text: /* SCTP kernel implementation
   * (C) Copyright IBM Corp. 2002, 2004
   * Copyright (c) 2002 Intel Corp.
   *
   * This file is part of the SCTP kernel implementation
   *
   * Sysctl related interfaces for SCTP.
   *
   * This SCTP implementation is free software;
   * you can redistribute it and/or modify it under the terms of
   * the GNU General Public License as published by
   * the Free Software Foundation; either version 2, or (at your option)
   * any later version.
   *
   * This SCTP implementation is distributed in the hope that it
   * will be useful, but WITHOUT ANY WARRANTY; without even the implied
   *                 ************************
   * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
   * See the GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with GNU CC; see the file COPYING.  If not, see
   * <http://www.gnu.org/licenses/>.
   *
   * 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:
   *    Mingqin Liu           <liuming@us.ibm.com>
   *    Jon Grimm             <jgrimm@us.ibm.com>
   *    Ardelle Fan           <ardelle.fan@intel.com>
   *    Ryan Layer            <rmlayer@us.ibm.com>
   *    Sridhar Samudrala     <sri@us.ibm.com>
   */
  
  #include <net/sctp/structs.h>
  #include <net/sctp/sctp.h>
  #include <linux/sysctl.h>
  
  static int zero = 0;
  static int one = 1;
  static int timer_max = 86400000; /* ms in one day */
  static int int_max = INT_MAX;
  static int sack_timer_min = 1;
  static int sack_timer_max = 500;
  static int addr_scope_max = 3; /* check sctp_scope_policy_t in include/net/sctp/constants.h for max entries */
  static int rwnd_scale_max = 16;
  static unsigned long max_autoclose_min = 0;
  static unsigned long max_autoclose_max =
  	(MAX_SCHEDULE_TIMEOUT / HZ > UINT_MAX)
  	? UINT_MAX : MAX_SCHEDULE_TIMEOUT / HZ;
  
  extern long sysctl_sctp_mem[3];
  extern int sysctl_sctp_rmem[3];
  extern int sysctl_sctp_wmem[3];
  
  static int proc_sctp_do_hmac_alg(struct ctl_table *ctl, int write,
  				void __user *buffer, size_t *lenp,
  				loff_t *ppos);
  static int proc_sctp_do_rto_min(struct ctl_table *ctl, int write,
  				void __user *buffer, size_t *lenp,
  				loff_t *ppos);
  static int proc_sctp_do_rto_max(struct ctl_table *ctl, int write,
  				void __user *buffer, size_t *lenp,
  				loff_t *ppos);
  
  static struct ctl_table sctp_table[] = {
  	{
  		.procname	= "sctp_mem",
  		.data		= &sysctl_sctp_mem,
  		.maxlen		= sizeof(sysctl_sctp_mem),
  		.mode		= 0644,
  		.proc_handler	= proc_doulongvec_minmax
  	},
  	{
  		.procname	= "sctp_rmem",
  		.data		= &sysctl_sctp_rmem,
  		.maxlen		= sizeof(sysctl_sctp_rmem),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec,
  	},
  	{
  		.procname	= "sctp_wmem",
  		.data		= &sysctl_sctp_wmem,
  		.maxlen		= sizeof(sysctl_sctp_wmem),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec,
  	},
  
  	{ /* sentinel */ }
  };
  
  static struct ctl_table sctp_net_table[] = {
  	{
  		.procname	= "rto_initial",
  		.data		= &init_net.sctp.rto_initial,
  		.maxlen		= sizeof(unsigned int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec_minmax,
  		.extra1         = &one,
  		.extra2         = &timer_max
  	},
  	{
  		.procname	= "rto_min",
  		.data		= &init_net.sctp.rto_min,
  		.maxlen		= sizeof(unsigned int),
  		.mode		= 0644,
  		.proc_handler	= proc_sctp_do_rto_min,
  		.extra1         = &one,
  		.extra2         = &init_net.sctp.rto_max
  	},
  	{
  		.procname	= "rto_max",
  		.data		= &init_net.sctp.rto_max,
  		.maxlen		= sizeof(unsigned int),
  		.mode		= 0644,
  		.proc_handler	= proc_sctp_do_rto_max,
  		.extra1         = &init_net.sctp.rto_min,
  		.extra2         = &timer_max
  	},
  	{
  		.procname	= "rto_alpha_exp_divisor",
  		.data		= &init_net.sctp.rto_alpha,
  		.maxlen		= sizeof(int),
  		.mode		= 0444,
  		.proc_handler	= proc_dointvec,
  	},
  	{
  		.procname	= "rto_beta_exp_divisor",
  		.data		= &init_net.sctp.rto_beta,
  		.maxlen		= sizeof(int),
  		.mode		= 0444,
  		.proc_handler	= proc_dointvec,
  	},
  	{
  		.procname	= "max_burst",
  		.data		= &init_net.sctp.max_burst,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec_minmax,
  		.extra1		= &zero,
  		.extra2		= &int_max
  	},
  	{
  		.procname	= "cookie_preserve_enable",
  		.data		= &init_net.sctp.cookie_preserve_enable,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec,
  	},
  	{
  		.procname	= "cookie_hmac_alg",
  		.data		= &init_net.sctp.sctp_hmac_alg,
  		.maxlen		= 8,
  		.mode		= 0644,
  		.proc_handler	= proc_sctp_do_hmac_alg,
  	},
  	{
  		.procname	= "valid_cookie_life",
  		.data		= &init_net.sctp.valid_cookie_life,
  		.maxlen		= sizeof(unsigned int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec_minmax,
  		.extra1         = &one,
  		.extra2         = &timer_max
  	},
  	{
  		.procname	= "sack_timeout",
  		.data		= &init_net.sctp.sack_timeout,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec_minmax,
  		.extra1         = &sack_timer_min,
  		.extra2         = &sack_timer_max,
  	},
  	{
  		.procname	= "hb_interval",
  		.data		= &init_net.sctp.hb_interval,
  		.maxlen		= sizeof(unsigned int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec_minmax,
  		.extra1         = &one,
  		.extra2         = &timer_max
  	},
  	{
  		.procname	= "association_max_retrans",
  		.data		= &init_net.sctp.max_retrans_association,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec_minmax,
  		.extra1		= &one,
  		.extra2		= &int_max
  	},
  	{
  		.procname	= "path_max_retrans",
  		.data		= &init_net.sctp.max_retrans_path,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec_minmax,
  		.extra1		= &one,
  		.extra2		= &int_max
  	},
  	{
  		.procname	= "max_init_retransmits",
  		.data		= &init_net.sctp.max_retrans_init,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec_minmax,
  		.extra1		= &one,
  		.extra2		= &int_max
  	},
  	{
  		.procname	= "pf_retrans",
  		.data		= &init_net.sctp.pf_retrans,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec_minmax,
  		.extra1		= &zero,
  		.extra2		= &int_max
  	},
  	{
  		.procname	= "sndbuf_policy",
  		.data		= &init_net.sctp.sndbuf_policy,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec,
  	},
  	{
  		.procname	= "rcvbuf_policy",
  		.data		= &init_net.sctp.rcvbuf_policy,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec,
  	},
  	{
  		.procname	= "default_auto_asconf",
  		.data		= &init_net.sctp.default_auto_asconf,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec,
  	},
  	{
  		.procname	= "addip_enable",
  		.data		= &init_net.sctp.addip_enable,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec,
  	},
  	{
  		.procname	= "addip_noauth_enable",
  		.data		= &init_net.sctp.addip_noauth,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec,
  	},
  	{
  		.procname	= "prsctp_enable",
  		.data		= &init_net.sctp.prsctp_enable,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec,
  	},
  	{
  		.procname	= "auth_enable",
  		.data		= &init_net.sctp.auth_enable,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec,
  	},
  	{
  		.procname	= "addr_scope_policy",
  		.data		= &init_net.sctp.scope_policy,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec_minmax,
  		.extra1		= &zero,
  		.extra2		= &addr_scope_max,
  	},
  	{
  		.procname	= "rwnd_update_shift",
  		.data		= &init_net.sctp.rwnd_upd_shift,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,
  		.proc_handler	= &proc_dointvec_minmax,
  		.extra1		= &one,
  		.extra2		= &rwnd_scale_max,
  	},
  	{
  		.procname	= "max_autoclose",
  		.data		= &init_net.sctp.max_autoclose,
  		.maxlen		= sizeof(unsigned long),
  		.mode		= 0644,
  		.proc_handler	= &proc_doulongvec_minmax,
  		.extra1		= &max_autoclose_min,
  		.extra2		= &max_autoclose_max,
  	},
  
  	{ /* sentinel */ }
  };
  
  static int proc_sctp_do_hmac_alg(struct ctl_table *ctl, int write,
  				void __user *buffer, size_t *lenp,
  				loff_t *ppos)
  {
  	struct net *net = current->nsproxy->net_ns;
  	char tmp[8];
  	struct ctl_table tbl;
  	int ret;
  	int changed = 0;
  	char *none = "none";
  
  	memset(&tbl, 0, sizeof(struct ctl_table));
  
  	if (write) {
  		tbl.data = tmp;
  		tbl.maxlen = 8;
  	} else {
  		tbl.data = net->sctp.sctp_hmac_alg ? : none;
  		tbl.maxlen = strlen(tbl.data);
  	}
  		ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
  
  	if (write) {
  #ifdef CONFIG_CRYPTO_MD5
  		if (!strncmp(tmp, "md5", 3)) {
  			net->sctp.sctp_hmac_alg = "md5";
  			changed = 1;
  		}
  #endif
  #ifdef CONFIG_CRYPTO_SHA1
  		if (!strncmp(tmp, "sha1", 4)) {
  			net->sctp.sctp_hmac_alg = "sha1";
  			changed = 1;
  		}
  #endif
  		if (!strncmp(tmp, "none", 4)) {
  			net->sctp.sctp_hmac_alg = NULL;
  			changed = 1;
  		}
  
  		if (!changed)
  			ret = -EINVAL;
  	}
  
  	return ret;
  }
  
  static int proc_sctp_do_rto_min(struct ctl_table *ctl, int write,
  				void __user *buffer, size_t *lenp,
  				loff_t *ppos)
  {
  	struct net *net = current->nsproxy->net_ns;
  	int new_value;
  	struct ctl_table tbl;
  	unsigned int min = *(unsigned int *) ctl->extra1;
  	unsigned int max = *(unsigned int *) ctl->extra2;
  	int ret;
  
  	memset(&tbl, 0, sizeof(struct ctl_table));
  	tbl.maxlen = sizeof(unsigned int);
  
  	if (write)
  		tbl.data = &new_value;
  	else
  		tbl.data = &net->sctp.rto_min;
  	ret = proc_dointvec(&tbl, write, buffer, lenp, ppos);
  	if (write) {
  		if (ret || new_value > max || new_value < min)
  			return -EINVAL;
  		net->sctp.rto_min = new_value;
  	}
  	return ret;
  }
  
  static int proc_sctp_do_rto_max(struct ctl_table *ctl, int write,
  				void __user *buffer, size_t *lenp,
  				loff_t *ppos)
  {
  	struct net *net = current->nsproxy->net_ns;
  	int new_value;
  	struct ctl_table tbl;
  	unsigned int min = *(unsigned int *) ctl->extra1;
  	unsigned int max = *(unsigned int *) ctl->extra2;
  	int ret;
  
  	memset(&tbl, 0, sizeof(struct ctl_table));
  	tbl.maxlen = sizeof(unsigned int);
  
  	if (write)
  		tbl.data = &new_value;
  	else
  		tbl.data = &net->sctp.rto_max;
  	ret = proc_dointvec(&tbl, write, buffer, lenp, ppos);
  	if (write) {
  		if (ret || new_value > max || new_value < min)
  			return -EINVAL;
  		net->sctp.rto_max = new_value;
  	}
  	return ret;
  }
  
  int sctp_sysctl_net_register(struct net *net)
  {
  	struct ctl_table *table = sctp_net_table;
  
  	if (!net_eq(net, &init_net)) {
  		int i;
  
  		table = kmemdup(sctp_net_table, sizeof(sctp_net_table), GFP_KERNEL);
  		if (!table)
  			return -ENOMEM;
  
  		for (i = 0; table[i].data; i++)
  			table[i].data += (char *)(&net->sctp) - (char *)&init_net.sctp;
  	}
  
  	net->sctp.sysctl_header = register_net_sysctl(net, "net/sctp", table);
  	return 0;
  }
  
  void sctp_sysctl_net_unregister(struct net *net)
  {
  	struct ctl_table *table;
  
  	table = net->sctp.sysctl_header->ctl_table_arg;
  	unregister_net_sysctl_table(net->sctp.sysctl_header);
  	kfree(table);
  }
  
  static struct ctl_table_header *sctp_sysctl_header;
  
  /* Sysctl registration.  */
  void sctp_sysctl_register(void)
  {
  	sctp_sysctl_header = register_net_sysctl(&init_net, "net/sctp", sctp_table);
  }
  
  /* Sysctl deregistration.  */
  void sctp_sysctl_unregister(void)
  {
  	unregister_net_sysctl_table(sctp_sysctl_header);
  }
  