/*
 * pythonmod_utils.c: utilities used by wrapper
 *
 * Copyright (c) 2009, Zdenek Vasicek (vasicek AT fit.vutbr.cz)
 *                     Marek Vavrusa  (xvavru00 AT stud.fit.vutbr.cz)
 *
 * This software is open source.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *    * Redistributions of source code must retain the above copyright notice,
 *      this list of conditions and the following disclaimer.
 *
 *    * Redistributions in binary form must reproduce the above copyright notice,
 *      this list of conditions and the following disclaimer in the documentation
 *      and/or other materials provided with the distribution.
 *
 *    * Neither the name of the organization nor the names of its
 *      contributors may be used to endorse or promote products derived from this
 *      software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */
/**
 * \file
 * Utility functions for the python module that perform stores and loads and
 * conversions.
 */
#include "config.h"
#include "pythonmod/pythonmod_utils.h"
#include "util/module.h"
#include "util/netevent.h"
#include "util/net_help.h"
#include "services/cache/dns.h"
#include "services/cache/rrset.h"
#include "util/data/msgparse.h"
#include "util/data/msgreply.h"
#include "util/storage/slabhash.h"
#include "util/regional.h"
#include "iterator/iter_delegpt.h"
#include "sldns/sbuffer.h"

#undef _POSIX_C_SOURCE
#undef _XOPEN_SOURCE
#include <Python.h>

/* Store the reply_info and query_info pair in message cache
 * (qstate->msg_cache) */
int storeQueryInCache(struct module_qstate* qstate, struct query_info* qinfo,
	struct reply_info* msgrep, int is_referral)
{
	if (!msgrep)
		return 0;

	/* authoritative answer can't be stored in cache */
	if (msgrep->authoritative) {
		PyErr_SetString(PyExc_ValueError,
			"Authoritative answer can't be stored");
		return 0;
	}

	return dns_cache_store(qstate->env, qinfo, msgrep, is_referral,
		qstate->prefetch_leeway, 0, NULL, qstate->query_flags);
}

/* Invalidate the message associated with query_info stored in message cache */
void invalidateQueryInCache(struct module_qstate* qstate,
	struct query_info* qinfo)
{
	hashvalue_type h;
	struct lruhash_entry* e;
	struct reply_info *r;
	size_t i, j;

	h = query_info_hash(qinfo, qstate->query_flags);
	if ((e=slabhash_lookup(qstate->env->msg_cache, h, qinfo, 0))) {
		r = (struct reply_info*)(e->data);
		if (r) {
			r->ttl = 0;
			if(rrset_array_lock(r->ref, r->rrset_count, *qstate->env->now)) {
				for(i=0; i< r->rrset_count; i++) {
					struct packed_rrset_data* data =
						(struct packed_rrset_data*) r->ref[i].key->entry.data;
					if(i>0 && r->ref[i].key == r->ref[i-1].key)
						continue;

					data->ttl = r->ttl;
					for(j=0; j<data->count + data->rrsig_count; j++)
						data->rr_ttl[j] = r->ttl;
				}
				rrset_array_unlock(r->ref, r->rrset_count);
			}
		}
		lock_rw_unlock(&e->lock);
	} else {
		log_info("invalidateQueryInCache: qinfo is not in cache");
	}
}

/* Create response according to the ldns packet content */
int createResponse(struct module_qstate* qstate, sldns_buffer* pkt)
{
	struct msg_parse* prs;
	struct edns_data edns;

	/* parse message */
	prs = (struct msg_parse*) regional_alloc(qstate->env->scratch,
		sizeof(struct msg_parse));
	if(!prs) {
		log_err("createResponse: out of memory on incoming message");
		return 0;
	}

	memset(prs, 0, sizeof(*prs));
	memset(&edns, 0, sizeof(edns));

	sldns_buffer_set_position(pkt, 0);
	if(parse_packet(pkt, prs, qstate->env->scratch) != LDNS_RCODE_NOERROR) {
		verbose(VERB_ALGO, "createResponse: parse error on reply packet");
		return 0;
	}
	/* edns is not examined, but removed from message to help cache */
	if(parse_extract_edns_from_response_msg(prs, &edns, qstate->env->scratch) !=
		LDNS_RCODE_NOERROR)
		return 0;

	/* remove CD-bit, we asked for in case we handle validation ourself */
	prs->flags &= ~BIT_CD;

	/* allocate response dns_msg in region */
	qstate->return_msg = (struct dns_msg*) regional_alloc(qstate->region,
		sizeof(struct dns_msg));
	if(!qstate->return_msg)
		return 0;

	memset(qstate->return_msg, 0, sizeof(*qstate->return_msg));
	if(!parse_create_msg(pkt, prs, NULL, &(qstate->return_msg)->qinfo,
		&(qstate->return_msg)->rep, qstate->region)) {
		log_err("createResponse: malloc failure: allocating incoming dns_msg");
		return 0;
	}

	/* Make sure that the RA flag is set (since the presence of
	* this module means that recursion is available) */
	/* qstate->return_msg->rep->flags |= BIT_RA; */

	/* Clear the AA flag */
	/* FIXME: does this action go here or in some other module? */
	/*qstate->return_msg->rep->flags &= ~BIT_AA; */

	/* make sure QR flag is on */
	/*qstate->return_msg->rep->flags |= BIT_QR; */

	if(verbosity >= VERB_ALGO)
		log_dns_msg("createResponse: packet:", &qstate->return_msg->qinfo,
			qstate->return_msg->rep);

	return 1;
}


/* Convert reply->addr to string */
void reply_addr2str(struct comm_reply* reply, char* dest, int maxlen)
{
	int af = (int)((struct sockaddr_in*) &(reply->addr))->sin_family;
	void* sinaddr = &((struct sockaddr_in*) &(reply->addr))->sin_addr;

	if(af == AF_INET6)
		sinaddr = &((struct sockaddr_in6*)&(reply->addr))->sin6_addr;
	dest[0] = 0;
	if (inet_ntop(af, sinaddr, dest, (socklen_t)maxlen) == 0)
		return;
	dest[maxlen-1] = 0;
}

/* Convert target->addr to string */
void delegpt_addr_addr2str(struct delegpt_addr* target, char *dest, int maxlen)
{
	int af = (int)((struct sockaddr_in*) &(target->addr))->sin_family;
	void* sinaddr = &((struct sockaddr_in*) &(target->addr))->sin_addr;

	if(af == AF_INET6)
		sinaddr = &((struct sockaddr_in6*)&(target->addr))->sin6_addr;
	dest[0] = 0;
	if (inet_ntop(af, sinaddr, dest, (socklen_t)maxlen) == 0)
		return;
	dest[maxlen-1] = 0;
}