selftests/bpf: Store BPF object files with .bpf.o extension

BPF object files are, in a way, the final artifact produced as part of
the ahead-of-time compilation process. That makes them somewhat special
compared to "regular" object files, which are a intermediate build
artifacts that can typically be removed safely. As such, it can make
sense to name them differently to make it easier to spot this difference
at a glance.

Among others, libbpf-bootstrap [0] has established the extension .bpf.o
for BPF object files. It seems reasonable to follow this example and
establish the same denomination for selftest build artifacts. To that
end, this change adjusts the corresponding part of the build system and
the test programs loading BPF object files to work with .bpf.o files.

[0] https://github.com/libbpf/libbpf-bootstrap

Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Müller <deso@posteo.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20220901222253.1199242-1-deso@posteo.net

selftests/bpf: Use libbpf 1.0 API mode instead of RLIMIT_MEMLOCK

We have switched to memcg-based memory accouting and thus the rlimit is
not needed any more. LIBBPF_STRICT_AUTO_RLIMIT_MEMLOCK was introduced in
libbpf for backward compatibility, so we can use it instead now. After
this change, the header tools/testing/selftests/bpf/bpf_rlimit.h can be
removed.

This patch also removes the useless header sys/resource.h from many files
in tools/testing/selftests/bpf/.

Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220409125958.92629-3-laoar.shao@gmail.com

selftests/bpf: Redo the switch to new libbpf XDP APIs

Switch to using new bpf_xdp_*() APIs across all selftests. Take
advantage of a more straightforward and user-friendly semantics of
old_prog_fd (0 means "don't care") in few places.

This is a redo of 544356524dd6 ("selftests/bpf: switch to new libbpf XDP
APIs"), which was previously reverted to minimize conflicts during bpf
and bpf-next tree merge.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20220202225916.3313522-6-andrii@kernel.org

selftests, bpf: Do not yet switch to new libbpf XDP APIs

Revert commit 544356524dd6 ("selftests/bpf: switch to new libbpf XDP APIs")
for now given this will heavily conflict with 4b27480dcaa7 ("bpf/selftests:
convert xdp_link test to ASSERT_* macros") upon merge. Andrii agreed to redo
the conversion cleanly after trees merged.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>

selftests/bpf: switch to new libbpf XDP APIs

Switch to using new bpf_xdp_*() APIs across all selftests. Take
advantage of a more straightforward and user-friendly semantics of
old_prog_fd (0 means "don't care") in few places.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20220120061422.2710637-4-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: Use explicit bpf_prog_test_load() calls everywhere

-Dbpf_prog_load_deprecated=bpf_prog_test_load trick is both ugly and
breaks when deprecation goes into effect due to macro magic. Convert all
the uses to explicit bpf_prog_test_load() calls which avoid deprecation
errors and makes everything less magical.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Dave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/bpf/20211103220845.2676888-12-andrii@kernel.org

selftests/bpf: Switch to new bpf_object__next_{map,program} APIs

Replace deprecated bpf_{map,program}__next APIs with newly added
bpf_object__next_{map,program} APIs, so that no compilation warnings
emit.

Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20211003165844.4054931-3-hengqi.chen@gmail.com

selftests/bpf: Normalize XDP section names in selftests

Convert almost all SEC("xdp_blah") uses to strict SEC("xdp") to comply
with strict libbpf 1.0 logic of exact section name match for XDP program
types. There is only one exception, which is only tested through
iproute2 and defines multiple XDP programs within the same BPF object.
Given iproute2 still works in non-strict libbpf mode and it doesn't have
means to specify XDP programs by its name (not section name/title),
leave that single file alone for now until iproute2 gains lookup by
function/program name.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Dave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/bpf/20210928161946.2512801-3-andrii@kernel.org

selftests: bpf: correct perror strings

perror(str) is basically equivalent to
print("%s: %s\n", str, strerror(errno)).
New line or colon at the end of str is
a mistake/breaks formatting.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

selftests/bpf: measure RTT from xdp using xdping

xdping allows us to get latency estimates from XDP. Output looks
like this:

./xdping -I eth4 192.168.55.8
Setting up XDP for eth4, please wait...
XDP setup disrupts network connectivity, hit Ctrl+C to quit

Normal ping RTT data
[Ignore final RTT; it is distorted by XDP using the reply]
PING 192.168.55.8 (192.168.55.8) from 192.168.55.7 eth4: 56(84) bytes of data.
64 bytes from 192.168.55.8: icmp_seq=1 ttl=64 time=0.302 ms
64 bytes from 192.168.55.8: icmp_seq=2 ttl=64 time=0.208 ms
64 bytes from 192.168.55.8: icmp_seq=3 ttl=64 time=0.163 ms
64 bytes from 192.168.55.8: icmp_seq=8 ttl=64 time=0.275 ms

4 packets transmitted, 4 received, 0% packet loss, time 3079ms
rtt min/avg/max/mdev = 0.163/0.237/0.302/0.054 ms

XDP RTT data:
64 bytes from 192.168.55.8: icmp_seq=5 ttl=64 time=0.02808 ms
64 bytes from 192.168.55.8: icmp_seq=6 ttl=64 time=0.02804 ms
64 bytes from 192.168.55.8: icmp_seq=7 ttl=64 time=0.02815 ms
64 bytes from 192.168.55.8: icmp_seq=8 ttl=64 time=0.02805 ms

The xdping program loads the associated xdping_kern.o BPF program
and attaches it to the specified interface. If run in client
mode (the default), it will add a map entry keyed by the
target IP address; this map will store RTT measurements, current
sequence number etc. Finally in client mode the ping command
is executed, and the xdping BPF program will use the last ICMP
reply, reformulate it as an ICMP request with the next sequence
number and XDP_TX it. After the reply to that request is received
we can measure RTT and repeat until the desired number of
measurements is made. This is why the sequence numbers in the
normal ping are 1, 2, 3 and 8. We XDP_TX a modified version
of ICMP reply 4 and keep doing this until we get the 4 replies
we need; hence the networking stack only sees reply 8, where
we have XDP_PASSed it upstream since we are done.

In server mode (-s), xdping simply takes ICMP requests and replies
to them in XDP rather than passing the request up to the networking
stack. No map entry is required.

xdping can be run in native XDP mode (the default, or specified
via -N) or in skb mode (-S).

A test program test_xdping.sh exercises some of these options.

Note that native XDP does not seem to XDP_TX for veths, hence -N
is not tested. Looking at the code, it looks like XDP_TX is
supported so I'm not sure if that's expected. Running xdping in
native mode for ixgbe as both client and server works fine.

Changes since v4

- close fds on cleanup (Song Liu)

Changes since v3

- fixed seq to be __be16 (Song Liu)
- fixed fd checks in xdping.c (Song Liu)

Changes since v2

- updated commit message to explain why seq number of last
ICMP reply is 8 not 4 (Song Liu)
- updated types of seq number, raddr and eliminated csum variable
in xdpclient/xdpserver functions as it was not needed (Song Liu)
- added XDPING_DEFAULT_COUNT definition and usage specification of
default/max counts (Song Liu)

Changes since v1
- moved from RFC to PATCH
- removed unused variable in ipv4_csum() (Song Liu)
- refactored ICMP checks into icmp_check() function called by client
and server programs and reworked client and server programs due
to lack of shared code (Song Liu)
- added checks to ensure that SKB and native mode are not requested
together (Song Liu)

Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>