| /* |
| * Copyright (C) 2012-2014 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 <limits.h> |
| #include <sys/prctl.h> |
| #include <sys/socket.h> |
| #include <sys/types.h> |
| #include <sys/un.h> |
| #include <unistd.h> |
| |
| #include <cutils/sockets.h> |
| #include <log/logger.h> |
| #include <private/android_filesystem_config.h> |
| #include <private/android_logger.h> |
| |
| #include "LogListener.h" |
| |
| LogListener::LogListener(LogBuffer *buf, LogReader *reader) |
| : SocketListener(getLogSocket(), false) |
| , logbuf(buf) |
| , reader(reader) |
| { } |
| |
| bool LogListener::onDataAvailable(SocketClient *cli) { |
| static bool name_set; |
| if (!name_set) { |
| prctl(PR_SET_NAME, "logd.writer"); |
| name_set = true; |
| } |
| |
| char buffer[sizeof_log_id_t + sizeof(uint16_t) + sizeof(log_time) |
| + LOGGER_ENTRY_MAX_PAYLOAD]; |
| struct iovec iov = { buffer, sizeof(buffer) }; |
| memset(buffer, 0, sizeof(buffer)); |
| |
| char control[CMSG_SPACE(sizeof(struct ucred))]; |
| struct msghdr hdr = { |
| NULL, |
| 0, |
| &iov, |
| 1, |
| control, |
| sizeof(control), |
| 0, |
| }; |
| |
| int socket = cli->getSocket(); |
| |
| ssize_t n = recvmsg(socket, &hdr, 0); |
| if (n <= (ssize_t)(sizeof(android_log_header_t))) { |
| return false; |
| } |
| |
| struct ucred *cred = NULL; |
| |
| struct cmsghdr *cmsg = CMSG_FIRSTHDR(&hdr); |
| while (cmsg != NULL) { |
| if (cmsg->cmsg_level == SOL_SOCKET |
| && cmsg->cmsg_type == SCM_CREDENTIALS) { |
| cred = (struct ucred *)CMSG_DATA(cmsg); |
| break; |
| } |
| cmsg = CMSG_NXTHDR(&hdr, cmsg); |
| } |
| |
| if (cred == NULL) { |
| return false; |
| } |
| |
| if (cred->uid == AID_LOGD) { |
| // ignore log messages we send to ourself. |
| // Such log messages are often generated by libraries we depend on |
| // which use standard Android logging. |
| return false; |
| } |
| |
| android_log_header_t *header = reinterpret_cast<android_log_header_t *>(buffer); |
| if (/* header->id < LOG_ID_MIN || */ header->id >= LOG_ID_MAX) { |
| return false; |
| } |
| |
| char *msg = ((char *)buffer) + sizeof(android_log_header_t); |
| n -= sizeof(android_log_header_t); |
| |
| // NB: hdr.msg_flags & MSG_TRUNC is not tested, silently passing a |
| // truncated message to the logs. |
| |
| logbuf->log((log_id_t)header->id, header->realtime, |
| cred->uid, cred->pid, header->tid, msg, |
| ((size_t) n <= USHRT_MAX) ? (unsigned short) n : USHRT_MAX); |
| reader->notifyNewLog(); |
| |
| return true; |
| } |
| |
| int LogListener::getLogSocket() { |
| static const char socketName[] = "logdw"; |
| int sock = android_get_control_socket(socketName); |
| |
| if (sock < 0) { |
| sock = socket_local_server(socketName, |
| ANDROID_SOCKET_NAMESPACE_RESERVED, |
| SOCK_DGRAM); |
| } |
| |
| int on = 1; |
| if (setsockopt(sock, SOL_SOCKET, SO_PASSCRED, &on, sizeof(on)) < 0) { |
| return -1; |
| } |
| return sock; |
| } |