/* * Copyright (C)2003,2004 USAGI/WIDE Project * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. * * Author: * Yasuyuki Kozakai @USAGI */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include static unsigned int nf_ct_icmpv6_timeout __read_mostly = 30*HZ; static bool icmpv6_pkt_to_tuple(const struct sk_buff *skb, unsigned int dataoff, struct nf_conntrack_tuple *tuple) { const struct icmp6hdr *hp; struct icmp6hdr _hdr; hp = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr); if (hp == NULL) return false; tuple->dst.u.icmp.type = hp->icmp6_type; tuple->src.u.icmp.id = hp->icmp6_identifier; tuple->dst.u.icmp.code = hp->icmp6_code; return true; } /* Add 1; spaces filled with 0. */ static const u_int8_t invmap[] = { [ICMPV6_ECHO_REQUEST - 128] = ICMPV6_ECHO_REPLY + 1, [ICMPV6_ECHO_REPLY - 128] = ICMPV6_ECHO_REQUEST + 1, [ICMPV6_NI_QUERY - 128] = ICMPV6_NI_REPLY + 1, [ICMPV6_NI_REPLY - 128] = ICMPV6_NI_QUERY +1 }; static const u_int8_t noct_valid_new[] = { [ICMPV6_MGM_QUERY - 130] = 1, [ICMPV6_MGM_REPORT -130] = 1, [ICMPV6_MGM_REDUCTION - 130] = 1, [NDISC_ROUTER_SOLICITATION - 130] = 1, [NDISC_ROUTER_ADVERTISEMENT - 130] = 1, [NDISC_NEIGHBOUR_SOLICITATION - 130] = 1, [NDISC_NEIGHBOUR_ADVERTISEMENT - 130] = 1, [ICMPV6_MLD2_REPORT - 130] = 1 }; static bool icmpv6_invert_tuple(struct nf_conntrack_tuple *tuple, const struct nf_conntrack_tuple *orig) { int type = orig->dst.u.icmp.type - 128; if (type < 0 || type >= sizeof(invmap) || !invmap[type]) return false; tuple->src.u.icmp.id = orig->src.u.icmp.id; tuple->dst.u.icmp.type = invmap[type] - 1; tuple->dst.u.icmp.code = orig->dst.u.icmp.code; return true; } /* Print out the per-protocol part of the tuple. */ static int icmpv6_print_tuple(struct seq_file *s, const struct nf_conntrack_tuple *tuple) { return seq_printf(s, "type=%u code=%u id=%u ", tuple->dst.u.icmp.type, tuple->dst.u.icmp.code, ntohs(tuple->src.u.icmp.id)); } /* Returns verdict for packet, or -1 for invalid. */ static int icmpv6_packet(struct nf_conn *ct, const struct sk_buff *skb, unsigned int dataoff, enum ip_conntrack_info ctinfo, u_int8_t pf, unsigned int hooknum) { /* Try to delete connection immediately after all replies: won't actually vanish as we still have skb, and del_timer means this will only run once even if count hits zero twice (theoretically possible with SMP) */ if (CTINFO2DIR(ctinfo) == IP_CT_DIR_REPLY) { if (atomic_dec_and_test(&ct->proto.icmp.count)) nf_ct_kill_acct(ct, ctinfo, skb); } else { atomic_inc(&ct->proto.icmp.count); nf_conntrack_event_cache(IPCT_PROTOINFO_VOLATILE, ct); nf_ct_refresh_acct(ct, ctinfo, skb, nf_ct_icmpv6_timeout); } return NF_ACCEPT; } /* Called when a new connection for this protocol found. */ static bool icmpv6_new(struct nf_conn *ct, const struct sk_buff *skb, unsigned int dataoff) { static const u_int8_t valid_new[] = { [ICMPV6_ECHO_REQUEST - 128] = 1, [ICMPV6_NI_QUERY - 128] = 1 }; int type = ct->tuplehash[0].tuple.dst.u.icmp.type - 128; if (type < 0 || type >= sizeof(valid_new) || !valid_new[type]) { /* Can't create a new ICMPv6 `conn' with this. */ pr_debug("icmpv6: can't create new conn with type %u\n", type + 128); nf_ct_dump_tuple_ipv6(&ct->tuplehash[0].tuple); return false; } atomic_set(&ct->proto.icmp.count, 0); return true; } static int icmpv6_error_message(struct net *net, struct sk_buff *skb, unsigned int icmp6off, enum ip_conntrack_info *ctinfo, unsigned int hooknum) { struct nf_conntrack_tuple intuple, origtuple; const struct nf_conntrack_tuple_hash *h; const struct nf_conntrack_l4proto *inproto; NF_CT_ASSERT(skb->nfct == NULL); /* Are they talking about one of our connections? */ if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb) + sizeof(struct ipv6hdr) + sizeof(struct icmp6hdr), PF_INET6, &origtuple)) { pr_debug("icmpv6_error: Can't get tuple\n"); return -NF_ACCEPT; } /* rcu_read_lock()ed by nf_hook_slow */ inproto = __nf_ct_l4proto_find(PF_INET6, origtuple.dst.protonum); /* Ordinarily, we'd expect the inverted tupleproto, but it's been preserved inside the ICMP. */ if (!nf_ct_invert_tuple(&intuple, &origtuple, &nf_conntrack_l3proto_ipv6, inproto)) { pr_debug("icmpv6_error: Can't invert tuple\n"); return -NF_ACCEPT; } *ctinfo = IP_CT_RELATED; h = nf_conntrack_find_get(net, &intuple); if (!h) { pr_debug("icmpv6_error: no match\n"); return -NF_ACCEPT; } else { if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY) *ctinfo += IP_CT_IS_REPLY; } /* Update skb to refer to this connection */ skb->nfct = &nf_ct_tuplehash_to_ctrack(h)->ct_general; skb->nfctinfo = *ctinfo; return -NF_ACCEPT; } static int icmpv6_error(struct net *net, struct sk_buff *skb, unsigned int dataoff, enum ip_conntrack_info *ctinfo, u_int8_t pf, unsigned int hooknum) { const struct icmp6hdr *icmp6h; struct icmp6hdr _ih; int type; icmp6h = skb_header_pointer(skb, dataoff, sizeof(_ih), &_ih); if (icmp6h == NULL) { if (LOG_INVALID(net, IPPROTO_ICMPV6)) nf_log_packet(PF_INET6, 0, skb, NULL, NULL, NULL, "nf_ct_icmpv6: short packet "); return -NF_ACCEPT; } if (net->ct.sysctl_checksum && hooknum == NF_INET_PRE_ROUTING && nf_ip6_checksum(skb, hooknum, dataoff, IPPROTO_ICMPV6)) { nf_log_packet(PF_INET6, 0, skb, NULL, NULL, NULL, "nf_ct_icmpv6: ICMPv6 checksum failed\n"); return -NF_ACCEPT; } type = icmp6h->icmp6_type - 130; if (type >= 0 && type < sizeof(noct_valid_new) && noct_valid_new[type]) { skb->nfct = &nf_conntrack_untracked.ct_general; skb->nfctinfo = IP_CT_NEW; nf_conntrack_get(skb->nfct); return NF_ACCEPT; } /* is not error message ? */ if (icmp6h->icmp6_type >= 128) return NF_ACCEPT; return icmpv6_error_message(net, skb, dataoff, ctinfo, hooknum); } #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE) #include #include static int icmpv6_tuple_to_nlattr(struct sk_buff *skb, const struct nf_conntrack_tuple *t) { NLA_PUT_BE16(skb, CTA_PROTO_ICMPV6_ID, t->src.u.icmp.id); NLA_PUT_U8(skb, CTA_PROTO_ICMPV6_TYPE, t->dst.u.icmp.type); NLA_PUT_U8(skb, CTA_PROTO_ICMPV6_CODE, t->dst.u.icmp.code); return 0; nla_put_failure: return -1; } static const struct nla_policy icmpv6_nla_policy[CTA_PROTO_MAX+1] = { [CTA_PROTO_ICMPV6_TYPE] = { .type = NLA_U8 }, [CTA_PROTO_ICMPV6_CODE] = { .type = NLA_U8 }, [CTA_PROTO_ICMPV6_ID] = { .type = NLA_U16 }, }; static int icmpv6_nlattr_to_tuple(struct nlattr *tb[], struct nf_conntrack_tuple *tuple) { if (!tb[CTA_PROTO_ICMPV6_TYPE] || !tb[CTA_PROTO_ICMPV6_CODE] || !tb[CTA_PROTO_ICMPV6_ID]) return -EINVAL; tuple->dst.u.icmp.type = nla_get_u8(tb[CTA_PROTO_ICMPV6_TYPE]); tuple->dst.u.icmp.code = nla_get_u8(tb[CTA_PROTO_ICMPV6_CODE]); tuple->src.u.icmp.id = nla_get_be16(tb[CTA_PROTO_ICMPV6_ID]); if (tuple->dst.u.icmp.type < 128 || tuple->dst.u.icmp.type - 128 >= sizeof(invmap) || !invmap[tuple->dst.u.icmp.type - 128]) return -EINVAL; return 0; } #endif #ifdef CONFIG_SYSCTL static struct ctl_table_header *icmpv6_sysctl_header; static struct ctl_table icmpv6_sysctl_table[] = { { .procname = "nf_conntrack_icmpv6_timeout", .data = &nf_ct_icmpv6_timeout, .maxlen = sizeof(unsigned int), .mode = 0644, .proc_handler = proc_dointvec_jiffies, }, { .ctl_name = 0 } }; #endif /* CONFIG_SYSCTL */ struct nf_conntrack_l4proto nf_conntrack_l4proto_icmpv6 __read_mostly = { .l3proto = PF_INET6, .l4proto = IPPROTO_ICMPV6, .name = "icmpv6", .pkt_to_tuple = icmpv6_pkt_to_tuple, .invert_tuple = icmpv6_invert_tuple, .print_tuple = icmpv6_print_tuple, .packet = icmpv6_packet, .new = icmpv6_new, .error = icmpv6_error, #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE) .tuple_to_nlattr = icmpv6_tuple_to_nlattr, .nlattr_to_tuple = icmpv6_nlattr_to_tuple, .nla_policy = icmpv6_nla_policy, #endif #ifdef CONFIG_SYSCTL .ctl_table_header = &icmpv6_sysctl_header, .ctl_table = icmpv6_sysctl_table, #endif };