int reply_info_parse(sldns_buffer* pkt, struct alloc_cache* alloc,
struct query_info* qinf, struct reply_info** rep,
struct regional* region, struct edns_data* edns)
{
/* use scratch pad region-allocator during parsing. */
struct msg_parse* msg;
int ret;
qinf->qname = NULL;
*rep = NULL;
if(!(msg = regional_alloc(region, sizeof(*msg)))) {
return LDNS_RCODE_SERVFAIL;
}
memset(msg, 0, sizeof(*msg));
sldns_buffer_set_position(pkt, 0);
if((ret = parse_packet(pkt, msg, region)) != 0) {
return ret;
}
if((ret = parse_extract_edns(msg, edns)) != 0)
return ret;
/* parse OK, allocate return structures */
/* this also performs dname decompression */
if(!parse_create_msg(pkt, msg, alloc, qinf, rep, NULL)) {
query_info_clear(qinf);
reply_info_parsedelete(*rep, alloc);
*rep = NULL;
return LDNS_RCODE_SERVFAIL;
}
return 0;
}
/* 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("storeResponse: 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, "storeResponse: parse error on reply packet");
return 0;
}
/* edns is not examined, but removed from message to help cache */
if(parse_extract_edns(prs, &edns) != 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("storeResponse: 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("storeResponse: packet:", &qstate->return_msg->qinfo, qstate->return_msg->rep);
return 1;
}
/** convert dns message in buffer to return_msg */
static int
parse_data(struct module_qstate* qstate, struct sldns_buffer* buf)
{
struct msg_parse* prs;
struct edns_data edns;
uint64_t timestamp, expiry;
time_t adjust;
size_t lim = sldns_buffer_limit(buf);
if(lim < LDNS_HEADER_SIZE+sizeof(timestamp)+sizeof(expiry))
return 0; /* too short */
/* remove timestamp and expiry from end */
sldns_buffer_read_at(buf, lim-sizeof(expiry), &expiry, sizeof(expiry));
sldns_buffer_read_at(buf, lim-sizeof(expiry)-sizeof(timestamp),
×tamp, sizeof(timestamp));
expiry = be64toh(expiry);
timestamp = be64toh(timestamp);
/* parse DNS packet */
regional_free_all(qstate->env->scratch);
prs = (struct msg_parse*)regional_alloc(qstate->env->scratch,
sizeof(struct msg_parse));
if(!prs)
return 0; /* out of memory */
memset(prs, 0, sizeof(*prs));
memset(&edns, 0, sizeof(edns));
sldns_buffer_set_limit(buf, lim - sizeof(expiry)-sizeof(timestamp));
if(parse_packet(buf, prs, qstate->env->scratch) != LDNS_RCODE_NOERROR) {
sldns_buffer_set_limit(buf, lim);
return 0;
}
if(parse_extract_edns(prs, &edns, qstate->env->scratch) !=
LDNS_RCODE_NOERROR) {
sldns_buffer_set_limit(buf, lim);
return 0;
}
qstate->return_msg = dns_alloc_msg(buf, prs, qstate->region);
sldns_buffer_set_limit(buf, lim);
if(!qstate->return_msg)
return 0;
qstate->return_rcode = LDNS_RCODE_NOERROR;
/* see how much of the TTL expired, and remove it */
if(*qstate->env->now <= (time_t)timestamp) {
verbose(VERB_ALGO, "cachedb msg adjust by zero");
return 1; /* message from the future (clock skew?) */
}
adjust = *qstate->env->now - (time_t)timestamp;
if(qstate->return_msg->rep->ttl < adjust) {
verbose(VERB_ALGO, "cachedb msg expired");
/* If serve-expired is enabled, we still use an expired message
* setting the TTL to 0. */
if(qstate->env->cfg->serve_expired)
adjust = -1;
else
return 0; /* message expired */
}
verbose(VERB_ALGO, "cachedb msg adjusted down by %d", (int)adjust);
adjust_msg_ttl(qstate->return_msg, adjust);
/* Similar to the unbound worker, if serve-expired is enabled and
* the msg would be considered to be expired, mark the state so a
* refetch will be scheduled. The comparison between 'expiry' and
* 'now' should be redundant given how these values were calculated,
* but we check it just in case as does good_expiry_and_qinfo(). */
if(qstate->env->cfg->serve_expired &&
(adjust == -1 || (time_t)expiry < *qstate->env->now)) {
qstate->need_refetch = 1;
}
return 1;
}
