+static int
+parse_flow_tun_flags(const char *s_, const char *(*bit_to_string)(uint32_t),
+ ovs_be16 *res)
+{
+ uint32_t result = 0;
+ char *save_ptr = NULL;
+ char *name;
+ int rc = 0;
+ char *s = xstrdup(s_);
+
+ for (name = strtok_r((char *)s, " |", &save_ptr); name;
+ name = strtok_r(NULL, " |", &save_ptr)) {
+ int name_len;
+ unsigned long long int flags;
+ uint32_t bit;
+ int n0;
+
+ if (sscanf(name, "%lli%n", &flags, &n0) > 0 && n0 > 0) {
+ result |= flags;
+ continue;
+ }
+ name_len = strlen(name);
+ for (bit = 1; bit; bit <<= 1) {
+ const char *fname = bit_to_string(bit);
+ size_t len;
+
+ if (!fname) {
+ continue;
+ }
+
+ len = strlen(fname);
+ if (len != name_len) {
+ continue;
+ }
+ if (!strncmp(name, fname, len)) {
+ result |= bit;
+ break;
+ }
+ }
+
+ if (!bit) {
+ rc = -ENOENT;
+ goto out;
+ }
+ }
+
+ *res = htons(result);
+out:
+ free(s);
+ return rc;
+}
+
+static char *
+mf_from_tun_flags_string(const char *s, ovs_be16 *valuep)
+{
+ if (!parse_flow_tun_flags(s, flow_tun_flag_to_string, valuep)) {
+ return NULL;
+ }
+
+ return xasprintf("%s: unknown tunnel flags (valid flags are \"df\", "
+ "\"csum\", \"key\"", s);
+}
+