server.c

早期freebsd实现

	if (lp == NULL)
		log(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;
		strcpy(lp->pathname, target);
		if (Tdest)
			strcpy(lp->target, Tdest);
		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 * Returns 0 if no update, 1 if remote doesn't exist, 2 if out of date
 * and 3 if comparing binaries to determine if out of date.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;
{
	register char *cp, *s;
	register off_t size;
	register time_t mtime;

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

	/*
	 * Check to see if the file exists on the remote machine.
	 */
	(void) sprintf(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(2, s, cp - s);
			}
			if (lfp != NULL)
				(void) fwrite(s, 1, cp - s, lfp);
		}
		return(0);

	case '\3':
		*--cp = '\0';
		if (lfp != NULL) 
			log(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) {
			log(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) sprintf(tp, "/%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) sprintf(buf, "Y%qd %ld\n", stb.st_size, 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;
{
	register char *cp;
	int f, mode, opts, 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;

	cp = cmd;
	opts = 0;
	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) sprintf(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) sprintf(tp, "/%s", cp);
	cp = rindex(target, '/');
	if (cp == NULL)
		strcpy(new, tempname);
	else if (cp == target)
		(void) sprintf(new, "/%s", tempname);
	else {
		*cp = '\0';
		(void) sprintf(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) sprintf(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:	(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) sprintf(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;
{
	register char *cp;
	struct stat stb;
	char *oldname;
	int opts, exists = 0;

	cp = cmd;
	opts = 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) sprintf(tp, "/%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;
{
	register char *cp;
	struct stat stb;

	cp = rindex(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;
{
	register int i;
	int uid, gid;
	extern char user[];
	extern int 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)