iodine/src/common.c
2012-02-04 20:34:03 +01:00

336 lines
6.4 KiB
C

/* Copyright (c) 2006-2009 Bjorn Andersson <flex@kryo.se>, Erik Ekman <yarrick@kryo.se>
* Copyright (c) 2007 Albert Lee <trisk@acm.jhu.edu>.
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <time.h>
#include <sys/types.h>
#include <sys/param.h>
#include <sys/stat.h>
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <stdint.h>
#include <unistd.h>
#include <string.h>
#include <ctype.h>
#include <fcntl.h>
#include <errno.h>
#ifdef WINDOWS32
#include <winsock2.h>
#include <conio.h>
#else
#include <arpa/nameser.h>
#ifdef DARWIN
#define BIND_8_COMPAT
#include <arpa/nameser_compat.h>
#endif
#include <termios.h>
#include <err.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <syslog.h>
#endif
#ifdef HAVE_SETCON
# include <selinux/selinux.h>
#endif
#include "common.h"
/* The raw header used when not using DNS protocol */
const unsigned char raw_header[RAW_HDR_LEN] = { 0x10, 0xd1, 0x9e, 0x00 };
/* daemon(3) exists only in 4.4BSD or later, and in GNU libc */
#if !defined(WINDOWS32) && !(defined(BSD) && (BSD >= 199306)) && !defined(__GLIBC__)
static int daemon(int nochdir, int noclose)
{
int fd, i;
switch (fork()) {
case 0:
break;
case -1:
return -1;
default:
_exit(0);
}
if (!nochdir) {
chdir("/");
}
if (setsid() < 0) {
return -1;
}
if (!noclose) {
if ((fd = open("/dev/null", O_RDWR)) >= 0) {
for (i = 0; i < 3; i++) {
dup2(fd, i);
}
if (fd > 2) {
close(fd);
}
}
}
return 0;
}
#endif
#if defined(__BEOS__) && !defined(__HAIKU__)
int setgroups(int count, int *groups)
{
/* errno = ENOSYS; */
return -1;
}
#endif
void
check_superuser(void (*usage_fn)(void))
{
#ifndef WINDOWS32
if (geteuid() != 0) {
warnx("Run as root and you'll be happy.\n");
usage_fn();
/* NOTREACHED */
}
#endif
}
int
open_dns(int localport, in_addr_t listen_ip)
{
struct sockaddr_in addr;
int flag = 1;
int fd;
memset(&addr, 0, sizeof(addr));
addr.sin_family = AF_INET;
addr.sin_port = htons(localport);
/* listen_ip already in network byte order from inet_addr, or 0 */
addr.sin_addr.s_addr = listen_ip;
if ((fd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0) {
fprintf(stderr, "got fd %d\n", fd);
err(1, "socket");
}
flag = 1;
#ifdef SO_REUSEPORT
setsockopt(fd, SOL_SOCKET, SO_REUSEPORT, (const void*) &flag, sizeof(flag));
#endif
setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, (const void*) &flag, sizeof(flag));
#ifndef WINDOWS32
/* To get destination address from each UDP datagram, see iodined.c:read_dns() */
setsockopt(fd, IPPROTO_IP, DSTADDR_SOCKOPT, (const void*) &flag, sizeof(flag));
#endif
#ifdef IP_OPT_DONT_FRAG
/* Set dont-fragment ip header flag */
flag = DONT_FRAG_VALUE;
setsockopt(fd, IPPROTO_IP, IP_OPT_DONT_FRAG, (const void*) &flag, sizeof(flag));
#endif
if(bind(fd, (struct sockaddr*)&addr, sizeof(addr)) < 0)
err(1, "bind");
fprintf(stderr, "Opened UDP socket\n");
return fd;
}
void
close_dns(int fd)
{
close(fd);
}
void
do_chroot(char *newroot)
{
#if !(defined(WINDOWS32) || defined(__BEOS__) || defined(__HAIKU__))
if (chroot(newroot) != 0 || chdir("/") != 0)
err(1, "%s", newroot);
seteuid(geteuid());
setuid(getuid());
#else
warnx("chroot not available");
#endif
}
void
do_setcon(char *context)
{
#ifdef HAVE_SETCON
if (-1 == setcon(context))
err(1, "%s", context);
#else
warnx("No SELinux support built in");
#endif
}
void
do_pidfile(char *pidfile)
{
#ifndef WINDOWS32
FILE *file;
if ((file = fopen(pidfile, "w")) == NULL) {
syslog(LOG_ERR, "Cannot write pidfile to %s, exiting", pidfile);
err(1, "do_pidfile: Can not write pidfile to %s", pidfile);
} else {
fprintf(file, "%d\n", (int)getpid());
fclose(file);
}
#else
fprintf(stderr, "Windows version does not support pid file\n");
#endif
}
void
do_detach()
{
#ifndef WINDOWS32
fprintf(stderr, "Detaching from terminal...\n");
daemon(0, 0);
umask(0);
alarm(0);
#else
fprintf(stderr, "Windows version does not support detaching\n");
#endif
}
void
read_password(char *buf, size_t len)
{
char pwd[80];
#ifndef WINDOWS32
struct termios old;
struct termios tp;
tcgetattr(0, &tp);
old = tp;
tp.c_lflag &= (~ECHO);
tcsetattr(0, TCSANOW, &tp);
#else
int i;
#endif
fprintf(stderr, "Enter password: ");
fflush(stderr);
#ifndef WINDOWS32
scanf("%79s", pwd);
#else
for (i = 0; i < sizeof(pwd); i++) {
pwd[i] = getch();
if (pwd[i] == '\r' || pwd[i] == '\n') {
pwd[i] = 0;
break;
} else if (pwd[i] == '\b') {
i--; /* Remove the \b char */
if (i >=0) i--; /* If not first char, remove one more */
}
}
#endif
fprintf(stderr, "\n");
#ifndef WINDOWS32
tcsetattr(0, TCSANOW, &old);
#endif
strncpy(buf, pwd, len);
buf[len-1] = '\0';
}
int
check_topdomain(char *str)
{
int i;
if(str[0] == '.') /* special case */
return 1;
for( i = 0; i < strlen(str); i++) {
if( isalpha(str[i]) || isdigit(str[i]) || str[i] == '-' || str[i] == '.' )
continue;
else
return 1;
}
return 0;
}
#ifdef WINDOWS32
int
inet_aton(const char *cp, struct in_addr *inp)
{
inp->s_addr = inet_addr(cp);
return inp->s_addr != INADDR_ANY;
}
void
warn(const char *fmt, ...)
{
va_list list;
va_start(list, fmt);
if (fmt) fprintf(stderr, fmt, list);
if (errno == 0) {
fprintf(stderr, ": WSA error %d\n", WSAGetLastError());
} else {
fprintf(stderr, ": %s\n", strerror(errno));
}
va_end(list);
}
void
warnx(const char *fmt, ...)
{
va_list list;
va_start(list, fmt);
if (fmt) fprintf(stderr, fmt, list);
fprintf(stderr, "\n");
va_end(list);
}
void
err(int eval, const char *fmt, ...)
{
va_list list;
va_start(list, fmt);
warn(fmt, list);
va_end(list);
exit(eval);
}
void
errx(int eval, const char *fmt, ...)
{
va_list list;
va_start(list, fmt);
warnx(fmt, list);
va_end(list);
exit(eval);
}
#endif