static int thisudp(struct dns_transmit *d)
{
const char *ip;
socketfree(d);
while (d->udploop < 4) {
for (;d->curserver < 16;++d->curserver) {
ip = d->servers + 16 * d->curserver;
if (byte_diff(ip,16,V6any)) {
d->query[2] = dns_random(256);
d->query[3] = dns_random(256);
d->s1 = 1 + socket_udp6();
if (!d->s1) { dns_transmit_free(d); return -1; }
if (randombind(d) == -1) { dns_transmit_free(d); return -1; }
if (socket_connect6(d->s1 - 1,ip,53,d->scope_id) == 0)
if (send(d->s1 - 1,d->query + 2,d->querylen - 2,0) == d->querylen - 2) {
struct taia now;
taia_now(&now);
taia_uint(&d->deadline,timeouts[d->udploop]);
taia_add(&d->deadline,&d->deadline,&now);
d->tcpstate = 0;
return 0;
}
socketfree(d);
}
}
++d->udploop;
d->curserver = 0;
}
dns_transmit_free(d); return -1;
}
int setup_udp_server_socket(const char ip[4], const char ip6[16], u16 port) {
char sip[FMT_IP6];
int fd;
fd = socket_udp6();
if(fd >= 0) {
if(socket_bind6(fd, ip6, port, 0) == -1) {
close(fd);
fd = socket_udp();
if(socket_bind4(fd, ip, port) == -1) {
ERROR("unable to create server socket: %s", strerror(errno));
} else {
fmt_ip4(sip, ip);
DEBUG("bound UDP socket on %s:%hu", sip, port);
}
} else {
fmt_ip6(sip, ip6);
DEBUG("bound UDP socket on [%s]:%hu", sip, port);
}
} else {
ERROR("unable to create UDP socket: %s", strerror(errno));
}
return fd;
}
int main()
{
char *x;
unsigned int i, j, k;
unsigned long cachesize;
static stralloc sa = {0};
x = env_get("INTERFACE");
if (x) scan_ulong(x,&interface);
x = env_get("IP");
if (!x)
strerr_die2x(111,FATAL,"$IP not set");
if (!ip6_scan(x,myipincoming))
strerr_die3x(111,FATAL,"unable to parse IP address ",x);
#if 0
/* if if IP is a mapped-IPv4 address, disable IPv6 functionality */
/* this is actually a bad idea */
if (ip6_isv4mapped(myipincoming))
noipv6 = 1;
#endif
udp53 = socket_udp6();
if (udp53 == -1)
strerr_die2sys(111,FATAL,"unable to create UDP socket: ");
if (socket_bind6_reuse(udp53,myipincoming,53,interface) == -1)
strerr_die2sys(111,FATAL,"unable to bind UDP socket: ");
tcp53 = socket_tcp6();
if (tcp53 == -1)
strerr_die2sys(111,FATAL,"unable to create TCP socket: ");
if (socket_bind6_reuse(tcp53,myipincoming,53,interface) == -1)
strerr_die2sys(111,FATAL,"unable to bind TCP socket: ");
droproot(FATAL);
socket_tryreservein(udp53,131072);
byte_zero(seed,sizeof seed);
read(0,seed,sizeof seed);
dns_random_init(seed);
close(0);
x = env_get("IPSEND");
if (!x)
strerr_die2x(111,FATAL,"$IPSEND not set");
if (!ip6_scan(x,myipoutgoing))
strerr_die3x(111,FATAL,"unable to parse IP address ",x);
x = env_get("CACHESIZE");
if (!x)
strerr_die2x(111,FATAL,"$CACHESIZE not set");
scan_ulong(x,&cachesize);
if (!cache_init(cachesize))
strerr_die3x(111,FATAL,"not enough memory for cache of size ",x);
if (openreadclose("ignoreip",&sa,64) < 0)
strerr_die2x(111,FATAL,"trouble reading ignoreip");
for(j = k = i = 0; i < sa.len; i++)
if (sa.s[i] == '\n') {
sa.s[i] = '\0';
if (!stralloc_readyplus(&ignoreip,16))
strerr_die2x(111,FATAL,"out of memory parsing ignoreip");
if (!ip6_scan(sa.s+k,ignoreip.s+j))
strerr_die3x(111,FATAL,"unable to parse address in ignoreip ",ignoreip.s+k);
j += 16;
k = i + 1;
}
ignoreip.len = j;
if (env_get("HIDETTL"))
response_hidettl();
if (env_get("FORWARDONLY"))
query_forwardonly();
if (!roots_init())
strerr_die2sys(111,FATAL,"unable to read servers: ");
if (socket_listen(tcp53,20) == -1)
strerr_die2sys(111,FATAL,"unable to listen on TCP socket: ");
log_startup();
doit();
}
