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#include <unistd.h>
#include <stdlib.h>
#include <stdint.h>
#include <stdio.h>
#include <syslog.h>
#include <string.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <netdb.h>
#include <pthread.h>
#include <pwd.h>
#include <errno.h>
#include <signal.h>
#include "packet.h"
#include "netascii.h"
static int stop = 0;
void stop_handler() {
stop = 1;
}
void usage(char* name) {
printf("USAGE: %s -d -u nobody -g nobody -a 127.0.0.1 -p 69 -t 128\n", name);
printf("\td: daemonize\n");
printf("\tu: username to run as (default: nobody)\n");
printf("\tg: group to run as (default: nobody)\n");
printf("\ta: address to bind to (default: 127.0.0.1)\n");
printf("\tp: port to bind to (default: 69)\n");
printf("\tt: number of worker threads to spawn (default 128)\n");
}
int main(int argc, char** argv) {
int daemonize = 0;
char addr[16], user[32], group[32];
memset(addr, '\0', sizeof(addr));
memset(user, '\0', sizeof(user));
memset(group, '\0', sizeof(group));
strcpy(addr, "127.0.0.1");
strcpy(user, "nobody");
strcpy(group, "nobody");
int port = 69;
int threadcount = 128;
int ch = 0;
while ((ch = getopt(argc, argv, "da:p:u:g:t:h")) != -1) {
switch (ch) {
case 'a':
//TODO: this is unsafe
strcpy(addr, optarg);
break;
case 'p':
port = atoi(optarg);
if ((port <= 0) || (port >= 65536)) {
fprintf(stderr, "invalid port specified.\n");
return -1;
}
break;
case 't':
threadcount = atoi(optarg);
if ((threadcount <= 0) || (threadcount > 51200)) {
fprintf(stderr, "threadcount must be between 1 and 51200\n");
return -1;
}
break;
case 'd':
daemonize = 1;
break;
case 'g':
if (daemonize) {
//TODO: this is unsafe
strcpy(group, optarg);
} else {
fprintf(stderr, "-g requires -d\n");
return -1;
}
break;
case 'u':
if (daemonize) {
//TODO: this is unsafe
strcpy(user, optarg);
} else {
fprintf(stderr, "-u requires -d\n");
return -1;
}
break;
case '?': case 'h':
usage(argv[0]);
return -1;
}
}
setlogmask(LOG_UPTO(LOG_INFO));
openlog(argv[0], LOG_PID | LOG_PERROR | LOG_NDELAY, LOG_FTP);
syslog(LOG_INFO, "starting up...");
if (daemonize) {
if (daemon(1, 0)) {
syslog(LOG_ERR, "failed to daemonize as requested!");
return -1;
} else {
syslog(LOG_INFO, "daemonized");
}
}
int s = socket(AF_INET, SOCK_DGRAM, 0);
if (s <= 0) {
syslog(LOG_ERR, "unable to bind socket!");
return -1;
}
struct sockaddr_in saddr;
saddr.sin_family = AF_INET;
saddr.sin_port = htons(port);
saddr.sin_addr.s_addr = inet_addr(addr);
if (bind(s, (struct sockaddr*)&saddr, sizeof(saddr)) < 0) {
switch (errno) {
case EACCES:
syslog(LOG_ERR, "socket bind failed: permission denied");
break;
case EADDRINUSE:
syslog(LOG_ERR, "socket bind failed: address already in use");
break;
case EADDRNOTAVAIL:
syslog(LOG_ERR, "socket bind failed: address not available");
break;
default:
syslog(LOG_ERR, "socket bind failed");
}
return -1;
}
syslog(LOG_INFO, "socket bind success");
//TODO: drop privs!
pthread_t threads[128];
memset(threads, '\0', sizeof(threads));
//TODO: spawn threadpool
while (!stop) {
struct sockaddr_in caddr;
unsigned int clen = sizeof(caddr);
char buf[1024];
if (recvfrom(s, buf, sizeof(buf), 0,
(struct sockaddr*)&caddr, &clen) < 0) {
syslog(LOG_ERR,
"got a client connection, but unable to receive data!");
}
//TODO: handle threadpool
}
return 0;
}
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