func userInGroup(u *user.User, g *Group) (bool, error) {
if u.Gid == g.Gid {
return true, nil
}
gid, err := strconv.Atoi(g.Gid)
if err != nil {
return false, err
}
nameC := C.CString(u.Username)
defer C.free(unsafe.Pointer(nameC))
groupC := C.gid_t(gid)
ngroupsC := C.int(0)
C.mygetgrouplist(nameC, groupC, nil, &ngroupsC)
ngroups := int(ngroupsC)
groups := C.malloc(C.size_t(int(unsafe.Sizeof(groupC)) * ngroups))
defer C.free(groups)
rv := C.mygetgrouplist(nameC, groupC, (*C.gid_t)(groups), &ngroupsC)
if rv == -1 {
return false, fmt.Errorf("user: membership of %s in %s: %s", u.Username, g.Name, syscall.Errno(rv))
}
ngroups = int(ngroupsC)
for i := 0; i < ngroups; i++ {
gid := C.group_at(C.int(i), (*C.gid_t)(groups))
if g.Gid == strconv.Itoa(int(gid)) {
return true, nil
}
}
return false, nil
}
func GetGroupList(u *user.User) ([]string, error) {
var members []string
gid, err := strconv.Atoi(u.Gid)
if err != nil {
return nil, err
}
nameC := C.CString(u.Username)
defer C.free(unsafe.Pointer(nameC))
groupC := C.gid_t(gid)
ngroupsC := C.int(0)
C.mygetgrouplist(nameC, groupC, nil, &ngroupsC)
ngroups := int(ngroupsC)
groups := C.malloc(C.size_t(int(unsafe.Sizeof(groupC)) * ngroups))
defer C.free(groups)
rv := C.mygetgrouplist(nameC, groupC, (*C.gid_t)(groups), &ngroupsC)
if rv == -1 {
return nil, fmt.Errorf("user: membership of %s in %s: %s", u.Username, u.Gid, syscall.Errno(rv))
}
ngroups = int(ngroupsC)
for i := 0; i < ngroups; i++ {
gid := C.group_at(C.int(i), (*C.gid_t)(groups))
gidS := strconv.Itoa(int(gid))
group, err := LookupGroupID(gidS)
if err != nil {
return nil, err
}
members = append(members, group.Name)
}
return members, nil
}
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 := C.gid_t(ug)
nameC := C.CString(u.Username)
defer C.free(unsafe.Pointer(nameC))
n := C.int(256)
gidsC := make([]C.gid_t, n)
rv := C.mygetgrouplist(nameC, userGID, &gidsC[0], &n)
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([]C.gid_t, n)
rv := C.mygetgrouplist(nameC, userGID, &gidsC[0], &n)
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
}
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)
}