--- /dev/null
+/* (C) 1999-2001 Paul `Rusty' Russell
+ * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
+ * (C) 2006-2010 Patrick McHardy <kaber@trash.net>
+ *
+ * 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.
+ */
+
+#include <linux/types.h>
+#include <linux/timer.h>
+#include <linux/netfilter.h>
+#include <linux/in.h>
+#include <linux/icmp.h>
+#include <linux/seq_file.h>
+#include <net/ip.h>
+#include <net/checksum.h>
+#include <linux/netfilter_ipv4.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/nf_log.h>
+
+static unsigned int nf_ct_icmp_timeout __read_mostly = 30*HZ;
+
+static inline struct nf_icmp_net *icmp_pernet(struct net *net)
+{
+ return &net->ct.nf_ct_proto.icmp;
+}
+
+static bool icmp_pkt_to_tuple(const struct sk_buff *skb, unsigned int dataoff,
+ struct nf_conntrack_tuple *tuple)
+{
+ const struct icmphdr *hp;
+ struct icmphdr _hdr;
+
+ hp = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr);
+ if (hp == NULL)
+ return false;
+
+ tuple->dst.u.icmp.type = hp->type;
+ tuple->src.u.icmp.id = hp->un.echo.id;
+ tuple->dst.u.icmp.code = hp->code;
+
+ return true;
+}
+
+/* Add 1; spaces filled with 0. */
+static const u_int8_t invmap[] = {
+ [ICMP_ECHO] = ICMP_ECHOREPLY + 1,
+ [ICMP_ECHOREPLY] = ICMP_ECHO + 1,
+ [ICMP_TIMESTAMP] = ICMP_TIMESTAMPREPLY + 1,
+ [ICMP_TIMESTAMPREPLY] = ICMP_TIMESTAMP + 1,
+ [ICMP_INFO_REQUEST] = ICMP_INFO_REPLY + 1,
+ [ICMP_INFO_REPLY] = ICMP_INFO_REQUEST + 1,
+ [ICMP_ADDRESS] = ICMP_ADDRESSREPLY + 1,
+ [ICMP_ADDRESSREPLY] = ICMP_ADDRESS + 1
+};
+
+static bool icmp_invert_tuple(struct nf_conntrack_tuple *tuple,
+ const struct nf_conntrack_tuple *orig)
+{
+ if (orig->dst.u.icmp.type >= sizeof(invmap) ||
+ !invmap[orig->dst.u.icmp.type])
+ return false;
+
+ tuple->src.u.icmp.id = orig->src.u.icmp.id;
+ tuple->dst.u.icmp.type = invmap[orig->dst.u.icmp.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 icmp_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 *icmp_get_timeouts(struct net *net)
+{
+ return &icmp_pernet(net)->timeout;
+}
+
+/* Returns verdict for packet, or -1 for invalid. */
+static int icmp_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 icmp_new(struct nf_conn *ct, const struct sk_buff *skb,
+ unsigned int dataoff, unsigned int *timeouts)
+{
+ static const u_int8_t valid_new[] = {
+ [ICMP_ECHO] = 1,
+ [ICMP_TIMESTAMP] = 1,
+ [ICMP_INFO_REQUEST] = 1,
+ [ICMP_ADDRESS] = 1
+ };
+
+ if (ct->tuplehash[0].tuple.dst.u.icmp.type >= sizeof(valid_new) ||
+ !valid_new[ct->tuplehash[0].tuple.dst.u.icmp.type]) {
+ /* Can't create a new ICMP `conn' with this. */
+ pr_debug("icmp: can't create new conn with type %u\n",
+ ct->tuplehash[0].tuple.dst.u.icmp.type);
+ nf_ct_dump_tuple_ip(&ct->tuplehash[0].tuple);
+ return false;
+ }
+ return true;
+}
+
+/* Returns conntrack if it dealt with ICMP, and filled in skb fields */
+static int
+icmp_error_message(struct net *net, struct nf_conn *tmpl, struct sk_buff *skb,
+ enum ip_conntrack_info *ctinfo,
+ unsigned int hooknum)
+{
+ struct nf_conntrack_tuple innertuple, origtuple;
+ const struct nf_conntrack_l4proto *innerproto;
+ const struct nf_conntrack_tuple_hash *h;
+ u16 zone = tmpl ? nf_ct_zone(tmpl) : NF_CT_DEFAULT_ZONE;
+
+ NF_CT_ASSERT(skb->nfct == NULL);
+
+ /* Are they talking about one of our connections? */
+ if (!nf_ct_get_tuplepr(skb,
+ skb_network_offset(skb) + ip_hdrlen(skb)
+ + sizeof(struct icmphdr),
+ PF_INET, &origtuple)) {
+ pr_debug("icmp_error_message: failed to get tuple\n");
+ return -NF_ACCEPT;
+ }
+
+ /* rcu_read_lock()ed by nf_hook_slow */
+ innerproto = __nf_ct_l4proto_find(PF_INET, origtuple.dst.protonum);
+
+ /* Ordinarily, we'd expect the inverted tupleproto, but it's
+ been preserved inside the ICMP. */
+ if (!nf_ct_invert_tuple(&innertuple, &origtuple,
+ &nf_conntrack_l3proto_ipv4, innerproto)) {
+ pr_debug("icmp_error_message: no match\n");
+ return -NF_ACCEPT;
+ }
+
+ *ctinfo = IP_CT_RELATED;
+
+ h = nf_conntrack_find_get(net, zone, &innertuple);
+ if (!h) {
+ pr_debug("icmp_error_message: no match\n");
+ return -NF_ACCEPT;
+ }
+
+ 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;
+}
+
+/* Small and modified version of icmp_rcv */
+static int
+icmp_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 icmphdr *icmph;
+ struct icmphdr _ih;
+
+ /* Not enough header? */
+ icmph = skb_header_pointer(skb, ip_hdrlen(skb), sizeof(_ih), &_ih);
+ if (icmph == NULL) {
+ if (LOG_INVALID(net, IPPROTO_ICMP))
+ nf_log_packet(net, PF_INET, 0, skb, NULL, NULL,
+ NULL, "nf_ct_icmp: short packet ");
+ return -NF_ACCEPT;
+ }
+
+ /* See ip_conntrack_proto_tcp.c */
+ if (net->ct.sysctl_checksum && hooknum == NF_INET_PRE_ROUTING &&
+ nf_ip_checksum(skb, hooknum, dataoff, 0)) {
+ if (LOG_INVALID(net, IPPROTO_ICMP))
+ nf_log_packet(net, PF_INET, 0, skb, NULL, NULL, NULL,
+ "nf_ct_icmp: bad HW ICMP checksum ");
+ return -NF_ACCEPT;
+ }
+
+ /*
+ * 18 is the highest 'known' ICMP type. Anything else is a mystery
+ *
+ * RFC 1122: 3.2.2 Unknown ICMP messages types MUST be silently
+ * discarded.
+ */
+ if (icmph->type > NR_ICMP_TYPES) {
+ if (LOG_INVALID(net, IPPROTO_ICMP))
+ nf_log_packet(net, PF_INET, 0, skb, NULL, NULL, NULL,
+ "nf_ct_icmp: invalid ICMP type ");
+ return -NF_ACCEPT;
+ }
+
+ /* Need to track icmp error message? */
+ if (icmph->type != ICMP_DEST_UNREACH &&
+ icmph->type != ICMP_SOURCE_QUENCH &&
+ icmph->type != ICMP_TIME_EXCEEDED &&
+ icmph->type != ICMP_PARAMETERPROB &&
+ icmph->type != ICMP_REDIRECT)
+ return NF_ACCEPT;
+
+ return icmp_error_message(net, tmpl, skb, ctinfo, hooknum);
+}
+
+#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
+
+#include <linux/netfilter/nfnetlink.h>
+#include <linux/netfilter/nfnetlink_conntrack.h>
+
+static int icmp_tuple_to_nlattr(struct sk_buff *skb,
+ const struct nf_conntrack_tuple *t)
+{
+ if (nla_put_be16(skb, CTA_PROTO_ICMP_ID, t->src.u.icmp.id) ||
+ nla_put_u8(skb, CTA_PROTO_ICMP_TYPE, t->dst.u.icmp.type) ||
+ nla_put_u8(skb, CTA_PROTO_ICMP_CODE, t->dst.u.icmp.code))
+ goto nla_put_failure;
+ return 0;
+
+nla_put_failure:
+ return -1;
+}
+
+static const struct nla_policy icmp_nla_policy[CTA_PROTO_MAX+1] = {
+ [CTA_PROTO_ICMP_TYPE] = { .type = NLA_U8 },
+ [CTA_PROTO_ICMP_CODE] = { .type = NLA_U8 },
+ [CTA_PROTO_ICMP_ID] = { .type = NLA_U16 },
+};
+
+static int icmp_nlattr_to_tuple(struct nlattr *tb[],
+ struct nf_conntrack_tuple *tuple)
+{
+ if (!tb[CTA_PROTO_ICMP_TYPE] ||
+ !tb[CTA_PROTO_ICMP_CODE] ||
+ !tb[CTA_PROTO_ICMP_ID])
+ return -EINVAL;
+
+ tuple->dst.u.icmp.type = nla_get_u8(tb[CTA_PROTO_ICMP_TYPE]);
+ tuple->dst.u.icmp.code = nla_get_u8(tb[CTA_PROTO_ICMP_CODE]);
+ tuple->src.u.icmp.id = nla_get_be16(tb[CTA_PROTO_ICMP_ID]);
+
+ if (tuple->dst.u.icmp.type >= sizeof(invmap) ||
+ !invmap[tuple->dst.u.icmp.type])
+ return -EINVAL;
+
+ return 0;
+}
+
+static int icmp_nlattr_tuple_size(void)
+{
+ return nla_policy_len(icmp_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 icmp_timeout_nlattr_to_obj(struct nlattr *tb[],
+ struct net *net, void *data)
+{
+ unsigned int *timeout = data;
+ struct nf_icmp_net *in = icmp_pernet(net);
+
+ if (tb[CTA_TIMEOUT_ICMP_TIMEOUT]) {
+ *timeout =
+ ntohl(nla_get_be32(tb[CTA_TIMEOUT_ICMP_TIMEOUT])) * HZ;
+ } else {
+ /* Set default ICMP timeout. */
+ *timeout = in->timeout;
+ }
+ return 0;
+}
+
+static int
+icmp_timeout_obj_to_nlattr(struct sk_buff *skb, const void *data)
+{
+ const unsigned int *timeout = data;
+
+ if (nla_put_be32(skb, CTA_TIMEOUT_ICMP_TIMEOUT, htonl(*timeout / HZ)))
+ goto nla_put_failure;
+ return 0;
+
+nla_put_failure:
+ return -ENOSPC;
+}
+
+static const struct nla_policy
+icmp_timeout_nla_policy[CTA_TIMEOUT_ICMP_MAX+1] = {
+ [CTA_TIMEOUT_ICMP_TIMEOUT] = { .type = NLA_U32 },
+};
+#endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
+
+#ifdef CONFIG_SYSCTL
+static struct ctl_table icmp_sysctl_table[] = {
+ {
+ .procname = "nf_conntrack_icmp_timeout",
+ .maxlen = sizeof(unsigned int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec_jiffies,
+ },
+ { }
+};
+#ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
+static struct ctl_table icmp_compat_sysctl_table[] = {
+ {
+ .procname = "ip_conntrack_icmp_timeout",
+ .maxlen = sizeof(unsigned int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec_jiffies,
+ },
+ { }
+};
+#endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
+#endif /* CONFIG_SYSCTL */
+
+static int icmp_kmemdup_sysctl_table(struct nf_proto_net *pn,
+ struct nf_icmp_net *in)
+{
+#ifdef CONFIG_SYSCTL
+ pn->ctl_table = kmemdup(icmp_sysctl_table,
+ sizeof(icmp_sysctl_table),
+ GFP_KERNEL);
+ if (!pn->ctl_table)
+ return -ENOMEM;
+
+ pn->ctl_table[0].data = &in->timeout;
+#endif
+ return 0;
+}
+
+static int icmp_kmemdup_compat_sysctl_table(struct nf_proto_net *pn,
+ struct nf_icmp_net *in)
+{
+#ifdef CONFIG_SYSCTL
+#ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
+ pn->ctl_compat_table = kmemdup(icmp_compat_sysctl_table,
+ sizeof(icmp_compat_sysctl_table),
+ GFP_KERNEL);
+ if (!pn->ctl_compat_table)
+ return -ENOMEM;
+
+ pn->ctl_compat_table[0].data = &in->timeout;
+#endif
+#endif
+ return 0;
+}
+
+static int icmp_init_net(struct net *net, u_int16_t proto)
+{
+ int ret;
+ struct nf_icmp_net *in = icmp_pernet(net);
+ struct nf_proto_net *pn = &in->pn;
+
+ in->timeout = nf_ct_icmp_timeout;
+
+ ret = icmp_kmemdup_compat_sysctl_table(pn, in);
+ if (ret < 0)
+ return ret;
+
+ ret = icmp_kmemdup_sysctl_table(pn, in);
+ if (ret < 0)
+ nf_ct_kfree_compat_sysctl_table(pn);
+
+ return ret;
+}
+
+static struct nf_proto_net *icmp_get_net_proto(struct net *net)
+{
+ return &net->ct.nf_ct_proto.icmp.pn;
+}
+
+struct nf_conntrack_l4proto nf_conntrack_l4proto_icmp __read_mostly =
+{
+ .l3proto = PF_INET,
+ .l4proto = IPPROTO_ICMP,
+ .name = "icmp",
+ .pkt_to_tuple = icmp_pkt_to_tuple,
+ .invert_tuple = icmp_invert_tuple,
+ .print_tuple = icmp_print_tuple,
+ .packet = icmp_packet,
+ .get_timeouts = icmp_get_timeouts,
+ .new = icmp_new,
+ .error = icmp_error,
+ .destroy = NULL,
+ .me = NULL,
+#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
+ .tuple_to_nlattr = icmp_tuple_to_nlattr,
+ .nlattr_tuple_size = icmp_nlattr_tuple_size,
+ .nlattr_to_tuple = icmp_nlattr_to_tuple,
+ .nla_policy = icmp_nla_policy,
+#endif
+#if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
+ .ctnl_timeout = {
+ .nlattr_to_obj = icmp_timeout_nlattr_to_obj,
+ .obj_to_nlattr = icmp_timeout_obj_to_nlattr,
+ .nlattr_max = CTA_TIMEOUT_ICMP_MAX,
+ .obj_size = sizeof(unsigned int),
+ .nla_policy = icmp_timeout_nla_policy,
+ },
+#endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
+ .init_net = icmp_init_net,
+ .get_net_proto = icmp_get_net_proto,
+};
Code Review / kvmfornfv.git / blobdiff