A share makes a directory accessible to SMB clients on the network. Each share is identified by a name. An SMB client sees only the share name, not the server's path to the shared directory.
Shares are commonly used to provide network access to home directories on a network file server. Each user is assigned a home directory. A share is persistent and remains defined regardless of whether users are connected to the server.
The SMB server provides a special kind of share called an autohome SMB share. An autohome share is a transient share of a user's home directory that is created when a user logs in and removed when the user logs out.
When a user browses the system, only statically defined shares and the user's autohome share will be listed.
Use the zfs set and share commands to set share properties that modify the attributes and behavior of an SMB share.
For more information about setting share properties for ZFS file system, see Sharing and Unsharing ZFS File Systems in Managing ZFS File Systems in Oracle Solaris 11.3. For information about the available options for the zfs set command, see the zfs_share(1M) man page.
There are two types of share properties: global and protocol-specific.
The global share properties include the following:
desc – Specifies an optional description of the share
path – Specifies the mount point of the share
The protocol-specific share properties for the SMB protocol include the following:
abe – Enables or disables access-based enumeration for a share
ad-container – Specifies the name of an AD container in which to publish a share
catia – Specifies whether to perform CATIA character substitution
dfsroot– Enables or disables DFS root support on a share
csc – Sets the client-side caching policy
guestok – Enables or disables guest access to a share
ro, rw, none – Sets host-based access rules for a share
The SMB server provides a per-share configuration property to support client-side caching for offline files. Although the SMB server enables you to configure this feature, only the client manages client-side caching and access to offline files. You can use the zfs command to configure this feature by setting the csc property for a share.
Valid values for the csc property are:
manual – Permits clients to cache files from the specified share for offline use as requested by users. However, automatic file-by-file reintegration is not permitted. manual is the default value.
auto – Permits clients to automatically cache files from the specified share for offline use, and permits file-by-file reintegration.
vdo – Permits clients to automatically cache files from the specified share for offline use, permits file-by-file reintegration, and permits clients to work from their local cache even while offline.
disabled – Disables client-side caching for the specified share.
For information about creating an SMB share, see How to Create an SMB Share (zfs). For more information about SMB share properties, see the share_smb(1M) man page.
The SMB server uses the following access-control mechanisms to limit access to data shared by using SMB:
Host-based access control limits access to shares based on which client system is making the request.
Share ACLs limit user and group access to shares.
File and directory ACLs limit user and group access to individual files and directories.
Host-based access control is applied first and grants or denies access to the client system. If the client system is granted access, the share ACL is then applied to grant or deny access to the user. Finally, the individual file and directory ACLs are consulted. You can access the data shared by using SMB only if all three access control mechanisms allow the access.
Shares are always created with the default share ACL and, unless otherwise specified when the share is created, default host-based access control. You can apply non-default share ACLs to the share after the share is created.
Host-based access control enables you to limit the access of a host or group of hosts to an SMB share. This host-based access control is enforced only for SMB access, not for local access or access through other protocols. By default, all hosts have full access to a share. The SMB server enforces host-based access control each time a client requests a connection to a share.
You can use the zfs set and share commands to specify host-based access control on a share. For more information, see How to Restrict Client Host Access to an SMB Share (zfs). For more information about share command, see the share(1M) man page. For more information about zfs command, see the zfs(1M) man page. For more information about SMB shares, see the share_smb(1M) man page. For information about the available options for sharing ZFS file system, see the zfs_share(1M) man page.
An ACL on a ZFS share provides the same level of access control as a Windows ACL does for its shares. Each share can have an ACL that includes entries to specify which types of access are allowed or denied to users and groups. Like host-based access control, this mechanism is a share-level form of access control and does not apply to local file access.
These share ACLs are only available for ZFS shares. You can manage a ZFS share's ACL in the Oracle Solaris OS by using the chmod and ls commands. For more information, see the chmod(1) and ls(1) man pages. You can also manage these ACLs by using the Windows share management GUI on a Windows client. For more information, see Setting ACLs on ZFS Files in Securing Files and Verifying File Integrity in Oracle Solaris 11.3.
Although a ZFS file system is used to store a share's ACL, the access control is enforced by the SMB server each time a client requests a connection to a share. Access control lists are enforced only for SMB access, not for local access or access through other protocols. The default ACL setting permits full access to everyone.
The autohome share feature eliminates the administrative task of defining and maintaining home directory shares for each user that accesses the system through the SMB protocol. The system creates autohome shares when a user logs in, and removes them when the user logs out. This process reduces the administrative effort needed to maintain user accounts, and increases the efficiency of service resources.
For example, if /home is a home directory that contains subdirectories for users bob and sally, you can manually define the shares as follows:
/home/bob
/home/sally
However, defining and maintaining directory shares in this way for each user is inconvenient. Instead, you can use the autohome feature.
To configure the autohome feature, you need to specify autohome share rules. For example, if a user's home directory is /fort/sally, the autohome path is /fort. The temporary share is named sally. Note that the user's home directory name must be the same as the user's login name. See How to Create a Specific Autohome Share Rule.
When a user logs in, the SMB server looks for a subdirectory that matches the user's name based on any rules that have been specified. If the server finds a match and if that share does not already exist, the subdirectory is added as a transient share. When the user logs out, the server removes that transient share.
Some Windows clients log a user out after 15 minutes of inactivity, which results in the autohome share disappearing from the list of defined shares. This behavior is expected for SMB autohome shares. Even after an SMB autohome share is removed, the share reappears when the user attempts to access the system (for example, in an Explorer window).
The SMB server can automatically share home directories when an SMB client connects. The autohome map file, /etc/smbautohome, uses the search options and rules to determine whether to share a home directory when an SMB client connects to the server.
For example, the following entries specify the autohome rules for a particular environment:
+nsswitch dc=ads,dc=oracle,dc=com,ou=users jane /home/?/& dc=ads,dc=oracle,dc=com,ou=users
The nsswitch autohome entry uses the naming service to match users to home directories. The second autohome entry specifies that the home directory for user jane is /home/j/jane.
A map entry uses the following format:
key location [ container ]
Specifies a user name
Specifies the fully qualified path for the user's home directory
Specifies an optional AD container
An AD container name is specified as a comma-separated list of attribute name-value pairs. The attributes use the LDAP distinguished name (DN) or relative distinguished name (RDN) format.
The DN or RDN must be specified in LDAP format by using the following prefixes:
cn= represents the common name.
ou= represents the organizational unit.
dc= represents the domain component.
cn=, ou=, and dc= are attribute types. For more information about AD container attribute names and values, see the share_smb(1M) man page.
The autohome feature supports the following wildcard substitutions for the value of the key field:
The ampersand (&) is expanded to the value of the key field for the entry in which it occurs. In the following example, & expands to jane:
jane /home/&
The question mark (?) is expanded to the value of the first character in the key field for the entry in which it occurs. In the following example, the path is expanded to /home/jj/jane:
jane /home/??/&
When supplied in the key field, the asterisk (*) is recognized as the “catch-all” entry. This type of entry matches any key not previously matched.
For example, the following entry would map any user to a home directory in /home in which the home directory name was the same as the user name:
* /home/&
The nsswitch map is used to request that the home directory be obtained from a password database, such as the local, NIS, or LDAP database. If an AD path is appended, it is used to publish shares.
+nsswitch
Like the asterisk wildcard entry, the nsswitch map is searched only if an appropriate rule is not matched by another map entry.