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/*
* Copyright 2016, 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 <debuggerd/client.h>
#include <fcntl.h>
#include <signal.h>
#include <stdlib.h>
#include <sys/poll.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#include <chrono>
#include <android-base/file.h>
#include <android-base/logging.h>
#include <android-base/stringprintf.h>
#include <android-base/unique_fd.h>
#include <cutils/sockets.h>
#include <debuggerd/handler.h>
#include <debuggerd/protocol.h>
#include <debuggerd/util.h>
using namespace std::chrono_literals;
using android::base::unique_fd;
static bool send_signal(pid_t pid, bool backtrace) {
sigval val;
val.sival_int = backtrace;
if (sigqueue(pid, DEBUGGER_SIGNAL, val) != 0) {
PLOG(ERROR) << "libdebuggerd_client: failed to send signal to pid " << pid;
return false;
}
return true;
}
template <typename Duration>
static void populate_timeval(struct timeval* tv, const Duration& duration) {
auto seconds = std::chrono::duration_cast<std::chrono::seconds>(duration);
auto microseconds = std::chrono::duration_cast<std::chrono::microseconds>(duration - seconds);
tv->tv_sec = static_cast<long>(seconds.count());
tv->tv_usec = static_cast<long>(microseconds.count());
}
bool debuggerd_trigger_dump(pid_t pid, unique_fd output_fd, DebuggerdDumpType dump_type,
int timeout_ms) {
LOG(INFO) << "libdebuggerd_client: started dumping process " << pid;
unique_fd sockfd;
const auto end = std::chrono::steady_clock::now() + std::chrono::milliseconds(timeout_ms);
auto time_left = [timeout_ms, &end]() { return end - std::chrono::steady_clock::now(); };
auto set_timeout = [timeout_ms, &time_left](int sockfd) {
if (timeout_ms <= 0) {
return -1;
}
auto remaining = time_left();
if (remaining < decltype(remaining)::zero()) {
LOG(ERROR) << "timeout expired";
return -1;
}
struct timeval timeout;
populate_timeval(&timeout, remaining);
if (setsockopt(sockfd, SOL_SOCKET, SO_RCVTIMEO, &timeout, sizeof(timeout)) != 0) {
return -1;
}
if (setsockopt(sockfd, SOL_SOCKET, SO_SNDTIMEO, &timeout, sizeof(timeout)) != 0) {
return -1;
}
return sockfd;
};
sockfd.reset(socket(AF_LOCAL, SOCK_SEQPACKET, 0));
if (sockfd == -1) {
PLOG(ERROR) << "libdebugger_client: failed to create socket";
return false;
}
if (socket_local_client_connect(set_timeout(sockfd.get()), kTombstonedInterceptSocketName,
ANDROID_SOCKET_NAMESPACE_RESERVED, SOCK_SEQPACKET) == -1) {
PLOG(ERROR) << "libdebuggerd_client: failed to connect to tombstoned";
return false;
}
InterceptRequest req = {.pid = pid };
if (!set_timeout(sockfd)) {
PLOG(ERROR) << "libdebugger_client: failed to set timeout";
return false;
}
// Create an intermediate pipe to pass to the other end.
unique_fd pipe_read, pipe_write;
if (!Pipe(&pipe_read, &pipe_write)) {
PLOG(ERROR) << "libdebuggerd_client: failed to create pipe";
return false;
}
if (send_fd(set_timeout(sockfd), &req, sizeof(req), std::move(pipe_write)) != sizeof(req)) {
PLOG(ERROR) << "libdebuggerd_client: failed to send output fd to tombstoned";
return false;
}
// Check to make sure we've successfully registered.
InterceptResponse response;
ssize_t rc =
TEMP_FAILURE_RETRY(recv(set_timeout(sockfd.get()), &response, sizeof(response), MSG_TRUNC));
if (rc == 0) {
LOG(ERROR) << "libdebuggerd_client: failed to read response from tombstoned: timeout reached?";
return false;
} else if (rc != sizeof(response)) {
LOG(ERROR)
<< "libdebuggerd_client: received packet of unexpected length from tombstoned: expected "
<< sizeof(response) << ", received " << rc;
return false;
}
if (response.status != InterceptStatus::kRegistered) {
LOG(ERROR) << "libdebuggerd_client: unexpected registration response: "
<< static_cast<int>(response.status);
return false;
}
bool backtrace = dump_type == kDebuggerdBacktrace;
send_signal(pid, backtrace);
rc = TEMP_FAILURE_RETRY(recv(set_timeout(sockfd.get()), &response, sizeof(response), MSG_TRUNC));
if (rc == 0) {
LOG(ERROR) << "libdebuggerd_client: failed to read response from tombstoned: timeout reached?";
return false;
} else if (rc != sizeof(response)) {
LOG(ERROR)
<< "libdebuggerd_client: received packet of unexpected length from tombstoned: expected "
<< sizeof(response) << ", received " << rc;
return false;
}
if (response.status != InterceptStatus::kStarted) {
response.error_message[sizeof(response.error_message) - 1] = '\0';
LOG(ERROR) << "libdebuggerd_client: tombstoned reported failure: " << response.error_message;
return false;
}
// Forward output from the pipe to the output fd.
while (true) {
auto remaining_ms = std::chrono::duration_cast<std::chrono::milliseconds>(time_left());
if (remaining_ms <= 1ms) {
LOG(ERROR) << "libdebuggerd_client: timeout expired";
return false;
}
struct pollfd pfd = {
.fd = pipe_read.get(), .events = POLLIN, .revents = 0,
};
rc = poll(&pfd, 1, remaining_ms.count());
if (rc == -1) {
if (errno == EINTR) {
continue;
} else {
PLOG(ERROR) << "libdebuggerd_client: error while polling";
return false;
}
} else if (rc == 0) {
LOG(ERROR) << "libdebuggerd_client: timeout expired";
return false;
}
char buf[1024];
rc = TEMP_FAILURE_RETRY(read(pipe_read.get(), buf, sizeof(buf)));
if (rc == 0) {
// Done.
break;
} else if (rc == -1) {
PLOG(ERROR) << "libdebuggerd_client: error while reading";
return false;
}
if (!android::base::WriteFully(output_fd.get(), buf, rc)) {
PLOG(ERROR) << "libdebuggerd_client: error while writing";
return false;
}
}
LOG(INFO) << "libdebuggerd_client: done dumping process " << pid;
return true;
}
int dump_backtrace_to_file(pid_t tid, int fd) {
return dump_backtrace_to_file_timeout(tid, fd, 0);
}
int dump_backtrace_to_file_timeout(pid_t tid, int fd, int timeout_secs) {
android::base::unique_fd copy(dup(fd));
if (copy == -1) {
return -1;
}
int timeout_ms = timeout_secs > 0 ? timeout_secs * 1000 : 0;
return debuggerd_trigger_dump(tid, std::move(copy), kDebuggerdBacktrace, timeout_ms) ? 0 : -1;
}
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