// SPDX-License-Identifier: GPL-2.0-or-later

  /* SCTP kernel implementation

   * Copyright (c) 2003 International Business Machines, Corp.
   *

   * This file is part of the SCTP kernel implementation

   *

   * Please send any bug reports or fixes you make to the
   * email address(es):

   *    lksctp developers <linux-sctp@vger.kernel.org>

   *

   * Written or modified by:
   *    Sridhar Samudrala <sri@us.ibm.com>

   */
  
  #include <linux/types.h>
  #include <linux/seq_file.h>
  #include <linux/init.h>

  #include <linux/export.h>

  #include <net/sctp/sctp.h>

  #include <net/ip.h> /* for snmp_fold_field */

  static const struct snmp_mib sctp_snmp_list[] = {

  	SNMP_MIB_ITEM("SctpCurrEstab", SCTP_MIB_CURRESTAB),
  	SNMP_MIB_ITEM("SctpActiveEstabs", SCTP_MIB_ACTIVEESTABS),
  	SNMP_MIB_ITEM("SctpPassiveEstabs", SCTP_MIB_PASSIVEESTABS),
  	SNMP_MIB_ITEM("SctpAborteds", SCTP_MIB_ABORTEDS),
  	SNMP_MIB_ITEM("SctpShutdowns", SCTP_MIB_SHUTDOWNS),
  	SNMP_MIB_ITEM("SctpOutOfBlues", SCTP_MIB_OUTOFBLUES),
  	SNMP_MIB_ITEM("SctpChecksumErrors", SCTP_MIB_CHECKSUMERRORS),
  	SNMP_MIB_ITEM("SctpOutCtrlChunks", SCTP_MIB_OUTCTRLCHUNKS),
  	SNMP_MIB_ITEM("SctpOutOrderChunks", SCTP_MIB_OUTORDERCHUNKS),
  	SNMP_MIB_ITEM("SctpOutUnorderChunks", SCTP_MIB_OUTUNORDERCHUNKS),
  	SNMP_MIB_ITEM("SctpInCtrlChunks", SCTP_MIB_INCTRLCHUNKS),
  	SNMP_MIB_ITEM("SctpInOrderChunks", SCTP_MIB_INORDERCHUNKS),
  	SNMP_MIB_ITEM("SctpInUnorderChunks", SCTP_MIB_INUNORDERCHUNKS),
  	SNMP_MIB_ITEM("SctpFragUsrMsgs", SCTP_MIB_FRAGUSRMSGS),
  	SNMP_MIB_ITEM("SctpReasmUsrMsgs", SCTP_MIB_REASMUSRMSGS),
  	SNMP_MIB_ITEM("SctpOutSCTPPacks", SCTP_MIB_OUTSCTPPACKS),
  	SNMP_MIB_ITEM("SctpInSCTPPacks", SCTP_MIB_INSCTPPACKS),

  	SNMP_MIB_ITEM("SctpT1InitExpireds", SCTP_MIB_T1_INIT_EXPIREDS),
  	SNMP_MIB_ITEM("SctpT1CookieExpireds", SCTP_MIB_T1_COOKIE_EXPIREDS),
  	SNMP_MIB_ITEM("SctpT2ShutdownExpireds", SCTP_MIB_T2_SHUTDOWN_EXPIREDS),
  	SNMP_MIB_ITEM("SctpT3RtxExpireds", SCTP_MIB_T3_RTX_EXPIREDS),
  	SNMP_MIB_ITEM("SctpT4RtoExpireds", SCTP_MIB_T4_RTO_EXPIREDS),
  	SNMP_MIB_ITEM("SctpT5ShutdownGuardExpireds", SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS),
  	SNMP_MIB_ITEM("SctpDelaySackExpireds", SCTP_MIB_DELAY_SACK_EXPIREDS),
  	SNMP_MIB_ITEM("SctpAutocloseExpireds", SCTP_MIB_AUTOCLOSE_EXPIREDS),
  	SNMP_MIB_ITEM("SctpT3Retransmits", SCTP_MIB_T3_RETRANSMITS),
  	SNMP_MIB_ITEM("SctpPmtudRetransmits", SCTP_MIB_PMTUD_RETRANSMITS),
  	SNMP_MIB_ITEM("SctpFastRetransmits", SCTP_MIB_FAST_RETRANSMITS),
  	SNMP_MIB_ITEM("SctpInPktSoftirq", SCTP_MIB_IN_PKT_SOFTIRQ),
  	SNMP_MIB_ITEM("SctpInPktBacklog", SCTP_MIB_IN_PKT_BACKLOG),
  	SNMP_MIB_ITEM("SctpInPktDiscards", SCTP_MIB_IN_PKT_DISCARDS),
  	SNMP_MIB_ITEM("SctpInDataChunkDiscards", SCTP_MIB_IN_DATA_CHUNK_DISCARDS),

  	SNMP_MIB_SENTINEL

  };

  /* Display sctp snmp mib statistics(/proc/net/sctp/snmp). */
  static int sctp_snmp_seq_show(struct seq_file *seq, void *v)
  {

  	unsigned long buff[SCTP_MIB_MAX];

  	struct net *net = seq->private;

  	int i;

  	memset(buff, 0, sizeof(unsigned long) * SCTP_MIB_MAX);
  
  	snmp_get_cpu_field_batch(buff, sctp_snmp_list,
  				 net->sctp.sctp_statistics);

  	for (i = 0; sctp_snmp_list[i].name; i++)

  		seq_printf(seq, "%-32s\t%ld
  ", sctp_snmp_list[i].name,

  						buff[i]);

  
  	return 0;
  }

  /* Dump local addresses of an association/endpoint. */
  static void sctp_seq_dump_local_addrs(struct seq_file *seq, struct sctp_ep_common *epb)
  {

  	struct sctp_association *asoc;

  	struct sctp_sockaddr_entry *laddr;

  	struct sctp_transport *peer;
  	union sctp_addr *addr, *primary = NULL;

  	struct sctp_af *af;

  	if (epb->type == SCTP_EP_TYPE_ASSOCIATION) {

  		asoc = sctp_assoc(epb);
  
  		peer = asoc->peer.primary_path;
  		if (unlikely(peer == NULL)) {

  			WARN(1, "Association %p with NULL primary path!
  ", asoc);

  			return;
  		}
  
  		primary = &peer->saddr;

  	}

  	rcu_read_lock();
  	list_for_each_entry_rcu(laddr, &epb->bind_addr.address_list, list) {
  		if (!laddr->valid)
  			continue;

  		addr = &laddr->a;

  		af = sctp_get_af_specific(addr->sa.sa_family);

  		if (primary && af->cmp_addr(addr, primary)) {
  			seq_printf(seq, "*");
  		}

  		af->seq_dump_addr(seq, addr);

  	}

  	rcu_read_unlock();

  }
  
  /* Dump remote addresses of an association. */
  static void sctp_seq_dump_remote_addrs(struct seq_file *seq, struct sctp_association *assoc)
  {

  	struct sctp_transport *transport;

  	union sctp_addr *addr, *primary;

  	struct sctp_af *af;

  	primary = &assoc->peer.primary_addr;

  	list_for_each_entry_rcu(transport, &assoc->peer.transport_addr_list,

  			transports) {

  		addr = &transport->ipaddr;

  		af = sctp_get_af_specific(addr->sa.sa_family);

  		if (af->cmp_addr(addr, primary)) {

  			seq_printf(seq, "*");
  		}

  		af->seq_dump_addr(seq, addr);

  	}
  }

  static void *sctp_eps_seq_start(struct seq_file *seq, loff_t *pos)

  {

  	if (*pos >= sctp_ep_hashsize)

  		return NULL;
  
  	if (*pos < 0)
  		*pos = 0;
  
  	if (*pos == 0)
  		seq_printf(seq, " ENDPT     SOCK   STY SST HBKT LPORT   UID INODE LADDRS
  ");

  	return (void *)pos;
  }
  
  static void sctp_eps_seq_stop(struct seq_file *seq, void *v)
  {

  }

  static void *sctp_eps_seq_next(struct seq_file *seq, void *v, loff_t *pos)

  {

  	if (++*pos >= sctp_ep_hashsize)

  		return NULL;

  	return pos;
  }

  /* Display sctp endpoints (/proc/net/sctp/eps). */
  static int sctp_eps_seq_show(struct seq_file *seq, void *v)
  {
  	struct sctp_hashbucket *head;
  	struct sctp_ep_common *epb;
  	struct sctp_endpoint *ep;
  	struct sock *sk;

  	int    hash = *(loff_t *)v;

  	if (hash >= sctp_ep_hashsize)

  		return -ENOMEM;

  	head = &sctp_ep_hashtable[hash];

  	read_lock_bh(&head->lock);

  	sctp_for_each_hentry(epb, &head->chain) {

  		ep = sctp_ep(epb);
  		sk = epb->sk;

  		if (!net_eq(sock_net(sk), seq_file_net(seq)))

  			continue;

  		seq_printf(seq, "%8pK %8pK %-3d %-3d %-4d %-5d %5u %5lu ", ep, sk,

  			   sctp_sk(sk)->type, sk->sk_state, hash,

  			   epb->bind_addr.port,

  			   from_kuid_munged(seq_user_ns(seq), sock_i_uid(sk)),
  			   sock_i_ino(sk));

  
  		sctp_seq_dump_local_addrs(seq, epb);
  		seq_printf(seq, "
  ");

  	}

  	read_unlock_bh(&head->lock);

  
  	return 0;
  }

  static const struct seq_operations sctp_eps_ops = {

  	.start = sctp_eps_seq_start,
  	.next  = sctp_eps_seq_next,
  	.stop  = sctp_eps_seq_stop,
  	.show  = sctp_eps_seq_show,
  };

  struct sctp_ht_iter {
  	struct seq_net_private p;
  	struct rhashtable_iter hti;
  };

  static void *sctp_transport_seq_start(struct seq_file *seq, loff_t *pos)

  {

  	struct sctp_ht_iter *iter = seq->private;

  	sctp_transport_walk_start(&iter->hti);

  	return sctp_transport_get_idx(seq_file_net(seq), &iter->hti, *pos);

  }

  static void sctp_transport_seq_stop(struct seq_file *seq, void *v)

  {

  	struct sctp_ht_iter *iter = seq->private;
  
  	sctp_transport_walk_stop(&iter->hti);

  }

  static void *sctp_transport_seq_next(struct seq_file *seq, void *v, loff_t *pos)

  {

  	struct sctp_ht_iter *iter = seq->private;

  	++*pos;

  	return sctp_transport_get_next(seq_file_net(seq), &iter->hti);

  }

  /* Display sctp associations (/proc/net/sctp/assocs). */
  static int sctp_assocs_seq_show(struct seq_file *seq, void *v)
  {

  	struct sctp_transport *transport;

  	struct sctp_association *assoc;

  	struct sctp_ep_common *epb;

  	struct sock *sk;

  	if (v == SEQ_START_TOKEN) {
  		seq_printf(seq, " ASSOC     SOCK   STY SST ST HBKT "
  				"ASSOC-ID TX_QUEUE RX_QUEUE UID INODE LPORT "
  				"RPORT LADDRS <-> RADDRS "
  				"HBINT INS OUTS MAXRT T1X T2X RTXC "
  				"wmema wmemq sndbuf rcvbuf
  ");
  		return 0;

  	}

  
  	transport = (struct sctp_transport *)v;
  	assoc = transport->asoc;
  	epb = &assoc->base;
  	sk = epb->sk;
  
  	seq_printf(seq,
  		   "%8pK %8pK %-3d %-3d %-2d %-4d "
  		   "%4d %8d %8d %7u %5lu %-5d %5d ",
  		   assoc, sk, sctp_sk(sk)->type, sk->sk_state,
  		   assoc->state, 0,
  		   assoc->assoc_id,
  		   assoc->sndbuf_used,
  		   atomic_read(&assoc->rmem_alloc),
  		   from_kuid_munged(seq_user_ns(seq), sock_i_uid(sk)),
  		   sock_i_ino(sk),
  		   epb->bind_addr.port,
  		   assoc->peer.port);
  	seq_printf(seq, " ");
  	sctp_seq_dump_local_addrs(seq, epb);
  	seq_printf(seq, "<-> ");
  	sctp_seq_dump_remote_addrs(seq, assoc);
  	seq_printf(seq, "\t%8lu %5d %5d %4d %4d %4d %8d "
  		   "%8d %8d %8d %8d",

  		assoc->hbinterval, assoc->stream.incnt,
  		assoc->stream.outcnt, assoc->max_retrans,

  		assoc->init_retries, assoc->shutdown_retries,
  		assoc->rtx_data_chunks,

  		refcount_read(&sk->sk_wmem_alloc),

  		sk->sk_wmem_queued,
  		sk->sk_sndbuf,
  		sk->sk_rcvbuf);
  	seq_printf(seq, "
  ");

  	sctp_transport_put(transport);

  	return 0;
  }

  static const struct seq_operations sctp_assoc_ops = {

  	.start = sctp_transport_seq_start,
  	.next  = sctp_transport_seq_next,
  	.stop  = sctp_transport_seq_stop,

  	.show  = sctp_assocs_seq_show,
  };

  static int sctp_remaddr_seq_show(struct seq_file *seq, void *v)
  {

  	struct sctp_association *assoc;

  	struct sctp_transport *transport, *tsp;

  	if (v == SEQ_START_TOKEN) {
  		seq_printf(seq, "ADDR ASSOC_ID HB_ACT RTO MAX_PATH_RTX "
  				"REM_ADDR_RTX START STATE
  ");
  		return 0;
  	}

  	transport = (struct sctp_transport *)v;

  	assoc = transport->asoc;

  
  	list_for_each_entry_rcu(tsp, &assoc->peer.transport_addr_list,
  				transports) {

  		/*
  		 * The remote address (ADDR)
  		 */
  		tsp->af_specific->seq_dump_addr(seq, &tsp->ipaddr);
  		seq_printf(seq, " ");
  		/*
  		 * The association ID (ASSOC_ID)
  		 */
  		seq_printf(seq, "%d ", tsp->asoc->assoc_id);
  
  		/*
  		 * If the Heartbeat is active (HB_ACT)
  		 * Note: 1 = Active, 0 = Inactive
  		 */
  		seq_printf(seq, "%d ", timer_pending(&tsp->hb_timer));
  
  		/*
  		 * Retransmit time out (RTO)
  		 */
  		seq_printf(seq, "%lu ", tsp->rto);
  
  		/*
  		 * Maximum path retransmit count (PATH_MAX_RTX)
  		 */
  		seq_printf(seq, "%d ", tsp->pathmaxrxt);
  
  		/*
  		 * remote address retransmit count (REM_ADDR_RTX)
  		 * Note: We don't have a way to tally this at the moment
  		 * so lets just leave it as zero for the moment
  		 */
  		seq_puts(seq, "0 ");
  
  		/*
  		 * remote address start time (START).  This is also not
  		 * currently implemented, but we can record it with a
  		 * jiffies marker in a subsequent patch
  		 */
  		seq_puts(seq, "0 ");
  
  		/*
  		 * The current state of this destination. I.e.
  		 * SCTP_ACTIVE, SCTP_INACTIVE, ...
  		 */
  		seq_printf(seq, "%d", tsp->state);

  		seq_printf(seq, "
  ");

  	}

  	sctp_transport_put(transport);

  	return 0;

  }
  
  static const struct seq_operations sctp_remaddr_ops = {

  	.start = sctp_transport_seq_start,
  	.next  = sctp_transport_seq_next,
  	.stop  = sctp_transport_seq_stop,

  	.show  = sctp_remaddr_seq_show,
  };

  /* Set up the proc fs entry for the SCTP protocol. */
  int __net_init sctp_proc_init(struct net *net)

  {

  	net->sctp.proc_net_sctp = proc_net_mkdir(net, "sctp", net->proc_net);
  	if (!net->sctp.proc_net_sctp)

  		return -ENOMEM;

  	if (!proc_create_net_single("snmp", 0444, net->sctp.proc_net_sctp,
  			 sctp_snmp_seq_show, NULL))

  		goto cleanup;

  	if (!proc_create_net("eps", 0444, net->sctp.proc_net_sctp,
  			&sctp_eps_ops, sizeof(struct seq_net_private)))

  		goto cleanup;

  	if (!proc_create_net("assocs", 0444, net->sctp.proc_net_sctp,
  			&sctp_assoc_ops, sizeof(struct sctp_ht_iter)))

  		goto cleanup;

  	if (!proc_create_net("remaddr", 0444, net->sctp.proc_net_sctp,
  			&sctp_remaddr_ops, sizeof(struct sctp_ht_iter)))

  		goto cleanup;

  	return 0;

  
  cleanup:
  	remove_proc_subtree("sctp", net->proc_net);
  	net->sctp.proc_net_sctp = NULL;
  	return -ENOMEM;

  }