0175b0747a
* Create a new userspace log daemon for handling logging messages.
Original-Change-Id: I75267df16359684490121e6c31cca48614d79856
Signed-off-by: Nick Kralevich <nnk@google.com>
* Merge conflicts
* rename new syslog daemon to logd to prevent confusion with bionic syslog
* replace racy getGroups call with KISS call to client->getGid()
* Timestamps are filed at logging source
* insert entries into list in timestamp order
* Added LogTimeEntry tail filtration handling
* Added region locking around LogWriter list
* separate threads for each writer
* /dev/socket/logd* permissions
Signed-off-by: Mark Salyzyn <salyzyn@google.com>
(cherry picked from commit 3e76e0a497)
Author: Nick Kralevich <nnk@google.com>
Change-Id: Ice88b1412d8f9daa7f9119b2b5aaf684a5e28098
115 lines
3.2 KiB
C++
115 lines
3.2 KiB
C++
/*
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* Copyright (C) 2012-2013 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 <dirent.h>
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#include <errno.h>
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#include <fcntl.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <sys/capability.h>
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#include <sys/stat.h>
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#include <sys/types.h>
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#include <linux/prctl.h>
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#include "private/android_filesystem_config.h"
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#include "CommandListener.h"
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#include "LogBuffer.h"
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#include "LogListener.h"
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static int drop_privs() {
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if (prctl(PR_SET_KEEPCAPS, 1) < 0) {
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return -1;
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}
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if (setgid(AID_LOGD) != 0) {
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return -1;
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}
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if (setuid(AID_LOGD) != 0) {
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return -1;
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}
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struct __user_cap_header_struct capheader;
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struct __user_cap_data_struct capdata[2];
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memset(&capheader, 0, sizeof(capheader));
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memset(&capdata, 0, sizeof(capdata));
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capheader.version = _LINUX_CAPABILITY_VERSION_3;
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capheader.pid = 0;
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capdata[CAP_TO_INDEX(CAP_SYSLOG)].permitted = CAP_TO_MASK(CAP_SYSLOG);
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capdata[CAP_TO_INDEX(CAP_SYSLOG)].effective = CAP_TO_MASK(CAP_SYSLOG);
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capdata[0].inheritable = 0;
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capdata[1].inheritable = 0;
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if (capset(&capheader, &capdata[0]) < 0) {
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return -1;
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}
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return 0;
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}
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// Foreground waits for exit of the three main persistent threads that
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// are started here. The three threads are created to manage UNIX
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// domain client sockets for writing, reading and controlling the user
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// space logger. Additional transitory per-client threads are created
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// for each reader once they register.
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int main() {
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if (drop_privs() != 0) {
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return -1;
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}
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// Serves the purpose of managing the last logs times read on a
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// socket connection, and as a reader lock on a range of log
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// entries.
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LastLogTimes *times = new LastLogTimes();
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// LogBuffer is the object which is responsible for holding all
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// log entries.
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LogBuffer *logBuf = new LogBuffer(times);
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// LogReader listens on /dev/socket/logdr. When a client
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// connects, log entries in the LogBuffer are written to the client.
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LogReader *reader = new LogReader(logBuf);
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if (reader->startListener()) {
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exit(1);
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}
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// LogListener listens on /dev/socket/logdw for client
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// initiated log messages. New log entries are added to LogBuffer
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// and LogReader is notified to send updates to connected clients.
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LogListener *swl = new LogListener(logBuf, reader);
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if (swl->startListener()) {
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exit(1);
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}
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// Command listener listens on /dev/socket/logd for incoming logd
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// administrative commands.
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CommandListener *cl = new CommandListener(logBuf, reader, swl);
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if (cl->startListener()) {
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exit(1);
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}
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pause();
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exit(0);
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}
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