- 04 Oct, 2018 5 commits
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Andrey Ignatov authored
libbpf is used more and more outside kernel tree. That means the library should follow good practices in library design and implementation to play well with third party code that uses it. One of such practices is to have a common prefix (or a few) for every interface, function or data structure, library provides. I helps to avoid name conflicts with other libraries and keeps API consistent. Inconsistent names in libbpf already cause problems in real life. E.g. an application can't use both libbpf and libnl due to conflicting symbols. Having common prefix will help to fix current and avoid future problems. libbpf already uses the following prefixes for its interfaces: * bpf_ for bpf system call wrappers, program/map/elf-object abstractions and a few other things; * btf_ for BTF related API; * libbpf_ for everything else. The patch renames function in str_error.h to have libbpf_ prefix since it misses one and doesn't fit well into the first two categories. Signed-off-by:
Andrey Ignatov <rdna@fb.com> Acked-by:
Alexei Starovoitov <ast@kernel.org> Signed-off-by:
Daniel Borkmann <daniel@iogearbox.net>
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Andrey Ignatov authored
libbpf is used more and more outside kernel tree. That means the library should follow good practices in library design and implementation to play well with third party code that uses it. One of such practices is to have a common prefix (or a few) for every interface, function or data structure, library provides. I helps to avoid name conflicts with other libraries and keeps API consistent. Inconsistent names in libbpf already cause problems in real life. E.g. an application can't use both libbpf and libnl due to conflicting symbols. Having common prefix will help to fix current and avoid future problems. libbpf already uses the following prefixes for its interfaces: * bpf_ for bpf system call wrappers, program/map/elf-object abstractions and a few other things; * btf_ for BTF related API; * libbpf_ for everything else. The patch adds libbpf_ prefix to interfaces in nlattr.h that use none of mentioned above prefixes and doesn't fit well into the first two categories. Since affected part of API is used in bpftool, the patch applies corresponding change to bpftool as well. Having it in a separate patch will cause a state of tree where bpftool is broken what may not be a good idea. Signed-off-by:
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Andrey Ignatov authored
libbpf is used more and more outside kernel tree. That means the library should follow good practices in library design and implementation to play well with third party code that uses it. One of such practices is to have a common prefix (or a few) for every interface, function or data structure, library provides. I helps to avoid name conflicts with other libraries and keeps API consistent. Inconsistent names in libbpf already cause problems in real life. E.g. an application can't use both libbpf and libnl due to conflicting symbols. Having common prefix will help to fix current and avoid future problems. libbpf already uses the following prefixes for its interfaces: * bpf_ for bpf system call wrappers, program/map/elf-object abstractions and a few other things; * btf_ for BTF related API; * libbpf_ for everything else. The patch adds libbpf_ prefix to functions and typedef in libbpf.h that use none of mentioned above prefixes and doesn't fit well into the first two categories. Since affected part of API is used in bpftool, the patch applies corresponding change to bpftool as well. Having it in a separate patch will cause a state of tree where bpftool is broken what may not be a good idea. Signed-off-by:
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Andrey Ignatov authored
This typedef is used only by implementation in netlink.c. Nothing uses it in public API. Move it to netlink.c. Signed-off-by:
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Joe Stringer authored
Stephen Rothwell reports the following link failure with IPv6 as module: x86_64-linux-gnu-ld: net/core/filter.o: in function `sk_lookup': (.text+0x19219): undefined reference to `__udp6_lib_lookup' Fix the build by only enabling the IPv6 socket lookup if IPv6 support is compiled into the kernel. Signed-off-by:
Joe Stringer <joe@wand.net.nz> Signed-off-by:
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- 03 Oct, 2018 14 commits
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Daniel Borkmann authored
Joe Stringer says: ==================== This series proposes a new helper for the BPF API which allows BPF programs to perform lookups for sockets in a network namespace. This would allow programs to determine early on in processing whether the stack is expecting to receive the packet, and perform some action (eg drop, forward somewhere) based on this information. The series is structured roughly into: * Misc refactor * Add the socket pointer type * Add reference tracking to ensure that socket references are freed * Extend the BPF API to add sk_lookup_xxx() / sk_release() functions * Add tests/documentation The helper proposed in this series includes a parameter for a tuple which must be filled in by the caller to determine the socket to look up. The simplest case would be filling with the contents of the packet, ie mapping the packet's 5-tuple into the parameter. In common cases, it may alternatively be useful to reverse the direction of the tuple and perform a lookup, to find the socket that initiates this connection; and if the BPF program ever performs a form of IP address translation, it may further be useful to be able to look up arbitrary tuples that are not based upon the packet, but instead based on state held in BPF maps or hardcoded in the BPF program. Currently, access into the socket's fields are limited to those which are otherwise already accessible, and are restricted to read-only access. Changes since v3: * New patch: "bpf: Reuse canonical string formatter for ctx errs" * Add PTR_TO_SOCKET to is_ctx_reg(). * Add a few new checks to prevent mixing of socket/non-socket pointers. * Swap order of checks in sock_filter_is_valid_access(). * Prefix register spill macros with "bpf_". * Add acks from previous round * Rebase Changes since v2: * New patch: "selftests/bpf: Generalize dummy program types". This enables adding verifier tests for socket lookup with tail calls. * Define the semantics of the new helpers more clearly in uAPI header. * Fix release of caller_net when netns is not specified. * Use skb->sk to find caller net when skb->dev is unavailable. * Fix build with !CONFIG_NET. * Replace ptr_id defensive coding when releasing reference state with an internal error (-EFAULT). * Remove flags argument to sk_release(). * Add several new assembly tests suggested by Daniel. * Add a few new C tests. * Fix typo in verifier error message. Changes since v1: * Limit netns_id field to 32 bits * Reuse reg_type_mismatch() in more places * Reduce the number of passes at convert_ctx_access() * Replace ptr_id defensive coding when releasing reference state with an internal error (-EFAULT) * Rework 'struct bpf_sock_tuple' to allow passing a packet pointer * Allow direct packet access from helper * Fix compile error with CONFIG_IPV6 enabled * Improve commit messages Changes since RFC: * Split up sk_lookup() into sk_lookup_tcp(), sk_lookup_udp(). * Only take references on the socket when necessary. * Make sk_release() only free the socket reference in this case. * Fix some runtime reference leaks: * Disallow BPF_LD_[ABS|IND] instructions while holding a reference. * Disallow bpf_tail_call() while holding a reference. * Prevent the same instruction being used for reference and other pointer type. * Simplify locating copies of a reference during helper calls by caching the pointer id from the caller. * Fix kbuild compilation warnings with particular configs. * Improve code comments describing the new verifier pieces. * Tested by Nitin ==================== Signed-off-by: -
Joe Stringer authored
Document the new pointer types in the verifier and how the pointer ID tracking works to ensure that references which are taken are later released. Signed-off-by:
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Joe Stringer authored
Add some tests that demonstrate and test the balanced lookup/free nature of socket lookup. Section names that start with "fail" represent programs that are expected to fail verification; all others should succeed. Signed-off-by:
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Joe Stringer authored
Allow the individual program load to be invoked. This will help with testing, where a single ELF may contain several sections, some of which denote subprograms that are expected to fail verification, along with some which are expected to pass verification. By allowing programs to be iterated and individually loaded, each program can be independently checked against its expected verification result. Signed-off-by:
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Joe Stringer authored
reference tracking: leak potential reference reference tracking: leak potential reference on stack reference tracking: leak potential reference on stack 2 reference tracking: zero potential reference reference tracking: copy and zero potential references reference tracking: release reference without check reference tracking: release reference reference tracking: release reference twice reference tracking: release reference twice inside branch reference tracking: alloc, check, free in one subbranch reference tracking: alloc, check, free in both subbranches reference tracking in call: free reference in subprog reference tracking in call: free reference in subprog and outside reference tracking in call: alloc & leak reference in subprog reference tracking in call: alloc in subprog, release outside reference tracking in call: sk_ptr leak into caller stack reference tracking in call: sk_ptr spill into caller stack reference tracking: allow LD_ABS reference tracking: forbid LD_ABS while holding reference reference tracking: allow LD_IND reference tracking: forbid LD_IND while holding reference reference tracking: check reference or tail call reference tracking: release reference then tail call reference tracking: leak possible reference over tail call reference tracking: leak checked reference over tail call reference tracking: mangle and release sock_or_null reference tracking: mangle and release sock reference tracking: access member reference tracking: write to member reference tracking: invalid 64-bit access of member reference tracking: access after release reference tracking: direct access for lookup unpriv: spill/fill of different pointers stx - ctx and sock unpriv: spill/fill of different pointers stx - leak sock unpriv: spill/fill of different pointers stx - sock and ctx (read) unpriv: spill/fill of different pointers stx - sock and ctx (write) Signed-off-by:
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Joe Stringer authored
Don't hardcode the dummy program types to SOCKET_FILTER type, as this prevents testing bpf_tail_call in conjunction with other program types. Instead, use the program type specified in the test case. Signed-off-by:
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Joe Stringer authored
This patch adds new BPF helper functions, bpf_sk_lookup_tcp() and bpf_sk_lookup_udp() which allows BPF programs to find out if there is a socket listening on this host, and returns a socket pointer which the BPF program can then access to determine, for instance, whether to forward or drop traffic. bpf_sk_lookup_xxx() may take a reference on the socket, so when a BPF program makes use of this function, it must subsequently pass the returned pointer into the newly added sk_release() to return the reference. By way of example, the following pseudocode would filter inbound connections at XDP if there is no corresponding service listening for the traffic: struct bpf_sock_tuple tuple; struct bpf_sock_ops *sk; populate_tuple(ctx, &tuple); // Extract the 5tuple from the packet sk = bpf_sk_lookup_tcp(ctx, &tuple, sizeof tuple, netns, 0); if (!sk) { // Couldn't find a socket listening for this traffic. Drop. return TC_ACT_SHOT; } bpf_sk_release(sk, 0); return TC_ACT_OK; Signed-off-by: -
Joe Stringer authored
Allow helper functions to acquire a reference and return it into a register. Specific pointer types such as the PTR_TO_SOCKET will implicitly represent such a reference. The verifier must ensure that these references are released exactly once in each path through the program. To achieve this, this commit assigns an id to the pointer and tracks it in the 'bpf_func_state', then when the function or program exits, verifies that all of the acquired references have been freed. When the pointer is passed to a function that frees the reference, it is removed from the 'bpf_func_state` and all existing copies of the pointer in registers are marked invalid. Signed-off-by:
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Joe Stringer authored
An upcoming commit will need very similar copy/realloc boilerplate, so refactor the existing stack copy/realloc functions into macros to simplify it. Signed-off-by:
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Joe Stringer authored
Teach the verifier a little bit about a new type of pointer, a PTR_TO_SOCKET. This pointer type is accessed from BPF through the 'struct bpf_sock' structure. Signed-off-by:
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Joe Stringer authored
This check will be reused by an upcoming commit for conditional jump checks for sockets. Refactor it a bit to simplify the later commit. Signed-off-by:
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Joe Stringer authored
The array "reg_type_str" provides canonical formatting of register types, however a couple of places would previously check whether a register represented the context and write the name "context" directly. An upcoming commit will add another pointer type to these statements, so to provide more accurate error messages in the verifier, update these error messages to use "reg_type_str" instead. Signed-off-by:
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Joe Stringer authored
An upcoming commit will add another two pointer types that need very similar behaviour, so generalise this function now. Signed-off-by:
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Joe Stringer authored
Add this iterator for spilled registers, it concentrates the details of how to get the current frame's spilled registers into a single macro while clarifying the intention of the code which is calling the macro. Signed-off-by:
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- 02 Oct, 2018 4 commits
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Daniel Borkmann authored
Jakub Kicinski says: ==================== This series makes the control message parsing for interacting with BPF maps more flexible. Up until now we had a hard limit in the ABI for key and value size to be 64B at most. Using TLV capability allows us to support large map entries. ==================== Signed-off-by: -
Jakub Kicinski authored
In current ABI the size of the messages carrying map elements was statically defined to at most 16 words of key and 16 words of value (NFP word is 4 bytes). We should not make this assumption and use the max key and value sizes from the BPF capability instead. To make sure old kernels don't get surprised with larger (or smaller) messages bump the FW ABI version to 3 when key/value size is different than 16 words. Signed-off-by:
Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by:
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Jakub Kicinski authored
Some apps may want to have higher MTU on the control vNIC/queue. Allow them to set the requested MTU at init time. Signed-off-by:
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Jakub Kicinski authored
Up until now we only had per-vNIC BPF ABI version capabilities, which are slightly awkward to use because bulk of the resources and configuration does not relate to any particular vNIC. Add a new capability for global ABI version and check the per-vNIC version are equal to it. Assume the ABI version 2 if no explicit version capability is present. Signed-off-by:
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- 01 Oct, 2018 11 commits
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Daniel Borkmann authored
Roman Gushchin says: ==================== This patchset implements per-cpu cgroup local storage and provides an example how per-cpu and shared cgroup local storage can be used for efficient accounting of network traffic. v4->v3: 1) incorporated Alexei's feedback v3->v2: 1) incorporated Song's feedback 2) rebased on top of current bpf-next v2->v1: 1) added a selftest implementing network counters 2) added a missing free() in cgroup local storage selftest ==================== Signed-off-by: -
Roman Gushchin authored
This commit adds a bpf kselftest, which demonstrates how percpu and shared cgroup local storage can be used for efficient lookup-free network accounting. Cgroup local storage provides generic memory area with a very efficient lookup free access. To avoid expensive atomic operations for each packet, per-cpu cgroup local storage is used. Each packet is initially charged to a per-cpu counter, and only if the counter reaches certain value (32 in this case), the charge is moved into the global atomic counter. This allows to amortize atomic operations, keeping reasonable accuracy. The test also implements a naive network traffic throttling, mostly to demonstrate the possibility of bpf cgroup--based network bandwidth control. Expected output: ./test_netcnt test_netcnt:PASS 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:
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Roman Gushchin authored
This commit extends the test_cgrp2_attach2 test to cover per-cpu cgroup storage. Bpf program will use shared and per-cpu cgroup storages simultaneously, so a better coverage of corresponding core code will be achieved. Expected output: $ ./test_cgrp2_attach2 Attached DROP prog. This ping in cgroup /foo should fail... ping: sendmsg: Operation not permitted Attached DROP prog. This ping in cgroup /foo/bar should fail... ping: sendmsg: Operation not permitted Attached PASS prog. This ping in cgroup /foo/bar should pass... Detached PASS from /foo/bar while DROP is attached to /foo. This ping in cgroup /foo/bar should fail... ping: sendmsg: Operation not permitted Attached PASS from /foo/bar and detached DROP from /foo. This ping in cgroup /foo/bar should pass... ### override:PASS ### multi:PASS Signed-off-by:
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Roman Gushchin authored
This test extends the cgroup storage test to use per-cpu flavor of the cgroup storage as well. The test initializes a per-cpu cgroup storage to some non-zero initial value (1000), and then simple bumps a per-cpu counter each time the shared counter is atomically incremented. Then it reads all per-cpu areas from the userspace side, and checks that the sum of values adds to the expected sum. Expected output: $ ./test_cgroup_storage test_cgroup_storage:PASS Signed-off-by:
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Roman Gushchin authored
This commits adds verifier tests covering per-cpu cgroup storage functionality. There are 6 new tests, which are exactly the same as for shared cgroup storage, but do use per-cpu cgroup storage map. Expected output: $ ./test_verifier #0/u add+sub+mul OK #0/p add+sub+mul OK ... #286/p invalid cgroup storage access 6 OK #287/p valid per-cpu cgroup storage access OK #288/p invalid per-cpu cgroup storage access 1 OK #289/p invalid per-cpu cgroup storage access 2 OK #290/p invalid per-cpu cgroup storage access 3 OK #291/p invalid per-cpu cgroup storage access 4 OK #292/p invalid per-cpu cgroup storage access 5 OK #293/p invalid per-cpu cgroup storage access 6 OK #294/p multiple registers share map_lookup_elem result OK ... #662/p mov64 src == dst OK #663/p mov64 src != dst OK Summary: 914 PASSED, 0 SKIPPED, 0 FAILED Signed-off-by:
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Roman Gushchin authored
This commit adds support for BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE map type. Signed-off-by:
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Roman Gushchin authored
The sync is required due to the appearance of a new map type: BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE, which implements per-cpu cgroup local storage. Signed-off-by:
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Roman Gushchin authored
Explicitly forbid creating map of per-cpu cgroup local storages. This behavior matches the behavior of shared cgroup storages. Signed-off-by:
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Roman Gushchin authored
This commit introduced per-cpu cgroup local storage. Per-cpu cgroup local storage is very similar to simple cgroup storage (let's call it shared), except all the data is per-cpu. The main goal of per-cpu variant is to implement super fast counters (e.g. packet counters), which don't require neither lookups, neither atomic operations. >From userspace's point of view, accessing a per-cpu cgroup storage is similar to other per-cpu map types (e.g. per-cpu hashmaps and arrays). Writing to a per-cpu cgroup storage is not atomic, but is performed by copying longs, so some minimal atomicity is here, exactly as with other per-cpu maps. Signed-off-by:
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Roman Gushchin authored
To simplify the following introduction of per-cpu cgroup storage, let's rework a bit a mechanism of passing a pointer to a cgroup storage into the bpf_get_local_storage(). Let's save a pointer to the corresponding bpf_cgroup_storage structure, instead of a pointer to the actual buffer. It will help us to handle per-cpu storage later, which has a different way of accessing to the actual data. Signed-off-by:
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Roman Gushchin authored
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:
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- 28 Sep, 2018 1 commit
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Yonghong Song authored
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:
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- 27 Sep, 2018 5 commits
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Daniel Borkmann authored
Andrey Ignatov says: ==================== This patch set introduces libbpf_attach_type_by_name function in libbpf to identify attach type by section name. This is useful to avoid writing same logic over and over again in user space applications that leverage libbpf. Patch 1 has more details on the new function and problem being solved. Patches 2 and 3 add support for new section names. Patch 4 uses new function in a selftest. Patch 5 adds selftest for libbpf_{prog,attach}_type_by_name. As a side note there are a lot of inconsistencies now between names used by libbpf and bpftool (e.g. cgroup/skb vs cgroup_skb, cgroup_device and device vs cgroup/dev, sockops vs sock_ops, etc). This patch set does not address it but it tries not to make it harder to address it in the future. ==================== Signed-off-by: -
Andrey Ignatov authored
Add selftest for libbpf functions libbpf_prog_type_by_name and libbpf_attach_type_by_name. Example of output: % ./tools/testing/selftests/bpf/test_section_names Summary: 35 PASSED, 0 FAILED Signed-off-by:
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Andrey Ignatov authored
Use newly introduced libbpf_attach_type_by_name in test_socket_cookie selftest. Signed-off-by:
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Andrey Ignatov authored
Add section names for BPF_SK_SKB_STREAM_PARSER and BPF_SK_SKB_STREAM_VERDICT attach types to be able to identify them in libbpf_attach_type_by_name. "stream_parser" and "stream_verdict" are used instead of simple "parser" and "verdict" just to avoid possible confusion in a place where attach type is used alone (e.g. in bpftool's show sub-commands) since there is another attach point that can be named as "verdict": BPF_SK_MSG_VERDICT. Signed-off-by:
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Andrey Ignatov authored
Add section names for BPF_CGROUP_INET_INGRESS and BPF_CGROUP_INET_EGRESS attach types to be able to identify them in libbpf_attach_type_by_name. "cgroup_skb" is used instead of "cgroup/skb" mostly to easy possible unifying of how libbpf and bpftool works with section names: * bpftool uses "cgroup_skb" to in "prog list" sub-command; * bpftool uses "ingress" and "egress" in "cgroup list" sub-command; * having two parts instead of three in a string like "cgroup_skb/ingress" can be leveraged to split it to prog_type part and attach_type part, or vise versa: use two parts to make a section name. Signed-off-by:
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