linux/kernel
Jakub Sitnicki 7f045a49fe bpf: Add link-based BPF program attachment to network namespace
Extend bpf() syscall subcommands that operate on bpf_link, that is
LINK_CREATE, LINK_UPDATE, OBJ_GET_INFO, to accept attach types tied to
network namespaces (only flow dissector at the moment).

Link-based and prog-based attachment can be used interchangeably, but only
one can exist at a time. Attempts to attach a link when a prog is already
attached directly, and the other way around, will be met with -EEXIST.
Attempts to detach a program when link exists result in -EINVAL.

Attachment of multiple links of same attach type to one netns is not
supported with the intention to lift the restriction when a use-case
presents itself. Because of that link create returns -E2BIG when trying to
create another netns link, when one already exists.

Link-based attachments to netns don't keep a netns alive by holding a ref
to it. Instead links get auto-detached from netns when the latter is being
destroyed, using a pernet pre_exit callback.

When auto-detached, link lives in defunct state as long there are open FDs
for it. -ENOLINK is returned if a user tries to update a defunct link.

Because bpf_link to netns doesn't hold a ref to struct net, special care is
taken when releasing, updating, or filling link info. The netns might be
getting torn down when any of these link operations are in progress. That
is why auto-detach and update/release/fill_info are synchronized by the
same mutex. Also, link ops have to always check if auto-detach has not
happened yet and if netns is still alive (refcnt > 0).

Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200531082846.2117903-5-jakub@cloudflare.com
2020-06-01 15:21:03 -07:00
..
bpf bpf: Add link-based BPF program attachment to network namespace 2020-06-01 15:21:03 -07:00
cgroup Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-05-31 17:48:46 -07:00
configs compiler: remove CONFIG_OPTIMIZE_INLINING entirely 2020-04-07 10:43:42 -07:00
debug SPDX patches for 5.7-rc1. 2020-04-03 13:12:26 -07:00
dma dma-debug: fix displaying of dma allocation type 2020-04-08 21:46:57 +02:00
events Merge branch 'work.sysctl' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-04-28 21:23:38 +02:00
gcov kernel/gcov/fs.c: gcov_seq_next() should increase position index 2020-04-10 15:36:22 -07:00
irq genirq: Remove setup_irq() and remove_irq() 2020-04-14 10:08:50 +02:00
livepatch New tracing features: 2019-11-27 11:42:01 -08:00
locking locking/lockdep: Improve 'invalid wait context' splat 2020-04-08 12:05:07 +02:00
power PM: hibernate: Freeze kernel threads in software_resume() 2020-04-27 10:30:30 +02:00
printk sysctl: pass kernel pointers to ->proc_handler 2020-04-27 02:07:40 -04:00
rcu Merge branch 'urgent-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/urgent 2020-04-14 08:36:41 +02:00
sched Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-05-31 17:48:46 -07:00
time Merge branch 'work.sysctl' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-04-28 21:23:38 +02:00
trace bpf: Use tracing helpers for lsm programs 2020-06-01 15:08:04 -07:00
.gitignore .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
acct.c acct: stop using get_seconds() 2019-12-18 18:07:31 +01:00
async.c
audit.c audit: check the length of userspace generated audit records 2020-04-20 17:10:58 -04:00
audit.h audit: trigger accompanying records when no rules present 2020-03-12 10:42:51 -04:00
audit_fsnotify.c fsnotify: use helpers to access data by data_type 2020-03-23 18:19:06 +01:00
audit_tree.c
audit_watch.c \n 2020-04-06 08:58:42 -07:00
auditfilter.c audit: fix error handling in audit_data_to_entry() 2020-02-22 20:36:47 -05:00
auditsc.c audit: trigger accompanying records when no rules present 2020-03-12 10:42:51 -04:00
backtracetest.c
bounds.c
capability.c
compat.c y2038: remove unused time32 interfaces 2020-02-21 11:22:15 -08:00
configs.c proc: convert everything to "struct proc_ops" 2020-02-04 03:05:26 +00:00
context_tracking.c context-tracking: Introduce CONFIG_HAVE_TIF_NOHZ 2020-02-14 16:05:04 +01:00
cpu.c CPU (hotplug) updates: 2020-03-30 18:06:39 -07:00
cpu_pm.c
crash_core.c
crash_dump.c
cred.c kernel: doc: remove outdated comment cred.c 2020-03-25 10:04:01 -05:00
delayacct.c
dma.c
elfcore.c kernel/elfcore.c: include proper prototypes 2019-09-25 17:51:39 -07:00
exec_domain.c
exit.c proc: Put thread_pid in release_task not proc_flush_pid 2020-04-24 15:49:00 -05:00
extable.c kernel/extable.c: use address-of operator on section symbols 2020-04-07 10:43:42 -07:00
fail_function.c
fork.c fork: prevent accidental access to clone3 features 2020-05-08 17:31:50 +02:00
freezer.c Revert "libata, freezer: avoid block device removal while system is frozen" 2019-10-06 09:11:37 -06:00
futex.c Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2020-03-30 16:17:15 -07:00
gen_kheaders.sh kheaders: explain why include/config/autoconf.h is excluded from md5sum 2019-11-11 20:10:01 +09:00
groups.c
hung_task.c
iomem.c
irq_work.c lockdep: Annotate irq_work 2020-03-21 16:00:24 +01:00
jump_label.c jump_label: Don't warn on __exit jump entries 2019-08-29 15:10:10 +01:00
kallsyms.c kallsyms: unexport kallsyms_lookup_name() and kallsyms_on_each_symbol() 2020-04-07 10:43:44 -07:00
kcmp.c kernel/kcmp.c: Use new infrastructure to fix deadlocks in execve 2020-03-25 10:04:01 -05:00
Kconfig.freezer
Kconfig.hz
Kconfig.locks sched/rt, locking: Use CONFIG_PREEMPTION 2019-12-08 14:37:36 +01:00
Kconfig.preempt sched/Kconfig: Fix spelling mistake in user-visible help text 2019-11-12 11:35:32 +01:00
kcov.c kernel/kcov.c: fix typos in kcov_remote_start documentation 2020-05-07 19:27:20 -07:00
kexec.c kexec: add machine_kexec_post_load() 2020-01-08 16:32:55 +00:00
kexec_core.c kexec: add machine_kexec_post_load() 2020-01-08 16:32:55 +00:00
kexec_elf.c kexec_elf: support 32 bit ELF files 2019-09-06 23:58:44 +02:00
kexec_file.c kexec: add machine_kexec_post_load() 2020-01-08 16:32:55 +00:00
kexec_internal.h kexec: add machine_kexec_post_load() 2020-01-08 16:32:55 +00:00
kheaders.c
kmod.c kmod: make request_module() return an error when autoloading is disabled 2020-04-10 15:36:22 -07:00
kprobes.c sysctl: pass kernel pointers to ->proc_handler 2020-04-27 02:07:40 -04:00
ksysfs.c
kthread.c kthread: Do not preempt current task if it is going to call schedule() 2020-03-20 13:06:20 +01:00
latencytop.c sysctl: pass kernel pointers to ->proc_handler 2020-04-27 02:07:40 -04:00
Makefile kcov: ignore fault-inject and stacktrace 2020-01-31 10:30:41 -08:00
module-internal.h
module.c kernel/module: Hide vermagic header file from general use 2020-04-21 13:27:37 -07:00
module_signature.c MODSIGN: Export module signature definitions 2019-08-05 18:39:56 -04:00
module_signing.c MODSIGN: Export module signature definitions 2019-08-05 18:39:56 -04:00
notifier.c x86/mm: split vmalloc_sync_all() 2020-03-21 18:56:06 -07:00
nsproxy.c ns: Introduce Time Namespace 2020-01-14 12:20:48 +01:00
padata.c crypto: pcrypt - simplify error handling in pcrypt_create_aead() 2020-03-06 12:28:24 +11:00
panic.c locking/refcount: Remove unused 'refcount_error_report()' function 2019-11-25 09:15:42 +01:00
params.c lockdown: Lock down module params that specify hardware parameters (eg. ioport) 2019-08-19 21:54:16 -07:00
pid.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2020-04-10 12:59:56 -07:00
pid_namespace.c sysctl: pass kernel pointers to ->proc_handler 2020-04-27 02:07:40 -04:00
profile.c proc: convert everything to "struct proc_ops" 2020-02-04 03:05:26 +00:00
ptrace.c ptrace: reintroduce usage of subjective credentials in ptrace_has_cap() 2020-01-18 13:51:39 +01:00
range.c
reboot.c
relay.c
resource.c mm/memory_hotplug.c: use PFN_UP / PFN_DOWN in walk_system_ram_range() 2019-09-24 15:54:09 -07:00
rseq.c rseq: Reject unknown flags on rseq unregister 2019-12-25 10:41:20 +01:00
seccomp.c sysctl: pass kernel pointers to ->proc_handler 2020-04-27 02:07:40 -04:00
signal.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2020-04-23 13:30:18 -07:00
smp.c cpu/hotplug: Move bringup of secondary CPUs out of smp_init() 2020-03-25 12:59:37 +01:00
smpboot.c
smpboot.h
softirq.c lockdep: Rename trace_{hard,soft}{irq_context,irqs_enabled}() 2020-03-21 16:03:54 +01:00
stackleak.c
stacktrace.c stacktrace: Get rid of unneeded '!!' pattern 2019-11-11 10:30:59 +01:00
stop_machine.c stop_machine: Make stop_cpus() static 2020-01-17 10:19:21 +01:00
sys.c sys/sysinfo: Respect boottime inside time namespace 2020-03-03 19:34:32 +01:00
sys_ni.c y2038: allow disabling time32 system calls 2019-11-15 14:38:30 +01:00
sysctl-test.c kunit: allow kunit tests to be loaded as a module 2020-01-09 16:42:29 -07:00
sysctl.c sysctl: Fix unused function warning 2020-05-05 11:59:32 -07:00
sysctl_binary.c sysctl: Remove the sysctl system call 2019-11-26 13:03:56 -06:00
task_work.c task_work_run: don't take ->pi_lock unconditionally 2020-03-02 14:06:33 -07:00
taskstats.c taskstats: fix data-race 2019-12-04 15:18:39 +01:00
test_kprobes.c
torture.c CPU (hotplug) updates: 2020-03-30 18:06:39 -07:00
tracepoint.c
tsacct.c tsacct: add 64-bit btime field 2019-12-18 18:07:31 +01:00
ucount.c ucount: Make sure ucounts in /proc/sys/user don't regress again 2020-04-07 21:51:27 +02:00
uid16.c
uid16.h
umh.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-05-15 13:48:59 -07:00
up.c smp/up: Make smp_call_function_single() match SMP semantics 2020-02-07 15:34:12 +01:00
user-return-notifier.c
user.c
user_namespace.c
utsname.c
utsname_sysctl.c sysctl: pass kernel pointers to ->proc_handler 2020-04-27 02:07:40 -04:00
watchdog.c sysctl: pass kernel pointers to ->proc_handler 2020-04-27 02:07:40 -04:00
watchdog_hld.c
workqueue.c workqueue: Remove the warning in wq_worker_sleeping() 2020-04-08 11:35:20 +02:00
workqueue_internal.h