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Systemd/src/resolve/resolved-bus.c

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/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
/***
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 "bus-errors.h"
#include "bus-util.h"
#include "resolved.h"
#include "resolved-dns-domain.h"
static int reply_query_state(DnsQuery *q) {
_cleanup_free_ char *ip = NULL;
const char *name;
int r;
if (q->request_hostname)
name = q->request_hostname;
else {
r = in_addr_to_string(q->request_family, &q->request_address, &ip);
if (r < 0)
return r;
name = ip;
}
switch (q->state) {
case DNS_TRANSACTION_NO_SERVERS:
return sd_bus_reply_method_errorf(q->request, BUS_ERROR_NO_NAME_SERVERS, "No appropriate name servers or networks for name found");
case DNS_TRANSACTION_TIMEOUT:
return sd_bus_reply_method_errorf(q->request, SD_BUS_ERROR_TIMEOUT, "Query timed out");
case DNS_TRANSACTION_ATTEMPTS_MAX_REACHED:
return sd_bus_reply_method_errorf(q->request, SD_BUS_ERROR_TIMEOUT, "All attempts to contact name servers or networks failed");
case DNS_TRANSACTION_RESOURCES:
return sd_bus_reply_method_errorf(q->request, BUS_ERROR_NO_RESOURCES, "Not enough resources");
case DNS_TRANSACTION_INVALID_REPLY:
return sd_bus_reply_method_errorf(q->request, BUS_ERROR_INVALID_REPLY, "Received invalid reply");
case DNS_TRANSACTION_FAILURE: {
_cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
if (q->answer_rcode == DNS_RCODE_NXDOMAIN)
sd_bus_error_setf(&error, _BUS_ERROR_DNS "NXDOMAIN", "'%s' not found", name);
else {
const char *rc, *n;
char p[3]; /* the rcode is 4 bits long */
rc = dns_rcode_to_string(q->answer_rcode);
if (!rc) {
sprintf(p, "%i", q->answer_rcode);
rc = p;
}
n = strappenda(_BUS_ERROR_DNS, rc);
sd_bus_error_setf(&error, n, "Could not resolve '%s', server or network returned error %s", name, rc);
}
return sd_bus_reply_method_error(q->request, &error);
}
case DNS_TRANSACTION_NULL:
case DNS_TRANSACTION_PENDING:
case DNS_TRANSACTION_SUCCESS:
default:
assert_not_reached("Impossible state");
}
}
static int append_address(sd_bus_message *reply, DnsResourceRecord *rr, int ifindex) {
int r;
assert(reply);
assert(rr);
r = sd_bus_message_open_container(reply, 'r', "iayi");
if (r < 0)
return r;
if (rr->key->type == DNS_TYPE_A) {
r = sd_bus_message_append(reply, "i", AF_INET);
if (r < 0)
return r;
r = sd_bus_message_append_array(reply, 'y', &rr->a.in_addr, sizeof(struct in_addr));
} else if (rr->key->type == DNS_TYPE_AAAA) {
r = sd_bus_message_append(reply, "i", AF_INET6);
if (r < 0)
return r;
r = sd_bus_message_append_array(reply, 'y', &rr->aaaa.in6_addr, sizeof(struct in6_addr));
} else
return -EAFNOSUPPORT;
if (r < 0)
return r;
r = sd_bus_message_append(reply, "i", ifindex);
if (r < 0)
return r;
r = sd_bus_message_close_container(reply);
if (r < 0)
return r;
return 0;
}
static void bus_method_resolve_hostname_complete(DnsQuery *q) {
_cleanup_(dns_resource_record_unrefp) DnsResourceRecord *cname = NULL, *canonical = NULL;
_cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
_cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL;
unsigned added = 0, i;
int r, ifindex;
assert(q);
if (q->state != DNS_TRANSACTION_SUCCESS) {
r = reply_query_state(q);
goto finish;
}
r = sd_bus_message_new_method_return(q->request, &reply);
if (r < 0)
goto finish;
r = sd_bus_message_open_container(reply, 'a', "(iayi)");
if (r < 0)
goto finish;
ifindex = q->answer_ifindex;
if (q->answer) {
answer = dns_answer_ref(q->answer);
for (i = 0; i < answer->n_rrs; i++) {
r = dns_question_matches_rr(q->question, answer->rrs[i]);
if (r < 0)
goto finish;
if (r == 0) {
/* Hmm, if this is not an address record,
maybe it's a cname? If so, remember this */
r = dns_question_matches_cname(q->question, answer->rrs[i]);
if (r < 0)
goto finish;
if (r > 0)
cname = dns_resource_record_ref(answer->rrs[i]);
continue;
}
r = append_address(reply, answer->rrs[i], ifindex);
if (r < 0)
goto finish;
if (!canonical)
canonical = dns_resource_record_ref(answer->rrs[i]);
added ++;
}
}
if (added <= 0) {
if (!cname) {
r = sd_bus_reply_method_errorf(q->request, BUS_ERROR_NO_SUCH_RR, "'%s' does not have any RR of requested type", q->request_hostname);
goto finish;
}
/* This has a cname? Then update the query with the
* new cname. */
r = dns_query_cname_redirect(q, cname->cname.name);
if (r < 0) {
if (r == -ELOOP)
r = sd_bus_reply_method_errorf(q->request, BUS_ERROR_CNAME_LOOP, "CNAME loop on '%s'", q->request_hostname);
else
r = sd_bus_reply_method_errno(q->request, -r, NULL);
goto finish;
}
/* Before we restart the query, let's see if any of
* the RRs we already got already answers our query */
for (i = 0; i < answer->n_rrs; i++) {
r = dns_question_matches_rr(q->question, answer->rrs[i]);
if (r < 0)
goto finish;
if (r == 0)
continue;
r = append_address(reply, answer->rrs[i], ifindex);
if (r < 0)
goto finish;
if (!canonical)
canonical = dns_resource_record_ref(answer->rrs[i]);
added++;
}
/* If we didn't find anything, then let's restart the
* query, this time with the cname */
if (added <= 0) {
r = dns_query_go(q);
if (r == -ESRCH) {
r = sd_bus_reply_method_errorf(q->request, BUS_ERROR_NO_NAME_SERVERS, "No appropriate name servers or networks for name found");
goto finish;
}
if (r < 0) {
r = sd_bus_reply_method_errno(q->request, -r, NULL);
goto finish;
}
return;
}
}
r = sd_bus_message_close_container(reply);
if (r < 0)
goto finish;
/* Return the precise spelling and uppercasing reported by the server */
assert(canonical);
r = sd_bus_message_append(reply, "s", DNS_RESOURCE_KEY_NAME(canonical->key));
if (r < 0)
goto finish;
r = sd_bus_send(q->manager->bus, reply, NULL);
finish:
if (r < 0) {
log_error("Failed to send hostname reply: %s", strerror(-r));
sd_bus_reply_method_errno(q->request, -r, NULL);
}
dns_query_free(q);
}
static int bus_method_resolve_hostname(sd_bus *bus, sd_bus_message *message, void *userdata, sd_bus_error *error) {
_cleanup_(dns_question_unrefp) DnsQuestion *question = NULL;
Manager *m = userdata;
const char *hostname;
int family;
DnsQuery *q;
int r;
assert(bus);
assert(message);
assert(m);
r = sd_bus_message_read(message, "si", &hostname, &family);
if (r < 0)
return r;
if (!IN_SET(family, AF_INET, AF_INET6, AF_UNSPEC))
return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Unknown address family %i", family);
if (!hostname_is_valid(hostname))
return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid hostname '%s'", hostname);
question = dns_question_new(family == AF_UNSPEC ? 2 : 1);
if (!question)
return -ENOMEM;
if (family != AF_INET6) {
_cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL;
key = dns_resource_key_new(DNS_CLASS_IN, DNS_TYPE_A, hostname);
if (!key)
return -ENOMEM;
r = dns_question_add(question, key);
if (r < 0)
return r;
}
if (family != AF_INET) {
_cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL;
key = dns_resource_key_new(DNS_CLASS_IN, DNS_TYPE_AAAA, hostname);
if (!key)
return -ENOMEM;
r = dns_question_add(question, key);
if (r < 0)
return r;
}
r = dns_query_new(m, &q, question);
if (r < 0)
return r;
q->request = sd_bus_message_ref(message);
q->request_family = family;
q->request_hostname = hostname;
q->complete = bus_method_resolve_hostname_complete;
r = dns_query_go(q);
if (r < 0) {
dns_query_free(q);
if (r == -ESRCH)
sd_bus_error_setf(error, BUS_ERROR_NO_NAME_SERVERS, "No appropriate name servers or networks for name found");
return r;
}
return 1;
}
static void bus_method_resolve_address_complete(DnsQuery *q) {
_cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
_cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL;
unsigned added = 0, i;
int r;
assert(q);
if (q->state != DNS_TRANSACTION_SUCCESS) {
r = reply_query_state(q);
goto finish;
}
r = sd_bus_message_new_method_return(q->request, &reply);
if (r < 0)
goto finish;
r = sd_bus_message_open_container(reply, 'a', "s");
if (r < 0)
goto finish;
if (q->answer) {
answer = dns_answer_ref(q->answer);
for (i = 0; i < answer->n_rrs; i++) {
r = dns_question_matches_rr(q->question, answer->rrs[i]);
if (r < 0)
goto finish;
if (r == 0)
continue;
r = sd_bus_message_append(reply, "s", answer->rrs[i]->ptr.name);
if (r < 0)
goto finish;
added ++;
}
}
if (added <= 0) {
_cleanup_free_ char *ip = NULL;
in_addr_to_string(q->request_family, &q->request_address, &ip);
r = sd_bus_reply_method_errorf(q->request, BUS_ERROR_NO_SUCH_RR, "Address '%s' does not have any RR of requested type", ip);
goto finish;
}
r = sd_bus_message_close_container(reply);
if (r < 0)
goto finish;
r = sd_bus_send(q->manager->bus, reply, NULL);
finish:
if (r < 0) {
log_error("Failed to send address reply: %s", strerror(-r));
sd_bus_reply_method_errno(q->request, -r, NULL);
}
dns_query_free(q);
}
static int bus_method_resolve_address(sd_bus *bus, sd_bus_message *message, void *userdata, sd_bus_error *error) {
_cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL;
_cleanup_(dns_question_unrefp) DnsQuestion *question = NULL;
_cleanup_free_ char *reverse = NULL;
Manager *m = userdata;
int family, ifindex;
const void *d;
DnsQuery *q;
size_t sz;
int r;
assert(bus);
assert(message);
assert(m);
r = sd_bus_message_read(message, "i", &family);
if (r < 0)
return r;
if (!IN_SET(family, AF_INET, AF_INET6))
return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Unknown address family %i", family);
r = sd_bus_message_read_array(message, 'y', &d, &sz);
if (r < 0)
return r;
if (sz != FAMILY_ADDRESS_SIZE(family))
return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid address size");
r = sd_bus_message_read(message, "i", &ifindex);
if (r < 0)
return r;
if (ifindex < 0)
return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid interface index");
r = dns_name_reverse(family, d, &reverse);
if (r < 0)
return r;
question = dns_question_new(1);
if (!question)
return -ENOMEM;
key = dns_resource_key_new_consume(DNS_CLASS_IN, DNS_TYPE_PTR, reverse);
if (!key)
return -ENOMEM;
reverse = NULL;
r = dns_question_add(question, key);
if (r < 0)
return r;
r = dns_query_new(m, &q, question);
if (r < 0)
return r;
q->request = sd_bus_message_ref(message);
q->request_family = family;
memcpy(&q->request_address, d, sz);
q->complete = bus_method_resolve_address_complete;
r = dns_query_go(q);
if (r < 0) {
dns_query_free(q);
if (r == -ESRCH)
sd_bus_error_setf(error, BUS_ERROR_NO_NAME_SERVERS, "No appropriate name servers or networks for name found");
return r;
}
return 1;
}
static void bus_method_resolve_record_complete(DnsQuery *q) {
_cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
_cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL;
unsigned added = 0, i;
int r;
assert(q);
if (q->state != DNS_TRANSACTION_SUCCESS) {
r = reply_query_state(q);
goto finish;
}
r = sd_bus_message_new_method_return(q->request, &reply);
if (r < 0)
goto finish;
r = sd_bus_message_open_container(reply, 'a', "(qqay)");
if (r < 0)
goto finish;
if (q->answer) {
answer = dns_answer_ref(q->answer);
for (i = 0; i < answer->n_rrs; i++) {
_cleanup_(dns_packet_unrefp) DnsPacket *p = NULL;
size_t start;
r = dns_question_matches_rr(q->question, answer->rrs[i]);
if (r < 0)
goto finish;
if (r == 0)
continue;
r = dns_packet_new(&p, DNS_PROTOCOL_DNS, 0);
if (r < 0)
goto finish;
r = dns_packet_append_rr(p, answer->rrs[i], &start);
if (r < 0)
goto finish;
r = sd_bus_message_open_container(reply, 'r', "qqay");
if (r < 0)
goto finish;
r = sd_bus_message_append(reply, "qq", answer->rrs[i]->key->class, answer->rrs[i]->key->type);
if (r < 0)
goto finish;
r = sd_bus_message_append_array(reply, 'y', DNS_PACKET_DATA(p) + start, p->size - start);
if (r < 0)
goto finish;
r = sd_bus_message_close_container(reply);
if (r < 0)
goto finish;
added ++;
}
}
if (added <= 0) {
r = sd_bus_reply_method_errorf(q->request, BUS_ERROR_NO_SUCH_RR, "Name '%s' does not have any RR of the requested type", q->request_hostname);
goto finish;
}
r = sd_bus_message_close_container(reply);
if (r < 0)
goto finish;
r = sd_bus_send(q->manager->bus, reply, NULL);
finish:
if (r < 0) {
log_error("Failed to send record reply: %s", strerror(-r));
sd_bus_reply_method_errno(q->request, -r, NULL);
}
dns_query_free(q);
}
static int bus_method_resolve_record(sd_bus *bus, sd_bus_message *message, void *userdata, sd_bus_error *error) {
_cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL;
_cleanup_(dns_question_unrefp) DnsQuestion *question = NULL;
_cleanup_free_ char *reverse = NULL;
Manager *m = userdata;
DnsQuery *q;
int r;
uint16_t class, type;
const char *name;
assert(bus);
assert(message);
assert(m);
r = sd_bus_message_read(message, "sqq", &name, &class, &type);
if (r < 0)
return r;
question = dns_question_new(1);
if (!question)
return -ENOMEM;
key = dns_resource_key_new(class, type, name);
if (!key)
return -ENOMEM;
r = dns_question_add(question, key);
if (r < 0)
return r;
r = dns_query_new(m, &q, question);
if (r < 0)
return r;
q->request = sd_bus_message_ref(message);
q->request_hostname = name;
q->complete = bus_method_resolve_record_complete;
r = dns_query_go(q);
if (r < 0) {
dns_query_free(q);
if (r == -ESRCH)
sd_bus_error_setf(error, BUS_ERROR_NO_NAME_SERVERS, "No appropriate name servers or networks for name found");
return r;
}
return 1;
}
static const sd_bus_vtable resolve_vtable[] = {
SD_BUS_VTABLE_START(0),
SD_BUS_METHOD("ResolveHostname", "si", "a(iayi)s", bus_method_resolve_hostname, SD_BUS_VTABLE_UNPRIVILEGED),
SD_BUS_METHOD("ResolveAddress", "iayi", "as", bus_method_resolve_address, SD_BUS_VTABLE_UNPRIVILEGED),
SD_BUS_METHOD("ResolveRecord", "sqq", "a(qqay)", bus_method_resolve_record, SD_BUS_VTABLE_UNPRIVILEGED),
SD_BUS_VTABLE_END,
};
static int on_bus_retry(sd_event_source *s, usec_t usec, void *userdata) {
Manager *m = userdata;
assert(s);
assert(m);
m->bus_retry_event_source = sd_event_source_unref(m->bus_retry_event_source);
manager_connect_bus(m);
return 0;
}
int manager_connect_bus(Manager *m) {
int r;
assert(m);
if (m->bus)
return 0;
r = sd_bus_default_system(&m->bus);
if (r < 0) {
/* We failed to connect? Yuck, we must be in early
* boot. Let's try in 5s again. As soon as we have
* kdbus we can stop doing this... */
log_debug("Failed to connect to bus, trying again in 5s: %s", strerror(-r));
r = sd_event_add_time(m->event, &m->bus_retry_event_source, CLOCK_MONOTONIC, now(CLOCK_MONOTONIC) + 5*USEC_PER_SEC, 0, on_bus_retry, m);
if (r < 0) {
log_error("Failed to install bus reconnect time event: %s", strerror(-r));
return r;
}
return 0;
}
r = sd_bus_add_object_vtable(m->bus, NULL, "/org/freedesktop/resolve1", "org.freedesktop.resolve1.Manager", resolve_vtable, m);
if (r < 0) {
log_error("Failed to register object: %s", strerror(-r));
return r;
}
r = sd_bus_request_name(m->bus, "org.freedesktop.resolve1", 0);
if (r < 0) {
log_error("Failed to register name: %s", strerror(-r));
return r;
}
r = sd_bus_attach_event(m->bus, m->event, 0);
if (r < 0) {
log_error("Failed to attach bus to event loop: %s", strerror(-r));
return r;
}
return 0;
}
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