From 2c3c1048746a4622d8c89a29670120dc8fab93c4 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 20:49:45 +0200 Subject: Adding upstream version 6.1.76. Signed-off-by: Daniel Baumann --- net/netfilter/nf_flow_table_ip.c | 689 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 689 insertions(+) create mode 100644 net/netfilter/nf_flow_table_ip.c (limited to 'net/netfilter/nf_flow_table_ip.c') diff --git a/net/netfilter/nf_flow_table_ip.c b/net/netfilter/nf_flow_table_ip.c new file mode 100644 index 000000000..6feaac9ab --- /dev/null +++ b/net/netfilter/nf_flow_table_ip.c @@ -0,0 +1,689 @@ +// SPDX-License-Identifier: GPL-2.0-only +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +/* For layer 4 checksum field offset. */ +#include +#include + +static int nf_flow_state_check(struct flow_offload *flow, int proto, + struct sk_buff *skb, unsigned int thoff) +{ + struct tcphdr *tcph; + + if (proto != IPPROTO_TCP) + return 0; + + tcph = (void *)(skb_network_header(skb) + thoff); + if (unlikely(tcph->fin || tcph->rst)) { + flow_offload_teardown(flow); + return -1; + } + + return 0; +} + +static void nf_flow_nat_ip_tcp(struct sk_buff *skb, unsigned int thoff, + __be32 addr, __be32 new_addr) +{ + struct tcphdr *tcph; + + tcph = (void *)(skb_network_header(skb) + thoff); + inet_proto_csum_replace4(&tcph->check, skb, addr, new_addr, true); +} + +static void nf_flow_nat_ip_udp(struct sk_buff *skb, unsigned int thoff, + __be32 addr, __be32 new_addr) +{ + struct udphdr *udph; + + udph = (void *)(skb_network_header(skb) + thoff); + if (udph->check || skb->ip_summed == CHECKSUM_PARTIAL) { + inet_proto_csum_replace4(&udph->check, skb, addr, + new_addr, true); + if (!udph->check) + udph->check = CSUM_MANGLED_0; + } +} + +static void nf_flow_nat_ip_l4proto(struct sk_buff *skb, struct iphdr *iph, + unsigned int thoff, __be32 addr, + __be32 new_addr) +{ + switch (iph->protocol) { + case IPPROTO_TCP: + nf_flow_nat_ip_tcp(skb, thoff, addr, new_addr); + break; + case IPPROTO_UDP: + nf_flow_nat_ip_udp(skb, thoff, addr, new_addr); + break; + } +} + +static void nf_flow_snat_ip(const struct flow_offload *flow, + struct sk_buff *skb, struct iphdr *iph, + unsigned int thoff, enum flow_offload_tuple_dir dir) +{ + __be32 addr, new_addr; + + switch (dir) { + case FLOW_OFFLOAD_DIR_ORIGINAL: + addr = iph->saddr; + new_addr = flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.dst_v4.s_addr; + iph->saddr = new_addr; + break; + case FLOW_OFFLOAD_DIR_REPLY: + addr = iph->daddr; + new_addr = flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.src_v4.s_addr; + iph->daddr = new_addr; + break; + } + csum_replace4(&iph->check, addr, new_addr); + + nf_flow_nat_ip_l4proto(skb, iph, thoff, addr, new_addr); +} + +static void nf_flow_dnat_ip(const struct flow_offload *flow, + struct sk_buff *skb, struct iphdr *iph, + unsigned int thoff, enum flow_offload_tuple_dir dir) +{ + __be32 addr, new_addr; + + switch (dir) { + case FLOW_OFFLOAD_DIR_ORIGINAL: + addr = iph->daddr; + new_addr = flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.src_v4.s_addr; + iph->daddr = new_addr; + break; + case FLOW_OFFLOAD_DIR_REPLY: + addr = iph->saddr; + new_addr = flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.dst_v4.s_addr; + iph->saddr = new_addr; + break; + } + csum_replace4(&iph->check, addr, new_addr); + + nf_flow_nat_ip_l4proto(skb, iph, thoff, addr, new_addr); +} + +static void nf_flow_nat_ip(const struct flow_offload *flow, struct sk_buff *skb, + unsigned int thoff, enum flow_offload_tuple_dir dir, + struct iphdr *iph) +{ + if (test_bit(NF_FLOW_SNAT, &flow->flags)) { + nf_flow_snat_port(flow, skb, thoff, iph->protocol, dir); + nf_flow_snat_ip(flow, skb, iph, thoff, dir); + } + if (test_bit(NF_FLOW_DNAT, &flow->flags)) { + nf_flow_dnat_port(flow, skb, thoff, iph->protocol, dir); + nf_flow_dnat_ip(flow, skb, iph, thoff, dir); + } +} + +static bool ip_has_options(unsigned int thoff) +{ + return thoff != sizeof(struct iphdr); +} + +static void nf_flow_tuple_encap(struct sk_buff *skb, + struct flow_offload_tuple *tuple) +{ + struct vlan_ethhdr *veth; + struct pppoe_hdr *phdr; + int i = 0; + + if (skb_vlan_tag_present(skb)) { + tuple->encap[i].id = skb_vlan_tag_get(skb); + tuple->encap[i].proto = skb->vlan_proto; + i++; + } + switch (skb->protocol) { + case htons(ETH_P_8021Q): + veth = (struct vlan_ethhdr *)skb_mac_header(skb); + tuple->encap[i].id = ntohs(veth->h_vlan_TCI); + tuple->encap[i].proto = skb->protocol; + break; + case htons(ETH_P_PPP_SES): + phdr = (struct pppoe_hdr *)skb_mac_header(skb); + tuple->encap[i].id = ntohs(phdr->sid); + tuple->encap[i].proto = skb->protocol; + break; + } +} + +static int nf_flow_tuple_ip(struct sk_buff *skb, const struct net_device *dev, + struct flow_offload_tuple *tuple, u32 *hdrsize, + u32 offset) +{ + struct flow_ports *ports; + unsigned int thoff; + struct iphdr *iph; + u8 ipproto; + + if (!pskb_may_pull(skb, sizeof(*iph) + offset)) + return -1; + + iph = (struct iphdr *)(skb_network_header(skb) + offset); + thoff = (iph->ihl * 4); + + if (ip_is_fragment(iph) || + unlikely(ip_has_options(thoff))) + return -1; + + thoff += offset; + + ipproto = iph->protocol; + switch (ipproto) { + case IPPROTO_TCP: + *hdrsize = sizeof(struct tcphdr); + break; + case IPPROTO_UDP: + *hdrsize = sizeof(struct udphdr); + break; +#ifdef CONFIG_NF_CT_PROTO_GRE + case IPPROTO_GRE: + *hdrsize = sizeof(struct gre_base_hdr); + break; +#endif + default: + return -1; + } + + if (iph->ttl <= 1) + return -1; + + if (!pskb_may_pull(skb, thoff + *hdrsize)) + return -1; + + switch (ipproto) { + case IPPROTO_TCP: + case IPPROTO_UDP: + ports = (struct flow_ports *)(skb_network_header(skb) + thoff); + tuple->src_port = ports->source; + tuple->dst_port = ports->dest; + break; + case IPPROTO_GRE: { + struct gre_base_hdr *greh; + + greh = (struct gre_base_hdr *)(skb_network_header(skb) + thoff); + if ((greh->flags & GRE_VERSION) != GRE_VERSION_0) + return -1; + break; + } + } + + iph = (struct iphdr *)(skb_network_header(skb) + offset); + + tuple->src_v4.s_addr = iph->saddr; + tuple->dst_v4.s_addr = iph->daddr; + tuple->l3proto = AF_INET; + tuple->l4proto = ipproto; + tuple->iifidx = dev->ifindex; + nf_flow_tuple_encap(skb, tuple); + + return 0; +} + +/* Based on ip_exceeds_mtu(). */ +static bool nf_flow_exceeds_mtu(const struct sk_buff *skb, unsigned int mtu) +{ + if (skb->len <= mtu) + return false; + + if (skb_is_gso(skb) && skb_gso_validate_network_len(skb, mtu)) + return false; + + return true; +} + +static inline bool nf_flow_dst_check(struct flow_offload_tuple *tuple) +{ + if (tuple->xmit_type != FLOW_OFFLOAD_XMIT_NEIGH && + tuple->xmit_type != FLOW_OFFLOAD_XMIT_XFRM) + return true; + + return dst_check(tuple->dst_cache, tuple->dst_cookie); +} + +static unsigned int nf_flow_xmit_xfrm(struct sk_buff *skb, + const struct nf_hook_state *state, + struct dst_entry *dst) +{ + skb_orphan(skb); + skb_dst_set_noref(skb, dst); + dst_output(state->net, state->sk, skb); + return NF_STOLEN; +} + +static bool nf_flow_skb_encap_protocol(const struct sk_buff *skb, __be16 proto, + u32 *offset) +{ + struct vlan_ethhdr *veth; + + switch (skb->protocol) { + case htons(ETH_P_8021Q): + veth = (struct vlan_ethhdr *)skb_mac_header(skb); + if (veth->h_vlan_encapsulated_proto == proto) { + *offset += VLAN_HLEN; + return true; + } + break; + case htons(ETH_P_PPP_SES): + if (nf_flow_pppoe_proto(skb) == proto) { + *offset += PPPOE_SES_HLEN; + return true; + } + break; + } + + return false; +} + +static void nf_flow_encap_pop(struct sk_buff *skb, + struct flow_offload_tuple_rhash *tuplehash) +{ + struct vlan_hdr *vlan_hdr; + int i; + + for (i = 0; i < tuplehash->tuple.encap_num; i++) { + if (skb_vlan_tag_present(skb)) { + __vlan_hwaccel_clear_tag(skb); + continue; + } + switch (skb->protocol) { + case htons(ETH_P_8021Q): + vlan_hdr = (struct vlan_hdr *)skb->data; + __skb_pull(skb, VLAN_HLEN); + vlan_set_encap_proto(skb, vlan_hdr); + skb_reset_network_header(skb); + break; + case htons(ETH_P_PPP_SES): + skb->protocol = nf_flow_pppoe_proto(skb); + skb_pull(skb, PPPOE_SES_HLEN); + skb_reset_network_header(skb); + break; + } + } +} + +static unsigned int nf_flow_queue_xmit(struct net *net, struct sk_buff *skb, + const struct flow_offload_tuple_rhash *tuplehash, + unsigned short type) +{ + struct net_device *outdev; + + outdev = dev_get_by_index_rcu(net, tuplehash->tuple.out.ifidx); + if (!outdev) + return NF_DROP; + + skb->dev = outdev; + dev_hard_header(skb, skb->dev, type, tuplehash->tuple.out.h_dest, + tuplehash->tuple.out.h_source, skb->len); + dev_queue_xmit(skb); + + return NF_STOLEN; +} + +unsigned int +nf_flow_offload_ip_hook(void *priv, struct sk_buff *skb, + const struct nf_hook_state *state) +{ + struct flow_offload_tuple_rhash *tuplehash; + struct nf_flowtable *flow_table = priv; + struct flow_offload_tuple tuple = {}; + enum flow_offload_tuple_dir dir; + struct flow_offload *flow; + struct net_device *outdev; + u32 hdrsize, offset = 0; + unsigned int thoff, mtu; + struct rtable *rt; + struct iphdr *iph; + __be32 nexthop; + int ret; + + if (skb->protocol != htons(ETH_P_IP) && + !nf_flow_skb_encap_protocol(skb, htons(ETH_P_IP), &offset)) + return NF_ACCEPT; + + if (nf_flow_tuple_ip(skb, state->in, &tuple, &hdrsize, offset) < 0) + return NF_ACCEPT; + + tuplehash = flow_offload_lookup(flow_table, &tuple); + if (tuplehash == NULL) + return NF_ACCEPT; + + dir = tuplehash->tuple.dir; + flow = container_of(tuplehash, struct flow_offload, tuplehash[dir]); + + mtu = flow->tuplehash[dir].tuple.mtu + offset; + if (unlikely(nf_flow_exceeds_mtu(skb, mtu))) + return NF_ACCEPT; + + iph = (struct iphdr *)(skb_network_header(skb) + offset); + thoff = (iph->ihl * 4) + offset; + if (nf_flow_state_check(flow, iph->protocol, skb, thoff)) + return NF_ACCEPT; + + if (!nf_flow_dst_check(&tuplehash->tuple)) { + flow_offload_teardown(flow); + return NF_ACCEPT; + } + + if (skb_try_make_writable(skb, thoff + hdrsize)) + return NF_DROP; + + flow_offload_refresh(flow_table, flow, false); + + nf_flow_encap_pop(skb, tuplehash); + thoff -= offset; + + iph = ip_hdr(skb); + nf_flow_nat_ip(flow, skb, thoff, dir, iph); + + ip_decrease_ttl(iph); + skb_clear_tstamp(skb); + + if (flow_table->flags & NF_FLOWTABLE_COUNTER) + nf_ct_acct_update(flow->ct, tuplehash->tuple.dir, skb->len); + + if (unlikely(tuplehash->tuple.xmit_type == FLOW_OFFLOAD_XMIT_XFRM)) { + rt = (struct rtable *)tuplehash->tuple.dst_cache; + memset(skb->cb, 0, sizeof(struct inet_skb_parm)); + IPCB(skb)->iif = skb->dev->ifindex; + IPCB(skb)->flags = IPSKB_FORWARDED; + return nf_flow_xmit_xfrm(skb, state, &rt->dst); + } + + switch (tuplehash->tuple.xmit_type) { + case FLOW_OFFLOAD_XMIT_NEIGH: + rt = (struct rtable *)tuplehash->tuple.dst_cache; + outdev = rt->dst.dev; + skb->dev = outdev; + nexthop = rt_nexthop(rt, flow->tuplehash[!dir].tuple.src_v4.s_addr); + skb_dst_set_noref(skb, &rt->dst); + neigh_xmit(NEIGH_ARP_TABLE, outdev, &nexthop, skb); + ret = NF_STOLEN; + break; + case FLOW_OFFLOAD_XMIT_DIRECT: + ret = nf_flow_queue_xmit(state->net, skb, tuplehash, ETH_P_IP); + if (ret == NF_DROP) + flow_offload_teardown(flow); + break; + } + + return ret; +} +EXPORT_SYMBOL_GPL(nf_flow_offload_ip_hook); + +static void nf_flow_nat_ipv6_tcp(struct sk_buff *skb, unsigned int thoff, + struct in6_addr *addr, + struct in6_addr *new_addr, + struct ipv6hdr *ip6h) +{ + struct tcphdr *tcph; + + tcph = (void *)(skb_network_header(skb) + thoff); + inet_proto_csum_replace16(&tcph->check, skb, addr->s6_addr32, + new_addr->s6_addr32, true); +} + +static void nf_flow_nat_ipv6_udp(struct sk_buff *skb, unsigned int thoff, + struct in6_addr *addr, + struct in6_addr *new_addr) +{ + struct udphdr *udph; + + udph = (void *)(skb_network_header(skb) + thoff); + if (udph->check || skb->ip_summed == CHECKSUM_PARTIAL) { + inet_proto_csum_replace16(&udph->check, skb, addr->s6_addr32, + new_addr->s6_addr32, true); + if (!udph->check) + udph->check = CSUM_MANGLED_0; + } +} + +static void nf_flow_nat_ipv6_l4proto(struct sk_buff *skb, struct ipv6hdr *ip6h, + unsigned int thoff, struct in6_addr *addr, + struct in6_addr *new_addr) +{ + switch (ip6h->nexthdr) { + case IPPROTO_TCP: + nf_flow_nat_ipv6_tcp(skb, thoff, addr, new_addr, ip6h); + break; + case IPPROTO_UDP: + nf_flow_nat_ipv6_udp(skb, thoff, addr, new_addr); + break; + } +} + +static void nf_flow_snat_ipv6(const struct flow_offload *flow, + struct sk_buff *skb, struct ipv6hdr *ip6h, + unsigned int thoff, + enum flow_offload_tuple_dir dir) +{ + struct in6_addr addr, new_addr; + + switch (dir) { + case FLOW_OFFLOAD_DIR_ORIGINAL: + addr = ip6h->saddr; + new_addr = flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.dst_v6; + ip6h->saddr = new_addr; + break; + case FLOW_OFFLOAD_DIR_REPLY: + addr = ip6h->daddr; + new_addr = flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.src_v6; + ip6h->daddr = new_addr; + break; + } + + nf_flow_nat_ipv6_l4proto(skb, ip6h, thoff, &addr, &new_addr); +} + +static void nf_flow_dnat_ipv6(const struct flow_offload *flow, + struct sk_buff *skb, struct ipv6hdr *ip6h, + unsigned int thoff, + enum flow_offload_tuple_dir dir) +{ + struct in6_addr addr, new_addr; + + switch (dir) { + case FLOW_OFFLOAD_DIR_ORIGINAL: + addr = ip6h->daddr; + new_addr = flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.src_v6; + ip6h->daddr = new_addr; + break; + case FLOW_OFFLOAD_DIR_REPLY: + addr = ip6h->saddr; + new_addr = flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.dst_v6; + ip6h->saddr = new_addr; + break; + } + + nf_flow_nat_ipv6_l4proto(skb, ip6h, thoff, &addr, &new_addr); +} + +static void nf_flow_nat_ipv6(const struct flow_offload *flow, + struct sk_buff *skb, + enum flow_offload_tuple_dir dir, + struct ipv6hdr *ip6h) +{ + unsigned int thoff = sizeof(*ip6h); + + if (test_bit(NF_FLOW_SNAT, &flow->flags)) { + nf_flow_snat_port(flow, skb, thoff, ip6h->nexthdr, dir); + nf_flow_snat_ipv6(flow, skb, ip6h, thoff, dir); + } + if (test_bit(NF_FLOW_DNAT, &flow->flags)) { + nf_flow_dnat_port(flow, skb, thoff, ip6h->nexthdr, dir); + nf_flow_dnat_ipv6(flow, skb, ip6h, thoff, dir); + } +} + +static int nf_flow_tuple_ipv6(struct sk_buff *skb, const struct net_device *dev, + struct flow_offload_tuple *tuple, u32 *hdrsize, + u32 offset) +{ + struct flow_ports *ports; + struct ipv6hdr *ip6h; + unsigned int thoff; + u8 nexthdr; + + thoff = sizeof(*ip6h) + offset; + if (!pskb_may_pull(skb, thoff)) + return -1; + + ip6h = (struct ipv6hdr *)(skb_network_header(skb) + offset); + + nexthdr = ip6h->nexthdr; + switch (nexthdr) { + case IPPROTO_TCP: + *hdrsize = sizeof(struct tcphdr); + break; + case IPPROTO_UDP: + *hdrsize = sizeof(struct udphdr); + break; +#ifdef CONFIG_NF_CT_PROTO_GRE + case IPPROTO_GRE: + *hdrsize = sizeof(struct gre_base_hdr); + break; +#endif + default: + return -1; + } + + if (ip6h->hop_limit <= 1) + return -1; + + if (!pskb_may_pull(skb, thoff + *hdrsize)) + return -1; + + switch (nexthdr) { + case IPPROTO_TCP: + case IPPROTO_UDP: + ports = (struct flow_ports *)(skb_network_header(skb) + thoff); + tuple->src_port = ports->source; + tuple->dst_port = ports->dest; + break; + case IPPROTO_GRE: { + struct gre_base_hdr *greh; + + greh = (struct gre_base_hdr *)(skb_network_header(skb) + thoff); + if ((greh->flags & GRE_VERSION) != GRE_VERSION_0) + return -1; + break; + } + } + + ip6h = (struct ipv6hdr *)(skb_network_header(skb) + offset); + + tuple->src_v6 = ip6h->saddr; + tuple->dst_v6 = ip6h->daddr; + tuple->l3proto = AF_INET6; + tuple->l4proto = nexthdr; + tuple->iifidx = dev->ifindex; + nf_flow_tuple_encap(skb, tuple); + + return 0; +} + +unsigned int +nf_flow_offload_ipv6_hook(void *priv, struct sk_buff *skb, + const struct nf_hook_state *state) +{ + struct flow_offload_tuple_rhash *tuplehash; + struct nf_flowtable *flow_table = priv; + struct flow_offload_tuple tuple = {}; + enum flow_offload_tuple_dir dir; + const struct in6_addr *nexthop; + struct flow_offload *flow; + struct net_device *outdev; + unsigned int thoff, mtu; + u32 hdrsize, offset = 0; + struct ipv6hdr *ip6h; + struct rt6_info *rt; + int ret; + + if (skb->protocol != htons(ETH_P_IPV6) && + !nf_flow_skb_encap_protocol(skb, htons(ETH_P_IPV6), &offset)) + return NF_ACCEPT; + + if (nf_flow_tuple_ipv6(skb, state->in, &tuple, &hdrsize, offset) < 0) + return NF_ACCEPT; + + tuplehash = flow_offload_lookup(flow_table, &tuple); + if (tuplehash == NULL) + return NF_ACCEPT; + + dir = tuplehash->tuple.dir; + flow = container_of(tuplehash, struct flow_offload, tuplehash[dir]); + + mtu = flow->tuplehash[dir].tuple.mtu + offset; + if (unlikely(nf_flow_exceeds_mtu(skb, mtu))) + return NF_ACCEPT; + + ip6h = (struct ipv6hdr *)(skb_network_header(skb) + offset); + thoff = sizeof(*ip6h) + offset; + if (nf_flow_state_check(flow, ip6h->nexthdr, skb, thoff)) + return NF_ACCEPT; + + if (!nf_flow_dst_check(&tuplehash->tuple)) { + flow_offload_teardown(flow); + return NF_ACCEPT; + } + + if (skb_try_make_writable(skb, thoff + hdrsize)) + return NF_DROP; + + flow_offload_refresh(flow_table, flow, false); + + nf_flow_encap_pop(skb, tuplehash); + + ip6h = ipv6_hdr(skb); + nf_flow_nat_ipv6(flow, skb, dir, ip6h); + + ip6h->hop_limit--; + skb_clear_tstamp(skb); + + if (flow_table->flags & NF_FLOWTABLE_COUNTER) + nf_ct_acct_update(flow->ct, tuplehash->tuple.dir, skb->len); + + if (unlikely(tuplehash->tuple.xmit_type == FLOW_OFFLOAD_XMIT_XFRM)) { + rt = (struct rt6_info *)tuplehash->tuple.dst_cache; + memset(skb->cb, 0, sizeof(struct inet6_skb_parm)); + IP6CB(skb)->iif = skb->dev->ifindex; + IP6CB(skb)->flags = IP6SKB_FORWARDED; + return nf_flow_xmit_xfrm(skb, state, &rt->dst); + } + + switch (tuplehash->tuple.xmit_type) { + case FLOW_OFFLOAD_XMIT_NEIGH: + rt = (struct rt6_info *)tuplehash->tuple.dst_cache; + outdev = rt->dst.dev; + skb->dev = outdev; + nexthop = rt6_nexthop(rt, &flow->tuplehash[!dir].tuple.src_v6); + skb_dst_set_noref(skb, &rt->dst); + neigh_xmit(NEIGH_ND_TABLE, outdev, nexthop, skb); + ret = NF_STOLEN; + break; + case FLOW_OFFLOAD_XMIT_DIRECT: + ret = nf_flow_queue_xmit(state->net, skb, tuplehash, ETH_P_IPV6); + if (ret == NF_DROP) + flow_offload_teardown(flow); + break; + } + + return ret; +} +EXPORT_SYMBOL_GPL(nf_flow_offload_ipv6_hook); -- cgit v1.2.3