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authorJosh Gao2016-10-18 20:17:52 -0500
committerJosh Gao2017-01-17 15:57:57 -0600
commitcbe70cb0a8cb0171f3802273050e851a47b090ed (patch)
tree87a2805f11d9fa5283fe169d9b155f5b08a94f85 /debuggerd/util.cpp
parent4c5c9db17b55bfcb2d62eec158440d0e794e30bb (diff)
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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
Diffstat (limited to 'debuggerd/util.cpp')
-rw-r--r--debuggerd/util.cpp96
1 files changed, 96 insertions, 0 deletions
diff --git a/debuggerd/util.cpp b/debuggerd/util.cpp
new file mode 100644
index 000000000..738abdf7b
--- /dev/null
+++ b/debuggerd/util.cpp
@@ -0,0 +1,96 @@
1/*
2 * Copyright 2016, The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#include "debuggerd/util.h"
18
19#include <sys/socket.h>
20
21#include <utility>
22
23#include <android-base/unique_fd.h>
24#include <cutils/sockets.h>
25
26ssize_t send_fd(int sockfd, const void* data, size_t len, android::base::unique_fd fd) {
27 char cmsg_buf[CMSG_SPACE(sizeof(int))];
28
29 iovec iov = { .iov_base = const_cast<void*>(data), .iov_len = len };
30 msghdr msg = {
31 .msg_iov = &iov, .msg_iovlen = 1, .msg_control = cmsg_buf, .msg_controllen = sizeof(cmsg_buf),
32 };
33 auto cmsg = CMSG_FIRSTHDR(&msg);
34 cmsg->cmsg_level = SOL_SOCKET;
35 cmsg->cmsg_type = SCM_RIGHTS;
36 cmsg->cmsg_len = CMSG_LEN(sizeof(int));
37 *reinterpret_cast<int*>(CMSG_DATA(cmsg)) = fd.get();
38
39 return TEMP_FAILURE_RETRY(sendmsg(sockfd, &msg, 0));
40}
41
42ssize_t recv_fd(int sockfd, void* _Nonnull data, size_t len,
43 android::base::unique_fd* _Nullable out_fd) {
44 char cmsg_buf[CMSG_SPACE(sizeof(int))];
45
46 iovec iov = { .iov_base = const_cast<void*>(data), .iov_len = len };
47 msghdr msg = {
48 .msg_iov = &iov,
49 .msg_iovlen = 1,
50 .msg_control = cmsg_buf,
51 .msg_controllen = sizeof(cmsg_buf),
52 .msg_flags = 0,
53 };
54 auto cmsg = CMSG_FIRSTHDR(&msg);
55 cmsg->cmsg_level = SOL_SOCKET;
56 cmsg->cmsg_type = SCM_RIGHTS;
57 cmsg->cmsg_len = CMSG_LEN(sizeof(int));
58
59 ssize_t result = TEMP_FAILURE_RETRY(recvmsg(sockfd, &msg, 0));
60 if (result == -1) {
61 return -1;
62 }
63
64 android::base::unique_fd fd;
65 bool received_fd = msg.msg_controllen == sizeof(cmsg_buf);
66 if (received_fd) {
67 fd.reset(*reinterpret_cast<int*>(CMSG_DATA(cmsg)));
68 }
69
70 if ((msg.msg_flags & MSG_TRUNC) != 0) {
71 errno = EFBIG;
72 return -1;
73 } else if ((msg.msg_flags & MSG_CTRUNC) != 0) {
74 errno = ERANGE;
75 return -1;
76 }
77
78 if (out_fd) {
79 *out_fd = std::move(fd);
80 } else if (received_fd) {
81 errno = ERANGE;
82 return -1;
83 }
84
85 return result;
86}
87
88bool Pipe(android::base::unique_fd* read, android::base::unique_fd* write) {
89 int pipefds[2];
90 if (pipe(pipefds) != 0) {
91 return false;
92 }
93 read->reset(pipefds[0]);
94 write->reset(pipefds[1]);
95 return true;
96}