+/* SPDX-License-Identifier: LGPL-2.1+ */
/***
- 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 "local-addresses.h"
#include "resolved-dns-synthesize.h"
-static int SYNTHESIZE_IFINDEX(int ifindex) {
+int dns_synthesize_ifindex(int ifindex) {
/* When the caller asked for resolving on a specific
* interface, we synthesize the answer for that
return LOOPBACK_IFINDEX;
}
-static int SYNTHESIZE_FAMILY(uint64_t flags) {
+int dns_synthesize_family(uint64_t flags) {
/* Picks an address family depending on set flags. This is
* purely for synthesized answers, where the family we return
return AF_UNSPEC;
}
-static DnsProtocol SYNTHESIZE_PROTOCOL(uint64_t flags) {
+DnsProtocol dns_synthesize_protocol(uint64_t flags) {
- /* Similar as SYNTHESIZE_FAMILY() but does this for the
+ /* Similar as dns_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
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));
+ 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);
+ r = dns_answer_add(*answer, rr, dns_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));
+ 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);
+ r = dns_answer_add(*answer, rr, dns_synthesize_ifindex(ifindex), DNS_ANSWER_AUTHENTICATED);
if (r < 0)
return r;
}
if (r < 0)
return r;
- r = answer_add_ptr(answer, DNS_RESOURCE_KEY_NAME(key), "localhost", SYNTHESIZE_IFINDEX(ifindex), DNS_ANSWER_AUTHENTICATED);
+ r = answer_add_ptr(answer, dns_resource_key_name(key), "localhost", dns_synthesize_ifindex(ifindex), DNS_ANSWER_AUTHENTICATED);
if (r < 0)
return r;
}
unsigned n_addresses,
int af, const union in_addr_union *match) {
+ bool added = false;
unsigned j;
int r;
r = dns_answer_add(*answer, rr, addresses[j].ifindex, DNS_ANSWER_AUTHENTICATED);
if (r < 0)
return r;
+
+ added = true;
}
- return 0;
+ return added;
}
static int synthesize_system_hostname_rr(Manager *m, const DnsResourceKey *key, int ifindex, DnsAnswer **answer) {
/* If we have no local addresses then use ::1
* and 127.0.0.2 as local ones. */
- if (af == AF_INET || af == AF_UNSPEC)
+ if (IN_SET(af, AF_INET, AF_UNSPEC))
buffer[n++] = (struct local_address) {
.family = AF_INET,
- .ifindex = SYNTHESIZE_IFINDEX(ifindex),
+ .ifindex = dns_synthesize_ifindex(ifindex),
.address.in.s_addr = htobe32(0x7F000002),
};
- if (af == AF_INET6 || af == AF_UNSPEC)
+ if (IN_SET(af, AF_INET6, AF_UNSPEC))
buffer[n++] = (struct local_address) {
.family = AF_INET6,
- .ifindex = SYNTHESIZE_IFINDEX(ifindex),
+ .ifindex = dns_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),
+ buffer, n);
}
}
- return answer_add_addresses_rr(answer, DNS_RESOURCE_KEY_NAME(key), addresses, 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;
+ bool added = false;
int n, r;
assert(m);
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": */
+ /* Always map the IPv4 address 127.0.0.2 to the local hostname, in addition to "localhost": */
+
+ r = dns_answer_reserve(answer, 4);
+ if (r < 0)
+ return r;
- r = dns_answer_reserve(answer, 3);
+ r = answer_add_ptr(answer, "2.0.0.127.in-addr.arpa", m->full_hostname, dns_synthesize_ifindex(ifindex), DNS_ANSWER_AUTHENTICATED);
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);
+ r = answer_add_ptr(answer, "2.0.0.127.in-addr.arpa", m->llmnr_hostname, dns_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);
+ r = answer_add_ptr(answer, "2.0.0.127.in-addr.arpa", m->mdns_hostname, dns_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);
+ r = answer_add_ptr(answer, "2.0.0.127.in-addr.arpa", "localhost", dns_synthesize_ifindex(ifindex), DNS_ANSWER_AUTHENTICATED);
if (r < 0)
return r;
- return 0;
+ return 1;
}
n = local_addresses(m->rtnl, ifindex, af, &addresses);
- if (n < 0)
+ if (n <= 0)
return n;
+ r = answer_add_addresses_ptr(answer, m->full_hostname, addresses, n, af, address);
+ if (r < 0)
+ return r;
+ if (r > 0)
+ added = true;
+
r = answer_add_addresses_ptr(answer, m->llmnr_hostname, addresses, n, af, address);
if (r < 0)
return r;
+ if (r > 0)
+ added = true;
- return answer_add_addresses_ptr(answer, m->mdns_hostname, addresses, n, af, address);
+ r = answer_add_addresses_ptr(answer, m->mdns_hostname, addresses, n, af, address);
+ if (r < 0)
+ return r;
+ if (r > 0)
+ added = true;
+
+ return added;
}
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;
+ int n = 0, af, r;
assert(m);
assert(key);
af = dns_type_to_af(key->type);
if (af >= 0) {
n = local_gateways(m->rtnl, ifindex, af, &addresses);
- if (n < 0)
- return n;
+ if (n <= 0)
+ return n; /* < 0 means: error; == 0 means we have no gateway */
}
- return answer_add_addresses_rr(answer, DNS_RESOURCE_KEY_NAME(key), addresses, n);
+ r = answer_add_addresses_rr(answer, dns_resource_key_name(key), addresses, n);
+ if (r < 0)
+ return r;
+
+ return 1; /* > 0 means: we have some gateway */
}
static int synthesize_gateway_ptr(Manager *m, int af, const union in_addr_union *address, int ifindex, DnsAnswer **answer) {
assert(answer);
n = local_gateways(m->rtnl, ifindex, af, &addresses);
- if (n < 0)
+ if (n <= 0)
return n;
- return answer_add_addresses_ptr(answer, "gateway", addresses, n, af, address);
+ 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) {
+ DnsAnswer **ret) {
_cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL;
DnsResourceKey *key;
+ bool found = false, nxdomain = false;
int r;
assert(m);
const char *name;
int af;
- if (key->class != DNS_CLASS_IN &&
- key->class != DNS_CLASS_ANY)
+ if (!IN_SET(key->class, DNS_CLASS_IN, DNS_CLASS_ANY))
continue;
- name = DNS_RESOURCE_KEY_NAME(key);
+ name = dns_resource_key_name(key);
if (is_localhost(name)) {
r = synthesize_gateway_rr(m, key, ifindex, &answer);
if (r < 0)
return log_error_errno(r, "Failed to synthesize gateway RRs: %m");
+ if (r == 0) { /* if we have no gateway return NXDOMAIN */
+ nxdomain = true;
+ continue;
+ }
} 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) {
return log_error_errno(r, "Failed to synthesize localhost PTR RRs: %m");
} else if (dns_name_address(name, &af, &address) > 0) {
+ int v, w;
- 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");
+ v = synthesize_system_hostname_ptr(m, af, &address, ifindex, &answer);
+ if (v < 0)
+ return log_error_errno(v, "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");
- }
- }
+ w = synthesize_gateway_ptr(m, af, &address, ifindex, &answer);
+ if (w < 0)
+ return log_error_errno(w, "Failed to synthesize gateway hostname PTR RR: %m");
- r = dns_answer_size(answer) > 0;
+ if (v == 0 && w == 0) /* This IP address is neither a local one nor a gateway */
+ continue;
- if (ret) {
- *ret = answer;
- answer = NULL;
+ } else
+ continue;
+
+ found = true;
}
- if (ret_protocol)
- *ret_protocol = SYNTHESIZE_PROTOCOL(flags);
+ if (found) {
+
+ if (ret)
+ *ret = TAKE_PTR(answer);
- if (ret_family)
- *ret_family = SYNTHESIZE_FAMILY(flags);
+ return 1;
+ } else if (nxdomain)
+ return -ENXIO;
- return r;
+ return 0;
}