bpftool: Implement link show support for tcx

Add support to dump tcx link information to bpftool. This adds a common helper show_link_ifindex_{plain,json}() which can be reused also for other link types. The plain text and json device output is the same format as in bpftool net dump. Below shows an example link dump output along with a cgroup link for comparison: # bpftool link [...] 10: cgroup prog 1977 cgroup_id 1 attach_type cgroup_inet6_post_bind [...] 13: tcx prog 2053 ifindex enp5s0(3) attach_type tcx_ingress 14: tcx prog 2080 ifindex enp5s0(3) attach_type tcx_egress [...] Equivalent json output: # bpftool link --json [...] { "id": 10, "type": "cgroup", "prog_id": 1977, "cgroup_id": 1, "attach_type": "cgroup_inet6_post_bind" }, [...] { "id": 13, "type": "tcx", "prog_id": 2053, "devname": "enp5s0", "ifindex": 3, "attach_type": "tcx_ingress" }, { "id": 14, "type": "tcx", "prog_id": 2080, "devname": "enp5s0", "ifindex": 3, "attach_type": "tcx_egress" } [...] Suggested-by: Yafang Shao <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Reviewed-by: Quentin Monnet <[email protected]> Acked-by: Yafang Shao <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Martin KaFai Lau <[email protected]>
libbpf · Aug 29, 2023 · b76b36e · b76b36e
1 parent dc53c79
commit b76b36e
Showing 1 changed file with 37 additions and 0 deletions.
diff --git a/src/link.c b/src/link.c
@@ -150,6  150,18 @@ static void show_link_attach_type_json(__u32 attach_type, json_writer_t *wtr)
 		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 ||
@@ -433,6  445,10 @@ static int show_link_close_json(int fd, struct bpf_link_info *info)
 	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_STRUCT_OPS:
 		jsonw_uint_field(json_wtr, "map_id",
 				 info->struct_ops.map_id);
@@ -509,6  525,22 @@ static void show_link_attach_type_plain(__u32 attach_type)
 		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);
@@ -745,6  777,11 @@ static int show_link_close_plain(int fd, struct bpf_link_info *info)
 	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_KPROBE_MULTI:
 		show_kprobe_multi_plain(info);
 		break;