nss: FreeBSD support

* tools/nss/libvirt_nss.[ch]: add BSD-comptabile wrappers and
   register via the nss_module_register() interface
 * m4/virt-nss.m4: add checks if we're building NSS for FreeBSD
 * tools/Makefile.am: handle target library name differences, as
   Linux needs libnss_libvirt.so.2 and FreeBSD needs
   nss_libvirt.so.1. Also, different syms files have to be used
   as Linux needs to export all the methods while FreeBSD
   only needs to have nss_module_register()
 * tests/nsstest.c, tests/nssmock.c: s/__linux__/NSS/
 * tests/nssmock.c: pass int instead of mode_t to va_arg() to please
   gcc 4.8
 * libvirt_nss_bsd.syms: FreeBSD syms file

m4/virt-nss.m4

@@ -23,6 +23,7 @@ AC_DEFUN([LIBVIRT_CHECK_NSS],[
       [enable Name Servie Switch plugin for resolving guest IP addresses])],
       [], [with_nss_plugin=check])
 
+  bsd_nss=no
   fail=0
   if test "x$with_nss_plugin" != "xno" ; then
     AC_CHECK_HEADERS([nss.h], [
@@ -39,11 +40,26 @@ AC_DEFUN([LIBVIRT_CHECK_NSS],[
 
     if test "x$with_nss_plugin" = "xyes" ; then
       AC_DEFINE_UNQUOTED([NSS], 1, [whether nss plugin is enabled])
+
+      AC_CHECK_TYPE([struct gaih_addrtuple],
+        [AC_DEFINE([HAVE_STRUCT_GAIH_ADDRTUPLE], [1],
+          [Defined if struct gaih_addrtuple exists in nss.h])],
+        [], [[#include <nss.h>
+        ]])
+
+      AC_CHECK_TYPES([ns_mtab, nss_module_unregister_fn],
+                     [AC_DEFINE([HAVE_BSD_NSS],
+                                [1],
+                                [whether using BSD style NSS])
+                      bsd_nss=yes
+                     ],
+                     [],
+                     [#include <nsswitch.h>])
     fi
   fi
 
   AM_CONDITIONAL(WITH_NSS, [test "x$with_nss_plugin" = "xyes"])
-
+  AM_CONDITIONAL(WITH_BSD_NSS, [test "x$bsd_nss" = "xyes"])
 ])
 
 AC_DEFUN([LIBVIRT_RESULT_NSS],[

tests/nssmock.c

@@ -20,7 +20,7 @@
 
 #include <config.h>
 
-#ifdef __linux__
+#ifdef NSS
 # include <stdio.h>
 # include <stdlib.h>
 # include <dlfcn.h>
@@ -107,7 +107,7 @@ open(const char *path, int flags, ...)
         va_list ap;
         mode_t mode;
         va_start(ap, flags);
-        mode = va_arg(ap, mode_t);
+        mode = va_arg(ap, int);
         va_end(ap);
         ret = realopen(newpath ? newpath : path, flags, mode);
     } else {
@@ -136,5 +136,5 @@ opendir(const char *path)
     return ret;
 }
 #else
-/* Nothing to override on non-__linux__ platforms */
+/* Nothing to override if NSS plugin is not enabled */
 #endif

tests/nsstest.c

@@ -22,7 +22,7 @@
 
 #include "testutils.h"
 
-#ifdef __linux__
+#ifdef NSS
 
 # include <stdbool.h>
 # include <arpa/inet.h>

tools/Makefile.am

@@ -417,8 +417,22 @@ CLEANFILES += wireshark/src/plugin.c
 
 endif WITH_WIRESHARK_DISSECTOR
 
+if WITH_BSD_NSS
+LIBVIRT_NSS_SYMBOL_FILE = \
+	$(srcdir)/nss/libvirt_nss_bsd.syms
+NSS_SO_VER = 1
+
+install-exec-hook:
+	cd $(DESTDIR)$(libdir) && \
+	  $(LN_S) libnss_libvirt.so.$(NSS_SO_VER) nss_libvirt.so.$(NSS_SO_VER)
+
+uninstall-local:
+	rm $(DESTDIR)$(libdir)/libnss_libvirt.so.$(NSS_SO_VER)
+else ! WITH_BSD_NSS
 LIBVIRT_NSS_SYMBOL_FILE = \
 	$(srcdir)/nss/libvirt_nss.syms
+NSS_SO_VER = 2
+endif ! WITH_BSD_NSS
 
 LIBVIRT_NSS_SOURCES = \
 	nss/libvirt_nss.c	\
@@ -449,7 +463,7 @@ nss_libnss_libvirt_la_LDFLAGS = \
 	-export-dynamic \
 	-avoid-version \
 	-shared \
-	-shrext .so.2
+	-shrext .so.$(NSS_SO_VER)
 
 nss_libnss_libvirt_la_LIBADD =  \
 	nss/libnss_libvirt_impl.la

tools/nss/libvirt_nss.c

@@ -29,11 +29,16 @@
 
 #include "libvirt_nss.h"
 
+#include <netinet/in.h>
 #include <resolv.h>
 #include <sys/types.h>
 #include <dirent.h>
 #include <arpa/inet.h>
 
+#if defined(HAVE_BSD_NSS)
+# include <nsswitch.h>
+#endif
+
 #include "virlease.h"
 #include "viralloc.h"
 #include "virfile.h"
@@ -65,7 +70,7 @@ do {                                                            \
 
 #define LEASEDIR LOCALSTATEDIR "/lib/libvirt/dnsmasq/"
 
-#define ALIGN(x) (((x) + __SIZEOF_POINTER__ - 1) & ~(__SIZEOF_POINTER__ - 1))
+#define LIBVIRT_ALIGN(x) (((x) + __SIZEOF_POINTER__ - 1) & ~(__SIZEOF_POINTER__ - 1))
 #define FAMILY_ADDRESS_SIZE(family) ((family) == AF_INET6 ? 16 : 4)
 
 typedef struct {
@@ -256,7 +261,7 @@ static inline void *
 move_and_align(void *buf, size_t len, size_t *idx)
 {
     char *buffer = buf;
-    size_t move = ALIGN(len);
+    size_t move = LIBVIRT_ALIGN(len);
 
     if (!idx)
         return buffer + move;
@@ -321,7 +326,7 @@ _nss_libvirt_gethostbyname3_r(const char *name, int af, struct hostent *result,
      * b) alias
      * c) addresses
      * d) NULL stem */
-    need = ALIGN(nameLen + 1) + naddr * ALIGN(alen) + (naddr + 2) * sizeof(char*);
+    need = LIBVIRT_ALIGN(nameLen + 1) + naddr * LIBVIRT_ALIGN(alen) + (naddr + 2) * sizeof(char*);
 
     if (buflen < need) {
         *errnop = ENOMEM;
@@ -383,6 +388,7 @@ _nss_libvirt_gethostbyname3_r(const char *name, int af, struct hostent *result,
     return ret;
 }
 
+#ifdef HAVE_STRUCT_GAIH_ADDRTUPLE
 enum nss_status
 _nss_libvirt_gethostbyname4_r(const char *name, struct gaih_addrtuple **pat,
                               char *buffer, size_t buflen, int *errnop,
@@ -426,7 +432,7 @@ _nss_libvirt_gethostbyname4_r(const char *name, struct gaih_addrtuple **pat,
     /* We need space for:
      * a) name
      * b) addresses */
-    need = ALIGN(nameLen + 1) + naddr * ALIGN(sizeof(struct gaih_addrtuple));
+    need = LIBVIRT_ALIGN(nameLen + 1) + naddr * LIBVIRT_ALIGN(sizeof(struct gaih_addrtuple));
 
     if (buflen < need) {
         *errnop = ENOMEM;
@@ -474,3 +480,128 @@ _nss_libvirt_gethostbyname4_r(const char *name, struct gaih_addrtuple **pat,
  cleanup:
     return ret;
 }
+#endif /* HAVE_STRUCT_GAIH_ADDRTUPLE */
+
+#if defined(HAVE_BSD_NSS)
+NSS_METHOD_PROTOTYPE(_nss_compat_getaddrinfo);
+NSS_METHOD_PROTOTYPE(_nss_compat_gethostbyname2_r);
+
+ns_mtab methods[] = {
+    { NSDB_HOSTS, "getaddrinfo", _nss_compat_getaddrinfo, NULL },
+    { NSDB_HOSTS, "gethostbyname", _nss_compat_gethostbyname2_r, NULL },
+    { NSDB_HOSTS, "gethostbyname2_r", _nss_compat_gethostbyname2_r, NULL },
+};
+
+static void
+aiforaf(const char *name, int af, struct addrinfo *pai, struct addrinfo **aip)
+{
+    int ret;
+    struct hostent resolved;
+    char buf[1024] = { 0 };
+    int err, herr;
+    struct addrinfo hints, *res0, *res;
+    char **addrList;
+
+    if ((ret = _nss_libvirt_gethostbyname2_r(name, af, &resolved,
+                                             buf, sizeof(buf),
+                                             &err, &herr)) != NS_SUCCESS)
+        return;
+
+    addrList = resolved.h_addr_list;
+    while (*addrList) {
+        virSocketAddr sa;
+        char *ipAddr = NULL;
+        void *address = *addrList;
+
+        memset(&sa, 0, sizeof(sa));
+        if (resolved.h_addrtype == AF_INET) {
+            virSocketAddrSetIPv4AddrNetOrder(&sa, *((uint32_t *) address));
+        } else {
+            virSocketAddrSetIPv6AddrNetOrder(&sa, address);
+        }
+
+        ipAddr = virSocketAddrFormat(&sa);
+
+        hints = *pai;
+        hints.ai_flags = AI_NUMERICHOST;
+        hints.ai_family = af;
+
+        if (getaddrinfo(ipAddr, NULL, &hints, &res0)) {
+            addrList++;
+            continue;
+        }
+
+        for (res = res0; res; res = res->ai_next)
+            res->ai_flags = pai->ai_flags;
+
+        (*aip)->ai_next = res0;
+        while ((*aip)->ai_next)
+           *aip = (*aip)->ai_next;
+
+        addrList++;
+    }
+}
+
+int
+_nss_compat_getaddrinfo(void *retval, void *mdata ATTRIBUTE_UNUSED, va_list ap)
+{
+    struct addrinfo sentinel, *cur, *ai;
+    const char *name;
+
+    name  = va_arg(ap, char *);
+    ai = va_arg(ap, struct addrinfo *);
+
+    memset(&sentinel, 0, sizeof(sentinel));
+    cur = &sentinel;
+
+    if ((ai->ai_family == AF_UNSPEC) || (ai->ai_family == AF_INET6))
+        aiforaf(name, AF_INET6, ai, &cur);
+    if ((ai->ai_family == AF_UNSPEC) || (ai->ai_family == AF_INET))
+        aiforaf(name, AF_INET, ai, &cur);
+
+    if (sentinel.ai_next == NULL) {
+        h_errno = HOST_NOT_FOUND;
+        return NS_NOTFOUND;
+    }
+    *((struct addrinfo **)retval) = sentinel.ai_next;
+
+    return NS_SUCCESS;
+}
+
+int
+_nss_compat_gethostbyname2_r(void *retval, void *mdata ATTRIBUTE_UNUSED, va_list ap)
+{
+    int ret;
+
+    const char *name;
+    int af;
+    struct hostent *result;
+    char *buffer;
+    size_t buflen;
+    int *errnop;
+    int *herrnop;
+
+    name = va_arg(ap, const char *);
+    af = va_arg(ap, int);
+    result = va_arg(ap, struct hostent *);
+    buffer = va_arg(ap, char *);
+    buflen = va_arg(ap, size_t);
+    errnop = va_arg(ap, int *);
+    herrnop = va_arg(ap, int *);
+
+    ret = _nss_libvirt_gethostbyname2_r(
+              name, af, result, buffer, buflen, errnop, herrnop);
+    *(struct hostent **)retval = (ret == NS_SUCCESS) ? result : NULL;
+
+    return ret;
+}
+
+ns_mtab*
+nss_module_register(const char *name ATTRIBUTE_UNUSED, unsigned int *size,
+                    nss_module_unregister_fn *unregister)
+{
+    *size = sizeof(methods) / sizeof(methods[0]);
+    *unregister = NULL;
+    return methods;
+}
+#endif /* HAVE_BSD_NSS */

tools/nss/libvirt_nss.h

@@ -45,8 +45,17 @@ 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);
+# ifdef HAVE_STRUCT_GAIH_ADDRTUPLE
 enum nss_status
 _nss_libvirt_gethostbyname4_r(const char *name, struct gaih_addrtuple **pat,
                               char *buffer, size_t buflen, int *errnop,
                               int *herrnop, int32_t *ttlp);
+# endif /* HAVE_STRUCT_GAIH_ADDRTUPLE */
+
+# if defined(HAVE_BSD_NSS)
+ns_mtab*
+nss_module_register(const char *name, unsigned int *size,
+                    nss_module_unregister_fn *unregister);
+# endif /* HAVE_BSD_NSS */
+
 #endif /* __LIBVIRT_NSS_H__ */

tools/nss/libvirt_nss_bsd.syms

@@ -0,0 +1,9 @@
+#
+# Officially exported symbols.
+#
+
+{
+global:
+    nss_module_register;
+local: *;
+};