/*
   * proc_llc.c - proc interface for LLC
   *
   * Copyright (c) 2001 by Jay Schulist <jschlst@samba.org>
   *		 2002-2003 by Arnaldo Carvalho de Melo <acme@conectiva.com.br>
   *
   * This program can be redistributed or modified under the terms of the
   * GNU General Public License as published by the Free Software Foundation.
   * This program is distributed without any warranty or implied warranty
   * of merchantability or fitness for a particular purpose.
   *
   * See the GNU General Public License for more details.
   */
  
  #include <linux/init.h>
  #include <linux/kernel.h>
  #include <linux/proc_fs.h>
  #include <linux/errno.h>
  #include <linux/seq_file.h>
  #include <linux/export.h>
  #include <net/net_namespace.h>
  #include <net/sock.h>
  #include <net/llc.h>
  #include <net/llc_c_ac.h>
  #include <net/llc_c_ev.h>
  #include <net/llc_c_st.h>
  #include <net/llc_conn.h>
  
  static void llc_ui_format_mac(struct seq_file *seq, u8 *addr)
  {
  	seq_printf(seq, "%pM", addr);
  }
  
  static struct sock *llc_get_sk_idx(loff_t pos)
  {
  	struct llc_sap *sap;
  	struct sock *sk = NULL;
  	int i;
  
  	list_for_each_entry_rcu(sap, &llc_sap_list, node) {
  		spin_lock_bh(&sap->sk_lock);
  		for (i = 0; i < LLC_SK_LADDR_HASH_ENTRIES; i++) {
  			struct hlist_nulls_head *head = &sap->sk_laddr_hash[i];
  			struct hlist_nulls_node *node;
  
  			sk_nulls_for_each(sk, node, head) {
  				if (!pos)
  					goto found; /* keep the lock */
  				--pos;
  			}
  		}
  		spin_unlock_bh(&sap->sk_lock);
  	}
  	sk = NULL;
  found:
  	return sk;
  }
  
  static void *llc_seq_start(struct seq_file *seq, loff_t *pos)
  {
  	loff_t l = *pos;
  
  	rcu_read_lock_bh();
  	return l ? llc_get_sk_idx(--l) : SEQ_START_TOKEN;
  }
  
  static struct sock *laddr_hash_next(struct llc_sap *sap, int bucket)
  {
  	struct hlist_nulls_node *node;
  	struct sock *sk = NULL;
  
  	while (++bucket < LLC_SK_LADDR_HASH_ENTRIES)
  		sk_nulls_for_each(sk, node, &sap->sk_laddr_hash[bucket])
  			goto out;
  
  out:
  	return sk;
  }
  
  static void *llc_seq_next(struct seq_file *seq, void *v, loff_t *pos)
  {
  	struct sock* sk, *next;
  	struct llc_sock *llc;
  	struct llc_sap *sap;
  
  	++*pos;
  	if (v == SEQ_START_TOKEN) {
  		sk = llc_get_sk_idx(0);
  		goto out;
  	}
  	sk = v;
  	next = sk_nulls_next(sk);
  	if (next) {
  		sk = next;
  		goto out;
  	}
  	llc = llc_sk(sk);
  	sap = llc->sap;
  	sk = laddr_hash_next(sap, llc_sk_laddr_hashfn(sap, &llc->laddr));
  	if (sk)
  		goto out;
  	spin_unlock_bh(&sap->sk_lock);
  	list_for_each_entry_continue_rcu(sap, &llc_sap_list, node) {
  		spin_lock_bh(&sap->sk_lock);
  		sk = laddr_hash_next(sap, -1);
  		if (sk)
  			break; /* keep the lock */
  		spin_unlock_bh(&sap->sk_lock);
  	}
  out:
  	return sk;
  }
  
  static void llc_seq_stop(struct seq_file *seq, void *v)
  {
  	if (v && v != SEQ_START_TOKEN) {
  		struct sock *sk = v;
  		struct llc_sock *llc = llc_sk(sk);
  		struct llc_sap *sap = llc->sap;
  
  		spin_unlock_bh(&sap->sk_lock);
  	}
  	rcu_read_unlock_bh();
  }
  
  static int llc_seq_socket_show(struct seq_file *seq, void *v)
  {
  	struct sock* sk;
  	struct llc_sock *llc;
  
  	if (v == SEQ_START_TOKEN) {
  		seq_puts(seq, "SKt Mc local_mac_sap        remote_mac_sap   "
  			      "    tx_queue rx_queue st uid link
  ");
  		goto out;
  	}
  	sk = v;
  	llc = llc_sk(sk);
  
  	/* FIXME: check if the address is multicast */
  	seq_printf(seq, "%2X  %2X ", sk->sk_type, 0);
  
  	if (llc->dev)
  		llc_ui_format_mac(seq, llc->dev->dev_addr);
  	else {
  		u8 addr[6] = {0,0,0,0,0,0};
  		llc_ui_format_mac(seq, addr);
  	}
  	seq_printf(seq, "@%02X ", llc->sap->laddr.lsap);
  	llc_ui_format_mac(seq, llc->daddr.mac);
  	seq_printf(seq, "@%02X %8d %8d %2d %3u %4d
  ", llc->daddr.lsap,
  		   sk_wmem_alloc_get(sk),
  		   sk_rmem_alloc_get(sk) - llc->copied_seq,
  		   sk->sk_state,
  		   from_kuid_munged(seq_user_ns(seq), sock_i_uid(sk)),
  		   llc->link);
  out:
  	return 0;
  }
  
  static const char *const llc_conn_state_names[] = {
  	[LLC_CONN_STATE_ADM] =        "adm",
  	[LLC_CONN_STATE_SETUP] =      "setup",
  	[LLC_CONN_STATE_NORMAL] =     "normal",
  	[LLC_CONN_STATE_BUSY] =       "busy",
  	[LLC_CONN_STATE_REJ] =        "rej",
  	[LLC_CONN_STATE_AWAIT] =      "await",
  	[LLC_CONN_STATE_AWAIT_BUSY] = "await_busy",
  	[LLC_CONN_STATE_AWAIT_REJ] =  "await_rej",
  	[LLC_CONN_STATE_D_CONN]	=     "d_conn",
  	[LLC_CONN_STATE_RESET] =      "reset",
  	[LLC_CONN_STATE_ERROR] =      "error",
  	[LLC_CONN_STATE_TEMP] =       "temp",
  };
  
  static int llc_seq_core_show(struct seq_file *seq, void *v)
  {
  	struct sock* sk;
  	struct llc_sock *llc;
  
  	if (v == SEQ_START_TOKEN) {
  		seq_puts(seq, "Connection list:
  "
  			      "dsap state      retr txw rxw pf ff sf df rs cs "
  			      "tack tpfc trs tbs blog busr
  ");
  		goto out;
  	}
  	sk = v;
  	llc = llc_sk(sk);
  
  	seq_printf(seq, " %02X  %-10s %3d  %3d %3d %2d %2d %2d %2d %2d %2d "
  			"%4d %4d %3d %3d %4d %4d
  ",
  		   llc->daddr.lsap, llc_conn_state_names[llc->state],
  		   llc->retry_count, llc->k, llc->rw, llc->p_flag, llc->f_flag,
  		   llc->s_flag, llc->data_flag, llc->remote_busy_flag,
  		   llc->cause_flag, timer_pending(&llc->ack_timer.timer),
  		   timer_pending(&llc->pf_cycle_timer.timer),
  		   timer_pending(&llc->rej_sent_timer.timer),
  		   timer_pending(&llc->busy_state_timer.timer),
  		   !!sk->sk_backlog.tail, !!sock_owned_by_user(sk));
  out:
  	return 0;
  }
  
  static const struct seq_operations llc_seq_socket_ops = {
  	.start  = llc_seq_start,
  	.next   = llc_seq_next,
  	.stop   = llc_seq_stop,
  	.show   = llc_seq_socket_show,
  };
  
  static const struct seq_operations llc_seq_core_ops = {
  	.start  = llc_seq_start,
  	.next   = llc_seq_next,
  	.stop   = llc_seq_stop,
  	.show   = llc_seq_core_show,
  };
  
  static int llc_seq_socket_open(struct inode *inode, struct file *file)
  {
  	return seq_open(file, &llc_seq_socket_ops);
  }
  
  static int llc_seq_core_open(struct inode *inode, struct file *file)
  {
  	return seq_open(file, &llc_seq_core_ops);
  }
  
  static const struct file_operations llc_seq_socket_fops = {
  	.owner		= THIS_MODULE,
  	.open		= llc_seq_socket_open,
  	.read		= seq_read,
  	.llseek		= seq_lseek,
  	.release	= seq_release,
  };
  
  static const struct file_operations llc_seq_core_fops = {
  	.owner		= THIS_MODULE,
  	.open		= llc_seq_core_open,
  	.read		= seq_read,
  	.llseek		= seq_lseek,
  	.release	= seq_release,
  };
  
  static struct proc_dir_entry *llc_proc_dir;
  
  int __init llc_proc_init(void)
  {
  	int rc = -ENOMEM;
  	struct proc_dir_entry *p;
  
  	llc_proc_dir = proc_mkdir("llc", init_net.proc_net);
  	if (!llc_proc_dir)
  		goto out;
  
  	p = proc_create("socket", S_IRUGO, llc_proc_dir, &llc_seq_socket_fops);
  	if (!p)
  		goto out_socket;
  
  	p = proc_create("core", S_IRUGO, llc_proc_dir, &llc_seq_core_fops);
  	if (!p)
  		goto out_core;
  
  	rc = 0;
  out:
  	return rc;
  out_core:
  	remove_proc_entry("socket", llc_proc_dir);
  out_socket:
  	remove_proc_entry("llc", init_net.proc_net);
  	goto out;
  }
  
  void llc_proc_exit(void)
  {
  	remove_proc_entry("socket", llc_proc_dir);
  	remove_proc_entry("core", llc_proc_dir);
  	remove_proc_entry("llc", init_net.proc_net);
  }