server.c

早期freebsd实现

/*
 * 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. 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.
 */

#ifndef lint
static char sccsid[] = "@(#)server.c	8.1 (Berkeley) 6/9/93";
#endif /* not lint */

#include <sys/wait.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	*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 __P((char *));
static void	clean __P((char *));
static void	comment __P((char *));
static void	dospecial __P((char *));
static int	fchog __P((int, char *, char *, char *, int));
static void	hardlink __P((char *));
static void	note __P((const char *, ...));
static void	query __P((char *));
static void	recvf __P((char *, int));
static void	removeit __P((struct stat *));
static int	response __P((void));
static void	rmchk __P((int));
static struct linkbuf *
		    savelink __P((struct stat *));
static void	sendf __P((char *, int));
static int	update __P((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];
	register char *cp;

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

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

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

	if (destdir) {
		strcpy(destcopy, dest);
		Tdest = destcopy;
	}
	sendf(rname, opts);
	Tdest = 0;
}

#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;
{
	register 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) {
			log(lfp, "%s: no password entry for uid %d \n",
				target, stb.st_uid);
			pw = NULL;
			(void)sprintf(user, ":%lu", stb.st_uid);
		}
	if (gr == NULL || gr->gr_gid != stb.st_gid)
		if ((gr = getgrgid(stb.st_gid)) == NULL) {
			log(lfp, "%s: no name for group %d\n",
				target, stb.st_gid);
			gr = NULL;
			(void)sprintf(group, ":%lu", stb.st_gid);
		}
	if (u == 1) {
		if (opts & VERIFY) {
			log(lfp, "need to install: %s\n", target);
			goto dospecial;
		}
		log(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) sprintf(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) {
				/* install link */
				if (*lp->target == 0)
				(void) sprintf(buf, "k%o %s %s\n", opts,
					lp->pathname, rname);
				else
				(void) sprintf(buf, "k%o %s/%s %s\n", opts,
					lp->target, lp->pathname, rname);
				if (debug)
					printf("buf = %s", buf);
				(void) write(rem, buf, strlen(buf));
				(void) response();
				return;
			}
		}
		(void) sprintf(buf, "K%o %o %qd %ld %s %s %s\n", opts,
			stb.st_mode & 07777, stb.st_size, 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) != 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) {
			log(lfp, "need to update: %s\n", target);
			goto dospecial;
		}
		log(lfp, "updating: %s\n", target);
	}

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

		if ((lp = savelink(&stb)) != NULL) {
			/* install link */
			if (*lp->target == 0)
			(void) sprintf(buf, "k%o %s %s\n", opts,
				lp->pathname, rname);
			else
			(void) sprintf(buf, "k%o %s/%s %s\n", opts,
				lp->target, lp->pathname, rname);
			if (debug)
				printf("buf = %s", buf);
			(void) write(rem, buf, strlen(buf));
			(void) response();
			return;
		}
	}

	if ((f = open(target, O_RDONLY, 0)) < 0) {
		error("%s: %s\n", target, strerror(errno));
		return;
	}
	(void) sprintf(buf, "R%o %o %qd %ld %s %s %s\n", opts,
		stb.st_mode & 07777, stb.st_size, 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;
		log(lfp, "special \"%s\"\n", sc->sc_name);
		if (opts & VERIFY)
			continue;
		(void) sprintf(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));