You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

256 lines
8.0 KiB

/*
* Copyright (C) 2012-2013 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <ctype.h>
#include <inttypes.h>
#include <poll.h>
#include <sched.h>
#include <sys/prctl.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <chrono>
#include <android-base/logging.h>
#include <android-base/stringprintf.h>
#include <cutils/sockets.h>
#include <private/android_filesystem_config.h>
#include <private/android_logger.h>
#include "LogBuffer.h"
#include "LogBufferElement.h"
#include "LogPermissions.h"
#include "LogReader.h"
#include "LogUtils.h"
#include "LogWriter.h"
static bool CanReadSecurityLogs(SocketClient* client) {
return client->getUid() == AID_SYSTEM || client->getGid() == AID_SYSTEM;
}
static std::string SocketClientToName(SocketClient* client) {
return android::base::StringPrintf("pid %d, fd %d", client->getPid(), client->getSocket());
}
class SocketLogWriter : public LogWriter {
public:
SocketLogWriter(LogReader* reader, SocketClient* client, bool privileged)
: LogWriter(client->getUid(), privileged), reader_(reader), client_(client) {}
bool Write(const logger_entry& entry, const char* msg) override {
struct iovec iovec[2];
iovec[0].iov_base = const_cast<logger_entry*>(&entry);
iovec[0].iov_len = entry.hdr_size;
iovec[1].iov_base = const_cast<char*>(msg);
iovec[1].iov_len = entry.len;
return client_->sendDatav(iovec, 1 + (entry.len != 0)) == 0;
}
void Release() override {
reader_->release(client_);
client_->decRef();
}
void Shutdown() override { shutdown(client_->getSocket(), SHUT_RDWR); }
std::string name() const override { return SocketClientToName(client_); }
private:
LogReader* reader_;
SocketClient* client_;
};
LogReader::LogReader(LogBuffer* logbuf, LogReaderList* reader_list)
: SocketListener(getLogSocket(), true), log_buffer_(logbuf), reader_list_(reader_list) {}
// Note returning false will release the SocketClient instance.
bool LogReader::onDataAvailable(SocketClient* cli) {
static bool name_set;
if (!name_set) {
prctl(PR_SET_NAME, "logd.reader");
name_set = true;
}
char buffer[255];
int len = read(cli->getSocket(), buffer, sizeof(buffer) - 1);
if (len <= 0) {
DoSocketDelete(cli);
return false;
}
buffer[len] = '\0';
// Clients are only allowed to send one command, disconnect them if they send another.
if (DoSocketDelete(cli)) {
return false;
}
unsigned long tail = 0;
static const char _tail[] = " tail=";
char* cp = strstr(buffer, _tail);
if (cp) {
tail = atol(cp + sizeof(_tail) - 1);
}
log_time start(log_time::EPOCH);
static const char _start[] = " start=";
cp = strstr(buffer, _start);
if (cp) {
// Parse errors will result in current time
start.strptime(cp + sizeof(_start) - 1, "%s.%q");
}
std::chrono::steady_clock::time_point deadline = {};
static const char _timeout[] = " timeout=";
cp = strstr(buffer, _timeout);
if (cp) {
long timeout_seconds = atol(cp + sizeof(_timeout) - 1);
deadline = std::chrono::steady_clock::now() + std::chrono::seconds(timeout_seconds);
}
unsigned int logMask = -1;
static const char _logIds[] = " lids=";
cp = strstr(buffer, _logIds);
if (cp) {
logMask = 0;
cp += sizeof(_logIds) - 1;
while (*cp != '\0') {
int val = 0;
while (isdigit(*cp)) {
val = val * 10 + *cp - '0';
++cp;
}
logMask |= 1 << val;
if (*cp != ',') {
break;
}
++cp;
}
}
pid_t pid = 0;
static const char _pid[] = " pid=";
cp = strstr(buffer, _pid);
if (cp) {
pid = atol(cp + sizeof(_pid) - 1);
}
bool nonBlock = false;
if (!fastcmp<strncmp>(buffer, "dumpAndClose", 12)) {
// Allow writer to get some cycles, and wait for pending notifications
sched_yield();
logd_lock.lock();
logd_lock.unlock();
sched_yield();
nonBlock = true;
}
bool privileged = clientHasLogCredentials(cli);
bool can_read_security = CanReadSecurityLogs(cli);
if (!can_read_security) {
logMask &= ~(1 << LOG_ID_SECURITY);
}
std::unique_ptr<LogWriter> socket_log_writer(new SocketLogWriter(this, cli, privileged));
uint64_t sequence = 1;
// Convert realtime to sequence number
if (start != log_time::EPOCH) {
bool start_time_set = false;
uint64_t last = sequence;
auto log_find_start = [pid, start, &sequence, &start_time_set, &last](
log_id_t, pid_t element_pid, uint64_t element_sequence,
log_time element_realtime) -> FilterResult {
if (pid && pid != element_pid) {
return FilterResult::kSkip;
}
if (start == element_realtime) {
sequence = element_sequence;
start_time_set = true;
return FilterResult::kStop;
} else {
if (start < element_realtime) {
sequence = last;
start_time_set = true;
return FilterResult::kStop;
}
last = element_sequence;
}
return FilterResult::kSkip;
};
auto lock = std::lock_guard{logd_lock};
auto flush_to_state = log_buffer_->CreateFlushToState(sequence, logMask);
log_buffer_->FlushTo(socket_log_writer.get(), *flush_to_state, log_find_start);
if (!start_time_set) {
if (nonBlock) {
return false;
}
sequence = log_buffer_->sequence();
}
}
LOG(INFO) << android::base::StringPrintf(
"logdr: UID=%d GID=%d PID=%d %c tail=%lu logMask=%x pid=%d "
"start=%" PRIu64 "ns deadline=%" PRIi64 "ns",
cli->getUid(), cli->getGid(), cli->getPid(), nonBlock ? 'n' : 'b', tail, logMask,
(int)pid, start.nsec(), static_cast<int64_t>(deadline.time_since_epoch().count()));
if (start == log_time::EPOCH) {
deadline = {};
}
auto lock = std::lock_guard{logd_lock};
auto entry = std::make_unique<LogReaderThread>(log_buffer_, reader_list_,
std::move(socket_log_writer), nonBlock, tail,
logMask, pid, start, sequence, deadline);
// release client and entry reference counts once done
cli->incRef();
reader_list_->reader_threads().emplace_front(std::move(entry));
// Set acceptable upper limit to wait for slow reader processing b/27242723
struct timeval t = { LOGD_SNDTIMEO, 0 };
setsockopt(cli->getSocket(), SOL_SOCKET, SO_SNDTIMEO, (const char*)&t,
sizeof(t));
return true;
}
bool LogReader::DoSocketDelete(SocketClient* cli) {
auto cli_name = SocketClientToName(cli);
auto lock = std::lock_guard{logd_lock};
for (const auto& reader : reader_list_->reader_threads()) {
if (reader->name() == cli_name) {
reader->Release();
return true;
}
}
return false;
}
int LogReader::getLogSocket() {
static const char socketName[] = "logdr";
int sock = android_get_control_socket(socketName);
if (sock < 0) {
sock = socket_local_server(
socketName, ANDROID_SOCKET_NAMESPACE_RESERVED, SOCK_SEQPACKET);
}
return sock;
}