Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1056 insertions, 0 deletions

diff --git a/tools/bpf/bpftool/link.c b/tools/bpf/bpftool/link.c
new file mode 100644
index 000000000..2e5c231e0
--- /dev/null
+++ b/tools/bpf/bpftool/link.c
@@ -0,0 +1,1056 @@
+// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+/* Copyright (C) 2020 Facebook */
+
+#include <errno.h>
+#include <linux/err.h>
+#include <linux/netfilter.h>
+#include <linux/netfilter_arp.h>
+#include <linux/perf_event.h>
+#include <net/if.h>
+#include <stdio.h>
+#include <unistd.h>
+
+#include <bpf/bpf.h>
+#include <bpf/hashmap.h>
+
+#include "json_writer.h"
+#include "main.h"
+#include "xlated_dumper.h"
+
+#define PERF_HW_CACHE_LEN 128
+
+static struct hashmap *link_table;
+static struct dump_data dd;
+
+static const char *perf_type_name[PERF_TYPE_MAX] = {
+	[PERF_TYPE_HARDWARE]			= "hardware",
+	[PERF_TYPE_SOFTWARE]			= "software",
+	[PERF_TYPE_TRACEPOINT]			= "tracepoint",
+	[PERF_TYPE_HW_CACHE]			= "hw-cache",
+	[PERF_TYPE_RAW]				= "raw",
+	[PERF_TYPE_BREAKPOINT]			= "breakpoint",
+};
+
+const char *event_symbols_hw[PERF_COUNT_HW_MAX] = {
+	[PERF_COUNT_HW_CPU_CYCLES]		= "cpu-cycles",
+	[PERF_COUNT_HW_INSTRUCTIONS]		= "instructions",
+	[PERF_COUNT_HW_CACHE_REFERENCES]	= "cache-references",
+	[PERF_COUNT_HW_CACHE_MISSES]		= "cache-misses",
+	[PERF_COUNT_HW_BRANCH_INSTRUCTIONS]	= "branch-instructions",
+	[PERF_COUNT_HW_BRANCH_MISSES]		= "branch-misses",
+	[PERF_COUNT_HW_BUS_CYCLES]		= "bus-cycles",
+	[PERF_COUNT_HW_STALLED_CYCLES_FRONTEND]	= "stalled-cycles-frontend",
+	[PERF_COUNT_HW_STALLED_CYCLES_BACKEND]	= "stalled-cycles-backend",
+	[PERF_COUNT_HW_REF_CPU_CYCLES]		= "ref-cycles",
+};
+
+const char *event_symbols_sw[PERF_COUNT_SW_MAX] = {
+	[PERF_COUNT_SW_CPU_CLOCK]		= "cpu-clock",
+	[PERF_COUNT_SW_TASK_CLOCK]		= "task-clock",
+	[PERF_COUNT_SW_PAGE_FAULTS]		= "page-faults",
+	[PERF_COUNT_SW_CONTEXT_SWITCHES]	= "context-switches",
+	[PERF_COUNT_SW_CPU_MIGRATIONS]		= "cpu-migrations",
+	[PERF_COUNT_SW_PAGE_FAULTS_MIN]		= "minor-faults",
+	[PERF_COUNT_SW_PAGE_FAULTS_MAJ]		= "major-faults",
+	[PERF_COUNT_SW_ALIGNMENT_FAULTS]	= "alignment-faults",
+	[PERF_COUNT_SW_EMULATION_FAULTS]	= "emulation-faults",
+	[PERF_COUNT_SW_DUMMY]			= "dummy",
+	[PERF_COUNT_SW_BPF_OUTPUT]		= "bpf-output",
+	[PERF_COUNT_SW_CGROUP_SWITCHES]		= "cgroup-switches",
+};
+
+const char *evsel__hw_cache[PERF_COUNT_HW_CACHE_MAX] = {
+	[PERF_COUNT_HW_CACHE_L1D]		= "L1-dcache",
+	[PERF_COUNT_HW_CACHE_L1I]		= "L1-icache",
+	[PERF_COUNT_HW_CACHE_LL]		= "LLC",
+	[PERF_COUNT_HW_CACHE_DTLB]		= "dTLB",
+	[PERF_COUNT_HW_CACHE_ITLB]		= "iTLB",
+	[PERF_COUNT_HW_CACHE_BPU]		= "branch",
+	[PERF_COUNT_HW_CACHE_NODE]		= "node",
+};
+
+const char *evsel__hw_cache_op[PERF_COUNT_HW_CACHE_OP_MAX] = {
+	[PERF_COUNT_HW_CACHE_OP_READ]		= "load",
+	[PERF_COUNT_HW_CACHE_OP_WRITE]		= "store",
+	[PERF_COUNT_HW_CACHE_OP_PREFETCH]	= "prefetch",
+};
+
+const char *evsel__hw_cache_result[PERF_COUNT_HW_CACHE_RESULT_MAX] = {
+	[PERF_COUNT_HW_CACHE_RESULT_ACCESS]	= "refs",
+	[PERF_COUNT_HW_CACHE_RESULT_MISS]	= "misses",
+};
+
+#define perf_event_name(array, id) ({			\
+	const char *event_str = NULL;			\
+							\
+	if ((id) < ARRAY_SIZE(array))			\
+		event_str = array[id];			\
+	event_str;					\
+})
+
+static int link_parse_fd(int *argc, char ***argv)
+{
+	int fd;
+
+	if (is_prefix(**argv, "id")) {
+		unsigned int id;
+		char *endptr;
+
+		NEXT_ARGP();
+
+		id = strtoul(**argv, &endptr, 0);
+		if (*endptr) {
+			p_err("can't parse %s as ID", **argv);
+			return -1;
+		}
+		NEXT_ARGP();
+
+		fd = bpf_link_get_fd_by_id(id);
+		if (fd < 0)
+			p_err("failed to get link with ID %d: %s", id, strerror(errno));
+		return fd;
+	} else if (is_prefix(**argv, "pinned")) {
+		char *path;
+
+		NEXT_ARGP();
+
+		path = **argv;
+		NEXT_ARGP();
+
+		return open_obj_pinned_any(path, BPF_OBJ_LINK);
+	}
+
+	p_err("expected 'id' or 'pinned', got: '%s'?", **argv);
+	return -1;
+}
+
+static void
+show_link_header_json(struct bpf_link_info *info, json_writer_t *wtr)
+{
+	const char *link_type_str;
+
+	jsonw_uint_field(wtr, "id", info->id);
+	link_type_str = libbpf_bpf_link_type_str(info->type);
+	if (link_type_str)
+		jsonw_string_field(wtr, "type", link_type_str);
+	else
+		jsonw_uint_field(wtr, "type", info->type);
+
+	jsonw_uint_field(json_wtr, "prog_id", info->prog_id);
+}
+
+static void show_link_attach_type_json(__u32 attach_type, json_writer_t *wtr)
+{
+	const char *attach_type_str;
+
+	attach_type_str = libbpf_bpf_attach_type_str(attach_type);
+	if (attach_type_str)
+		jsonw_string_field(wtr, "attach_type", attach_type_str);
+	else
+		jsonw_uint_field(wtr, "attach_type", attach_type);
+}
+
+static void show_link_ifindex_json(__u32 ifindex, json_writer_t *wtr)
+{
+	char devname[IF_NAMESIZE] = "(unknown)";
+
+	if (ifindex)
+		if_indextoname(ifindex, devname);
+	else
+		snprintf(devname, sizeof(devname), "(detached)");
+	jsonw_string_field(wtr, "devname", devname);
+	jsonw_uint_field(wtr, "ifindex", ifindex);
+}
+
+static bool is_iter_map_target(const char *target_name)
+{
+	return strcmp(target_name, "bpf_map_elem") == 0 ||
+	       strcmp(target_name, "bpf_sk_storage_map") == 0;
+}
+
+static bool is_iter_cgroup_target(const char *target_name)
+{
+	return strcmp(target_name, "cgroup") == 0;
+}
+
+static const char *cgroup_order_string(__u32 order)
+{
+	switch (order) {
+	case BPF_CGROUP_ITER_ORDER_UNSPEC:
+		return "order_unspec";
+	case BPF_CGROUP_ITER_SELF_ONLY:
+		return "self_only";
+	case BPF_CGROUP_ITER_DESCENDANTS_PRE:
+		return "descendants_pre";
+	case BPF_CGROUP_ITER_DESCENDANTS_POST:
+		return "descendants_post";
+	case BPF_CGROUP_ITER_ANCESTORS_UP:
+		return "ancestors_up";
+	default: /* won't happen */
+		return "unknown";
+	}
+}
+
+static bool is_iter_task_target(const char *target_name)
+{
+	return strcmp(target_name, "task") == 0 ||
+		strcmp(target_name, "task_file") == 0 ||
+		strcmp(target_name, "task_vma") == 0;
+}
+
+static void show_iter_json(struct bpf_link_info *info, json_writer_t *wtr)
+{
+	const char *target_name = u64_to_ptr(info->iter.target_name);
+
+	jsonw_string_field(wtr, "target_name", target_name);
+
+	if (is_iter_map_target(target_name))
+		jsonw_uint_field(wtr, "map_id", info->iter.map.map_id);
+	else if (is_iter_task_target(target_name)) {
+		if (info->iter.task.tid)
+			jsonw_uint_field(wtr, "tid", info->iter.task.tid);
+		else if (info->iter.task.pid)
+			jsonw_uint_field(wtr, "pid", info->iter.task.pid);
+	}
+
+	if (is_iter_cgroup_target(target_name)) {
+		jsonw_lluint_field(wtr, "cgroup_id", info->iter.cgroup.cgroup_id);
+		jsonw_string_field(wtr, "order",
+				   cgroup_order_string(info->iter.cgroup.order));
+	}
+}
+
+void netfilter_dump_json(const struct bpf_link_info *info, json_writer_t *wtr)
+{
+	jsonw_uint_field(json_wtr, "pf",
+			 info->netfilter.pf);
+	jsonw_uint_field(json_wtr, "hook",
+			 info->netfilter.hooknum);
+	jsonw_int_field(json_wtr, "prio",
+			 info->netfilter.priority);
+	jsonw_uint_field(json_wtr, "flags",
+			 info->netfilter.flags);
+}
+
+static int get_prog_info(int prog_id, struct bpf_prog_info *info)
+{
+	__u32 len = sizeof(*info);
+	int err, prog_fd;
+
+	prog_fd = bpf_prog_get_fd_by_id(prog_id);
+	if (prog_fd < 0)
+		return prog_fd;
+
+	memset(info, 0, sizeof(*info));
+	err = bpf_prog_get_info_by_fd(prog_fd, info, &len);
+	if (err)
+		p_err("can't get prog info: %s", strerror(errno));
+	close(prog_fd);
+	return err;
+}
+
+static int cmp_u64(const void *A, const void *B)
+{
+	const __u64 *a = A, *b = B;
+
+	return *a - *b;
+}
+
+static void
+show_kprobe_multi_json(struct bpf_link_info *info, json_writer_t *wtr)
+{
+	__u32 i, j = 0;
+	__u64 *addrs;
+
+	jsonw_bool_field(json_wtr, "retprobe",
+			 info->kprobe_multi.flags & BPF_F_KPROBE_MULTI_RETURN);
+	jsonw_uint_field(json_wtr, "func_cnt", info->kprobe_multi.count);
+	jsonw_name(json_wtr, "funcs");
+	jsonw_start_array(json_wtr);
+	addrs = u64_to_ptr(info->kprobe_multi.addrs);
+	qsort(addrs, info->kprobe_multi.count, sizeof(addrs[0]), cmp_u64);
+
+	/* Load it once for all. */
+	if (!dd.sym_count)
+		kernel_syms_load(&dd);
+	for (i = 0; i < dd.sym_count; i++) {
+		if (dd.sym_mapping[i].address != addrs[j])
+			continue;
+		jsonw_start_object(json_wtr);
+		jsonw_uint_field(json_wtr, "addr", dd.sym_mapping[i].address);
+		jsonw_string_field(json_wtr, "func", dd.sym_mapping[i].name);
+		/* Print null if it is vmlinux */
+		if (dd.sym_mapping[i].module[0] == '\0') {
+			jsonw_name(json_wtr, "module");
+			jsonw_null(json_wtr);
+		} else {
+			jsonw_string_field(json_wtr, "module", dd.sym_mapping[i].module);
+		}
+		jsonw_end_object(json_wtr);
+		if (j++ == info->kprobe_multi.count)
+			break;
+	}
+	jsonw_end_array(json_wtr);
+}
+
+static void
+show_perf_event_kprobe_json(struct bpf_link_info *info, json_writer_t *wtr)
+{
+	jsonw_bool_field(wtr, "retprobe", info->perf_event.type == BPF_PERF_EVENT_KRETPROBE);
+	jsonw_uint_field(wtr, "addr", info->perf_event.kprobe.addr);
+	jsonw_string_field(wtr, "func",
+			   u64_to_ptr(info->perf_event.kprobe.func_name));
+	jsonw_uint_field(wtr, "offset", info->perf_event.kprobe.offset);
+}
+
+static void
+show_perf_event_uprobe_json(struct bpf_link_info *info, json_writer_t *wtr)
+{
+	jsonw_bool_field(wtr, "retprobe", info->perf_event.type == BPF_PERF_EVENT_URETPROBE);
+	jsonw_string_field(wtr, "file",
+			   u64_to_ptr(info->perf_event.uprobe.file_name));
+	jsonw_uint_field(wtr, "offset", info->perf_event.uprobe.offset);
+}
+
+static void
+show_perf_event_tracepoint_json(struct bpf_link_info *info, json_writer_t *wtr)
+{
+	jsonw_string_field(wtr, "tracepoint",
+			   u64_to_ptr(info->perf_event.tracepoint.tp_name));
+}
+
+static char *perf_config_hw_cache_str(__u64 config)
+{
+	const char *hw_cache, *result, *op;
+	char *str = malloc(PERF_HW_CACHE_LEN);
+
+	if (!str) {
+		p_err("mem alloc failed");
+		return NULL;
+	}
+
+	hw_cache = perf_event_name(evsel__hw_cache, config & 0xff);
+	if (hw_cache)
+		snprintf(str, PERF_HW_CACHE_LEN, "%s-", hw_cache);
+	else
+		snprintf(str, PERF_HW_CACHE_LEN, "%lld-", config & 0xff);
+
+	op = perf_event_name(evsel__hw_cache_op, (config >> 8) & 0xff);
+	if (op)
+		snprintf(str + strlen(str), PERF_HW_CACHE_LEN - strlen(str),
+			 "%s-", op);
+	else
+		snprintf(str + strlen(str), PERF_HW_CACHE_LEN - strlen(str),
+			 "%lld-", (config >> 8) & 0xff);
+
+	result = perf_event_name(evsel__hw_cache_result, config >> 16);
+	if (result)
+		snprintf(str + strlen(str), PERF_HW_CACHE_LEN - strlen(str),
+			 "%s", result);
+	else
+		snprintf(str + strlen(str), PERF_HW_CACHE_LEN - strlen(str),
+			 "%lld", config >> 16);
+	return str;
+}
+
+static const char *perf_config_str(__u32 type, __u64 config)
+{
+	const char *perf_config;
+
+	switch (type) {
+	case PERF_TYPE_HARDWARE:
+		perf_config = perf_event_name(event_symbols_hw, config);
+		break;
+	case PERF_TYPE_SOFTWARE:
+		perf_config = perf_event_name(event_symbols_sw, config);
+		break;
+	case PERF_TYPE_HW_CACHE:
+		perf_config = perf_config_hw_cache_str(config);
+		break;
+	default:
+		perf_config = NULL;
+		break;
+	}
+	return perf_config;
+}
+
+static void
+show_perf_event_event_json(struct bpf_link_info *info, json_writer_t *wtr)
+{
+	__u64 config = info->perf_event.event.config;
+	__u32 type = info->perf_event.event.type;
+	const char *perf_type, *perf_config;
+
+	perf_type = perf_event_name(perf_type_name, type);
+	if (perf_type)
+		jsonw_string_field(wtr, "event_type", perf_type);
+	else
+		jsonw_uint_field(wtr, "event_type", type);
+
+	perf_config = perf_config_str(type, config);
+	if (perf_config)
+		jsonw_string_field(wtr, "event_config", perf_config);
+	else
+		jsonw_uint_field(wtr, "event_config", config);
+
+	if (type == PERF_TYPE_HW_CACHE && perf_config)
+		free((void *)perf_config);
+}
+
+static int show_link_close_json(int fd, struct bpf_link_info *info)
+{
+	struct bpf_prog_info prog_info;
+	const char *prog_type_str;
+	int err;
+
+	jsonw_start_object(json_wtr);
+
+	show_link_header_json(info, json_wtr);
+
+	switch (info->type) {
+	case BPF_LINK_TYPE_RAW_TRACEPOINT:
+		jsonw_string_field(json_wtr, "tp_name",
+				   u64_to_ptr(info->raw_tracepoint.tp_name));
+		break;
+	case BPF_LINK_TYPE_TRACING:
+		err = get_prog_info(info->prog_id, &prog_info);
+		if (err)
+			return err;
+
+		prog_type_str = libbpf_bpf_prog_type_str(prog_info.type);
+		/* libbpf will return NULL for variants unknown to it. */
+		if (prog_type_str)
+			jsonw_string_field(json_wtr, "prog_type", prog_type_str);
+		else
+			jsonw_uint_field(json_wtr, "prog_type", prog_info.type);
+
+		show_link_attach_type_json(info->tracing.attach_type,
+					   json_wtr);
+		jsonw_uint_field(json_wtr, "target_obj_id", info->tracing.target_obj_id);
+		jsonw_uint_field(json_wtr, "target_btf_id", info->tracing.target_btf_id);
+		break;
+	case BPF_LINK_TYPE_CGROUP:
+		jsonw_lluint_field(json_wtr, "cgroup_id",
+				   info->cgroup.cgroup_id);
+		show_link_attach_type_json(info->cgroup.attach_type, json_wtr);
+		break;
+	case BPF_LINK_TYPE_ITER:
+		show_iter_json(info, json_wtr);
+		break;
+	case BPF_LINK_TYPE_NETNS:
+		jsonw_uint_field(json_wtr, "netns_ino",
+				 info->netns.netns_ino);
+		show_link_attach_type_json(info->netns.attach_type, json_wtr);
+		break;
+	case BPF_LINK_TYPE_NETFILTER:
+		netfilter_dump_json(info, json_wtr);
+		break;
+	case BPF_LINK_TYPE_TCX:
+		show_link_ifindex_json(info->tcx.ifindex, json_wtr);
+		show_link_attach_type_json(info->tcx.attach_type, json_wtr);
+		break;
+	case BPF_LINK_TYPE_XDP:
+		show_link_ifindex_json(info->xdp.ifindex, json_wtr);
+		break;
+	case BPF_LINK_TYPE_STRUCT_OPS:
+		jsonw_uint_field(json_wtr, "map_id",
+				 info->struct_ops.map_id);
+		break;
+	case BPF_LINK_TYPE_KPROBE_MULTI:
+		show_kprobe_multi_json(info, json_wtr);
+		break;
+	case BPF_LINK_TYPE_PERF_EVENT:
+		switch (info->perf_event.type) {
+		case BPF_PERF_EVENT_EVENT:
+			show_perf_event_event_json(info, json_wtr);
+			break;
+		case BPF_PERF_EVENT_TRACEPOINT:
+			show_perf_event_tracepoint_json(info, json_wtr);
+			break;
+		case BPF_PERF_EVENT_KPROBE:
+		case BPF_PERF_EVENT_KRETPROBE:
+			show_perf_event_kprobe_json(info, json_wtr);
+			break;
+		case BPF_PERF_EVENT_UPROBE:
+		case BPF_PERF_EVENT_URETPROBE:
+			show_perf_event_uprobe_json(info, json_wtr);
+			break;
+		default:
+			break;
+		}
+		break;
+	default:
+		break;
+	}
+
+	if (!hashmap__empty(link_table)) {
+		struct hashmap_entry *entry;
+
+		jsonw_name(json_wtr, "pinned");
+		jsonw_start_array(json_wtr);
+		hashmap__for_each_key_entry(link_table, entry, info->id)
+			jsonw_string(json_wtr, entry->pvalue);
+		jsonw_end_array(json_wtr);
+	}
+
+	emit_obj_refs_json(refs_table, info->id, json_wtr);
+
+	jsonw_end_object(json_wtr);
+
+	return 0;
+}
+
+static void show_link_header_plain(struct bpf_link_info *info)
+{
+	const char *link_type_str;
+
+	printf("%u: ", info->id);
+	link_type_str = libbpf_bpf_link_type_str(info->type);
+	if (link_type_str)
+		printf("%s  ", link_type_str);
+	else
+		printf("type %u  ", info->type);
+
+	if (info->type == BPF_LINK_TYPE_STRUCT_OPS)
+		printf("map %u  ", info->struct_ops.map_id);
+	else
+		printf("prog %u  ", info->prog_id);
+}
+
+static void show_link_attach_type_plain(__u32 attach_type)
+{
+	const char *attach_type_str;
+
+	attach_type_str = libbpf_bpf_attach_type_str(attach_type);
+	if (attach_type_str)
+		printf("attach_type %s  ", attach_type_str);
+	else
+		printf("attach_type %u  ", attach_type);
+}
+
+static void show_link_ifindex_plain(__u32 ifindex)
+{
+	char devname[IF_NAMESIZE * 2] = "(unknown)";
+	char tmpname[IF_NAMESIZE];
+	char *ret = NULL;
+
+	if (ifindex)
+		ret = if_indextoname(ifindex, tmpname);
+	else
+		snprintf(devname, sizeof(devname), "(detached)");
+	if (ret)
+		snprintf(devname, sizeof(devname), "%s(%d)",
+			 tmpname, ifindex);
+	printf("ifindex %s  ", devname);
+}
+
+static void show_iter_plain(struct bpf_link_info *info)
+{
+	const char *target_name = u64_to_ptr(info->iter.target_name);
+
+	printf("target_name %s  ", target_name);
+
+	if (is_iter_map_target(target_name))
+		printf("map_id %u  ", info->iter.map.map_id);
+	else if (is_iter_task_target(target_name)) {
+		if (info->iter.task.tid)
+			printf("tid %u ", info->iter.task.tid);
+		else if (info->iter.task.pid)
+			printf("pid %u ", info->iter.task.pid);
+	}
+
+	if (is_iter_cgroup_target(target_name)) {
+		printf("cgroup_id %llu  ", info->iter.cgroup.cgroup_id);
+		printf("order %s  ",
+		       cgroup_order_string(info->iter.cgroup.order));
+	}
+}
+
+static const char * const pf2name[] = {
+	[NFPROTO_INET] = "inet",
+	[NFPROTO_IPV4] = "ip",
+	[NFPROTO_ARP] = "arp",
+	[NFPROTO_NETDEV] = "netdev",
+	[NFPROTO_BRIDGE] = "bridge",
+	[NFPROTO_IPV6] = "ip6",
+};
+
+static const char * const inethook2name[] = {
+	[NF_INET_PRE_ROUTING] = "prerouting",
+	[NF_INET_LOCAL_IN] = "input",
+	[NF_INET_FORWARD] = "forward",
+	[NF_INET_LOCAL_OUT] = "output",
+	[NF_INET_POST_ROUTING] = "postrouting",
+};
+
+static const char * const arphook2name[] = {
+	[NF_ARP_IN] = "input",
+	[NF_ARP_OUT] = "output",
+};
+
+void netfilter_dump_plain(const struct bpf_link_info *info)
+{
+	const char *hookname = NULL, *pfname = NULL;
+	unsigned int hook = info->netfilter.hooknum;
+	unsigned int pf = info->netfilter.pf;
+
+	if (pf < ARRAY_SIZE(pf2name))
+		pfname = pf2name[pf];
+
+	switch (pf) {
+	case NFPROTO_BRIDGE: /* bridge shares numbers with enum nf_inet_hooks */
+	case NFPROTO_IPV4:
+	case NFPROTO_IPV6:
+	case NFPROTO_INET:
+		if (hook < ARRAY_SIZE(inethook2name))
+			hookname = inethook2name[hook];
+		break;
+	case NFPROTO_ARP:
+		if (hook < ARRAY_SIZE(arphook2name))
+			hookname = arphook2name[hook];
+	default:
+		break;
+	}
+
+	if (pfname)
+		printf("\n\t%s", pfname);
+	else
+		printf("\n\tpf: %d", pf);
+
+	if (hookname)
+		printf(" %s", hookname);
+	else
+		printf(", hook %u,", hook);
+
+	printf(" prio %d", info->netfilter.priority);
+
+	if (info->netfilter.flags)
+		printf(" flags 0x%x", info->netfilter.flags);
+}
+
+static void show_kprobe_multi_plain(struct bpf_link_info *info)
+{
+	__u32 i, j = 0;
+	__u64 *addrs;
+
+	if (!info->kprobe_multi.count)
+		return;
+
+	if (info->kprobe_multi.flags & BPF_F_KPROBE_MULTI_RETURN)
+		printf("\n\tkretprobe.multi  ");
+	else
+		printf("\n\tkprobe.multi  ");
+	printf("func_cnt %u  ", info->kprobe_multi.count);
+	addrs = (__u64 *)u64_to_ptr(info->kprobe_multi.addrs);
+	qsort(addrs, info->kprobe_multi.count, sizeof(__u64), cmp_u64);
+
+	/* Load it once for all. */
+	if (!dd.sym_count)
+		kernel_syms_load(&dd);
+	if (!dd.sym_count)
+		return;
+
+	printf("\n\t%-16s %s", "addr", "func [module]");
+	for (i = 0; i < dd.sym_count; i++) {
+		if (dd.sym_mapping[i].address != addrs[j])
+			continue;
+		printf("\n\t%016lx %s",
+		       dd.sym_mapping[i].address, dd.sym_mapping[i].name);
+		if (dd.sym_mapping[i].module[0] != '\0')
+			printf(" [%s]  ", dd.sym_mapping[i].module);
+		else
+			printf("  ");
+
+		if (j++ == info->kprobe_multi.count)
+			break;
+	}
+}
+
+static void show_perf_event_kprobe_plain(struct bpf_link_info *info)
+{
+	const char *buf;
+
+	buf = u64_to_ptr(info->perf_event.kprobe.func_name);
+	if (buf[0] == '\0' && !info->perf_event.kprobe.addr)
+		return;
+
+	if (info->perf_event.type == BPF_PERF_EVENT_KRETPROBE)
+		printf("\n\tkretprobe ");
+	else
+		printf("\n\tkprobe ");
+	if (info->perf_event.kprobe.addr)
+		printf("%llx ", info->perf_event.kprobe.addr);
+	printf("%s", buf);
+	if (info->perf_event.kprobe.offset)
+		printf("+%#x", info->perf_event.kprobe.offset);
+	printf("  ");
+}
+
+static void show_perf_event_uprobe_plain(struct bpf_link_info *info)
+{
+	const char *buf;
+
+	buf = u64_to_ptr(info->perf_event.uprobe.file_name);
+	if (buf[0] == '\0')
+		return;
+
+	if (info->perf_event.type == BPF_PERF_EVENT_URETPROBE)
+		printf("\n\turetprobe ");
+	else
+		printf("\n\tuprobe ");
+	printf("%s+%#x  ", buf, info->perf_event.uprobe.offset);
+}
+
+static void show_perf_event_tracepoint_plain(struct bpf_link_info *info)
+{
+	const char *buf;
+
+	buf = u64_to_ptr(info->perf_event.tracepoint.tp_name);
+	if (buf[0] == '\0')
+		return;
+
+	printf("\n\ttracepoint %s  ", buf);
+}
+
+static void show_perf_event_event_plain(struct bpf_link_info *info)
+{
+	__u64 config = info->perf_event.event.config;
+	__u32 type = info->perf_event.event.type;
+	const char *perf_type, *perf_config;
+
+	printf("\n\tevent ");
+	perf_type = perf_event_name(perf_type_name, type);
+	if (perf_type)
+		printf("%s:", perf_type);
+	else
+		printf("%u :", type);
+
+	perf_config = perf_config_str(type, config);
+	if (perf_config)
+		printf("%s  ", perf_config);
+	else
+		printf("%llu  ", config);
+
+	if (type == PERF_TYPE_HW_CACHE && perf_config)
+		free((void *)perf_config);
+}
+
+static int show_link_close_plain(int fd, struct bpf_link_info *info)
+{
+	struct bpf_prog_info prog_info;
+	const char *prog_type_str;
+	int err;
+
+	show_link_header_plain(info);
+
+	switch (info->type) {
+	case BPF_LINK_TYPE_RAW_TRACEPOINT:
+		printf("\n\ttp '%s'  ",
+		       (const char *)u64_to_ptr(info->raw_tracepoint.tp_name));
+		break;
+	case BPF_LINK_TYPE_TRACING:
+		err = get_prog_info(info->prog_id, &prog_info);
+		if (err)
+			return err;
+
+		prog_type_str = libbpf_bpf_prog_type_str(prog_info.type);
+		/* libbpf will return NULL for variants unknown to it. */
+		if (prog_type_str)
+			printf("\n\tprog_type %s  ", prog_type_str);
+		else
+			printf("\n\tprog_type %u  ", prog_info.type);
+
+		show_link_attach_type_plain(info->tracing.attach_type);
+		if (info->tracing.target_obj_id || info->tracing.target_btf_id)
+			printf("\n\ttarget_obj_id %u  target_btf_id %u  ",
+			       info->tracing.target_obj_id,
+			       info->tracing.target_btf_id);
+		break;
+	case BPF_LINK_TYPE_CGROUP:
+		printf("\n\tcgroup_id %zu  ", (size_t)info->cgroup.cgroup_id);
+		show_link_attach_type_plain(info->cgroup.attach_type);
+		break;
+	case BPF_LINK_TYPE_ITER:
+		show_iter_plain(info);
+		break;
+	case BPF_LINK_TYPE_NETNS:
+		printf("\n\tnetns_ino %u  ", info->netns.netns_ino);
+		show_link_attach_type_plain(info->netns.attach_type);
+		break;
+	case BPF_LINK_TYPE_NETFILTER:
+		netfilter_dump_plain(info);
+		break;
+	case BPF_LINK_TYPE_TCX:
+		printf("\n\t");
+		show_link_ifindex_plain(info->tcx.ifindex);
+		show_link_attach_type_plain(info->tcx.attach_type);
+		break;
+	case BPF_LINK_TYPE_XDP:
+		printf("\n\t");
+		show_link_ifindex_plain(info->xdp.ifindex);
+		break;
+	case BPF_LINK_TYPE_KPROBE_MULTI:
+		show_kprobe_multi_plain(info);
+		break;
+	case BPF_LINK_TYPE_PERF_EVENT:
+		switch (info->perf_event.type) {
+		case BPF_PERF_EVENT_EVENT:
+			show_perf_event_event_plain(info);
+			break;
+		case BPF_PERF_EVENT_TRACEPOINT:
+			show_perf_event_tracepoint_plain(info);
+			break;
+		case BPF_PERF_EVENT_KPROBE:
+		case BPF_PERF_EVENT_KRETPROBE:
+			show_perf_event_kprobe_plain(info);
+			break;
+		case BPF_PERF_EVENT_UPROBE:
+		case BPF_PERF_EVENT_URETPROBE:
+			show_perf_event_uprobe_plain(info);
+			break;
+		default:
+			break;
+		}
+		break;
+	default:
+		break;
+	}
+
+	if (!hashmap__empty(link_table)) {
+		struct hashmap_entry *entry;
+
+		hashmap__for_each_key_entry(link_table, entry, info->id)
+			printf("\n\tpinned %s", (char *)entry->pvalue);
+	}
+	emit_obj_refs_plain(refs_table, info->id, "\n\tpids ");
+
+	printf("\n");
+
+	return 0;
+}
+
+static int do_show_link(int fd)
+{
+	struct bpf_link_info info;
+	__u32 len = sizeof(info);
+	__u64 *addrs = NULL;
+	char buf[PATH_MAX];
+	int count;
+	int err;
+
+	memset(&info, 0, sizeof(info));
+	buf[0] = '\0';
+again:
+	err = bpf_link_get_info_by_fd(fd, &info, &len);
+	if (err) {
+		p_err("can't get link info: %s",
+		      strerror(errno));
+		close(fd);
+		return err;
+	}
+	if (info.type == BPF_LINK_TYPE_RAW_TRACEPOINT &&
+	    !info.raw_tracepoint.tp_name) {
+		info.raw_tracepoint.tp_name = ptr_to_u64(&buf);
+		info.raw_tracepoint.tp_name_len = sizeof(buf);
+		goto again;
+	}
+	if (info.type == BPF_LINK_TYPE_ITER &&
+	    !info.iter.target_name) {
+		info.iter.target_name = ptr_to_u64(&buf);
+		info.iter.target_name_len = sizeof(buf);
+		goto again;
+	}
+	if (info.type == BPF_LINK_TYPE_KPROBE_MULTI &&
+	    !info.kprobe_multi.addrs) {
+		count = info.kprobe_multi.count;
+		if (count) {
+			addrs = calloc(count, sizeof(__u64));
+			if (!addrs) {
+				p_err("mem alloc failed");
+				close(fd);
+				return -ENOMEM;
+			}
+			info.kprobe_multi.addrs = ptr_to_u64(addrs);
+			goto again;
+		}
+	}
+	if (info.type == BPF_LINK_TYPE_PERF_EVENT) {
+		switch (info.perf_event.type) {
+		case BPF_PERF_EVENT_TRACEPOINT:
+			if (!info.perf_event.tracepoint.tp_name) {
+				info.perf_event.tracepoint.tp_name = ptr_to_u64(&buf);
+				info.perf_event.tracepoint.name_len = sizeof(buf);
+				goto again;
+			}
+			break;
+		case BPF_PERF_EVENT_KPROBE:
+		case BPF_PERF_EVENT_KRETPROBE:
+			if (!info.perf_event.kprobe.func_name) {
+				info.perf_event.kprobe.func_name = ptr_to_u64(&buf);
+				info.perf_event.kprobe.name_len = sizeof(buf);
+				goto again;
+			}
+			break;
+		case BPF_PERF_EVENT_UPROBE:
+		case BPF_PERF_EVENT_URETPROBE:
+			if (!info.perf_event.uprobe.file_name) {
+				info.perf_event.uprobe.file_name = ptr_to_u64(&buf);
+				info.perf_event.uprobe.name_len = sizeof(buf);
+				goto again;
+			}
+			break;
+		default:
+			break;
+		}
+	}
+
+	if (json_output)
+		show_link_close_json(fd, &info);
+	else
+		show_link_close_plain(fd, &info);
+
+	if (addrs)
+		free(addrs);
+	close(fd);
+	return 0;
+}
+
+static int do_show(int argc, char **argv)
+{
+	__u32 id = 0;
+	int err, fd;
+
+	if (show_pinned) {
+		link_table = hashmap__new(hash_fn_for_key_as_id,
+					  equal_fn_for_key_as_id, NULL);
+		if (IS_ERR(link_table)) {
+			p_err("failed to create hashmap for pinned paths");
+			return -1;
+		}
+		build_pinned_obj_table(link_table, BPF_OBJ_LINK);
+	}
+	build_obj_refs_table(&refs_table, BPF_OBJ_LINK);
+
+	if (argc == 2) {
+		fd = link_parse_fd(&argc, &argv);
+		if (fd < 0)
+			return fd;
+		do_show_link(fd);
+		goto out;
+	}
+
+	if (argc)
+		return BAD_ARG();
+
+	if (json_output)
+		jsonw_start_array(json_wtr);
+	while (true) {
+		err = bpf_link_get_next_id(id, &id);
+		if (err) {
+			if (errno == ENOENT)
+				break;
+			p_err("can't get next link: %s%s", strerror(errno),
+			      errno == EINVAL ? " -- kernel too old?" : "");
+			break;
+		}
+
+		fd = bpf_link_get_fd_by_id(id);
+		if (fd < 0) {
+			if (errno == ENOENT)
+				continue;
+			p_err("can't get link by id (%u): %s",
+			      id, strerror(errno));
+			break;
+		}
+
+		err = do_show_link(fd);
+		if (err)
+			break;
+	}
+	if (json_output)
+		jsonw_end_array(json_wtr);
+
+	delete_obj_refs_table(refs_table);
+
+	if (show_pinned)
+		delete_pinned_obj_table(link_table);
+
+out:
+	if (dd.sym_count)
+		kernel_syms_destroy(&dd);
+	return errno == ENOENT ? 0 : -1;
+}
+
+static int do_pin(int argc, char **argv)
+{
+	int err;
+
+	err = do_pin_any(argc, argv, link_parse_fd);
+	if (!err && json_output)
+		jsonw_null(json_wtr);
+	return err;
+}
+
+static int do_detach(int argc, char **argv)
+{
+	int err, fd;
+
+	if (argc != 2) {
+		p_err("link specifier is invalid or missing\n");
+		return 1;
+	}
+
+	fd = link_parse_fd(&argc, &argv);
+	if (fd < 0)
+		return 1;
+
+	err = bpf_link_detach(fd);
+	if (err)
+		err = -errno;
+	close(fd);
+	if (err) {
+		p_err("failed link detach: %s", strerror(-err));
+		return 1;
+	}
+
+	if (json_output)
+		jsonw_null(json_wtr);
+
+	return 0;
+}
+
+static int do_help(int argc, char **argv)
+{
+	if (json_output) {
+		jsonw_null(json_wtr);
+		return 0;
+	}
+
+	fprintf(stderr,
+		"Usage: %1$s %2$s { show | list }   [LINK]\n"
+		"       %1$s %2$s pin        LINK  FILE\n"
+		"       %1$s %2$s detach     LINK\n"
+		"       %1$s %2$s help\n"
+		"\n"
+		"       " HELP_SPEC_LINK "\n"
+		"       " HELP_SPEC_OPTIONS " |\n"
+		"                    {-f|--bpffs} | {-n|--nomount} }\n"
+		"",
+		bin_name, argv[-2]);
+
+	return 0;
+}
+
+static const struct cmd cmds[] = {
+	{ "show",	do_show },
+	{ "list",	do_show },
+	{ "help",	do_help },
+	{ "pin",	do_pin },
+	{ "detach",	do_detach },
+	{ 0 }
+};
+
+int do_link(int argc, char **argv)
+{
+	return cmd_select(cmds, argc, argv, do_help);
+}