samples: bpf: Convert xdp_redirect_map_multi to XDP samples helper

Use the libbpf skeleton facility and other utilities provided by XDP
samples helper. Also adapt to change of type of mac address map, so that
no resizing is required.

Add a new flag for sample mask that skips priting the
from_device->to_device heading for each line, as xdp_redirect_map_multi
may have two devices but the flow of data may be bidirectional, so the
output would be confusing.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210821002010.845777-23-memxor@gmail.com

samples/bpf/Makefile

@@ -39,7 +39,6 @@ tprogs-y += lwt_len_hist
 tprogs-y += xdp_tx_iptunnel
 tprogs-y += test_map_in_map
 tprogs-y += per_socket_stats_example
-tprogs-y += xdp_redirect_map_multi
 tprogs-y += xdp_rxq_info
 tprogs-y += syscall_tp
 tprogs-y += cpustat
@@ -54,6 +53,7 @@ tprogs-y += ibumad
 tprogs-y += hbm
 
 tprogs-y += xdp_redirect_cpu
+tprogs-y += xdp_redirect_map_multi
 tprogs-y += xdp_redirect_map
 tprogs-y += xdp_redirect
 tprogs-y += xdp_monitor
@@ -100,7 +100,6 @@ lwt_len_hist-objs := lwt_len_hist_user.o
 xdp_tx_iptunnel-objs := xdp_tx_iptunnel_user.o
 test_map_in_map-objs := test_map_in_map_user.o
 per_socket_stats_example-objs := cookie_uid_helper_example.o
-xdp_redirect_map_multi-objs := xdp_redirect_map_multi_user.o
 xdp_rxq_info-objs := xdp_rxq_info_user.o
 syscall_tp-objs := syscall_tp_user.o
 cpustat-objs := cpustat_user.o
@@ -114,6 +113,7 @@ xdp_sample_pkts-objs := xdp_sample_pkts_user.o
 ibumad-objs := ibumad_user.o
 hbm-objs := hbm.o $(CGROUP_HELPERS)
 
+xdp_redirect_map_multi-objs := xdp_redirect_map_multi_user.o $(XDP_SAMPLE)
 xdp_redirect_cpu-objs := xdp_redirect_cpu_user.o $(XDP_SAMPLE)
 xdp_redirect_map-objs := xdp_redirect_map_user.o $(XDP_SAMPLE)
 xdp_redirect-objs := xdp_redirect_user.o $(XDP_SAMPLE)
@@ -310,6 +310,7 @@ $(BPF_SAMPLES_PATH)/*.c: verify_target_bpf $(LIBBPF)
 $(src)/*.c: verify_target_bpf $(LIBBPF)
 
 $(obj)/xdp_redirect_cpu_user.o: $(obj)/xdp_redirect_cpu.skel.h
+$(obj)/xdp_redirect_map_multi_user.o: $(obj)/xdp_redirect_map_multi.skel.h
 $(obj)/xdp_redirect_map_user.o: $(obj)/xdp_redirect_map.skel.h
 $(obj)/xdp_redirect_user.o: $(obj)/xdp_redirect.skel.h
 $(obj)/xdp_monitor_user.o: $(obj)/xdp_monitor.skel.h

samples/bpf/xdp_redirect_map_multi_user.c

 // SPDX-License-Identifier: GPL-2.0
+static const char *__doc__ =
+"XDP multi redirect tool, using BPF_MAP_TYPE_DEVMAP and BPF_F_BROADCAST flag for bpf_redirect_map\n"
+"Usage: xdp_redirect_map_multi <IFINDEX|IFNAME> <IFINDEX|IFNAME> ... <IFINDEX|IFNAME>\n";
+
 #include <linux/bpf.h>
 #include <linux/if_link.h>
 #include <assert.h>
+#include <getopt.h>
 #include <errno.h>
 #include <signal.h>
 #include <stdio.h>
@@ -15,106 +20,54 @@
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <netinet/in.h>
-
-#include "bpf_util.h"
+#include <linux/if_ether.h>
 #include <bpf/bpf.h>
 #include <bpf/libbpf.h>
+#include "bpf_util.h"
+#include "xdp_sample_user.h"
+#include "xdp_redirect_map_multi.skel.h"
 
 #define MAX_IFACE_NUM 32
-
-static __u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
 static int ifaces[MAX_IFACE_NUM] = {};
-static int rxcnt_map_fd;
-
-static void int_exit(int sig)
-{
-	__u32 prog_id = 0;
-	int i;
-
-	for (i = 0; ifaces[i] > 0; i++) {
-		if (bpf_get_link_xdp_id(ifaces[i], &prog_id, xdp_flags)) {
-			printf("bpf_get_link_xdp_id failed\n");
-			exit(1);
-		}
-		if (prog_id)
-			bpf_set_link_xdp_fd(ifaces[i], -1, xdp_flags);
-	}
-
-	exit(0);
-}
-
-static void poll_stats(int interval)
-{
-	unsigned int nr_cpus = bpf_num_possible_cpus();
-	__u64 values[nr_cpus], prev[nr_cpus];
-
-	memset(prev, 0, sizeof(prev));
-
-	while (1) {
-		__u64 sum = 0;
-		__u32 key = 0;
-		int i;
-
-		sleep(interval);
-		assert(bpf_map_lookup_elem(rxcnt_map_fd, &key, values) == 0);
-		for (i = 0; i < nr_cpus; i++)
-			sum += (values[i] - prev[i]);
-		if (sum)
-			printf("Forwarding %10llu pkt/s\n", sum / interval);
-		memcpy(prev, values, sizeof(values));
-	}
-}
-
-static int get_mac_addr(unsigned int ifindex, void *mac_addr)
-{
-	char ifname[IF_NAMESIZE];
-	struct ifreq ifr;
-	int fd, ret = -1;
-
-	fd = socket(AF_INET, SOCK_DGRAM, 0);
-	if (fd < 0)
-		return ret;
-
-	if (!if_indextoname(ifindex, ifname))
-		goto err_out;
-
-	strcpy(ifr.ifr_name, ifname);
 
-	if (ioctl(fd, SIOCGIFHWADDR, &ifr) != 0)
-		goto err_out;
+static int mask = SAMPLE_RX_CNT | SAMPLE_REDIRECT_ERR_MAP_CNT |
+		  SAMPLE_EXCEPTION_CNT | SAMPLE_DEVMAP_XMIT_CNT |
+		  SAMPLE_DEVMAP_XMIT_CNT_MULTI | SAMPLE_SKIP_HEADING;
 
-	memcpy(mac_addr, ifr.ifr_hwaddr.sa_data, 6 * sizeof(char));
-	ret = 0;
+DEFINE_SAMPLE_INIT(xdp_redirect_map_multi);
 
-err_out:
-	close(fd);
-	return ret;
-}
+static const struct option long_options[] = {
+	{ "help", no_argument, NULL, 'h' },
+	{ "skb-mode", no_argument, NULL, 'S' },
+	{ "force", no_argument, NULL, 'F' },
+	{ "load-egress", no_argument, NULL, 'X' },
+	{ "stats", no_argument, NULL, 's' },
+	{ "interval", required_argument, NULL, 'i' },
+	{ "verbose", no_argument, NULL, 'v' },
+	{}
+};
 
-static int update_mac_map(struct bpf_object *obj)
+static int update_mac_map(struct bpf_map *map)
 {
-	int i, ret = -1, mac_map_fd;
+	int mac_map_fd = bpf_map__fd(map);
 	unsigned char mac_addr[6];
 	unsigned int ifindex;
-
-	mac_map_fd = bpf_object__find_map_fd_by_name(obj, "mac_map");
-	if (mac_map_fd < 0) {
-		printf("find mac map fd failed\n");
-		return ret;
-	}
+	int i, ret = -1;
 
 	for (i = 0; ifaces[i] > 0; i++) {
 		ifindex = ifaces[i];
 
 		ret = get_mac_addr(ifindex, mac_addr);
 		if (ret < 0) {
-			printf("get interface %d mac failed\n", ifindex);
+			fprintf(stderr, "get interface %d mac failed\n",
+				ifindex);
 			return ret;
 		}
 
 		ret = bpf_map_update_elem(mac_map_fd, &ifindex, mac_addr, 0);
-		if (ret) {
-			perror("bpf_update_elem mac_map_fd");
+		if (ret < 0) {
+			fprintf(stderr, "Failed to update mac address for ifindex %d\n",
+				ifindex);
 			return ret;
 		}
 	}
@@ -122,181 +75,159 @@ static int update_mac_map(struct bpf_object *obj)
 	return 0;
 }
 
-static void usage(const char *prog)
-{
-	fprintf(stderr,
-		"usage: %s [OPTS] <IFNAME|IFINDEX> <IFNAME|IFINDEX> ...\n"
-		"OPTS:\n"
-		"    -S    use skb-mode\n"
-		"    -N    enforce native mode\n"
-		"    -F    force loading prog\n"
-		"    -X    load xdp program on egress\n",
-		prog);
-}
-
 int main(int argc, char **argv)
 {
-	int i, ret, opt, forward_map_fd, max_ifindex = 0;
-	struct bpf_program *ingress_prog, *egress_prog;
-	int ingress_prog_fd, egress_prog_fd = 0;
-	struct bpf_devmap_val devmap_val;
-	bool attach_egress_prog = false;
+	struct bpf_devmap_val devmap_val = {};
+	struct xdp_redirect_map_multi *skel;
+	struct bpf_program *ingress_prog;
+	bool xdp_devmap_attached = false;
+	struct bpf_map *forward_map;
+	int ret = EXIT_FAIL_OPTION;
+	unsigned long interval = 2;
 	char ifname[IF_NAMESIZE];
-	struct bpf_map *mac_map;
-	struct bpf_object *obj;
 	unsigned int ifindex;
-	char filename[256];
-
-	while ((opt = getopt(argc, argv, "SNFX")) != -1) {
+	bool generic = false;
+	bool force = false;
+	bool tried = false;
+	bool error = true;
+	int i, opt;
+
+	while ((opt = getopt_long(argc, argv, "hSFXi:vs",
+				  long_options, NULL)) != -1) {
 		switch (opt) {
 		case 'S':
-			xdp_flags |= XDP_FLAGS_SKB_MODE;
-			break;
-		case 'N':
-			/* default, set below */
+			generic = true;
+			/* devmap_xmit tracepoint not available */
+			mask &= ~(SAMPLE_DEVMAP_XMIT_CNT |
+				  SAMPLE_DEVMAP_XMIT_CNT_MULTI);
 			break;
 		case 'F':
-			xdp_flags &= ~XDP_FLAGS_UPDATE_IF_NOEXIST;
+			force = true;
 			break;
 		case 'X':
-			attach_egress_prog = true;
+			xdp_devmap_attached = true;
+			break;
+		case 'i':
+			interval = strtoul(optarg, NULL, 0);
+			break;
+		case 'v':
+			sample_switch_mode();
 			break;
+		case 's':
+			mask |= SAMPLE_REDIRECT_MAP_CNT;
+			break;
+		case 'h':
+			error = false;
 		default:
-			usage(basename(argv[0]));
-			return 1;
+			sample_usage(argv, long_options, __doc__, mask, error);
+			return ret;
 		}
 	}
 
-	if (!(xdp_flags & XDP_FLAGS_SKB_MODE)) {
-		xdp_flags |= XDP_FLAGS_DRV_MODE;
-	} else if (attach_egress_prog) {
-		printf("Load xdp program on egress with SKB mode not supported yet\n");
-		return 1;
+	if (argc <= optind + 1) {
+		sample_usage(argv, long_options, __doc__, mask, error);
+		return ret;
+	}
+
+	skel = xdp_redirect_map_multi__open();
+	if (!skel) {
+		fprintf(stderr, "Failed to xdp_redirect_map_multi__open: %s\n",
+			strerror(errno));
+		ret = EXIT_FAIL_BPF;
+		goto end;
 	}
 
-	if (optind == argc) {
-		printf("usage: %s <IFNAME|IFINDEX> <IFNAME|IFINDEX> ...\n", argv[0]);
-		return 1;
+	ret = sample_init_pre_load(skel);
+	if (ret < 0) {
+		fprintf(stderr, "Failed to sample_init_pre_load: %s\n", strerror(-ret));
+		ret = EXIT_FAIL_BPF;
+		goto end_destroy;
 	}
 
-	printf("Get interfaces");
+	ret = EXIT_FAIL_OPTION;
 	for (i = 0; i < MAX_IFACE_NUM && argv[optind + i]; i++) {
 		ifaces[i] = if_nametoindex(argv[optind + i]);
 		if (!ifaces[i])
 			ifaces[i] = strtoul(argv[optind + i], NULL, 0);
 		if (!if_indextoname(ifaces[i], ifname)) {
-			perror("Invalid interface name or i");
-			return 1;
+			fprintf(stderr, "Bad interface index or name\n");
+			sample_usage(argv, long_options, __doc__, mask, true);
+			goto end_destroy;
 		}
 
-		/* Find the largest index number */
-		if (ifaces[i] > max_ifindex)
-			max_ifindex = ifaces[i];
-
-		printf(" %d", ifaces[i]);
+		skel->rodata->from_match[i] = ifaces[i];
+		skel->rodata->to_match[i] = ifaces[i];
 	}
-	printf("\n");
 
-	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
-
-	obj = bpf_object__open(filename);
-	if (libbpf_get_error(obj)) {
-		printf("ERROR: opening BPF object file failed\n");
-		obj = NULL;
-		goto err_out;
-	}
-
-	/* Reset the map size to max ifindex + 1 */
-	if (attach_egress_prog) {
-		mac_map = bpf_object__find_map_by_name(obj, "mac_map");
-		ret = bpf_map__resize(mac_map, max_ifindex + 1);
+	ret = xdp_redirect_map_multi__load(skel);
 	if (ret < 0) {
-			printf("ERROR: reset mac map size failed\n");
-			goto err_out;
-		}
-	}
-
-	/* load BPF program */
-	if (bpf_object__load(obj)) {
-		printf("ERROR: loading BPF object file failed\n");
-		goto err_out;
+		fprintf(stderr, "Failed to xdp_redirect_map_multi__load: %s\n",
+			strerror(errno));
+		ret = EXIT_FAIL_BPF;
+		goto end_destroy;
 	}
 
-	if (xdp_flags & XDP_FLAGS_SKB_MODE) {
-		ingress_prog = bpf_object__find_program_by_name(obj, "xdp_redirect_map_general");
-		forward_map_fd = bpf_object__find_map_fd_by_name(obj, "forward_map_general");
-	} else {
-		ingress_prog = bpf_object__find_program_by_name(obj, "xdp_redirect_map_native");
-		forward_map_fd = bpf_object__find_map_fd_by_name(obj, "forward_map_native");
-	}
-	if (!ingress_prog || forward_map_fd < 0) {
-		printf("finding ingress_prog/forward_map in obj file failed\n");
-		goto err_out;
-	}
-
-	ingress_prog_fd = bpf_program__fd(ingress_prog);
-	if (ingress_prog_fd < 0) {
-		printf("find ingress_prog fd failed\n");
-		goto err_out;
-	}
-
-	rxcnt_map_fd = bpf_object__find_map_fd_by_name(obj, "rxcnt");
-	if (rxcnt_map_fd < 0) {
-		printf("bpf_object__find_map_fd_by_name failed\n");
-		goto err_out;
-	}
-
-	if (attach_egress_prog) {
+	if (xdp_devmap_attached) {
 		/* Update mac_map with all egress interfaces' mac addr */
-		if (update_mac_map(obj) < 0) {
-			printf("Error: update mac map failed");
-			goto err_out;
-		}
-
-		/* Find egress prog fd */
-		egress_prog = bpf_object__find_program_by_name(obj, "xdp_devmap_prog");
-		if (!egress_prog) {
-			printf("finding egress_prog in obj file failed\n");
-			goto err_out;
+		if (update_mac_map(skel->maps.mac_map) < 0) {
+			fprintf(stderr, "Updating mac address failed\n");
+			ret = EXIT_FAIL;
+			goto end_destroy;
 		}
-		egress_prog_fd = bpf_program__fd(egress_prog);
-		if (egress_prog_fd < 0) {
-			printf("find egress_prog fd failed\n");
-			goto err_out;
 	}
+
+	ret = sample_init(skel, mask);
+	if (ret < 0) {
+		fprintf(stderr, "Failed to initialize sample: %s\n", strerror(-ret));
+		ret = EXIT_FAIL;
+		goto end_destroy;
 	}
 
-	/* Remove attached program when program is interrupted or killed */
-	signal(SIGINT, int_exit);
-	signal(SIGTERM, int_exit);
+	ingress_prog = skel->progs.xdp_redirect_map_native;
+	forward_map = skel->maps.forward_map_native;
 
-	/* Init forward multicast groups */
 	for (i = 0; ifaces[i] > 0; i++) {
 		ifindex = ifaces[i];
 
+		ret = EXIT_FAIL_XDP;
+restart:
 		/* bind prog_fd to each interface */
-		ret = bpf_set_link_xdp_fd(ifindex, ingress_prog_fd, xdp_flags);
-		if (ret) {
-			printf("Set xdp fd failed on %d\n", ifindex);
-			goto err_out;
+		if (sample_install_xdp(ingress_prog, ifindex, generic, force) < 0) {
+			if (generic && !tried) {
+				fprintf(stderr,
+					"Trying fallback to sizeof(int) as value_size for devmap in generic mode\n");
+				ingress_prog = skel->progs.xdp_redirect_map_general;
+				forward_map = skel->maps.forward_map_general;
+				tried = true;
+				goto restart;
+			}
+			goto end_destroy;
 		}
 
 		/* Add all the interfaces to forward group and attach
-		 * egress devmap programe if exist
+		 * egress devmap program if exist
 		 */
 		devmap_val.ifindex = ifindex;
-		devmap_val.bpf_prog.fd = egress_prog_fd;
-		ret = bpf_map_update_elem(forward_map_fd, &ifindex, &devmap_val, 0);
-		if (ret) {
-			perror("bpf_map_update_elem forward_map");
-			goto err_out;
+		if (xdp_devmap_attached)
+			devmap_val.bpf_prog.fd = bpf_program__fd(skel->progs.xdp_devmap_prog);
+		ret = bpf_map_update_elem(bpf_map__fd(forward_map), &ifindex, &devmap_val, 0);
+		if (ret < 0) {
+			fprintf(stderr, "Failed to update devmap value: %s\n",
+				strerror(errno));
+			ret = EXIT_FAIL_BPF;
+			goto end_destroy;
 		}
 	}
 
-	poll_stats(2);
-
-	return 0;
-
-err_out:
-	return 1;
+	ret = sample_run(interval, NULL, NULL);
+	if (ret < 0) {
+		fprintf(stderr, "Failed during sample run: %s\n", strerror(-ret));
+		ret = EXIT_FAIL;
+		goto end_destroy;
+	}
+	ret = EXIT_OK;
+end_destroy:
+	xdp_redirect_map_multi__destroy(skel);
+end:
+	sample_exit(ret);
 }

samples/bpf/xdp_sample_user.c

@@ -1510,7 +1510,7 @@ static int sample_timer_cb(int timerfd, struct stats_record **rec,
 	if (ret < 0)
 		return ret;
 
-	if (sample_xdp_cnt == 2) {
+	if (sample_xdp_cnt == 2 && !(sample_mask & SAMPLE_SKIP_HEADING)) {
 		char fi[IFNAMSIZ];
 		char to[IFNAMSIZ];
 		const char *f, *t;

samples/bpf/xdp_sample_user.h

@@ -19,6 +19,7 @@ enum stats_mask {
 	SAMPLE_REDIRECT_MAP_CNT      = SAMPLE_REDIRECT_CNT | _SAMPLE_REDIRECT_MAP,
 	SAMPLE_REDIRECT_ERR_MAP_CNT  = SAMPLE_REDIRECT_ERR_CNT | _SAMPLE_REDIRECT_MAP,
 	SAMPLE_DEVMAP_XMIT_CNT_MULTI = 1U << 8,
+	SAMPLE_SKIP_HEADING	     = 1U << 9,
 };
 
 /* Exit return codes */