From ebddb1404900657b7f03a56ee4c34a9d218c4030 Mon Sep 17 00:00:00 2001 From: Xin Long Date: Thu, 8 Dec 2022 11:56:12 -0500 Subject: [PATCH] net: move the nat function to nf_nat_ovs for ovs and tc There are two nat functions are nearly the same in both OVS and TC code, (ovs_)ct_nat_execute() and ovs_ct_nat/tcf_ct_act_nat(). This patch creates nf_nat_ovs.c under netfilter and moves them there then exports nf_ct_nat() so that it can be shared by both OVS and TC, and keeps the nat (type) check and nat flag update in OVS and TC's own place, as these parts are different between OVS and TC. Note that in OVS nat function it was using skb->protocol to get the proto as it already skips vlans in key_extract(), while it doesn't in TC, and TC has to call skb_protocol() to get proto. So in nf_ct_nat_execute(), we keep using skb_protocol() which works for both OVS and TC contrack. Signed-off-by: Xin Long Acked-by: Aaron Conole Acked-by: Pablo Neira Ayuso Signed-off-by: David S. Miller --- include/net/netfilter/nf_nat.h | 4 + net/netfilter/Kconfig | 3 + net/netfilter/Makefile | 1 + net/netfilter/nf_nat_ovs.c | 135 ++++++++++++++++++++++++++++++++ net/openvswitch/Kconfig | 1 + net/openvswitch/conntrack.c | 137 +++------------------------------ net/sched/Kconfig | 1 + net/sched/act_ct.c | 134 +++----------------------------- 8 files changed, 165 insertions(+), 251 deletions(-) create mode 100644 net/netfilter/nf_nat_ovs.c diff --git a/include/net/netfilter/nf_nat.h b/include/net/netfilter/nf_nat.h index e9eb01e99d2f..9877f064548a 100644 --- a/include/net/netfilter/nf_nat.h +++ b/include/net/netfilter/nf_nat.h @@ -104,6 +104,10 @@ unsigned int nf_nat_inet_fn(void *priv, struct sk_buff *skb, const struct nf_hook_state *state); +int nf_ct_nat(struct sk_buff *skb, struct nf_conn *ct, + enum ip_conntrack_info ctinfo, int *action, + const struct nf_nat_range2 *range, bool commit); + static inline int nf_nat_initialized(const struct nf_conn *ct, enum nf_nat_manip_type manip) { diff --git a/net/netfilter/Kconfig b/net/netfilter/Kconfig index 0846bd75b1da..f71b41c7ce2f 100644 --- a/net/netfilter/Kconfig +++ b/net/netfilter/Kconfig @@ -459,6 +459,9 @@ config NF_NAT_REDIRECT config NF_NAT_MASQUERADE bool +config NF_NAT_OVS + bool + config NETFILTER_SYNPROXY tristate diff --git a/net/netfilter/Makefile b/net/netfilter/Makefile index 1d4db1943936..3754eb06fb41 100644 --- a/net/netfilter/Makefile +++ b/net/netfilter/Makefile @@ -59,6 +59,7 @@ obj-$(CONFIG_NF_LOG_SYSLOG) += nf_log_syslog.o obj-$(CONFIG_NF_NAT) += nf_nat.o nf_nat-$(CONFIG_NF_NAT_REDIRECT) += nf_nat_redirect.o nf_nat-$(CONFIG_NF_NAT_MASQUERADE) += nf_nat_masquerade.o +nf_nat-$(CONFIG_NF_NAT_OVS) += nf_nat_ovs.o ifeq ($(CONFIG_NF_NAT),m) nf_nat-$(CONFIG_DEBUG_INFO_BTF_MODULES) += nf_nat_bpf.o diff --git a/net/netfilter/nf_nat_ovs.c b/net/netfilter/nf_nat_ovs.c new file mode 100644 index 000000000000..551abd2da614 --- /dev/null +++ b/net/netfilter/nf_nat_ovs.c @@ -0,0 +1,135 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Support nat functions for openvswitch and used by OVS and TC conntrack. */ + +#include + +/* Modelled after nf_nat_ipv[46]_fn(). + * range is only used for new, uninitialized NAT state. + * Returns either NF_ACCEPT or NF_DROP. + */ +static int nf_ct_nat_execute(struct sk_buff *skb, struct nf_conn *ct, + enum ip_conntrack_info ctinfo, int *action, + const struct nf_nat_range2 *range, + enum nf_nat_manip_type maniptype) +{ + __be16 proto = skb_protocol(skb, true); + int hooknum, err = NF_ACCEPT; + + /* See HOOK2MANIP(). */ + if (maniptype == NF_NAT_MANIP_SRC) + hooknum = NF_INET_LOCAL_IN; /* Source NAT */ + else + hooknum = NF_INET_LOCAL_OUT; /* Destination NAT */ + + switch (ctinfo) { + case IP_CT_RELATED: + case IP_CT_RELATED_REPLY: + if (proto == htons(ETH_P_IP) && + ip_hdr(skb)->protocol == IPPROTO_ICMP) { + if (!nf_nat_icmp_reply_translation(skb, ct, ctinfo, + hooknum)) + err = NF_DROP; + goto out; + } else if (IS_ENABLED(CONFIG_IPV6) && proto == htons(ETH_P_IPV6)) { + __be16 frag_off; + u8 nexthdr = ipv6_hdr(skb)->nexthdr; + int hdrlen = ipv6_skip_exthdr(skb, + sizeof(struct ipv6hdr), + &nexthdr, &frag_off); + + if (hdrlen >= 0 && nexthdr == IPPROTO_ICMPV6) { + if (!nf_nat_icmpv6_reply_translation(skb, ct, + ctinfo, + hooknum, + hdrlen)) + err = NF_DROP; + goto out; + } + } + /* Non-ICMP, fall thru to initialize if needed. */ + fallthrough; + case IP_CT_NEW: + /* Seen it before? This can happen for loopback, retrans, + * or local packets. + */ + if (!nf_nat_initialized(ct, maniptype)) { + /* Initialize according to the NAT action. */ + err = (range && range->flags & NF_NAT_RANGE_MAP_IPS) + /* Action is set up to establish a new + * mapping. + */ + ? nf_nat_setup_info(ct, range, maniptype) + : nf_nat_alloc_null_binding(ct, hooknum); + if (err != NF_ACCEPT) + goto out; + } + break; + + case IP_CT_ESTABLISHED: + case IP_CT_ESTABLISHED_REPLY: + break; + + default: + err = NF_DROP; + goto out; + } + + err = nf_nat_packet(ct, ctinfo, hooknum, skb); + if (err == NF_ACCEPT) + *action |= BIT(maniptype); +out: + return err; +} + +int nf_ct_nat(struct sk_buff *skb, struct nf_conn *ct, + enum ip_conntrack_info ctinfo, int *action, + const struct nf_nat_range2 *range, bool commit) +{ + enum nf_nat_manip_type maniptype; + int err, ct_action = *action; + + *action = 0; + + /* Add NAT extension if not confirmed yet. */ + if (!nf_ct_is_confirmed(ct) && !nf_ct_nat_ext_add(ct)) + return NF_DROP; /* Can't NAT. */ + + if (ctinfo != IP_CT_NEW && (ct->status & IPS_NAT_MASK) && + (ctinfo != IP_CT_RELATED || commit)) { + /* NAT an established or related connection like before. */ + if (CTINFO2DIR(ctinfo) == IP_CT_DIR_REPLY) + /* This is the REPLY direction for a connection + * for which NAT was applied in the forward + * direction. Do the reverse NAT. + */ + maniptype = ct->status & IPS_SRC_NAT + ? NF_NAT_MANIP_DST : NF_NAT_MANIP_SRC; + else + maniptype = ct->status & IPS_SRC_NAT + ? NF_NAT_MANIP_SRC : NF_NAT_MANIP_DST; + } else if (ct_action & BIT(NF_NAT_MANIP_SRC)) { + maniptype = NF_NAT_MANIP_SRC; + } else if (ct_action & BIT(NF_NAT_MANIP_DST)) { + maniptype = NF_NAT_MANIP_DST; + } else { + return NF_ACCEPT; + } + + err = nf_ct_nat_execute(skb, ct, ctinfo, action, range, maniptype); + if (err == NF_ACCEPT && ct->status & IPS_DST_NAT) { + if (ct->status & IPS_SRC_NAT) { + if (maniptype == NF_NAT_MANIP_SRC) + maniptype = NF_NAT_MANIP_DST; + else + maniptype = NF_NAT_MANIP_SRC; + + err = nf_ct_nat_execute(skb, ct, ctinfo, action, range, + maniptype); + } else if (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL) { + err = nf_ct_nat_execute(skb, ct, ctinfo, action, NULL, + NF_NAT_MANIP_SRC); + } + } + return err; +} +EXPORT_SYMBOL_GPL(nf_ct_nat); diff --git a/net/openvswitch/Kconfig b/net/openvswitch/Kconfig index 15bd287f5cbd..747d537a3f06 100644 --- a/net/openvswitch/Kconfig +++ b/net/openvswitch/Kconfig @@ -15,6 +15,7 @@ config OPENVSWITCH select NET_MPLS_GSO select DST_CACHE select NET_NSH + select NF_NAT_OVS if NF_NAT help Open vSwitch is a multilayer Ethernet switch targeted at virtualized environments. In addition to supporting a variety of features diff --git a/net/openvswitch/conntrack.c b/net/openvswitch/conntrack.c index 58c9f0edc3c4..c8b137649ca4 100644 --- a/net/openvswitch/conntrack.c +++ b/net/openvswitch/conntrack.c @@ -726,144 +726,27 @@ static void ovs_nat_update_key(struct sw_flow_key *key, } } -/* Modelled after nf_nat_ipv[46]_fn(). - * range is only used for new, uninitialized NAT state. - * Returns either NF_ACCEPT or NF_DROP. - */ -static int ovs_ct_nat_execute(struct sk_buff *skb, struct nf_conn *ct, - enum ip_conntrack_info ctinfo, - const struct nf_nat_range2 *range, - enum nf_nat_manip_type maniptype, struct sw_flow_key *key) -{ - int hooknum, err = NF_ACCEPT; - - /* See HOOK2MANIP(). */ - if (maniptype == NF_NAT_MANIP_SRC) - hooknum = NF_INET_LOCAL_IN; /* Source NAT */ - else - hooknum = NF_INET_LOCAL_OUT; /* Destination NAT */ - - switch (ctinfo) { - case IP_CT_RELATED: - case IP_CT_RELATED_REPLY: - if (IS_ENABLED(CONFIG_NF_NAT) && - skb->protocol == htons(ETH_P_IP) && - ip_hdr(skb)->protocol == IPPROTO_ICMP) { - if (!nf_nat_icmp_reply_translation(skb, ct, ctinfo, - hooknum)) - err = NF_DROP; - goto out; - } else if (IS_ENABLED(CONFIG_IPV6) && - skb->protocol == htons(ETH_P_IPV6)) { - __be16 frag_off; - u8 nexthdr = ipv6_hdr(skb)->nexthdr; - int hdrlen = ipv6_skip_exthdr(skb, - sizeof(struct ipv6hdr), - &nexthdr, &frag_off); - - if (hdrlen >= 0 && nexthdr == IPPROTO_ICMPV6) { - if (!nf_nat_icmpv6_reply_translation(skb, ct, - ctinfo, - hooknum, - hdrlen)) - err = NF_DROP; - goto out; - } - } - /* Non-ICMP, fall thru to initialize if needed. */ - fallthrough; - case IP_CT_NEW: - /* Seen it before? This can happen for loopback, retrans, - * or local packets. - */ - if (!nf_nat_initialized(ct, maniptype)) { - /* Initialize according to the NAT action. */ - err = (range && range->flags & NF_NAT_RANGE_MAP_IPS) - /* Action is set up to establish a new - * mapping. - */ - ? nf_nat_setup_info(ct, range, maniptype) - : nf_nat_alloc_null_binding(ct, hooknum); - if (err != NF_ACCEPT) - goto out; - } - break; - - case IP_CT_ESTABLISHED: - case IP_CT_ESTABLISHED_REPLY: - break; - - default: - err = NF_DROP; - goto out; - } - - err = nf_nat_packet(ct, ctinfo, hooknum, skb); -out: - /* Update the flow key if NAT successful. */ - if (err == NF_ACCEPT) - ovs_nat_update_key(key, skb, maniptype); - - return err; -} - /* Returns NF_DROP if the packet should be dropped, NF_ACCEPT otherwise. */ static int ovs_ct_nat(struct net *net, struct sw_flow_key *key, const struct ovs_conntrack_info *info, struct sk_buff *skb, struct nf_conn *ct, enum ip_conntrack_info ctinfo) { - enum nf_nat_manip_type maniptype; - int err; + int err, action = 0; if (!(info->nat & OVS_CT_NAT)) return NF_ACCEPT; + if (info->nat & OVS_CT_SRC_NAT) + action |= BIT(NF_NAT_MANIP_SRC); + if (info->nat & OVS_CT_DST_NAT) + action |= BIT(NF_NAT_MANIP_DST); - /* Add NAT extension if not confirmed yet. */ - if (!nf_ct_is_confirmed(ct) && !nf_ct_nat_ext_add(ct)) - return NF_DROP; /* Can't NAT. */ + err = nf_ct_nat(skb, ct, ctinfo, &action, &info->range, info->commit); - /* Determine NAT type. - * Check if the NAT type can be deduced from the tracked connection. - * Make sure new expected connections (IP_CT_RELATED) are NATted only - * when committing. - */ - if (ctinfo != IP_CT_NEW && ct->status & IPS_NAT_MASK && - (ctinfo != IP_CT_RELATED || info->commit)) { - /* NAT an established or related connection like before. */ - if (CTINFO2DIR(ctinfo) == IP_CT_DIR_REPLY) - /* This is the REPLY direction for a connection - * for which NAT was applied in the forward - * direction. Do the reverse NAT. - */ - maniptype = ct->status & IPS_SRC_NAT - ? NF_NAT_MANIP_DST : NF_NAT_MANIP_SRC; - else - maniptype = ct->status & IPS_SRC_NAT - ? NF_NAT_MANIP_SRC : NF_NAT_MANIP_DST; - } else if (info->nat & OVS_CT_SRC_NAT) { - maniptype = NF_NAT_MANIP_SRC; - } else if (info->nat & OVS_CT_DST_NAT) { - maniptype = NF_NAT_MANIP_DST; - } else { - return NF_ACCEPT; /* Connection is not NATed. */ - } - err = ovs_ct_nat_execute(skb, ct, ctinfo, &info->range, maniptype, key); - - if (err == NF_ACCEPT && ct->status & IPS_DST_NAT) { - if (ct->status & IPS_SRC_NAT) { - if (maniptype == NF_NAT_MANIP_SRC) - maniptype = NF_NAT_MANIP_DST; - else - maniptype = NF_NAT_MANIP_SRC; - - err = ovs_ct_nat_execute(skb, ct, ctinfo, &info->range, - maniptype, key); - } else if (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL) { - err = ovs_ct_nat_execute(skb, ct, ctinfo, NULL, - NF_NAT_MANIP_SRC, key); - } - } + if (action & BIT(NF_NAT_MANIP_SRC)) + ovs_nat_update_key(key, skb, NF_NAT_MANIP_SRC); + if (action & BIT(NF_NAT_MANIP_DST)) + ovs_nat_update_key(key, skb, NF_NAT_MANIP_DST); return err; } diff --git a/net/sched/Kconfig b/net/sched/Kconfig index 4662a6ce8a7e..777d6b50505c 100644 --- a/net/sched/Kconfig +++ b/net/sched/Kconfig @@ -977,6 +977,7 @@ config NET_ACT_TUNNEL_KEY config NET_ACT_CT tristate "connection tracking tc action" depends on NET_CLS_ACT && NF_CONNTRACK && (!NF_NAT || NF_NAT) && NF_FLOW_TABLE + select NF_NAT_OVS if NF_NAT help Say Y here to allow sending the packets to conntrack module. diff --git a/net/sched/act_ct.c b/net/sched/act_ct.c index eac4e07eb56b..0ca2bb8ed026 100644 --- a/net/sched/act_ct.c +++ b/net/sched/act_ct.c @@ -864,90 +864,6 @@ static void tcf_ct_params_free_rcu(struct rcu_head *head) tcf_ct_params_free(params); } -#if IS_ENABLED(CONFIG_NF_NAT) -/* Modelled after nf_nat_ipv[46]_fn(). - * range is only used for new, uninitialized NAT state. - * Returns either NF_ACCEPT or NF_DROP. - */ -static int ct_nat_execute(struct sk_buff *skb, struct nf_conn *ct, - enum ip_conntrack_info ctinfo, - const struct nf_nat_range2 *range, - enum nf_nat_manip_type maniptype) -{ - __be16 proto = skb_protocol(skb, true); - int hooknum, err = NF_ACCEPT; - - /* See HOOK2MANIP(). */ - if (maniptype == NF_NAT_MANIP_SRC) - hooknum = NF_INET_LOCAL_IN; /* Source NAT */ - else - hooknum = NF_INET_LOCAL_OUT; /* Destination NAT */ - - switch (ctinfo) { - case IP_CT_RELATED: - case IP_CT_RELATED_REPLY: - if (proto == htons(ETH_P_IP) && - ip_hdr(skb)->protocol == IPPROTO_ICMP) { - if (!nf_nat_icmp_reply_translation(skb, ct, ctinfo, - hooknum)) - err = NF_DROP; - goto out; - } else if (IS_ENABLED(CONFIG_IPV6) && proto == htons(ETH_P_IPV6)) { - __be16 frag_off; - u8 nexthdr = ipv6_hdr(skb)->nexthdr; - int hdrlen = ipv6_skip_exthdr(skb, - sizeof(struct ipv6hdr), - &nexthdr, &frag_off); - - if (hdrlen >= 0 && nexthdr == IPPROTO_ICMPV6) { - if (!nf_nat_icmpv6_reply_translation(skb, ct, - ctinfo, - hooknum, - hdrlen)) - err = NF_DROP; - goto out; - } - } - /* Non-ICMP, fall thru to initialize if needed. */ - fallthrough; - case IP_CT_NEW: - /* Seen it before? This can happen for loopback, retrans, - * or local packets. - */ - if (!nf_nat_initialized(ct, maniptype)) { - /* Initialize according to the NAT action. */ - err = (range && range->flags & NF_NAT_RANGE_MAP_IPS) - /* Action is set up to establish a new - * mapping. - */ - ? nf_nat_setup_info(ct, range, maniptype) - : nf_nat_alloc_null_binding(ct, hooknum); - if (err != NF_ACCEPT) - goto out; - } - break; - - case IP_CT_ESTABLISHED: - case IP_CT_ESTABLISHED_REPLY: - break; - - default: - err = NF_DROP; - goto out; - } - - err = nf_nat_packet(ct, ctinfo, hooknum, skb); -out: - if (err == NF_ACCEPT) { - if (maniptype == NF_NAT_MANIP_SRC) - tc_skb_cb(skb)->post_ct_snat = 1; - if (maniptype == NF_NAT_MANIP_DST) - tc_skb_cb(skb)->post_ct_dnat = 1; - } - return err; -} -#endif /* CONFIG_NF_NAT */ - static void tcf_ct_act_set_mark(struct nf_conn *ct, u32 mark, u32 mask) { #if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) @@ -987,52 +903,22 @@ static int tcf_ct_act_nat(struct sk_buff *skb, bool commit) { #if IS_ENABLED(CONFIG_NF_NAT) - int err; - enum nf_nat_manip_type maniptype; + int err, action = 0; if (!(ct_action & TCA_CT_ACT_NAT)) return NF_ACCEPT; + if (ct_action & TCA_CT_ACT_NAT_SRC) + action |= BIT(NF_NAT_MANIP_SRC); + if (ct_action & TCA_CT_ACT_NAT_DST) + action |= BIT(NF_NAT_MANIP_DST); - /* Add NAT extension if not confirmed yet. */ - if (!nf_ct_is_confirmed(ct) && !nf_ct_nat_ext_add(ct)) - return NF_DROP; /* Can't NAT. */ + err = nf_ct_nat(skb, ct, ctinfo, &action, range, commit); - if (ctinfo != IP_CT_NEW && (ct->status & IPS_NAT_MASK) && - (ctinfo != IP_CT_RELATED || commit)) { - /* NAT an established or related connection like before. */ - if (CTINFO2DIR(ctinfo) == IP_CT_DIR_REPLY) - /* This is the REPLY direction for a connection - * for which NAT was applied in the forward - * direction. Do the reverse NAT. - */ - maniptype = ct->status & IPS_SRC_NAT - ? NF_NAT_MANIP_DST : NF_NAT_MANIP_SRC; - else - maniptype = ct->status & IPS_SRC_NAT - ? NF_NAT_MANIP_SRC : NF_NAT_MANIP_DST; - } else if (ct_action & TCA_CT_ACT_NAT_SRC) { - maniptype = NF_NAT_MANIP_SRC; - } else if (ct_action & TCA_CT_ACT_NAT_DST) { - maniptype = NF_NAT_MANIP_DST; - } else { - return NF_ACCEPT; - } + if (action & BIT(NF_NAT_MANIP_SRC)) + tc_skb_cb(skb)->post_ct_snat = 1; + if (action & BIT(NF_NAT_MANIP_DST)) + tc_skb_cb(skb)->post_ct_dnat = 1; - err = ct_nat_execute(skb, ct, ctinfo, range, maniptype); - if (err == NF_ACCEPT && ct->status & IPS_DST_NAT) { - if (ct->status & IPS_SRC_NAT) { - if (maniptype == NF_NAT_MANIP_SRC) - maniptype = NF_NAT_MANIP_DST; - else - maniptype = NF_NAT_MANIP_SRC; - - err = ct_nat_execute(skb, ct, ctinfo, range, - maniptype); - } else if (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL) { - err = ct_nat_execute(skb, ct, ctinfo, NULL, - NF_NAT_MANIP_SRC); - } - } return err; #else return NF_ACCEPT;