| /* SPDX-License-Identifier: LGPL-2.1-or-later */ |
| |
| #include <errno.h> |
| #include <netdb.h> |
| #include <nss.h> |
| #include <stdlib.h> |
| #include <sys/types.h> |
| #include <unistd.h> |
| |
| #include "errno-util.h" |
| #include "in-addr-util.h" |
| #include "macro.h" |
| #include "nss-util.h" |
| #include "resolved-def.h" |
| #include "signal-util.h" |
| #include "string-util.h" |
| #include "strv.h" |
| #include "varlink.h" |
| |
| NSS_GETHOSTBYNAME_PROTOTYPES(resolve); |
| NSS_GETHOSTBYADDR_PROTOTYPES(resolve); |
| |
| static bool error_shall_fallback(const char *error_id) { |
| return STR_IN_SET(error_id, |
| VARLINK_ERROR_DISCONNECTED, |
| VARLINK_ERROR_TIMEOUT, |
| VARLINK_ERROR_PROTOCOL, |
| VARLINK_ERROR_INTERFACE_NOT_FOUND, |
| VARLINK_ERROR_METHOD_NOT_FOUND, |
| VARLINK_ERROR_METHOD_NOT_IMPLEMENTED); |
| } |
| |
| static int connect_to_resolved(Varlink **ret) { |
| _cleanup_(varlink_unrefp) Varlink *link = NULL; |
| int r; |
| |
| r = varlink_connect_address(&link, "/run/systemd/resolve/io.systemd.Resolve"); |
| if (r < 0) |
| return r; |
| |
| r = varlink_set_relative_timeout(link, SD_RESOLVED_QUERY_TIMEOUT_USEC); |
| if (r < 0) |
| return r; |
| |
| *ret = TAKE_PTR(link); |
| return 0; |
| } |
| |
| static uint32_t ifindex_to_scopeid(int family, const void *a, int ifindex) { |
| struct in6_addr in6; |
| |
| if (family != AF_INET6) |
| return 0; |
| |
| /* Some apps can't deal with the scope ID attached to non-link-local addresses. Hence, let's suppress that. */ |
| |
| assert(sizeof(in6) == FAMILY_ADDRESS_SIZE(AF_INET6)); |
| memcpy(&in6, a, sizeof(struct in6_addr)); |
| |
| return IN6_IS_ADDR_LINKLOCAL(&in6) ? ifindex : 0; |
| } |
| |
| static int json_dispatch_ifindex(const char *name, JsonVariant *variant, JsonDispatchFlags flags, void *userdata) { |
| int *ifi = userdata; |
| intmax_t t; |
| |
| assert(variant); |
| assert(ifi); |
| |
| if (!json_variant_is_integer(variant)) |
| return json_log(variant, flags, SYNTHETIC_ERRNO(EINVAL), "JSON field '%s' is not an integer.", strna(name)); |
| |
| t = json_variant_integer(variant); |
| if (t <= 0 || t > INT_MAX) |
| return json_log(variant, flags, SYNTHETIC_ERRNO(EINVAL), "JSON field '%s' is out of bounds for an interface index.", strna(name)); |
| |
| *ifi = (int) t; |
| return 0; |
| } |
| |
| static int json_dispatch_family(const char *name, JsonVariant *variant, JsonDispatchFlags flags, void *userdata) { |
| int *family = userdata; |
| intmax_t t; |
| |
| assert(variant); |
| assert(family); |
| |
| if (!json_variant_is_integer(variant)) |
| return json_log(variant, flags, SYNTHETIC_ERRNO(EINVAL), "JSON field '%s' is not an integer.", strna(name)); |
| |
| t = json_variant_integer(variant); |
| if (t < 0 || t > INT_MAX) |
| return json_log(variant, flags, SYNTHETIC_ERRNO(EINVAL), "JSON field '%s' is not a valid family.", strna(name)); |
| |
| *family = (int) t; |
| return 0; |
| } |
| |
| typedef struct ResolveHostnameReply { |
| JsonVariant *addresses; |
| char *name; |
| uint64_t flags; |
| } ResolveHostnameReply; |
| |
| static void resolve_hostname_reply_destroy(ResolveHostnameReply *p) { |
| assert(p); |
| |
| json_variant_unref(p->addresses); |
| free(p->name); |
| } |
| |
| static const JsonDispatch resolve_hostname_reply_dispatch_table[] = { |
| { "addresses", JSON_VARIANT_ARRAY, json_dispatch_variant, offsetof(ResolveHostnameReply, addresses), JSON_MANDATORY }, |
| { "name", JSON_VARIANT_STRING, json_dispatch_string, offsetof(ResolveHostnameReply, name), 0 }, |
| { "flags", JSON_VARIANT_UNSIGNED, json_dispatch_uint64, offsetof(ResolveHostnameReply, flags), 0 }, |
| {} |
| }; |
| |
| typedef struct AddressParameters { |
| int ifindex; |
| int family; |
| union in_addr_union address; |
| size_t address_size; |
| } AddressParameters; |
| |
| static int json_dispatch_address(const char *name, JsonVariant *variant, JsonDispatchFlags flags, void *userdata) { |
| AddressParameters *p = userdata; |
| union in_addr_union buf = {}; |
| JsonVariant *i; |
| size_t n, k = 0; |
| |
| assert(variant); |
| assert(p); |
| |
| if (!json_variant_is_array(variant)) |
| return json_log(variant, flags, SYNTHETIC_ERRNO(EINVAL), "JSON field '%s' is not an array.", strna(name)); |
| |
| n = json_variant_elements(variant); |
| if (!IN_SET(n, 4, 16)) |
| return json_log(variant, flags, SYNTHETIC_ERRNO(EINVAL), "JSON field '%s' is array of unexpected size.", strna(name)); |
| |
| JSON_VARIANT_ARRAY_FOREACH(i, variant) { |
| intmax_t b; |
| |
| if (!json_variant_is_integer(i)) |
| return json_log(variant, flags, SYNTHETIC_ERRNO(EINVAL), "Element %zu of JSON field '%s' is not an integer.", k, strna(name)); |
| |
| b = json_variant_integer(i); |
| if (b < 0 || b > 0xff) |
| return json_log(variant, flags, SYNTHETIC_ERRNO(EINVAL), "Element %zu of JSON field '%s' is out of range 0…255.", k, strna(name)); |
| |
| buf.bytes[k++] = (uint8_t) b; |
| } |
| |
| p->address = buf; |
| p->address_size = k; |
| |
| return 0; |
| } |
| |
| static const JsonDispatch address_parameters_dispatch_table[] = { |
| { "ifindex", JSON_VARIANT_INTEGER, json_dispatch_ifindex, offsetof(AddressParameters, ifindex), 0 }, |
| { "family", JSON_VARIANT_INTEGER, json_dispatch_family, offsetof(AddressParameters, family), JSON_MANDATORY }, |
| { "address", JSON_VARIANT_ARRAY, json_dispatch_address, 0, JSON_MANDATORY }, |
| {} |
| }; |
| |
| enum nss_status _nss_resolve_gethostbyname4_r( |
| const char *name, |
| struct gaih_addrtuple **pat, |
| char *buffer, size_t buflen, |
| int *errnop, int *h_errnop, |
| int32_t *ttlp) { |
| |
| _cleanup_(resolve_hostname_reply_destroy) ResolveHostnameReply p = {}; |
| _cleanup_(json_variant_unrefp) JsonVariant *cparams = NULL; |
| struct gaih_addrtuple *r_tuple = NULL, *r_tuple_first = NULL; |
| _cleanup_(varlink_unrefp) Varlink *link = NULL; |
| const char *canonical = NULL, *error_id = NULL; |
| JsonVariant *entry, *rparams; |
| size_t l, ms, idx, c = 0; |
| char *r_name; |
| int r; |
| |
| PROTECT_ERRNO; |
| BLOCK_SIGNALS(NSS_SIGNALS_BLOCK); |
| |
| assert(name); |
| assert(pat); |
| assert(buffer); |
| assert(errnop); |
| assert(h_errnop); |
| |
| r = connect_to_resolved(&link); |
| if (r < 0) |
| goto fail; |
| |
| r = json_build(&cparams, JSON_BUILD_OBJECT( |
| JSON_BUILD_PAIR("name", JSON_BUILD_STRING(name)))); |
| if (r < 0) |
| goto fail; |
| |
| r = varlink_call(link, "io.systemd.Resolve.ResolveHostname", cparams, &rparams, &error_id, NULL); |
| if (r < 0) { |
| if (!error_shall_fallback(error_id)) |
| goto not_found; |
| |
| /* Return NSS_STATUS_UNAVAIL when communication with systemd-resolved fails, allowing falling |
| back to other nss modules. Treat all other error conditions as NOTFOUND. This includes |
| DNSSEC errors and suchlike. (We don't use UNAVAIL in this case so that the nsswitch.conf |
| configuration can distinguish such executed but negative replies from complete failure to |
| talk to resolved). */ |
| goto fail; |
| } |
| |
| r = json_dispatch(rparams, resolve_hostname_reply_dispatch_table, NULL, 0, &p); |
| if (r < 0) |
| goto fail; |
| if (json_variant_is_blank_object(p.addresses)) |
| goto not_found; |
| |
| JSON_VARIANT_ARRAY_FOREACH(entry, p.addresses) { |
| AddressParameters q = {}; |
| |
| r = json_dispatch(entry, address_parameters_dispatch_table, NULL, 0, &q); |
| if (r < 0) |
| goto fail; |
| |
| if (!IN_SET(q.family, AF_INET, AF_INET6)) |
| continue; |
| |
| if (q.address_size != FAMILY_ADDRESS_SIZE(q.family)) { |
| r = -EINVAL; |
| goto fail; |
| } |
| |
| c++; |
| } |
| |
| canonical = p.name ?: name; |
| |
| l = strlen(canonical); |
| ms = ALIGN(l+1) + ALIGN(sizeof(struct gaih_addrtuple)) * c; |
| if (buflen < ms) { |
| UNPROTECT_ERRNO; |
| *errnop = ERANGE; |
| *h_errnop = NETDB_INTERNAL; |
| return NSS_STATUS_TRYAGAIN; |
| } |
| |
| /* First, append name */ |
| r_name = buffer; |
| memcpy(r_name, canonical, l+1); |
| idx = ALIGN(l+1); |
| |
| /* Second, append addresses */ |
| r_tuple_first = (struct gaih_addrtuple*) (buffer + idx); |
| |
| JSON_VARIANT_ARRAY_FOREACH(entry, p.addresses) { |
| AddressParameters q = {}; |
| |
| r = json_dispatch(entry, address_parameters_dispatch_table, NULL, 0, &q); |
| if (r < 0) |
| goto fail; |
| |
| if (!IN_SET(q.family, AF_INET, AF_INET6)) |
| continue; |
| |
| r_tuple = (struct gaih_addrtuple*) (buffer + idx); |
| r_tuple->next = (struct gaih_addrtuple*) ((char*) r_tuple + ALIGN(sizeof(struct gaih_addrtuple))); |
| r_tuple->name = r_name; |
| r_tuple->family = q.family; |
| r_tuple->scopeid = ifindex_to_scopeid(q.family, &q.address, q.ifindex); |
| memcpy(r_tuple->addr, &q.address, q.address_size); |
| |
| idx += ALIGN(sizeof(struct gaih_addrtuple)); |
| } |
| |
| assert(r_tuple); |
| r_tuple->next = NULL; /* Override last next pointer */ |
| |
| assert(idx == ms); |
| |
| if (*pat) |
| **pat = *r_tuple_first; |
| else |
| *pat = r_tuple_first; |
| |
| if (ttlp) |
| *ttlp = 0; |
| |
| /* Explicitly reset both *h_errnop and h_errno to work around |
| * https://bugzilla.redhat.com/show_bug.cgi?id=1125975 */ |
| *h_errnop = NETDB_SUCCESS; |
| h_errno = 0; |
| |
| return NSS_STATUS_SUCCESS; |
| |
| fail: |
| UNPROTECT_ERRNO; |
| *errnop = -r; |
| *h_errnop = NO_RECOVERY; |
| return NSS_STATUS_UNAVAIL; |
| |
| not_found: |
| *h_errnop = HOST_NOT_FOUND; |
| return NSS_STATUS_NOTFOUND; |
| } |
| |
| enum nss_status _nss_resolve_gethostbyname3_r( |
| const char *name, |
| int af, |
| struct hostent *result, |
| char *buffer, size_t buflen, |
| int *errnop, int *h_errnop, |
| int32_t *ttlp, |
| char **canonp) { |
| |
| _cleanup_(resolve_hostname_reply_destroy) ResolveHostnameReply p = {}; |
| _cleanup_(json_variant_unrefp) JsonVariant *cparams = NULL; |
| char *r_name, *r_aliases, *r_addr, *r_addr_list; |
| _cleanup_(varlink_unrefp) Varlink *link = NULL; |
| const char *canonical, *error_id = NULL; |
| size_t l, idx, ms, alen, i = 0, c = 0; |
| JsonVariant *entry, *rparams; |
| int r; |
| |
| PROTECT_ERRNO; |
| BLOCK_SIGNALS(NSS_SIGNALS_BLOCK); |
| |
| assert(name); |
| assert(result); |
| assert(buffer); |
| assert(errnop); |
| assert(h_errnop); |
| |
| if (af == AF_UNSPEC) |
| af = AF_INET; |
| |
| if (!IN_SET(af, AF_INET, AF_INET6)) { |
| r = -EAFNOSUPPORT; |
| goto fail; |
| } |
| |
| r = connect_to_resolved(&link); |
| if (r < 0) |
| goto fail; |
| |
| r = json_build(&cparams, JSON_BUILD_OBJECT(JSON_BUILD_PAIR("name", JSON_BUILD_STRING(name)), |
| JSON_BUILD_PAIR("family", JSON_BUILD_INTEGER(af)))); |
| if (r < 0) |
| goto fail; |
| |
| r = varlink_call(link, "io.systemd.Resolve.ResolveHostname", cparams, &rparams, &error_id, NULL); |
| if (r < 0) { |
| if (!error_shall_fallback(error_id)) |
| goto not_found; |
| |
| goto fail; |
| } |
| |
| r = json_dispatch(rparams, resolve_hostname_reply_dispatch_table, NULL, 0, &p); |
| if (r < 0) |
| goto fail; |
| if (json_variant_is_blank_object(p.addresses)) |
| goto not_found; |
| |
| JSON_VARIANT_ARRAY_FOREACH(entry, p.addresses) { |
| AddressParameters q = {}; |
| |
| r = json_dispatch(entry, address_parameters_dispatch_table, NULL, 0, &q); |
| if (r < 0) |
| goto fail; |
| |
| if (!IN_SET(q.family, AF_INET, AF_INET6)) |
| continue; |
| |
| if (q.address_size != FAMILY_ADDRESS_SIZE(q.family)) { |
| r = -EINVAL; |
| goto fail; |
| } |
| |
| c++; |
| } |
| |
| canonical = p.name ?: name; |
| |
| alen = FAMILY_ADDRESS_SIZE(af); |
| l = strlen(canonical); |
| |
| ms = ALIGN(l+1) + c*ALIGN(alen) + (c+2) * sizeof(char*); |
| |
| if (buflen < ms) { |
| UNPROTECT_ERRNO; |
| *errnop = ERANGE; |
| *h_errnop = NETDB_INTERNAL; |
| return NSS_STATUS_TRYAGAIN; |
| } |
| |
| /* First, append name */ |
| r_name = buffer; |
| memcpy(r_name, canonical, l+1); |
| idx = ALIGN(l+1); |
| |
| /* Second, create empty aliases array */ |
| r_aliases = buffer + idx; |
| ((char**) r_aliases)[0] = NULL; |
| idx += sizeof(char*); |
| |
| /* Third, append addresses */ |
| r_addr = buffer + idx; |
| |
| JSON_VARIANT_ARRAY_FOREACH(entry, p.addresses) { |
| AddressParameters q = {}; |
| |
| r = json_dispatch(entry, address_parameters_dispatch_table, NULL, 0, &q); |
| if (r < 0) |
| goto fail; |
| |
| if (q.family != af) |
| continue; |
| |
| if (q.address_size != alen) { |
| r = -EINVAL; |
| goto fail; |
| } |
| |
| memcpy(r_addr + i*ALIGN(alen), &q.address, alen); |
| i++; |
| } |
| |
| assert(i == c); |
| idx += c * ALIGN(alen); |
| |
| /* Fourth, append address pointer array */ |
| r_addr_list = buffer + idx; |
| for (i = 0; i < c; i++) |
| ((char**) r_addr_list)[i] = r_addr + i*ALIGN(alen); |
| |
| ((char**) r_addr_list)[i] = NULL; |
| idx += (c+1) * sizeof(char*); |
| |
| assert(idx == ms); |
| |
| result->h_name = r_name; |
| result->h_aliases = (char**) r_aliases; |
| result->h_addrtype = af; |
| result->h_length = alen; |
| result->h_addr_list = (char**) r_addr_list; |
| |
| if (ttlp) |
| *ttlp = 0; |
| |
| if (canonp) |
| *canonp = r_name; |
| |
| /* Explicitly reset both *h_errnop and h_errno to work around |
| * https://bugzilla.redhat.com/show_bug.cgi?id=1125975 */ |
| *h_errnop = NETDB_SUCCESS; |
| h_errno = 0; |
| |
| return NSS_STATUS_SUCCESS; |
| |
| fail: |
| UNPROTECT_ERRNO; |
| *errnop = -r; |
| *h_errnop = NO_RECOVERY; |
| return NSS_STATUS_UNAVAIL; |
| |
| not_found: |
| *h_errnop = HOST_NOT_FOUND; |
| return NSS_STATUS_NOTFOUND; |
| } |
| |
| typedef struct ResolveAddressReply { |
| JsonVariant *names; |
| uint64_t flags; |
| } ResolveAddressReply; |
| |
| static void resolve_address_reply_destroy(ResolveAddressReply *p) { |
| assert(p); |
| |
| json_variant_unref(p->names); |
| } |
| |
| static const JsonDispatch resolve_address_reply_dispatch_table[] = { |
| { "names", JSON_VARIANT_ARRAY, json_dispatch_variant, offsetof(ResolveAddressReply, names), JSON_MANDATORY }, |
| { "flags", JSON_VARIANT_UNSIGNED, json_dispatch_uint64, offsetof(ResolveAddressReply, flags), 0 }, |
| {} |
| }; |
| |
| typedef struct NameParameters { |
| int ifindex; |
| char *name; |
| } NameParameters; |
| |
| static void name_parameters_destroy(NameParameters *p) { |
| assert(p); |
| |
| free(p->name); |
| } |
| |
| static const JsonDispatch name_parameters_dispatch_table[] = { |
| { "ifindex", JSON_VARIANT_INTEGER, json_dispatch_ifindex, offsetof(NameParameters, ifindex), 0 }, |
| { "name", JSON_VARIANT_UNSIGNED, json_dispatch_string, offsetof(NameParameters, name), JSON_MANDATORY }, |
| {} |
| }; |
| |
| enum nss_status _nss_resolve_gethostbyaddr2_r( |
| const void* addr, socklen_t len, |
| int af, |
| struct hostent *result, |
| char *buffer, size_t buflen, |
| int *errnop, int *h_errnop, |
| int32_t *ttlp) { |
| |
| _cleanup_(resolve_address_reply_destroy) ResolveAddressReply p = {}; |
| _cleanup_(json_variant_unrefp) JsonVariant *cparams = NULL; |
| char *r_name, *r_aliases, *r_addr, *r_addr_list; |
| _cleanup_(varlink_unrefp) Varlink *link = NULL; |
| JsonVariant *entry, *rparams; |
| const char *n, *error_id; |
| unsigned c = 0, i = 0; |
| size_t ms = 0, idx; |
| int r; |
| |
| PROTECT_ERRNO; |
| BLOCK_SIGNALS(NSS_SIGNALS_BLOCK); |
| |
| assert(addr); |
| assert(result); |
| assert(buffer); |
| assert(errnop); |
| assert(h_errnop); |
| |
| if (!IN_SET(af, AF_INET, AF_INET6)) { |
| UNPROTECT_ERRNO; |
| *errnop = EAFNOSUPPORT; |
| *h_errnop = NO_DATA; |
| return NSS_STATUS_UNAVAIL; |
| } |
| |
| if (len != FAMILY_ADDRESS_SIZE(af)) { |
| r = -EINVAL; |
| goto fail; |
| } |
| |
| r = connect_to_resolved(&link); |
| if (r < 0) |
| goto fail; |
| |
| r = json_build(&cparams, JSON_BUILD_OBJECT(JSON_BUILD_PAIR("address", JSON_BUILD_BYTE_ARRAY(addr, len)), |
| JSON_BUILD_PAIR("family", JSON_BUILD_INTEGER(af)))); |
| if (r < 0) |
| goto fail; |
| |
| r = varlink_call(link, "io.systemd.Resolve.ResolveAddress", cparams, &rparams, &error_id, NULL); |
| if (r < 0) { |
| if (!error_shall_fallback(error_id)) |
| goto not_found; |
| |
| goto fail; |
| } |
| |
| r = json_dispatch(rparams, resolve_address_reply_dispatch_table, NULL, 0, &p); |
| if (r < 0) |
| goto fail; |
| if (json_variant_is_blank_object(p.names)) |
| goto not_found; |
| |
| JSON_VARIANT_ARRAY_FOREACH(entry, p.names) { |
| _cleanup_(name_parameters_destroy) NameParameters q = {}; |
| |
| r = json_dispatch(entry, name_parameters_dispatch_table, NULL, 0, &q); |
| if (r < 0) |
| goto fail; |
| |
| ms += ALIGN(strlen(q.name) + 1); |
| } |
| |
| ms += ALIGN(len) + /* the address */ |
| 2 * sizeof(char*) + /* pointers to the address, plus trailing NULL */ |
| json_variant_elements(p.names) * sizeof(char*); /* pointers to aliases, plus trailing NULL */ |
| |
| if (buflen < ms) { |
| UNPROTECT_ERRNO; |
| *errnop = ERANGE; |
| *h_errnop = NETDB_INTERNAL; |
| return NSS_STATUS_TRYAGAIN; |
| } |
| |
| /* First, place address */ |
| r_addr = buffer; |
| memcpy(r_addr, addr, len); |
| idx = ALIGN(len); |
| |
| /* Second, place address list */ |
| r_addr_list = buffer + idx; |
| ((char**) r_addr_list)[0] = r_addr; |
| ((char**) r_addr_list)[1] = NULL; |
| idx += sizeof(char*) * 2; |
| |
| /* Third, reserve space for the aliases array */ |
| r_aliases = buffer + idx; |
| idx += sizeof(char*) * c; |
| |
| /* Fourth, place aliases */ |
| i = 0; |
| r_name = buffer + idx; |
| JSON_VARIANT_ARRAY_FOREACH(entry, p.names) { |
| _cleanup_(name_parameters_destroy) NameParameters q = {}; |
| size_t l; |
| char *z; |
| |
| r = json_dispatch(entry, name_parameters_dispatch_table, NULL, 0, &q); |
| if (r < 0) |
| goto fail; |
| |
| l = strlen(q.name); |
| z = buffer + idx; |
| memcpy(z, n, l+1); |
| |
| if (i > 0) |
| ((char**) r_aliases)[i-1] = z; |
| i++; |
| |
| idx += ALIGN(l+1); |
| } |
| |
| ((char**) r_aliases)[c-1] = NULL; |
| assert(idx == ms); |
| |
| result->h_name = r_name; |
| result->h_aliases = (char**) r_aliases; |
| result->h_addrtype = af; |
| result->h_length = len; |
| result->h_addr_list = (char**) r_addr_list; |
| |
| if (ttlp) |
| *ttlp = 0; |
| |
| /* Explicitly reset both *h_errnop and h_errno to work around |
| * https://bugzilla.redhat.com/show_bug.cgi?id=1125975 */ |
| *h_errnop = NETDB_SUCCESS; |
| h_errno = 0; |
| |
| return NSS_STATUS_SUCCESS; |
| |
| fail: |
| UNPROTECT_ERRNO; |
| *errnop = -r; |
| *h_errnop = NO_RECOVERY; |
| return NSS_STATUS_UNAVAIL; |
| |
| not_found: |
| *h_errnop = HOST_NOT_FOUND; |
| return NSS_STATUS_NOTFOUND; |
| } |
| |
| NSS_GETHOSTBYNAME_FALLBACKS(resolve); |
| NSS_GETHOSTBYADDR_FALLBACKS(resolve); |