ifc_utils.c revision 021d0a2e7cd7c65036d425b7bef775bbc1733864
1/* 2 * Copyright 2008, The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17#include <stdio.h> 18#include <stdlib.h> 19#include <unistd.h> 20#include <string.h> 21#include <errno.h> 22 23#include <sys/socket.h> 24#include <sys/select.h> 25#include <sys/types.h> 26#include <netinet/in.h> 27#include <arpa/inet.h> 28#include <net/if.h> 29 30#include <linux/if.h> 31#include <linux/if_ether.h> 32#include <linux/if_arp.h> 33#include <linux/sockios.h> 34#include <linux/route.h> 35#include <linux/ipv6_route.h> 36#include <netdb.h> 37#include <linux/wireless.h> 38 39#ifdef ANDROID 40#define LOG_TAG "NetUtils" 41#include <cutils/log.h> 42#include <cutils/properties.h> 43#else 44#include <stdio.h> 45#include <string.h> 46#define LOGD printf 47#define LOGW printf 48#endif 49 50static int ifc_ctl_sock = -1; 51static int ifc_ctl_sock6 = -1; 52void printerr(char *fmt, ...); 53 54in_addr_t prefixLengthToIpv4Netmask(int prefix_length) 55{ 56 in_addr_t mask = 0; 57 58 // C99 (6.5.7): shifts of 32 bits have undefined results 59 if (prefix_length <= 0 || prefix_length > 32) { 60 return 0; 61 } 62 63 mask = ~mask << (32 - prefix_length); 64 mask = htonl(mask); 65 66 return mask; 67} 68 69int ipv4NetmaskToPrefixLength(in_addr_t mask) 70{ 71 mask = ntohl(mask); 72 int prefixLength = 0; 73 uint32_t m = (uint32_t)mask; 74 while (m & 0x80000000) { 75 prefixLength++; 76 m = m << 1; 77 } 78 return prefixLength; 79} 80 81static const char *ipaddr_to_string(in_addr_t addr) 82{ 83 struct in_addr in_addr; 84 85 in_addr.s_addr = addr; 86 return inet_ntoa(in_addr); 87} 88 89int ifc_init(void) 90{ 91 if (ifc_ctl_sock == -1) { 92 ifc_ctl_sock = socket(AF_INET, SOCK_DGRAM, 0); 93 if (ifc_ctl_sock < 0) { 94 printerr("socket() failed: %s\n", strerror(errno)); 95 } 96 } 97 return ifc_ctl_sock < 0 ? -1 : 0; 98} 99 100int ifc_init6(void) 101{ 102 if (ifc_ctl_sock6 == -1) { 103 ifc_ctl_sock6 = socket(AF_INET6, SOCK_DGRAM, 0); 104 if (ifc_ctl_sock6 < 0) { 105 printerr("socket() failed: %s\n", strerror(errno)); 106 } 107 } 108 return ifc_ctl_sock6 < 0 ? -1 : 0; 109} 110 111void ifc_close(void) 112{ 113 if (ifc_ctl_sock != -1) { 114 (void)close(ifc_ctl_sock); 115 ifc_ctl_sock = -1; 116 } 117} 118 119void ifc_close6(void) 120{ 121 if (ifc_ctl_sock6 != -1) { 122 (void)close(ifc_ctl_sock6); 123 ifc_ctl_sock6 = -1; 124 } 125} 126 127static void ifc_init_ifr(const char *name, struct ifreq *ifr) 128{ 129 memset(ifr, 0, sizeof(struct ifreq)); 130 strncpy(ifr->ifr_name, name, IFNAMSIZ); 131 ifr->ifr_name[IFNAMSIZ - 1] = 0; 132} 133 134int ifc_get_hwaddr(const char *name, void *ptr) 135{ 136 int r; 137 struct ifreq ifr; 138 ifc_init_ifr(name, &ifr); 139 140 r = ioctl(ifc_ctl_sock, SIOCGIFHWADDR, &ifr); 141 if(r < 0) return -1; 142 143 memcpy(ptr, &ifr.ifr_hwaddr.sa_data, ETH_ALEN); 144 return 0; 145} 146 147int ifc_get_ifindex(const char *name, int *if_indexp) 148{ 149 int r; 150 struct ifreq ifr; 151 ifc_init_ifr(name, &ifr); 152 153 r = ioctl(ifc_ctl_sock, SIOCGIFINDEX, &ifr); 154 if(r < 0) return -1; 155 156 *if_indexp = ifr.ifr_ifindex; 157 return 0; 158} 159 160static int ifc_set_flags(const char *name, unsigned set, unsigned clr) 161{ 162 struct ifreq ifr; 163 ifc_init_ifr(name, &ifr); 164 165 if(ioctl(ifc_ctl_sock, SIOCGIFFLAGS, &ifr) < 0) return -1; 166 ifr.ifr_flags = (ifr.ifr_flags & (~clr)) | set; 167 return ioctl(ifc_ctl_sock, SIOCSIFFLAGS, &ifr); 168} 169 170int ifc_up(const char *name) 171{ 172 return ifc_set_flags(name, IFF_UP, 0); 173} 174 175int ifc_down(const char *name) 176{ 177 return ifc_set_flags(name, 0, IFF_UP); 178} 179 180static void init_sockaddr_in(struct sockaddr *sa, in_addr_t addr) 181{ 182 struct sockaddr_in *sin = (struct sockaddr_in *) sa; 183 sin->sin_family = AF_INET; 184 sin->sin_port = 0; 185 sin->sin_addr.s_addr = addr; 186} 187 188int ifc_set_addr(const char *name, in_addr_t addr) 189{ 190 struct ifreq ifr; 191 192 ifc_init_ifr(name, &ifr); 193 init_sockaddr_in(&ifr.ifr_addr, addr); 194 195 return ioctl(ifc_ctl_sock, SIOCSIFADDR, &ifr); 196} 197 198int ifc_set_hwaddr(const char *name, const void *ptr) 199{ 200 int r; 201 struct ifreq ifr; 202 ifc_init_ifr(name, &ifr); 203 204 ifr.ifr_hwaddr.sa_family = ARPHRD_ETHER; 205 memcpy(&ifr.ifr_hwaddr.sa_data, ptr, ETH_ALEN); 206 return ioctl(ifc_ctl_sock, SIOCSIFHWADDR, &ifr); 207} 208 209int ifc_set_prefixLength(const char *name, int prefixLength) 210{ 211 struct ifreq ifr; 212 // TODO - support ipv6 213 if (prefixLength > 32 || prefixLength < 0) return -1; 214 215 in_addr_t mask = prefixLengthToIpv4Netmask(prefixLength); 216 ifc_init_ifr(name, &ifr); 217 init_sockaddr_in(&ifr.ifr_addr, mask); 218 219 return ioctl(ifc_ctl_sock, SIOCSIFNETMASK, &ifr); 220} 221 222int ifc_get_addr(const char *name, in_addr_t *addr) 223{ 224 struct ifreq ifr; 225 int ret = 0; 226 227 ifc_init_ifr(name, &ifr); 228 if (addr != NULL) { 229 ret = ioctl(ifc_ctl_sock, SIOCGIFADDR, &ifr); 230 if (ret < 0) { 231 *addr = 0; 232 } else { 233 *addr = ((struct sockaddr_in*) &ifr.ifr_addr)->sin_addr.s_addr; 234 } 235 } 236 return ret; 237} 238 239int ifc_get_info(const char *name, in_addr_t *addr, int *prefixLength, unsigned *flags) 240{ 241 struct ifreq ifr; 242 ifc_init_ifr(name, &ifr); 243 244 if (addr != NULL) { 245 if(ioctl(ifc_ctl_sock, SIOCGIFADDR, &ifr) < 0) { 246 *addr = 0; 247 } else { 248 *addr = ((struct sockaddr_in*) &ifr.ifr_addr)->sin_addr.s_addr; 249 } 250 } 251 252 if (prefixLength != NULL) { 253 if(ioctl(ifc_ctl_sock, SIOCGIFNETMASK, &ifr) < 0) { 254 *prefixLength = 0; 255 } else { 256 *prefixLength = ipv4NetmaskToPrefixLength((int) 257 ((struct sockaddr_in*) &ifr.ifr_addr)->sin_addr.s_addr); 258 } 259 } 260 261 if (flags != NULL) { 262 if(ioctl(ifc_ctl_sock, SIOCGIFFLAGS, &ifr) < 0) { 263 *flags = 0; 264 } else { 265 *flags = ifr.ifr_flags; 266 } 267 } 268 269 return 0; 270} 271 272int ifc_act_on_ipv4_route(int action, const char *ifname, struct in_addr dst, int prefix_length, 273 struct in_addr gw) 274{ 275 struct rtentry rt; 276 int result; 277 in_addr_t netmask; 278 279 memset(&rt, 0, sizeof(rt)); 280 281 rt.rt_dst.sa_family = AF_INET; 282 rt.rt_dev = (void*) ifname; 283 284 netmask = prefixLengthToIpv4Netmask(prefix_length); 285 init_sockaddr_in(&rt.rt_genmask, netmask); 286 init_sockaddr_in(&rt.rt_dst, dst.s_addr); 287 rt.rt_flags = RTF_UP; 288 289 if (prefix_length == 32) { 290 rt.rt_flags |= RTF_HOST; 291 } 292 293 if (gw.s_addr != 0) { 294 rt.rt_flags |= RTF_GATEWAY; 295 init_sockaddr_in(&rt.rt_gateway, gw.s_addr); 296 } 297 298 ifc_init(); 299 300 if (ifc_ctl_sock < 0) { 301 return -errno; 302 } 303 304 result = ioctl(ifc_ctl_sock, action, &rt); 305 if (result < 0) { 306 if (errno == EEXIST) { 307 result = 0; 308 } else { 309 result = -errno; 310 } 311 } 312 ifc_close(); 313 return result; 314} 315 316int ifc_create_default_route(const char *name, in_addr_t gw) 317{ 318 struct in_addr in_dst, in_gw; 319 320 in_dst.s_addr = 0; 321 in_gw.s_addr = gw; 322 323 return ifc_act_on_route(SIOCADDRT, name, in_dst, 0, in_gw); 324} 325 326int ifc_enable(const char *ifname) 327{ 328 int result; 329 330 ifc_init(); 331 result = ifc_up(ifname); 332 ifc_close(); 333 return result; 334} 335 336int ifc_disable(const char *ifname) 337{ 338 unsigned addr, count; 339 int result; 340 341 ifc_init(); 342 result = ifc_down(ifname); 343 344 ifc_set_addr(ifname, 0); 345 for (count=0, addr=1;((addr != 0) && (count < 255)); count++) { 346 if (ifc_get_addr(ifname, &addr) < 0) 347 break; 348 if (addr) 349 ifc_set_addr(ifname, 0); 350 } 351 352 ifc_close(); 353 return result; 354} 355 356int ifc_reset_connections(const char *ifname) 357{ 358#ifdef HAVE_ANDROID_OS 359 int result, success; 360 in_addr_t myaddr; 361 struct ifreq ifr; 362 struct in6_ifreq ifr6; 363 364 /* IPv4. Clear connections on the IP address. */ 365 ifc_init(); 366 ifc_get_info(ifname, &myaddr, NULL, NULL); 367 ifc_init_ifr(ifname, &ifr); 368 init_sockaddr_in(&ifr.ifr_addr, myaddr); 369 result = ioctl(ifc_ctl_sock, SIOCKILLADDR, &ifr); 370 ifc_close(); 371 372 /* 373 * IPv6. On Linux, when an interface goes down it loses all its IPv6 374 * addresses, so we don't know which connections belonged to that interface 375 * So we clear all unused IPv6 connections on the device by specifying an 376 * empty IPv6 address. 377 */ 378 ifc_init6(); 379 // This implicitly specifies an address of ::, i.e., kill all IPv6 sockets. 380 memset(&ifr6, 0, sizeof(ifr6)); 381 success = ioctl(ifc_ctl_sock6, SIOCKILLADDR, &ifr6); 382 if (result == 0) { 383 result = success; 384 } 385 ifc_close6(); 386 387 return result; 388#else 389 return 0; 390#endif 391} 392 393/* 394 * Remove the routes associated with the named interface. 395 */ 396int ifc_remove_host_routes(const char *name) 397{ 398 char ifname[64]; 399 in_addr_t dest, gway, mask; 400 int flags, refcnt, use, metric, mtu, win, irtt; 401 struct rtentry rt; 402 FILE *fp; 403 struct in_addr addr; 404 405 fp = fopen("/proc/net/route", "r"); 406 if (fp == NULL) 407 return -1; 408 /* Skip the header line */ 409 if (fscanf(fp, "%*[^\n]\n") < 0) { 410 fclose(fp); 411 return -1; 412 } 413 ifc_init(); 414 for (;;) { 415 int nread = fscanf(fp, "%63s%X%X%X%d%d%d%X%d%d%d\n", 416 ifname, &dest, &gway, &flags, &refcnt, &use, &metric, &mask, 417 &mtu, &win, &irtt); 418 if (nread != 11) { 419 break; 420 } 421 if ((flags & (RTF_UP|RTF_HOST)) != (RTF_UP|RTF_HOST) 422 || strcmp(ifname, name) != 0) { 423 continue; 424 } 425 memset(&rt, 0, sizeof(rt)); 426 rt.rt_dev = (void *)name; 427 init_sockaddr_in(&rt.rt_dst, dest); 428 init_sockaddr_in(&rt.rt_gateway, gway); 429 init_sockaddr_in(&rt.rt_genmask, mask); 430 addr.s_addr = dest; 431 if (ioctl(ifc_ctl_sock, SIOCDELRT, &rt) < 0) { 432 LOGD("failed to remove route for %s to %s: %s", 433 ifname, inet_ntoa(addr), strerror(errno)); 434 } 435 } 436 fclose(fp); 437 ifc_close(); 438 return 0; 439} 440 441/* 442 * Removes the default route for the named interface. 443 */ 444int ifc_remove_default_route(const char *ifname) 445{ 446 struct rtentry rt; 447 int result; 448 449 ifc_init(); 450 memset(&rt, 0, sizeof(rt)); 451 rt.rt_dev = (void *)ifname; 452 rt.rt_flags = RTF_UP|RTF_GATEWAY; 453 init_sockaddr_in(&rt.rt_dst, 0); 454 if ((result = ioctl(ifc_ctl_sock, SIOCDELRT, &rt)) < 0) { 455 LOGD("failed to remove default route for %s: %s", ifname, strerror(errno)); 456 } 457 ifc_close(); 458 return result; 459} 460 461int 462ifc_configure(const char *ifname, 463 in_addr_t address, 464 uint32_t prefixLength, 465 in_addr_t gateway, 466 in_addr_t dns1, 467 in_addr_t dns2) { 468 469 char dns_prop_name[PROPERTY_KEY_MAX]; 470 471 ifc_init(); 472 473 if (ifc_up(ifname)) { 474 printerr("failed to turn on interface %s: %s\n", ifname, strerror(errno)); 475 ifc_close(); 476 return -1; 477 } 478 if (ifc_set_addr(ifname, address)) { 479 printerr("failed to set ipaddr %s: %s\n", ipaddr_to_string(address), strerror(errno)); 480 ifc_close(); 481 return -1; 482 } 483 if (ifc_set_prefixLength(ifname, prefixLength)) { 484 printerr("failed to set prefixLength %d: %s\n", prefixLength, strerror(errno)); 485 ifc_close(); 486 return -1; 487 } 488 if (ifc_create_default_route(ifname, gateway)) { 489 printerr("failed to set default route %s: %s\n", ipaddr_to_string(gateway), strerror(errno)); 490 ifc_close(); 491 return -1; 492 } 493 494 ifc_close(); 495 496 snprintf(dns_prop_name, sizeof(dns_prop_name), "net.%s.dns1", ifname); 497 property_set(dns_prop_name, dns1 ? ipaddr_to_string(dns1) : ""); 498 snprintf(dns_prop_name, sizeof(dns_prop_name), "net.%s.dns2", ifname); 499 property_set(dns_prop_name, dns2 ? ipaddr_to_string(dns2) : ""); 500 501 return 0; 502} 503 504int ifc_act_on_ipv6_route(int action, const char *ifname, struct in6_addr dst, int prefix_length, 505 struct in6_addr gw) 506{ 507 struct in6_rtmsg rtmsg; 508 int result; 509 int ifindex; 510 511 memset(&rtmsg, 0, sizeof(rtmsg)); 512 513 ifindex = if_nametoindex(ifname); 514 if (ifindex == 0) { 515 printerr("if_nametoindex() failed: interface %s\n", ifname); 516 return -ENXIO; 517 } 518 519 rtmsg.rtmsg_ifindex = ifindex; 520 rtmsg.rtmsg_dst = dst; 521 rtmsg.rtmsg_dst_len = prefix_length; 522 rtmsg.rtmsg_flags = RTF_UP; 523 524 if (prefix_length == 128) { 525 rtmsg.rtmsg_flags |= RTF_HOST; 526 } 527 528 if (memcmp(&gw, &in6addr_any, sizeof(in6addr_any))) { 529 rtmsg.rtmsg_flags |= RTF_GATEWAY; 530 rtmsg.rtmsg_gateway = gw; 531 } 532 533 ifc_init6(); 534 535 if (ifc_ctl_sock6 < 0) { 536 return -errno; 537 } 538 539 result = ioctl(ifc_ctl_sock6, action, &rtmsg); 540 if (result < 0) { 541 if (errno == EEXIST) { 542 result = 0; 543 } else { 544 result = -errno; 545 } 546 } 547 ifc_close6(); 548 return result; 549} 550 551int ifc_act_on_route(int action, const char *ifname, const char *dst, int prefix_length, 552 const char *gw) 553{ 554 int ret = 0; 555 struct sockaddr_in ipv4_dst, ipv4_gw; 556 struct sockaddr_in6 ipv6_dst, ipv6_gw; 557 struct addrinfo hints, *addr_ai, *gw_ai; 558 559 memset(&hints, 0, sizeof(hints)); 560 hints.ai_family = AF_UNSPEC; /* Allow IPv4 or IPv6 */ 561 hints.ai_flags = AI_NUMERICHOST; 562 563 ret = getaddrinfo(dst, NULL, &hints, &addr_ai); 564 565 if (ret != 0) { 566 printerr("getaddrinfo failed: invalid address %s\n", dst); 567 return -EINVAL; 568 } 569 570 if (gw == NULL || (strlen(gw) == 0)) { 571 if (addr_ai->ai_family == AF_INET6) { 572 gw = "::"; 573 } else if (addr_ai->ai_family == AF_INET) { 574 gw = "0.0.0.0"; 575 } 576 } 577 578 if (((addr_ai->ai_family == AF_INET6) && (prefix_length < 0 || prefix_length > 128)) || 579 ((addr_ai->ai_family == AF_INET) && (prefix_length < 0 || prefix_length > 32))) { 580 printerr("ifc_add_route: invalid prefix length"); 581 freeaddrinfo(addr_ai); 582 return -EINVAL; 583 } 584 585 ret = getaddrinfo(gw, NULL, &hints, &gw_ai); 586 if (ret != 0) { 587 printerr("getaddrinfo failed: invalid gateway %s\n", gw); 588 freeaddrinfo(addr_ai); 589 return -EINVAL; 590 } 591 592 if (addr_ai->ai_family != gw_ai->ai_family) { 593 printerr("ifc_add_route: different address families: %s and %s\n", dst, gw); 594 freeaddrinfo(addr_ai); 595 freeaddrinfo(gw_ai); 596 return -EINVAL; 597 } 598 599 if (addr_ai->ai_family == AF_INET6) { 600 memcpy(&ipv6_dst, addr_ai->ai_addr, sizeof(struct sockaddr_in6)); 601 memcpy(&ipv6_gw, gw_ai->ai_addr, sizeof(struct sockaddr_in6)); 602 ret = ifc_act_on_ipv6_route(action, ifname, ipv6_dst.sin6_addr, 603 prefix_length, ipv6_gw.sin6_addr); 604 } else if (addr_ai->ai_family == AF_INET) { 605 memcpy(&ipv4_dst, addr_ai->ai_addr, sizeof(struct sockaddr_in)); 606 memcpy(&ipv4_gw, gw_ai->ai_addr, sizeof(struct sockaddr_in)); 607 ret = ifc_act_on_ipv4_route(action, ifname, ipv4_dst.sin_addr, 608 prefix_length, ipv4_gw.sin_addr); 609 } else { 610 printerr("ifc_add_route: getaddrinfo returned un supported address family %d\n", 611 addr_ai->ai_family); 612 ret = -EAFNOSUPPORT; 613 } 614 615 freeaddrinfo(addr_ai); 616 freeaddrinfo(gw_ai); 617 return ret; 618} 619 620int ifc_add_route(const char *ifname, const char *dst, int prefix_length, const char *gw) 621{ 622 return ifc_act_on_route(SIOCADDRT, ifname, dst, prefix_length, gw); 623} 624 625int ifc_remove_route(const char *ifname, const char*dst, int prefix_length, const char *gw) 626{ 627 return ifc_act_on_route(SIOCDELRT, ifname, dst, prefix_length, gw); 628} 629