ຄູ່ມືຂັ້ນຕອນໂດຍຂັ້ນຕອນເພື່ອຕັ້ງຄ່າ BIND DNS server ໃນສະພາບແວດລ້ອມ chroot ສໍາລັບ Red Hat (RHEL/CentOS) 7

ການ​ແປ​ບົດ​ຄວາມ​ທີ່​ໄດ້​ກະ​ກຽມ​ສໍາ​ລັບ​ນັກ​ຮຽນ​ຫຼັກ​ສູດ​ "ຄວາມປອດໄພ Linux". ມີຄວາມສົນໃຈໃນການພັດທະນາໃນທິດທາງນີ້? ເບິ່ງການບັນທຶກການອອກອາກາດຂອງຊັ້ນຕົ້ນສະບັບຂອງ Ivan Piskunov "ຄວາມປອດໄພໃນ Linux ທຽບກັບ Windows ແລະ MacOS"

ໃນບົດຄວາມນີ້, ຂ້າພະເຈົ້າຈະແນະນໍາທ່ານຜ່ານຂັ້ນຕອນການຕັ້ງຄ່າ DNS server ໃນ RHEL 7 ຫຼື CentOS 7. ຂ້ອຍໃຊ້ Red Hat Enterprise Linux 7.4 ສໍາລັບການສາທິດ. ເປົ້າຫມາຍຂອງພວກເຮົາແມ່ນເພື່ອສ້າງຫນຶ່ງບັນທຶກ A ແລະຫນຶ່ງບັນທຶກ PTR ສໍາລັບເຂດການຊອກຫາທາງຫນ້າແລະທາງຂວາງ, ຕາມລໍາດັບ.

ທໍາອິດ, ຕິດຕັ້ງຊຸດ rpm ທີ່ຈໍາເປັນສໍາລັບເຄື່ອງແມ່ຂ່າຍ DNS.

ຫມາຍເຫດ: ສໍາລັບ RHEL ທ່ານຕ້ອງມີ ການສະໝັກໃຊ້ RHN ທີ່ໃຊ້ຢູ່, ຫຼືທ່ານສາມາດ ຕັ້ງຄ່າບ່ອນເກັບມ້ຽນອອບໄລນ໌ໃນທ້ອງຖິ່ນ, ທີ່ຜູ້ຈັດການຊຸດ "yum" ສາມາດຕິດຕັ້ງແພັກເກັດ rpm ແລະຄວາມເພິ່ງພາອາໄສທີ່ຈໍາເປັນ.

# yum install bind bind-chroot caching-nameserver

ການຕັ້ງຄ່າຂອງຂ້ອຍ:

# hostname
golinuxhub-client.example
Мой IP-адрес 192.168.1.7
# ip address | egrep 'inet.*enp0s3'
    inet 192.168.1.7/24 brd 192.168.1.255 scope global dynamic enp0s3

ເນື່ອງຈາກພວກເຮົາຈະໃຊ້ chroot, ພວກເຮົາຈໍາເປັນຕ້ອງປິດການບໍລິການ.

# systemctl stop named
# systemctl disable named

ຫຼັງຈາກນັ້ນ, ຄັດລອກໄຟລ໌ທີ່ຕ້ອງການເຂົ້າໄປໃນ chroot directory.
ຫມາຍ​ເຫດ​. ໃຊ້ການໂຕ້ຖຽງ -p ໃນ​ທີມ​ງານ​ cp ເພື່ອຮັກສາສິດ ແລະເຈົ້າຂອງ.

[root@golinuxhub-client ~]# cp -rpvf /usr/share/doc/bind-9.9.4/sample/etc/*  /var/named/chroot/etc/
‘/usr/share/doc/bind-9.9.4/sample/etc/named.conf’ -> ‘/var/named/chroot/etc/named.conf’
‘/usr/share/doc/bind-9.9.4/sample/etc/named.rfc1912.zones’ -> ‘/var/named/chroot/etc/named.rfc1912.zones’

ຫຼັງຈາກນັ້ນ, ຄັດລອກໄຟລ໌ທີ່ກ່ຽວຂ້ອງກັບເຂດດັ່ງກ່າວໄປຫາສະຖານທີ່ໃຫມ່.

[root@golinuxhub-client ~]# cp -rpvf /usr/share/doc/bind-9.9.4/sample/var/named/* /var/named/chroot/var/named/
‘/usr/share/doc/bind-9.9.4/sample/var/named/data’ -> ‘/var/named/chroot/var/named/data’
‘/usr/share/doc/bind-9.9.4/sample/var/named/my.external.zone.db’ -> ‘/var/named/chroot/var/named/my.external.zone.db’
‘/usr/share/doc/bind-9.9.4/sample/var/named/my.internal.zone.db’ -> ‘/var/named/chroot/var/named/my.internal.zone.db’
‘/usr/share/doc/bind-9.9.4/sample/var/named/named.ca’ -> ‘/var/named/chroot/var/named/named.ca’
‘/usr/share/doc/bind-9.9.4/sample/var/named/named.empty’ -> ‘/var/named/chroot/var/named/named.empty’
‘/usr/share/doc/bind-9.9.4/sample/var/named/named.localhost’ -> ‘/var/named/chroot/var/named/named.localhost’
‘/usr/share/doc/bind-9.9.4/sample/var/named/named.loopback’ -> ‘/var/named/chroot/var/named/named.loopback’
‘/usr/share/doc/bind-9.9.4/sample/var/named/slaves’ -> ‘/var/named/chroot/var/named/slaves’
‘/usr/share/doc/bind-9.9.4/sample/var/named/slaves/my.ddns.internal.zone.db’ -> ‘/var/named/chroot/var/named/slaves/my.ddns.internal.zone.db’
‘/usr/share/doc/bind-9.9.4/sample/var/named/slaves/my.slave.internal.zone.db’ -> ‘/var/named/chroot/var/named/slaves/my.slave.internal.zone.db’
```bash
Теперь давайте посмотрим на основной файл конфигурации.
```bash
# cd /var/named/chroot/etc/

ລຶບເນື້ອຫາຂອງ name.conf ແລະວາງສິ່ງຕໍ່ໄປນີ້.

[root@golinuxhub-client etc]# vim named.conf
options {
        listen-on port 53 { 127.0.0.1; any; };
#       listen-on-v6 port 53 { ::1; };
        directory       "/var/named";
        dump-file       "/var/named/data/cache_dump.db";
        statistics-file "/var/named/data/named_stats.txt";
        memstatistics-file "/var/named/data/named_mem_stats.txt";
        allow-query     { localhost; any; };
        allow-query-cache { localhost; any; };
};

logging {
        channel default_debug {
                file "data/named.run";
                severity dynamic;
        };
};

view my_resolver {
        match-clients      { localhost; any; };
        recursion yes;
        include "/etc/named.rfc1912.zones";
};

ຂໍ້ມູນສະເພາະເຂດຕ້ອງຖືກເພີ່ມໃສ່ /var/named/chroot/etc/named.rfc1912.zones. ເພີ່ມລາຍການຂ້າງລຸ່ມນີ້. ໄຟລ໌ example.zone ແມ່ນໄຟລ໌ເຂດການຊອກຫາໄປຂ້າງໜ້າ, ແລະ ຕົວຢ່າງ.rzone - ໄຟລ໌ເຂດກັບຄືນ.

ຫມາຍເຫດສໍາຄັນ: ເຂດການຊອກຫາແບບກົງກັນຂ້າມປະກອບມີ 1.168.192 ເພາະວ່າທີ່ຢູ່ IP ຂອງຂ້ອຍແມ່ນ 192.168.1.7.

zone "example" IN {
        type master;
        file "example.zone";
        allow-update { none; };
};

zone "1.168.192.in-addr.arpa" IN {
        type master;
        file "example.rzone";
        allow-update { none; };
};

ໄຟລ໌ທີ່ກ່ຽວຂ້ອງກັບເຂດຕ່າງໆແມ່ນຢູ່ບ່ອນນີ້:

# cd /var/named/chroot/var/named/

ຕໍ່ໄປ, ພວກເຮົາຈະສ້າງໄຟລ໌ສໍາລັບເຂດຕໍ່ຫນ້າແລະ reverse. ຊື່ໄຟລ໌ຈະຄືກັນກັບຂ້າງເທິງໃນໄຟລ໌ ຊື່.rfc1912.zones. ພວກເຮົາມີແມ່ແບບເລີ່ມຕົ້ນຫຼາຍອັນທີ່ພວກເຮົາສາມາດນຳໃຊ້ໄດ້.

# cp -p named.localhost  example.zone
# cp -p named.loopback example.rzone

ດັ່ງທີ່ເຈົ້າສາມາດເຫັນໄດ້, ການອະນຸຍາດໃນປະຈຸບັນຢູ່ໃນທຸກໄຟລ໌ແລະໄດເລກະທໍລີເປັນຂອງ ຮາກ.

[root@golinuxhub-client named]# ll
total 32
drwxr-xr-x. 2 root root    6 May 22  2017 data
-rw-r--r--. 1 root root  168 May 22  2017 example.rzone
-rw-r--r--. 1 root root  152 May 22  2017 example.zone
-rw-r--r--. 1 root root   56 May 22  2017 my.external.zone.db
-rw-r--r--. 1 root root   56 May 22  2017 my.internal.zone.db
-rw-r--r--. 1 root root 2281 May 22  2017 named.ca
-rw-r--r--. 1 root root  152 May 22  2017 named.empty
-rw-r--r--. 1 root root  152 May 22  2017 named.localhost
-rw-r--r--. 1 root root  168 May 22  2017 named.loopback
drwxr-xr-x. 2 root root   71 Feb 12 21:02 slaves

ປ່ຽນການອະນຸຍາດຂອງທຸກໄຟລ໌ເພື່ອຊີ້ບອກຜູ້ໃຊ້ເປັນເຈົ້າຂອງ ຮາກ ແລະກຸ່ມ ຊື່ວ່າ.

# chown root:named *

ແຕ່ສໍາລັບຂໍ້ມູນເຈົ້າຂອງຈະຕ້ອງເປັນ ຊື່: ຊື່.

# chown -R  named:named data
# ls -l
total 32
drwxr-xr-x. 2 named named    6 May 22  2017 data
-rw-r--r--. 1 root  named  168 May 22  2017 example.rzone
-rw-r--r--. 1 root  named  152 May 22  2017 example.zone
-rw-r--r--. 1 root  named   56 May 22  2017 my.external.zone.db
-rw-r--r--. 1 root  named   56 May 22  2017 my.internal.zone.db
-rw-r--r--. 1 root  named 2281 May 22  2017 named.ca
-rw-r--r--. 1 root  named  152 May 22  2017 named.empty
-rw-r--r--. 1 root  named  152 May 22  2017 named.localhost
-rw-r--r--. 1 root  named  168 May 22  2017 named.loopback
drwxr-xr-x. 2 root  named   71 Feb 12 21:02 slaves

ເພີ່ມເນື້ອຫາຕໍ່ໄປນີ້ໃສ່ໄຟລ໌ເຂດສົ່ງຕໍ່ຂອງທ່ານ. ໃນທີ່ນີ້ພວກເຮົາສ້າງບັນທຶກ A ສໍາລັບ localhost (golinuxhub-client) ແລະອື່ນສໍາລັບເຄື່ອງແມ່ຂ່າຍ (golinuxhub-server).

# vim example.zone
$TTL 1D
@       IN SOA  example. root (
                                        1       ; serial
                                        3H      ; refresh
                                        15M     ; retry
                                        1W      ; expire
                                        1D )    ; minimum

                IN NS           example.

                        IN A 192.168.1.7
golinuxhub-server       IN A 192.168.1.5
golinuxhub-client       IN A 192.169.1.7

ຕໍ່ໄປ, ຕື່ມເນື້ອໃນໃສ່ໄຟລ໌ເຂດກັບຄືນ. ນີ້ພວກເຮົາສ້າງບັນທຶກ PTR ສໍາລັບ golinuxhub-client ແລະສໍາລັບ golinuxhub-server.

# vim example.rzone
$TTL 1D
@       IN SOA  example. root.example. (
                                        1997022700      ; serial
                                        28800           ; refresh
                                        14400           ; retry
                                        3600000         ; expire
                                        86400  )        ; minimum

        IN NS   example.
5       IN PTR  golinuxhub-server.example.
7       IN PTR  golinuxhub-client.example.

ກ່ອນທີ່ພວກເຮົາຈະເປີດບໍລິການ ຊື່-chroot, ໃຫ້ກວດເບິ່ງການຕັ້ງຄ່າຂອງໄຟລ໌ເຂດ.

[root@golinuxhub-client named]# named-checkzone golinuxhub-client.example example.zone
zone golinuxhub-client.example/IN: loaded serial 1
OK

[root@golinuxhub-client named]# named-checkzone golinuxhub-client.example example.rzone
zone golinuxhub-client.example/IN: loaded serial 1997022700
OK

ທຸກຢ່າງເບິ່ງດີ. ຕອນນີ້ກວດເບິ່ງໄຟລ໌ການຕັ້ງຄ່າໂດຍໃຊ້ຄໍາສັ່ງຕໍ່ໄປນີ້.

[root@golinuxhub-client named]# named-checkconf -t /var/named/chroot/ /etc/named.conf

ດັ່ງນັ້ນ, ທຸກສິ່ງທຸກຢ່າງໄດ້ສໍາເລັດສົບຜົນສໍາເລັດ.

[root@golinuxhub-client named]# echo $?
0

ຫມາຍເຫດສໍາຄັນ: ຂ້ອຍມີ SELinux ຢູ່ໃນຮູບແບບການອະນຸຍາດ

# getenforce
Permissive

ທຸກສິ່ງທຸກຢ່າງເບິ່ງດີ, ສະນັ້ນມັນເຖິງເວລາທີ່ຈະເປີດຕົວບໍລິການຂອງພວກເຮົາ ຊື່-chroot .

[root@golinuxhub-client named]# systemctl restart named-chroot

[root@golinuxhub-client named]# systemctl status named-chroot
● named-chroot.service - Berkeley Internet Name Domain (DNS)
   Loaded: loaded (/usr/lib/systemd/system/named-chroot.service; disabled; vendor preset: disabled)
   Active: active (running) since Mon 2018-02-12 21:53:23 IST; 19s ago
  Process: 5236 ExecStop=/bin/sh -c /usr/sbin/rndc stop > /dev/null 2>&1 || /bin/kill -TERM $MAINPID (code=exited, status=0/SUCCESS)
  Process: 5327 ExecStart=/usr/sbin/named -u named -c ${NAMEDCONF} -t /var/named/chroot $OPTIONS (code=exited, status=0/SUCCESS)
  Process: 5325 ExecStartPre=/bin/bash -c if [ ! "$DISABLE_ZONE_CHECKING" == "yes" ]; then /usr/sbin/named-checkconf -t /var/named/chroot -z "$NAMEDCONF"; else echo "Checking of zone files is disabled"; fi (code=exited, status=0/SUCCESS)
 Main PID: 5330 (named)
   CGroup: /system.slice/named-chroot.service
           └─5330 /usr/sbin/named -u named -c /etc/named.conf -t /var/named/chroot

Feb 12 21:53:23 golinuxhub-client.example named[5330]: managed-keys-zone/my_resolver: loaded serial 0
Feb 12 21:53:23 golinuxhub-client.example named[5330]: zone 0.in-addr.arpa/IN/my_resolver: loaded serial 0
Feb 12 21:53:23 golinuxhub-client.example named[5330]: zone 1.0.0.127.in-addr.arpa/IN/my_resolver: loaded serial 0
Feb 12 21:53:23 golinuxhub-client.example named[5330]: zone 1.168.192.in-addr.arpa/IN/my_resolver: loaded serial 1997022700
Feb 12 21:53:23 golinuxhub-client.example named[5330]: zone example/IN/my_resolver: loaded serial 1
Feb 12 21:53:23 golinuxhub-client.example named[5330]: zone localhost/IN/my_resolver: loaded serial 0
Feb 12 21:53:23 golinuxhub-client.example named[5330]: zone 1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.ip6.arpa/IN/my_resolver: loaded serial 0
Feb 12 21:53:23 golinuxhub-client.example named[5330]: zone localhost.localdomain/IN/my_resolver: loaded serial 0
Feb 12 21:53:23 golinuxhub-client.example named[5330]: all zones loaded
Feb 12 21:53:23 golinuxhub-client.example named[5330]: running
```bash
Убедитесь, что resolv.conf содержит ваш IP-адрес, чтобы он мог работать в качестве DNS-сервера.
```bash
# cat /etc/resolv.conf
search example
nameserver 192.168.1.7
```bash
Давайте проверим наш DNS-сервер для обратной зоны, используя dig.
```bash
[root@golinuxhub-client named]# dig -x 192.168.1.5

; <<>> DiG 9.9.4-RedHat-9.9.4-50.el7 <<>> -x 192.168.1.5
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 40331
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 1, ADDITIONAL: 2

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;5.1.168.192.in-addr.arpa.      IN      PTR

;; ANSWER SECTION:
5.1.168.192.in-addr.arpa. 86400 IN      PTR     golinuxhub-server.example.

;; AUTHORITY SECTION:
1.168.192.in-addr.arpa. 86400   IN      NS      example.

;; ADDITIONAL SECTION:
example.                86400   IN      A       192.168.1.7

;; Query time: 1 msec
;; SERVER: 192.168.1.7#53(192.168.1.7)
;; WHEN: Mon Feb 12 22:13:17 IST 2018
;; MSG SIZE  rcvd: 122

ດັ່ງທີ່ເຈົ້າສາມາດເຫັນໄດ້, ພວກເຮົາໄດ້ຮັບການຕອບສະຫນອງໃນທາງບວກ (ANSWER) ຕໍ່ການຮ້ອງຂໍຂອງພວກເຮົາ (QUERY).

[root@golinuxhub-client named]# dig -x 192.168.1.7

; <<>> DiG 9.9.4-RedHat-9.9.4-50.el7 <<>> -x 192.168.1.7
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 55804
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 1, ADDITIONAL: 2

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;7.1.168.192.in-addr.arpa.      IN      PTR

;; ANSWER SECTION:
7.1.168.192.in-addr.arpa. 86400 IN      PTR     golinuxhub-client.example.

;; AUTHORITY SECTION:
1.168.192.in-addr.arpa. 86400   IN      NS      example.

;; ADDITIONAL SECTION:
example.                86400   IN      A       192.168.1.7

;; Query time: 1 msec
;; SERVER: 192.168.1.7#53(192.168.1.7)
;; WHEN: Mon Feb 12 22:12:54 IST 2018
;; MSG SIZE  rcvd: 122

ພວກເຮົາສາມາດກວດເບິ່ງເຂດໂດຍກົງໃນລັກສະນະດຽວກັນ.

[root@golinuxhub-client named]# nslookup golinuxhub-client.example
Server:         192.168.1.7
Address:        192.168.1.7#53

Name:   golinuxhub-client.example
Address: 192.169.1.7

[root@golinuxhub-client named]# nslookup golinuxhub-server.example
Server:         192.168.1.7
Address:        192.168.1.7#53

Name:   golinuxhub-server.example
Address: 192.168.1.5

ບົດຄວາມນີ້ແມ່ນລ້າສະໄຫມເລັກນ້ອຍໃນ RHEL 7 ທ່ານບໍ່ຈໍາເປັນຕ້ອງຄັດລອກໄຟລ໌ການຕັ້ງຄ່າການຜູກມັດເຂົ້າໄປໃນ chroot. ການສອນແບບເທື່ອລະຂັ້ນຕອນ: ກຳນົດຄ່າ DNS Server ໂດຍໃຊ້ bind chroot (CentOS/RHEL 7).

ແຫຼ່ງຂໍ້ມູນ: www.habr.com