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#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdarg.h>
#include <errno.h>
#include <signal.h>
#include <limits.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include "ip/ip_misc.h"
extern char ** environ;
extern int getopt(int, char *const*, const char *);
extern int optind;
extern char * optarg;
char * progname = "mini-inetd";
int debug = 0;
int max_connections = 0;
static void
usage()
{
fprintf(stderr,
"Usage: %s [-d] [-m max] port program [argv0 argv1 ...]\n",
progname);
exit(1);
}
static void
vfatal(const char *fmt, va_list args)
{
fputs(progname, stderr);
fputs(": ", stderr);
vfprintf(stderr, fmt, args);
putc('\n', stderr);
exit(1);
}
static void
fatal(const char *fmt, ...)
{
va_list args;
va_start(args, fmt);
vfatal(fmt, args);
va_end(args);
}
static void
reap_children(int signo)
{
pid_t child;
int status;
char buf[64 + sizeof(long) * CHAR_BIT];
while ((child = waitpid(-1, &status, WNOHANG)) > (pid_t)0)
{
if (debug)
{
sprintf(buf, "Child %ld died\n", (long)child);
write(2, buf, strlen(buf));
}
}
signal(signo, &reap_children);
}
int
main(int argc, char **argv)
{
int sd;
pid_t child;
int option;
char *host;
char *port;
while ((option = getopt (argc, argv, "dm:")) != EOF)
{
switch ((char)option)
{
case 'd':
debug++;
break;
case 'm':
max_connections = atoi(optarg);
break;
default:
usage();
/* NOTREACHED */
}
}
if (argc - optind < 2)
usage();
port = strrchr(argv[optind], ':');
if (port != NULL) {
*(port++) = '\0';
host = argv[optind];
} else {
port = argv[optind];
host = NULL;
}
if ((sd = tcp_listen(host, port)) < 0)
fatal("Can't listen to port %s: %s", argv[optind], strerror(errno));
/* Reap children */
#if defined(SIGCHLD)
signal(SIGCHLD, &reap_children);
#elif defined(SIGCLD)
signal(SIGCLD, &reap_children);
#endif
while (1)
{
struct sockaddr_in them;
int len = sizeof them;
int ns = accept(sd, (struct sockaddr*)&them, &len);
if (ns < 0) {
if (errno == EINTR)
continue;
fatal("Accept failed: %s", strerror(errno));
}
switch (child = fork()) {
case -1:
perror("Can't fork");
break;
case 0:
/* Child */
close(sd);
dup2(ns, 0);
dup2(ns, 1);
execve(argv[optind+1], argv+optind+2, environ);
fatal("Can't start %s: %s", argv[optind+1], strerror(errno));
default:
/* Parent */
if (debug)
fprintf(stderr, "Forked child %ld\n", (long)child);
close(ns);
break;
}
if (max_connections > 0 && --max_connections <= 0)
break;
}
return 0;
}
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