picnoir/Systemd
1
0
Fork 0
Code Issues Pull requests Projects Releases Wiki Activity
Systemd/src/nss-resolve/nss-resolve.c
Lennart Poettering 03976f7b4a sd-bus: introduce new sd_bus_flush_close_unref() call 
sd_bus_flush_close_unref() is a call that simply combines sd_bus_flush()
(which writes all unwritten messages out) + sd_bus_close() (which
terminates the connection, releasing all unread messages) +
sd_bus_unref() (which frees the connection).

The combination of this call is used pretty frequently in systemd tools
right before exiting, and should also be relevant for most external
clients, and is hence useful to cover in a call of its own.

Previously the combination of the three calls was already done in the
_cleanup_bus_close_unref_ macro, but this was only available internally.

Also see #327
2015-07-03 19:49:03 +02:00

708 lines
21 KiB
C
Raw Blame History

/*-*- 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 <nss.h>
#include <netdb.h>
#include <errno.h>
#include <string.h>
#include <stdlib.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_flush_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_flush_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_flush_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);
Reference in a new issue View git blame Copy permalink