logd: institute getGroups for socket credentials
(cherry pick from commit 4d851290fc81eb36d2fcf76e6f06213a28b877f5)
Change-Id: Ib8be84d2a3f873e91fb1495df439a498f395c137
diff --git a/logd/CommandListener.cpp b/logd/CommandListener.cpp
index f5cb8dc..202d542 100644
--- a/logd/CommandListener.cpp
+++ b/logd/CommandListener.cpp
@@ -1,5 +1,5 @@
/*
- * Copyright (C) 2012-2013 The Android Open Source Project
+ * 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.
@@ -24,10 +24,11 @@
#include <sys/socket.h>
#include <sys/types.h>
-#include <sysutils/SocketClient.h>
#include <private/android_filesystem_config.h>
+#include <sysutils/SocketClient.h>
#include "CommandListener.h"
+#include "LogCommand.h"
CommandListener::CommandListener(LogBuffer *buf, LogReader * /*reader*/,
LogListener * /*swl*/)
@@ -62,9 +63,7 @@
int CommandListener::ClearCmd::runCommand(SocketClient *cli,
int argc, char **argv) {
- if ((cli->getUid() != AID_ROOT)
- && (cli->getGid() != AID_ROOT)
- && (cli->getGid() != AID_LOG)) {
+ if (!clientHasLogCredentials(cli)) {
cli->sendMsg("Permission Denied");
return 0;
}
@@ -75,7 +74,7 @@
}
int id = atoi(argv[1]);
- if ((id < LOG_ID_MIN) || (id >= LOG_ID_MAX)) {
+ if ((id < LOG_ID_MIN) || (LOG_ID_MAX <= id)) {
cli->sendMsg("Range Error");
return 0;
}
@@ -85,7 +84,6 @@
return 0;
}
-
CommandListener::GetBufSizeCmd::GetBufSizeCmd(LogBuffer *buf)
: LogCommand("getLogSize")
, mBuf(*buf)
@@ -99,7 +97,7 @@
}
int id = atoi(argv[1]);
- if ((id < LOG_ID_MIN) || (id >= LOG_ID_MAX)) {
+ if ((id < LOG_ID_MIN) || (LOG_ID_MAX <= id)) {
cli->sendMsg("Range Error");
return 0;
}
@@ -124,7 +122,7 @@
}
int id = atoi(argv[1]);
- if ((id < LOG_ID_MIN) || (id >= LOG_ID_MAX)) {
+ if ((id < LOG_ID_MIN) || (LOG_ID_MAX <= id)) {
cli->sendMsg("Range Error");
return 0;
}
diff --git a/logd/FlushCommand.cpp b/logd/FlushCommand.cpp
index f6f8cb8..0b8c31b 100644
--- a/logd/FlushCommand.cpp
+++ b/logd/FlushCommand.cpp
@@ -1,5 +1,5 @@
/*
- * Copyright (C) 2012-2013 The Android Open Source Project
+ * 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.
@@ -15,11 +15,12 @@
*/
#include <stdlib.h>
-#include <private/android_filesystem_config.h>
+
#include "FlushCommand.h"
#include "LogBufferElement.h"
-#include "LogTimes.h"
+#include "LogCommand.h"
#include "LogReader.h"
+#include "LogTimes.h"
FlushCommand::FlushCommand(LogReader &reader,
bool nonBlock,
@@ -80,7 +81,5 @@
}
bool FlushCommand::hasReadLogs(SocketClient *client) {
- return (client->getUid() == AID_ROOT)
- || (client->getGid() == AID_ROOT)
- || (client->getGid() == AID_LOG);
+ return clientHasLogCredentials(client);
}
diff --git a/logd/LogCommand.cpp b/logd/LogCommand.cpp
index 6ccc93e..0873e63 100644
--- a/logd/LogCommand.cpp
+++ b/logd/LogCommand.cpp
@@ -1,5 +1,5 @@
/*
- * Copyright (C) 2012-2013 The Android Open Source Project
+ * 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.
@@ -14,8 +14,117 @@
* limitations under the License.
*/
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <private/android_filesystem_config.h>
+
#include "LogCommand.h"
LogCommand::LogCommand(const char *cmd)
: FrameworkCommand(cmd) {
}
+
+// gets a list of supplementary group IDs associated with
+// the socket peer. This is implemented by opening
+// /proc/PID/status and look for the "Group:" line.
+//
+// This function introduces races especially since status
+// can change 'shape' while reading, the net result is err
+// on lack of permission.
+//
+// Race-free alternative is to introduce pairs of sockets
+// and threads for each command and reading, one each that
+// has open permissions, and one that has restricted
+// permissions.
+
+static bool groupIsLog(char *buf) {
+ char *ptr;
+ static const char ws[] = " \n";
+ bool ret = false;
+
+ for (buf = strtok_r(buf, ws, &ptr); buf; buf = strtok_r(NULL, ws, &ptr)) {
+ errno = 0;
+ gid_t Gid = strtol(buf, NULL, 10);
+ if (errno != 0) {
+ return false;
+ }
+ if (Gid == AID_LOG) {
+ ret = true;
+ }
+ }
+ return ret;
+}
+
+bool clientHasLogCredentials(SocketClient * cli) {
+ uid_t uid = cli->getUid();
+ if (uid == AID_ROOT) {
+ return true;
+ }
+
+ gid_t gid = cli->getGid();
+ if ((gid == AID_ROOT) || (gid == AID_LOG)) {
+ return true;
+ }
+
+ // FYI We will typically be here for 'adb logcat'
+ bool ret = false;
+
+ char filename[1024];
+ snprintf(filename, sizeof(filename), "/proc/%d/status", cli->getPid());
+
+ FILE *file = fopen(filename, "r");
+ if (!file) {
+ return ret;
+ }
+
+ bool foundGid = false;
+ bool foundUid = false;
+
+ char line[1024];
+ while (fgets(line, sizeof(line), file)) {
+ static const char groups_string[] = "Groups:\t";
+ static const char uid_string[] = "Uid:\t";
+ static const char gid_string[] = "Gid:\t";
+
+ if (strncmp(groups_string, line, strlen(groups_string)) == 0) {
+ ret = groupIsLog(line + strlen(groups_string));
+ if (!ret) {
+ break;
+ }
+ } else if (strncmp(uid_string, line, strlen(uid_string)) == 0) {
+ uid_t u[4] = { (uid_t) -1, (uid_t) -1, (uid_t) -1, (uid_t) -1};
+
+ sscanf(line + strlen(uid_string), "%u\t%u\t%u\t%u",
+ &u[0], &u[1], &u[2], &u[3]);
+
+ // Protect against PID reuse by checking that the UID is the same
+ if ((uid != u[0]) || (uid != u[1]) || (uid != u[2]) || (uid != u[3])) {
+ ret = false;
+ break;
+ }
+ foundUid = true;
+ } else if (strncmp(gid_string, line, strlen(gid_string)) == 0) {
+ gid_t g[4] = { (gid_t) -1, (gid_t) -1, (gid_t) -1, (gid_t) -1};
+
+ sscanf(line + strlen(gid_string), "%u\t%u\t%u\t%u",
+ &g[0], &g[1], &g[2], &g[3]);
+
+ // Protect against PID reuse by checking that the GID is the same
+ if ((gid != g[0]) || (gid != g[1]) || (gid != g[2]) || (gid != g[3])) {
+ ret = false;
+ break;
+ }
+ foundGid = true;
+ }
+ }
+
+ fclose(file);
+
+ if (!foundGid || !foundUid) {
+ ret = false;
+ }
+
+ return ret;
+}
diff --git a/logd/LogCommand.h b/logd/LogCommand.h
index aef6706..e3b96a2 100644
--- a/logd/LogCommand.h
+++ b/logd/LogCommand.h
@@ -1,5 +1,5 @@
/*
- * Copyright (C) 2012-2013 The Android Open Source Project
+ * 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.
@@ -17,6 +17,7 @@
#ifndef _LOGD_COMMAND_H
#define _LOGD_COMMAND_H
+#include <sysutils/SocketClient.h>
#include <sysutils/FrameworkCommand.h>
class LogCommand : public FrameworkCommand {
@@ -25,4 +26,6 @@
virtual ~LogCommand() {}
};
+bool clientHasLogCredentials(SocketClient * cli);
+
#endif