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Disable UDP on TLS configured ports #437

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Disable UDP on TLS configured ports #437

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36 changes: 24 additions & 12 deletions nsd.c
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Original file line number Diff line number Diff line change
Expand Up @@ -266,7 +266,8 @@ setup_socket(

static void
figure_socket_servers(
struct nsd_socket *sock, struct ip_address_option *ip)
struct nsd_socket *sock, struct ip_address_option *ip,
const char* tls_port)
{
int i;
struct range_option *server;
Expand All @@ -275,6 +276,14 @@ figure_socket_servers(
region_add_cleanup(nsd.region, free, sock->servers);
nsd_bitset_init(sock->servers, nsd.child_count);

if(sock->addr.ai_socktype == SOCK_DGRAM && tls_port &&
using_tls_port((struct sockaddr *)&sock->addr.ai_addr, tls_port))
{
/* This is for a UDP socket that has the same port as tls-port;
* skip. */
return;
}

if(!ip || !ip->servers) {
/* every server must listen on this socket */
for(i = 0; i < (int)nsd.child_count; i++) {
Expand Down Expand Up @@ -321,7 +330,7 @@ static void
figure_default_sockets(
struct nsd_socket **udp, struct nsd_socket **tcp, size_t *ifs,
const char *node, const char *udp_port, const char *tcp_port,
const struct addrinfo *hints)
const char *tls_port, const struct addrinfo *hints)
{
size_t i = 0, n = 1;
struct addrinfo ai[2] = { *hints, *hints };
Expand Down Expand Up @@ -371,11 +380,11 @@ figure_default_sockets(
(*udp)[i].flags |= NSD_SOCKET_IS_OPTIONAL;
(*udp)[i].fib = -1;
copyaddrinfo(&(*udp)[i].addr, addrs[0]);
figure_socket_servers(&(*udp)[i], NULL);
figure_socket_servers(&(*udp)[i], NULL, tls_port);
(*tcp)[i].flags |= NSD_SOCKET_IS_OPTIONAL;
(*tcp)[i].fib = -1;
copyaddrinfo(&(*tcp)[i].addr, addrs[1]);
figure_socket_servers(&(*tcp)[i], NULL);
figure_socket_servers(&(*tcp)[i], NULL, tls_port);
i++;
} else {
log_msg(LOG_WARNING, "No IPv6, fallback to IPv4. getaddrinfo: %s",
Expand All @@ -395,9 +404,9 @@ figure_default_sockets(

*ifs = i + 1;
setup_socket(&(*udp)[i], node, udp_port, &ai[0]);
figure_socket_servers(&(*udp)[i], NULL);
figure_socket_servers(&(*udp)[i], NULL, tls_port);
setup_socket(&(*tcp)[i], node, tcp_port, &ai[1]);
figure_socket_servers(&(*tcp)[i], NULL);
figure_socket_servers(&(*tcp)[i], NULL, tls_port);
}

#ifdef HAVE_GETIFADDRS
Expand Down Expand Up @@ -456,7 +465,7 @@ figure_sockets(
struct nsd_socket **udp, struct nsd_socket **tcp, size_t *ifs,
struct ip_address_option *ips,
const char *node, const char *udp_port, const char *tcp_port,
const struct addrinfo *hints)
const char *tls_port, const struct addrinfo *hints)
{
size_t i = 0;
struct addrinfo ai = *hints;
Expand All @@ -468,7 +477,8 @@ figure_sockets(

if(!ips) {
figure_default_sockets(
udp, tcp, ifs, node, udp_port, tcp_port, hints);
udp, tcp, ifs, node, udp_port, tcp_port,
tls_port, hints);
return;
}

Expand All @@ -493,10 +503,10 @@ figure_sockets(
for(ip = ips, i = 0; ip; ip = ip->next, i++) {
ai.ai_socktype = SOCK_DGRAM;
setup_socket(&(*udp)[i], ip->address, udp_port, &ai);
figure_socket_servers(&(*udp)[i], ip);
figure_socket_servers(&(*udp)[i], ip, tls_port);
ai.ai_socktype = SOCK_STREAM;
setup_socket(&(*tcp)[i], ip->address, tcp_port, &ai);
figure_socket_servers(&(*tcp)[i], ip);
figure_socket_servers(&(*tcp)[i], ip, tls_port);
if(ip->fib != -1) {
(*udp)[i].fib = ip->fib;
(*tcp)[i].fib = ip->fib;
Expand Down Expand Up @@ -1355,11 +1365,13 @@ main(int argc, char *argv[])

resolve_interface_names(nsd.options);
figure_sockets(&nsd.udp, &nsd.tcp, &nsd.ifs,
nsd.options->ip_addresses, NULL, udp_port, tcp_port, &hints);
nsd.options->ip_addresses, NULL, udp_port, tcp_port,
nsd.options->tls_port, &hints);

if(nsd.options->verify_enable) {
figure_sockets(&nsd.verify_udp, &nsd.verify_tcp, &nsd.verify_ifs,
nsd.options->verify_ip_addresses, "localhost", verify_port, verify_port, &hints);
nsd.options->verify_ip_addresses, "localhost",
verify_port, verify_port, NULL, &hints);
setup_verifier_environment();
}

Expand Down
2 changes: 2 additions & 0 deletions nsd.conf.5.in
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Original file line number Diff line number Diff line change
Expand Up @@ -567,6 +567,8 @@ openssl ocsp -no_nonce \\
.B tls\-port:\fR <number>
The port number on which to provide TCP TLS service, default is 853, only
interfaces configured with that port number as @number get DNS over TLS service.
UDP service is implicitly turned off for the same port as to not mix encrypted
and plain text communication.
.TP
.B tls\-auth\-port:\fR <number>
The port number on which to provide TCP TLS service to authenticated clients only.
Expand Down
1 change: 1 addition & 0 deletions nsd.conf.sample.in
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Original file line number Diff line number Diff line change
Expand Up @@ -258,6 +258,7 @@ server:
# Service clients over TLS (on the TCP sockets), with plain DNS inside
# the TLS stream. Give the certificate to use and private key.
# Default is "" (disabled). Requires restart to take effect.
# UDP on the same port is implicitly turned off.
# tls-service-key: "path/to/privatekeyfile.key"
# tls-service-pem: "path/to/publiccertfile.pem"
# tls-service-ocsp: "path/to/ocsp.pem"
Expand Down
1 change: 1 addition & 0 deletions nsd.h
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Original file line number Diff line number Diff line change
Expand Up @@ -447,6 +447,7 @@ SSL_CTX* server_tls_ctx_setup(char* key, char* pem, char* verifypem);
SSL_CTX* server_tls_ctx_create(struct nsd *nsd, char* verifypem, char* ocspfile);
void perform_openssl_init(void);
#endif
int using_tls_port(struct sockaddr* addr, const char* tls_port);
ssize_t block_read(struct nsd* nsd, int s, void* p, ssize_t sz, int timeout);

#endif /* NSD_H */