[unix-history] / usr / src / libexec / tftpd / tftpd.c

/*	tftpd.c	4.3	82/10/08	*/

/*
 * Trivial file transfer protocol server.
 */
#include <sys/types.h>
#include <net/in.h>
#include <sys/socket.h>
#include <signal.h>
#include <sys/ioctl.h>
#include <stat.h>
#include <stdio.h>
#include <wait.h>
#include <errno.h>
#include <ctype.h>
#include <netdb.h>
#include "tftp.h"

extern	int errno;
struct	sockaddr_in sin = { AF_INET };
int	f;
int	options;
char	buf[BUFSIZ];

main(argc, argv)
	char *argv[];
{
	union wait status;
	struct sockaddr_in from;
	register struct tftphdr *tp;
	register int n;
	struct servent *sp;

	sp = getservbyname("tftp", "udp");
	if (sp == 0) {
		fprintf(stderr, "tftpd: udp/tftp: unknown service\n");
		exit(1);
	}
	sin.sin_port = htons(sp->s_port);
#ifndef DEBUG
	if (fork())
		exit(0);
	for (f = 0; f < 10; f++)
		(void) close(f);
	(void) open("/", 0);
	(void) dup2(0, 1);
	(void) dup2(0, 2);
	{ int t = open("/dev/tty", 2);
	  if (t >= 0) {
		ioctl(t, TIOCNOTTY, (char *)0);
		(void) close(t);
	  }
	}
#endif
	argc--, argv++;
	if (argc > 0 && !strcmp(argv[0], "-d"))
		options |= SO_DEBUG;
	for (;;) {
		errno = 0;
		f = socket(SOCK_DGRAM, 0, &sin, options);
		if (f < 0) {
			perror("socket");
			sleep(5);
			continue;
		}
again:
		n = receive(f, &from, buf, sizeof (buf));
		if (n <= 0) {
			if (n < 0)
				perror("receive");
			goto again;
		}
		tp = (struct tftphdr *)buf;
#if vax || pdp11
		tp->th_opcode = ntohs(tp->th_opcode);
#endif
		if (tp->th_opcode == RRQ || tp->th_opcode == WRQ)
			if (fork() == 0)
				tftp(&from, tp, n);
		(void) close(f);
#ifdef notdef
		while (wait3(status, WNOHANG, 0) > 0)
#else
		while (wait3(status, 0, 0) > 0)
			continue;
	}
}

int	validate_access();
int	sendfile(), recvfile();

struct formats {
	char	*f_mode;
	int	(*f_validate)();
	int	(*f_send)();
	int	(*f_recv)();
} formats[] = {
	{ "netascii",	validate_access,	sendfile,	recvfile },
	{ "octet",	validate_access,	sendfile,	recvfile },
#ifdef notdef
	{ "mail",	validate_user,		sendmail,	recvmail },
#endif
	{ 0 }
};

int	fd;			/* file being transferred */

/*
 * Handle initial connection protocol.
 */
tftp(client, tp, size)
	struct sockaddr_in *client;
	struct tftphdr *tp;
	int size;
{
	register char *cp;
	int first = 1, ecode;
	register struct formats *pf;
	char *filename, *mode;

	if (connect(f, client) < 0) {
		perror("connect");
		exit(1);
	}
	filename = cp = tp->th_stuff;
again:
	while (cp < buf + size) {
		if (*cp == '\0')
			break;
		cp++;
	}
	if (*cp != '\0') {
		nak(EBADOP);
		exit(1);
	}
	if (first) {
		mode = ++cp;
		first = 0;
		goto again;
	}
	for (cp = mode; *cp; cp++)
		if (isupper(*cp))
			*cp = tolower(*cp);
	for (pf = formats; pf->f_mode; pf++)
		if (strcmp(pf->f_mode, mode) == 0)
			break;
	if (pf->f_mode == 0) {
		nak(EBADOP);
		exit(1);
	}
	ecode = (*pf->f_validate)(filename, client, tp->th_opcode);
	if (ecode) {
		nak(ecode);
		exit(1);
	}
	if (tp->th_opcode == WRQ)
		(*pf->f_recv)(pf);
	else
		(*pf->f_send)(pf);
	exit(0);
}

/*
 * Validate file access.  Since we
 * have no uid or gid, for now require
 * file to exist and be publicly
 * readable/writable.
 * Note also, full path name must be
 * given as we have no login directory.
 */
validate_access(file, client, mode)
	char *file;
	struct sockaddr_in *client;
	int mode;
{
	struct stat stbuf;

	if (*file != '/')
		return (EACCESS);
	if (stat(file, &stbuf) < 0)
		return (errno == ENOENT ? ENOTFOUND : EACCESS);
	if (mode == RRQ) {
		if ((stbuf.st_mode&(S_IREAD >> 6)) == 0)
			return (EACCESS);
	} else {
		if ((stbuf.st_mode&(S_IWRITE >> 6)) == 0)
			return (EACCESS);
	}
	fd = open(file, mode == RRQ ? 0 : 1);
	if (fd < 0)
		return (errno + 100);
	return (0);
}

int timeout;

timer()
{
	timeout += TIMEOUT;
	if (timeout >= MAXTIMEOUT)
		exit(1);
	alarm(TIMEOUT);
}

/*
 * Send the requested file.
 */
sendfile(pf)
	struct format *pf;
{
	register struct tftphdr *tp;
	register int block = 1, size, n;

	sigset(SIGALRM, timer);
	tp = (struct tftphdr *)buf;
	do {
		size = read(fd, tp->th_data, SEGSIZE);
		if (size < 0) {
			nak(errno + 100);
			break;
		}
		tp->th_opcode = htons((u_short)DATA);
		tp->th_block = htons((u_short)block);
		timeout = 0;
		alarm(TIMEOUT);
rexmt:
		if (write(f, buf, size + 4) != size + 4) {
			perror("send");
			break;
		}
again:
		n = read(f, buf, sizeof (buf));
		if (n <= 0) {
			if (n == 0)
				goto again;
			if (errno == EINTR)
				goto rexmt;
			alarm(0);
			perror("receive");
			break;
		}
		alarm(0);
#if vax || pdp11
		tp->th_opcode = ntohs(tp->th_opcode);
		tp->th_block = ntohs(tp->th_block);
#endif
		if (tp->th_opcode == ERROR)
			break;
		if (tp->th_opcode != ACK || tp->th_block != block)
			goto again;
		block++;
	} while (size == SEGSIZE);
	(void) close(fd);
}

/*
 * Receive a file.
 */
recvfile(pf)
	struct format *pf;
{
	register struct tftphdr *tp;
	register int block = 0, n, size;

	sigset(SIGALRM, timer);
	tp = (struct tftphdr *)buf;
	do {
		timeout = 0;
		alarm(TIMEOUT);
		tp->th_opcode = htons((u_short)ACK);
		tp->th_block = htons((u_short)block);
		block++;
rexmt:
		if (write(f, buf, 4) != 4) {
			perror("ack");
			break;
		}
again:
		n = read(f, buf, sizeof (buf));
		if (n <= 0) {
			if (n == 0)
				goto again;
			if (errno == EINTR)
				goto rexmt;
			alarm(0);
			perror("receive");
			break;
		}
		alarm(0);
#if vax || pdp11
		tp->th_opcode = ntohs(tp->th_opcode);
		tp->th_block = ntohs(tp->th_block);
#endif
		if (tp->th_opcode == ERROR)
			break;
		if (tp->th_opcode != DATA || block != tp->th_block)
			goto again;
		size = write(fd, tp->th_data, n - 4);
		if (size < 0) {
			nak(errno + 100);
			break;
		}
	} while (size == SEGSIZE);
	tp->th_opcode = htons((u_short)ACK);
	tp->th_block = htons((u_short)(block));
	(void) write(f, buf, 4);
	(void) close(fd);
}

struct errmsg {
	int	e_code;
	char	*e_msg;
} errmsgs[] = {
	{ EUNDEF,	"Undefined error code" },
	{ ENOTFOUND,	"File not found" },
	{ EACCESS,	"Access violation" },
	{ ENOSPACE,	"Disk full or allocation exceeded" },
	{ EBADOP,	"Illegal TFTP operation" },
	{ EBADID,	"Unknown transfer ID" },
	{ EEXISTS,	"File already exists" },
	{ ENOUSER,	"No such user" },
	{ -1,		0 }
};

/*
 * Send a nak packet (error message).
 * Error code passed in is one of the
 * standard TFTP codes, or a UNIX errno
 * offset by 100.
 */
nak(error)
	int error;
{
	register struct tftphdr *tp;
	int length;
	register struct errmsg *pe;
	extern char *sys_errlist[];

	tp = (struct tftphdr *)buf;
	tp->th_opcode = htons((u_short)ERROR);
	tp->th_code = htons((u_short)error);
	for (pe = errmsgs; pe->e_code >= 0; pe++)
		if (pe->e_code == error)
			break;
	if (pe->e_code < 0)
		pe->e_msg = sys_errlist[error - 100];
	strcpy(tp->th_msg, pe->e_msg);
	length = strlen(pe->e_msg);
	tp->th_msg[length] = '\0';
	length += 5;
	if (write(f, buf, length) != length)
		perror("nak");
}
Commit	Line	Data
4d5e33bd	1	/* tftpd.c 4.3 82/10/08 */
f8675e8e SL	2
	3	/*
	4	* Trivial file transfer protocol server.
	5	*/
	6	#include <sys/types.h>
	7	#include <net/in.h>
	8	#include <sys/socket.h>
	9	#include <signal.h>
	10	#include <sys/ioctl.h>
	11	#include <stat.h>
	12	#include <stdio.h>
	13	#include <wait.h>
	14	#include <errno.h>
	15	#include <ctype.h>
4d5e33bd	16	#include <netdb.h>
f8675e8e SL	17	#include "tftp.h"
f8675e8e SL	18
f8675e8e	19	extern int errno;
4d5e33bd	20	struct sockaddr_in sin = { AF_INET };
f8675e8e SL	21	int f;
	22	int options;
	23	char buf[BUFSIZ];
	24
	25	main(argc, argv)
	26	char *argv[];
	27	{
	28	union wait status;
	29	struct sockaddr_in from;
	30	register struct tftphdr *tp;
	31	register int n;
4d5e33bd	32	struct servent *sp;
f8675e8e	33
4d5e33bd SL	34	sp = getservbyname("tftp", "udp");
	35	if (sp == 0) {
	36	fprintf(stderr, "tftpd: udp/tftp: unknown service\n");
	37	exit(1);
	38	}
	39	sin.sin_port = htons(sp->s_port);
f8675e8e SL	40	#ifndef DEBUG
	41	if (fork())
	42	exit(0);
	43	for (f = 0; f < 10; f++)
	44	(void) close(f);
	45	(void) open("/", 0);
	46	(void) dup2(0, 1);
	47	(void) dup2(0, 2);
	48	{ int t = open("/dev/tty", 2);
	49	if (t >= 0) {
	50	ioctl(t, TIOCNOTTY, (char *)0);
	51	(void) close(t);
	52	}
	53	}
f8675e8e SL	54	#endif
	55	argc--, argv++;
	56	if (argc > 0 && !strcmp(argv[0], "-d"))
	57	options \|= SO_DEBUG;
	58	for (;;) {
	59	errno = 0;
	60	f = socket(SOCK_DGRAM, 0, &sin, options);
	61	if (f < 0) {
	62	perror("socket");
	63	sleep(5);
	64	continue;
	65	}
	66	again:
	67	n = receive(f, &from, buf, sizeof (buf));
	68	if (n <= 0) {
	69	if (n < 0)
	70	perror("receive");
	71	goto again;
	72	}
	73	tp = (struct tftphdr *)buf;
	74	#if vax \|\| pdp11
	75	tp->th_opcode = ntohs(tp->th_opcode);
	76	#endif
	77	if (tp->th_opcode == RRQ \|\| tp->th_opcode == WRQ)
	78	if (fork() == 0)
	79	tftp(&from, tp, n);
	80	(void) close(f);
	81	#ifdef notdef
	82	while (wait3(status, WNOHANG, 0) > 0)
	83	#else
	84	while (wait3(status, 0, 0) > 0)
	85	continue;
	86	}
	87	}
	88
	89	int validate_access();
	90	int sendfile(), recvfile();
	91
	92	struct formats {
	93	char *f_mode;
	94	int (*f_validate)();
	95	int (*f_send)();
	96	int (*f_recv)();
	97	} formats[] = {
	98	{ "netascii", validate_access, sendfile, recvfile },
	99	{ "octet", validate_access, sendfile, recvfile },
	100	#ifdef notdef
	101	{ "mail", validate_user, sendmail, recvmail },
	102	#endif
	103	{ 0 }
	104	};
	105
	106	int fd; /* file being transferred */
	107
	108	/*
	109	* Handle initial connection protocol.
	110	*/
	111	tftp(client, tp, size)
	112	struct sockaddr_in *client;
	113	struct tftphdr *tp;
	114	int size;
	115	{
	116	register char *cp;
	117	int first = 1, ecode;
118	register struct formats *pf;
119	char filename, mode;
120
121	if (connect(f, client) < 0) {
122	perror("connect");
123	exit(1);
124	}
125	filename = cp = tp->th_stuff;
126	again:
127	while (cp < buf + size) {
128	if (*cp == '\0')
129	break;
130	cp++;
131	}
132	if (*cp != '\0') {
133	nak(EBADOP);
134	exit(1);
135	}
136	if (first) {
137	mode = ++cp;
138	first = 0;
139	goto again;
140	}
141	for (cp = mode; *cp; cp++)
142	if (isupper(*cp))
143	cp = tolower(cp);
144	for (pf = formats; pf->f_mode; pf++)
145	if (strcmp(pf->f_mode, mode) == 0)
146	break;
147	if (pf->f_mode == 0) {
148	nak(EBADOP);
149	exit(1);
150	}
151	ecode = (*pf->f_validate)(filename, client, tp->th_opcode);
152	if (ecode) {
153	nak(ecode);
154	exit(1);
155	}
156	if (tp->th_opcode == WRQ)
157	(*pf->f_recv)(pf);
158	else
159	(*pf->f_send)(pf);
160	exit(0);
161	}
162
163	/*
164	* Validate file access. Since we
165	* have no uid or gid, for now require
166	* file to exist and be publicly
167	* readable/writable.
168	* Note also, full path name must be
169	* given as we have no login directory.
170	*/
171	validate_access(file, client, mode)
172	char *file;
173	struct sockaddr_in *client;
174	int mode;
175	{
176	struct stat stbuf;
177
178	if (*file != '/')
179	return (EACCESS);
180	if (stat(file, &stbuf) < 0)
181	return (errno == ENOENT ? ENOTFOUND : EACCESS);
182	if (mode == RRQ) {
183	if ((stbuf.st_mode&(S_IREAD >> 6)) == 0)
184	return (EACCESS);
185	} else {
186	if ((stbuf.st_mode&(S_IWRITE >> 6)) == 0)
187	return (EACCESS);
188	}
189	fd = open(file, mode == RRQ ? 0 : 1);
190	if (fd < 0)
191	return (errno + 100);
192	return (0);
193	}
194
195	int timeout;
196
197	timer()
198	{
199	timeout += TIMEOUT;
200	if (timeout >= MAXTIMEOUT)
201	exit(1);
202	alarm(TIMEOUT);
203	}
204
205	/*
206	* Send the requested file.
207	*/
208	sendfile(pf)
209	struct format *pf;
210	{
211	register struct tftphdr *tp;
212	register int block = 1, size, n;
213
214	sigset(SIGALRM, timer);
215	tp = (struct tftphdr *)buf;
216	do {
217	size = read(fd, tp->th_data, SEGSIZE);
218	if (size < 0) {
219	nak(errno + 100);
220	break;
221	}
222	tp->th_opcode = htons((u_short)DATA);
223	tp->th_block = htons((u_short)block);
224	timeout = 0;
225	alarm(TIMEOUT);
226	rexmt:
227	if (write(f, buf, size + 4) != size + 4) {
228	perror("send");
229	break;
230	}
231	again:
232	n = read(f, buf, sizeof (buf));
233	if (n <= 0) {
234	if (n == 0)
235	goto again;
236	if (errno == EINTR)
237	goto rexmt;
238	alarm(0);
239	perror("receive");
240	break;
241	}
242	alarm(0);
243	#if vax \|\| pdp11
244	tp->th_opcode = ntohs(tp->th_opcode);
245	tp->th_block = ntohs(tp->th_block);
246	#endif
247	if (tp->th_opcode == ERROR)
248	break;
249	if (tp->th_opcode != ACK \|\| tp->th_block != block)
250	goto again;
251	block++;
252	} while (size == SEGSIZE);
253	(void) close(fd);
254	}
255
256	/*
257	* Receive a file.
258	*/
259	recvfile(pf)
260	struct format *pf;
261	{
262	register struct tftphdr *tp;
263	register int block = 0, n, size;
264
265	sigset(SIGALRM, timer);
266	tp = (struct tftphdr *)buf;
267	do {
268	timeout = 0;
269	alarm(TIMEOUT);
270	tp->th_opcode = htons((u_short)ACK);
271	tp->th_block = htons((u_short)block);
272	block++;
273	rexmt:
274	if (write(f, buf, 4) != 4) {
275	perror("ack");
276	break;
277	}
278	again:
279	n = read(f, buf, sizeof (buf));
280	if (n <= 0) {
281	if (n == 0)
282	goto again;
283	if (errno == EINTR)
284	goto rexmt;
285	alarm(0);
286	perror("receive");
287	break;
288	}
289	alarm(0);
290	#if vax \|\| pdp11
291	tp->th_opcode = ntohs(tp->th_opcode);
292	tp->th_block = ntohs(tp->th_block);
293	#endif
294	if (tp->th_opcode == ERROR)
295	break;
296	if (tp->th_opcode != DATA \|\| block != tp->th_block)
297	goto again;
298	size = write(fd, tp->th_data, n - 4);
299	if (size < 0) {
300	nak(errno + 100);
301	break;
302	}
303	} while (size == SEGSIZE);
304	tp->th_opcode = htons((u_short)ACK);
305	tp->th_block = htons((u_short)(block));
306	(void) write(f, buf, 4);
307	(void) close(fd);
308	}
309
310	struct errmsg {
311	int e_code;
312	char *e_msg;
313	} errmsgs[] = {
314	{ EUNDEF, "Undefined error code" },
315	{ ENOTFOUND, "File not found" },
316	{ EACCESS, "Access violation" },
317	{ ENOSPACE, "Disk full or allocation exceeded" },
318	{ EBADOP, "Illegal TFTP operation" },
319	{ EBADID, "Unknown transfer ID" },
320	{ EEXISTS, "File already exists" },
321	{ ENOUSER, "No such user" },
322	{ -1, 0 }
323	};
324
325	/*
326	* Send a nak packet (error message).
327	* Error code passed in is one of the
328	* standard TFTP codes, or a UNIX errno
329	* offset by 100.
330	*/
331	nak(error)
332	int error;
333	{
334	register struct tftphdr *tp;
335	int length;
336	register struct errmsg *pe;
337	extern char *sys_errlist[];
338
339	tp = (struct tftphdr *)buf;
340	tp->th_opcode = htons((u_short)ERROR);
341	tp->th_code = htons((u_short)error);
342	for (pe = errmsgs; pe->e_code >= 0; pe++)
343	if (pe->e_code == error)
344	break;
345	if (pe->e_code < 0)
346	pe->e_msg = sys_errlist[error - 100];
347	strcpy(tp->th_msg, pe->e_msg);
348	length = strlen(pe->e_msg);
349	tp->th_msg[length] = '\0';
350	length += 5;
351	if (write(f, buf, length) != length)
352	perror("nak");
353	}