->description);
 505                 }
 506
 507 #endif
 508                 printf("\n");
 509                 ++dev_num;
 510         }
 511
 512         if (!dev_num) {
 513                 printf("No suitable network interfaces found.\n");
 514         }
 515
 516         return 0;
 517 }