libbpf: move xsk.{c,h} into selftests/bpf

Remove deprecated xsk APIs from libbpf. But given we have selftests
relying on this, move those files (with minimal adjustments to make them
compilable) under selftests/bpf.

We also remove all the removed APIs from libbpf.map, while overall
keeping version inheritance chain, as most APIs are backwards
compatible so there is no need to reassign them as LIBBPF_1.0.0 versions.

Cc: Magnus Karlsson <magnus.karlsson@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20220627211527.2245459-2-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

4 files changed, 1582 insertions, 1 deletions

diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index 4fbd88a8ed9e..e32a28fe8bc1 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -230,6 +230,8 @@ $(OUTPUT)/xdping: $(TESTING_HELPERS)
 $(OUTPUT)/flow_dissector_load: $(TESTING_HELPERS)
 $(OUTPUT)/test_maps: $(TESTING_HELPERS)
 $(OUTPUT)/test_verifier: $(TESTING_HELPERS) $(CAP_HELPERS)
+$(OUTPUT)/xsk.o: $(BPFOBJ)
+$(OUTPUT)/xdpxceiver: $(OUTPUT)/xsk.o
 
 BPFTOOL ?= $(DEFAULT_BPFTOOL)
 $(DEFAULT_BPFTOOL): $(wildcard $(BPFTOOLDIR)/*.[ch] $(BPFTOOLDIR)/Makefile)    \
diff --git a/tools/testing/selftests/bpf/xdpxceiver.c b/tools/testing/selftests/bpf/xdpxceiver.c
index e5992a6b5e09..019c567b6b4e 100644
--- a/tools/testing/selftests/bpf/xdpxceiver.c
+++ b/tools/testing/selftests/bpf/xdpxceiver.c
@@ -97,7 +97,7 @@
 #include <time.h>
 #include <unistd.h>
 #include <stdatomic.h>
-#include <bpf/xsk.h>
+#include "xsk.h"
 #include "xdpxceiver.h"
 #include "../kselftest.h"
 
diff --git a/tools/testing/selftests/bpf/xsk.c b/tools/testing/selftests/bpf/xsk.c
new file mode 100644
index 000000000000..eb50c3f336f8
--- /dev/null
+++ b/tools/testing/selftests/bpf/xsk.c
@@ -0,0 +1,1264 @@
+// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
+
+/*
+ * AF_XDP user-space access library.
+ *
+ * Copyright(c) 2018 - 2019 Intel Corporation.
+ *
+ * Author(s): Magnus Karlsson <magnus.karlsson@intel.com>
+ */
+
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <arpa/inet.h>
+#include <asm/barrier.h>
+#include <linux/compiler.h>
+#include <linux/ethtool.h>
+#include <linux/filter.h>
+#include <linux/if_ether.h>
+#include <linux/if_packet.h>
+#include <linux/if_xdp.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/sockios.h>
+#include <net/if.h>
+#include <sys/ioctl.h>
+#include <sys/mman.h>
+#include <sys/socket.h>
+#include <sys/types.h>
+#include <linux/if_link.h>
+
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+#include "xsk.h"
+
+#ifndef SOL_XDP
+ #define SOL_XDP 283
+#endif
+
+#ifndef AF_XDP
+ #define AF_XDP 44
+#endif
+
+#ifndef PF_XDP
+ #define PF_XDP AF_XDP
+#endif
+
+#define pr_warn(fmt, ...) fprintf(stderr, fmt, ##__VA_ARGS__)
+
+enum xsk_prog {
+	XSK_PROG_FALLBACK,
+	XSK_PROG_REDIRECT_FLAGS,
+};
+
+struct xsk_umem {
+	struct xsk_ring_prod *fill_save;
+	struct xsk_ring_cons *comp_save;
+	char *umem_area;
+	struct xsk_umem_config config;
+	int fd;
+	int refcount;
+	struct list_head ctx_list;
+	bool rx_ring_setup_done;
+	bool tx_ring_setup_done;
+};
+
+struct xsk_ctx {
+	struct xsk_ring_prod *fill;
+	struct xsk_ring_cons *comp;
+	__u32 queue_id;
+	struct xsk_umem *umem;
+	int refcount;
+	int ifindex;
+	struct list_head list;
+	int prog_fd;
+	int link_fd;
+	int xsks_map_fd;
+	char ifname[IFNAMSIZ];
+	bool has_bpf_link;
+};
+
+struct xsk_socket {
+	struct xsk_ring_cons *rx;
+	struct xsk_ring_prod *tx;
+	__u64 outstanding_tx;
+	struct xsk_ctx *ctx;
+	struct xsk_socket_config config;
+	int fd;
+};
+
+struct xsk_nl_info {
+	bool xdp_prog_attached;
+	int ifindex;
+	int fd;
+};
+
+/* Up until and including Linux 5.3 */
+struct xdp_ring_offset_v1 {
+	__u64 producer;
+	__u64 consumer;
+	__u64 desc;
+};
+
+/* Up until and including Linux 5.3 */
+struct xdp_mmap_offsets_v1 {
+	struct xdp_ring_offset_v1 rx;
+	struct xdp_ring_offset_v1 tx;
+	struct xdp_ring_offset_v1 fr;
+	struct xdp_ring_offset_v1 cr;
+};
+
+int xsk_umem__fd(const struct xsk_umem *umem)
+{
+	return umem ? umem->fd : -EINVAL;
+}
+
+int xsk_socket__fd(const struct xsk_socket *xsk)
+{
+	return xsk ? xsk->fd : -EINVAL;
+}
+
+static bool xsk_page_aligned(void *buffer)
+{
+	unsigned long addr = (unsigned long)buffer;
+
+	return !(addr & (getpagesize() - 1));
+}
+
+static void xsk_set_umem_config(struct xsk_umem_config *cfg,
+				const struct xsk_umem_config *usr_cfg)
+{
+	if (!usr_cfg) {
+		cfg->fill_size = XSK_RING_PROD__DEFAULT_NUM_DESCS;
+		cfg->comp_size = XSK_RING_CONS__DEFAULT_NUM_DESCS;
+		cfg->frame_size = XSK_UMEM__DEFAULT_FRAME_SIZE;
+		cfg->frame_headroom = XSK_UMEM__DEFAULT_FRAME_HEADROOM;
+		cfg->flags = XSK_UMEM__DEFAULT_FLAGS;
+		return;
+	}
+
+	cfg->fill_size = usr_cfg->fill_size;
+	cfg->comp_size = usr_cfg->comp_size;
+	cfg->frame_size = usr_cfg->frame_size;
+	cfg->frame_headroom = usr_cfg->frame_headroom;
+	cfg->flags = usr_cfg->flags;
+}
+
+static int xsk_set_xdp_socket_config(struct xsk_socket_config *cfg,
+				     const struct xsk_socket_config *usr_cfg)
+{
+	if (!usr_cfg) {
+		cfg->rx_size = XSK_RING_CONS__DEFAULT_NUM_DESCS;
+		cfg->tx_size = XSK_RING_PROD__DEFAULT_NUM_DESCS;
+		cfg->libbpf_flags = 0;
+		cfg->xdp_flags = 0;
+		cfg->bind_flags = 0;
+		return 0;
+	}
+
+	if (usr_cfg->libbpf_flags & ~XSK_LIBBPF_FLAGS__INHIBIT_PROG_LOAD)
+		return -EINVAL;
+
+	cfg->rx_size = usr_cfg->rx_size;
+	cfg->tx_size = usr_cfg->tx_size;
+	cfg->libbpf_flags = usr_cfg->libbpf_flags;
+	cfg->xdp_flags = usr_cfg->xdp_flags;
+	cfg->bind_flags = usr_cfg->bind_flags;
+
+	return 0;
+}
+
+static void xsk_mmap_offsets_v1(struct xdp_mmap_offsets *off)
+{
+	struct xdp_mmap_offsets_v1 off_v1;
+
+	/* getsockopt on a kernel <= 5.3 has no flags fields.
+	 * Copy over the offsets to the correct places in the >=5.4 format
+	 * and put the flags where they would have been on that kernel.
+	 */
+	memcpy(&off_v1, off, sizeof(off_v1));
+
+	off->rx.producer = off_v1.rx.producer;
+	off->rx.consumer = off_v1.rx.consumer;
+	off->rx.desc = off_v1.rx.desc;
+	off->rx.flags = off_v1.rx.consumer + sizeof(__u32);
+
+	off->tx.producer = off_v1.tx.producer;
+	off->tx.consumer = off_v1.tx.consumer;
+	off->tx.desc = off_v1.tx.desc;
+	off->tx.flags = off_v1.tx.consumer + sizeof(__u32);
+
+	off->fr.producer = off_v1.fr.producer;
+	off->fr.consumer = off_v1.fr.consumer;
+	off->fr.desc = off_v1.fr.desc;
+	off->fr.flags = off_v1.fr.consumer + sizeof(__u32);
+
+	off->cr.producer = off_v1.cr.producer;
+	off->cr.consumer = off_v1.cr.consumer;
+	off->cr.desc = off_v1.cr.desc;
+	off->cr.flags = off_v1.cr.consumer + sizeof(__u32);
+}
+
+static int xsk_get_mmap_offsets(int fd, struct xdp_mmap_offsets *off)
+{
+	socklen_t optlen;
+	int err;
+
+	optlen = sizeof(*off);
+	err = getsockopt(fd, SOL_XDP, XDP_MMAP_OFFSETS, off, &optlen);
+	if (err)
+		return err;
+
+	if (optlen == sizeof(*off))
+		return 0;
+
+	if (optlen == sizeof(struct xdp_mmap_offsets_v1)) {
+		xsk_mmap_offsets_v1(off);
+		return 0;
+	}
+
+	return -EINVAL;
+}
+
+static int xsk_create_umem_rings(struct xsk_umem *umem, int fd,
+				 struct xsk_ring_prod *fill,
+				 struct xsk_ring_cons *comp)
+{
+	struct xdp_mmap_offsets off;
+	void *map;
+	int err;
+
+	err = setsockopt(fd, SOL_XDP, XDP_UMEM_FILL_RING,
+			 &umem->config.fill_size,
+			 sizeof(umem->config.fill_size));
+	if (err)
+		return -errno;
+
+	err = setsockopt(fd, SOL_XDP, XDP_UMEM_COMPLETION_RING,
+			 &umem->config.comp_size,
+			 sizeof(umem->config.comp_size));
+	if (err)
+		return -errno;
+
+	err = xsk_get_mmap_offsets(fd, &off);
+	if (err)
+		return -errno;
+
+	map = mmap(NULL, off.fr.desc + umem->config.fill_size * sizeof(__u64),
+		   PROT_READ | PROT_WRITE, MAP_SHARED | MAP_POPULATE, fd,
+		   XDP_UMEM_PGOFF_FILL_RING);
+	if (map == MAP_FAILED)
+		return -errno;
+
+	fill->mask = umem->config.fill_size - 1;
+	fill->size = umem->config.fill_size;
+	fill->producer = map + off.fr.producer;
+	fill->consumer = map + off.fr.consumer;
+	fill->flags = map + off.fr.flags;
+	fill->ring = map + off.fr.desc;
+	fill->cached_cons = umem->config.fill_size;
+
+	map = mmap(NULL, off.cr.desc + umem->config.comp_size * sizeof(__u64),
+		   PROT_READ | PROT_WRITE, MAP_SHARED | MAP_POPULATE, fd,
+		   XDP_UMEM_PGOFF_COMPLETION_RING);
+	if (map == MAP_FAILED) {
+		err = -errno;
+		goto out_mmap;
+	}
+
+	comp->mask = umem->config.comp_size - 1;
+	comp->size = umem->config.comp_size;
+	comp->producer = map + off.cr.producer;
+	comp->consumer = map + off.cr.consumer;
+	comp->flags = map + off.cr.flags;
+	comp->ring = map + off.cr.desc;
+
+	return 0;
+
+out_mmap:
+	munmap(map, off.fr.desc + umem->config.fill_size * sizeof(__u64));
+	return err;
+}
+
+int xsk_umem__create(struct xsk_umem **umem_ptr, void *umem_area,
+		     __u64 size, struct xsk_ring_prod *fill,
+		     struct xsk_ring_cons *comp,
+		     const struct xsk_umem_config *usr_config)
+{
+	struct xdp_umem_reg mr;
+	struct xsk_umem *umem;
+	int err;
+
+	if (!umem_area || !umem_ptr || !fill || !comp)
+		return -EFAULT;
+	if (!size && !xsk_page_aligned(umem_area))
+		return -EINVAL;
+
+	umem = calloc(1, sizeof(*umem));
+	if (!umem)
+		return -ENOMEM;
+
+	umem->fd = socket(AF_XDP, SOCK_RAW | SOCK_CLOEXEC, 0);
+	if (umem->fd < 0) {
+		err = -errno;
+		goto out_umem_alloc;
+	}
+
+	umem->umem_area = umem_area;
+	INIT_LIST_HEAD(&umem->ctx_list);
+	xsk_set_umem_config(&umem->config, usr_config);
+
+	memset(&mr, 0, sizeof(mr));
+	mr.addr = (uintptr_t)umem_area;
+	mr.len = size;
+	mr.chunk_size = umem->config.frame_size;
+	mr.headroom = umem->config.frame_headroom;
+	mr.flags = umem->config.flags;
+
+	err = setsockopt(umem->fd, SOL_XDP, XDP_UMEM_REG, &mr, sizeof(mr));
+	if (err) {
+		err = -errno;
+		goto out_socket;
+	}
+
+	err = xsk_create_umem_rings(umem, umem->fd, fill, comp);
+	if (err)
+		goto out_socket;
+
+	umem->fill_save = fill;
+	umem->comp_save = comp;
+	*umem_ptr = umem;
+	return 0;
+
+out_socket:
+	close(umem->fd);
+out_umem_alloc:
+	free(umem);
+	return err;
+}
+
+struct xsk_umem_config_v1 {
+	__u32 fill_size;
+	__u32 comp_size;
+	__u32 frame_size;
+	__u32 frame_headroom;
+};
+
+static enum xsk_prog get_xsk_prog(void)
+{
+	enum xsk_prog detected = XSK_PROG_FALLBACK;
+	char data_in = 0, data_out;
+	struct bpf_insn insns[] = {
+		BPF_LD_MAP_FD(BPF_REG_1, 0),
+		BPF_MOV64_IMM(BPF_REG_2, 0),
+		BPF_MOV64_IMM(BPF_REG_3, XDP_PASS),
+		BPF_EMIT_CALL(BPF_FUNC_redirect_map),
+		BPF_EXIT_INSN(),
+	};
+	LIBBPF_OPTS(bpf_test_run_opts, opts,
+		.data_in = &data_in,
+		.data_size_in = 1,
+		.data_out = &data_out,
+	);
+
+	int prog_fd, map_fd, ret, insn_cnt = ARRAY_SIZE(insns);
+
+	map_fd = bpf_map_create(BPF_MAP_TYPE_XSKMAP, NULL, sizeof(int), sizeof(int), 1, NULL);
+	if (map_fd < 0)
+		return detected;
+
+	insns[0].imm = map_fd;
+
+	prog_fd = bpf_prog_load(BPF_PROG_TYPE_XDP, NULL, "GPL", insns, insn_cnt, NULL);
+	if (prog_fd < 0) {
+		close(map_fd);
+		return detected;
+	}
+
+	ret = bpf_prog_test_run_opts(prog_fd, &opts);
+	if (!ret && opts.retval == XDP_PASS)
+		detected = XSK_PROG_REDIRECT_FLAGS;
+	close(prog_fd);
+	close(map_fd);
+	return detected;
+}
+
+static int xsk_load_xdp_prog(struct xsk_socket *xsk)
+{
+	static const int log_buf_size = 16 * 1024;
+	struct xsk_ctx *ctx = xsk->ctx;
+	char log_buf[log_buf_size];
+	int prog_fd;
+
+	/* This is the fallback C-program:
+	 * SEC("xdp_sock") int xdp_sock_prog(struct xdp_md *ctx)
+	 * {
+	 *     int ret, index = ctx->rx_queue_index;
+	 *
+	 *     // A set entry here means that the correspnding queue_id
+	 *     // has an active AF_XDP socket bound to it.
+	 *     ret = bpf_redirect_map(&xsks_map, index, XDP_PASS);
+	 *     if (ret > 0)
+	 *         return ret;
+	 *
+	 *     // Fallback for pre-5.3 kernels, not supporting default
+	 *     // action in the flags parameter.
+	 *     if (bpf_map_lookup_elem(&xsks_map, &index))
+	 *         return bpf_redirect_map(&xsks_map, index, 0);
+	 *     return XDP_PASS;
+	 * }
+	 */
+	struct bpf_insn prog[] = {
+		/* r2 = *(u32 *)(r1 + 16) */
+		BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1, 16),
+		/* *(u32 *)(r10 - 4) = r2 */
+		BPF_STX_MEM(BPF_W, BPF_REG_10, BPF_REG_2, -4),
+		/* r1 = xskmap[] */
+		BPF_LD_MAP_FD(BPF_REG_1, ctx->xsks_map_fd),
+		/* r3 = XDP_PASS */
+		BPF_MOV64_IMM(BPF_REG_3, 2),
+		/* call bpf_redirect_map */
+		BPF_EMIT_CALL(BPF_FUNC_redirect_map),
+		/* if w0 != 0 goto pc+13 */
+		BPF_JMP32_IMM(BPF_JSGT, BPF_REG_0, 0, 13),
+		/* r2 = r10 */
+		BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
+		/* r2 += -4 */
+		BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -4),
+		/* r1 = xskmap[] */
+		BPF_LD_MAP_FD(BPF_REG_1, ctx->xsks_map_fd),
+		/* call bpf_map_lookup_elem */
+		BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem),
+		/* r1 = r0 */
+		BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
+		/* r0 = XDP_PASS */
+		BPF_MOV64_IMM(BPF_REG_0, 2),
+		/* if r1 == 0 goto pc+5 */
+		BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 5),
+		/* r2 = *(u32 *)(r10 - 4) */
+		BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_10, -4),
+		/* r1 = xskmap[] */
+		BPF_LD_MAP_FD(BPF_REG_1, ctx->xsks_map_fd),
+		/* r3 = 0 */
+		BPF_MOV64_IMM(BPF_REG_3, 0),
+		/* call bpf_redirect_map */
+		BPF_EMIT_CALL(BPF_FUNC_redirect_map),
+		/* The jumps are to this instruction */
+		BPF_EXIT_INSN(),
+	};
+
+	/* This is the post-5.3 kernel C-program:
+	 * SEC("xdp_sock") int xdp_sock_prog(struct xdp_md *ctx)
+	 * {
+	 *     return bpf_redirect_map(&xsks_map, ctx->rx_queue_index, XDP_PASS);
+	 * }
+	 */
+	struct bpf_insn prog_redirect_flags[] = {
+		/* r2 = *(u32 *)(r1 + 16) */
+		BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1, 16),
+		/* r1 = xskmap[] */
+		BPF_LD_MAP_FD(BPF_REG_1, ctx->xsks_map_fd),
+		/* r3 = XDP_PASS */
+		BPF_MOV64_IMM(BPF_REG_3, 2),
+		/* call bpf_redirect_map */
+		BPF_EMIT_CALL(BPF_FUNC_redirect_map),
+		BPF_EXIT_INSN(),
+	};
+	size_t insns_cnt[] = {ARRAY_SIZE(prog),
+			      ARRAY_SIZE(prog_redirect_flags),
+	};
+	struct bpf_insn *progs[] = {prog, prog_redirect_flags};
+	enum xsk_prog option = get_xsk_prog();
+	LIBBPF_OPTS(bpf_prog_load_opts, opts,
+		.log_buf = log_buf,
+		.log_size = log_buf_size,
+	);
+
+	prog_fd = bpf_prog_load(BPF_PROG_TYPE_XDP, NULL, "LGPL-2.1 or BSD-2-Clause",
+				progs[option], insns_cnt[option], &opts);
+	if (prog_fd < 0) {
+		pr_warn("BPF log buffer:\n%s", log_buf);
+		return prog_fd;
+	}
+
+	ctx->prog_fd = prog_fd;
+	return 0;
+}
+
+static int xsk_create_bpf_link(struct xsk_socket *xsk)
+{
+	DECLARE_LIBBPF_OPTS(bpf_link_create_opts, opts);
+	struct xsk_ctx *ctx = xsk->ctx;
+	__u32 prog_id = 0;
+	int link_fd;
+	int err;
+
+	err = bpf_xdp_query_id(ctx->ifindex, xsk->config.xdp_flags, &prog_id);
+	if (err) {
+		pr_warn("getting XDP prog id failed\n");
+		return err;
+	}
+
+	/* if there's a netlink-based XDP prog loaded on interface, bail out
+	 * and ask user to do the removal by himself
+	 */
+	if (prog_id) {
+		pr_warn("Netlink-based XDP prog detected, please unload it in order to launch AF_XDP prog\n");
+		return -EINVAL;
+	}
+
+	opts.flags = xsk->config.xdp_flags & ~(XDP_FLAGS_UPDATE_IF_NOEXIST | XDP_FLAGS_REPLACE);
+
+	link_fd = bpf_link_create(ctx->prog_fd, ctx->ifindex, BPF_XDP, &opts);
+	if (link_fd < 0) {
+		pr_warn("bpf_link_create failed: %s\n", strerror(errno));
+		return link_fd;
+	}
+
+	ctx->link_fd = link_fd;
+	return 0;
+}
+
+/* Copy up to sz - 1 bytes from zero-terminated src string and ensure that dst
+ * is zero-terminated string no matter what (unless sz == 0, in which case
+ * it's a no-op). It's conceptually close to FreeBSD's strlcpy(), but differs
+ * in what is returned. Given this is internal helper, it's trivial to extend
+ * this, when necessary. Use this instead of strncpy inside libbpf source code.
+ */
+static inline void libbpf_strlcpy(char *dst, const char *src, size_t sz)
+{
+        size_t i;
+
+        if (sz == 0)
+                return;
+
+        sz--;
+        for (i = 0; i < sz && src[i]; i++)
+                dst[i] = src[i];
+        dst[i] = '\0';
+}
+
+static int xsk_get_max_queues(struct xsk_socket *xsk)
+{
+	struct ethtool_channels channels = { .cmd = ETHTOOL_GCHANNELS };
+	struct xsk_ctx *ctx = xsk->ctx;
+	struct ifreq ifr = {};
+	int fd, err, ret;
+
+	fd = socket(AF_LOCAL, SOCK_DGRAM | SOCK_CLOEXEC, 0);
+	if (fd < 0)
+		return -errno;
+
+	ifr.ifr_data = (void *)&channels;
+	libbpf_strlcpy(ifr.ifr_name, ctx->ifname, IFNAMSIZ);
+	err = ioctl(fd, SIOCETHTOOL, &ifr);
+	if (err && errno != EOPNOTSUPP) {
+		ret = -errno;
+		goto out;
+	}
+
+	if (err) {
+		/* If the device says it has no channels, then all traffic
+		 * is sent to a single stream, so max queues = 1.
+		 */
+		ret = 1;
+	} else {
+		/* Take the max of rx, tx, combined. Drivers return
+		 * the number of channels in different ways.
+		 */
+		ret = max(channels.max_rx, channels.max_tx);
+		ret = max(ret, (int)channels.max_combined);
+	}
+
+out:
+	close(fd);
+	return ret;
+}
+
+static int xsk_create_bpf_maps(struct xsk_socket *xsk)
+{
+	struct xsk_ctx *ctx = xsk->ctx;
+	int max_queues;
+	int fd;
+
+	max_queues = xsk_get_max_queues(xsk);
+	if (max_queues < 0)
+		return max_queues;
+
+	fd = bpf_map_create(BPF_MAP_TYPE_XSKMAP, "xsks_map",
+			    sizeof(int), sizeof(int), max_queues, NULL);
+	if (fd < 0)
+		return fd;
+
+	ctx->xsks_map_fd = fd;
+
+	return 0;
+}
+
+static void xsk_delete_bpf_maps(struct xsk_socket *xsk)
+{
+	struct xsk_ctx *ctx = xsk->ctx;
+
+	bpf_map_delete_elem(ctx->xsks_map_fd, &ctx->queue_id);
+	close(ctx->xsks_map_fd);
+}
+
+static int xsk_lookup_bpf_maps(struct xsk_socket *xsk)
+{
+	__u32 i, *map_ids, num_maps, prog_len = sizeof(struct bpf_prog_info);
+	__u32 map_len = sizeof(struct bpf_map_info);
+	struct bpf_prog_info prog_info = {};
+	struct xsk_ctx *ctx = xsk->ctx;
+	struct bpf_map_info map_info;
+	int fd, err;
+
+	err = bpf_obj_get_info_by_fd(ctx->prog_fd, &prog_info, &prog_len);
+	if (err)
+		return err;
+
+	num_maps = prog_info.nr_map_ids;
+
+	map_ids = calloc(prog_info.nr_map_ids, sizeof(*map_ids));
+	if (!map_ids)
+		return -ENOMEM;
+
+	memset(&prog_info, 0, prog_len);
+	prog_info.nr_map_ids = num_maps;
+	prog_info.map_ids = (__u64)(unsigned long)map_ids;
+
+	err = bpf_obj_get_info_by_fd(ctx->prog_fd, &prog_info, &prog_len);
+	if (err)
+		goto out_map_ids;
+
+	ctx->xsks_map_fd = -1;
+
+	for (i = 0; i < prog_info.nr_map_ids; i++) {
+		fd = bpf_map_get_fd_by_id(map_ids[i]);
+		if (fd < 0)
+			continue;
+
+		memset(&map_info, 0, map_len);
+		err = bpf_obj_get_info_by_fd(fd, &map_info, &map_len);
+		if (err) {
+			close(fd);
+			continue;
+		}
+
+		if (!strncmp(map_info.name, "xsks_map", sizeof(map_info.name))) {
+			ctx->xsks_map_fd = fd;
+			break;
+		}
+
+		close(fd);
+	}
+
+	if (ctx->xsks_map_fd == -1)
+		err = -ENOENT;
+
+out_map_ids:
+	free(map_ids);
+	return err;
+}
+
+static int xsk_set_bpf_maps(struct xsk_socket *xsk)
+{
+	struct xsk_ctx *ctx = xsk->ctx;
+
+	return bpf_map_update_elem(ctx->xsks_map_fd, &ctx->queue_id,
+				   &xsk->fd, 0);
+}
+
+static int xsk_link_lookup(int ifindex, __u32 *prog_id, int *link_fd)
+{
+	struct bpf_link_info link_info;
+	__u32 link_len;
+	__u32 id = 0;
+	int err;
+	int fd;
+
+	while (true) {
+		err = bpf_link_get_next_id(id, &id);
+		if (err) {
+			if (errno == ENOENT) {
+				err = 0;
+				break;
+			}
+			pr_warn("can't get next link: %s\n", strerror(errno));
+			break;
+		}
+
+		fd = bpf_link_get_fd_by_id(id);
+		if (fd < 0) {
+			if (errno == ENOENT)
+				continue;
+			pr_warn("can't get link by id (%u): %s\n", id, strerror(errno));
+			err = -errno;
+			break;
+		}
+
+		link_len = sizeof(struct bpf_link_info);
+		memset(&link_info, 0, link_len);
+		err = bpf_obj_get_info_by_fd(fd, &link_info, &link_len);
+		if (err) {
+			pr_warn("can't get link info: %s\n", strerror(errno));
+			close(fd);
+			break;
+		}
+		if (link_info.type == BPF_LINK_TYPE_XDP) {
+			if (link_info.xdp.ifindex == ifindex) {
+				*link_fd = fd;
+				if (prog_id)
+					*prog_id = link_info.prog_id;
+				break;
+			}
+		}
+		close(fd);
+	}
+
+	return err;
+}
+
+static bool xsk_probe_bpf_link(void)
+{
+	LIBBPF_OPTS(bpf_link_create_opts, opts, .flags = XDP_FLAGS_SKB_MODE);
+	struct bpf_insn insns[2] = {
+		BPF_MOV64_IMM(BPF_REG_0, XDP_PASS),
+		BPF_EXIT_INSN()
+	};
+	int prog_fd, link_fd = -1, insn_cnt = ARRAY_SIZE(insns);
+	int ifindex_lo = 1;
+	bool ret = false;
+	int err;
+
+	err = xsk_link_lookup(ifindex_lo, NULL, &link_fd);
+	if (err)
+		return ret;
+
+	if (link_fd >= 0)
+		return true;
+
+	prog_fd = bpf_prog_load(BPF_PROG_TYPE_XDP, NULL, "GPL", insns, insn_cnt, NULL);
+	if (prog_fd < 0)
+		return ret;
+
+	link_fd = bpf_link_create(prog_fd, ifindex_lo, BPF_XDP, &opts);
+	close(prog_fd);
+
+	if (link_fd >= 0) {
+		ret = true;
+		close(link_fd);
+	}
+
+	return ret;
+}
+
+static int xsk_create_xsk_struct(int ifindex, struct xsk_socket *xsk)
+{
+	char ifname[IFNAMSIZ];
+	struct xsk_ctx *ctx;
+	char *interface;
+
+	ctx = calloc(1, sizeof(*ctx));
+	if (!ctx)
+		return -ENOMEM;
+
+	interface = if_indextoname(ifindex, &ifname[0]);
+	if (!interface) {
+		free(ctx);
+		return -errno;
+	}
+
+	ctx->ifindex = ifindex;
+	libbpf_strlcpy(ctx->ifname, ifname, IFNAMSIZ);
+
+	xsk->ctx = ctx;
+	xsk->ctx->has_bpf_link = xsk_probe_bpf_link();
+
+	return 0;
+}
+
+static int xsk_init_xdp_res(struct xsk_socket *xsk,
+			    int *xsks_map_fd)
+{
+	struct xsk_ctx *ctx = xsk->ctx;
+	int err;
+
+	err = xsk_create_bpf_maps(xsk);
+	if (err)
+		return err;
+
+	err = xsk_load_xdp_prog(xsk);
+	if (err)
+		goto err_load_xdp_prog;
+
+	if (ctx->has_bpf_link)
+		err = xsk_create_bpf_link(xsk);
+	else
+		err = bpf_xdp_attach(xsk->ctx->ifindex, ctx->prog_fd,
+				     xsk->config.xdp_flags, NULL);
+
+	if (err)
+		goto err_attach_xdp_prog;
+
+	if (!xsk->rx)
+		return err;
+
+	err = xsk_set_bpf_maps(xsk);
+	if (err)
+		goto err_set_bpf_maps;
+
+	return err;
+
+err_set_bpf_maps:
+	if (ctx->has_bpf_link)
+		close(ctx->link_fd);
+	else
+		bpf_xdp_detach(ctx->ifindex, 0, NULL);
+err_attach_xdp_prog:
+	close(ctx->prog_fd);
+err_load_xdp_prog:
+	xsk_delete_bpf_maps(xsk);
+	return err;
+}
+
+static int xsk_lookup_xdp_res(struct xsk_socket *xsk, int *xsks_map_fd, int prog_id)
+{
+	struct xsk_ctx *ctx = xsk->ctx;
+	int err;
+
+	ctx->prog_fd = bpf_prog_get_fd_by_id(prog_id);
+	if (ctx->prog_fd < 0) {
+		err = -errno;
+		goto err_prog_fd;
+	}
+	err = xsk_lookup_bpf_maps(xsk);
+	if (err)
+		goto err_lookup_maps;
+
+	if (!xsk->rx)
+		return err;
+
+	err = xsk_set_bpf_maps(xsk);
+	if (err)
+		goto err_set_maps;
+
+	return err;
+
+err_set_maps:
+	close(ctx->xsks_map_fd);
+err_lookup_maps:
+	close(ctx->prog_fd);
+err_prog_fd:
+	if (ctx->has_bpf_link)
+		close(ctx->link_fd);
+	return err;
+}
+
+static int __xsk_setup_xdp_prog(struct xsk_socket *_xdp, int *xsks_map_fd)
+{
+	struct xsk_socket *xsk = _xdp;
+	struct xsk_ctx *ctx = xsk->ctx;
+	__u32 prog_id = 0;
+	int err;
+
+	if (ctx->has_bpf_link)
+		err = xsk_link_lookup(ctx->ifindex, &prog_id, &ctx->link_fd);
+	else
+		err = bpf_xdp_query_id(ctx->ifindex, xsk->config.xdp_flags, &prog_id);
+
+	if (err)
+		return err;
+
+	err = !prog_id ? xsk_init_xdp_res(xsk, xsks_map_fd) :
+			 xsk_lookup_xdp_res(xsk, xsks_map_fd, prog_id);
+
+	if (!err && xsks_map_fd)
+		*xsks_map_fd = ctx->xsks_map_fd;
+
+	return err;
+}
+
+static struct xsk_ctx *xsk_get_ctx(struct xsk_umem *umem, int ifindex,
+				   __u32 queue_id)
+{
+	struct xsk_ctx *ctx;
+
+	if (list_empty(&umem->ctx_list))
+		return NULL;
+
+	list_for_each_entry(ctx, &umem->ctx_list, list) {
+		if (ctx->ifindex == ifindex && ctx->queue_id == queue_id) {
+			ctx->refcount++;
+			return ctx;
+		}
+	}
+
+	return NULL;
+}
+
+static void xsk_put_ctx(struct xsk_ctx *ctx, bool unmap)
+{
+	struct xsk_umem *umem = ctx->umem;
+	struct xdp_mmap_offsets off;
+	int err;
+
+	if (--ctx->refcount)
+		return;
+
+	if (!unmap)
+		goto out_free;
+
+	err = xsk_get_mmap_offsets(umem->fd, &off);
+	if (err)
+		goto out_free;
+
+	munmap(ctx->fill->ring - off.fr.desc, off.fr.desc + umem->config.fill_size *
+	       sizeof(__u64));
+	munmap(ctx->comp->ring - off.cr.desc, off.cr.desc + umem->config.comp_size *
+	       sizeof(__u64));
+
+out_free:
+	list_del(&ctx->list);
+	free(ctx);
+}
+
+static struct xsk_ctx *xsk_create_ctx(struct xsk_socket *xsk,
+				      struct xsk_umem *umem, int ifindex,
+				      const char *ifname, __u32 queue_id,
+				      struct xsk_ring_prod *fill,
+				      struct xsk_ring_cons *comp)
+{
+	struct xsk_ctx *ctx;
+	int err;
+
+	ctx = calloc(1, sizeof(*ctx));
+	if (!ctx)
+		return NULL;
+
+	if (!umem->fill_save) {
+		err = xsk_create_umem_rings(umem, xsk->fd, fill, comp);
+		if (err) {
+			free(ctx);
+			return NULL;
+		}
+	} else if (umem->fill_save != fill || umem->comp_save != comp) {
+		/* Copy over rings to new structs. */
+		memcpy(fill, umem->fill_save, sizeof(*fill));
+		memcpy(comp, umem->comp_save, sizeof(*comp));
+	}
+
+	ctx->ifindex = ifindex;
+	ctx->refcount = 1;
+	ctx->umem = umem;
+	ctx->queue_id = queue_id;
+	libbpf_strlcpy(ctx->ifname, ifname, IFNAMSIZ);
+
+	ctx->fill = fill;
+	ctx->comp = comp;
+	list_add(&ctx->list, &umem->ctx_list);
+	return ctx;
+}
+
+static void xsk_destroy_xsk_struct(struct xsk_socket *xsk)
+{
+	free(xsk->ctx);
+	free(xsk);
+}
+
+int xsk_socket__update_xskmap(struct xsk_socket *xsk, int fd)
+{
+	xsk->ctx->xsks_map_fd = fd;
+	return xsk_set_bpf_maps(xsk);
+}
+
+int xsk_setup_xdp_prog(int ifindex, int *xsks_map_fd)
+{
+	struct xsk_socket *xsk;
+	int res;
+
+	xsk = calloc(1, sizeof(*xsk));
+	if (!xsk)
+		return -ENOMEM;
+
+	res = xsk_create_xsk_struct(ifindex, xsk);
+	if (res) {
+		free(xsk);
+		return -EINVAL;
+	}
+
+	res = __xsk_setup_xdp_prog(xsk, xsks_map_fd);
+
+	xsk_destroy_xsk_struct(xsk);
+
+	return res;
+}
+
+int xsk_socket__create_shared(struct xsk_socket **xsk_ptr,
+			      const char *ifname,
+			      __u32 queue_id, struct xsk_umem *umem,
+			      struct xsk_ring_cons *rx,
+			      struct xsk_ring_prod *tx,
+			      struct xsk_ring_prod *fill,
+			      struct xsk_ring_cons *comp,
+			      const struct xsk_socket_config *usr_config)
+{
+	bool unmap, rx_setup_done = false, tx_setup_done = false;
+	void *rx_map = NULL, *tx_map = NULL;
+	struct sockaddr_xdp sxdp = {};
+	struct xdp_mmap_offsets off;
+	struct xsk_socket *xsk;
+	struct xsk_ctx *ctx;
+	int err, ifindex;
+
+	if (!umem || !xsk_ptr || !(rx || tx))
+		return -EFAULT;
+
+	unmap = umem->fill_save != fill;
+
+	xsk = calloc(1, sizeof(*xsk));
+	if (!xsk)
+		return -ENOMEM;
+
+	err = xsk_set_xdp_socket_config(&xsk->config, usr_config);
+	if (err)
+		goto out_xsk_alloc;
+
+	xsk->outstanding_tx = 0;
+	ifindex = if_nametoindex(ifname);
+	if (!ifindex) {
+		err = -errno;
+		goto out_xsk_alloc;
+	}
+
+	if (umem->refcount++ > 0) {
+		xsk->fd = socket(AF_XDP, SOCK_RAW | SOCK_CLOEXEC, 0);
+		if (xsk->fd < 0) {
+			err = -errno;
+			goto out_xsk_alloc;
+		}
+	} else {
+		xsk->fd = umem->fd;
+		rx_setup_done = umem->rx_ring_setup_done;
+		tx_setup_done = umem->tx_ring_setup_done;
+	}
+
+	ctx = xsk_get_ctx(umem, ifindex, queue_id);
+	if (!ctx) {
+		if (!fill || !comp) {
+			err = -EFAULT;
+			goto out_socket;
+		}
+
+		ctx = xsk_create_ctx(xsk, umem, ifindex, ifname, queue_id,
+				     fill, comp);
+		if (!ctx) {
+			err = -ENOMEM;
+			goto out_socket;
+		}
+	}
+	xsk->ctx = ctx;
+	xsk->ctx->has_bpf_link = xsk_probe_bpf_link();
+
+	if (rx && !rx_setup_done) {
+		err = setsockopt(xsk->fd, SOL_XDP, XDP_RX_RING,
+				 &xsk->config.rx_size,
+				 sizeof(xsk->config.rx_size));
+		if (err) {
+			err = -errno;
+			goto out_put_ctx;
+		}
+		if (xsk->fd == umem->fd)
+			umem->rx_ring_setup_done = true;
+	}
+	if (tx && !tx_setup_done) {
+		err = setsockopt(xsk->fd, SOL_XDP, XDP_TX_RING,
+				 &xsk->config.tx_size,
+				 sizeof(xsk->config.tx_size));
+		if (err) {
+			err = -errno;
+			goto out_put_ctx;
+		}
+		if (xsk->fd == umem->fd)
+			umem->tx_ring_setup_done = true;
+	}
+
+	err = xsk_get_mmap_offsets(xsk->fd, &off);
+	if (err) {
+		err = -errno;
+		goto out_put_ctx;
+	}
+
+	if (rx) {
+		rx_map = mmap(NULL, off.rx.desc +
+			      xsk->config.rx_size * sizeof(struct xdp_desc),
+			      PROT_READ | PROT_WRITE, MAP_SHARED | MAP_POPULATE,
+			      xsk->fd, XDP_PGOFF_RX_RING);
+		if (rx_map == MAP_FAILED) {
+			err = -errno;
+			goto out_put_ctx;
+		}
+
+		rx->mask = xsk->config.rx_size - 1;
+		rx->size = xsk->config.rx_size;
+		rx->producer = rx_map + off.rx.producer;
+		rx->consumer = rx_map + off.rx.consumer;
+		rx->flags = rx_map + off.rx.flags;
+		rx->ring = rx_map + off.rx.desc;
+		rx->cached_prod = *rx->producer;
+		rx->cached_cons = *rx->consumer;
+	}
+	xsk->rx = rx;
+
+	if (tx) {
+		tx_map = mmap(NULL, off.tx.desc +
+			      xsk->config.tx_size * sizeof(struct xdp_desc),
+			      PROT_READ | PROT_WRITE, MAP_SHARED | MAP_POPULATE,
+			      xsk->fd, XDP_PGOFF_TX_RING);
+		if (tx_map == MAP_FAILED) {
+			err = -errno;
+			goto out_mmap_rx;
+		}
+
+		tx->mask = xsk->config.tx_size - 1;
+		tx->size = xsk->config.tx_size;
+		tx->producer = tx_map + off.tx.producer;
+		tx->consumer = tx_map + off.tx.consumer;
+		tx->flags = tx_map + off.tx.flags;
+		tx->ring = tx_map + off.tx.desc;
+		tx->cached_prod = *tx->producer;
+		/* cached_cons is r->size bigger than the real consumer pointer
+		 * See xsk_prod_nb_free
+		 */
+		tx->cached_cons = *tx->consumer + xsk->config.tx_size;
+	}
+	xsk->tx = tx;
+
+	sxdp.sxdp_family = PF_XDP;
+	sxdp.sxdp_ifindex = ctx->ifindex;
+	sxdp.sxdp_queue_id = ctx->queue_id;
+	if (umem->refcount > 1) {
+		sxdp.sxdp_flags |= XDP_SHARED_UMEM;
+		sxdp.sxdp_shared_umem_fd = umem->fd;
+	} else {
+		sxdp.sxdp_flags = xsk->config.bind_flags;
+	}
+
+	err = bind(xsk->fd, (struct sockaddr *)&sxdp, sizeof(sxdp));
+	if (err) {
+		err = -errno;
+		goto out_mmap_tx;
+	}
+
+	ctx->prog_fd = -1;
+
+	if (!(xsk->config.libbpf_flags & XSK_LIBBPF_FLAGS__INHIBIT_PROG_LOAD)) {
+		err = __xsk_setup_xdp_prog(xsk, NULL);
+		if (err)
+			goto out_mmap_tx;
+	}
+
+	*xsk_ptr = xsk;
+	umem->fill_save = NULL;
+	umem->comp_save = NULL;
+	return 0;
+
+out_mmap_tx:
+	if (tx)
+		munmap(tx_map, off.tx.desc +
+		       xsk->config.tx_size * sizeof(struct xdp_desc));
+out_mmap_rx:
+	if (rx)
+		munmap(rx_map, off.rx.desc +
+		       xsk->config.rx_size * sizeof(struct xdp_desc));
+out_put_ctx:
+	xsk_put_ctx(ctx, unmap);
+out_socket:
+	if (--umem->refcount)
+		close(xsk->fd);
+out_xsk_alloc:
+	free(xsk);
+	return err;
+}
+
+int xsk_socket__create(struct xsk_socket **xsk_ptr, const char *ifname,
+		       __u32 queue_id, struct xsk_umem *umem,
+		       struct xsk_ring_cons *rx, struct xsk_ring_prod *tx,
+		       const struct xsk_socket_config *usr_config)
+{
+	if (!umem)
+		return -EFAULT;
+
+	return xsk_socket__create_shared(xsk_ptr, ifname, queue_id, umem,
+					 rx, tx, umem->fill_save,
+					 umem->comp_save, usr_config);
+}
+
+int xsk_umem__delete(struct xsk_umem *umem)
+{
+	struct xdp_mmap_offsets off;
+	int err;
+
+	if (!umem)
+		return 0;
+
+	if (umem->refcount)
+		return -EBUSY;
+
+	err = xsk_get_mmap_offsets(umem->fd, &off);
+	if (!err && umem->fill_save && umem->comp_save) {
+		munmap(umem->fill_save->ring - off.fr.desc,
+		       off.fr.desc + umem->config.fill_size * sizeof(__u64));
+		munmap(umem->comp_save->ring - off.cr.desc,
+		       off.cr.desc + umem->config.comp_size * sizeof(__u64));
+	}
+
+	close(umem->fd);
+	free(umem);
+
+	return 0;
+}
+
+void xsk_socket__delete(struct xsk_socket *xsk)
+{
+	size_t desc_sz = sizeof(struct xdp_desc);
+	struct xdp_mmap_offsets off;
+	struct xsk_umem *umem;
+	struct xsk_ctx *ctx;
+	int err;
+
+	if (!xsk)
+		return;
+
+	ctx = xsk->ctx;
+	umem = ctx->umem;
+	if (ctx->prog_fd != -1) {
+		xsk_delete_bpf_maps(xsk);
+		close(ctx->prog_fd);
+		if (ctx->has_bpf_link)
+			close(ctx->link_fd);
+	}
+
+	err = xsk_get_mmap_offsets(xsk->fd, &off);
+	if (!err) {
+		if (xsk->rx) {
+			munmap(xsk->rx->ring - off.rx.desc,
+			       off.rx.desc + xsk->config.rx_size * desc_sz);
+		}
+		if (xsk->tx) {
+			munmap(xsk->tx->ring - off.tx.desc,
+			       off.tx.desc + xsk->config.tx_size * desc_sz);
+		}
+	}
+
+	xsk_put_ctx(ctx, true);
+
+	umem->refcount--;
+	/* Do not close an fd that also has an associated umem connected
+	 * to it.
+	 */
+	if (xsk->fd != umem->fd)
+		close(xsk->fd);
+	free(xsk);
+}
diff --git a/tools/testing/selftests/bpf/xsk.h b/tools/testing/selftests/bpf/xsk.h
new file mode 100644
index 000000000000..915e7135337c
--- /dev/null
+++ b/tools/testing/selftests/bpf/xsk.h
@@ -0,0 +1,315 @@
+/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
+
+/*
+ * AF_XDP user-space access library.
+ *
+ * Copyright (c) 2018 - 2019 Intel Corporation.
+ * Copyright (c) 2019 Facebook
+ *
+ * Author(s): Magnus Karlsson <magnus.karlsson@intel.com>
+ */
+
+#ifndef __XSK_H
+#define __XSK_H
+
+#include <stdio.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <linux/if_xdp.h>
+
+#include <bpf/libbpf.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* This whole API has been deprecated and moved to libxdp that can be found at
+ * https://github.com/xdp-project/xdp-tools. The APIs are exactly the same so
+ * it should just be linking with libxdp instead of libbpf for this set of
+ * functionality. If not, please submit a bug report on the aforementioned page.
+ */
+
+/* Load-Acquire Store-Release barriers used by the XDP socket
+ * library. The following macros should *NOT* be considered part of
+ * the xsk.h API, and is subject to change anytime.
+ *
+ * LIBRARY INTERNAL
+ */
+
+#define __XSK_READ_ONCE(x) (*(volatile typeof(x) *)&x)
+#define __XSK_WRITE_ONCE(x, v) (*(volatile typeof(x) *)&x) = (v)
+
+#if defined(__i386__) || defined(__x86_64__)
+# define libbpf_smp_store_release(p, v)					\
+	do {								\
+		asm volatile("" : : : "memory");			\
+		__XSK_WRITE_ONCE(*p, v);				\
+	} while (0)
+# define libbpf_smp_load_acquire(p)					\
+	({								\
+		typeof(*p) ___p1 = __XSK_READ_ONCE(*p);			\
+		asm volatile("" : : : "memory");			\
+		___p1;							\
+	})
+#elif defined(__aarch64__)
+# define libbpf_smp_store_release(p, v)					\
+		asm volatile ("stlr %w1, %0" : "=Q" (*p) : "r" (v) : "memory")
+# define libbpf_smp_load_acquire(p)					\
+	({								\
+		typeof(*p) ___p1;					\
+		asm volatile ("ldar %w0, %1"				\
+			      : "=r" (___p1) : "Q" (*p) : "memory");	\
+		___p1;							\
+	})
+#elif defined(__riscv)
+# define libbpf_smp_store_release(p, v)					\
+	do {								\
+		asm volatile ("fence rw,w" : : : "memory");		\
+		__XSK_WRITE_ONCE(*p, v);				\
+	} while (0)
+# define libbpf_smp_load_acquire(p)					\
+	({								\
+		typeof(*p) ___p1 = __XSK_READ_ONCE(*p);			\
+		asm volatile ("fence r,rw" : : : "memory");		\
+		___p1;							\
+	})
+#endif
+
+#ifndef libbpf_smp_store_release
+#define libbpf_smp_store_release(p, v)					\
+	do {								\
+		__sync_synchronize();					\
+		__XSK_WRITE_ONCE(*p, v);				\
+	} while (0)
+#endif
+
+#ifndef libbpf_smp_load_acquire
+#define libbpf_smp_load_acquire(p)					\
+	({								\
+		typeof(*p) ___p1 = __XSK_READ_ONCE(*p);			\
+		__sync_synchronize();					\
+		___p1;							\
+	})
+#endif
+
+/* LIBRARY INTERNAL -- END */
+
+/* Do not access these members directly. Use the functions below. */
+#define DEFINE_XSK_RING(name) \
+struct name { \
+	__u32 cached_prod; \
+	__u32 cached_cons; \
+	__u32 mask; \
+	__u32 size; \
+	__u32 *producer; \
+	__u32 *consumer; \
+	void *ring; \
+	__u32 *flags; \
+}
+
+DEFINE_XSK_RING(xsk_ring_prod);
+DEFINE_XSK_RING(xsk_ring_cons);
+
+/* For a detailed explanation on the memory barriers associated with the
+ * ring, please take a look at net/xdp/xsk_queue.h.
+ */
+
+struct xsk_umem;
+struct xsk_socket;
+
+static inline __u64 *xsk_ring_prod__fill_addr(struct xsk_ring_prod *fill,
+					      __u32 idx)
+{
+	__u64 *addrs = (__u64 *)fill->ring;
+
+	return &addrs[idx & fill->mask];
+}
+
+static inline const __u64 *
+xsk_ring_cons__comp_addr(const struct xsk_ring_cons *comp, __u32 idx)
+{
+	const __u64 *addrs = (const __u64 *)comp->ring;
+
+	return &addrs[idx & comp->mask];
+}
+
+static inline struct xdp_desc *xsk_ring_prod__tx_desc(struct xsk_ring_prod *tx,
+						      __u32 idx)
+{
+	struct xdp_desc *descs = (struct xdp_desc *)tx->ring;
+
+	return &descs[idx & tx->mask];
+}
+
+static inline const struct xdp_desc *
+xsk_ring_cons__rx_desc(const struct xsk_ring_cons *rx, __u32 idx)
+{
+	const struct xdp_desc *descs = (const struct xdp_desc *)rx->ring;
+
+	return &descs[idx & rx->mask];
+}
+
+static inline int xsk_ring_prod__needs_wakeup(const struct xsk_ring_prod *r)
+{
+	return *r->flags & XDP_RING_NEED_WAKEUP;
+}
+
+static inline __u32 xsk_prod_nb_free(struct xsk_ring_prod *r, __u32 nb)
+{
+	__u32 free_entries = r->cached_cons - r->cached_prod;
+
+	if (free_entries >= nb)
+		return free_entries;
+
+	/* Refresh the local tail pointer.
+	 * cached_cons is r->size bigger than the real consumer pointer so
+	 * that this addition can be avoided in the more frequently
+	 * executed code that computs free_entries in the beginning of
+	 * this function. Without this optimization it whould have been
+	 * free_entries = r->cached_prod - r->cached_cons + r->size.
+	 */
+	r->cached_cons = libbpf_smp_load_acquire(r->consumer);
+	r->cached_cons += r->size;
+
+	return r->cached_cons - r->cached_prod;
+}
+
+static inline __u32 xsk_cons_nb_avail(struct xsk_ring_cons *r, __u32 nb)
+{
+	__u32 entries = r->cached_prod - r->cached_cons;
+
+	if (entries == 0) {
+		r->cached_prod = libbpf_smp_load_acquire(r->producer);
+		entries = r->cached_prod - r->cached_cons;
+	}
+
+	return (entries > nb) ? nb : entries;
+}
+
+static inline __u32 xsk_ring_prod__reserve(struct xsk_ring_prod *prod, __u32 nb, __u32 *idx)
+{
+	if (xsk_prod_nb_free(prod, nb) < nb)
+		return 0;
+
+	*idx = prod->cached_prod;
+	prod->cached_prod += nb;
+
+	return nb;
+}
+
+static inline void xsk_ring_prod__submit(struct xsk_ring_prod *prod, __u32 nb)
+{
+	/* Make sure everything has been written to the ring before indicating
+	 * this to the kernel by writing the producer pointer.
+	 */
+	libbpf_smp_store_release(prod->producer, *prod->producer + nb);
+}
+
+static inline __u32 xsk_ring_cons__peek(struct xsk_ring_cons *cons, __u32 nb, __u32 *idx)
+{
+	__u32 entries = xsk_cons_nb_avail(cons, nb);
+
+	if (entries > 0) {
+		*idx = cons->cached_cons;
+		cons->cached_cons += entries;
+	}
+
+	return entries;
+}
+
+static inline void xsk_ring_cons__cancel(struct xsk_ring_cons *cons, __u32 nb)
+{
+	cons->cached_cons -= nb;
+}
+
+static inline void xsk_ring_cons__release(struct xsk_ring_cons *cons, __u32 nb)
+{
+	/* Make sure data has been read before indicating we are done
+	 * with the entries by updating the consumer pointer.
+	 */
+	libbpf_smp_store_release(cons->consumer, *cons->consumer + nb);
+
+}
+
+static inline void *xsk_umem__get_data(void *umem_area, __u64 addr)
+{
+	return &((char *)umem_area)[addr];
+}
+
+static inline __u64 xsk_umem__extract_addr(__u64 addr)
+{
+	return addr & XSK_UNALIGNED_BUF_ADDR_MASK;
+}
+
+static inline __u64 xsk_umem__extract_offset(__u64 addr)
+{
+	return addr >> XSK_UNALIGNED_BUF_OFFSET_SHIFT;
+}
+
+static inline __u64 xsk_umem__add_offset_to_addr(__u64 addr)
+{
+	return xsk_umem__extract_addr(addr) + xsk_umem__extract_offset(addr);
+}
+
+int xsk_umem__fd(const struct xsk_umem *umem);
+int xsk_socket__fd(const struct xsk_socket *xsk);
+
+#define XSK_RING_CONS__DEFAULT_NUM_DESCS      2048
+#define XSK_RING_PROD__DEFAULT_NUM_DESCS      2048
+#define XSK_UMEM__DEFAULT_FRAME_SHIFT    12 /* 4096 bytes */
+#define XSK_UMEM__DEFAULT_FRAME_SIZE     (1 << XSK_UMEM__DEFAULT_FRAME_SHIFT)
+#define XSK_UMEM__DEFAULT_FRAME_HEADROOM 0
+#define XSK_UMEM__DEFAULT_FLAGS 0
+
+struct xsk_umem_config {
+	__u32 fill_size;
+	__u32 comp_size;
+	__u32 frame_size;
+	__u32 frame_headroom;
+	__u32 flags;
+};
+
+int xsk_setup_xdp_prog(int ifindex, int *xsks_map_fd);
+int xsk_socket__update_xskmap(struct xsk_socket *xsk, int xsks_map_fd);
+
+/* Flags for the libbpf_flags field. */
+#define XSK_LIBBPF_FLAGS__INHIBIT_PROG_LOAD (1 << 0)
+
+struct xsk_socket_config {
+	__u32 rx_size;
+	__u32 tx_size;
+	__u32 libbpf_flags;
+	__u32 xdp_flags;
+	__u16 bind_flags;
+};
+
+/* Set config to NULL to get the default configuration. */
+int xsk_umem__create(struct xsk_umem **umem,
+		     void *umem_area, __u64 size,
+		     struct xsk_ring_prod *fill,
+		     struct xsk_ring_cons *comp,
+		     const struct xsk_umem_config *config);
+int xsk_socket__create(struct xsk_socket **xsk,
+		       const char *ifname, __u32 queue_id,
+		       struct xsk_umem *umem,
+		       struct xsk_ring_cons *rx,
+		       struct xsk_ring_prod *tx,
+		       const struct xsk_socket_config *config);
+int xsk_socket__create_shared(struct xsk_socket **xsk_ptr,
+			      const char *ifname,
+			      __u32 queue_id, struct xsk_umem *umem,
+			      struct xsk_ring_cons *rx,
+			      struct xsk_ring_prod *tx,
+			      struct xsk_ring_prod *fill,
+			      struct xsk_ring_cons *comp,
+			      const struct xsk_socket_config *config);
+
+/* Returns 0 for success and -EBUSY if the umem is still in use. */
+int xsk_umem__delete(struct xsk_umem *umem);
+void xsk_socket__delete(struct xsk_socket *xsk);
+
+#ifdef __cplusplus
+} /* extern "C" */
+#endif
+
+#endif /* __XSK_H */