// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB /* - * net/sched/act_ct.c Connection Tracking action * * Authors: Paul Blakey * Yossi Kuperman * Marcelo Ricardo Leitner */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include static struct workqueue_struct *act_ct_wq; static struct rhashtable zones_ht; static DEFINE_MUTEX(zones_mutex); struct tcf_ct_flow_table { struct rhash_head node; /* In zones tables */ struct rcu_work rwork; struct nf_flowtable nf_ft; refcount_t ref; u16 zone; bool dying; }; static const struct rhashtable_params zones_params = { .head_offset = offsetof(struct tcf_ct_flow_table, node), .key_offset = offsetof(struct tcf_ct_flow_table, zone), .key_len = sizeof_field(struct tcf_ct_flow_table, zone), .automatic_shrinking = true, }; static struct flow_action_entry * tcf_ct_flow_table_flow_action_get_next(struct flow_action *flow_action) { int i = flow_action->num_entries++; return &flow_action->entries[i]; } static void tcf_ct_add_mangle_action(struct flow_action *action, enum flow_action_mangle_base htype, u32 offset, u32 mask, u32 val) { struct flow_action_entry *entry; entry = tcf_ct_flow_table_flow_action_get_next(action); entry->id = FLOW_ACTION_MANGLE; entry->mangle.htype = htype; entry->mangle.mask = ~mask; entry->mangle.offset = offset; entry->mangle.val = val; } /* The following nat helper functions check if the inverted reverse tuple * (target) is different then the current dir tuple - meaning nat for ports * and/or ip is needed, and add the relevant mangle actions. */ static void tcf_ct_flow_table_add_action_nat_ipv4(const struct nf_conntrack_tuple *tuple, struct nf_conntrack_tuple target, struct flow_action *action) { if (memcmp(&target.src.u3, &tuple->src.u3, sizeof(target.src.u3))) tcf_ct_add_mangle_action(action, FLOW_ACT_MANGLE_HDR_TYPE_IP4, offsetof(struct iphdr, saddr), 0xFFFFFFFF, be32_to_cpu(target.src.u3.ip)); if (memcmp(&target.dst.u3, &tuple->dst.u3, sizeof(target.dst.u3))) tcf_ct_add_mangle_action(action, FLOW_ACT_MANGLE_HDR_TYPE_IP4, offsetof(struct iphdr, daddr), 0xFFFFFFFF, be32_to_cpu(target.dst.u3.ip)); } static void tcf_ct_add_ipv6_addr_mangle_action(struct flow_action *action, union nf_inet_addr *addr, u32 offset) { int i; for (i = 0; i < sizeof(struct in6_addr) / sizeof(u32); i++) tcf_ct_add_mangle_action(action, FLOW_ACT_MANGLE_HDR_TYPE_IP6, i * sizeof(u32) + offset, 0xFFFFFFFF, be32_to_cpu(addr->ip6[i])); } static void tcf_ct_flow_table_add_action_nat_ipv6(const struct nf_conntrack_tuple *tuple, struct nf_conntrack_tuple target, struct flow_action *action) { if (memcmp(&target.src.u3, &tuple->src.u3, sizeof(target.src.u3))) tcf_ct_add_ipv6_addr_mangle_action(action, &target.src.u3, offsetof(struct ipv6hdr, saddr)); if (memcmp(&target.dst.u3, &tuple->dst.u3, sizeof(target.dst.u3))) tcf_ct_add_ipv6_addr_mangle_action(action, &target.dst.u3, offsetof(struct ipv6hdr, daddr)); } static void tcf_ct_flow_table_add_action_nat_tcp(const struct nf_conntrack_tuple *tuple, struct nf_conntrack_tuple target, struct flow_action *action) { __be16 target_src = target.src.u.tcp.port; __be16 target_dst = target.dst.u.tcp.port; if (target_src != tuple->src.u.tcp.port) tcf_ct_add_mangle_action(action, FLOW_ACT_MANGLE_HDR_TYPE_TCP, offsetof(struct tcphdr, source), 0xFFFF, be16_to_cpu(target_src)); if (target_dst != tuple->dst.u.tcp.port) tcf_ct_add_mangle_action(action, FLOW_ACT_MANGLE_HDR_TYPE_TCP, offsetof(struct tcphdr, dest), 0xFFFF, be16_to_cpu(target_dst)); } static void tcf_ct_flow_table_add_action_nat_udp(const struct nf_conntrack_tuple *tuple, struct nf_conntrack_tuple target, struct flow_action *action) { __be16 target_src = target.src.u.udp.port; __be16 target_dst = target.dst.u.udp.port; if (target_src != tuple->src.u.udp.port) tcf_ct_add_mangle_action(action, FLOW_ACT_MANGLE_HDR_TYPE_UDP, offsetof(struct udphdr, source), 0xFFFF, be16_to_cpu(target_src)); if (target_dst != tuple->dst.u.udp.port) tcf_ct_add_mangle_action(action, FLOW_ACT_MANGLE_HDR_TYPE_UDP, offsetof(struct udphdr, dest), 0xFFFF, be16_to_cpu(target_dst)); } static void tcf_ct_flow_table_add_action_meta(struct nf_conn *ct, enum ip_conntrack_dir dir, struct flow_action *action) { struct nf_conn_labels *ct_labels; struct flow_action_entry *entry; enum ip_conntrack_info ctinfo; u32 *act_ct_labels; entry = tcf_ct_flow_table_flow_action_get_next(action); entry->id = FLOW_ACTION_CT_METADATA; #if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) entry->ct_metadata.mark = READ_ONCE(ct->mark); #endif ctinfo = dir == IP_CT_DIR_ORIGINAL ? IP_CT_ESTABLISHED : IP_CT_ESTABLISHED_REPLY; /* aligns with the CT reference on the SKB nf_ct_set */ entry->ct_metadata.cookie = (unsigned long)ct | ctinfo; entry->ct_metadata.orig_dir = dir == IP_CT_DIR_ORIGINAL; act_ct_labels = entry->ct_metadata.labels; ct_labels = nf_ct_labels_find(ct); if (ct_labels) memcpy(act_ct_labels, ct_labels->bits, NF_CT_LABELS_MAX_SIZE); else memset(act_ct_labels, 0, NF_CT_LABELS_MAX_SIZE); } static int tcf_ct_flow_table_add_action_nat(struct net *net, struct nf_conn *ct, enum ip_conntrack_dir dir, struct flow_action *action) { const struct nf_conntrack_tuple *tuple = &ct->tuplehash[dir].tuple; struct nf_conntrack_tuple target; if (!(ct->status & IPS_NAT_MASK)) return 0; nf_ct_invert_tuple(&target, &ct->tuplehash[!dir].tuple); switch (tuple->src.l3num) { case NFPROTO_IPV4: tcf_ct_flow_table_add_action_nat_ipv4(tuple, target, action); break; case NFPROTO_IPV6: tcf_ct_flow_table_add_action_nat_ipv6(tuple, target, action); break; default: return -EOPNOTSUPP; } switch (nf_ct_protonum(ct)) { case IPPROTO_TCP: tcf_ct_flow_table_add_action_nat_tcp(tuple, target, action); break; case IPPROTO_UDP: tcf_ct_flow_table_add_action_nat_udp(tuple, target, action); break; default: return -EOPNOTSUPP; } return 0; } static int tcf_ct_flow_table_fill_actions(struct net *net, const struct flow_offload *flow, enum flow_offload_tuple_dir tdir, struct nf_flow_rule *flow_rule) { struct flow_action *action = &flow_rule->rule->action; int num_entries = action->num_entries; struct nf_conn *ct = flow->ct; enum ip_conntrack_dir dir; int i, err; switch (tdir) { case FLOW_OFFLOAD_DIR_ORIGINAL: dir = IP_CT_DIR_ORIGINAL; break; case FLOW_OFFLOAD_DIR_REPLY: dir = IP_CT_DIR_REPLY; break; default: return -EOPNOTSUPP; } err = tcf_ct_flow_table_add_action_nat(net, ct, dir, action); if (err) goto err_nat; tcf_ct_flow_table_add_action_meta(ct, dir, action); return 0; err_nat: /* Clear filled actions */ for (i = num_entries; i < action->num_entries; i++) memset(&action->entries[i], 0, sizeof(action->entries[i])); action->num_entries = num_entries; return err; } static struct nf_flowtable_type flowtable_ct = { .action = tcf_ct_flow_table_fill_actions, .owner = THIS_MODULE, }; static int tcf_ct_flow_table_get(struct tcf_ct_params *params) { struct tcf_ct_flow_table *ct_ft; int err = -ENOMEM; mutex_lock(&zones_mutex); ct_ft = rhashtable_lookup_fast(&zones_ht, ¶ms->zone, zones_params); if (ct_ft && refcount_inc_not_zero(&ct_ft->ref)) goto out_unlock; ct_ft = kzalloc(sizeof(*ct_ft), GFP_KERNEL); if (!ct_ft) goto err_alloc; refcount_set(&ct_ft->ref, 1); ct_ft->zone = params->zone; err = rhashtable_insert_fast(&zones_ht, &ct_ft->node, zones_params); if (err) goto err_insert; ct_ft->nf_ft.type = &flowtable_ct; ct_ft->nf_ft.flags |= NF_FLOWTABLE_HW_OFFLOAD | NF_FLOWTABLE_COUNTER; err = nf_flow_table_init(&ct_ft->nf_ft); if (err) goto err_init; __module_get(THIS_MODULE); out_unlock: params->ct_ft = ct_ft; params->nf_ft = &ct_ft->nf_ft; mutex_unlock(&zones_mutex); return 0; err_init: rhashtable_remove_fast(&zones_ht, &ct_ft->node, zones_params); err_insert: kfree(ct_ft); err_alloc: mutex_unlock(&zones_mutex); return err; } static void tcf_ct_flow_table_cleanup_work(struct work_struct *work) { struct flow_block_cb *block_cb, *tmp_cb; struct tcf_ct_flow_table *ct_ft; struct flow_block *block; ct_ft = container_of(to_rcu_work(work), struct tcf_ct_flow_table, rwork); nf_flow_table_free(&ct_ft->nf_ft); /* Remove any remaining callbacks before cleanup */ block = &ct_ft->nf_ft.flow_block; down_write(&ct_ft->nf_ft.flow_block_lock); list_for_each_entry_safe(block_cb, tmp_cb, &block->cb_list, list) { list_del(&block_cb->list); flow_block_cb_free(block_cb); } up_write(&ct_ft->nf_ft.flow_block_lock); kfree(ct_ft); module_put(THIS_MODULE); } static void tcf_ct_flow_table_put(struct tcf_ct_params *params) { struct tcf_ct_flow_table *ct_ft = params->ct_ft; if (refcount_dec_and_test(¶ms->ct_ft->ref)) { rhashtable_remove_fast(&zones_ht, &ct_ft->node, zones_params); INIT_RCU_WORK(&ct_ft->rwork, tcf_ct_flow_table_cleanup_work); queue_rcu_work(act_ct_wq, &ct_ft->rwork); } } static void tcf_ct_flow_table_add(struct tcf_ct_flow_table *ct_ft, struct nf_conn *ct, bool tcp) { struct flow_offload *entry; int err; if (test_and_set_bit(IPS_OFFLOAD_BIT, &ct->status)) return; entry = flow_offload_alloc(ct); if (!entry) { WARN_ON_ONCE(1); goto err_alloc; } if (tcp) { ct->proto.tcp.seen[0].flags |= IP_CT_TCP_FLAG_BE_LIBERAL; ct->proto.tcp.seen[1].flags |= IP_CT_TCP_FLAG_BE_LIBERAL; } err = flow_offload_add(&ct_ft->nf_ft, entry); if (err) goto err_add; return; err_add: flow_offload_free(entry); err_alloc: clear_bit(IPS_OFFLOAD_BIT, &ct->status); } static void tcf_ct_flow_table_process_conn(struct tcf_ct_flow_table *ct_ft, struct nf_conn *ct, enum ip_conntrack_info ctinfo) { bool tcp = false; if (ctinfo != IP_CT_ESTABLISHED && ctinfo != IP_CT_ESTABLISHED_REPLY) return; switch (nf_ct_protonum(ct)) { case IPPROTO_TCP: tcp = true; if (ct->proto.tcp.state != TCP_CONNTRACK_ESTABLISHED) return; break; case IPPROTO_UDP: break; default: return; } if (nf_ct_ext_exist(ct, NF_CT_EXT_HELPER) || ct->status & IPS_SEQ_ADJUST) return; tcf_ct_flow_table_add(ct_ft, ct, tcp); } static bool tcf_ct_flow_table_fill_tuple_ipv4(struct sk_buff *skb, struct flow_offload_tuple *tuple, struct tcphdr **tcph) { struct flow_ports *ports; unsigned int thoff; struct iphdr *iph; if (!pskb_network_may_pull(skb, sizeof(*iph))) return false; iph = ip_hdr(skb); thoff = iph->ihl * 4; if (ip_is_fragment(iph) || unlikely(thoff != sizeof(struct iphdr))) return false; if (iph->protocol != IPPROTO_TCP && iph->protocol != IPPROTO_UDP) return false; if (iph->ttl <= 1) return false; if (!pskb_network_may_pull(skb, iph->protocol == IPPROTO_TCP ? thoff + sizeof(struct tcphdr) : thoff + sizeof(*ports))) return false; iph = ip_hdr(skb); if (iph->protocol == IPPROTO_TCP) *tcph = (void *)(skb_network_header(skb) + thoff); ports = (struct flow_ports *)(skb_network_header(skb) + thoff); tuple->src_v4.s_addr = iph->saddr; tuple->dst_v4.s_addr = iph->daddr; tuple->src_port = ports->source; tuple->dst_port = ports->dest; tuple->l3proto = AF_INET; tuple->l4proto = iph->protocol; return true; } static bool tcf_ct_flow_table_fill_tuple_ipv6(struct sk_buff *skb, struct flow_offload_tuple *tuple, struct tcphdr **tcph) { struct flow_ports *ports; struct ipv6hdr *ip6h; unsigned int thoff; if (!pskb_network_may_pull(skb, sizeof(*ip6h))) return false; ip6h = ipv6_hdr(skb); if (ip6h->nexthdr != IPPROTO_TCP && ip6h->nexthdr != IPPROTO_UDP) return false; if (ip6h->hop_limit <= 1) return false; thoff = sizeof(*ip6h); if (!pskb_network_may_pull(skb, ip6h->nexthdr == IPPROTO_TCP ? thoff + sizeof(struct tcphdr) : thoff + sizeof(*ports))) return false; ip6h = ipv6_hdr(skb); if (ip6h->nexthdr == IPPROTO_TCP) *tcph = (void *)(skb_network_header(skb) + thoff); ports = (struct flow_ports *)(skb_network_header(skb) + thoff); tuple->src_v6 = ip6h->saddr; tuple->dst_v6 = ip6h->daddr; tuple->src_port = ports->source; tuple->dst_port = ports->dest; tuple->l3proto = AF_INET6; tuple->l4proto = ip6h->nexthdr; return true; } static bool tcf_ct_flow_table_lookup(struct tcf_ct_params *p, struct sk_buff *skb, u8 family) { struct nf_flowtable *nf_ft = &p->ct_ft->nf_ft; struct flow_offload_tuple_rhash *tuplehash; struct flow_offload_tuple tuple = {}; enum ip_conntrack_info ctinfo; struct tcphdr *tcph = NULL; struct flow_offload *flow; struct nf_conn *ct; u8 dir; switch (family) { case NFPROTO_IPV4: if (!tcf_ct_flow_table_fill_tuple_ipv4(skb, &tuple, &tcph)) return false; break; case NFPROTO_IPV6: if (!tcf_ct_flow_table_fill_tuple_ipv6(skb, &tuple, &tcph)) return false; break; default: return false; } tuplehash = flow_offload_lookup(nf_ft, &tuple); if (!tuplehash) return false; dir = tuplehash->tuple.dir; flow = container_of(tuplehash, struct flow_offload, tuplehash[dir]); ct = flow->ct; if (tcph && (unlikely(tcph->fin || tcph->rst))) { flow_offload_teardown(flow); return false; } ctinfo = dir == FLOW_OFFLOAD_DIR_ORIGINAL ? IP_CT_ESTABLISHED : IP_CT_ESTABLISHED_REPLY; flow_offload_refresh(nf_ft, flow); nf_conntrack_get(&ct->ct_general); nf_ct_set(skb, ct, ctinfo); if (nf_ft->flags & NF_FLOWTABLE_COUNTER) nf_ct_acct_update(ct, dir, skb->len); return true; } static int tcf_ct_flow_tables_init(void) { return rhashtable_init(&zones_ht, &zones_params); } static void tcf_ct_flow_tables_uninit(void) { rhashtable_destroy(&zones_ht); } static struct tc_action_ops act_ct_ops; static unsigned int ct_net_id; struct tc_ct_action_net { struct tc_action_net tn; /* Must be first */ bool labels; }; /* Determine whether skb->_nfct is equal to the result of conntrack lookup. */ static bool tcf_ct_skb_nfct_cached(struct net *net, struct sk_buff *skb, u16 zone_id, bool force) { enum ip_conntrack_info ctinfo; struct nf_conn *ct; ct = nf_ct_get(skb, &ctinfo); if (!ct) return false; if (!net_eq(net, read_pnet(&ct->ct_net))) goto drop_ct; if (nf_ct_zone(ct)->id != zone_id) goto drop_ct; /* Force conntrack entry direction. */ if (force && CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL) { if (nf_ct_is_confirmed(ct)) nf_ct_kill(ct); goto drop_ct; } return true; drop_ct: nf_ct_put(ct); nf_ct_set(skb, NULL, IP_CT_UNTRACKED); return false; } /* Trim the skb to the length specified by the IP/IPv6 header, * removing any trailing lower-layer padding. This prepares the skb * for higher-layer processing that assumes skb->len excludes padding * (such as nf_ip_checksum). The caller needs to pull the skb to the * network header, and ensure ip_hdr/ipv6_hdr points to valid data. */ static int tcf_ct_skb_network_trim(struct sk_buff *skb, int family) { unsigned int len; int err; switch (family) { case NFPROTO_IPV4: len = ntohs(ip_hdr(skb)->tot_len); break; case NFPROTO_IPV6: len = sizeof(struct ipv6hdr) + ntohs(ipv6_hdr(skb)->payload_len); break; default: len = skb->len; } err = pskb_trim_rcsum(skb, len); return err; } static u8 tcf_ct_skb_nf_family(struct sk_buff *skb) { u8 family = NFPROTO_UNSPEC; switch (skb_protocol(skb, true)) { case htons(ETH_P_IP): family = NFPROTO_IPV4; break; case htons(ETH_P_IPV6): family = NFPROTO_IPV6; break; default: break; } return family; } static int tcf_ct_ipv4_is_fragment(struct sk_buff *skb, bool *frag) { unsigned int len; len = skb_network_offset(skb) + sizeof(struct iphdr); if (unlikely(skb->len < len)) return -EINVAL; if (unlikely(!pskb_may_pull(skb, len))) return -ENOMEM; *frag = ip_is_fragment(ip_hdr(skb)); return 0; } static int tcf_ct_ipv6_is_fragment(struct sk_buff *skb, bool *frag) { unsigned int flags = 0, len, payload_ofs = 0; unsigned short frag_off; int nexthdr; len = skb_network_offset(skb) + sizeof(struct ipv6hdr); if (unlikely(skb->len < len)) return -EINVAL; if (unlikely(!pskb_may_pull(skb, len))) return -ENOMEM; nexthdr = ipv6_find_hdr(skb, &payload_ofs, -1, &frag_off, &flags); if (unlikely(nexthdr < 0)) return -EPROTO; *frag = flags & IP6_FH_F_FRAG; return 0; } static int tcf_ct_handle_fragments(struct net *net, struct sk_buff *skb, u8 family, u16 zone, bool *defrag) { enum ip_conntrack_info ctinfo; struct nf_conn *ct; int err = 0; bool frag; u16 mru; /* Previously seen (loopback)? Ignore. */ ct = nf_ct_get(skb, &ctinfo); if ((ct && !nf_ct_is_template(ct)) || ctinfo == IP_CT_UNTRACKED) return 0; if (family == NFPROTO_IPV4) err = tcf_ct_ipv4_is_fragment(skb, &frag); else err = tcf_ct_ipv6_is_fragment(skb, &frag); if (err || !frag) return err; mru = tc_skb_cb(skb)->mru; if (family == NFPROTO_IPV4) { enum ip_defrag_users user = IP_DEFRAG_CONNTRACK_IN + zone; memset(IPCB(skb), 0, sizeof(struct inet_skb_parm)); local_bh_disable(); err = ip_defrag(net, skb, user); local_bh_enable(); if (err && err != -EINPROGRESS) return err; if (!err) { *defrag = true; mru = IPCB(skb)->frag_max_size; } } else { /* NFPROTO_IPV6 */ #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6) enum ip6_defrag_users user = IP6_DEFRAG_CONNTRACK_IN + zone; memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm)); err = nf_ct_frag6_gather(net, skb, user); if (err && err != -EINPROGRESS) goto out_free; if (!err) { *defrag = true; mru = IP6CB(skb)->frag_max_size; } #else err = -EOPNOTSUPP; goto out_free; #endif } if (err != -EINPROGRESS) tc_skb_cb(skb)->mru = mru; skb_clear_hash(skb); skb->ignore_df = 1; return err; out_free: kfree_skb(skb); return err; } static void tcf_ct_params_free(struct rcu_head *head) { struct tcf_ct_params *params = container_of(head, struct tcf_ct_params, rcu); tcf_ct_flow_table_put(params); if (params->tmpl) nf_ct_put(params->tmpl); kfree(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); 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; } out: 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) u32 new_mark; if (!mask) return; new_mark = mark | (READ_ONCE(ct->mark) & ~(mask)); if (READ_ONCE(ct->mark) != new_mark) { WRITE_ONCE(ct->mark, new_mark); if (nf_ct_is_confirmed(ct)) nf_conntrack_event_cache(IPCT_MARK, ct); } #endif } static void tcf_ct_act_set_labels(struct nf_conn *ct, u32 *labels, u32 *labels_m) { #if IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) size_t labels_sz = sizeof_field(struct tcf_ct_params, labels); if (!memchr_inv(labels_m, 0, labels_sz)) return; nf_connlabels_replace(ct, labels, labels_m, 4); #endif } static int tcf_ct_act_nat(struct sk_buff *skb, struct nf_conn *ct, enum ip_conntrack_info ctinfo, int ct_action, struct nf_nat_range2 *range, bool commit) { #if IS_ENABLED(CONFIG_NF_NAT) int err; enum nf_nat_manip_type maniptype; if (!(ct_action & TCA_CT_ACT_NAT)) return NF_ACCEPT; /* 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 & 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; } 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; #endif } static int tcf_ct_act(struct sk_buff *skb, const struct tc_action *a, struct tcf_result *res) { struct net *net = dev_net(skb->dev); bool cached, commit, clear, force; enum ip_conntrack_info ctinfo; struct tcf_ct *c = to_ct(a); struct nf_conn *tmpl = NULL; struct nf_hook_state state; int nh_ofs, err, retval; struct tcf_ct_params *p; bool skip_add = false; bool defrag = false; struct nf_conn *ct; u8 family; p = rcu_dereference_bh(c->params); retval = READ_ONCE(c->tcf_action); commit = p->ct_action & TCA_CT_ACT_COMMIT; clear = p->ct_action & TCA_CT_ACT_CLEAR; force = p->ct_action & TCA_CT_ACT_FORCE; tmpl = p->tmpl; tcf_lastuse_update(&c->tcf_tm); tcf_action_update_bstats(&c->common, skb); if (clear) { tc_skb_cb(skb)->post_ct = false; ct = nf_ct_get(skb, &ctinfo); if (ct) { nf_ct_put(ct); nf_ct_set(skb, NULL, IP_CT_UNTRACKED); } goto out_clear; } family = tcf_ct_skb_nf_family(skb); if (family == NFPROTO_UNSPEC) goto drop; /* The conntrack module expects to be working at L3. * We also try to pull the IPv4/6 header to linear area */ nh_ofs = skb_network_offset(skb); skb_pull_rcsum(skb, nh_ofs); err = tcf_ct_handle_fragments(net, skb, family, p->zone, &defrag); if (err) goto out_frag; err = tcf_ct_skb_network_trim(skb, family); if (err) goto drop; /* If we are recirculating packets to match on ct fields and * committing with a separate ct action, then we don't need to * actually run the packet through conntrack twice unless it's for a * different zone. */ cached = tcf_ct_skb_nfct_cached(net, skb, p->zone, force); if (!cached) { if (tcf_ct_flow_table_lookup(p, skb, family)) { skip_add = true; goto do_nat; } /* Associate skb with specified zone. */ if (tmpl) { nf_conntrack_put(skb_nfct(skb)); nf_conntrack_get(&tmpl->ct_general); nf_ct_set(skb, tmpl, IP_CT_NEW); } state.hook = NF_INET_PRE_ROUTING; state.net = net; state.pf = family; err = nf_conntrack_in(skb, &state); if (err != NF_ACCEPT) goto out_push; } do_nat: ct = nf_ct_get(skb, &ctinfo); if (!ct) goto out_push; nf_ct_deliver_cached_events(ct); err = tcf_ct_act_nat(skb, ct, ctinfo, p->ct_action, &p->range, commit); if (err != NF_ACCEPT) goto drop; if (commit) { tcf_ct_act_set_mark(ct, p->mark, p->mark_mask); tcf_ct_act_set_labels(ct, p->labels, p->labels_mask); /* This will take care of sending queued events * even if the connection is already confirmed. */ if (nf_conntrack_confirm(skb) != NF_ACCEPT) goto drop; } if (!skip_add) tcf_ct_flow_table_process_conn(p->ct_ft, ct, ctinfo); out_push: skb_push_rcsum(skb, nh_ofs); tc_skb_cb(skb)->post_ct = true; tc_skb_cb(skb)->zone = p->zone; out_clear: if (defrag) qdisc_skb_cb(skb)->pkt_len = skb->len; return retval; out_frag: if (err != -EINPROGRESS) tcf_action_inc_drop_qstats(&c->common); return TC_ACT_CONSUMED; drop: tcf_action_inc_drop_qstats(&c->common); return TC_ACT_SHOT; } static const struct nla_policy ct_policy[TCA_CT_MAX + 1] = { [TCA_CT_ACTION] = { .type = NLA_U16 }, [TCA_CT_PARMS] = NLA_POLICY_EXACT_LEN(sizeof(struct tc_ct)), [TCA_CT_ZONE] = { .type = NLA_U16 }, [TCA_CT_MARK] = { .type = NLA_U32 }, [TCA_CT_MARK_MASK] = { .type = NLA_U32 }, [TCA_CT_LABELS] = { .type = NLA_BINARY, .len = 128 / BITS_PER_BYTE }, [TCA_CT_LABELS_MASK] = { .type = NLA_BINARY, .len = 128 / BITS_PER_BYTE }, [TCA_CT_NAT_IPV4_MIN] = { .type = NLA_U32 }, [TCA_CT_NAT_IPV4_MAX] = { .type = NLA_U32 }, [TCA_CT_NAT_IPV6_MIN] = NLA_POLICY_EXACT_LEN(sizeof(struct in6_addr)), [TCA_CT_NAT_IPV6_MAX] = NLA_POLICY_EXACT_LEN(sizeof(struct in6_addr)), [TCA_CT_NAT_PORT_MIN] = { .type = NLA_U16 }, [TCA_CT_NAT_PORT_MAX] = { .type = NLA_U16 }, }; static int tcf_ct_fill_params_nat(struct tcf_ct_params *p, struct tc_ct *parm, struct nlattr **tb, struct netlink_ext_ack *extack) { struct nf_nat_range2 *range; if (!(p->ct_action & TCA_CT_ACT_NAT)) return 0; if (!IS_ENABLED(CONFIG_NF_NAT)) { NL_SET_ERR_MSG_MOD(extack, "Netfilter nat isn't enabled in kernel"); return -EOPNOTSUPP; } if (!(p->ct_action & (TCA_CT_ACT_NAT_SRC | TCA_CT_ACT_NAT_DST))) return 0; if ((p->ct_action & TCA_CT_ACT_NAT_SRC) && (p->ct_action & TCA_CT_ACT_NAT_DST)) { NL_SET_ERR_MSG_MOD(extack, "dnat and snat can't be enabled at the same time"); return -EOPNOTSUPP; } range = &p->range; if (tb[TCA_CT_NAT_IPV4_MIN]) { struct nlattr *max_attr = tb[TCA_CT_NAT_IPV4_MAX]; p->ipv4_range = true; range->flags |= NF_NAT_RANGE_MAP_IPS; range->min_addr.ip = nla_get_in_addr(tb[TCA_CT_NAT_IPV4_MIN]); range->max_addr.ip = max_attr ? nla_get_in_addr(max_attr) : range->min_addr.ip; } else if (tb[TCA_CT_NAT_IPV6_MIN]) { struct nlattr *max_attr = tb[TCA_CT_NAT_IPV6_MAX]; p->ipv4_range = false; range->flags |= NF_NAT_RANGE_MAP_IPS; range->min_addr.in6 = nla_get_in6_addr(tb[TCA_CT_NAT_IPV6_MIN]); range->max_addr.in6 = max_attr ? nla_get_in6_addr(max_attr) : range->min_addr.in6; } if (tb[TCA_CT_NAT_PORT_MIN]) { range->flags |= NF_NAT_RANGE_PROTO_SPECIFIED; range->min_proto.all = nla_get_be16(tb[TCA_CT_NAT_PORT_MIN]); range->max_proto.all = tb[TCA_CT_NAT_PORT_MAX] ? nla_get_be16(tb[TCA_CT_NAT_PORT_MAX]) : range->min_proto.all; } return 0; } static void tcf_ct_set_key_val(struct nlattr **tb, void *val, int val_type, void *mask, int mask_type, int len) { if (!tb[val_type]) return; nla_memcpy(val, tb[val_type], len); if (!mask) return; if (mask_type == TCA_CT_UNSPEC || !tb[mask_type]) memset(mask, 0xff, len); else nla_memcpy(mask, tb[mask_type], len); } static int tcf_ct_fill_params(struct net *net, struct tcf_ct_params *p, struct tc_ct *parm, struct nlattr **tb, struct netlink_ext_ack *extack) { struct tc_ct_action_net *tn = net_generic(net, ct_net_id); struct nf_conntrack_zone zone; struct nf_conn *tmpl; int err; p->zone = NF_CT_DEFAULT_ZONE_ID; tcf_ct_set_key_val(tb, &p->ct_action, TCA_CT_ACTION, NULL, TCA_CT_UNSPEC, sizeof(p->ct_action)); if (p->ct_action & TCA_CT_ACT_CLEAR) return 0; err = tcf_ct_fill_params_nat(p, parm, tb, extack); if (err) return err; if (tb[TCA_CT_MARK]) { if (!IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)) { NL_SET_ERR_MSG_MOD(extack, "Conntrack mark isn't enabled."); return -EOPNOTSUPP; } tcf_ct_set_key_val(tb, &p->mark, TCA_CT_MARK, &p->mark_mask, TCA_CT_MARK_MASK, sizeof(p->mark)); } if (tb[TCA_CT_LABELS]) { if (!IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS)) { NL_SET_ERR_MSG_MOD(extack, "Conntrack labels isn't enabled."); return -EOPNOTSUPP; } if (!tn->labels) { NL_SET_ERR_MSG_MOD(extack, "Failed to set connlabel length"); return -EOPNOTSUPP; } tcf_ct_set_key_val(tb, p->labels, TCA_CT_LABELS, p->labels_mask, TCA_CT_LABELS_MASK, sizeof(p->labels)); } if (tb[TCA_CT_ZONE]) { if (!IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES)) { NL_SET_ERR_MSG_MOD(extack, "Conntrack zones isn't enabled."); return -EOPNOTSUPP; } tcf_ct_set_key_val(tb, &p->zone, TCA_CT_ZONE, NULL, TCA_CT_UNSPEC, sizeof(p->zone)); } nf_ct_zone_init(&zone, p->zone, NF_CT_DEFAULT_ZONE_DIR, 0); tmpl = nf_ct_tmpl_alloc(net, &zone, GFP_KERNEL); if (!tmpl) { NL_SET_ERR_MSG_MOD(extack, "Failed to allocate conntrack template"); return -ENOMEM; } __set_bit(IPS_CONFIRMED_BIT, &tmpl->status); p->tmpl = tmpl; return 0; } static int tcf_ct_init(struct net *net, struct nlattr *nla, struct nlattr *est, struct tc_action **a, struct tcf_proto *tp, u32 flags, struct netlink_ext_ack *extack) { struct tc_action_net *tn = net_generic(net, ct_net_id); bool bind = flags & TCA_ACT_FLAGS_BIND; struct tcf_ct_params *params = NULL; struct nlattr *tb[TCA_CT_MAX + 1]; struct tcf_chain *goto_ch = NULL; struct tc_ct *parm; struct tcf_ct *c; int err, res = 0; u32 index; if (!nla) { NL_SET_ERR_MSG_MOD(extack, "Ct requires attributes to be passed"); return -EINVAL; } err = nla_parse_nested(tb, TCA_CT_MAX, nla, ct_policy, extack); if (err < 0) return err; if (!tb[TCA_CT_PARMS]) { NL_SET_ERR_MSG_MOD(extack, "Missing required ct parameters"); return -EINVAL; } parm = nla_data(tb[TCA_CT_PARMS]); index = parm->index; err = tcf_idr_check_alloc(tn, &index, a, bind); if (err < 0) return err; if (!err) { err = tcf_idr_create_from_flags(tn, index, est, a, &act_ct_ops, bind, flags); if (err) { tcf_idr_cleanup(tn, index); return err; } res = ACT_P_CREATED; } else { if (bind) return 0; if (!(flags & TCA_ACT_FLAGS_REPLACE)) { tcf_idr_release(*a, bind); return -EEXIST; } } err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack); if (err < 0) goto cleanup; c = to_ct(*a); params = kzalloc(sizeof(*params), GFP_KERNEL); if (unlikely(!params)) { err = -ENOMEM; goto cleanup; } err = tcf_ct_fill_params(net, params, parm, tb, extack); if (err) goto cleanup; err = tcf_ct_flow_table_get(params); if (err) goto cleanup_params; spin_lock_bh(&c->tcf_lock); goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch); params = rcu_replace_pointer(c->params, params, lockdep_is_held(&c->tcf_lock)); spin_unlock_bh(&c->tcf_lock); if (goto_ch) tcf_chain_put_by_act(goto_ch); if (params) call_rcu(¶ms->rcu, tcf_ct_params_free); return res; cleanup_params: if (params->tmpl) nf_ct_put(params->tmpl); cleanup: if (goto_ch) tcf_chain_put_by_act(goto_ch); kfree(params); tcf_idr_release(*a, bind); return err; } static void tcf_ct_cleanup(struct tc_action *a) { struct tcf_ct_params *params; struct tcf_ct *c = to_ct(a); params = rcu_dereference_protected(c->params, 1); if (params) call_rcu(¶ms->rcu, tcf_ct_params_free); } static int tcf_ct_dump_key_val(struct sk_buff *skb, void *val, int val_type, void *mask, int mask_type, int len) { int err; if (mask && !memchr_inv(mask, 0, len)) return 0; err = nla_put(skb, val_type, len, val); if (err) return err; if (mask_type != TCA_CT_UNSPEC) { err = nla_put(skb, mask_type, len, mask); if (err) return err; } return 0; } static int tcf_ct_dump_nat(struct sk_buff *skb, struct tcf_ct_params *p) { struct nf_nat_range2 *range = &p->range; if (!(p->ct_action & TCA_CT_ACT_NAT)) return 0; if (!(p->ct_action & (TCA_CT_ACT_NAT_SRC | TCA_CT_ACT_NAT_DST))) return 0; if (range->flags & NF_NAT_RANGE_MAP_IPS) { if (p->ipv4_range) { if (nla_put_in_addr(skb, TCA_CT_NAT_IPV4_MIN, range->min_addr.ip)) return -1; if (nla_put_in_addr(skb, TCA_CT_NAT_IPV4_MAX, range->max_addr.ip)) return -1; } else { if (nla_put_in6_addr(skb, TCA_CT_NAT_IPV6_MIN, &range->min_addr.in6)) return -1; if (nla_put_in6_addr(skb, TCA_CT_NAT_IPV6_MAX, &range->max_addr.in6)) return -1; } } if (range->flags & NF_NAT_RANGE_PROTO_SPECIFIED) { if (nla_put_be16(skb, TCA_CT_NAT_PORT_MIN, range->min_proto.all)) return -1; if (nla_put_be16(skb, TCA_CT_NAT_PORT_MAX, range->max_proto.all)) return -1; } return 0; } static inline int tcf_ct_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref) { unsigned char *b = skb_tail_pointer(skb); struct tcf_ct *c = to_ct(a); struct tcf_ct_params *p; struct tc_ct opt = { .index = c->tcf_index, .refcnt = refcount_read(&c->tcf_refcnt) - ref, .bindcnt = atomic_read(&c->tcf_bindcnt) - bind, }; struct tcf_t t; spin_lock_bh(&c->tcf_lock); p = rcu_dereference_protected(c->params, lockdep_is_held(&c->tcf_lock)); opt.action = c->tcf_action; if (tcf_ct_dump_key_val(skb, &p->ct_action, TCA_CT_ACTION, NULL, TCA_CT_UNSPEC, sizeof(p->ct_action))) goto nla_put_failure; if (p->ct_action & TCA_CT_ACT_CLEAR) goto skip_dump; if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) && tcf_ct_dump_key_val(skb, &p->mark, TCA_CT_MARK, &p->mark_mask, TCA_CT_MARK_MASK, sizeof(p->mark))) goto nla_put_failure; if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) && tcf_ct_dump_key_val(skb, p->labels, TCA_CT_LABELS, p->labels_mask, TCA_CT_LABELS_MASK, sizeof(p->labels))) goto nla_put_failure; if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) && tcf_ct_dump_key_val(skb, &p->zone, TCA_CT_ZONE, NULL, TCA_CT_UNSPEC, sizeof(p->zone))) goto nla_put_failure; if (tcf_ct_dump_nat(skb, p)) goto nla_put_failure; skip_dump: if (nla_put(skb, TCA_CT_PARMS, sizeof(opt), &opt)) goto nla_put_failure; tcf_tm_dump(&t, &c->tcf_tm); if (nla_put_64bit(skb, TCA_CT_TM, sizeof(t), &t, TCA_CT_PAD)) goto nla_put_failure; spin_unlock_bh(&c->tcf_lock); return skb->len; nla_put_failure: spin_unlock_bh(&c->tcf_lock); nlmsg_trim(skb, b); return -1; } static int tcf_ct_walker(struct net *net, struct sk_buff *skb, struct netlink_callback *cb, int type, const struct tc_action_ops *ops, struct netlink_ext_ack *extack) { struct tc_action_net *tn = net_generic(net, ct_net_id); return tcf_generic_walker(tn, skb, cb, type, ops, extack); } static int tcf_ct_search(struct net *net, struct tc_action **a, u32 index) { struct tc_action_net *tn = net_generic(net, ct_net_id); return tcf_idr_search(tn, a, index); } static void tcf_stats_update(struct tc_action *a, u64 bytes, u64 packets, u64 drops, u64 lastuse, bool hw) { struct tcf_ct *c = to_ct(a); tcf_action_update_stats(a, bytes, packets, drops, hw); c->tcf_tm.lastuse = max_t(u64, c->tcf_tm.lastuse, lastuse); } static struct tc_action_ops act_ct_ops = { .kind = "ct", .id = TCA_ID_CT, .owner = THIS_MODULE, .act = tcf_ct_act, .dump = tcf_ct_dump, .init = tcf_ct_init, .cleanup = tcf_ct_cleanup, .walk = tcf_ct_walker, .lookup = tcf_ct_search, .stats_update = tcf_stats_update, .size = sizeof(struct tcf_ct), }; static __net_init int ct_init_net(struct net *net) { unsigned int n_bits = sizeof_field(struct tcf_ct_params, labels) * 8; struct tc_ct_action_net *tn = net_generic(net, ct_net_id); if (nf_connlabels_get(net, n_bits - 1)) { tn->labels = false; pr_err("act_ct: Failed to set connlabels length"); } else { tn->labels = true; } return tc_action_net_init(net, &tn->tn, &act_ct_ops); } static void __net_exit ct_exit_net(struct list_head *net_list) { struct net *net; rtnl_lock(); list_for_each_entry(net, net_list, exit_list) { struct tc_ct_action_net *tn = net_generic(net, ct_net_id); if (tn->labels) nf_connlabels_put(net); } rtnl_unlock(); tc_action_net_exit(net_list, ct_net_id); } static struct pernet_operations ct_net_ops = { .init = ct_init_net, .exit_batch = ct_exit_net, .id = &ct_net_id, .size = sizeof(struct tc_ct_action_net), }; static int __init ct_init_module(void) { int err; act_ct_wq = alloc_ordered_workqueue("act_ct_workqueue", 0); if (!act_ct_wq) return -ENOMEM; err = tcf_ct_flow_tables_init(); if (err) goto err_tbl_init; err = tcf_register_action(&act_ct_ops, &ct_net_ops); if (err) goto err_register; static_branch_inc(&tcf_frag_xmit_count); return 0; err_register: tcf_ct_flow_tables_uninit(); err_tbl_init: destroy_workqueue(act_ct_wq); return err; } static void __exit ct_cleanup_module(void) { static_branch_dec(&tcf_frag_xmit_count); tcf_unregister_action(&act_ct_ops, &ct_net_ops); tcf_ct_flow_tables_uninit(); destroy_workqueue(act_ct_wq); } module_init(ct_init_module); module_exit(ct_cleanup_module); MODULE_AUTHOR("Paul Blakey "); MODULE_AUTHOR("Yossi Kuperman "); MODULE_AUTHOR("Marcelo Ricardo Leitner "); MODULE_DESCRIPTION("Connection tracking action"); MODULE_LICENSE("GPL v2");