Mark Salyzyn | 0175b07 | 2014-02-26 09:50:16 -0800 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2012-2014 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 | |
Mark Salyzyn | c4e4823 | 2017-05-04 13:54:46 -0700 | [diff] [blame^] | 17 | #include <ctype.h> |
Mark Salyzyn | e0fa291 | 2014-04-28 16:39:04 -0700 | [diff] [blame] | 18 | #include <limits.h> |
Mark Salyzyn | c4e4823 | 2017-05-04 13:54:46 -0700 | [diff] [blame^] | 19 | #include <stdio.h> |
Mark Salyzyn | 4690640 | 2016-01-12 10:08:03 -0800 | [diff] [blame] | 20 | #include <sys/cdefs.h> |
Mark Salyzyn | 8daa9af | 2014-04-28 14:07:23 -0700 | [diff] [blame] | 21 | #include <sys/prctl.h> |
Mark Salyzyn | 0175b07 | 2014-02-26 09:50:16 -0800 | [diff] [blame] | 22 | #include <sys/socket.h> |
| 23 | #include <sys/types.h> |
| 24 | #include <sys/un.h> |
| 25 | #include <unistd.h> |
| 26 | |
| 27 | #include <cutils/sockets.h> |
Mark Salyzyn | e3aeeee | 2015-03-17 07:56:32 -0700 | [diff] [blame] | 28 | #include <private/android_filesystem_config.h> |
Mark Salyzyn | b5f6e45 | 2015-01-16 13:38:07 -0800 | [diff] [blame] | 29 | #include <private/android_logger.h> |
Mark Salyzyn | 0175b07 | 2014-02-26 09:50:16 -0800 | [diff] [blame] | 30 | |
Mark Salyzyn | 2ad0bd0 | 2016-02-23 08:55:43 -0800 | [diff] [blame] | 31 | #include "LogBuffer.h" |
Mark Salyzyn | 0175b07 | 2014-02-26 09:50:16 -0800 | [diff] [blame] | 32 | #include "LogListener.h" |
Mark Salyzyn | 083b037 | 2015-12-04 10:59:45 -0800 | [diff] [blame] | 33 | #include "LogUtils.h" |
Mark Salyzyn | 0175b07 | 2014-02-26 09:50:16 -0800 | [diff] [blame] | 34 | |
Chenjie Luo | fafea32 | 2017-04-27 16:49:09 -0700 | [diff] [blame] | 35 | LogListener::LogListener(LogBufferInterface* buf, LogReader* reader) |
Mark Salyzyn | 501c373 | 2017-03-10 14:31:54 -0800 | [diff] [blame] | 36 | : SocketListener(getLogSocket(), false), logbuf(buf), reader(reader) { |
Mark Salyzyn | 7718778 | 2015-05-12 15:21:31 -0700 | [diff] [blame] | 37 | } |
Mark Salyzyn | 0175b07 | 2014-02-26 09:50:16 -0800 | [diff] [blame] | 38 | |
Mark Salyzyn | 501c373 | 2017-03-10 14:31:54 -0800 | [diff] [blame] | 39 | bool LogListener::onDataAvailable(SocketClient* cli) { |
Mark Salyzyn | e3aeeee | 2015-03-17 07:56:32 -0700 | [diff] [blame] | 40 | static bool name_set; |
| 41 | if (!name_set) { |
| 42 | prctl(PR_SET_NAME, "logd.writer"); |
| 43 | name_set = true; |
| 44 | } |
Mark Salyzyn | 8daa9af | 2014-04-28 14:07:23 -0700 | [diff] [blame] | 45 | |
Mark Salyzyn | 501c373 | 2017-03-10 14:31:54 -0800 | [diff] [blame] | 46 | char buffer[sizeof_log_id_t + sizeof(uint16_t) + sizeof(log_time) + |
| 47 | LOGGER_ENTRY_MAX_PAYLOAD]; |
Mark Salyzyn | 0175b07 | 2014-02-26 09:50:16 -0800 | [diff] [blame] | 48 | struct iovec iov = { buffer, sizeof(buffer) }; |
Mark Salyzyn | 0175b07 | 2014-02-26 09:50:16 -0800 | [diff] [blame] | 49 | |
Elliott Hughes | 5f4a946 | 2016-06-06 19:56:24 -0700 | [diff] [blame] | 50 | alignas(4) char control[CMSG_SPACE(sizeof(struct ucred))]; |
Mark Salyzyn | 0175b07 | 2014-02-26 09:50:16 -0800 | [diff] [blame] | 51 | struct msghdr hdr = { |
Mark Salyzyn | 501c373 | 2017-03-10 14:31:54 -0800 | [diff] [blame] | 52 | NULL, 0, &iov, 1, control, sizeof(control), 0, |
Mark Salyzyn | 0175b07 | 2014-02-26 09:50:16 -0800 | [diff] [blame] | 53 | }; |
| 54 | |
| 55 | int socket = cli->getSocket(); |
| 56 | |
Mark Salyzyn | 1d9c7e7 | 2015-12-15 12:30:46 -0800 | [diff] [blame] | 57 | // To clear the entire buffer is secure/safe, but this contributes to 1.68% |
| 58 | // overhead under logging load. We are safe because we check counts. |
| 59 | // memset(buffer, 0, sizeof(buffer)); |
Mark Salyzyn | 0175b07 | 2014-02-26 09:50:16 -0800 | [diff] [blame] | 60 | ssize_t n = recvmsg(socket, &hdr, 0); |
Mark Salyzyn | b5f6e45 | 2015-01-16 13:38:07 -0800 | [diff] [blame] | 61 | if (n <= (ssize_t)(sizeof(android_log_header_t))) { |
Mark Salyzyn | 0175b07 | 2014-02-26 09:50:16 -0800 | [diff] [blame] | 62 | return false; |
| 63 | } |
| 64 | |
Mark Salyzyn | 501c373 | 2017-03-10 14:31:54 -0800 | [diff] [blame] | 65 | struct ucred* cred = NULL; |
Mark Salyzyn | 0175b07 | 2014-02-26 09:50:16 -0800 | [diff] [blame] | 66 | |
Mark Salyzyn | 501c373 | 2017-03-10 14:31:54 -0800 | [diff] [blame] | 67 | struct cmsghdr* cmsg = CMSG_FIRSTHDR(&hdr); |
Mark Salyzyn | 0175b07 | 2014-02-26 09:50:16 -0800 | [diff] [blame] | 68 | while (cmsg != NULL) { |
Mark Salyzyn | 501c373 | 2017-03-10 14:31:54 -0800 | [diff] [blame] | 69 | if (cmsg->cmsg_level == SOL_SOCKET && |
| 70 | cmsg->cmsg_type == SCM_CREDENTIALS) { |
| 71 | cred = (struct ucred*)CMSG_DATA(cmsg); |
Mark Salyzyn | 0175b07 | 2014-02-26 09:50:16 -0800 | [diff] [blame] | 72 | break; |
| 73 | } |
| 74 | cmsg = CMSG_NXTHDR(&hdr, cmsg); |
| 75 | } |
| 76 | |
Mark Salyzyn | c4e4823 | 2017-05-04 13:54:46 -0700 | [diff] [blame^] | 77 | struct ucred fake_cred; |
Mark Salyzyn | 0175b07 | 2014-02-26 09:50:16 -0800 | [diff] [blame] | 78 | if (cred == NULL) { |
Mark Salyzyn | c4e4823 | 2017-05-04 13:54:46 -0700 | [diff] [blame^] | 79 | cred = &fake_cred; |
| 80 | cred->pid = 0; |
| 81 | cred->uid = DEFAULT_OVERFLOWUID; |
Mark Salyzyn | 0175b07 | 2014-02-26 09:50:16 -0800 | [diff] [blame] | 82 | } |
| 83 | |
Mark Salyzyn | e3aeeee | 2015-03-17 07:56:32 -0700 | [diff] [blame] | 84 | if (cred->uid == AID_LOGD) { |
Mark Salyzyn | 0175b07 | 2014-02-26 09:50:16 -0800 | [diff] [blame] | 85 | // ignore log messages we send to ourself. |
| 86 | // Such log messages are often generated by libraries we depend on |
| 87 | // which use standard Android logging. |
| 88 | return false; |
| 89 | } |
| 90 | |
Mark Salyzyn | 501c373 | 2017-03-10 14:31:54 -0800 | [diff] [blame] | 91 | android_log_header_t* header = |
| 92 | reinterpret_cast<android_log_header_t*>(buffer); |
| 93 | if (/* header->id < LOG_ID_MIN || */ header->id >= LOG_ID_MAX || |
| 94 | header->id == LOG_ID_KERNEL) { |
Mark Salyzyn | 0175b07 | 2014-02-26 09:50:16 -0800 | [diff] [blame] | 95 | return false; |
| 96 | } |
Mark Salyzyn | 0175b07 | 2014-02-26 09:50:16 -0800 | [diff] [blame] | 97 | |
Mark Salyzyn | 083b037 | 2015-12-04 10:59:45 -0800 | [diff] [blame] | 98 | if ((header->id == LOG_ID_SECURITY) && |
Mark Salyzyn | 501c373 | 2017-03-10 14:31:54 -0800 | [diff] [blame] | 99 | (!__android_log_security() || |
| 100 | !clientHasLogCredentials(cred->uid, cred->gid, cred->pid))) { |
Mark Salyzyn | 083b037 | 2015-12-04 10:59:45 -0800 | [diff] [blame] | 101 | return false; |
| 102 | } |
| 103 | |
Mark Salyzyn | c4e4823 | 2017-05-04 13:54:46 -0700 | [diff] [blame^] | 104 | // Check credential validity, acquire corrected details if not supplied. |
| 105 | if (cred->pid == 0) { |
| 106 | cred->pid = logbuf ? logbuf->tidToPid(header->tid) |
| 107 | : android::tidToPid(header->tid); |
| 108 | if (cred->pid == getpid()) { |
| 109 | // We expect that /proc/<tid>/ is accessible to self even without |
| 110 | // readproc group, so that we will always drop messages that come |
| 111 | // from any of our logd threads and their library calls. |
| 112 | return false; // ignore self |
| 113 | } |
| 114 | } |
| 115 | if (cred->uid == DEFAULT_OVERFLOWUID) { |
| 116 | uid_t uid = |
| 117 | logbuf ? logbuf->pidToUid(cred->pid) : android::pidToUid(cred->pid); |
| 118 | if (uid == AID_LOGD) { |
| 119 | uid = logbuf ? logbuf->pidToUid(header->tid) |
| 120 | : android::pidToUid(cred->pid); |
| 121 | } |
| 122 | if (uid != AID_LOGD) cred->uid = uid; |
| 123 | } |
| 124 | |
Mark Salyzyn | 501c373 | 2017-03-10 14:31:54 -0800 | [diff] [blame] | 125 | char* msg = ((char*)buffer) + sizeof(android_log_header_t); |
Mark Salyzyn | b5f6e45 | 2015-01-16 13:38:07 -0800 | [diff] [blame] | 126 | n -= sizeof(android_log_header_t); |
Mark Salyzyn | 0175b07 | 2014-02-26 09:50:16 -0800 | [diff] [blame] | 127 | |
Mark Salyzyn | 22e287d | 2014-03-21 13:12:16 -0700 | [diff] [blame] | 128 | // NB: hdr.msg_flags & MSG_TRUNC is not tested, silently passing a |
| 129 | // truncated message to the logs. |
Mark Salyzyn | e0fa291 | 2014-04-28 16:39:04 -0700 | [diff] [blame] | 130 | |
Chenjie Luo | fafea32 | 2017-04-27 16:49:09 -0700 | [diff] [blame] | 131 | if (logbuf != nullptr) { |
| 132 | int res = logbuf->log( |
| 133 | (log_id_t)header->id, header->realtime, cred->uid, cred->pid, |
| 134 | header->tid, msg, |
| 135 | ((size_t)n <= USHRT_MAX) ? (unsigned short)n : USHRT_MAX); |
| 136 | if (res > 0 && reader != nullptr) { |
| 137 | reader->notifyNewLog(); |
| 138 | } |
Mark Salyzyn | 202e153 | 2015-02-09 08:21:05 -0800 | [diff] [blame] | 139 | } |
Mark Salyzyn | 0175b07 | 2014-02-26 09:50:16 -0800 | [diff] [blame] | 140 | |
| 141 | return true; |
| 142 | } |
| 143 | |
| 144 | int LogListener::getLogSocket() { |
Mark Salyzyn | dfc47e8 | 2014-03-24 10:26:47 -0700 | [diff] [blame] | 145 | static const char socketName[] = "logdw"; |
| 146 | int sock = android_get_control_socket(socketName); |
| 147 | |
Mark Salyzyn | 54d8ff1 | 2017-05-05 15:32:10 -0700 | [diff] [blame] | 148 | if (sock < 0) { // logd started up in init.sh |
Mark Salyzyn | 501c373 | 2017-03-10 14:31:54 -0800 | [diff] [blame] | 149 | sock = socket_local_server( |
| 150 | socketName, ANDROID_SOCKET_NAMESPACE_RESERVED, SOCK_DGRAM); |
Mark Salyzyn | dfc47e8 | 2014-03-24 10:26:47 -0700 | [diff] [blame] | 151 | |
Mark Salyzyn | 54d8ff1 | 2017-05-05 15:32:10 -0700 | [diff] [blame] | 152 | int on = 1; |
| 153 | if (setsockopt(sock, SOL_SOCKET, SO_PASSCRED, &on, sizeof(on))) { |
| 154 | return -1; |
| 155 | } |
Mark Salyzyn | 0175b07 | 2014-02-26 09:50:16 -0800 | [diff] [blame] | 156 | } |
| 157 | return sock; |
| 158 | } |