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* bpf: cgroup: Fix build error without CONFIG_NETYueHaibing2019-07-081-0/+4
| | | | | | | | | | | | | | | | | | | | | | If CONFIG_NET is not set and CONFIG_CGROUP_BPF=y, gcc building fails: kernel/bpf/cgroup.o: In function `cg_sockopt_func_proto': cgroup.c:(.text+0x237e): undefined reference to `bpf_sk_storage_get_proto' cgroup.c:(.text+0x2394): undefined reference to `bpf_sk_storage_delete_proto' kernel/bpf/cgroup.o: In function `__cgroup_bpf_run_filter_getsockopt': (.text+0x2a1f): undefined reference to `lock_sock_nested' (.text+0x2ca2): undefined reference to `release_sock' kernel/bpf/cgroup.o: In function `__cgroup_bpf_run_filter_setsockopt': (.text+0x3006): undefined reference to `lock_sock_nested' (.text+0x32bb): undefined reference to `release_sock' Reported-by: Hulk Robot <hulkci@huawei.com> Suggested-by: Stanislav Fomichev <sdf@fomichev.me> Fixes: 0d01da6afc54 ("bpf: implement getsockopt and setsockopt hooks") Signed-off-by: YueHaibing <yuehaibing@huawei.com> Acked-by: Yonghong Song <yhs@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* bpf: implement getsockopt and setsockopt hooksStanislav Fomichev2019-06-271-0/+333
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* bpf: fix cgroup bpf release synchronizationRoman Gushchin2019-06-271-1/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since commit 4bfc0bb2c60e ("bpf: decouple the lifetime of cgroup_bpf from cgroup itself"), cgroup_bpf release occurs asynchronously (from a worker context), and before the release of the cgroup itself. This introduced a previously non-existing race between the release and update paths. E.g. if a leaf's cgroup_bpf is released and a new bpf program is attached to the one of ancestor cgroups at the same time. The race may result in double-free and other memory corruptions. To fix the problem, let's protect the body of cgroup_bpf_release() with cgroup_mutex, as it was effectively previously, when all this code was called from the cgroup release path with cgroup mutex held. Also let's skip cgroups, which have no chances to invoke a bpf program, on the update path. If the cgroup bpf refcnt reached 0, it means that the cgroup is offline (no attached processes), and there are no associated sockets left. It means there is no point in updating effective progs array! And it can lead to a leak, if it happens after the release. So, let's skip such cgroups. Big thanks for Tejun Heo for discovering and debugging of this problem! Fixes: 4bfc0bb2c60e ("bpf: decouple the lifetime of cgroup_bpf from cgroup itself") Reported-by: Tejun Heo <tj@kernel.org> Signed-off-by: Roman Gushchin <guro@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller2019-06-221-4/+1
|\ | | | | | | | | | | Minor SPDX change conflict. Signed-off-by: David S. Miller <davem@davemloft.net>
| * treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 451Thomas Gleixner2019-06-191-4/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Based on 1 normalized pattern(s): this file is subject to the terms and conditions of version 2 of the gnu general public license see the file copying in the main directory of the linux distribution for more details extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 5 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Enrico Weigelt <info@metux.net> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190604081200.872755311@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | bpf: Update __cgroup_bpf_run_filter_skb with cnbrakmo2019-05-311-5/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For egress packets, __cgroup_bpf_fun_filter_skb() will now call BPF_PROG_CGROUP_INET_EGRESS_RUN_ARRAY() instead of PROG_CGROUP_RUN_ARRAY() in order to propagate congestion notifications (cn) requests to TCP callers. For egress packets, this function can return: NET_XMIT_SUCCESS (0) - continue with packet output NET_XMIT_DROP (1) - drop packet and notify TCP to call cwr NET_XMIT_CN (2) - continue with packet output and notify TCP to call cwr -EPERM - drop packet For ingress packets, this function will return -EPERM if any attached program was found and if it returned != 1 during execution. Otherwise 0 is returned. Signed-off-by: Lawrence Brakmo <brakmo@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* | bpf: cgroup: properly use bpf_prog_array apiStanislav Fomichev2019-05-291-11/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that we don't have __rcu markers on the bpf_prog_array helpers, let's use proper rcu_dereference_protected to obtain array pointer under mutex. We also don't need __rcu annotations on cgroup_bpf.inactive since it's not read/updated concurrently. v4: * drop cgroup_rcu_xyz wrappers and use rcu APIs directly; presumably should be more clear to understand which mutex/refcount protects each particular place v3: * amend cgroup_rcu_dereference to include percpu_ref_is_dying; cgroup_bpf is now reference counted and we don't hold cgroup_mutex anymore in cgroup_bpf_release v2: * replace xchg with rcu_swap_protected Cc: Roman Gushchin <guro@fb.com> Signed-off-by: Stanislav Fomichev <sdf@google.com> Acked-by: Roman Gushchin <guro@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* | bpf: decouple the lifetime of cgroup_bpf from cgroup itselfRoman Gushchin2019-05-281-4/+37
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently the lifetime of bpf programs attached to a cgroup is bound to the lifetime of the cgroup itself. It means that if a user forgets (or intentionally avoids) to detach a bpf program before removing the cgroup, it will stay attached up to the release of the cgroup. Since the cgroup can stay in the dying state (the state between being rmdir()'ed and being released) for a very long time, it leads to a waste of memory. Also, it blocks a possibility to implement the memcg-based memory accounting for bpf objects, because a circular reference dependency will occur. Charged memory pages are pinning the corresponding memory cgroup, and if the memory cgroup is pinning the attached bpf program, nothing will be ever released. A dying cgroup can not contain any processes, so the only chance for an attached bpf program to be executed is a live socket associated with the cgroup. So in order to release all bpf data early, let's count associated sockets using a new percpu refcounter. On cgroup removal the counter is transitioned to the atomic mode, and as soon as it reaches 0, all bpf programs are detached. Because cgroup_bpf_release() can block, it can't be called from the percpu ref counter callback directly, so instead an asynchronous work is scheduled. The reference counter is not socket specific, and can be used for any other types of programs, which can be executed from a cgroup-bpf hook outside of the process context, had such a need arise in the future. Signed-off-by: Roman Gushchin <guro@fb.com> Cc: jolsa@redhat.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* bpf: add map helper functions push, pop, peek in more BPF programsAlban Crequy2019-04-161-0/+6
| | | | | | | | | | | | | | | | commit f1a2e44a3aec ("bpf: add queue and stack maps") introduced new BPF helper functions: - BPF_FUNC_map_push_elem - BPF_FUNC_map_pop_elem - BPF_FUNC_map_peek_elem but they were made available only for network BPF programs. This patch makes them available for tracepoint, cgroup and lirc programs. Signed-off-by: Alban Crequy <alban@kinvolk.io> Cc: Mauricio Vasquez B <mauricio.vasquez@polito.it> Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* bpf: Fix distinct pointer types warning for ARCH=i386Andrey Ignatov2019-04-121-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | Fix a new warning reported by kbuild for make ARCH=i386: In file included from kernel/bpf/cgroup.c:11:0: kernel/bpf/cgroup.c: In function '__cgroup_bpf_run_filter_sysctl': include/linux/kernel.h:827:29: warning: comparison of distinct pointer types lacks a cast (!!(sizeof((typeof(x) *)1 == (typeof(y) *)1))) ^ include/linux/kernel.h:841:4: note: in expansion of macro '__typecheck' (__typecheck(x, y) && __no_side_effects(x, y)) ^~~~~~~~~~~ include/linux/kernel.h:851:24: note: in expansion of macro '__safe_cmp' __builtin_choose_expr(__safe_cmp(x, y), \ ^~~~~~~~~~ include/linux/kernel.h:860:19: note: in expansion of macro '__careful_cmp' #define min(x, y) __careful_cmp(x, y, <) ^~~~~~~~~~~~~ >> kernel/bpf/cgroup.c:837:17: note: in expansion of macro 'min' ctx.new_len = min(PAGE_SIZE, *pcount); ^~~ Fixes: 4e63acdff864 ("bpf: Introduce bpf_sysctl_{get,set}_new_value helpers") Signed-off-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* bpf: Introduce bpf_strtol and bpf_strtoul helpersAndrey Ignatov2019-04-121-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 Ignatov2019-04-121-3/+51
| | | | | | | | | | | | 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/+80
| | | | | | | | | | | | | | | | | | | | | | | | | | 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 Ignatov2019-04-121-0/+65
| | | | | | | | | | | | | | | | | | | | | | | | | | | 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/+69
| | | | | | | | | | | | | | | 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/+92
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 base proto function for cgroup-bpf programsAndrey Ignatov2019-04-121-1/+7
| | | | | | | | | | | | Currently kernel/bpf/cgroup.c contains only one program type and one proto function cgroup_dev_func_proto(). It'd be useful to have base proto function that can be reused for new cgroup-bpf program types coming soon. Introduce cgroup_base_func_proto(). Signed-off-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller2019-02-081-1/+1
|\ | | | | | | | | | | | | | | | | | | An ipvlan bug fix in 'net' conflicted with the abstraction away of the IPV6 specific support in 'net-next'. Similarly, a bug fix for mlx5 in 'net' conflicted with the flow action conversion in 'net-next'. Signed-off-by: David S. Miller <davem@davemloft.net>
| * bpf: run bpf programs with preemption disabledAlexei Starovoitov2019-01-311-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Disabled preemption is necessary for proper access to per-cpu maps from BPF programs. But the sender side of socket filters didn't have preemption disabled: unix_dgram_sendmsg->sk_filter->sk_filter_trim_cap->bpf_prog_run_save_cb->BPF_PROG_RUN and a combination of af_packet with tun device didn't disable either: tpacket_snd->packet_direct_xmit->packet_pick_tx_queue->ndo_select_queue-> tun_select_queue->tun_ebpf_select_queue->bpf_prog_run_clear_cb->BPF_PROG_RUN Disable preemption before executing BPF programs (both classic and extended). Reported-by: Jann Horn <jannh@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* | bpf, cgroups: clean up kerneldoc warningsValdis Kletnieks2019-01-311-1/+2
|/ | | | | | | | | | | | | | | | | Building with W=1 reveals some bitrot: CC kernel/bpf/cgroup.o kernel/bpf/cgroup.c:238: warning: Function parameter or member 'flags' not described in '__cgroup_bpf_attach' kernel/bpf/cgroup.c:367: warning: Function parameter or member 'unused_flags' not described in '__cgroup_bpf_detach' Add a kerneldoc line for 'flags'. Fixing the warning for 'unused_flags' is best approached by removing the unused parameter on the function call. Signed-off-by: Valdis Kletnieks <valdis.kletnieks@vt.edu> Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* bpf: Annotate implicit fall through in cgroup_dev_func_protoMathieu Malaterre2019-01-171-0/+1
| | | | | | | | | | | | There is a plan to build the kernel with -Wimplicit-fallthrough and this place in the code produced a warnings (W=1). This commit removes the following warning: kernel/bpf/cgroup.c:719:6: warning: this statement may fall through [-Wimplicit-fallthrough=] Signed-off-by: Mathieu Malaterre <malat@debian.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* bpf: add cg_skb_is_valid_access for BPF_PROG_TYPE_CGROUP_SKBSong Liu2018-10-191-0/+6
| | | | | | | | | | | | | BPF programs of BPF_PROG_TYPE_CGROUP_SKB need to access headers in the skb. This patch enables direct access of skb for these programs. Two helper functions bpf_compute_and_save_data_end() and bpf_restore_data_end() are introduced. There are used in __cgroup_bpf_run_filter_skb(), to compute proper data_end for the BPF program, and restore original data afterwards. Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* bpf: extend cgroup bpf core to allow multiple cgroup storage typesRoman Gushchin2018-10-011-22/+52
| | | | | | | | | | | | | | | | | | | In order to introduce per-cpu cgroup storage, let's generalize bpf cgroup core to support multiple cgroup storage types. Potentially, per-node cgroup storage can be added later. This commit is mostly a formal change that replaces cgroup_storage pointer with a array of cgroup_storage pointers. It doesn't actually introduce a new storage type, it will be done later. Each bpf program is now able to have one cgroup storage of each type. Signed-off-by: Roman Gushchin <guro@fb.com> Acked-by: Song Liu <songliubraving@fb.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* bpf: permit CGROUP_DEVICE programs accessing helper bpf_get_current_cgroup_id()Yonghong Song2018-09-281-0/+2
| | | | | | | | | | | | | | | | | | | | | Currently, helper bpf_get_current_cgroup_id() is not permitted for CGROUP_DEVICE type of programs. If the helper is used in such cases, the verifier will log the following error: 0: (bf) r6 = r1 1: (69) r7 = *(u16 *)(r6 +0) 2: (85) call bpf_get_current_cgroup_id#80 unknown func bpf_get_current_cgroup_id#80 The bpf_get_current_cgroup_id() is useful for CGROUP_DEVICE type of programs in order to customize action based on cgroup id. This patch added such a support. Cc: Roman Gushchin <guro@fb.com> Signed-off-by: Yonghong Song <yhs@fb.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Roman Gushchin <guro@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* bpf: introduce update_effective_progs()Roman Gushchin2018-08-071-54/+45
| | | | | | | | | | | | | | | | | __cgroup_bpf_attach() and __cgroup_bpf_detach() functions have a good amount of duplicated code, which is possible to eliminate by introducing the update_effective_progs() helper function. The update_effective_progs() calls compute_effective_progs() and then in case of success it calls activate_effective_progs() for each descendant cgroup. In case of failure (OOM), it releases allocated prog arrays and return the error code. Signed-off-by: Roman Gushchin <guro@fb.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* bpf: introduce the bpf_get_local_storage() helper functionRoman Gushchin2018-08-031-0/+2
| | | | | | | | | | | | | | | | The bpf_get_local_storage() helper function is used to get a pointer to the bpf local storage from a bpf program. It takes a pointer to a storage map and flags as arguments. Right now it accepts only cgroup storage maps, and flags argument has to be 0. Further it can be extended to support other types of local storage: e.g. thread local storage etc. Signed-off-by: Roman Gushchin <guro@fb.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* bpf: extend bpf_prog_array to store pointers to the cgroup storageRoman Gushchin2018-08-031-9/+12
| | | | | | | | | | | | | | This patch converts bpf_prog_array from an array of prog pointers to the array of struct bpf_prog_array_item elements. This allows to save a cgroup storage pointer for each bpf program efficiently attached to a cgroup. Signed-off-by: Roman Gushchin <guro@fb.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* bpf: allocate cgroup storage entries on attaching bpf programsRoman Gushchin2018-08-031-4/+31
| | | | | | | | | | | | | | | If a bpf program is using cgroup local storage, allocate a bpf_cgroup_storage structure automatically on attaching the program to a cgroup and save the pointer into the corresponding bpf_prog_list entry. Analogically, release the cgroup local storage on detaching of the bpf program. Signed-off-by: Roman Gushchin <guro@fb.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* bpf: fix rcu annotations in compute_effective_progs()Roman Gushchin2018-07-181-4/+3
| | | | | | | | | | | | | | | | | The progs local variable in compute_effective_progs() is marked as __rcu, which is not correct. This is a local pointer, which is initialized by bpf_prog_array_alloc(), which also now returns a generic non-rcu pointer. The real rcu-protected pointer is *array (array is a pointer to an RCU-protected pointer), so the assignment should be performed using rcu_assign_pointer(). Fixes: 324bda9e6c5a ("bpf: multi program support for cgroup+bpf") Signed-off-by: Roman Gushchin <guro@fb.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* bpf: fix attach type BPF_LIRC_MODE2 dependency wrt CONFIG_CGROUP_BPFSean Young2018-06-261-0/+54
| | | | | | | | | | | | | | | | | If the kernel is compiled with CONFIG_CGROUP_BPF not enabled, it is not possible to attach, detach or query IR BPF programs to /dev/lircN devices, making them impossible to use. For embedded devices, it should be possible to use IR decoding without cgroups or CONFIG_CGROUP_BPF enabled. This change requires some refactoring, since bpf_prog_{attach,detach,query} functions are now always compiled, but their code paths for cgroups need moving out. Rather than a #ifdef CONFIG_CGROUP_BPF in kernel/bpf/syscall.c, moving them to kernel/bpf/cgroup.c and kernel/bpf/sockmap.c does not require #ifdefs since that is already conditionally compiled. Fixes: f4364dcfc86d ("media: rc: introduce BPF_PROG_LIRC_MODE2") Signed-off-by: Sean Young <sean@mess.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* bpf: Hooks for sys_sendmsgAndrey Ignatov2018-05-281-1/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In addition to already existing BPF hooks for sys_bind and sys_connect, the patch provides new hooks for sys_sendmsg. It leverages existing BPF program type `BPF_PROG_TYPE_CGROUP_SOCK_ADDR` that provides access to socket itlself (properties like family, type, protocol) and user-passed `struct sockaddr *` so that BPF program can override destination IP and port for system calls such as sendto(2) or sendmsg(2) and/or assign source IP to the socket. The hooks are implemented as two new attach types: `BPF_CGROUP_UDP4_SENDMSG` and `BPF_CGROUP_UDP6_SENDMSG` for UDPv4 and UDPv6 correspondingly. UDPv4 and UDPv6 separate attach types for same reason as sys_bind and sys_connect hooks, i.e. to prevent reading from / writing to e.g. user_ip6 fields when user passes sockaddr_in since it'd be out-of-bound. The difference with already existing hooks is sys_sendmsg are implemented only for unconnected UDP. For TCP it doesn't make sense to change user-provided `struct sockaddr *` at sendto(2)/sendmsg(2) time since socket either was already connected and has source/destination set or wasn't connected and call to sendto(2)/sendmsg(2) would lead to ENOTCONN anyway. Connected UDP is already handled by sys_connect hooks that can override source/destination at connect time and use fast-path later, i.e. these hooks don't affect UDP fast-path. Rewriting source IP is implemented differently than that in sys_connect hooks. When sys_sendmsg is used with unconnected UDP it doesn't work to just bind socket to desired local IP address since source IP can be set on per-packet basis by using ancillary data (cmsg(3)). So no matter if socket is bound or not, source IP has to be rewritten on every call to sys_sendmsg. To do so two new fields are added to UAPI `struct bpf_sock_addr`; * `msg_src_ip4` to set source IPv4 for UDPv4; * `msg_src_ip6` to set source IPv6 for UDPv6. 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>
* bpf: Hooks for sys_bindAndrey Ignatov2018-03-311-0/+36
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | == The problem == There is a use-case when all processes inside a cgroup should use one single IP address on a host that has multiple IP configured. Those processes should use the IP for both ingress and egress, for TCP and UDP traffic. So TCP/UDP servers should be bound to that IP to accept incoming connections on it, and TCP/UDP clients should make outgoing connections from that IP. It should not require changing application code since it's often not possible. Currently it's solved by intercepting glibc wrappers around syscalls such as `bind(2)` and `connect(2)`. It's done by a shared library that is preloaded for every process in a cgroup so that whenever TCP/UDP server calls `bind(2)`, the library replaces IP in sockaddr before passing arguments to syscall. When application calls `connect(2)` the library transparently binds the local end of connection to that IP (`bind(2)` with `IP_BIND_ADDRESS_NO_PORT` to avoid performance penalty). Shared library approach is fragile though, e.g.: * some applications clear env vars (incl. `LD_PRELOAD`); * `/etc/ld.so.preload` doesn't help since some applications are linked with option `-z nodefaultlib`; * other applications don't use glibc and there is nothing to intercept. == The solution == The patch provides much more reliable in-kernel solution for the 1st part of the problem: binding TCP/UDP servers on desired IP. It does not depend on application environment and implementation details (whether glibc is used or not). It adds new eBPF program type `BPF_PROG_TYPE_CGROUP_SOCK_ADDR` and attach types `BPF_CGROUP_INET4_BIND` and `BPF_CGROUP_INET6_BIND` (similar to already existing `BPF_CGROUP_INET_SOCK_CREATE`). The new program type is intended to be used with sockets (`struct sock`) in a cgroup and provided by user `struct sockaddr`. Pointers to both of them are parts of the context passed to programs of newly added types. The new attach types provides hooks in `bind(2)` system call for both IPv4 and IPv6 so that one can write a program to override IP addresses and ports user program tries to bind to and apply such a program for whole cgroup. == Implementation notes == [1] Separate attach types for `AF_INET` and `AF_INET6` are added intentionally to prevent reading/writing to offsets that don't make sense for corresponding socket family. E.g. if user passes `sockaddr_in` it doesn't make sense to read from / write to `user_ip6[]` context fields. [2] The write access to `struct bpf_sock_addr_kern` is implemented using special field as an additional "register". There are just two registers in `sock_addr_convert_ctx_access`: `src` with value to write and `dst` with pointer to context that can't be changed not to break later instructions. But the fields, allowed to write to, are not available directly and to access them address of corresponding pointer has to be loaded first. To get additional register the 1st not used by `src` and `dst` one is taken, its content is saved to `bpf_sock_addr_kern.tmp_reg`, then the register is used to load address of pointer field, and finally the register's content is restored from the temporary field after writing `src` value. Signed-off-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* bpf: Check attach type at prog load timeAndrey Ignatov2018-03-311-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | == The problem == There are use-cases when a program of some type can be attached to multiple attach points and those attach points must have different permissions to access context or to call helpers. E.g. context structure may have fields for both IPv4 and IPv6 but it doesn't make sense to read from / write to IPv6 field when attach point is somewhere in IPv4 stack. Same applies to BPF-helpers: it may make sense to call some helper from some attach point, but not from other for same prog type. == The solution == Introduce `expected_attach_type` field in in `struct bpf_attr` for `BPF_PROG_LOAD` command. If scenario described in "The problem" section is the case for some prog type, the field will be checked twice: 1) At load time prog type is checked to see if attach type for it must be known to validate program permissions correctly. Prog will be rejected with EINVAL if it's the case and `expected_attach_type` is not specified or has invalid value. 2) At attach time `attach_type` is compared with `expected_attach_type`, if prog type requires to have one, and, if they differ, attach will be rejected with EINVAL. The `expected_attach_type` is now available as part of `struct bpf_prog` in both `bpf_verifier_ops->is_valid_access()` and `bpf_verifier_ops->get_func_proto()` () and can be used to check context accesses and calls to helpers correspondingly. Initially the idea was discussed by Alexei Starovoitov <ast@fb.com> and Daniel Borkmann <daniel@iogearbox.net> here: https://marc.info/?l=linux-netdev&m=152107378717201&w=2 Signed-off-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* bpf/cgroup: fix a verification error for a CGROUP_DEVICE type progYonghong Song2017-12-191-2/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The tools/testing/selftests/bpf test program test_dev_cgroup fails with the following error when compiled with llvm 6.0. (I did not try with earlier versions.) libbpf: load bpf program failed: Permission denied libbpf: -- BEGIN DUMP LOG --- libbpf: 0: (61) r2 = *(u32 *)(r1 +4) 1: (b7) r0 = 0 2: (55) if r2 != 0x1 goto pc+8 R0=inv0 R1=ctx(id=0,off=0,imm=0) R2=inv1 R10=fp0 3: (69) r2 = *(u16 *)(r1 +0) invalid bpf_context access off=0 size=2 ... The culprit is the following statement in dev_cgroup.c: short type = ctx->access_type & 0xFFFF; This code is typical as the ctx->access_type is assigned as below in kernel/bpf/cgroup.c: struct bpf_cgroup_dev_ctx ctx = { .access_type = (access << 16) | dev_type, .major = major, .minor = minor, }; The compiler converts it to u16 access while the verifier cgroup_dev_is_valid_access rejects any non u32 access. This patch permits the field access_type to be accessible with type u16 and u8 as well. Signed-off-by: Yonghong Song <yhs@fb.com> Tested-by: Roman Gushchin <guro@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* bpf, cgroup: implement eBPF-based device controller for cgroup v2Roman Gushchin2017-11-051-0/+67
| | | | | | | | | | | | | | | | | | | | Cgroup v2 lacks the device controller, provided by cgroup v1. This patch adds a new eBPF program type, which in combination of previously added ability to attach multiple eBPF programs to a cgroup, will provide a similar functionality, but with some additional flexibility. This patch introduces a BPF_PROG_TYPE_CGROUP_DEVICE program type. A program takes major and minor device numbers, device type (block/character) and access type (mknod/read/write) as parameters and returns an integer which defines if the operation should be allowed or terminated with -EPERM. Signed-off-by: Roman Gushchin <guro@fb.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Tejun Heo <tj@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
* bpf: remove redundant variable old_flagsColin Ian King2017-10-111-2/+0
| | | | | | | | | | | | Variable old_flags is being assigned but is never read; it is redundant and can be removed. Cleans up clang warning: Value stored to 'old_flags' is never read Signed-off-by: Colin Ian King <colin.king@canonical.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
* bpf: introduce BPF_PROG_QUERY commandAlexei Starovoitov2017-10-041-0/+46
| | | | | | | | | | | | | introduce BPF_PROG_QUERY command to retrieve a set of either attached programs to given cgroup or a set of effective programs that will execute for events within a cgroup Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> for cgroup bits Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* bpf: multi program support for cgroup+bpfAlexei Starovoitov2017-10-041-131/+336
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | introduce BPF_F_ALLOW_MULTI flag that can be used to attach multiple bpf programs to a cgroup. The difference between three possible flags for BPF_PROG_ATTACH command: - NONE(default): No further bpf programs allowed in the subtree. - BPF_F_ALLOW_OVERRIDE: If a sub-cgroup installs some bpf program, the program in this cgroup yields to sub-cgroup program. - BPF_F_ALLOW_MULTI: If a sub-cgroup installs some bpf program, that cgroup program gets run in addition to the program in this cgroup. NONE and BPF_F_ALLOW_OVERRIDE existed before. This patch doesn't change their behavior. It only clarifies the semantics in relation to new flag. Only one program is allowed to be attached to a cgroup with NONE or BPF_F_ALLOW_OVERRIDE flag. Multiple programs are allowed to be attached to a cgroup with BPF_F_ALLOW_MULTI flag. They are executed in FIFO order (those that were attached first, run first) The programs of sub-cgroup are executed first, then programs of this cgroup and then programs of parent cgroup. All eligible programs are executed regardless of return code from earlier programs. To allow efficient execution of multiple programs attached to a cgroup and to avoid penalizing cgroups without any programs attached introduce 'struct bpf_prog_array' which is RCU protected array of pointers to bpf programs. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> for cgroup bits Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* bpf: BPF support for sock_opsLawrence Brakmo2017-07-011-0/+37
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Created a new BPF program type, BPF_PROG_TYPE_SOCK_OPS, and a corresponding struct that allows BPF programs of this type to access some of the socket's fields (such as IP addresses, ports, etc.). It uses the existing bpf cgroups infrastructure so the programs can be attached per cgroup with full inheritance support. The program will be called at appropriate times to set relevant connections parameters such as buffer sizes, SYN and SYN-ACK RTOs, etc., based on connection information such as IP addresses, port numbers, etc. Alghough there are already 3 mechanisms to set parameters (sysctls, route metrics and setsockopts), this new mechanism provides some distinct advantages. Unlike sysctls, it can set parameters per connection. In contrast to route metrics, it can also use port numbers and information provided by a user level program. In addition, it could set parameters probabilistically for evaluation purposes (i.e. do something different on 10% of the flows and compare results with the other 90% of the flows). Also, in cases where IPv6 addresses contain geographic information, the rules to make changes based on the distance (or RTT) between the hosts are much easier than route metric rules and can be global. Finally, unlike setsockopt, it oes not require application changes and it can be updated easily at any time. Although the bpf cgroup framework already contains a sock related program type (BPF_PROG_TYPE_CGROUP_SOCK), I created the new type (BPF_PROG_TYPE_SOCK_OPS) beccause the existing type expects to be called only once during the connections's lifetime. In contrast, the new program type will be called multiple times from different places in the network stack code. For example, before sending SYN and SYN-ACKs to set an appropriate timeout, when the connection is established to set congestion control, etc. As a result it has "op" field to specify the type of operation requested. The purpose of this new program type is to simplify setting connection parameters, such as buffer sizes, TCP's SYN RTO, etc. For example, it is easy to use facebook's internal IPv6 addresses to determine if both hosts of a connection are in the same datacenter. Therefore, it is easy to write a BPF program to choose a small SYN RTO value when both hosts are in the same datacenter. This patch only contains the framework to support the new BPF program type, following patches add the functionality to set various connection parameters. This patch defines a new BPF program type: BPF_PROG_TYPE_SOCKET_OPS and a new bpf syscall command to load a new program of this type: BPF_PROG_LOAD_SOCKET_OPS. Two new corresponding structs (one for the kernel one for the user/BPF program): /* kernel version */ struct bpf_sock_ops_kern { struct sock *sk; __u32 op; union { __u32 reply; __u32 replylong[4]; }; }; /* user version * Some fields are in network byte order reflecting the sock struct * Use the bpf_ntohl helper macro in samples/bpf/bpf_endian.h to * convert them to host byte order. */ struct bpf_sock_ops { __u32 op; union { __u32 reply; __u32 replylong[4]; }; __u32 family; __u32 remote_ip4; /* In network byte order */ __u32 local_ip4; /* In network byte order */ __u32 remote_ip6[4]; /* In network byte order */ __u32 local_ip6[4]; /* In network byte order */ __u32 remote_port; /* In network byte order */ __u32 local_port; /* In host byte horder */ }; Currently there are two types of ops. The first type expects the BPF program to return a value which is then used by the caller (or a negative value to indicate the operation is not supported). The second type expects state changes to be done by the BPF program, for example through a setsockopt BPF helper function, and they ignore the return value. The reply fields of the bpf_sockt_ops struct are there in case a bpf program needs to return a value larger than an integer. Signed-off-by: Lawrence Brakmo <brakmo@fb.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* bpf: pass sk to helper functionsWillem de Bruijn2017-04-111-1/+4
| | | | | | | | | | | | | BPF helper functions access socket fields through skb->sk. This is not set in ingress cgroup and socket filters. The association is only made in skb_set_owner_r once the filter has accepted the packet. Sk is available as socket lookup has taken place. Temporarily set skb->sk to sk in these cases. Signed-off-by: Willem de Bruijn <willemb@google.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* bpf: introduce BPF_F_ALLOW_OVERRIDE flagAlexei Starovoitov2017-02-121-12/+47
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If BPF_F_ALLOW_OVERRIDE flag is used in BPF_PROG_ATTACH command to the given cgroup the descendent cgroup will be able to override effective bpf program that was inherited from this cgroup. By default it's not passed, therefore override is disallowed. Examples: 1. prog X attached to /A with default prog Y fails to attach to /A/B and /A/B/C Everything under /A runs prog X 2. prog X attached to /A with allow_override. prog Y fails to attach to /A/B with default (non-override) prog M attached to /A/B with allow_override. Everything under /A/B runs prog M only. 3. prog X attached to /A with allow_override. prog Y fails to attach to /A with default. The user has to detach first to switch the mode. In the future this behavior may be extended with a chain of non-overridable programs. Also fix the bug where detach from cgroup where nothing is attached was not throwing error. Return ENOENT in such case. Add several testcases and adjust libbpf. Fixes: 3007098494be ("cgroup: add support for eBPF programs") Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Daniel Mack <daniel@zonque.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* bpf: Add new cgroup attach type to enable sock modificationsDavid Ahern2016-12-021-0/+33
| | | | | | | | | | | | | | | | | Add new cgroup based program type, BPF_PROG_TYPE_CGROUP_SOCK. Similar to BPF_PROG_TYPE_CGROUP_SKB programs can be attached to a cgroup and run any time a process in the cgroup opens an AF_INET or AF_INET6 socket. Currently only sk_bound_dev_if is exported to userspace for modification by a bpf program. This allows a cgroup to be configured such that AF_INET{6} sockets opened by processes are automatically bound to a specific device. In turn, this enables the running of programs that do not support SO_BINDTODEVICE in a specific VRF context / L3 domain. Signed-off-by: David Ahern <dsa@cumulusnetworks.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* bpf: Refactor cgroups code in prep for new typeDavid Ahern2016-12-021-5/+5
| | | | | | | | Code move and rename only; no functional change intended. Signed-off-by: David Ahern <dsa@cumulusnetworks.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* bpf: cgroup: fix documentation of __cgroup_bpf_update()Daniel Mack2016-11-291-2/+2
| | | | | | | | | | | There's a 'not' missing in one paragraph. Add it. Fixes: 3007098494be ("cgroup: add support for eBPF programs") Signed-off-by: Daniel Mack <daniel@zonque.org> Reported-by: Rami Rosen <roszenrami@gmail.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* cgroup: add support for eBPF programsDaniel Mack2016-11-251-0/+167
This patch adds two sets of eBPF program pointers to struct cgroup. One for such that are directly pinned to a cgroup, and one for such that are effective for it. To illustrate the logic behind that, assume the following example cgroup hierarchy. A - B - C \ D - E If only B has a program attached, it will be effective for B, C, D and E. If D then attaches a program itself, that will be effective for both D and E, and the program in B will only affect B and C. Only one program of a given type is effective for a cgroup. Attaching and detaching programs will be done through the bpf(2) syscall. For now, ingress and egress inet socket filtering are the only supported use-cases. Signed-off-by: Daniel Mack <daniel@zonque.org> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
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