acl: implement Update in C
The original implementation was effectively just writing C in Go. Signed-off-by: Ophestra <cat@gensokyo.uk>
This commit is contained in:
parent
7e69893264
commit
e85be67fd9
SSH Key Fingerprint:
SHA256:gQ67O0enBZ7UdZypgtspB2FDM1g3GVw8nX0XSdcFw8Q
69
acl/acl-update.c
Normal file
69
acl/acl-update.c
Normal file
@ -0,0 +1,69 @@
|
||||
#include "acl-update.h"
|
||||
#include <stdlib.h>
|
||||
#include <stdbool.h>
|
||||
#include <sys/acl.h>
|
||||
#include <acl/libacl.h>
|
||||
|
||||
int f_acl_update_file_by_uid(const char *path_p, uid_t uid, acl_perm_t *perms, size_t plen) {
|
||||
int ret = -1;
|
||||
bool v;
|
||||
int i;
|
||||
acl_t acl;
|
||||
acl_entry_t entry;
|
||||
acl_tag_t tag_type;
|
||||
void *qualifier_p;
|
||||
acl_permset_t permset;
|
||||
|
||||
acl = acl_get_file(path_p, ACL_TYPE_ACCESS);
|
||||
if (acl == NULL)
|
||||
goto out;
|
||||
|
||||
// prune entries by uid
|
||||
for (i = acl_get_entry(acl, ACL_FIRST_ENTRY, &entry); i == 1; i = acl_get_entry(acl, ACL_NEXT_ENTRY, &entry)) {
|
||||
if (acl_get_tag_type(entry, &tag_type) != 0)
|
||||
return -1;
|
||||
if (tag_type != ACL_USER)
|
||||
continue;
|
||||
|
||||
qualifier_p = acl_get_qualifier(entry);
|
||||
if (qualifier_p == NULL)
|
||||
return -1;
|
||||
v = *(uid_t *)qualifier_p == uid;
|
||||
acl_free(qualifier_p);
|
||||
|
||||
if (!v)
|
||||
continue;
|
||||
|
||||
acl_delete_entry(acl, entry);
|
||||
}
|
||||
|
||||
if (plen == 0)
|
||||
goto set;
|
||||
|
||||
if (acl_create_entry(&acl, &entry) != 0)
|
||||
goto out;
|
||||
if (acl_get_permset(entry, &permset) != 0)
|
||||
goto out;
|
||||
for (i = 0; i < plen; i++) {
|
||||
if (acl_add_perm(permset, perms[i]) != 0)
|
||||
goto out;
|
||||
}
|
||||
if (acl_set_tag_type(entry, ACL_USER) != 0)
|
||||
goto out;
|
||||
if (acl_set_qualifier(entry, (void *)&uid) != 0)
|
||||
goto out;
|
||||
|
||||
set:
|
||||
if (acl_calc_mask(&acl) != 0)
|
||||
goto out;
|
||||
if (acl_valid(acl) != 0)
|
||||
goto out;
|
||||
if (acl_set_file(path_p, ACL_TYPE_ACCESS, acl) == 0)
|
||||
ret = 0;
|
||||
|
||||
out:
|
||||
free((void *)path_p);
|
||||
if (acl != NULL)
|
||||
acl_free((void *)acl);
|
||||
return ret;
|
||||
}
|
||||
3
acl/acl-update.h
Normal file
3
acl/acl-update.h
Normal file
@ -0,0 +1,3 @@
|
||||
#include <sys/acl.h>
|
||||
|
||||
int f_acl_update_file_by_uid(const char *path_p, uid_t uid, acl_perm_t *perms, size_t plen);
|
||||
193
acl/acl.go
193
acl/acl.go
@ -1,197 +1,36 @@
|
||||
// Package acl implements simple ACL manipulation via libacl.
|
||||
package acl
|
||||
|
||||
import (
|
||||
"errors"
|
||||
"runtime"
|
||||
"syscall"
|
||||
"unsafe"
|
||||
)
|
||||
|
||||
/*
|
||||
#cgo linux pkg-config: --static libacl
|
||||
|
||||
#include <stdlib.h>
|
||||
#include <sys/acl.h>
|
||||
#include <acl/libacl.h>
|
||||
|
||||
static acl_t _go_acl_get_file(const char *path_p, acl_type_t type) {
|
||||
acl_t acl = acl_get_file(path_p, type);
|
||||
free((void *)path_p);
|
||||
return acl;
|
||||
}
|
||||
|
||||
static int _go_acl_set_file(const char *path_p, acl_type_t type, acl_t acl) {
|
||||
if (acl_valid(acl) != 0) {
|
||||
return -1;
|
||||
}
|
||||
|
||||
int ret = acl_set_file(path_p, type, acl);
|
||||
free((void *)path_p);
|
||||
return ret;
|
||||
}
|
||||
#include "acl-update.h"
|
||||
*/
|
||||
import "C"
|
||||
|
||||
func getFile(name string, t C.acl_type_t) (*ACL, error) {
|
||||
a, err := C._go_acl_get_file(C.CString(name), t)
|
||||
if errors.Is(err, syscall.ENODATA) {
|
||||
err = nil
|
||||
}
|
||||
|
||||
return newACL(a), err
|
||||
}
|
||||
|
||||
func (acl *ACL) setFile(name string, t C.acl_type_t) error {
|
||||
_, err := C._go_acl_set_file(C.CString(name), t, acl.acl)
|
||||
return err
|
||||
}
|
||||
|
||||
func newACL(a C.acl_t) *ACL {
|
||||
acl := &ACL{a}
|
||||
runtime.SetFinalizer(acl, (*ACL).free)
|
||||
return acl
|
||||
}
|
||||
|
||||
type ACL struct {
|
||||
acl C.acl_t
|
||||
}
|
||||
|
||||
func (acl *ACL) free() {
|
||||
C.acl_free(unsafe.Pointer(acl.acl))
|
||||
|
||||
// no need for a finalizer anymore
|
||||
runtime.SetFinalizer(acl, nil)
|
||||
}
|
||||
type Perm C.acl_perm_t
|
||||
|
||||
const (
|
||||
Read = C.ACL_READ
|
||||
Write = C.ACL_WRITE
|
||||
Execute = C.ACL_EXECUTE
|
||||
|
||||
TypeDefault = C.ACL_TYPE_DEFAULT
|
||||
TypeAccess = C.ACL_TYPE_ACCESS
|
||||
|
||||
UndefinedTag = C.ACL_UNDEFINED_TAG
|
||||
UserObj = C.ACL_USER_OBJ
|
||||
User = C.ACL_USER
|
||||
GroupObj = C.ACL_GROUP_OBJ
|
||||
Group = C.ACL_GROUP
|
||||
Mask = C.ACL_MASK
|
||||
Other = C.ACL_OTHER
|
||||
Read Perm = C.ACL_READ
|
||||
Write Perm = C.ACL_WRITE
|
||||
Execute Perm = C.ACL_EXECUTE
|
||||
)
|
||||
|
||||
type (
|
||||
Perm C.acl_perm_t
|
||||
)
|
||||
|
||||
func (acl *ACL) removeEntry(tt C.acl_tag_t, tq int) error {
|
||||
var e C.acl_entry_t
|
||||
|
||||
// get first entry
|
||||
if r, err := C.acl_get_entry(acl.acl, C.ACL_FIRST_ENTRY, &e); err != nil {
|
||||
return err
|
||||
} else if r == 0 {
|
||||
// return on acl with no entries
|
||||
return nil
|
||||
}
|
||||
|
||||
for {
|
||||
if r, err := C.acl_get_entry(acl.acl, C.ACL_NEXT_ENTRY, &e); err != nil {
|
||||
return err
|
||||
} else if r == 0 {
|
||||
// return on drained acl
|
||||
return nil
|
||||
}
|
||||
|
||||
var (
|
||||
q int
|
||||
t C.acl_tag_t
|
||||
)
|
||||
|
||||
// get current entry tag type
|
||||
if _, err := C.acl_get_tag_type(e, &t); err != nil {
|
||||
return err
|
||||
}
|
||||
|
||||
// get current entry qualifier
|
||||
if rq, err := C.acl_get_qualifier(e); err != nil {
|
||||
// neither ACL_USER nor ACL_GROUP
|
||||
if errors.Is(err, syscall.EINVAL) {
|
||||
continue
|
||||
}
|
||||
|
||||
return err
|
||||
} else {
|
||||
q = *(*int)(rq)
|
||||
C.acl_free(rq)
|
||||
}
|
||||
|
||||
// delete on match
|
||||
if t == tt && q == tq {
|
||||
_, err := C.acl_delete_entry(acl.acl, e)
|
||||
return err
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// Update replaces ACL_USER entry with qualifier uid.
|
||||
func Update(name string, uid int, perms ...Perm) error {
|
||||
// read acl from file
|
||||
a, err := getFile(name, TypeAccess)
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
// free acl on return if get is successful
|
||||
defer a.free()
|
||||
|
||||
// remove existing entry
|
||||
if err = a.removeEntry(User, uid); err != nil {
|
||||
return err
|
||||
}
|
||||
|
||||
// create new entry if perms are passed
|
||||
var p *Perm
|
||||
if len(perms) > 0 {
|
||||
// create new acl entry
|
||||
var e C.acl_entry_t
|
||||
if _, err = C.acl_create_entry(&a.acl, &e); err != nil {
|
||||
return err
|
||||
}
|
||||
|
||||
// get perm set of new entry
|
||||
var p C.acl_permset_t
|
||||
if _, err = C.acl_get_permset(e, &p); err != nil {
|
||||
return err
|
||||
}
|
||||
|
||||
// add target perms
|
||||
for _, perm := range perms {
|
||||
if _, err = C.acl_add_perm(p, C.acl_perm_t(perm)); err != nil {
|
||||
return err
|
||||
}
|
||||
}
|
||||
|
||||
// set perm set to new entry
|
||||
if _, err = C.acl_set_permset(e, p); err != nil {
|
||||
return err
|
||||
}
|
||||
|
||||
// set user tag to new entry
|
||||
if _, err = C.acl_set_tag_type(e, User); err != nil {
|
||||
return err
|
||||
}
|
||||
|
||||
// set qualifier (uid) to new entry
|
||||
if _, err = C.acl_set_qualifier(e, unsafe.Pointer(&uid)); err != nil {
|
||||
return err
|
||||
}
|
||||
p = &perms[0]
|
||||
}
|
||||
|
||||
// calculate mask after update
|
||||
if _, err = C.acl_calc_mask(&a.acl); err != nil {
|
||||
return err
|
||||
r, err := C.f_acl_update_file_by_uid(
|
||||
C.CString(name),
|
||||
C.uid_t(uid),
|
||||
(*C.acl_perm_t)(p),
|
||||
C.size_t(len(perms)),
|
||||
)
|
||||
if r == 0 {
|
||||
return nil
|
||||
}
|
||||
|
||||
// write acl to file
|
||||
return a.setFile(name, TypeAccess)
|
||||
return err
|
||||
}
|
||||
|
||||
Loading…
Reference in New Issue
Block a user