From: Pablo Neira Ayuso Date: Wed, 24 Mar 2021 02:30:41 +0100 Subject: [PATCH] netfilter: flowtable: add vlan support Add the vlan id and protocol to the flow tuple to uniquely identify flows from the receive path. For the transmit path, dev_hard_header() on the vlan device push the headers. This patch includes support for two vlan headers (QinQ) from the ingress path. Add a generic encap field to the flowtable entry which stores the protocol and the tag id. This allows to reuse these fields in the PPPoE support coming in a later patch. Signed-off-by: Pablo Neira Ayuso --- --- a/include/net/netfilter/nf_flow_table.h +++ b/include/net/netfilter/nf_flow_table.h @@ -95,6 +95,8 @@ enum flow_offload_xmit_type { FLOW_OFFLOAD_XMIT_DIRECT, }; +#define NF_FLOW_TABLE_ENCAP_MAX 2 + struct flow_offload_tuple { union { struct in_addr src_v4; @@ -113,13 +115,17 @@ struct flow_offload_tuple { u8 l3proto; u8 l4proto; + struct { + u16 id; + __be16 proto; + } encap[NF_FLOW_TABLE_ENCAP_MAX]; /* All members above are keys for lookups, see flow_offload_hash(). */ struct { } __hash; - u8 dir:6, - xmit_type:2; - + u8 dir:4, + xmit_type:2, + encap_num:2; u16 mtu; union { struct dst_entry *dst_cache; @@ -174,6 +180,11 @@ struct nf_flow_route { struct dst_entry *dst; struct { u32 ifindex; + struct { + u16 id; + __be16 proto; + } encap[NF_FLOW_TABLE_ENCAP_MAX]; + u8 num_encaps; } in; struct { u32 ifindex; --- a/net/netfilter/nf_flow_table_core.c +++ b/net/netfilter/nf_flow_table_core.c @@ -80,6 +80,7 @@ static int flow_offload_fill_route(struc { struct flow_offload_tuple *flow_tuple = &flow->tuplehash[dir].tuple; struct dst_entry *dst = route->tuple[dir].dst; + int i, j = 0; switch (flow_tuple->l3proto) { case NFPROTO_IPV4: @@ -91,6 +92,12 @@ static int flow_offload_fill_route(struc } flow_tuple->iifidx = route->tuple[dir].in.ifindex; + for (i = route->tuple[dir].in.num_encaps - 1; i >= 0; i--) { + flow_tuple->encap[j].id = route->tuple[dir].in.encap[i].id; + flow_tuple->encap[j].proto = route->tuple[dir].in.encap[i].proto; + j++; + } + flow_tuple->encap_num = route->tuple[dir].in.num_encaps; switch (route->tuple[dir].xmit_type) { case FLOW_OFFLOAD_XMIT_DIRECT: --- a/net/netfilter/nf_flow_table_ip.c +++ b/net/netfilter/nf_flow_table_ip.c @@ -136,23 +136,44 @@ static bool ip_has_options(unsigned int return thoff != sizeof(struct iphdr); } +static void nf_flow_tuple_encap(struct sk_buff *skb, + struct flow_offload_tuple *tuple) +{ + 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++; + } + if (skb->protocol == htons(ETH_P_8021Q)) { + struct vlan_ethhdr *veth = (struct vlan_ethhdr *)skb_mac_header(skb); + + tuple->encap[i].id = ntohs(veth->h_vlan_TCI); + tuple->encap[i].proto = skb->protocol; + } +} + static int nf_flow_tuple_ip(struct sk_buff *skb, const struct net_device *dev, - struct flow_offload_tuple *tuple, u32 *hdrsize) + struct flow_offload_tuple *tuple, u32 *hdrsize, + u32 offset) { struct flow_ports *ports; unsigned int thoff; struct iphdr *iph; - if (!pskb_may_pull(skb, sizeof(*iph))) + if (!pskb_may_pull(skb, sizeof(*iph) + offset)) return -1; - iph = ip_hdr(skb); - thoff = iph->ihl * 4; + 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; + switch (iph->protocol) { case IPPROTO_TCP: *hdrsize = sizeof(struct tcphdr); @@ -167,11 +188,10 @@ static int nf_flow_tuple_ip(struct sk_bu if (iph->ttl <= 1) return -1; - thoff = iph->ihl * 4; if (!pskb_may_pull(skb, thoff + *hdrsize)) return -1; - iph = ip_hdr(skb); + iph = (struct iphdr *)(skb_network_header(skb) + offset); ports = (struct flow_ports *)(skb_network_header(skb) + thoff); tuple->src_v4.s_addr = iph->saddr; @@ -181,6 +201,7 @@ static int nf_flow_tuple_ip(struct sk_bu tuple->l3proto = AF_INET; tuple->l4proto = iph->protocol; tuple->iifidx = dev->ifindex; + nf_flow_tuple_encap(skb, tuple); return 0; } @@ -207,6 +228,43 @@ static unsigned int nf_flow_xmit_xfrm(st return NF_STOLEN; } +static bool nf_flow_skb_encap_protocol(const struct sk_buff *skb, __be16 proto, + u32 *offset) +{ + if (skb->protocol == htons(ETH_P_8021Q)) { + struct vlan_ethhdr *veth; + + veth = (struct vlan_ethhdr *)skb_mac_header(skb); + if (veth->h_vlan_encapsulated_proto == proto) { + *offset += VLAN_HLEN; + return true; + } + } + + 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; + } + if (skb->protocol == 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; + } + } +} + static unsigned int nf_flow_queue_xmit(struct net *net, struct sk_buff *skb, const struct flow_offload_tuple_rhash *tuplehash, unsigned short type) @@ -235,17 +293,18 @@ nf_flow_offload_ip_hook(void *priv, stru 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; - unsigned int thoff; struct iphdr *iph; __be32 nexthop; - u32 hdrsize; int ret; - if (skb->protocol != htons(ETH_P_IP)) + 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) < 0) + if (nf_flow_tuple_ip(skb, state->in, &tuple, &hdrsize, offset) < 0) return NF_ACCEPT; tuplehash = flow_offload_lookup(flow_table, &tuple); @@ -255,11 +314,12 @@ nf_flow_offload_ip_hook(void *priv, stru dir = tuplehash->tuple.dir; flow = container_of(tuplehash, struct flow_offload, tuplehash[dir]); - if (unlikely(nf_flow_exceeds_mtu(skb, flow->tuplehash[dir].tuple.mtu))) + mtu = flow->tuplehash[dir].tuple.mtu + offset; + if (unlikely(nf_flow_exceeds_mtu(skb, mtu))) return NF_ACCEPT; - iph = ip_hdr(skb); - thoff = iph->ihl * 4; + 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; @@ -277,6 +337,9 @@ nf_flow_offload_ip_hook(void *priv, stru flow_offload_refresh(flow_table, flow); + nf_flow_encap_pop(skb, tuplehash); + thoff -= offset; + iph = ip_hdr(skb); nf_flow_nat_ip(flow, skb, thoff, dir, iph); @@ -418,16 +481,18 @@ static void nf_flow_nat_ipv6(const struc } static int nf_flow_tuple_ipv6(struct sk_buff *skb, const struct net_device *dev, - struct flow_offload_tuple *tuple, u32 *hdrsize) + struct flow_offload_tuple *tuple, u32 *hdrsize, + u32 offset) { struct flow_ports *ports; struct ipv6hdr *ip6h; unsigned int thoff; - if (!pskb_may_pull(skb, sizeof(*ip6h))) + thoff = sizeof(*ip6h) + offset; + if (!pskb_may_pull(skb, thoff)) return -1; - ip6h = ipv6_hdr(skb); + ip6h = (struct ipv6hdr *)(skb_network_header(skb) + offset); switch (ip6h->nexthdr) { case IPPROTO_TCP: @@ -443,11 +508,10 @@ static int nf_flow_tuple_ipv6(struct sk_ if (ip6h->hop_limit <= 1) return -1; - thoff = sizeof(*ip6h); if (!pskb_may_pull(skb, thoff + *hdrsize)) return -1; - ip6h = ipv6_hdr(skb); + ip6h = (struct ipv6hdr *)(skb_network_header(skb) + offset); ports = (struct flow_ports *)(skb_network_header(skb) + thoff); tuple->src_v6 = ip6h->saddr; @@ -457,6 +521,7 @@ static int nf_flow_tuple_ipv6(struct sk_ tuple->l3proto = AF_INET6; tuple->l4proto = ip6h->nexthdr; tuple->iifidx = dev->ifindex; + nf_flow_tuple_encap(skb, tuple); return 0; } @@ -472,15 +537,17 @@ nf_flow_offload_ipv6_hook(void *priv, st 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; - u32 hdrsize; int ret; - if (skb->protocol != htons(ETH_P_IPV6)) + 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) < 0) + if (nf_flow_tuple_ipv6(skb, state->in, &tuple, &hdrsize, offset) < 0) return NF_ACCEPT; tuplehash = flow_offload_lookup(flow_table, &tuple); @@ -490,11 +557,13 @@ nf_flow_offload_ipv6_hook(void *priv, st dir = tuplehash->tuple.dir; flow = container_of(tuplehash, struct flow_offload, tuplehash[dir]); - if (unlikely(nf_flow_exceeds_mtu(skb, flow->tuplehash[dir].tuple.mtu))) + mtu = flow->tuplehash[dir].tuple.mtu + offset; + if (unlikely(nf_flow_exceeds_mtu(skb, mtu))) return NF_ACCEPT; - if (nf_flow_state_check(flow, ipv6_hdr(skb)->nexthdr, skb, - sizeof(*ip6h))) + 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 (tuplehash->tuple.xmit_type == FLOW_OFFLOAD_XMIT_NEIGH || @@ -506,11 +575,13 @@ nf_flow_offload_ipv6_hook(void *priv, st } } - if (skb_try_make_writable(skb, sizeof(*ip6h) + hdrsize)) + if (skb_try_make_writable(skb, thoff + hdrsize)) return NF_DROP; flow_offload_refresh(flow_table, flow); + nf_flow_encap_pop(skb, tuplehash); + ip6h = ipv6_hdr(skb); nf_flow_nat_ipv6(flow, skb, dir, ip6h); --- a/net/netfilter/nft_flow_offload.c +++ b/net/netfilter/nft_flow_offload.c @@ -66,6 +66,11 @@ static int nft_dev_fill_forward_path(con struct nft_forward_info { const struct net_device *indev; const struct net_device *outdev; + struct id { + __u16 id; + __be16 proto; + } encap[NF_FLOW_TABLE_ENCAP_MAX]; + u8 num_encaps; u8 h_source[ETH_ALEN]; u8 h_dest[ETH_ALEN]; enum flow_offload_xmit_type xmit_type; @@ -84,9 +89,23 @@ static void nft_dev_path_info(const stru path = &stack->path[i]; switch (path->type) { case DEV_PATH_ETHERNET: + case DEV_PATH_VLAN: info->indev = path->dev; if (is_zero_ether_addr(info->h_source)) memcpy(info->h_source, path->dev->dev_addr, ETH_ALEN); + + if (path->type == DEV_PATH_ETHERNET) + break; + + /* DEV_PATH_VLAN */ + if (info->num_encaps >= NF_FLOW_TABLE_ENCAP_MAX) { + info->indev = NULL; + break; + } + info->outdev = path->dev; + info->encap[info->num_encaps].id = path->encap.id; + info->encap[info->num_encaps].proto = path->encap.proto; + info->num_encaps++; break; case DEV_PATH_BRIDGE: if (is_zero_ether_addr(info->h_source)) @@ -94,7 +113,6 @@ static void nft_dev_path_info(const stru info->xmit_type = FLOW_OFFLOAD_XMIT_DIRECT; break; - case DEV_PATH_VLAN: default: info->indev = NULL; break; @@ -130,6 +148,7 @@ static void nft_dev_forward_path(struct struct net_device_path_stack stack; struct nft_forward_info info = {}; unsigned char ha[ETH_ALEN]; + int i; if (nft_dev_fill_forward_path(route, dst, ct, dir, ha, &stack) >= 0) nft_dev_path_info(&stack, &info, ha); @@ -138,6 +157,11 @@ static void nft_dev_forward_path(struct return; route->tuple[!dir].in.ifindex = info.indev->ifindex; + for (i = 0; i < info.num_encaps; i++) { + route->tuple[!dir].in.encap[i].id = info.encap[i].id; + route->tuple[!dir].in.encap[i].proto = info.encap[i].proto; + } + route->tuple[!dir].in.num_encaps = info.num_encaps; if (info.xmit_type == FLOW_OFFLOAD_XMIT_DIRECT) { memcpy(route->tuple[dir].out.h_source, info.h_source, ETH_ALEN);