There are situations, specially when using non-folded mode, where we are
interested only in very high latencies that happen due to blocking.

While we can certainly filter out the very small ones out of the output, it is a
lot more convenient to do this from the tool itself, as it would be difficult
from an external filter to do this in one pass.

But if we are to discard unused measurements, we can do even better: we can
change the bpf code itself not to grab those traces, and gain a bit of
efficiency in scenarios in which we are only concerned about peak latencies.

This scheme can be easily extended to also allow a maximum cap in the latencies
we are interested in.

After this patch is applied, the options -m and -M can be used to set those
limits respectively.

Fixes: #588

[tcpconnect] filter traced connection based on destination ports

Test:
While running:
while [ 1 ]; do nc -w 1 100.127.0.1 80; nc -w 1 100.127.0.1 81; done

root@vagrant:/mnt/bcc# ./tools/tcpconnect.py
PID    COMM         IP SADDR            DADDR            DPORT
19978  nc           4  10.0.2.15        100.127.0.1      80
19979  nc           4  10.0.2.15        100.127.0.1      81
19980  nc           4  10.0.2.15        100.127.0.1      80
19981  nc           4  10.0.2.15        100.127.0.1      81
root@vagrant:/mnt/bcc# ./tools/tcpconnect.py  -P 80
PID    COMM         IP SADDR            DADDR            DPORT
19987  nc           4  10.0.2.15        100.127.0.1      80
19989  nc           4  10.0.2.15        100.127.0.1      80
19991  nc           4  10.0.2.15        100.127.0.1      80
19993  nc           4  10.0.2.15        100.127.0.1      80
19995  nc           4  10.0.2.15        100.127.0.1      80
root@vagrant:/mnt/bcc# ./tools/tcpconnect.py  -P 80,81
PID    COMM         IP SADDR            DADDR            DPORT
8725   nc           4  10.0.2.15        100.127.0.1      80
8726   nc           4  10.0.2.15        100.127.0.1      81
8727   nc           4  10.0.2.15        100.127.0.1      80
8728   nc           4  10.0.2.15        100.127.0.1      81
8729   nc           4  10.0.2.15        100.127.0.1      80

Fixes #681

* add new tool: capable

* refactor a little, remove extra bpf_get_current_pid_tgid()

Use tempfile module to create a temp file

Fix some review input

Fix style check

Style

Style check

Remove builtin module from python test to run fedora ctest

Let the program calling bpf_prog_load to handle the log buffer

Check max instruction before the syscall. Fix other review comment

minor cleanup + process partial name matching

Signed-off-by: KarimAllah Ahmed <karim.allah.ahmed@gmail.com>

Signed-off-by: KarimAllah Ahmed <karim.allah.ahmed@gmail.com>

... since they are unused.
Signed-off-by: KarimAllah Ahmed <karim.allah.ahmed@gmail.com>

Prepare debian changelog for v0.2.0 tag

Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

examples: fix indentation in tracing/tcpv4connect

Python doesn't like mixing spaces and tabs.

fileslower: use de->d_name.name, add filtering

fix biosnoop after kernel change

offcputime improvements: use less RAM, add PID/TID support

Add perf_submit_skb

For BPF_PROG_TYPE_SCHED_CLS/ACT, the upstream kernel has recently added a
feature to efficiently output skb + meta data:
commit 555c8a8623a3 ("bpf: avoid stack copy and use skb ctx for event output")

This patch adds perf_submit_skb to BPF_PERF_OUTPUT macro.  It takes
an extra u32 argument.  perf_submit_skb will then be expanded to
bpf_perf_event_output properly to consider the newly added
u32 argument as the skb's len.

Other than the above described changes, perf_submit_skb is almost
a carbon copy of the perf_submit except the removal of the 'string name'
variable since I cannot find a specific use of it.

Note that the 3rd param type of bpf_perf_event_output has also been
changed from u32 to u64.

Added a sample program tc_perf_event.py.  Here is how the output
looks like:
[root@arch-fb-vm1 networking]# ./tc_perf_event.py
Try: "ping -6 ff02::1%me"

CPU SRC IP                           DST IP       Magic
0   fe80::982f:5dff:fec1:e52b        ff02::1      0xfaceb00c
0   fe80::982f:5dff:fec1:e52b        ff02::1      0xfaceb00c
0   fe80::982f:5dff:fec1:e52b        ff02::1      0xfaceb00c
1   fe80::982f:5dff:fec1:e52b        ff02::1      0xfaceb00c
1   fe80::982f:5dff:fec1:e52b        ff02::1      0xfaceb00c
1   fe80::982f:5dff:fec1:e52b        ff02::1      0xfaceb00c

Minor adjustments to the documentation

Fix a few typos
Add missing link
Reword update() description sentence

fix build with 4.0 llvm trunk

Signed-off-by: Alexei Starovoitov <ast@fb.com>

As reported in #664:
In cases where the AST contains a MemberExpr with an invalid opLoc,
rewrite will fail but prior to this change would segfault. Fail a little
more gracefully, even though the program will still be rejected.
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

Tool to sniff data contents before encrypted with OpenSSL

Now it also captures gnutls_record_send and gnutls_record_recv calls.
Added options to filter by pid or command name, or just one lib.

Add tool as talked in iovisor-dev 'BCC: bpf_probe_read read function arguments'

This reverts commit c6688dda4e856be43b8651afe92d7e32e63faea9.

killsnoop: use current time replace timestamp and default output

* debian packaging: Add missing Build-dependencies

* Add clang-format-3.7 to build-depends
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

* debian packaging: Build with -DBCC_KERNEL_HAS_SOURCE_DIR=1

This is required to use the distro-provided includes on Debian/Ubuntu

dcsnoop: use PERF_EVENT_OUTPUT