1// Copyright 2016 The Go Authors. All rights reserved. 2// Use of this source code is governed by a BSD-style 3// license that can be found in the LICENSE file. 4 5//go:build (dragonfly || darwin || freebsd || (!android && linux) || netbsd || openbsd || (solaris && !illumos)) && cgo && !osusergo 6 7package user 8 9import ( 10 "fmt" 11 "strconv" 12 "unsafe" 13) 14 15/* 16#include <unistd.h> 17#include <sys/types.h> 18*/ 19import "C" 20 21const maxGroups = 2048 22 23func listGroups(u *User) ([]string, error) { 24 ug, err := strconv.Atoi(u.Gid) 25 if err != nil { 26 return nil, fmt.Errorf("user: list groups for %s: invalid gid %q", u.Username, u.Gid) 27 } 28 userGID := C.gid_t(ug) 29 nameC := make([]byte, len(u.Username)+1) 30 copy(nameC, u.Username) 31 32 n := C.int(256) 33 gidsC := make([]C.gid_t, n) 34 rv := getGroupList((*C.char)(unsafe.Pointer(&nameC[0])), userGID, &gidsC[0], &n) 35 if rv == -1 { 36 // Mac is the only Unix that does not set n properly when rv == -1, so 37 // we need to use different logic for Mac vs. the other OS's. 38 if err := groupRetry(u.Username, nameC, userGID, &gidsC, &n); err != nil { 39 return nil, err 40 } 41 } 42 gidsC = gidsC[:n] 43 gids := make([]string, 0, n) 44 for _, g := range gidsC[:n] { 45 gids = append(gids, strconv.Itoa(int(g))) 46 } 47 return gids, nil 48} 49