License cleanup: add SPDX GPL-2.0 license identifier to files with no license
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.
By default all files without license information are under the default
license of the kernel, which is GPL version 2.
Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.
This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.
How this work was done:
Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,
Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.
The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.
The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.
Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).
All documentation files were explicitly excluded.
The following heuristics were used to determine which SPDX license
identifiers to apply.
- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.
For non */uapi/* files that summary was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139
and resulted in the first patch in this series.
If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930
and resulted in the second patch in this series.
- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:
SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1
and that resulted in the third patch in this series.
- when the two scanners agreed on the detected license(s), that became
the concluded license(s).
- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.
- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).
- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.
- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.
In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.
Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.
Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.
In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.
Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct
This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.
These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-01 22:07:57 +08:00
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/* SPDX-License-Identifier: GPL-2.0 */
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2016-11-23 23:52:26 +08:00
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#ifndef _BPF_CGROUP_H
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#define _BPF_CGROUP_H
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2018-09-28 22:45:36 +08:00
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#include <linux/bpf.h>
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2018-07-07 05:34:29 +08:00
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#include <linux/errno.h>
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2016-11-23 23:52:26 +08:00
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#include <linux/jump_label.h>
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2018-08-03 05:27:19 +08:00
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#include <linux/percpu.h>
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bpf: decouple the lifetime of cgroup_bpf from cgroup itself
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>
2019-05-26 00:37:39 +08:00
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#include <linux/percpu-refcount.h>
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2018-08-03 05:27:18 +08:00
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#include <linux/rbtree.h>
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2016-11-23 23:52:26 +08:00
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#include <uapi/linux/bpf.h>
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struct sock;
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2018-03-31 06:08:02 +08:00
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struct sockaddr;
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2016-11-23 23:52:26 +08:00
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struct cgroup;
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struct sk_buff;
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2018-08-03 05:27:18 +08:00
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struct bpf_map;
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struct bpf_prog;
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bpf: BPF support for sock_ops
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>
2017-07-01 11:02:40 +08:00
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struct bpf_sock_ops_kern;
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2018-08-03 05:27:18 +08:00
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struct bpf_cgroup_storage;
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2019-02-28 04:59:24 +08:00
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struct ctl_table;
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struct ctl_table_header;
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2016-11-23 23:52:26 +08:00
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#ifdef CONFIG_CGROUP_BPF
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extern struct static_key_false cgroup_bpf_enabled_key;
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#define cgroup_bpf_enabled static_branch_unlikely(&cgroup_bpf_enabled_key)
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2018-09-28 22:45:40 +08:00
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DECLARE_PER_CPU(struct bpf_cgroup_storage*,
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bpf_cgroup_storage[MAX_BPF_CGROUP_STORAGE_TYPE]);
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2018-09-28 22:45:36 +08:00
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#define for_each_cgroup_storage_type(stype) \
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for (stype = 0; stype < MAX_BPF_CGROUP_STORAGE_TYPE; stype++)
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2018-08-03 05:27:19 +08:00
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2018-08-03 05:27:18 +08:00
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struct bpf_cgroup_storage_map;
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struct bpf_storage_buffer {
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struct rcu_head rcu;
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char data[0];
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};
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struct bpf_cgroup_storage {
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2018-09-28 22:45:43 +08:00
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union {
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struct bpf_storage_buffer *buf;
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void __percpu *percpu_buf;
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};
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2018-08-03 05:27:18 +08:00
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struct bpf_cgroup_storage_map *map;
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struct bpf_cgroup_storage_key key;
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struct list_head list;
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struct rb_node node;
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struct rcu_head rcu;
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};
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2017-10-03 13:50:21 +08:00
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struct bpf_prog_list {
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struct list_head node;
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struct bpf_prog *prog;
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2018-09-28 22:45:36 +08:00
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struct bpf_cgroup_storage *storage[MAX_BPF_CGROUP_STORAGE_TYPE];
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2017-10-03 13:50:21 +08:00
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};
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struct bpf_prog_array;
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2016-11-23 23:52:26 +08:00
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struct cgroup_bpf {
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2017-10-03 13:50:21 +08:00
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/* array of effective progs in this cgroup */
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struct bpf_prog_array __rcu *effective[MAX_BPF_ATTACH_TYPE];
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/* attached progs to this cgroup and attach flags
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* when flags == 0 or BPF_F_ALLOW_OVERRIDE the progs list will
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* have either zero or one element
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* when BPF_F_ALLOW_MULTI the list can have up to BPF_CGROUP_MAX_PROGS
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2016-11-23 23:52:26 +08:00
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*/
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2017-10-03 13:50:21 +08:00
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struct list_head progs[MAX_BPF_ATTACH_TYPE];
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u32 flags[MAX_BPF_ATTACH_TYPE];
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/* temp storage for effective prog array used by prog_attach/detach */
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2019-05-29 05:14:43 +08:00
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struct bpf_prog_array *inactive;
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bpf: decouple the lifetime of cgroup_bpf from cgroup itself
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>
2019-05-26 00:37:39 +08:00
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/* reference counter used to detach bpf programs after cgroup removal */
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struct percpu_ref refcnt;
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/* cgroup_bpf is released using a work queue */
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struct work_struct release_work;
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2016-11-23 23:52:26 +08:00
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};
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2017-10-03 13:50:21 +08:00
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int cgroup_bpf_inherit(struct cgroup *cgrp);
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bpf: decouple the lifetime of cgroup_bpf from cgroup itself
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>
2019-05-26 00:37:39 +08:00
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void cgroup_bpf_offline(struct cgroup *cgrp);
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2016-11-23 23:52:26 +08:00
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2017-10-03 13:50:21 +08:00
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int __cgroup_bpf_attach(struct cgroup *cgrp, struct bpf_prog *prog,
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enum bpf_attach_type type, u32 flags);
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int __cgroup_bpf_detach(struct cgroup *cgrp, struct bpf_prog *prog,
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2019-01-29 14:47:06 +08:00
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enum bpf_attach_type type);
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2017-10-03 13:50:22 +08:00
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int __cgroup_bpf_query(struct cgroup *cgrp, const union bpf_attr *attr,
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union bpf_attr __user *uattr);
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2016-11-23 23:52:26 +08:00
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2017-10-03 13:50:21 +08:00
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/* Wrapper for __cgroup_bpf_*() protected by cgroup_mutex */
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int cgroup_bpf_attach(struct cgroup *cgrp, struct bpf_prog *prog,
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enum bpf_attach_type type, u32 flags);
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int cgroup_bpf_detach(struct cgroup *cgrp, struct bpf_prog *prog,
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enum bpf_attach_type type, u32 flags);
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2017-10-03 13:50:22 +08:00
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int cgroup_bpf_query(struct cgroup *cgrp, const union bpf_attr *attr,
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union bpf_attr __user *uattr);
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2016-11-23 23:52:26 +08:00
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2016-12-02 00:48:03 +08:00
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int __cgroup_bpf_run_filter_skb(struct sock *sk,
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struct sk_buff *skb,
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enum bpf_attach_type type);
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2016-12-02 00:48:04 +08:00
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int __cgroup_bpf_run_filter_sk(struct sock *sk,
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enum bpf_attach_type type);
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2018-03-31 06:08:02 +08:00
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int __cgroup_bpf_run_filter_sock_addr(struct sock *sk,
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struct sockaddr *uaddr,
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2018-05-25 23:55:23 +08:00
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enum bpf_attach_type type,
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void *t_ctx);
|
2018-03-31 06:08:02 +08:00
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bpf: BPF support for sock_ops
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>
2017-07-01 11:02:40 +08:00
|
|
|
int __cgroup_bpf_run_filter_sock_ops(struct sock *sk,
|
|
|
|
|
struct bpf_sock_ops_kern *sock_ops,
|
|
|
|
|
enum bpf_attach_type type);
|
|
|
|
|
|
2017-11-05 21:15:32 +08:00
|
|
|
int __cgroup_bpf_check_dev_permission(short dev_type, u32 major, u32 minor,
|
|
|
|
|
short access, enum bpf_attach_type type);
|
|
|
|
|
|
2019-02-28 04:59:24 +08:00
|
|
|
int __cgroup_bpf_run_filter_sysctl(struct ctl_table_header *head,
|
|
|
|
|
struct ctl_table *table, int write,
|
2019-03-08 10:38:43 +08:00
|
|
|
void __user *buf, size_t *pcount,
|
2019-03-08 10:50:52 +08:00
|
|
|
loff_t *ppos, void **new_buf,
|
|
|
|
|
enum bpf_attach_type type);
|
2019-02-28 04:59:24 +08:00
|
|
|
|
bpf: implement getsockopt and setsockopt hooks
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>
2019-06-28 04:38:47 +08:00
|
|
|
int __cgroup_bpf_run_filter_setsockopt(struct sock *sock, int *level,
|
|
|
|
|
int *optname, char __user *optval,
|
|
|
|
|
int *optlen, char **kernel_optval);
|
|
|
|
|
int __cgroup_bpf_run_filter_getsockopt(struct sock *sk, int level,
|
|
|
|
|
int optname, char __user *optval,
|
|
|
|
|
int __user *optlen, int max_optlen,
|
|
|
|
|
int retval);
|
|
|
|
|
|
2018-09-28 22:45:36 +08:00
|
|
|
static inline enum bpf_cgroup_storage_type cgroup_storage_type(
|
|
|
|
|
struct bpf_map *map)
|
2018-08-03 05:27:19 +08:00
|
|
|
{
|
2018-09-28 22:45:43 +08:00
|
|
|
if (map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE)
|
|
|
|
|
return BPF_CGROUP_STORAGE_PERCPU;
|
|
|
|
|
|
2018-09-28 22:45:36 +08:00
|
|
|
return BPF_CGROUP_STORAGE_SHARED;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static inline void bpf_cgroup_storage_set(struct bpf_cgroup_storage
|
|
|
|
|
*storage[MAX_BPF_CGROUP_STORAGE_TYPE])
|
|
|
|
|
{
|
|
|
|
|
enum bpf_cgroup_storage_type stype;
|
2018-08-03 05:27:19 +08:00
|
|
|
|
2018-09-28 22:45:40 +08:00
|
|
|
for_each_cgroup_storage_type(stype)
|
|
|
|
|
this_cpu_write(bpf_cgroup_storage[stype], storage[stype]);
|
2018-08-03 05:27:19 +08:00
|
|
|
}
|
|
|
|
|
|
2018-09-28 22:45:36 +08:00
|
|
|
struct bpf_cgroup_storage *bpf_cgroup_storage_alloc(struct bpf_prog *prog,
|
|
|
|
|
enum bpf_cgroup_storage_type stype);
|
2018-08-03 05:27:18 +08:00
|
|
|
void bpf_cgroup_storage_free(struct bpf_cgroup_storage *storage);
|
|
|
|
|
void bpf_cgroup_storage_link(struct bpf_cgroup_storage *storage,
|
|
|
|
|
struct cgroup *cgroup,
|
|
|
|
|
enum bpf_attach_type type);
|
|
|
|
|
void bpf_cgroup_storage_unlink(struct bpf_cgroup_storage *storage);
|
|
|
|
|
int bpf_cgroup_storage_assign(struct bpf_prog *prog, struct bpf_map *map);
|
|
|
|
|
void bpf_cgroup_storage_release(struct bpf_prog *prog, struct bpf_map *map);
|
|
|
|
|
|
2018-09-28 22:45:43 +08:00
|
|
|
int bpf_percpu_cgroup_storage_copy(struct bpf_map *map, void *key, void *value);
|
|
|
|
|
int bpf_percpu_cgroup_storage_update(struct bpf_map *map, void *key,
|
|
|
|
|
void *value, u64 flags);
|
|
|
|
|
|
2016-12-02 00:48:03 +08:00
|
|
|
/* Wrappers for __cgroup_bpf_run_filter_skb() guarded by cgroup_bpf_enabled. */
|
|
|
|
|
#define BPF_CGROUP_RUN_PROG_INET_INGRESS(sk, skb) \
|
|
|
|
|
({ \
|
|
|
|
|
int __ret = 0; \
|
|
|
|
|
if (cgroup_bpf_enabled) \
|
|
|
|
|
__ret = __cgroup_bpf_run_filter_skb(sk, skb, \
|
|
|
|
|
BPF_CGROUP_INET_INGRESS); \
|
|
|
|
|
\
|
|
|
|
|
__ret; \
|
2016-11-23 23:52:26 +08:00
|
|
|
})
|
|
|
|
|
|
2016-12-02 00:48:03 +08:00
|
|
|
#define BPF_CGROUP_RUN_PROG_INET_EGRESS(sk, skb) \
|
|
|
|
|
({ \
|
|
|
|
|
int __ret = 0; \
|
|
|
|
|
if (cgroup_bpf_enabled && sk && sk == skb->sk) { \
|
|
|
|
|
typeof(sk) __sk = sk_to_full_sk(sk); \
|
|
|
|
|
if (sk_fullsock(__sk)) \
|
|
|
|
|
__ret = __cgroup_bpf_run_filter_skb(__sk, skb, \
|
|
|
|
|
BPF_CGROUP_INET_EGRESS); \
|
|
|
|
|
} \
|
|
|
|
|
__ret; \
|
2016-11-23 23:52:26 +08:00
|
|
|
})
|
|
|
|
|
|
2018-03-31 06:08:07 +08:00
|
|
|
#define BPF_CGROUP_RUN_SK_PROG(sk, type) \
|
2016-12-02 00:48:04 +08:00
|
|
|
({ \
|
|
|
|
|
int __ret = 0; \
|
2018-02-23 14:58:41 +08:00
|
|
|
if (cgroup_bpf_enabled) { \
|
2018-03-31 06:08:07 +08:00
|
|
|
__ret = __cgroup_bpf_run_filter_sk(sk, type); \
|
2016-12-02 00:48:04 +08:00
|
|
|
} \
|
|
|
|
|
__ret; \
|
|
|
|
|
})
|
|
|
|
|
|
2018-03-31 06:08:07 +08:00
|
|
|
#define BPF_CGROUP_RUN_PROG_INET_SOCK(sk) \
|
|
|
|
|
BPF_CGROUP_RUN_SK_PROG(sk, BPF_CGROUP_INET_SOCK_CREATE)
|
|
|
|
|
|
|
|
|
|
#define BPF_CGROUP_RUN_PROG_INET4_POST_BIND(sk) \
|
|
|
|
|
BPF_CGROUP_RUN_SK_PROG(sk, BPF_CGROUP_INET4_POST_BIND)
|
|
|
|
|
|
|
|
|
|
#define BPF_CGROUP_RUN_PROG_INET6_POST_BIND(sk) \
|
|
|
|
|
BPF_CGROUP_RUN_SK_PROG(sk, BPF_CGROUP_INET6_POST_BIND)
|
|
|
|
|
|
2018-03-31 06:08:02 +08:00
|
|
|
#define BPF_CGROUP_RUN_SA_PROG(sk, uaddr, type) \
|
|
|
|
|
({ \
|
|
|
|
|
int __ret = 0; \
|
|
|
|
|
if (cgroup_bpf_enabled) \
|
2018-05-25 23:55:23 +08:00
|
|
|
__ret = __cgroup_bpf_run_filter_sock_addr(sk, uaddr, type, \
|
|
|
|
|
NULL); \
|
2018-03-31 06:08:02 +08:00
|
|
|
__ret; \
|
|
|
|
|
})
|
|
|
|
|
|
2018-05-25 23:55:23 +08:00
|
|
|
#define BPF_CGROUP_RUN_SA_PROG_LOCK(sk, uaddr, type, t_ctx) \
|
2018-03-31 06:08:05 +08:00
|
|
|
({ \
|
|
|
|
|
int __ret = 0; \
|
|
|
|
|
if (cgroup_bpf_enabled) { \
|
|
|
|
|
lock_sock(sk); \
|
2018-05-25 23:55:23 +08:00
|
|
|
__ret = __cgroup_bpf_run_filter_sock_addr(sk, uaddr, type, \
|
|
|
|
|
t_ctx); \
|
2018-03-31 06:08:05 +08:00
|
|
|
release_sock(sk); \
|
|
|
|
|
} \
|
|
|
|
|
__ret; \
|
|
|
|
|
})
|
|
|
|
|
|
2018-03-31 06:08:02 +08:00
|
|
|
#define BPF_CGROUP_RUN_PROG_INET4_BIND(sk, uaddr) \
|
|
|
|
|
BPF_CGROUP_RUN_SA_PROG(sk, uaddr, BPF_CGROUP_INET4_BIND)
|
|
|
|
|
|
|
|
|
|
#define BPF_CGROUP_RUN_PROG_INET6_BIND(sk, uaddr) \
|
|
|
|
|
BPF_CGROUP_RUN_SA_PROG(sk, uaddr, BPF_CGROUP_INET6_BIND)
|
|
|
|
|
|
2018-03-31 06:08:05 +08:00
|
|
|
#define BPF_CGROUP_PRE_CONNECT_ENABLED(sk) (cgroup_bpf_enabled && \
|
|
|
|
|
sk->sk_prot->pre_connect)
|
|
|
|
|
|
|
|
|
|
#define BPF_CGROUP_RUN_PROG_INET4_CONNECT(sk, uaddr) \
|
|
|
|
|
BPF_CGROUP_RUN_SA_PROG(sk, uaddr, BPF_CGROUP_INET4_CONNECT)
|
|
|
|
|
|
|
|
|
|
#define BPF_CGROUP_RUN_PROG_INET6_CONNECT(sk, uaddr) \
|
|
|
|
|
BPF_CGROUP_RUN_SA_PROG(sk, uaddr, BPF_CGROUP_INET6_CONNECT)
|
|
|
|
|
|
|
|
|
|
#define BPF_CGROUP_RUN_PROG_INET4_CONNECT_LOCK(sk, uaddr) \
|
2018-05-25 23:55:23 +08:00
|
|
|
BPF_CGROUP_RUN_SA_PROG_LOCK(sk, uaddr, BPF_CGROUP_INET4_CONNECT, NULL)
|
2018-03-31 06:08:05 +08:00
|
|
|
|
|
|
|
|
#define BPF_CGROUP_RUN_PROG_INET6_CONNECT_LOCK(sk, uaddr) \
|
2018-05-25 23:55:23 +08:00
|
|
|
BPF_CGROUP_RUN_SA_PROG_LOCK(sk, uaddr, BPF_CGROUP_INET6_CONNECT, NULL)
|
|
|
|
|
|
|
|
|
|
#define BPF_CGROUP_RUN_PROG_UDP4_SENDMSG_LOCK(sk, uaddr, t_ctx) \
|
|
|
|
|
BPF_CGROUP_RUN_SA_PROG_LOCK(sk, uaddr, BPF_CGROUP_UDP4_SENDMSG, t_ctx)
|
|
|
|
|
|
|
|
|
|
#define BPF_CGROUP_RUN_PROG_UDP6_SENDMSG_LOCK(sk, uaddr, t_ctx) \
|
|
|
|
|
BPF_CGROUP_RUN_SA_PROG_LOCK(sk, uaddr, BPF_CGROUP_UDP6_SENDMSG, t_ctx)
|
2018-03-31 06:08:05 +08:00
|
|
|
|
bpf: fix unconnected udp hooks
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>
2019-06-07 07:48:57 +08:00
|
|
|
#define BPF_CGROUP_RUN_PROG_UDP4_RECVMSG_LOCK(sk, uaddr) \
|
|
|
|
|
BPF_CGROUP_RUN_SA_PROG_LOCK(sk, uaddr, BPF_CGROUP_UDP4_RECVMSG, NULL)
|
|
|
|
|
|
|
|
|
|
#define BPF_CGROUP_RUN_PROG_UDP6_RECVMSG_LOCK(sk, uaddr) \
|
|
|
|
|
BPF_CGROUP_RUN_SA_PROG_LOCK(sk, uaddr, BPF_CGROUP_UDP6_RECVMSG, NULL)
|
|
|
|
|
|
bpf: BPF support for sock_ops
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>
2017-07-01 11:02:40 +08:00
|
|
|
#define BPF_CGROUP_RUN_PROG_SOCK_OPS(sock_ops) \
|
|
|
|
|
({ \
|
|
|
|
|
int __ret = 0; \
|
|
|
|
|
if (cgroup_bpf_enabled && (sock_ops)->sk) { \
|
|
|
|
|
typeof(sk) __sk = sk_to_full_sk((sock_ops)->sk); \
|
2017-07-18 02:42:55 +08:00
|
|
|
if (__sk && sk_fullsock(__sk)) \
|
bpf: BPF support for sock_ops
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>
2017-07-01 11:02:40 +08:00
|
|
|
__ret = __cgroup_bpf_run_filter_sock_ops(__sk, \
|
|
|
|
|
sock_ops, \
|
|
|
|
|
BPF_CGROUP_SOCK_OPS); \
|
|
|
|
|
} \
|
|
|
|
|
__ret; \
|
|
|
|
|
})
|
2017-11-05 21:15:32 +08:00
|
|
|
|
|
|
|
|
#define BPF_CGROUP_RUN_PROG_DEVICE_CGROUP(type, major, minor, access) \
|
|
|
|
|
({ \
|
|
|
|
|
int __ret = 0; \
|
|
|
|
|
if (cgroup_bpf_enabled) \
|
|
|
|
|
__ret = __cgroup_bpf_check_dev_permission(type, major, minor, \
|
|
|
|
|
access, \
|
|
|
|
|
BPF_CGROUP_DEVICE); \
|
|
|
|
|
\
|
|
|
|
|
__ret; \
|
|
|
|
|
})
|
2019-02-28 04:59:24 +08:00
|
|
|
|
|
|
|
|
|
2019-03-08 10:50:52 +08:00
|
|
|
#define BPF_CGROUP_RUN_PROG_SYSCTL(head, table, write, buf, count, pos, nbuf) \
|
2019-02-28 04:59:24 +08:00
|
|
|
({ \
|
|
|
|
|
int __ret = 0; \
|
|
|
|
|
if (cgroup_bpf_enabled) \
|
|
|
|
|
__ret = __cgroup_bpf_run_filter_sysctl(head, table, write, \
|
2019-03-08 10:50:52 +08:00
|
|
|
buf, count, pos, nbuf, \
|
2019-02-28 04:59:24 +08:00
|
|
|
BPF_CGROUP_SYSCTL); \
|
|
|
|
|
__ret; \
|
|
|
|
|
})
|
|
|
|
|
|
bpf: implement getsockopt and setsockopt hooks
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>
2019-06-28 04:38:47 +08:00
|
|
|
#define BPF_CGROUP_RUN_PROG_SETSOCKOPT(sock, level, optname, optval, optlen, \
|
|
|
|
|
kernel_optval) \
|
|
|
|
|
({ \
|
|
|
|
|
int __ret = 0; \
|
|
|
|
|
if (cgroup_bpf_enabled) \
|
|
|
|
|
__ret = __cgroup_bpf_run_filter_setsockopt(sock, level, \
|
|
|
|
|
optname, optval, \
|
|
|
|
|
optlen, \
|
|
|
|
|
kernel_optval); \
|
|
|
|
|
__ret; \
|
|
|
|
|
})
|
|
|
|
|
|
|
|
|
|
#define BPF_CGROUP_GETSOCKOPT_MAX_OPTLEN(optlen) \
|
|
|
|
|
({ \
|
|
|
|
|
int __ret = 0; \
|
|
|
|
|
if (cgroup_bpf_enabled) \
|
|
|
|
|
get_user(__ret, optlen); \
|
|
|
|
|
__ret; \
|
|
|
|
|
})
|
|
|
|
|
|
|
|
|
|
#define BPF_CGROUP_RUN_PROG_GETSOCKOPT(sock, level, optname, optval, optlen, \
|
|
|
|
|
max_optlen, retval) \
|
|
|
|
|
({ \
|
|
|
|
|
int __ret = retval; \
|
|
|
|
|
if (cgroup_bpf_enabled) \
|
|
|
|
|
__ret = __cgroup_bpf_run_filter_getsockopt(sock, level, \
|
|
|
|
|
optname, optval, \
|
|
|
|
|
optlen, max_optlen, \
|
|
|
|
|
retval); \
|
|
|
|
|
__ret; \
|
|
|
|
|
})
|
|
|
|
|
|
2018-06-19 07:04:24 +08:00
|
|
|
int cgroup_bpf_prog_attach(const union bpf_attr *attr,
|
|
|
|
|
enum bpf_prog_type ptype, struct bpf_prog *prog);
|
|
|
|
|
int cgroup_bpf_prog_detach(const union bpf_attr *attr,
|
|
|
|
|
enum bpf_prog_type ptype);
|
|
|
|
|
int cgroup_bpf_prog_query(const union bpf_attr *attr,
|
|
|
|
|
union bpf_attr __user *uattr);
|
2016-11-23 23:52:26 +08:00
|
|
|
#else
|
|
|
|
|
|
2018-06-19 07:04:24 +08:00
|
|
|
struct bpf_prog;
|
2016-11-23 23:52:26 +08:00
|
|
|
struct cgroup_bpf {};
|
2017-10-03 13:50:21 +08:00
|
|
|
static inline int cgroup_bpf_inherit(struct cgroup *cgrp) { return 0; }
|
bpf: decouple the lifetime of cgroup_bpf from cgroup itself
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>
2019-05-26 00:37:39 +08:00
|
|
|
static inline void cgroup_bpf_offline(struct cgroup *cgrp) {}
|
2016-11-23 23:52:26 +08:00
|
|
|
|
2018-06-19 07:04:24 +08:00
|
|
|
static inline int cgroup_bpf_prog_attach(const union bpf_attr *attr,
|
|
|
|
|
enum bpf_prog_type ptype,
|
|
|
|
|
struct bpf_prog *prog)
|
|
|
|
|
{
|
|
|
|
|
return -EINVAL;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static inline int cgroup_bpf_prog_detach(const union bpf_attr *attr,
|
|
|
|
|
enum bpf_prog_type ptype)
|
|
|
|
|
{
|
|
|
|
|
return -EINVAL;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static inline int cgroup_bpf_prog_query(const union bpf_attr *attr,
|
|
|
|
|
union bpf_attr __user *uattr)
|
|
|
|
|
{
|
|
|
|
|
return -EINVAL;
|
|
|
|
|
}
|
|
|
|
|
|
2018-09-28 22:45:36 +08:00
|
|
|
static inline void bpf_cgroup_storage_set(
|
|
|
|
|
struct bpf_cgroup_storage *storage[MAX_BPF_CGROUP_STORAGE_TYPE]) {}
|
2018-08-03 05:27:18 +08:00
|
|
|
static inline int bpf_cgroup_storage_assign(struct bpf_prog *prog,
|
|
|
|
|
struct bpf_map *map) { return 0; }
|
|
|
|
|
static inline void bpf_cgroup_storage_release(struct bpf_prog *prog,
|
|
|
|
|
struct bpf_map *map) {}
|
|
|
|
|
static inline struct bpf_cgroup_storage *bpf_cgroup_storage_alloc(
|
2019-03-08 14:45:51 +08:00
|
|
|
struct bpf_prog *prog, enum bpf_cgroup_storage_type stype) { return NULL; }
|
2018-08-03 05:27:18 +08:00
|
|
|
static inline void bpf_cgroup_storage_free(
|
|
|
|
|
struct bpf_cgroup_storage *storage) {}
|
2018-09-28 22:45:43 +08:00
|
|
|
static inline int bpf_percpu_cgroup_storage_copy(struct bpf_map *map, void *key,
|
|
|
|
|
void *value) {
|
|
|
|
|
return 0;
|
|
|
|
|
}
|
|
|
|
|
static inline int bpf_percpu_cgroup_storage_update(struct bpf_map *map,
|
|
|
|
|
void *key, void *value, u64 flags) {
|
|
|
|
|
return 0;
|
|
|
|
|
}
|
2018-08-03 05:27:18 +08:00
|
|
|
|
2018-05-25 23:55:22 +08:00
|
|
|
#define cgroup_bpf_enabled (0)
|
2018-03-31 06:08:05 +08:00
|
|
|
#define BPF_CGROUP_PRE_CONNECT_ENABLED(sk) (0)
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2016-11-23 23:52:26 +08:00
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#define BPF_CGROUP_RUN_PROG_INET_INGRESS(sk,skb) ({ 0; })
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#define BPF_CGROUP_RUN_PROG_INET_EGRESS(sk,skb) ({ 0; })
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2016-12-02 00:48:04 +08:00
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#define BPF_CGROUP_RUN_PROG_INET_SOCK(sk) ({ 0; })
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2018-03-31 06:08:02 +08:00
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#define BPF_CGROUP_RUN_PROG_INET4_BIND(sk, uaddr) ({ 0; })
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#define BPF_CGROUP_RUN_PROG_INET6_BIND(sk, uaddr) ({ 0; })
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2018-03-31 06:08:07 +08:00
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#define BPF_CGROUP_RUN_PROG_INET4_POST_BIND(sk) ({ 0; })
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#define BPF_CGROUP_RUN_PROG_INET6_POST_BIND(sk) ({ 0; })
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2018-03-31 06:08:05 +08:00
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#define BPF_CGROUP_RUN_PROG_INET4_CONNECT(sk, uaddr) ({ 0; })
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#define BPF_CGROUP_RUN_PROG_INET4_CONNECT_LOCK(sk, uaddr) ({ 0; })
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#define BPF_CGROUP_RUN_PROG_INET6_CONNECT(sk, uaddr) ({ 0; })
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#define BPF_CGROUP_RUN_PROG_INET6_CONNECT_LOCK(sk, uaddr) ({ 0; })
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2018-05-25 23:55:23 +08:00
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#define BPF_CGROUP_RUN_PROG_UDP4_SENDMSG_LOCK(sk, uaddr, t_ctx) ({ 0; })
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#define BPF_CGROUP_RUN_PROG_UDP6_SENDMSG_LOCK(sk, uaddr, t_ctx) ({ 0; })
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bpf: fix unconnected udp hooks
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>
2019-06-07 07:48:57 +08:00
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#define BPF_CGROUP_RUN_PROG_UDP4_RECVMSG_LOCK(sk, uaddr) ({ 0; })
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#define BPF_CGROUP_RUN_PROG_UDP6_RECVMSG_LOCK(sk, uaddr) ({ 0; })
|
bpf: BPF support for sock_ops
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>
2017-07-01 11:02:40 +08:00
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|
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#define BPF_CGROUP_RUN_PROG_SOCK_OPS(sock_ops) ({ 0; })
|
2017-11-05 21:15:32 +08:00
|
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#define BPF_CGROUP_RUN_PROG_DEVICE_CGROUP(type,major,minor,access) ({ 0; })
|
2019-03-08 10:50:52 +08:00
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#define BPF_CGROUP_RUN_PROG_SYSCTL(head,table,write,buf,count,pos,nbuf) ({ 0; })
|
bpf: implement getsockopt and setsockopt hooks
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>
2019-06-28 04:38:47 +08:00
|
|
|
#define BPF_CGROUP_GETSOCKOPT_MAX_OPTLEN(optlen) ({ 0; })
|
|
|
|
|
#define BPF_CGROUP_RUN_PROG_GETSOCKOPT(sock, level, optname, optval, \
|
|
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|
|
optlen, max_optlen, retval) ({ retval; })
|
|
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|
|
#define BPF_CGROUP_RUN_PROG_SETSOCKOPT(sock, level, optname, optval, optlen, \
|
|
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|
|
kernel_optval) ({ 0; })
|
2016-11-23 23:52:26 +08:00
|
|
|
|
2018-09-28 22:45:36 +08:00
|
|
|
#define for_each_cgroup_storage_type(stype) for (; false; )
|
|
|
|
|
|
2016-11-23 23:52:26 +08:00
|
|
|
#endif /* CONFIG_CGROUP_BPF */
|
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#endif /* _BPF_CGROUP_H */
|