| /*-*- 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 <limits.h> |
| #include <nss.h> |
| #include <sys/types.h> |
| #include <netdb.h> |
| #include <errno.h> |
| #include <string.h> |
| #include <unistd.h> |
| #include <net/if.h> |
| #include <stdlib.h> |
| #include <arpa/inet.h> |
| #include <dlfcn.h> |
| |
| #include "sd-bus.h" |
| #include "bus-util.h" |
| #include "bus-common-errors.h" |
| #include "macro.h" |
| #include "nss-util.h" |
| #include "util.h" |
| #include "in-addr-util.h" |
| |
| NSS_GETHOSTBYNAME_PROTOTYPES(resolve); |
| NSS_GETHOSTBYADDR_PROTOTYPES(resolve); |
| |
| #define DNS_CALL_TIMEOUT_USEC (45*USEC_PER_SEC) |
| |
| typedef void (*voidfunc_t)(void); |
| |
| static voidfunc_t find_fallback(const char *module, const char *symbol) { |
| void *dl; |
| |
| /* Try to find a fallback NSS module symbol */ |
| |
| dl = dlopen(module, RTLD_LAZY|RTLD_NODELETE); |
| if (!dl) |
| return NULL; |
| |
| return dlsym(dl, symbol); |
| } |
| |
| static bool bus_error_shall_fallback(sd_bus_error *e) { |
| return sd_bus_error_has_name(e, SD_BUS_ERROR_SERVICE_UNKNOWN) || |
| sd_bus_error_has_name(e, SD_BUS_ERROR_NAME_HAS_NO_OWNER) || |
| sd_bus_error_has_name(e, SD_BUS_ERROR_NO_REPLY) || |
| sd_bus_error_has_name(e, SD_BUS_ERROR_ACCESS_DENIED); |
| } |
| |
| static int count_addresses(sd_bus_message *m, int af, const char **canonical) { |
| int c = 0, r, ifindex; |
| |
| assert(m); |
| assert(canonical); |
| |
| r = sd_bus_message_read(m, "i", &ifindex); |
| if (r < 0) |
| return r; |
| |
| r = sd_bus_message_enter_container(m, 'a', "(iay)"); |
| if (r < 0) |
| return r; |
| |
| while ((r = sd_bus_message_enter_container(m, 'r', "iay")) > 0) { |
| int family; |
| |
| r = sd_bus_message_read(m, "i", &family); |
| if (r < 0) |
| return r; |
| |
| r = sd_bus_message_skip(m, "ay"); |
| if (r < 0) |
| return r; |
| |
| r = sd_bus_message_exit_container(m); |
| if (r < 0) |
| return r; |
| |
| if (af != AF_UNSPEC && family != af) |
| continue; |
| |
| c ++; |
| } |
| if (r < 0) |
| return r; |
| |
| r = sd_bus_message_exit_container(m); |
| if (r < 0) |
| return r; |
| |
| r = sd_bus_message_read(m, "s", canonical); |
| if (r < 0) |
| return r; |
| |
| r = sd_bus_message_rewind(m, true); |
| if (r < 0) |
| return r; |
| |
| return c; |
| } |
| |
| 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_bus_message_unref_ sd_bus_message *req = NULL, *reply = NULL; |
| _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL; |
| struct gaih_addrtuple *r_tuple, *r_tuple_first = NULL; |
| _cleanup_bus_close_unref_ sd_bus *bus = NULL; |
| const char *canonical = NULL; |
| size_t l, ms, idx; |
| char *r_name; |
| int c, r, i = 0, ifindex; |
| |
| assert(name); |
| assert(pat); |
| assert(buffer); |
| assert(errnop); |
| assert(h_errnop); |
| |
| r = sd_bus_open_system(&bus); |
| if (r < 0) |
| goto fail; |
| |
| r = sd_bus_message_new_method_call( |
| bus, |
| &req, |
| "org.freedesktop.resolve1", |
| "/org/freedesktop/resolve1", |
| "org.freedesktop.resolve1.Manager", |
| "ResolveHostname"); |
| if (r < 0) |
| goto fail; |
| |
| r = sd_bus_message_set_auto_start(req, false); |
| if (r < 0) |
| goto fail; |
| |
| r = sd_bus_message_append(req, "isit", 0, name, AF_UNSPEC, (uint64_t) 0); |
| if (r < 0) |
| goto fail; |
| |
| r = sd_bus_call(bus, req, DNS_CALL_TIMEOUT_USEC, &error, &reply); |
| if (r < 0) { |
| if (sd_bus_error_has_name(&error, _BUS_ERROR_DNS "NXDOMAIN")) { |
| *errnop = ESRCH; |
| *h_errnop = HOST_NOT_FOUND; |
| return NSS_STATUS_NOTFOUND; |
| } |
| |
| if (bus_error_shall_fallback(&error)) { |
| |
| enum nss_status (*fallback)( |
| const char *name, |
| struct gaih_addrtuple **pat, |
| char *buffer, size_t buflen, |
| int *errnop, int *h_errnop, |
| int32_t *ttlp); |
| |
| fallback = (enum nss_status (*)(const char *name, |
| struct gaih_addrtuple **pat, |
| char *buffer, size_t buflen, |
| int *errnop, int *h_errnop, |
| int32_t *ttlp)) |
| find_fallback("libnss_dns.so.2", "_nss_dns_gethostbyname4_r"); |
| if (fallback) |
| return fallback(name, pat, buffer, buflen, errnop, h_errnop, ttlp); |
| } |
| |
| *errnop = -r; |
| *h_errnop = NO_RECOVERY; |
| return NSS_STATUS_UNAVAIL; |
| } |
| |
| c = count_addresses(reply, AF_UNSPEC, &canonical); |
| if (c < 0) { |
| r = c; |
| goto fail; |
| } |
| if (c == 0) { |
| *errnop = ESRCH; |
| *h_errnop = HOST_NOT_FOUND; |
| return NSS_STATUS_NOTFOUND; |
| } |
| |
| if (isempty(canonical)) |
| canonical = name; |
| |
| l = strlen(canonical); |
| ms = ALIGN(l+1) + ALIGN(sizeof(struct gaih_addrtuple)) * c; |
| if (buflen < ms) { |
| *errnop = ENOMEM; |
| *h_errnop = TRY_AGAIN; |
| 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); |
| |
| r = sd_bus_message_read(reply, "i", &ifindex); |
| if (r < 0) |
| goto fail; |
| |
| if (ifindex < 0) { |
| r = -EINVAL; |
| goto fail; |
| } |
| |
| r = sd_bus_message_enter_container(reply, 'a', "(iay)"); |
| if (r < 0) |
| goto fail; |
| |
| while ((r = sd_bus_message_enter_container(reply, 'r', "iay")) > 0) { |
| int family; |
| const void *a; |
| size_t sz; |
| |
| r = sd_bus_message_read(reply, "i", &family); |
| if (r < 0) |
| goto fail; |
| |
| r = sd_bus_message_read_array(reply, 'y', &a, &sz); |
| if (r < 0) |
| goto fail; |
| |
| r = sd_bus_message_exit_container(reply); |
| if (r < 0) |
| goto fail; |
| |
| if (!IN_SET(family, AF_INET, AF_INET6)) |
| continue; |
| |
| if (sz != FAMILY_ADDRESS_SIZE(family)) { |
| r = -EINVAL; |
| goto fail; |
| } |
| |
| r_tuple = (struct gaih_addrtuple*) (buffer + idx); |
| r_tuple->next = i == c-1 ? NULL : (struct gaih_addrtuple*) ((char*) r_tuple + ALIGN(sizeof(struct gaih_addrtuple))); |
| r_tuple->name = r_name; |
| r_tuple->family = family; |
| r_tuple->scopeid = ifindex; |
| memcpy(r_tuple->addr, a, sz); |
| |
| idx += ALIGN(sizeof(struct gaih_addrtuple)); |
| i++; |
| } |
| if (r < 0) |
| goto fail; |
| |
| assert(i == c); |
| assert(idx == ms); |
| |
| if (*pat) |
| **pat = *r_tuple_first; |
| else |
| *pat = r_tuple_first; |
| |
| if (ttlp) |
| *ttlp = 0; |
| |
| /* Explicitly reset all error variables */ |
| *errnop = 0; |
| *h_errnop = NETDB_SUCCESS; |
| h_errno = 0; |
| |
| return NSS_STATUS_SUCCESS; |
| |
| fail: |
| *errnop = -r; |
| *h_errnop = NO_DATA; |
| return NSS_STATUS_UNAVAIL; |
| } |
| |
| 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_bus_message_unref_ sd_bus_message *req = NULL, *reply = NULL; |
| _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL; |
| char *r_name, *r_aliases, *r_addr, *r_addr_list; |
| _cleanup_bus_close_unref_ sd_bus *bus = NULL; |
| size_t l, idx, ms, alen; |
| const char *canonical; |
| int c, r, i = 0, ifindex; |
| |
| assert(name); |
| assert(result); |
| assert(buffer); |
| assert(errnop); |
| assert(h_errnop); |
| |
| if (af == AF_UNSPEC) |
| af = AF_INET; |
| |
| if (af != AF_INET && af != AF_INET6) { |
| r = -EAFNOSUPPORT; |
| goto fail; |
| } |
| |
| r = sd_bus_open_system(&bus); |
| if (r < 0) |
| goto fail; |
| |
| r = sd_bus_message_new_method_call( |
| bus, |
| &req, |
| "org.freedesktop.resolve1", |
| "/org/freedesktop/resolve1", |
| "org.freedesktop.resolve1.Manager", |
| "ResolveHostname"); |
| if (r < 0) |
| goto fail; |
| |
| r = sd_bus_message_set_auto_start(req, false); |
| if (r < 0) |
| goto fail; |
| |
| r = sd_bus_message_append(req, "isit", 0, name, af, (uint64_t) 0); |
| if (r < 0) |
| goto fail; |
| |
| r = sd_bus_call(bus, req, DNS_CALL_TIMEOUT_USEC, &error, &reply); |
| if (r < 0) { |
| if (sd_bus_error_has_name(&error, _BUS_ERROR_DNS "NXDOMAIN")) { |
| *errnop = ESRCH; |
| *h_errnop = HOST_NOT_FOUND; |
| return NSS_STATUS_NOTFOUND; |
| } |
| |
| if (bus_error_shall_fallback(&error)) { |
| |
| enum nss_status (*fallback)( |
| const char *name, |
| int af, |
| struct hostent *result, |
| char *buffer, size_t buflen, |
| int *errnop, int *h_errnop, |
| int32_t *ttlp, |
| char **canonp); |
| |
| fallback = (enum nss_status (*)(const char *name, |
| int af, |
| struct hostent *result, |
| char *buffer, size_t buflen, |
| int *errnop, int *h_errnop, |
| int32_t *ttlp, |
| char **canonp)) |
| find_fallback("libnss_dns.so.2", "_nss_dns_gethostbyname3_r"); |
| if (fallback) |
| return fallback(name, af, result, buffer, buflen, errnop, h_errnop, ttlp, canonp); |
| } |
| |
| *errnop = -r; |
| *h_errnop = NO_RECOVERY; |
| return NSS_STATUS_UNAVAIL; |
| } |
| |
| c = count_addresses(reply, af, &canonical); |
| if (c < 0) { |
| r = c; |
| goto fail; |
| } |
| if (c == 0) { |
| *errnop = ESRCH; |
| *h_errnop = HOST_NOT_FOUND; |
| return NSS_STATUS_NOTFOUND; |
| } |
| |
| if (isempty(canonical)) |
| canonical = name; |
| |
| alen = FAMILY_ADDRESS_SIZE(af); |
| l = strlen(canonical); |
| |
| ms = ALIGN(l+1) + c * ALIGN(alen) + (c+2) * sizeof(char*); |
| |
| if (buflen < ms) { |
| *errnop = ENOMEM; |
| *h_errnop = TRY_AGAIN; |
| 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; |
| |
| r = sd_bus_message_read(reply, "i", &ifindex); |
| if (r < 0) |
| goto fail; |
| |
| if (ifindex < 0) { |
| r = -EINVAL; |
| goto fail; |
| } |
| |
| r = sd_bus_message_enter_container(reply, 'a', "(iay)"); |
| if (r < 0) |
| goto fail; |
| |
| while ((r = sd_bus_message_enter_container(reply, 'r', "iay")) > 0) { |
| int family; |
| const void *a; |
| size_t sz; |
| |
| r = sd_bus_message_read(reply, "i", &family); |
| if (r < 0) |
| goto fail; |
| |
| r = sd_bus_message_read_array(reply, 'y', &a, &sz); |
| if (r < 0) |
| goto fail; |
| |
| r = sd_bus_message_exit_container(reply); |
| if (r < 0) |
| goto fail; |
| |
| if (family != af) |
| continue; |
| |
| if (sz != alen) { |
| r = -EINVAL; |
| goto fail; |
| } |
| |
| memcpy(r_addr + i*ALIGN(alen), a, alen); |
| i++; |
| } |
| if (r < 0) |
| goto fail; |
| |
| 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; |
| |
| /* Explicitly reset all error variables */ |
| *errnop = 0; |
| *h_errnop = NETDB_SUCCESS; |
| h_errno = 0; |
| |
| if (ttlp) |
| *ttlp = 0; |
| |
| if (canonp) |
| *canonp = r_name; |
| |
| return NSS_STATUS_SUCCESS; |
| |
| fail: |
| *errnop = -r; |
| *h_errnop = NO_DATA; |
| return NSS_STATUS_UNAVAIL; |
| } |
| |
| 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_bus_message_unref_ sd_bus_message *req = NULL, *reply = NULL; |
| _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL; |
| char *r_name, *r_aliases, *r_addr, *r_addr_list; |
| _cleanup_bus_close_unref_ sd_bus *bus = NULL; |
| unsigned c = 0, i = 0; |
| size_t ms = 0, idx; |
| const char *n; |
| int r, ifindex; |
| |
| assert(addr); |
| assert(result); |
| assert(buffer); |
| assert(errnop); |
| assert(h_errnop); |
| |
| if (!IN_SET(af, AF_INET, AF_INET6)) { |
| *errnop = EAFNOSUPPORT; |
| *h_errnop = NO_DATA; |
| return NSS_STATUS_UNAVAIL; |
| } |
| |
| if (len != FAMILY_ADDRESS_SIZE(af)) { |
| *errnop = EINVAL; |
| *h_errnop = NO_RECOVERY; |
| return NSS_STATUS_UNAVAIL; |
| } |
| |
| r = sd_bus_open_system(&bus); |
| if (r < 0) |
| goto fail; |
| |
| r = sd_bus_message_new_method_call( |
| bus, |
| &req, |
| "org.freedesktop.resolve1", |
| "/org/freedesktop/resolve1", |
| "org.freedesktop.resolve1.Manager", |
| "ResolveAddress"); |
| if (r < 0) |
| goto fail; |
| |
| r = sd_bus_message_set_auto_start(req, false); |
| if (r < 0) |
| goto fail; |
| |
| r = sd_bus_message_append(req, "ii", 0, af); |
| if (r < 0) |
| goto fail; |
| |
| r = sd_bus_message_append_array(req, 'y', addr, len); |
| if (r < 0) |
| goto fail; |
| |
| r = sd_bus_message_append(req, "t", (uint64_t) 0); |
| if (r < 0) |
| goto fail; |
| |
| r = sd_bus_call(bus, req, DNS_CALL_TIMEOUT_USEC, &error, &reply); |
| if (r < 0) { |
| if (sd_bus_error_has_name(&error, _BUS_ERROR_DNS "NXDOMAIN")) { |
| *errnop = ESRCH; |
| *h_errnop = HOST_NOT_FOUND; |
| return NSS_STATUS_NOTFOUND; |
| } |
| |
| if (bus_error_shall_fallback(&error)) { |
| |
| enum nss_status (*fallback)( |
| const void* addr, socklen_t len, |
| int af, |
| struct hostent *result, |
| char *buffer, size_t buflen, |
| int *errnop, int *h_errnop, |
| int32_t *ttlp); |
| |
| fallback = (enum nss_status (*)( |
| const void* addr, socklen_t len, |
| int af, |
| struct hostent *result, |
| char *buffer, size_t buflen, |
| int *errnop, int *h_errnop, |
| int32_t *ttlp)) |
| find_fallback("libnss_dns.so.2", "_nss_dns_gethostbyaddr2_r"); |
| |
| if (fallback) |
| return fallback(addr, len, af, result, buffer, buflen, errnop, h_errnop, ttlp); |
| } |
| |
| *errnop = -r; |
| *h_errnop = NO_RECOVERY; |
| return NSS_STATUS_UNAVAIL; |
| } |
| |
| r = sd_bus_message_read(reply, "i", &ifindex); |
| if (r < 0) |
| goto fail; |
| |
| if (ifindex < 0) { |
| r = -EINVAL; |
| goto fail; |
| } |
| |
| r = sd_bus_message_enter_container(reply, 'a', "s"); |
| if (r < 0) |
| goto fail; |
| |
| while ((r = sd_bus_message_read(reply, "s", &n)) > 0) { |
| c++; |
| ms += ALIGN(strlen(n) + 1); |
| } |
| if (r < 0) |
| goto fail; |
| |
| r = sd_bus_message_rewind(reply, false); |
| if (r < 0) |
| return r; |
| |
| if (c <= 0) { |
| *errnop = ESRCH; |
| *h_errnop = HOST_NOT_FOUND; |
| return NSS_STATUS_NOTFOUND; |
| } |
| |
| ms += ALIGN(len) + /* the address */ |
| 2 * sizeof(char*) + /* pointers to the address, plus trailing NULL */ |
| c * sizeof(char*); /* pointers to aliases, plus trailing NULL */ |
| |
| if (buflen < ms) { |
| *errnop = ENOMEM; |
| *h_errnop = TRY_AGAIN; |
| 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; |
| while ((r = sd_bus_message_read(reply, "s", &n)) > 0) { |
| char *p; |
| size_t l; |
| |
| l = strlen(n); |
| p = buffer + idx; |
| memcpy(p, n, l+1); |
| |
| if (i > 1) |
| ((char**) r_aliases)[i-1] = p; |
| i++; |
| |
| idx += ALIGN(l+1); |
| } |
| if (r < 0) |
| goto fail; |
| |
| ((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 all error variables */ |
| *errnop = 0; |
| *h_errnop = NETDB_SUCCESS; |
| h_errno = 0; |
| |
| return NSS_STATUS_SUCCESS; |
| |
| fail: |
| *errnop = -r; |
| *h_errnop = NO_DATA; |
| return NSS_STATUS_UNAVAIL; |
| } |
| |
| NSS_GETHOSTBYNAME_FALLBACKS(resolve); |
| NSS_GETHOSTBYADDR_FALLBACKS(resolve); |