--- /dev/null
+/*
+ * xt_HMARK - Netfilter module to set mark by means of hashing
+ *
+ * (C) 2012 by Hans Schillstrom <hans.schillstrom@ericsson.com>
+ * (C) 2012 by Pablo Neira Ayuso <pablo@netfilter.org>
+ *
+ * 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/module.h>
+#include <linux/skbuff.h>
+#include <linux/icmp.h>
+
+#include <linux/netfilter/x_tables.h>
+#include <linux/netfilter/xt_HMARK.h>
+
+#include <net/ip.h>
+#if IS_ENABLED(CONFIG_NF_CONNTRACK)
+#include <net/netfilter/nf_conntrack.h>
+#endif
+#if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
+#include <net/ipv6.h>
+#include <linux/netfilter_ipv6/ip6_tables.h>
+#endif
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Hans Schillstrom <hans.schillstrom@ericsson.com>");
+MODULE_DESCRIPTION("Xtables: packet marking using hash calculation");
+MODULE_ALIAS("ipt_HMARK");
+MODULE_ALIAS("ip6t_HMARK");
+
+struct hmark_tuple {
+ __be32 src;
+ __be32 dst;
+ union hmark_ports uports;
+ u8 proto;
+};
+
+static inline __be32 hmark_addr6_mask(const __be32 *addr32, const __be32 *mask)
+{
+ return (addr32[0] & mask[0]) ^
+ (addr32[1] & mask[1]) ^
+ (addr32[2] & mask[2]) ^
+ (addr32[3] & mask[3]);
+}
+
+static inline __be32
+hmark_addr_mask(int l3num, const __be32 *addr32, const __be32 *mask)
+{
+ switch (l3num) {
+ case AF_INET:
+ return *addr32 & *mask;
+ case AF_INET6:
+ return hmark_addr6_mask(addr32, mask);
+ }
+ return 0;
+}
+
+static inline void hmark_swap_ports(union hmark_ports *uports,
+ const struct xt_hmark_info *info)
+{
+ union hmark_ports hp;
+ u16 src, dst;
+
+ hp.b32 = (uports->b32 & info->port_mask.b32) | info->port_set.b32;
+ src = ntohs(hp.b16.src);
+ dst = ntohs(hp.b16.dst);
+
+ if (dst > src)
+ uports->v32 = (dst << 16) | src;
+ else
+ uports->v32 = (src << 16) | dst;
+}
+
+static int
+hmark_ct_set_htuple(const struct sk_buff *skb, struct hmark_tuple *t,
+ const struct xt_hmark_info *info)
+{
+#if IS_ENABLED(CONFIG_NF_CONNTRACK)
+ enum ip_conntrack_info ctinfo;
+ struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
+ struct nf_conntrack_tuple *otuple;
+ struct nf_conntrack_tuple *rtuple;
+
+ if (ct == NULL || nf_ct_is_untracked(ct))
+ return -1;
+
+ otuple = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple;
+ rtuple = &ct->tuplehash[IP_CT_DIR_REPLY].tuple;
+
+ t->src = hmark_addr_mask(otuple->src.l3num, otuple->src.u3.ip6,
+ info->src_mask.ip6);
+ t->dst = hmark_addr_mask(otuple->src.l3num, rtuple->src.u3.ip6,
+ info->dst_mask.ip6);
+
+ if (info->flags & XT_HMARK_FLAG(XT_HMARK_METHOD_L3))
+ return 0;
+
+ t->proto = nf_ct_protonum(ct);
+ if (t->proto != IPPROTO_ICMP) {
+ t->uports.b16.src = otuple->src.u.all;
+ t->uports.b16.dst = rtuple->src.u.all;
+ hmark_swap_ports(&t->uports, info);
+ }
+
+ return 0;
+#else
+ return -1;
+#endif
+}
+
+/* This hash function is endian independent, to ensure consistent hashing if
+ * the cluster is composed of big and little endian systems. */
+static inline u32
+hmark_hash(struct hmark_tuple *t, const struct xt_hmark_info *info)
+{
+ u32 hash;
+ u32 src = ntohl(t->src);
+ u32 dst = ntohl(t->dst);
+
+ if (dst < src)
+ swap(src, dst);
+
+ hash = jhash_3words(src, dst, t->uports.v32, info->hashrnd);
+ hash = hash ^ (t->proto & info->proto_mask);
+
+ return reciprocal_scale(hash, info->hmodulus) + info->hoffset;
+}
+
+static void
+hmark_set_tuple_ports(const struct sk_buff *skb, unsigned int nhoff,
+ struct hmark_tuple *t, const struct xt_hmark_info *info)
+{
+ int protoff;
+
+ protoff = proto_ports_offset(t->proto);
+ if (protoff < 0)
+ return;
+
+ nhoff += protoff;
+ if (skb_copy_bits(skb, nhoff, &t->uports, sizeof(t->uports)) < 0)
+ return;
+
+ hmark_swap_ports(&t->uports, info);
+}
+
+#if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
+static int get_inner6_hdr(const struct sk_buff *skb, int *offset)
+{
+ struct icmp6hdr *icmp6h, _ih6;
+
+ icmp6h = skb_header_pointer(skb, *offset, sizeof(_ih6), &_ih6);
+ if (icmp6h == NULL)
+ return 0;
+
+ if (icmp6h->icmp6_type && icmp6h->icmp6_type < 128) {
+ *offset += sizeof(struct icmp6hdr);
+ return 1;
+ }
+ return 0;
+}
+
+static int
+hmark_pkt_set_htuple_ipv6(const struct sk_buff *skb, struct hmark_tuple *t,
+ const struct xt_hmark_info *info)
+{
+ struct ipv6hdr *ip6, _ip6;
+ int flag = IP6_FH_F_AUTH;
+ unsigned int nhoff = 0;
+ u16 fragoff = 0;
+ int nexthdr;
+
+ ip6 = (struct ipv6hdr *) (skb->data + skb_network_offset(skb));
+ nexthdr = ipv6_find_hdr(skb, &nhoff, -1, &fragoff, &flag);
+ if (nexthdr < 0)
+ return 0;
+ /* No need to check for icmp errors on fragments */
+ if ((flag & IP6_FH_F_FRAG) || (nexthdr != IPPROTO_ICMPV6))
+ goto noicmp;
+ /* Use inner header in case of ICMP errors */
+ if (get_inner6_hdr(skb, &nhoff)) {
+ ip6 = skb_header_pointer(skb, nhoff, sizeof(_ip6), &_ip6);
+ if (ip6 == NULL)
+ return -1;
+ /* If AH present, use SPI like in ESP. */
+ flag = IP6_FH_F_AUTH;
+ nexthdr = ipv6_find_hdr(skb, &nhoff, -1, &fragoff, &flag);
+ if (nexthdr < 0)
+ return -1;
+ }
+noicmp:
+ t->src = hmark_addr6_mask(ip6->saddr.s6_addr32, info->src_mask.ip6);
+ t->dst = hmark_addr6_mask(ip6->daddr.s6_addr32, info->dst_mask.ip6);
+
+ if (info->flags & XT_HMARK_FLAG(XT_HMARK_METHOD_L3))
+ return 0;
+
+ t->proto = nexthdr;
+ if (t->proto == IPPROTO_ICMPV6)
+ return 0;
+
+ if (flag & IP6_FH_F_FRAG)
+ return 0;
+
+ hmark_set_tuple_ports(skb, nhoff, t, info);
+ return 0;
+}
+
+static unsigned int
+hmark_tg_v6(struct sk_buff *skb, const struct xt_action_param *par)
+{
+ const struct xt_hmark_info *info = par->targinfo;
+ struct hmark_tuple t;
+
+ memset(&t, 0, sizeof(struct hmark_tuple));
+
+ if (info->flags & XT_HMARK_FLAG(XT_HMARK_CT)) {
+ if (hmark_ct_set_htuple(skb, &t, info) < 0)
+ return XT_CONTINUE;
+ } else {
+ if (hmark_pkt_set_htuple_ipv6(skb, &t, info) < 0)
+ return XT_CONTINUE;
+ }
+
+ skb->mark = hmark_hash(&t, info);
+ return XT_CONTINUE;
+}
+#endif
+
+static int get_inner_hdr(const struct sk_buff *skb, int iphsz, int *nhoff)
+{
+ const struct icmphdr *icmph;
+ struct icmphdr _ih;
+
+ /* Not enough header? */
+ icmph = skb_header_pointer(skb, *nhoff + iphsz, sizeof(_ih), &_ih);
+ if (icmph == NULL || icmph->type > NR_ICMP_TYPES)
+ return 0;
+
+ /* 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 0;
+
+ *nhoff += iphsz + sizeof(_ih);
+ return 1;
+}
+
+static int
+hmark_pkt_set_htuple_ipv4(const struct sk_buff *skb, struct hmark_tuple *t,
+ const struct xt_hmark_info *info)
+{
+ struct iphdr *ip, _ip;
+ int nhoff = skb_network_offset(skb);
+
+ ip = (struct iphdr *) (skb->data + nhoff);
+ if (ip->protocol == IPPROTO_ICMP) {
+ /* Use inner header in case of ICMP errors */
+ if (get_inner_hdr(skb, ip->ihl * 4, &nhoff)) {
+ ip = skb_header_pointer(skb, nhoff, sizeof(_ip), &_ip);
+ if (ip == NULL)
+ return -1;
+ }
+ }
+
+ t->src = ip->saddr & info->src_mask.ip;
+ t->dst = ip->daddr & info->dst_mask.ip;
+
+ if (info->flags & XT_HMARK_FLAG(XT_HMARK_METHOD_L3))
+ return 0;
+
+ t->proto = ip->protocol;
+
+ /* ICMP has no ports, skip */
+ if (t->proto == IPPROTO_ICMP)
+ return 0;
+
+ /* follow-up fragments don't contain ports, skip all fragments */
+ if (ip->frag_off & htons(IP_MF | IP_OFFSET))
+ return 0;
+
+ hmark_set_tuple_ports(skb, (ip->ihl * 4) + nhoff, t, info);
+
+ return 0;
+}
+
+static unsigned int
+hmark_tg_v4(struct sk_buff *skb, const struct xt_action_param *par)
+{
+ const struct xt_hmark_info *info = par->targinfo;
+ struct hmark_tuple t;
+
+ memset(&t, 0, sizeof(struct hmark_tuple));
+
+ if (info->flags & XT_HMARK_FLAG(XT_HMARK_CT)) {
+ if (hmark_ct_set_htuple(skb, &t, info) < 0)
+ return XT_CONTINUE;
+ } else {
+ if (hmark_pkt_set_htuple_ipv4(skb, &t, info) < 0)
+ return XT_CONTINUE;
+ }
+
+ skb->mark = hmark_hash(&t, info);
+ return XT_CONTINUE;
+}
+
+static int hmark_tg_check(const struct xt_tgchk_param *par)
+{
+ const struct xt_hmark_info *info = par->targinfo;
+
+ if (!info->hmodulus) {
+ pr_info("xt_HMARK: hash modulus can't be zero\n");
+ return -EINVAL;
+ }
+ if (info->proto_mask &&
+ (info->flags & XT_HMARK_FLAG(XT_HMARK_METHOD_L3))) {
+ pr_info("xt_HMARK: proto mask must be zero with L3 mode\n");
+ return -EINVAL;
+ }
+ if (info->flags & XT_HMARK_FLAG(XT_HMARK_SPI_MASK) &&
+ (info->flags & (XT_HMARK_FLAG(XT_HMARK_SPORT_MASK) |
+ XT_HMARK_FLAG(XT_HMARK_DPORT_MASK)))) {
+ pr_info("xt_HMARK: spi-mask and port-mask can't be combined\n");
+ return -EINVAL;
+ }
+ if (info->flags & XT_HMARK_FLAG(XT_HMARK_SPI) &&
+ (info->flags & (XT_HMARK_FLAG(XT_HMARK_SPORT) |
+ XT_HMARK_FLAG(XT_HMARK_DPORT)))) {
+ pr_info("xt_HMARK: spi-set and port-set can't be combined\n");
+ return -EINVAL;
+ }
+ return 0;
+}
+
+static struct xt_target hmark_tg_reg[] __read_mostly = {
+ {
+ .name = "HMARK",
+ .family = NFPROTO_IPV4,
+ .target = hmark_tg_v4,
+ .targetsize = sizeof(struct xt_hmark_info),
+ .checkentry = hmark_tg_check,
+ .me = THIS_MODULE,
+ },
+#if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
+ {
+ .name = "HMARK",
+ .family = NFPROTO_IPV6,
+ .target = hmark_tg_v6,
+ .targetsize = sizeof(struct xt_hmark_info),
+ .checkentry = hmark_tg_check,
+ .me = THIS_MODULE,
+ },
+#endif
+};
+
+static int __init hmark_tg_init(void)
+{
+ return xt_register_targets(hmark_tg_reg, ARRAY_SIZE(hmark_tg_reg));
+}
+
+static void __exit hmark_tg_exit(void)
+{
+ xt_unregister_targets(hmark_tg_reg, ARRAY_SIZE(hmark_tg_reg));
+}
+
+module_init(hmark_tg_init);
+module_exit(hmark_tg_exit);
Code Review / kvmfornfv.git / blobdiff