ftp.c

tftp的示例代码,写得不错,值得一看

		/*
		 * What we've got at this point is a string of comma
		 * separated one-byte unsigned integer values.
		 * The first four are the an IP address. The fifth is
		 * the MSB of the port number, the sixth is the LSB.
		 * From that we'll prepare a sockaddr_in.
		 */

		if (sscanf(pasv,"%d,%d,%d,%d,%d,%d",
			   &a0, &a1, &a2, &a3, &p0, &p1) != 6) {
			printf("Passive mode address scan failure. Shouldn't happen!\n");
			goto bad;
		}

		bzero(&data_addr, sizeof(data_addr));
		data_addr.sin_family = AF_INET;
		a = (char *)&data_addr.sin_addr.s_addr;
		a[0] = a0 & 0xff;
		a[1] = a1 & 0xff;
		a[2] = a2 & 0xff;
		a[3] = a3 & 0xff;
		p = (char *)&data_addr.sin_port;
		p[0] = p0 & 0xff;
		p[1] = p1 & 0xff;

		if (connect(data, (struct sockaddr *)&data_addr,
			    sizeof(data_addr)) < 0) {
			perror("ftp: connect");
			goto bad;
		}
#if defined(IP_TOS) && defined(IPTOS_THROUGPUT)
		on = IPTOS_THROUGHPUT;
		if (setsockopt(data, IPPROTO_IP, IP_TOS, (char *)&on,
			       sizeof(int)) < 0)
			perror("ftp: setsockopt TOS (ignored)");
#endif
		return(0);
	}

noport:
	data_addr = myctladdr;
	if (sendport)
		data_addr.sin_port = 0;	/* let system pick one */
	if (data != -1)
		close(data);
	data = socket(AF_INET, SOCK_STREAM, 0);
	if (data < 0) {
		error (0, errno, "socket");
		if (tmpno)
			sendport = 1;
		return (1);
	}
	if (!sendport)
		if (setsockopt(data, SOL_SOCKET, SO_REUSEADDR, (char *)&on, sizeof (on)) < 0) {
			error (0, errno, "setsockopt (reuse address)");
			goto bad;
		}
	if (bind(data, (struct sockaddr *)&data_addr, sizeof (data_addr)) < 0) {
		error (0, errno, "bind");
		goto bad;
	}
	if (options & SO_DEBUG &&
	    setsockopt(data, SOL_SOCKET, SO_DEBUG, (char *)&on, sizeof (on)) < 0)
		error (0, errno, "setsockopt (ignored)");
	len = sizeof (data_addr);
	if (getsockname(data, (struct sockaddr *)&data_addr, &len) < 0) {
		error (0, errno, "getsockname");
		goto bad;
	}
	if (listen(data, 1) < 0)
		error (0, errno, "listen");
	if (sendport) {
		a = (char *)&data_addr.sin_addr;
		p = (char *)&data_addr.sin_port;
#define	UC(b)	(((int)b)&0xff)
		result =
		    command("PORT %d,%d,%d,%d,%d,%d",
		      UC(a[0]), UC(a[1]), UC(a[2]), UC(a[3]),
		      UC(p[0]), UC(p[1]));
		if (result == ERROR && sendport == -1) {
			sendport = 0;
			tmpno = 1;
			goto noport;
		}
		return (result != COMPLETE);
	}
	if (tmpno)
		sendport = 1;
#if defined (IP_TOS) && defined (IPPROTO_IP) && defined (IPTOS_THROUGHPUT)
	on = IPTOS_THROUGHPUT;
	if (setsockopt(data, IPPROTO_IP, IP_TOS, (char *)&on, sizeof(int)) < 0)
		error (0, errno, "setsockopt TOS (ignored)");
#endif
	return (0);
bad:
	close(data), data = -1;
	if (tmpno)
		sendport = 1;
	return (1);
}

FILE *
dataconn(lmode)
	char *lmode;
{
	struct sockaddr_in from;
	int s, fromlen = sizeof (from), tos;

	if (passivemode)
		return (fdopen(data, lmode));

	s = accept(data, (struct sockaddr *) &from, &fromlen);
	if (s < 0) {
		error (0, errno, "accept");
		close(data), data = -1;
		return (NULL);
	}
	close(data);
	data = s;
#if defined (IP_TOS) && defined (IPPROTO_IP) && defined (IPTOS_THROUGHPUT)
	tos = IPTOS_THROUGHPUT;
	if (setsockopt(s, IPPROTO_IP, IP_TOS, (char *)&tos, sizeof(int)) < 0)
		error (0, errno, "setsockopt TOS (ignored)");
#endif
	return (fdopen(data, lmode));
}

void
ptransfer(direction, bytes, t0, t1)
	char *direction;
	long bytes;
	struct timeval *t0, *t1;
{
	struct timeval td;
	float s;
	long bs;

	if (verbose) {
		tvsub(&td, t1, t0);
		s = td.tv_sec + (td.tv_usec / 1000000.);
#define	nz(x)	((x) == 0 ? 1 : (x))
		bs = bytes / nz(s);
		printf("%ld bytes %s in %.3g seconds (%ld bytes/s)\n",
		    bytes, direction, s, bs);
	}
}

/*
void
tvadd(tsum, t0)
	struct timeval *tsum, *t0;
{

	tsum->tv_sec += t0->tv_sec;
	tsum->tv_usec += t0->tv_usec;
	if (tsum->tv_usec > 1000000)
		tsum->tv_sec++, tsum->tv_usec -= 1000000;
}
*/

void
tvsub(tdiff, t1, t0)
	struct timeval *tdiff, *t1, *t0;
{

	tdiff->tv_sec = t1->tv_sec - t0->tv_sec;
	tdiff->tv_usec = t1->tv_usec - t0->tv_usec;
	if (tdiff->tv_usec < 0)
		tdiff->tv_sec--, tdiff->tv_usec += 1000000;
}

void
psabort(sig)
  int sig;
{

	abrtflag++;
}

void
pswitch(flag)
	int flag;
{
	sig_t oldintr;
	static struct comvars {
		int connect;
		char *name;
		struct sockaddr_in mctl;
		struct sockaddr_in hctl;
		FILE *in;
		FILE *out;
		int tpe;
		int curtpe;
		int cpnd;
		int sunqe;
		int runqe;
		int mcse;
		int ntflg;
		char nti[17];
		char nto[17];
		int mapflg;
		char *mi;
		char *mo;
	} proxstruct = {0}, tmpstruct = {0};
	struct comvars *ip, *op;

	abrtflag = 0;
	oldintr = signal(SIGINT, psabort);
	if (flag) {
		if (proxy)
			return;
		ip = &tmpstruct;
		op = &proxstruct;
		proxy++;
	} else {
		if (!proxy)
			return;
		ip = &proxstruct;
		op = &tmpstruct;
		proxy = 0;
	}
	ip->connect = connected;
	connected = op->connect;

	if (ip->name)
		free (ip->name);
	ip->name = hostname;
	hostname = op->name;
	op->name = 0;

	ip->hctl = hisctladdr;
	hisctladdr = op->hctl;
	ip->mctl = myctladdr;
	myctladdr = op->mctl;
	ip->in = cin;
	cin = op->in;
	ip->out = cout;
	cout = op->out;
	ip->tpe = type;
	type = op->tpe;
	ip->curtpe = curtype;
	curtype = op->curtpe;
	ip->cpnd = cpend;
	cpend = op->cpnd;
	ip->sunqe = sunique;
	sunique = op->sunqe;
	ip->runqe = runique;
	runique = op->runqe;
	ip->mcse = mcase;
	mcase = op->mcse;
	ip->ntflg = ntflag;
	ntflag = op->ntflg;
	strncpy(ip->nti, ntin, sizeof(ntin) - 1);
	(ip->nti)[strlen(ip->nti)] = '\0';
	strcpy(ntin, op->nti);
	strncpy(ip->nto, ntout, sizeof(ntout) - 1);
	(ip->nto)[strlen(ip->nto)] = '\0';
	strcpy(ntout, op->nto);
	ip->mapflg = mapflag;
	mapflag = op->mapflg;

	if (ip->mi)
		free (ip->mi);
	ip->mi = mapin;
	mapin = op->mi;
	op->mi = 0;

	if (ip->mo)
		free (ip->mo);
	ip->mo = mapout;
	mapout = op->mo;
	op->mo = 0;

	signal(SIGINT, oldintr);
	if (abrtflag) {
		abrtflag = 0;
		(*oldintr)(SIGINT);
	}
}

void
abortpt(sig)
  int sig;
{

	printf("\n");
	fflush(stdout);
	ptabflg++;
	mflag = 0;
	abrtflag = 0;
	longjmp(ptabort, 1);
}

void
proxtrans(cmd, local, remote)
	char *cmd, *local, *remote;
{
	sig_t oldintr;
	int secndflag = 0, prox_type, nfnd;
	char *cmd2;
	fd_set mask;

	if (strcmp(cmd, "RETR"))
		cmd2 = "RETR";
	else
		cmd2 = runique ? "STOU" : "STOR";
	if ((prox_type = type) == 0) {
		if (unix_server && unix_proxy)
			prox_type = TYPE_I;
		else
			prox_type = TYPE_A;
	}
	if (curtype != prox_type)
		changetype(prox_type, 1);
	if (command("PASV") != COMPLETE) {
		printf("proxy server does not support third party transfers.\n");
		return;
	}
	pswitch(0);
	if (!connected) {
		printf("No primary connection\n");
		pswitch(1);
		code = -1;
		return;
	}
	if (curtype != prox_type)
		changetype(prox_type, 1);
	if (command("PORT %s", pasv) != COMPLETE) {
		pswitch(1);
		return;
	}
	if (setjmp(ptabort))
		goto abort;
	oldintr = signal(SIGINT, abortpt);
	if (command("%s %s", cmd, remote) != PRELIM) {
		signal(SIGINT, oldintr);
		pswitch(1);
		return;
	}
	sleep(2);
	pswitch(1);
	secndflag++;
	if (command("%s %s", cmd2, local) != PRELIM)
		goto abort;
	ptflag++;
	getreply(0);
	pswitch(0);
	getreply(0);
	signal(SIGINT, oldintr);
	pswitch(1);
	ptflag = 0;
	printf("local: %s remote: %s\n", local, remote);
	return;
abort:
	signal(SIGINT, SIG_IGN);
	ptflag = 0;
	if (strcmp(cmd, "RETR") && !proxy)
		pswitch(1);
	else if (!strcmp(cmd, "RETR") && proxy)
		pswitch(0);
	if (!cpend && !secndflag) {  /* only here if cmd = "STOR" (proxy=1) */
		if (command("%s %s", cmd2, local) != PRELIM) {
			pswitch(0);
			if (cpend)
				abort_remote((FILE *) NULL);
		}
		pswitch(1);
		if (ptabflg)
			code = -1;
		signal(SIGINT, oldintr);
		return;
	}
	if (cpend)
		abort_remote((FILE *) NULL);
	pswitch(!proxy);
	if (!cpend && !secndflag) {  /* only if cmd = "RETR" (proxy=1) */
		if (command("%s %s", cmd2, local) != PRELIM) {
			pswitch(0);
			if (cpend)
				abort_remote((FILE *) NULL);
			pswitch(1);
			if (ptabflg)
				code = -1;
			signal(SIGINT, oldintr);
			return;
		}
	}
	if (cpend)
		abort_remote((FILE *) NULL);
	pswitch(!proxy);
	if (cpend) {
		FD_ZERO(&mask);
		FD_SET(fileno(cin), &mask);
		if ((nfnd = empty(&mask, 10)) <= 0) {
			if (nfnd < 0) {
				error (0, errno, "abort");
			}
			if (ptabflg)
				code = -1;
			lostpeer();
		}
		getreply(0);
		getreply(0);
	}
	if (proxy)
		pswitch(0);
	pswitch(1);
	if (ptabflg)
		code = -1;
	signal(SIGINT, oldintr);
}

void
reset(argc, argv)
	int argc;
	char *argv[];
{
	fd_set mask;
	int nfnd = 1;

	FD_ZERO(&mask);
	while (nfnd > 0) {
		FD_SET(fileno(cin), &mask);
		if ((nfnd = empty(&mask,0)) < 0) {
			error (0, errno, "reset");
			code = -1;
			lostpeer();
		}
		else if (nfnd) {
			getreply(0);
		}
	}
}

char *
gunique(local)
	char *local;
{
	static char *new = 0;
	char *cp;
	int d, count=0;
	char ext = '1';

	if (new)
		free (new);
	new = malloc (strlen (local) + 1 + 3 + 1); /* '.' + 100 + '\0' */
	if (! new) {
		printf ("gunique: malloc failed.\n");
		return 0;
	}
	strcpy (new, local);

	cp = new + strlen(new);
	*cp++ = '.';
	for (;;) {
		struct stat st;

		if (++count == 100) {
 			printf("runique: can't find unique file name.\n");
			return ((char *) 0);
		}
		*cp++ = ext;
		*cp = '\0';
		if (ext == '9')
			ext = '0';
		else
			ext++;

		if (stat (new, &st) != 0)
		    if (errno == ENOENT)
				return new;
			else
			  	return 0;

		if (ext != '0')
			cp--;
		else if (*(cp - 2) == '.')
			*(cp - 1) = '1';
		else {
			*(cp - 2) = *(cp - 2) + 1;
			cp--;
		}
	}
}

void
abort_remote(din)
	FILE *din;
{
	char buf[BUFSIZ];
	int nfnd;
	fd_set mask;

	/*
	 * send IAC in urgent mode instead of DM because 4.3BSD places oob mark
	 * after urgent byte rather than before as is protocol now
	 */
	sprintf(buf, "%c%c%c", IAC, IP, IAC);
	if (send(fileno(cout), buf, 3, MSG_OOB) != 3)
		error (0, errno, "abort");
	fprintf(cout,"%cABOR\r\n", DM);
	fflush(cout);
	FD_ZERO(&mask);
	FD_SET(fileno(cin), &mask);
	if (din) {
		FD_SET(fileno(din), &mask);
	}
	if ((nfnd = empty(&mask, 10)) <= 0) {
		if (nfnd < 0) {
			error (0, errno, "abort");
		}
		if (ptabflg)
			code = -1;
		lostpeer();
	}
	if (din && FD_ISSET(fileno(din), &mask)) {
		while (read(fileno(din), buf, BUFSIZ) > 0)
			/* LOOP */;
	}
	if (getreply(0) == ERROR && code == 552) {
		/* 552 needed for nic style abort */
		getreply(0);
	}
	getreply(0);
}