1 /* 2 * Copyright (C) 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 #include <stdlib.h> 17 #include <string.h> 18 19 #define LOG_TAG "NetlinkEvent" 20 #include <cutils/log.h> 21 22 #include <sysutils/NetlinkEvent.h> 23 24 #include <sys/types.h> 25 #include <sys/socket.h> 26 #include <netinet/in.h> 27 #include <netinet/icmp6.h> 28 #include <arpa/inet.h> 29 #include <net/if.h> 30 31 #include <linux/if.h> 32 #include <linux/if_addr.h> 33 #include <linux/if_link.h> 34 #include <linux/netfilter/nfnetlink.h> 35 #include <linux/netfilter/nfnetlink_log.h> 36 #include <linux/netfilter_ipv4/ipt_ULOG.h> 37 38 /* From kernel's net/netfilter/xt_quota2.c */ 39 const int LOCAL_QLOG_NL_EVENT = 112; 40 const int LOCAL_NFLOG_PACKET = NFNL_SUBSYS_ULOG << 8 | NFULNL_MSG_PACKET; 41 42 #include <linux/netlink.h> 43 #include <linux/rtnetlink.h> 44 45 #include <netlink/attr.h> 46 #include <netlink/genl/genl.h> 47 #include <netlink/handlers.h> 48 #include <netlink/msg.h> 49 NetlinkEvent()50 NetlinkEvent::NetlinkEvent() { 51 mAction = Action::kUnknown; 52 memset(mParams, 0, sizeof(mParams)); 53 mPath = NULL; 54 mSubsystem = NULL; 55 } 56 ~NetlinkEvent()57 NetlinkEvent::~NetlinkEvent() { 58 int i; 59 if (mPath) 60 free(mPath); 61 if (mSubsystem) 62 free(mSubsystem); 63 for (i = 0; i < NL_PARAMS_MAX; i++) { 64 if (!mParams[i]) 65 break; 66 free(mParams[i]); 67 } 68 } 69 dump()70 void NetlinkEvent::dump() { 71 int i; 72 73 for (i = 0; i < NL_PARAMS_MAX; i++) { 74 if (!mParams[i]) 75 break; 76 SLOGD("NL param '%s'\n", mParams[i]); 77 } 78 } 79 80 /* 81 * Returns the message name for a message in the NETLINK_ROUTE family, or NULL 82 * if parsing that message is not supported. 83 */ rtMessageName(int type)84 static const char *rtMessageName(int type) { 85 #define NL_EVENT_RTM_NAME(rtm) case rtm: return #rtm; 86 switch (type) { 87 NL_EVENT_RTM_NAME(RTM_NEWLINK); 88 NL_EVENT_RTM_NAME(RTM_DELLINK); 89 NL_EVENT_RTM_NAME(RTM_NEWADDR); 90 NL_EVENT_RTM_NAME(RTM_DELADDR); 91 NL_EVENT_RTM_NAME(RTM_NEWROUTE); 92 NL_EVENT_RTM_NAME(RTM_DELROUTE); 93 NL_EVENT_RTM_NAME(RTM_NEWNDUSEROPT); 94 NL_EVENT_RTM_NAME(LOCAL_QLOG_NL_EVENT); 95 NL_EVENT_RTM_NAME(LOCAL_NFLOG_PACKET); 96 default: 97 return NULL; 98 } 99 #undef NL_EVENT_RTM_NAME 100 } 101 102 /* 103 * Checks that a binary NETLINK_ROUTE message is long enough for a payload of 104 * size bytes. 105 */ checkRtNetlinkLength(const struct nlmsghdr * nh,size_t size)106 static bool checkRtNetlinkLength(const struct nlmsghdr *nh, size_t size) { 107 if (nh->nlmsg_len < NLMSG_LENGTH(size)) { 108 SLOGE("Got a short %s message\n", rtMessageName(nh->nlmsg_type)); 109 return false; 110 } 111 return true; 112 } 113 114 /* 115 * Utility function to log errors. 116 */ maybeLogDuplicateAttribute(bool isDup,const char * attributeName,const char * messageName)117 static bool maybeLogDuplicateAttribute(bool isDup, 118 const char *attributeName, 119 const char *messageName) { 120 if (isDup) { 121 SLOGE("Multiple %s attributes in %s, ignoring\n", attributeName, messageName); 122 return true; 123 } 124 return false; 125 } 126 127 /* 128 * Parse a RTM_NEWLINK message. 129 */ parseIfInfoMessage(const struct nlmsghdr * nh)130 bool NetlinkEvent::parseIfInfoMessage(const struct nlmsghdr *nh) { 131 struct ifinfomsg *ifi = (struct ifinfomsg *) NLMSG_DATA(nh); 132 if (!checkRtNetlinkLength(nh, sizeof(*ifi))) 133 return false; 134 135 if ((ifi->ifi_flags & IFF_LOOPBACK) != 0) { 136 return false; 137 } 138 139 int len = IFLA_PAYLOAD(nh); 140 struct rtattr *rta; 141 for (rta = IFLA_RTA(ifi); RTA_OK(rta, len); rta = RTA_NEXT(rta, len)) { 142 switch(rta->rta_type) { 143 case IFLA_IFNAME: 144 asprintf(&mParams[0], "INTERFACE=%s", (char *) RTA_DATA(rta)); 145 mAction = (ifi->ifi_flags & IFF_LOWER_UP) ? Action::kLinkUp : 146 Action::kLinkDown; 147 mSubsystem = strdup("net"); 148 return true; 149 } 150 } 151 152 return false; 153 } 154 155 /* 156 * Parse a RTM_NEWADDR or RTM_DELADDR message. 157 */ parseIfAddrMessage(const struct nlmsghdr * nh)158 bool NetlinkEvent::parseIfAddrMessage(const struct nlmsghdr *nh) { 159 struct ifaddrmsg *ifaddr = (struct ifaddrmsg *) NLMSG_DATA(nh); 160 struct ifa_cacheinfo *cacheinfo = NULL; 161 char addrstr[INET6_ADDRSTRLEN] = ""; 162 char ifname[IFNAMSIZ] = ""; 163 164 if (!checkRtNetlinkLength(nh, sizeof(*ifaddr))) 165 return false; 166 167 // Sanity check. 168 int type = nh->nlmsg_type; 169 if (type != RTM_NEWADDR && type != RTM_DELADDR) { 170 SLOGE("parseIfAddrMessage on incorrect message type 0x%x\n", type); 171 return false; 172 } 173 174 // For log messages. 175 const char *msgtype = rtMessageName(type); 176 177 struct rtattr *rta; 178 int len = IFA_PAYLOAD(nh); 179 for (rta = IFA_RTA(ifaddr); RTA_OK(rta, len); rta = RTA_NEXT(rta, len)) { 180 if (rta->rta_type == IFA_ADDRESS) { 181 // Only look at the first address, because we only support notifying 182 // one change at a time. 183 if (maybeLogDuplicateAttribute(*addrstr != '\0', "IFA_ADDRESS", msgtype)) 184 continue; 185 186 // Convert the IP address to a string. 187 if (ifaddr->ifa_family == AF_INET) { 188 struct in_addr *addr4 = (struct in_addr *) RTA_DATA(rta); 189 if (RTA_PAYLOAD(rta) < sizeof(*addr4)) { 190 SLOGE("Short IPv4 address (%zu bytes) in %s", 191 RTA_PAYLOAD(rta), msgtype); 192 continue; 193 } 194 inet_ntop(AF_INET, addr4, addrstr, sizeof(addrstr)); 195 } else if (ifaddr->ifa_family == AF_INET6) { 196 struct in6_addr *addr6 = (struct in6_addr *) RTA_DATA(rta); 197 if (RTA_PAYLOAD(rta) < sizeof(*addr6)) { 198 SLOGE("Short IPv6 address (%zu bytes) in %s", 199 RTA_PAYLOAD(rta), msgtype); 200 continue; 201 } 202 inet_ntop(AF_INET6, addr6, addrstr, sizeof(addrstr)); 203 } else { 204 SLOGE("Unknown address family %d\n", ifaddr->ifa_family); 205 continue; 206 } 207 208 // Find the interface name. 209 if (!if_indextoname(ifaddr->ifa_index, ifname)) { 210 SLOGD("Unknown ifindex %d in %s", ifaddr->ifa_index, msgtype); 211 } 212 213 } else if (rta->rta_type == IFA_CACHEINFO) { 214 // Address lifetime information. 215 if (maybeLogDuplicateAttribute(cacheinfo, "IFA_CACHEINFO", msgtype)) 216 continue; 217 218 if (RTA_PAYLOAD(rta) < sizeof(*cacheinfo)) { 219 SLOGE("Short IFA_CACHEINFO (%zu vs. %zu bytes) in %s", 220 RTA_PAYLOAD(rta), sizeof(cacheinfo), msgtype); 221 continue; 222 } 223 224 cacheinfo = (struct ifa_cacheinfo *) RTA_DATA(rta); 225 } 226 } 227 228 if (addrstr[0] == '\0') { 229 SLOGE("No IFA_ADDRESS in %s\n", msgtype); 230 return false; 231 } 232 233 // Fill in netlink event information. 234 mAction = (type == RTM_NEWADDR) ? Action::kAddressUpdated : 235 Action::kAddressRemoved; 236 mSubsystem = strdup("net"); 237 asprintf(&mParams[0], "ADDRESS=%s/%d", addrstr, ifaddr->ifa_prefixlen); 238 asprintf(&mParams[1], "INTERFACE=%s", ifname); 239 asprintf(&mParams[2], "FLAGS=%u", ifaddr->ifa_flags); 240 asprintf(&mParams[3], "SCOPE=%u", ifaddr->ifa_scope); 241 242 if (cacheinfo) { 243 asprintf(&mParams[4], "PREFERRED=%u", cacheinfo->ifa_prefered); 244 asprintf(&mParams[5], "VALID=%u", cacheinfo->ifa_valid); 245 asprintf(&mParams[6], "CSTAMP=%u", cacheinfo->cstamp); 246 asprintf(&mParams[7], "TSTAMP=%u", cacheinfo->tstamp); 247 } 248 249 return true; 250 } 251 252 /* 253 * Parse a QLOG_NL_EVENT message. 254 */ parseUlogPacketMessage(const struct nlmsghdr * nh)255 bool NetlinkEvent::parseUlogPacketMessage(const struct nlmsghdr *nh) { 256 const char *devname; 257 ulog_packet_msg_t *pm = (ulog_packet_msg_t *) NLMSG_DATA(nh); 258 if (!checkRtNetlinkLength(nh, sizeof(*pm))) 259 return false; 260 261 devname = pm->indev_name[0] ? pm->indev_name : pm->outdev_name; 262 asprintf(&mParams[0], "ALERT_NAME=%s", pm->prefix); 263 asprintf(&mParams[1], "INTERFACE=%s", devname); 264 mSubsystem = strdup("qlog"); 265 mAction = Action::kChange; 266 return true; 267 } 268 269 /* 270 * Parse a LOCAL_NFLOG_PACKET message. 271 */ parseNfPacketMessage(struct nlmsghdr * nh)272 bool NetlinkEvent::parseNfPacketMessage(struct nlmsghdr *nh) { 273 int uid = -1; 274 int len = 0; 275 char* raw = NULL; 276 277 struct nlattr *uid_attr = nlmsg_find_attr(nh, sizeof(struct genlmsghdr), NFULA_UID); 278 if (uid_attr) { 279 uid = ntohl(nla_get_u32(uid_attr)); 280 } 281 282 struct nlattr *payload = nlmsg_find_attr(nh, sizeof(struct genlmsghdr), NFULA_PAYLOAD); 283 if (payload) { 284 /* First 256 bytes is plenty */ 285 len = nla_len(payload); 286 if (len > 256) len = 256; 287 raw = (char*) nla_data(payload); 288 } 289 290 char* hex = (char*) calloc(1, 5 + (len * 2)); 291 strcpy(hex, "HEX="); 292 for (int i = 0; i < len; i++) { 293 hex[4 + (i * 2)] = "0123456789abcdef"[(raw[i] >> 4) & 0xf]; 294 hex[5 + (i * 2)] = "0123456789abcdef"[raw[i] & 0xf]; 295 } 296 297 asprintf(&mParams[0], "UID=%d", uid); 298 mParams[1] = hex; 299 mSubsystem = strdup("strict"); 300 mAction = Action::kChange; 301 return true; 302 } 303 304 /* 305 * Parse a RTM_NEWROUTE or RTM_DELROUTE message. 306 */ parseRtMessage(const struct nlmsghdr * nh)307 bool NetlinkEvent::parseRtMessage(const struct nlmsghdr *nh) { 308 uint8_t type = nh->nlmsg_type; 309 const char *msgname = rtMessageName(type); 310 311 // Sanity check. 312 if (type != RTM_NEWROUTE && type != RTM_DELROUTE) { 313 SLOGE("%s: incorrect message type %d (%s)\n", __func__, type, msgname); 314 return false; 315 } 316 317 struct rtmsg *rtm = (struct rtmsg *) NLMSG_DATA(nh); 318 if (!checkRtNetlinkLength(nh, sizeof(*rtm))) 319 return false; 320 321 if (// Ignore static routes we've set up ourselves. 322 (rtm->rtm_protocol != RTPROT_KERNEL && 323 rtm->rtm_protocol != RTPROT_RA) || 324 // We're only interested in global unicast routes. 325 (rtm->rtm_scope != RT_SCOPE_UNIVERSE) || 326 (rtm->rtm_type != RTN_UNICAST) || 327 // We don't support source routing. 328 (rtm->rtm_src_len != 0) || 329 // Cloned routes aren't real routes. 330 (rtm->rtm_flags & RTM_F_CLONED)) { 331 return false; 332 } 333 334 int family = rtm->rtm_family; 335 int prefixLength = rtm->rtm_dst_len; 336 337 // Currently we only support: destination, (one) next hop, ifindex. 338 char dst[INET6_ADDRSTRLEN] = ""; 339 char gw[INET6_ADDRSTRLEN] = ""; 340 char dev[IFNAMSIZ] = ""; 341 342 size_t len = RTM_PAYLOAD(nh); 343 struct rtattr *rta; 344 for (rta = RTM_RTA(rtm); RTA_OK(rta, len); rta = RTA_NEXT(rta, len)) { 345 switch (rta->rta_type) { 346 case RTA_DST: 347 if (maybeLogDuplicateAttribute(*dst, "RTA_DST", msgname)) 348 continue; 349 if (!inet_ntop(family, RTA_DATA(rta), dst, sizeof(dst))) 350 return false; 351 continue; 352 case RTA_GATEWAY: 353 if (maybeLogDuplicateAttribute(*gw, "RTA_GATEWAY", msgname)) 354 continue; 355 if (!inet_ntop(family, RTA_DATA(rta), gw, sizeof(gw))) 356 return false; 357 continue; 358 case RTA_OIF: 359 if (maybeLogDuplicateAttribute(*dev, "RTA_OIF", msgname)) 360 continue; 361 if (!if_indextoname(* (int *) RTA_DATA(rta), dev)) 362 return false; 363 default: 364 continue; 365 } 366 } 367 368 // If there's no RTA_DST attribute, then: 369 // - If the prefix length is zero, it's the default route. 370 // - If the prefix length is nonzero, there's something we don't understand. 371 // Ignore the event. 372 if (!*dst && !prefixLength) { 373 if (family == AF_INET) { 374 strncpy(dst, "0.0.0.0", sizeof(dst)); 375 } else if (family == AF_INET6) { 376 strncpy(dst, "::", sizeof(dst)); 377 } 378 } 379 380 // A useful route must have a destination and at least either a gateway or 381 // an interface. 382 if (!*dst || (!*gw && !*dev)) 383 return false; 384 385 // Fill in netlink event information. 386 mAction = (type == RTM_NEWROUTE) ? Action::kRouteUpdated : 387 Action::kRouteRemoved; 388 mSubsystem = strdup("net"); 389 asprintf(&mParams[0], "ROUTE=%s/%d", dst, prefixLength); 390 asprintf(&mParams[1], "GATEWAY=%s", (*gw) ? gw : ""); 391 asprintf(&mParams[2], "INTERFACE=%s", (*dev) ? dev : ""); 392 393 return true; 394 } 395 396 /* 397 * Parse a RTM_NEWNDUSEROPT message. 398 */ parseNdUserOptMessage(const struct nlmsghdr * nh)399 bool NetlinkEvent::parseNdUserOptMessage(const struct nlmsghdr *nh) { 400 struct nduseroptmsg *msg = (struct nduseroptmsg *) NLMSG_DATA(nh); 401 if (!checkRtNetlinkLength(nh, sizeof(*msg))) 402 return false; 403 404 // Check the length is valid. 405 int len = NLMSG_PAYLOAD(nh, sizeof(*msg)); 406 if (msg->nduseropt_opts_len > len) { 407 SLOGE("RTM_NEWNDUSEROPT invalid length %d > %d\n", 408 msg->nduseropt_opts_len, len); 409 return false; 410 } 411 len = msg->nduseropt_opts_len; 412 413 // Check address family and packet type. 414 if (msg->nduseropt_family != AF_INET6) { 415 SLOGE("RTM_NEWNDUSEROPT message for unknown family %d\n", 416 msg->nduseropt_family); 417 return false; 418 } 419 420 if (msg->nduseropt_icmp_type != ND_ROUTER_ADVERT || 421 msg->nduseropt_icmp_code != 0) { 422 SLOGE("RTM_NEWNDUSEROPT message for unknown ICMPv6 type/code %d/%d\n", 423 msg->nduseropt_icmp_type, msg->nduseropt_icmp_code); 424 return false; 425 } 426 427 // Find the interface name. 428 char ifname[IFNAMSIZ]; 429 if (!if_indextoname(msg->nduseropt_ifindex, ifname)) { 430 SLOGE("RTM_NEWNDUSEROPT on unknown ifindex %d\n", 431 msg->nduseropt_ifindex); 432 return false; 433 } 434 435 // The kernel sends a separate netlink message for each ND option in the RA. 436 // So only parse the first ND option in the message. 437 struct nd_opt_hdr *opthdr = (struct nd_opt_hdr *) (msg + 1); 438 439 // The length is in multiples of 8 octets. 440 uint16_t optlen = opthdr->nd_opt_len; 441 if (optlen * 8 > len) { 442 SLOGE("Invalid option length %d > %d for ND option %d\n", 443 optlen * 8, len, opthdr->nd_opt_type); 444 return false; 445 } 446 447 if (opthdr->nd_opt_type == ND_OPT_RDNSS) { 448 // DNS Servers (RFC 6106). 449 // Each address takes up 2*8 octets, and the header takes up 8 octets. 450 // So for a valid option with one or more addresses, optlen must be 451 // odd and greater than 1. 452 if ((optlen < 3) || !(optlen & 0x1)) { 453 SLOGE("Invalid optlen %d for RDNSS option\n", optlen); 454 return false; 455 } 456 const int numaddrs = (optlen - 1) / 2; 457 458 // Find the lifetime. 459 struct nd_opt_rdnss *rndss_opt = (struct nd_opt_rdnss *) opthdr; 460 const uint32_t lifetime = ntohl(rndss_opt->nd_opt_rdnss_lifetime); 461 462 // Construct "SERVERS=<comma-separated string of DNS addresses>". 463 static const char kServerTag[] = "SERVERS="; 464 static const size_t kTagLength = strlen(kServerTag); 465 // Reserve sufficient space for an IPv6 link-local address: all but the 466 // last address are followed by ','; the last is followed by '\0'. 467 static const size_t kMaxSingleAddressLength = 468 INET6_ADDRSTRLEN + strlen("%") + IFNAMSIZ + strlen(","); 469 const size_t bufsize = kTagLength + numaddrs * kMaxSingleAddressLength; 470 char *buf = (char *) malloc(bufsize); 471 if (!buf) { 472 SLOGE("RDNSS option: out of memory\n"); 473 return false; 474 } 475 strcpy(buf, kServerTag); 476 size_t pos = kTagLength; 477 478 struct in6_addr *addrs = (struct in6_addr *) (rndss_opt + 1); 479 for (int i = 0; i < numaddrs; i++) { 480 if (i > 0) { 481 buf[pos++] = ','; 482 } 483 inet_ntop(AF_INET6, addrs + i, buf + pos, bufsize - pos); 484 pos += strlen(buf + pos); 485 if (IN6_IS_ADDR_LINKLOCAL(addrs + i)) { 486 buf[pos++] = '%'; 487 pos += strlcpy(buf + pos, ifname, bufsize - pos); 488 } 489 } 490 buf[pos] = '\0'; 491 492 mAction = Action::kRdnss; 493 mSubsystem = strdup("net"); 494 asprintf(&mParams[0], "INTERFACE=%s", ifname); 495 asprintf(&mParams[1], "LIFETIME=%u", lifetime); 496 mParams[2] = buf; 497 } else { 498 SLOGD("Unknown ND option type %d\n", opthdr->nd_opt_type); 499 return false; 500 } 501 502 return true; 503 } 504 505 /* 506 * Parse a binary message from a NETLINK_ROUTE netlink socket. 507 * 508 * Note that this function can only parse one message, because the message's 509 * content has to be stored in the class's member variables (mAction, 510 * mSubsystem, etc.). Invalid or unrecognized messages are skipped, but if 511 * there are multiple valid messages in the buffer, only the first one will be 512 * returned. 513 * 514 * TODO: consider only ever looking at the first message. 515 */ parseBinaryNetlinkMessage(char * buffer,int size)516 bool NetlinkEvent::parseBinaryNetlinkMessage(char *buffer, int size) { 517 struct nlmsghdr *nh; 518 519 for (nh = (struct nlmsghdr *) buffer; 520 NLMSG_OK(nh, (unsigned) size) && (nh->nlmsg_type != NLMSG_DONE); 521 nh = NLMSG_NEXT(nh, size)) { 522 523 if (!rtMessageName(nh->nlmsg_type)) { 524 SLOGD("Unexpected netlink message type %d\n", nh->nlmsg_type); 525 continue; 526 } 527 528 if (nh->nlmsg_type == RTM_NEWLINK) { 529 if (parseIfInfoMessage(nh)) 530 return true; 531 532 } else if (nh->nlmsg_type == LOCAL_QLOG_NL_EVENT) { 533 if (parseUlogPacketMessage(nh)) 534 return true; 535 536 } else if (nh->nlmsg_type == RTM_NEWADDR || 537 nh->nlmsg_type == RTM_DELADDR) { 538 if (parseIfAddrMessage(nh)) 539 return true; 540 541 } else if (nh->nlmsg_type == RTM_NEWROUTE || 542 nh->nlmsg_type == RTM_DELROUTE) { 543 if (parseRtMessage(nh)) 544 return true; 545 546 } else if (nh->nlmsg_type == RTM_NEWNDUSEROPT) { 547 if (parseNdUserOptMessage(nh)) 548 return true; 549 550 } else if (nh->nlmsg_type == LOCAL_NFLOG_PACKET) { 551 if (parseNfPacketMessage(nh)) 552 return true; 553 554 } 555 } 556 557 return false; 558 } 559 560 /* If the string between 'str' and 'end' begins with 'prefixlen' characters 561 * from the 'prefix' array, then return 'str + prefixlen', otherwise return 562 * NULL. 563 */ 564 static const char* has_prefix(const char * str,const char * end,const char * prefix,size_t prefixlen)565 has_prefix(const char* str, const char* end, const char* prefix, size_t prefixlen) 566 { 567 if ((end-str) >= (ptrdiff_t)prefixlen && !memcmp(str, prefix, prefixlen)) 568 return str + prefixlen; 569 else 570 return NULL; 571 } 572 573 /* Same as strlen(x) for constant string literals ONLY */ 574 #define CONST_STRLEN(x) (sizeof(x)-1) 575 576 /* Convenience macro to call has_prefix with a constant string literal */ 577 #define HAS_CONST_PREFIX(str,end,prefix) has_prefix((str),(end),prefix,CONST_STRLEN(prefix)) 578 579 580 /* 581 * Parse an ASCII-formatted message from a NETLINK_KOBJECT_UEVENT 582 * netlink socket. 583 */ parseAsciiNetlinkMessage(char * buffer,int size)584 bool NetlinkEvent::parseAsciiNetlinkMessage(char *buffer, int size) { 585 const char *s = buffer; 586 const char *end; 587 int param_idx = 0; 588 int first = 1; 589 590 if (size == 0) 591 return false; 592 593 /* Ensure the buffer is zero-terminated, the code below depends on this */ 594 buffer[size-1] = '\0'; 595 596 end = s + size; 597 while (s < end) { 598 if (first) { 599 const char *p; 600 /* buffer is 0-terminated, no need to check p < end */ 601 for (p = s; *p != '@'; p++) { 602 if (!*p) { /* no '@', should not happen */ 603 return false; 604 } 605 } 606 mPath = strdup(p+1); 607 first = 0; 608 } else { 609 const char* a; 610 if ((a = HAS_CONST_PREFIX(s, end, "ACTION=")) != NULL) { 611 if (!strcmp(a, "add")) 612 mAction = Action::kAdd; 613 else if (!strcmp(a, "remove")) 614 mAction = Action::kRemove; 615 else if (!strcmp(a, "change")) 616 mAction = Action::kChange; 617 } else if ((a = HAS_CONST_PREFIX(s, end, "SEQNUM=")) != NULL) { 618 mSeq = atoi(a); 619 } else if ((a = HAS_CONST_PREFIX(s, end, "SUBSYSTEM=")) != NULL) { 620 mSubsystem = strdup(a); 621 } else if (param_idx < NL_PARAMS_MAX) { 622 mParams[param_idx++] = strdup(s); 623 } 624 } 625 s += strlen(s) + 1; 626 } 627 return true; 628 } 629 decode(char * buffer,int size,int format)630 bool NetlinkEvent::decode(char *buffer, int size, int format) { 631 if (format == NetlinkListener::NETLINK_FORMAT_BINARY 632 || format == NetlinkListener::NETLINK_FORMAT_BINARY_UNICAST) { 633 return parseBinaryNetlinkMessage(buffer, size); 634 } else { 635 return parseAsciiNetlinkMessage(buffer, size); 636 } 637 } 638 findParam(const char * paramName)639 const char *NetlinkEvent::findParam(const char *paramName) { 640 size_t len = strlen(paramName); 641 for (int i = 0; i < NL_PARAMS_MAX && mParams[i] != NULL; ++i) { 642 const char *ptr = mParams[i] + len; 643 if (!strncmp(mParams[i], paramName, len) && *ptr == '=') 644 return ++ptr; 645 } 646 647 SLOGE("NetlinkEvent::FindParam(): Parameter '%s' not found", paramName); 648 return NULL; 649 } 650