Commit Graph

7 Commits

Author SHA1 Message Date
Simon Sundberg
93b6c0eafa pping: Major refactor and add -f and -c options
Merge the pping_kern_tc.c, pping_kern_xdp.c and pping_helpers.h into
the single file pping_kern.c. Do not change any of the BPF code,
except renaming the map ts_start to packet_ts.

To handle both BPF programs kept in single ELF-file, change loading
mechanism to extract and attach both tc and XDP programs from it. Also
refactor main-method into several smaller functions to reduce its
size.

Finally, added the --force (-f) and --cleanup-interval (-c) options to
the argument parsing, and improved the parsing of the
--rate-limit (-r) option.

NOTE: The verifier rejects program in it's current state as too
large (over 1 million instructions). Setting the TCP_MAX_OPTIONS in
pping_kern.c to 5 (or less) solves this. Unsure at the moment what
causes the verifier to think the program is so large, as the code in
pping_kern.c is identical to the one from the three files it was
merged from.

Signed-off-by: Simon Sundberg <simon.sundberg@kau.se>
2021-04-15 14:13:54 +02:00
Simon Sundberg
1446e6edec pping: Load tc-bpf program with libbpf
Load and pin the tc-bpf program in pping.c using libbpf, and only
attach the pinned program using iproute. That way, can use features
that are not supported by the old iproute loader, even if iproute does
not have libbpf support.

To support this change, extend bpf_egress_loader with option to load
pinned program. Additionally, remove configure script and parts of
Makefile that are no longer needed. Furthermore, remove multiple
definitions of ts_start map, and place singular definition in
pping_helpers.h which is included by both BPF programs.

Also, some minor fixes based on Toke's review.

Signed-off-by: Simon Sundberg <simon.sundberg@kau.se>
2021-03-02 17:40:51 +01:00
Simon Sundberg
7410d5cc2c pping: Various minor fixes
Perform various fixes and tweaks:
- Rename several defines to make them more informative
- Remove unrolling of loop in BPF programs
- Reuse defines for program sections between userspace and kernel
  space programs
- Perform fork+exec to run bpf_egress_loader script instead of
  system()
- Add comment to copied scripts indicating I've modified them
- Add pping.h and pping_helpers.h as dependencies in Makefile

Also, add a brief description of what PPing is and how it works to
README

Signed-off-by: Simon Sundberg <simon.sundberg@kau.se>
2021-02-04 19:48:01 +01:00
Simon Sundberg
8b42ba1e22 pping: TC-BPF use BTF map if iproute has libbpf
Copy setup from traffic-pacing-edt to use BTF-defined map if configure
detects that iproute2 has libbpf support, otherwise fall back on
bpf_elf_map. Also fix a minor bug with setting default value for SEC
in bpf_egress_loader.sh.

Signed-off-by: Simon Sundberg <simon.sundberg@kau.se>
2021-02-04 19:45:59 +01:00
Simon Sundberg
954c66b0e8 pping: Add TC-BPF program for egress
Split and rename files so there is one userspace program (pping) and
two kernel-space ones (one for XDP and one for TC-BPF).

Copy the shell script for loading the TC-BPF program from
traffic-pacing-edt folder, but add support for loading a specific
section.

The XDP and TC-BPF programs do not share the ts_start map, so program
does not work.

Signed-off-by: Simon Sundberg <simon.sundberg@kau.se>
2021-02-04 19:39:16 +01:00
Simon Sundberg
45b138b6ab pping: Add perf-buffer
The XDP program pushes the calculated RTTs to userspace through the
perf-buffer and the userspace program polls it to print them out

Signed-off-by: Simon Sundberg <simon.sundberg@kau.se>
2021-02-04 19:38:23 +01:00
Simon Sundberg
135ae974e9 pping: Start pping implementation
Add a XDP program to parse TCP timestamps and a simple loader

Signed-off-by: Simon Sundberg <simon.sundberg@kau.se>
2021-02-04 19:37:15 +01:00