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// Copyright 2016 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
//go:build cgo && !osusergo
// +build cgo,!osusergo
package user
/*
#include <unistd.h>
#include <sys/types.h>
#include <stdlib.h>
static int mygetgrouplist(const char* user, gid_t group, gid_t* groups, int* ngroups) {
int* buf = malloc(*ngroups * sizeof(int));
int rv = getgrouplist(user, (int) group, buf, ngroups);
int i;
if (rv == 0) {
for (i = 0; i < *ngroups; i++) {
groups[i] = (gid_t) buf[i];
}
}
free(buf);
return rv;
}
*/
import "C"
import (
"fmt"
"unsafe"
)
func getGroupList(name *C.char, userGID C.gid_t, gids *C.gid_t, n *C.int) C.int {
return C.mygetgrouplist(name, userGID, gids, n)
}
// groupRetry retries getGroupList with an increasingly large size for n. The
// result is stored in gids.
func groupRetry(username string, name []byte, userGID C.gid_t, gids *[]C.gid_t, n *C.int) error {
*n = C.int(256 * 2)
for {
*gids = make([]C.gid_t, *n)
rv := getGroupList((*C.char)(unsafe.Pointer(&name[0])), userGID, &(*gids)[0], n)
if rv >= 0 {
// n is set correctly
break
}
if *n > maxGroups {
return fmt.Errorf("user: %q is a member of more than %d groups", username, maxGroups)
}
*n = *n * C.int(2)
}
return nil
}
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