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Merge pull request #22546 from poettering/resolved-bus-error-reply-rework

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resolved: rework how we reply to D-Bus messages for resolution requests
This commit is contained in:
Luca Boccassi
2022-02-18 22:20:17 +00:00
committed by GitHub
parent 2234cd6a0b 2471a977b1
commit 915e2786f4
1 changed files with 105 additions and 39 deletions
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src/resolve/resolved-bus.c
+105 -39
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@@ -59,57 +59,122 @@ static int dns_query_bus_track(DnsQuery *q, sd_bus_message *m) {
return 0;
}
static sd_bus_message *dns_query_steal_request(DnsQuery *q) {
assert(q);
/* Find the main query, it's the one that owns the message */
while (q->auxiliary_for)
q = q->auxiliary_for;
/* Let's take the request message out of the DnsQuery object, so that we never send requests twice */
return TAKE_PTR(q->bus_request);
}
_sd_printf_(3, 4) static int reply_method_errorf(
DnsQuery *query,
const char *error_name,
const char *format,
...) {
_cleanup_(sd_bus_message_unrefp) sd_bus_message *req = NULL;
va_list ap;
int r;
assert(query);
assert(format);
req = dns_query_steal_request(query);
if (!req) /* No bus message set anymore? then we already replied already, let's not answer a second time */
return 0;
va_start(ap, format);
r = sd_bus_reply_method_errorfv(req, error_name, format, ap);
va_end(ap);
return r;
}
_sd_printf_(3, 4) static int reply_method_errnof(
DnsQuery *query,
int err,
const char *format,
...) {
_cleanup_(sd_bus_message_unrefp) sd_bus_message *req = NULL;
int r;
assert(query);
req = dns_query_steal_request(query);
if (!req) /* No bus message set anymore? then we already replied already, let's not answer a second time */
return 0;
if (format) {
va_list ap;
va_start(ap, format);
r = sd_bus_reply_method_errnofv(req, err, format, ap);
va_end(ap);
} else
r = sd_bus_reply_method_errno(req, err, NULL);
return r;
}
static int reply_query_state(DnsQuery *q) {
assert(q);
assert(q->bus_request);
switch (q->state) {
case DNS_TRANSACTION_NO_SERVERS:
return sd_bus_reply_method_errorf(q->bus_request, BUS_ERROR_NO_NAME_SERVERS, "No appropriate name servers or networks for name found");
return reply_method_errorf(q, 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->bus_request, SD_BUS_ERROR_TIMEOUT, "Query timed out");
return reply_method_errorf(q, SD_BUS_ERROR_TIMEOUT, "Query timed out");
case DNS_TRANSACTION_ATTEMPTS_MAX_REACHED:
return sd_bus_reply_method_errorf(q->bus_request, SD_BUS_ERROR_TIMEOUT, "All attempts to contact name servers or networks failed");
return reply_method_errorf(q, SD_BUS_ERROR_TIMEOUT, "All attempts to contact name servers or networks failed");
case DNS_TRANSACTION_INVALID_REPLY:
return sd_bus_reply_method_errorf(q->bus_request, BUS_ERROR_INVALID_REPLY, "Received invalid reply");
return reply_method_errorf(q, BUS_ERROR_INVALID_REPLY, "Received invalid reply");
case DNS_TRANSACTION_ERRNO:
return sd_bus_reply_method_errnof(q->bus_request, q->answer_errno, "Lookup failed due to system error: %m");
return reply_method_errnof(q, q->answer_errno, "Lookup failed due to system error: %m");
case DNS_TRANSACTION_ABORTED:
return sd_bus_reply_method_errorf(q->bus_request, BUS_ERROR_ABORTED, "Query aborted");
return reply_method_errorf(q, BUS_ERROR_ABORTED, "Query aborted");
case DNS_TRANSACTION_DNSSEC_FAILED:
return sd_bus_reply_method_errorf(q->bus_request, BUS_ERROR_DNSSEC_FAILED, "DNSSEC validation failed: %s",
dnssec_result_to_string(q->answer_dnssec_result));
return reply_method_errorf(q, BUS_ERROR_DNSSEC_FAILED, "DNSSEC validation failed: %s",
dnssec_result_to_string(q->answer_dnssec_result));
case DNS_TRANSACTION_NO_TRUST_ANCHOR:
return sd_bus_reply_method_errorf(q->bus_request, BUS_ERROR_NO_TRUST_ANCHOR, "No suitable trust anchor known");
return reply_method_errorf(q, BUS_ERROR_NO_TRUST_ANCHOR, "No suitable trust anchor known");
case DNS_TRANSACTION_RR_TYPE_UNSUPPORTED:
return sd_bus_reply_method_errorf(q->bus_request, BUS_ERROR_RR_TYPE_UNSUPPORTED, "Server does not support requested resource record type");
return reply_method_errorf(q, BUS_ERROR_RR_TYPE_UNSUPPORTED, "Server does not support requested resource record type");
case DNS_TRANSACTION_NETWORK_DOWN:
return sd_bus_reply_method_errorf(q->bus_request, BUS_ERROR_NETWORK_DOWN, "Network is down");
return reply_method_errorf(q, BUS_ERROR_NETWORK_DOWN, "Network is down");
case DNS_TRANSACTION_NOT_FOUND:
/* We return this as NXDOMAIN. This is only generated when a host doesn't implement LLMNR/TCP, and we
* thus quickly know that we cannot resolve an in-addr.arpa or ip6.arpa address. */
return sd_bus_reply_method_errorf(q->bus_request, _BUS_ERROR_DNS "NXDOMAIN", "'%s' not found", dns_query_string(q));
return reply_method_errorf(q, _BUS_ERROR_DNS "NXDOMAIN", "'%s' not found", dns_query_string(q));
case DNS_TRANSACTION_NO_SOURCE:
return sd_bus_reply_method_errorf(q->bus_request, BUS_ERROR_NO_SOURCE, "All suitable resolution sources turned off");
return reply_method_errorf(q, BUS_ERROR_NO_SOURCE, "All suitable resolution sources turned off");
case DNS_TRANSACTION_STUB_LOOP:
return sd_bus_reply_method_errorf(q->bus_request, BUS_ERROR_STUB_LOOP, "Configured DNS server loops back to us");
return reply_method_errorf(q, BUS_ERROR_STUB_LOOP, "Configured DNS server loops back to us");
case DNS_TRANSACTION_RCODE_FAILURE: {
_cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
_cleanup_(sd_bus_message_unrefp) sd_bus_message *req = NULL;
req = dns_query_steal_request(q);
if (!req) /* No bus message set anymore? then we already replied already, let's not answer a second time */
return 0;
if (q->answer_rcode == DNS_RCODE_NXDOMAIN)
sd_bus_error_setf(&error, _BUS_ERROR_DNS "NXDOMAIN", "'%s' not found", dns_query_string(q));
@@ -127,7 +192,7 @@ static int reply_query_state(DnsQuery *q) {
sd_bus_error_setf(&error, n, "Could not resolve '%s', server or network returned error %s", dns_query_string(q), rc);
}
return sd_bus_reply_method_error(q->bus_request, &error);
return sd_bus_reply_method_error(req, &error);
}
case DNS_TRANSACTION_NULL:
@@ -198,7 +263,7 @@ static void bus_method_resolve_hostname_complete(DnsQuery *query) {
r = dns_query_process_cname_many(q);
if (r == -ELOOP) {
r = sd_bus_reply_method_errorf(q->bus_request, BUS_ERROR_CNAME_LOOP, "CNAME loop detected, or CNAME resolving disabled on '%s'", dns_query_string(q));
r = reply_method_errorf(q, BUS_ERROR_CNAME_LOOP, "CNAME loop detected, or CNAME resolving disabled on '%s'", dns_query_string(q));
goto finish;
}
if (r < 0)
@@ -238,7 +303,7 @@ static void bus_method_resolve_hostname_complete(DnsQuery *query) {
}
if (added <= 0) {
r = sd_bus_reply_method_errorf(q->bus_request, BUS_ERROR_NO_SUCH_RR, "'%s' does not have any RR of the requested type", dns_query_string(q));
r = reply_method_errorf(q, BUS_ERROR_NO_SUCH_RR, "'%s' does not have any RR of the requested type", dns_query_string(q));
goto finish;
}
@@ -261,12 +326,13 @@ static void bus_method_resolve_hostname_complete(DnsQuery *query) {
if (r < 0)
goto finish;
q->bus_request = sd_bus_message_unref(q->bus_request);
r = sd_bus_send(q->manager->bus, reply, NULL);
finish:
if (r < 0) {
log_error_errno(r, "Failed to send hostname reply: %m");
sd_bus_reply_method_errno(q->bus_request, r, NULL);
(void) reply_method_errnof(q, r, NULL);
}
}
@@ -488,7 +554,7 @@ static void bus_method_resolve_address_complete(DnsQuery *query) {
r = dns_query_process_cname_many(q);
if (r == -ELOOP) {
r = sd_bus_reply_method_errorf(q->bus_request, BUS_ERROR_CNAME_LOOP, "CNAME loop detected, or CNAME resolving disabled on '%s'", dns_query_string(q));
r = reply_method_errorf(q, BUS_ERROR_CNAME_LOOP, "CNAME loop detected, or CNAME resolving disabled on '%s'", dns_query_string(q));
goto finish;
}
if (r < 0)
@@ -533,7 +599,7 @@ static void bus_method_resolve_address_complete(DnsQuery *query) {
_cleanup_free_ char *ip = NULL;
(void) in_addr_to_string(q->request_family, &q->request_address, &ip);
r = sd_bus_reply_method_errorf(q->bus_request, BUS_ERROR_NO_SUCH_RR,
r = reply_method_errorf(q, BUS_ERROR_NO_SUCH_RR,
"Address '%s' does not have any RR of requested type", strnull(ip));
goto finish;
}
@@ -546,12 +612,13 @@ static void bus_method_resolve_address_complete(DnsQuery *query) {
if (r < 0)
goto finish;
q->bus_request = sd_bus_message_unref(q->bus_request);
r = sd_bus_send(q->manager->bus, reply, NULL);
finish:
if (r < 0) {
log_error_errno(r, "Failed to send address reply: %m");
sd_bus_reply_method_errno(q->bus_request, r, NULL);
(void) reply_method_errnof(q, r, NULL);
}
}
@@ -661,7 +728,7 @@ static void bus_method_resolve_record_complete(DnsQuery *query) {
r = dns_query_process_cname_many(q);
if (r == -ELOOP) {
r = sd_bus_reply_method_errorf(q->bus_request, BUS_ERROR_CNAME_LOOP, "CNAME loop detected, or CNAME resolving disabled on '%s'", dns_query_string(q));
r = reply_method_errorf(q, BUS_ERROR_CNAME_LOOP, "CNAME loop detected, or CNAME resolving disabled on '%s'", dns_query_string(q));
goto finish;
}
if (r < 0)
@@ -697,7 +764,7 @@ static void bus_method_resolve_record_complete(DnsQuery *query) {
}
if (added <= 0) {
r = sd_bus_reply_method_errorf(q->bus_request, BUS_ERROR_NO_SUCH_RR, "Name '%s' does not have any RR of the requested type", dns_query_string(q));
r = reply_method_errorf(q, BUS_ERROR_NO_SUCH_RR, "Name '%s' does not have any RR of the requested type", dns_query_string(q));
goto finish;
}
@@ -709,12 +776,13 @@ static void bus_method_resolve_record_complete(DnsQuery *query) {
if (r < 0)
goto finish;
q->bus_request = sd_bus_message_unref(q->bus_request);
r = sd_bus_send(q->manager->bus, reply, NULL);
finish:
if (r < 0) {
log_error_errno(r, "Failed to send record reply: %m");
sd_bus_reply_method_errno(q->bus_request, r, NULL);
(void) reply_method_errnof(q, r, NULL);
}
}
@@ -1002,7 +1070,7 @@ static void resolve_service_all_complete(DnsQuery *query) {
assert(bad->auxiliary_result != 0);
if (bad->auxiliary_result == -ELOOP) {
r = sd_bus_reply_method_errorf(q->bus_request, BUS_ERROR_CNAME_LOOP, "CNAME loop detected, or CNAME resolving disabled on '%s'", dns_query_string(bad));
r = reply_method_errorf(q, BUS_ERROR_CNAME_LOOP, "CNAME loop detected, or CNAME resolving disabled on '%s'", dns_query_string(bad));
goto finish;
}
@@ -1046,7 +1114,7 @@ static void resolve_service_all_complete(DnsQuery *query) {
}
if (added <= 0) {
r = sd_bus_reply_method_errorf(q->bus_request, BUS_ERROR_NO_SUCH_RR, "'%s' does not have any RR of the requested type", dns_query_string(q));
r = reply_method_errorf(q, BUS_ERROR_NO_SUCH_RR, "'%s' does not have any RR of the requested type", dns_query_string(q));
goto finish;
}
@@ -1087,12 +1155,13 @@ static void resolve_service_all_complete(DnsQuery *query) {
if (r < 0)
goto finish;
q->bus_request = sd_bus_message_unref(q->bus_request);
r = sd_bus_send(q->manager->bus, reply, NULL);
finish:
if (r < 0) {
log_error_errno(r, "Failed to send service reply: %m");
sd_bus_reply_method_errno(q->bus_request, r, NULL);
(void) reply_method_errnof(q, r, NULL);
}
}
@@ -1177,7 +1246,7 @@ static void bus_method_resolve_service_complete(DnsQuery *query) {
r = dns_query_process_cname_many(q);
if (r == -ELOOP) {
r = sd_bus_reply_method_errorf(q->bus_request, BUS_ERROR_CNAME_LOOP, "CNAME loop detected, or CNAME resolving disabled on '%s'", dns_query_string(q));
r = reply_method_errorf(q, BUS_ERROR_CNAME_LOOP, "CNAME loop detected, or CNAME resolving disabled on '%s'", dns_query_string(q));
goto finish;
}
if (r < 0)
@@ -1218,18 +1287,15 @@ static void bus_method_resolve_service_complete(DnsQuery *query) {
}
if (has_root_domain && found <= 0) {
/* If there's exactly one SRV RR and it uses
* the root domain as hostname, then the
* service is explicitly not offered on the
* domain. Report this as a recognizable
* error. See RFC 2782, Section "Usage
* Rules". */
r = sd_bus_reply_method_errorf(q->bus_request, BUS_ERROR_NO_SUCH_SERVICE, "'%s' does not provide the requested service", dns_query_string(q));
/* If there's exactly one SRV RR and it uses the root domain as hostname, then the service is
* explicitly not offered on the domain. Report this as a recognizable error. See RFC 2782,
* Section "Usage Rules". */
r = reply_method_errorf(q, BUS_ERROR_NO_SUCH_SERVICE, "'%s' does not provide the requested service", dns_query_string(q));
goto finish;
}
if (found <= 0) {
r = sd_bus_reply_method_errorf(q->bus_request, BUS_ERROR_NO_SUCH_RR, "'%s' does not have any RR of the requested type", dns_query_string(q));
r = reply_method_errorf(q, BUS_ERROR_NO_SUCH_RR, "'%s' does not have any RR of the requested type", dns_query_string(q));
goto finish;
}
@@ -1240,7 +1306,7 @@ static void bus_method_resolve_service_complete(DnsQuery *query) {
finish:
if (r < 0) {
log_error_errno(r, "Failed to send service reply: %m");
sd_bus_reply_method_errno(q->bus_request, r, NULL);
(void) reply_method_errnof(q, r, NULL);
}
}