If an exception occurs in hostwatch, sshuttle exits. Problems
read/writing the ~/.sshuttle.hosts cache file on the remote machine
would therefore cause sshuttle to exit. With this patch, we simply
continue running without writing/reading the cache file in the remote
home directory. This serves as an alternate fix for
pull request #322 which proposed storing the cache file elsewhere.
A list of included changes:
- If we can't read or write the host cache file on the server,
continue running. Hosts can be collected through the netstat,
/etc/hosts, etc and the information can be reconstructed each run if
a cache file isn't available to read. We write a log() message when
this occurs.
- Add additional types of exceptions to handle.
- Continue even if we cannot read /etc/hosts on the server.
- Update man page to mention the cache file on the remote host.
- Indicate that messages are related to remote host instead of local
host.
- Add comments and descriptions to the code.
The output in the examples provided in the man page hadn't been
updated as sshuttle changed its output over time.
The example of testing sshuttle without a remote host was removed. It
was the first example previously and it is something that is unlikely
users will wish to do.
Also:
- Update some --help messages.
- Manpage: Fix a typo.
- Manpage: Mention that host specified with -r can be an ssh alias.
- Eliminate variable only used once.
11 years ago in commit 384d0e7c1d,
hostwatch was updated to use netstat to find hosts, and
_check_smb()/_check_nmb() were edited to immediately return. This
patch removes all of the unused code in these two functions.
Even when --tmark was used, the iptables code always used '1' for the
mark. This patch corrects the problem.
Previously, it wasn't clear if the tmark should be supplied in
hexadecimal or as an integer. This makes it use hexadecimal, checks
that the input is hexadecimal, and updates the associated
documentation.
This patch also makes --ttl information get passed to the firewall in
a way that matches how other information gets passed. The ttl and
tmark information are passed next to each other in many places and
this patch also makes the order consistent.
If the user specifies --to-ns (tells the remote server which DNS
server to use for lookups coming from sshuttle), then either --ns-host
or --dns need to also be used (route DNS requests through sshuttle).
A previous commit incorrectly made it so --to-ns and --ns-host
couldn't be successfully used together.
Attempts to fix#641.
Issue #631 suggests that we should warn about users who add sshuttle
to sudoers because it isn't obvious that when a user can run sshuttle
as root, they can run any command as root using sshuttle's -e or
--ssh-cmd parameters.
This patch adds a comment that warns about this problem to the sudoers
file. It also prints the warning to the console if the user uses an
option that writes the data directly to the file. This patch also
causes the output of the sudoers-add command to be printed to the
console so that the user can see the name of the file that was
created.
There is room for improvement: Warnings could be added to the
documentation and/or these parameters could be removed entirely.
It is possible for DNS requests to go through systemd's DNS resolution
system (which includes a cache) before sshuttle has an opportunity to
intercept the requests. The DNS entries in the cache may become
outdated when sshuttle starts or exits. This patch fixes the problem
by flushing the cache when sshuttle firewall starts and exits.
