logd: initial checkin.
* Create a new userspace log daemon for handling logging messages.
Original-Change-Id: I75267df16359684490121e6c31cca48614d79856
Signed-off-by: Nick Kralevich <nnk@google.com>
* Merge conflicts
* rename new syslog daemon to logd to prevent confusion with bionic syslog
* replace racy getGroups call with KISS call to client->getGid()
* Timestamps are filed at logging source
* insert entries into list in timestamp order
* Added LogTimeEntry tail filtration handling
* Added region locking around LogWriter list
* separate threads for each writer
* /dev/socket/logd* permissions
Signed-off-by: Mark Salyzyn <salyzyn@google.com>
(cherry picked from commit 3e76e0a49760c4970b7cda6153e51026af98e4f3)
Author: Nick Kralevich <nnk@google.com>
Change-Id: Ice88b1412d8f9daa7f9119b2b5aaf684a5e28098
diff --git a/logd/LogListener.cpp b/logd/LogListener.cpp
new file mode 100644
index 0000000..c6b248b
--- /dev/null
+++ b/logd/LogListener.cpp
@@ -0,0 +1,108 @@
+/*
+ * 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 <sys/socket.h>
+#include <sys/types.h>
+#include <sys/un.h>
+#include <unistd.h>
+
+#include <cutils/sockets.h>
+#include <log/logger.h>
+
+#include "LogListener.h"
+
+LogListener::LogListener(LogBuffer *buf, LogReader *reader)
+ : SocketListener(getLogSocket(), false)
+ , logbuf(buf)
+ , reader(reader)
+{ }
+
+bool LogListener::onDataAvailable(SocketClient *cli) {
+ char buffer[1024];
+ 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_log_id_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 == getuid()) {
+ // 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;
+ }
+
+ // First log element is always log_id.
+ log_id_t log_id = (log_id_t) *((typeof_log_id_t *) buffer);
+ if (log_id < 0 || log_id >= LOG_ID_MAX) {
+ return false;
+ }
+
+ char *msg = ((char *)buffer) + sizeof_log_id_t;
+ n -= sizeof_log_id_t;
+
+ log_time realtime(msg);
+ msg += sizeof(log_time);
+ n -= sizeof(log_time);
+
+ unsigned short len = n;
+ if (len == n) {
+ logbuf->log(log_id, realtime, cred->uid, cred->pid, msg, len);
+ reader->notifyNewLog();
+ }
+
+ return true;
+}
+
+int LogListener::getLogSocket() {
+ int sock = android_get_control_socket("logdw");
+ int on = 1;
+ if (setsockopt(sock, SOL_SOCKET, SO_PASSCRED, &on, sizeof(on)) < 0) {
+ return -1;
+ }
+ return sock;
+}