libxtables: Combine the two extension option mergers

For extending the command parser's struct option array, there is
xtables_merge_options() and xtables_options_xfrm(). Since their bodies
were almost identical, make the latter a wrapper of the former by
transforming the passed struct xt_option_entry array into a temporary
struct option one before handing over.

Signed-off-by: Phil Sutter <phil@nwl.cc>

diff --git a/libxtables/xtoptions.c b/libxtables/xtoptions.c
index b16bbfbe323116e2c9201adbce9fcd35236b80fb..0667315ceccf89b26d9deeeda4cfb83c693e6acb 100644 (file)
--- a/libxtables/xtoptions.c
+++ b/libxtables/xtoptions.c
@@ -73,56 +73,21 @@ struct option *
 xtables_options_xfrm(struct option *orig_opts, struct option *oldopts,
                     const struct xt_option_entry *entry, unsigned int *offset)
 {
-       unsigned int num_orig, num_old = 0, num_new, i;
+       int num_new, i;
        struct option *merge, *mp;
 
-       if (entry == NULL)
-               return oldopts;
-       for (num_orig = 0; orig_opts[num_orig].name != NULL; ++num_orig)
-               ;
-       if (oldopts != NULL)
-               for (num_old = 0; oldopts[num_old].name != NULL; ++num_old)
-                       ;
        for (num_new = 0; entry[num_new].name != NULL; ++num_new)
                ;
 
-       /*
-        * Since @oldopts also has @orig_opts already (and does so at the
-        * start), skip these entries.
-        */
-       if (oldopts != NULL) {
-               oldopts += num_orig;
-               num_old -= num_orig;
-       }
-
-       merge = malloc(sizeof(*mp) * (num_orig + num_old + num_new + 1));
-       if (merge == NULL)
-               return NULL;
-
-       /* Let the base options -[ADI...] have precedence over everything */
-       memcpy(merge, orig_opts, sizeof(*mp) * num_orig);
-       mp = merge + num_orig;
-
-       /* Second, the new options */
-       xt_params->option_offset += XT_OPTION_OFFSET_SCALE;
-       *offset = xt_params->option_offset;
-
-       for (i = 0; i < num_new; ++i, ++mp, ++entry) {
-               mp->name         = entry->name;
-               mp->has_arg      = entry->type != XTTYPE_NONE;
-               mp->flag         = NULL;
-               mp->val          = entry->id + *offset;
-       }
-
-       /* Third, the old options */
-       if (oldopts != NULL) {
-               memcpy(mp, oldopts, sizeof(*mp) * num_old);
-               mp += num_old;
+       mp = xtables_calloc(num_new, sizeof(*mp));
+       for (i = 0; i < num_new; i++) {
+               mp[i].name      = entry[i].name;
+               mp[i].has_arg   = entry[i].type != XTTYPE_NONE;
+               mp[i].val       = entry[i].id;
        }
-       xtables_free_opts(0);
+       merge = xtables_merge_options(orig_opts, oldopts, mp, offset);
 
-       /* Clear trailing entry */
-       memset(mp, 0, sizeof(*mp));
+       free(mp);
        return merge;
 }