ftpd.c

来自「<B>Digital的Unix操作系统VAX 4.2源码</B>」· C语言 代码 · 共 1,298 行 · 第 1/2 页

 * encapulation of the date subject
 * to Mode, Structure, and Type.
 *
 * NB: Form isn't handled.
 */
send_data(instr, outstr)
	FILE *instr, *outstr;
{
	register int c;
	int netfd, filefd, cnt;
	char buf[BUFSIZ];

	transflag++;
	if (setjmp(urgcatch)) {
		transflag = 0;
		return(-1);
	}
	switch (type) {

	case TYPE_A:
		while ((c = getc(instr)) != EOF) {
			if (c == '\n') {
				if (ferror (outstr)) {
					transflag = 0;
					return (1);
				}
				(void) putc('\r', outstr);
			}
			(void) putc(c, outstr);
		/*	if (c == '\r')			*/
		/*		putc ('\0', outstr);	*/
		}
		transflag = 0;
		if (ferror (instr) || ferror (outstr)) {
			return (1);
		}
		return (0);
		
	case TYPE_I:
	case TYPE_L:
		netfd = fileno(outstr);
		filefd = fileno(instr);

		while ((cnt = read(filefd, buf, sizeof (buf))) > 0) {
			if (write(netfd, buf, cnt) < 0) {
				transflag = 0;
				return (1);
			}
		}
		transflag = 0;
		return (cnt < 0);
	}
	reply(550, "Unimplemented TYPE %d in send_data", type);
	transflag = 0;
	return (-1);
}

/*
 * Transfer data from peer to
 * "outstr" using the appropriate
 * encapulation of the data subject
 * to Mode, Structure, and Type.
 *
 * N.B.: Form isn't handled.
 */
receive_data(instr, outstr)
	FILE *instr, *outstr;
{
	register int c;
	int cnt;
	char buf[BUFSIZ];


	transflag++;
	if (setjmp(urgcatch)) {
		transflag = 0;
		return(-1);
	}
	switch (type) {

	case TYPE_I:
	case TYPE_L:
		while ((cnt = read(fileno(instr), buf, sizeof buf)) > 0) {
			if (write(fileno(outstr), buf, cnt) < 0) {
				transflag = 0;
				return (1);
			}
		}
		transflag = 0;
		return (cnt < 0);

	case TYPE_E:
		reply(553, "TYPE E not implemented.");
		transflag = 0;
		return (-1);

	case TYPE_A:
		while ((c = getc(instr)) != EOF) {
			while (c == '\r') {
				if (ferror (outstr)) {
					transflag = 0;
					return (1);
				}
				if ((c = getc(instr)) != '\n')
					(void) putc ('\r', outstr);
			/*	if (c == '\0')			*/
			/*		continue;		*/
			}
			(void) putc (c, outstr);
		}
		transflag = 0;
		if (ferror (instr) || ferror (outstr))
			return (1);
		return (0);
	}
	transflag = 0;
	fatal("Unknown type in receive_data.");
	/*NOTREACHED*/
}

fatal(s)
	char *s;
{
	reply(451, "Error in server: %s\n", s);
	reply(221, "Closing connection due to server error.");
	dologout(0);
}

reply(va_alist)
va_dcl
{
	va_list args;
	int n;
	char *s;

	va_start(args);
	n = va_arg(args, int);
	s = va_arg(args, char *);
	sprintf(aud_msg, "%d ", n);
	vsprintf(aud_msg+strlen(aud_msg), s, args);
	fputs(aud_msg, stdout);
	puts("\r");
	(void) fflush(stdout);
	if (debug) {
		char buf[BUFSIZ];

		syslog(LOG_DEBUG, "<--- %d ", n);
		vsprintf(buf, s, args);
		syslog(LOG_DEBUG, buf);
	}
}

lreply(va_alist)
va_dcl
{
	va_list args;
	int n;
	char *s;

	va_start(args);
	n = va_arg(args, int);
	s = va_arg(args, char *);
	sprintf(aud_msg, "%d-", n);
	vsprintf(aud_msg+strlen(aud_msg), s, args);
	fputs(aud_msg, stdout);
	puts("\r");
	(void) fflush(stdout);
	if (debug) {
		char buf[BUFSIZ];

		syslog(LOG_DEBUG, "<--- %d- ", n);
		vsprintf(buf, s, args);
		syslog(LOG_DEBUG, buf);
	}
}

ack(s)
	char *s;
{
	reply(250, "%s command successful.", s);
}

nack(s)
	char *s;
{
	reply(502, "%s command not implemented.", s);
}

yyerror(s)
	char *s;
{
	char *cp;

	cp = index(cbuf,'\n');
	*cp = '\0';
	reply(500, "'%s': command not understood.",cbuf);
}

delete(name)
	char *name;
{
	struct stat st;

	if (stat(name, &st) < 0) {
		reply(550, "%s: %s.", name, sys_errlist[errno]);
		return;
	}
	if ((st.st_mode&S_IFMT) == S_IFDIR) {
		if (rmdir(name) < 0) {
			reply(550, "%s: %s.", name, sys_errlist[errno]);
			return;
		}
		goto done;
	}
	if (unlink(name) < 0) {
		reply(550, "%s: %s.", name, sys_errlist[errno]);
		return;
	}
done:
	ack("DELE");
}

cwd(path)
	char *path;
{

	if (chdir(path) < 0) {
		reply(550, "%s: %s.", path, sys_errlist[errno]);
		return;
	}
	ack("CWD");
}

makedir(name)
	char *name;
{
	struct stat st;
	int dochown = stat(name, &st) < 0;
	
	if (mkdir(name, 0777) < 0) {
		reply(550, "%s: %s.", name, sys_errlist[errno]);
		return;
	}
	if (dochown)
		(void) chown(name, pw->pw_uid, -1);
	reply(257, "MKD command successful.");
}

removedir(name)
	char *name;
{

	if (rmdir(name) < 0) {
		reply(550, "%s: %s.", name, sys_errlist[errno]);
		return;
	}
	ack("RMD");
}

pwd()
{
	char path[MAXPATHLEN + 1];

	if (getwd(path) == NULL) {
		reply(550, "%s.", path);
		return;
	}
	reply(257, "\"%s\" is current directory.", path);
}

char *
renamefrom(name)
	char *name;
{
	struct stat st;

	if (stat(name, &st) < 0) {
		reply(550, "%s: %s.", name, sys_errlist[errno]);
		return ((char *)0);
	}
	reply(350, "File exists, ready for destination name");
	return (name);
}

renamecmd(from, to)
	char *from, *to;
{

	if (rename(from, to) < 0) {
		reply(550, "rename: %s.", sys_errlist[errno]);
		return;
	}
	ack("RNTO");
}

dolog(sin)
	struct sockaddr_in *sin;
{
	struct hostent *hp = gethostbyaddr(&sin->sin_addr,
		sizeof (struct in_addr), AF_INET);
	time_t t;
	extern char *ctime();
	char *ti;
	char st[80];

	if (hp) {
		(void) strncpy(remotehost, hp->h_name, sizeof (remotehost));
		endhostent();
	} else
		(void) strncpy(remotehost, inet_ntoa(sin->sin_addr),
		    sizeof (remotehost));
	if (!logging)
		return;
	t = time((time_t *) 0);
	ti = ctime(&t);
	strncpy(st,ti,strlen(ti)-1); /* get rid of CR */
	syslog(LOG_INFO,"FTPD: connection from %s at %s", remotehost, st);
}

#include <utmp.h>

#define	SCPYN(a, b)	(void) strncpy(a, b, sizeof (a))
struct	utmp utmp;

/*
 * Record login in wtmp file.
 */
dologin(p)
	struct passwd *p;
{
	char line[32];

	if (wtmp >= 0) {
		/* hack, but must be unique and no tty line */
		(void) sprintf(line, "ftp%d", getpid());
		SCPYN(utmp.ut_line, line);
		SCPYN(utmp.ut_name, p->pw_name);
		SCPYN(utmp.ut_host, remotehost);
		utmp.ut_time = (long) time((time_t *) 0);
		(void) write(wtmp, (char *)&utmp, sizeof (utmp));
		if (!guest) {		/* anon must hang on */
			(void) close(wtmp);
			wtmp = -1;
		}
	}
}

/*
 * Record logout in wtmp file
 * and exit with supplied status.
 */
dologout(status)
	int status;
{

	if (logged_in) {
		(void) seteuid(0);
		if (wtmp < 0)
			wtmp = open("/usr/adm/wtmp", O_WRONLY|O_APPEND);
		if (wtmp >= 0) {
			SCPYN(utmp.ut_name, "");
			SCPYN(utmp.ut_host, "");
			utmp.ut_time = (long) time((time_t *) 0);
			(void) write(wtmp, (char *)&utmp, sizeof (utmp));
			(void) close(wtmp);
		}
	}
	/* beware of flushing buffers after a SIGPIPE */
	_exit(status);
}

/*
 * Special version of popen which avoids
 * call to shell.  This insures noone may 
 * create a pipe to a hidden program as a side
 * effect of a list or dir command.
 */
#define	tst(a,b)	(*mode == 'r'? (b) : (a))
#define	RDR	0
#define	WTR	1
static	int popen_pid[5];

static char *
nextarg(cpp)
	char *cpp;
{
	register char *cp = cpp;

	if (cp == 0)
		return (cp);
	while (*cp && *cp != ' ' && *cp != '\t')
		cp++;
	if (*cp == ' ' || *cp == '\t') {
		*cp++ = '\0';
		while (*cp == ' ' || *cp == '\t')
			cp++;
	}
	if (cp == cpp)
		return ((char *)0);
	return (cp);
}

FILE *
popen(cmd, mode)
	char *cmd, *mode;
{
	int p[2], ac, gac;
	register myside, hisside, pid;
	char *av[20], *gav[512];
	register char *cp;

	if (pipe(p) < 0)
		return (NULL);
	cp = cmd, ac = 0;
	/* break up string into pieces */
	do {
		av[ac++] = cp;
		cp = nextarg(cp);
	} while (cp && *cp && ac < 20);
	av[ac] = (char *)0;
	gav[0] = av[0];
	/* glob each piece */
	for (gac = ac = 1; av[ac] != NULL; ac++) {
		char **pop;
		extern char **glob(), **copyblk();

		pop = glob(av[ac]);
		if (pop == (char **)NULL) {	/* globbing failed */
			char *vv[2];

			vv[0] = av[ac];
			vv[1] = 0;
			pop = copyblk(vv);
		}
		av[ac] = (char *)pop;		/* save to free later */
		while (*pop && gac < 512)
			gav[gac++] = *pop++;
	}
	gav[gac] = (char *)0;
	myside = tst(p[WTR], p[RDR]);
	hisside = tst(p[RDR], p[WTR]);
	if ((pid = fork()) == 0) {
		/* myside and hisside reverse roles in child */
		(void) close(myside);
		(void) dup2(hisside, tst(0, 1));
		(void) close(hisside);
		execv(gav[0], gav);
		_exit(1);
	}
	for (ac = 1; av[ac] != NULL; ac++)
		blkfree((char **)av[ac]);
	if (pid == -1)
		return (NULL);
	popen_pid[myside] = pid;
	(void) close(hisside);
	return (fdopen(myside, mode));
}

pclose(ptr)
	FILE *ptr;
{
	register f, r;
	register void (*hstat)(), (*istat)(), (*qstat)();
	int status;

	f = fileno(ptr);
	(void) fclose(ptr);
	istat = signal(SIGINT, SIG_IGN);
	qstat = signal(SIGQUIT, SIG_IGN);
	hstat = signal(SIGHUP, SIG_IGN);
	while ((r = wait(&status)) != popen_pid[f] && r != -1)
		;
	if (r == -1)
		status = -1;
	(void) signal(SIGINT, istat);
	(void) signal(SIGQUIT, qstat);
	(void) signal(SIGHUP, hstat);
	return (status);
}

/*
 * Check user requesting login priviledges.
 * Disallow anyone who does not have a standard
 * shell returned by getusershell() (/etc/shells).
 * Disallow anyone mentioned in the file FTPUSERS
 * to allow people such as uucp to be avoided.
 */
checkuser(name)
	register char *name;
{
	register char *cp;
	FILE *fd;
	struct passwd *p;
	char *shell;
	int found = 0;
	char line[BUFSIZ], *index(), *getusershell();

	if ((p = getpwnam(name)) == NULL)
		return (0);
	if ((shell = p->pw_shell) == NULL || *shell == 0)
		shell = "/bin/sh";
#ifdef 43BSD
	while ((cp = getusershell()) != NULL)
		if (strcmp(cp, shell) == 0)
			break;
	endusershell();
#else
	endpwent();
#endif 43BSD
	if (cp == NULL)
		return (0);
	if ((fd = fopen(FTPUSERS, "r")) == NULL)
		return (1);
	while (fgets(line, sizeof (line), fd) != NULL) {
		if ((cp = index(line, '\n')) != NULL)
			*cp = '\0';
		if (strcmp(line, name) == 0) {
			found++;
			break;
		}
	}
	(void) fclose(fd);
	return (!found);
}

void
myoob()
{
	char *cp;

	/* only process if transfer occurring */
	if (!transflag) {
		return;
	}
	cp = tmpline;
	if (getline(cp, 7, stdin) == NULL) {
		reply(221, "You could at least say goodby.");
		dologout(0);
	}
	upper(cp);
	if (strcmp(cp, "ABOR\r\n"))
		return;
	tmpline[0] = '\0';
	reply(426,"Transfer aborted. Data connection closed.");
	reply(226,"Abort successful");
	longjmp(urgcatch, 1);
}

/*
 * Note: The 530 reply codes could be 4xx codes, except nothing is
 * given in the state tables except 421 which implies an exit.  (RFC959)
 */
passive()
{
	int len;
	struct sockaddr_in tmp;
	register char *p, *a;

	pdata = socket(AF_INET, SOCK_STREAM, 0);
	if (pdata < 0) {
		reply(530, "Can't open passive connection");
		return;
	}
	tmp = ctrl_addr;
	tmp.sin_port = 0;
	seteuid(0);
	if (bind(pdata, (struct sockaddr *) &tmp, sizeof(tmp)) < 0) {
		seteuid(pw->pw_uid);
		(void) close(pdata);
		pdata = -1;
		reply(530, "Can't open passive connection");
		return;
	}
	seteuid(pw->pw_uid);
	len = sizeof(tmp);
	if (getsockname(pdata, (char *) &tmp, &len) < 0) {
		(void) close(pdata);
		pdata = -1;
		reply(530, "Can't open passive connection");
		return;
	}
	if (listen(pdata, 1) < 0) {
		(void) close(pdata);
		pdata = -1;
		reply(530, "Can't open passive connection");
		return;
	}
	a = (char *) &tmp.sin_addr;
	p = (char *) &tmp.sin_port;

#define UC(b) (((int) b) & 0xff)

	reply(227, "Entering Passive Mode (%d,%d,%d,%d,%d,%d)", UC(a[0]),
		UC(a[1]), UC(a[2]), UC(a[3]), UC(p[0]), UC(p[1]));
}

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

	if (cp) {
		*cp = '\0';
	}
	d = access(cp ? local : ".", 2);
	if (cp) {
		*cp = '/';
	}
	if (d < 0) {
		syslog(LOG_ERR, "%s: %m", local);
		return((char *) 0);
	}
	(void) strcpy(new, local);
	cp = new + strlen(new);
	*cp++ = '.';
	while (!d) {
		if (++count == 100) {
			reply(452, "Unique file name not cannot be created.");
			return((char *) 0);
		}
		*cp++ = ext;
		*cp = '\0';
		if (ext == '9') {
			ext = '0';
		}
		else {
			ext++;
		}
		if ((d = access(new, 0)) < 0) {
			break;
		}
		if (ext != '0') {
			cp--;
		}
		else if (*(cp - 2) == '.') {
			*(cp - 1) = '1';
		}
		else {
			*(cp - 2) = *(cp - 2) + 1;
			cp--;
		}
	}
	return(new);
}