1 files changed, 115 insertions, 0 deletions

diff --git a/libpwdgrp/initgroups.c b/libpwdgrp/initgroups.c
new file mode 100644
index 000000000..9b5dcbcb2
--- /dev/null
+++ b/libpwdgrp/initgroups.c
@@ -0,0 +1,115 @@
+/*
+ * initgroups.c - This file is part of the libc-8086/grp package for ELKS,
+ * Copyright (C) 1995, 1996 Nat Friedman <ndf@linux.mit.edu>.
+ * 
+ *  This library is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU Library General Public
+ *  License as published by the Free Software Foundation; either
+ *  version 2 of the License, or (at your option) any later version.
+ *
+ *  This library is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  Library General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Library General Public
+ *  License along with this library; if not, write to the Free
+ *  Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ */
+
+#include "busybox.h" 
+
+#include <unistd.h>
+#include <string.h>
+#include <fcntl.h>
+#include "grp.h"
+
+/*
+ * Define GR_SCALE_DYNAMIC if you want grp to dynamically scale its read buffer
+ * so that lines of any length can be used.  On very very small systems,
+ * you may want to leave this undefined becasue it will make the grp functions
+ * somewhat larger (because of the inclusion of malloc and the code necessary).
+ * On larger systems, you will want to define this, because grp will _not_
+ * deal with long lines gracefully (they will be skipped).
+ */
+#undef GR_SCALE_DYNAMIC
+
+#ifndef GR_SCALE_DYNAMIC
+/*
+ * If scaling is not dynamic, the buffers will be statically allocated, and
+ * maximums must be chosen.  GR_MAX_LINE_LEN is the maximum number of
+ * characters per line in the group file.  GR_MAX_MEMBERS is the maximum
+ * number of members of any given group.
+ */
+#define GR_MAX_LINE_LEN 128
+/* GR_MAX_MEMBERS = (GR_MAX_LINE_LEN-(24+3+6))/9 */
+#define GR_MAX_MEMBERS 11
+
+#endif /* !GR_SCALE_DYNAMIC */
+
+
+/*
+ * Define GR_DYNAMIC_GROUP_LIST to make initgroups() dynamically allocate
+ * space for it's GID array before calling setgroups().  This is probably
+ * unnecessary scalage, so it's undefined by default.
+ */
+#undef GR_DYNAMIC_GROUP_LIST
+
+#ifndef GR_DYNAMIC_GROUP_LIST
+/*
+ * GR_MAX_GROUPS is the size of the static array initgroups() uses for
+ * its static GID array if GR_DYNAMIC_GROUP_LIST isn't defined.
+ */
+#define GR_MAX_GROUPS 64
+
+#endif /* !GR_DYNAMIC_GROUP_LIST */
+
+int initgroups(__const char *user, gid_t gid)
+{
+        register struct group *group;
+
+#ifndef GR_DYNAMIC_GROUP_LIST
+        gid_t group_list[GR_MAX_GROUPS];
+#else
+        gid_t *group_list = NULL;
+#endif
+        register char **tmp_mem;
+        int num_groups;
+        int grp_fd;
+
+
+        if ((grp_fd = open("/etc/group", O_RDONLY)) < 0)
+                return -1;
+
+        num_groups = 0;
+#ifdef GR_DYNAMIC_GROUP_LIST
+        group_list = (gid_t *) realloc(group_list, 1);
+#endif
+        group_list[num_groups] = gid;
+#ifndef GR_DYNAMIC_GROUP_LIST
+        while (num_groups < GR_MAX_GROUPS &&
+                   (group = __getgrent(grp_fd)) != NULL)
+#else
+        while ((group = __getgrent(grp_fd)) != NULL)
+#endif
+        {
+                if (group->gr_gid != gid);
+                {
+                        tmp_mem = group->gr_mem;
+                        while (*tmp_mem != NULL) {
+                                if (!strcmp(*tmp_mem, user)) {
+                                        num_groups++;
+#ifdef GR_DYNAMIC_GROUP_LIST
+                                        group_list = (gid_t *) realloc(group_list, num_groups *
+                                                sizeof(gid_t *));
+#endif
+                                        group_list[num_groups] = group->gr_gid;
+                                }
+                                tmp_mem++;
+                        }
+                }
+        }
+        close(grp_fd);
+        return setgroups(num_groups, group_list);
+}