1 files changed, 20 insertions, 8 deletions

diff --git a/util-linux/mount.c b/util-linux/mount.c
index 13590ceb4..eb8b7ba7b 100644
--- a/util-linux/mount.c
+++ b/util-linux/mount.c
@@ -1931,7 +1931,6 @@ static int singlemount(struct mntent *mp, int ignore_busy)
                 int len;
                 char c;
                 char *hostname, *share;
-                char *dotted, *ip;
                 len_and_sockaddr *lsa;
 
                 // Parse mp->mnt_fsname of the form "//hostname/share[/dir1/dir2]"
@@ -1971,13 +1970,26 @@ static int singlemount(struct mntent *mp, int ignore_busy)
                 if (!lsa)
                         goto report_error;
 
-                // Insert "ip=..." option into options
-                dotted = xmalloc_sockaddr2dotted_noport(&lsa->u.sa);
-                if (ENABLE_FEATURE_CLEAN_UP) free(lsa);
-                ip = xasprintf("ip=%s", dotted);
-                if (ENABLE_FEATURE_CLEAN_UP) free(dotted);
-                parse_mount_options(ip, &filteropts);
-                if (ENABLE_FEATURE_CLEAN_UP) free(ip);
+                // If there is no "ip=..." option yet
+                if (!is_prefixed_with(filteropts, ",ip="+1)
+                 && !strstr(filteropts, ",ip=")
+                ) {
+                        char *dotted, *ip;
+                        // Insert "ip=..." option into options
+                        dotted = xmalloc_sockaddr2dotted_noport(&lsa->u.sa);
+                        if (ENABLE_FEATURE_CLEAN_UP) free(lsa);
+                        ip = xasprintf("ip=%s", dotted);
+                        if (ENABLE_FEATURE_CLEAN_UP) free(dotted);
+// Note: IPv6 scoped addresses ("host%iface", see RFC 4007) should be
+// handled by libc in getnameinfo() (inside xmalloc_sockaddr2dotted_noport()).
+// Currently, glibc does not support that (has no NI_NUMERICSCOPE),
+// musl apparently does. This results in "ip=numericIPv6%iface_name"
+// (instead of _numeric_ iface_id) with glibc.
+// This probably should be fixed in glibc, not here.
+// The workaround is to manually specify correct "ip=ADDR%n" option.
+                        parse_mount_options(ip, &filteropts);
+                        if (ENABLE_FEATURE_CLEAN_UP) free(ip);
+                }
 
                 mp->mnt_type = (char*)"cifs";
                 rc = mount_it_now(mp, vfsflags, filteropts);