The DUP System

This release adds the long-awaited support for authentication via SSH (implementing the DUP Protocol Specification v2.0). It is no longer necessary to start dupds on the target hosts. Instead, an SSH server should be run on all target hosts with password-less key-based authentication enabled for the respective user. The user should then start an ssh-agent session before invoking dup. Then dup will automatically start the dupd processes and use SSH for authentication and encryption of the control data (in particular, process names and arguments). DUP will also secure the establishment of data streams in the system. This release also adds some minor improvements and various bugfixes. Most importantly, IPv6 support was improved, making the code more robust on dual-stack machines. The build no longer includes DUP applications (such as FiDES or the microbenchmarks); these are still available in SVN and may see separate releases in the future.

In addition to fixing various bugs (see ChangeLog), this release improves the performance of most filters, especially for long lines of input, adds support for writing a PID file to dupd, increases the number of file descriptors to 65536 (overriding FD_SETSIZE), fixed various performance issues in dup to dupd communication and also adds caching of DNS lookups to dupd. The language and network protocol are entirely backwards-compatible, the main changes for this release either improve performance or fix (largely minor) bugs.