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author | Nick Kralevich <nnk@google.com> | 2011-04-27 13:09:24 -0700 |
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committer | Nick Kralevich <nnk@google.com> | 2011-04-27 13:09:24 -0700 |
commit | b0d0e260bd6118959fa0e2d3c84037b3e0178551 (patch) | |
tree | 1f1ba33b53e8d0608f6d034f767a90c41eaf3fef /libcutils | |
parent | 66acffad765add93c8fc74592725eec901867393 (diff) | |
parent | 2baeb89882259661e17d7f631ae7f8987cf53c46 (diff) | |
download | system_core-b0d0e260bd6118959fa0e2d3c84037b3e0178551.zip system_core-b0d0e260bd6118959fa0e2d3c84037b3e0178551.tar.gz system_core-b0d0e260bd6118959fa0e2d3c84037b3e0178551.tar.bz2 |
resolved conflicts for merge of 2baeb898 to honeycomb-plus-aosp
Change-Id: Ib3169b3a36aa13ef413da624355b1737e9b76fd9
Diffstat (limited to 'libcutils')
-rw-r--r-- | libcutils/Android.mk | 2 | ||||
-rw-r--r-- | libcutils/uevent.c | 70 |
2 files changed, 71 insertions, 1 deletions
diff --git a/libcutils/Android.mk b/libcutils/Android.mk index b6c5382..25d36da 100644 --- a/libcutils/Android.mk +++ b/libcutils/Android.mk @@ -109,7 +109,7 @@ else #!sim # ======================================================== include $(CLEAR_VARS) LOCAL_MODULE := libcutils -LOCAL_SRC_FILES := $(commonSources) ashmem-dev.c mq.c android_reboot.c +LOCAL_SRC_FILES := $(commonSources) ashmem-dev.c mq.c android_reboot.c uevent.c ifeq ($(TARGET_ARCH),arm) LOCAL_SRC_FILES += arch-arm/memset32.S diff --git a/libcutils/uevent.c b/libcutils/uevent.c new file mode 100644 index 0000000..3533c00 --- /dev/null +++ b/libcutils/uevent.c @@ -0,0 +1,70 @@ +/* + * 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; +} |