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

1 files changed, 105 insertions, 0 deletions

diff --git a/logd/LogReader.cpp b/logd/LogReader.cpp
new file mode 100644
index 000000000..5b540bf5d
--- /dev/null
+++ b/logd/LogReader.cpp
@@ -0,0 +1,105 @@
+/*
+ * Copyright (C) 2012-2013 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 <poll.h>
+#include <sys/socket.h>
+#include <cutils/sockets.h>
+
+#include "LogReader.h"
+#include "FlushCommand.h"
+
+LogReader::LogReader(LogBuffer *logbuf)
+        : SocketListener("logdr", true)
+        , mLogbuf(*logbuf)
+{ }
+
+// When we are notified a new log entry is available, inform
+// all of our listening sockets.
+void LogReader::notifyNewLog() {
+    FlushCommand command(*this);
+    runOnEachSocket(&command);
+}
+
+bool LogReader::onDataAvailable(SocketClient *cli) {
+    char buffer[255];
+
+    int len = read(cli->getSocket(), buffer, sizeof(buffer) - 1);
+    if (len <= 0) {
+        doSocketDelete(cli);
+        return false;
+    }
+    buffer[len] = '\0';
+
+    unsigned long tail = 0;
+    static const char _tail[] = " tail=";
+    char *cp = strstr(buffer, _tail);
+    if (cp) {
+        tail = atol(cp + sizeof(_tail) - 1);
+    }
+
+    unsigned int logMask = -1;
+    static const char _logIds[] = " lids=";
+    cp = strstr(buffer, _logIds);
+    if (cp) {
+        logMask = 0;
+        cp += sizeof(_logIds) - 1;
+        while (*cp && *cp != '\0') {
+            int val = 0;
+            while (('0' <= *cp) && (*cp <= '9')) {
+                val *= 10;
+                val += *cp - '0';
+                ++cp;
+            }
+            logMask |= 1 << val;
+            if (*cp != ',') {
+                break;
+            }
+            ++cp;
+        }
+    }
+
+    pid_t pid = 0;
+    static const char _pid[] = " pid=";
+    cp = strstr(buffer, _pid);
+    if (cp) {
+        pid = atol(cp + sizeof(_pid) - 1);
+    }
+
+    bool nonBlock = false;
+    if (strncmp(buffer, "dumpAndClose", 12) == 0) {
+        nonBlock = true;
+    }
+
+    FlushCommand command(*this, nonBlock, tail, logMask, pid);
+    command.runSocketCommand(cli);
+    return true;
+}
+
+void LogReader::doSocketDelete(SocketClient *cli) {
+    LastLogTimes &times = mLogbuf.mTimes;
+    LogTimeEntry::lock();
+    LastLogTimes::iterator it = times.begin();
+    while(it != times.end()) {
+        LogTimeEntry *entry = (*it);
+        if (entry->mClient == cli) {
+            times.erase(it);
+            entry->release_Locked();
+            break;
+        }
+        it++;
+    }
+    LogTimeEntry::unlock();
+}