Imported Upstream version 93u+upstream

1 files changed, 222 insertions, 0 deletions

diff --git a/src/lib/libast/path/pathcanon.c b/src/lib/libast/path/pathcanon.c
new file mode 100644
index 0000000..8d3cfa6
--- /dev/null
+++ b/src/lib/libast/path/pathcanon.c
@@ -0,0 +1,222 @@
+/***********************************************************************
+*                                                                      *
+*               This software is part of the ast package               *
+*          Copyright (c) 1985-2011 AT&T Intellectual Property          *
+*                      and is licensed under the                       *
+*                 Eclipse Public License, Version 1.0                  *
+*                    by AT&T Intellectual Property                     *
+*                                                                      *
+*                A copy of the License is available at                 *
+*          http://www.eclipse.org/org/documents/epl-v10.html           *
+*         (with md5 checksum b35adb5213ca9657e911e9befb180842)         *
+*                                                                      *
+*              Information and Software Systems Research               *
+*                            AT&T Research                             *
+*                           Florham Park NJ                            *
+*                                                                      *
+*                 Glenn Fowler <gsf@research.att.com>                  *
+*                  David Korn <dgk@research.att.com>                   *
+*                   Phong Vo <kpv@research.att.com>                    *
+*                                                                      *
+***********************************************************************/
+#pragma prototyped
+/*
+ * Glenn Fowler
+ * AT&T Research
+ *
+ * in-place path name canonicalization -- preserves the logical view
+ * pointer to trailing 0 in path returned
+ *
+ *	remove redundant .'s and /'s
+ *	move ..'s to the front
+ *	/.. preserved (for pdu and newcastle hacks)
+ *	FS_3D handles ...
+ *	if (flags&PATH_PHYSICAL) then symlinks resolved at each component
+ *	if (flags&PATH_DOTDOT) then each .. checked for access
+ *	if (flags&PATH_EXISTS) then path must exist at each component
+ *	if (flags&PATH_VERIFIED(n)) then first n chars of path exist
+ * 
+ * longer pathname possible if (flags&PATH_PHYSICAL) or FS_3D ... involved
+ * 0 returned on error and if (flags&(PATH_DOTDOT|PATH_EXISTS)) then path
+ * will contain the components following the failure point
+ */
+
+#define _AST_API_H	1
+
+#include <ast.h>
+#include <ls.h>
+#include <fs3d.h>
+#include <error.h>
+
+char*
+pathcanon(char* path, int flags)
+{
+	return pathcanon_20100601(path, PATH_MAX, flags);
+}
+
+#undef	_AST_API_H
+
+#include <ast_api.h>
+
+char*
+pathcanon_20100601(char* path, size_t size, int flags)
+{
+	register char*	p;
+	register char*	r;
+	register char*	s;
+	register char*	t;
+	register int	dots;
+	char*		phys;
+	char*		v;
+	int		loop;
+	int		oerrno;
+#if defined(FS_3D)
+	long		visits = 0;
+#endif
+
+	oerrno = errno;
+	dots = loop = 0;
+	phys = path;
+	v = path + ((flags >> 5) & 01777);
+	if (!size)
+		size = strlen(path) + 1;
+	if (*path == '/')
+	{
+		if (*(path + 1) == '/' && *astconf("PATH_LEADING_SLASHES", NiL, NiL) == '1')
+			do path++; while (*path == '/' && *(path + 1) == '/');
+		if (!*(path + 1))
+			return path + 1;
+	}
+	p = r = s = t = path;
+	for (;;)
+		switch (*t++ = *s++)
+		{
+		case '.':
+			dots++;
+			break;
+		case 0:
+			s--;
+			/*FALLTHROUGH*/
+		case '/':
+			while (*s == '/') s++;
+			switch (dots)
+			{
+			case 1:
+				t -= 2;
+				break;
+			case 2:
+				if ((flags & (PATH_DOTDOT|PATH_EXISTS)) == PATH_DOTDOT && (t - 2) >= v)
+				{
+					struct stat	st;
+
+					*(t - 2) = 0;
+					if (stat(phys, &st))
+					{
+						strcpy(path, s);
+						return 0;
+					}
+					*(t - 2) = '.';
+				}
+#if PRESERVE_TRAILING_SLASH
+				if (t - 5 < r) r = t;
+#else
+				if (t - 5 < r)
+				{
+					if (t - 4 == r) t = r + 1;
+					else r = t;
+				}
+#endif
+				else for (t -= 5; t > r && *(t - 1) != '/'; t--);
+				break;
+			case 3:
+#if defined(FS_3D)
+				{
+					char*		x;
+					char*		o;
+					int		c;
+
+					o = t;
+					if ((t -= 5) <= path) t = path + 1;
+					c = *t;
+					*t = 0;
+					if (x = pathnext(phys, s - (*s != 0), &visits))
+					{
+						r = path;
+						if (t == r + 1) x = r;
+						v = s = t = x;
+					}
+					else
+					{
+						*t = c;
+						t = o;
+					}
+				}
+#else
+				r = t;
+#endif
+				break;
+			default:
+				if ((flags & PATH_PHYSICAL) && loop < 32 && (t - 1) > path)
+				{
+					int	c;
+					char	buf[PATH_MAX];
+
+					c = *(t - 1);
+					*(t - 1) = 0;
+					dots = pathgetlink(phys, buf, sizeof(buf));
+					*(t - 1) = c;
+					if (dots > 0)
+					{
+						loop++;
+						strcpy(buf + dots, s - (*s != 0));
+						if (*buf == '/') p = r = path;
+						v = s = t = p;
+						strcpy(p, buf);
+					}
+					else if (dots < 0 && errno == ENOENT)
+					{
+						if (flags & PATH_EXISTS)
+						{
+							strcpy(path, s);
+							return 0;
+						}
+						flags &= ~(PATH_PHYSICAL|PATH_DOTDOT);
+					}
+					dots = 4;
+				}
+				break;
+			}
+			if (dots >= 4 && (flags & PATH_EXISTS) && (t - 1) >= v && (t > path + 1 || t > path && *(t - 1) && *(t - 1) != '/'))
+			{
+				struct stat	st;
+
+				*(t - 1) = 0;
+				if (stat(phys, &st))
+				{
+					strcpy(path, s);
+					return 0;
+				}
+				v = t;
+				if (*s) *(t - 1) = '/';
+			}
+			if (!*s)
+			{
+				if (t > path && !*(t - 1)) t--;
+				if (t == path) *t++ = '.';
+#if DONT_PRESERVE_TRAILING_SLASH
+				else if (t > path + 1 && *(t - 1) == '/') t--;
+#else
+				else if ((s <= path || *(s - 1) != '/') && t > path + 1 && *(t - 1) == '/') t--;
+#endif
+				*t = 0;
+				errno = oerrno;
+				return t;
+			}
+			dots = 0;
+			p = t;
+			break;
+		default:
+			dots = 4;
+			break;
+		}
+}