/* * This is a module which is used for queueing packets and communicating with * userspace via nfnetlink. * * (C) 2005 by Harald Welte * (C) 2007 by Patrick McHardy * * Based on the old ipv4-only ip_queue.c: * (C) 2000-2002 James Morris * (C) 2003-2005 Netfilter Core Team * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. * */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) #include "../bridge/br_private.h" #endif #if IS_ENABLED(CONFIG_NF_CONNTRACK) #include #endif #define NFQNL_QMAX_DEFAULT 1024 /* We're using struct nlattr which has 16bit nla_len. Note that nla_len * includes the header length. Thus, the maximum packet length that we * support is 65531 bytes. We send truncated packets if the specified length * is larger than that. Userspace can check for presence of NFQA_CAP_LEN * attribute to detect truncation. */ #define NFQNL_MAX_COPY_RANGE (0xffff - NLA_HDRLEN) struct nfqnl_instance { struct hlist_node hlist; /* global list of queues */ struct rcu_head rcu; u32 peer_portid; unsigned int queue_maxlen; unsigned int copy_range; unsigned int queue_dropped; unsigned int queue_user_dropped; u_int16_t queue_num; /* number of this queue */ u_int8_t copy_mode; u_int32_t flags; /* Set using NFQA_CFG_FLAGS */ /* * Following fields are dirtied for each queued packet, * keep them in same cache line if possible. */ spinlock_t lock ____cacheline_aligned_in_smp; unsigned int queue_total; unsigned int id_sequence; /* 'sequence' of pkt ids */ struct list_head queue_list; /* packets in queue */ }; typedef int (*nfqnl_cmpfn)(struct nf_queue_entry *, unsigned long); static unsigned int nfnl_queue_net_id __read_mostly; #define INSTANCE_BUCKETS 16 struct nfnl_queue_net { spinlock_t instances_lock; struct hlist_head instance_table[INSTANCE_BUCKETS]; }; static struct nfnl_queue_net *nfnl_queue_pernet(struct net *net) { return net_generic(net, nfnl_queue_net_id); } static inline u_int8_t instance_hashfn(u_int16_t queue_num) { return ((queue_num >> 8) ^ queue_num) % INSTANCE_BUCKETS; } static struct nfqnl_instance * instance_lookup(struct nfnl_queue_net *q, u_int16_t queue_num) { struct hlist_head *head; struct nfqnl_instance *inst; head = &q->instance_table[instance_hashfn(queue_num)]; hlist_for_each_entry_rcu(inst, head, hlist) { if (inst->queue_num == queue_num) return inst; } return NULL; } static struct nfqnl_instance * instance_create(struct nfnl_queue_net *q, u_int16_t queue_num, u32 portid) { struct nfqnl_instance *inst; unsigned int h; int err; spin_lock(&q->instances_lock); if (instance_lookup(q, queue_num)) { err = -EEXIST; goto out_unlock; } inst = kzalloc(sizeof(*inst), GFP_ATOMIC); if (!inst) { err = -ENOMEM; goto out_unlock; } inst->queue_num = queue_num; inst->peer_portid = portid; inst->queue_maxlen = NFQNL_QMAX_DEFAULT; inst->copy_range = NFQNL_MAX_COPY_RANGE; inst->copy_mode = NFQNL_COPY_NONE; spin_lock_init(&inst->lock); INIT_LIST_HEAD(&inst->queue_list); if (!try_module_get(THIS_MODULE)) { err = -EAGAIN; goto out_free; } h = instance_hashfn(queue_num); hlist_add_head_rcu(&inst->hlist, &q->instance_table[h]); spin_unlock(&q->instances_lock); return inst; out_free: kfree(inst); out_unlock: spin_unlock(&q->instances_lock); return ERR_PTR(err); } static void nfqnl_flush(struct nfqnl_instance *queue, nfqnl_cmpfn cmpfn, unsigned long data); static void instance_destroy_rcu(struct rcu_head *head) { struct nfqnl_instance *inst = container_of(head, struct nfqnl_instance, rcu); nfqnl_flush(inst, NULL, 0); kfree(inst); module_put(THIS_MODULE); } static void __instance_destroy(struct nfqnl_instance *inst) { hlist_del_rcu(&inst->hlist); call_rcu(&inst->rcu, instance_destroy_rcu); } static void instance_destroy(struct nfnl_queue_net *q, struct nfqnl_instance *inst) { spin_lock(&q->instances_lock); __instance_destroy(inst); spin_unlock(&q->instances_lock); } static inline void __enqueue_entry(struct nfqnl_instance *queue, struct nf_queue_entry *entry) { list_add_tail(&entry->list, &queue->queue_list); queue->queue_total++; } static void __dequeue_entry(struct nfqnl_instance *queue, struct nf_queue_entry *entry) { list_del(&entry->list); queue->queue_total--; } static struct nf_queue_entry * find_dequeue_entry(struct nfqnl_instance *queue, unsigned int id) { struct nf_queue_entry *entry = NULL, *i; spin_lock_bh(&queue->lock); list_for_each_entry(i, &queue->queue_list, list) { if (i->id == id) { entry = i; break; } } if (entry) __dequeue_entry(queue, entry); spin_unlock_bh(&queue->lock); return entry; } static void nfqnl_reinject(struct nf_queue_entry *entry, unsigned int verdict) { struct nf_ct_hook *ct_hook; int err; if (verdict == NF_ACCEPT || verdict == NF_REPEAT || verdict == NF_STOP) { rcu_read_lock(); ct_hook = rcu_dereference(nf_ct_hook); if (ct_hook) { err = ct_hook->update(entry->state.net, entry->skb); if (err < 0) verdict = NF_DROP; } rcu_read_unlock(); } nf_reinject(entry, verdict); } static void nfqnl_flush(struct nfqnl_instance *queue, nfqnl_cmpfn cmpfn, unsigned long data) { struct nf_queue_entry *entry, *next; spin_lock_bh(&queue->lock); list_for_each_entry_safe(entry, next, &queue->queue_list, list) { if (!cmpfn || cmpfn(entry, data)) { list_del(&entry->list); queue->queue_total--; nfqnl_reinject(entry, NF_DROP); } } spin_unlock_bh(&queue->lock); } static int nfqnl_put_packet_info(struct sk_buff *nlskb, struct sk_buff *packet, bool csum_verify) { __u32 flags = 0; if (packet->ip_summed == CHECKSUM_PARTIAL) flags = NFQA_SKB_CSUMNOTREADY; else if (csum_verify) flags = NFQA_SKB_CSUM_NOTVERIFIED; if (skb_is_gso(packet)) flags |= NFQA_SKB_GSO; return flags ? nla_put_be32(nlskb, NFQA_SKB_INFO, htonl(flags)) : 0; } static int nfqnl_put_sk_uidgid(struct sk_buff *skb, struct sock *sk) { const struct cred *cred; if (!sk_fullsock(sk)) return 0; read_lock_bh(&sk->sk_callback_lock); if (sk->sk_socket && sk->sk_socket->file) { cred = sk->sk_socket->file->f_cred; if (nla_put_be32(skb, NFQA_UID, htonl(from_kuid_munged(&init_user_ns, cred->fsuid)))) goto nla_put_failure; if (nla_put_be32(skb, NFQA_GID, htonl(from_kgid_munged(&init_user_ns, cred->fsgid)))) goto nla_put_failure; } read_unlock_bh(&sk->sk_callback_lock); return 0; nla_put_failure: read_unlock_bh(&sk->sk_callback_lock); return -1; } static u32 nfqnl_get_sk_secctx(struct sk_buff *skb, char **secdata) { u32 seclen = 0; #if IS_ENABLED(CONFIG_NETWORK_SECMARK) if (!skb || !sk_fullsock(skb->sk)) return 0; read_lock_bh(&skb->sk->sk_callback_lock); if (skb->secmark) security_secid_to_secctx(skb->secmark, secdata, &seclen); read_unlock_bh(&skb->sk->sk_callback_lock); #endif return seclen; } static u32 nfqnl_get_bridge_size(struct nf_queue_entry *entry) { struct sk_buff *entskb = entry->skb; u32 nlalen = 0; if (entry->state.pf != PF_BRIDGE || !skb_mac_header_was_set(entskb)) return 0; if (skb_vlan_tag_present(entskb)) nlalen += nla_total_size(nla_total_size(sizeof(__be16)) + nla_total_size(sizeof(__be16))); if (entskb->network_header > entskb->mac_header) nlalen += nla_total_size((entskb->network_header - entskb->mac_header)); return nlalen; } static int nfqnl_put_bridge(struct nf_queue_entry *entry, struct sk_buff *skb) { struct sk_buff *entskb = entry->skb; if (entry->state.pf != PF_BRIDGE || !skb_mac_header_was_set(entskb)) return 0; if (skb_vlan_tag_present(entskb)) { struct nlattr *nest; nest = nla_nest_start(skb, NFQA_VLAN | NLA_F_NESTED); if (!nest) goto nla_put_failure; if (nla_put_be16(skb, NFQA_VLAN_TCI, htons(entskb->vlan_tci)) || nla_put_be16(skb, NFQA_VLAN_PROTO, entskb->vlan_proto)) goto nla_put_failure; nla_nest_end(skb, nest); } if (entskb->mac_header < entskb->network_header) { int len = (int)(entskb->network_header - entskb->mac_header); if (nla_put(skb, NFQA_L2HDR, len, skb_mac_header(entskb))) goto nla_put_failure; } return 0; nla_put_failure: return -1; } static struct sk_buff * nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue, struct nf_queue_entry *entry, __be32 **packet_id_ptr) { size_t size; size_t data_len = 0, cap_len = 0; unsigned int hlen = 0; struct sk_buff *skb; struct nlattr *nla; struct nfqnl_msg_packet_hdr *pmsg; struct nlmsghdr *nlh; struct nfgenmsg *nfmsg; struct sk_buff *entskb = entry->skb; struct net_device *indev; struct net_device *outdev; struct nf_conn *ct = NULL; enum ip_conntrack_info uninitialized_var(ctinfo); struct nfnl_ct_hook *nfnl_ct; bool csum_verify; char *secdata = NULL; u32 seclen = 0; size = nlmsg_total_size(sizeof(struct nfgenmsg)) + nla_total_size(sizeof(struct nfqnl_msg_packet_hdr)) + nla_total_size(sizeof(u_int32_t)) /* ifindex */ + nla_total_size(sizeof(u_int32_t)) /* ifindex */ #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) + nla_total_size(sizeof(u_int32_t)) /* ifindex */ + nla_total_size(sizeof(u_int32_t)) /* ifindex */ #endif + nla_total_size(sizeof(u_int32_t)) /* mark */ + nla_total_size(sizeof(struct nfqnl_msg_packet_hw)) + nla_total_size(sizeof(u_int32_t)) /* skbinfo */ + nla_total_size(sizeof(u_int32_t)); /* cap_len */ if (entskb->tstamp) size += nla_total_size(sizeof(struct nfqnl_msg_packet_timestamp)); size += nfqnl_get_bridge_size(entry); if (entry->state.hook <= NF_INET_FORWARD || (entry->state.hook == NF_INET_POST_ROUTING && entskb->sk == NULL)) csum_verify = !skb_csum_unnecessary(entskb); else csum_verify = false; outdev = entry->state.out; switch ((enum nfqnl_config_mode)READ_ONCE(queue->copy_mode)) { case NFQNL_COPY_META: case NFQNL_COPY_NONE: break; case NFQNL_COPY_PACKET: if (!(queue->flags & NFQA_CFG_F_GSO) && entskb->ip_summed == CHECKSUM_PARTIAL && skb_checksum_help(entskb)) return NULL; data_len = READ_ONCE(queue->copy_range); if (data_len > entskb->len) data_len = entskb->len; hlen = skb_zerocopy_headlen(entskb); hlen = min_t(unsigned int, hlen, data_len); size += sizeof(struct nlattr) + hlen; cap_len = entskb->len; break; } nfnl_ct = rcu_dereference(nfnl_ct_hook); if (queue->flags & NFQA_CFG_F_CONNTRACK) { if (nfnl_ct != NULL) { ct = nfnl_ct->get_ct(entskb, &ctinfo); if (ct != NULL) size += nfnl_ct->build_size(ct); } } if (queue->flags & NFQA_CFG_F_UID_GID) { size += (nla_total_size(sizeof(u_int32_t)) /* uid */ + nla_total_size(sizeof(u_int32_t))); /* gid */ } if ((queue->flags & NFQA_CFG_F_SECCTX) && entskb->sk) { seclen = nfqnl_get_sk_secctx(entskb, &secdata); if (seclen) size += nla_total_size(seclen); } skb = alloc_skb(size, GFP_ATOMIC); if (!skb) { skb_tx_error(entskb); goto nlmsg_failure; } nlh = nlmsg_put(skb, 0, 0, nfnl_msg_type(NFNL_SUBSYS_QUEUE, NFQNL_MSG_PACKET), sizeof(struct nfgenmsg), 0); if (!nlh) { skb_tx_error(entskb); kfree_skb(skb); goto nlmsg_failure; } nfmsg = nlmsg_data(nlh); nfmsg->nfgen_family = entry->state.pf; nfmsg->version = NFNETLINK_V0; nfmsg->res_id = htons(queue->queue_num); nla = __nla_reserve(skb, NFQA_PACKET_HDR, sizeof(*pmsg)); pmsg = nla_data(nla); pmsg->hw_protocol = entskb->protocol; pmsg->hook = entry->state.hook; *packet_id_ptr = &pmsg->packet_id; indev = entry->state.in; if (indev) { #if !IS_ENABLED(CONFIG_BRIDGE_NETFILTER) if (nla_put_be32(skb, NFQA_IFINDEX_INDEV, htonl(indev->ifindex))) goto nla_put_failure; #else if (entry->state.pf == PF_BRIDGE) { /* Case 1: indev is physical input device, we need to * look for bridge group (when called from * netfilter_bridge) */ if (nla_put_be32(skb, NFQA_IFINDEX_PHYSINDEV, htonl(indev->ifindex)) || /* this is the bridge group "brX" */ /* rcu_read_lock()ed by __nf_queue */ nla_put_be32(skb, NFQA_IFINDEX_INDEV, htonl(br_port_get_rcu(indev)->br->dev->ifindex))) goto nla_put_failure; } else { int physinif; /* Case 2: indev is bridge group, we need to look for * physical device (when called from ipv4) */ if (nla_put_be32(skb, NFQA_IFINDEX_INDEV, htonl(indev->ifindex))) goto nla_put_failure; physinif = nf_bridge_get_physinif(entskb); if (physinif && nla_put_be32(skb, NFQA_IFINDEX_PHYSINDEV, htonl(physinif))) goto nla_put_failure; } #endif } if (outdev) { #if !IS_ENABLED(CONFIG_BRIDGE_NETFILTER) if (nla_put_be32(skb, NFQA_IFINDEX_OUTDEV, htonl(outdev->ifindex))) goto nla_put_failure; #else if (entry->state.pf == PF_BRIDGE) { /* Case 1: outdev is physical output device, we need to * look for bridge group (when called from * netfilter_bridge) */ if (nla_put_be32(skb, NFQA_IFINDEX_PHYSOUTDEV, htonl(outdev->ifindex)) || /* this is the bridge group "brX" */ /* rcu_read_lock()ed by __nf_queue */ nla_put_be32(skb, NFQA_IFINDEX_OUTDEV, htonl(br_port_get_rcu(outdev)->br->dev->ifindex))) goto nla_put_failure; } else { int physoutif; /* Case 2: outdev is bridge group, we need to look for * physical output device (when called from ipv4) */ if (nla_put_be32(skb, NFQA_IFINDEX_OUTDEV, htonl(outdev->ifindex))) goto nla_put_failure; physoutif = nf_bridge_get_physoutif(entskb); if (physoutif && nla_put_be32(skb, NFQA_IFINDEX_PHYSOUTDEV, htonl(physoutif))) goto nla_put_failure; } #endif } if (entskb->mark && nla_put_be32(skb, NFQA_MARK, htonl(entskb->mark))) goto nla_put_failure; if (indev && entskb->dev && entskb->mac_header != entskb->network_header) { struct nfqnl_msg_packet_hw phw; int len; memset(&phw, 0, sizeof(phw)); len = dev_parse_header(entskb, phw.hw_addr); if (len) { phw.hw_addrlen = htons(len); if (nla_put(skb, NFQA_HWADDR, sizeof(phw), &phw)) goto nla_put_failure; } } if (nfqnl_put_bridge(entry, skb) < 0) goto nla_put_failure; if (entskb->tstamp) { struct nfqnl_msg_packet_timestamp ts; struct timespec64 kts = ktime_to_timespec64(entskb->tstamp); ts.sec = cpu_to_be64(kts.tv_sec); ts.usec = cpu_to_be64(kts.tv_nsec / NSEC_PER_USEC); if (nla_put(skb, NFQA_TIMESTAMP, sizeof(ts), &ts)) goto nla_put_failure; } if ((queue->flags & NFQA_CFG_F_UID_GID) && entskb->sk && nfqnl_put_sk_uidgid(skb, entskb->sk) < 0) goto nla_put_failure; if (seclen && nla_put(skb, NFQA_SECCTX, seclen, secdata)) goto nla_put_failure; if (ct && nfnl_ct->build(skb, ct, ctinfo, NFQA_CT, NFQA_CT_INFO) < 0) goto nla_put_failure; if (cap_len > data_len && nla_put_be32(skb, NFQA_CAP_LEN, htonl(cap_len))) goto nla_put_failure; if (nfqnl_put_packet_info(skb, entskb, csum_verify)) goto nla_put_failure; if (data_len) { struct nlattr *nla; if (skb_tailroom(skb) < sizeof(*nla) + hlen) goto nla_put_failure; nla = skb_put(skb, sizeof(*nla)); nla->nla_type = NFQA_PAYLOAD; nla->nla_len = nla_attr_size(data_len); if (skb_zerocopy(skb, entskb, data_len, hlen)) goto nla_put_failure; } nlh->nlmsg_len = skb->len; if (seclen) security_release_secctx(secdata, seclen); return skb; nla_put_failure: skb_tx_error(entskb); kfree_skb(skb); net_err_ratelimited("nf_queue: error creating packet message\n"); nlmsg_failure: if (seclen) security_release_secctx(secdata, seclen); return NULL; } static bool nf_ct_drop_unconfirmed(const struct nf_queue_entry *entry) { #if IS_ENABLED(CONFIG_NF_CONNTRACK) static const unsigned long flags = IPS_CONFIRMED | IPS_DYING; const struct nf_conn *ct = (void *)skb_nfct(entry->skb); if (ct && ((ct->status & flags) == IPS_DYING)) return true; #endif return false; } static int __nfqnl_enqueue_packet(struct net *net, struct nfqnl_instance *queue, struct nf_queue_entry *entry) { struct sk_buff *nskb; int err = -ENOBUFS; __be32 *packet_id_ptr; int failopen = 0; nskb = nfqnl_build_packet_message(net, queue, entry, &packet_id_ptr); if (nskb == NULL) { err = -ENOMEM; goto err_out; } spin_lock_bh(&queue->lock); if (nf_ct_drop_unconfirmed(entry)) goto err_out_free_nskb; if (queue->queue_total >= queue->queue_maxlen) { if (queue->flags & NFQA_CFG_F_FAIL_OPEN) { failopen = 1; err = 0; } else { queue->queue_dropped++; net_warn_ratelimited("nf_queue: full at %d entries, dropping packets(s)\n", queue->queue_total); } goto err_out_free_nskb; } entry->id = ++queue->id_sequence; *packet_id_ptr = htonl(entry->id); /* nfnetlink_unicast will either free the nskb or add it to a socket */ err = nfnetlink_unicast(nskb, net, queue->peer_portid, MSG_DONTWAIT); if (err < 0) { if (queue->flags & NFQA_CFG_F_FAIL_OPEN) { failopen = 1; err = 0; } else { queue->queue_user_dropped++; } goto err_out_unlock; } __enqueue_entry(queue, entry); spin_unlock_bh(&queue->lock); return 0; err_out_free_nskb: kfree_skb(nskb); err_out_unlock: spin_unlock_bh(&queue->lock); if (failopen) nfqnl_reinject(entry, NF_ACCEPT); err_out: return err; } static struct nf_queue_entry * nf_queue_entry_dup(struct nf_queue_entry *e) { struct nf_queue_entry *entry = kmemdup(e, e->size, GFP_ATOMIC); if (entry) nf_queue_entry_get_refs(entry); return entry; } #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) /* When called from bridge netfilter, skb->data must point to MAC header * before calling skb_gso_segment(). Else, original MAC header is lost * and segmented skbs will be sent to wrong destination. */ static void nf_bridge_adjust_skb_data(struct sk_buff *skb) { if (nf_bridge_info_get(skb)) __skb_push(skb, skb->network_header - skb->mac_header); } static void nf_bridge_adjust_segmented_data(struct sk_buff *skb) { if (nf_bridge_info_get(skb)) __skb_pull(skb, skb->network_header - skb->mac_header); } #else #define nf_bridge_adjust_skb_data(s) do {} while (0) #define nf_bridge_adjust_segmented_data(s) do {} while (0) #endif static void free_entry(struct nf_queue_entry *entry) { nf_queue_entry_release_refs(entry); kfree(entry); } static int __nfqnl_enqueue_packet_gso(struct net *net, struct nfqnl_instance *queue, struct sk_buff *skb, struct nf_queue_entry *entry) { int ret = -ENOMEM; struct nf_queue_entry *entry_seg; nf_bridge_adjust_segmented_data(skb); if (skb->next == NULL) { /* last packet, no need to copy entry */ struct sk_buff *gso_skb = entry->skb; entry->skb = skb; ret = __nfqnl_enqueue_packet(net, queue, entry); if (ret) entry->skb = gso_skb; return ret; } skb_mark_not_on_list(skb); entry_seg = nf_queue_entry_dup(entry); if (entry_seg) { entry_seg->skb = skb; ret = __nfqnl_enqueue_packet(net, queue, entry_seg); if (ret) free_entry(entry_seg); } return ret; } static int nfqnl_enqueue_packet(struct nf_queue_entry *entry, unsigned int queuenum) { unsigned int queued; struct nfqnl_instance *queue; struct sk_buff *skb, *segs; int err = -ENOBUFS; struct net *net = entry->state.net; struct nfnl_queue_net *q = nfnl_queue_pernet(net); /* rcu_read_lock()ed by nf_hook_thresh */ queue = instance_lookup(q, queuenum); if (!queue) return -ESRCH; if (queue->copy_mode == NFQNL_COPY_NONE) return -EINVAL; skb = entry->skb; switch (entry->state.pf) { case NFPROTO_IPV4: skb->protocol = htons(ETH_P_IP); break; case NFPROTO_IPV6: skb->protocol = htons(ETH_P_IPV6); break; } if ((queue->flags & NFQA_CFG_F_GSO) || !skb_is_gso(skb)) return __nfqnl_enqueue_packet(net, queue, entry); nf_bridge_adjust_skb_data(skb); segs = skb_gso_segment(skb, 0); /* Does not use PTR_ERR to limit the number of error codes that can be * returned by nf_queue. For instance, callers rely on -ESRCH to * mean 'ignore this hook'. */ if (IS_ERR_OR_NULL(segs)) goto out_err; queued = 0; err = 0; do { struct sk_buff *nskb = segs->next; if (err == 0) err = __nfqnl_enqueue_packet_gso(net, queue, segs, entry); if (err == 0) queued++; else kfree_skb(segs); segs = nskb; } while (segs); if (queued) { if (err) /* some segments are already queued */ free_entry(entry); kfree_skb(skb); return 0; } out_err: nf_bridge_adjust_segmented_data(skb); return err; } static int nfqnl_mangle(void *data, int data_len, struct nf_queue_entry *e, int diff) { struct sk_buff *nskb; if (diff < 0) { if (pskb_trim(e->skb, data_len)) return -ENOMEM; } else if (diff > 0) { if (data_len > 0xFFFF) return -EINVAL; if (diff > skb_tailroom(e->skb)) { nskb = skb_copy_expand(e->skb, skb_headroom(e->skb), diff, GFP_ATOMIC); if (!nskb) return -ENOMEM; kfree_skb(e->skb); e->skb = nskb; } skb_put(e->skb, diff); } if (!skb_make_writable(e->skb, data_len)) return -ENOMEM; skb_copy_to_linear_data(e->skb, data, data_len); e->skb->ip_summed = CHECKSUM_NONE; return 0; } static int nfqnl_set_mode(struct nfqnl_instance *queue, unsigned char mode, unsigned int range) { int status = 0; spin_lock_bh(&queue->lock); switch (mode) { case NFQNL_COPY_NONE: case NFQNL_COPY_META: queue->copy_mode = mode; queue->copy_range = 0; break; case NFQNL_COPY_PACKET: queue->copy_mode = mode; if (range == 0 || range > NFQNL_MAX_COPY_RANGE) queue->copy_range = NFQNL_MAX_COPY_RANGE; else queue->copy_range = range; break; default: status = -EINVAL; } spin_unlock_bh(&queue->lock); return status; } static int dev_cmp(struct nf_queue_entry *entry, unsigned long ifindex) { #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) int physinif, physoutif; physinif = nf_bridge_get_physinif(entry->skb); physoutif = nf_bridge_get_physoutif(entry->skb); if (physinif == ifindex || physoutif == ifindex) return 1; #endif if (entry->state.in) if (entry->state.in->ifindex == ifindex) return 1; if (entry->state.out) if (entry->state.out->ifindex == ifindex) return 1; return 0; } /* drop all packets with either indev or outdev == ifindex from all queue * instances */ static void nfqnl_dev_drop(struct net *net, int ifindex) { int i; struct nfnl_queue_net *q = nfnl_queue_pernet(net); rcu_read_lock(); for (i = 0; i < INSTANCE_BUCKETS; i++) { struct nfqnl_instance *inst; struct hlist_head *head = &q->instance_table[i]; hlist_for_each_entry_rcu(inst, head, hlist) nfqnl_flush(inst, dev_cmp, ifindex); } rcu_read_unlock(); } static int nfqnl_rcv_dev_event(struct notifier_block *this, unsigned long event, void *ptr) { struct net_device *dev = netdev_notifier_info_to_dev(ptr); /* Drop any packets associated with the downed device */ if (event == NETDEV_DOWN) nfqnl_dev_drop(dev_net(dev), dev->ifindex); return NOTIFY_DONE; } static struct notifier_block nfqnl_dev_notifier = { .notifier_call = nfqnl_rcv_dev_event, }; static void nfqnl_nf_hook_drop(struct net *net) { struct nfnl_queue_net *q = nfnl_queue_pernet(net); int i; for (i = 0; i < INSTANCE_BUCKETS; i++) { struct nfqnl_instance *inst; struct hlist_head *head = &q->instance_table[i]; hlist_for_each_entry_rcu(inst, head, hlist) nfqnl_flush(inst, NULL, 0); } } static int nfqnl_rcv_nl_event(struct notifier_block *this, unsigned long event, void *ptr) { struct netlink_notify *n = ptr; struct nfnl_queue_net *q = nfnl_queue_pernet(n->net); if (event == NETLINK_URELEASE && n->protocol == NETLINK_NETFILTER) { int i; /* destroy all instances for this portid */ spin_lock(&q->instances_lock); for (i = 0; i < INSTANCE_BUCKETS; i++) { struct hlist_node *t2; struct nfqnl_instance *inst; struct hlist_head *head = &q->instance_table[i]; hlist_for_each_entry_safe(inst, t2, head, hlist) { if (n->portid == inst->peer_portid) __instance_destroy(inst); } } spin_unlock(&q->instances_lock); } return NOTIFY_DONE; } static struct notifier_block nfqnl_rtnl_notifier = { .notifier_call = nfqnl_rcv_nl_event, }; static const struct nla_policy nfqa_vlan_policy[NFQA_VLAN_MAX + 1] = { [NFQA_VLAN_TCI] = { .type = NLA_U16}, [NFQA_VLAN_PROTO] = { .type = NLA_U16}, }; static const struct nla_policy nfqa_verdict_policy[NFQA_MAX+1] = { [NFQA_VERDICT_HDR] = { .len = sizeof(struct nfqnl_msg_verdict_hdr) }, [NFQA_MARK] = { .type = NLA_U32 }, [NFQA_PAYLOAD] = { .type = NLA_UNSPEC }, [NFQA_CT] = { .type = NLA_UNSPEC }, [NFQA_EXP] = { .type = NLA_UNSPEC }, [NFQA_VLAN] = { .type = NLA_NESTED }, }; static const struct nla_policy nfqa_verdict_batch_policy[NFQA_MAX+1] = { [NFQA_VERDICT_HDR] = { .len = sizeof(struct nfqnl_msg_verdict_hdr) }, [NFQA_MARK] = { .type = NLA_U32 }, }; static struct nfqnl_instance * verdict_instance_lookup(struct nfnl_queue_net *q, u16 queue_num, u32 nlportid) { struct nfqnl_instance *queue; queue = instance_lookup(q, queue_num); if (!queue) return ERR_PTR(-ENODEV); if (queue->peer_portid != nlportid) return ERR_PTR(-EPERM); return queue; } static struct nfqnl_msg_verdict_hdr* verdicthdr_get(const struct nlattr * const nfqa[]) { struct nfqnl_msg_verdict_hdr *vhdr; unsigned int verdict; if (!nfqa[NFQA_VERDICT_HDR]) return NULL; vhdr = nla_data(nfqa[NFQA_VERDICT_HDR]); verdict = ntohl(vhdr->verdict) & NF_VERDICT_MASK; if (verdict > NF_MAX_VERDICT || verdict == NF_STOLEN) return NULL; return vhdr; } static int nfq_id_after(unsigned int id, unsigned int max) { return (int)(id - max) > 0; } static int nfqnl_recv_verdict_batch(struct net *net, struct sock *ctnl, struct sk_buff *skb, const struct nlmsghdr *nlh, const struct nlattr * const nfqa[], struct netlink_ext_ack *extack) { struct nfgenmsg *nfmsg = nlmsg_data(nlh); struct nf_queue_entry *entry, *tmp; unsigned int verdict, maxid; struct nfqnl_msg_verdict_hdr *vhdr; struct nfqnl_instance *queue; LIST_HEAD(batch_list); u16 queue_num = ntohs(nfmsg->res_id); struct nfnl_queue_net *q = nfnl_queue_pernet(net); queue = verdict_instance_lookup(q, queue_num, NETLINK_CB(skb).portid); if (IS_ERR(queue)) return PTR_ERR(queue); vhdr = verdicthdr_get(nfqa); if (!vhdr) return -EINVAL; verdict = ntohl(vhdr->verdict); maxid = ntohl(vhdr->id); spin_lock_bh(&queue->lock); list_for_each_entry_safe(entry, tmp, &queue->queue_list, list) { if (nfq_id_after(entry->id, maxid)) break; __dequeue_entry(queue, entry); list_add_tail(&entry->list, &batch_list); } spin_unlock_bh(&queue->lock); if (list_empty(&batch_list)) return -ENOENT; list_for_each_entry_safe(entry, tmp, &batch_list, list) { if (nfqa[NFQA_MARK]) entry->skb->mark = ntohl(nla_get_be32(nfqa[NFQA_MARK])); nfqnl_reinject(entry, verdict); } return 0; } static struct nf_conn *nfqnl_ct_parse(struct nfnl_ct_hook *nfnl_ct, const struct nlmsghdr *nlh, const struct nlattr * const nfqa[], struct nf_queue_entry *entry, enum ip_conntrack_info *ctinfo) { struct nf_conn *ct; ct = nfnl_ct->get_ct(entry->skb, ctinfo); if (ct == NULL) return NULL; if (nfnl_ct->parse(nfqa[NFQA_CT], ct) < 0) return NULL; if (nfqa[NFQA_EXP]) nfnl_ct->attach_expect(nfqa[NFQA_EXP], ct, NETLINK_CB(entry->skb).portid, nlmsg_report(nlh)); return ct; } static int nfqa_parse_bridge(struct nf_queue_entry *entry, const struct nlattr * const nfqa[]) { if (nfqa[NFQA_VLAN]) { struct nlattr *tb[NFQA_VLAN_MAX + 1]; int err; err = nla_parse_nested(tb, NFQA_VLAN_MAX, nfqa[NFQA_VLAN], nfqa_vlan_policy, NULL); if (err < 0) return err; if (!tb[NFQA_VLAN_TCI] || !tb[NFQA_VLAN_PROTO]) return -EINVAL; __vlan_hwaccel_put_tag(entry->skb, nla_get_be16(tb[NFQA_VLAN_PROTO]), ntohs(nla_get_be16(tb[NFQA_VLAN_TCI]))); } if (nfqa[NFQA_L2HDR]) { int mac_header_len = entry->skb->network_header - entry->skb->mac_header; if (mac_header_len != nla_len(nfqa[NFQA_L2HDR])) return -EINVAL; else if (mac_header_len > 0) memcpy(skb_mac_header(entry->skb), nla_data(nfqa[NFQA_L2HDR]), mac_header_len); } return 0; } static int nfqnl_recv_verdict(struct net *net, struct sock *ctnl, struct sk_buff *skb, const struct nlmsghdr *nlh, const struct nlattr * const nfqa[], struct netlink_ext_ack *extack) { struct nfgenmsg *nfmsg = nlmsg_data(nlh); u_int16_t queue_num = ntohs(nfmsg->res_id); struct nfqnl_msg_verdict_hdr *vhdr; struct nfqnl_instance *queue; unsigned int verdict; struct nf_queue_entry *entry; enum ip_conntrack_info uninitialized_var(ctinfo); struct nfnl_ct_hook *nfnl_ct; struct nf_conn *ct = NULL; struct nfnl_queue_net *q = nfnl_queue_pernet(net); int err; queue = verdict_instance_lookup(q, queue_num, NETLINK_CB(skb).portid); if (IS_ERR(queue)) return PTR_ERR(queue); vhdr = verdicthdr_get(nfqa); if (!vhdr) return -EINVAL; verdict = ntohl(vhdr->verdict); entry = find_dequeue_entry(queue, ntohl(vhdr->id)); if (entry == NULL) return -ENOENT; /* rcu lock already held from nfnl->call_rcu. */ nfnl_ct = rcu_dereference(nfnl_ct_hook); if (nfqa[NFQA_CT]) { if (nfnl_ct != NULL) ct = nfqnl_ct_parse(nfnl_ct, nlh, nfqa, entry, &ctinfo); } if (entry->state.pf == PF_BRIDGE) { err = nfqa_parse_bridge(entry, nfqa); if (err < 0) return err; } if (nfqa[NFQA_PAYLOAD]) { u16 payload_len = nla_len(nfqa[NFQA_PAYLOAD]); int diff = payload_len - entry->skb->len; if (nfqnl_mangle(nla_data(nfqa[NFQA_PAYLOAD]), payload_len, entry, diff) < 0) verdict = NF_DROP; if (ct && diff) nfnl_ct->seq_adjust(entry->skb, ct, ctinfo, diff); } if (nfqa[NFQA_MARK]) entry->skb->mark = ntohl(nla_get_be32(nfqa[NFQA_MARK])); nfqnl_reinject(entry, verdict); return 0; } static int nfqnl_recv_unsupp(struct net *net, struct sock *ctnl, struct sk_buff *skb, const struct nlmsghdr *nlh, const struct nlattr * const nfqa[], struct netlink_ext_ack *extack) { return -ENOTSUPP; } static const struct nla_policy nfqa_cfg_policy[NFQA_CFG_MAX+1] = { [NFQA_CFG_CMD] = { .len = sizeof(struct nfqnl_msg_config_cmd) }, [NFQA_CFG_PARAMS] = { .len = sizeof(struct nfqnl_msg_config_params) }, [NFQA_CFG_QUEUE_MAXLEN] = { .type = NLA_U32 }, [NFQA_CFG_MASK] = { .type = NLA_U32 }, [NFQA_CFG_FLAGS] = { .type = NLA_U32 }, }; static const struct nf_queue_handler nfqh = { .outfn = nfqnl_enqueue_packet, .nf_hook_drop = nfqnl_nf_hook_drop, }; static int nfqnl_recv_config(struct net *net, struct sock *ctnl, struct sk_buff *skb, const struct nlmsghdr *nlh, const struct nlattr * const nfqa[], struct netlink_ext_ack *extack) { struct nfgenmsg *nfmsg = nlmsg_data(nlh); u_int16_t queue_num = ntohs(nfmsg->res_id); struct nfqnl_instance *queue; struct nfqnl_msg_config_cmd *cmd = NULL; struct nfnl_queue_net *q = nfnl_queue_pernet(net); __u32 flags = 0, mask = 0; int ret = 0; if (nfqa[NFQA_CFG_CMD]) { cmd = nla_data(nfqa[NFQA_CFG_CMD]); /* Obsolete commands without queue context */ switch (cmd->command) { case NFQNL_CFG_CMD_PF_BIND: return 0; case NFQNL_CFG_CMD_PF_UNBIND: return 0; } } /* Check if we support these flags in first place, dependencies should * be there too not to break atomicity. */ if (nfqa[NFQA_CFG_FLAGS]) { if (!nfqa[NFQA_CFG_MASK]) { /* A mask is needed to specify which flags are being * changed. */ return -EINVAL; } flags = ntohl(nla_get_be32(nfqa[NFQA_CFG_FLAGS])); mask = ntohl(nla_get_be32(nfqa[NFQA_CFG_MASK])); if (flags >= NFQA_CFG_F_MAX) return -EOPNOTSUPP; #if !IS_ENABLED(CONFIG_NETWORK_SECMARK) if (flags & mask & NFQA_CFG_F_SECCTX) return -EOPNOTSUPP; #endif if ((flags & mask & NFQA_CFG_F_CONNTRACK) && !rcu_access_pointer(nfnl_ct_hook)) { #ifdef CONFIG_MODULES nfnl_unlock(NFNL_SUBSYS_QUEUE); request_module("ip_conntrack_netlink"); nfnl_lock(NFNL_SUBSYS_QUEUE); if (rcu_access_pointer(nfnl_ct_hook)) return -EAGAIN; #endif return -EOPNOTSUPP; } } rcu_read_lock(); queue = instance_lookup(q, queue_num); if (queue && queue->peer_portid != NETLINK_CB(skb).portid) { ret = -EPERM; goto err_out_unlock; } if (cmd != NULL) { switch (cmd->command) { case NFQNL_CFG_CMD_BIND: if (queue) { ret = -EBUSY; goto err_out_unlock; } queue = instance_create(q, queue_num, NETLINK_CB(skb).portid); if (IS_ERR(queue)) { ret = PTR_ERR(queue); goto err_out_unlock; } break; case NFQNL_CFG_CMD_UNBIND: if (!queue) { ret = -ENODEV; goto err_out_unlock; } instance_destroy(q, queue); goto err_out_unlock; case NFQNL_CFG_CMD_PF_BIND: case NFQNL_CFG_CMD_PF_UNBIND: break; default: ret = -ENOTSUPP; goto err_out_unlock; } } if (!queue) { ret = -ENODEV; goto err_out_unlock; } if (nfqa[NFQA_CFG_PARAMS]) { struct nfqnl_msg_config_params *params = nla_data(nfqa[NFQA_CFG_PARAMS]); nfqnl_set_mode(queue, params->copy_mode, ntohl(params->copy_range)); } if (nfqa[NFQA_CFG_QUEUE_MAXLEN]) { __be32 *queue_maxlen = nla_data(nfqa[NFQA_CFG_QUEUE_MAXLEN]); spin_lock_bh(&queue->lock); queue->queue_maxlen = ntohl(*queue_maxlen); spin_unlock_bh(&queue->lock); } if (nfqa[NFQA_CFG_FLAGS]) { spin_lock_bh(&queue->lock); queue->flags &= ~mask; queue->flags |= flags & mask; spin_unlock_bh(&queue->lock); } err_out_unlock: rcu_read_unlock(); return ret; } static const struct nfnl_callback nfqnl_cb[NFQNL_MSG_MAX] = { [NFQNL_MSG_PACKET] = { .call_rcu = nfqnl_recv_unsupp, .attr_count = NFQA_MAX, }, [NFQNL_MSG_VERDICT] = { .call_rcu = nfqnl_recv_verdict, .attr_count = NFQA_MAX, .policy = nfqa_verdict_policy }, [NFQNL_MSG_CONFIG] = { .call = nfqnl_recv_config, .attr_count = NFQA_CFG_MAX, .policy = nfqa_cfg_policy }, [NFQNL_MSG_VERDICT_BATCH]={ .call_rcu = nfqnl_recv_verdict_batch, .attr_count = NFQA_MAX, .policy = nfqa_verdict_batch_policy }, }; static const struct nfnetlink_subsystem nfqnl_subsys = { .name = "nf_queue", .subsys_id = NFNL_SUBSYS_QUEUE, .cb_count = NFQNL_MSG_MAX, .cb = nfqnl_cb, }; #ifdef CONFIG_PROC_FS struct iter_state { struct seq_net_private p; unsigned int bucket; }; static struct hlist_node *get_first(struct seq_file *seq) { struct iter_state *st = seq->private; struct net *net; struct nfnl_queue_net *q; if (!st) return NULL; net = seq_file_net(seq); q = nfnl_queue_pernet(net); for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) { if (!hlist_empty(&q->instance_table[st->bucket])) return q->instance_table[st->bucket].first; } return NULL; } static struct hlist_node *get_next(struct seq_file *seq, struct hlist_node *h) { struct iter_state *st = seq->private; struct net *net = seq_file_net(seq); h = h->next; while (!h) { struct nfnl_queue_net *q; if (++st->bucket >= INSTANCE_BUCKETS) return NULL; q = nfnl_queue_pernet(net); h = q->instance_table[st->bucket].first; } return h; } static struct hlist_node *get_idx(struct seq_file *seq, loff_t pos) { struct hlist_node *head; head = get_first(seq); if (head) while (pos && (head = get_next(seq, head))) pos--; return pos ? NULL : head; } static void *seq_start(struct seq_file *s, loff_t *pos) __acquires(nfnl_queue_pernet(seq_file_net(s))->instances_lock) { spin_lock(&nfnl_queue_pernet(seq_file_net(s))->instances_lock); return get_idx(s, *pos); } static void *seq_next(struct seq_file *s, void *v, loff_t *pos) { (*pos)++; return get_next(s, v); } static void seq_stop(struct seq_file *s, void *v) __releases(nfnl_queue_pernet(seq_file_net(s))->instances_lock) { spin_unlock(&nfnl_queue_pernet(seq_file_net(s))->instances_lock); } static int seq_show(struct seq_file *s, void *v) { const struct nfqnl_instance *inst = v; seq_printf(s, "%5u %6u %5u %1u %5u %5u %5u %8u %2d\n", inst->queue_num, inst->peer_portid, inst->queue_total, inst->copy_mode, inst->copy_range, inst->queue_dropped, inst->queue_user_dropped, inst->id_sequence, 1); return 0; } static const struct seq_operations nfqnl_seq_ops = { .start = seq_start, .next = seq_next, .stop = seq_stop, .show = seq_show, }; #endif /* PROC_FS */ static int __net_init nfnl_queue_net_init(struct net *net) { unsigned int i; struct nfnl_queue_net *q = nfnl_queue_pernet(net); for (i = 0; i < INSTANCE_BUCKETS; i++) INIT_HLIST_HEAD(&q->instance_table[i]); spin_lock_init(&q->instances_lock); #ifdef CONFIG_PROC_FS if (!proc_create_net("nfnetlink_queue", 0440, net->nf.proc_netfilter, &nfqnl_seq_ops, sizeof(struct iter_state))) return -ENOMEM; #endif nf_register_queue_handler(net, &nfqh); return 0; } static void __net_exit nfnl_queue_net_exit(struct net *net) { struct nfnl_queue_net *q = nfnl_queue_pernet(net); unsigned int i; nf_unregister_queue_handler(net); #ifdef CONFIG_PROC_FS remove_proc_entry("nfnetlink_queue", net->nf.proc_netfilter); #endif for (i = 0; i < INSTANCE_BUCKETS; i++) WARN_ON_ONCE(!hlist_empty(&q->instance_table[i])); } static void nfnl_queue_net_exit_batch(struct list_head *net_exit_list) { synchronize_rcu(); } static struct pernet_operations nfnl_queue_net_ops = { .init = nfnl_queue_net_init, .exit = nfnl_queue_net_exit, .exit_batch = nfnl_queue_net_exit_batch, .id = &nfnl_queue_net_id, .size = sizeof(struct nfnl_queue_net), }; static int __init nfnetlink_queue_init(void) { int status; status = register_pernet_subsys(&nfnl_queue_net_ops); if (status < 0) { pr_err("failed to register pernet ops\n"); goto out; } netlink_register_notifier(&nfqnl_rtnl_notifier); status = nfnetlink_subsys_register(&nfqnl_subsys); if (status < 0) { pr_err("failed to create netlink socket\n"); goto cleanup_netlink_notifier; } status = register_netdevice_notifier(&nfqnl_dev_notifier); if (status < 0) { pr_err("failed to register netdevice notifier\n"); goto cleanup_netlink_subsys; } return status; cleanup_netlink_subsys: nfnetlink_subsys_unregister(&nfqnl_subsys); cleanup_netlink_notifier: netlink_unregister_notifier(&nfqnl_rtnl_notifier); unregister_pernet_subsys(&nfnl_queue_net_ops); out: return status; } static void __exit nfnetlink_queue_fini(void) { unregister_netdevice_notifier(&nfqnl_dev_notifier); nfnetlink_subsys_unregister(&nfqnl_subsys); netlink_unregister_notifier(&nfqnl_rtnl_notifier); unregister_pernet_subsys(&nfnl_queue_net_ops); rcu_barrier(); /* Wait for completion of call_rcu()'s */ } MODULE_DESCRIPTION("netfilter packet queue handler"); MODULE_AUTHOR("Harald Welte "); MODULE_LICENSE("GPL"); MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_QUEUE); module_init(nfnetlink_queue_init); module_exit(nfnetlink_queue_fini);