nss_wrapper: add capability to load nss modules.

Guenther

diff --git a/lib/nss_wrapper/nss_wrapper.c b/lib/nss_wrapper/nss_wrapper.c
index cffa04401fb915abc037e5042d51fe89e7852f45..a2cd0ac52e5cd6b80125fd7e1682dadec46adf1b 100644 (file)
--- a/lib/nss_wrapper/nss_wrapper.c
+++ b/lib/nss_wrapper/nss_wrapper.c
@@ -37,6 +37,7 @@
 #include "../replace/replace.h"
 #include "system/passwd.h"
 #include "system/filesys.h"
+#include "../nsswitch/nsstest.h"
 
 #else /* _SAMBA_BUILD_ */
 
@@ -139,9 +140,33 @@
 #define NWRAP_VERBOSE(args)
 #endif
 
+struct nwrap_module_nss_fns {
+       NSS_STATUS (*_nss_getpwnam_r)(const char *name, struct passwd *result, char *buffer,
+                                     size_t buflen, int *errnop);
+       NSS_STATUS (*_nss_getpwuid_r)(uid_t uid, struct passwd *result, char *buffer,
+                                     size_t buflen, int *errnop);
+       NSS_STATUS (*_nss_setpwent)(void);
+       NSS_STATUS (*_nss_getpwent_r)(struct passwd *result, char *buffer,
+                                     size_t buflen, int *errnop);
+       NSS_STATUS (*_nss_endpwent)(void);
+       NSS_STATUS (*_nss_initgroups)(const char *user, gid_t group, long int *start,
+                                     long int *size, gid_t **groups, long int limit, int *errnop);
+       NSS_STATUS (*_nss_getgrnam_r)(const char *name, struct group *result, char *buffer,
+                                     size_t buflen, int *errnop);
+       NSS_STATUS (*_nss_getgrgid_r)(gid_t gid, struct group *result, char *buffer,
+                                     size_t buflen, int *errnop);
+       NSS_STATUS (*_nss_setgrent)(void);
+       NSS_STATUS (*_nss_getgrent_r)(struct group *result, char *buffer,
+                                     size_t buflen, int *errnop);
+       NSS_STATUS (*_nss_endgrent)(void);
+};
+
 struct nwrap_backend {
        const char *name;
+       const char *so_path;
+       void *so_handle;
        struct nwrap_ops *ops;
+       struct nwrap_module_nss_fns *fns;
 };
 
 struct nwrap_ops {
@@ -286,8 +311,94 @@ struct nwrap_gr nwrap_gr_global;
 static bool nwrap_gr_parse_line(struct nwrap_cache *nwrap, char *line);
 static void nwrap_gr_unload(struct nwrap_cache *nwrap);
 
+static void *nwrap_load_module_fn(struct nwrap_backend *b,
+                                 const char *fn_name)
+{
+       void *res;
+       char *s;
+
+       if (!b->so_handle) {
+               NWRAP_ERROR(("%s: no handle\n",
+                            __location__));
+               return NULL;
+       }
+
+       if (asprintf(&s, "_nss_%s_%s", b->name, fn_name) == -1) {
+               NWRAP_ERROR(("%s: out of memory\n",
+                            __location__));
+               return NULL;
+       }
+
+       res = dlsym(b->so_handle, s);
+       if (!res) {
+               NWRAP_ERROR(("%s: cannot find function %s in %s\n",
+                            __location__, s, b->so_path));
+       }
+       free(s);
+       s = NULL;
+       return res;
+}
+
+static struct nwrap_module_nss_fns *nwrap_load_module_fns(struct nwrap_backend *b)
+{
+       struct nwrap_module_nss_fns *fns;
+
+       if (!b->so_handle) {
+               return NULL;
+       }
+
+       fns = (struct nwrap_module_nss_fns *)malloc(sizeof(struct nwrap_module_nss_fns));
+       if (!fns) {
+               return NULL;
+       }
+
+       fns->_nss_getpwnam_r    = (NSS_STATUS (*)(const char *, struct passwd *, char *, size_t, int *))
+                                 nwrap_load_module_fn(b, "getpwnam_r");
+       fns->_nss_getpwuid_r    = (NSS_STATUS (*)(uid_t, struct passwd *, char *, size_t, int *))
+                                 nwrap_load_module_fn(b, "getpwuid_r");
+       fns->_nss_setpwent      = (NSS_STATUS(*)(void))
+                                 nwrap_load_module_fn(b, "setpwent");
+       fns->_nss_getpwent_r    = (NSS_STATUS (*)(struct passwd *, char *, size_t, int *))
+                                 nwrap_load_module_fn(b, "getpwent_r");
+       fns->_nss_endpwent      = (NSS_STATUS(*)(void))
+                                 nwrap_load_module_fn(b, "endpwent");
+       fns->_nss_initgroups    = (NSS_STATUS (*)(const char *, gid_t, long int *, long int *, gid_t **, long int, int *))
+                                 nwrap_load_module_fn(b, "initgroups_dyn");
+       fns->_nss_getgrnam_r    = (NSS_STATUS (*)(const char *, struct group *, char *, size_t, int *))
+                                 nwrap_load_module_fn(b, "getgrnam_r");
+       fns->_nss_getgrgid_r    = (NSS_STATUS (*)(gid_t, struct group *, char *, size_t, int *))
+                                 nwrap_load_module_fn(b, "getgrgid_r");
+       fns->_nss_setgrent      = (NSS_STATUS(*)(void))
+                                 nwrap_load_module_fn(b, "setgrent");
+       fns->_nss_getgrent_r    = (NSS_STATUS (*)(struct group *, char *, size_t, int *))
+                                 nwrap_load_module_fn(b, "getgrent_r");
+       fns->_nss_endgrent      = (NSS_STATUS(*)(void))
+                                 nwrap_load_module_fn(b, "endgrent");
+
+       return fns;
+}
+
+static void *nwrap_load_module(const char *so_path)
+{
+       void *h;
+
+       if (!so_path || !strlen(so_path)) {
+               return NULL;
+       }
+
+       h = dlopen(so_path, RTLD_LAZY);
+       if (!h) {
+               NWRAP_ERROR(("%s: cannot open shared library %s\n",
+                            __location__, so_path));
+               return NULL;
+       }
+
+       return h;
+}
+
 static bool nwrap_module_init(const char *name,
                              struct nwrap_ops *ops,
+                             const char *so_path,
                              int *num_backends,
                              struct nwrap_backend **backends)
 {
@@ -300,6 +411,9 @@ static bool nwrap_module_init(const char *name,
 
        (*backends)[*num_backends].name = name;
        (*backends)[*num_backends].ops = ops;
+       (*backends)[*num_backends].so_path = so_path;
+       (*backends)[*num_backends].so_handle = nwrap_load_module(so_path);
+       (*backends)[*num_backends].fns = nwrap_load_module_fns(&((*backends)[*num_backends]));
 
        (*num_backends)++;
 
@@ -311,7 +425,7 @@ static void nwrap_backend_init(struct nwrap_main *r)
        r->num_backends = 0;
        r->backends = NULL;
 
-       if (!nwrap_module_init("files", &nwrap_files_ops,
+       if (!nwrap_module_init("files", &nwrap_files_ops, NULL,
                               &r->num_backends,
                               &r->backends)) {
                NWRAP_ERROR(("%s: failed to initialize 'files' backend\n",