debuggerd: advance our amazing bet.
Remove debuggerd in favor of a helper process that gets execed by
crashing processes.
Bug: http://b/30705528
Test: debuggerd_test
Change-Id: I9906c69473989cbf7fe5ea6cccf9a9c563d75906
diff --git a/debuggerd/util.cpp b/debuggerd/util.cpp
new file mode 100644
index 0000000..738abdf
--- /dev/null
+++ b/debuggerd/util.cpp
@@ -0,0 +1,96 @@
+/*
+ * 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/util.h"
+
+#include <sys/socket.h>
+
+#include <utility>
+
+#include <android-base/unique_fd.h>
+#include <cutils/sockets.h>
+
+ssize_t send_fd(int sockfd, const void* data, size_t len, android::base::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,
+ android::base::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;
+ }
+
+ android::base::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(android::base::unique_fd* read, android::base::unique_fd* write) {
+ int pipefds[2];
+ if (pipe(pipefds) != 0) {
+ return false;
+ }
+ read->reset(pipefds[0]);
+ write->reset(pipefds[1]);
+ return true;
+}