Table of Contents

Samba

Samba is a free open-source implementation of SMB that provides network file and print services for clients running Windows, Linux, and macOS. The version included in the OpenWrt feeds is samba4.

Prerequisites

To share a connected USB or eSATA drive (HDD, SSD, Flash) on your network you will first need to install USB drivers and the file system. Below are common examples:

USB: kmod-usb3 kmod-usb-storage-uas usbutils block-mount mount-utils luci-app-hd-idle

Filesystems: kmod-fs-ext4 kmod-fs-exfat kmod-fs-ntfs3

You only need to install the filesystem your drive is formattted to. For NTFS setup see writable_ntfs. There are many more available, in LuCI filter System → Software for “kmod-fs” if your using one not listed above.

Installation

1. Install luci-app-samba4. Any dependencies, such as samba4-server, are installed automatically.

2. Configure Samba in LuCI on the Services → Network Shares page. It is recommended that you use LuCI for the initial configuration and only edit /etc/samba/smb.conf.template if needed via LuCI Edit Template tab, or from the shell. Basic LuCI configuration example is provided below:

3. Basic installation is complete. You can now read/write network shares on your LAN. For example, access a share named 'storage' hosted on your router default IP using Windows File Explorer with: \\192.168.1.1\storage\.

4. For automatic network discovery on Windows: opkg install wsdd2. Note this may need separate configuration.

Windows, Linux, and macOS include SMB support in their file browsers. Android (like OpenWrt is also Linux-based) can browse shares with apps like X-plore, or for media playback with VLC or Kodi. If your OS is missing support, simply install an app.

Advanced usage

The basic configuration from the LuCI page described above should work well for most users. For further configuration keep reading and see samba.

After modifying any of the config files, restart the Samba server so that your changes take effect:

service samba4 restart

When Samba is restarted this way, the file /etc/samba/smb.conf is (re)created from to the uci configuration file and /etc/samba/smb.conf.template.

Per user security

  1. Create Samba user(s) by first manually adding entries to /etc/passwd and /etc/group
  2. Use smbpasswd -a username to create and assign a password for samba for that user (note that command write them to /etc/samba/smbpasswd)

:!: Select a value for the uid/gid that is >=1000 to avoid possible collisions with system reserved values of <1000.

Example entry for /etc/passwd:

foo:x:1001:1001:smb user:/dev/null:/bin/false

Example entry for /etc/group:

foo:x:1001:foo

Set up shared directories permissions according to your needs using chown and chmod. Any unknown usernames used for authentication against Samba are mapped to a guest login silently by default.

Custom configuration surpassing the UCI configuration

SMB is the built-in way to share network resources between computers running Windows, even in a professional environment. Thus Samba can be very complicated to configure, especially if using Active Directory! It is also not the protocol of choice to accomplish this task in a Linux or Mac environment. So, if for whatever reasons above configuration does not give you desired access to your shares, you can of course circumvent the uci system and hack the original Samba configuration files instead or in addition. There may be entries which do not have a counterpart in UCI and thus can only be configured that way. Just bear in mind, that the uci config will overwrite the values configured with it (but not the whole configuration) at every boot up! If you want configure Samba directly with /etc/samba/smb.conf instead of /etc/config/samba, it is possible to make changes to the smb.conf survive a reboot using the procedure below.

First, prevent OpenWrt from starting Samba at boot time, thus overwriting /etc/samba/smb.conf with the settings in the uci file /etc/config/samba:

service samba4 disable

Then add the following lines to /etc/rc.local to allow smbd and nmbd to start at boot time, using /etc/samba/smb.conf as the configuration file

smbd -D
nmbd -D

Now edit your /etc/samba/smb.conf all you like without worrying they will be lost the next time you reboot!

Configuration as an Apple Time Machine Disk

The LuCI interface can be used to easily setup a share intended to be used as an Apple Time Machine Disk.

Troubleshooting

  1. If luci-app-samba4 is not working or can't be found in LuCI → execute “rm /tmp/luci-indexcache” or restart router.
  2. Is the partition you want to share mounted correctly? In LuCI check System → Mount Points or /etc/config/fstab.
  3. Does Samba have read/write access to the partition?
  4. Is Samba running? ps aux should show smbd -D and nmbd -D up and running.
  5. Is your Samba configuration right?
  6. Does your firewall allow clients to access the service on your router?

Check access to shares

Some hints in advance:

Instead of looking up the whole configuration step by step, you maybe want to have a look at Samba.org: Example Network Configurations. Chapter 1: No-Frills Samba Servers. Notice that you can already achieve a great deal of security by neatly setting up the Firewall Documentation.

Start on boot

After installing the packages described in Installation, Samba will start on boot. This can be confirmed in the LuCI System → Startup page. If there is an issue, follow the same procedure as with most OpenWrt packages: The first command will create a symlink /etc/rc.d/S60samba, the second will only start samba right now.

service samba4 enable
service samba4 start

Browsing shares fails

When Samba is configured, the shares are set browse-able, but they still don't appear when browsing the network, then it may be that local master = yes is missing from /etc/samba/smb.conf.template. Also check if preferred master = yes is in /etc/samba/smb.conf.template.

Cannot write to a Samba share

If you cannot write to the share, Samba may not have the proper permissions to write to the shared folder.

Some have reported success by modifying the permissions and owner of the folder:

chmod -R 777 /mnt/sda1
chown -R nobody /mnt/sda1

If you are sharing a drive mounted wish fstab, you may need to modify /etc/config/fstab to include 'umask=000' in the options section.

config 'mount'
        option 'options' 'rw,umask=000'
        option 'enabled_fsck' '0'
        option 'enabled' '1'
        option 'device' '/dev/scsi/host0/bus0/target0/lun0/part1'
        option 'target' '/mnt/usbdisk'
        option 'fstype' 'vfat'

More info here: https://forum.openwrt.org/viewtopic.php?id=26625

International characters support

If you need to read/write files and folders with accented characters.

sed -i -e "/unix charset/s/ISO-8859-1/UTF-8/" /etc/samba/smb.conf.template

Throughput

Since netfilter tracks every connection, it may improve throughput to disable conntrack for Samba connections if you use NAT.

uci -q delete firewall.samba_nsds_nt
uci set firewall.samba_nsds_nt="rule"
uci set firewall.samba_nsds_nt.name="NoTrack-Samba/NS/DS"
uci set firewall.samba_nsds_nt.src="lan"
uci set firewall.samba_nsds_nt.dest="lan"
uci set firewall.samba_nsds_nt.dest_port="137-138"
uci set firewall.samba_nsds_nt.proto="udp"
uci set firewall.samba_nsds_nt.target="NOTRACK"
uci -q delete firewall.samba_ss_nt
uci set firewall.samba_ss_nt="rule"
uci set firewall.samba_ss_nt.name="NoTrack-Samba/SS"
uci set firewall.samba_ss_nt.src="lan"
uci set firewall.samba_ss_nt.dest="lan"
uci set firewall.samba_ss_nt.dest_port="139"
uci set firewall.samba_ss_nt.proto="tcp"
uci set firewall.samba_ss_nt.target="NOTRACK"
uci -q delete firewall.samba_smb_nt
uci set firewall.samba_smb_nt="rule"
uci set firewall.samba_smb_nt.name="NoTrack-Samba/SMB"
uci set firewall.samba_smb_nt.src="lan"
uci set firewall.samba_smb_nt.dest="lan"
uci set firewall.samba_smb_nt.dest_port="445"
uci set firewall.samba_smb_nt.proto="tcp"
uci set firewall.samba_smb_nt.target="NOTRACK"
uci commit firewall
service firewall restart

Remote Access

For remote access configure your firewall as per below. See port explanation. Use caution here, as you may eventually expose your network to security concerns. Samba and many other packages are not always updated to the latest CVEs between releases. This is not needed for LAN access to your shares, file sharing such as SMB and NAS are typically best used for LAN access for this reason.

uci -q delete firewall.samba_nsds
uci set firewall.samba_nsds="rule"
uci set firewall.samba_nsds.name="Allow-Samba/NS/DS"
uci set firewall.samba_nsds.src="lan"
uci set firewall.samba_nsds.dest_port="137-138"
uci set firewall.samba_nsds.proto="udp"
uci set firewall.samba_nsds.target="ACCEPT"
uci -q delete firewall.samba_ss
uci set firewall.samba_ss="rule"
uci set firewall.samba_ss.name="Allow-Samba/SS"
uci set firewall.samba_ss.src="lan"
uci set firewall.samba_ss.dest_port="139"
uci set firewall.samba_ss.proto="tcp"
uci set firewall.samba_ss.target="ACCEPT"
uci -q delete firewall.samba_smb
uci set firewall.samba_smb="rule"
uci set firewall.samba_smb.name="Allow-Samba/SMB"
uci set firewall.samba_smb.src="lan"
uci set firewall.samba_smb.dest_port="445"
uci set firewall.samba_smb.proto="tcp"
uci set firewall.samba_smb.target="ACCEPT"
uci commit firewall
service firewall restart

Network discovery with Apple

Apple Spotlight connections was resolved in 2023 versions of Samba4. Some older versions of macOS (e.g. Yosemite) have problems discovering SMB network shares broadcasted by each client over the LAN, you can set up a WINS server on your router which will help them out.

A WINS server is a central name server analogous to DNS but for a local network. This service will discover SMB shares then make them available over WINS. Macs will connect to WINS to receive the list of network shares, hopefully with more success than discovering network shares themselves.

We will edit the UCI template (/etc/samba/smb.conf.template) instead of directly changing /etc/samba/smb.conf so as to maintain compatibility with UCI and LuCI.

Log into LuCI, go to Services > Network Shares, go to the Edit Template tab, and add or change the following entries in the “[global]” section in the template.

[global]
	domain master = yes
	local master = yes
	name resolve order = wins lmhosts hosts bcast
	os level = 99
	preferred master = yes
	wins support = yes

Save & Apply the changes.

You can also configure dnsmasq to broadcast the WINS server address via DHCP:

uci add_list dhcp.lan.dhcp_option="44,$(uci get network.lan.ipaddr)"
uci commit dhcp
service dnsmasq restart

SMB network shares should appear in Network home a few minutes after rebooting the Mac.

Network discovery with Windows

Install wsdd2:

opkg update
opkg install wsdd2

Notes

  1. Devices with minimum 128MB RAM is recommended. Devices with less RAM will have memory issues, adding 128-256MB swap might help.
  2. Samba main website
  3. Ksmbd is a kernel server alternative for SMBv3 protocol
  4. usb-drives-quickstart USB quickstart guide