Both BPF filter and action will allow users to specify run
multiple times, and only the last one will be considered by
the kernel. Explicitly refuse such command lines.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
bpf_parse_common() parses and loads the program. Rename it
accordingly.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Program type is needed both for parsing and loading of
the program. Parsing may also induce the type based on
signatures from __bpf_prog_meta. Instead of passing
the type around keep it in struct bpf_cfg_in.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Consolidate dump of prog info to use bpf_dump_prog_info() when possible.
Moving forward, we want to have a consistent output for BPF progs when
being dumped. E.g. in cls/act case we used to dump tag as a separate
netlink attribute before we had BPF_OBJ_GET_INFO_BY_FD bpf(2) command.
Move dumping tag into bpf_dump_prog_info() as well, and only dump the
netlink attribute for older kernels. Also, reuse bpf_dump_prog_info()
for XDP case, so we can dump tag and whether program was jited, which
we currently don't show.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
dump more than TCA_ACT_MAX_PRIO actions per batch when the kernel
supports it.
Introduced keyword "since" for time based filtering of actions.
Some example (we have 400 actions bound to 400 filters); at
installation time. Using updated when tc setting the time of
interest to 120 seconds earlier (we see 400 actions):
prompt$ hackedtc actions ls action gact since 120000| grep index | wc -l
400
go get some coffee and wait for > 120 seconds and try again:
prompt$ hackedtc actions ls action gact since 120000 | grep index | wc -l
0
Lets see a filter bound to one of these actions:
....
filter pref 10 u32
filter pref 10 u32 fh 800: ht divisor 1
filter pref 10 u32 fh 800::800 order 2048 key ht 800 bkt 0 flowid 1:10 (rule hit 2 success 1)
match 7f000002/ffffffff at 12 (success 1 )
action order 1: gact action pass
random type none pass val 0
index 23 ref 2 bind 1 installed 1145 sec used 802 sec
Action statistics:
Sent 84 bytes 1 pkt (dropped 0, overlimits 0 requeues 0)
backlog 0b 0p requeues 0
...
that coffee took long, no? It was good.
Now lets ping -c 1 127.0.0.2, then run the actions again:
prompt$ hackedtc actions ls action gact since 120 | grep index | wc -l
1
More details please:
prompt$ hackedtc -s actions ls action gact since 120000
action order 0: gact action pass
random type none pass val 0
index 23 ref 2 bind 1 installed 1270 sec used 30 sec
Action statistics:
Sent 168 bytes 2 pkt (dropped 0, overlimits 0 requeues 0)
backlog 0b 0p requeues 0
And the filter?
filter pref 10 u32
filter pref 10 u32 fh 800: ht divisor 1
filter pref 10 u32 fh 800::800 order 2048 key ht 800 bkt 0 flowid 1:10 (rule hit 4 success 2)
match 7f000002/ffffffff at 12 (success 2 )
action order 1: gact action pass
random type none pass val 0
index 23 ref 2 bind 1 installed 1324 sec used 84 sec
Action statistics:
Sent 168 bytes 2 pkt (dropped 0, overlimits 0 requeues 0)
backlog 0b 0p requeues 0
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
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>
Currently there is no way of querying whether a filter is
offloaded to HW or not when using "both" policy (where none
of skip_sw or skip_hw flags are set by user-space).
Add two new flags, "in hw" and "not in hw" such that user
space can determine if a filter is actually offloaded to
hw or not. The "in hw" UAPI semantics was chosen so it's
similar to the "skip hw" flag logic.
If none of these two flags are set, this signals running
over older kernel.
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
We already export TCA_BPF_TAG resp. TCA_ACT_BPF_TAG from kernel commit
f1f7714ea51c ("bpf: rework prog_digest into prog_tag"), thus also dump
it when filter/actions are shown.
Signed-off-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>
Add support for controling hardware offload using (now standard)
skip_sw and skip_hw flags in cls_bpf.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
We need to fill handle when provided by the user, even if no further
argument is provided. Thus, move the test for arg to the correct location,
so that it works correctly:
# tc filter show dev foo egress
filter protocol all pref 1 bpf
filter protocol all pref 1 bpf handle 0x1 bpf.o:[classifier] direct-action
filter protocol all pref 1 bpf handle 0x2 bpf.o:[classifier] direct-action
# tc filter del dev foo egress prio 1 handle 2 bpf
# tc filter show dev foo egress
filter protocol all pref 1 bpf
filter protocol all pref 1 bpf handle 0x1 bpf.o:[classifier] direct-action
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This larger work addresses one of the bigger remaining issues on
tc's eBPF frontend, that is, to allow for persistent file descriptors.
Whenever tc parses the ELF object, extracts and loads maps into the
kernel, these file descriptors will be out of reach after the tc
instance exits.
Meaning, for simple (unnested) programs which contain one or
multiple maps, the kernel holds a reference, and they will live
on inside the kernel until the program holding them is unloaded,
but they will be out of reach for user space, even worse with
(also multiple nested) tail calls.
For this issue, we introduced the concept of an agent that can
receive the set of file descriptors from the tc instance creating
them, in order to be able to further inspect/update map data for
a specific use case. However, while that is more tied towards
specific applications, it still doesn't easily allow for sharing
maps accross multiple tc instances and would require a daemon to
be running in the background. F.e. when a map should be shared by
two eBPF programs, one attached to ingress, one to egress, this
currently doesn't work with the tc frontend.
This work solves exactly that, i.e. if requested, maps can now be
_arbitrarily_ shared between object files (PIN_GLOBAL_NS) or within
a single object (but various program sections, PIN_OBJECT_NS) without
"loosing" the file descriptor set. To make that happen, we use eBPF
object pinning introduced in kernel commit b2197755b263 ("bpf: add
support for persistent maps/progs") for exactly this purpose.
The shipped examples/bpf/bpf_shared.c code from this patch can be
easily applied, for instance, as:
- classifier-classifier shared:
tc filter add dev foo parent 1: bpf obj shared.o sec egress
tc filter add dev foo parent ffff: bpf obj shared.o sec ingress
- classifier-action shared (here: late binding to a dummy classifier):
tc actions add action bpf obj shared.o sec egress pass index 42
tc filter add dev foo parent ffff: bpf obj shared.o sec ingress
tc filter add dev foo parent 1: bpf bytecode '1,6 0 0 4294967295,' \
action bpf index 42
The toy example increments a shared counter on egress and dumps its
value on ingress (if no sharing (PIN_NONE) would have been chosen,
map value is 0, of course, due to the two map instances being created):
[...]
<idle>-0 [002] ..s. 38264.788234: : map val: 4
<idle>-0 [002] ..s. 38264.788919: : map val: 4
<idle>-0 [002] ..s. 38264.789599: : map val: 5
[...]
... thus if both sections reference the pinned map(s) in question,
tc will take care of fetching the appropriate file descriptor.
The patch has been tested extensively on both, classifier and
action sides.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
When having optional classid, most minimal command can be sth
like:
tc filter add dev foo parent X: bpf obj prog.o
Therefore, adapt the code so that a next argument will not be
enforced as the case currently.
Also, minor cleanup on the classid, where we should rather
have used addattr32(), and add flags for exec configuration,
for example (using short notation):
tc filter add dev foo parent X: bpf da obj prog.o
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Error was:
f_bpf.o: In function `bpf_parse_opt':
f_bpf.c:(.text+0x88f): undefined reference to `secure_getenv'
m_bpf.o: In function `parse_bpf':
m_bpf.c:(.text+0x587): undefined reference to `secure_getenv'
collect2: error: ld returned 1 exit status
There is no special reason to use the secure version of getenv, thus let's
simply use getenv().
CC: Daniel Borkmann <daniel@iogearbox.net>
Fixes: 88eea53954 ("tc: {f,m}_bpf: allow to retrieve uds path from env")
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Tested-by: Yegor Yefremov <yegorslists@googlemail.com>
Currently, only on error we get a log dump, but I found it useful when
working with eBPF to have an option to also dump the log on success.
Also spotted a typo in a header comment, which is fixed here as well.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
This work follows upon commit 6256f8c9e4 ("tc, bpf: finalize eBPF
support for cls and act front-end") and takes up the idea proposed by
Hannes Frederic Sowa to spawn a shell (or any other command) that holds
generated eBPF map file descriptors.
File descriptors, based on their id, are being fetched from the same
unix domain socket as demonstrated in the bpf_agent, the shell spawned
via execvpe(2) and the map fds passed over the environment, and thus
are made available to applications in the fashion of std{in,out,err}
for read/write access, for example in case of iproute2's examples/bpf/:
# env | grep BPF
BPF_NUM_MAPS=3
BPF_MAP1=6 <- BPF_MAP_ID_QUEUE (id 1)
BPF_MAP0=5 <- BPF_MAP_ID_PROTO (id 0)
BPF_MAP2=7 <- BPF_MAP_ID_DROPS (id 2)
# ls -la /proc/self/fd
[...]
lrwx------. 1 root root 64 Apr 14 16:46 0 -> /dev/pts/4
lrwx------. 1 root root 64 Apr 14 16:46 1 -> /dev/pts/4
lrwx------. 1 root root 64 Apr 14 16:46 2 -> /dev/pts/4
[...]
lrwx------. 1 root root 64 Apr 14 16:46 5 -> anon_inode:bpf-map
lrwx------. 1 root root 64 Apr 14 16:46 6 -> anon_inode:bpf-map
lrwx------. 1 root root 64 Apr 14 16:46 7 -> anon_inode:bpf-map
The advantage (as opposed to the direct/native usage) is that now the
shell is map fd owner and applications can terminate and easily reattach
to descriptors w/o any kernel changes. Moreover, multiple applications
can easily read/write eBPF maps simultaneously.
To further allow users for experimenting with that, next step is to add
a small helper that can get along with simple data types, so that also
shell scripts can make use of bpf syscall, f.e to read/write into maps.
Generally, this allows for prepopulating maps, or any runtime altering
which could influence eBPF program behaviour (f.e. different run-time
classifications, skb modifications, ...), dumping of statistics, etc.
Reference: http://thread.gmane.org/gmane.linux.network/357471/focus=357860
Suggested-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
This work finalizes both eBPF front-ends for the classifier and action
part in tc, it allows for custom ELF section selection, a simplified tc
command frontend (while keeping compat), reusing of common maps between
classifier and actions residing in the same object file, and exporting
of all map fds to an eBPF agent for handing off further control in user
space.
It also adds an extensive example of how eBPF can be used, and a minimal
self-contained example agent that dumps map data. The example is well
documented and hopefully provides a good starting point into programming
cls_bpf and act_bpf.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Acked-by: Thomas Graf <tgraf@suug.ch>
Acked-by: Jiri Pirko <jiri@resnulli.us>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
This work adds the tc frontend for kernel commit e2e9b6541dd4 ("cls_bpf:
add initial eBPF support for programmable classifiers").
A C-like classifier program (f.e. see e2e9b6541dd4) is being compiled via
LLVM's eBPF backend into an ELF file, that is then being passed to tc. tc
then loads, if any, eBPF maps and eBPF opcodes (with fixed-up eBPF map file
descriptors) out of its dedicated sections, and via bpf(2) into the kernel
and then the resulting fd via netlink down to cls_bpf. cls_bpf allows for
annotations, currently, I've used the file name for that, so that the user
can easily identify his filter when dumping configurations back.
Example usage:
clang -O2 -emit-llvm -c cls.c -o - | llc -march=bpf -filetype=obj -o cls.o
tc filter add dev em1 parent 1: bpf run object-file cls.o classid x:y
tc filter show dev em1 [...]
filter parent 1: protocol all pref 49152 bpf handle 0x1 flowid x:y cls.o
I placed the parser bits derived from Alexei's kernel sample, into tc_bpf.c
as my next step is to also add the same support for BPF action, so we can
have a fully fledged eBPF classifier and action in tc.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
We need limits.h for LONG_MIN and LONG_MAX, sys/param.h for MIN and
sys/select for struct timeval.
This fixes the following compile errors with musl libc:
f_bpf.c: In function 'bpf_parse_opt':
f_bpf.c:181:12: error: 'LONG_MIN' undeclared (first use in this function)
if (h == LONG_MIN || h == LONG_MAX) {
^
...
tc_util.o: In function `print_tcstats2_attr':
tc_util.c:(.text+0x13fe): undefined reference to `MIN'
tc_util.c:(.text+0x1465): undefined reference to `MIN'
tc_util.c:(.text+0x14ce): undefined reference to `MIN'
tc_util.c:(.text+0x154c): undefined reference to `MIN'
tc_util.c:(.text+0x160a): undefined reference to `MIN'
tc_util.o:tc_util.c:(.text+0x174e): more undefined references to `MIN' follow
...
tc_stab.o: In function `print_size_table':
tc_stab.c:(.text+0x40f): undefined reference to `MIN'
...
fdb.c:247:30: error: 'ULONG_MAX' undeclared (first use in this function)
(vni >> 24) || vni == ULONG_MAX)
^
lnstat.h:28:17: error: field 'last_read' has incomplete type
struct timeval last_read; /* last time of read */
^
Signed-off-by: Natanael Copa <ncopa@alpinelinux.org>
This is the iproute2 part of the kernel patch "net: sched:
add BPF-based traffic classifier".
[Will re-submit later again for iproute2 when window for
-next submissions opens.]
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Cc: Thomas Graf <tgraf@suug.ch>
