Add new instruction for the nf_tables VM that allows us to specify what
flows are offloaded. This has an explicit dependency with the conntrack
subsystem.
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
---
include/uapi/linux/netfilter/nf_tables.h | 9 +
net/netfilter/Kconfig | 7 +
net/netfilter/Makefile | 1 +
net/netfilter/nft_flow_offload.c | 331 +++++++++++++++++++++++++++++++
4 files changed, 348 insertions(+)
create mode 100644 net/netfilter/nft_flow_offload.c
diff --git a/include/uapi/linux/netfilter/nf_tables.h b/include/uapi/linux/netfilter/nf_tables.h
index 871afa4871bf..2edde548de68 100644
--- a/include/uapi/linux/netfilter/nf_tables.h
+++ b/include/uapi/linux/netfilter/nf_tables.h
@@ -948,6 +948,15 @@ enum nft_ct_attributes {
};
#define NFTA_CT_MAX (__NFTA_CT_MAX - 1)
+/**
+ * enum nft_ct_offload_attributes - ct offload expression attributes
+ */
+enum nft_offload_attributes {
+ NFTA_CT_OFFLOAD_UNSPEC,
+ __NFTA_CT_OFFLOAD_MAX,
+};
+#define NFTA_CT_OFFLOAD_MAX (__NFTA_CT_OFFLOAD_MAX - 1)
+
enum nft_limit_type {
NFT_LIMIT_PKTS,
NFT_LIMIT_PKT_BYTES
diff --git a/net/netfilter/Kconfig b/net/netfilter/Kconfig
index f022ca91f49d..0a5c33cfaeb8 100644
--- a/net/netfilter/Kconfig
+++ b/net/netfilter/Kconfig
@@ -504,6 +504,13 @@ config NFT_CT
This option adds the "ct" expression that you can use to match
connection tracking information such as the flow state.
+config NFT_FLOW_OFFLOAD
+ depends on NF_CONNTRACK
+ tristate "Netfilter nf_tables hardware flow offload module"
+ help
+ This option adds the "flow_offload" expression that you can use to
+ choose what flows are placed into the hardware.
+
config NFT_SET_RBTREE
tristate "Netfilter nf_tables rbtree set module"
help
diff --git a/net/netfilter/Makefile b/net/netfilter/Makefile
index 518f54113e06..801ce5c25e5d 100644
--- a/net/netfilter/Makefile
+++ b/net/netfilter/Makefile
@@ -86,6 +86,7 @@ obj-$(CONFIG_NFT_META) += nft_meta.o
obj-$(CONFIG_NFT_RT) += nft_rt.o
obj-$(CONFIG_NFT_NUMGEN) += nft_numgen.o
obj-$(CONFIG_NFT_CT) += nft_ct.o
+obj-$(CONFIG_NFT_FLOW_OFFLOAD) += nft_flow_offload.o
obj-$(CONFIG_NFT_LIMIT) += nft_limit.o
obj-$(CONFIG_NFT_NAT) += nft_nat.o
obj-$(CONFIG_NFT_OBJREF) += nft_objref.o
diff --git a/net/netfilter/nft_flow_offload.c b/net/netfilter/nft_flow_offload.c
new file mode 100644
index 000000000000..d38d185a19a5
--- /dev/null
+++ b/net/netfilter/nft_flow_offload.c
@@ -0,0 +1,331 @@
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/netlink.h>
+#include <linux/netfilter.h>
+#include <linux/workqueue.h>
+#include <linux/spinlock.h>
+#include <linux/netfilter/nf_tables.h>
+#include <net/flow_offload.h>
+#include <net/netfilter/nf_tables.h>
+#include <net/netfilter/nf_tables_core.h>
+#include <net/netfilter/nf_conntrack_core.h>
+#include <linux/netfilter/nf_conntrack_common.h>
+
+union flow_gateway {
+ __be32 ip;
+ struct in6_addr ip6;
+};
+
+static int flow_offload_iterate_cleanup(struct nf_conn *ct, void *data)
+{
+ struct flow_offload_tuple_rhash *tuplehash;
+ struct flow_offload_tuple tuple = {};
+ struct net_device *indev = data;
+ struct flow_offload *flow;
+
+ if (!test_and_clear_bit(IPS_OFFLOAD_BIT, &ct->status))
+ return 0;
+
+ tuple.src_v4 = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u3.in;
+ tuple.dst_v4 = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u3.in;
+ tuple.src_port = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u.tcp.port;
+ tuple.dst_port = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u.tcp.port;
+ tuple.l3proto = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num;
+ tuple.l4proto = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum;
+
+ tuplehash = flow_offload_lookup(&tuple);
+ BUG_ON(!tuplehash);
+
+ if (indev && tuplehash->tuple.iifidx != indev->ifindex)
+ return 0;
+
+ flow = container_of(tuplehash, struct flow_offload,
+ tuplehash[tuplehash->tuple.dir]);
+
+ flow_offload_del(flow);
+
+ /* Do not remove this conntrack from table. */
+ return 0;
+}
+
+static void flow_offload_cleanup(struct net *net,
+ const struct net_device *dev)
+{
+ nf_ct_iterate_cleanup_net(net, flow_offload_iterate_cleanup,
+ (void *)dev, 0, 0);
+}
+
+static int flow_offload_netdev_event(struct notifier_block *this,
+ unsigned long event, void *ptr)
+{
+ const struct net_device *dev = netdev_notifier_info_to_dev(ptr);
+
+ if (event != NETDEV_DOWN)
+ return NOTIFY_DONE;
+
+ flow_offload_cleanup(dev_net(dev), dev);
+
+ return NOTIFY_DONE;
+}
+
+static struct notifier_block flow_offload_netdev_notifier = {
+ .notifier_call = flow_offload_netdev_event,
+};
+
+static struct flow_offload *
+flow_offload_alloc(const struct nf_conn *ct, int iifindex, int oifindex,
+ union flow_gateway *orig_gateway,
+ union flow_gateway *reply_gateway)
+{
+ struct flow_offload *flow;
+
+ flow = kzalloc(sizeof(*flow), GFP_ATOMIC);
+ if (!flow)
+ return NULL;
+
+ switch (ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num) {
+ case NFPROTO_IPV4:
+ flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.src_v4 =
+ ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u3.in;
+ flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.dst_v4 =
+ ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u3.in;
+ flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.src_v4 =
+ ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.u3.in;
+ flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.dst_v4 =
+ ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u3.in;
+ flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.l3proto =
+ ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num;
+ flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.l4proto =
+ ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum;
+ flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.l3proto =
+ ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num;
+ flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.l4proto =
+ ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum;
+ flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.gateway =
+ orig_gateway->ip;
+ flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.gateway =
+ reply_gateway->ip;
+ break;
+ case NFPROTO_IPV6:
+ flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.src_v6 =
+ ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u3.in6;
+ flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.dst_v6 =
+ ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u3.in6;
+ flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.src_v6 =
+ ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.u3.in6;
+ flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.dst_v6 =
+ ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u3.in6;
+ flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.l3proto =
+ ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num;
+ flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.l4proto =
+ ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum;
+ flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.l3proto =
+ ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num;
+ flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.l4proto =
+ ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum;
+ flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.gateway6 =
+ orig_gateway->ip6;
+ flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.gateway6 =
+ reply_gateway->ip6;
+ break;
+ }
+
+ flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.src_port =
+ ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u.tcp.port;
+ flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.dst_port =
+ ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u.tcp.port;
+ flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.src_port =
+ ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.u.tcp.port;
+ flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.dst_port =
+ ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u.tcp.port;
+
+ flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.dir = FLOW_OFFLOAD_DIR_ORIGINAL;
+ flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.dir = FLOW_OFFLOAD_DIR_REPLY;
+
+ flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.iifidx = oifindex;
+ flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.oifidx = iifindex;
+ flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.iifidx = iifindex;
+ flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.oifidx = oifindex;
+
+ if (ct->status & IPS_SRC_NAT)
+ flow->flags |= FLOW_OFFLOAD_SNAT;
+ else if (ct->status & IPS_DST_NAT)
+ flow->flags |= FLOW_OFFLOAD_DNAT;
+
+ return flow;
+}
+
+static int nft_flow_route(const struct nft_pktinfo *pkt,
+ const struct nf_conn *ct,
+ union flow_gateway *orig_gw,
+ union flow_gateway *reply_gw)
+{
+ const struct dst_entry *reply_dst = skb_dst(pkt->skb);
+ struct dst_entry *orig_dst;
+ const struct nf_afinfo *ai;
+ struct flowi fl;
+
+ memset(&fl, 0, sizeof(fl));
+ switch (nft_pf(pkt)) {
+ case NFPROTO_IPV4:
+ fl.u.ip4.daddr = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u3.ip;
+ break;
+ case NFPROTO_IPV6:
+ fl.u.ip6.daddr = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u3.in6;
+ break;
+ }
+
+ ai = nf_get_afinfo(nft_pf(pkt));
+ if (ai) {
+ ai->route(nft_net(pkt), &orig_dst, &fl, false);
+ if (!orig_dst)
+ return -ENOENT;
+ }
+
+ switch (nft_pf(pkt)) {
+ case NFPROTO_IPV4: {
+ const struct rtable *orig_rt = (const struct rtable *)orig_dst;
+ const struct rtable *reply_rt =
+ (const struct rtable *)reply_dst;
+
+ orig_gw->ip = orig_rt->rt_gateway;
+ reply_gw->ip = reply_rt->rt_gateway;
+ break;
+ }
+ case NFPROTO_IPV6:
+ break;
+ default:
+ break;
+ }
+
+ dst_release(orig_dst);
+
+ return 0;
+}
+
+static void nft_flow_offload_eval(const struct nft_expr *expr,
+ struct nft_regs *regs,
+ const struct nft_pktinfo *pkt)
+{
+ union flow_gateway orig_gateway, reply_gateway;
+ struct net_device *outdev = pkt->xt.state->out;
+ struct net_device *indev = pkt->xt.state->in;
+ enum ip_conntrack_info ctinfo;
+ struct flow_offload *flow;
+ struct nf_conn *ct;
+ int ret;
+
+ ct = nf_ct_get(pkt->skb, &ctinfo);
+ if (!ct)
+ goto out;
+
+ switch (ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum) {
+ case IPPROTO_TCP:
+ case IPPROTO_UDP:
+ break;
+ default:
+ goto out;
+ }
+
+ if (test_bit(IPS_HELPER_BIT, &ct->status))
+ goto out;
+
+ if (ctinfo == IP_CT_NEW ||
+ ctinfo == IP_CT_RELATED)
+ goto out;
+
+ if (test_and_set_bit(IPS_OFFLOAD_BIT, &ct->status))
+ goto out;
+
+ if (nft_flow_route(pkt, ct, &orig_gateway, &reply_gateway) < 0)
+ goto err1;
+
+ flow = flow_offload_alloc(ct, indev->ifindex, outdev->ifindex,
+ &orig_gateway, &reply_gateway);
+ if (!flow)
+ goto err1;
+
+ ret = flow_offload_add(flow);
+ if (ret < 0)
+ goto err2;
+
+ return;
+err2:
+ kfree(flow);
+err1:
+ clear_bit(IPS_OFFLOAD_BIT, &ct->status);
+out:
+ regs->verdict.code = NFT_BREAK;
+}
+
+static int nft_flow_offload_validate(const struct nft_ctx *ctx,
+ const struct nft_expr *expr,
+ const struct nft_data **data)
+{
+ unsigned int hook_mask = (1 << NF_INET_FORWARD);
+
+ return nft_chain_validate_hooks(ctx->chain, hook_mask);
+}
+
+static int nft_flow_offload_init(const struct nft_ctx *ctx,
+ const struct nft_expr *expr,
+ const struct nlattr * const tb[])
+{
+ return nf_ct_netns_get(ctx->net, ctx->afi->family);
+}
+
+static void nft_flow_offload_destroy(const struct nft_ctx *ctx,
+ const struct nft_expr *expr)
+{
+ nf_ct_netns_put(ctx->net, ctx->afi->family);
+}
+
+static int nft_flow_offload_dump(struct sk_buff *skb, const struct nft_expr *expr)
+{
+ return 0;
+}
+
+struct nft_expr_type nft_flow_offload_type;
+static const struct nft_expr_ops nft_flow_offload_ops = {
+ .type = &nft_flow_offload_type,
+ .size = NFT_EXPR_SIZE(0),
+ .eval = nft_flow_offload_eval,
+ .init = nft_flow_offload_init,
+ .destroy = nft_flow_offload_destroy,
+ .validate = nft_flow_offload_validate,
+ .dump = nft_flow_offload_dump,
+};
+
+struct nft_expr_type nft_flow_offload_type __read_mostly = {
+ .name = "flow_offload",
+ .ops = &nft_flow_offload_ops,
+ .maxattr = NFTA_CT_OFFLOAD_MAX,
+ .owner = THIS_MODULE,
+};
+
+static int __init nft_flow_offload_module_init(void)
+{
+ register_netdevice_notifier(&flow_offload_netdev_notifier);
+
+ return nft_register_expr(&nft_flow_offload_type);
+}
+
+static void __exit nft_flow_offload_module_exit(void)
+{
+ struct net *net;
+
+ nft_unregister_expr(&nft_flow_offload_type);
+ unregister_netdevice_notifier(&flow_offload_netdev_notifier);
+ rtnl_lock();
+ for_each_net(net)
+ flow_offload_cleanup(net, NULL);
+ rtnl_unlock();
+}
+
+module_init(nft_flow_offload_module_init);
+module_exit(nft_flow_offload_module_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>");
+MODULE_ALIAS_NFT_EXPR("flow_offload");
--
2.11.0
--
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