1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
12 #include "errno-util.h"
13 #include "in-addr-util.h"
16 #include "resolved-def.h"
17 #include "signal-util.h"
18 #include "string-util.h"
22 static JsonDispatchFlags json_dispatch_flags
= 0;
24 static void setup_logging(void) {
25 log_parse_environment();
28 json_dispatch_flags
= JSON_LOG
;
31 static void setup_logging_once(void) {
32 static pthread_once_t once
= PTHREAD_ONCE_INIT
;
33 assert_se(pthread_once(&once
, setup_logging
) == 0);
36 #define NSS_ENTRYPOINT_BEGIN \
37 BLOCK_SIGNALS(NSS_SIGNALS_BLOCK); \
40 NSS_GETHOSTBYNAME_PROTOTYPES(resolve
);
41 NSS_GETHOSTBYADDR_PROTOTYPES(resolve
);
43 static bool error_shall_fallback(const char *error_id
) {
44 return STR_IN_SET(error_id
,
45 VARLINK_ERROR_DISCONNECTED
,
46 VARLINK_ERROR_TIMEOUT
,
47 VARLINK_ERROR_PROTOCOL
,
48 VARLINK_ERROR_INTERFACE_NOT_FOUND
,
49 VARLINK_ERROR_METHOD_NOT_FOUND
,
50 VARLINK_ERROR_METHOD_NOT_IMPLEMENTED
);
53 static int connect_to_resolved(Varlink
**ret
) {
54 _cleanup_(varlink_unrefp
) Varlink
*link
= NULL
;
57 r
= varlink_connect_address(&link
, "/run/systemd/resolve/io.systemd.Resolve");
61 r
= varlink_set_relative_timeout(link
, SD_RESOLVED_QUERY_TIMEOUT_USEC
);
65 *ret
= TAKE_PTR(link
);
69 static uint32_t ifindex_to_scopeid(int family
, const void *a
, int ifindex
) {
72 if (family
!= AF_INET6
|| ifindex
== 0)
75 /* Some apps can't deal with the scope ID attached to non-link-local addresses. Hence, let's suppress that. */
77 assert(sizeof(in6
) == FAMILY_ADDRESS_SIZE(AF_INET6
));
78 memcpy(&in6
, a
, sizeof(struct in6_addr
));
80 return in6_addr_is_link_local(&in6
) ? ifindex
: 0;
83 static int json_dispatch_ifindex(const char *name
, JsonVariant
*variant
, JsonDispatchFlags flags
, void *userdata
) {
90 if (!json_variant_is_integer(variant
))
91 return json_log(variant
, flags
, SYNTHETIC_ERRNO(EINVAL
), "JSON field '%s' is not an integer.", strna(name
));
93 t
= json_variant_integer(variant
);
95 return json_log(variant
, flags
, SYNTHETIC_ERRNO(EINVAL
), "JSON field '%s' is out of bounds for an interface index.", strna(name
));
101 static int json_dispatch_family(const char *name
, JsonVariant
*variant
, JsonDispatchFlags flags
, void *userdata
) {
102 int *family
= userdata
;
108 if (!json_variant_is_integer(variant
))
109 return json_log(variant
, flags
, SYNTHETIC_ERRNO(EINVAL
), "JSON field '%s' is not an integer.", strna(name
));
111 t
= json_variant_integer(variant
);
112 if (t
< 0 || t
> INT_MAX
)
113 return json_log(variant
, flags
, SYNTHETIC_ERRNO(EINVAL
), "JSON field '%s' is not a valid family.", strna(name
));
119 typedef struct ResolveHostnameReply
{
120 JsonVariant
*addresses
;
123 } ResolveHostnameReply
;
125 static void resolve_hostname_reply_destroy(ResolveHostnameReply
*p
) {
128 json_variant_unref(p
->addresses
);
132 static const JsonDispatch resolve_hostname_reply_dispatch_table
[] = {
133 { "addresses", JSON_VARIANT_ARRAY
, json_dispatch_variant
, offsetof(ResolveHostnameReply
, addresses
), JSON_MANDATORY
},
134 { "name", JSON_VARIANT_STRING
, json_dispatch_string
, offsetof(ResolveHostnameReply
, name
), 0 },
135 { "flags", JSON_VARIANT_UNSIGNED
, json_dispatch_uint64
, offsetof(ResolveHostnameReply
, flags
), 0 },
139 typedef struct AddressParameters
{
142 union in_addr_union address
;
146 static int json_dispatch_address(const char *name
, JsonVariant
*variant
, JsonDispatchFlags flags
, void *userdata
) {
147 AddressParameters
*p
= userdata
;
148 union in_addr_union buf
= {};
155 if (!json_variant_is_array(variant
))
156 return json_log(variant
, flags
, SYNTHETIC_ERRNO(EINVAL
), "JSON field '%s' is not an array.", strna(name
));
158 n
= json_variant_elements(variant
);
159 if (!IN_SET(n
, 4, 16))
160 return json_log(variant
, flags
, SYNTHETIC_ERRNO(EINVAL
), "JSON field '%s' is array of unexpected size.", strna(name
));
162 JSON_VARIANT_ARRAY_FOREACH(i
, variant
) {
165 if (!json_variant_is_integer(i
))
166 return json_log(variant
, flags
, SYNTHETIC_ERRNO(EINVAL
), "Element %zu of JSON field '%s' is not an integer.", k
, strna(name
));
168 b
= json_variant_integer(i
);
169 if (b
< 0 || b
> 0xff)
170 return json_log(variant
, flags
, SYNTHETIC_ERRNO(EINVAL
), "Element %zu of JSON field '%s' is out of range 0…255.", k
, strna(name
));
172 buf
.bytes
[k
++] = (uint8_t) b
;
181 static const JsonDispatch address_parameters_dispatch_table
[] = {
182 { "ifindex", JSON_VARIANT_INTEGER
, json_dispatch_ifindex
, offsetof(AddressParameters
, ifindex
), 0 },
183 { "family", JSON_VARIANT_INTEGER
, json_dispatch_family
, offsetof(AddressParameters
, family
), JSON_MANDATORY
},
184 { "address", JSON_VARIANT_ARRAY
, json_dispatch_address
, 0, JSON_MANDATORY
},
188 static uint64_t query_flags(void) {
192 /* Allow callers to turn off validation, when we resolve via nss-resolve */
194 r
= getenv_bool_secure("SYSTEMD_NSS_RESOLVE_VALIDATE");
195 if (r
< 0 && r
!= -ENXIO
)
196 log_debug_errno(r
, "Failed to parse $SYSTEMD_NSS_RESOLVE_VALIDATE value, ignoring.");
198 f
|= SD_RESOLVED_NO_VALIDATE
;
203 enum nss_status
_nss_resolve_gethostbyname4_r(
205 struct gaih_addrtuple
**pat
,
206 char *buffer
, size_t buflen
,
207 int *errnop
, int *h_errnop
,
210 _cleanup_(resolve_hostname_reply_destroy
) ResolveHostnameReply p
= {};
211 _cleanup_(json_variant_unrefp
) JsonVariant
*cparams
= NULL
;
212 struct gaih_addrtuple
*r_tuple
= NULL
, *r_tuple_first
= NULL
;
213 _cleanup_(varlink_unrefp
) Varlink
*link
= NULL
;
214 const char *canonical
= NULL
, *error_id
= NULL
;
215 JsonVariant
*entry
, *rparams
;
216 size_t l
, ms
, idx
, c
= 0;
221 NSS_ENTRYPOINT_BEGIN
;
229 r
= connect_to_resolved(&link
);
233 r
= json_build(&cparams
, JSON_BUILD_OBJECT(
234 JSON_BUILD_PAIR("name", JSON_BUILD_STRING(name
)),
235 JSON_BUILD_PAIR("flags", JSON_BUILD_UNSIGNED(query_flags()))));
239 /* Return NSS_STATUS_UNAVAIL when communication with systemd-resolved fails, allowing falling
240 * back to other nss modules. Treat all other error conditions as NOTFOUND. This includes
241 * DNSSEC errors and suchlike. (We don't use UNAVAIL in this case so that the nsswitch.conf
242 * configuration can distinguish such executed but negative replies from complete failure to
243 * talk to resolved). */
244 r
= varlink_call(link
, "io.systemd.Resolve.ResolveHostname", cparams
, &rparams
, &error_id
, NULL
);
247 if (!isempty(error_id
)) {
248 if (!error_shall_fallback(error_id
))
253 r
= json_dispatch(rparams
, resolve_hostname_reply_dispatch_table
, NULL
, json_dispatch_flags
, &p
);
256 if (json_variant_is_blank_object(p
.addresses
))
259 JSON_VARIANT_ARRAY_FOREACH(entry
, p
.addresses
) {
260 AddressParameters q
= {};
262 r
= json_dispatch(entry
, address_parameters_dispatch_table
, NULL
, json_dispatch_flags
, &q
);
266 if (!IN_SET(q
.family
, AF_INET
, AF_INET6
))
269 if (q
.address_size
!= FAMILY_ADDRESS_SIZE(q
.family
)) {
277 canonical
= p
.name
?: name
;
279 l
= strlen(canonical
);
280 ms
= ALIGN(l
+1) + ALIGN(sizeof(struct gaih_addrtuple
)) * c
;
284 *h_errnop
= NETDB_INTERNAL
;
285 return NSS_STATUS_TRYAGAIN
;
288 /* First, append name */
290 memcpy(r_name
, canonical
, l
+1);
293 /* Second, append addresses */
294 r_tuple_first
= (struct gaih_addrtuple
*) (buffer
+ idx
);
296 JSON_VARIANT_ARRAY_FOREACH(entry
, p
.addresses
) {
297 AddressParameters q
= {};
299 r
= json_dispatch(entry
, address_parameters_dispatch_table
, NULL
, json_dispatch_flags
, &q
);
303 if (!IN_SET(q
.family
, AF_INET
, AF_INET6
))
306 r_tuple
= (struct gaih_addrtuple
*) (buffer
+ idx
);
307 r_tuple
->next
= (struct gaih_addrtuple
*) ((char*) r_tuple
+ ALIGN(sizeof(struct gaih_addrtuple
)));
308 r_tuple
->name
= r_name
;
309 r_tuple
->family
= q
.family
;
310 r_tuple
->scopeid
= ifindex_to_scopeid(q
.family
, &q
.address
, q
.ifindex
);
311 memcpy(r_tuple
->addr
, &q
.address
, q
.address_size
);
313 idx
+= ALIGN(sizeof(struct gaih_addrtuple
));
317 r_tuple
->next
= NULL
; /* Override last next pointer */
322 **pat
= *r_tuple_first
;
324 *pat
= r_tuple_first
;
329 /* Explicitly reset both *h_errnop and h_errno to work around
330 * https://bugzilla.redhat.com/show_bug.cgi?id=1125975 */
331 *h_errnop
= NETDB_SUCCESS
;
334 return NSS_STATUS_SUCCESS
;
339 *h_errnop
= NO_RECOVERY
;
340 return NSS_STATUS_UNAVAIL
;
343 *h_errnop
= HOST_NOT_FOUND
;
344 return NSS_STATUS_NOTFOUND
;
347 enum nss_status
_nss_resolve_gethostbyname3_r(
350 struct hostent
*result
,
351 char *buffer
, size_t buflen
,
352 int *errnop
, int *h_errnop
,
356 _cleanup_(resolve_hostname_reply_destroy
) ResolveHostnameReply p
= {};
357 _cleanup_(json_variant_unrefp
) JsonVariant
*cparams
= NULL
;
358 char *r_name
, *r_aliases
, *r_addr
, *r_addr_list
;
359 _cleanup_(varlink_unrefp
) Varlink
*link
= NULL
;
360 const char *canonical
, *error_id
= NULL
;
361 size_t l
, idx
, ms
, alen
, i
= 0, c
= 0;
362 JsonVariant
*entry
, *rparams
;
366 NSS_ENTRYPOINT_BEGIN
;
377 if (!IN_SET(af
, AF_INET
, AF_INET6
)) {
382 r
= connect_to_resolved(&link
);
386 r
= json_build(&cparams
, JSON_BUILD_OBJECT(JSON_BUILD_PAIR("name", JSON_BUILD_STRING(name
)),
387 JSON_BUILD_PAIR("family", JSON_BUILD_INTEGER(af
)),
388 JSON_BUILD_PAIR("flags", JSON_BUILD_UNSIGNED(query_flags()))));
392 r
= varlink_call(link
, "io.systemd.Resolve.ResolveHostname", cparams
, &rparams
, &error_id
, NULL
);
395 if (!isempty(error_id
)) {
396 if (!error_shall_fallback(error_id
))
401 r
= json_dispatch(rparams
, resolve_hostname_reply_dispatch_table
, NULL
, json_dispatch_flags
, &p
);
404 if (json_variant_is_blank_object(p
.addresses
))
407 JSON_VARIANT_ARRAY_FOREACH(entry
, p
.addresses
) {
408 AddressParameters q
= {};
410 r
= json_dispatch(entry
, address_parameters_dispatch_table
, NULL
, json_dispatch_flags
, &q
);
414 if (!IN_SET(q
.family
, AF_INET
, AF_INET6
))
417 if (q
.address_size
!= FAMILY_ADDRESS_SIZE(q
.family
)) {
425 canonical
= p
.name
?: name
;
427 alen
= FAMILY_ADDRESS_SIZE(af
);
428 l
= strlen(canonical
);
430 ms
= ALIGN(l
+1) + c
*ALIGN(alen
) + (c
+2) * sizeof(char*);
435 *h_errnop
= NETDB_INTERNAL
;
436 return NSS_STATUS_TRYAGAIN
;
439 /* First, append name */
441 memcpy(r_name
, canonical
, l
+1);
444 /* Second, create empty aliases array */
445 r_aliases
= buffer
+ idx
;
446 ((char**) r_aliases
)[0] = NULL
;
447 idx
+= sizeof(char*);
449 /* Third, append addresses */
450 r_addr
= buffer
+ idx
;
452 JSON_VARIANT_ARRAY_FOREACH(entry
, p
.addresses
) {
453 AddressParameters q
= {};
455 r
= json_dispatch(entry
, address_parameters_dispatch_table
, NULL
, json_dispatch_flags
, &q
);
462 if (q
.address_size
!= alen
) {
467 memcpy(r_addr
+ i
*ALIGN(alen
), &q
.address
, alen
);
472 idx
+= c
* ALIGN(alen
);
474 /* Fourth, append address pointer array */
475 r_addr_list
= buffer
+ idx
;
476 for (i
= 0; i
< c
; i
++)
477 ((char**) r_addr_list
)[i
] = r_addr
+ i
*ALIGN(alen
);
479 ((char**) r_addr_list
)[i
] = NULL
;
480 idx
+= (c
+1) * sizeof(char*);
484 result
->h_name
= r_name
;
485 result
->h_aliases
= (char**) r_aliases
;
486 result
->h_addrtype
= af
;
487 result
->h_length
= alen
;
488 result
->h_addr_list
= (char**) r_addr_list
;
496 /* Explicitly reset both *h_errnop and h_errno to work around
497 * https://bugzilla.redhat.com/show_bug.cgi?id=1125975 */
498 *h_errnop
= NETDB_SUCCESS
;
501 return NSS_STATUS_SUCCESS
;
506 *h_errnop
= NO_RECOVERY
;
507 return NSS_STATUS_UNAVAIL
;
510 *h_errnop
= HOST_NOT_FOUND
;
511 return NSS_STATUS_NOTFOUND
;
514 typedef struct ResolveAddressReply
{
517 } ResolveAddressReply
;
519 static void resolve_address_reply_destroy(ResolveAddressReply
*p
) {
522 json_variant_unref(p
->names
);
525 static const JsonDispatch resolve_address_reply_dispatch_table
[] = {
526 { "names", JSON_VARIANT_ARRAY
, json_dispatch_variant
, offsetof(ResolveAddressReply
, names
), JSON_MANDATORY
},
527 { "flags", JSON_VARIANT_UNSIGNED
, json_dispatch_uint64
, offsetof(ResolveAddressReply
, flags
), 0 },
531 typedef struct NameParameters
{
536 static void name_parameters_destroy(NameParameters
*p
) {
542 static const JsonDispatch name_parameters_dispatch_table
[] = {
543 { "ifindex", JSON_VARIANT_INTEGER
, json_dispatch_ifindex
, offsetof(NameParameters
, ifindex
), 0 },
544 { "name", JSON_VARIANT_UNSIGNED
, json_dispatch_string
, offsetof(NameParameters
, name
), JSON_MANDATORY
},
548 enum nss_status
_nss_resolve_gethostbyaddr2_r(
549 const void* addr
, socklen_t len
,
551 struct hostent
*result
,
552 char *buffer
, size_t buflen
,
553 int *errnop
, int *h_errnop
,
556 _cleanup_(resolve_address_reply_destroy
) ResolveAddressReply p
= {};
557 _cleanup_(json_variant_unrefp
) JsonVariant
*cparams
= NULL
;
558 char *r_name
, *r_aliases
, *r_addr
, *r_addr_list
;
559 _cleanup_(varlink_unrefp
) Varlink
*link
= NULL
;
560 JsonVariant
*entry
, *rparams
;
561 const char *n
, *error_id
;
562 unsigned c
= 0, i
= 0;
567 NSS_ENTRYPOINT_BEGIN
;
575 if (!IN_SET(af
, AF_INET
, AF_INET6
)) {
577 *errnop
= EAFNOSUPPORT
;
579 return NSS_STATUS_UNAVAIL
;
582 if (len
!= FAMILY_ADDRESS_SIZE(af
)) {
587 r
= connect_to_resolved(&link
);
591 r
= json_build(&cparams
, JSON_BUILD_OBJECT(JSON_BUILD_PAIR("address", JSON_BUILD_BYTE_ARRAY(addr
, len
)),
592 JSON_BUILD_PAIR("family", JSON_BUILD_INTEGER(af
)),
593 JSON_BUILD_PAIR("flags", JSON_BUILD_UNSIGNED(query_flags()))));
597 r
= varlink_call(link
, "io.systemd.Resolve.ResolveAddress", cparams
, &rparams
, &error_id
, NULL
);
600 if (!isempty(error_id
)) {
601 if (!error_shall_fallback(error_id
))
606 r
= json_dispatch(rparams
, resolve_address_reply_dispatch_table
, NULL
, json_dispatch_flags
, &p
);
609 if (json_variant_is_blank_object(p
.names
))
612 JSON_VARIANT_ARRAY_FOREACH(entry
, p
.names
) {
613 _cleanup_(name_parameters_destroy
) NameParameters q
= {};
615 r
= json_dispatch(entry
, name_parameters_dispatch_table
, NULL
, json_dispatch_flags
, &q
);
619 ms
+= ALIGN(strlen(q
.name
) + 1);
622 ms
+= ALIGN(len
) + /* the address */
623 2 * sizeof(char*) + /* pointers to the address, plus trailing NULL */
624 json_variant_elements(p
.names
) * sizeof(char*); /* pointers to aliases, plus trailing NULL */
629 *h_errnop
= NETDB_INTERNAL
;
630 return NSS_STATUS_TRYAGAIN
;
633 /* First, place address */
635 memcpy(r_addr
, addr
, len
);
638 /* Second, place address list */
639 r_addr_list
= buffer
+ idx
;
640 ((char**) r_addr_list
)[0] = r_addr
;
641 ((char**) r_addr_list
)[1] = NULL
;
642 idx
+= sizeof(char*) * 2;
644 /* Third, reserve space for the aliases array */
645 r_aliases
= buffer
+ idx
;
646 idx
+= sizeof(char*) * c
;
648 /* Fourth, place aliases */
650 r_name
= buffer
+ idx
;
651 JSON_VARIANT_ARRAY_FOREACH(entry
, p
.names
) {
652 _cleanup_(name_parameters_destroy
) NameParameters q
= {};
656 r
= json_dispatch(entry
, name_parameters_dispatch_table
, NULL
, json_dispatch_flags
, &q
);
665 ((char**) r_aliases
)[i
-1] = z
;
671 ((char**) r_aliases
)[c
-1] = NULL
;
674 result
->h_name
= r_name
;
675 result
->h_aliases
= (char**) r_aliases
;
676 result
->h_addrtype
= af
;
677 result
->h_length
= len
;
678 result
->h_addr_list
= (char**) r_addr_list
;
683 /* Explicitly reset both *h_errnop and h_errno to work around
684 * https://bugzilla.redhat.com/show_bug.cgi?id=1125975 */
685 *h_errnop
= NETDB_SUCCESS
;
688 return NSS_STATUS_SUCCESS
;
693 *h_errnop
= NO_RECOVERY
;
694 return NSS_STATUS_UNAVAIL
;
697 *h_errnop
= HOST_NOT_FOUND
;
698 return NSS_STATUS_NOTFOUND
;
701 NSS_GETHOSTBYNAME_FALLBACKS(resolve
);
702 NSS_GETHOSTBYADDR_FALLBACKS(resolve
);