// SPDX-License-Identifier: GPL-2.0

  #include <linux/in.h>
  #include <linux/inet.h>
  #include <linux/list.h>
  #include <linux/module.h>
  #include <linux/net.h>
  #include <linux/proc_fs.h>
  #include <linux/rculist.h>
  #include <linux/seq_file.h>
  #include <linux/socket.h>
  #include <net/inet_sock.h>
  #include <net/kcm.h>
  #include <net/net_namespace.h>
  #include <net/netns/generic.h>
  #include <net/tcp.h>
  
  #ifdef CONFIG_PROC_FS

  static struct kcm_mux *kcm_get_first(struct seq_file *seq)
  {
  	struct net *net = seq_file_net(seq);
  	struct kcm_net *knet = net_generic(net, kcm_net_id);
  
  	return list_first_or_null_rcu(&knet->mux_list,
  				      struct kcm_mux, kcm_mux_list);
  }
  
  static struct kcm_mux *kcm_get_next(struct kcm_mux *mux)
  {
  	struct kcm_net *knet = mux->knet;
  
  	return list_next_or_null_rcu(&knet->mux_list, &mux->kcm_mux_list,
  				     struct kcm_mux, kcm_mux_list);
  }
  
  static struct kcm_mux *kcm_get_idx(struct seq_file *seq, loff_t pos)
  {
  	struct net *net = seq_file_net(seq);
  	struct kcm_net *knet = net_generic(net, kcm_net_id);
  	struct kcm_mux *m;
  
  	list_for_each_entry_rcu(m, &knet->mux_list, kcm_mux_list) {
  		if (!pos)
  			return m;
  		--pos;
  	}
  	return NULL;
  }
  
  static void *kcm_seq_next(struct seq_file *seq, void *v, loff_t *pos)
  {
  	void *p;
  
  	if (v == SEQ_START_TOKEN)
  		p = kcm_get_first(seq);
  	else
  		p = kcm_get_next(v);
  	++*pos;
  	return p;
  }
  
  static void *kcm_seq_start(struct seq_file *seq, loff_t *pos)
  	__acquires(rcu)
  {
  	rcu_read_lock();
  
  	if (!*pos)
  		return SEQ_START_TOKEN;
  	else
  		return kcm_get_idx(seq, *pos - 1);
  }
  
  static void kcm_seq_stop(struct seq_file *seq, void *v)
  	__releases(rcu)
  {
  	rcu_read_unlock();
  }
  
  struct kcm_proc_mux_state {
  	struct seq_net_private p;
  	int idx;
  };

  static void kcm_format_mux_header(struct seq_file *seq)
  {
  	struct net *net = seq_file_net(seq);
  	struct kcm_net *knet = net_generic(net, kcm_net_id);
  
  	seq_printf(seq,
  		   "*** KCM statistics (%d MUX) ****
  ",
  		   knet->count);
  
  	seq_printf(seq,
  		   "%-14s %-10s %-16s %-10s %-16s %-8s %-8s %-8s %-8s %s",
  		   "Object",
  		   "RX-Msgs",
  		   "RX-Bytes",
  		   "TX-Msgs",
  		   "TX-Bytes",
  		   "Recv-Q",
  		   "Rmem",
  		   "Send-Q",
  		   "Smem",
  		   "Status");
  
  	/* XXX: pdsts header stuff here */
  	seq_puts(seq, "
  ");
  }
  
  static void kcm_format_sock(struct kcm_sock *kcm, struct seq_file *seq,
  			    int i, int *len)
  {
  	seq_printf(seq,
  		   "   kcm-%-7u %-10llu %-16llu %-10llu %-16llu %-8d %-8d %-8d %-8s ",
  		   kcm->index,
  		   kcm->stats.rx_msgs,
  		   kcm->stats.rx_bytes,
  		   kcm->stats.tx_msgs,
  		   kcm->stats.tx_bytes,
  		   kcm->sk.sk_receive_queue.qlen,
  		   sk_rmem_alloc_get(&kcm->sk),
  		   kcm->sk.sk_write_queue.qlen,
  		   "-");
  
  	if (kcm->tx_psock)
  		seq_printf(seq, "Psck-%u ", kcm->tx_psock->index);
  
  	if (kcm->tx_wait)
  		seq_puts(seq, "TxWait ");
  
  	if (kcm->tx_wait_more)
  		seq_puts(seq, "WMore ");
  
  	if (kcm->rx_wait)
  		seq_puts(seq, "RxWait ");
  
  	seq_puts(seq, "
  ");
  }
  
  static void kcm_format_psock(struct kcm_psock *psock, struct seq_file *seq,
  			     int i, int *len)
  {
  	seq_printf(seq,
  		   "   psock-%-5u %-10llu %-16llu %-10llu %-16llu %-8d %-8d %-8d %-8d ",
  		   psock->index,

  		   psock->strp.stats.msgs,
  		   psock->strp.stats.bytes,

  		   psock->stats.tx_msgs,
  		   psock->stats.tx_bytes,
  		   psock->sk->sk_receive_queue.qlen,
  		   atomic_read(&psock->sk->sk_rmem_alloc),
  		   psock->sk->sk_write_queue.qlen,

  		   refcount_read(&psock->sk->sk_wmem_alloc));

  
  	if (psock->done)
  		seq_puts(seq, "Done ");
  
  	if (psock->tx_stopped)
  		seq_puts(seq, "TxStop ");

  	if (psock->strp.stopped)

  		seq_puts(seq, "RxStop ");
  
  	if (psock->tx_kcm)
  		seq_printf(seq, "Rsvd-%d ", psock->tx_kcm->index);

  	if (!psock->strp.paused && !psock->ready_rx_msg) {

  		if (psock->sk->sk_receive_queue.qlen) {

  			if (psock->strp.need_bytes)

  				seq_printf(seq, "RxWait=%u ",

  					   psock->strp.need_bytes);

  			else
  				seq_printf(seq, "RxWait ");
  		}
  	} else  {

  		if (psock->strp.paused)

  			seq_puts(seq, "RxPause ");
  
  		if (psock->ready_rx_msg)
  			seq_puts(seq, "RdyRx ");
  	}

  
  	seq_puts(seq, "
  ");
  }
  
  static void
  kcm_format_mux(struct kcm_mux *mux, loff_t idx, struct seq_file *seq)
  {
  	int i, len;
  	struct kcm_sock *kcm;
  	struct kcm_psock *psock;
  
  	/* mux information */
  	seq_printf(seq,
  		   "%-6s%-8s %-10llu %-16llu %-10llu %-16llu %-8s %-8s %-8s %-8s ",
  		   "mux", "",
  		   mux->stats.rx_msgs,
  		   mux->stats.rx_bytes,
  		   mux->stats.tx_msgs,
  		   mux->stats.tx_bytes,
  		   "-", "-", "-", "-");
  
  	seq_printf(seq, "KCMs: %d, Psocks %d
  ",
  		   mux->kcm_socks_cnt, mux->psocks_cnt);
  
  	/* kcm sock information */
  	i = 0;
  	spin_lock_bh(&mux->lock);
  	list_for_each_entry(kcm, &mux->kcm_socks, kcm_sock_list) {
  		kcm_format_sock(kcm, seq, i, &len);
  		i++;
  	}
  	i = 0;
  	list_for_each_entry(psock, &mux->psocks, psock_list) {
  		kcm_format_psock(psock, seq, i, &len);
  		i++;
  	}
  	spin_unlock_bh(&mux->lock);
  }
  
  static int kcm_seq_show(struct seq_file *seq, void *v)
  {
  	struct kcm_proc_mux_state *mux_state;
  
  	mux_state = seq->private;
  	if (v == SEQ_START_TOKEN) {
  		mux_state->idx = 0;
  		kcm_format_mux_header(seq);
  	} else {
  		kcm_format_mux(v, mux_state->idx, seq);
  		mux_state->idx++;
  	}
  	return 0;
  }

  static const struct seq_operations kcm_seq_ops = {
  	.show	= kcm_seq_show,
  	.start	= kcm_seq_start,
  	.next	= kcm_seq_next,
  	.stop	= kcm_seq_stop,
  };

  static int kcm_stats_seq_show(struct seq_file *seq, void *v)
  {
  	struct kcm_psock_stats psock_stats;
  	struct kcm_mux_stats mux_stats;

  	struct strp_aggr_stats strp_stats;

  	struct kcm_mux *mux;
  	struct kcm_psock *psock;
  	struct net *net = seq->private;
  	struct kcm_net *knet = net_generic(net, kcm_net_id);
  
  	memset(&mux_stats, 0, sizeof(mux_stats));
  	memset(&psock_stats, 0, sizeof(psock_stats));

  	memset(&strp_stats, 0, sizeof(strp_stats));

  
  	mutex_lock(&knet->mutex);
  
  	aggregate_mux_stats(&knet->aggregate_mux_stats, &mux_stats);
  	aggregate_psock_stats(&knet->aggregate_psock_stats,
  			      &psock_stats);

  	aggregate_strp_stats(&knet->aggregate_strp_stats,
  			     &strp_stats);

  	list_for_each_entry(mux, &knet->mux_list, kcm_mux_list) {

  		spin_lock_bh(&mux->lock);
  		aggregate_mux_stats(&mux->stats, &mux_stats);
  		aggregate_psock_stats(&mux->aggregate_psock_stats,
  				      &psock_stats);

  		aggregate_strp_stats(&mux->aggregate_strp_stats,
  				     &strp_stats);
  		list_for_each_entry(psock, &mux->psocks, psock_list) {

  			aggregate_psock_stats(&psock->stats, &psock_stats);

  			save_strp_stats(&psock->strp, &strp_stats);
  		}

  		spin_unlock_bh(&mux->lock);
  	}
  
  	mutex_unlock(&knet->mutex);
  
  	seq_printf(seq,
  		   "%-8s %-10s %-16s %-10s %-16s %-10s %-10s %-10s %-10s %-10s
  ",
  		   "MUX",
  		   "RX-Msgs",
  		   "RX-Bytes",
  		   "TX-Msgs",
  		   "TX-Bytes",
  		   "TX-Retries",
  		   "Attach",
  		   "Unattach",
  		   "UnattchRsvd",
  		   "RX-RdyDrops");
  
  	seq_printf(seq,
  		   "%-8s %-10llu %-16llu %-10llu %-16llu %-10u %-10u %-10u %-10u %-10u
  ",
  		   "",
  		   mux_stats.rx_msgs,
  		   mux_stats.rx_bytes,
  		   mux_stats.tx_msgs,
  		   mux_stats.tx_bytes,
  		   mux_stats.tx_retries,
  		   mux_stats.psock_attach,
  		   mux_stats.psock_unattach_rsvd,
  		   mux_stats.psock_unattach,
  		   mux_stats.rx_ready_drops);
  
  	seq_printf(seq,

  		   "%-8s %-10s %-16s %-10s %-16s %-10s %-10s %-10s %-10s %-10s %-10s %-10s %-10s %-10s %-10s %-10s
  ",

  		   "Psock",
  		   "RX-Msgs",
  		   "RX-Bytes",
  		   "TX-Msgs",
  		   "TX-Bytes",
  		   "Reserved",
  		   "Unreserved",
  		   "RX-Aborts",

  		   "RX-Intr",
  		   "RX-Unrecov",

  		   "RX-MemFail",
  		   "RX-NeedMor",
  		   "RX-BadLen",

  		   "RX-TooBig",

  		   "RX-Timeout",

  		   "TX-Aborts");
  
  	seq_printf(seq,

  		   "%-8s %-10llu %-16llu %-10llu %-16llu %-10llu %-10llu %-10u %-10u %-10u %-10u %-10u %-10u %-10u %-10u %-10u
  ",

  		   "",

  		   strp_stats.msgs,
  		   strp_stats.bytes,

  		   psock_stats.tx_msgs,
  		   psock_stats.tx_bytes,
  		   psock_stats.reserved,
  		   psock_stats.unreserved,

  		   strp_stats.aborts,
  		   strp_stats.interrupted,
  		   strp_stats.unrecov_intr,
  		   strp_stats.mem_fail,
  		   strp_stats.need_more_hdr,
  		   strp_stats.bad_hdr_len,
  		   strp_stats.msg_too_big,
  		   strp_stats.msg_timeouts,

  		   psock_stats.tx_aborts);
  
  	return 0;
  }

  static int kcm_proc_init_net(struct net *net)
  {

  	if (!proc_create_net_single("kcm_stats", 0444, net->proc_net,
  			 kcm_stats_seq_show, NULL))

  		goto out_kcm_stats;

  	if (!proc_create_net("kcm", 0444, net->proc_net, &kcm_seq_ops,
  			sizeof(struct kcm_proc_mux_state)))

  		goto out_kcm;
  
  	return 0;
  
  out_kcm:
  	remove_proc_entry("kcm_stats", net->proc_net);
  out_kcm_stats:

  	return -ENOMEM;

  }
  
  static void kcm_proc_exit_net(struct net *net)
  {

  	remove_proc_entry("kcm", net->proc_net);

  	remove_proc_entry("kcm_stats", net->proc_net);
  }
  
  static struct pernet_operations kcm_net_ops = {
  	.init = kcm_proc_init_net,
  	.exit = kcm_proc_exit_net,
  };
  
  int __init kcm_proc_init(void)
  {
  	return register_pernet_subsys(&kcm_net_ops);
  }
  
  void __exit kcm_proc_exit(void)
  {
  	unregister_pernet_subsys(&kcm_net_ops);
  }
  
  #endif /* CONFIG_PROC_FS */