nss: Implement _nss_libvirt_gethostbyname3_r

The implementation is pretty straightforward. Moreover, because
of the nature of things, gethostbyname_r and gethostbyname2_r can
be implemented at the same time too.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
This commit is contained in:
Michal Privoznik 2016-02-14 11:38:37 +01:00
parent 8054706c3f
commit 7dbcb26f7f
9 changed files with 440 additions and 9 deletions

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@ -43,3 +43,27 @@
# undef WITH_YAJL
# undef WITH_YAJL2
#endif
/*
* With the NSS module it's the same story as virt-login-shell. See the
* explanation above.
*/
#ifdef LIBVIRT_NSS
# undef HAVE_LIBDEVMAPPER_H
# undef HAVE_LIBNL
# undef HAVE_LIBNL3
# undef HAVE_LIBSASL2
# undef WITH_CAPNG
# undef WITH_CURL
# undef WITH_DTRACE_PROBES
# undef WITH_GNUTLS
# undef WITH_GNUTLS_GCRYPT
# undef WITH_MACVTAP
# undef WITH_NUMACTL
# undef WITH_SASL
# undef WITH_SSH2
# undef WITH_VIRTUALPORT
# undef WITH_SECDRIVER_SELINUX
# undef WITH_SECDRIVER_APPARMOR
# undef WITH_CAPNG
#endif /* LIBVIRT_NSS */

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@ -2946,6 +2946,63 @@ endif WITH_LIBVIRTD
endif WITH_SECDRIVER_APPARMOR
EXTRA_DIST += $(SECURITY_DRIVER_APPARMOR_HELPER_SOURCES)
noinst_LTLIBRARIES += libvirt-nss.la
libvirt_nss_la_SOURCES = \
util/viralloc.c \
util/viralloc.h \
util/virbitmap.c \
util/virbitmap.h \
util/virbuffer.c \
util/virbuffer.h \
util/vircommand.c \
util/vircommand.h \
util/virerror.c \
util/virerror.h \
util/virfile.c \
util/virfile.h \
util/virjson.c \
util/virjson.h \
util/virkmod.c \
util/virkmod.h \
util/virlease.c \
util/virlease.h \
util/virlog.c \
util/virlog.h \
util/virobject.c \
util/virobject.h \
util/virpidfile.c \
util/virpidfile.h \
util/virprocess.c \
util/virprocess.h \
util/virsocketaddr.c \
util/virsocketaddr.h \
util/virstring.c \
util/virstring.h \
util/virthread.c \
util/virthread.h \
util/virthreadjob.c \
util/virthreadjob.h \
util/virtime.c \
util/virtime.h \
util/virutil.c \
util/virutil.h \
$(NULL)
libvirt_nss_la_CFLAGS = \
-DLIBVIRT_NSS \
$(AM_CFLAGS) \
$(YAJL_CFLAGS) \
$(NULL)
libvirt_nss_la_LDFLAGS = \
$(AM_LDFLAGS) \
$(NULL)
libvirt_nss_la_LIBADD = \
$(YAJL_LIBS) \
$(NULL)
install-data-local: install-init install-systemd
if WITH_LIBVIRTD
$(MKDIR_P) "$(DESTDIR)$(localstatedir)/lib/libvirt/lockd"

View File

@ -67,7 +67,6 @@
#include "virlog.h"
#include "virprocess.h"
#include "virstring.h"
#include "virstoragefile.h"
#include "virutil.h"
#include "c-ctype.h"
@ -554,7 +553,7 @@ int virFileUpdatePerm(const char *path,
#if defined(__linux__) && HAVE_DECL_LO_FLAGS_AUTOCLEAR && \
!defined(LIBVIRT_SETUID_RPC_CLIENT)
!defined(LIBVIRT_SETUID_RPC_CLIENT) && !defined(LIBVIRT_NSS)
# if HAVE_DECL_LOOP_CTL_GET_FREE

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@ -30,6 +30,7 @@
#include "virstring.h"
#include "virerror.h"
#include "viralloc.h"
#include "virutil.h"
#define VIR_FROM_THIS VIR_FROM_NETWORK

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@ -429,10 +429,16 @@ nss_libnss_libvirt_impl_la_SOURCES = \
$(LIBVIRT_NSS_SOURCES)
nss_libnss_libvirt_impl_la_CFLAGS = \
-DLIBVIRT_NSS \
$(AM_CFLAGS) \
$(WARN_CFLAGS) \
$(PIE_CFLAGS) \
$(COVERAGE_CFLAGS)
$(COVERAGE_CFLAGS) \
$(LIBXML_CFLAGS)
nss_libnss_libvirt_impl_la_LIBADD = \
../gnulib/lib/libgnu.la \
../src/libvirt-nss.la
if WITH_NSS
nss_libnss_libvirt_la_SOURCES =

View File

@ -29,8 +29,338 @@
#include "libvirt_nss.h"
int
blah(int c)
#include <resolv.h>
#include <sys/types.h>
#include <dirent.h>
#include <arpa/inet.h>
#include "virlease.h"
#include "viralloc.h"
#include "virfile.h"
#include "virerror.h"
#include "virstring.h"
#include "virsocketaddr.h"
#include "configmake.h"
#if 0
# define ERROR(...) \
do { \
char ebuf[1024]; \
fprintf(stderr, "ERROR %s:%d : ", __FUNCTION__, __LINE__); \
fprintf(stderr, __VA_ARGS__); \
fprintf(stderr, " : %s\n", virStrerror(errno, ebuf, sizeof(ebuf))); \
fprintf(stderr, "\n"); \
} while (0)
# define DEBUG(...) \
do { \
fprintf(stderr, "DEBUG %s:%d : ", __FUNCTION__, __LINE__); \
fprintf(stderr, __VA_ARGS__); \
fprintf(stderr, "\n"); \
} while (0)
#else
# define ERROR(...) do { } while (0)
# define DEBUG(...) do { } while (0)
#endif
#define LEASEDIR LOCALSTATEDIR "/lib/libvirt/dnsmasq/"
#define ALIGN(x) (((x) + __SIZEOF_POINTER__ - 1) & ~(__SIZEOF_POINTER__ - 1))
#define FAMILY_ADDRESS_SIZE(family) ((family) == AF_INET6 ? 16 : 4)
typedef struct {
unsigned char addr[16];
int af;
} leaseAddress;
/**
* findLease:
* @name: domain name to lookup
* @af: address family
* @address: all the addresses found for selected @af
* @naddress: number of elements in @address array
* @found: whether @name has been found
* @errnop: errno pointer
*
* Lookup @name in libvirt's IP database, parse it and store all
* addresses found in @address array. Callers can choose which
* address family (@af) should be returned. Currently only
* AF_INET (IPv4) and AF_INET6 (IPv6) are supported. As a corner
* case, AF_UNSPEC may be passed to @af in which case no address
* filtering is done and addresses from both families are
* returned.
*
* Returns -1 on error
* 0 on success
*/
static int
findLease(const char *name,
int af,
leaseAddress **address,
size_t *naddress,
bool *found,
int *errnop)
{
return c;
DIR *dir = NULL;
int ret = -1;
const char *leaseDir = LEASEDIR;
struct dirent *entry;
virJSONValuePtr leases_array = NULL;
ssize_t i, nleases;
leaseAddress *tmpAddress = NULL;
size_t ntmpAddress = 0;
*address = NULL;
*naddress = 0;
*found = false;
if (af != AF_UNSPEC && af != AF_INET && af != AF_INET6) {
errno = EAFNOSUPPORT;
goto cleanup;
}
if (!(dir = opendir(leaseDir))) {
ERROR("Failed to open dir '%s'", leaseDir);
goto cleanup;
}
if (!(leases_array = virJSONValueNewArray())) {
ERROR("Failed to create json array");
goto cleanup;
}
DEBUG("Dir: %s", leaseDir);
while ((ret = virDirRead(dir, &entry, leaseDir)) > 0) {
char *path;
if (entry->d_name[0] == '.')
continue;
if (!virFileHasSuffix(entry->d_name, ".status"))
continue;
if (!(path = virFileBuildPath(leaseDir, entry->d_name, NULL)))
goto cleanup;
DEBUG("Processing %s", path);
if (virLeaseReadCustomLeaseFile(leases_array, path, NULL, NULL) < 0) {
ERROR("Unable to parse %s", path);
VIR_FREE(path);
goto cleanup;
}
VIR_FREE(path);
}
closedir(dir);
dir = NULL;
nleases = virJSONValueArraySize(leases_array);
DEBUG("Read %zd leases", nleases);
for (i = 0; i < nleases; i++) {
virJSONValuePtr lease;
const char *lease_name;
virSocketAddr sa;
const char *ipAddr;
int family;
lease = virJSONValueArrayGet(leases_array, i);
if (!lease) {
/* This should never happen (TM) */
ERROR("Unable to get element %zd of %zd", i, nleases);
goto cleanup;
}
lease_name = virJSONValueObjectGetString(lease, "hostname");
if (STRNEQ_NULLABLE(name, lease_name))
continue;
DEBUG("Found record for %s", lease_name);
*found = true;
if (!(ipAddr = virJSONValueObjectGetString(lease, "ip-address"))) {
ERROR("ip-address field missing for %s", name);
goto cleanup;
}
DEBUG("IP address: %s", ipAddr);
if (virSocketAddrParse(&sa, ipAddr, AF_UNSPEC) < 0) {
ERROR("Unable to parse %s", ipAddr);
goto cleanup;
}
family = VIR_SOCKET_ADDR_FAMILY(&sa);
if (af != AF_UNSPEC && af != family) {
DEBUG("Skipping address which family is %d, %d requested", family, af);
continue;
}
if (VIR_REALLOC_N_QUIET(tmpAddress, ntmpAddress + 1) < 0) {
ERROR("Out of memory");
goto cleanup;
}
tmpAddress[ntmpAddress].af = family;
memcpy(tmpAddress[ntmpAddress].addr,
(family == AF_INET ?
(void *) &sa.data.inet4.sin_addr.s_addr :
(void *) &sa.data.inet6.sin6_addr.s6_addr),
FAMILY_ADDRESS_SIZE(family));
ntmpAddress++;
}
*address = tmpAddress;
*naddress = ntmpAddress;
tmpAddress = NULL;
ntmpAddress = 0;
ret = 0;
cleanup:
*errnop = errno;
VIR_FREE(tmpAddress);
virJSONValueFree(leases_array);
if (dir)
closedir(dir);
return ret;
}
enum nss_status
_nss_libvirt_gethostbyname_r(const char *name, struct hostent *result,
char *buffer, size_t buflen, int *errnop,
int *herrnop)
{
int af = ((_res.options & RES_USE_INET6) ? AF_INET6 : AF_INET);
return _nss_libvirt_gethostbyname3_r(name, af, result, buffer, buflen,
errnop, herrnop, NULL, NULL);
}
enum nss_status
_nss_libvirt_gethostbyname2_r(const char *name, int af, struct hostent *result,
char *buffer, size_t buflen, int *errnop,
int *herrnop)
{
return _nss_libvirt_gethostbyname3_r(name, af, result, buffer, buflen,
errnop, herrnop, NULL, NULL);
}
enum nss_status
_nss_libvirt_gethostbyname3_r(const char *name, int af, struct hostent *result,
char *buffer, size_t buflen, int *errnop,
int *herrnop, int32_t *ttlp, char **canonp)
{
enum nss_status ret = NSS_STATUS_UNAVAIL;
char *r_name, **r_aliases, *r_addr, **r_addr_list;
leaseAddress *addr = NULL;
size_t naddr, i;
bool found = false;
size_t nameLen, need, idx;
int alen;
int r;
/* findLease is capable of returning both IPv4 and IPv6.
* However, this function has no way of telling user back the
* family per each address returned. Therefore, if @af ==
* AF_UNSPEC return just one family instead of a mixture of
* both. Dice picked the former one. */
if (af == AF_UNSPEC)
af = AF_INET;
if ((r = findLease(name, af, &addr, &naddr, &found, errnop)) < 0) {
/* Error occurred. Return immediately. */
if (*errnop == EAGAIN) {
*herrnop = TRY_AGAIN;
return NSS_STATUS_TRYAGAIN;
} else {
*herrnop = NO_RECOVERY;
return NSS_STATUS_UNAVAIL;
}
}
if (!found) {
/* NOT found */
*errnop = ESRCH;
*herrnop = HOST_NOT_FOUND;
return NSS_STATUS_NOTFOUND;
} else if (!naddr) {
/* Found, but no data */
*errnop = ENXIO;
*herrnop = NO_DATA;
return NSS_STATUS_UNAVAIL;
}
/* Found and have data */
alen = FAMILY_ADDRESS_SIZE(addr[0].af);
nameLen = strlen(name);
/* We need space for:
* a) name
* b) alias
* c) addresses
* d) NULL stem */
need = ALIGN(nameLen + 1) + naddr * ALIGN(alen) + (naddr + 2) * sizeof(char*);
if (buflen < need) {
*errnop = ENOMEM;
*herrnop = TRY_AGAIN;
ret = NSS_STATUS_TRYAGAIN;
goto cleanup;
}
/* First, append name */
r_name = buffer;
memcpy(r_name, name, nameLen + 1);
idx = ALIGN(nameLen + 1);
/* Second, create aliases array */
r_aliases = (char **) buffer + idx;
r_aliases[0] = NULL;
idx += sizeof(char*);
/* Third, append address */
r_addr = buffer + idx;
for (i = 0; i < naddr; i++)
memcpy(r_addr + i * ALIGN(alen), addr[i].addr, alen);
idx += naddr * ALIGN(alen);
/* Third, append address pointer array */
r_addr_list = (char **) buffer + idx;
for (i = 0; i < naddr; i++)
r_addr_list[i] = r_addr + i * ALIGN(alen);
r_addr_list[i] = NULL;
idx += (naddr + 1) * sizeof(char*);
/* At this point, idx == need */
DEBUG("Done idx:%zd need:%zd", idx, need);
result->h_name = r_name;
result->h_aliases = r_aliases;
result->h_addrtype = af;
result->h_length = alen;
result->h_addr_list = r_addr_list;
if (ttlp)
*ttlp = 0;
if (canonp)
*canonp = r_name;
/* Explicitly reset all error variables */
*errnop = 0;
*herrnop = NETDB_SUCCESS;
h_errno = 0;
ret = NSS_STATUS_SUCCESS;
cleanup:
VIR_FREE(addr);
return ret;
}

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@ -32,5 +32,17 @@
# include <nss.h>
# include <netdb.h>
int blah(int c);
enum nss_status
_nss_libvirt_gethostbyname_r(const char *name, struct hostent *result,
char *buffer, size_t buflen, int *errnop,
int *herrnop);
enum nss_status
_nss_libvirt_gethostbyname2_r(const char *name, int af, struct hostent *result,
char *buffer, size_t buflen, int *errnop,
int *herrnop);
enum nss_status
_nss_libvirt_gethostbyname3_r(const char *name, int af, struct hostent *result,
char *buffer, size_t buflen, int *errnop,
int *herrnop, int32_t *ttlp, char **canonp);
#endif /* __LIBVIRT_NSS_H__ */

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@ -4,6 +4,8 @@
{
global:
blah;
_nss_libvirt_gethostbyname_r;
_nss_libvirt_gethostbyname2_r;
_nss_libvirt_gethostbyname3_r;
local: *;
};