Commit Graph

192 Commits

Author SHA1 Message Date
Andrey Ignatov
bafa7afe63 libbpf: Support cgroup_skb/{e,in}gress section names
Add section names for BPF_CGROUP_INET_INGRESS and BPF_CGROUP_INET_EGRESS
attach types to be able to identify them in libbpf_attach_type_by_name.

"cgroup_skb" is used instead of "cgroup/skb" mostly to easy possible
unifying of how libbpf and bpftool works with section names:
* bpftool uses "cgroup_skb" to in "prog list" sub-command;
* bpftool uses "ingress" and "egress" in "cgroup list" sub-command;
* having two parts instead of three in a string like "cgroup_skb/ingress"
  can be leveraged to split it to prog_type part and attach_type part,
  or vise versa: use two parts to make a section name.

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-09-27 21:14:59 +02:00
Andrey Ignatov
956b620fcf libbpf: Introduce libbpf_attach_type_by_name
There is a common use-case when ELF object contains multiple BPF
programs and every program has its own section name. If it's cgroup-bpf
then programs have to be 1) loaded and 2) attached to a cgroup.

It's convenient to have information necessary to load BPF program
together with program itself. This is where section name works fine in
conjunction with libbpf_prog_type_by_name that identifies prog_type and
expected_attach_type and these can be used with BPF_PROG_LOAD.

But there is currently no way to identify attach_type by section name
and it leads to messy code in user space that reinvents guessing logic
every time it has to identify attach type to use with BPF_PROG_ATTACH.

The patch introduces libbpf_attach_type_by_name that guesses attach type
by section name if a program can be attached.

The difference between expected_attach_type provided by
libbpf_prog_type_by_name and attach_type provided by
libbpf_attach_type_by_name is the former is used at BPF_PROG_LOAD time
and can be zero if a program of prog_type X has only one corresponding
attach type Y whether the latter provides specific attach type to use
with BPF_PROG_ATTACH.

No new section names were added to section_names array. Only existing
ones were reorganized and attach_type was added where appropriate.

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-09-27 21:14:59 +02:00
David S. Miller
105bc1306e Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Daniel Borkmann says:

====================
pull-request: bpf-next 2018-09-25

The following pull-request contains BPF updates for your *net-next* tree.

The main changes are:

1) Allow for RX stack hardening by implementing the kernel's flow
   dissector in BPF. Idea was originally presented at netconf 2017 [0].
   Quote from merge commit:

     [...] Because of the rigorous checks of the BPF verifier, this
     provides significant security guarantees. In particular, the BPF
     flow dissector cannot get inside of an infinite loop, as with
     CVE-2013-4348, because BPF programs are guaranteed to terminate.
     It cannot read outside of packet bounds, because all memory accesses
     are checked. Also, with BPF the administrator can decide which
     protocols to support, reducing potential attack surface. Rarely
     encountered protocols can be excluded from dissection and the
     program can be updated without kernel recompile or reboot if a
     bug is discovered. [...]

   Also, a sample flow dissector has been implemented in BPF as part
   of this work, from Petar and Willem.

   [0] http://vger.kernel.org/netconf2017_files/rx_hardening_and_udp_gso.pdf

2) Add support for bpftool to list currently active attachment
   points of BPF networking programs providing a quick overview
   similar to bpftool's perf subcommand, from Yonghong.

3) Fix a verifier pruning instability bug where a union member
   from the register state was not cleared properly leading to
   branches not being pruned despite them being valid candidates,
   from Alexei.

4) Various smaller fast-path optimizations in XDP's map redirect
   code, from Jesper.

5) Enable to recognize BPF_MAP_TYPE_REUSEPORT_SOCKARRAY maps
   in bpftool, from Roman.

6) Remove a duplicate check in libbpf that probes for function
   storage, from Taeung.

7) Fix an issue in test_progs by avoid checking for errno since
   on success its value should not be checked, from Mauricio.

8) Fix unused variable warning in bpf_getsockopt() helper when
   CONFIG_INET is not configured, from Anders.

9) Fix a compilation failure in the BPF sample code's use of
   bpf_flow_keys, from Prashant.

10) Minor cleanups in BPF code, from Yue and Zhong.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-09-25 20:29:38 -07:00
Arnaldo Carvalho de Melo
6d41907c63 tools lib bpf: Provide wrapper for strerror_r to build in !_GNU_SOURCE systems
Same problem that got fixed in a similar fashion in tools/perf/ in
c8b5f2c96d ("tools: Introduce str_error_r()"), fix it in the same
way, licensing needs to be sorted out to libbpf to use libapi, so,
for this simple case, just get the same wrapper in tools/lib/bpf.

This makes libbpf and its users (bpftool, selftests, perf) to build
again in Alpine Linux 3.[45678] and edge.

Acked-by: Alexei Starovoitov <ast@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: Hendrik Brueckner <brueckner@linux.ibm.com>
Cc: Jakub Kicinski <jakub.kicinski@netronome.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Quentin Monnet <quentin.monnet@netronome.com>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: Yonghong Song <yhs@fb.com>
Fixes: 1ce6a9fc15 ("bpf: fix build error in libbpf with EXTRA_CFLAGS="-Wp, -D_FORTIFY_SOURCE=2 -O2"")
Link: https://lkml.kernel.org/r/20180917151636.GA21790@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2018-09-18 10:16:18 -03:00
Petar Penkov
c22fbae76c bpf: support flow dissector in libbpf and bpftool
This patch extends libbpf and bpftool to work with programs of type
BPF_PROG_TYPE_FLOW_DISSECTOR.

Signed-off-by: Petar Penkov <ppenkov@google.com>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-09-14 12:04:33 -07:00
Yonghong Song
9d0b3c1f14 tools/bpf: fix a netlink recv issue
Commit f7010770fb ("tools/bpf: move bpf/lib netlink related
functions into a new file") introduced a while loop for the
netlink recv path. This while loop is needed since the
buffer in recv syscall may not be enough to hold all the
information and in such cases multiple recv calls are needed.

There is a bug introduced by the above commit as
the while loop may block on recv syscall if there is no
more messages are expected. The netlink message header
flag NLM_F_MULTI is used to indicate that more messages
are expected and this patch fixed the bug by doing
further recv syscall only if multipart message is expected.

The patch added another fix regarding to message length of 0.
When netlink recv returns message length of 0, there will be
no more messages for returning data so the while loop
can end.

Fixes: f7010770fb ("tools/bpf: move bpf/lib netlink related functions into a new file")
Reported-by: Björn Töpel <bjorn.topel@intel.com>
Tested-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-09-11 14:26:30 -07:00
Yonghong Song
36f1678d9e tools/bpf: add more netlink functionalities in lib/bpf
This patch added a few netlink attribute parsing functions
and the netlink API functions to query networking links, tc classes,
tc qdiscs and tc filters. For example, the following API is
to get networking links:
  int nl_get_link(int sock, unsigned int nl_pid,
                  dump_nlmsg_t dump_link_nlmsg,
                  void *cookie);

Note that when the API is called, the user also provided a
callback function with the following signature:
  int (*dump_nlmsg_t)(void *cookie, void *msg, struct nlattr **tb);

The "cookie" is the parameter the user passed to the API and will
be available for the callback function.
The "msg" is the information about the result, e.g., ifinfomsg or
tcmsg. The "tb" is the parsed netlink attributes.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-09-06 22:34:08 -07:00
Yonghong Song
f7010770fb tools/bpf: move bpf/lib netlink related functions into a new file
There are no functionality change for this patch.

In the subsequent patches, more netlink related library functions
will be added and a separate file is better than cluttering bpf.c.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-09-06 22:34:08 -07:00
Taeung Song
69495d2a52 libbpf: Remove the duplicate checking of function storage
After the commit eac7d84519 ("tools: libbpf: don't return '.text'
as a program for multi-function programs"), bpf_program__next()
in bpf_object__for_each_program skips the function storage such as .text,
so eliminate the duplicate checking.

Cc: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Taeung Song <treeze.taeung@gmail.com>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-09-05 22:16:00 -07:00
David S. Miller
c1617fb4c5 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Daniel Borkmann says:

====================
pull-request: bpf-next 2018-08-13

The following pull-request contains BPF updates for your *net-next* tree.

The main changes are:

1) Add driver XDP support for veth. This can be used in conjunction with
   redirect of another XDP program e.g. sitting on NIC so the xdp_frame
   can be forwarded to the peer veth directly without modification,
   from Toshiaki.

2) Add a new BPF map type REUSEPORT_SOCKARRAY and prog type SK_REUSEPORT
   in order to provide more control and visibility on where a SO_REUSEPORT
   sk should be located, and the latter enables to directly select a sk
   from the bpf map. This also enables map-in-map for application migration
   use cases, from Martin.

3) Add a new BPF helper bpf_skb_ancestor_cgroup_id() that returns the id
   of cgroup v2 that is the ancestor of the cgroup associated with the
   skb at the ancestor_level, from Andrey.

4) Implement BPF fs map pretty-print support based on BTF data for regular
   hash table and LRU map, from Yonghong.

5) Decouple the ability to attach BTF for a map from the key and value
   pretty-printer in BPF fs, and enable further support of BTF for maps for
   percpu and LPM trie, from Daniel.

6) Implement a better BPF sample of using XDP's CPU redirect feature for
   load balancing SKB processing to remote CPU. The sample implements the
   same XDP load balancing as Suricata does which is symmetric hash based
   on IP and L4 protocol, from Jesper.

7) Revert adding NULL pointer check with WARN_ON_ONCE() in __xdp_return()'s
   critical path as it is ensured that the allocator is present, from Björn.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-13 10:07:23 -07:00
David S. Miller
6a92ef08a1 Merge ra.kernel.org:/pub/scm/linux/kernel/git/davem/net 2018-08-11 17:52:00 -07:00
Martin KaFai Lau
91134d849a bpf: Test BPF_PROG_TYPE_SK_REUSEPORT
This patch add tests for the new BPF_PROG_TYPE_SK_REUSEPORT.

The tests cover:
- IPv4/IPv6 + TCP/UDP
- TCP syncookie
- TCP fastopen
- Cases when the bpf_sk_select_reuseport() returning errors
- Cases when the bpf prog returns SK_DROP
- Values from sk_reuseport_md
- outer_map => reuseport_array

The test depends on
commit 3eee1f75f2 ("bpf: fix bpf_skb_load_bytes_relative pkt length check")

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-08-11 01:58:46 +02:00
Martin KaFai Lau
6bc8529c41 bpf: test BPF_MAP_TYPE_REUSEPORT_SOCKARRAY
This patch adds tests for the new BPF_MAP_TYPE_REUSEPORT_SOCKARRAY.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-08-11 01:58:46 +02:00
David S. Miller
1ba982806c Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Daniel Borkmann says:

====================
pull-request: bpf-next 2018-08-07

The following pull-request contains BPF updates for your *net-next* tree.

The main changes are:

1) Add cgroup local storage for BPF programs, which provides a fast
   accessible memory for storing various per-cgroup data like number
   of transmitted packets, etc, from Roman.

2) Support bpf_get_socket_cookie() BPF helper in several more program
   types that have a full socket available, from Andrey.

3) Significantly improve the performance of perf events which are
   reported from BPF offload. Also convert a couple of BPF AF_XDP
   samples overto use libbpf, both from Jakub.

4) seg6local LWT provides the End.DT6 action, which allows to
   decapsulate an outer IPv6 header containing a Segment Routing Header.
   Adds this action now to the seg6local BPF interface, from Mathieu.

5) Do not mark dst register as unbounded in MOV64 instruction when
   both src and dst register are the same, from Arthur.

6) Define u_smp_rmb() and u_smp_wmb() to their respective barrier
   instructions on arm64 for the AF_XDP sample code, from Brian.

7) Convert the tcp_client.py and tcp_server.py BPF selftest scripts
   over from Python 2 to Python 3, from Jeremy.

8) Enable BTF build flags to the BPF sample code Makefile, from Taeung.

9) Remove an unnecessary rcu_read_lock() in run_lwt_bpf(), from Taehee.

10) Several improvements to the README.rst from the BPF documentation
    to make it more consistent with RST format, from Tobin.

11) Replace all occurrences of strerror() by calls to strerror_r()
    in libbpf and fix a FORTIFY_SOURCE build error along with it,
    from Thomas.

12) Fix a bug in bpftool's get_btf() function to correctly propagate
    an error via PTR_ERR(), from Yue.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-07 11:02:05 -07:00
Martin KaFai Lau
74682128c6 bpf: btf: Change tools/lib/bpf/btf to LGPL
This patch changes the tools/lib/bpf/btf.[ch] to LGPL which
is inline with libbpf also.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-08-06 08:44:48 +02:00
Jakub Kicinski
6534770d6f tools: bpf: fix BTF code added twice to different trees
commit 38d5d3b3d5 ("bpf: Introduce BPF_ANNOTATE_KV_PAIR")

added to the bpf and net trees what

commit 92b57121ca ("bpf: btf: export btf types and name by offset from lib")

has already added to bpf-next/net-next, but in slightly different
location.  Remove the duplicates (to fix build of libbpf).

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-02 19:45:14 -07:00
David S. Miller
89b1698c93 Merge ra.kernel.org:/pub/scm/linux/kernel/git/davem/net
The BTF conflicts were simple overlapping changes.

The virtio_net conflict was an overlap of a fix of statistics counter,
happening alongisde a move over to a bonafide statistics structure
rather than counting value on the stack.

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-02 10:55:32 -07:00
Thomas Richter
1ce6a9fc15 bpf: fix build error in libbpf with EXTRA_CFLAGS="-Wp, -D_FORTIFY_SOURCE=2 -O2"
Commit 531b014e7a ("tools: bpf: make use of reallocarray") causes
a compiler error when building the perf tool in the linux-next tree.
Compile file tools/lib/bpf/libbpf.c on a FEDORA 28 installation with
gcc compiler version: gcc (GCC) 8.0.1 20180324 (Red Hat 8.0.1-0.20)
shows this error message:

  [root@p23lp27] # make V=1 EXTRA_CFLAGS="-Wp,-D_FORTIFY_SOURCE=2 -O2"
  [...]
  make -f /home6/tmricht/linux-next/tools/build/Makefile.build
  	dir=./util/scripting-engines obj=libperf
  libbpf.c: In function ‘bpf_object__elf_collect’:
  libbpf.c:811:15: error: ignoring return value of ‘strerror_r’,
  		declared with attribute warn_unused_result [-Werror=unused-result]
       strerror_r(-err, errmsg, sizeof(errmsg));
                 ^
  cc1: all warnings being treated as errors
  mv: cannot stat './.libbpf.o.tmp': No such file or directory
  /home6/tmricht/linux-next/tools/build/Makefile.build:96: recipe for target 'libbpf.o' failed

Replace all occurrences of strerror() by calls to strerror_r(). To
keep the compiler quiet also use the return value from strerror_r()
otherwise a 'variable set but not use' warning which is treated as
error terminates the compile.

Fixes: 531b014e7a ("tools: bpf: make use of reallocarray")
Suggested-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Suggested-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Hendrik Brueckner <brueckner@linux.ibm.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-31 02:08:55 +02:00
Thomas Richter
b611da43b6 perf build: Build error in libbpf missing initialization
In linux-next tree compiling the perf tool with additional make flags
EXTRA_CFLAGS="-Wp,-D_FORTIFY_SOURCE=2 -O2" causes a compiler error.
It is the warning 'variable may be used uninitialized' which is treated
as error: I compile it using a FEDORA 28 installation, my gcc compiler
version: gcc (GCC) 8.0.1 20180324 (Red Hat 8.0.1-0.20). The file that
causes the error is tools/lib/bpf/libbpf.c.

  [root@p23lp27] # make V=1 EXTRA_CFLAGS="-Wp,-D_FORTIFY_SOURCE=2 -O2"
  [...]
  Makefile.config:849: No openjdk development package found, please
     install JDK package, e.g. openjdk-8-jdk, java-1.8.0-openjdk-devel
  Warning: Kernel ABI header at 'tools/include/uapi/linux/if_link.h'
          differs from latest version at 'include/uapi/linux/if_link.h'
    CC       libbpf.o
  libbpf.c: In function ‘bpf_perf_event_read_simple’:
  libbpf.c:2342:6: error: ‘ret’ may be used uninitialized in this
  			function [-Werror=maybe-uninitialized]
    int ret;
        ^
  cc1: all warnings being treated as errors
  mv: cannot stat './.libbpf.o.tmp': No such file or directory
  /home6/tmricht/linux-next/tools/build/Makefile.build:96: recipe for target 'libbpf.o' failed

Suggested-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-28 21:22:40 +02:00
Jakub Kicinski
6d4b198b0b tools: libbpf: add bpf_object__find_program_by_title()
Allow users to find programs by section names.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-27 07:18:44 +02:00
Jakub Kicinski
1e960043e8 tools: libbpf: handle NULL program gracefully in bpf_program__nth_fd()
bpf_map__fd() handles NULL map gracefully and returns -EINVAL.
bpf_program__fd() and bpf_program__nth_fd() crash in this case.
Make the behaviour more consistent by validating prog pointer
as well.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-27 07:18:44 +02:00
Martin KaFai Lau
38d5d3b3d5 bpf: Introduce BPF_ANNOTATE_KV_PAIR
This patch introduces BPF_ANNOTATE_KV_PAIR to signal the
bpf loader about the btf key_type and value_type of a bpf map.
Please refer to the changes in test_btf_haskv.c for its usage.
Both iproute2 and libbpf loader will then have the same
convention to find out the map's btf_key_type_id and
btf_value_type_id from a map's name.

Fixes: 8a138aed4a ("bpf: btf: Add BTF support to libbpf")
Suggested-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-25 06:57:55 +02:00
Martin KaFai Lau
5b891af7fc bpf: Replace [u]int32_t and [u]int64_t in libbpf
This patch replaces [u]int32_t and [u]int64_t usage with
__[su]32 and __[su]64.  The same change goes for [u]int16_t
and [u]int8_t.

Fixes: 8a138aed4a ("bpf: btf: Add BTF support to libbpf")
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-25 06:57:55 +02:00
Jakub Kicinski
b4b5bffd6c tools: libbpf: remove libelf-getphdrnum feature detection
libbpf does not depend on libelf-getphdrnum feature, don't check it.

$ git grep HAVE_ELF_GETPHDRNUM_SUPPORT
tools/perf/Makefile.config:    CFLAGS += -DHAVE_ELF_GETPHDRNUM_SUPPORT
tools/perf/util/symbol-elf.c:#ifndef HAVE_ELF_GETPHDRNUM_SUPPORT

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-07-16 16:36:49 -07:00
Okash Khawaja
92b57121ca bpf: btf: export btf types and name by offset from lib
This patch introduces btf__resolve_type() function and exports two
existing functions from libbpf. btf__resolve_type follows modifier
types like const and typedef until it hits a type which actually takes
up memory, and then returns it. This function follows similar pattern
to btf__resolve_size but instead of computing size, it just returns
the type.

These  functions will be used in the followig patch which parses
information inside array of `struct btf_type *`. btf_name_by_offset is
used for printing variable names.

Signed-off-by: Okash Khawaja <osk@fb.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-14 13:00:40 +02:00
Jakub Kicinski
26736eb9a4 tools: libbpf: allow map reuse
More advanced applications may want to only replace programs without
destroying associated maps.  Allow libbpf users to achieve that.
Instead of always creating all of the maps at load time, expose to
users an API to reconstruct the map object from already existing
map.

The map parameters are read from the kernel and replace the parameters
of the ELF map.  libbpf does not restrict the map replacement, i.e.
the reused map does not have to be compatible with the ELF map
definition.  We relay on the verifier for checking the compatibility
between maps and programs.  The ELF map definition is completely
overwritten by the information read from the kernel, to make sure
libbpf's view of map object corresponds to the actual map.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Acked-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-11 22:13:34 +02:00
Jakub Kicinski
531b014e7a tools: bpf: make use of reallocarray
reallocarray() is a safer variant of realloc which checks for
multiplication overflow in case of array allocation.  Since it's
not available in Glibc < 2.26 import kernel's overflow.h and
add a static inline implementation when needed.  Use feature
detection to probe for existence of reallocarray.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-11 22:13:34 +02:00
Jakub Kicinski
8d13406c02 tools: libbpf: move library error code into a separate file
libbpf_strerror() depends on XSI-compliant (POSIX) version of
strerror_r(), which prevents us from using GNU-extensions in
libbpf.c, like reallocarray() or dup3().  Move error printing
code into a separate file to allow it to continue using POSIX
strerror_r().

No functional changes.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-11 22:13:34 +02:00
Jakub Kicinski
07f2d4eac2 tools: libbpf: add extended attributes version of bpf_object__open()
Similarly to bpf_prog_load() users of bpf_object__open() may need
to specify the expected program type.  Program type is needed at
open to avoid the kernel version check for program types which don't
require it.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Acked-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-11 22:13:34 +02:00
Jakub Kicinski
f83fb22c6c tools: libbpf: recognize offload neutral maps
Add helper to libbpf for recognizing maps which should not have
ifindex set when program is loaded.  These maps only contain
host metadata and therefore are not marked for offload, e.g.
the perf event map.

Use this helper in bpf_prog_load_xattr().

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-11 22:13:34 +02:00
Jakub Kicinski
b60df2a0e1 tools: libbpf: expose the prog type guessing from section name logic
libbpf can guess program type based on ELF section names.  As libbpf
becomes more popular its association between section name strings and
types becomes more of a standard.  Allow libbpf users to use the same
logic for matching strings to types, e.g. when the string originates
from command line.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Acked-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-11 22:13:33 +02:00
Jakub Kicinski
eac7d84519 tools: libbpf: don't return '.text' as a program for multi-function programs
Make bpf_program__next() skip over '.text' section if object file
has pseudo calls.  The '.text' section is hardly a program in that
case, it's more of a storage for code of functions other than main.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-01 01:01:50 +02:00
Jakub Kicinski
9a94f277c4 tools: libbpf: restore the ability to load programs from .text section
libbpf used to be able to load programs from the default section
called '.text'.  It's not very common to leave sections unnamed,
but if it happens libbpf will fail to load the programs reporting
-EINVAL from the kernel.  The -EINVAL comes from bpf_obj_name_cpy()
because since 48cca7e44f ("libbpf: add support for bpf_call")
libbpf does not resolve program names for programs in '.text',
defaulting to '.text'.  '.text', however, does not pass the
(isalnum(*src) || *src == '_') check in bpf_obj_name_cpy().

With few extra lines of code we can limit the pseudo call
assumptions only to objects which actually contain code relocations.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-01 01:01:50 +02:00
Jakub Kicinski
9aba36139a tools: libbpf: allow setting ifindex for programs and maps
Users of bpf_object__open()/bpf_object__load() APIs may want to
load the programs and maps onto a device for offload.  Allow
setting ifindex on those sub-objects.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-01 01:01:50 +02:00
Jakub Kicinski
d9b683d746 tools: libbpf: add section names for missing program types
Specify default section names for BPF_PROG_TYPE_LIRC_MODE2
and BPF_PROG_TYPE_LWT_SEG6LOCAL, these are the only two
missing right now.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-01 01:01:50 +02:00
Sean Young
6bdd533cee bpf: add selftest for lirc_mode2 type program
This is simple test over rc-loopback.

Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-30 12:40:14 +02:00
Andrey Ignatov
72481f398c libbpf: Support guessing sendmsg{4,6} progs
libbpf can guess prog type and expected attach type based on section
name. Add hints for "cgroup/sendmsg4" and "cgroup/sendmsg6" section
names.

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-28 17:41:03 +02:00
Andrey Ignatov
a493f5f9d8 libbpf: Install btf.h with libbpf
install_headers target should contain all headers that are part of
libbpf. Add missing btf.h

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-28 00:25:32 +02:00
David S. Miller
90fed9c946 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Alexei Starovoitov says:

====================
pull-request: bpf-next 2018-05-24

The following pull-request contains BPF updates for your *net-next* tree.

The main changes are:

1) Björn Töpel cleans up AF_XDP (removes rebind, explicit cache alignment from uapi, etc).

2) David Ahern adds mtu checks to bpf_ipv{4,6}_fib_lookup() helpers.

3) Jesper Dangaard Brouer adds bulking support to ndo_xdp_xmit.

4) Jiong Wang adds support for indirect and arithmetic shifts to NFP

5) Martin KaFai Lau cleans up BTF uapi and makes the btf_header extensible.

6) Mathieu Xhonneux adds an End.BPF action to seg6local with BPF helpers allowing
   to edit/grow/shrink a SRH and apply on a packet generic SRv6 actions.

7) Sandipan Das adds support for bpf2bpf function calls in ppc64 JIT.

8) Yonghong Song adds BPF_TASK_FD_QUERY command for introspection of tracing events.

9) other misc fixes from Gustavo A. R. Silva, Sirio Balmelli, John Fastabend, and Magnus Karlsson
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-24 22:20:51 -04:00
Yonghong Song
30687ad94e tools/bpf: sync kernel header bpf.h and add bpf_task_fd_query in libbpf
Sync kernel header bpf.h to tools/include/uapi/linux/bpf.h and
implement bpf_task_fd_query() in libbpf. The test programs
in samples/bpf and tools/testing/selftests/bpf, and later bpftool
will use this libbpf function to query kernel.

Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-05-24 18:18:19 -07:00
Mathieu Xhonneux
004d4b274e ipv6: sr: Add seg6local action End.BPF
This patch adds the End.BPF action to the LWT seg6local infrastructure.
This action works like any other seg6local End action, meaning that an IPv6
header with SRH is needed, whose DA has to be equal to the SID of the
action. It will also advance the SRH to the next segment, the BPF program
does not have to take care of this.

Since the BPF program may not be a source of instability in the kernel, it
is important to ensure that the integrity of the packet is maintained
before yielding it back to the IPv6 layer. The hook hence keeps track if
the SRH has been altered through the helpers, and re-validates its
content if needed with seg6_validate_srh. The state kept for validation is
stored in a per-CPU buffer. The BPF program is not allowed to directly
write into the packet, and only some fields of the SRH can be altered
through the helper bpf_lwt_seg6_store_bytes.

Performances profiling has shown that the SRH re-validation does not induce
a significant overhead. If the altered SRH is deemed as invalid, the packet
is dropped.

This validation is also done before executing any action through
bpf_lwt_seg6_action, and will not be performed again if the SRH is not
modified after calling the action.

The BPF program may return 3 types of return codes:
    - BPF_OK: the End.BPF action will look up the next destination through
             seg6_lookup_nexthop.
    - BPF_REDIRECT: if an action has been executed through the
          bpf_lwt_seg6_action helper, the BPF program should return this
          value, as the skb's destination is already set and the default
          lookup should not be performed.
    - BPF_DROP : the packet will be dropped.

Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com>
Acked-by: David Lebrun <dlebrun@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-24 11:57:36 +02:00
Sirio Balmelli
a1c818109c tools/lib/libbpf.c: fix string format to allow build on arm32
On arm32, 'cd tools/testing/selftests/bpf && make' fails with:

libbpf.c:80:10: error: format ‘%ld’ expects argument of type ‘long int’, but argument 4 has type ‘int64_t {aka long long int}’ [-Werror=format=]
   (func)("libbpf: " fmt, ##__VA_ARGS__); \
          ^
libbpf.c:83:30: note: in expansion of macro ‘__pr’
 #define pr_warning(fmt, ...) __pr(__pr_warning, fmt, ##__VA_ARGS__)
                              ^~~~
libbpf.c:1072:3: note: in expansion of macro ‘pr_warning’
   pr_warning("map:%s value_type:%s has BTF type_size:%ld != value_size:%u\n",

To fix, typecast 'key_size' and amend format string.

Signed-off-by: Sirio Balmelli <sirio@b-ad.ch>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-23 20:18:00 +02:00
Martin KaFai Lau
61746dbe1a bpf: btf: Add tests for the btf uapi changes
This patch does the followings:
1. Modify libbpf and test_btf to reflect the uapi changes in btf
2. Add test for the btf_header changes
3. Add tests for array->index_type
4. Add err_str check to the tests
5. Fix a 4 bytes hole in "struct test #1" by swapping "m" and "n"

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-23 12:03:32 +02:00
David S. Miller
6f6e434aa2 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
S390 bpf_jit.S is removed in net-next and had changes in 'net',
since that code isn't used any more take the removal.

TLS data structures split the TX and RX components in 'net-next',
put the new struct members from the bug fix in 'net' into the RX
part.

The 'net-next' tree had some reworking of how the ERSPAN code works in
the GRE tunneling code, overlapping with a one-line headroom
calculation fix in 'net'.

Overlapping changes in __sock_map_ctx_update_elem(), keep the bits
that read the prog members via READ_ONCE() into local variables
before using them.

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-21 16:01:54 -04:00
David Beckett
f0307a7ed1 libbpf: add ifindex to enable offload support
BPF programs currently can only be offloaded using iproute2. This
patch will allow programs to be offloaded using libbpf calls.

Signed-off-by: David Beckett <david.beckett@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-17 00:54:26 +02:00
Jakub Kicinski
17387dd5ac tools: bpf: don't complain about no kernel version for networking code
BPF programs only have to specify the target kernel version for
tracing related hooks, in networking world that requirement does
not really apply.  Loosen the checks in libbpf to reflect that.

bpf_object__open() users will continue to see the error for backward
compatibility (and because prog_type is not available there).

Error code for NULL file name is changed from ENOENT to EINVAL,
as it seems more appropriate, hopefully, that's an OK change.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-11 01:40:52 +02:00
Jakub Kicinski
2eb57bb8f6 tools: bpf: improve comments in libbpf.h
Fix spelling mistakes, improve and clarify the language of comments
in libbpf.h.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-11 01:40:52 +02:00
Jakub Kicinski
d0cabbb021 tools: bpf: move the event reading loop to libbpf
There are two copies of event reading loop - in bpftool and
trace_helpers "library".  Consolidate them and move the code
to libbpf.  Return codes from trace_helpers are kept, but
renamed to include LIBBPF prefix.

Suggested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-11 01:40:52 +02:00
Jakub Kicinski
3597683c9d tools: bpf: handle NULL return in bpf_prog_load_xattr()
bpf_object__open() can return error pointer as well as NULL.
Fix error handling in bpf_prog_load_xattr() (and indirectly
bpf_prog_load()).

Fixes: 6f6d33f3b3 ("bpf: selftests add sockmap tests")
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-11 00:20:53 +02:00
Martin KaFai Lau
cd8b89280c bpf: btf: Tests for BPF_OBJ_GET_INFO_BY_FD and BPF_BTF_GET_FD_BY_ID
This patch adds test for BPF_BTF_GET_FD_BY_ID and the new
btf_id/btf_key_id/btf_value_id in the "struct bpf_map_info".

It also modifies the existing BPF_OBJ_GET_INFO_BY_FD test
to reflect the new "struct bpf_btf_info".

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Alexei Starovoitov <ast@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-09 17:25:14 +02:00