// 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";

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");

        return 0;
}