initgroups_dyn: Refactor adding a group into an add_group function

Signed-off-by: Anders Kaseorg <andersk@mit.edu>

diff --git a/nonlocal-group.c b/nonlocal-group.c
index fa7fbaf5c2400ae8d4efad6f0a3868afd6ce4d87..987b58ed5b54f09cbbacd1c2d5a3d09346c81ebf 100644 (file)
--- a/nonlocal-group.c
+++ b/nonlocal-group.c
@@ -279,6 +279,39 @@ _nss_nonlocal_getgrgid_r(gid_t gid, struct group *grp,
     return check_nonlocal_group(grp->gr_name, grp, errnop);
 }
 
+static bool
+add_group(gid_t group, long int *start, long int *size, gid_t **groupsp,
+         long int limit, int *errnop, enum nss_status *status)
+{
+    int i, old_errno = errno;
+    for (i = 0; i < *start; ++i)
+       if ((*groupsp)[i] == group)
+           return true;
+    if (*start + 1 > *size) {
+       gid_t *newgroups;
+       long int newsize = 2 * *size;
+       if (limit > 0) {
+           if (*size >= limit) {
+               *status = NSS_STATUS_SUCCESS;
+               return false;
+           }
+           if (newsize > limit)
+               newsize = limit;
+       }
+       newgroups = realloc(*groupsp, newsize * sizeof((*groupsp)[0]));
+       errno = old_errno;
+       if (newgroups == NULL) {
+           *errnop = ENOMEM;
+           *status = NSS_STATUS_TRYAGAIN;
+           return false;
+       }
+       *groupsp = newgroups;
+       *size = newsize;
+    }
+    (*groupsp)[(*start)++] = group;
+    return true;
+}
+
 enum nss_status
 _nss_nonlocal_initgroups_dyn(const char *user, gid_t group, long int *start,
                             long int *size, gid_t **groupsp, long int limit,
@@ -292,10 +325,9 @@ _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, gid;
+    gid_t local_users_gid;
     int is_local = 0;
     char *buffer;
-    int old_errno;
     int in, out, i;
 
     /* Check that the user is a nonlocal user before adding any groups. */
@@ -305,8 +337,6 @@ _nss_nonlocal_initgroups_dyn(const char *user, gid_t group, long int *start,
     else if (status != NSS_STATUS_SUCCESS)
        is_local = 1;
 
-    old_errno = errno;
-
     status = get_local_group(MAGIC_LOCAL_GROUPNAME,
                             &local_users_group, &buffer, errnop);
     if (status == NSS_STATUS_SUCCESS) {
@@ -321,47 +351,22 @@ _nss_nonlocal_initgroups_dyn(const char *user, gid_t group, long int *start,
     }
 
     if (is_local) {
-       gid = local_users_gid;
+       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);
        if (status == NSS_STATUS_SUCCESS) {
-           gid = nonlocal_users_group.gr_gid;
            free(buffer);
+           if (!add_group(nonlocal_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);
-           gid = -1;
-       }
-    }
-
-    if (gid != -1) {
-       int i;
-       for (i = 0; i < *start; ++i)
-           if ((*groupsp)[i] == gid)
-               break;
-       if (i >= *start) {
-           if (*start + 1 > *size) {
-               gid_t *newgroups;
-               long int newsize = 2 * *size;
-               if (limit > 0) {
-                   if (*size >= limit)
-                       return NSS_STATUS_SUCCESS;
-                   if (newsize > limit)
-                       newsize = limit;
-               }
-               newgroups = realloc(*groupsp, newsize * sizeof((*groupsp)[0]));
-               errno = old_errno;
-               if (newgroups == NULL) {
-                   *errnop = ENOMEM;
-                   return NSS_STATUS_TRYAGAIN;
-               }
-               *groupsp = newgroups;
-               *size = newsize;
-           }
-           (*groupsp)[(*start)++] = gid;
        }
     }