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/*
* Copyright (C) 2012 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 <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <netdb.h>
#include <net/if.h>
#include <netinet/in.h>
#include <stdlib.h>
#include <string.h>
#include <sys/wait.h>
#define LOG_TAG "Netd"
#include <android-base/stringprintf.h>
#include <cutils/sockets.h>
#include <log/log.h>
#include "Controllers.h"
#include "NetdConstants.h"
#include "IptablesRestoreController.h"
int execIptablesRestoreWithOutput(IptablesTarget target, const std::string& commands,
std::string *output) {
return android::net::gCtls->iptablesRestoreCtrl.execute(target, commands, output);
}
int execIptablesRestore(IptablesTarget target, const std::string& commands) {
return execIptablesRestoreWithOutput(target, commands, nullptr);
}
int execIptablesRestoreCommand(IptablesTarget target, const std::string& table,
const std::string& command, std::string *output) {
std::string fullCmd = android::base::StringPrintf("*%s\n%s\nCOMMIT\n", table.c_str(),
command.c_str());
return execIptablesRestoreWithOutput(target, fullCmd, output);
}
/*
* Check an interface name for plausibility. This should e.g. help against
* directory traversal.
*/
bool isIfaceName(const std::string& name) {
size_t i;
if ((name.empty()) || (name.size() > IFNAMSIZ)) {
return false;
}
/* First character must be alphanumeric */
if (!isalnum(name[0])) {
return false;
}
for (i = 1; i < name.size(); i++) {
if (!isalnum(name[i]) && (name[i] != '_') && (name[i] != '-')
&& (name[i] != ':') && (name[i] != '.')) {
return false;
}
}
return true;
}
int parsePrefix(const char *prefix, uint8_t *family, void *address, int size, uint8_t *prefixlen) {
if (!prefix || !family || !address || !prefixlen) {
return -EFAULT;
}
// Find the '/' separating address from prefix length.
const char *slash = strchr(prefix, '/');
const char *prefixlenString = slash + 1;
if (!slash || !*prefixlenString)
return -EINVAL;
// Convert the prefix length to a uint8_t.
char *endptr;
unsigned templen;
templen = strtoul(prefixlenString, &endptr, 10);
if (*endptr || templen > 255) {
return -EINVAL;
}
*prefixlen = templen;
// Copy the address part of the prefix to a local buffer. We have to copy
// because inet_pton and getaddrinfo operate on null-terminated address
// strings, but prefix is const and has '/' after the address.
std::string addressString(prefix, slash - prefix);
// Parse the address.
addrinfo *res;
addrinfo hints = {
.ai_flags = AI_NUMERICHOST,
};
int ret = getaddrinfo(addressString.c_str(), nullptr, &hints, &res);
if (ret || !res) {
return -EINVAL; // getaddrinfo return values are not errno values.
}
// Convert the address string to raw address bytes.
void *rawAddress;
int rawLength;
switch (res[0].ai_family) {
case AF_INET: {
if (*prefixlen > 32) {
return -EINVAL;
}
sockaddr_in *sin = (sockaddr_in *) res[0].ai_addr;
rawAddress = &sin->sin_addr;
rawLength = 4;
break;
}
case AF_INET6: {
if (*prefixlen > 128) {
return -EINVAL;
}
sockaddr_in6 *sin6 = (sockaddr_in6 *) res[0].ai_addr;
rawAddress = &sin6->sin6_addr;
rawLength = 16;
break;
}
default: {
freeaddrinfo(res);
return -EAFNOSUPPORT;
}
}
if (rawLength > size) {
freeaddrinfo(res);
return -ENOSPC;
}
*family = res[0].ai_family;
memcpy(address, rawAddress, rawLength);
freeaddrinfo(res);
return rawLength;
}
void blockSigpipe() {
sigset_t mask;
sigemptyset(&mask);
sigaddset(&mask, SIGPIPE);
if (sigprocmask(SIG_BLOCK, &mask, nullptr) != 0)
ALOGW("WARNING: SIGPIPE not blocked\n");
}
void setCloseOnExec(const char *sock) {
int fd = android_get_control_socket(sock);
int flags = fcntl(fd, F_GETFD, 0);
if (flags == -1) {
ALOGE("Can't get fd flags for control socket %s", sock);
flags = 0;
}
flags |= FD_CLOEXEC;
if (fcntl(fd, F_SETFD, flags) == -1) {
ALOGE("Can't set control socket %s to FD_CLOEXEC", sock);
}
}
// SIGTERM with timeout first, if fail, SIGKILL
void stopProcess(int pid, const char* processName) {
int err = kill(pid, SIGTERM);
if (err) {
err = errno;
}
if (err == ESRCH) {
// This means that someone else inside netd called this helper function,
// which is a programming error. There's no point in calling waitpid() here since we
// know that the process is gone.
ALOGE("%s child process %d unexpectedly disappeared", processName, pid);
return;
}
if (err) {
ALOGE("Error killing %s child process %d: %s", processName, pid, strerror(err));
}
int status = 0;
int ret = 0;
for (int count = 0; ret == 0 && count < 50; count++) {
usleep(100000); // sleep 0.1s to wait for process stop.
ret = waitpid(pid, &status, WNOHANG);
}
if (ret == 0) {
ALOGE("Failed to SIGTERM %s pid=%d, try SIGKILL", processName, pid);
kill(pid, SIGKILL);
ret = waitpid(pid, &status, 0);
}
if (ret == -1) {
ALOGE("Error waiting for %s child process %d: %s", processName, pid, strerror(errno));
} else {
ALOGD("%s process %d terminated status=%d", processName, pid, status);
}
}
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