platform_system_core/debuggerd/util.cpp
Narayan Kamath 2d377cd688 tombstoned: Add a shared library version of libtombstoned_client...
.. for ART and the frameworks to link against. In the new stack dumping
scheme (see related bug), the Java runtime will communicate with
tombstoned in order to obtain a FD to which it can write its traces.

Also move things around to separate headers that are private
implementation details from headers that constitute the public debuggerd
API. There are currently only three such headers :

- tombstoned/tombstoned.h
- debuggerd/client.h
- debuggerd/handler.h

Bug: 32064548
Test: make

Change-Id: If1b8578550e373d84828b180bbe585f1088d1aa3
2017-05-22 16:55:21 +01:00

98 lines
2.6 KiB
C++

/*
* 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 "util.h"
#include <sys/socket.h>
#include <utility>
#include <android-base/unique_fd.h>
#include <cutils/sockets.h>
#include "protocol.h"
using android::base::unique_fd;
ssize_t send_fd(int sockfd, const void* data, size_t len, unique_fd fd) {
char cmsg_buf[CMSG_SPACE(sizeof(int))];
iovec iov = { .iov_base = const_cast<void*>(data), .iov_len = len };
msghdr msg = {
.msg_iov = &iov, .msg_iovlen = 1, .msg_control = cmsg_buf, .msg_controllen = sizeof(cmsg_buf),
};
auto cmsg = CMSG_FIRSTHDR(&msg);
cmsg->cmsg_level = SOL_SOCKET;
cmsg->cmsg_type = SCM_RIGHTS;
cmsg->cmsg_len = CMSG_LEN(sizeof(int));
*reinterpret_cast<int*>(CMSG_DATA(cmsg)) = fd.get();
return TEMP_FAILURE_RETRY(sendmsg(sockfd, &msg, 0));
}
ssize_t recv_fd(int sockfd, void* _Nonnull data, size_t len, unique_fd* _Nullable out_fd) {
char cmsg_buf[CMSG_SPACE(sizeof(int))];
iovec iov = { .iov_base = const_cast<void*>(data), .iov_len = len };
msghdr msg = {
.msg_iov = &iov,
.msg_iovlen = 1,
.msg_control = cmsg_buf,
.msg_controllen = sizeof(cmsg_buf),
.msg_flags = 0,
};
auto cmsg = CMSG_FIRSTHDR(&msg);
cmsg->cmsg_level = SOL_SOCKET;
cmsg->cmsg_type = SCM_RIGHTS;
cmsg->cmsg_len = CMSG_LEN(sizeof(int));
ssize_t result = TEMP_FAILURE_RETRY(recvmsg(sockfd, &msg, 0));
if (result == -1) {
return -1;
}
unique_fd fd;
bool received_fd = msg.msg_controllen == sizeof(cmsg_buf);
if (received_fd) {
fd.reset(*reinterpret_cast<int*>(CMSG_DATA(cmsg)));
}
if ((msg.msg_flags & MSG_TRUNC) != 0) {
errno = EFBIG;
return -1;
} else if ((msg.msg_flags & MSG_CTRUNC) != 0) {
errno = ERANGE;
return -1;
}
if (out_fd) {
*out_fd = std::move(fd);
} else if (received_fd) {
errno = ERANGE;
return -1;
}
return result;
}
bool Pipe(unique_fd* read, unique_fd* write) {
int pipefds[2];
if (pipe(pipefds) != 0) {
return false;
}
read->reset(pipefds[0]);
write->reset(pipefds[1]);
return true;
}