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- /*
- * 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 <yasuyuki.kozakai@toshiba.co.jp>
- */
- #include <linux/types.h>
- #include <linux/timer.h>
- #include <linux/module.h>
- #include <linux/netfilter.h>
- #include <linux/in6.h>
- #include <linux/icmpv6.h>
- #include <linux/ipv6.h>
- #include <net/ipv6.h>
- #include <net/ip6_checksum.h>
- #include <linux/seq_file.h>
- #include <linux/netfilter_ipv6.h>
- #include <net/netfilter/nf_conntrack_tuple.h>
- #include <net/netfilter/nf_conntrack_l4proto.h>
- #include <net/netfilter/nf_conntrack_core.h>
- #include <net/netfilter/nf_conntrack_zones.h>
- #include <net/netfilter/ipv6/nf_conntrack_icmpv6.h>
- #include <net/netfilter/nf_log.h>
- static unsigned int nf_ct_icmpv6_timeout __read_mostly = 30*HZ;
- static inline struct nf_icmp_net *icmpv6_pernet(struct net *net)
- {
- return &net->ct.nf_ct_proto.icmpv6;
- }
- static bool icmpv6_pkt_to_tuple(const struct sk_buff *skb,
- unsigned int dataoff,
- struct net *net,
- 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 void icmpv6_print_tuple(struct seq_file *s,
- const struct nf_conntrack_tuple *tuple)
- {
- 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));
- }
- static unsigned int *icmpv6_get_timeouts(struct net *net)
- {
- return &icmpv6_pernet(net)->timeout;
- }
- /* 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,
- unsigned int *timeout)
- {
- /* Do not immediately delete the connection after the first
- successful reply to avoid excessive conntrackd traffic
- and also to handle correctly ICMP echo reply duplicates. */
- nf_ct_refresh_acct(ct, ctinfo, skb, *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, unsigned int *timeouts)
- {
- 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);
- if (LOG_INVALID(nf_ct_net(ct), IPPROTO_ICMPV6))
- nf_log_packet(nf_ct_net(ct), PF_INET6, 0, skb, NULL,
- NULL, NULL,
- "nf_ct_icmpv6: invalid new with type %d ",
- type + 128);
- return false;
- }
- return true;
- }
- static int
- icmpv6_error_message(struct net *net, struct nf_conn *tmpl,
- 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;
- struct nf_conntrack_zone tmp;
- 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, net, &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, nf_ct_zone_tmpl(tmpl, skb, &tmp),
- &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 nf_conn *tmpl,
- 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(net, 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)) {
- if (LOG_INVALID(net, IPPROTO_ICMPV6))
- nf_log_packet(net, PF_INET6, 0, skb, NULL, NULL, NULL,
- "nf_ct_icmpv6: ICMPv6 checksum failed ");
- return -NF_ACCEPT;
- }
- type = icmp6h->icmp6_type - 130;
- if (type >= 0 && type < sizeof(noct_valid_new) &&
- noct_valid_new[type]) {
- skb->nfct = &nf_ct_untracked_get()->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, tmpl, skb, dataoff, ctinfo, hooknum);
- }
- #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
- #include <linux/netfilter/nfnetlink.h>
- #include <linux/netfilter/nfnetlink_conntrack.h>
- static int icmpv6_tuple_to_nlattr(struct sk_buff *skb,
- const struct nf_conntrack_tuple *t)
- {
- if (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))
- goto nla_put_failure;
- 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;
- }
- static int icmpv6_nlattr_tuple_size(void)
- {
- return nla_policy_len(icmpv6_nla_policy, CTA_PROTO_MAX + 1);
- }
- #endif
- #if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
- #include <linux/netfilter/nfnetlink.h>
- #include <linux/netfilter/nfnetlink_cttimeout.h>
- static int icmpv6_timeout_nlattr_to_obj(struct nlattr *tb[],
- struct net *net, void *data)
- {
- unsigned int *timeout = data;
- struct nf_icmp_net *in = icmpv6_pernet(net);
- if (tb[CTA_TIMEOUT_ICMPV6_TIMEOUT]) {
- *timeout =
- ntohl(nla_get_be32(tb[CTA_TIMEOUT_ICMPV6_TIMEOUT])) * HZ;
- } else {
- /* Set default ICMPv6 timeout. */
- *timeout = in->timeout;
- }
- return 0;
- }
- static int
- icmpv6_timeout_obj_to_nlattr(struct sk_buff *skb, const void *data)
- {
- const unsigned int *timeout = data;
- if (nla_put_be32(skb, CTA_TIMEOUT_ICMPV6_TIMEOUT, htonl(*timeout / HZ)))
- goto nla_put_failure;
- return 0;
- nla_put_failure:
- return -ENOSPC;
- }
- static const struct nla_policy
- icmpv6_timeout_nla_policy[CTA_TIMEOUT_ICMPV6_MAX+1] = {
- [CTA_TIMEOUT_ICMPV6_TIMEOUT] = { .type = NLA_U32 },
- };
- #endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
- #ifdef CONFIG_SYSCTL
- static struct ctl_table icmpv6_sysctl_table[] = {
- {
- .procname = "nf_conntrack_icmpv6_timeout",
- .maxlen = sizeof(unsigned int),
- .mode = 0644,
- .proc_handler = proc_dointvec_jiffies,
- },
- { }
- };
- #endif /* CONFIG_SYSCTL */
- static int icmpv6_kmemdup_sysctl_table(struct nf_proto_net *pn,
- struct nf_icmp_net *in)
- {
- #ifdef CONFIG_SYSCTL
- pn->ctl_table = kmemdup(icmpv6_sysctl_table,
- sizeof(icmpv6_sysctl_table),
- GFP_KERNEL);
- if (!pn->ctl_table)
- return -ENOMEM;
- pn->ctl_table[0].data = &in->timeout;
- #endif
- return 0;
- }
- static int icmpv6_init_net(struct net *net, u_int16_t proto)
- {
- struct nf_icmp_net *in = icmpv6_pernet(net);
- struct nf_proto_net *pn = &in->pn;
- in->timeout = nf_ct_icmpv6_timeout;
- return icmpv6_kmemdup_sysctl_table(pn, in);
- }
- static struct nf_proto_net *icmpv6_get_net_proto(struct net *net)
- {
- return &net->ct.nf_ct_proto.icmpv6.pn;
- }
- 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,
- .get_timeouts = icmpv6_get_timeouts,
- .new = icmpv6_new,
- .error = icmpv6_error,
- #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
- .tuple_to_nlattr = icmpv6_tuple_to_nlattr,
- .nlattr_tuple_size = icmpv6_nlattr_tuple_size,
- .nlattr_to_tuple = icmpv6_nlattr_to_tuple,
- .nla_policy = icmpv6_nla_policy,
- #endif
- #if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
- .ctnl_timeout = {
- .nlattr_to_obj = icmpv6_timeout_nlattr_to_obj,
- .obj_to_nlattr = icmpv6_timeout_obj_to_nlattr,
- .nlattr_max = CTA_TIMEOUT_ICMP_MAX,
- .obj_size = sizeof(unsigned int),
- .nla_policy = icmpv6_timeout_nla_policy,
- },
- #endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
- .init_net = icmpv6_init_net,
- .get_net_proto = icmpv6_get_net_proto,
- };
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