samples/bpf: Convert XDP samples to libbpf usage

Some of XDP samples that are attaching the bpf program to the interface
via libbpf's bpf_set_link_xdp_fd are still using the bpf_load.c for
loading and manipulating the ebpf program and maps. Convert them to do
this through libbpf usage and remove bpf_load from the picture.

While at it remove what looks like debug leftover in
xdp_redirect_map_user.c

In xdp_redirect_cpu, change the way that the program to be loaded onto
interface is chosen - user now needs to pass the program's section name
instead of the relative number. In case of typo print out the section
names to choose from.

Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

1 files changed, 54 insertions, 21 deletions

diff --git a/samples/bpf/xdp_router_ipv4_user.c b/samples/bpf/xdp_router_ipv4_user.c
index b2b4dfa776c8..cea2306f5ab7 100644
--- a/samples/bpf/xdp_router_ipv4_user.c
+++ b/samples/bpf/xdp_router_ipv4_user.c
@@ -15,7 +15,6 @@
 #include <string.h>
 #include <sys/socket.h>
 #include <unistd.h>
-#include "bpf_load.h"
 #include <bpf/bpf.h>
 #include <arpa/inet.h>
 #include <fcntl.h>
@@ -25,11 +24,17 @@
 #include <sys/ioctl.h>
 #include <sys/syscall.h>
 #include "bpf_util.h"
+#include "bpf/libbpf.h"
 
 int sock, sock_arp, flags = 0;
 static int total_ifindex;
 int *ifindex_list;
 char buf[8192];
+static int lpm_map_fd;
+static int rxcnt_map_fd;
+static int arp_table_map_fd;
+static int exact_match_map_fd;
+static int tx_port_map_fd;
 
 static int get_route_table(int rtm_family);
 static void int_exit(int sig)
@@ -186,7 +191,8 @@ static void read_route(struct nlmsghdr *nh, int nll)
 				bpf_set_link_xdp_fd(ifindex_list[i], -1, flags);
 			exit(0);
 		}
-		assert(bpf_map_update_elem(map_fd[4], &route.iface, &route.iface, 0) == 0);
+		assert(bpf_map_update_elem(tx_port_map_fd,
+					   &route.iface, &route.iface, 0) == 0);
 		if (rtm_family == AF_INET) {
 			struct trie_value {
 				__u8 prefix[4];
@@ -207,11 +213,16 @@ static void read_route(struct nlmsghdr *nh, int nll)
 			direct_entry.arp.dst = 0;
 			if (route.dst_len == 32) {
 				if (nh->nlmsg_type == RTM_DELROUTE) {
-					assert(bpf_map_delete_elem(map_fd[3], &route.dst) == 0);
+					assert(bpf_map_delete_elem(exact_match_map_fd,
+								   &route.dst) == 0);
 				} else {
-					if (bpf_map_lookup_elem(map_fd[2], &route.dst, &direct_entry.arp.mac) == 0)
+					if (bpf_map_lookup_elem(arp_table_map_fd,
+								&route.dst,
+								&direct_entry.arp.mac) == 0)
 						direct_entry.arp.dst = route.dst;
-					assert(bpf_map_update_elem(map_fd[3], &route.dst, &direct_entry, 0) == 0);
+					assert(bpf_map_update_elem(exact_match_map_fd,
+								   &route.dst,
+								   &direct_entry, 0) == 0);
 				}
 			}
 			for (i = 0; i < 4; i++)
@@ -225,7 +236,7 @@ static void read_route(struct nlmsghdr *nh, int nll)
 			       route.gw, route.dst_len,
 			       route.metric,
 			       route.iface_name);
-			if (bpf_map_lookup_elem(map_fd[0], prefix_key,
+			if (bpf_map_lookup_elem(lpm_map_fd, prefix_key,
 						prefix_value) < 0) {
 				for (i = 0; i < 4; i++)
 					prefix_value->prefix[i] = prefix_key->data[i];
@@ -234,7 +245,7 @@ static void read_route(struct nlmsghdr *nh, int nll)
 				prefix_value->gw = route.gw;
 				prefix_value->metric = route.metric;
 
-				assert(bpf_map_update_elem(map_fd[0],
+				assert(bpf_map_update_elem(lpm_map_fd,
 							   prefix_key,
 							   prefix_value, 0
 							   ) == 0);
@@ -247,7 +258,7 @@ static void read_route(struct nlmsghdr *nh, int nll)
 					       prefix_key->data[2],
 					       prefix_key->data[3],
 					       prefix_key->prefixlen);
-					assert(bpf_map_delete_elem(map_fd[0],
+					assert(bpf_map_delete_elem(lpm_map_fd,
 								   prefix_key
 								   ) == 0);
 					/* Rereading the route table to check if
@@ -275,8 +286,7 @@ static void read_route(struct nlmsghdr *nh, int nll)
 					prefix_value->ifindex = route.iface;
 					prefix_value->gw = route.gw;
 					prefix_value->metric = route.metric;
-					assert(bpf_map_update_elem(
-								   map_fd[0],
+					assert(bpf_map_update_elem(lpm_map_fd,
 								   prefix_key,
 								   prefix_value,
 								   0) == 0);
@@ -401,7 +411,8 @@ static void read_arp(struct nlmsghdr *nh, int nll)
 		arp_entry.mac = atol(mac);
 		printf("%x\t\t%llx\n", arp_entry.dst, arp_entry.mac);
 		if (ndm_family == AF_INET) {
-			if (bpf_map_lookup_elem(map_fd[3], &arp_entry.dst,
+			if (bpf_map_lookup_elem(exact_match_map_fd,
+						&arp_entry.dst,
 						&direct_entry) == 0) {
 				if (nh->nlmsg_type == RTM_DELNEIGH) {
 					direct_entry.arp.dst = 0;
@@ -410,16 +421,17 @@ static void read_arp(struct nlmsghdr *nh, int nll)
 					direct_entry.arp.dst = arp_entry.dst;
 					direct_entry.arp.mac = arp_entry.mac;
 				}
-				assert(bpf_map_update_elem(map_fd[3],
+				assert(bpf_map_update_elem(exact_match_map_fd,
 							   &arp_entry.dst,
 							   &direct_entry, 0
 							   ) == 0);
 				memset(&direct_entry, 0, sizeof(direct_entry));
 			}
 			if (nh->nlmsg_type == RTM_DELNEIGH) {
-				assert(bpf_map_delete_elem(map_fd[2], &arp_entry.dst) == 0);
+				assert(bpf_map_delete_elem(arp_table_map_fd,
+							   &arp_entry.dst) == 0);
 			} else if (nh->nlmsg_type == RTM_NEWNEIGH) {
-				assert(bpf_map_update_elem(map_fd[2],
+				assert(bpf_map_update_elem(arp_table_map_fd,
 							   &arp_entry.dst,
 							   &arp_entry.mac, 0
 							   ) == 0);
@@ -553,7 +565,8 @@ static int monitor_route(void)
 		for (key = 0; key < nr_keys; key++) {
 			__u64 sum = 0;
 
-			assert(bpf_map_lookup_elem(map_fd[1], &key, values) == 0);
+			assert(bpf_map_lookup_elem(rxcnt_map_fd,
+						   &key, values) == 0);
 			for (i = 0; i < nr_cpus; i++)
 				sum += (values[i] - prev[key][i]);
 			if (sum)
@@ -596,11 +609,18 @@ cleanup:
 
 int main(int ac, char **argv)
 {
+	struct bpf_prog_load_attr prog_load_attr = {
+		.prog_type	= BPF_PROG_TYPE_XDP,
+	};
+	struct bpf_object *obj;
 	char filename[256];
 	char **ifname_list;
+	int prog_fd;
 	int i = 1;
 
 	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+	prog_load_attr.file = filename;
+
 	if (ac < 2) {
 		printf("usage: %s [-S] Interface name list\n", argv[0]);
 		return 1;
@@ -614,15 +634,28 @@ int main(int ac, char **argv)
 		total_ifindex = ac - 1;
 		ifname_list = (argv + 1);
 	}
-	if (load_bpf_file(filename)) {
-		printf("%s", bpf_log_buf);
+
+	if (bpf_prog_load_xattr(&prog_load_attr, &obj, &prog_fd))
 		return 1;
-	}
+
 	printf("\n**************loading bpf file*********************\n\n\n");
-	if (!prog_fd[0]) {
-		printf("load_bpf_file: %s\n", strerror(errno));
+	if (!prog_fd) {
+		printf("bpf_prog_load_xattr: %s\n", strerror(errno));
 		return 1;
 	}
+
+	lpm_map_fd = bpf_object__find_map_fd_by_name(obj, "lpm_map");
+	rxcnt_map_fd = bpf_object__find_map_fd_by_name(obj, "rxcnt");
+	arp_table_map_fd = bpf_object__find_map_fd_by_name(obj, "arp_table");
+	exact_match_map_fd = bpf_object__find_map_fd_by_name(obj,
+							     "exact_match");
+	tx_port_map_fd = bpf_object__find_map_fd_by_name(obj, "tx_port");
+	if (lpm_map_fd < 0 || rxcnt_map_fd < 0 || arp_table_map_fd < 0 ||
+	    exact_match_map_fd < 0 || tx_port_map_fd < 0) {
+		printf("bpf_object__find_map_fd_by_name failed\n");
+		return 1;
+	}
+
 	ifindex_list = (int *)malloc(total_ifindex * sizeof(int *));
 	for (i = 0; i < total_ifindex; i++) {
 		ifindex_list[i] = if_nametoindex(ifname_list[i]);
@@ -633,7 +666,7 @@ int main(int ac, char **argv)
 		}
 	}
 	for (i = 0; i < total_ifindex; i++) {
-		if (bpf_set_link_xdp_fd(ifindex_list[i], prog_fd[0], flags) < 0) {
+		if (bpf_set_link_xdp_fd(ifindex_list[i], prog_fd, flags) < 0) {
 			printf("link set xdp fd failed\n");
 			int recovery_index = i;