summaryrefslogtreecommitdiffstats
path: root/include/uapi/linux/bpf.h
Commit message (Collapse)AuthorAgeFilesLines
* sock: make cookie generation global instead of per netnsDaniel Borkmann2019-08-091-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | Generating and retrieving socket cookies are a useful feature that is exposed to BPF for various program types through bpf_get_socket_cookie() helper. The fact that the cookie counter is per netns is quite a limitation for BPF in practice in particular for programs in host namespace that use socket cookies as part of a map lookup key since they will be causing socket cookie collisions e.g. when attached to BPF cgroup hooks or cls_bpf on tc egress in host namespace handling container traffic from veth or ipvlan devices with peer in different netns. Change the counter to be global instead. Socket cookie consumers must assume the value as opqaue in any case. Not every socket must have a cookie generated and knowledge of the counter value itself does not provide much value either way hence conversion to global is fine. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Cc: Eric Dumazet <edumazet@google.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Willem de Bruijn <willemb@google.com> Cc: Martynas Pumputis <m@lambda.lt> Signed-off-by: David S. Miller <davem@davemloft.net>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds2019-07-191-2/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull networking fixes from David Miller: 1) Fix AF_XDP cq entry leak, from Ilya Maximets. 2) Fix handling of PHY power-down on RTL8411B, from Heiner Kallweit. 3) Add some new PCI IDs to iwlwifi, from Ihab Zhaika. 4) Fix handling of neigh timers wrt. entries added by userspace, from Lorenzo Bianconi. 5) Various cases of missing of_node_put(), from Nishka Dasgupta. 6) The new NET_ACT_CT needs to depend upon NF_NAT, from Yue Haibing. 7) Various RDS layer fixes, from Gerd Rausch. 8) Fix some more fallout from TCQ_F_CAN_BYPASS generalization, from Cong Wang. 9) Fix FIB source validation checks over loopback, also from Cong Wang. 10) Use promisc for unsupported number of filters, from Justin Chen. 11) Missing sibling route unlink on failure in ipv6, from Ido Schimmel. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (90 commits) tcp: fix tcp_set_congestion_control() use from bpf hook ag71xx: fix return value check in ag71xx_probe() ag71xx: fix error return code in ag71xx_probe() usb: qmi_wwan: add D-Link DWM-222 A2 device ID bnxt_en: Fix VNIC accounting when enabling aRFS on 57500 chips. net: dsa: sja1105: Fix missing unlock on error in sk_buff() gve: replace kfree with kvfree selftests/bpf: fix test_xdp_noinline on s390 selftests/bpf: fix "valid read map access into a read-only array 1" on s390 net/mlx5: Replace kfree with kvfree MAINTAINERS: update netsec driver ipv6: Unlink sibling route in case of failure liquidio: Replace vmalloc + memset with vzalloc udp: Fix typo in net/ipv4/udp.c net: bcmgenet: use promisc for unsupported filters ipv6: rt6_check should return NULL if 'from' is NULL tipc: initialize 'validated' field of received packets selftests: add a test case for rp_filter fib: relax source validation check for loopback packets mlxsw: spectrum: Do not process learned records with a dummy FID ...
| * bpf: allow wide aligned loads for bpf_sock_addr user_ip6 and msg_src_ip6Stanislav Fomichev2019-07-151-2/+2
| | | | | | | | | | | | | | | | | | Add explicit check for u64 loads of user_ip6 and msg_src_ip6 and update the comment. Cc: Yonghong Song <yhs@fb.com> Signed-off-by: Stanislav Fomichev <sdf@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* | docs: cgroup-v1: add it to the admin-guide bookMauro Carvalho Chehab2019-07-151-1/+1
|/ | | | | | Those files belong to the admin guide, so add them. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-nextLinus Torvalds2019-07-111-7/+74
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull networking updates from David Miller: "Some highlights from this development cycle: 1) Big refactoring of ipv6 route and neigh handling to support nexthop objects configurable as units from userspace. From David Ahern. 2) Convert explored_states in BPF verifier into a hash table, significantly decreased state held for programs with bpf2bpf calls, from Alexei Starovoitov. 3) Implement bpf_send_signal() helper, from Yonghong Song. 4) Various classifier enhancements to mvpp2 driver, from Maxime Chevallier. 5) Add aRFS support to hns3 driver, from Jian Shen. 6) Fix use after free in inet frags by allocating fqdirs dynamically and reworking how rhashtable dismantle occurs, from Eric Dumazet. 7) Add act_ctinfo packet classifier action, from Kevin Darbyshire-Bryant. 8) Add TFO key backup infrastructure, from Jason Baron. 9) Remove several old and unused ISDN drivers, from Arnd Bergmann. 10) Add devlink notifications for flash update status to mlxsw driver, from Jiri Pirko. 11) Lots of kTLS offload infrastructure fixes, from Jakub Kicinski. 12) Add support for mv88e6250 DSA chips, from Rasmus Villemoes. 13) Various enhancements to ipv6 flow label handling, from Eric Dumazet and Willem de Bruijn. 14) Support TLS offload in nfp driver, from Jakub Kicinski, Dirk van der Merwe, and others. 15) Various improvements to axienet driver including converting it to phylink, from Robert Hancock. 16) Add PTP support to sja1105 DSA driver, from Vladimir Oltean. 17) Add mqprio qdisc offload support to dpaa2-eth, from Ioana Radulescu. 18) Add devlink health reporting to mlx5, from Moshe Shemesh. 19) Convert stmmac over to phylink, from Jose Abreu. 20) Add PTP PHC (Physical Hardware Clock) support to mlxsw, from Shalom Toledo. 21) Add nftables SYNPROXY support, from Fernando Fernandez Mancera. 22) Convert tcp_fastopen over to use SipHash, from Ard Biesheuvel. 23) Track spill/fill of constants in BPF verifier, from Alexei Starovoitov. 24) Support bounded loops in BPF, from Alexei Starovoitov. 25) Various page_pool API fixes and improvements, from Jesper Dangaard Brouer. 26) Just like ipv4, support ref-countless ipv6 route handling. From Wei Wang. 27) Support VLAN offloading in aquantia driver, from Igor Russkikh. 28) Add AF_XDP zero-copy support to mlx5, from Maxim Mikityanskiy. 29) Add flower GRE encap/decap support to nfp driver, from Pieter Jansen van Vuuren. 30) Protect against stack overflow when using act_mirred, from John Hurley. 31) Allow devmap map lookups from eBPF, from Toke Høiland-Jørgensen. 32) Use page_pool API in netsec driver, Ilias Apalodimas. 33) Add Google gve network driver, from Catherine Sullivan. 34) More indirect call avoidance, from Paolo Abeni. 35) Add kTLS TX HW offload support to mlx5, from Tariq Toukan. 36) Add XDP_REDIRECT support to bnxt_en, from Andy Gospodarek. 37) Add MPLS manipulation actions to TC, from John Hurley. 38) Add sending a packet to connection tracking from TC actions, and then allow flower classifier matching on conntrack state. From Paul Blakey. 39) Netfilter hw offload support, from Pablo Neira Ayuso" * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (2080 commits) net/mlx5e: Return in default case statement in tx_post_resync_params mlx5: Return -EINVAL when WARN_ON_ONCE triggers in mlx5e_tls_resync(). net: dsa: add support for BRIDGE_MROUTER attribute pkt_sched: Include const.h net: netsec: remove static declaration for netsec_set_tx_de() net: netsec: remove superfluous if statement netfilter: nf_tables: add hardware offload support net: flow_offload: rename tc_cls_flower_offload to flow_cls_offload net: flow_offload: add flow_block_cb_is_busy() and use it net: sched: remove tcf block API drivers: net: use flow block API net: sched: use flow block API net: flow_offload: add flow_block_cb_{priv, incref, decref}() net: flow_offload: add list handling functions net: flow_offload: add flow_block_cb_alloc() and flow_block_cb_free() net: flow_offload: rename TCF_BLOCK_BINDER_TYPE_* to FLOW_BLOCK_BINDER_TYPE_* net: flow_offload: rename TC_BLOCK_{UN}BIND to FLOW_BLOCK_{UN}BIND net: flow_offload: add flow_block_cb_setup_simple() net: hisilicon: Add an tx_desc to adapt HI13X1_GMAC net: hisilicon: Add an rx_desc to adapt HI13X1_GMAC ...
| * Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller2019-07-091-0/+1
| |\ | | | | | | | | | | | | | | | Two cases of overlapping changes, nothing fancy. Signed-off-by: David S. Miller <davem@davemloft.net>
| | * bpf: fix uapi bpf_prog_info fields alignmentBaruch Siach2019-06-291-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge commit 1c8c5a9d38f60 ("Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next") undid the fix from commit 36f9814a494 ("bpf: fix uapi hole for 32 bit compat applications") by taking the gpl_compatible 1-bit field definition from commit b85fab0e67b162 ("bpf: Add gpl_compatible flag to struct bpf_prog_info") as is. That breaks architectures with 16-bit alignment like m68k. Add 31-bit pad after gpl_compatible to restore alignment of following fields. Thanks to Dmitry V. Levin his analysis of this bug history. Signed-off-by: Baruch Siach <baruch@tkos.co.il> Acked-by: Song Liu <songliubraving@fb.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| * | bpf: allow wide (u64) aligned stores for some fields of bpf_sock_addrStanislav Fomichev2019-07-081-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since commit cd17d7770578 ("bpf/tools: sync bpf.h") clang decided that it can do a single u64 store into user_ip6[2] instead of two separate u32 ones: # 17: (18) r2 = 0x100000000000000 # ; ctx->user_ip6[2] = bpf_htonl(DST_REWRITE_IP6_2); # 19: (7b) *(u64 *)(r1 +16) = r2 # invalid bpf_context access off=16 size=8 >From the compiler point of view it does look like a correct thing to do, so let's support it on the kernel side. Credit to Andrii Nakryiko for a proper implementation of bpf_ctx_wide_store_ok. Cc: Andrii Nakryiko <andriin@fb.com> Cc: Yonghong Song <yhs@fb.com> Fixes: cd17d7770578 ("bpf/tools: sync bpf.h") Reported-by: kernel test robot <rong.a.chen@intel.com> Acked-by: Yonghong Song <yhs@fb.com> Acked-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Stanislav Fomichev <sdf@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| * | bpf: add icsk_retransmits to bpf_tcp_sockStanislav Fomichev2019-07-031-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add some inet_connection_sock fields to bpf_tcp_sock that might be useful for debugging congestion control issues. Cc: Eric Dumazet <edumazet@google.com> Cc: Priyaranjan Jha <priyarjha@google.com> Cc: Yuchung Cheng <ycheng@google.com> Cc: Soheil Hassas Yeganeh <soheil@google.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Acked-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Stanislav Fomichev <sdf@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| * | bpf: add dsack_dups/delivered{, _ce} to bpf_tcp_sockStanislav Fomichev2019-07-031-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add more fields to bpf_tcp_sock that might be useful for debugging congestion control issues. Cc: Eric Dumazet <edumazet@google.com> Cc: Priyaranjan Jha <priyarjha@google.com> Cc: Yuchung Cheng <ycheng@google.com> Cc: Soheil Hassas Yeganeh <soheil@google.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Acked-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Stanislav Fomichev <sdf@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| * | bpf: add BPF_CGROUP_SOCK_OPS callback that is executed on every RTTStanislav Fomichev2019-07-031-1/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Performance impact should be minimal because it's under a new BPF_SOCK_OPS_RTT_CB_FLAG flag that has to be explicitly enabled. Suggested-by: Eric Dumazet <edumazet@google.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Priyaranjan Jha <priyarjha@google.com> Cc: Yuchung Cheng <ycheng@google.com> Cc: Soheil Hassas Yeganeh <soheil@google.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Acked-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Stanislav Fomichev <sdf@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| * | bpf_xdp_redirect_map: Perform map lookup in eBPF helperToke Høiland-Jørgensen2019-06-291-2/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The bpf_redirect_map() helper used by XDP programs doesn't return any indication of whether it can successfully redirect to the map index it was given. Instead, BPF programs have to track this themselves, leading to programs using duplicate maps to track which entries are populated in the devmap. This patch fixes this by moving the map lookup into the bpf_redirect_map() helper, which makes it possible to return failure to the eBPF program. The lower bits of the flags argument is used as the return code, which means that existing users who pass a '0' flag argument will get XDP_ABORTED. With this, a BPF program can check the return code from the helper call and react by, for instance, substituting a different redirect. This works for any type of map used for redirect. Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Acked-by: Jonathan Lemon <jonathan.lemon@gmail.com> Acked-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| * | bpf: implement getsockopt and setsockopt hooksStanislav Fomichev2019-06-281-0/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Implement new BPF_PROG_TYPE_CGROUP_SOCKOPT program type and BPF_CGROUP_{G,S}ETSOCKOPT cgroup hooks. BPF_CGROUP_SETSOCKOPT can modify user setsockopt arguments before passing them down to the kernel or bypass kernel completely. BPF_CGROUP_GETSOCKOPT can can inspect/modify getsockopt arguments that kernel returns. Both hooks reuse existing PTR_TO_PACKET{,_END} infrastructure. The buffer memory is pre-allocated (because I don't think there is a precedent for working with __user memory from bpf). This might be slow to do for each {s,g}etsockopt call, that's why I've added __cgroup_bpf_prog_array_is_empty that exits early if there is nothing attached to a cgroup. Note, however, that there is a race between __cgroup_bpf_prog_array_is_empty and BPF_PROG_RUN_ARRAY where cgroup program layout might have changed; this should not be a problem because in general there is a race between multiple calls to {s,g}etsocktop and user adding/removing bpf progs from a cgroup. The return code of the BPF program is handled as follows: * 0: EPERM * 1: success, continue with next BPF program in the cgroup chain v9: * allow overwriting setsockopt arguments (Alexei Starovoitov): * use set_fs (same as kernel_setsockopt) * buffer is always kzalloc'd (no small on-stack buffer) v8: * use s32 for optlen (Andrii Nakryiko) v7: * return only 0 or 1 (Alexei Starovoitov) * always run all progs (Alexei Starovoitov) * use optval=0 as kernel bypass in setsockopt (Alexei Starovoitov) (decided to use optval=-1 instead, optval=0 might be a valid input) * call getsockopt hook after kernel handlers (Alexei Starovoitov) v6: * rework cgroup chaining; stop as soon as bpf program returns 0 or 2; see patch with the documentation for the details * drop Andrii's and Martin's Acked-by (not sure they are comfortable with the new state of things) v5: * skip copy_to_user() and put_user() when ret == 0 (Martin Lau) v4: * don't export bpf_sk_fullsock helper (Martin Lau) * size != sizeof(__u64) for uapi pointers (Martin Lau) * offsetof instead of bpf_ctx_range when checking ctx access (Martin Lau) v3: * typos in BPF_PROG_CGROUP_SOCKOPT_RUN_ARRAY comments (Andrii Nakryiko) * reverse christmas tree in BPF_PROG_CGROUP_SOCKOPT_RUN_ARRAY (Andrii Nakryiko) * use __bpf_md_ptr instead of __u32 for optval{,_end} (Martin Lau) * use BPF_FIELD_SIZEOF() for consistency (Martin Lau) * new CG_SOCKOPT_ACCESS macro to wrap repeated parts v2: * moved bpf_sockopt_kern fields around to remove a hole (Martin Lau) * aligned bpf_sockopt_kern->buf to 8 bytes (Martin Lau) * bpf_prog_array_is_empty instead of bpf_prog_array_length (Martin Lau) * added [0,2] return code check to verifier (Martin Lau) * dropped unused buf[64] from the stack (Martin Lau) * use PTR_TO_SOCKET for bpf_sockopt->sk (Martin Lau) * dropped bpf_target_off from ctx rewrites (Martin Lau) * use return code for kernel bypass (Martin Lau & Andrii Nakryiko) Cc: Andrii Nakryiko <andriin@fb.com> Cc: Martin Lau <kafai@fb.com> Signed-off-by: Stanislav Fomichev <sdf@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * | Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextDavid S. Miller2019-06-201-0/+6
| |\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Alexei Starovoitov says: ==================== pull-request: bpf-next 2019-06-19 The following pull-request contains BPF updates for your *net-next* tree. The main changes are: 1) new SO_REUSEPORT_DETACH_BPF setsocktopt, from Martin. 2) BTF based map definition, from Andrii. 3) support bpf_map_lookup_elem for xskmap, from Jonathan. 4) bounded loops and scalar precision logic in the verifier, from Alexei. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
| | * | bpf: export bpf_sock for BPF_PROG_TYPE_SOCK_OPS prog typeStanislav Fomichev2019-06-151-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | And let it use bpf_sk_storage_{get,delete} helpers to access socket storage. Kernel context (struct bpf_sock_ops_kern) already has sk member, so I just expose it to the BPF hooks. I use PTR_TO_SOCKET_OR_NULL and return NULL in !is_fullsock case. I also export bpf_tcp_sock to make it possible to access tcp socket stats. Cc: Martin Lau <kafai@fb.com> Signed-off-by: Stanislav Fomichev <sdf@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| | * | bpf: export bpf_sock for BPF_PROG_TYPE_CGROUP_SOCK_ADDR prog typeStanislav Fomichev2019-06-151-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | And let it use bpf_sk_storage_{get,delete} helpers to access socket storage. Kernel context (struct bpf_sock_addr_kern) already has sk member, so I just expose it to the BPF hooks. Using PTR_TO_SOCKET instead of PTR_TO_SOCK_COMMON should be safe because the hook is called on bind/connect. Cc: Martin Lau <kafai@fb.com> Signed-off-by: Stanislav Fomichev <sdf@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| | * | bpf: Allow bpf_map_lookup_elem() on an xskmapJonathan Lemon2019-06-111-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, the AF_XDP code uses a separate map in order to determine if an xsk is bound to a queue. Instead of doing this, have bpf_map_lookup_elem() return a xdp_sock. Rearrange some xdp_sock members to eliminate structure holes. Remove selftest - will be added back in later patch. Signed-off-by: Jonathan Lemon <jonathan.lemon@gmail.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * | | Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller2019-06-181-2/+4
| |\ \ \ | | |/ / | |/| / | | |/ | | | | | | | | | Honestly all the conflicts were simple overlapping changes, nothing really interesting to report. Signed-off-by: David S. Miller <davem@davemloft.net>
| * | bpf: introduce new bpf prog load flags "BPF_F_TEST_RND_HI32"Jiong Wang2019-05-251-0/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | x86_64 and AArch64 perhaps are two arches that running bpf testsuite frequently, however the zero extension insertion pass is not enabled for them because of their hardware support. It is critical to guarantee the pass correction as it is supposed to be enabled at default for a couple of other arches, for example PowerPC, SPARC, arm, NFP etc. Therefore, it would be very useful if there is a way to test this pass on for example x86_64. The test methodology employed by this set is "poisoning" useless bits. High 32-bit of a definition is randomized if it is identified as not used by any later insn. Such randomization is only enabled under testing mode which is gated by the new bpf prog load flags "BPF_F_TEST_RND_HI32". Suggested-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Jiong Wang <jiong.wang@netronome.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * | bpf: implement bpf_send_signal() helperYonghong Song2019-05-241-1/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch tries to solve the following specific use case. Currently, bpf program can already collect stack traces through kernel function get_perf_callchain() when certain events happens (e.g., cache miss counter or cpu clock counter overflows). But such stack traces are not enough for jitted programs, e.g., hhvm (jited php). To get real stack trace, jit engine internal data structures need to be traversed in order to get the real user functions. bpf program itself may not be the best place to traverse the jit engine as the traversing logic could be complex and it is not a stable interface either. Instead, hhvm implements a signal handler, e.g. for SIGALARM, and a set of program locations which it can dump stack traces. When it receives a signal, it will dump the stack in next such program location. Such a mechanism can be implemented in the following way: . a perf ring buffer is created between bpf program and tracing app. . once a particular event happens, bpf program writes to the ring buffer and the tracing app gets notified. . the tracing app sends a signal SIGALARM to the hhvm. But this method could have large delays and causing profiling results skewed. This patch implements bpf_send_signal() helper to send a signal to hhvm in real time, resulting in intended stack traces. Acked-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* | | Merge branch 'for-5.3' of ↵Linus Torvalds2019-07-091-1/+1
|\ \ \ | |_|/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup updates from Tejun Heo: "Documentation updates and the addition of cgroup_parse_float() which will be used by new controllers including blk-iocost" * 'for-5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: docs: cgroup-v1: convert docs to ReST and rename to *.rst cgroup: Move cgroup_parse_float() implementation out of CONFIG_SYSFS cgroup: add cgroup_parse_float()
| * | docs: cgroup-v1: convert docs to ReST and rename to *.rstMauro Carvalho Chehab2019-06-141-1/+1
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Convert the cgroup-v1 files to ReST format, in order to allow a later addition to the admin-guide. The conversion is actually: - add blank lines and identation in order to identify paragraphs; - fix tables markups; - add some lists markups; - mark literal blocks; - adjust title markups. At its new index.rst, let's add a :orphan: while this is not linked to the main index.rst file, in order to avoid build warnings. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Tejun Heo <tj@kernel.org>
* | bpf: simplify definition of BPF_FIB_LOOKUP related flagsMartynas Pumputis2019-06-131-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Previously, the BPF_FIB_LOOKUP_{DIRECT,OUTPUT} flags in the BPF UAPI were defined with the help of BIT macro. This had the following issues: - In order to use any of the flags, a user was required to depend on <linux/bits.h>. - No other flag in bpf.h uses the macro, so it seems that an unwritten convention is to use (1 << (nr)) to define BPF-related flags. Fixes: 87f5fc7e48dd ("bpf: Provide helper to do forwarding lookups in kernel FIB table") Signed-off-by: Martynas Pumputis <m@lambda.lt> Acked-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* | bpf: fix unconnected udp hooksDaniel Borkmann2019-06-071-0/+2
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Intention of cgroup bind/connect/sendmsg BPF hooks is to act transparently to applications as also stated in original motivation in 7828f20e3779 ("Merge branch 'bpf-cgroup-bind-connect'"). When recently integrating the latter two hooks into Cilium to enable host based load-balancing with Kubernetes, I ran into the issue that pods couldn't start up as DNS got broken. Kubernetes typically sets up DNS as a service and is thus subject to load-balancing. Upon further debugging, it turns out that the cgroupv2 sendmsg BPF hooks API is currently insufficient and thus not usable as-is for standard applications shipped with most distros. To break down the issue we ran into with a simple example: # cat /etc/resolv.conf nameserver 147.75.207.207 nameserver 147.75.207.208 For the purpose of a simple test, we set up above IPs as service IPs and transparently redirect traffic to a different DNS backend server for that node: # cilium service list ID Frontend Backend 1 147.75.207.207:53 1 => 8.8.8.8:53 2 147.75.207.208:53 1 => 8.8.8.8:53 The attached BPF program is basically selecting one of the backends if the service IP/port matches on the cgroup hook. DNS breaks here, because the hooks are not transparent enough to applications which have built-in msg_name address checks: # nslookup 1.1.1.1 ;; reply from unexpected source: 8.8.8.8#53, expected 147.75.207.207#53 ;; reply from unexpected source: 8.8.8.8#53, expected 147.75.207.208#53 ;; reply from unexpected source: 8.8.8.8#53, expected 147.75.207.207#53 [...] ;; connection timed out; no servers could be reached # dig 1.1.1.1 ;; reply from unexpected source: 8.8.8.8#53, expected 147.75.207.207#53 ;; reply from unexpected source: 8.8.8.8#53, expected 147.75.207.208#53 ;; reply from unexpected source: 8.8.8.8#53, expected 147.75.207.207#53 [...] ; <<>> DiG 9.11.3-1ubuntu1.7-Ubuntu <<>> 1.1.1.1 ;; global options: +cmd ;; connection timed out; no servers could be reached For comparison, if none of the service IPs is used, and we tell nslookup to use 8.8.8.8 directly it works just fine, of course: # nslookup 1.1.1.1 8.8.8.8 1.1.1.1.in-addr.arpa name = one.one.one.one. In order to fix this and thus act more transparent to the application, this needs reverse translation on recvmsg() side. A minimal fix for this API is to add similar recvmsg() hooks behind the BPF cgroups static key such that the program can track state and replace the current sockaddr_in{,6} with the original service IP. From BPF side, this basically tracks the service tuple plus socket cookie in an LRU map where the reverse NAT can then be retrieved via map value as one example. Side-note: the BPF cgroups static key should be converted to a per-hook static key in future. Same example after this fix: # cilium service list ID Frontend Backend 1 147.75.207.207:53 1 => 8.8.8.8:53 2 147.75.207.208:53 1 => 8.8.8.8:53 Lookups work fine now: # nslookup 1.1.1.1 1.1.1.1.in-addr.arpa name = one.one.one.one. Authoritative answers can be found from: # dig 1.1.1.1 ; <<>> DiG 9.11.3-1ubuntu1.7-Ubuntu <<>> 1.1.1.1 ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 51550 ;; flags: qr rd ra ad; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1 ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 512 ;; QUESTION SECTION: ;1.1.1.1. IN A ;; AUTHORITY SECTION: . 23426 IN SOA a.root-servers.net. nstld.verisign-grs.com. 2019052001 1800 900 604800 86400 ;; Query time: 17 msec ;; SERVER: 147.75.207.207#53(147.75.207.207) ;; WHEN: Tue May 21 12:59:38 UTC 2019 ;; MSG SIZE rcvd: 111 And from an actual packet level it shows that we're using the back end server when talking via 147.75.207.20{7,8} front end: # tcpdump -i any udp [...] 12:59:52.698732 IP foo.42011 > google-public-dns-a.google.com.domain: 18803+ PTR? 1.1.1.1.in-addr.arpa. (38) 12:59:52.698735 IP foo.42011 > google-public-dns-a.google.com.domain: 18803+ PTR? 1.1.1.1.in-addr.arpa. (38) 12:59:52.701208 IP google-public-dns-a.google.com.domain > foo.42011: 18803 1/0/0 PTR one.one.one.one. (67) 12:59:52.701208 IP google-public-dns-a.google.com.domain > foo.42011: 18803 1/0/0 PTR one.one.one.one. (67) [...] In order to be flexible and to have same semantics as in sendmsg BPF programs, we only allow return codes in [1,1] range. In the sendmsg case the program is called if msg->msg_name is present which can be the case in both, connected and unconnected UDP. The former only relies on the sockaddr_in{,6} passed via connect(2) if passed msg->msg_name was NULL. Therefore, on recvmsg side, we act in similar way to call into the BPF program whenever a non-NULL msg->msg_name was passed independent of sk->sk_state being TCP_ESTABLISHED or not. Note that for TCP case, the msg->msg_name is ignored in the regular recvmsg path and therefore not relevant. For the case of ip{,v6}_recv_error() paths, picked up via MSG_ERRQUEUE, the hook is not called. This is intentional as it aligns with the same semantics as in case of TCP cgroup BPF hooks right now. This might be better addressed in future through a different bpf_attach_type such that this case can be distinguished from the regular recvmsg paths, for example. Fixes: 1cedee13d25a ("bpf: Hooks for sys_sendmsg") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Andrey Ignatov <rdna@fb.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Martynas Pumputis <m@lambda.lt> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* bpf: fix minor issues in documentation for BPF helpers.Quentin Monnet2019-05-131-49/+54
| | | | | | | | | | | | | | This commit brings many minor fixes to the documentation for BPF helper functions. Mostly, this is limited to formatting fixes and improvements. In particular, fix broken formatting for bpf_skb_adjust_room(). Besides formatting, replace the mention of "bpf_fullsock()" (that is not associated with any function or type exposed to the user) in the description of bpf_sk_storage_get() by "full socket". Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com> Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* bpf: fix recurring typo in documentation for BPF helpersQuentin Monnet2019-05-131-19/+19
| | | | | | | | | | | "Underlaying packet buffer" should be an "underlying" one, in the warning about invalidated data and data_end pointers. Through copy-and-paste, the typo occurred no fewer than 19 times in the documentation. Let's fix it. Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com> Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* bpf: Introduce bpf sk local storageMartin KaFai Lau2019-04-271-1/+43
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | After allowing a bpf prog to - directly read the skb->sk ptr - get the fullsock bpf_sock by "bpf_sk_fullsock()" - get the bpf_tcp_sock by "bpf_tcp_sock()" - get the listener sock by "bpf_get_listener_sock()" - avoid duplicating the fields of "(bpf_)sock" and "(bpf_)tcp_sock" into different bpf running context. this patch is another effort to make bpf's network programming more intuitive to do (together with memory and performance benefit). When bpf prog needs to store data for a sk, the current practice is to define a map with the usual 4-tuples (src/dst ip/port) as the key. If multiple bpf progs require to store different sk data, multiple maps have to be defined. Hence, wasting memory to store the duplicated keys (i.e. 4 tuples here) in each of the bpf map. [ The smallest key could be the sk pointer itself which requires some enhancement in the verifier and it is a separate topic. ] Also, the bpf prog needs to clean up the elem when sk is freed. Otherwise, the bpf map will become full and un-usable quickly. The sk-free tracking currently could be done during sk state transition (e.g. BPF_SOCK_OPS_STATE_CB). The size of the map needs to be predefined which then usually ended-up with an over-provisioned map in production. Even the map was re-sizable, while the sk naturally come and go away already, this potential re-size operation is arguably redundant if the data can be directly connected to the sk itself instead of proxy-ing through a bpf map. This patch introduces sk->sk_bpf_storage to provide local storage space at sk for bpf prog to use. The space will be allocated when the first bpf prog has created data for this particular sk. The design optimizes the bpf prog's lookup (and then optionally followed by an inline update). bpf_spin_lock should be used if the inline update needs to be protected. BPF_MAP_TYPE_SK_STORAGE: ----------------------- To define a bpf "sk-local-storage", a BPF_MAP_TYPE_SK_STORAGE map (new in this patch) needs to be created. Multiple BPF_MAP_TYPE_SK_STORAGE maps can be created to fit different bpf progs' needs. The map enforces BTF to allow printing the sk-local-storage during a system-wise sk dump (e.g. "ss -ta") in the future. The purpose of a BPF_MAP_TYPE_SK_STORAGE map is not for lookup/update/delete a "sk-local-storage" data from a particular sk. Think of the map as a meta-data (or "type") of a "sk-local-storage". This particular "type" of "sk-local-storage" data can then be stored in any sk. The main purposes of this map are mostly: 1. Define the size of a "sk-local-storage" type. 2. Provide a similar syscall userspace API as the map (e.g. lookup/update, map-id, map-btf...etc.) 3. Keep track of all sk's storages of this "type" and clean them up when the map is freed. sk->sk_bpf_storage: ------------------ The main lookup/update/delete is done on sk->sk_bpf_storage (which is a "struct bpf_sk_storage"). When doing a lookup, the "map" pointer is now used as the "key" to search on the sk_storage->list. The "map" pointer is actually serving as the "type" of the "sk-local-storage" that is being requested. To allow very fast lookup, it should be as fast as looking up an array at a stable-offset. At the same time, it is not ideal to set a hard limit on the number of sk-local-storage "type" that the system can have. Hence, this patch takes a cache approach. The last search result from sk_storage->list is cached in sk_storage->cache[] which is a stable sized array. Each "sk-local-storage" type has a stable offset to the cache[] array. In the future, a map's flag could be introduced to do cache opt-out/enforcement if it became necessary. The cache size is 16 (i.e. 16 types of "sk-local-storage"). Programs can share map. On the program side, having a few bpf_progs running in the networking hotpath is already a lot. The bpf_prog should have already consolidated the existing sock-key-ed map usage to minimize the map lookup penalty. 16 has enough runway to grow. All sk-local-storage data will be removed from sk->sk_bpf_storage during sk destruction. bpf_sk_storage_get() and bpf_sk_storage_delete(): ------------------------------------------------ Instead of using bpf_map_(lookup|update|delete)_elem(), the bpf prog needs to use the new helper bpf_sk_storage_get() and bpf_sk_storage_delete(). The verifier can then enforce the ARG_PTR_TO_SOCKET argument. The bpf_sk_storage_get() also allows to "create" new elem if one does not exist in the sk. It is done by the new BPF_SK_STORAGE_GET_F_CREATE flag. An optional value can also be provided as the initial value during BPF_SK_STORAGE_GET_F_CREATE. The BPF_MAP_TYPE_SK_STORAGE also supports bpf_spin_lock. Together, it has eliminated the potential use cases for an equivalent bpf_map_update_elem() API (for bpf_prog) in this patch. Misc notes: ---------- 1. map_get_next_key is not supported. From the userspace syscall perspective, the map has the socket fd as the key while the map can be shared by pinned-file or map-id. Since btf is enforced, the existing "ss" could be enhanced to pretty print the local-storage. Supporting a kernel defined btf with 4 tuples as the return key could be explored later also. 2. The sk->sk_lock cannot be acquired. Atomic operations is used instead. e.g. cmpxchg is done on the sk->sk_bpf_storage ptr. Please refer to the source code comments for the details in synchronization cases and considerations. 3. The mem is charged to the sk->sk_omem_alloc as the sk filter does. Benchmark: --------- Here is the benchmark data collected by turning on the "kernel.bpf_stats_enabled" sysctl. Two bpf progs are tested: One bpf prog with the usual bpf hashmap (max_entries = 8192) with the sk ptr as the key. (verifier is modified to support sk ptr as the key That should have shortened the key lookup time.) Another bpf prog is with the new BPF_MAP_TYPE_SK_STORAGE. Both are storing a "u32 cnt", do a lookup on "egress_skb/cgroup" for each egress skb and then bump the cnt. netperf is used to drive data with 4096 connected UDP sockets. BPF_MAP_TYPE_HASH with a modifier verifier (152ns per bpf run) 27: cgroup_skb name egress_sk_map tag 74f56e832918070b run_time_ns 58280107540 run_cnt 381347633 loaded_at 2019-04-15T13:46:39-0700 uid 0 xlated 344B jited 258B memlock 4096B map_ids 16 btf_id 5 BPF_MAP_TYPE_SK_STORAGE in this patch (66ns per bpf run) 30: cgroup_skb name egress_sk_stora tag d4aa70984cc7bbf6 run_time_ns 25617093319 run_cnt 390989739 loaded_at 2019-04-15T13:47:54-0700 uid 0 xlated 168B jited 156B memlock 4096B map_ids 17 btf_id 6 Here is a high-level picture on how are the objects organized: sk ┌──────┐ │ │ │ │ │ │ │*sk_bpf_storage─────▶ bpf_sk_storage └──────┘ ┌───────┐ ┌───────────┤ list │ │ │ │ │ │ │ │ │ │ │ └───────┘ │ │ elem │ ┌────────┐ ├─▶│ snode │ │ ├────────┤ │ │ data │ bpf_map │ ├────────┤ ┌─────────┐ │ │map_node│◀─┬─────┤ list │ │ └────────┘ │ │ │ │ │ │ │ │ elem │ │ │ │ ┌────────┐ │ └─────────┘ └─▶│ snode │ │ ├────────┤ │ bpf_map │ data │ │ ┌─────────┐ ├────────┤ │ │ list ├───────▶│map_node│ │ │ │ └────────┘ │ │ │ │ │ │ elem │ └─────────┘ ┌────────┐ │ ┌─▶│ snode │ │ │ ├────────┤ │ │ │ data │ │ │ ├────────┤ │ │ │map_node│◀─┘ │ └────────┘ │ │ │ ┌───────┐ sk └──────────│ list │ ┌──────┐ │ │ │ │ │ │ │ │ │ │ │ │ └───────┘ │*sk_bpf_storage───────▶bpf_sk_storage └──────┘ Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* bpf: add writable context for raw tracepointsMatt Mullins2019-04-271-0/+1
| | | | | | | | | | | | | | | | | | This is an opt-in interface that allows a tracepoint to provide a safe buffer that can be written from a BPF_PROG_TYPE_RAW_TRACEPOINT program. The size of the buffer must be a compile-time constant, and is checked before allowing a BPF program to attach to a tracepoint that uses this feature. The pointer to this buffer will be the first argument of tracepoints that opt in; the pointer is valid and can be bpf_probe_read() by both BPF_PROG_TYPE_RAW_TRACEPOINT and BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE programs that attach to such a tracepoint, but the buffer to which it points may only be written by the latter. Signed-off-by: Matt Mullins <mmullins@fb.com> Acked-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* bpf: allow clearing all sock_ops callback flagsViet Hoang Tran2019-04-171-1/+8
| | | | | | | | | | | | | | | The helper function bpf_sock_ops_cb_flags_set() can be used to both set and clear the sock_ops callback flags. However, its current behavior is not consistent. BPF program may clear a flag if more than one were set, or replace a flag with another one, but cannot clear all flags. This patch also updates the documentation to clarify the ability to clear flags of this helper function. Signed-off-by: Hoang Tran <hoang.tran@uclouvain.be> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* bpf: fix whitespace for ENCAP_L2 defines in bpf.hAlan Maguire2019-04-161-3/+3
| | | | | | | | replace tab after #define with space in line with rest of definitions Signed-off-by: Alan Maguire <alan.maguire@oracle.com> Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* bpf: Introduce bpf_strtol and bpf_strtoul helpersAndrey Ignatov2019-04-121-1/+50
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add bpf_strtol and bpf_strtoul to convert a string to long and unsigned long correspondingly. It's similar to user space strtol(3) and strtoul(3) with a few changes to the API: * instead of NUL-terminated C string the helpers expect buffer and buffer length; * resulting long or unsigned long is returned in a separate result-argument; * return value is used to indicate success or failure, on success number of consumed bytes is returned that can be used to identify position to read next if the buffer is expected to contain multiple integers; * instead of *base* argument, *flags* is used that provides base in 5 LSB, other bits are reserved for future use; * number of supported bases is limited. Documentation for the new helpers is provided in bpf.h UAPI. The helpers are made available to BPF_PROG_TYPE_CGROUP_SYSCTL programs to be able to convert string input to e.g. "ulongvec" output. E.g. "net/ipv4/tcp_mem" consists of three ulong integers. They can be parsed by calling to bpf_strtoul three times. Implementation notes: Implementation includes "../../lib/kstrtox.h" to reuse integer parsing functions. It's done exactly same way as fs/proc/base.c already does. Unfortunately existing kstrtoX function can't be used directly since they fail if any invalid character is present right after integer in the string. Existing simple_strtoX functions can't be used either since they're obsolete and don't handle overflow properly. Signed-off-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* bpf: Add file_pos field to bpf_sysctl ctxAndrey Ignatov2019-04-121-0/+3
| | | | | | | | | | | | Add file_pos field to bpf_sysctl context to read and write sysctl file position at which sysctl is being accessed (read or written). The field can be used to e.g. override whole sysctl value on write to sysctl even when sys_write is called by user space with file_pos > 0. Or BPF program may reject such accesses. Signed-off-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* bpf: Introduce bpf_sysctl_{get,set}_new_value helpersAndrey Ignatov2019-04-121-1/+37
| | | | | | | | | | | | | | | | | | | | | | | | | | Add helpers to work with new value being written to sysctl by user space. bpf_sysctl_get_new_value() copies value being written to sysctl into provided buffer. bpf_sysctl_set_new_value() overrides new value being written by user space with a one from provided buffer. Buffer should contain string representation of the value, similar to what can be seen in /proc/sys/. Both helpers can be used only on sysctl write. File position matters and can be managed by an interface that will be introduced separately. E.g. if user space calls sys_write to a file in /proc/sys/ at file position = X, where X > 0, then the value set by bpf_sysctl_set_new_value() will be written starting from X. If program wants to override whole value with specified buffer, file position has to be set to zero. Documentation for the new helpers is provided in bpf.h UAPI. Signed-off-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* bpf: Introduce bpf_sysctl_get_current_value helperAndrey Ignatov2019-04-121-1/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | Add bpf_sysctl_get_current_value() helper to copy current sysctl value into provided by BPF_PROG_TYPE_CGROUP_SYSCTL program buffer. It provides same string as user space can see by reading corresponding file in /proc/sys/, including new line, etc. Documentation for the new helper is provided in bpf.h UAPI. Since current value is kept in ctl_table->data in a parsed form, ctl_table->proc_handler() with write=0 is called to read that data and convert it to a string. Such a string can later be parsed by a program using helpers that will be introduced separately. Unfortunately it's not trivial to provide API to access parsed data due to variety of data representations (string, intvec, uintvec, ulongvec, custom structures, even NULL, etc). Instead it's assumed that user know how to handle specific sysctl they're interested in and appropriate helpers can be used. Since ctl_table->proc_handler() expects __user buffer, conversion to __user happens for kernel allocated one where the value is stored. Signed-off-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* bpf: Introduce bpf_sysctl_get_name helperAndrey Ignatov2019-04-121-1/+21
| | | | | | | | | | | | | | | Add bpf_sysctl_get_name() helper to copy sysctl name (/proc/sys/ entry) into provided by BPF_PROG_TYPE_CGROUP_SYSCTL program buffer. By default full name (w/o /proc/sys/) is copied, e.g. "net/ipv4/tcp_mem". If BPF_F_SYSCTL_BASE_NAME flag is set, only base name will be copied, e.g. "tcp_mem". Documentation for the new helper is provided in bpf.h UAPI. Signed-off-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* bpf: Sysctl hookAndrey Ignatov2019-04-121-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Containerized applications may run as root and it may create problems for whole host. Specifically such applications may change a sysctl and affect applications in other containers. Furthermore in existing infrastructure it may not be possible to just completely disable writing to sysctl, instead such a process should be gradual with ability to log what sysctl are being changed by a container, investigate, limit the set of writable sysctl to currently used ones (so that new ones can not be changed) and eventually reduce this set to zero. The patch introduces new program type BPF_PROG_TYPE_CGROUP_SYSCTL and attach type BPF_CGROUP_SYSCTL to solve these problems on cgroup basis. New program type has access to following minimal context: struct bpf_sysctl { __u32 write; }; Where @write indicates whether sysctl is being read (= 0) or written (= 1). Helpers to access sysctl name and value will be introduced separately. BPF_CGROUP_SYSCTL attach point is added to sysctl code right before passing control to ctl_table->proc_handler so that BPF program can either allow or deny access to sysctl. Suggested-by: Roman Gushchin <guro@fb.com> Signed-off-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* bpf: add layer 2 encap support to bpf_skb_adjust_roomAlan Maguire2019-04-111-0/+10
| | | | | | | | | | | | | | | | | | | | | | | | | commit 868d523535c2 ("bpf: add bpf_skb_adjust_room encap flags") introduced support to bpf_skb_adjust_room for GSO-friendly GRE and UDP encapsulation. For GSO to work for skbs, the inner headers (mac and network) need to be marked. For L3 encapsulation using bpf_skb_adjust_room, the mac and network headers are identical. Here we provide a way of specifying the inner mac header length for cases where L2 encap is desired. Such an approach can support encapsulated ethernet headers, MPLS headers etc. For example to convert from a packet of form [eth][ip][tcp] to [eth][ip][udp][inner mac][ip][tcp], something like the following could be done: headroom = sizeof(iph) + sizeof(struct udphdr) + inner_maclen; ret = bpf_skb_adjust_room(skb, headroom, BPF_ADJ_ROOM_MAC, BPF_F_ADJ_ROOM_ENCAP_L4_UDP | BPF_F_ADJ_ROOM_ENCAP_L3_IPV4 | BPF_F_ADJ_ROOM_ENCAP_L2(inner_maclen)); Signed-off-by: Alan Maguire <alan.maguire@oracle.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* bpf: support input __sk_buff context in BPF_PROG_TEST_RUNStanislav Fomichev2019-04-111-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add new set of arguments to bpf_attr for BPF_PROG_TEST_RUN: * ctx_in/ctx_size_in - input context * ctx_out/ctx_size_out - output context The intended use case is to pass some meta data to the test runs that operate on skb (this has being brought up on recent LPC). For programs that use bpf_prog_test_run_skb, support __sk_buff input and output. Initially, from input __sk_buff, copy _only_ cb and priority into skb, all other non-zero fields are prohibited (with EINVAL). If the user has set ctx_out/ctx_size_out, copy the potentially modified __sk_buff back to the userspace. We require all fields of input __sk_buff except the ones we explicitly support to be set to zero. The expectation is that in the future we might add support for more fields and we want to fail explicitly if the user runs the program on the kernel where we don't yet support them. The API is intentionally vague (i.e. we don't explicitly add __sk_buff to bpf_attr, but ctx_in) to potentially let other test_run types use this interface in the future (this can be xdp_md for xdp types for example). v4: * don't copy more than allowed in bpf_ctx_init [Martin] v3: * handle case where ctx_in is NULL, but ctx_out is not [Martin] * convert size==0 checks to ptr==NULL checks and add some extra ptr checks [Martin] v2: * Addressed comments from Martin Lau Signed-off-by: Stanislav Fomichev <sdf@google.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* bpf: add syscall side map freeze supportDaniel Borkmann2019-04-101-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds a new BPF_MAP_FREEZE command which allows to "freeze" the map globally as read-only / immutable from syscall side. Map permission handling has been refactored into map_get_sys_perms() and drops FMODE_CAN_WRITE in case of locked map. Main use case is to allow for setting up .rodata sections from the BPF ELF which are loaded into the kernel, meaning BPF loader first allocates map, sets up map value by copying .rodata section into it and once complete, it calls BPF_MAP_FREEZE on the map fd to prevent further modifications. Right now BPF_MAP_FREEZE only takes map fd as argument while remaining bpf_attr members are required to be zero. I didn't add write-only locking here as counterpart since I don't have a concrete use-case for it on my side, and I think it makes probably more sense to wait once there is actually one. In that case bpf_attr can be extended as usual with a flag field and/or others where flag 0 means that we lock the map read-only hence this doesn't prevent to add further extensions to BPF_MAP_FREEZE upon need. A map creation flag like BPF_F_WRONCE was not considered for couple of reasons: i) in case of a generic implementation, a map can consist of more than just one element, thus there could be multiple map updates needed to set the map into a state where it can then be made immutable, ii) WRONCE indicates exact one-time write before it is then set immutable. A generic implementation would set a bit atomically on map update entry (if unset), indicating that every subsequent update from then onwards will need to bail out there. However, map updates can fail, so upon failure that flag would need to be unset again and the update attempt would need to be repeated for it to be eventually made immutable. While this can be made race-free, this approach feels less clean and in combination with reason i), it's not generic enough. A dedicated BPF_MAP_FREEZE command directly sets the flag and caller has the guarantee that map is immutable from syscall side upon successful return for any future syscall invocations that would alter the map state, which is also more intuitive from an API point of view. A command name such as BPF_MAP_LOCK has been avoided as it's too close with BPF map spin locks (which already has BPF_F_LOCK flag). BPF_MAP_FREEZE is so far only enabled for privileged users. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* bpf: add program side {rd, wr}only support for mapsDaniel Borkmann2019-04-101-1/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This work adds two new map creation flags BPF_F_RDONLY_PROG and BPF_F_WRONLY_PROG in order to allow for read-only or write-only BPF maps from a BPF program side. Today we have BPF_F_RDONLY and BPF_F_WRONLY, but this only applies to system call side, meaning the BPF program has full read/write access to the map as usual while bpf(2) calls with map fd can either only read or write into the map depending on the flags. BPF_F_RDONLY_PROG and BPF_F_WRONLY_PROG allows for the exact opposite such that verifier is going to reject program loads if write into a read-only map or a read into a write-only map is detected. For read-only map case also some helpers are forbidden for programs that would alter the map state such as map deletion, update, etc. As opposed to the two BPF_F_RDONLY / BPF_F_WRONLY flags, BPF_F_RDONLY_PROG as well as BPF_F_WRONLY_PROG really do correspond to the map lifetime. We've enabled this generic map extension to various non-special maps holding normal user data: array, hash, lru, lpm, local storage, queue and stack. Further generic map types could be followed up in future depending on use-case. Main use case here is to forbid writes into .rodata map values from verifier side. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* bpf: implement lookup-free direct value access for mapsDaniel Borkmann2019-04-101-1/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This generic extension to BPF maps allows for directly loading an address residing inside a BPF map value as a single BPF ldimm64 instruction! The idea is similar to what BPF_PSEUDO_MAP_FD does today, which is a special src_reg flag for ldimm64 instruction that indicates that inside the first part of the double insns's imm field is a file descriptor which the verifier then replaces as a full 64bit address of the map into both imm parts. For the newly added BPF_PSEUDO_MAP_VALUE src_reg flag, the idea is the following: the first part of the double insns's imm field is again a file descriptor corresponding to the map, and the second part of the imm field is an offset into the value. The verifier will then replace both imm parts with an address that points into the BPF map value at the given value offset for maps that support this operation. Currently supported is array map with single entry. It is possible to support more than just single map element by reusing both 16bit off fields of the insns as a map index, so full array map lookup could be expressed that way. It hasn't been implemented here due to lack of concrete use case, but could easily be done so in future in a compatible way, since both off fields right now have to be 0 and would correctly denote a map index 0. The BPF_PSEUDO_MAP_VALUE is a distinct flag as otherwise with BPF_PSEUDO_MAP_FD we could not differ offset 0 between load of map pointer versus load of map's value at offset 0, and changing BPF_PSEUDO_MAP_FD's encoding into off by one to differ between regular map pointer and map value pointer would add unnecessary complexity and increases barrier for debugability thus less suitable. Using the second part of the imm field as an offset into the value does /not/ come with limitations since maximum possible value size is in u32 universe anyway. This optimization allows for efficiently retrieving an address to a map value memory area without having to issue a helper call which needs to prepare registers according to calling convention, etc, without needing the extra NULL test, and without having to add the offset in an additional instruction to the value base pointer. The verifier then treats the destination register as PTR_TO_MAP_VALUE with constant reg->off from the user passed offset from the second imm field, and guarantees that this is within bounds of the map value. Any subsequent operations are normally treated as typical map value handling without anything extra needed from verification side. The two map operations for direct value access have been added to array map for now. In future other types could be supported as well depending on the use case. The main use case for this commit is to allow for BPF loader support for global variables that reside in .data/.rodata/.bss sections such that we can directly load the address of them with minimal additional infrastructure required. Loader support has been added in subsequent commits for libbpf library. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* bpf: add bpf_skb_adjust_room encap flagsWillem de Bruijn2019-03-221-1/+15
| | | | | | | | | | | | | | | | | | | | | | | | When pushing tunnel headers, annotate skbs in the same way as tunnel devices. For GSO packets, the network stack requires certain fields set to segment packets with tunnel headers. gro_gse_segment depends on transport and inner mac header, for instance. Add an option to pass this information. Remove the restriction on len_diff to network header length, which is too short, e.g., for GRE protocols. Changes v1->v2: - document new flags - BPF_F_ADJ_ROOM_MASK moved v2->v3: - BPF_F_ADJ_ROOM_ENCAP_L3_MASK moved Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* bpf: add bpf_skb_adjust_room flag BPF_F_ADJ_ROOM_FIXED_GSOWillem de Bruijn2019-03-221-2/+7
| | | | | | | | | | | | | | | | | | | bpf_skb_adjust_room adjusts gso_size of gso packets to account for the pushed or popped header room. This is not allowed with UDP, where gso_size delineates datagrams. Add an option to avoid these updates and allow this call for datagrams. It can also be used with TCP, when MSS is known to allow headroom, e.g., through MSS clamping or route MTU. Changes v1->v2: - document flag BPF_F_ADJ_ROOM_FIXED_GSO - do not expose BPF_F_ADJ_ROOM_MASK through uapi, as it may change. Link: https://patchwork.ozlabs.org/patch/1052497/ Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* bpf: add bpf_skb_adjust_room mode BPF_ADJ_ROOM_MACWillem de Bruijn2019-03-221-1/+5
| | | | | | | | | | | | | | | | bpf_skb_adjust_room net allows inserting room in an skb. Existing mode BPF_ADJ_ROOM_NET inserts room after the network header by pulling the skb, moving the network header forward and zeroing the new space. Add new mode BPF_ADJUST_ROOM_MAC that inserts room after the mac header. This allows inserting tunnel headers in front of the network header without having to recreate the network header in the original space, avoiding two copies. Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* bpf: add helper to check for a valid SYN cookieLorenz Bauer2019-03-221-1/+17
| | | | | | | | | | | | | | Using bpf_skc_lookup_tcp it's possible to ascertain whether a packet belongs to a known connection. However, there is one corner case: no sockets are created if SYN cookies are active. This means that the final ACK in the 3WHS is misclassified. Using the helper, we can look up the listening socket via bpf_skc_lookup_tcp and then check whether a packet is a valid SYN cookie ACK. Signed-off-by: Lorenz Bauer <lmb@cloudflare.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* bpf: add skc_lookup_tcp helperLorenz Bauer2019-03-221-1/+19
| | | | | | | | Allow looking up a sock_common. This gives eBPF programs access to timewait and request sockets. Signed-off-by: Lorenz Bauer <lmb@cloudflare.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* bpf: add documentation for helpers bpf_spin_lock(), bpf_spin_unlock()Quentin Monnet2019-03-141-0/+55
| | | | | | | | | | | | | | | Add documentation for the BPF spinlock-related helpers to the doc in bpf.h. I added the constraints and restrictions coming with the use of spinlocks for BPF: not all of it is directly related to the use of the helper, but I thought it would be nice for users to find them in the man page. This list of restrictions is nearly a verbatim copy of the list in Alexei's commit log for those helpers. Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com> Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* bpf: fix documentation for eBPF helpersQuentin Monnet2019-03-141-63/+65
| | | | | | | | | | | | | | | | | | | | | | | Another round of minor fixes for the documentation of the BPF helpers located in the UAPI bpf.h header file. Changes include: - Moving around description of some helpers, to keep the descriptions in the same order as helpers are declared (bpf_map_push_elem(), leftover from commit 90b1023f68c7 ("bpf: fix documentation for eBPF helpers"), bpf_rc_keydown(), and bpf_skb_ancestor_cgroup_id()). - Fixing typos ("contex" -> "context"). - Harmonising return types ("void* " -> "void *", "uint64_t" -> "u64"). - Addition of the "bpf_" prefix to bpf_get_storage(). - Light additions of RST markup on some keywords. - Empty line deletion between description and return value for bpf_tcp_sock(). - Edit for the description for bpf_skb_ecn_set_ce() (capital letters, acronym expansion, no effect if ECT not set, more details on return value). Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com> Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* bpf: Add bpf_get_listener_sock(struct bpf_sock *sk) helperMartin KaFai Lau2019-03-131-1/+10
| | | | | | | | | | | | | | | | | | | | | | | | | Add a new helper "struct bpf_sock *bpf_get_listener_sock(struct bpf_sock *sk)" which returns a bpf_sock in TCP_LISTEN state. It will trace back to the listener sk from a request_sock if possible. It returns NULL for all other cases. No reference is taken because the helper ensures the sk is in SOCK_RCU_FREE (where the TCP_LISTEN sock should be in). Hence, bpf_sk_release() is unnecessary and the verifier does not allow bpf_sk_release(listen_sk) to be called either. The following is also allowed because the bpf_prog is run under rcu_read_lock(): sk = bpf_sk_lookup_tcp(); /* if (!sk) { ... } */ listen_sk = bpf_get_listener_sock(sk); /* if (!listen_sk) { ... } */ bpf_sk_release(sk); src_port = listen_sk->src_port; /* Allowed */ Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* bpf: add bpf helper bpf_skb_ecn_set_cebrakmo2019-03-021-1/+9
| | | | | | | | | | | | | | | | | | | This patch adds a new bpf helper BPF_FUNC_skb_ecn_set_ce "int bpf_skb_ecn_set_ce(struct sk_buff *skb)". It is added to BPF_PROG_TYPE_CGROUP_SKB typed bpf_prog which currently can be attached to the ingress and egress path. The helper is needed because his type of bpf_prog cannot modify the skb directly. This helper is used to set the ECN field of ECN capable IP packets to ce (congestion encountered) in the IPv6 or IPv4 header of the skb. It can be used by a bpf_prog to manage egress or ingress network bandwdith limit per cgroupv2 by inducing an ECN response in the TCP sender. This works best when using DCTCP. Signed-off-by: Lawrence Brakmo <brakmo@fb.com> Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
generated by cgit v1.2.3-55-g7522 (git 2.39.0) at 2024-05-24 23:34:45 +0200