--- realpath.c.orig Fri Aug 15 19:22:17 2003
+++ realpath.c Tue Dec 9 14:36:32 2003
@@ -40,8 +40,27 @@
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
+#include <sys/attr.h>
+#include <sys/vnode.h>
#include "un-namespace.h"
+struct attrs {
+ u_int32_t len;
+ attrreference_t name;
+ fsobj_type_t type;
+ char buf[PATH_MAX];
+};
+
+static struct attrlist alist = {
+ ATTR_BIT_MAP_COUNT,
+ 0,
+ ATTR_CMN_NAME | ATTR_CMN_OBJTYPE,
+ 0,
+ 0,
+ 0,
+ 0,
+};
+
/*
* char *realpath(const char *path, char resolved[PATH_MAX]);
*
@@ -52,11 +71,12 @@
char *
realpath(const char *path, char resolved[PATH_MAX])
{
+ struct attrs attrs;
struct stat sb;
char *p, *q, *s;
- size_t left_len, resolved_len;
+ size_t left_len, resolved_len, save_resolved_len;
unsigned symlinks;
- int serrno, slen;
+ int serrno, slen, useattrs, islink;
char left[PATH_MAX], next_token[PATH_MAX], symlink[PATH_MAX];
serrno = errno;
@@ -127,6 +147,13 @@
}
/*
+ * Save resolved_len, so that we can later null out
+ * the the appended next_token, and replace with the
+ * real name (matters on case-insensitive filesystems).
+ */
+ save_resolved_len = resolved_len;
+
+ /*
* Append the next path component and lstat() it. If
* lstat() fails we still can return successfully if
* there are no more path components left.
@@ -136,14 +163,22 @@
errno = ENAMETOOLONG;
return (NULL);
}
- if (lstat(resolved, &sb) != 0) {
+ if (getattrlist(resolved, &alist, &attrs, sizeof(attrs), FSOPT_NOFOLLOW) == 0) {
+ useattrs = 1;
+ islink = (attrs.type == VLNK);
+ } else if (errno == EOPNOTSUPP || errno == EINVAL) {
+ if ((useattrs = lstat(resolved, &sb)) == 0)
+ islink = S_ISLNK(sb.st_mode);
+ } else
+ useattrs = -1;
+ if (useattrs < 0) {
if (errno == ENOENT && p == NULL) {
errno = serrno;
return (resolved);
}
return (NULL);
}
- if (S_ISLNK(sb.st_mode)) {
+ if (islink) {
if (symlinks++ > MAXSYMLINKS) {
errno = ELOOP;
return (NULL);
@@ -184,7 +219,30 @@
}
}
left_len = strlcpy(left, symlink, sizeof(left));
+ } else if (useattrs) {
+ /*
+ * attrs already has the real name.
+ */
+
+ resolved[save_resolved_len] = '\0';
+ resolved_len = strlcat(resolved, (const char *)&attrs.name + attrs.name.attr_dataoffset, PATH_MAX);
+ if (resolved_len >= PATH_MAX) {
+ errno = ENAMETOOLONG;
+ return (NULL);
+ }
}
+ /*
+ * For the case of useattrs == 0, we could scan the directory
+ * and try to match the inode. There are many problems with
+ * this: (1) the directory may not be readable, (2) for multiple
+ * hard links, we would find the first, but not necessarily
+ * the one specified in the path, (3) we can't try to do
+ * a case-insensitive search to match the right one in (2),
+ * because the underlying filesystem may do things like
+ * decompose composed characters. For most cases, doing
+ * nothing is the right thing when useattrs == 0, so we punt
+ * for now.
+ */
}
/*