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authorYann Sionneau <yann@sionneau.net>2020-10-19 08:09:54 +0200
committerWaldemar Brodkorb <wbx@openadk.org>2020-10-19 09:51:48 +0200
commit27b5b58381dfebb32315f78410694ba6b6551b8e (patch)
tree8c7523bc7f918207b6aceb4daf2356e809f6760b /libc
parentb335e9d7de011d814e4cce87e2156bb13ccc7c3d (diff)
hasmntopt: better option matching
Previous implementation was respecting the man page description of what the function should do. Also the function does not seem to be defined by POSIX. But... to be really useful the function needs to handle option matching and not just substring matching. This is copy pasted from glibc. This fixes issue reported by https://github.com/wbx-github/uclibc-ng/issues/8 that can happen for instance there: https://github.com/frida/glib/blob/master/gio/gunixmounts.c#L622 Signed-off-by: Yann Sionneau <yann@sionneau.net>
Diffstat (limited to 'libc')
-rw-r--r--libc/misc/mntent/mntent.c21
1 files changed, 19 insertions, 2 deletions
diff --git a/libc/misc/mntent/mntent.c b/libc/misc/mntent/mntent.c
index 608f84c1a..610e35af6 100644
--- a/libc/misc/mntent/mntent.c
+++ b/libc/misc/mntent/mntent.c
@@ -1,5 +1,6 @@
/*
* Copyright (C) 2000-2006 Erik Andersen <andersen@uclibc.org>
+ * Copyright (C) 1995-2020 Free Software Foundation, Inc.
*
* Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
*/
@@ -92,9 +93,25 @@ int addmntent(FILE * filep, const struct mntent *mnt)
mnt->mnt_type, mnt->mnt_opts, mnt->mnt_freq, mnt->mnt_passno) < 0 ? 1 : 0);
}
-char *hasmntopt(const struct mntent *mnt, const char *opt)
+/* Search MNT->mnt_opts for an option matching OPT.
+ Returns the address of the substring, or null if none found. */
+char *hasmntopt (const struct mntent *mnt, const char *opt)
{
- return strstr(mnt->mnt_opts, opt);
+ const size_t optlen = strlen(opt);
+ char *rest = mnt->mnt_opts, *p;
+
+ while ((p = strstr(rest, opt)) != NULL) {
+ if ((p == rest || p[-1] == ',')
+ && (p[optlen] == '\0' || p[optlen] == '=' || p[optlen] == ','))
+ return p;
+
+ rest = strchr(p, ',');
+ if (rest == NULL)
+ break;
+ ++rest;
+ }
+
+ return NULL;
}
FILE *setmntent(const char *name, const char *mode)