This is merely to silence the compiler warning. If write to stderr
failed, assume that printing an error message will fail as well so don't
even try.
Signed-off-by: Phil Sutter <phil@nwl.cc>
If fopen() succeeded but len != PATH_MAX, the function leaks the open
FILE pointer. Fix this by checking len value before calling fopen().
Signed-off-by: Phil Sutter <phil@nwl.cc>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
bpf_parse_string() will now correctly handle:
- Extraneous whitespace,
- OPs on multiple lines and
- overlong file names.
The added feature of allowing to have OPs on multiple lines (like e.g.
tcpdump prints them) is rather a side effect of fixing detection of
malformed bytecode files having random content on a second line, like
e.g.:
| 4,40 0 0 12,21 0 1 2048,6 0 0 262144,6 0 0 0
| foobar
Cc: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Phil Sutter <phil@nwl.cc>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
When bpf fs mount path is from env, behavior is currently broken as
we continue to search in default paths, thus fix this up.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Currently, it's still quite hard to figure out if a prog passed the
verifier, but later gets rejected due to different tail call ownership.
Figure out whether that is the case and provide appropriate error
messages to the user.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Make use of TCA_BPF_ID/TCA_ACT_BPF_ID that we exposed and print the ID
of the programs loaded and use the new BPF_OBJ_GET_INFO_BY_FD command
for dumping further information about the program, currently whether
the attached program is jited.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Add support for map in map in the loader and add a small example program.
The outer map uses inner_id to reference a bpf_elf_map with a given ID
as the inner type. Loading maps is done in three passes, i) all non-map
in map maps are loaded, ii) all map in map maps are loaded based on the
inner_id map spec of a non-map in map with corresponding id, and iii)
related inner maps are attached to the map in map with given inner_idx
key. Pinned objetcs are assumed to be managed externally, so they are
only retrieved from BPF fs.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
When LLVM wrongly generates a rodata relo entry (llvm BZ #33599),
then just bail out instead of probing for prog w/o reloc, which
will fail in this case anyway.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
I noticed we currently don't dump an error message when a pinned
program couldn't be retrieved, thus add a hint to the user.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Jan-Erik reported an assertion in bpf_prog_to_subdir() failed where
type was BPF_PROG_TYPE_UNSPEC, which is only used in bpf_init_env()
to auto-mount and cache the bpf fs mount point.
Therefore, make sure when bpf_init_env() is called multiple times
(f.e. eBPF classifier with eBPF action attached) and bpf_mnt_cached
is set already that the type is also valid. In bpf_init_env(), we're
only interested in the mount point and not a type-specific subdir.
Fixes: e42256699c ("bpf: make tc's bpf loader generic and move into lib")
Reported-by: Jan-Erik Rediger <janerik@rediger.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Adds support to configure BPF programs as nexthop actions via the LWT
framework.
Example:
ip route add 192.168.253.2/32 \
encap bpf out obj lwt_len_hist_kern.o section len_hist \
dev veth0
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Now that we made the BPF loader generic as a library, reuse it
for loading XDP programs as well. This basically adds a minimal
start of a facility for iproute2 to load XDP programs. There
currently only exists the xdp1_user.c sample code in the kernel
tree that sets up netlink directly and an iovisor/bcc front-end.
Since we have all the necessary infrastructure in place already
from tc side, we can just reuse its loader back-end and thus
facilitate migration and usability among the two for people
familiar with tc/bpf already. Sharing maps, performing tail calls,
etc works the same way as with tc. Naturally, once kernel
configuration API evolves, we will extend new features for XDP
here as well, resp. extend dumping of related netlink attributes.
Minimal example:
clang -target bpf -O2 -Wall -c prog.c -o prog.o
ip [-force] link set dev em1 xdp obj prog.o # attaching
ip [-d] link # dumping
ip link set dev em1 xdp off # detaching
For the dump, intention is that in the first line for each ip
link entry, we'll see "xdp" to indicate that this device has an
XDP program attached. Once we dump some more useful information
via netlink (digest, etc), idea is that 'ip -d link' will then
display additional relevant program information below the "link/
ether [...]" output line for such devices, for example.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Kernel commit 21116b7068b9 ("bpf: add owner_prog_type and accounted mem
to array map's fdinfo") added support for telling the owner prog type in
case of prog arrays. Give a notification to the user when they differ,
and the program eventually fails to load.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
The log buffer is automatically grown when the verifier output does not
fit into the default buffer size. The number of growing attempts was
not sufficient to reach the maximum buffer size so far.
Perform 9 iterations to reach max and let the 10th one fail.
j:0 i:65536 max:16777215
j:1 i:131072 max:16777215
j:2 i:262144 max:16777215
j:3 i:524288 max:16777215
j:4 i:1048576 max:16777215
j:5 i:2097152 max:16777215
j:6 i:4194304 max:16777215
j:7 i:8388608 max:16777215
j:8 i:16777216 max:16777215
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
This work moves the bpf loader into the iproute2 library and reworks
the tc specific parts into generic code. It's useful as we can then
more easily support new program types by just having the same ELF
loader backend. Joint work with Thomas Graf. I hacked a rough start
of a test suite to make sure nothing breaks [1] and looks all good.
[1] https://github.com/borkmann/clsact/blob/master/test_bpf.sh
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Thomas Graf <tgraf@suug.ch>
