linux中ACL权限

1.ACL权限简介与开启

一.ACL权限是为了解决所有者/所属组/其他人三种身份不足的问题

二.查看分区ACL权限是否开启

dumpe2fs命令是查询指定分区详细文件系统信息的命令

dumpe2fs -h /dev/sda3

-h 仅显示超级块中信息,而不显示磁盘块组的详细信息

[root@izm5e2q95pbpe1hh0kkwoiz ~]# df -h
Filesystem      Size  Used Avail Use% Mounted on
/dev/vda1        40G   14G   25G  36% /
devtmpfs        911M     0  911M   0% /dev
tmpfs           920M     0  920M   0% /dev/shm
tmpfs           920M  548K  920M   1% /run
tmpfs           920M     0  920M   0% /sys/fs/cgroup
tmpfs           184M     0  184M   0% /run/user/0
tmpfs           184M     0  184M   0% /run/user/1002
[root@izm5e2q95pbpe1hh0kkwoiz ~]# dumpe2fs -h /dev/vda1
dumpe2fs 1.42.9 (28-Dec-2013)
Filesystem volume name:   <none>
Last mounted on:          /
Filesystem UUID:          eb448abb-3012-4d8d-bcde-94434d586a31
Filesystem magic number:  0xEF53
Filesystem revision #:    1 (dynamic)
Filesystem features:      has_journal ext_attr resize_inode dir_index filetype needs_recovery extent flex_bg sparse_super large_file huge_file uninit_bg dir_nlink extra_isize
Filesystem flags:         signed_directory_hash 
Default mount options:    user_xattr acl
Filesystem state:         clean
Errors behavior:          Continue
Filesystem OS type:       Linux
Inode count:              2621440
Block count:              10485248
Reserved block count:     524262
Free blocks:              8958387
Free inodes:              2519237
First block:              0
Block size:               4096
Fragment size:            4096
Reserved GDT blocks:      1021
Blocks per group:         32768
Fragments per group:      32768
Inodes per group:         8192
Inode blocks per group:   512
RAID stride:              32639
Flex block group size:    16
Filesystem created:       Sun Oct 15 23:18:59 2017
Last mount time:          Tue Aug 14 10:15:43 2018
Last write time:          Tue Aug 14 18:15:42 2018
Mount count:              6
Maximum mount count:      -1
Last checked:             Wed Jun 27 22:35:57 2018
Check interval:           0 (<none>)
Lifetime writes:          30 GB
Reserved blocks uid:      0 (user root)
Reserved blocks gid:      0 (group root)
First inode:              11
Inode size:               256
Required extra isize:     28
Desired extra isize:      28
Journal inode:            8
First orphan inode:       1050280
Default directory hash:   half_md4
Directory Hash Seed:      2579899c-6862-4625-a8e6-425550384200
Journal backup:           inode blocks
Journal features:         journal_incompat_revoke
Journal size:             128M
Journal length:           32768
Journal sequence:         0x006beeea
Journal start:            22131

Default mount options: user_xattr acl显示支持acl

三.临时开启分区ACL权限

重新挂载根分区,并挂载加入acl权限

mount -o remount,acl /

四.永久开启分区ACL权限(一定要谨慎)

# 加入acl
vim /etc/fstab
UUID=eb448abb-3012-4d8d-bcde-94434d586a31 /                       ext4    defaults        1 1
修改为
UUID=eb448abb-3012-4d8d-bcde-94434d586a31 /                       ext4    defaults,acl        1 1

# 重新挂载文件系统或重新启动系统,使修改生效
mount -o remount /

2.查看和设定ACL权限

一.查看ACL命令

查看acl权限

getfacle 文件名

二.设定ACL权限的命令

setfacl 选项 文件名

选项	作用
-m	设定ACL权限
-x	删除指定的ACL权限
-b	删除所有的ACL全新啊
-d	设定默认ACL权限
-k	删除默认ACL权限
-R	递归设定ACL权限

三.给用户设定ACL权限和给组设定ACL权限

# 进入tmp目录
[root@izm5e2q95pbpe1hh0kkwoiz /]# cd /tmp

# 创建project目录
[root@izm5e2q95pbpe1hh0kkwoiz tmp]# mkdir project

# 查看是否创建
[root@izm5e2q95pbpe1hh0kkwoiz tmp]# ls
Aegis-<Guid(5A2C30A2-A87D-490A-9281-6765EDAD7CBA)>  eternityz  hsperfdata_root  issue.soft  Japan  mysql.sock  php-cgi.sock  project  systemd-private-9255c5ee9ec84f5987c1d9ba485e177e-ntpd.service-eKcnmD  test.txt

# 添加用户zhangsan
[root@izm5e2q95pbpe1hh0kkwoiz tmp]# useradd zhangsan

# 添加用户lisi
[root@izm5e2q95pbpe1hh0kkwoiz tmp]# useradd lisi

# 添加组tgroup
[root@izm5e2q95pbpe1hh0kkwoiz tmp]# groupadd tgroup

# 将zhangsan添加到组tgroup中
[root@izm5e2q95pbpe1hh0kkwoiz tmp]# gpasswd -a zhangsan tgroup
Adding user zhangsan to group tgroup

# 将lisi添加到组tgroup中
[root@izm5e2q95pbpe1hh0kkwoiz tmp]# gpasswd -a lisi tgroup
Adding user lisi to group tgroup

# 查看组内的用户(最后一行)
[root@izm5e2q95pbpe1hh0kkwoiz tmp]# cat /etc/group
root:x:0:eternity
bin:x:1:
daemon:x:2:
sys:x:3:
adm:x:4:
tty:x:5:
disk:x:6:
lp:x:7:
mem:x:8:
kmem:x:9:
wheel:x:10:
cdrom:x:11:
mail:x:12:postfix
man:x:15:
dialout:x:18:
floppy:x:19:
games:x:20:
tape:x:30:
video:x:39:
ftp:x:50:
lock:x:54:
audio:x:63:
nobody:x:99:
users:x:100:
utmp:x:22:
utempter:x:35:
ssh_keys:x:999:
input:x:998:
systemd-journal:x:190:
systemd-network:x:192:
dbus:x:81:
polkitd:x:997:
postdrop:x:90:
postfix:x:89:
chrony:x:996:
sshd:x:74:
ntp:x:38:
tcpdump:x:72:
nscd:x:28:
screen:x:84:
mysql:x:1000:
www:x:1001:
rabbitmq:x:995:
eternity:x:1002:
eternityz:x:1003:
slocate:x:21:
saslauth:x:76:
mailnull:x:47:
smmsp:x:51:
zhangsan:x:1004:
lisi:x:1005:
tgroup:x:1006:zhangsan,lisi

# 将project目录的所属组更改为tgroup
[root@izm5e2q95pbpe1hh0kkwoiz tmp]# chown root:tgroup project

# 将project目录的权限更改为770
[root@izm5e2q95pbpe1hh0kkwoiz tmp]# chmod 770 project

# 查看更改权限的project目录
[root@izm5e2q95pbpe1hh0kkwoiz tmp]# ll -d project
drwxrwx--- 2 root tgroup 4096 Dec 10 17:00 project

# 增加试听学员st
[root@izm5e2q95pbpe1hh0kkwoiz tmp]# useradd st

# 修改试听学员st的密码
[root@izm5e2q95pbpe1hh0kkwoiz tmp]# passwd st
Changing password for user st.
New password: 
BAD PASSWORD: The password is shorter than 8 characters
Retype new password: 
passwd: all authentication tokens updated successfully.

# 给试听学员st设定ACL权限rx
[root@izm5e2q95pbpe1hh0kkwoiz tmp]# setfacl -m u:st:rx project

# 查看ACL权限
[root@izm5e2q95pbpe1hh0kkwoiz tmp]# getfacl project
# file: project
# owner: root
# group: tgroup
user::rwx
user:st:r-x  #st用户拥有rx权限
group::rwx
mask::rwx
other::---

# 切换到st用户
[root@izm5e2q95pbpe1hh0kkwoiz tmp]# su - st

# 进入/tmp/project目录
[st@izm5e2q95pbpe1hh0kkwoiz ~]$ cd /tmp/project

# 创建文件test.txt,提示没有权限
[st@izm5e2q95pbpe1hh0kkwoiz project]$ touch test.txt
touch: cannot touch ‘test.txt’: Permission denied

# 退出st用户
[st@izm5e2q95pbpe1hh0kkwoiz project]$ exit
logout

# 增加组tgroup2
[root@izm5e2q95pbpe1hh0kkwoiz tmp]# groupadd tgroup2

# 给组tgroup2设定ACL权限rwx
[root@izm5e2q95pbpe1hh0kkwoiz tmp]# setfacl -m g:tgroup2:rwx project

# 查看ACL权限
[root@izm5e2q95pbpe1hh0kkwoiz tmp]# getfacl project
# file: project
# owner: root
# group: tgroup
user::rwx
user:st:r-x # 用户st拥有ACL权限rx
group::rwx
group:tgroup2:rwx # 组tgroup2拥有ACL权限rwx
mask::rwx
other::---

有ACL权限和没ACL权限的文件夹

# 没有ACL权限的后面没有+号
[root@izm5e2q95pbpe1hh0kkwoiz tmp]# ll -d project
drwxrwx--- 2 root tgroup 4096 Dec 10 17:00 project

[root@izm5e2q95pbpe1hh0kkwoiz tmp]# setfacl -m u:st:rx project

# 有ACL权限的后面带着+号
[root@izm5e2q95pbpe1hh0kkwoiz tmp]# ll -d project
drwxrwx---+ 2 root tgroup 4096 Dec 10 17:00 project

3.最大有效权限和删除ACL权限

一.最大有效权限mask

[root@izm5e2q95pbpe1hh0kkwoiz tmp]# getfacl project
# file: project
# owner: root
# group: tgroup
user::rwx
user:st:r-x
group::rwx
group:st:rwx
group:tgroup2:rwx
mask::rwx
other::---

mask是用来指定最大有效权限的.如果我给用户赋予了ACL权限,是需要和mask的权限"相与"才能得到用户的真正权限

A	B	and
r	r	r
r	-	-
-	r	-
-	-	-

修改mask的值

setfacl -m m:rx project

# 更改mask的值
[root@izm5e2q95pbpe1hh0kkwoiz tmp]# setfacl -m m:rx project

# 查询ACL权限
[root@izm5e2q95pbpe1hh0kkwoiz tmp]# getfacl project
# file: project
# owner: root
# group: tgroup
user::rwx
user:st:r-x
group::rwx                      #effective:r-x
group:st:rwx                    #effective:r-x
group:tgroup2:rwx               #effective:r-x
mask::r-x
other::---

    mask的值只影响具有ACL权限的,不影响用户的权限
    用户st的权限为rx
    组st的ACL权限是rwx,但是实际生效的只是rx权限
    组tgroup2的ACL权限是rwx,但是实际生效的是rx权限

二.删除ACL权限

删除指定用户的ACL权限

setfacl -x u:用户名 文件/文件夹

删除指定用户组的ACL权限

setfacl -x g:组名 文件/文件夹

# 之前的有组tgroup2的ACL权限
[root@izm5e2q95pbpe1hh0kkwoiz tmp]# getfacl project
# file: project
# owner: root
# group: tgroup
user::rwx
user:st:r-x
group::rwx                      #effective:r-x
group:st:rwx                    #effective:r-x
group:tgroup2:rwx               #effective:r-x
mask::r-x
other::---

# 移除组tgroup2的ACL权限
[root@izm5e2q95pbpe1hh0kkwoiz tmp]# setfacl -x g:tgroup2 project

# 再次查询,tgroup2的ACL权限没有了
[root@izm5e2q95pbpe1hh0kkwoiz tmp]# getfacl project
# file: project
# owner: root
# group: tgroup
user::rwx
user:st:r-x
group::rwx
group:st:rwx
mask::rwx
other::---

删除文件或文件假的所有的ACL权限

sefacl -b 文件/文件夹

# 之前project目录的ACL权限
[root@izm5e2q95pbpe1hh0kkwoiz tmp]# getfacl project
# file: project
# owner: root
# group: tgroup
user::rwx
user:st:r-x
group::rwx
group:st:rwx
mask::rwx
other::---

# 移除所有的ACL权限
[root@izm5e2q95pbpe1hh0kkwoiz tmp]# setfacl -b project

# 再次查询,ACL权限和mask都没有了
[root@izm5e2q95pbpe1hh0kkwoiz tmp]# getfacl project
# file: project
# owner: root
# group: tgroup
user::rwx
group::rwx
other::---

4.默认ACL权限和递归ACL权限

一.递归ACL权限

递归是父目录在设定ACL权限时,所有的子文件和子目录也会拥有相同的ACL权限

setfacl -m u:用户名:权限 -R 文件夹

# -R必须在后面,否则报错

# 给文件夹及下面的所有文件及文件夹设置ACL权限,运行此命令后,新建的文件不具备ACL权限

二.默认ACL权限

默认ACL权限的作用是如果给父目录设定了默认ACL权限,那么父目录中所有新建的子文件都会继承父目录的ACL权限

setfacl -m d:u:用户名:权限 文件夹

# 运行上面的命令之后,以后此文件夹下新建文件或文件夹都具备ACL权限