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authorGravatar Paul Fox <pgf@brightstareng.com>2007-11-08 20:00:36 +0000
committerGravatar Paul Fox <pgf@brightstareng.com>2007-11-08 20:00:36 +0000
commit599bbfbd9be0073c262319a120174fad5a60113e (patch)
treed1145b8f98fd138241c72ac4601389d748b5d580 /libbb
parentabbd363261cf3a9b18e611c524f8103fb68f539b (diff)
downloadbusybox-599bbfbd9be0073c262319a120174fad5a60113e.tar.gz
busybox-599bbfbd9be0073c262319a120174fad5a60113e.tar.bz2
xmalloc_follow_symlinks() -- fix ELOOP issue with absolute paths,
return full path in cases where path doesn't resolve to a link. change name to better differentiate from xmalloc_readlink().
Diffstat (limited to 'libbb')
-rw-r--r--libbb/update_passwd.c2
-rw-r--r--libbb/xreadlink.c37
2 files changed, 23 insertions, 16 deletions
diff --git a/libbb/update_passwd.c b/libbb/update_passwd.c
index e99db40c0..d10e863c6 100644
--- a/libbb/update_passwd.c
+++ b/libbb/update_passwd.c
@@ -52,7 +52,7 @@ int update_passwd(const char *filename, const char *username,
int cnt = 0;
int ret = -1; /* failure */
- filename = xmalloc_readlink_follow(filename);
+ filename = xmalloc_follow_symlinks(filename);
if (filename == NULL)
return -1;
diff --git a/libbb/xreadlink.c b/libbb/xreadlink.c
index f7948cbf3..a5f7eb8be 100644
--- a/libbb/xreadlink.c
+++ b/libbb/xreadlink.c
@@ -33,13 +33,16 @@ char *xmalloc_readlink(const char *path)
}
/*
- * this routine is not the same as realpath(), which canonicalizes
- * the given path completely. this routine only follows trailing
- * symlinks until a real file is reached, and returns its name.
- * intermediate symlinks are not expanded. as above, a malloced
- * char* is returned, which must be freed.
+ * this routine is not the same as realpath(), which
+ * canonicalizes the given path completely. this routine only
+ * follows trailing symlinks until a real file is reached, and
+ * returns its name. if the path ends in a dangling link, or if
+ * the target doesn't exist, the path is returned in any case.
+ * intermediate symlinks in the path are not expanded -- only
+ * those at the tail.
+ * a malloced char* is returned, which must be freed by the caller.
*/
-char *xmalloc_readlink_follow(const char *path)
+char *xmalloc_follow_symlinks(const char *path)
{
char *buf;
char *lpc;
@@ -47,23 +50,27 @@ char *xmalloc_readlink_follow(const char *path)
int bufsize;
int looping = MAXSYMLINKS + 1;
- linkpath = xstrdup(path);
+ buf = xstrdup(path);
goto jump_in;
while (1) {
- if (!--looping) {
- free(linkpath);
- free(buf);
- return NULL;
- }
+
linkpath = xmalloc_readlink(buf);
if (!linkpath) {
- if (errno == EINVAL) /* not a symlink */
+ /* not a symlink, or doesn't exist */
+ if (errno == EINVAL || errno == ENOENT)
return buf;
free(buf);
return NULL;
}
- if (linkpath[0] != '/') {
+
+ if (!--looping) {
+ free(linkpath);
+ free(buf);
+ return NULL;
+ }
+
+ if (*linkpath != '/') {
bufsize += strlen(linkpath);
buf = xrealloc(buf, bufsize);
lpc = bb_get_last_path_component_strip(buf);
@@ -71,8 +78,8 @@ char *xmalloc_readlink_follow(const char *path)
free(linkpath);
} else {
free(buf);
- jump_in:
buf = linkpath;
+ jump_in:
bufsize = strlen(buf) + 1;
}
}