CASPER_SERVICE_STDIO - Casper will not close the first three descriptors (stdin,
stdout and stderr) this can be helpful for debugging.
CASPER_SERVICE_FD - Capser will not close all other descriptors, this can
be useful for a filesystem service.
- WARNS can be inherited from lib/Makefile.inc
- CFLAGS referred to a non-existent directory and this shouldn't be needed
anyhow due to the build picking up includes from WORLDTMP.
Sponsored by: EMC / Isilon Storage Division
After calling the cap_init(3) function Casper will fork from it's original
process, using pdfork(2). Forking from a process has a lot of advantages:
1. We have the same cwd as the original process.
2. The same uid, gid and groups.
3. The same MAC labels.
4. The same descriptor table.
5. The same routing table.
6. The same umask.
7. The same cpuset(1).
From now services are also in form of libraries.
We also removed libcapsicum at all and converts existing program using Casper
to new architecture.
Discussed with: pjd, jonathan, ed, drysdale@google.com, emaste
Partially reviewed by: drysdale@google.com, bdrewery
Approved by: pjd (mentor)
Differential Revision: https://reviews.freebsd.org/D4277
