Short answer: you can't. Ports below 1024 can be opened only by root. As per comment - well, you can, using CAP_NET_BIND_SERVICE, but that approach, applied to java bin will make any java program to be run with this setting, which is undesirable, if not a security risk.
The long answer: you can redirect connections on port 80 to some other port you can open as normal user.
Run as root:
# iptables -t nat -A PREROUTING -p tcp --dport 80 -j REDIRECT --to-port 8080
As loopback devices (like localhost) do not use the prerouting rules, if you need to use localhost, etc., add this rule as well (thanks @Francesco):
# iptables -t nat -I OUTPUT -p tcp -d 127.0.0.1 --dport 80 -j REDIRECT --to-ports 8080
NOTE: The above solution is not well suited for multi-user systems, as any user can open port 8080 (or any other high port you decide to use), thus intercepting the traffic. (Credits to CesarB).
EDIT: as per comment question - to delete the above rule:
# iptables -t nat --line-numbers -n -L
This will output something like:
Chain PREROUTING (policy ACCEPT)
num target prot opt source destination
1 REDIRECT tcp -- 0.0.0.0/0 0.0.0.0/0 tcp dpt:8080 redir ports 8088
2 REDIRECT tcp -- 0.0.0.0/0 0.0.0.0/0 tcp dpt:80 redir ports 8080
The rule you are interested in is nr. 2, so to delete it:
# iptables -t nat -D PREROUTING 2
There are two common ways of dealing with a mixture of local and centralized accounts (be it LDAP or NIS or whatever). Your third update covers one of them.
- Local accounts use a non-
/home base directory for homes
- LDAP/central use a non-
/home base directory for homes
I commonly use option #1 and create /local then setup my local accounts to have home directories there such as /local/admin, /local/sysadmin, /local/joe, etc. I then use autofs to control mounting of centralized/remote home directories under /home much in the same way you're describing in "Update 3".
I presume your server is exporting home directories with NFS? If manually mounting the NFS export on the client works as expected but autofs does not, your problem is almost certainly your autofs configuration.
For assistance with your autofs problem, please post the contents of /etc/nsswitch.conf, /etc/(open)ldap/ldap.conf, /etc/ldap.conf and /etc/auto.master and /etc/auto.home (or whatever/wherever the relevant autofs configurations are).
Best Answer
I don't know if you mean the CIFS FS will be served from linux or just mounted under linux on the clients.
However many non linux cifs implementations do not support stuff like symlinks and unix sockets so most window managers will die with a non linux cifs home dir.
Auth is no problem you can just use winbindd and you can as you say use pam_mount to actually mount the dirs on loging.
We have 6 labs of about 250 linux/windows dual boots. Their home dirs are mounted from a linux cifs share using AD logon scripts for windows and pam_mount and winbind under linux.