int response_cname(const char *c,const char *d,uint32 ttl)
{
if (!response_rstart(c,DNS_T_CNAME,ttl)) return 0;
if (!response_addname(d)) return 0;
response_rfinish(RESPONSE_ANSWER);
return 1;
}
int response_cname(char *c,char *d)
{
if (!response_rstart(c,DNS_T_CNAME,"\0\0\0\0")) return 0;
if (!response_addname(d)) return 0;
response_rfinish(RESPONSE_ANSWER);
return 1;
}
int response_rstart(char *d,char type[2],char ttl[4])
{
if (!response_addname(d)) return 0;
if (!response_addbytes(type,2)) return 0;
if (!response_addbytes(DNS_C_IN,2)) return 0;
if (!response_addbytes(ttl,4)) return 0;
if (!response_addbytes("\0\0",2)) return 0;
dpos = response_len;
return 1;
}
int response_query(char *q,char qtype[2])
{
response_len = 0;
name_num = 0;
if (!response_addbytes("\0\0\201\200\0\1\0\0\0\0\0\0",12)) return 0;
if (!response_addname(q)) return 0;
if (!response_addbytes(qtype,2)) return 0;
if (!response_addbytes(DNS_C_IN,2)) return 0;
tctarget = response_len;
return 1;
}
int response_rstart(const char *d,const char type[2],uint32 ttl)
{
char ttlstr[4];
if (!response_addname(d)) return 0;
if (!response_addbytes(type,2)) return 0;
if (!response_addbytes(DNS_C_IN,2)) return 0;
if (flaghidettl) ttl = 0;
uint32_pack_big(ttlstr,ttl);
if (!response_addbytes(ttlstr,4)) return 0;
if (!response_addbytes("\0\0",2)) return 0;
dpos = response_len;
return 1;
}
int
response_query (const char *q, const char qtype[2], const char qclass[2])
{
response_len = name_num = 0;
if (!response_addbytes ("\0\0\201\200\0\1\0\0\0\0\0\0", 12))
return 0;
if (!response_addname (q))
return 0;
if (!response_addbytes (qtype, 2))
return 0;
if (!response_addbytes (qclass, 2))
return 0;
tctarget = response_len;
return 1;
}
static int doname(void)
{
dpos = dns_packet_getname(data,dlen,dpos,&d1);
if (!dpos) return 0;
return response_addname(d1);
}
static int doit(char *q,char qtype[2])
{
unsigned int bpos;
unsigned int anpos;
unsigned int aupos;
unsigned int arpos;
char *control;
char *wild;
int flaggavesoa;
int flagfound;
int r;
int flagns;
int flagauthoritative;
char x[20];
uint16 u16;
char addr[8][4];
int addrnum;
uint32 addrttl;
int i;
anpos = response_len;
control = q;
for (;;) {
flagns = 0;
flagauthoritative = 0;
cdb_findstart(&c);
while (r = find(control,0)) {
if (r == -1) return 0;
if (byte_equal(type,2,DNS_T_SOA)) flagauthoritative = 1;
if (byte_equal(type,2,DNS_T_NS)) flagns = 1;
}
if (flagns) break;
if (!*control) {
/* q is not within our bailiwick */
flagfound = 0;
if (byte_diff(lameip,4,"\0\0\0\0"))
if (byte_equal(qtype,2,DNS_T_A) || byte_equal(qtype,2,DNS_T_ANY)) {
if (!response_rstart(q,DNS_T_A,3600)) return 0;
if (!response_addbytes(lameip,4)) return 0;
response_rfinish(RESPONSE_ANSWER);
flagfound = 1;
}
if (lamemx)
if (byte_equal(qtype,2,DNS_T_MX) || byte_equal(qtype,2,DNS_T_ANY)) {
if (!response_rstart(q,DNS_T_MX,3600)) return 0;
if (!response_addbytes("\0\0",2)) return 0;
if (!response_addname(lamemx)) return 0;
response_rfinish(RESPONSE_ANSWER);
flagfound = 1;
}
if (lametxt.len)
if (byte_equal(qtype,2,DNS_T_TXT) || byte_equal(qtype,2,DNS_T_ANY)) {
if (!response_rstart(q,DNS_T_TXT,3600)) return 0;
if (!response_addbytes(lametxt.s,lametxt.len)) return 0;
response_rfinish(RESPONSE_ANSWER);
flagfound = 1;
}
if (flagfound) return 2;
return 0;
}
control += *control;
control += 1;
}
if (!flagauthoritative) {
response[2] &= ~4;
goto AUTHORITY; /* q is in a child zone */
}
flaggavesoa = 0;
flagfound = 0;
wild = q;
for (;;) {
addrnum = 0;
addrttl = 0;
cdb_findstart(&c);
while (r = find(wild,wild != q)) {
if (r == -1) return 0;
flagfound = 1;
if (flaggavesoa && byte_equal(type,2,DNS_T_SOA)) continue;
if (byte_diff(type,2,qtype) && byte_diff(qtype,2,DNS_T_ANY) && byte_diff(type,2,DNS_T_CNAME)) continue;
if (byte_equal(type,2,DNS_T_A) && (dlen - dpos == 4)) {
addrttl = ttl;
i = dns_random(addrnum + 1);
if (i < 8) {
if ((i < addrnum) && (addrnum < 8))
byte_copy(addr[addrnum],4,addr[i]);
byte_copy(addr[i],4,data + dpos);
}
if (addrnum < 1000000) ++addrnum;
continue;
}
if (!response_rstart(q,type,ttl)) return 0;
if (byte_equal(type,2,DNS_T_NS) || byte_equal(type,2,DNS_T_CNAME) || byte_equal(type,2,DNS_T_PTR)) {
if (!doname()) return 0;
}
else if (byte_equal(type,2,DNS_T_MX)) {
if (!dobytes(2)) return 0;
if (!doname()) return 0;
}
else if (byte_equal(type,2,DNS_T_SOA)) {
if (!doname()) return 0;
if (!doname()) return 0;
if (!dobytes(20)) return 0;
flaggavesoa = 1;
}
else
if (!response_addbytes(data + dpos,dlen - dpos)) return 0;
response_rfinish(RESPONSE_ANSWER);
}
for (i = 0;i < addrnum;++i)
if (i < 8) {
if (!response_rstart(q,DNS_T_A,addrttl)) return 0;
if (!response_addbytes(addr[i],4)) return 0;
response_rfinish(RESPONSE_ANSWER);
}
if (flagfound) break;
if (wild == control) break;
if (!*wild) break; /* impossible */
wild += *wild;
wild += 1;
}
if (!flagfound)
response_nxdomain();
AUTHORITY:
aupos = response_len;
if (flagauthoritative && (aupos == anpos)) {
cdb_findstart(&c);
while (r = find(control,0)) {
if (r == -1) return 0;
if (byte_equal(type,2,DNS_T_SOA)) {
if (!response_rstart(control,DNS_T_SOA,ttl)) return 0;
if (!doname()) return 0;
if (!doname()) return 0;
if (!dobytes(20)) return 0;
response_rfinish(RESPONSE_AUTHORITY);
break;
}
}
}
else
if (want(control,DNS_T_NS)) {
cdb_findstart(&c);
while (r = find(control,0)) {
if (r == -1) return 0;
if (byte_equal(type,2,DNS_T_NS)) {
if (!response_rstart(control,DNS_T_NS,ttl)) return 0;
if (!doname()) return 0;
response_rfinish(RESPONSE_AUTHORITY);
}
}
}
arpos = response_len;
bpos = anpos;
while (bpos < arpos) {
bpos = dns_packet_skipname(response,arpos,bpos); if (!bpos) return 0;
bpos = dns_packet_copy(response,arpos,bpos,x,10); if (!bpos) return 0;
if (byte_equal(x,2,DNS_T_NS) || byte_equal(x,2,DNS_T_MX)) {
if (byte_equal(x,2,DNS_T_NS)) {
if (!dns_packet_getname(response,arpos,bpos,&d1)) return 0;
}
else
if (!dns_packet_getname(response,arpos,bpos + 2,&d1)) return 0;
case_lowerb(d1,dns_domain_length(d1));
if (want(d1,DNS_T_A)) {
cdb_findstart(&c);
while (r = find(d1,0)) {
if (r == -1) return 0;
if (byte_equal(type,2,DNS_T_A)) {
if (!response_rstart(d1,DNS_T_A,ttl)) return 0;
if (!dobytes(4)) return 0;
response_rfinish(RESPONSE_ADDITIONAL);
}
}
}
}
uint16_unpack_big(x + 8,&u16);
bpos += u16;
}
if (flagauthoritative && (response_len > 512)) {
byte_zero(response + RESPONSE_ADDITIONAL,2);
response_len = arpos;
if (response_len > 512) {
byte_zero(response + RESPONSE_AUTHORITY,2);
response_len = aupos;
}
}
return 1;
}
