am de35f274: am 03752be0: am 0c297f5e: Merge "Revert "Fold uevent message origin checking from init into libcutils.""
* commit 'de35f2741c4e32e331a92be99f7c04b92b94beb2':
Revert "Fold uevent message origin checking from init into libcutils."
diff --git a/include/cutils/uevent.h b/include/cutils/uevent.h
deleted file mode 100644
index 587149c..0000000
--- a/include/cutils/uevent.h
+++ /dev/null
@@ -1,32 +0,0 @@
-/*
- * Copyright (C) 2011 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.
- */
-
-#ifndef __CUTILS_UEVENT_H
-#define __CUTILS_UEVENT_H
-
-#include <sys/socket.h>
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-ssize_t uevent_checked_recv(int socket, void *buffer, size_t length);
-
-#ifdef __cplusplus
-}
-#endif
-
-#endif /* __CUTILS_UEVENT_H */
diff --git a/init/devices.c b/init/devices.c
index a200c95..bc36ac1 100644
--- a/init/devices.c
+++ b/init/devices.c
@@ -34,8 +34,6 @@
#include <asm/page.h>
#include <sys/wait.h>
-#include <cutils/uevent.h>
-
#include "devices.h"
#include "util.h"
#include "log.h"
@@ -772,9 +770,35 @@
#define UEVENT_MSG_LEN 1024
void handle_device_fd()
{
- char msg[UEVENT_MSG_LEN+2];
- int n;
- while ((n = uevent_checked_recv(device_fd, msg, UEVENT_MSG_LEN)) > 0) {
+ for(;;) {
+ char msg[UEVENT_MSG_LEN+2];
+ char cred_msg[CMSG_SPACE(sizeof(struct ucred))];
+ struct iovec iov = {msg, sizeof(msg)};
+ struct sockaddr_nl snl;
+ struct msghdr hdr = {&snl, sizeof(snl), &iov, 1, cred_msg, sizeof(cred_msg), 0};
+
+ ssize_t n = recvmsg(device_fd, &hdr, 0);
+ if (n <= 0) {
+ break;
+ }
+
+ if ((snl.nl_groups != 1) || (snl.nl_pid != 0)) {
+ /* ignoring non-kernel netlink multicast message */
+ continue;
+ }
+
+ struct cmsghdr * cmsg = CMSG_FIRSTHDR(&hdr);
+ if (cmsg == NULL || cmsg->cmsg_type != SCM_CREDENTIALS) {
+ /* no sender credentials received, ignore message */
+ continue;
+ }
+
+ struct ucred * cred = (struct ucred *)CMSG_DATA(cmsg);
+ if (cred->uid != 0) {
+ /* message from non-root user, ignore */
+ continue;
+ }
+
if(n >= UEVENT_MSG_LEN) /* overflow -- discard */
continue;
diff --git a/libcutils/Android.mk b/libcutils/Android.mk
index 44c2042..b6c5382 100644
--- a/libcutils/Android.mk
+++ b/libcutils/Android.mk
@@ -74,7 +74,6 @@
mspace.c \
selector.c \
tztime.c \
- uevent.c \
zygote.c
commonHostSources += \
diff --git a/libcutils/uevent.c b/libcutils/uevent.c
deleted file mode 100644
index 3533c00..0000000
--- a/libcutils/uevent.c
+++ /dev/null
@@ -1,70 +0,0 @@
-/*
- * Copyright (C) 2011 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 <cutils/uevent.h>
-
-#include <errno.h>
-#include <strings.h>
-
-#include <linux/netlink.h>
-
-/**
- * Like recv(), but checks that messages actually originate from the kernel.
- */
-ssize_t uevent_checked_recv(int socket, void *buffer, size_t length) {
- struct iovec iov = { buffer, length };
- struct sockaddr_nl addr;
- char control[CMSG_SPACE(sizeof(struct ucred))];
- struct msghdr hdr = {
- &addr,
- sizeof(addr),
- &iov,
- 1,
- control,
- sizeof(control),
- 0,
- };
-
- ssize_t n = recvmsg(socket, &hdr, 0);
- if (n <= 0) {
- return n;
- }
-
- if (addr.nl_groups == 0 || addr.nl_pid != 0) {
- /* ignoring non-kernel or unicast netlink message */
- goto out;
- }
-
- struct cmsghdr *cmsg = CMSG_FIRSTHDR(&hdr);
- if (cmsg == NULL || cmsg->cmsg_type != SCM_CREDENTIALS) {
- /* ignoring netlink message with no sender credentials */
- goto out;
- }
-
- struct ucred *cred = (struct ucred *)CMSG_DATA(cmsg);
- if (cred->uid != 0) {
- /* ignoring netlink message from non-root user */
- goto out;
- }
-
- return n;
-
-out:
- /* clear residual potentially malicious data */
- bzero(buffer, length);
- errno = EIO;
- return -1;
-}