X-Git-Url: http://andersk.mit.edu/gitweb/nss_nonlocal.git/blobdiff_plain/dfc6e2925bb98ec0bbffba50fce0c5a2b0515902..34cfeb2823b7262b81a42c6fff29146216353552:/nonlocal-group.c

diff --git a/nonlocal-group.c b/nonlocal-group.c
index 987b58e..aa9c588 100644
--- a/nonlocal-group.c
+++ b/nonlocal-group.c
@@ -38,7 +38,18 @@
 #include "nsswitch-internal.h"
 #include "nonlocal.h"
 
+/*
+ * If the MAGIC_NONLOCAL_GROUPNAME local group exists, then nonlocal
+ * users will be automatically added to it.  Furthermore, if a local
+ * user is added to this group, then that user will inherit any
+ * nonlocal supplementary gids from a nonlocal user of the same name.
+ */
 #define MAGIC_NONLOCAL_GROUPNAME "nss-nonlocal-users"
+
+/*
+ * If the MAGIC_LOCAL_GROUPNAME local group exists, then local users
+ * will be automatically added to it.
+ */
 #define MAGIC_LOCAL_GROUPNAME "nss-local-users"
 
 
@@ -325,52 +336,60 @@ _nss_nonlocal_initgroups_dyn(const char *user, gid_t group, long int *start,
     const __typeof__(&_nss_nonlocal_initgroups_dyn) self = NULL;
 
     struct group local_users_group, nonlocal_users_group;
-    gid_t local_users_gid;
-    int is_local = 0;
+    bool is_nonlocal = true;
     char *buffer;
     int in, out, i;
 
-    /* Check that the user is a nonlocal user before adding any groups. */
+    /* Check that the user is a nonlocal user, or a member of the
+     * MAGIC_NONLOCAL_GROUPNAME group, before adding any groups. */
     status = check_nonlocal_user(user, errnop);
-    if (status == NSS_STATUS_TRYAGAIN)
+    if (status == NSS_STATUS_TRYAGAIN) {
 	return status;
-    else if (status != NSS_STATUS_SUCCESS)
-	is_local = 1;
+    } else if (status != NSS_STATUS_SUCCESS) {
+	is_nonlocal = false;
 
-    status = get_local_group(MAGIC_LOCAL_GROUPNAME,
-			     &local_users_group, &buffer, errnop);
-    if (status == NSS_STATUS_SUCCESS) {
-	local_users_gid = local_users_group.gr_gid;
-	free(buffer);
-    } else if (status == NSS_STATUS_TRYAGAIN) {
-	return status;
-    } else {
-	syslog(LOG_WARNING, "nss_nonlocal: Group %s does not exist locally!",
-	       MAGIC_LOCAL_GROUPNAME);
-	local_users_gid = -1;
-    }
-
-    if (is_local) {
-	if (!add_group(local_users_gid, start, size, groupsp, limit, errnop,
-		       &status))
-	    return status;
-    } else {
- 	status = get_local_group(MAGIC_NONLOCAL_GROUPNAME,
-				 &nonlocal_users_group, &buffer, errnop);
+	status = get_local_group(MAGIC_LOCAL_GROUPNAME,
+				 &local_users_group, &buffer, errnop);
 	if (status == NSS_STATUS_SUCCESS) {
 	    free(buffer);
-	    if (!add_group(nonlocal_users_group.gr_gid, start, size, groupsp,
+	    if (!add_group(local_users_group.gr_gid, start, size, groupsp,
 			   limit, errnop, &status))
 		return status;
 	} else if (status == NSS_STATUS_TRYAGAIN) {
 	    return status;
 	} else {
-	    syslog(LOG_WARNING, "nss_nonlocal: Group %s does not exist locally!",
-		   MAGIC_NONLOCAL_GROUPNAME);
+	    syslog(LOG_WARNING,
+		   "nss_nonlocal: Group %s does not exist locally!",
+		   MAGIC_LOCAL_GROUPNAME);
 	}
     }
 
-    if (is_local)
+    status = get_local_group(MAGIC_NONLOCAL_GROUPNAME,
+			     &nonlocal_users_group, &buffer, errnop);
+    if (status == NSS_STATUS_SUCCESS) {
+	free(buffer);
+	if (is_nonlocal) {
+	    if (!add_group(nonlocal_users_group.gr_gid, start, size, groupsp,
+			   limit, errnop, &status))
+		return status;
+	} else {
+	    int i;
+	    for (i = 0; i < *start; ++i) {
+		if ((*groupsp)[i] == nonlocal_users_group.gr_gid) {
+		    is_nonlocal = true;
+		    break;
+		}
+	    }
+	}
+    } else if (status == NSS_STATUS_TRYAGAIN) {
+	if (is_nonlocal)
+	    return status;
+    } else {
+	syslog(LOG_WARNING, "nss_nonlocal: Group %s does not exist locally!",
+	       MAGIC_NONLOCAL_GROUPNAME);
+    }
+
+    if (!is_nonlocal)
 	return NSS_STATUS_SUCCESS;
 
     in = out = *start;
@@ -390,13 +409,6 @@ _nss_nonlocal_initgroups_dyn(const char *user, gid_t group, long int *start,
 	if (i < out)
 	    continue;
 
-	/* Don't let users get into MAGIC_LOCAL_GROUPNAME from nonlocal reasons. */
-	if (local_users_gid == (*groupsp)[in]) {
-	    syslog(LOG_WARNING, "nss_nonlocal: Nonlocal user %s removed from special local users group %s",
-		   user, MAGIC_LOCAL_GROUPNAME);
-	    continue;
-	}
-
 	status = check_nonlocal_gid(user, (*groupsp)[in], &nonlocal_errno);
 	if (status == NSS_STATUS_SUCCESS) {
 	    (*groupsp)[out++] = (*groupsp)[in];