1.ACL權限簡介與開啟

一.ACL權限是為了解決所有者/所屬組/其他人三種身份不足的問題

二.查看磁區ACL權限是否開啟

dumpe2fs命令是查詢指定磁區詳細檔案系統資訊的命令

dumpe2fs -h /dev/sda3

-h 僅顯示超級塊中資訊,而不顯示磁盤塊組的詳細資訊

[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顯示支持acl

三.臨時開啟磁區ACL權限

重新掛載根磁區,并掛載加入acl權限

mount -o remount,acl /

四.永久開啟磁區ACL權限(一定要謹慎)

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

# 重新掛載檔案系統或重新啟動系統,使修改生效
mount -o remount /

2.查看和設定ACL權限

一.查看ACL命令

查看acl權限

getfacle 檔案名

二.設定ACL權限的命令

setfacl 選項 檔案名

三.給用戶設定ACL權限和給組設定ACL權限

# 進入tmp目錄
[root@izm5e2q95pbpe1hh0kkwoiz /]# cd /tmp

# 創建project目錄
[root@izm5e2q95pbpe1hh0kkwoiz tmp]# mkdir project

# 查看是否創建
[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

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

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

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

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

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

# 查看組內的用戶(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

# 將project目錄的所屬組更改為tgroup
[root@izm5e2q95pbpe1hh0kkwoiz tmp]# chown root:tgroup project

# 將project目錄的權限更改為770
[root@izm5e2q95pbpe1hh0kkwoiz tmp]# chmod 770 project

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

# 增加試聽學員st
[root@izm5e2q95pbpe1hh0kkwoiz tmp]# useradd st

# 修改試聽學員st的密碼
[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.

# 給試聽學員st設定ACL權限rx
[root@izm5e2q95pbpe1hh0kkwoiz tmp]# setfacl -m u:st:rx project

# 查看ACL權限
[root@izm5e2q95pbpe1hh0kkwoiz tmp]# getfacl project
# file: project
# owner: root
# group: tgroup
user::rwx
user:st:r-x  #st用戶擁有rx權限
group::rwx
mask::rwx
other::---

# 切換到st用戶
[root@izm5e2q95pbpe1hh0kkwoiz tmp]# su - st

# 進入/tmp/project目錄
[st@izm5e2q95pbpe1hh0kkwoiz ~]$ cd /tmp/project

# 創建檔案test.txt,提示沒有權限
[st@izm5e2q95pbpe1hh0kkwoiz project]$ touch test.txt
touch: cannot touch ‘test.txt’: Permission denied

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

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

# 給組tgroup2設定ACL權限rwx
[root@izm5e2q95pbpe1hh0kkwoiz tmp]# setfacl -m g:tgroup2:rwx project

# 查看ACL權限
[root@izm5e2q95pbpe1hh0kkwoiz tmp]# getfacl project
# file: project
# owner: root
# group: tgroup
user::rwx
user:st:r-x # 用戶st擁有ACL權限rx
group::rwx
group:tgroup2:rwx # 組tgroup2擁有ACL權限rwx
mask::rwx
other::---

有ACL權限和沒ACL權限的檔案夾

# 沒有ACL權限的后面沒有+號
[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權限的后面帶著+號
[root@izm5e2q95pbpe1hh0kkwoiz tmp]# ll -d project
drwxrwx---+ 2 root tgroup 4096 Dec 10 17:00 project

3.最大有效權限和洗掉ACL權限

一.最大有效權限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是用來指定最大有效權限的.如果我給用戶賦予了ACL權限,是需要和mask的權限"相與"才能得到用戶的真正權限

修改mask的值

setfacl -m m:rx project

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

# 查詢ACL權限
[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的值只影響具有ACL權限的,不影響用戶的權限
    用戶st的權限為rx
    組st的ACL權限是rwx,但是實際生效的只是rx權限
    組tgroup2的ACL權限是rwx,但是實際生效的是rx權限

二.洗掉ACL權限

洗掉指定用戶的ACL權限

setfacl -x u:用戶名 檔案/檔案夾

洗掉指定用戶組的ACL權限

setfacl -x g:組名 檔案/檔案夾

# 之前的有組tgroup2的ACL權限
[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::---

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

# 再次查詢,tgroup2的ACL權限沒有了
[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::---

洗掉檔案或檔案假的所有的ACL權限

sefacl -b 檔案/檔案夾

# 之前project目錄的ACL權限
[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權限
[root@izm5e2q95pbpe1hh0kkwoiz tmp]# setfacl -b project

# 再次查詢,ACL權限和mask都沒有了
[root@izm5e2q95pbpe1hh0kkwoiz tmp]# getfacl project
# file: project
# owner: root
# group: tgroup
user::rwx
group::rwx
other::---

4.默認ACL權限和遞回ACL權限

一.遞回ACL權限

遞回是父目錄在設定ACL權限時,所有的子檔案和子目錄也會擁有相同的ACL權限

setfacl -m u:用戶名:權限 -R 檔案夾

# -R必須在后面,否則報錯

# 給檔案夾及下面的所有檔案及檔案夾設定ACL權限,運行此命令后,新建的檔案不具備ACL權限

二.默認ACL權限

默認ACL權限的作用是如果給父目錄設定了默認ACL權限,那么父目錄中所有新建的子檔案都會繼承父目錄的ACL權限

setfacl -m d:u:用戶名:權限 檔案夾

# 運行上面的命令之后,以后此檔案夾下新建檔案或檔案夾都具備ACL權限

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