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Sample program using SO_COOKIE
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Added a per socket traffic monitoring option to illustrate the usage
of new getsockopt SO_COOKIE. The program is based on the socket traffic
monitoring program using xt_eBPF and in the new option the data entry
can be directly accessed using socket cookie. The cookie retrieved
allow us to lookup an element in the eBPF for a specific socket.

Signed-off-by: Chenbo Feng <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
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@davem330
Chenbo Feng authored and davem330 committed Apr 8, 2017
1 parent 5daab9d commit 00f660e
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Showing 2 changed files with 127 additions and 23 deletions.
146 changes: 125 additions & 21 deletions samples/bpf/cookie_uid_helper_example.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -4,10 +4,11 @@
* program into the xt_bpf match.
*
* TEST:
* ./run_cookie_uid_helper_example.sh
* Then generate some traffic in variate ways. ping 0 -c 10 would work
* but the cookie and uid in this case could both be 0. A sample output
* with some traffic generated by web browser is shown below:
* ./run_cookie_uid_helper_example.sh -option
* option:
* -t: do traffic monitoring test, the program will continuously
* print out network traffic happens after program started A sample
* output is shown below:
*
* cookie: 877, uid: 0x3e8, Pakcet Count: 20, Bytes Count: 11058
* cookie: 132, uid: 0x0, Pakcet Count: 2, Bytes Count: 286
Expand All @@ -18,6 +19,10 @@
* cookie: 0, uid: 0x0, Pakcet Count: 6, Bytes Count: 712
* cookie: 880, uid: 0xfffe, Pakcet Count: 1, Bytes Count: 70
*
* -s: do getsockopt SO_COOKIE test, the program will set up a pair of
* UDP sockets and send packets between them. And read out the traffic data
* directly from the ebpf map based on the socket cookie.
*
* Clean up: if using shell script, the script file will delete the iptables
* rule and unmount the bpf program when exit. Else the iptables rule need
* to be deleted by hand, see run_cookie_uid_helper_example.sh for detail.
Expand All @@ -34,6 +39,8 @@
#include <limits.h>
#include <linux/bpf.h>
#include <linux/if_ether.h>
#include <net/if.h>
#include <signal.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
Expand All @@ -46,6 +53,8 @@
#include <bpf/bpf.h>
#include "libbpf.h"

#define PORT 8888

struct stats {
uint32_t uid;
uint64_t packets;
Expand All @@ -54,6 +63,8 @@ struct stats {

static int map_fd, prog_fd;

static bool test_finish;

static void maps_create(void)
{
map_fd = bpf_create_map(BPF_MAP_TYPE_HASH, sizeof(uint32_t),
Expand Down Expand Up @@ -164,7 +175,7 @@ static void prog_attach_iptables(char *file)
printf("file path too long: %s\n", file);
exit(1);
}
sprintf(rules, "iptables -A INPUT -m bpf --object-pinned %s -j ACCEPT",
sprintf(rules, "iptables -A OUTPUT -m bpf --object-pinned %s -j ACCEPT",
file);
ret = system(rules);
if (ret < 0) {
Expand All @@ -177,7 +188,8 @@ static void print_table(void)
{
struct stats curEntry;
uint32_t curN = UINT32_MAX;
uint32_t nextN, res;
uint32_t nextN;
int res;

while (bpf_map_get_next_key(map_fd, &curN, &nextN) > -1) {
curN = nextN;
Expand All @@ -193,25 +205,117 @@ static void print_table(void)
}
}

int main(int argc, char *argv[])
static void udp_client(void)
{
if (argc > 2) {
printf("Too many argument provided\n");
return 1;
} else if (argc < 2) {
printf("Usage: %s bpfObjName\n", argv[0]);
return 1;
struct sockaddr_in si_other = {0};
struct sockaddr_in si_me = {0};
struct stats dataEntry;
int s_rcv, s_send, i, recv_len;
char message = 'a';
char buf;
uint64_t cookie;
int res;
socklen_t cookie_len = sizeof(cookie);
socklen_t slen = sizeof(si_other);

s_rcv = socket(PF_INET, SOCK_DGRAM, 0);
if (s_rcv < 0)
error(1, errno, "rcv socket creat failed!\n");
si_other.sin_family = AF_INET;
si_other.sin_port = htons(PORT);
if (inet_aton("127.0.0.1", &si_other.sin_addr) == 0)
error(1, errno, "inet_aton\n");
if (bind(s_rcv, (struct sockaddr *)&si_other, sizeof(si_other)) == -1)
error(1, errno, "bind\n");
s_send = socket(PF_INET, SOCK_DGRAM, 0);
if (s_send < 0)
error(1, errno, "send socket creat failed!\n");
res = getsockopt(s_send, SOL_SOCKET, SO_COOKIE, &cookie, &cookie_len);
if (res < 0)
printf("get cookie failed: %s\n", strerror(errno));
res = bpf_map_lookup_elem(map_fd, &cookie, &dataEntry);
if (res != -1)
error(1, errno, "socket stat found while flow not active\n");
for (i = 0; i < 10; i++) {
res = sendto(s_send, &message, sizeof(message), 0,
(struct sockaddr *)&si_other, slen);
if (res == -1)
error(1, errno, "send\n");
if (res != sizeof(message))
error(1, 0, "%uB != %luB\n", res, sizeof(message));
recv_len = recvfrom(s_rcv, &buf, sizeof(buf), 0,
(struct sockaddr *)&si_me, &slen);
if (recv_len < 0)
error(1, errno, "revieve\n");
res = memcmp(&(si_other.sin_addr), &(si_me.sin_addr),
sizeof(si_me.sin_addr));
if (res != 0)
error(1, EFAULT, "sender addr error: %d\n", res);
printf("Message received: %c\n", buf);
res = bpf_map_lookup_elem(map_fd, &cookie, &dataEntry);
if (res < 0)
error(1, errno, "lookup sk stat failed, cookie: %lu\n",
cookie);
printf("cookie: %lu, uid: 0x%x, Packet Count: %lu,"
" Bytes Count: %lu\n\n", cookie, dataEntry.uid,
dataEntry.packets, dataEntry.bytes);
}
close(s_send);
close(s_rcv);
}

maps_create();
prog_load();
prog_attach_iptables(argv[1]);
static int usage(void)
{
printf("Usage: ./run_cookie_uid_helper_example.sh"
" bpfObjName -option\n"
" -t traffic monitor test\n"
" -s getsockopt cookie test\n");
return 1;
}

while (true) {
print_table();
printf("\n");
sleep(1);
};
void finish(int ret)
{
test_finish = true;
}

int main(int argc, char *argv[])
{
int opt;
bool cfg_test_traffic = false;
bool cfg_test_cookie = false;

if (argc != 3)
return usage();
while ((opt = getopt(argc, argv, "ts")) != -1) {
switch (opt) {
case 't':
cfg_test_traffic = true;
break;
case 's':
cfg_test_cookie = true;
break;

default:
printf("unknown option %c\n", opt);
usage();
return -1;
}
}
maps_create();
prog_load();
prog_attach_iptables(argv[2]);
if (cfg_test_traffic) {
if (signal(SIGINT, finish) == SIG_ERR)
error(1, errno, "register handler failed");
while (!test_finish) {
print_table();
printf("\n");
sleep(1);
};
} else if (cfg_test_cookie) {
udp_client();
}
close(prog_fd);
close(map_fd);
return 0;
}
4 changes: 2 additions & 2 deletions samples/bpf/run_cookie_uid_helper_example.sh
100644 → 100755
View file
Original file line number Diff line number Diff line change
Expand Up @@ -4,11 +4,11 @@ root_dir=$local_dir/../..
mnt_dir=$(mktemp -d --tmp)

on_exit() {
iptables -D INPUT -m bpf --object-pinned ${mnt_dir}/bpf_prog -j ACCEPT
iptables -D OUTPUT -m bpf --object-pinned ${mnt_dir}/bpf_prog -j ACCEPT
umount ${mnt_dir}
rm -r ${mnt_dir}
}

trap on_exit EXIT
mount -t bpf bpf ${mnt_dir}
./per_socket_stats_example ${mnt_dir}/bpf_prog
./per_socket_stats_example ${mnt_dir}/bpf_prog $1

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