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Mariusz DudekAlexei Starovoitov
Mariusz Dudek
authored and
Alexei Starovoitov
committed
samples/bpf: Sample application for eBPF load and socket creation split
Introduce a sample program to demonstrate the control and data plane split. For the control plane part a new program called xdpsock_ctrl_proc is introduced. For the data plane part, some code was added to xdpsock_user.c to act as the data plane entity. Application xdpsock_ctrl_proc works as control entity with sudo privileges (CAP_SYS_ADMIN and CAP_NET_ADMIN are sufficient) and the extended xdpsock as data plane entity with CAP_NET_RAW capability only. Usage example: sudo ./samples/bpf/xdpsock_ctrl_proc -i <interface> sudo ./samples/bpf/xdpsock -i <interface> -q <queue_id> -n <interval> -N -l -R Signed-off-by: Mariusz Dudek <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Acked-by: Magnus Karlsson <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
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‎samples/bpf/Makefile‎

Lines changed: 3 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -48,6 +48,7 @@ tprogs-y += syscall_tp
4848
tprogs-y += cpustat
4949
tprogs-y += xdp_adjust_tail
5050
tprogs-y += xdpsock
51+
tprogs-y += xdpsock_ctrl_proc
5152
tprogs-y += xsk_fwd
5253
tprogs-y += xdp_fwd
5354
tprogs-y += task_fd_query
@@ -105,6 +106,7 @@ syscall_tp-objs := syscall_tp_user.o
105106
cpustat-objs := cpustat_user.o
106107
xdp_adjust_tail-objs := xdp_adjust_tail_user.o
107108
xdpsock-objs := xdpsock_user.o
109+
xdpsock_ctrl_proc-objs := xdpsock_ctrl_proc.o
108110
xsk_fwd-objs := xsk_fwd.o
109111
xdp_fwd-objs := xdp_fwd_user.o
110112
task_fd_query-objs := task_fd_query_user.o $(TRACE_HELPERS)
@@ -202,7 +204,7 @@ TPROGLDLIBS_tracex4 += -lrt
202204
TPROGLDLIBS_trace_output += -lrt
203205
TPROGLDLIBS_map_perf_test += -lrt
204206
TPROGLDLIBS_test_overhead += -lrt
205-
TPROGLDLIBS_xdpsock += -pthread
207+
TPROGLDLIBS_xdpsock += -pthread -lcap
206208
TPROGLDLIBS_xsk_fwd += -pthread
207209

208210
# Allows pointing LLC/CLANG to a LLVM backend with bpf support, redefine on cmdline:

‎samples/bpf/xdpsock.h‎

Lines changed: 8 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -8,4 +8,12 @@
88

99
#define MAX_SOCKS 4
1010

11+
#define SOCKET_NAME "sock_cal_bpf_fd"
12+
#define MAX_NUM_OF_CLIENTS 10
13+
14+
#define CLOSE_CONN 1
15+
16+
typedef __u64 u64;
17+
typedef __u32 u32;
18+
1119
#endif /* XDPSOCK_H */

‎samples/bpf/xdpsock_ctrl_proc.c‎

Lines changed: 187 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,187 @@
1+
// SPDX-License-Identifier: GPL-2.0
2+
/* Copyright(c) 2017 - 2018 Intel Corporation. */
3+
4+
#include <errno.h>
5+
#include <getopt.h>
6+
#include <libgen.h>
7+
#include <net/if.h>
8+
#include <stdio.h>
9+
#include <stdlib.h>
10+
#include <sys/socket.h>
11+
#include <sys/un.h>
12+
#include <unistd.h>
13+
14+
#include <bpf/bpf.h>
15+
#include <bpf/xsk.h>
16+
#include "xdpsock.h"
17+
18+
static const char *opt_if = "";
19+
20+
static struct option long_options[] = {
21+
{"interface", required_argument, 0, 'i'},
22+
{0, 0, 0, 0}
23+
};
24+
25+
static void usage(const char *prog)
26+
{
27+
const char *str =
28+
" Usage: %s [OPTIONS]\n"
29+
" Options:\n"
30+
" -i, --interface=n Run on interface n\n"
31+
"\n";
32+
fprintf(stderr, "%s\n", str);
33+
34+
exit(0);
35+
}
36+
37+
static void parse_command_line(int argc, char **argv)
38+
{
39+
int option_index, c;
40+
41+
opterr = 0;
42+
43+
for (;;) {
44+
c = getopt_long(argc, argv, "i:",
45+
long_options, &option_index);
46+
if (c == -1)
47+
break;
48+
49+
switch (c) {
50+
case 'i':
51+
opt_if = optarg;
52+
break;
53+
default:
54+
usage(basename(argv[0]));
55+
}
56+
}
57+
}
58+
59+
static int send_xsks_map_fd(int sock, int fd)
60+
{
61+
char cmsgbuf[CMSG_SPACE(sizeof(int))];
62+
struct msghdr msg;
63+
struct iovec iov;
64+
int value = 0;
65+
66+
if (fd == -1) {
67+
fprintf(stderr, "Incorrect fd = %d\n", fd);
68+
return -1;
69+
}
70+
iov.iov_base = &value;
71+
iov.iov_len = sizeof(int);
72+
73+
msg.msg_name = NULL;
74+
msg.msg_namelen = 0;
75+
msg.msg_iov = &iov;
76+
msg.msg_iovlen = 1;
77+
msg.msg_flags = 0;
78+
msg.msg_control = cmsgbuf;
79+
msg.msg_controllen = CMSG_LEN(sizeof(int));
80+
81+
struct cmsghdr *cmsg = CMSG_FIRSTHDR(&msg);
82+
83+
cmsg->cmsg_level = SOL_SOCKET;
84+
cmsg->cmsg_type = SCM_RIGHTS;
85+
cmsg->cmsg_len = CMSG_LEN(sizeof(int));
86+
87+
*(int *)CMSG_DATA(cmsg) = fd;
88+
int ret = sendmsg(sock, &msg, 0);
89+
90+
if (ret == -1) {
91+
fprintf(stderr, "Sendmsg failed with %s", strerror(errno));
92+
return -errno;
93+
}
94+
95+
return ret;
96+
}
97+
98+
int
99+
main(int argc, char **argv)
100+
{
101+
struct sockaddr_un server;
102+
int listening = 1;
103+
int rval, msgsock;
104+
int ifindex = 0;
105+
int flag = 1;
106+
int cmd = 0;
107+
int sock;
108+
int err;
109+
int xsks_map_fd;
110+
111+
parse_command_line(argc, argv);
112+
113+
ifindex = if_nametoindex(opt_if);
114+
if (ifindex == 0) {
115+
fprintf(stderr, "Unable to get ifindex for Interface %s. Reason:%s",
116+
opt_if, strerror(errno));
117+
return -errno;
118+
}
119+
120+
sock = socket(AF_UNIX, SOCK_STREAM, 0);
121+
if (sock < 0) {
122+
fprintf(stderr, "Opening socket stream failed: %s", strerror(errno));
123+
return -errno;
124+
}
125+
126+
server.sun_family = AF_UNIX;
127+
strcpy(server.sun_path, SOCKET_NAME);
128+
129+
setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &flag, sizeof(int));
130+
131+
if (bind(sock, (struct sockaddr *)&server, sizeof(struct sockaddr_un))) {
132+
fprintf(stderr, "Binding to socket stream failed: %s", strerror(errno));
133+
return -errno;
134+
}
135+
136+
listen(sock, MAX_NUM_OF_CLIENTS);
137+
138+
err = xsk_setup_xdp_prog(ifindex, &xsks_map_fd);
139+
if (err) {
140+
fprintf(stderr, "Setup of xdp program failed\n");
141+
goto close_sock;
142+
}
143+
144+
while (listening) {
145+
msgsock = accept(sock, 0, 0);
146+
if (msgsock == -1) {
147+
fprintf(stderr, "Error accepting connection: %s", strerror(errno));
148+
err = -errno;
149+
goto close_sock;
150+
}
151+
err = send_xsks_map_fd(msgsock, xsks_map_fd);
152+
if (err <= 0) {
153+
fprintf(stderr, "Error %d sending xsks_map_fd\n", err);
154+
goto cleanup;
155+
}
156+
do {
157+
rval = read(msgsock, &cmd, sizeof(int));
158+
if (rval < 0) {
159+
fprintf(stderr, "Error reading stream message");
160+
} else {
161+
if (cmd != CLOSE_CONN)
162+
fprintf(stderr, "Recv unknown cmd = %d\n", cmd);
163+
listening = 0;
164+
break;
165+
}
166+
} while (rval > 0);
167+
}
168+
close(msgsock);
169+
close(sock);
170+
unlink(SOCKET_NAME);
171+
172+
/* Unset fd for given ifindex */
173+
err = bpf_set_link_xdp_fd(ifindex, -1, 0);
174+
if (err) {
175+
fprintf(stderr, "Error when unsetting bpf prog_fd for ifindex(%d)\n", ifindex);
176+
return err;
177+
}
178+
179+
return 0;
180+
181+
cleanup:
182+
close(msgsock);
183+
close_sock:
184+
close(sock);
185+
unlink(SOCKET_NAME);
186+
return err;
187+
}

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