// SPDX-License-Identifier: GPL-2.0
/* Copyright Amazon.com Inc. or its affiliates. */
#include <vmlinux.h>
#include "bpf_tracing_net.h"
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_endian.h>

char _license[] SEC("license") = "GPL";

SEC(".maps") struct {
	__uint(type, BPF_MAP_TYPE_SOCKMAP);
	__uint(max_entries, 1);
	__type(key, __u32);
	__type(value, __u64);
} sockmap;

static long sock_i_ino(const struct sock *sk)
{
	const struct socket *sk_socket = sk->sk_socket;
	const struct inode *inode;
	unsigned long ino;

	if (!sk_socket)
		return 0;

	inode = &container_of(sk_socket, struct socket_alloc, socket)->vfs_inode;
	bpf_probe_read_kernel(&ino, sizeof(ino), &inode->i_ino);
	return ino;
}

SEC("iter/unix")
int dump_unix(struct bpf_iter__unix *ctx)
{
	struct unix_sock *unix_sk = ctx->unix_sk;
	struct sock *sk = (struct sock *)unix_sk;
	struct seq_file *seq;
	__u32 seq_num;

	if (!unix_sk)
		return 0;

	seq = ctx->meta->seq;
	seq_num = ctx->meta->seq_num;
	if (seq_num == 0)
		BPF_SEQ_PRINTF(seq, "Num               RefCount Protocol Flags    Type St    Inode Path\n");

	BPF_SEQ_PRINTF(seq, "%pK: %08X %08X %08X %04X %02X %8lu",
		       unix_sk,
		       sk->sk_refcnt.refs.counter,
		       0,
		       sk->sk_state == TCP_LISTEN ? __SO_ACCEPTCON : 0,
		       sk->sk_type,
		       sk->sk_socket ?
		       (sk->sk_state == TCP_ESTABLISHED ? SS_CONNECTED : SS_UNCONNECTED) :
		       (sk->sk_state == TCP_ESTABLISHED ? SS_CONNECTING : SS_DISCONNECTING),
		       sock_i_ino(sk));

	if (unix_sk->addr) {
		if (unix_sk->addr->name->sun_path[0]) {
			BPF_SEQ_PRINTF(seq, " %s", unix_sk->addr->name->sun_path);
		} else {
			/* The name of the abstract UNIX domain socket starts
			 * with '\0' and can contain '\0'.  The null bytes
			 * should be escaped as done in unix_seq_show().
			 */
			__u64 i, len;

			len = unix_sk->addr->len - sizeof(short);

			BPF_SEQ_PRINTF(seq, " @");

			for (i = 1; i < len; i++) {
				/* unix_validate_addr() tests this upper bound. */
				if (i >= sizeof(struct sockaddr_un))
					break;

				BPF_SEQ_PRINTF(seq, "%c",
					       unix_sk->addr->name->sun_path[i] ?:
					       '@');
			}
		}
	}

	BPF_SEQ_PRINTF(seq, "\n");

	/* Test for deadlock. */
	bpf_map_update_elem(&sockmap, &(int){0}, sk, 0);

	return 0;
}
