r2868: Well, I'm not quite sure what I'm doing back in Samba 3.0, but anyway...

I've been grumbling about under-efficient calls in SAMR, and finally
got around to fixing some of them.

We now call sys_getgroups() (which in turn calls initgroups(), until
glibc 3.4 is released) to figure out a user's group membership.  This
is far, far more efficient than scanning all the groups looking for a
match, and is still the 'posix way', just using an effiecient call.

The seperate issue of 'who is in this group' remains, but this one has
been biting some people.

I need to talk to VL about how best to exersise nasty corner cases,
but my initial tests hold strong.  (The code is also much simpiler
than before, which has to count for something :-)

Andrew Bartlett
(This used to be commit dc19f161698dab5b71d61fa2bacc7e7b8da5fbba)

2 files changed, 63 insertions, 12 deletions

diff --git a/source3/lib/util.c b/source3/lib/util.c
index 5e88bd896f..89cf1bfa02 100644
--- a/source3/lib/util.c
+++ b/source3/lib/util.c
@@ -289,6 +289,28 @@ BOOL in_group(gid_t group, gid_t current_gid, int ngroups, const gid_t *groups)
 }
 
 /****************************************************************************
+ Add a gid to an array of gids if it's not already there.
+****************************************************************************/
+
+void add_gid_to_array_unique(gid_t gid, gid_t **gids, int *num)
+{
+	int i;
+
+	for (i=0; i<*num; i++) {
+		if ((*gids)[i] == gid)
+			return;
+	}
+	
+	*gids = Realloc(*gids, (*num+1) * sizeof(gid_t));
+
+	if (*gids == NULL)
+		return;
+
+	(*gids)[*num] = gid;
+	*num += 1;
+}
+
+/****************************************************************************
  Like atoi but gets the value up to the separator character.
 ****************************************************************************/
 
diff --git a/source3/lib/util_smbd.c b/source3/lib/util_smbd.c
index 071f20b416..36c3104e55 100644
--- a/source3/lib/util_smbd.c
+++ b/source3/lib/util_smbd.c
@@ -37,29 +37,58 @@
   NOTE! uses become_root() to gain correct priviages on systems
   that lack a native getgroups() call (uses initgroups and getgroups)
 */
-int getgroups_user(const char *user, gid_t **groups)
+BOOL getgroups_user(const char *user, gid_t **ret_groups, int *ngroups)
 {
 	struct passwd *pwd;
 	int ngrp, max_grp;
+	gid_t *temp_groups;
+	gid_t *groups;
+	int i;
 
 	pwd = getpwnam_alloc(user);
-	if (!pwd) return -1;
+	if (!pwd) return False;
 
 	max_grp = groups_max();
-	(*groups) = (gid_t *)malloc(sizeof(gid_t) * max_grp);
-	if (! *groups) {
+	temp_groups = (gid_t *)malloc(sizeof(gid_t) * max_grp);
+	if (! temp_groups) {
 		passwd_free(&pwd);
-		errno = ENOMEM;
-		return -1;
+		return False;
 	}
 
-	ngrp = sys_getgrouplist(user, pwd->pw_gid, *groups, &max_grp);
-	if (ngrp <= 0) {
-		passwd_free(&pwd);
-		free(*groups);
-		return ngrp;
+	if (sys_getgrouplist(user, pwd->pw_gid, temp_groups, &max_grp) == -1) {
+		
+		gid_t *groups_tmp;
+		
+		groups_tmp = Realloc(temp_groups, sizeof(gid_t) * max_grp);
+		
+		if (!groups_tmp) {
+			SAFE_FREE(temp_groups);
+			return False;
+		}
+		temp_groups = groups_tmp;
+		
+		if (sys_getgrouplist(user, pwd->pw_gid, temp_groups, &max_grp) == -1) {
+			DEBUG(0, ("get_user_groups: failed to get the unix group list\n"));
+			passwd_free(&pwd);
+			SAFE_FREE(temp_groups);
+			return False;
+		}
 	}
+	
+	ngrp = 0;
+	groups = NULL;
+
+	/* Add in primary group first */
+	add_gid_to_array_unique(pwd->pw_gid, &groups, &ngrp);
 
 	passwd_free(&pwd);
-	return ngrp;
+
+	for (i=0; i<max_grp; i++)
+		add_gid_to_array_unique(temp_groups[i], &groups, &ngrp);
+
+	*ngroups = ngrp;
+	*ret_groups = groups;
+	SAFE_FREE(temp_groups);
+	return True;
 }
+