[PATCH bpf-next v5 6/8] samples/bpf: Add a "force" flag to XDP samples

From: Maciej Fijalkowski <hidden>
Date: 2019-02-01 00:20:28
Subsystem: bpf [general] (safe dynamic programs and tools), the rest, xdp (express data path) · Maintainers: Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Linus Torvalds, David S. Miller, Jakub Kicinski, Jesper Dangaard Brouer, John Fastabend

Make xdp samples consistent with iproute2 behavior and set the
XDP_FLAGS_UPDATE_IF_NOEXIST by default when setting the xdp program on
interface. Provide an option for user to force the program loading,
which as a result will not include the mentioned flag in
bpf_set_link_xdp_fd call.

Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Reviewed-by: Jakub Kicinski <redacted>
Acked-by: John Fastabend <john.fastabend@gmail.com>
---
 samples/bpf/xdp1_user.c             | 10 +++++---
 samples/bpf/xdp_adjust_tail_user.c  |  8 ++++--
 samples/bpf/xdp_redirect_cpu_user.c |  8 ++++--
 samples/bpf/xdp_redirect_map_user.c | 10 +++++---
 samples/bpf/xdp_redirect_user.c     | 10 +++++---
 samples/bpf/xdp_router_ipv4_user.c  | 50 +++++++++++++++++++++++++++----------
 samples/bpf/xdp_rxq_info_user.c     |  8 ++++--
 samples/bpf/xdp_sample_pkts_user.c  | 40 +++++++++++++++++++++++------
 samples/bpf/xdp_tx_iptunnel_user.c  |  8 ++++--
 samples/bpf/xdpsock_user.c          |  7 ++++--
 10 files changed, 119 insertions(+), 40 deletions(-)

diff --git a/samples/bpf/xdp1_user.c b/samples/bpf/xdp1_user.c
index 8bfda95c77ad..505bce207165 100644
--- a/samples/bpf/xdp1_user.c
+++ b/samples/bpf/xdp1_user.c

@@ -22,7 +22,7 @@
 #include "bpf/libbpf.h"
 
 static int ifindex;
-static __u32 xdp_flags;
+static __u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
 
 static void int_exit(int sig)
 {

@@ -63,7 +63,8 @@ static void usage(const char *prog)
 		"usage: %s [OPTS] IFACE\n\n"
 		"OPTS:\n"
 		"    -S    use skb-mode\n"
-		"    -N    enforce native mode\n",
+		"    -N    enforce native mode\n"
+		"    -F    force loading prog\n",
 		prog);
 }

@@ -73,7 +74,7 @@ int main(int argc, char **argv)
 	struct bpf_prog_load_attr prog_load_attr = {
 		.prog_type	= BPF_PROG_TYPE_XDP,
 	};
-	const char *optstr = "SN";
+	const char *optstr = "FSN";
 	int prog_fd, map_fd, opt;
 	struct bpf_object *obj;
 	struct bpf_map *map;

@@ -87,6 +88,9 @@ int main(int argc, char **argv)
 		case 'N':
 			xdp_flags |= XDP_FLAGS_DRV_MODE;
 			break;
+		case 'F':
+			xdp_flags &= ~XDP_FLAGS_UPDATE_IF_NOEXIST;
+			break;
 		default:
 			usage(basename(argv[0]));
 			return 1;

diff --git a/samples/bpf/xdp_adjust_tail_user.c b/samples/bpf/xdp_adjust_tail_user.c
index 3042ce37dae8..049bddf7778b 100644
--- a/samples/bpf/xdp_adjust_tail_user.c
+++ b/samples/bpf/xdp_adjust_tail_user.c

@@ -24,7 +24,7 @@
 #define STATS_INTERVAL_S 2U
 
 static int ifindex = -1;
-static __u32 xdp_flags;
+static __u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
 
 static void int_exit(int sig)
 {

@@ -60,6 +60,7 @@ static void usage(const char *cmd)
 	printf("    -T <stop-after-X-seconds> Default: 0 (forever)\n");
 	printf("    -S use skb-mode\n");
 	printf("    -N enforce native mode\n");
+	printf("    -F force loading prog\n");
 	printf("    -h Display this help\n");
 }

@@ -70,8 +71,8 @@ int main(int argc, char **argv)
 		.prog_type	= BPF_PROG_TYPE_XDP,
 	};
 	unsigned char opt_flags[256] = {};
+	const char *optstr = "i:T:SNFh";
 	unsigned int kill_after_s = 0;
-	const char *optstr = "i:T:SNh";
 	int i, prog_fd, map_fd, opt;
 	struct bpf_object *obj;
 	struct bpf_map *map;

@@ -96,6 +97,9 @@ int main(int argc, char **argv)
 		case 'N':
 			xdp_flags |= XDP_FLAGS_DRV_MODE;
 			break;
+		case 'F':
+			xdp_flags &= ~XDP_FLAGS_UPDATE_IF_NOEXIST;
+			break;
 		default:
 			usage(argv[0]);
 			return 1;

diff --git a/samples/bpf/xdp_redirect_cpu_user.c b/samples/bpf/xdp_redirect_cpu_user.c
index 8645ddc2da0e..0224afb55845 100644
--- a/samples/bpf/xdp_redirect_cpu_user.c
+++ b/samples/bpf/xdp_redirect_cpu_user.c

@@ -33,7 +33,7 @@ static int ifindex = -1;
 static char ifname_buf[IF_NAMESIZE];
 static char *ifname;
 
-static __u32 xdp_flags;
+static __u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
 static int cpu_map_fd;
 static int rx_cnt_map_fd;
 static int redirect_err_cnt_map_fd;

@@ -62,6 +62,7 @@ static const struct option long_options[] = {
 	{"cpu",		required_argument,	NULL, 'c' },
 	{"stress-mode", no_argument,		NULL, 'x' },
 	{"no-separators", no_argument,		NULL, 'z' },
+	{"force",	no_argument,		NULL, 'F' },
 	{0, 0, NULL,  0 }
 };

@@ -651,7 +652,7 @@ int main(int argc, char **argv)
 	mark_cpus_unavailable();
 
 	/* Parse commands line args */
-	while ((opt = getopt_long(argc, argv, "hSd:",
+	while ((opt = getopt_long(argc, argv, "hSd:s:p:q:c:xzF",
 				  long_options, &longindex)) != -1) {
 		switch (opt) {
 		case 'd':

@@ -700,6 +701,9 @@ int main(int argc, char **argv)
 		case 'q':
 			qsize = atoi(optarg);
 			break;
+		case 'F':
+			xdp_flags &= ~XDP_FLAGS_UPDATE_IF_NOEXIST;
+			break;
 		case 'h':
 		error:
 		default:

diff --git a/samples/bpf/xdp_redirect_map_user.c b/samples/bpf/xdp_redirect_map_user.c
index 60d46eea225b..470e1a7e8810 100644
--- a/samples/bpf/xdp_redirect_map_user.c
+++ b/samples/bpf/xdp_redirect_map_user.c

@@ -30,7 +30,7 @@ static int ifindex_in;
 static int ifindex_out;
 static bool ifindex_out_xdp_dummy_attached = true;
 
-static __u32 xdp_flags;
+static __u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
 static int rxcnt_map_fd;
 
 static void int_exit(int sig)

@@ -70,7 +70,8 @@ static void usage(const char *prog)
 		"usage: %s [OPTS] IFINDEX_IN IFINDEX_OUT\n\n"
 		"OPTS:\n"
 		"    -S    use skb-mode\n"
-		"    -N    enforce native mode\n",
+		"    -N    enforce native mode\n"
+		"    -F    force loading prog\n",
 		prog);
 }

@@ -82,7 +83,7 @@ int main(int argc, char **argv)
 	};
 	struct bpf_program *prog, *dummy_prog;
 	int prog_fd, dummy_prog_fd;
-	const char *optstr = "SN";
+	const char *optstr = "FSN";
 	struct bpf_object *obj;
 	int ret, opt, key = 0;
 	char filename[256];

@@ -96,6 +97,9 @@ int main(int argc, char **argv)
 		case 'N':
 			xdp_flags |= XDP_FLAGS_DRV_MODE;
 			break;
+		case 'F':
+			xdp_flags &= ~XDP_FLAGS_UPDATE_IF_NOEXIST;
+			break;
 		default:
 			usage(basename(argv[0]));
 			return 1;

diff --git a/samples/bpf/xdp_redirect_user.c b/samples/bpf/xdp_redirect_user.c
index 93404820df68..be6058cda97c 100644
--- a/samples/bpf/xdp_redirect_user.c
+++ b/samples/bpf/xdp_redirect_user.c

@@ -30,7 +30,7 @@ static int ifindex_in;
 static int ifindex_out;
 static bool ifindex_out_xdp_dummy_attached = true;
 
-static __u32 xdp_flags;
+static __u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
 static int rxcnt_map_fd;
 
 static void int_exit(int sig)

@@ -70,7 +70,8 @@ static void usage(const char *prog)
 		"usage: %s [OPTS] IFINDEX_IN IFINDEX_OUT\n\n"
 		"OPTS:\n"
 		"    -S    use skb-mode\n"
-		"    -N    enforce native mode\n",
+		"    -N    enforce native mode\n"
+		"    -F    force loading prog\n",
 		prog);
 }

@@ -83,7 +84,7 @@ int main(int argc, char **argv)
 	};
 	struct bpf_program *prog, *dummy_prog;
 	int prog_fd, tx_port_map_fd, opt;
-	const char *optstr = "SN";
+	const char *optstr = "FSN";
 	struct bpf_object *obj;
 	char filename[256];
 	int dummy_prog_fd;

@@ -97,6 +98,9 @@ int main(int argc, char **argv)
 		case 'N':
 			xdp_flags |= XDP_FLAGS_DRV_MODE;
 			break;
+		case 'F':
+			xdp_flags &= ~XDP_FLAGS_UPDATE_IF_NOEXIST;
+			break;
 		default:
 			usage(basename(argv[0]));
 			return 1;

diff --git a/samples/bpf/xdp_router_ipv4_user.c b/samples/bpf/xdp_router_ipv4_user.c
index c63c6beec7d6..208d6a996478 100644
--- a/samples/bpf/xdp_router_ipv4_user.c
+++ b/samples/bpf/xdp_router_ipv4_user.c

@@ -26,8 +26,9 @@
 #include "bpf_util.h"
 #include "bpf/libbpf.h"
 #include <sys/resource.h>
+#include <libgen.h>
 
-int sock, sock_arp, flags = 0;
+int sock, sock_arp, flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
 static int total_ifindex;
 int *ifindex_list;
 char buf[8192];

@@ -608,33 +609,56 @@ static int monitor_route(void)
 	return ret;
 }
 
+static void usage(const char *prog)
+{
+	fprintf(stderr,
+		"%s: %s [OPTS] interface name list\n\n"
+		"OPTS:\n"
+		"    -S    use skb-mode\n"
+		"    -F    force loading prog\n",
+		__func__, prog);
+}
+
 int main(int ac, char **argv)
 {
 	struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
 	struct bpf_prog_load_attr prog_load_attr = {
 		.prog_type	= BPF_PROG_TYPE_XDP,
 	};
+	const char *optstr = "SF";
 	struct bpf_object *obj;
 	char filename[256];
 	char **ifname_list;
-	int prog_fd;
+	int prog_fd, opt;
 	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;
+	total_ifindex = ac - 1;
+	ifname_list = (argv + 1);
+
+	while ((opt = getopt(ac, argv, optstr)) != -1) {
+		switch (opt) {
+		case 'S':
+			flags |= XDP_FLAGS_SKB_MODE;
+			total_ifindex--;
+			ifname_list++;
+			break;
+		case 'F':
+			flags &= ~XDP_FLAGS_UPDATE_IF_NOEXIST;
+			total_ifindex--;
+			ifname_list++;
+			break;
+		default:
+			usage(basename(argv[0]));
+			return 1;
+		}
 	}
-	if (!strcmp(argv[1], "-S")) {
-		flags = XDP_FLAGS_SKB_MODE;
-		total_ifindex = ac - 2;
-		ifname_list = (argv + 2);
-	} else {
-		flags = 0;
-		total_ifindex = ac - 1;
-		ifname_list = (argv + 1);
+
+	if (optind == ac) {
+		usage(basename(argv[0]));
+		return 1;
 	}
 
 	if (setrlimit(RLIMIT_MEMLOCK, &r)) {

diff --git a/samples/bpf/xdp_rxq_info_user.c b/samples/bpf/xdp_rxq_info_user.c
index ef26f882f92f..e7a98c2a440f 100644
--- a/samples/bpf/xdp_rxq_info_user.c
+++ b/samples/bpf/xdp_rxq_info_user.c

@@ -30,7 +30,7 @@ static int ifindex = -1;
 static char ifname_buf[IF_NAMESIZE];
 static char *ifname;
 
-static __u32 xdp_flags;
+static __u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
 
 static struct bpf_map *stats_global_map;
 static struct bpf_map *rx_queue_index_map;

@@ -52,6 +52,7 @@ static const struct option long_options[] = {
 	{"action",	required_argument,	NULL, 'a' },
 	{"readmem", 	no_argument,		NULL, 'r' },
 	{"swapmac", 	no_argument,		NULL, 'm' },
+	{"force",	no_argument,		NULL, 'F' },
 	{0, 0, NULL,  0 }
 };

@@ -487,7 +488,7 @@ int main(int argc, char **argv)
 	}
 
 	/* Parse commands line args */
-	while ((opt = getopt_long(argc, argv, "hSd:",
+	while ((opt = getopt_long(argc, argv, "FhSrmzd:s:a:",
 				  long_options, &longindex)) != -1) {
 		switch (opt) {
 		case 'd':

@@ -524,6 +525,9 @@ int main(int argc, char **argv)
 		case 'm':
 			cfg_options |= SWAP_MAC;
 			break;
+		case 'F':
+			xdp_flags &= ~XDP_FLAGS_UPDATE_IF_NOEXIST;
+			break;
 		case 'h':
 		error:
 		default:

diff --git a/samples/bpf/xdp_sample_pkts_user.c b/samples/bpf/xdp_sample_pkts_user.c
index 5f5828ee0761..62f34827c775 100644
--- a/samples/bpf/xdp_sample_pkts_user.c
+++ b/samples/bpf/xdp_sample_pkts_user.c

@@ -13,6 +13,8 @@
 #include <libbpf.h>
 #include <bpf/bpf.h>
 #include <sys/resource.h>
+#include <libgen.h>
+#include <linux/if_link.h>
 
 #include "perf-sys.h"
 #include "trace_helpers.h"

@@ -21,12 +23,13 @@
 static int pmu_fds[MAX_CPUS], if_idx;
 static struct perf_event_mmap_page *headers[MAX_CPUS];
 static char *if_name;
+static __u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
 
 static int do_attach(int idx, int fd, const char *name)
 {
 	int err;
 
-	err = bpf_set_link_xdp_fd(idx, fd, 0);
+	err = bpf_set_link_xdp_fd(idx, fd, xdp_flags);
 	if (err < 0)
 		printf("ERROR: failed to attach program to %s\n", name);

@@ -98,21 +101,42 @@ static void sig_handler(int signo)
 	exit(0);
 }
 
+static void usage(const char *prog)
+{
+	fprintf(stderr,
+		"%s: %s [OPTS] <ifname|ifindex>\n\n"
+		"OPTS:\n"
+		"    -F    force loading prog\n",
+		__func__, prog);
+}
+
 int main(int argc, char **argv)
 {
 	struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
 	struct bpf_prog_load_attr prog_load_attr = {
 		.prog_type	= BPF_PROG_TYPE_XDP,
 	};
+	const char *optstr = "F";
+	int prog_fd, map_fd, opt;
 	struct bpf_object *obj;
 	struct bpf_map *map;
-	int prog_fd, map_fd;
 	char filename[256];
 	int ret, err, i;
 	int numcpus;
 
-	if (argc < 2) {
-		printf("Usage: %s <ifname>\n", argv[0]);
+	while ((opt = getopt(argc, argv, optstr)) != -1) {
+		switch (opt) {
+		case 'F':
+			xdp_flags &= ~XDP_FLAGS_UPDATE_IF_NOEXIST;
+			break;
+		default:
+			usage(basename(argv[0]));
+			return 1;
+		}
+	}
+
+	if (optind == argc) {
+		usage(basename(argv[0]));
 		return 1;
 	}

@@ -143,16 +167,16 @@ int main(int argc, char **argv)
 	}
 	map_fd = bpf_map__fd(map);
 
-	if_idx = if_nametoindex(argv[1]);
+	if_idx = if_nametoindex(argv[optind]);
 	if (!if_idx)
-		if_idx = strtoul(argv[1], NULL, 0);
+		if_idx = strtoul(argv[optind], NULL, 0);
 
 	if (!if_idx) {
 		fprintf(stderr, "Invalid ifname\n");
 		return 1;
 	}
-	if_name = argv[1];
-	err = do_attach(if_idx, prog_fd, argv[1]);
+	if_name = argv[optind];
+	err = do_attach(if_idx, prog_fd, if_name);
 	if (err)
 		return err;

diff --git a/samples/bpf/xdp_tx_iptunnel_user.c b/samples/bpf/xdp_tx_iptunnel_user.c
index 5093d8220da5..e3de60930d27 100644
--- a/samples/bpf/xdp_tx_iptunnel_user.c
+++ b/samples/bpf/xdp_tx_iptunnel_user.c

@@ -25,7 +25,7 @@
 #define STATS_INTERVAL_S 2U
 
 static int ifindex = -1;
-static __u32 xdp_flags = 0;
+static __u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
 static int rxcnt_map_fd;
 
 static void int_exit(int sig)

@@ -83,6 +83,7 @@ static void usage(const char *cmd)
 	printf("    -P <IP-Protocol> Default is TCP\n");
 	printf("    -S use skb-mode\n");
 	printf("    -N enforce native mode\n");
+	printf("    -F Force loading the XDP prog\n");
 	printf("    -h Display this help\n");
 }

@@ -145,7 +146,7 @@ int main(int argc, char **argv)
 	};
 	struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
 	int min_port = 0, max_port = 0, vip2tnl_map_fd;
-	const char *optstr = "i:a:p:s:d:m:T:P:SNh";
+	const char *optstr = "i:a:p:s:d:m:T:P:FSNh";
 	unsigned char opt_flags[256] = {};
 	unsigned int kill_after_s = 0;
 	struct iptnl_info tnl = {};

@@ -217,6 +218,9 @@ int main(int argc, char **argv)
 		case 'N':
 			xdp_flags |= XDP_FLAGS_DRV_MODE;
 			break;
+		case 'F':
+			xdp_flags &= ~XDP_FLAGS_UPDATE_IF_NOEXIST;
+			break;
 		default:
 			usage(argv[0]);
 			return 1;

diff --git a/samples/bpf/xdpsock_user.c b/samples/bpf/xdpsock_user.c
index 57ecadc58403..188723784768 100644
--- a/samples/bpf/xdpsock_user.c
+++ b/samples/bpf/xdpsock_user.c

@@ -68,7 +68,7 @@ enum benchmark_type {
 };
 
 static enum benchmark_type opt_bench = BENCH_RXDROP;
-static u32 opt_xdp_flags;
+static u32 opt_xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
 static const char *opt_if = "";
 static int opt_ifindex;
 static int opt_queue;

@@ -682,7 +682,7 @@ 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, "Frtli:q:psSNn:cz", long_options,
 				&option_index);
 		if (c == -1)
 			break;

@@ -725,6 +725,9 @@ static void parse_command_line(int argc, char **argv)
 		case 'c':
 			opt_xdp_bind_flags |= XDP_COPY;
 			break;
+		case 'F':
+			opt_xdp_flags &= ~XDP_FLAGS_UPDATE_IF_NOEXIST;
+			break;
 		default:
 			usage(basename(argv[0]));
 		}

-- 
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