/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __LINUX_NET_AFUNIX_H
#define __LINUX_NET_AFUNIX_H

#include <linux/socket.h>
#include <linux/un.h>
#include <linux/mutex.h>
#include <linux/refcount.h>
#include <net/sock.h>

#if IS_ENABLED(CONFIG_UNIX)
struct unix_sock *unix_get_socket(struct file *filp);
#else
static inline struct unix_sock *unix_get_socket(struct file *filp)
{
    return NULL;
}
#endif

extern unsigned int unix_tot_inflight;
void unix_add_edges(struct scm_fp_list *fpl, struct unix_sock *receiver);
void unix_del_edges(struct scm_fp_list *fpl);
void unix_update_edges(struct unix_sock *receiver);
int unix_prepare_fpl(struct scm_fp_list *fpl);
void unix_destroy_fpl(struct scm_fp_list *fpl);
void unix_gc(void);
void wait_for_unix_gc(struct scm_fp_list *fpl);

struct unix_vertex {
    struct list_head edges;
    struct list_head entry;
    struct list_head scc_entry;
    unsigned long out_degree;
    unsigned long index;
    unsigned long scc_index;
};

struct unix_edge {
    struct unix_sock *predecessor;
    struct unix_sock *successor;
    struct list_head vertex_entry;
    struct list_head stack_entry;
};

struct sock *unix_peer_get(struct sock *sk);

#define UNIX_HASH_MOD    (256 - 1)
#define UNIX_HASH_SIZE    (256 * 2)
#define UNIX_HASH_BITS    8

struct unix_address {
    refcount_t    refcnt;
    int        len;
    struct sockaddr_un name[];
};

struct unix_skb_parms {
    struct pid        *pid;        /* Skb credentials    */
    kuid_t            uid;
    kgid_t            gid;
    struct scm_fp_list    *fp;        /* Passed files        */
#ifdef CONFIG_SECURITY_NETWORK
    u32            secid;        /* Security ID        */
#endif
    u32            consumed;
} __randomize_layout;

struct scm_stat {
    atomic_t nr_fds;
    unsigned long nr_unix_fds;
};

#define UNIXCB(skb)    (*(struct unix_skb_parms *)&((skb)->cb))
#define UNIXCB_SAFE_RANDSTRUCT_CAST(skb)    \
    (*(struct unix_skb_parms *)SAFE_RANDSTRUCT_CAST(&((skb)->cb)))

/* The AF_UNIX socket */
struct unix_sock {
    /* WARNING: sk has to be the first member */
    struct sock        sk;
    struct unix_address    *addr;
    struct path        path;
    struct mutex        iolock, bindlock;
    struct sock        *peer;
    struct sock        *listener;
    struct unix_vertex    *vertex;
    spinlock_t        lock;
    struct socket_wq    peer_wq;
    wait_queue_entry_t    peer_wake;
    struct scm_stat        scm_stat;
#if IS_ENABLED(CONFIG_AF_UNIX_OOB)
    struct sk_buff        *oob_skb;
#endif
};

#define unix_sk(ptr) container_of_const(ptr, struct unix_sock, sk)
#define unix_peer(sk) (unix_sk(sk)->peer)

#define unix_state_lock(s)    spin_lock(&unix_sk(s)->lock)
#define unix_state_unlock(s)    spin_unlock(&unix_sk(s)->lock)
enum unix_socket_lock_class {
    U_LOCK_NORMAL,
    U_LOCK_SECOND,    /* for double locking, see unix_state_double_lock(). */
    U_LOCK_DIAG, /* used while dumping icons, see sk_diag_dump_icons(). */
    U_LOCK_GC_LISTENER, /* used for listening socket while determining gc
                 * candidates to close a small race window.
                 */
};

static inline void unix_state_lock_nested(struct sock *sk,
                   enum unix_socket_lock_class subclass)
{
    spin_lock_nested(&unix_sk(sk)->lock, subclass);
}

#define peer_wait peer_wq.wait

long unix_inq_len(struct sock *sk);
long unix_outq_len(struct sock *sk);

int __unix_dgram_recvmsg(struct sock *sk, struct msghdr *msg, size_t size,
             int flags);
int __unix_stream_recvmsg(struct sock *sk, struct msghdr *msg, size_t size,
              int flags);
#ifdef CONFIG_SYSCTL
int unix_sysctl_register(struct net *net);
void unix_sysctl_unregister(struct net *net);
#else
static inline int unix_sysctl_register(struct net *net) { return 0; }
static inline void unix_sysctl_unregister(struct net *net) {}
#endif

#ifdef CONFIG_BPF_SYSCALL
extern struct proto unix_dgram_proto;
extern struct proto unix_stream_proto;

int unix_dgram_bpf_update_proto(struct sock *sk, struct sk_psock *psock, bool restore);
int unix_stream_bpf_update_proto(struct sock *sk, struct sk_psock *psock, bool restore);
void __init unix_bpf_build_proto(void);
#else
static inline void __init unix_bpf_build_proto(void)
{}
#endif
#endif