Allow ldconfig.host to build ld.so.cache for target, regardless of

the target system's byteorder

1 files changed, 163 insertions, 0 deletions

diff --git a/utils/chroot_realpath.c b/utils/chroot_realpath.c
new file mode 100644
index 000000000..43ce9a528
--- /dev/null
+++ b/utils/chroot_realpath.c
@@ -0,0 +1,163 @@
+/*
+ * chroot_realpath.c -- reslove pathname as if inside chroot
+ * Based on realpath.c Copyright (C) 1993 Rick Sladkey <jrs@world.std.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Library Public License as published by
+ * the Free Software Foundation; either version 2, 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 Library Public License for more details.
+ *
+ * 2005/09/12: Dan Howell (modified from realpath.c to emulate chroot)
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <sys/types.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <string.h>
+#include <strings.h>
+#include <limits.h>				/* for PATH_MAX */
+#include <sys/param.h>			/* for MAXPATHLEN */
+#include <errno.h>
+#ifndef __set_errno
+#define __set_errno(val) ((errno) = (val))
+#endif
+
+#include <sys/stat.h>			/* for S_IFLNK */
+
+#ifndef PATH_MAX
+#define PATH_MAX _POSIX_PATH_MAX
+#endif
+
+#define MAX_READLINKS 32
+
+char *chroot_realpath(const char *chroot, const char *path, char resolved_path[])
+{
+	char copy_path[PATH_MAX];
+	char link_path[PATH_MAX];
+	char got_path[PATH_MAX];
+	char *got_path_root = got_path;
+	char *new_path = got_path;
+	char *max_path;
+	int readlinks = 0;
+	int n;
+	int chroot_len;
+
+	/* Trivial case. */
+	if (chroot == NULL || *chroot == '\0' ||
+	    (*chroot == '/' && chroot[1] == '\0')) {
+		strcpy(resolved_path, path);
+		return resolved_path;
+	}
+
+	chroot_len = strlen(chroot);
+
+	if (chroot_len + strlen(path) >= PATH_MAX - 3) {
+		__set_errno(ENAMETOOLONG);
+		return NULL;
+	}
+
+	/* Make a copy of the source path since we may need to modify it. */
+	strcpy(copy_path, path);
+	path = copy_path;
+	max_path = copy_path + PATH_MAX - chroot_len - 3;
+
+	/* Start with the chroot path. */
+	strcpy(new_path, chroot);
+	new_path += chroot_len;
+	while (*new_path == '/' && new_path > got_path)
+		new_path--;
+	got_path_root = new_path;
+	*new_path++ = '/';
+
+	/* Expand each slash-separated pathname component. */
+	while (*path != '\0') {
+		/* Ignore stray "/". */
+		if (*path == '/') {
+			path++;
+			continue;
+		}
+		if (*path == '.') {
+			/* Ignore ".". */
+			if (path[1] == '\0' || path[1] == '/') {
+				path++;
+				continue;
+			}
+			if (path[1] == '.') {
+				if (path[2] == '\0' || path[2] == '/') {
+					path += 2;
+					/* Ignore ".." at root. */
+					if (new_path == got_path_root + 1)
+						continue;
+					/* Handle ".." by backing up. */
+					while ((--new_path)[-1] != '/');
+					continue;
+				}
+			}
+		}
+		/* Safely copy the next pathname component. */
+		while (*path != '\0' && *path != '/') {
+			if (path > max_path) {
+				__set_errno(ENAMETOOLONG);
+				return NULL;
+			}
+			*new_path++ = *path++;
+		}
+		if (*path == '\0')
+			/* Don't follow symlink for last pathname component. */
+			break;
+#ifdef S_IFLNK
+		/* Protect against infinite loops. */
+		if (readlinks++ > MAX_READLINKS) {
+			__set_errno(ELOOP);
+			return NULL;
+		}
+		/* See if latest pathname component is a symlink. */
+		*new_path = '\0';
+		n = readlink(got_path, link_path, PATH_MAX - 1);
+		if (n < 0) {
+			/* EINVAL means the file exists but isn't a symlink. */
+			if (errno != EINVAL) {
+				/* Make sure it's null terminated. */
+				*new_path = '\0';
+				strcpy(resolved_path, got_path);
+				return NULL;
+			}
+		} else {
+			/* Note: readlink doesn't add the null byte. */
+			link_path[n] = '\0';
+			if (*link_path == '/')
+				/* Start over for an absolute symlink. */
+				new_path = got_path_root;
+			else
+				/* Otherwise back up over this component. */
+				while (*(--new_path) != '/');
+			/* Safe sex check. */
+			if (strlen(path) + n >= PATH_MAX - 2) {
+				__set_errno(ENAMETOOLONG);
+				return NULL;
+			}
+			/* Insert symlink contents into path. */
+			strcat(link_path, path);
+			strcpy(copy_path, link_path);
+			path = copy_path;
+		}
+#endif							/* S_IFLNK */
+		*new_path++ = '/';
+	}
+	/* Delete trailing slash but don't whomp a lone slash. */
+	if (new_path != got_path + 1 && new_path[-1] == '/')
+		new_path--;
+	/* Make sure it's null terminated. */
+	*new_path = '\0';
+	strcpy(resolved_path, got_path);
+	return resolved_path;
+}