int
rfc2671RROptPack(char *buf, size_t sz, ssize_t edns_sz)
{
// set the OPT record correctly. base it on a macro size of the Squid DNS read buffer
static rfc1035_rr opt;
// EDNS OPT record says only what our DNS buffer size is so far.
snprintf(opt.name, RFC1035_MAXHOSTNAMESZ, ".");
opt.type = RFC1035_TYPE_OPT;
opt._class = min(edns_sz, (ssize_t)SQUID_UDP_SO_RCVBUF-1);
opt.ttl = 0; // relevant?
opt.rdata = NULL;
opt.rdlength = 0;
return rfc1035RRPack(buf, sz, &opt);
}
ssize_t rfc1035BuildAReply(const char *hostname, const ACL_ARGV *ip_argv,
const char *dnsname, const char *dns_ip,
unsigned short qid, char *buf, size_t sz)
{
rfc1035_message h;
rfc1035_rr rr;
size_t offset = 0;
unsigned int nip;
int i;
memset(&h, '\0', sizeof(h));
h.id = qid;
h.qr = 1;
h.opcode = 0; /* QUERY */
h.aa = 0;
h.tc = 0;
h.rd = 1;
h.ra = 0;
h.rcode = 0;
h.qdcount = 1;
h.ancount = ip_argv->argc;
h.nscount = (dnsname && *dnsname) ? 1 : 0;
h.arcount = (h.nscount && dns_ip && *dns_ip) ? 1 : 0;
offset += rfc1035HeaderPack(buf + offset, sz - offset, &h);
offset += rfc1035QuestionPack(buf + offset, sz - offset, hostname,
RFC1035_TYPE_A, RFC1035_CLASS_IN);
for (i = 0; i < ip_argv->argc; i++) {
memset(&rr, 0, sizeof(rr));
snprintf(rr.name, sizeof(rr.name), "%s", hostname);
rr.type = RFC1035_TYPE_A;
rr.tclass = RFC1035_CLASS_IN;
rr.ttl = 5;
rr.rdlength = 4;
nip = inet_addr(ip_argv->argv[i]);
rr.rdata = (char*) acl_mycalloc(1, rr.rdlength);
memcpy(rr.rdata, &nip, rr.rdlength);
offset += rfc1035RRPack(&rr, buf + offset, sz - offset);
acl_myfree(rr.rdata);
}
if (h.nscount) {
memset(&rr, 0, sizeof(rr));
snprintf(rr.name, sizeof(rr.name), "%s", dnsname);
rr.type = RFC1035_TYPE_NS;
rr.tclass = RFC1035_CLASS_IN;
rr.ttl = 5;
rr.rdlength = (unsigned short) strlen(dnsname);
rr.rdata = acl_mystrdup(dnsname);
offset += rfc1035RRPack(&rr, buf + offset, sz - offset);
acl_myfree(rr.rdata);
}
if (h.arcount) {
memset(&rr, 0, sizeof(rr));
snprintf(rr.name, sizeof(rr.name), "%s", dnsname);
rr.type = RFC1035_TYPE_NS;
rr.tclass = RFC1035_CLASS_IN;
rr.ttl = 5;
rr.rdlength = (unsigned short) strlen(dns_ip);
rr.rdata = acl_mystrdup(dns_ip);
offset += rfc1035RRPack(&rr, buf + offset, sz - offset);
acl_myfree(rr.rdata);
}
return ((int) offset);
}