7 files changed, 94 insertions, 11 deletions

diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
index b0f1913763a3..9dc9625651dc 100644
--- a/tools/lib/bpf/bpf.c
+++ b/tools/lib/bpf/bpf.c
@@ -810,6 +810,22 @@ int bpf_link_create(int prog_fd, int target_fd,
 		if (!OPTS_ZEROED(opts, tcx))
 			return libbpf_err(-EINVAL);
 		break;
+	case BPF_NETKIT_PRIMARY:
+	case BPF_NETKIT_PEER:
+		relative_fd = OPTS_GET(opts, netkit.relative_fd, 0);
+		relative_id = OPTS_GET(opts, netkit.relative_id, 0);
+		if (relative_fd && relative_id)
+			return libbpf_err(-EINVAL);
+		if (relative_id) {
+			attr.link_create.netkit.relative_id = relative_id;
+			attr.link_create.flags |= BPF_F_ID;
+		} else {
+			attr.link_create.netkit.relative_fd = relative_fd;
+		}
+		attr.link_create.netkit.expected_revision = OPTS_GET(opts, netkit.expected_revision, 0);
+		if (!OPTS_ZEROED(opts, netkit))
+			return libbpf_err(-EINVAL);
+		break;
 	default:
 		if (!OPTS_ZEROED(opts, flags))
 			return libbpf_err(-EINVAL);
diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h
index 74c2887cfd24..d0f53772bdc0 100644
--- a/tools/lib/bpf/bpf.h
+++ b/tools/lib/bpf/bpf.h
@@ -415,6 +415,11 @@ struct bpf_link_create_opts {
 			__u32 relative_id;
 			__u64 expected_revision;
 		} tcx;
+		struct {
+			__u32 relative_fd;
+			__u32 relative_id;
+			__u64 expected_revision;
+		} netkit;
 	};
 	size_t :0;
 };
diff --git a/tools/lib/bpf/elf.c b/tools/lib/bpf/elf.c
index 2a158e8a8b7c..2a62bf411bb3 100644
--- a/tools/lib/bpf/elf.c
+++ b/tools/lib/bpf/elf.c
@@ -141,14 +141,15 @@ static int elf_sym_iter_new(struct elf_sym_iter *iter,
 	iter->versyms = elf_getdata(scn, 0);
 
 	scn = elf_find_next_scn_by_type(elf, SHT_GNU_verdef, NULL);
-	if (!scn) {
-		pr_debug("elf: failed to find verdef ELF sections in '%s'\n", binary_path);
-		return -ENOENT;
-	}
-	if (!gelf_getshdr(scn, &sh))
+	if (!scn)
+		return 0;
+
+	iter->verdefs = elf_getdata(scn, 0);
+	if (!iter->verdefs || !gelf_getshdr(scn, &sh)) {
+		pr_warn("elf: failed to get verdef ELF section in '%s'\n", binary_path);
 		return -EINVAL;
+	}
 	iter->verdef_strtabidx = sh.sh_link;
-	iter->verdefs = elf_getdata(scn, 0);
 
 	return 0;
 }
@@ -199,6 +200,9 @@ static const char *elf_get_vername(struct elf_sym_iter *iter, int ver)
 	GElf_Verdef verdef;
 	int offset;
 
+	if (!iter->verdefs)
+		return NULL;
+
 	offset = 0;
 	while (gelf_getverdef(iter->verdefs, offset, &verdef)) {
 		if (verdef.vd_ndx != ver) {
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index a295f6acf98f..e067be95da3c 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -126,6 +126,8 @@ static const char * const attach_type_name[] = {
 	[BPF_TCX_INGRESS]		= "tcx_ingress",
 	[BPF_TCX_EGRESS]		= "tcx_egress",
 	[BPF_TRACE_UPROBE_MULTI]	= "trace_uprobe_multi",
+	[BPF_NETKIT_PRIMARY]		= "netkit_primary",
+	[BPF_NETKIT_PEER]		= "netkit_peer",
 };
 
 static const char * const link_type_name[] = {
@@ -142,6 +144,7 @@ static const char * const link_type_name[] = {
 	[BPF_LINK_TYPE_NETFILTER]		= "netfilter",
 	[BPF_LINK_TYPE_TCX]			= "tcx",
 	[BPF_LINK_TYPE_UPROBE_MULTI]		= "uprobe_multi",
+	[BPF_LINK_TYPE_NETKIT]			= "netkit",
 };
 
 static const char * const map_type_name[] = {
@@ -8915,6 +8918,8 @@ static const struct bpf_sec_def section_defs[] = {
 	SEC_DEF("tc",			SCHED_CLS, 0, SEC_NONE), /* deprecated / legacy, use tcx */
 	SEC_DEF("classifier",		SCHED_CLS, 0, SEC_NONE), /* deprecated / legacy, use tcx */
 	SEC_DEF("action",		SCHED_ACT, 0, SEC_NONE), /* deprecated / legacy, use tcx */
+	SEC_DEF("netkit/primary",	SCHED_CLS, BPF_NETKIT_PRIMARY, SEC_NONE),
+	SEC_DEF("netkit/peer",		SCHED_CLS, BPF_NETKIT_PEER, SEC_NONE),
 	SEC_DEF("tracepoint+",		TRACEPOINT, 0, SEC_NONE, attach_tp),
 	SEC_DEF("tp+",			TRACEPOINT, 0, SEC_NONE, attach_tp),
 	SEC_DEF("raw_tracepoint+",	RAW_TRACEPOINT, 0, SEC_NONE, attach_raw_tp),
@@ -12126,6 +12131,40 @@ bpf_program__attach_tcx(const struct bpf_program *prog, int ifindex,
 	return bpf_program_attach_fd(prog, ifindex, "tcx", &link_create_opts);
 }
 
+struct bpf_link *
+bpf_program__attach_netkit(const struct bpf_program *prog, int ifindex,
+			   const struct bpf_netkit_opts *opts)
+{
+	LIBBPF_OPTS(bpf_link_create_opts, link_create_opts);
+	__u32 relative_id;
+	int relative_fd;
+
+	if (!OPTS_VALID(opts, bpf_netkit_opts))
+		return libbpf_err_ptr(-EINVAL);
+
+	relative_id = OPTS_GET(opts, relative_id, 0);
+	relative_fd = OPTS_GET(opts, relative_fd, 0);
+
+	/* validate we don't have unexpected combinations of non-zero fields */
+	if (!ifindex) {
+		pr_warn("prog '%s': target netdevice ifindex cannot be zero\n",
+			prog->name);
+		return libbpf_err_ptr(-EINVAL);
+	}
+	if (relative_fd && relative_id) {
+		pr_warn("prog '%s': relative_fd and relative_id cannot be set at the same time\n",
+			prog->name);
+		return libbpf_err_ptr(-EINVAL);
+	}
+
+	link_create_opts.netkit.expected_revision = OPTS_GET(opts, expected_revision, 0);
+	link_create_opts.netkit.relative_fd = relative_fd;
+	link_create_opts.netkit.relative_id = relative_id;
+	link_create_opts.flags = OPTS_GET(opts, flags, 0);
+
+	return bpf_program_attach_fd(prog, ifindex, "netkit", &link_create_opts);
+}
+
 struct bpf_link *bpf_program__attach_freplace(const struct bpf_program *prog,
 					      int target_fd,
 					      const char *attach_func_name)
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index 475378438545..6cd9c501624f 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -800,6 +800,21 @@ LIBBPF_API struct bpf_link *
 bpf_program__attach_tcx(const struct bpf_program *prog, int ifindex,
 			const struct bpf_tcx_opts *opts);
 
+struct bpf_netkit_opts {
+	/* size of this struct, for forward/backward compatibility */
+	size_t sz;
+	__u32 flags;
+	__u32 relative_fd;
+	__u32 relative_id;
+	__u64 expected_revision;
+	size_t :0;
+};
+#define bpf_netkit_opts__last_field expected_revision
+
+LIBBPF_API struct bpf_link *
+bpf_program__attach_netkit(const struct bpf_program *prog, int ifindex,
+			   const struct bpf_netkit_opts *opts);
+
 struct bpf_map;
 
 LIBBPF_API struct bpf_link *bpf_map__attach_struct_ops(const struct bpf_map *map);
diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map
index cc973b678a39..b52dc28dc8af 100644
--- a/tools/lib/bpf/libbpf.map
+++ b/tools/lib/bpf/libbpf.map
@@ -398,6 +398,7 @@ LIBBPF_1.3.0 {
 		bpf_object__unpin;
 		bpf_prog_detach_opts;
 		bpf_program__attach_netfilter;
+		bpf_program__attach_netkit;
 		bpf_program__attach_tcx;
 		bpf_program__attach_uprobe_multi;
 		ring__avail_data_size;
diff --git a/tools/lib/bpf/libbpf_common.h b/tools/lib/bpf/libbpf_common.h
index b7060f254486..8fe248e14eb6 100644
--- a/tools/lib/bpf/libbpf_common.h
+++ b/tools/lib/bpf/libbpf_common.h
@@ -79,11 +79,14 @@
  */
 #define LIBBPF_OPTS_RESET(NAME, ...)					    \
 	do {								    \
-		memset(&NAME, 0, sizeof(NAME));				    \
-		NAME = (typeof(NAME)) {					    \
-			.sz = sizeof(NAME),				    \
-			__VA_ARGS__					    \
-		};							    \
+		typeof(NAME) ___##NAME = ({ 				    \
+			memset(&___##NAME, 0, sizeof(NAME));		    \
+			(typeof(NAME)) {				    \
+				.sz = sizeof(NAME),			    \
+				__VA_ARGS__				    \
+			};						    \
+		});							    \
+		memcpy(&NAME, &___##NAME, sizeof(NAME));		    \
 	} while (0)
 
 #endif /* __LIBBPF_LIBBPF_COMMON_H */