Descriptor table is a shared object; it's not a place where you can
stick temporary references to files, especially when we don't need
an opened file at all.
Cc: stable@vger.kernel.org # v4.14
Fixes: 98589a0998 ("netfilter: xt_bpf: Fix XT_BPF_MODE_FD_PINNED mode of 'xt_bpf_info_v1'")
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Report to the user ifindex and namespace information of offloaded
programs. If device has disappeared return -ENODEV. Specify the
namespace using dev/inode combination.
CC: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Bound programs are quite useless after their device disappears.
They are simply waiting for reference count to go to zero,
don't list them in BPF_PROG_GET_NEXT_ID by freeing their ID
early.
Note that orphaned offload programs will return -ENODEV on
BPF_OBJ_GET_INFO_BY_FD so user will never see ID 0.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
We currently use aux->offload to indicate that program is bound
to a specific device. This forces us to keep the offload structure
around even after the device is gone. Add a bool member to
struct bpf_prog_aux to indicate if offload was requested.
Suggested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Right now kallsyms handling is not working with JITed subprogs.
The reason is that when in 1c2a088a66 ("bpf: x64: add JIT support
for multi-function programs") in jit_subprogs() they are passed
to bpf_prog_kallsyms_add(), then their prog type is 0, which BPF
core will think it's a cBPF program as only cBPF programs have a
0 type. Thus, they need to inherit the type from the main prog.
Once that is fixed, they are indeed added to the BPF kallsyms
infra, but their tag is 0. Therefore, since intention is to add
them as bpf_prog_F_<tag>, we need to pass them to bpf_prog_calc_tag()
first. And once this is resolved, there is a use-after-free on
prog cleanup: we remove the kallsyms entry from the main prog,
later walk all subprogs and call bpf_jit_free() on them. However,
the kallsyms linkage was never released on them. Thus, do that
for all subprogs right in __bpf_prog_put() when refcount hits 0.
Fixes: 1c2a088a66 ("bpf: x64: add JIT support for multi-function programs")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Typical JIT does several passes over bpf instructions to
compute total size and relative offsets of jumps and calls.
With multitple bpf functions calling each other all relative calls
will have invalid offsets intially therefore we need to additional
last pass over the program to emit calls with correct offsets.
For example in case of three bpf functions:
main:
call foo
call bpf_map_lookup
exit
foo:
call bar
exit
bar:
exit
We will call bpf_int_jit_compile() indepedently for main(), foo() and bar()
x64 JIT typically does 4-5 passes to converge.
After these initial passes the image for these 3 functions
will be good except call targets, since start addresses of
foo() and bar() are unknown when we were JITing main()
(note that call bpf_map_lookup will be resolved properly
during initial passes).
Once start addresses of 3 functions are known we patch
call_insn->imm to point to right functions and call
bpf_int_jit_compile() again which needs only one pass.
Additional safety checks are done to make sure this
last pass doesn't produce image that is larger or smaller
than previous pass.
When constant blinding is on it's applied to all functions
at the first pass, since doing it once again at the last
pass can change size of the JITed code.
Tested on x64 and arm64 hw with JIT on/off, blinding on/off.
x64 jits bpf-to-bpf calls correctly while arm64 falls back to interpreter.
All other JITs that support normal BPF_CALL will behave the same way
since bpf-to-bpf call is equivalent to bpf-to-kernel call from
JITs point of view.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This reverts commit bd601b6ada ("bpf: report offload info to user
space"). The ifindex by itself is not sufficient, we should provide
information on which network namespace this ifindex belongs to.
After considering some options we concluded that it's best to just
remove this API for now, and rework it in -next.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
bpf_prog_get_type() is identical to bpf_prog_get_type_dev(),
with false passed as attach_drv. Instead of keeping it as
an exported symbol turn it into static inline wrapper.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
With TC shared block changes we can't depend on correct netdev
pointer being available in cls_bpf. Move the device validation
to the driver. Core will only make sure that offloaded programs
are always attached in the driver (or in HW by the driver). We
trust that drivers which implement offload callbacks will perform
necessary checks.
Moving the checks to the driver is generally a useful thing,
in practice the check should be against a switchdev instance,
not a netdev, given that most ASICs will probably allow using
the same program on many ports.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
bpf_target_prog seems long and clunky, rename it to prog_ifindex.
We don't want to call this field just ifindex, because maps
may need a similar field in the future and bpf_attr members for
programs and maps are unnamed.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cgroup v2 lacks the device controller, provided by cgroup v1.
This patch adds a new eBPF program type, which in combination
of previously added ability to attach multiple eBPF programs
to a cgroup, will provide a similar functionality, but with some
additional flexibility.
This patch introduces a BPF_PROG_TYPE_CGROUP_DEVICE program type.
A program takes major and minor device numbers, device type
(block/character) and access type (mknod/read/write) as parameters
and returns an integer which defines if the operation should be
allowed or terminated with -EPERM.
Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
If TC program is loaded with skip_sw flag, we should allow
the device-specific programs to be accepted.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pass the netdev pointer to bpf_prog_get_type(). This way
BPF code can decide whether the device matches what the
code was loaded/translated for.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Extend struct bpf_prog_info to contain information about program
being bound to a device. Since the netdev may get destroyed while
program still exists we need a flag to indicate the program is
loaded for a device, even if the device is gone.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The fact that we don't know which device the program is going
to be used on is quite limiting in current eBPF infrastructure.
We have to reverse or limit the changes which kernel makes to
the loaded bytecode if we want it to be offloaded to a networking
device. We also have to invent new APIs for debugging and
troubleshooting support.
Make it possible to load programs for a specific netdev. This
helps us to bring the debug information closer to the core
eBPF infrastructure (e.g. we will be able to reuse the verifer
log in device JIT). It allows device JITs to perform translation
on the original bytecode.
__bpf_prog_get() when called to get a reference for an attachment
point will now refuse to give it if program has a device assigned.
Following patches will add a version of that function which passes
the expected netdev in. @type argument in __bpf_prog_get() is
renamed to attach_type to make it clearer that it's only set on
attachment.
All calls to ndo_bpf are protected by rtnl, only verifier callbacks
are not. We need a wait queue to make sure netdev doesn't get
destroyed while verifier is still running and calling its driver.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Introduce a bpf object related check when sending and receiving files
through unix domain socket as well as binder. It checks if the receiving
process have privilege to read/write the bpf map or use the bpf program.
This check is necessary because the bpf maps and programs are using a
anonymous inode as their shared inode so the normal way of checking the
files and sockets when passing between processes cannot work properly on
eBPF object. This check only works when the BPF_SYSCALL is configured.
Signed-off-by: Chenbo Feng <fengc@google.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Reviewed-by: James Morris <james.l.morris@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Introduce several LSM hooks for the syscalls that will allow the
userspace to access to eBPF object such as eBPF programs and eBPF maps.
The security check is aimed to enforce a per object security protection
for eBPF object so only processes with the right priviliges can
read/write to a specific map or use a specific eBPF program. Besides
that, a general security hook is added before the multiplexer of bpf
syscall to check the cmd and the attribute used for the command. The
actual security module can decide which command need to be checked and
how the cmd should be checked.
Signed-off-by: Chenbo Feng <fengc@google.com>
Acked-by: James Morris <james.l.morris@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Introduce the map read/write flags to the eBPF syscalls that returns the
map fd. The flags is used to set up the file mode when construct a new
file descriptor for bpf maps. To not break the backward capability, the
f_flags is set to O_RDWR if the flag passed by syscall is 0. Otherwise
it should be O_RDONLY or O_WRONLY. When the userspace want to modify or
read the map content, it will check the file mode to see if it is
allowed to make the change.
Signed-off-by: Chenbo Feng <fengc@google.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Since the verifier ops don't have to be associated with
the program for its entire lifetime we can move it to
verifier's struct bpf_verifier_env.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
struct bpf_verifier_ops contains both verifier ops and operations
used later during program's lifetime (test_run). Split the runtime
ops into a different structure.
BPF_PROG_TYPE() will now append ## _prog_ops or ## _verifier_ops
to the names.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The 'cpumap' is primarily used as a backend map for XDP BPF helper
call bpf_redirect_map() and XDP_REDIRECT action, like 'devmap'.
This patch implement the main part of the map. It is not connected to
the XDP redirect system yet, and no SKB allocation are done yet.
The main concern in this patch is to ensure the datapath can run
without any locking. This adds complexity to the setup and tear-down
procedure, which assumptions are extra carefully documented in the
code comments.
V2:
- make sure array isn't larger than NR_CPUS
- make sure CPUs added is a valid possible CPU
V3: fix nitpicks from Jakub Kicinski <kubakici@wp.pl>
V5:
- Restrict map allocation to root / CAP_SYS_ADMIN
- WARN_ON_ONCE if queue is not empty on tear-down
- Return -EPERM on memlock limit instead of -ENOMEM
- Error code in __cpu_map_entry_alloc() also handle ptr_ring_cleanup()
- Moved cpu_map_enqueue() to next patch
V6: all notice by Daniel Borkmann
- Fix err return code in cpu_map_alloc() introduced in V5
- Move cpu_possible() check after max_entries boundary check
- Forbid usage initially in check_map_func_compatibility()
V7:
- Fix alloc error path spotted by Daniel Borkmann
- Did stress test adding+removing CPUs from the map concurrently
- Fixed refcnt issue on cpu_map_entry, kthread started too soon
- Make sure packets are flushed during tear-down, involved use of
rcu_barrier() and kthread_run only exit after queue is empty
- Fix alloc error path in __cpu_map_entry_alloc() for ptr_ring
V8:
- Nitpicking comments and gramma by Edward Cree
- Fix missing semi-colon introduced in V7 due to rebasing
- Move struct bpf_cpu_map_entry members cpu+map_id to tracepoint patch
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
During get_info_by_fd, the prog/map name is memcpy-ed. It depends
on the prog->aux->name and map->name to be zero initialized.
bpf_prog_aux is easy to guarantee that aux->name is zero init.
The name in bpf_map may be harder to be guaranteed in the future when
new map type is added.
Hence, this patch makes bpf_obj_name_cpy() to always zero init
the prog/map name.
Suggested-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
introduce BPF_PROG_QUERY command to retrieve a set of either
attached programs to given cgroup or a set of effective programs
that will execute for events within a cgroup
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
for cgroup bits
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
introduce BPF_F_ALLOW_MULTI flag that can be used to attach multiple
bpf programs to a cgroup.
The difference between three possible flags for BPF_PROG_ATTACH command:
- NONE(default): No further bpf programs allowed in the subtree.
- BPF_F_ALLOW_OVERRIDE: If a sub-cgroup installs some bpf program,
the program in this cgroup yields to sub-cgroup program.
- BPF_F_ALLOW_MULTI: If a sub-cgroup installs some bpf program,
that cgroup program gets run in addition to the program in this cgroup.
NONE and BPF_F_ALLOW_OVERRIDE existed before. This patch doesn't
change their behavior. It only clarifies the semantics in relation
to new flag.
Only one program is allowed to be attached to a cgroup with
NONE or BPF_F_ALLOW_OVERRIDE flag.
Multiple programs are allowed to be attached to a cgroup with
BPF_F_ALLOW_MULTI flag. They are executed in FIFO order
(those that were attached first, run first)
The programs of sub-cgroup are executed first, then programs of
this cgroup and then programs of parent cgroup.
All eligible programs are executed regardless of return code from
earlier programs.
To allow efficient execution of multiple programs attached to a cgroup
and to avoid penalizing cgroups without any programs attached
introduce 'struct bpf_prog_array' which is RCU protected array
of pointers to bpf programs.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
for cgroup bits
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch uses u64_to_user_ptr() to cast info.map_ids to a userspace ptr.
It also tags the user_map_ids with '__user' for sparse check.
Fixes: cb4d2b3f03 ("bpf: Add name, load_time, uid and map_ids to bpf_prog_info")
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch allows userspace to specify a name for a map
during BPF_MAP_CREATE.
The map's name can later be exported to user space
via BPF_OBJ_GET_INFO_BY_FD.
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Alexei Starovoitov <ast@fb.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
The patch adds name and load_time to struct bpf_prog_aux. They
are also exported to bpf_prog_info.
The bpf_prog's name is passed by userspace during BPF_PROG_LOAD.
The kernel only stores the first (BPF_PROG_NAME_LEN - 1) bytes
and the name stored in the kernel is always \0 terminated.
The kernel will reject name that contains characters other than
isalnum() and '_'. It will also reject name that is not null
terminated.
The existing 'user->uid' of the bpf_prog_aux is also exported to
the bpf_prog_info as created_by_uid.
The existing 'used_maps' of the bpf_prog_aux is exported to
the newly added members 'nr_map_ids' and 'map_ids' of
the bpf_prog_info. On the input, nr_map_ids tells how
big the userspace's map_ids buffer is. On the output,
nr_map_ids tells the exact user_map_cnt and it will only
copy up to the userspace's map_ids buffer is allowed.
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Alexei Starovoitov <ast@fb.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
The bpf map sockmap supports adding programs via attach commands. This
patch adds the detach command to keep the API symmetric and allow
users to remove previously added programs. Otherwise the user would
have to delete the map and re-add it to get in this state.
This also adds a series of additional tests to capture detach operation
and also attaching/detaching invalid prog types.
API note: socks will run (or not run) programs depending on the state
of the map at the time the sock is added. We do not for example walk
the map and remove programs from previously attached socks.
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
In the initial sockmap API we provided strparser and verdict programs
using a single attach command by extending the attach API with a the
attach_bpf_fd2 field.
However, if we add other programs in the future we will be adding a
field for every new possible type, attach_bpf_fd(3,4,..). This
seems a bit clumsy for an API. So lets push the programs using two
new type fields.
BPF_SK_SKB_STREAM_PARSER
BPF_SK_SKB_STREAM_VERDICT
This has the advantage of having a readable name and can easily be
extended in the future.
Updates to samples and sockmap included here also generalize tests
slightly to support upcoming patch for multiple map support.
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Fixes: 174a79ff95 ("bpf: sockmap with sk redirect support")
Suggested-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The current map creation API does not allow to provide the numa-node
preference. The memory usually comes from where the map-creation-process
is running. The performance is not ideal if the bpf_prog is known to
always run in a numa node different from the map-creation-process.
One of the use case is sharding on CPU to different LRU maps (i.e.
an array of LRU maps). Here is the test result of map_perf_test on
the INNER_LRU_HASH_PREALLOC test if we force the lru map used by
CPU0 to be allocated from a remote numa node:
[ The machine has 20 cores. CPU0-9 at node 0. CPU10-19 at node 1 ]
># taskset -c 10 ./map_perf_test 512 8 1260000 8000000
5:inner_lru_hash_map_perf pre-alloc 1628380 events per sec
4:inner_lru_hash_map_perf pre-alloc 1626396 events per sec
3:inner_lru_hash_map_perf pre-alloc 1626144 events per sec
6:inner_lru_hash_map_perf pre-alloc 1621657 events per sec
2:inner_lru_hash_map_perf pre-alloc 1621534 events per sec
1:inner_lru_hash_map_perf pre-alloc 1620292 events per sec
7:inner_lru_hash_map_perf pre-alloc 1613305 events per sec
0:inner_lru_hash_map_perf pre-alloc 1239150 events per sec #<<<
After specifying numa node:
># taskset -c 10 ./map_perf_test 512 8 1260000 8000000
5:inner_lru_hash_map_perf pre-alloc 1629627 events per sec
3:inner_lru_hash_map_perf pre-alloc 1628057 events per sec
1:inner_lru_hash_map_perf pre-alloc 1623054 events per sec
6:inner_lru_hash_map_perf pre-alloc 1616033 events per sec
2:inner_lru_hash_map_perf pre-alloc 1614630 events per sec
4:inner_lru_hash_map_perf pre-alloc 1612651 events per sec
7:inner_lru_hash_map_perf pre-alloc 1609337 events per sec
0:inner_lru_hash_map_perf pre-alloc 1619340 events per sec #<<<
This patch adds one field, numa_node, to the bpf_attr. Since numa node 0
is a valid node, a new flag BPF_F_NUMA_NODE is also added. The numa_node
field is honored if and only if the BPF_F_NUMA_NODE flag is set.
Numa node selection is not supported for percpu map.
This patch does not change all the kmalloc. F.e.
'htab = kzalloc()' is not changed since the object
is small enough to stay in the cache.
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
"map" is a valid pointer. We wanted to return "err" instead. Also
let's return a zero literal at the end.
Fixes: 174a79ff95 ("bpf: sockmap with sk redirect support")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Recently we added a new map type called dev map used to forward XDP
packets between ports (6093ec2dc3). This patches introduces a
similar notion for sockets.
A sockmap allows users to add participating sockets to a map. When
sockets are added to the map enough context is stored with the
map entry to use the entry with a new helper
bpf_sk_redirect_map(map, key, flags)
This helper (analogous to bpf_redirect_map in XDP) is given the map
and an entry in the map. When called from a sockmap program, discussed
below, the skb will be sent on the socket using skb_send_sock().
With the above we need a bpf program to call the helper from that will
then implement the send logic. The initial site implemented in this
series is the recv_sock hook. For this to work we implemented a map
attach command to add attributes to a map. In sockmap we add two
programs a parse program and a verdict program. The parse program
uses strparser to build messages and pass them to the verdict program.
The parse programs use the normal strparser semantics. The verdict
program is of type SK_SKB.
The verdict program returns a verdict SK_DROP, or SK_REDIRECT for
now. Additional actions may be added later. When SK_REDIRECT is
returned, expected when bpf program uses bpf_sk_redirect_map(), the
sockmap logic will consult per cpu variables set by the helper routine
and pull the sock entry out of the sock map. This pattern follows the
existing redirect logic in cls and xdp programs.
This gives the flow,
recv_sock -> str_parser (parse_prog) -> verdict_prog -> skb_send_sock
\
-> kfree_skb
As an example use case a message based load balancer may use specific
logic in the verdict program to select the sock to send on.
Sample programs are provided in future patches that hopefully illustrate
the user interfaces. Also selftests are in follow-on patches.
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
bpf_prog_inc_not_zero will be used by upcoming sockmap patches this
patch simply exports it so we can pull it in.
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The function check_uarg_tail_zero() was created from bpf(2) for
BPF_OBJ_GET_INFO_BY_FD without taking the access_ok() nor the PAGE_SIZE
checks. Make this checks more generally available while unlikely to be
triggered, extend the memory range check and add an explanation
including why the ToCToU should not be a security concern.
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Kees Cook <keescook@chromium.org>
Cc: Martin KaFai Lau <kafai@fb.com>
Link: https://lkml.kernel.org/r/CAGXu5j+vRGFvJZmjtAcT8Hi8B+Wz0e1b6VKYZHfQP_=DXzC4CQ@mail.gmail.com
Signed-off-by: David S. Miller <davem@davemloft.net>
The function check_uarg_tail_zero() may be useful for other part of the
code in the syscall.c file. Move this function at the beginning of the
file.
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Kees Cook <keescook@chromium.org>
Cc: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
bpf_prog_size(prog->len) is not the correct length we want to dump
back to user space. The code in bpf_prog_get_info_by_fd() uses this
to copy prog->insnsi to user space, but bpf_prog_size(prog->len) also
includes the size of struct bpf_prog itself plus program instructions
and is usually used either in context of accounting or for bpf_prog_alloc()
et al, thus we copy out of bounds in bpf_prog_get_info_by_fd()
potentially. Use the correct bpf_prog_insn_size() instead.
Fixes: 1e27097690 ("bpf: Add BPF_OBJ_GET_INFO_BY_FD")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
err in bpf_prog_get_info_by_fd() still holds 0 at that time from prior
check_uarg_tail_zero() check. Explicitly return -EFAULT instead, so
user space can be notified of buggy behavior.
Fixes: 1e27097690 ("bpf: Add BPF_OBJ_GET_INFO_BY_FD")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We do export through fdinfo already whether a prog is JITed or not,
given a program load can fail in case of either prog or tail call map
has JITed property, but neither both are JITed or not JITed, we can
facilitate error reporting in loaders like iproute2 through exporting
owner_jited of tail call map. We already do export owner_prog_type
through this facility, so parser can pick up both for comparison.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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>
This patch allows userspace to do BPF_MAP_LOOKUP_ELEM on
BPF_MAP_TYPE_PROG_ARRAY,
BPF_MAP_TYPE_ARRAY_OF_MAPS and
BPF_MAP_TYPE_HASH_OF_MAPS.
The lookup returns a prog-id or map-id to the userspace.
The userspace can then use the BPF_PROG_GET_FD_BY_ID
or BPF_MAP_GET_FD_BY_ID to get a fd.
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
A single BPF_OBJ_GET_INFO_BY_FD cmd is used to obtain the info
for both bpf_prog and bpf_map. The kernel can figure out the
fd is associated with a bpf_prog or bpf_map.
The suggested struct bpf_prog_info and struct bpf_map_info are
not meant to be a complete list and it is not the goal of this patch.
New fields can be added in the future patch.
The focus of this patch is to create the interface,
BPF_OBJ_GET_INFO_BY_FD cmd for exposing the bpf_prog's and
bpf_map's info.
The obj's info, which will be extended (and get bigger) over time, is
separated from the bpf_attr to avoid bloating the bpf_attr.
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Alexei Starovoitov <ast@fb.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add BPF_MAP_GET_FD_BY_ID command to allow user to get a fd
from a bpf_map's ID.
bpf_map_inc_not_zero() is added and is called with map_idr_lock
held.
__bpf_map_put() is also added which has the 'bool do_idr_lock'
param to decide if the map_idr_lock should be acquired when
freeing the map->id.
In the error path of bpf_map_inc_not_zero(), it may have to
call __bpf_map_put(map, false) which does not need
to take the map_idr_lock when freeing the map->id.
It is currently limited to CAP_SYS_ADMIN which we can
consider to lift it in followup patches.
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Alexei Starovoitov <ast@fb.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add BPF_PROG_GET_FD_BY_ID command to allow user to get a fd
from a bpf_prog's ID.
bpf_prog_inc_not_zero() is added and is called with prog_idr_lock
held.
__bpf_prog_put() is also added which has the 'bool do_idr_lock'
param to decide if the prog_idr_lock should be acquired when
freeing the prog->id.
In the error path of bpf_prog_inc_not_zero(), it may have to
call __bpf_prog_put(map, false) which does not need
to take the prog_idr_lock when freeing the prog->id.
It is currently limited to CAP_SYS_ADMIN which we can
consider to lift it in followup patches.
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Alexei Starovoitov <ast@fb.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch adds BPF_PROG_GET_NEXT_ID and BPF_MAP_GET_NEXT_ID
to allow userspace to iterate all bpf_prog IDs and bpf_map IDs.
The API is trying to be consistent with the existing
BPF_MAP_GET_NEXT_KEY.
It is currently limited to CAP_SYS_ADMIN which we can
consider to lift it in followup patches.
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Alexei Starovoitov <ast@fb.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
