picnoir/Systemd
1
0
Fork 0
Code Issues Pull requests Projects Releases Wiki Activity

resolved: add dns_packet_set_flags()

Browse source 
We need to support the TC bit in queries in case known answers exceed the
maximum packet size. Factor out the flags compilation to
dns_packet_set_flags() and make it externally available.
This commit is contained in:
Daniel Mack 2015-12-09 11:55:54 +01:00
parent ee8d930568
commit dbfbb6e776
2 changed files with 44 additions and 21 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

63
src/resolve/resolved-dns-packet.c
View file

@ -65,40 +65,44 @@ int dns_packet_new(DnsPacket **ret, DnsProtocol protocol, size_t mtu) {
return 0;
}
int dns_packet_new_query(DnsPacket **ret, DnsProtocol protocol, size_t mtu, bool dnssec_checking_disabled) {
DnsPacket *p;
void dns_packet_set_flags(DnsPacket *p, bool dnssec_checking_disabled, bool truncated) {
DnsPacketHeader *h;
int r;
assert(ret);
r = dns_packet_new(&p, protocol, mtu);
if (r < 0)
return r;
assert(p);
h = DNS_PACKET_HEADER(p);
if (protocol == DNS_PROTOCOL_LLMNR)
switch(p->protocol) {
case DNS_PROTOCOL_LLMNR:
assert(!truncated);
h->flags = htobe16(DNS_PACKET_MAKE_FLAGS(0 /* qr */,
0 /* opcode */,
0 /* c */,
0 /* tc */,
0/* tc */,
0 /* t */,
0 /* ra */,
0 /* ad */,
0 /* cd */,
0 /* rcode */));
else if (protocol == DNS_PROTOCOL_MDNS)
h->flags = htobe16(DNS_PACKET_MAKE_FLAGS(0 /* qr */,
0 /* opcode */,
0 /* aa */,
0 /* tc */,
0 /* rd (ask for recursion) */,
0 /* ra */,
0 /* ad */,
0 /* cd */,
0 /* rcode */));
else
break;
case DNS_PROTOCOL_MDNS:
h->flags = htobe16(DNS_PACKET_MAKE_FLAGS(0 /* qr */,
0 /* opcode */,
0 /* aa */,
truncated /* tc */,
0 /* rd (ask for recursion) */,
0 /* ra */,
0 /* ad */,
0 /* cd */,
0 /* rcode */));
break;
default:
assert(!truncated);
h->flags = htobe16(DNS_PACKET_MAKE_FLAGS(0 /* qr */,
0 /* opcode */,
0 /* aa */,
@ -108,6 +112,23 @@ int dns_packet_new_query(DnsPacket **ret, DnsProtocol protocol, size_t mtu, bool
0 /* ad */,
dnssec_checking_disabled /* cd */,
0 /* rcode */));
}
}
int dns_packet_new_query(DnsPacket **ret, DnsProtocol protocol, size_t mtu, bool dnssec_checking_disabled) {
DnsPacket *p;
int r;
assert(ret);
r = dns_packet_new(&p, protocol, mtu);
if (r < 0)
return r;
/* Always set the TC bit to 0 initially.
* If there are multiple packets later, we'll update the bit shortly before sending.
*/
dns_packet_set_flags(p, dnssec_checking_disabled, false);
*ret = p;
return 0;

2
src/resolve/resolved-dns-packet.h
View file

@ -146,6 +146,8 @@ static inline unsigned DNS_PACKET_RRCOUNT(DnsPacket *p) {
int dns_packet_new(DnsPacket **p, DnsProtocol protocol, size_t mtu);
int dns_packet_new_query(DnsPacket **p, DnsProtocol protocol, size_t mtu, bool dnssec_checking_disabled);
void dns_packet_set_flags(DnsPacket *p, bool dnssec_checking_disabled, bool truncated);
DnsPacket *dns_packet_ref(DnsPacket *p);
DnsPacket *dns_packet_unref(DnsPacket *p);