4 files changed, 84 insertions, 94 deletions

diff --git a/samples/bpf/trace_output_user.c b/samples/bpf/trace_output_user.c
index 2dd1d39b152a..8ee47699a870 100644
--- a/samples/bpf/trace_output_user.c
+++ b/samples/bpf/trace_output_user.c
@@ -18,9 +18,6 @@
 #include <libbpf.h>
 #include "bpf_load.h"
 #include "perf-sys.h"
-#include "trace_helpers.h"
-
-static int pmu_fd;
 
 static __u64 time_get_ns(void)
 {
@@ -31,12 +28,12 @@ static __u64 time_get_ns(void)
 }
 
 static __u64 start_time;
+static __u64 cnt;
 
 #define MAX_CNT 100000ll
 
-static int print_bpf_output(void *data, int size)
+static void print_bpf_output(void *ctx, int cpu, void *data, __u32 size)
 {
-	static __u64 cnt;
 	struct {
 		__u64 pid;
 		__u64 cookie;
@@ -45,7 +42,7 @@ static int print_bpf_output(void *data, int size)
 	if (e->cookie != 0x12345678) {
 		printf("BUG pid %llx cookie %llx sized %d\n",
 		       e->pid, e->cookie, size);
-		return LIBBPF_PERF_EVENT_ERROR;
+		return;
 	}
 
 	cnt++;
@@ -53,30 +50,14 @@ static int print_bpf_output(void *data, int size)
 	if (cnt == MAX_CNT) {
 		printf("recv %lld events per sec\n",
 		       MAX_CNT * 1000000000ll / (time_get_ns() - start_time));
-		return LIBBPF_PERF_EVENT_DONE;
+		return;
 	}
-
-	return LIBBPF_PERF_EVENT_CONT;
-}
-
-static void test_bpf_perf_event(void)
-{
-	struct perf_event_attr attr = {
-		.sample_type = PERF_SAMPLE_RAW,
-		.type = PERF_TYPE_SOFTWARE,
-		.config = PERF_COUNT_SW_BPF_OUTPUT,
-	};
-	int key = 0;
-
-	pmu_fd = sys_perf_event_open(&attr, -1/*pid*/, 0/*cpu*/, -1/*group_fd*/, 0);
-
-	assert(pmu_fd >= 0);
-	assert(bpf_map_update_elem(map_fd[0], &key, &pmu_fd, BPF_ANY) == 0);
-	ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE, 0);
 }
 
 int main(int argc, char **argv)
 {
+	struct perf_buffer_opts pb_opts = {};
+	struct perf_buffer *pb;
 	char filename[256];
 	FILE *f;
 	int ret;
@@ -88,16 +69,20 @@ int main(int argc, char **argv)
 		return 1;
 	}
 
-	test_bpf_perf_event();
-
-	if (perf_event_mmap(pmu_fd) < 0)
+	pb_opts.sample_cb = print_bpf_output;
+	pb = perf_buffer__new(map_fd[0], 8, &pb_opts);
+	ret = libbpf_get_error(pb);
+	if (ret) {
+		printf("failed to setup perf_buffer: %d\n", ret);
 		return 1;
+	}
 
 	f = popen("taskset 1 dd if=/dev/zero of=/dev/null", "r");
 	(void) f;
 
 	start_time = time_get_ns();
-	ret = perf_event_poller(pmu_fd, print_bpf_output);
+	while ((ret = perf_buffer__poll(pb, 1000)) >= 0 && cnt < MAX_CNT) {
+	}
 	kill(0, SIGINT);
 	return ret;
 }
diff --git a/samples/bpf/xdp_fwd_kern.c b/samples/bpf/xdp_fwd_kern.c
index a7e94e7ff87d..701a30f258b1 100644
--- a/samples/bpf/xdp_fwd_kern.c
+++ b/samples/bpf/xdp_fwd_kern.c
@@ -23,7 +23,8 @@
 
 #define IPV6_FLOWINFO_MASK              cpu_to_be32(0x0FFFFFFF)
 
-struct bpf_map_def SEC("maps") tx_port = {
+/* For TX-traffic redirect requires net_device ifindex to be in this devmap */
+struct bpf_map_def SEC("maps") xdp_tx_ports = {
 	.type = BPF_MAP_TYPE_DEVMAP,
 	.key_size = sizeof(int),
 	.value_size = sizeof(int),
@@ -102,14 +103,34 @@ static __always_inline int xdp_fwd_flags(struct xdp_md *ctx, u32 flags)
 	fib_params.ifindex = ctx->ingress_ifindex;
 
 	rc = bpf_fib_lookup(ctx, &fib_params, sizeof(fib_params), flags);
-
-	/* verify egress index has xdp support
-	 * TO-DO bpf_map_lookup_elem(&tx_port, &key) fails with
-	 *       cannot pass map_type 14 into func bpf_map_lookup_elem#1:
-	 * NOTE: without verification that egress index supports XDP
-	 *       forwarding packets are dropped.
+	/*
+	 * Some rc (return codes) from bpf_fib_lookup() are important,
+	 * to understand how this XDP-prog interacts with network stack.
+	 *
+	 * BPF_FIB_LKUP_RET_NO_NEIGH:
+	 *  Even if route lookup was a success, then the MAC-addresses are also
+	 *  needed.  This is obtained from arp/neighbour table, but if table is
+	 *  (still) empty then BPF_FIB_LKUP_RET_NO_NEIGH is returned.  To avoid
+	 *  doing ARP lookup directly from XDP, then send packet to normal
+	 *  network stack via XDP_PASS and expect it will do ARP resolution.
+	 *
+	 * BPF_FIB_LKUP_RET_FWD_DISABLED:
+	 *  The bpf_fib_lookup respect sysctl net.ipv{4,6}.conf.all.forwarding
+	 *  setting, and will return BPF_FIB_LKUP_RET_FWD_DISABLED if not
+	 *  enabled this on ingress device.
 	 */
-	if (rc == 0) {
+	if (rc == BPF_FIB_LKUP_RET_SUCCESS) {
+		/* Verify egress index has been configured as TX-port.
+		 * (Note: User can still have inserted an egress ifindex that
+		 * doesn't support XDP xmit, which will result in packet drops).
+		 *
+		 * Note: lookup in devmap supported since 0cdbb4b09a0.
+		 * If not supported will fail with:
+		 *  cannot pass map_type 14 into func bpf_map_lookup_elem#1:
+		 */
+		if (!bpf_map_lookup_elem(&xdp_tx_ports, &fib_params.ifindex))
+			return XDP_PASS;
+
 		if (h_proto == htons(ETH_P_IP))
 			ip_decrease_ttl(iph);
 		else if (h_proto == htons(ETH_P_IPV6))
@@ -117,7 +138,7 @@ static __always_inline int xdp_fwd_flags(struct xdp_md *ctx, u32 flags)
 
 		memcpy(eth->h_dest, fib_params.dmac, ETH_ALEN);
 		memcpy(eth->h_source, fib_params.smac, ETH_ALEN);
-		return bpf_redirect_map(&tx_port, fib_params.ifindex, 0);
+		return bpf_redirect_map(&xdp_tx_ports, fib_params.ifindex, 0);
 	}
 
 	return XDP_PASS;
diff --git a/samples/bpf/xdp_fwd_user.c b/samples/bpf/xdp_fwd_user.c
index 5b46ee12c696..97ff1dad7669 100644
--- a/samples/bpf/xdp_fwd_user.c
+++ b/samples/bpf/xdp_fwd_user.c
@@ -27,14 +27,20 @@
 #include "libbpf.h"
 #include <bpf/bpf.h>
 
-
-static int do_attach(int idx, int fd, const char *name)
+static int do_attach(int idx, int prog_fd, int map_fd, const char *name)
 {
 	int err;
 
-	err = bpf_set_link_xdp_fd(idx, fd, 0);
-	if (err < 0)
+	err = bpf_set_link_xdp_fd(idx, prog_fd, 0);
+	if (err < 0) {
 		printf("ERROR: failed to attach program to %s\n", name);
+		return err;
+	}
+
+	/* Adding ifindex as a possible egress TX port */
+	err = bpf_map_update_elem(map_fd, &idx, &idx, 0);
+	if (err)
+		printf("ERROR: failed using device %s as TX-port\n", name);
 
 	return err;
 }
@@ -47,6 +53,9 @@ static int do_detach(int idx, const char *name)
 	if (err < 0)
 		printf("ERROR: failed to detach program from %s\n", name);
 
+	/* TODO: Remember to cleanup map, when adding use of shared map
+	 *  bpf_map_delete_elem((map_fd, &idx);
+	 */
 	return err;
 }
 
@@ -67,10 +76,10 @@ int main(int argc, char **argv)
 	};
 	const char *prog_name = "xdp_fwd";
 	struct bpf_program *prog;
+	int prog_fd, map_fd = -1;
 	char filename[PATH_MAX];
 	struct bpf_object *obj;
 	int opt, i, idx, err;
-	int prog_fd, map_fd;
 	int attach = 1;
 	int ret = 0;
 
@@ -103,8 +112,14 @@ int main(int argc, char **argv)
 			return 1;
 		}
 
-		if (bpf_prog_load_xattr(&prog_load_attr, &obj, &prog_fd))
+		err = bpf_prog_load_xattr(&prog_load_attr, &obj, &prog_fd);
+		if (err) {
+			printf("Does kernel support devmap lookup?\n");
+			/* If not, the error message will be:
+			 *  "cannot pass map_type 14 into func bpf_map_lookup_elem#1"
+			 */
 			return 1;
+		}
 
 		prog = bpf_object__find_program_by_title(obj, prog_name);
 		prog_fd = bpf_program__fd(prog);
@@ -113,16 +128,12 @@ int main(int argc, char **argv)
 			return 1;
 		}
 		map_fd = bpf_map__fd(bpf_object__find_map_by_name(obj,
-								  "tx_port"));
+							"xdp_tx_ports"));
 		if (map_fd < 0) {
 			printf("map not found: %s\n", strerror(map_fd));
 			return 1;
 		}
 	}
-	if (attach) {
-		for (i = 1; i < 64; ++i)
-			bpf_map_update_elem(map_fd, &i, &i, 0);
-	}
 
 	for (i = optind; i < argc; ++i) {
 		idx = if_nametoindex(argv[i]);
@@ -138,7 +149,7 @@ int main(int argc, char **argv)
 			if (err)
 				ret = err;
 		} else {
-			err = do_attach(idx, prog_fd, argv[i]);
+			err = do_attach(idx, prog_fd, map_fd, argv[i]);
 			if (err)
 				ret = err;
 		}
diff --git a/samples/bpf/xdp_sample_pkts_user.c b/samples/bpf/xdp_sample_pkts_user.c
index dc66345a929a..3002714e3cd5 100644
--- a/samples/bpf/xdp_sample_pkts_user.c
+++ b/samples/bpf/xdp_sample_pkts_user.c
@@ -17,14 +17,13 @@
 #include <linux/if_link.h>
 
 #include "perf-sys.h"
-#include "trace_helpers.h"
 
 #define MAX_CPUS 128
-static int pmu_fds[MAX_CPUS], if_idx;
-static struct perf_event_mmap_page *headers[MAX_CPUS];
+static int if_idx;
 static char *if_name;
 static __u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
 static __u32 prog_id;
+static struct perf_buffer *pb = NULL;
 
 static int do_attach(int idx, int fd, const char *name)
 {
@@ -73,7 +72,7 @@ static int do_detach(int idx, const char *name)
 
 #define SAMPLE_SIZE 64
 
-static int print_bpf_output(void *data, int size)
+static void print_bpf_output(void *ctx, int cpu, void *data, __u32 size)
 {
 	struct {
 		__u16 cookie;
@@ -83,45 +82,20 @@ static int print_bpf_output(void *data, int size)
 	int i;
 
 	if (e->cookie != 0xdead) {
-		printf("BUG cookie %x sized %d\n",
-		       e->cookie, size);
-		return LIBBPF_PERF_EVENT_ERROR;
+		printf("BUG cookie %x sized %d\n", e->cookie, size);
+		return;
 	}
 
 	printf("Pkt len: %-5d bytes. Ethernet hdr: ", e->pkt_len);
 	for (i = 0; i < 14 && i < e->pkt_len; i++)
 		printf("%02x ", e->pkt_data[i]);
 	printf("\n");
-
-	return LIBBPF_PERF_EVENT_CONT;
-}
-
-static void test_bpf_perf_event(int map_fd, int num)
-{
-	struct perf_event_attr attr = {
-		.sample_type = PERF_SAMPLE_RAW,
-		.type = PERF_TYPE_SOFTWARE,
-		.config = PERF_COUNT_SW_BPF_OUTPUT,
-		.wakeup_events = 1, /* get an fd notification for every event */
-	};
-	int i;
-
-	for (i = 0; i < num; i++) {
-		int key = i;
-
-		pmu_fds[i] = sys_perf_event_open(&attr, -1/*pid*/, i/*cpu*/,
-						 -1/*group_fd*/, 0);
-
-		assert(pmu_fds[i] >= 0);
-		assert(bpf_map_update_elem(map_fd, &key,
-					   &pmu_fds[i], BPF_ANY) == 0);
-		ioctl(pmu_fds[i], PERF_EVENT_IOC_ENABLE, 0);
-	}
 }
 
 static void sig_handler(int signo)
 {
 	do_detach(if_idx, if_name);
+	perf_buffer__free(pb);
 	exit(0);
 }
 
@@ -140,13 +114,13 @@ int main(int argc, char **argv)
 	struct bpf_prog_load_attr prog_load_attr = {
 		.prog_type	= BPF_PROG_TYPE_XDP,
 	};
+	struct perf_buffer_opts pb_opts = {};
 	const char *optstr = "F";
 	int prog_fd, map_fd, opt;
 	struct bpf_object *obj;
 	struct bpf_map *map;
 	char filename[256];
-	int ret, err, i;
-	int numcpus;
+	int ret, err;
 
 	while ((opt = getopt(argc, argv, optstr)) != -1) {
 		switch (opt) {
@@ -169,10 +143,6 @@ int main(int argc, char **argv)
 		return 1;
 	}
 
-	numcpus = get_nprocs();
-	if (numcpus > MAX_CPUS)
-		numcpus = MAX_CPUS;
-
 	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
 	prog_load_attr.file = filename;
 
@@ -211,14 +181,17 @@ int main(int argc, char **argv)
 		return 1;
 	}
 
-	test_bpf_perf_event(map_fd, numcpus);
+	pb_opts.sample_cb = print_bpf_output;
+	pb = perf_buffer__new(map_fd, 8, &pb_opts);
+	err = libbpf_get_error(pb);
+	if (err) {
+		perror("perf_buffer setup failed");
+		return 1;
+	}
 
-	for (i = 0; i < numcpus; i++)
-		if (perf_event_mmap_header(pmu_fds[i], &headers[i]) < 0)
-			return 1;
+	while ((ret = perf_buffer__poll(pb, 1000)) >= 0) {
+	}
 
-	ret = perf_event_poller_multi(pmu_fds, headers, numcpus,
-				      print_bpf_output);
 	kill(0, SIGINT);
 	return ret;
 }