From: Andrew Tridgell <tridge@samba.org>
Date: Sun, 31 Mar 2002 05:01:05 +0000 (+0200)
Subject: use realpath() to handle multiple levels of symlinks
X-Git-Tag: v1.1~6
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=0b82aa4f7254dd1539534faffbe84983fe5d792f;p=thirdparty%2Fccache.git

use realpath() to handle multiple levels of symlinks
---

diff --git a/README b/README
index 4baf89eab..8cd244bdf 100644
--- a/README
+++ b/README
@@ -151,9 +151,5 @@ please let me know.
 ===================
 Andrew Tridgell
 http://samba.org/~tridge/
+bugs@ccache.samba.org
 March 2002
-
-PS: I get far too much email to answer, so don't be surprised if you
-have a hard time getting hold of me. You might try the
-#samba-technical IRC channel on irc.openprojects.net if you need me
-quickly.
diff --git a/ccache.c b/ccache.c
index 265aa0c10..d4270124f 100644
--- a/ccache.c
+++ b/ccache.c
@@ -368,22 +368,19 @@ static void find_compiler(int argc, char **argv)
 		    lstat(fname, &st1) == 0 &&
 		    stat(fname, &st2) == 0 &&
 		    S_ISREG(st2.st_mode)) {
-			char buf[1024];
-			int len;
-
 			/* if its a symlink then ensure it doesn't
                            point at something called "ccache" */
 			if (S_ISLNK(st1.st_mode)) {
-				char *p;
-				len = readlink(fname, buf, sizeof(buf));
-				if (len != -1 && len < (int)sizeof(buf)) {
-					buf[len] = 0;
-					p = basename(buf);
+				char *buf = x_realpath(fname);
+				if (buf) {
+					char *p = basename(buf);
 					if (strcmp(p, MYNAME) == 0) {
 						/* its a link to "ccache" ! */
 						free(p);
+						free(buf);
 						continue;
 					}
+					free(buf);
 					free(p);
 				}
 			}
diff --git a/ccache.h b/ccache.h
index 354b47324..908bc30b4 100644
--- a/ccache.h
+++ b/ccache.h
@@ -18,6 +18,7 @@
 #include <utime.h>
 #include <stdarg.h>
 #include <dirent.h>
+#include <limits.h>
 
 #define STATUS_NOTFOUND 3
 #define STATUS_FATAL 4
@@ -76,6 +77,7 @@ char *dirname(char *s);
 int lock_fd(int fd);
 size_t file_size(struct stat *st);
 int safe_open(const char *fname);
+char *x_realpath(const char *path);
 
 void stats_update(enum stats stat);
 void stats_zero(void);
diff --git a/util.c b/util.c
index 7ef5baee4..2a155d219 100644
--- a/util.c
+++ b/util.c
@@ -295,3 +295,33 @@ size_t value_units(const char *s)
 	}
 	return v;
 }
+
+
+/*
+  a sane realpath() function, trying to cope with stupid path limits and 
+  a broken API
+*/
+char *x_realpath(const char *path)
+{
+	int maxlen;
+	char *ret, *p;
+#ifdef PATH_MAX
+	maxlen = PATH_MAX;
+#elif defined(MAXPATHLEN)
+	maxlen = MAXPATHLEN;
+#elif defined(_PC_PATH_MAX)
+	maxlen = pathconf(path, _PC_PATH_MAX);
+#endif
+	if (maxlen < 4096) maxlen = 4096;
+	
+	ret = x_malloc(maxlen);
+	
+	p = realpath(path, ret);
+	if (p) {
+		p = x_strdup(p);
+		free(ret);
+		return p;
+	}
+	free(ret);
+	return NULL;
+}