net/netfilter/nf_conntrack_proto_generic.c

   1 /* (C) 1999-2001 Paul `Rusty' Russell
   2  * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 as
   6  * published by the Free Software Foundation.
   7  */
   8
   9 #include <linux/types.h>
  10 #include <linux/jiffies.h>
  11 #include <linux/timer.h>
  12 #include <linux/netfilter.h>
  13 #include <net/netfilter/nf_conntrack_l4proto.h>
  14
  15 static unsigned int nf_ct_generic_timeout __read_mostly = 600*HZ;
  16
  17 static inline struct nf_generic_net *generic_pernet(struct net *net)
  18 {
  19         return &net->ct.nf_ct_proto.generic;
  20 }
  21
  22 static bool generic_pkt_to_tuple(const struct sk_buff *skb,
  23                                  unsigned int dataoff,
  24                                  struct nf_conntrack_tuple *tuple)
  25 {
  26         tuple->src.u.all = 0;
  27         tuple->dst.u.all = 0;
  28
  29         return true;
  30 }
  31
  32 static bool generic_invert_tuple(struct nf_conntrack_tuple *tuple,
  33                                  const struct nf_conntrack_tuple *orig)
  34 {
  35         tuple->src.u.all = 0;
  36         tuple->dst.u.all = 0;
  37
  38         return true;
  39 }
  40
  41 /* Print out the per-protocol part of the tuple. */
  42 static int generic_print_tuple(struct seq_file *s,
  43                                const struct nf_conntrack_tuple *tuple)
  44 {
  45         return 0;
  46 }
  47
  48 static unsigned int *generic_get_timeouts(struct net *net)
  49 {
  50         return &(generic_pernet(net)->timeout);
  51 }
  52
  53 /* Returns verdict for packet, or -1 for invalid. */
  54 static int generic_packet(struct nf_conn *ct,
  55                           const struct sk_buff *skb,
  56                           unsigned int dataoff,
  57                           enum ip_conntrack_info ctinfo,
  58                           u_int8_t pf,
  59                           unsigned int hooknum,
  60                           unsigned int *timeout)
  61 {
  62         nf_ct_refresh_acct(ct, ctinfo, skb, *timeout);
  63         return NF_ACCEPT;
  64 }
  65
  66 /* Called when a new connection for this protocol found. */
  67 static bool generic_new(struct nf_conn *ct, const struct sk_buff *skb,
  68                         unsigned int dataoff, unsigned int *timeouts)
  69 {
  70         return true;
  71 }
  72
  73 #if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
  74
  75 #include <linux/netfilter/nfnetlink.h>
  76 #include <linux/netfilter/nfnetlink_cttimeout.h>
  77
  78 static int generic_timeout_nlattr_to_obj(struct nlattr *tb[],
  79                                          struct net *net, void *data)
  80 {
  81         unsigned int *timeout = data;
  82         struct nf_generic_net *gn = generic_pernet(net);
  83
  84         if (tb[CTA_TIMEOUT_GENERIC_TIMEOUT])
  85                 *timeout =
  86                     ntohl(nla_get_be32(tb[CTA_TIMEOUT_GENERIC_TIMEOUT])) * HZ;
  87         else {
  88                 /* Set default generic timeout. */
  89                 *timeout = gn->timeout;
  90         }
  91
  92         return 0;
  93 }
  94
  95 static int
  96 generic_timeout_obj_to_nlattr(struct sk_buff *skb, const void *data)
  97 {
  98         const unsigned int *timeout = data;
  99
 100         if (nla_put_be32(skb, CTA_TIMEOUT_GENERIC_TIMEOUT, htonl(*timeout / HZ)))
 101                 goto nla_put_failure;
 102
 103         return 0;
 104
 105 nla_put_failure:
 106         return -ENOSPC;
 107 }
 108
 109 static const struct nla_policy
 110 generic_timeout_nla_policy[CTA_TIMEOUT_GENERIC_MAX+1] = {
 111         [CTA_TIMEOUT_GENERIC_TIMEOUT]   = { .type = NLA_U32 },
 112 };
 113 #endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
 114
 115 #ifdef CONFIG_SYSCTL
 116 static struct ctl_table generic_sysctl_table[] = {
 117         {
 118                 .procname       = "nf_conntrack_generic_timeout",
 119                 .maxlen         = sizeof(unsigned int),
 120                 .mode           = 0644,
 121                 .proc_handler   = proc_dointvec_jiffies,
 122         },
 123         { }
 124 };
 125 #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
 126 static struct ctl_table generic_compat_sysctl_table[] = {
 127         {
 128                 .procname       = "ip_conntrack_generic_timeout",
 129                 .maxlen         = sizeof(unsigned int),
 130                 .mode           = 0644,
 131                 .proc_handler   = proc_dointvec_jiffies,
 132         },
 133         { }
 134 };
 135 #endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
 136 #endif /* CONFIG_SYSCTL */
 137
 138 static int generic_kmemdup_sysctl_table(struct nf_proto_net *pn,
 139                                         struct nf_generic_net *gn)
 140 {
 141 #ifdef CONFIG_SYSCTL
 142         pn->ctl_table = kmemdup(generic_sysctl_table,
 143                                 sizeof(generic_sysctl_table),
 144                                 GFP_KERNEL);
 145         if (!pn->ctl_table)
 146                 return -ENOMEM;
 147
 148         pn->ctl_table[0].data = &gn->timeout;
 149 #endif
 150         return 0;
 151 }
 152
 153 static int generic_kmemdup_compat_sysctl_table(struct nf_proto_net *pn,
 154                                                struct nf_generic_net *gn)
 155 {
 156 #ifdef CONFIG_SYSCTL
 157 #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
 158         pn->ctl_compat_table = kmemdup(generic_compat_sysctl_table,
 159                                        sizeof(generic_compat_sysctl_table),
 160                                        GFP_KERNEL);
 161         if (!pn->ctl_compat_table)
 162                 return -ENOMEM;
 163
 164         pn->ctl_compat_table[0].data = &gn->timeout;
 165 #endif
 166 #endif
 167         return 0;
 168 }
 169
 170 static int generic_init_net(struct net *net, u_int16_t proto)
 171 {
 172         int ret;
 173         struct nf_generic_net *gn = generic_pernet(net);
 174         struct nf_proto_net *pn = &gn->pn;
 175
 176         gn->timeout = nf_ct_generic_timeout;
 177
 178         ret = generic_kmemdup_compat_sysctl_table(pn, gn);
 179         if (ret < 0)
 180                 return ret;
 181
 182         ret = generic_kmemdup_sysctl_table(pn, gn);
 183         if (ret < 0)
 184                 nf_ct_kfree_compat_sysctl_table(pn);
 185
 186         return ret;
 187 }
 188
 189 static struct nf_proto_net *generic_get_net_proto(struct net *net)
 190 {
 191         return &net->ct.nf_ct_proto.generic.pn;
 192 }
 193
 194 struct nf_conntrack_l4proto nf_conntrack_l4proto_generic __read_mostly =
 195 {
 196         .l3proto                = PF_UNSPEC,
 197         .l4proto                = 255,
 198         .name                   = "unknown",
 199         .pkt_to_tuple           = generic_pkt_to_tuple,
 200         .invert_tuple           = generic_invert_tuple,
 201         .print_tuple            = generic_print_tuple,
 202         .packet                 = generic_packet,
 203         .get_timeouts           = generic_get_timeouts,
 204         .new                    = generic_new,
 205 #if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
 206         .ctnl_timeout           = {
 207                 .nlattr_to_obj  = generic_timeout_nlattr_to_obj,
 208                 .obj_to_nlattr  = generic_timeout_obj_to_nlattr,
 209                 .nlattr_max     = CTA_TIMEOUT_GENERIC_MAX,
 210                 .obj_size       = sizeof(unsigned int),
 211                 .nla_policy     = generic_timeout_nla_policy,
 212         },
 213 #endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
 214         .init_net               = generic_init_net,
 215         .get_net_proto          = generic_get_net_proto,
 216 };