/*
* This slave does iptoname conversions, and identquery lookups.
*
* The philosophy is to keep this program as simple/small as possible.
* It does normal fork()s, so the smaller it is, the faster it goes.
*
* $Id: slave.c,v 1.2 2005/08/08 09:43:07 murrayma Exp $
*/
#include "config.h"
#include <errno.h>
#include <netdb.h>
#include <netinet/in.h>
#include <sys/wait.h>
#include <sys/file.h>
#include <sys/ioctl.h>
#include <signal.h>
#include "slave.h"
#include <arpa/inet.h>
#include <debug.h>
pid_t parent_pid;
#define MAX_STRING 8000
char *arg_for_errors;
char *format_inet_addr(dest, addr)
char *dest;
long addr;
{
sprintf(dest, "%ld.%ld.%ld.%ld", (addr & 0xFF000000) >> 24,
(addr & 0x00FF0000) >> 16, (addr & 0x0000FF00) >> 8,
(addr & 0x000000FF));
return (dest + strlen(dest));
}
/*
* copy a string, returning pointer to the null terminator of dest
*/
char *string_append(char *dest, const char *src)
{
while ((*dest = *src)) {
++dest;
++src;
}
return (dest);
}
void child_timeout_signal()
{
exit(1);
}
int query(ip, orig_arg)
char *ip;
char *orig_arg;
{
char *comma;
char *port_pair;
struct hostent *hp;
struct sockaddr_in sin;
int s;
FILE *f;
char result[MAX_STRING];
char buf[MAX_STRING];
char buf2[MAX_STRING];
char buf3[MAX_STRING];
char arg[MAX_STRING];
size_t len;
char *p;
unsigned long addr;
addr = inet_addr(ip);
if (addr == -1) {
return (-1);
}
hp = gethostbyaddr((char *) &addr, sizeof(addr), AF_INET);
if (hp && !isdigit(*(hp->h_name))) {
p = string_append(buf, ip);
*p++ = ' ';
p = string_append(p, hp->h_name);
*p++ = '\n';
*p++ = '\0';
} else {
sprintf(buf, "%s %s\n", ip, ip);
}
arg_for_errors = orig_arg;
strcpy(arg, orig_arg);
comma = (char *) strrchr(arg, ',');
if (comma == NULL) {
return (-1);
}
*comma = 0;
port_pair = (char *) strrchr(arg, ',');
if (port_pair == NULL) {
return (-1);
}
*port_pair++ = 0;
*comma = ',';
hp = gethostbyname(arg);
if (hp == NULL) {
static struct hostent def;
static struct in_addr defaddr;
static char *alist[1];
static char namebuf[128];
defaddr.s_addr = inet_addr(arg);
if (defaddr.s_addr == -1) {
return (-1);
}
strcpy(namebuf, arg);
def.h_name = namebuf;
def.h_addr_list = alist;
def.h_addr = (char *) &defaddr;
def.h_length = sizeof(struct in_addr);
def.h_addrtype = AF_INET;
def.h_aliases = 0;
hp = &def;
}
sin.sin_family = hp->h_addrtype;
bcopy(hp->h_addr, (char *) &sin.sin_addr, hp->h_length);
sin.sin_port = htons(113); /*
* ident port
*/
s = socket(hp->h_addrtype, SOCK_STREAM, 0);
if (s < 0) {
return (-1);
}
if (connect(s, (struct sockaddr *) &sin, sizeof(sin)) < 0) {
if (errno != ECONNREFUSED && errno != ETIMEDOUT &&
errno != ENETUNREACH && errno != EHOSTUNREACH) {
close(s);
return (-1);
}
buf2[0] = '\0';
} else {
len = strlen(port_pair);
if (write(s, port_pair, len) != len) {
close(s);
return (-1);
}
if (write(s, "\r\n", 2) != 2) {
close(s);
return (-1);
}
f = fdopen(s, "r");
{
int c;
p = result;
while ((c = fgetc(f)) != EOF) {
if (c == '\n')
break;
if (isprint(c)) {
*p++ = c;
if (p - result == MAX_STRING - 1)
break;
}
}
*p = '\0';
}
(void) fclose(f);
p = (char *) format_inet_addr(buf2, ntohl(sin.sin_addr.s_addr));
*p++ = ' ';
p = string_append(p, result);
*p++ = '\n';
*p++ = '\0';
}
sprintf(buf3, "%s%s", buf, buf2);
write(1, buf3, strlen(buf3));
return (0);
}
void child_signal()
{
/*
* collect any children
*/
#ifdef NEXT
while (wait3(NULL, WNOHANG, NULL) > 0);
#else
while (waitpid(0, NULL, WNOHANG) > 0);
#endif
signal(SIGCHLD, child_signal);
}
void alarm_signal()
{
struct itimerval itime;
struct timeval interval;
if (getppid() != parent_pid) {
exit(1);
}
signal(SIGALRM, alarm_signal);
interval.tv_sec = 120; /*
* 2 minutes
*/
interval.tv_usec = 0;
itime.it_interval = interval;
itime.it_value = interval;
setitimer(ITIMER_REAL, &itime, 0);
}
int main(argc, argv)
int argc;
char **argv;
{
char arg[MAX_STRING + 1];
char *p;
int len;
dprintk("slave booting.");
parent_pid = getppid();
if (parent_pid == 1) {
exit(1);
}
alarm_signal();
signal(SIGCHLD, child_signal);
signal(SIGPIPE, SIG_DFL);
for (;;) {
len = read(0, arg, MAX_STRING);
if (len == 0)
break;
if (len < 0) {
if (errno == EINTR) {
errno = 0;
continue;
}
break;
}
arg[len] = '\0';
p = strchr(arg, '\n');
if (p)
*p = '\0';
switch (fork()) {
case -1:
exit(1);
case 0: /*
* child
*/
{
dprintk("child booted.\n");
/*
* we don't want to try this for more than 5
* * * * * minutes
*/
struct itimerval itime;
struct timeval interval;
interval.tv_sec = 300; /*
* 5 minutes
*/
interval.tv_usec = 0;
itime.it_interval = interval;
itime.it_value = interval;
signal(SIGALRM, child_timeout_signal);
setitimer(ITIMER_REAL, &itime, 0);
}
exit(query(arg, p + 1) != 0);
}
/*
* collect any children
*/
#ifdef NEXT
while (wait3(NULL, WNOHANG, NULL) > 0);
#else
while (waitpid(0, NULL, WNOHANG) > 0);
#endif
}
exit(0);
}