463 lines
15 KiB
C++
463 lines
15 KiB
C++
/*
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* Copyright (C) 2008 The Android Open Source Project
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#include <stdlib.h>
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#include <string.h>
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#define LOG_TAG "NetlinkEvent"
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#include <cutils/log.h>
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#include <sysutils/NetlinkEvent.h>
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#include <sys/types.h>
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#include <sys/socket.h>
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#include <netinet/in.h>
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#include <netinet/icmp6.h>
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#include <arpa/inet.h>
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#include <net/if.h>
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#include <linux/if.h>
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#include <linux/netfilter/nfnetlink.h>
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#include <linux/netfilter_ipv4/ipt_ULOG.h>
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/* From kernel's net/netfilter/xt_quota2.c */
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const int QLOG_NL_EVENT = 112;
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#include <linux/netlink.h>
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#include <linux/rtnetlink.h>
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const int NetlinkEvent::NlActionUnknown = 0;
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const int NetlinkEvent::NlActionAdd = 1;
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const int NetlinkEvent::NlActionRemove = 2;
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const int NetlinkEvent::NlActionChange = 3;
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const int NetlinkEvent::NlActionLinkUp = 4;
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const int NetlinkEvent::NlActionLinkDown = 5;
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const int NetlinkEvent::NlActionAddressUpdated = 6;
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const int NetlinkEvent::NlActionAddressRemoved = 7;
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const int NetlinkEvent::NlActionRdnss = 8;
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NetlinkEvent::NetlinkEvent() {
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mAction = NlActionUnknown;
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memset(mParams, 0, sizeof(mParams));
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mPath = NULL;
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mSubsystem = NULL;
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}
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NetlinkEvent::~NetlinkEvent() {
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int i;
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if (mPath)
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free(mPath);
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if (mSubsystem)
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free(mSubsystem);
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for (i = 0; i < NL_PARAMS_MAX; i++) {
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if (!mParams[i])
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break;
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free(mParams[i]);
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}
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}
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void NetlinkEvent::dump() {
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int i;
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for (i = 0; i < NL_PARAMS_MAX; i++) {
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if (!mParams[i])
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break;
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SLOGD("NL param '%s'\n", mParams[i]);
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}
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}
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/*
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* Parse a RTM_NEWADDR or RTM_DELADDR message.
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*/
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bool NetlinkEvent::parseIfAddrMessage(int type, struct ifaddrmsg *ifaddr,
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int rtasize) {
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struct rtattr *rta;
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struct ifa_cacheinfo *cacheinfo = NULL;
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char addrstr[INET6_ADDRSTRLEN] = "";
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// Sanity check.
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if (type != RTM_NEWADDR && type != RTM_DELADDR) {
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SLOGE("parseIfAddrMessage on incorrect message type 0x%x\n", type);
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return false;
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}
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// For log messages.
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const char *msgtype = (type == RTM_NEWADDR) ? "RTM_NEWADDR" : "RTM_DELADDR";
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for (rta = IFA_RTA(ifaddr); RTA_OK(rta, rtasize);
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rta = RTA_NEXT(rta, rtasize)) {
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if (rta->rta_type == IFA_ADDRESS) {
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// Only look at the first address, because we only support notifying
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// one change at a time.
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if (*addrstr != '\0') {
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SLOGE("Multiple IFA_ADDRESSes in %s, ignoring\n", msgtype);
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continue;
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}
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// Convert the IP address to a string.
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if (ifaddr->ifa_family == AF_INET) {
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struct in_addr *addr4 = (struct in_addr *) RTA_DATA(rta);
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if (RTA_PAYLOAD(rta) < sizeof(*addr4)) {
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SLOGE("Short IPv4 address (%d bytes) in %s",
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RTA_PAYLOAD(rta), msgtype);
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continue;
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}
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inet_ntop(AF_INET, addr4, addrstr, sizeof(addrstr));
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} else if (ifaddr->ifa_family == AF_INET6) {
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struct in6_addr *addr6 = (struct in6_addr *) RTA_DATA(rta);
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if (RTA_PAYLOAD(rta) < sizeof(*addr6)) {
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SLOGE("Short IPv6 address (%d bytes) in %s",
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RTA_PAYLOAD(rta), msgtype);
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continue;
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}
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inet_ntop(AF_INET6, addr6, addrstr, sizeof(addrstr));
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} else {
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SLOGE("Unknown address family %d\n", ifaddr->ifa_family);
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continue;
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}
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// Find the interface name.
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char ifname[IFNAMSIZ + 1];
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if (!if_indextoname(ifaddr->ifa_index, ifname)) {
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SLOGE("Unknown ifindex %d in %s", ifaddr->ifa_index, msgtype);
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return false;
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}
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// Fill in interface information.
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mAction = (type == RTM_NEWADDR) ? NlActionAddressUpdated :
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NlActionAddressRemoved;
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mSubsystem = strdup("net");
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asprintf(&mParams[0], "ADDRESS=%s/%d", addrstr,
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ifaddr->ifa_prefixlen);
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asprintf(&mParams[1], "INTERFACE=%s", ifname);
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asprintf(&mParams[2], "FLAGS=%u", ifaddr->ifa_flags);
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asprintf(&mParams[3], "SCOPE=%u", ifaddr->ifa_scope);
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} else if (rta->rta_type == IFA_CACHEINFO) {
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// Address lifetime information.
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if (cacheinfo) {
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// We only support one address.
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SLOGE("Multiple IFA_CACHEINFOs in %s, ignoring\n", msgtype);
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continue;
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}
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if (RTA_PAYLOAD(rta) < sizeof(*cacheinfo)) {
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SLOGE("Short IFA_CACHEINFO (%d vs. %d bytes) in %s",
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RTA_PAYLOAD(rta), sizeof(cacheinfo), msgtype);
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continue;
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}
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cacheinfo = (struct ifa_cacheinfo *) RTA_DATA(rta);
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asprintf(&mParams[4], "PREFERRED=%u", cacheinfo->ifa_prefered);
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asprintf(&mParams[5], "VALID=%u", cacheinfo->ifa_valid);
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asprintf(&mParams[6], "CSTAMP=%u", cacheinfo->cstamp);
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asprintf(&mParams[7], "TSTAMP=%u", cacheinfo->tstamp);
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}
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}
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if (addrstr[0] == '\0') {
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SLOGE("No IFA_ADDRESS in %s\n", msgtype);
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return false;
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}
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return true;
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}
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/*
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<<<<<<< HEAD
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* Parse a RTM_NEWNDUSEROPT message.
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*/
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bool NetlinkEvent::parseNdUserOptMessage(struct nduseroptmsg *msg, int len) {
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// Check the length is valid.
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if (msg->nduseropt_opts_len > len) {
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SLOGE("RTM_NEWNDUSEROPT invalid length %d > %d\n",
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msg->nduseropt_opts_len, len);
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return false;
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}
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len = msg->nduseropt_opts_len;
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// Check address family and packet type.
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if (msg->nduseropt_family != AF_INET6) {
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SLOGE("RTM_NEWNDUSEROPT message for unknown family %d\n",
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msg->nduseropt_family);
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return false;
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}
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if (msg->nduseropt_icmp_type != ND_ROUTER_ADVERT ||
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msg->nduseropt_icmp_code != 0) {
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SLOGE("RTM_NEWNDUSEROPT message for unknown ICMPv6 type/code %d/%d\n",
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msg->nduseropt_icmp_type, msg->nduseropt_icmp_code);
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return false;
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}
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// Find the interface name.
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char ifname[IFNAMSIZ + 1];
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if (!if_indextoname(msg->nduseropt_ifindex, ifname)) {
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SLOGE("RTM_NEWNDUSEROPT on unknown ifindex %d\n",
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msg->nduseropt_ifindex);
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return false;
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}
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// The kernel sends a separate netlink message for each ND option in the RA.
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// So only parse the first ND option in the message.
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struct nd_opt_hdr *opthdr = (struct nd_opt_hdr *) (msg + 1);
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// The length is in multiples of 8 octets.
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uint16_t optlen = opthdr->nd_opt_len;
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if (optlen * 8 > len) {
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SLOGE("Invalid option length %d > %d for ND option %d\n",
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optlen * 8, len, opthdr->nd_opt_type);
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return false;
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}
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if (opthdr->nd_opt_type == ND_OPT_RDNSS) {
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// DNS Servers (RFC 6106).
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// Each address takes up 2*8 octets, and the header takes up 8 octets.
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// So for a valid option with one or more addresses, optlen must be
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// odd and greater than 1.
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if ((optlen < 3) || !(optlen & 0x1)) {
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SLOGE("Invalid optlen %d for RDNSS option\n", optlen);
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return false;
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}
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int numaddrs = (optlen - 1) / 2;
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// Find the lifetime.
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struct nd_opt_rdnss *rndss_opt = (struct nd_opt_rdnss *) opthdr;
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uint32_t lifetime = ntohl(rndss_opt->nd_opt_rdnss_lifetime);
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// Construct "SERVERS=<comma-separated string of DNS addresses>".
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// Reserve (INET6_ADDRSTRLEN + 1) chars for each address: all but the
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// the last address are followed by ','; the last is followed by '\0'.
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static const char kServerTag[] = "SERVERS=";
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static const int kTagLength = sizeof(kServerTag) - 1;
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int bufsize = kTagLength + numaddrs * (INET6_ADDRSTRLEN + 1);
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char *buf = (char *) malloc(bufsize);
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if (!buf) {
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SLOGE("RDNSS option: out of memory\n");
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return false;
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}
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strcpy(buf, kServerTag);
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int pos = kTagLength;
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struct in6_addr *addrs = (struct in6_addr *) (rndss_opt + 1);
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for (int i = 0; i < numaddrs; i++) {
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if (i > 0) {
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buf[pos++] = ',';
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}
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inet_ntop(AF_INET6, addrs + i, buf + pos, bufsize - pos);
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pos += strlen(buf + pos);
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}
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buf[pos] = '\0';
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mAction = NlActionRdnss;
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mSubsystem = strdup("net");
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asprintf(&mParams[0], "INTERFACE=%s", ifname);
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asprintf(&mParams[1], "LIFETIME=%u", lifetime);
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mParams[2] = buf;
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} else {
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SLOGD("Unknown ND option type %d\n", opthdr->nd_opt_type);
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return false;
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}
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return true;
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}
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/*
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* Parse a binary message from a NETLINK_ROUTE netlink socket.
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*/
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bool NetlinkEvent::parseBinaryNetlinkMessage(char *buffer, int size) {
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const struct nlmsghdr *nh;
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for (nh = (struct nlmsghdr *) buffer;
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NLMSG_OK(nh, (unsigned) size) && (nh->nlmsg_type != NLMSG_DONE);
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nh = NLMSG_NEXT(nh, size)) {
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if (nh->nlmsg_type == RTM_NEWLINK) {
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int len = nh->nlmsg_len - sizeof(*nh);
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struct ifinfomsg *ifi;
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if (sizeof(*ifi) > (size_t) len) {
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SLOGE("Got a short RTM_NEWLINK message\n");
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continue;
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}
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ifi = (ifinfomsg *)NLMSG_DATA(nh);
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if ((ifi->ifi_flags & IFF_LOOPBACK) != 0) {
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continue;
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}
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struct rtattr *rta = (struct rtattr *)
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((char *) ifi + NLMSG_ALIGN(sizeof(*ifi)));
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len = NLMSG_PAYLOAD(nh, sizeof(*ifi));
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while(RTA_OK(rta, len)) {
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switch(rta->rta_type) {
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case IFLA_IFNAME:
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char buffer[16 + IFNAMSIZ];
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snprintf(buffer, sizeof(buffer), "INTERFACE=%s",
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(char *) RTA_DATA(rta));
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mParams[0] = strdup(buffer);
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mAction = (ifi->ifi_flags & IFF_LOWER_UP) ?
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NlActionLinkUp : NlActionLinkDown;
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mSubsystem = strdup("net");
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break;
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}
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rta = RTA_NEXT(rta, len);
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}
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} else if (nh->nlmsg_type == QLOG_NL_EVENT) {
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char *devname;
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ulog_packet_msg_t *pm;
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size_t len = nh->nlmsg_len - sizeof(*nh);
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if (sizeof(*pm) > len) {
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SLOGE("Got a short QLOG message\n");
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continue;
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}
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pm = (ulog_packet_msg_t *)NLMSG_DATA(nh);
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devname = pm->indev_name[0] ? pm->indev_name : pm->outdev_name;
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asprintf(&mParams[0], "ALERT_NAME=%s", pm->prefix);
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asprintf(&mParams[1], "INTERFACE=%s", devname);
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mSubsystem = strdup("qlog");
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mAction = NlActionChange;
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} else if (nh->nlmsg_type == RTM_NEWADDR ||
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nh->nlmsg_type == RTM_DELADDR) {
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int len = nh->nlmsg_len - sizeof(*nh);
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struct ifaddrmsg *ifa;
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if (sizeof(*ifa) > (size_t) len) {
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SLOGE("Got a short RTM_xxxADDR message\n");
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continue;
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}
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ifa = (ifaddrmsg *)NLMSG_DATA(nh);
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size_t rtasize = IFA_PAYLOAD(nh);
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if (!parseIfAddrMessage(nh->nlmsg_type, ifa, rtasize)) {
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continue;
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}
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} else if (nh->nlmsg_type == RTM_NEWNDUSEROPT) {
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int len = nh->nlmsg_len - sizeof(*nh);
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struct nduseroptmsg *ndmsg = (struct nduseroptmsg *) NLMSG_DATA(nh);
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if (sizeof(*ndmsg) > (size_t) len) {
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SLOGE("Got a short RTM_NEWNDUSEROPT message\n");
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continue;
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}
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size_t optsize = NLMSG_PAYLOAD(nh, sizeof(*ndmsg));
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if (!parseNdUserOptMessage(ndmsg, optsize)) {
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continue;
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}
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} else {
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SLOGD("Unexpected netlink message. type=0x%x\n",
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nh->nlmsg_type);
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}
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}
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return true;
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}
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/* If the string between 'str' and 'end' begins with 'prefixlen' characters
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* from the 'prefix' array, then return 'str + prefixlen', otherwise return
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* NULL.
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*/
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static const char*
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has_prefix(const char* str, const char* end, const char* prefix, size_t prefixlen)
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{
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if ((end-str) >= (ptrdiff_t)prefixlen && !memcmp(str, prefix, prefixlen))
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return str + prefixlen;
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else
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return NULL;
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}
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/* Same as strlen(x) for constant string literals ONLY */
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#define CONST_STRLEN(x) (sizeof(x)-1)
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/* Convenience macro to call has_prefix with a constant string literal */
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#define HAS_CONST_PREFIX(str,end,prefix) has_prefix((str),(end),prefix,CONST_STRLEN(prefix))
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/*
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* Parse an ASCII-formatted message from a NETLINK_KOBJECT_UEVENT
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* netlink socket.
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*/
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bool NetlinkEvent::parseAsciiNetlinkMessage(char *buffer, int size) {
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const char *s = buffer;
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const char *end;
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int param_idx = 0;
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int i;
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int first = 1;
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if (size == 0)
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return false;
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/* Ensure the buffer is zero-terminated, the code below depends on this */
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buffer[size-1] = '\0';
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end = s + size;
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while (s < end) {
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if (first) {
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const char *p;
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/* buffer is 0-terminated, no need to check p < end */
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for (p = s; *p != '@'; p++) {
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if (!*p) { /* no '@', should not happen */
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return false;
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}
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}
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mPath = strdup(p+1);
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first = 0;
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} else {
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const char* a;
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if ((a = HAS_CONST_PREFIX(s, end, "ACTION=")) != NULL) {
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if (!strcmp(a, "add"))
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mAction = NlActionAdd;
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else if (!strcmp(a, "remove"))
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mAction = NlActionRemove;
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else if (!strcmp(a, "change"))
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mAction = NlActionChange;
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} else if ((a = HAS_CONST_PREFIX(s, end, "SEQNUM=")) != NULL) {
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mSeq = atoi(a);
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} else if ((a = HAS_CONST_PREFIX(s, end, "SUBSYSTEM=")) != NULL) {
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mSubsystem = strdup(a);
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} else if (param_idx < NL_PARAMS_MAX) {
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mParams[param_idx++] = strdup(s);
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}
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}
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s += strlen(s) + 1;
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}
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return true;
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}
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bool NetlinkEvent::decode(char *buffer, int size, int format) {
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if (format == NetlinkListener::NETLINK_FORMAT_BINARY) {
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return parseBinaryNetlinkMessage(buffer, size);
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} else {
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return parseAsciiNetlinkMessage(buffer, size);
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}
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}
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const char *NetlinkEvent::findParam(const char *paramName) {
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size_t len = strlen(paramName);
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for (int i = 0; i < NL_PARAMS_MAX && mParams[i] != NULL; ++i) {
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const char *ptr = mParams[i] + len;
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if (!strncmp(mParams[i], paramName, len) && *ptr == '=')
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return ++ptr;
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}
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SLOGE("NetlinkEvent::FindParam(): Parameter '%s' not found", paramName);
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return NULL;
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}
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