Daniel Borkmann bd570ff970 bpf: add event output helper for notifications/sampling/logging ... This patch adds a new helper for cls/act programs that can push events to user space applications. For networking, this can be f.e. for sampling, debugging, logging purposes or pushing of arbitrary wake-up events. The idea is similar to a43eec3042 ("bpf: introduce bpf_perf_event_output() helper") and 39111695b1 ("samples: bpf: add bpf_perf_event_output example"). The eBPF program utilizes a perf event array map that user space populates with fds from perf_event_open(), the eBPF program calls into the helper f.e. as skb_event_output(skb, &my_map, BPF_F_CURRENT_CPU, raw, sizeof(raw)) so that the raw data is pushed into the fd f.e. at the map index of the current CPU. User space can poll/mmap/etc on this and has a data channel for receiving events that can be post-processed. The nice thing is that since the eBPF program and user space application making use of it are tightly coupled, they can define their own arbitrary raw data format and what/when they want to push. While f.e. packet headers could be one part of the meta data that is being pushed, this is not a substitute for things like packet sockets as whole packet is not being pushed and push is only done in a single direction. Intention is more of a generically usable, efficient event pipe to applications. Workflow is that tc can pin the map and applications can attach themselves e.g. after cls/act setup to one or multiple map slots, demuxing is done by the eBPF program. Adding this facility is with minimal effort, it reuses the helper introduced in a43eec3042 ("bpf: introduce bpf_perf_event_output() helper") and we get its functionality for free by overloading its BPF_FUNC_ identifier for cls/act programs, ctx is currently unused, but will be made use of in future. Example will be added to iproute2's BPF example files. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>		2016-04-19 20:26:11 -04:00
..
blktrace.c	kernel/...: convert pr_warning to pr_warn	2016-03-22 15:36:02 -07:00
bpf_trace.c	bpf: add event output helper for notifications/sampling/logging	2016-04-19 20:26:11 -04:00
ftrace.c	Nothing major this round. Mostly small clean ups and fixes.	2016-03-24 10:52:25 -07:00
Kconfig
Makefile
power-traces.c
ring_buffer_benchmark.c
ring_buffer.c
rpm-traces.c
trace_benchmark.c
trace_benchmark.h
trace_branch.c
trace_clock.c
trace_entries.h
trace_event_perf.c	perf: split perf_trace_buf_prepare into alloc and update parts	2016-04-07 21:04:26 -04:00
trace_events_filter_test.h
trace_events_filter.c	tracing: Make ftrace_event_field checking functions available	2016-03-08 11:19:29 -05:00
trace_events_trigger.c	tracing: Use flags instead of bool in trigger structure	2016-03-08 11:19:36 -05:00
trace_events.c	bpf: sanitize bpf tracepoint access	2016-04-07 21:04:26 -04:00
trace_export.c
trace_functions_graph.c	arch, ftrace: for KASAN put hard/soft IRQ entries into separate sections	2016-03-25 16:37:42 -07:00
trace_functions.c
trace_irqsoff.c	tracing: Remove redundant reset per-CPU buff in irqsoff tracer	2016-03-18 16:39:11 -04:00
trace_kdb.c
trace_kprobe.c	perf: split perf_trace_buf_prepare into alloc and update parts	2016-04-07 21:04:26 -04:00
trace_mmiotrace.c	kernel/...: convert pr_warning to pr_warn	2016-03-22 15:36:02 -07:00
trace_nop.c	tracing: Fix typoes in code comment and printk in trace_nop.c	2016-03-08 11:23:57 -05:00
trace_output.c	tracing: Record and show NMI state	2016-03-22 18:04:10 -04:00
trace_output.h
trace_printk.c	tracing: Fix trace_printk() to print when not using bprintk()	2016-03-22 18:02:40 -04:00
trace_probe.c	kernel/...: convert pr_warning to pr_warn	2016-03-22 15:36:02 -07:00
trace_probe.h
trace_sched_switch.c
trace_sched_wakeup.c
trace_selftest_dynamic.c
trace_selftest.c
trace_seq.c
trace_stack.c
trace_stat.c	kernel/...: convert pr_warning to pr_warn	2016-03-22 15:36:02 -07:00
trace_stat.h
trace_syscalls.c	perf: split perf_trace_buf_prepare into alloc and update parts	2016-04-07 21:04:26 -04:00
trace_uprobe.c	perf: split perf_trace_buf_prepare into alloc and update parts	2016-04-07 21:04:26 -04:00
trace.c	Nothing major this round. Mostly small clean ups and fixes.	2016-03-24 10:52:25 -07:00
trace.h	tracing: Record and show NMI state	2016-03-22 18:04:10 -04:00