samples/bpf: Remove the xdp_rxq_info utility

The functionality of this utility has been incorporated into the xdp-bench
utility in xdp-tools, by way of the --rxq-stats argument to the 'drop',
'pass' and 'tx' commands of xdp-bench.

Some examples of how to convert xdp_rxq_info invocations into equivalent
xdp-bench commands:

xdp_rxq_info -d eth0
  --> xdp-bench pass --rxq-stats eth0

xdp_rxq_info -d eth0 -a XDP_DROP -m
  --> xdp-bench drop --rxq-stats -p swap-macs eth0

Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/r/20230824102255.1561885-4-toke@redhat.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

samples/bpf/Makefile

@@ -41,7 +41,6 @@ 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_rxq_info
 tprogs-y += syscall_tp
 tprogs-y += cpustat
 tprogs-y += xdp_adjust_tail
@@ -96,7 +95,6 @@ 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_rxq_info-objs := xdp_rxq_info_user.o
 syscall_tp-objs := syscall_tp_user.o
 cpustat-objs := cpustat_user.o
 xdp_adjust_tail-objs := xdp_adjust_tail_user.o
@@ -151,7 +149,6 @@ always-y += tcp_clamp_kern.o
 always-y += tcp_basertt_kern.o
 always-y += tcp_tos_reflect_kern.o
 always-y += tcp_dumpstats_kern.o
-always-y += xdp_rxq_info_kern.o
 always-y += xdp2skb_meta_kern.o
 always-y += syscall_tp_kern.o
 always-y += cpustat_kern.o

samples/bpf/xdp_rxq_info_kern.c

@@ -1,140 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0
- * Copyright (c) 2017 Jesper Dangaard Brouer, Red Hat Inc.
- *
- *  Example howto extract XDP RX-queue info
- */
-#include <uapi/linux/bpf.h>
-#include <uapi/linux/if_ether.h>
-#include <uapi/linux/in.h>
-#include <bpf/bpf_helpers.h>
-
-/* Config setup from with userspace
- *
- * User-side setup ifindex in config_map, to verify that
- * ctx->ingress_ifindex is correct (against configured ifindex)
- */
-struct config {
-	__u32 action;
-	int ifindex;
-	__u32 options;
-};
-enum cfg_options_flags {
-	NO_TOUCH = 0x0U,
-	READ_MEM = 0x1U,
-	SWAP_MAC = 0x2U,
-};
-
-struct {
-	__uint(type, BPF_MAP_TYPE_ARRAY);
-	__type(key, int);
-	__type(value, struct config);
-	__uint(max_entries, 1);
-} config_map SEC(".maps");
-
-/* Common stats data record (shared with userspace) */
-struct datarec {
-	__u64 processed;
-	__u64 issue;
-};
-
-struct {
-	__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
-	__type(key, u32);
-	__type(value, struct datarec);
-	__uint(max_entries, 1);
-} stats_global_map SEC(".maps");
-
-#define MAX_RXQs 64
-
-/* Stats per rx_queue_index (per CPU) */
-struct {
-	__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
-	__type(key, u32);
-	__type(value, struct datarec);
-	__uint(max_entries, MAX_RXQs + 1);
-} rx_queue_index_map SEC(".maps");
-
-static __always_inline
-void swap_src_dst_mac(void *data)
-{
-	unsigned short *p = data;
-	unsigned short dst[3];
-
-	dst[0] = p[0];
-	dst[1] = p[1];
-	dst[2] = p[2];
-	p[0] = p[3];
-	p[1] = p[4];
-	p[2] = p[5];
-	p[3] = dst[0];
-	p[4] = dst[1];
-	p[5] = dst[2];
-}
-
-SEC("xdp_prog0")
-int  xdp_prognum0(struct xdp_md *ctx)
-{
-	void *data_end = (void *)(long)ctx->data_end;
-	void *data     = (void *)(long)ctx->data;
-	struct datarec *rec, *rxq_rec;
-	int ingress_ifindex;
-	struct config *config;
-	u32 key = 0;
-
-	/* Global stats record */
-	rec = bpf_map_lookup_elem(&stats_global_map, &key);
-	if (!rec)
-		return XDP_ABORTED;
-	rec->processed++;
-
-	/* Accessing ctx->ingress_ifindex, cause BPF to rewrite BPF
-	 * instructions inside kernel to access xdp_rxq->dev->ifindex
-	 */
-	ingress_ifindex = ctx->ingress_ifindex;
-
-	config = bpf_map_lookup_elem(&config_map, &key);
-	if (!config)
-		return XDP_ABORTED;
-
-	/* Simple test: check ctx provided ifindex is as expected */
-	if (ingress_ifindex != config->ifindex) {
-		/* count this error case */
-		rec->issue++;
-		return XDP_ABORTED;
-	}
-
-	/* Update stats per rx_queue_index. Handle if rx_queue_index
-	 * is larger than stats map can contain info for.
-	 */
-	key = ctx->rx_queue_index;
-	if (key >= MAX_RXQs)
-		key = MAX_RXQs;
-	rxq_rec = bpf_map_lookup_elem(&rx_queue_index_map, &key);
-	if (!rxq_rec)
-		return XDP_ABORTED;
-	rxq_rec->processed++;
-	if (key == MAX_RXQs)
-		rxq_rec->issue++;
-
-	/* Default: Don't touch packet data, only count packets */
-	if (unlikely(config->options & (READ_MEM|SWAP_MAC))) {
-		struct ethhdr *eth = data;
-
-		if (eth + 1 > data_end)
-			return XDP_ABORTED;
-
-		/* Avoid compiler removing this: Drop non 802.3 Ethertypes */
-		if (ntohs(eth->h_proto) < ETH_P_802_3_MIN)
-			return XDP_ABORTED;
-
-		/* XDP_TX requires changing MAC-addrs, else HW may drop.
-		 * Can also be enabled with --swapmac (for test purposes)
-		 */
-		if (unlikely(config->options & SWAP_MAC))
-			swap_src_dst_mac(data);
-	}
-
-	return config->action;
-}
-
-char _license[] SEC("license") = "GPL";