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.orgSigned-off-by: Alexei Starovoitov <ast@kernel.org>

tools/lib/bpf/Build

 libbpf-y := libbpf.o bpf.o nlattr.o btf.o libbpf_errno.o str_error.o \
-	    netlink.o bpf_prog_linfo.o libbpf_probes.o xsk.o hashmap.o \
+	    netlink.o bpf_prog_linfo.o libbpf_probes.o hashmap.o \
 	    btf_dump.o ringbuf.o strset.o linker.o gen_loader.o relo_core.o \
 	    usdt.o

tools/lib/bpf/Makefile

@@ -237,7 +237,7 @@ install_lib: all_cmd
 		$(call do_install_mkdir,$(libdir_SQ)); \
 		cp -fpR $(LIB_FILE) $(DESTDIR)$(libdir_SQ)
 
-SRC_HDRS := bpf.h libbpf.h btf.h libbpf_common.h libbpf_legacy.h xsk.h	     \
+SRC_HDRS := bpf.h libbpf.h btf.h libbpf_common.h libbpf_legacy.h	     \
 	    bpf_helpers.h bpf_tracing.h bpf_endian.h bpf_core_read.h	     \
 	    skel_internal.h libbpf_version.h usdt.bpf.h
 GEN_HDRS := $(BPF_GENERATED)

tools/lib/bpf/libbpf.map

@@ -147,12 +147,6 @@ LIBBPF_0.0.2 {
 		btf_ext__new;
 		btf_ext__reloc_func_info;
 		btf_ext__reloc_line_info;
-		xsk_umem__create;
-		xsk_socket__create;
-		xsk_umem__delete;
-		xsk_socket__delete;
-		xsk_umem__fd;
-		xsk_socket__fd;
 		bpf_program__get_prog_info_linear;
 		bpf_program__bpil_addr_to_offs;
 		bpf_program__bpil_offs_to_addr;
@@ -183,7 +177,6 @@ LIBBPF_0.0.4 {
 		perf_buffer__new;
 		perf_buffer__new_raw;
 		perf_buffer__poll;
-		xsk_umem__create;
 } LIBBPF_0.0.3;
 
 LIBBPF_0.0.5 {
@@ -336,7 +329,6 @@ LIBBPF_0.2.0 {
 		perf_buffer__buffer_fd;
 		perf_buffer__epoll_fd;
 		perf_buffer__consume_buffer;
-		xsk_socket__create_shared;
 } LIBBPF_0.1.0;
 
 LIBBPF_0.3.0 {
@@ -348,8 +340,6 @@ LIBBPF_0.3.0 {
 		btf__new_empty_split;
 		btf__new_split;
 		ring_buffer__epoll_fd;
-		xsk_setup_xdp_prog;
-		xsk_socket__update_xskmap;
 } LIBBPF_0.2.0;
 
 LIBBPF_0.4.0 {
@@ -468,6 +458,4 @@ LIBBPF_1.0.0 {
 		libbpf_bpf_link_type_str;
 		libbpf_bpf_map_type_str;
 		libbpf_bpf_prog_type_str;
-
-	local: *;
 };

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)    \

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"
 

tools/lib/bpf/xsk.c → tools/testing/selftests/bpf/xsk.c

@@ -30,16 +30,10 @@
 #include <sys/types.h>
 #include <linux/if_link.h>
 
-#include "bpf.h"
-#include "libbpf.h"
-#include "libbpf_internal.h"
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
 #include "xsk.h"
 
-/* entire xsk.h and xsk.c is going away in libbpf 1.0, so ignore all internal
- * uses of deprecated APIs
- */
-#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
-
 #ifndef SOL_XDP
  #define SOL_XDP 283
 #endif
@@ -52,6 +46,8 @@
  #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,
@@ -286,11 +282,10 @@ static int xsk_create_umem_rings(struct xsk_umem *umem, int fd,
 	return err;
 }
 
-DEFAULT_VERSION(xsk_umem__create_v0_0_4, xsk_umem__create, LIBBPF_0.0.4)
-int xsk_umem__create_v0_0_4(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)
+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;
@@ -351,25 +346,9 @@ struct xsk_umem_config_v1 {
 	__u32 frame_headroom;
 };
 
-COMPAT_VERSION(xsk_umem__create_v0_0_2, xsk_umem__create, LIBBPF_0.0.2)
-int xsk_umem__create_v0_0_2(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 xsk_umem_config config;
-
-	memcpy(&config, usr_config, sizeof(struct xsk_umem_config_v1));
-	config.flags = 0;
-
-	return xsk_umem__create_v0_0_4(umem_ptr, umem_area, size, fill, comp,
-					&config);
-}
-
 static enum xsk_prog get_xsk_prog(void)
 {
 	enum xsk_prog detected = XSK_PROG_FALLBACK;
-	__u32 size_out, retval, duration;
 	char data_in = 0, data_out;
 	struct bpf_insn insns[] = {
 		BPF_LD_MAP_FD(BPF_REG_1, 0),
@@ -378,6 +357,12 @@ static enum xsk_prog get_xsk_prog(void)
 		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);
@@ -392,8 +377,8 @@ static enum xsk_prog get_xsk_prog(void)
 		return detected;
 	}
 
-	ret = bpf_prog_test_run(prog_fd, 0, &data_in, 1, &data_out, &size_out, &retval, &duration);
-	if (!ret && retval == XDP_PASS)
+	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);
@@ -510,7 +495,7 @@ static int xsk_create_bpf_link(struct xsk_socket *xsk)
 	int link_fd;
 	int err;
 
-	err = bpf_get_link_xdp_id(ctx->ifindex, &prog_id, xsk->config.xdp_flags);
+	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;
@@ -536,6 +521,25 @@ static int xsk_create_bpf_link(struct xsk_socket *xsk)
 	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 };
@@ -792,8 +796,8 @@ static int xsk_init_xdp_res(struct xsk_socket *xsk,
 	if (ctx->has_bpf_link)
 		err = xsk_create_bpf_link(xsk);
 	else
-		err = bpf_set_link_xdp_fd(xsk->ctx->ifindex, ctx->prog_fd,
-					  xsk->config.xdp_flags);
+		err = bpf_xdp_attach(xsk->ctx->ifindex, ctx->prog_fd,
+				     xsk->config.xdp_flags, NULL);
 
 	if (err)
 		goto err_attach_xdp_prog;
@@ -811,7 +815,7 @@ static int xsk_init_xdp_res(struct xsk_socket *xsk,
 	if (ctx->has_bpf_link)
 		close(ctx->link_fd);
 	else
-		bpf_set_link_xdp_fd(ctx->ifindex, -1, 0);
+		bpf_xdp_detach(ctx->ifindex, 0, NULL);
 err_attach_xdp_prog:
 	close(ctx->prog_fd);
 err_load_xdp_prog:
@@ -862,7 +866,7 @@ static int __xsk_setup_xdp_prog(struct xsk_socket *_xdp, int *xsks_map_fd)
 	if (ctx->has_bpf_link)
 		err = xsk_link_lookup(ctx->ifindex, &prog_id, &ctx->link_fd);
 	else
-		err = bpf_get_link_xdp_id(ctx->ifindex, &prog_id, xsk->config.xdp_flags);
+		err = bpf_xdp_query_id(ctx->ifindex, xsk->config.xdp_flags, &prog_id);
 
 	if (err)
 		return err;

tools/lib/bpf/xsk.h → tools/testing/selftests/bpf/xsk.h

@@ -9,15 +9,15 @@
  * Author(s): Magnus Karlsson <magnus.karlsson@intel.com>
  */
 
-#ifndef __LIBBPF_XSK_H
-#define __LIBBPF_XSK_H
+#ifndef __XSK_H
+#define __XSK_H
 
 #include <stdio.h>
 #include <stdint.h>
 #include <stdbool.h>
 #include <linux/if_xdp.h>
 
-#include "libbpf.h"
+#include <bpf/libbpf.h>
 
 #ifdef __cplusplus
 extern "C" {
@@ -251,9 +251,7 @@ static inline __u64 xsk_umem__add_offset_to_addr(__u64 addr)
 	return xsk_umem__extract_addr(addr) + xsk_umem__extract_offset(addr);
 }
 
-LIBBPF_API LIBBPF_DEPRECATED_SINCE(0, 7, "AF_XDP support deprecated and moved to libxdp")
 int xsk_umem__fd(const struct xsk_umem *umem);
-LIBBPF_API LIBBPF_DEPRECATED_SINCE(0, 7, "AF_XDP support deprecated and moved to libxdp")
 int xsk_socket__fd(const struct xsk_socket *xsk);
 
 #define XSK_RING_CONS__DEFAULT_NUM_DESCS      2048
@@ -271,9 +269,7 @@ struct xsk_umem_config {
 	__u32 flags;
 };
 
-LIBBPF_API LIBBPF_DEPRECATED_SINCE(0, 7, "AF_XDP support deprecated and moved to libxdp")
 int xsk_setup_xdp_prog(int ifindex, int *xsks_map_fd);
-LIBBPF_API LIBBPF_DEPRECATED_SINCE(0, 7, "AF_XDP support deprecated and moved to libxdp")
 int xsk_socket__update_xskmap(struct xsk_socket *xsk, int xsks_map_fd);
 
 /* Flags for the libbpf_flags field. */
@@ -288,32 +284,17 @@ struct xsk_socket_config {
 };
 
 /* Set config to NULL to get the default configuration. */
-LIBBPF_API LIBBPF_DEPRECATED_SINCE(0, 7, "AF_XDP support deprecated and moved to libxdp")
 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);
-LIBBPF_API LIBBPF_DEPRECATED_SINCE(0, 7, "AF_XDP support deprecated and moved to libxdp")
-int xsk_umem__create_v0_0_2(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);
-LIBBPF_API LIBBPF_DEPRECATED_SINCE(0, 7, "AF_XDP support deprecated and moved to libxdp")
-int xsk_umem__create_v0_0_4(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);
-LIBBPF_API LIBBPF_DEPRECATED_SINCE(0, 7, "AF_XDP support deprecated and moved to libxdp")
 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);
-LIBBPF_API LIBBPF_DEPRECATED_SINCE(0, 7, "AF_XDP support deprecated and moved to libxdp")
 int xsk_socket__create_shared(struct xsk_socket **xsk_ptr,
 			      const char *ifname,
 			      __u32 queue_id, struct xsk_umem *umem,
@@ -324,13 +305,11 @@ int xsk_socket__create_shared(struct xsk_socket **xsk_ptr,
 			      const struct xsk_socket_config *config);
 
 /* Returns 0 for success and -EBUSY if the umem is still in use. */
-LIBBPF_API LIBBPF_DEPRECATED_SINCE(0, 7, "AF_XDP support deprecated and moved to libxdp")
 int xsk_umem__delete(struct xsk_umem *umem);
-LIBBPF_API LIBBPF_DEPRECATED_SINCE(0, 7, "AF_XDP support deprecated and moved to libxdp")
 void xsk_socket__delete(struct xsk_socket *xsk);
 
 #ifdef __cplusplus
 } /* extern "C" */
 #endif
 
-#endif /* __LIBBPF_XSK_H */
+#endif /* __XSK_H */