| // 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. |
| |
| // +build dragonfly darwin freebsd !android,linux netbsd openbsd |
| |
| package user |
| |
| import ( |
| "fmt" |
| "strconv" |
| "syscall" |
| ) |
| |
| /* |
| #include <unistd.h> |
| #include <sys/types.h> |
| */ |
| |
| const maxGroups = 2048 |
| |
| func listGroups(u *User) ([]string, error) { |
| ug, err := strconv.Atoi(u.Gid) |
| if err != nil { |
| return nil, fmt.Errorf("user: list groups for %s: invalid gid %q", u.Username, u.Gid) |
| } |
| userGID := syscall.Gid_t(ug) |
| nameC, err := syscall.BytePtrFromString(u.Username) |
| if err != nil { |
| return nil, fmt.Errorf("user: invalid user name %q: %v", strconv.Quote(u.Username), err) |
| } |
| |
| n := int32(256) |
| gidsC := make([]syscall.Gid_t, n) |
| syscall.Entersyscall() |
| rv := libc_getgrouplist(nameC, userGID, &gidsC[0], &n) |
| syscall.Exitsyscall() |
| if rv == -1 { |
| // More than initial buffer, but now n contains the correct size. |
| const maxGroups = 2048 |
| if n > maxGroups { |
| return nil, fmt.Errorf("user: list groups for %s: member of more than %d groups", u.Username, maxGroups) |
| } |
| gidsC = make([]syscall.Gid_t, n) |
| syscall.Entersyscall() |
| rv := libc_getgrouplist(nameC, userGID, &gidsC[0], &n) |
| syscall.Exitsyscall() |
| if rv == -1 { |
| return nil, fmt.Errorf("user: list groups for %s failed (changed groups?)", u.Username) |
| } |
| } |
| gidsC = gidsC[:n] |
| gids := make([]string, 0, n) |
| for _, g := range gidsC[:n] { |
| gids = append(gids, strconv.Itoa(int(g))) |
| } |
| return gids, nil |
| } |