kernel/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 bool nf_generic_should_process(u8 proto)
  18 {
  19         switch (proto) {
  20 #ifdef CONFIG_NF_CT_PROTO_SCTP_MODULE
  21         case IPPROTO_SCTP:
  22                 return false;
  23 #endif
  24 #ifdef CONFIG_NF_CT_PROTO_DCCP_MODULE
  25         case IPPROTO_DCCP:
  26                 return false;
  27 #endif
  28 #ifdef CONFIG_NF_CT_PROTO_GRE_MODULE
  29         case IPPROTO_GRE:
  30                 return false;
  31 #endif
  32 #ifdef CONFIG_NF_CT_PROTO_UDPLITE_MODULE
  33         case IPPROTO_UDPLITE:
  34                 return false;
  35 #endif
  36         default:
  37                 return true;
  38         }
  39 }
  40
  41 static inline struct nf_generic_net *generic_pernet(struct net *net)
  42 {
  43         return &net->ct.nf_ct_proto.generic;
  44 }
  45
  46 static bool generic_pkt_to_tuple(const struct sk_buff *skb,
  47                                  unsigned int dataoff,
  48                                  struct nf_conntrack_tuple *tuple)
  49 {
  50         tuple->src.u.all = 0;
  51         tuple->dst.u.all = 0;
  52
  53         return true;
  54 }
  55
  56 static bool generic_invert_tuple(struct nf_conntrack_tuple *tuple,
  57                                  const struct nf_conntrack_tuple *orig)
  58 {
  59         tuple->src.u.all = 0;
  60         tuple->dst.u.all = 0;
  61
  62         return true;
  63 }
  64
  65 /* Print out the per-protocol part of the tuple. */
  66 static void generic_print_tuple(struct seq_file *s,
  67                                 const struct nf_conntrack_tuple *tuple)
  68 {
  69 }
  70
  71 static unsigned int *generic_get_timeouts(struct net *net)
  72 {
  73         return &(generic_pernet(net)->timeout);
  74 }
  75
  76 /* Returns verdict for packet, or -1 for invalid. */
  77 static int generic_packet(struct nf_conn *ct,
  78                           const struct sk_buff *skb,
  79                           unsigned int dataoff,
  80                           enum ip_conntrack_info ctinfo,
  81                           u_int8_t pf,
  82                           unsigned int hooknum,
  83                           unsigned int *timeout)
  84 {
  85         nf_ct_refresh_acct(ct, ctinfo, skb, *timeout);
  86         return NF_ACCEPT;
  87 }
  88
  89 /* Called when a new connection for this protocol found. */
  90 static bool generic_new(struct nf_conn *ct, const struct sk_buff *skb,
  91                         unsigned int dataoff, unsigned int *timeouts)
  92 {
  93         return nf_generic_should_process(nf_ct_protonum(ct));
  94 }
  95
  96 #if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
  97
  98 #include <linux/netfilter/nfnetlink.h>
  99 #include <linux/netfilter/nfnetlink_cttimeout.h>
 100
 101 static int generic_timeout_nlattr_to_obj(struct nlattr *tb[],
 102                                          struct net *net, void *data)
 103 {
 104         unsigned int *timeout = data;
 105         struct nf_generic_net *gn = generic_pernet(net);
 106
 107         if (tb[CTA_TIMEOUT_GENERIC_TIMEOUT])
 108                 *timeout =
 109                     ntohl(nla_get_be32(tb[CTA_TIMEOUT_GENERIC_TIMEOUT])) * HZ;
 110         else {
 111                 /* Set default generic timeout. */
 112                 *timeout = gn->timeout;
 113         }
 114
 115         return 0;
 116 }
 117
 118 static int
 119 generic_timeout_obj_to_nlattr(struct sk_buff *skb, const void *data)
 120 {
 121         const unsigned int *timeout = data;
 122
 123         if (nla_put_be32(skb, CTA_TIMEOUT_GENERIC_TIMEOUT, htonl(*timeout / HZ)))
 124                 goto nla_put_failure;
 125
 126         return 0;
 127
 128 nla_put_failure:
 129         return -ENOSPC;
 130 }
 131
 132 static const struct nla_policy
 133 generic_timeout_nla_policy[CTA_TIMEOUT_GENERIC_MAX+1] = {
 134         [CTA_TIMEOUT_GENERIC_TIMEOUT]   = { .type = NLA_U32 },
 135 };
 136 #endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
 137
 138 #ifdef CONFIG_SYSCTL
 139 static struct ctl_table generic_sysctl_table[] = {
 140         {
 141                 .procname       = "nf_conntrack_generic_timeout",
 142                 .maxlen         = sizeof(unsigned int),
 143                 .mode           = 0644,
 144                 .proc_handler   = proc_dointvec_jiffies,
 145         },
 146         { }
 147 };
 148 #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
 149 static struct ctl_table generic_compat_sysctl_table[] = {
 150         {
 151                 .procname       = "ip_conntrack_generic_timeout",
 152                 .maxlen         = sizeof(unsigned int),
 153                 .mode           = 0644,
 154                 .proc_handler   = proc_dointvec_jiffies,
 155         },
 156         { }
 157 };
 158 #endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
 159 #endif /* CONFIG_SYSCTL */
 160
 161 static int generic_kmemdup_sysctl_table(struct nf_proto_net *pn,
 162                                         struct nf_generic_net *gn)
 163 {
 164 #ifdef CONFIG_SYSCTL
 165         pn->ctl_table = kmemdup(generic_sysctl_table,
 166                                 sizeof(generic_sysctl_table),
 167                                 GFP_KERNEL);
 168         if (!pn->ctl_table)
 169                 return -ENOMEM;
 170
 171         pn->ctl_table[0].data = &gn->timeout;
 172 #endif
 173         return 0;
 174 }
 175
 176 static int generic_kmemdup_compat_sysctl_table(struct nf_proto_net *pn,
 177                                                struct nf_generic_net *gn)
 178 {
 179 #ifdef CONFIG_SYSCTL
 180 #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
 181         pn->ctl_compat_table = kmemdup(generic_compat_sysctl_table,
 182                                        sizeof(generic_compat_sysctl_table),
 183                                        GFP_KERNEL);
 184         if (!pn->ctl_compat_table)
 185                 return -ENOMEM;
 186
 187         pn->ctl_compat_table[0].data = &gn->timeout;
 188 #endif
 189 #endif
 190         return 0;
 191 }
 192
 193 static int generic_init_net(struct net *net, u_int16_t proto)
 194 {
 195         int ret;
 196         struct nf_generic_net *gn = generic_pernet(net);
 197         struct nf_proto_net *pn = &gn->pn;
 198
 199         gn->timeout = nf_ct_generic_timeout;
 200
 201         ret = generic_kmemdup_compat_sysctl_table(pn, gn);
 202         if (ret < 0)
 203                 return ret;
 204
 205         ret = generic_kmemdup_sysctl_table(pn, gn);
 206         if (ret < 0)
 207                 nf_ct_kfree_compat_sysctl_table(pn);
 208
 209         return ret;
 210 }
 211
 212 static struct nf_proto_net *generic_get_net_proto(struct net *net)
 213 {
 214         return &net->ct.nf_ct_proto.generic.pn;
 215 }
 216
 217 struct nf_conntrack_l4proto nf_conntrack_l4proto_generic __read_mostly =
 218 {
 219         .l3proto                = PF_UNSPEC,
 220         .l4proto                = 255,
 221         .name                   = "unknown",
 222         .pkt_to_tuple           = generic_pkt_to_tuple,
 223         .invert_tuple           = generic_invert_tuple,
 224         .print_tuple            = generic_print_tuple,
 225         .packet                 = generic_packet,
 226         .get_timeouts           = generic_get_timeouts,
 227         .new                    = generic_new,
 228 #if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
 229         .ctnl_timeout           = {
 230                 .nlattr_to_obj  = generic_timeout_nlattr_to_obj,
 231                 .obj_to_nlattr  = generic_timeout_obj_to_nlattr,
 232                 .nlattr_max     = CTA_TIMEOUT_GENERIC_MAX,
 233                 .obj_size       = sizeof(unsigned int),
 234                 .nla_policy     = generic_timeout_nla_policy,
 235         },
 236 #endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
 237         .init_net               = generic_init_net,
 238         .get_net_proto          = generic_get_net_proto,
 239 };