3311eea1d3
The issues were the following: - The code in decode() didn't handle the degenerate case where the input buffer is full of '@' - The code in decode() assumed the input buffer is properly zero-terminated. - The code in decode() would not check that it doesn't overwrite the mParams[] array. - The code in findParam() would check mParams[i] before checking the value of 'i' Also remove un-necessary calls to strlen() at runtime. Change-Id: I8acead959bd10d97c5380b08958fcb796248a010
136 lines
4 KiB
C++
136 lines
4 KiB
C++
/*
|
|
* Copyright (C) 2008 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 <stdlib.h>
|
|
#include <string.h>
|
|
|
|
#define LOG_TAG "NetlinkEvent"
|
|
#include <cutils/log.h>
|
|
|
|
#include <sysutils/NetlinkEvent.h>
|
|
|
|
const int NetlinkEvent::NlActionUnknown = 0;
|
|
const int NetlinkEvent::NlActionAdd = 1;
|
|
const int NetlinkEvent::NlActionRemove = 2;
|
|
const int NetlinkEvent::NlActionChange = 3;
|
|
|
|
NetlinkEvent::NetlinkEvent() {
|
|
mAction = NlActionUnknown;
|
|
memset(mParams, 0, sizeof(mParams));
|
|
mPath = NULL;
|
|
mSubsystem = NULL;
|
|
}
|
|
|
|
NetlinkEvent::~NetlinkEvent() {
|
|
int i;
|
|
if (mPath)
|
|
free(mPath);
|
|
if (mSubsystem)
|
|
free(mSubsystem);
|
|
for (i = 0; i < NL_PARAMS_MAX; i++) {
|
|
if (!mParams[i])
|
|
break;
|
|
free(mParams[i]);
|
|
}
|
|
}
|
|
|
|
void NetlinkEvent::dump() {
|
|
int i;
|
|
|
|
for (i = 0; i < NL_PARAMS_MAX; i++) {
|
|
if (!mParams[i])
|
|
break;
|
|
SLOGD("NL param '%s'\n", mParams[i]);
|
|
}
|
|
}
|
|
|
|
/* If the string between 'str' and 'end' begins with 'prefixlen' characters
|
|
* from the 'prefix' array, then return 'str + prefixlen', otherwise return
|
|
* NULL.
|
|
*/
|
|
static const char*
|
|
has_prefix(const char* str, const char* end, const char* prefix, size_t prefixlen)
|
|
{
|
|
if ((end-str) >= (ptrdiff_t)prefixlen && !memcmp(str, prefix, prefixlen))
|
|
return str + prefixlen;
|
|
else
|
|
return NULL;
|
|
}
|
|
|
|
/* Same as strlen(x) for constant string literals ONLY */
|
|
#define CONST_STRLEN(x) (sizeof(x)-1)
|
|
|
|
/* Convenience macro to call has_prefix with a constant string literal */
|
|
#define HAS_CONST_PREFIX(str,end,prefix) has_prefix((str),(end),prefix,CONST_STRLEN(prefix))
|
|
|
|
|
|
bool NetlinkEvent::decode(char *buffer, int size) {
|
|
const char *s = buffer;
|
|
const char *end;
|
|
int param_idx = 0;
|
|
int i;
|
|
int first = 1;
|
|
|
|
if (size == 0)
|
|
return false;
|
|
|
|
/* Ensure the buffer is zero-terminated, the code below depends on this */
|
|
buffer[size-1] = '\0';
|
|
|
|
end = s + size;
|
|
while (s < end) {
|
|
if (first) {
|
|
const char *p;
|
|
/* buffer is 0-terminated, no need to check p < end */
|
|
for (p = s; *p != '@'; p++) {
|
|
if (!*p) { /* no '@', should not happen */
|
|
return false;
|
|
}
|
|
}
|
|
mPath = strdup(p+1);
|
|
first = 0;
|
|
} else {
|
|
const char* a;
|
|
if ((a = HAS_CONST_PREFIX(s, end, "ACTION=")) != NULL) {
|
|
if (!strcmp(a, "add"))
|
|
mAction = NlActionAdd;
|
|
else if (!strcmp(a, "remove"))
|
|
mAction = NlActionRemove;
|
|
else if (!strcmp(a, "change"))
|
|
mAction = NlActionChange;
|
|
} else if ((a = HAS_CONST_PREFIX(s, end, "SEQNUM=")) != NULL) {
|
|
mSeq = atoi(a);
|
|
} else if ((a = HAS_CONST_PREFIX(s, end, "SUBSYSTEM=")) != NULL) {
|
|
mSubsystem = strdup(a);
|
|
} else if (param_idx < NL_PARAMS_MAX) {
|
|
mParams[param_idx++] = strdup(s);
|
|
}
|
|
}
|
|
s += strlen(s) + 1;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
const char *NetlinkEvent::findParam(const char *paramName) {
|
|
size_t len = strlen(paramName);
|
|
for (int i = 0; i < NL_PARAMS_MAX && mParams[i] != NULL; ++i) {
|
|
const char *ptr = mParams[i] + len;
|
|
if (!strncmp(mParams[i], paramName, len) && *ptr == '=')
|
|
return ++ptr;
|
|
}
|
|
|
|
SLOGE("NetlinkEvent::FindParam(): Parameter '%s' not found", paramName);
|
|
return NULL;
|
|
}
|