| 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 net *net, 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 | bool ret; |
| 94 | |
| 95 | ret = nf_generic_should_process(nf_ct_protonum(ct)); |
| 96 | if (!ret) |
| 97 | pr_warn_once("conntrack: generic helper won't handle protocol %d. Please consider loading the specific helper module.\n", |
| 98 | nf_ct_protonum(ct)); |
| 99 | return ret; |
| 100 | } |
| 101 | |
| 102 | #if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT) |
| 103 | |
| 104 | #include <linux/netfilter/nfnetlink.h> |
| 105 | #include <linux/netfilter/nfnetlink_cttimeout.h> |
| 106 | |
| 107 | static int generic_timeout_nlattr_to_obj(struct nlattr *tb[], |
| 108 | struct net *net, void *data) |
| 109 | { |
| 110 | unsigned int *timeout = data; |
| 111 | struct nf_generic_net *gn = generic_pernet(net); |
| 112 | |
| 113 | if (tb[CTA_TIMEOUT_GENERIC_TIMEOUT]) |
| 114 | *timeout = |
| 115 | ntohl(nla_get_be32(tb[CTA_TIMEOUT_GENERIC_TIMEOUT])) * HZ; |
| 116 | else { |
| 117 | /* Set default generic timeout. */ |
| 118 | *timeout = gn->timeout; |
| 119 | } |
| 120 | |
| 121 | return 0; |
| 122 | } |
| 123 | |
| 124 | static int |
| 125 | generic_timeout_obj_to_nlattr(struct sk_buff *skb, const void *data) |
| 126 | { |
| 127 | const unsigned int *timeout = data; |
| 128 | |
| 129 | if (nla_put_be32(skb, CTA_TIMEOUT_GENERIC_TIMEOUT, htonl(*timeout / HZ))) |
| 130 | goto nla_put_failure; |
| 131 | |
| 132 | return 0; |
| 133 | |
| 134 | nla_put_failure: |
| 135 | return -ENOSPC; |
| 136 | } |
| 137 | |
| 138 | static const struct nla_policy |
| 139 | generic_timeout_nla_policy[CTA_TIMEOUT_GENERIC_MAX+1] = { |
| 140 | [CTA_TIMEOUT_GENERIC_TIMEOUT] = { .type = NLA_U32 }, |
| 141 | }; |
| 142 | #endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */ |
| 143 | |
| 144 | #ifdef CONFIG_SYSCTL |
| 145 | static struct ctl_table generic_sysctl_table[] = { |
| 146 | { |
| 147 | .procname = "nf_conntrack_generic_timeout", |
| 148 | .maxlen = sizeof(unsigned int), |
| 149 | .mode = 0644, |
| 150 | .proc_handler = proc_dointvec_jiffies, |
| 151 | }, |
| 152 | { } |
| 153 | }; |
| 154 | #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT |
| 155 | static struct ctl_table generic_compat_sysctl_table[] = { |
| 156 | { |
| 157 | .procname = "ip_conntrack_generic_timeout", |
| 158 | .maxlen = sizeof(unsigned int), |
| 159 | .mode = 0644, |
| 160 | .proc_handler = proc_dointvec_jiffies, |
| 161 | }, |
| 162 | { } |
| 163 | }; |
| 164 | #endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */ |
| 165 | #endif /* CONFIG_SYSCTL */ |
| 166 | |
| 167 | static int generic_kmemdup_sysctl_table(struct nf_proto_net *pn, |
| 168 | struct nf_generic_net *gn) |
| 169 | { |
| 170 | #ifdef CONFIG_SYSCTL |
| 171 | pn->ctl_table = kmemdup(generic_sysctl_table, |
| 172 | sizeof(generic_sysctl_table), |
| 173 | GFP_KERNEL); |
| 174 | if (!pn->ctl_table) |
| 175 | return -ENOMEM; |
| 176 | |
| 177 | pn->ctl_table[0].data = &gn->timeout; |
| 178 | #endif |
| 179 | return 0; |
| 180 | } |
| 181 | |
| 182 | static int generic_kmemdup_compat_sysctl_table(struct nf_proto_net *pn, |
| 183 | struct nf_generic_net *gn) |
| 184 | { |
| 185 | #ifdef CONFIG_SYSCTL |
| 186 | #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT |
| 187 | pn->ctl_compat_table = kmemdup(generic_compat_sysctl_table, |
| 188 | sizeof(generic_compat_sysctl_table), |
| 189 | GFP_KERNEL); |
| 190 | if (!pn->ctl_compat_table) |
| 191 | return -ENOMEM; |
| 192 | |
| 193 | pn->ctl_compat_table[0].data = &gn->timeout; |
| 194 | #endif |
| 195 | #endif |
| 196 | return 0; |
| 197 | } |
| 198 | |
| 199 | static int generic_init_net(struct net *net, u_int16_t proto) |
| 200 | { |
| 201 | int ret; |
| 202 | struct nf_generic_net *gn = generic_pernet(net); |
| 203 | struct nf_proto_net *pn = &gn->pn; |
| 204 | |
| 205 | gn->timeout = nf_ct_generic_timeout; |
| 206 | |
| 207 | ret = generic_kmemdup_compat_sysctl_table(pn, gn); |
| 208 | if (ret < 0) |
| 209 | return ret; |
| 210 | |
| 211 | ret = generic_kmemdup_sysctl_table(pn, gn); |
| 212 | if (ret < 0) |
| 213 | nf_ct_kfree_compat_sysctl_table(pn); |
| 214 | |
| 215 | return ret; |
| 216 | } |
| 217 | |
| 218 | static struct nf_proto_net *generic_get_net_proto(struct net *net) |
| 219 | { |
| 220 | return &net->ct.nf_ct_proto.generic.pn; |
| 221 | } |
| 222 | |
| 223 | struct nf_conntrack_l4proto nf_conntrack_l4proto_generic __read_mostly = |
| 224 | { |
| 225 | .l3proto = PF_UNSPEC, |
| 226 | .l4proto = 255, |
| 227 | .name = "unknown", |
| 228 | .pkt_to_tuple = generic_pkt_to_tuple, |
| 229 | .invert_tuple = generic_invert_tuple, |
| 230 | .print_tuple = generic_print_tuple, |
| 231 | .packet = generic_packet, |
| 232 | .get_timeouts = generic_get_timeouts, |
| 233 | .new = generic_new, |
| 234 | #if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT) |
| 235 | .ctnl_timeout = { |
| 236 | .nlattr_to_obj = generic_timeout_nlattr_to_obj, |
| 237 | .obj_to_nlattr = generic_timeout_obj_to_nlattr, |
| 238 | .nlattr_max = CTA_TIMEOUT_GENERIC_MAX, |
| 239 | .obj_size = sizeof(unsigned int), |
| 240 | .nla_policy = generic_timeout_nla_policy, |
| 241 | }, |
| 242 | #endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */ |
| 243 | .init_net = generic_init_net, |
| 244 | .get_net_proto = generic_get_net_proto, |
| 245 | }; |