Hunter Trap GVG Knockback

[Nyaniverse]

Good day rAthena,

I am currently trying to edit my Blast Mine to be able to get knocked back using Arrow Shower. ( I want it to behave like how it behaves in non-gvg maps)

I am very new to source coding so I am not even sure on what I should work with, I know that I have to look at this particular area, but I am not sure on what or how I should proceed. Any tips or guide on what to do next would be really appreciated.

/**
 * Checks if unit can be knocked back / stopped by skills.
 * @param bl: Object to check
 * @param flag
 *		0x1 - Offensive (not set: self skill, e.g. Backslide)
 *		0x2 - Knockback type (not set: Stop type, e.g. Ankle Snare)
 *		0x4 - Boss attack
 *		0x8 - Ignore target player 'special_state.no_knockback'
 * @return reason for immunity
 *		UB_KNOCKABLE - can be knocked back / stopped
 *		UB_NO_KNOCKBACK_MAP - at WOE/BG map
 *		UB_MD_KNOCKBACK_IMMUNE - target is MD_KNOCKBACK_IMMUNE
 *		UB_TARGET_BASILICA - target is in Basilica area (Pre-Renewal)
 *		UB_TARGET_NO_KNOCKBACK - target has 'special_state.no_knockback'
 *		UB_TARGET_TRAP - target is trap that cannot be knocked back
 */
enum e_unit_blown unit_blown_immune(struct block_list* bl, uint8 flag)
{
	if ((flag&0x1)
		&& (map_flag_gvg2(bl->m) || map_getmapflag(bl->m, MF_BATTLEGROUND))
		&& ((flag&0x2) || !(battle_config.skill_trap_type&0x1)))
		return UB_NO_KNOCKBACK_MAP; // No knocking back in WoE / BG
	
	switch (bl->type) {
		case BL_MOB:
			// Immune can't be knocked back
			if (((flag&0x1) && status_bl_has_mode(bl,MD_KNOCKBACKIMMUNE))
				&& ((flag&0x2) || !(battle_config.skill_trap_type&0x2)))
				return UB_MD_KNOCKBACK_IMMUNE;
			break;
		case BL_PC: {
				map_session_data *sd = BL_CAST(BL_PC, bl);

#ifndef RENEWAL
				// Basilica caster can't be knocked-back by normal monsters.
				if( !(flag&0x4) && sd->sc.getSCE(SC_BASILICA) && sd->sc.getSCE(SC_BASILICA)->val4 == sd->bl.id)
					return UB_TARGET_BASILICA;
#endif
				// Target has special_state.no_knockback (equip)
				if( (flag&(0x1|0x2)) && !(flag&0x8) && sd->special_state.no_knockback )
					return UB_TARGET_NO_KNOCKBACK;
			}
			break;
		
		case BL_SKILL: {
				struct skill_unit* su = (struct skill_unit *)bl;
				// Trap cannot be knocked back
				if (su && su->group && skill_get_unit_flag(su->group->skill_id, UF_NOKNOCKBACK))
					return UB_TARGET_TRAP;
			}
			break;
	}

	//Object can be knocked back / stopped
	return UB_KNOCKABLE;
}