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

resolved: split out RR synthesis logic into its own C file

Browse source 
Also, while we are at it, set the "authenticated" bit for everything we synthesize
This commit is contained in:
Lennart Poettering 2016-01-20 22:06:26 +01:00
parent d07b43a18e
commit 839a4a20d8
4 changed files with 464 additions and 368 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

2
Makefile.am
View file

@ -5188,6 +5188,8 @@ systemd_resolved_SOURCES = \
src/resolve/resolved-dns-packet.c \
src/resolve/resolved-dns-query.h \
src/resolve/resolved-dns-query.c \
src/resolve/resolved-dns-synthesize.h \
src/resolve/resolved-dns-synthesize.c \
src/resolve/resolved-dns-transaction.h \
src/resolve/resolved-dns-transaction.c \
src/resolve/resolved-dns-scope.h \

386
src/resolve/resolved-dns-query.c
View file

@ -24,6 +24,7 @@
#include "hostname-util.h"
#include "local-addresses.h"
#include "resolved-dns-query.h"
#include "resolved-dns-synthesize.h"
#include "string-util.h"
/* How long to wait for the query in total */
@ -547,328 +548,15 @@ fail:
return r;
}
static int SYNTHESIZE_IFINDEX(int ifindex) {
/* When the caller asked for resolving on a specific
* interface, we synthesize the answer for that
* interface. However, if nothing specific was claimed and we
* only return localhost RRs, we synthesize the answer for
* localhost. */
if (ifindex > 0)
return ifindex;
return LOOPBACK_IFINDEX;
}
static int SYNTHESIZE_FAMILY(uint64_t flags) {
/* Picks an address family depending on set flags. This is
* purely for synthesized answers, where the family we return
* for the reply should match what was requested in the
* question, even though we are synthesizing the answer
* here. */
if (!(flags & SD_RESOLVED_DNS)) {
if (flags & SD_RESOLVED_LLMNR_IPV4)
return AF_INET;
if (flags & SD_RESOLVED_LLMNR_IPV6)
return AF_INET6;
}
return AF_UNSPEC;
}
static DnsProtocol SYNTHESIZE_PROTOCOL(uint64_t flags) {
/* Similar as SYNTHESIZE_FAMILY() but does this for the
* protocol. If resolving via DNS was requested, we claim it
* was DNS. Similar, if nothing specific was
* requested. However, if only resolving via LLMNR was
* requested we return that. */
if (flags & SD_RESOLVED_DNS)
return DNS_PROTOCOL_DNS;
if (flags & SD_RESOLVED_LLMNR)
return DNS_PROTOCOL_LLMNR;
return DNS_PROTOCOL_DNS;
}
static int synthesize_localhost_rr(DnsQuery *q, const DnsResourceKey *key, DnsAnswer **answer) {
int r;
assert(q);
assert(key);
assert(answer);
r = dns_answer_reserve(answer, 2);
if (r < 0)
return r;
if (IN_SET(key->type, DNS_TYPE_A, DNS_TYPE_ANY)) {
_cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL;
rr = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_A, DNS_RESOURCE_KEY_NAME(key));
if (!rr)
return -ENOMEM;
rr->a.in_addr.s_addr = htobe32(INADDR_LOOPBACK);
r = dns_answer_add(*answer, rr, SYNTHESIZE_IFINDEX(q->ifindex), DNS_ANSWER_AUTHENTICATED);
if (r < 0)
return r;
}
if (IN_SET(key->type, DNS_TYPE_AAAA, DNS_TYPE_ANY)) {
_cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL;
rr = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_AAAA, DNS_RESOURCE_KEY_NAME(key));
if (!rr)
return -ENOMEM;
rr->aaaa.in6_addr = in6addr_loopback;
r = dns_answer_add(*answer, rr, SYNTHESIZE_IFINDEX(q->ifindex), DNS_ANSWER_AUTHENTICATED);
if (r < 0)
return r;
}
return 0;
}
static int answer_add_ptr(DnsAnswer **answer, const char *from, const char *to, int ifindex, DnsAnswerFlags flags) {
_cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL;
rr = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_PTR, from);
if (!rr)
return -ENOMEM;
rr->ptr.name = strdup(to);
if (!rr->ptr.name)
return -ENOMEM;
return dns_answer_add(*answer, rr, ifindex, flags);
}
static int synthesize_localhost_ptr(DnsQuery *q, const DnsResourceKey *key, DnsAnswer **answer) {
int r;
assert(q);
assert(key);
assert(answer);
if (IN_SET(key->type, DNS_TYPE_PTR, DNS_TYPE_ANY)) {
r = dns_answer_reserve(answer, 1);
if (r < 0)
return r;
r = answer_add_ptr(answer, DNS_RESOURCE_KEY_NAME(key), "localhost", SYNTHESIZE_IFINDEX(q->ifindex), DNS_ANSWER_AUTHENTICATED);
if (r < 0)
return r;
}
return 0;
}
static int answer_add_addresses_rr(
DnsAnswer **answer,
const char *name,
struct local_address *addresses,
unsigned n_addresses) {
unsigned j;
int r;
assert(answer);
assert(name);
r = dns_answer_reserve(answer, n_addresses);
if (r < 0)
return r;
for (j = 0; j < n_addresses; j++) {
_cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL;
r = dns_resource_record_new_address(&rr, addresses[j].family, &addresses[j].address, name);
if (r < 0)
return r;
r = dns_answer_add(*answer, rr, addresses[j].ifindex, DNS_ANSWER_AUTHENTICATED);
if (r < 0)
return r;
}
return 0;
}
static int answer_add_addresses_ptr(
DnsAnswer **answer,
const char *name,
struct local_address *addresses,
unsigned n_addresses,
int af, const union in_addr_union *match) {
unsigned j;
int r;
assert(answer);
assert(name);
for (j = 0; j < n_addresses; j++) {
_cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL;
if (af != AF_UNSPEC) {
if (addresses[j].family != af)
continue;
if (match && !in_addr_equal(af, match, &addresses[j].address))
continue;
}
r = dns_answer_reserve(answer, 1);
if (r < 0)
return r;
r = dns_resource_record_new_reverse(&rr, addresses[j].family, &addresses[j].address, name);
if (r < 0)
return r;
r = dns_answer_add(*answer, rr, addresses[j].ifindex, DNS_ANSWER_AUTHENTICATED);
if (r < 0)
return r;
}
return 0;
}
static int synthesize_system_hostname_rr(DnsQuery *q, const DnsResourceKey *key, DnsAnswer **answer) {
_cleanup_free_ struct local_address *addresses = NULL;
int n = 0, af;
assert(q);
assert(key);
assert(answer);
af = dns_type_to_af(key->type);
if (af >= 0) {
n = local_addresses(q->manager->rtnl, q->ifindex, af, &addresses);
if (n < 0)
return n;
if (n == 0) {
struct local_address buffer[2];
/* If we have no local addresses then use ::1
* and 127.0.0.2 as local ones. */
if (af == AF_INET || af == AF_UNSPEC)
buffer[n++] = (struct local_address) {
.family = AF_INET,
.ifindex = SYNTHESIZE_IFINDEX(q->ifindex),
.address.in.s_addr = htobe32(0x7F000002),
};
if (af == AF_INET6 || af == AF_UNSPEC)
buffer[n++] = (struct local_address) {
.family = AF_INET6,
.ifindex = SYNTHESIZE_IFINDEX(q->ifindex),
.address.in6 = in6addr_loopback,
};
return answer_add_addresses_rr(answer, DNS_RESOURCE_KEY_NAME(key), buffer, n);
}
}
return answer_add_addresses_rr(answer, DNS_RESOURCE_KEY_NAME(key), addresses, n);
}
static int synthesize_system_hostname_ptr(DnsQuery *q, int af, const union in_addr_union *address, DnsAnswer **answer) {
_cleanup_free_ struct local_address *addresses = NULL;
int n, r;
assert(q);
assert(address);
assert(answer);
if (af == AF_INET && address->in.s_addr == htobe32(0x7F000002)) {
/* Always map the IPv4 address 127.0.0.2 to the local
* hostname, in addition to "localhost": */
r = dns_answer_reserve(answer, 3);
if (r < 0)
return r;
r = answer_add_ptr(answer, "2.0.0.127.in-addr.arpa", q->manager->llmnr_hostname, SYNTHESIZE_IFINDEX(q->ifindex), DNS_ANSWER_AUTHENTICATED);
if (r < 0)
return r;
r = answer_add_ptr(answer, "2.0.0.127.in-addr.arpa", q->manager->mdns_hostname, SYNTHESIZE_IFINDEX(q->ifindex), DNS_ANSWER_AUTHENTICATED);
if (r < 0)
return r;
r = answer_add_ptr(answer, "2.0.0.127.in-addr.arpa", "localhost", SYNTHESIZE_IFINDEX(q->ifindex), DNS_ANSWER_AUTHENTICATED);
if (r < 0)
return r;
return 0;
}
n = local_addresses(q->manager->rtnl, q->ifindex, af, &addresses);
if (n < 0)
return n;
r = answer_add_addresses_ptr(answer, q->manager->llmnr_hostname, addresses, n, af, address);
if (r < 0)
return r;
return answer_add_addresses_ptr(answer, q->manager->mdns_hostname, addresses, n, af, address);
}
static int synthesize_gateway_rr(DnsQuery *q, const DnsResourceKey *key, DnsAnswer **answer) {
_cleanup_free_ struct local_address *addresses = NULL;
int n = 0, af;
assert(q);
assert(key);
assert(answer);
af = dns_type_to_af(key->type);
if (af >= 0) {
n = local_gateways(q->manager->rtnl, q->ifindex, af, &addresses);
if (n < 0)
return n;
}
return answer_add_addresses_rr(answer, DNS_RESOURCE_KEY_NAME(key), addresses, n);
}
static int synthesize_gateway_ptr(DnsQuery *q, int af, const union in_addr_union *address, DnsAnswer **answer) {
_cleanup_free_ struct local_address *addresses = NULL;
int n;
assert(q);
assert(address);
assert(answer);
n = local_gateways(q->manager->rtnl, q->ifindex, af, &addresses);
if (n < 0)
return n;
return answer_add_addresses_ptr(answer, "gateway", addresses, n, af, address);
}
static int dns_query_synthesize_reply(DnsQuery *q, DnsTransactionState *state) {
_cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL;
DnsResourceKey *key;
int r;
DnsProtocol protocol;
int family, r;
assert(q);
assert(state);
/* Tries to synthesize localhost RR replies where appropriate */
/* Tries to synthesize localhost RR replies (and others) where appropriate */
if (!IN_SET(*state,
DNS_TRANSACTION_RCODE_FAILURE,
@ -878,64 +566,26 @@ static int dns_query_synthesize_reply(DnsQuery *q, DnsTransactionState *state) {
DNS_TRANSACTION_NETWORK_DOWN))
return 0;
DNS_QUESTION_FOREACH(key, q->question_utf8) {
union in_addr_union address;
const char *name;
int af;
r = dns_synthesize_answer(
q->manager,
q->question_utf8,
q->ifindex,
q->flags,
&answer,
&protocol,
&family);
if (key->class != DNS_CLASS_IN &&
key->class != DNS_CLASS_ANY)
continue;
if (r <= 0)
return r;
name = DNS_RESOURCE_KEY_NAME(key);
dns_query_reset_answer(q);
if (is_localhost(name)) {
r = synthesize_localhost_rr(q, key, &answer);
if (r < 0)
return log_error_errno(r, "Failed to synthesize localhost RRs: %m");
} else if (manager_is_own_hostname(q->manager, name)) {
r = synthesize_system_hostname_rr(q, key, &answer);
if (r < 0)
return log_error_errno(r, "Failed to synthesize system hostname RRs: %m");
} else if (is_gateway_hostname(name)) {
r = synthesize_gateway_rr(q, key, &answer);
if (r < 0)
return log_error_errno(r, "Failed to synthesize gateway RRs: %m");
} else if ((dns_name_endswith(name, "127.in-addr.arpa") > 0 && dns_name_equal(name, "2.0.0.127.in-addr.arpa") == 0) ||
dns_name_equal(name, "1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.ip6.arpa") > 0) {
r = synthesize_localhost_ptr(q, key, &answer);
if (r < 0)
return log_error_errno(r, "Failed to synthesize localhost PTR RRs: %m");
} else if (dns_name_address(name, &af, &address) > 0) {
r = synthesize_system_hostname_ptr(q, af, &address, &answer);
if (r < 0)
return log_error_errno(r, "Failed to synthesize system hostname PTR RR: %m");
r = synthesize_gateway_ptr(q, af, &address, &answer);
if (r < 0)
return log_error_errno(r, "Failed to synthesize gateway hostname PTR RR: %m");
}
}
if (!answer)
return 0;
dns_answer_unref(q->answer);
q->answer = answer;
answer = NULL;
q->answer_rcode = DNS_RCODE_SUCCESS;
q->answer_protocol = SYNTHESIZE_PROTOCOL(q->flags);
q->answer_family = SYNTHESIZE_FAMILY(q->flags);
q->answer_protocol = protocol;
q->answer_family = family;
q->answer_authenticated = true;
*state = DNS_TRANSACTION_SUCCESS;

418
src/resolve/resolved-dns-synthesize.c Normal file
View file

@ -0,0 +1,418 @@
/***
This file is part of systemd.
Copyright 2014 Lennart Poettering
systemd is free software; you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
systemd is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
#include "alloc-util.h"
#include "hostname-util.h"
#include "local-addresses.h"
#include "resolved-dns-synthesize.h"
static int SYNTHESIZE_IFINDEX(int ifindex) {
/* When the caller asked for resolving on a specific
* interface, we synthesize the answer for that
* interface. However, if nothing specific was claimed and we
* only return localhost RRs, we synthesize the answer for
* localhost. */
if (ifindex > 0)
return ifindex;
return LOOPBACK_IFINDEX;
}
static int SYNTHESIZE_FAMILY(uint64_t flags) {
/* Picks an address family depending on set flags. This is
* purely for synthesized answers, where the family we return
* for the reply should match what was requested in the
* question, even though we are synthesizing the answer
* here. */
if (!(flags & SD_RESOLVED_DNS)) {
if (flags & (SD_RESOLVED_LLMNR_IPV4|SD_RESOLVED_MDNS_IPV4))
return AF_INET;
if (flags & (SD_RESOLVED_LLMNR_IPV6|SD_RESOLVED_MDNS_IPV6))
return AF_INET6;
}
return AF_UNSPEC;
}
static DnsProtocol SYNTHESIZE_PROTOCOL(uint64_t flags) {
/* Similar as SYNTHESIZE_FAMILY() but does this for the
* protocol. If resolving via DNS was requested, we claim it
* was DNS. Similar, if nothing specific was
* requested. However, if only resolving via LLMNR was
* requested we return that. */
if (flags & SD_RESOLVED_DNS)
return DNS_PROTOCOL_DNS;
if (flags & SD_RESOLVED_LLMNR)
return DNS_PROTOCOL_LLMNR;
if (flags & SD_RESOLVED_MDNS)
return DNS_PROTOCOL_MDNS;
return DNS_PROTOCOL_DNS;
}
static int synthesize_localhost_rr(Manager *m, const DnsResourceKey *key, int ifindex, DnsAnswer **answer) {
int r;
assert(m);
assert(key);
assert(answer);
r = dns_answer_reserve(answer, 2);
if (r < 0)
return r;
if (IN_SET(key->type, DNS_TYPE_A, DNS_TYPE_ANY)) {
_cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL;
rr = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_A, DNS_RESOURCE_KEY_NAME(key));
if (!rr)
return -ENOMEM;
rr->a.in_addr.s_addr = htobe32(INADDR_LOOPBACK);
r = dns_answer_add(*answer, rr, SYNTHESIZE_IFINDEX(ifindex), DNS_ANSWER_AUTHENTICATED);
if (r < 0)
return r;
}
if (IN_SET(key->type, DNS_TYPE_AAAA, DNS_TYPE_ANY)) {
_cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL;
rr = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_AAAA, DNS_RESOURCE_KEY_NAME(key));
if (!rr)
return -ENOMEM;
rr->aaaa.in6_addr = in6addr_loopback;
r = dns_answer_add(*answer, rr, SYNTHESIZE_IFINDEX(ifindex), DNS_ANSWER_AUTHENTICATED);
if (r < 0)
return r;
}
return 0;
}
static int answer_add_ptr(DnsAnswer **answer, const char *from, const char *to, int ifindex, DnsAnswerFlags flags) {
_cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL;
rr = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_PTR, from);
if (!rr)
return -ENOMEM;
rr->ptr.name = strdup(to);
if (!rr->ptr.name)
return -ENOMEM;
return dns_answer_add(*answer, rr, ifindex, flags);
}
static int synthesize_localhost_ptr(Manager *m, const DnsResourceKey *key, int ifindex, DnsAnswer **answer) {
int r;
assert(m);
assert(key);
assert(answer);
if (IN_SET(key->type, DNS_TYPE_PTR, DNS_TYPE_ANY)) {
r = dns_answer_reserve(answer, 1);
if (r < 0)
return r;
r = answer_add_ptr(answer, DNS_RESOURCE_KEY_NAME(key), "localhost", SYNTHESIZE_IFINDEX(ifindex), DNS_ANSWER_AUTHENTICATED);
if (r < 0)
return r;
}
return 0;
}
static int answer_add_addresses_rr(
DnsAnswer **answer,
const char *name,
struct local_address *addresses,
unsigned n_addresses) {
unsigned j;
int r;
assert(answer);
assert(name);
r = dns_answer_reserve(answer, n_addresses);
if (r < 0)
return r;
for (j = 0; j < n_addresses; j++) {
_cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL;
r = dns_resource_record_new_address(&rr, addresses[j].family, &addresses[j].address, name);
if (r < 0)
return r;
r = dns_answer_add(*answer, rr, addresses[j].ifindex, DNS_ANSWER_AUTHENTICATED);
if (r < 0)
return r;
}
return 0;
}
static int answer_add_addresses_ptr(
DnsAnswer **answer,
const char *name,
struct local_address *addresses,
unsigned n_addresses,
int af, const union in_addr_union *match) {
unsigned j;
int r;
assert(answer);
assert(name);
for (j = 0; j < n_addresses; j++) {
_cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL;
if (af != AF_UNSPEC) {
if (addresses[j].family != af)
continue;
if (match && !in_addr_equal(af, match, &addresses[j].address))
continue;
}
r = dns_answer_reserve(answer, 1);
if (r < 0)
return r;
r = dns_resource_record_new_reverse(&rr, addresses[j].family, &addresses[j].address, name);
if (r < 0)
return r;
r = dns_answer_add(*answer, rr, addresses[j].ifindex, DNS_ANSWER_AUTHENTICATED);
if (r < 0)
return r;
}
return 0;
}
static int synthesize_system_hostname_rr(Manager *m, const DnsResourceKey *key, int ifindex, DnsAnswer **answer) {
_cleanup_free_ struct local_address *addresses = NULL;
int n = 0, af;
assert(m);
assert(key);
assert(answer);
af = dns_type_to_af(key->type);
if (af >= 0) {
n = local_addresses(m->rtnl, ifindex, af, &addresses);
if (n < 0)
return n;
if (n == 0) {
struct local_address buffer[2];
/* If we have no local addresses then use ::1
* and 127.0.0.2 as local ones. */
if (af == AF_INET || af == AF_UNSPEC)
buffer[n++] = (struct local_address) {
.family = AF_INET,
.ifindex = SYNTHESIZE_IFINDEX(ifindex),
.address.in.s_addr = htobe32(0x7F000002),
};
if (af == AF_INET6 || af == AF_UNSPEC)
buffer[n++] = (struct local_address) {
.family = AF_INET6,
.ifindex = SYNTHESIZE_IFINDEX(ifindex),
.address.in6 = in6addr_loopback,
};
return answer_add_addresses_rr(answer, DNS_RESOURCE_KEY_NAME(key), buffer, n);
}
}
return answer_add_addresses_rr(answer, DNS_RESOURCE_KEY_NAME(key), addresses, n);
}
static int synthesize_system_hostname_ptr(Manager *m, int af, const union in_addr_union *address, int ifindex, DnsAnswer **answer) {
_cleanup_free_ struct local_address *addresses = NULL;
int n, r;
assert(m);
assert(address);
assert(answer);
if (af == AF_INET && address->in.s_addr == htobe32(0x7F000002)) {
/* Always map the IPv4 address 127.0.0.2 to the local
* hostname, in addition to "localhost": */
r = dns_answer_reserve(answer, 3);
if (r < 0)
return r;
r = answer_add_ptr(answer, "2.0.0.127.in-addr.arpa", m->llmnr_hostname, SYNTHESIZE_IFINDEX(ifindex), DNS_ANSWER_AUTHENTICATED);
if (r < 0)
return r;
r = answer_add_ptr(answer, "2.0.0.127.in-addr.arpa", m->mdns_hostname, SYNTHESIZE_IFINDEX(ifindex), DNS_ANSWER_AUTHENTICATED);
if (r < 0)
return r;
r = answer_add_ptr(answer, "2.0.0.127.in-addr.arpa", "localhost", SYNTHESIZE_IFINDEX(ifindex), DNS_ANSWER_AUTHENTICATED);
if (r < 0)
return r;
return 0;
}
n = local_addresses(m->rtnl, ifindex, af, &addresses);
if (n < 0)
return n;
r = answer_add_addresses_ptr(answer, m->llmnr_hostname, addresses, n, af, address);
if (r < 0)
return r;
return answer_add_addresses_ptr(answer, m->mdns_hostname, addresses, n, af, address);
}
static int synthesize_gateway_rr(Manager *m, const DnsResourceKey *key, int ifindex, DnsAnswer **answer) {
_cleanup_free_ struct local_address *addresses = NULL;
int n = 0, af;
assert(m);
assert(key);
assert(answer);
af = dns_type_to_af(key->type);
if (af >= 0) {
n = local_gateways(m->rtnl, ifindex, af, &addresses);
if (n < 0)
return n;
}
return answer_add_addresses_rr(answer, DNS_RESOURCE_KEY_NAME(key), addresses, n);
}
static int synthesize_gateway_ptr(Manager *m, int af, const union in_addr_union *address, int ifindex, DnsAnswer **answer) {
_cleanup_free_ struct local_address *addresses = NULL;
int n;
assert(m);
assert(address);
assert(answer);
n = local_gateways(m->rtnl, ifindex, af, &addresses);
if (n < 0)
return n;
return answer_add_addresses_ptr(answer, "gateway", addresses, n, af, address);
}
int dns_synthesize_answer(
Manager *m,
DnsQuestion *q,
int ifindex,
uint64_t flags,
DnsAnswer **ret,
DnsProtocol *ret_protocol,
int *ret_family) {
_cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL;
DnsResourceKey *key;
int r;
assert(m);
assert(q);
DNS_QUESTION_FOREACH(key, q) {
union in_addr_union address;
const char *name;
int af;
if (key->class != DNS_CLASS_IN &&
key->class != DNS_CLASS_ANY)
continue;
name = DNS_RESOURCE_KEY_NAME(key);
if (is_localhost(name)) {
r = synthesize_localhost_rr(m, key, ifindex, &answer);
if (r < 0)
return log_error_errno(r, "Failed to synthesize localhost RRs: %m");
} else if (manager_is_own_hostname(m, name)) {
r = synthesize_system_hostname_rr(m, key, ifindex, &answer);
if (r < 0)
return log_error_errno(r, "Failed to synthesize system hostname RRs: %m");
} else if (is_gateway_hostname(name)) {
r = synthesize_gateway_rr(m, key, ifindex, &answer);
if (r < 0)
return log_error_errno(r, "Failed to synthesize gateway RRs: %m");
} else if ((dns_name_endswith(name, "127.in-addr.arpa") > 0 && dns_name_equal(name, "2.0.0.127.in-addr.arpa") == 0) ||
dns_name_equal(name, "1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.ip6.arpa") > 0) {
r = synthesize_localhost_ptr(m, key, ifindex, &answer);
if (r < 0)
return log_error_errno(r, "Failed to synthesize localhost PTR RRs: %m");
} else if (dns_name_address(name, &af, &address) > 0) {
r = synthesize_system_hostname_ptr(m, af, &address, ifindex, &answer);
if (r < 0)
return log_error_errno(r, "Failed to synthesize system hostname PTR RR: %m");
r = synthesize_gateway_ptr(m, af, &address, ifindex, &answer);
if (r < 0)
return log_error_errno(r, "Failed to synthesize gateway hostname PTR RR: %m");
}
}
r = dns_answer_size(answer) > 0;
if (ret) {
*ret = answer;
answer = NULL;
}
if (ret_protocol)
*ret_protocol = SYNTHESIZE_PROTOCOL(flags);
if (ret_family)
*ret_family = SYNTHESIZE_FAMILY(flags);
return r;
}

26
src/resolve/resolved-dns-synthesize.h Normal file
View file

@ -0,0 +1,26 @@
#pragma once
/***
This file is part of systemd.
Copyright 2016 Lennart Poettering
systemd is free software; you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
systemd is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
#include "resolved-dns-answer.h"
#include "resolved-dns-question.h"
#include "resolved-manager.h"
int dns_synthesize_answer(Manager *m, DnsQuestion *q, int ifindex, uint64_t flags, DnsAnswer **ret, DnsProtocol *ret_protocol, int *ret_family);