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 <mariuszx.dudek@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Magnus Karlsson <magnus.karlsson@intel.com>
Link: https://lore.kernel.org/bpf/20201203090546.11976-3-mariuszx.dudek@intel.com
This commit is contained in:
Mariusz Dudek 2020-12-03 10:05:46 +01:00 committed by Alexei Starovoitov
parent e459f49b43
commit 3627d9702d
4 changed files with 337 additions and 6 deletions

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@ -48,6 +48,7 @@ tprogs-y += syscall_tp
tprogs-y += cpustat
tprogs-y += xdp_adjust_tail
tprogs-y += xdpsock
tprogs-y += xdpsock_ctrl_proc
tprogs-y += xsk_fwd
tprogs-y += xdp_fwd
tprogs-y += task_fd_query
@ -105,6 +106,7 @@ syscall_tp-objs := syscall_tp_user.o
cpustat-objs := cpustat_user.o
xdp_adjust_tail-objs := xdp_adjust_tail_user.o
xdpsock-objs := xdpsock_user.o
xdpsock_ctrl_proc-objs := xdpsock_ctrl_proc.o
xsk_fwd-objs := xsk_fwd.o
xdp_fwd-objs := xdp_fwd_user.o
task_fd_query-objs := task_fd_query_user.o $(TRACE_HELPERS)
@ -202,7 +204,7 @@ TPROGLDLIBS_tracex4 += -lrt
TPROGLDLIBS_trace_output += -lrt
TPROGLDLIBS_map_perf_test += -lrt
TPROGLDLIBS_test_overhead += -lrt
TPROGLDLIBS_xdpsock += -pthread
TPROGLDLIBS_xdpsock += -pthread -lcap
TPROGLDLIBS_xsk_fwd += -pthread
# Allows pointing LLC/CLANG to a LLVM backend with bpf support, redefine on cmdline:

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@ -8,4 +8,12 @@
#define MAX_SOCKS 4
#define SOCKET_NAME "sock_cal_bpf_fd"
#define MAX_NUM_OF_CLIENTS 10
#define CLOSE_CONN 1
typedef __u64 u64;
typedef __u32 u32;
#endif /* XDPSOCK_H */

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@ -0,0 +1,187 @@
// SPDX-License-Identifier: GPL-2.0
/* Copyright(c) 2017 - 2018 Intel Corporation. */
#include <errno.h>
#include <getopt.h>
#include <libgen.h>
#include <net/if.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <unistd.h>
#include <bpf/bpf.h>
#include <bpf/xsk.h>
#include "xdpsock.h"
static const char *opt_if = "";
static struct option long_options[] = {
{"interface", required_argument, 0, 'i'},
{0, 0, 0, 0}
};
static void usage(const char *prog)
{
const char *str =
" Usage: %s [OPTIONS]\n"
" Options:\n"
" -i, --interface=n Run on interface n\n"
"\n";
fprintf(stderr, "%s\n", str);
exit(0);
}
static void parse_command_line(int argc, char **argv)
{
int option_index, c;
opterr = 0;
for (;;) {
c = getopt_long(argc, argv, "i:",
long_options, &option_index);
if (c == -1)
break;
switch (c) {
case 'i':
opt_if = optarg;
break;
default:
usage(basename(argv[0]));
}
}
}
static int send_xsks_map_fd(int sock, int fd)
{
char cmsgbuf[CMSG_SPACE(sizeof(int))];
struct msghdr msg;
struct iovec iov;
int value = 0;
if (fd == -1) {
fprintf(stderr, "Incorrect fd = %d\n", fd);
return -1;
}
iov.iov_base = &value;
iov.iov_len = sizeof(int);
msg.msg_name = NULL;
msg.msg_namelen = 0;
msg.msg_iov = &iov;
msg.msg_iovlen = 1;
msg.msg_flags = 0;
msg.msg_control = cmsgbuf;
msg.msg_controllen = CMSG_LEN(sizeof(int));
struct cmsghdr *cmsg = CMSG_FIRSTHDR(&msg);
cmsg->cmsg_level = SOL_SOCKET;
cmsg->cmsg_type = SCM_RIGHTS;
cmsg->cmsg_len = CMSG_LEN(sizeof(int));
*(int *)CMSG_DATA(cmsg) = fd;
int ret = sendmsg(sock, &msg, 0);
if (ret == -1) {
fprintf(stderr, "Sendmsg failed with %s", strerror(errno));
return -errno;
}
return ret;
}
int
main(int argc, char **argv)
{
struct sockaddr_un server;
int listening = 1;
int rval, msgsock;
int ifindex = 0;
int flag = 1;
int cmd = 0;
int sock;
int err;
int xsks_map_fd;
parse_command_line(argc, argv);
ifindex = if_nametoindex(opt_if);
if (ifindex == 0) {
fprintf(stderr, "Unable to get ifindex for Interface %s. Reason:%s",
opt_if, strerror(errno));
return -errno;
}
sock = socket(AF_UNIX, SOCK_STREAM, 0);
if (sock < 0) {
fprintf(stderr, "Opening socket stream failed: %s", strerror(errno));
return -errno;
}
server.sun_family = AF_UNIX;
strcpy(server.sun_path, SOCKET_NAME);
setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &flag, sizeof(int));
if (bind(sock, (struct sockaddr *)&server, sizeof(struct sockaddr_un))) {
fprintf(stderr, "Binding to socket stream failed: %s", strerror(errno));
return -errno;
}
listen(sock, MAX_NUM_OF_CLIENTS);
err = xsk_setup_xdp_prog(ifindex, &xsks_map_fd);
if (err) {
fprintf(stderr, "Setup of xdp program failed\n");
goto close_sock;
}
while (listening) {
msgsock = accept(sock, 0, 0);
if (msgsock == -1) {
fprintf(stderr, "Error accepting connection: %s", strerror(errno));
err = -errno;
goto close_sock;
}
err = send_xsks_map_fd(msgsock, xsks_map_fd);
if (err <= 0) {
fprintf(stderr, "Error %d sending xsks_map_fd\n", err);
goto cleanup;
}
do {
rval = read(msgsock, &cmd, sizeof(int));
if (rval < 0) {
fprintf(stderr, "Error reading stream message");
} else {
if (cmd != CLOSE_CONN)
fprintf(stderr, "Recv unknown cmd = %d\n", cmd);
listening = 0;
break;
}
} while (rval > 0);
}
close(msgsock);
close(sock);
unlink(SOCKET_NAME);
/* Unset fd for given ifindex */
err = bpf_set_link_xdp_fd(ifindex, -1, 0);
if (err) {
fprintf(stderr, "Error when unsetting bpf prog_fd for ifindex(%d)\n", ifindex);
return err;
}
return 0;
cleanup:
close(msgsock);
close_sock:
close(sock);
unlink(SOCKET_NAME);
return err;
}

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@ -24,10 +24,12 @@
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/capability.h>
#include <sys/mman.h>
#include <sys/resource.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <sys/un.h>
#include <time.h>
#include <unistd.h>
@ -96,6 +98,7 @@ static bool opt_need_wakeup = true;
static u32 opt_num_xsks = 1;
static u32 prog_id;
static bool opt_busy_poll;
static bool opt_reduced_cap;
struct xsk_ring_stats {
unsigned long rx_npkts;
@ -154,6 +157,7 @@ struct xsk_socket_info {
static int num_socks;
struct xsk_socket_info *xsks[MAX_SOCKS];
int sock;
static unsigned long get_nsecs(void)
{
@ -461,6 +465,7 @@ static void *poller(void *arg)
static void remove_xdp_program(void)
{
u32 curr_prog_id = 0;
int cmd = CLOSE_CONN;
if (bpf_get_link_xdp_id(opt_ifindex, &curr_prog_id, opt_xdp_flags)) {
printf("bpf_get_link_xdp_id failed\n");
@ -472,6 +477,13 @@ static void remove_xdp_program(void)
printf("couldn't find a prog id on a given interface\n");
else
printf("program on interface changed, not removing\n");
if (opt_reduced_cap) {
if (write(sock, &cmd, sizeof(int)) < 0) {
fprintf(stderr, "Error writing into stream socket: %s", strerror(errno));
exit(EXIT_FAILURE);
}
}
}
static void int_exit(int sig)
@ -854,7 +866,7 @@ static struct xsk_socket_info *xsk_configure_socket(struct xsk_umem_info *umem,
xsk->umem = umem;
cfg.rx_size = XSK_RING_CONS__DEFAULT_NUM_DESCS;
cfg.tx_size = XSK_RING_PROD__DEFAULT_NUM_DESCS;
if (opt_num_xsks > 1)
if (opt_num_xsks > 1 || opt_reduced_cap)
cfg.libbpf_flags = XSK_LIBBPF_FLAGS__INHIBIT_PROG_LOAD;
else
cfg.libbpf_flags = 0;
@ -913,6 +925,7 @@ static struct option long_options[] = {
{"app-stats", no_argument, 0, 'a'},
{"irq-string", no_argument, 0, 'I'},
{"busy-poll", no_argument, 0, 'B'},
{"reduce-cap", no_argument, 0, 'R'},
{0, 0, 0, 0}
};
@ -935,7 +948,7 @@ static void usage(const char *prog)
" -m, --no-need-wakeup Turn off use of driver need wakeup flag.\n"
" -f, --frame-size=n Set the frame size (must be a power of two in aligned mode, default is %d).\n"
" -u, --unaligned Enable unaligned chunk placement\n"
" -M, --shared-umem Enable XDP_SHARED_UMEM\n"
" -M, --shared-umem Enable XDP_SHARED_UMEM (cannot be used with -R)\n"
" -F, --force Force loading the XDP prog\n"
" -d, --duration=n Duration in secs to run command.\n"
" Default: forever.\n"
@ -952,6 +965,7 @@ static void usage(const char *prog)
" -a, --app-stats Display application (syscall) statistics.\n"
" -I, --irq-string Display driver interrupt statistics for interface associated with irq-string.\n"
" -B, --busy-poll Busy poll.\n"
" -R, --reduce-cap Use reduced capabilities (cannot be used with -M)\n"
"\n";
fprintf(stderr, str, prog, XSK_UMEM__DEFAULT_FRAME_SIZE,
opt_batch_size, MIN_PKT_SIZE, MIN_PKT_SIZE,
@ -967,7 +981,7 @@ static void parse_command_line(int argc, char **argv)
opterr = 0;
for (;;) {
c = getopt_long(argc, argv, "Frtli:q:pSNn:czf:muMd:b:C:s:P:xQaI:B",
c = getopt_long(argc, argv, "Frtli:q:pSNn:czf:muMd:b:C:s:P:xQaI:BR",
long_options, &option_index);
if (c == -1)
break;
@ -1069,6 +1083,9 @@ static void parse_command_line(int argc, char **argv)
case 'B':
opt_busy_poll = 1;
break;
case 'R':
opt_reduced_cap = true;
break;
default:
usage(basename(argv[0]));
}
@ -1090,6 +1107,11 @@ static void parse_command_line(int argc, char **argv)
opt_xsk_frame_size);
usage(basename(argv[0]));
}
if (opt_reduced_cap && opt_num_xsks > 1) {
fprintf(stderr, "ERROR: -M and -R cannot be used together\n");
usage(basename(argv[0]));
}
}
static void kick_tx(struct xsk_socket_info *xsk)
@ -1487,19 +1509,116 @@ static void apply_setsockopt(struct xsk_socket_info *xsk)
exit_with_error(errno);
}
static int recv_xsks_map_fd_from_ctrl_node(int sock, int *_fd)
{
char cms[CMSG_SPACE(sizeof(int))];
struct cmsghdr *cmsg;
struct msghdr msg;
struct iovec iov;
int value;
int len;
iov.iov_base = &value;
iov.iov_len = sizeof(int);
msg.msg_name = 0;
msg.msg_namelen = 0;
msg.msg_iov = &iov;
msg.msg_iovlen = 1;
msg.msg_flags = 0;
msg.msg_control = (caddr_t)cms;
msg.msg_controllen = sizeof(cms);
len = recvmsg(sock, &msg, 0);
if (len < 0) {
fprintf(stderr, "Recvmsg failed length incorrect.\n");
return -EINVAL;
}
if (len == 0) {
fprintf(stderr, "Recvmsg failed no data\n");
return -EINVAL;
}
cmsg = CMSG_FIRSTHDR(&msg);
*_fd = *(int *)CMSG_DATA(cmsg);
return 0;
}
static int
recv_xsks_map_fd(int *xsks_map_fd)
{
struct sockaddr_un server;
int err;
sock = socket(AF_UNIX, SOCK_STREAM, 0);
if (sock < 0) {
fprintf(stderr, "Error opening socket stream: %s", strerror(errno));
return errno;
}
server.sun_family = AF_UNIX;
strcpy(server.sun_path, SOCKET_NAME);
if (connect(sock, (struct sockaddr *)&server, sizeof(struct sockaddr_un)) < 0) {
close(sock);
fprintf(stderr, "Error connecting stream socket: %s", strerror(errno));
return errno;
}
err = recv_xsks_map_fd_from_ctrl_node(sock, xsks_map_fd);
if (err) {
fprintf(stderr, "Error %d recieving fd\n", err);
return err;
}
return 0;
}
int main(int argc, char **argv)
{
struct __user_cap_header_struct hdr = { _LINUX_CAPABILITY_VERSION_3, 0 };
struct __user_cap_data_struct data[2] = { { 0 } };
struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
bool rx = false, tx = false;
struct xsk_umem_info *umem;
struct bpf_object *obj;
int xsks_map_fd = 0;
pthread_t pt;
int i, ret;
void *bufs;
parse_command_line(argc, argv);
if (opt_num_xsks > 1)
load_xdp_program(argv, &obj);
if (opt_reduced_cap) {
if (capget(&hdr, data) < 0)
fprintf(stderr, "Error getting capabilities\n");
data->effective &= CAP_TO_MASK(CAP_NET_RAW);
data->permitted &= CAP_TO_MASK(CAP_NET_RAW);
if (capset(&hdr, data) < 0)
fprintf(stderr, "Setting capabilities failed\n");
if (capget(&hdr, data) < 0) {
fprintf(stderr, "Error getting capabilities\n");
} else {
fprintf(stderr, "Capabilities EFF %x Caps INH %x Caps Per %x\n",
data[0].effective, data[0].inheritable, data[0].permitted);
fprintf(stderr, "Capabilities EFF %x Caps INH %x Caps Per %x\n",
data[1].effective, data[1].inheritable, data[1].permitted);
}
} else {
if (setrlimit(RLIMIT_MEMLOCK, &r)) {
fprintf(stderr, "ERROR: setrlimit(RLIMIT_MEMLOCK) \"%s\"\n",
strerror(errno));
exit(EXIT_FAILURE);
}
if (opt_num_xsks > 1)
load_xdp_program(argv, &obj);
}
/* Reserve memory for the umem. Use hugepages if unaligned chunk mode */
bufs = mmap(NULL, NUM_FRAMES * opt_xsk_frame_size,
@ -1534,6 +1653,21 @@ int main(int argc, char **argv)
if (opt_num_xsks > 1 && opt_bench != BENCH_TXONLY)
enter_xsks_into_map(obj);
if (opt_reduced_cap) {
ret = recv_xsks_map_fd(&xsks_map_fd);
if (ret) {
fprintf(stderr, "Error %d receiving xsks_map_fd\n", ret);
exit_with_error(ret);
}
if (xsks[0]->xsk) {
ret = xsk_socket__update_xskmap(xsks[0]->xsk, xsks_map_fd);
if (ret) {
fprintf(stderr, "Update of BPF map failed(%d)\n", ret);
exit_with_error(ret);
}
}
}
signal(SIGINT, int_exit);
signal(SIGTERM, int_exit);
signal(SIGABRT, int_exit);