RE: [PATCH bpf-next 7/7] samples: bpf: add support for XDP_ATTACH to xdpsock

-----Original Message-----
From: Björn Töpel [mailto:bjorn.topel@gmail.com]
Sent: Friday, December 7, 2018 7:45 PM
To: bjorn.topel@gmail.com; Karlsson, Magnus <magnus.karlsson@intel.com>;
magnus.karlsson@gmail.com; ast@kernel.org; daniel@iogearbox.net;
netdev@vger.kernel.org
Cc: Topel, Bjorn <redacted>; brouer@redhat.com;
u9012063@gmail.com; Zhang, Qi Z [off-list ref]
Subject: [PATCH bpf-next 7/7] samples: bpf: add support for XDP_ATTACH to
xdpsock

From: Björn Töpel <redacted>

Teach the sample xdpsock application about XDP_ATTACH.

Signed-off-by: Björn Töpel <redacted>
---
 samples/bpf/xdpsock_user.c | 108 +++++++++++++++++++++++--------------
 1 file changed, 67 insertions(+), 41 deletions(-)

diff --git a/samples/bpf/xdpsock_user.c b/samples/bpf/xdpsock_user.c index

57ecadc58403..12f908b60468 100644

--- a/samples/bpf/xdpsock_user.c
+++ b/samples/bpf/xdpsock_user.c

@@ -633,7 +633,8 @@ static void int_exit(int sig)  {
 	(void)sig;
 	dump_stats();
-	bpf_set_link_xdp_fd(opt_ifindex, -1, opt_xdp_flags);
+	if (!(opt_xdp_bind_flags & XDP_ATTACH))
+		bpf_set_link_xdp_fd(opt_ifindex, -1, opt_xdp_flags);
 	exit(EXIT_SUCCESS);
 }

@@ -650,6 +651,7 @@ static struct option long_options[] = {
 	{"interval", required_argument, 0, 'n'},
 	{"zero-copy", no_argument, 0, 'z'},
 	{"copy", no_argument, 0, 'c'},
+	{"attach", no_argument, 0, 'a'},
 	{0, 0, 0, 0}
 };

@@ -670,6 +672,7 @@ static void usage(const char *prog)
 		"  -n, --interval=n	Specify statistics update interval (default 1

sec).\n"
 		"  -z, --zero-copy      Force zero-copy mode.\n"
 		"  -c, --copy           Force copy mode.\n"
+		"  -a, --attach         XDP_ATTACH mode.\n"
 		"\n";
 	fprintf(stderr, str, prog);
 	exit(EXIT_FAILURE);

@@ -682,7 +685,7 @@ static void parse_command_line(int argc, char **argv)
 	opterr = 0;

 	for (;;) {
-		c = getopt_long(argc, argv, "rtli:q:psSNn:cz", long_options,
+		c = getopt_long(argc, argv, "rtli:q:psSNn:cza", long_options,
 				&option_index);
 		if (c == -1)
 			break;

@@ -725,11 +728,22 @@ static void parse_command_line(int argc, char

**argv)
 		case 'c':
 			opt_xdp_bind_flags |= XDP_COPY;
 			break;
+		case 'a':
+			opt_xdp_bind_flags |= XDP_ATTACH;
+			break;
 		default:
 			usage(basename(argv[0]));
 		}
 	}

+	if (opt_xdp_bind_flags & XDP_ATTACH) {
+		if (opt_xdp_flags & XDP_FLAGS_DRV_MODE)
+			opt_xdp_bind_flags |= XDP_BUILTIN_DRV_MODE;
+		if (opt_xdp_flags & XDP_FLAGS_SKB_MODE)
+			opt_xdp_bind_flags |= XDP_BUILTIN_SKB_MODE;
+
+	}
+
 	opt_ifindex = if_nametoindex(opt_if);
 	if (!opt_ifindex) {
 		fprintf(stderr, "ERROR: interface \"%s\" does not exist\n", @@
-903,7 +917,7 @@ int main(int argc, char **argv)
 	struct bpf_prog_load_attr prog_load_attr = {
 		.prog_type	= BPF_PROG_TYPE_XDP,
 	};
-	int prog_fd, qidconf_map, xsks_map;
+	int prog_fd, qidconf_map, xsks_map = -1;
 	struct bpf_object *obj;
 	char xdp_filename[256];
 	struct bpf_map *map;

@@ -918,59 +932,71 @@ int main(int argc, char **argv)
 		exit(EXIT_FAILURE);
 	}

-	snprintf(xdp_filename, sizeof(xdp_filename), "%s_kern.o", argv[0]);
-	prog_load_attr.file = xdp_filename;
+	if (!(opt_xdp_bind_flags & XDP_ATTACH)) {
+		snprintf(xdp_filename, sizeof(xdp_filename), "%s_kern.o",
+			 argv[0]);
+		prog_load_attr.file = xdp_filename;

-	if (bpf_prog_load_xattr(&prog_load_attr, &obj, &prog_fd))
-		exit(EXIT_FAILURE);
-	if (prog_fd < 0) {
-		fprintf(stderr, "ERROR: no program found: %s\n",
-			strerror(prog_fd));
-		exit(EXIT_FAILURE);
-	}
+		if (bpf_prog_load_xattr(&prog_load_attr, &obj, &prog_fd))
+			exit(EXIT_FAILURE);
+		if (prog_fd < 0) {
+			fprintf(stderr, "ERROR: no program found: %s\n",
+				strerror(prog_fd));
+			exit(EXIT_FAILURE);
+		}

-	map = bpf_object__find_map_by_name(obj, "qidconf_map");
-	qidconf_map = bpf_map__fd(map);
-	if (qidconf_map < 0) {
-		fprintf(stderr, "ERROR: no qidconf map found: %s\n",
-			strerror(qidconf_map));
-		exit(EXIT_FAILURE);
-	}
+		map = bpf_object__find_map_by_name(obj, "qidconf_map");
+		qidconf_map = bpf_map__fd(map);
+		if (qidconf_map < 0) {
+			fprintf(stderr, "ERROR: no qidconf map found: %s\n",
+				strerror(qidconf_map));
+			exit(EXIT_FAILURE);
+		}

-	map = bpf_object__find_map_by_name(obj, "xsks_map");
-	xsks_map = bpf_map__fd(map);
-	if (xsks_map < 0) {
-		fprintf(stderr, "ERROR: no xsks map found: %s\n",
-			strerror(xsks_map));
-		exit(EXIT_FAILURE);
-	}
+		map = bpf_object__find_map_by_name(obj, "xsks_map");
+		xsks_map = bpf_map__fd(map);
+		if (xsks_map < 0) {
+			fprintf(stderr, "ERROR: no xsks map found: %s\n",
+				strerror(xsks_map));
+			exit(EXIT_FAILURE);
+		}

-	if (bpf_set_link_xdp_fd(opt_ifindex, prog_fd, opt_xdp_flags) < 0) {
-		fprintf(stderr, "ERROR: link set xdp fd failed\n");
-		exit(EXIT_FAILURE);
-	}
+		if (bpf_set_link_xdp_fd(opt_ifindex, prog_fd,
+					opt_xdp_flags) < 0) {
+			fprintf(stderr, "ERROR: link set xdp fd failed\n");
+			exit(EXIT_FAILURE);
+		}

-	ret = bpf_map_update_elem(qidconf_map, &key, &opt_queue, 0);
-	if (ret) {
-		fprintf(stderr, "ERROR: bpf_map_update_elem qidconf\n");
-		exit(EXIT_FAILURE);
+		ret = bpf_map_update_elem(qidconf_map, &key, &opt_queue, 0);
+		if (ret) {
+			fprintf(stderr, "ERROR: bpf_map_update_elem qidconf\n");
+			exit(EXIT_FAILURE);
+		}
 	}

 	/* Create sockets... */
 	xsks[num_socks++] = xsk_configure(NULL);

 #if RR_LB
+	if (opt_xdp_bind_flags & XDP_ATTACH)
+		exit(EXIT_FAILURE);
+
 	for (i = 0; i < MAX_SOCKS - 1; i++)
 		xsks[num_socks++] = xsk_configure(xsks[0]->umem);  #endif

-	/* ...and insert them into the map. */
-	for (i = 0; i < num_socks; i++) {
-		key = i;
-		ret = bpf_map_update_elem(xsks_map, &key, &xsks[i]->sfd, 0);
-		if (ret) {
-			fprintf(stderr, "ERROR: bpf_map_update_elem %d\n", i);
-			exit(EXIT_FAILURE);
+	if (!(opt_xdp_bind_flags & XDP_ATTACH)) {
+		/* ...and insert them into the map. */
+		for (i = 0; i < num_socks; i++) {
+			key = i;
+			ret = bpf_map_update_elem(xsks_map, &key,
+						  &xsks[i]->sfd, 0);
+			if (ret) {
+				fprintf(stderr,
+					"ERROR: bpf_map_update_elem %d\n",
+					i);
+				exit(EXIT_FAILURE);
+			}
 		}
 	}

--

2.19.1