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<title>linux-toradex.git/samples/bpf, branch v4.0-rc1</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>samples: bpf: relax test_maps check</title>
<updated>2015-01-27T01:20:40+00:00</updated>
<author>
<name>Alexei Starovoitov</name>
<email>ast@plumgrid.com</email>
</author>
<published>2015-01-23T01:11:09+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=ba1a68bf1308a71a07d2462f4c38c242e08f92ba'/>
<id>ba1a68bf1308a71a07d2462f4c38c242e08f92ba</id>
<content type='text'>
hash map is unordered, so get_next_key() iterator shouldn't
rely on particular order of elements. So relax this test.

Fixes: ffb65f27a155 ("bpf: add a testsuite for eBPF maps")
Reported-by: Michael Holzheu &lt;holzheu@linux.vnet.ibm.com&gt;
Signed-off-by: Alexei Starovoitov &lt;ast@plumgrid.com&gt;
Acked-by: Daniel Borkmann &lt;dborkman@redhat.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
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<pre>
hash map is unordered, so get_next_key() iterator shouldn't
rely on particular order of elements. So relax this test.

Fixes: ffb65f27a155 ("bpf: add a testsuite for eBPF maps")
Reported-by: Michael Holzheu &lt;holzheu@linux.vnet.ibm.com&gt;
Signed-off-by: Alexei Starovoitov &lt;ast@plumgrid.com&gt;
Acked-by: Daniel Borkmann &lt;dborkman@redhat.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>samples: bpf: large eBPF program in C</title>
<updated>2014-12-06T05:47:34+00:00</updated>
<author>
<name>Alexei Starovoitov</name>
<email>ast@plumgrid.com</email>
</author>
<published>2014-12-01T23:06:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=fbe3310840c65f3cf97dd90d23e177d061c376f2'/>
<id>fbe3310840c65f3cf97dd90d23e177d061c376f2</id>
<content type='text'>
sockex2_kern.c is purposefully large eBPF program in C.
llvm compiles ~200 lines of C code into ~300 eBPF instructions.

It's similar to __skb_flow_dissect() to demonstrate that complex packet parsing
can be done by eBPF.
Then it uses (struct flow_keys)-&gt;dst IP address (or hash of ipv6 dst) to keep
stats of number of packets per IP.
User space loads eBPF program, attaches it to loopback interface and prints
dest_ip-&gt;#packets stats every second.

Usage:
$sudo samples/bpf/sockex2
ip 127.0.0.1 count 19
ip 127.0.0.1 count 178115
ip 127.0.0.1 count 369437
ip 127.0.0.1 count 559841
ip 127.0.0.1 count 750539

Signed-off-by: Alexei Starovoitov &lt;ast@plumgrid.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
sockex2_kern.c is purposefully large eBPF program in C.
llvm compiles ~200 lines of C code into ~300 eBPF instructions.

It's similar to __skb_flow_dissect() to demonstrate that complex packet parsing
can be done by eBPF.
Then it uses (struct flow_keys)-&gt;dst IP address (or hash of ipv6 dst) to keep
stats of number of packets per IP.
User space loads eBPF program, attaches it to loopback interface and prints
dest_ip-&gt;#packets stats every second.

Usage:
$sudo samples/bpf/sockex2
ip 127.0.0.1 count 19
ip 127.0.0.1 count 178115
ip 127.0.0.1 count 369437
ip 127.0.0.1 count 559841
ip 127.0.0.1 count 750539

Signed-off-by: Alexei Starovoitov &lt;ast@plumgrid.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>samples: bpf: trivial eBPF program in C</title>
<updated>2014-12-06T05:47:33+00:00</updated>
<author>
<name>Alexei Starovoitov</name>
<email>ast@plumgrid.com</email>
</author>
<published>2014-12-01T23:06:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=a80857822b0c2ed608c93504bd3687b78f20c619'/>
<id>a80857822b0c2ed608c93504bd3687b78f20c619</id>
<content type='text'>
this example does the same task as previous socket example
in assembler, but this one does it in C.

eBPF program in kernel does:
    /* assume that packet is IPv4, load one byte of IP-&gt;proto */
    int index = load_byte(skb, ETH_HLEN + offsetof(struct iphdr, protocol));
    long *value;

    value = bpf_map_lookup_elem(&amp;my_map, &amp;index);
    if (value)
        __sync_fetch_and_add(value, 1);

Corresponding user space reads map[tcp], map[udp], map[icmp]
and prints protocol stats every second

Signed-off-by: Alexei Starovoitov &lt;ast@plumgrid.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
this example does the same task as previous socket example
in assembler, but this one does it in C.

eBPF program in kernel does:
    /* assume that packet is IPv4, load one byte of IP-&gt;proto */
    int index = load_byte(skb, ETH_HLEN + offsetof(struct iphdr, protocol));
    long *value;

    value = bpf_map_lookup_elem(&amp;my_map, &amp;index);
    if (value)
        __sync_fetch_and_add(value, 1);

Corresponding user space reads map[tcp], map[udp], map[icmp]
and prints protocol stats every second

Signed-off-by: Alexei Starovoitov &lt;ast@plumgrid.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>samples: bpf: elf_bpf file loader</title>
<updated>2014-12-06T05:47:33+00:00</updated>
<author>
<name>Alexei Starovoitov</name>
<email>ast@plumgrid.com</email>
</author>
<published>2014-12-01T23:06:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=249b812d8005ec38e351ee763ceb85d56b155064'/>
<id>249b812d8005ec38e351ee763ceb85d56b155064</id>
<content type='text'>
simple .o parser and loader using BPF syscall.
.o is a standard ELF generated by LLVM backend

It parses elf file compiled by llvm .c-&gt;.o
- parses 'maps' section and creates maps via BPF syscall
- parses 'license' section and passes it to syscall
- parses elf relocations for BPF maps and adjusts BPF_LD_IMM64 insns
  by storing map_fd into insn-&gt;imm and marking such insns as BPF_PSEUDO_MAP_FD
- loads eBPF programs via BPF syscall

One ELF file can contain multiple BPF programs.

int load_bpf_file(char *path);
populates prog_fd[] and map_fd[] with FDs received from bpf syscall

bpf_helpers.h - helper functions available to eBPF programs written in C

Signed-off-by: Alexei Starovoitov &lt;ast@plumgrid.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
simple .o parser and loader using BPF syscall.
.o is a standard ELF generated by LLVM backend

It parses elf file compiled by llvm .c-&gt;.o
- parses 'maps' section and creates maps via BPF syscall
- parses 'license' section and passes it to syscall
- parses elf relocations for BPF maps and adjusts BPF_LD_IMM64 insns
  by storing map_fd into insn-&gt;imm and marking such insns as BPF_PSEUDO_MAP_FD
- loads eBPF programs via BPF syscall

One ELF file can contain multiple BPF programs.

int load_bpf_file(char *path);
populates prog_fd[] and map_fd[] with FDs received from bpf syscall

bpf_helpers.h - helper functions available to eBPF programs written in C

Signed-off-by: Alexei Starovoitov &lt;ast@plumgrid.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>samples: bpf: example of stateful socket filtering</title>
<updated>2014-12-06T05:47:32+00:00</updated>
<author>
<name>Alexei Starovoitov</name>
<email>ast@plumgrid.com</email>
</author>
<published>2014-12-01T23:06:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=03f4723ed7a52bd31da26eefe2cdde563ea0f468'/>
<id>03f4723ed7a52bd31da26eefe2cdde563ea0f468</id>
<content type='text'>
this socket filter example does:
- creates arraymap in kernel with key 4 bytes and value 8 bytes

- loads eBPF program which assumes that packet is IPv4 and loads one byte of
  IP-&gt;proto from the packet and uses it as a key in a map

  r0 = skb-&gt;data[ETH_HLEN + offsetof(struct iphdr, protocol)];
  *(u32*)(fp - 4) = r0;
  value = bpf_map_lookup_elem(map_fd, fp - 4);
  if (value)
       (*(u64*)value) += 1;

- attaches this program to raw socket

- every second user space reads map[IPPROTO_TCP], map[IPPROTO_UDP], map[IPPROTO_ICMP]
  to see how many packets of given protocol were seen on loopback interface

Usage:
$sudo samples/bpf/sock_example
TCP 0 UDP 0 ICMP 0 packets
TCP 187600 UDP 0 ICMP 4 packets
TCP 376504 UDP 0 ICMP 8 packets
TCP 563116 UDP 0 ICMP 12 packets
TCP 753144 UDP 0 ICMP 16 packets

Signed-off-by: Alexei Starovoitov &lt;ast@plumgrid.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
this socket filter example does:
- creates arraymap in kernel with key 4 bytes and value 8 bytes

- loads eBPF program which assumes that packet is IPv4 and loads one byte of
  IP-&gt;proto from the packet and uses it as a key in a map

  r0 = skb-&gt;data[ETH_HLEN + offsetof(struct iphdr, protocol)];
  *(u32*)(fp - 4) = r0;
  value = bpf_map_lookup_elem(map_fd, fp - 4);
  if (value)
       (*(u64*)value) += 1;

- attaches this program to raw socket

- every second user space reads map[IPPROTO_TCP], map[IPPROTO_UDP], map[IPPROTO_ICMP]
  to see how many packets of given protocol were seen on loopback interface

Usage:
$sudo samples/bpf/sock_example
TCP 0 UDP 0 ICMP 0 packets
TCP 187600 UDP 0 ICMP 4 packets
TCP 376504 UDP 0 ICMP 8 packets
TCP 563116 UDP 0 ICMP 12 packets
TCP 753144 UDP 0 ICMP 16 packets

Signed-off-by: Alexei Starovoitov &lt;ast@plumgrid.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>bpf: remove test map scaffolding and user proper types</title>
<updated>2014-11-18T18:44:00+00:00</updated>
<author>
<name>Alexei Starovoitov</name>
<email>ast@plumgrid.com</email>
</author>
<published>2014-11-14T01:36:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=7943c0f329d33f531607d66f5781f2210e1e278c'/>
<id>7943c0f329d33f531607d66f5781f2210e1e278c</id>
<content type='text'>
proper types and function helpers are ready. Use them in verifier testsuite.
Remove temporary stubs

Signed-off-by: Alexei Starovoitov &lt;ast@plumgrid.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
proper types and function helpers are ready. Use them in verifier testsuite.
Remove temporary stubs

Signed-off-by: Alexei Starovoitov &lt;ast@plumgrid.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>bpf: add a testsuite for eBPF maps</title>
<updated>2014-11-18T18:43:59+00:00</updated>
<author>
<name>Alexei Starovoitov</name>
<email>ast@plumgrid.com</email>
</author>
<published>2014-11-14T01:36:48+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=ffb65f27a15583379567b6a59a9758163b7f5750'/>
<id>ffb65f27a15583379567b6a59a9758163b7f5750</id>
<content type='text'>
. check error conditions and sanity of hash and array map APIs
. check large maps (that kernel gracefully switches to vmalloc from kmalloc)
. check multi-process parallel access and stress test

Signed-off-by: Alexei Starovoitov &lt;ast@plumgrid.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
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<pre>
. check error conditions and sanity of hash and array map APIs
. check large maps (that kernel gracefully switches to vmalloc from kmalloc)
. check multi-process parallel access and stress test

Signed-off-by: Alexei Starovoitov &lt;ast@plumgrid.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>samples: bpf: add a verifier test and summary line</title>
<updated>2014-10-30T19:44:37+00:00</updated>
<author>
<name>Alexei Starovoitov</name>
<email>ast@plumgrid.com</email>
</author>
<published>2014-10-28T22:11:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=342ded409608f84fe929216efe0ca2d45e2656be'/>
<id>342ded409608f84fe929216efe0ca2d45e2656be</id>
<content type='text'>
- add a test specifically targeting verifier state pruning.
It checks state propagation between registers, storing that
state into stack and state pruning algorithm recognizing
equivalent stack and register states.

- add summary line to spot failures easier

Signed-off-by: Alexei Starovoitov &lt;ast@plumgrid.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
- add a test specifically targeting verifier state pruning.
It checks state propagation between registers, storing that
state into stack and state pruning algorithm recognizing
equivalent stack and register states.

- add summary line to spot failures easier

Signed-off-by: Alexei Starovoitov &lt;ast@plumgrid.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>bpf: fix bug in eBPF verifier</title>
<updated>2014-10-22T01:43:46+00:00</updated>
<author>
<name>Alexei Starovoitov</name>
<email>ast@plumgrid.com</email>
</author>
<published>2014-10-20T21:54:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=32bf08a6257b9c7380dcd040af3c0858eee3ef05'/>
<id>32bf08a6257b9c7380dcd040af3c0858eee3ef05</id>
<content type='text'>
while comparing for verifier state equivalency the comparison
was missing a check for uninitialized register.
Make sure it does so and add a testcase.

Fixes: f1bca824dabb ("bpf: add search pruning optimization to verifier")
Cc: Hannes Frederic Sowa &lt;hannes@stressinduktion.org&gt;
Signed-off-by: Alexei Starovoitov &lt;ast@plumgrid.com&gt;
Acked-by: Hannes Frederic Sowa &lt;hannes@stressinduktion.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
while comparing for verifier state equivalency the comparison
was missing a check for uninitialized register.
Make sure it does so and add a testcase.

Fixes: f1bca824dabb ("bpf: add search pruning optimization to verifier")
Cc: Hannes Frederic Sowa &lt;hannes@stressinduktion.org&gt;
Signed-off-by: Alexei Starovoitov &lt;ast@plumgrid.com&gt;
Acked-by: Hannes Frederic Sowa &lt;hannes@stressinduktion.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>bpf: add tests to verifier testsuite</title>
<updated>2014-10-02T01:30:33+00:00</updated>
<author>
<name>Alexei Starovoitov</name>
<email>ast@plumgrid.com</email>
</author>
<published>2014-09-30T01:50:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=fd10c2ef3e0ad82a4003d8005f3e7716d19a9376'/>
<id>fd10c2ef3e0ad82a4003d8005f3e7716d19a9376</id>
<content type='text'>
add 4 extra tests to cover jump verification better

Signed-off-by: Alexei Starovoitov &lt;ast@plumgrid.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
add 4 extra tests to cover jump verification better

Signed-off-by: Alexei Starovoitov &lt;ast@plumgrid.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
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