X-Git-Url: https://mattmccutchen.net/rsync/rsync.git/blobdiff_plain/1b2d733af23599b2cc173c8a275b895760f66258..28b519c93b6db30b6520d46f8cd65160213fddd2:/syscall.c

diff --git a/syscall.c b/syscall.c
index 31528590..1ed36f3c 100644
--- a/syscall.c
+++ b/syscall.c
@@ -1,45 +1,117 @@
-/* 
-   Copyright (C) Andrew Tridgell 1998
-   
-   This program is free software; you can redistribute it and/or modify
-   it under the terms of the GNU General Public License as published by
-   the Free Software Foundation; either version 2 of the License, or
-   (at your option) any later version.
-   
-   This program is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-   GNU General Public License for more details.
-   
-   You should have received a copy of the GNU General Public License
-   along with this program; if not, write to the Free Software
-   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
-*/
-
 /*
-  syscall wrappers to ensure that nothing gets done in dry_run mode
-  */
+ * Syscall wrappers to ensure that nothing gets done in dry_run mode
+ * and to handle system peculiarities.
+ *
+ * Copyright (C) 1998 Andrew Tridgell
+ * Copyright (C) 2002 Martin Pool
+ * Copyright (C) 2003-2009 Wayne Davison
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, visit the http://fsf.org website.
+ */
 
 #include "rsync.h"
 
+#if !defined MKNOD_CREATES_SOCKETS && defined HAVE_SYS_UN_H
+#include <sys/un.h>
+#endif
+#ifdef HAVE_SYS_ATTR_H
+#include <sys/attr.h>
+#endif
+
+#if defined HAVE_SYS_FALLOCATE && !defined HAVE_FALLOCATE
+#include <sys/syscall.h>
+#endif
+
 extern int dry_run;
+extern int am_root;
+extern int am_sender;
+extern int read_only;
+extern int list_only;
+extern int preserve_perms;
+extern int preserve_executability;
+
+#define RETURN_ERROR_IF(x,e) \
+	do { \
+		if (x) { \
+			errno = (e); \
+			return -1; \
+		} \
+	} while (0)
 
-int do_unlink(char *fname)
+#define RETURN_ERROR_IF_RO_OR_LO RETURN_ERROR_IF(read_only || list_only, EROFS)
+
+int do_unlink(const char *fname)
 {
 	if (dry_run) return 0;
+	RETURN_ERROR_IF_RO_OR_LO;
 	return unlink(fname);
 }
 
-int do_symlink(char *fname1, char *fname2)
+#ifdef SUPPORT_LINKS
+int do_symlink(const char *lnk, const char *fname)
 {
 	if (dry_run) return 0;
-	return symlink(fname1, fname2);
+	RETURN_ERROR_IF_RO_OR_LO;
+
+#ifdef NO_SYMLINK_XATTRS
+	/* For --fake-super, we create a normal file with mode 0600
+	 * and write the lnk into it. */
+	if (am_root < 0) {
+		int ok, len = strlen(lnk);
+		int fd = open(fname, O_WRONLY|O_CREAT|O_TRUNC, S_IWUSR|S_IRUSR);
+		if (fd < 0)
+			return -1;
+		ok = write(fd, lnk, len) == len;
+		if (close(fd) < 0)
+			ok = 0;
+		return ok ? 0 : -1;
+	}
+#endif
+
+	return symlink(lnk, fname);
 }
 
-#if HAVE_LINK
-int do_link(char *fname1, char *fname2)
+#ifdef NO_SYMLINK_XATTRS
+ssize_t do_readlink(const char *path, char *buf, size_t bufsiz)
+{
+	/* For --fake-super, we read the link from the file. */
+	if (am_root < 0) {
+		int fd = open(path, O_RDONLY|O_NOFOLLOW);
+		if (fd >= 0) {
+			int len = read(fd, buf, bufsiz);
+			close(fd);
+			return len;
+		}
+		if (errno != ELOOP)
+			return -1;
+		/* A real symlink needs to be turned into a fake one on the receiving
+		 * side, so tell the generator that the link has no length. */
+		if (!am_sender)
+			return 0;
+		/* Otherwise fall through and let the sender report the real length. */
+	}
+
+	return readlink(path, buf, bufsiz);
+}
+#endif
+#endif
+
+#ifdef HAVE_LINK
+int do_link(const char *fname1, const char *fname2)
 {
 	if (dry_run) return 0;
+	RETURN_ERROR_IF_RO_OR_LO;
 	return link(fname1, fname2);
 }
 #endif
@@ -47,51 +119,327 @@ int do_link(char *fname1, char *fname2)
 int do_lchown(const char *path, uid_t owner, gid_t group)
 {
 	if (dry_run) return 0;
+	RETURN_ERROR_IF_RO_OR_LO;
+#ifndef HAVE_LCHOWN
+#define lchown chown
+#endif
 	return lchown(path, owner, group);
 }
 
-#if HAVE_MKNOD
-int do_mknod(char *pathname, mode_t mode, dev_t dev)
+int do_mknod(const char *pathname, mode_t mode, dev_t dev)
 {
 	if (dry_run) return 0;
+	RETURN_ERROR_IF_RO_OR_LO;
+
+	/* For --fake-super, we create a normal file with mode 0600. */
+	if (am_root < 0) {
+		int fd = open(pathname, O_WRONLY|O_CREAT|O_TRUNC, S_IWUSR|S_IRUSR);
+		if (fd < 0 || close(fd) < 0)
+			return -1;
+		return 0;
+	}
+
+#if !defined MKNOD_CREATES_FIFOS && defined HAVE_MKFIFO
+	if (S_ISFIFO(mode))
+		return mkfifo(pathname, mode);
+#endif
+#if !defined MKNOD_CREATES_SOCKETS && defined HAVE_SYS_UN_H
+	if (S_ISSOCK(mode)) {
+		int sock;
+		struct sockaddr_un saddr;
+#ifdef HAVE_SOCKADDR_UN_LEN
+		unsigned int len =
+#endif
+		    strlcpy(saddr.sun_path, pathname, sizeof saddr.sun_path);
+#ifdef HAVE_SOCKADDR_UN_LEN
+		saddr.sun_len = len >= sizeof saddr.sun_path
+			      ? sizeof saddr.sun_path : len + 1;
+#endif
+		saddr.sun_family = AF_UNIX;
+
+		if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) < 0
+		    || (unlink(pathname) < 0 && errno != ENOENT)
+		    || (bind(sock, (struct sockaddr*)&saddr, sizeof saddr)) < 0)
+			return -1;
+		close(sock);
+#ifdef HAVE_CHMOD
+		return do_chmod(pathname, mode);
+#else
+		return 0;
+#endif
+	}
+#endif
+#ifdef HAVE_MKNOD
 	return mknod(pathname, mode, dev);
-}
+#else
+	return -1;
 #endif
+}
 
-int do_rmdir(char *pathname)
+int do_rmdir(const char *pathname)
 {
 	if (dry_run) return 0;
+	RETURN_ERROR_IF_RO_OR_LO;
 	return rmdir(pathname);
 }
 
-int do_open(char *pathname, int flags, mode_t mode)
+int do_open(const char *pathname, int flags, mode_t mode)
 {
-	if (dry_run) return -1;
-	return open(pathname, flags, mode);
+	if (flags != O_RDONLY) {
+		RETURN_ERROR_IF(dry_run, 0);
+		RETURN_ERROR_IF_RO_OR_LO;
+	}
+
+	return open(pathname, flags | O_BINARY, mode);
 }
 
-#if HAVE_CHMOD
+#ifdef HAVE_CHMOD
 int do_chmod(const char *path, mode_t mode)
 {
+	int code;
 	if (dry_run) return 0;
-	return chmod(path, mode);
+	RETURN_ERROR_IF_RO_OR_LO;
+#ifdef HAVE_LCHMOD
+	code = lchmod(path, mode & CHMOD_BITS);
+#else
+	if (S_ISLNK(mode)) {
+# if defined HAVE_SETATTRLIST
+		struct attrlist attrList;
+		uint32_t m = mode & CHMOD_BITS; /* manpage is wrong: not mode_t! */
+
+		memset(&attrList, 0, sizeof attrList);
+		attrList.bitmapcount = ATTR_BIT_MAP_COUNT;
+		attrList.commonattr = ATTR_CMN_ACCESSMASK;
+		code = setattrlist(path, &attrList, &m, sizeof m, FSOPT_NOFOLLOW);
+# else
+		code = 1;
+# endif
+	} else
+		code = chmod(path, mode & CHMOD_BITS); /* DISCOURAGED FUNCTION */
+#endif /* !HAVE_LCHMOD */
+	if (code != 0 && (preserve_perms || preserve_executability))
+		return code;
+	return 0;
 }
 #endif
 
-int do_rename(char *fname1, char *fname2)
+int do_rename(const char *fname1, const char *fname2)
 {
 	if (dry_run) return 0;
+	RETURN_ERROR_IF_RO_OR_LO;
 	return rename(fname1, fname2);
 }
 
+#ifdef HAVE_FTRUNCATE
+int do_ftruncate(int fd, OFF_T size)
+{
+	int ret;
+
+	if (dry_run) return 0;
+	RETURN_ERROR_IF_RO_OR_LO;
+
+	do {
+		ret = ftruncate(fd, size);
+	} while (ret < 0 && errno == EINTR);
+
+	return ret;
+}
+#endif
+
+void trim_trailing_slashes(char *name)
+{
+	int l;
+	/* Some BSD systems cannot make a directory if the name
+	 * contains a trailing slash.
+	 * <http://www.opensource.apple.com/bugs/X/BSD%20Kernel/2734739.html> */
+
+	/* Don't change empty string; and also we can't improve on
+	 * "/" */
+
+	l = strlen(name);
+	while (l > 1) {
+		if (name[--l] != '/')
+			break;
+		name[l] = '\0';
+	}
+}
+
 int do_mkdir(char *fname, mode_t mode)
 {
 	if (dry_run) return 0;
+	RETURN_ERROR_IF_RO_OR_LO;
+	trim_trailing_slashes(fname);
 	return mkdir(fname, mode);
 }
 
-char *do_mktemp(char *template)
+/* like mkstemp but forces permissions */
+int do_mkstemp(char *template, mode_t perms)
+{
+	RETURN_ERROR_IF(dry_run, 0);
+	RETURN_ERROR_IF(read_only, EROFS);
+	perms |= S_IWUSR;
+
+#if defined HAVE_SECURE_MKSTEMP && defined HAVE_FCHMOD && (!defined HAVE_OPEN64 || defined HAVE_MKSTEMP64)
+	{
+		int fd = mkstemp(template);
+		if (fd == -1)
+			return -1;
+		if (fchmod(fd, perms) != 0 && preserve_perms) {
+			int errno_save = errno;
+			close(fd);
+			unlink(template);
+			errno = errno_save;
+			return -1;
+		}
+#if defined HAVE_SETMODE && O_BINARY
+		setmode(fd, O_BINARY);
+#endif
+		return fd;
+	}
+#else
+	if (!mktemp(template))
+		return -1;
+	return do_open(template, O_RDWR|O_EXCL|O_CREAT, perms);
+#endif
+}
+
+int do_stat(const char *fname, STRUCT_STAT *st)
 {
-	if (dry_run) return NULL;
-	return mktemp(template);
+#ifdef USE_STAT64_FUNCS
+	return stat64(fname, st);
+#else
+	return stat(fname, st);
+#endif
 }
+
+int do_lstat(const char *fname, STRUCT_STAT *st)
+{
+#ifdef SUPPORT_LINKS
+# ifdef USE_STAT64_FUNCS
+	return lstat64(fname, st);
+# else
+	return lstat(fname, st);
+# endif
+#else
+	return do_stat(fname, st);
+#endif
+}
+
+int do_fstat(int fd, STRUCT_STAT *st)
+{
+#ifdef USE_STAT64_FUNCS
+	return fstat64(fd, st);
+#else
+	return fstat(fd, st);
+#endif
+}
+
+OFF_T do_lseek(int fd, OFF_T offset, int whence)
+{
+#ifdef HAVE_LSEEK64
+#if !SIZEOF_OFF64_T
+	OFF_T lseek64();
+#else
+	off64_t lseek64();
+#endif
+	return lseek64(fd, offset, whence);
+#else
+	return lseek(fd, offset, whence);
+#endif
+}
+
+#ifdef HAVE_UTIMENSAT
+int do_utimensat(const char *fname, time_t modtime, uint32 mod_nsec)
+{
+	struct timespec t[2];
+
+	if (dry_run) return 0;
+	RETURN_ERROR_IF_RO_OR_LO;
+
+	t[0].tv_sec = 0;
+	t[0].tv_nsec = UTIME_NOW;
+	t[1].tv_sec = modtime;
+	t[1].tv_nsec = mod_nsec;
+	return utimensat(AT_FDCWD, fname, t, AT_SYMLINK_NOFOLLOW);
+}
+#endif
+
+#ifdef HAVE_LUTIMES
+int do_lutimes(const char *fname, time_t modtime, uint32 mod_nsec)
+{
+	struct timeval t[2];
+
+	if (dry_run) return 0;
+	RETURN_ERROR_IF_RO_OR_LO;
+
+	t[0].tv_sec = time(NULL);
+	t[0].tv_usec = 0;
+	t[1].tv_sec = modtime;
+	t[1].tv_usec = mod_nsec / 1000;
+	return lutimes(fname, t);
+}
+#endif
+
+#ifdef HAVE_UTIMES
+int do_utimes(const char *fname, time_t modtime, uint32 mod_nsec)
+{
+	struct timeval t[2];
+
+	if (dry_run) return 0;
+	RETURN_ERROR_IF_RO_OR_LO;
+
+	t[0].tv_sec = time(NULL);
+	t[0].tv_usec = 0;
+	t[1].tv_sec = modtime;
+	t[1].tv_usec = mod_nsec / 1000;
+	return utimes(fname, t);
+}
+
+#elif defined HAVE_UTIME
+int do_utime(const char *fname, time_t modtime, UNUSED(uint32 mod_nsec))
+{
+#ifdef HAVE_STRUCT_UTIMBUF
+	struct utimbuf tbuf;
+#else
+	time_t t[2];
+#endif
+
+	if (dry_run) return 0;
+	RETURN_ERROR_IF_RO_OR_LO;
+
+# ifdef HAVE_STRUCT_UTIMBUF
+	tbuf.actime = time(NULL);
+	tbuf.modtime = modtime;
+	return utime(fname, &tbuf);
+# else
+	t[0] = time(NULL);
+	t[1] = modtime;
+	return utime(fname, t);
+# endif
+}
+
+#else
+#error Need utimes or utime function.
+#endif
+
+#ifdef SUPPORT_PREALLOCATION
+int do_fallocate(int fd, OFF_T offset, OFF_T length)
+{
+#ifdef FALLOC_FL_KEEP_SIZE
+#define DO_FALLOC_OPTIONS FALLOC_FL_KEEP_SIZE
+#else
+#define DO_FALLOC_OPTIONS 0
+#endif
+	RETURN_ERROR_IF(dry_run, 0);
+	RETURN_ERROR_IF_RO_OR_LO;
+#if defined HAVE_FALLOCATE
+	return fallocate(fd, DO_FALLOC_OPTIONS, offset, length);
+#elif defined HAVE_SYS_FALLOCATE
+	return syscall(SYS_fallocate, fd, DO_FALLOC_OPTIONS, (loff_t)offset, (loff_t)length);
+#elif defined HAVE_EFFICIENT_POSIX_FALLOCATE
+	return posix_fallocate(fd, offset, length);
+#else
+#error Coding error in SUPPORT_PREALLOCATION logic.
+#endif
+}
+#endif