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rcsid[] and sccsid[] and copyright[] are essentially unmaintained (and
unmaintainable).  these days, people use source.  these id's do not provide
any benefit, and do hurt the small install media
(the 33,000 line diff is essentially mechanical)
ok with the idea millert, ok dms

/*	$OpenBSD: server.c,v 1.32 2009/10/27 23:59:41 deraadt Exp $	*/

/*
 * Copyright (c) 1983, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/wait.h>

#include <stdarg.h>
#include <libgen.h>

#include "defs.h"

#define	ack() 	(void) write(rem, "\0\n", 2)
#define	err() 	(void) write(rem, "\1\n", 2)

struct	linkbuf *ihead;		/* list of files with more than one link */
char	buf[BUFSIZ];		/* general purpose buffer */
char	target[BUFSIZ];		/* target/source directory name */
char	source[BUFSIZ];		/* source directory name */
char	*tp;			/* pointer to end of target name */
char	*Tdest;			/* pointer to last T dest*/
int	catname;		/* cat name to target name */
char	*stp[32];		/* stack of saved tp's for directories */
int	oumask;			/* old umask for creating files */

extern	FILE *lfp;		/* log file for mailing changes */

static int	chkparent(char *);
static void	clean(char *);
static void	comment(char *);
static void	dospecial(char *);
static int	fchog(int, char *, char *, char *, int);
static void	hardlink(char *);
static void	note(const char *, ...);
static void	query(char *);
static void	recvf(char *, int);
static void	removeit(struct stat *);
static int	response(void);
static void	rmchk(int);
static struct linkbuf *
		    savelink(struct stat *);
static void	sendf(char *, int);
static int	update(char *, int, struct stat *);

/*
 * Server routine to read requests and process them.
 * Commands are:
 *	Tname	- Transmit file if out of date
 *	Vname	- Verify if file out of date or not
 *	Qname	- Query if file exists. Return mtime & size if it does.
 */
void
server()
{
	char cmdbuf[BUFSIZ];
	char *cp;

	signal(SIGHUP, cleanup);
	signal(SIGINT, cleanup);
	signal(SIGQUIT, cleanup);
	signal(SIGTERM, cleanup);
	signal(SIGPIPE, cleanup);

	rem = 0;
	oumask = umask(0);
	(void) snprintf(buf, sizeof(buf), "V%d\n", VERSION);
	(void) write(rem, buf, strlen(buf));

#if	!defined(DIRECT_RCMD)
	if (getuid() != geteuid()) {
		error("This version of rdist should not be installed setuid.\n");
		return;
	}
#endif	/* DIRECT_RCMD */

	for (;;) {
		cp = cmdbuf;
		if (read(rem, cp, 1) <= 0)
			return;
		if (*cp++ == '\n') {
			error("server: expected control record\n");
			continue;
		}
		do {
			if (read(rem, cp, 1) != 1)
				cleanup(0);
		} while (*cp++ != '\n' && cp < &cmdbuf[BUFSIZ]);
		*--cp = '\0';
		cp = cmdbuf;
		switch (*cp++) {
		case 'T':  /* init target file/directory name */
			catname = 1;	/* target should be directory */
			goto dotarget;

		case 't':  /* init target file/directory name */
			catname = 0;
		dotarget:
			if (exptilde(target, cp, sizeof (target)) == NULL)
				continue;
			tp = target;
			while (*tp)
				tp++;
			ack();
			continue;

		case 'R':  /* Transfer a regular file. */
			recvf(cp, S_IFREG);
			continue;

		case 'D':  /* Transfer a directory. */
			recvf(cp, S_IFDIR);
			continue;

		case 'K':  /* Transfer symbolic link. */
			recvf(cp, S_IFLNK);
			continue;

		case 'k':  /* Transfer hard link. */
			hardlink(cp);
			continue;

		case 'E':  /* End. (of directory) */
			*tp = '\0';
			if (catname <= 0) {
				error("server: too many 'E's\n");
				continue;
			}
			tp = stp[--catname];
			*tp = '\0';
			ack();
			continue;

		case 'C':  /* Clean. Cleanup a directory */
			clean(cp);
			continue;

		case 'Q':  /* Query. Does the file/directory exist? */
			query(cp);
			continue;

		case 'S':  /* Special. Execute commands */
			dospecial(cp);
			continue;

#ifdef notdef
		/*
		 * These entries are reserved but not currently used.
		 * The intent is to allow remote hosts to have master copies.
		 * Currently, only the host rdist runs on can have masters.
		 */
		case 'X':  /* start a new list of files to exclude */
			except = bp = NULL;
		case 'x':  /* add name to list of files to exclude */
			if (*cp == '\0') {
				ack();
				continue;
			}
			if (*cp == '~') {
				if (exptilde(buf, cp, sizeof (buf)) == NULL)
					continue;
				cp = buf;
			}
			if (bp == NULL)
				except = bp = expand(makeblock(NAME, cp), E_VARS);
			else
				bp->b_next = expand(makeblock(NAME, cp), E_VARS);
			while (bp->b_next != NULL)
				bp = bp->b_next;
			ack();
			continue;

		case 'I':  /* Install. Transfer file if out of date. */
			opts = 0;
			while (*cp >= '0' && *cp <= '7')
				opts = (opts << 3) | (*cp++ - '0');
			if (*cp++ != ' ') {
				error("server: options not delimited\n");
				return;
			}
			install(cp, opts);
			continue;

		case 'L':  /* Log. save message in log file */
			logit(lfp, "%s", cp);
			continue;
#endif

		case '\1':
			nerrs++;
			continue;

		case '\2':
			return;

		default:
			error("server: unknown command '%s'\n", cp);
		case '\0':
			continue;
		}
	}
}

/*
 * Update the file(s) if they are different.
 * destdir = 1 if destination should be a directory
 * (i.e., more than one source is being copied to the same destination).
 */
void
install(src, dest, destdir, opts)
	char *src, *dest;
	int destdir, opts;
{
	char *rname;
	char destcopy[BUFSIZ];

	if (opts & WHOLE)
		source[0] = '\0';
	else
		strlcpy(source, src, sizeof source);

	if (dest == NULL) {
		opts &= ~WHOLE; /* WHOLE mode only useful if renaming */
		dest = src;
	}

	if (nflag || debug) {
		printf("%s%s%s%s%s %s %s\n", opts & VERIFY ? "verify":"install",
			opts & WHOLE ? " -w" : "",
			opts & YOUNGER ? " -y" : "",
			opts & COMPARE ? " -b" : "",
			opts & REMOVE ? " -R" : "", src, dest);
		if (nflag)
			return;
	}

	rname = exptilde(target, src, sizeof(target));
	if (rname == NULL)
		return;
	tp = target;
	while (*tp)
		tp++;
	/*
	 * If we are renaming a directory and we want to preserve
	 * the directory hierarchy (-w), we must strip off the leading
	 * directory name and preserve the rest.
	 */
	if (opts & WHOLE) {
		while (*rname == '/')
			rname++;
		destdir = 1;
	} else {
		rname = basename(target);
	}
	if (debug)
		printf("target = %s, rname = %s\n", target, rname);
	/*
	 * Pass the destination file/directory name to remote.
	 */
	(void) snprintf(buf, sizeof(buf), "%c%s\n", destdir ? 'T' : 't', dest);
	if (debug)
		printf("buf = %s", buf);
	(void) write(rem, buf, strlen(buf));
	if (response() < 0)
		return;

	/*
	 * Save the name of the remote target destination if we are
	 * in WHOLE mode (destdir > 0) or if the source and destination
	 * are not the same.  This info will be used later for maintaining
	 * hardlink info.
	 */
	if (destdir || (src && dest && strcmp(src, dest))) {
		strlcpy(destcopy, dest, sizeof destcopy);
		Tdest = destcopy;
	}
	sendf(rname, opts);
	Tdest = 0;
}

static char *
remotename(pathname, src)
	char *pathname;
	char *src;
{
	char *cp;
	int len;

	cp = pathname;
	len = strlen(src);
	if (0 == strncmp(pathname, src, len))
	        cp += len;
	if (*cp == '/')
	        cp ++;
	return(cp);
}

void
installlink(lp, rname, opts)
	struct linkbuf *lp;
	char *rname;
	int opts;
{
	if (*lp->target == 0)
		(void) snprintf(buf, sizeof(buf), "k%o %s %s\n",
		    opts, lp->pathname, rname);
	else
		(void) snprintf(buf, sizeof(buf), "k%o %s/%s %s\n",
		    opts, lp->target,
		    remotename(lp->pathname, lp->src), rname);

	if (debug) {
	        printf("lp->src      = %s\n", lp->src);
	        printf("lp->target   = %s\n", lp->target);
	        printf("lp->pathname = %s\n", lp->pathname);
	        printf("rname        = %s\n", rname);
	        printf("buf          = %s",   buf);
	}
	(void) write(rem, buf, strlen(buf));
	(void) response();
}

#define protoname() (pw ? pw->pw_name : user)
#define protogroup() (gr ? gr->gr_name : group)
/*
 * Transfer the file or directory in target[].
 * rname is the name of the file on the remote host.
 */
static void
sendf(rname, opts)
	char *rname;
	int opts;
{
	struct subcmd *sc;
	struct stat stb;
	int sizerr, f, u, len;
	off_t i;
	DIR *d;
	struct direct *dp;
	char *otp, *cp;
	extern struct subcmd *subcmds;
	static char user[15], group[15];

	if (debug)
		printf("sendf(%s, %x)\n", rname, opts);

	if (except(target))
		return;
	if ((opts & FOLLOW ? stat(target, &stb) : lstat(target, &stb)) < 0) {
		error("%s: %s\n", target, strerror(errno));
		return;
	}
	if ((u = update(rname, opts, &stb)) == 0) {
		if ((stb.st_mode & S_IFMT) == S_IFREG && stb.st_nlink > 1)
			(void) savelink(&stb);
		return;
	}

	if (pw == NULL || pw->pw_uid != stb.st_uid)
		if ((pw = getpwuid(stb.st_uid)) == NULL) {
			logit(lfp, "%s: no password entry for uid %u \n",
				target, stb.st_uid);
			pw = NULL;
			(void) snprintf(user, sizeof(user), ":%u", stb.st_uid);
		}
	if (gr == NULL || gr->gr_gid != stb.st_gid)
		if ((gr = getgrgid(stb.st_gid)) == NULL) {
			logit(lfp, "%s: no name for group %u\n",
				target, stb.st_gid);
			gr = NULL;
			(void) snprintf(group, sizeof(group), ":%u",
				stb.st_gid);
		}
	if (u == 1) {
		if (opts & VERIFY) {
			logit(lfp, "need to install: %s\n", target);
			goto dospecial;
		}
		logit(lfp, "installing: %s\n", target);
		opts &= ~(COMPARE|REMOVE);
	}

	switch (stb.st_mode & S_IFMT) {
	case S_IFDIR:
		if ((d = opendir(target)) == NULL) {
			error("%s: %s\n", target, strerror(errno));
			return;
		}
		(void) snprintf(buf, sizeof(buf), "D%o %04o 0 0 %s %s %s\n",
			opts, stb.st_mode & 07777, protoname(), protogroup(),
			rname);
		if (debug)
			printf("buf = %s", buf);
		(void) write(rem, buf, strlen(buf));
		if (response() < 0) {
			closedir(d);
			return;
		}

		if (opts & REMOVE)
			rmchk(opts);

		otp = tp;
		len = tp - target;
		while (dp = readdir(d)) {
			if (!strcmp(dp->d_name, ".") ||
			    !strcmp(dp->d_name, ".."))
				continue;
			if (len + 1 + strlen(dp->d_name) >= BUFSIZ - 1) {
				error("%s/%s: Name too long\n", target,
					dp->d_name);
				continue;
			}
			tp = otp;
			*tp++ = '/';
			cp = dp->d_name;
			while (*tp++ = *cp++)
				;
			tp--;
			sendf(dp->d_name, opts);
		}
		closedir(d);
		(void) write(rem, "E\n", 2);
		(void) response();
		tp = otp;
		*tp = '\0';
		return;

	case S_IFLNK:
		if (u != 1)
			opts |= COMPARE;
		if (stb.st_nlink > 1) {
			struct linkbuf *lp;

			if ((lp = savelink(&stb)) != NULL) {
				installlink(lp, rname, opts);
				return;
			}
		}
		(void) snprintf(buf, sizeof(buf), "K%o %o %qd %ld %s %s %s\n",
			opts, stb.st_mode & 07777, stb.st_size,
			(long)stb.st_mtime, protoname(), protogroup(), rname);
		if (debug)
			printf("buf = %s", buf);
		(void) write(rem, buf, strlen(buf));
		if (response() < 0)
			return;
		sizerr = (readlink(target, buf, BUFSIZ-1) != stb.st_size);
		(void) write(rem, buf, stb.st_size);
		if (debug)
			printf("readlink = %.*s\n", (int)stb.st_size, buf);
		goto done;

	case S_IFREG:
		break;

	default:
		error("%s: not a file or directory\n", target);
		return;
	}

	if (u == 2) {
		if (opts & VERIFY) {
			logit(lfp, "need to update: %s\n", target);
			goto dospecial;
		}
		logit(lfp, "updating: %s\n", target);
	}

	if (stb.st_nlink > 1) {
		struct linkbuf *lp;

		if ((lp = savelink(&stb)) != NULL) {
			installlink(lp, rname, opts);
			return;
		}
	}

	if ((f = open(target, O_RDONLY)) < 0) {
		error("%s: %s\n", target, strerror(errno));
		return;
	}
	(void) snprintf(buf, sizeof(buf), "R%o %o %qd %ld %s %s %s\n", opts,
		stb.st_mode & 07777, stb.st_size, (long)stb.st_mtime,
		protoname(), protogroup(), rname);
	if (debug)
		printf("buf = %s", buf);
	(void) write(rem, buf, strlen(buf));
	if (response() < 0) {
		(void) close(f);
		return;
	}
	sizerr = 0;
	for (i = 0; i < stb.st_size; i += BUFSIZ) {
		int amt = BUFSIZ;
		if (i + amt > stb.st_size)
			amt = stb.st_size - i;
		if (sizerr == 0 && read(f, buf, amt) != amt)
			sizerr = 1;
		(void) write(rem, buf, amt);
	}
	(void) close(f);
done:
	if (sizerr) {
		error("%s: file changed size\n", target);
		err();
	} else
		ack();
	f = response();
	if (f < 0 || f == 0 && (opts & COMPARE))
		return;
dospecial:
	for (sc = subcmds; sc != NULL; sc = sc->sc_next) {
		if (sc->sc_type != SPECIAL)
			continue;
		if (sc->sc_args != NULL && !inlist(sc->sc_args, target))
			continue;
		logit(lfp, "special \"%s\"\n", sc->sc_name);
		if (opts & VERIFY)
			continue;
		(void) snprintf(buf, sizeof(buf), "SFILE=%s;%s\n", target,
			sc->sc_name);
		if (debug)
			printf("buf = %s", buf);
		(void) write(rem, buf, strlen(buf));
		while (response() > 0)
			;
	}
}

static struct linkbuf *
savelink(stp)
	struct stat *stp;
{
	struct linkbuf *lp;

	for (lp = ihead; lp != NULL; lp = lp->nextp)
		if (lp->inum == stp->st_ino && lp->devnum == stp->st_dev) {
			lp->count--;
			return(lp);
		}
	lp = (struct linkbuf *) malloc(sizeof(*lp));
	if (lp == NULL)
		logit(lfp, "out of memory, link information lost\n");
	else {
		lp->nextp = ihead;
		ihead = lp;
		lp->inum = stp->st_ino;
		lp->devnum = stp->st_dev;
		lp->count = stp->st_nlink - 1;
		strlcpy(lp->pathname, target, sizeof lp->pathname);
		strlcpy(lp->src, source, sizeof lp->src);
		if (Tdest)
			strlcpy(lp->target, Tdest, sizeof lp->target);
		else
			*lp->target = 0;
	}
	return(NULL);
}

/*
 * Check to see if file needs to be updated on the remote machine.
 * Returns 0 if no update, 1 if remote doesn't exist, 2 if out of date
 * and 3 if comparing binaries to determine if out of date.
 */
static int
update(rname, opts, stp)
	char *rname;
	int opts;
	struct stat *stp;
{
	char *cp, *s;
	off_t size;
	time_t mtime;

	if (debug) 
		printf("update(%s, %x, %p)\n", rname, opts, stp);

	/*
	 * Check to see if the file exists on the remote machine.
	 */
	(void) snprintf(buf, sizeof(buf), "Q%s\n", rname);
	if (debug)
		printf("buf = %s", buf);
	(void) write(rem, buf, strlen(buf));
again:
	cp = s = buf;
	do {
		if (read(rem, cp, 1) != 1)
			lostconn(0);
	} while (*cp++ != '\n' && cp < &buf[BUFSIZ]);

	switch (*s++) {
	case 'Y':
		break;

	case 'N':  /* file doesn't exist so install it */
		return(1);

	case '\1':
		nerrs++;
		if (*s != '\n') {
			if (!iamremote) {
				fflush(stdout);
				(void) write(STDERR_FILENO, s, cp - s);
			}
			if (lfp != NULL)
				(void) fwrite(s, 1, cp - s, lfp);
		}
		return(0);

	case '\3':
		*--cp = '\0';
		if (lfp != NULL) 
			logit(lfp, "update: note: %s\n", s);
		goto again;

	default:
		*--cp = '\0';
		error("update: unexpected response '%s'\n", s);
		return(0);
	}

	if (*s == '\n')
		return(2);

	if (opts & COMPARE)
		return(3);

	size = 0;
	while (isdigit(*s))
		size = size * 10 + (*s++ - '0');
	if (*s++ != ' ') {
		error("update: size not delimited\n");
		return(0);
	}
	mtime = 0;
	while (isdigit(*s))
		mtime = mtime * 10 + (*s++ - '0');
	if (*s != '\n') {
		error("update: mtime not delimited\n");
		return(0);
	}
	/*
	 * File needs to be updated?
	 */
	if (opts & YOUNGER) {
		if (stp->st_mtime == mtime)
			return(0);
		if (stp->st_mtime < mtime) {
			logit(lfp, "Warning: %s: remote copy is newer\n", target);
			return(0);
		}
	} else if (stp->st_mtime == mtime && stp->st_size == size)
		return(0);
	return(2);
}

/*
 * Query. Check to see if file exists. Return one of the following:
 *	N\n		- doesn't exist
 *	Ysize mtime\n	- exists and its a regular file (size & mtime of file)
 *	Y\n		- exists and its a directory or symbolic link
 *	^Aerror message\n
 */
static void
query(name)
	char *name;
{
	struct stat stb;

	if (catname)
		(void) snprintf(tp, sizeof(target) - (tp - target),
			"/%s", name);

	if (lstat(target, &stb) < 0) {
		if (errno == ENOENT)
			(void) write(rem, "N\n", 2);
		else
			error("%s:%s: %s\n", host, target, strerror(errno));
		*tp = '\0';
		return;
	}

	switch (stb.st_mode & S_IFMT) {
	case S_IFREG:
		(void) snprintf(buf, sizeof(buf), "Y%qd %ld\n", stb.st_size,
			(long)stb.st_mtime);
		(void) write(rem, buf, strlen(buf));
		break;

	case S_IFLNK:
	case S_IFDIR:
		(void) write(rem, "Y\n", 2);
		break;

	default:
		error("%s: not a file or directory\n", name);
		break;
	}
	*tp = '\0';
}

static void
recvf(cmd, type)
	char *cmd;
	int type;
{
	char *cp = cmd;
	int f = -1, mode, opts = 0, wrerr, olderrno;
	off_t i, size;
	time_t mtime;
	struct stat stb;
	struct timeval tvp[2];
	char *owner, *group;
	char new[BUFSIZ];
	extern char *tempname;

	while (*cp >= '0' && *cp <= '7')
		opts = (opts << 3) | (*cp++ - '0');
	if (*cp++ != ' ') {
		error("recvf: options not delimited\n");
		return;
	}
	mode = 0;
	while (*cp >= '0' && *cp <= '7')
		mode = (mode << 3) | (*cp++ - '0');
	if (*cp++ != ' ') {
		error("recvf: mode not delimited\n");
		return;
	}
	size = 0;
	while (isdigit(*cp))
		size = size * 10 + (*cp++ - '0');
	if (*cp++ != ' ') {
		error("recvf: size not delimited\n");
		return;
	}
	mtime = 0;
	while (isdigit(*cp))
		mtime = mtime * 10 + (*cp++ - '0');
	if (*cp++ != ' ') {
		error("recvf: mtime not delimited\n");
		return;
	}
	owner = cp;
	while (*cp && *cp != ' ')
		cp++;
	if (*cp != ' ') {
		error("recvf: owner name not delimited\n");
		return;
	}
	*cp++ = '\0';
	group = cp;
	while (*cp && *cp != ' ')
		cp++;
	if (*cp != ' ') {
		error("recvf: group name not delimited\n");
		return;
	}
	*cp++ = '\0';

	if (type == S_IFDIR) {
		if (catname >= sizeof(stp)) {
			error("%s:%s: too many directory levels\n",
				host, target);
			return;
		}
		stp[catname] = tp;
		if (catname++) {
			*tp++ = '/';
			while (*tp++ = *cp++)
				;
			tp--;
		}
		if (opts & VERIFY) {
			ack();
			return;
		}
		if (lstat(target, &stb) == 0) {
			if (ISDIR(stb.st_mode)) {
				if ((stb.st_mode & 07777) == mode) {
					ack();
					return;
				}
				buf[0] = '\0';
				(void) snprintf(buf + 1, sizeof(buf) - 1,
					"%s: Warning: remote mode %o != local mode %o\n",
					target, stb.st_mode & 07777, mode);
				(void) write(rem, buf, strlen(buf + 1) + 1);
				return;
			}
			errno = ENOTDIR;
		} else if (errno == ENOENT && (mkdir(target, mode) == 0 ||
		    chkparent(target) == 0 && mkdir(target, mode) == 0)) {
			if (fchog(-1, target, owner, group, mode) == 0)
				ack();
			return;
		}
		error("%s:%s: %s\n", host, target, strerror(errno));
		tp = stp[--catname];
		*tp = '\0';
		return;
	}

	if (catname)
		(void) snprintf(tp, sizeof(target) - (tp - target), "/%s", cp);
	cp = strrchr(target, '/');
	if (cp == NULL)
		strlcpy(new, tempname, sizeof new);
	else if (cp == target)
		(void) snprintf(new, sizeof(new), "/%s", tempname);
	else {
		*cp = '\0';
		(void) snprintf(new, sizeof(new), "%s/%s", target, tempname);
		*cp = '/';
	}

	if (type == S_IFLNK) {
		int j;

		ack();
		cp = buf;
		for (i = 0; i < size; i += j) {
			if ((j = read(rem, cp, size - i)) <= 0)
				cleanup(0);
			cp += j;
		}
		*cp = '\0';
		if (response() < 0) {
			err();
			return;
		}
		if (symlink(buf, new) < 0) {
			if (errno != ENOENT || chkparent(new) < 0 ||
			    symlink(buf, new) < 0)
				goto badnew1;
		}
		mode &= 0777;
		if (opts & COMPARE) {
			char tbuf[BUFSIZ];

			if ((i = readlink(target, tbuf, BUFSIZ)) >= 0 &&
			    i == size && strncmp(buf, tbuf, size) == 0) {
				(void) unlink(new);
				ack();
				return;
			}
			if (opts & VERIFY)
				goto differ;
		}
		goto fixup;
	}

	if ((f = creat(new, mode)) < 0) {
		if (errno != ENOENT || chkparent(new) < 0 ||
		    (f = creat(new, mode)) < 0)
			goto badnew1;
	}

	ack();
	wrerr = 0;
	for (i = 0; i < size; i += BUFSIZ) {
		int amt = BUFSIZ;

		cp = buf;
		if (i + amt > size)
			amt = size - i;
		do {
			int j = read(rem, cp, amt);

			if (j <= 0) {
				(void) close(f);
				(void) unlink(new);
				cleanup(0);
			}
			amt -= j;
			cp += j;
		} while (amt > 0);
		amt = BUFSIZ;
		if (i + amt > size)
			amt = size - i;
		if (wrerr == 0 && write(f, buf, amt) != amt) {
			olderrno = errno;
			wrerr++;
		}
	}
	if (response() < 0) {
		err();
		goto badnew2;
	}
	if (wrerr)
		goto badnew1;
	if (opts & COMPARE) {
		FILE *f1, *f2;
		int c;

		if ((f1 = fopen(target, "r")) == NULL)
			goto badtarget;
		if ((f2 = fopen(new, "r")) == NULL) {
badnew1:		error("%s:%s: %s\n", host, new, strerror(errno));
			goto badnew2;
		}
		while ((c = getc(f1)) == getc(f2))
			if (c == EOF) {
				(void) fclose(f1);
				(void) fclose(f2);
				ack();
				goto badnew2;
			}
		(void) fclose(f1);
		(void) fclose(f2);
		if (opts & VERIFY) {
differ:			buf[0] = '\0';
			(void) snprintf(buf + 1, sizeof(buf) - 1,
				"need to update: %s\n",target);
			(void) write(rem, buf, strlen(buf + 1) + 1);
			goto badnew2;
		}
	}

	/*
	 * Set last modified time
	 */
	tvp[0].tv_sec = time(0);
	tvp[0].tv_usec = 0;
	tvp[1].tv_sec = mtime;
	tvp[1].tv_usec = 0;
	if (utimes(new, tvp) < 0)
		note("%s: utimes failed %s: %s\n", host, new, strerror(errno));

	if (fchog(f, new, owner, group, mode) < 0) {
badnew2:	
		if (f >= 0)
			(void) close(f);
		(void) unlink(new);
		return;
	}
	(void) close(f);

fixup:	if (rename(new, target) < 0) {
badtarget:	error("%s:%s: %s\n", host, target, strerror(errno));
		(void) unlink(new);
		return;
	}

	if (opts & COMPARE) {
		buf[0] = '\0';
		(void) snprintf(buf + 1, sizeof(buf) - 1,
			"updated %s\n", target);
		(void) write(rem, buf, strlen(buf + 1) + 1);
	} else
		ack();
}

/*
 * Creat a hard link to existing file.
 */
static void
hardlink(cmd)
	char *cmd;
{
	char *cp = cmd;
	struct stat stb;
	char *oldname;
	int opts = 0, exists = 0;

	while (*cp >= '0' && *cp <= '7')
		opts = (opts << 3) | (*cp++ - '0');
	if (*cp++ != ' ') {
		error("hardlink: options not delimited\n");
		return;
	}
	oldname = cp;
	while (*cp && *cp != ' ')
		cp++;
	if (*cp != ' ') {
		error("hardlink: oldname name not delimited\n");
		return;
	}
	*cp++ = '\0';

	if (catname) {
		(void) snprintf(tp, sizeof(target) - (tp - target), "/%s", cp);
	}
	if (lstat(target, &stb) == 0) {
		int mode = stb.st_mode & S_IFMT;
		if (mode != S_IFREG && mode != S_IFLNK) {
			error("%s:%s: not a regular file\n", host, target);
			return;
		}
		exists = 1;
	}
	if (chkparent(target) < 0 ) {
		error("%s:%s: %s (no parent)\n",
			host, target, strerror(errno));
		return;
	}
	if (exists && (unlink(target) < 0)) {
		error("%s:%s: %s (unlink)\n",
			host, target, strerror(errno));
		return;
	}
	if (link(oldname, target) < 0) {
		error("%s:can't link %s to %s\n",
			host, target, oldname);
		return;
	}
	ack();
}

/*
 * Check to see if parent directory exists and create one if not.
 */
static int
chkparent(name)
	char *name;
{
	char *cp;
	struct stat stb;

	cp = strrchr(name, '/');
	if (cp == NULL || cp == name)
		return(0);
	*cp = '\0';
	if (lstat(name, &stb) < 0) {
		if (errno == ENOENT && chkparent(name) >= 0 &&
		    mkdir(name, 0777 & ~oumask) >= 0) {
			*cp = '/';
			return(0);
		}
	} else if (ISDIR(stb.st_mode)) {
		*cp = '/';
		return(0);
	}
	*cp = '/';
	return(-1);
}

/*
 * Change owner, group and mode of file.
 */
static int
fchog(fd, file, owner, group, mode)
	int fd;
	char *file, *owner, *group;
	int mode;
{
	int i;
	uid_t uid;
	gid_t gid;
	extern char user[];
	extern uid_t userid;

	uid = userid;
	if (userid == 0) {
		if (*owner == ':') {
			uid = atoi(owner + 1);
		} else if (pw == NULL || strcmp(owner, pw->pw_name) != 0) {
			if ((pw = getpwnam(owner)) == NULL) {
				if (mode & 04000) {
					note("%s:%s: unknown login name, clearing setuid",
						host, owner);
					mode &= ~04000;
					uid = 0;
				}
			} else
				uid = pw->pw_uid;
		} else
			uid = pw->pw_uid;
		if (*group == ':') {
			gid = atoi(group + 1);
			goto ok;
		}
	} else if ((mode & 04000) && strcmp(user, owner) != 0)
		mode &= ~04000;
	gid = -1;
	if (gr == NULL || strcmp(group, gr->gr_name) != 0) {
		if ((*group == ':' && (getgrgid(gid = atoi(group + 1)) == NULL))
		   || ((gr = getgrnam(group)) == NULL)) {
			if (mode & 02000) {
				note("%s:%s: unknown group", host, group);
				mode &= ~02000;
			}
		} else
			gid = gr->gr_gid;
	} else
		gid = gr->gr_gid;
	if (userid && gid >= 0) {
		if (gr) for (i = 0; gr->gr_mem[i] != NULL; i++)
			if (!(strcmp(user, gr->gr_mem[i])))
				goto ok;
		mode &= ~02000;
		gid = -1;
	}
ok:	if (fd != -1 && fchown(fd, uid, gid) < 0 || chown(file, uid, gid) < 0)
		note("%s: %s chown: %s", host, file, strerror(errno));
	else if (mode & 07000 &&
	   (fd != -1 && fchmod(fd, mode) < 0 || chmod(file, mode) < 0))
		note("%s: %s chmod: %s", host, file, strerror(errno));
	return(0);
}

/*
 * Check for files on the machine being updated that are not on the master
 * machine and remove them.
 */
static void
rmchk(opts)
	int opts;
{
	char *cp, *s;
	struct stat stb;

	if (debug)
		printf("rmchk()\n");

	/*
	 * Tell the remote to clean the files from the last directory sent.
	 */
	(void) snprintf(buf, sizeof(buf), "C%o\n", opts & VERIFY);
	if (debug)
		printf("buf = %s", buf);
	(void) write(rem, buf, strlen(buf));
	if (response() < 0)
		return;
	for (;;) {
		cp = s = buf;
		do {
			if (read(rem, cp, 1) != 1)
				lostconn(0);
		} while (*cp++ != '\n' && cp < &buf[BUFSIZ]);

		switch (*s++) {
		case 'Q': /* Query if file should be removed */
			/*
			 * Return the following codes to remove query.
			 * N\n -- file exists - DON'T remove.
			 * Y\n -- file doesn't exist - REMOVE.
			 */
			*--cp = '\0';
			(void) snprintf(tp, sizeof(target) - (tp - target),
				"/%s", s);
			if (debug)
				printf("check %s\n", target);
			if (except(target))
				(void) write(rem, "N\n", 2);
			else if (lstat(target, &stb) < 0)
				(void) write(rem, "Y\n", 2);
			else
				(void) write(rem, "N\n", 2);
			break;

		case '\0':
			*--cp = '\0';
			if (*s != '\0')
				logit(lfp, "%s\n", s);
			break;

		case 'E':
			*tp = '\0';
			ack();
			return;

		case '\1':
		case '\2':
			nerrs++;
			if (*s != '\n') {
				if (!iamremote) {
					fflush(stdout);
					(void) write(STDERR_FILENO, s, cp - s);
				}
				if (lfp != NULL)
					(void) fwrite(s, 1, cp - s, lfp);
			}
			if (buf[0] == '\2')
				lostconn(0);
			break;

		default:
			error("rmchk: unexpected response '%s'\n", buf);
			err();
		}
	}
}

/*
 * Check the current directory (initialized by the 'T' command to server())
 * for extraneous files and remove them.
 */
static void
clean(cp)
	char *cp;
{
	DIR *d;
	struct direct *dp;
	struct stat stb;
	char *otp;
	int len, opts;

	opts = 0;
	while (*cp >= '0' && *cp <= '7')
		opts = (opts << 3) | (*cp++ - '0');
	if (*cp != '\0') {
		error("clean: options not delimited\n");
		return;
	}
	if ((d = opendir(target)) == NULL) {
		error("%s:%s: %s\n", host, target, strerror(errno));
		return;
	}
	ack();

	otp = tp;
	len = tp - target;
	while (dp = readdir(d)) {
		if (!strcmp(dp->d_name, ".") || !strcmp(dp->d_name, ".."))
			continue;
		if (len + 1 + strlen(dp->d_name) >= BUFSIZ - 1) {
			error("%s:%s/%s: Name too long\n",
				host, target, dp->d_name);
			continue;
		}
		tp = otp;
		*tp++ = '/';
		cp = dp->d_name;
		while (*tp++ = *cp++)
			;
		tp--;
		if (lstat(target, &stb) < 0) {
			error("%s:%s: %s\n", host, target, strerror(errno));
			continue;
		}
		(void) snprintf(buf, sizeof(buf), "Q%s\n", dp->d_name);
		(void) write(rem, buf, strlen(buf));
		cp = buf;
		do {
			if (read(rem, cp, 1) != 1)
				cleanup(0);
		} while (*cp++ != '\n' && cp < &buf[BUFSIZ]);
		*--cp = '\0';
		cp = buf;
		if (*cp != 'Y')
			continue;
		if (opts & VERIFY) {
			cp = buf;
			*cp++ = '\0';
			(void) snprintf(cp, sizeof(buf) - 1,
				"need to remove: %s\n", target);
			(void) write(rem, buf, strlen(cp) + 1);
		} else
			removeit(&stb);
	}
	closedir(d);
	(void) write(rem, "E\n", 2);
	(void) response();
	tp = otp;
	*tp = '\0';
}

/*
 * Remove a file or directory (recursively) and send back an acknowledge
 * or an error message.
 */
static void
removeit(stp)
	struct stat *stp;
{
	DIR *d;
	struct direct *dp;
	char *cp;
	struct stat stb;
	char *otp;
	int len;

	switch (stp->st_mode & S_IFMT) {
	case S_IFREG:
	case S_IFLNK:
		if (unlink(target) < 0)
			goto bad;
		goto removed;

	case S_IFDIR:
		break;

	default:
		error("%s:%s: not a plain file\n", host, target);
		return;
	}

	if ((d = opendir(target)) == NULL)
		goto bad;

	otp = tp;
	len = tp - target;
	while (dp = readdir(d)) {
		if (!strcmp(dp->d_name, ".") || !strcmp(dp->d_name, ".."))
			continue;
		if (len + 1 + strlen(dp->d_name) >= BUFSIZ - 1) {
			error("%s:%s/%s: Name too long\n",
				host, target, dp->d_name);
			continue;
		}
		tp = otp;
		*tp++ = '/';
		cp = dp->d_name;
		while (*tp++ = *cp++)
			;
		tp--;
		if (lstat(target, &stb) < 0) {
			error("%s:%s: %s\n", host, target, strerror(errno));
			continue;
		}
		removeit(&stb);
	}
	closedir(d);
	tp = otp;
	*tp = '\0';
	if (rmdir(target) < 0) {
bad:
		error("%s:%s: %s\n", host, target, strerror(errno));
		return;
	}
removed:
	cp = buf;
	*cp++ = '\0';
	(void) snprintf(cp, sizeof(buf) - 1, "removed %s\n", target);
	(void) write(rem, buf, strlen(cp) + 1);
}

/*
 * Execute a shell command to handle special cases.
 */
static void
dospecial(cmd)
	char *cmd;
{
	int fd[2], status;
	char *cp, *s;
	char sbuf[BUFSIZ];
	pid_t pid, i;
#if     defined(DIRECT_RCMD)
	extern uid_t userid;
	extern gid_t groupid;
#endif  /* DIRECT_RCMD */

	if (pipe(fd) < 0) {
		error("%s\n", strerror(errno));
		return;
	}
	if ((pid = fork()) == 0) {
		/*
		 * Return everything the shell commands print.
		 */
		(void) close(0);
		(void) close(1);
		(void) close(2);
		(void) open(_PATH_DEVNULL, O_RDONLY);
		(void) dup(fd[1]);
		(void) dup(fd[1]);
		(void) close(fd[0]);
		(void) close(fd[1]);
#if	defined(DIRECT_RCMD)
		if (setgroups(1, &groupid) == -1 ||
		    setresgid(groupid, groupid, groupid) == -1 ||
		    setresuid(userid, userid, userid) == -1)
			_exit(127);
#endif	/* DIRECT_RCMD */
		execl(_PATH_BSHELL, "sh", "-c", cmd, (char *)NULL);
		_exit(127);
	}
	(void) close(fd[1]);
	s = sbuf;
	*s++ = '\0';
	while ((i = read(fd[0], buf, sizeof(buf))) > 0) {
		cp = buf;
		do {
			*s++ = *cp++;
			if (cp[-1] != '\n') {
				if (s < &sbuf[sizeof(sbuf)-1])
					continue;
				*s++ = '\n';
			}
			/*
			 * Throw away blank lines.
			 */
			if (s == &sbuf[2]) {
				s--;
				continue;
			}
			(void) write(rem, sbuf, s - sbuf);
			s = &sbuf[1];
		} while (--i);
	}
	if (s > &sbuf[1]) {
		*s++ = '\n';
		(void) write(rem, sbuf, s - sbuf);
	}
	while ((i = wait(&status)) != pid && i != -1)
		;
	if (i == -1)
		status = -1;
	(void) close(fd[0]);
	if (status)
		error("shell returned %d\n", status);
	else
		ack();
}

void
logit(FILE *fp, const char *fmt, ...)
{
	va_list ap;

	va_start(ap, fmt);
	/* Print changes locally if not quiet mode */
	if (!qflag)
		(void) vprintf(fmt, ap);

	/* Save changes (for mailing) if really updating files */
	if (!(options & VERIFY) && fp != NULL)
		(void) vfprintf(fp, fmt, ap);
	va_end(ap);
}

void
error(const char *fmt, ...)
{
	static FILE *fp;
	va_list ap;

	va_start(ap, fmt);
	++nerrs;
	if (iamremote) {
		if (!fp && (rem < 0 || !(fp = fdopen(rem, "w"))))
			return;
		(void) fprintf(fp, "%crdist: ", 0x01);
		(void) vfprintf(fp, fmt, ap);
		fflush(fp);
	}
	else {
		fflush(stdout);
		(void) fprintf(stderr, "rdist: ");
		(void) vfprintf(stderr, fmt, ap);
		fflush(stderr);
	}
	if (lfp != NULL) {
		(void) fprintf(lfp, "rdist: ");
		(void) vfprintf(lfp, fmt, ap);
		fflush(lfp);
	}
	va_end(ap);
}

void
fatal(const char *fmt, ...)
{
	static FILE *fp;
	va_list ap;

	va_start(ap, fmt);
	++nerrs;
	if (!fp && !(fp = fdopen(rem, "w")))
		return;
	if (iamremote) {
		(void) fprintf(fp, "%crdist: ", 0x02);
		(void) vfprintf(fp, fmt, ap);
		fflush(fp);
	}
	else {
		fflush(stdout);
		(void) fprintf(stderr, "rdist: ");
		(void) vfprintf(stderr, fmt, ap);
		fflush(stderr);
	}
	if (lfp != NULL) {
		(void) fprintf(lfp, "rdist: ");
		(void) vfprintf(lfp, fmt, ap);
		fflush(lfp);
	}
	va_end(ap);
	cleanup(0);
}

static int
response()
{
	char *cp, *s;
	char resp[BUFSIZ];

	if (debug)
		printf("response()\n");

	cp = s = resp;
	do {
		if (read(rem, cp, 1) != 1)
			lostconn(0);
	} while (*cp++ != '\n' && cp < &resp[BUFSIZ]);

	switch (*s++) {
	case '\0':
		*--cp = '\0';
		if (*s != '\0') {
			logit(lfp, "%s\n", s);
			return(1);
		}
		return(0);
	case '\3':
		*--cp = '\0';
		logit(lfp, "Note: %s\n",s);
		return(response());

	default:
		s--;
		/* fall into... */
	case '\1':
	case '\2':
		nerrs++;
		if (*s != '\n') {
			if (!iamremote) {
				fflush(stdout);
				(void) write(STDERR_FILENO, s, cp - s);
			}
			if (lfp != NULL)
				(void) fwrite(s, 1, cp - s, lfp);
		}
		if (resp[0] == '\2')
			lostconn(0);
		return(-1);
	}
}

/*
 * Remove temporary files and do any cleanup operations before exiting.
 */
void
cleanup(signo)
	int signo;
{
	(void) unlink(tempfile);
	exit(1);
}

static void
note(const char *fmt, ...)
{
	static char buf[BUFSIZ];
	va_list ap;

	va_start(ap, fmt);
	(void) vsnprintf(buf, sizeof(buf), fmt, ap);
	va_end(ap);
	comment(buf);
}

static void
comment(s)
	char *s;
{
	char c;

	c = '\3';
	write(rem, &c, 1);
	write(rem, s, strlen(s));
	c = '\n';
	write(rem, &c, 1);
}