--- /dev/null
+/*
+ * This is a module which is used for queueing packets and communicating with
+ * userspace via nfnetlink.
+ *
+ * (C) 2005 by Harald Welte <laforge@netfilter.org>
+ * (C) 2007 by Patrick McHardy <kaber@trash.net>
+ *
+ * Based on the old ipv4-only ip_queue.c:
+ * (C) 2000-2002 James Morris <jmorris@intercode.com.au>
+ * (C) 2003-2005 Netfilter Core Team <coreteam@netfilter.org>
+ *
+ * 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.
+ *
+ */
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/init.h>
+#include <linux/spinlock.h>
+#include <linux/slab.h>
+#include <linux/notifier.h>
+#include <linux/netdevice.h>
+#include <linux/netfilter.h>
+#include <linux/proc_fs.h>
+#include <linux/netfilter_ipv4.h>
+#include <linux/netfilter_ipv6.h>
+#include <linux/netfilter_bridge.h>
+#include <linux/netfilter/nfnetlink.h>
+#include <linux/netfilter/nfnetlink_queue.h>
+#include <linux/list.h>
+#include <net/sock.h>
+#include <net/tcp_states.h>
+#include <net/netfilter/nf_queue.h>
+#include <net/netns/generic.h>
+#include <net/netfilter/nfnetlink_queue.h>
+
+#include <linux/atomic.h>
+
+#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
+#include "../bridge/br_private.h"
+#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;
+ 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 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_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--;
+ nf_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 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);
+ bool csum_verify;
+
+ 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.tv64)
+ size += nla_total_size(sizeof(struct nfqnl_msg_packet_timestamp));
+
+ 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)ACCESS_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 = ACCESS_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;
+ }
+
+ if (queue->flags & NFQA_CFG_F_CONNTRACK)
+ ct = nfqnl_ct_get(entskb, &size, &ctinfo);
+
+ 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 */
+ }
+
+ skb = nfnetlink_alloc_skb(net, size, queue->peer_portid,
+ GFP_ATOMIC);
+ if (!skb) {
+ skb_tx_error(entskb);
+ return NULL;
+ }
+
+ nlh = nlmsg_put(skb, 0, 0,
+ NFNL_SUBSYS_QUEUE << 8 | NFQNL_MSG_PACKET,
+ sizeof(struct nfgenmsg), 0);
+ if (!nlh) {
+ skb_tx_error(entskb);
+ kfree_skb(skb);
+ return NULL;
+ }
+ 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 (entskb->tstamp.tv64) {
+ struct nfqnl_msg_packet_timestamp ts;
+ struct timeval tv = ktime_to_timeval(entskb->tstamp);
+ ts.sec = cpu_to_be64(tv.tv_sec);
+ ts.usec = cpu_to_be64(tv.tv_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 (ct && nfqnl_ct_put(skb, ct, ctinfo) < 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 = (struct nlattr *)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;
+ return skb;
+
+nla_put_failure:
+ skb_tx_error(entskb);
+ kfree_skb(skb);
+ net_err_ratelimited("nf_queue: error creating packet message\n");
+ return NULL;
+}
+
+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 (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) {
+ 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)
+ nf_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) {
+ if (nf_queue_entry_get_refs(entry))
+ return entry;
+ kfree(entry);
+ }
+ return NULL;
+}
+
+#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 (skb->nf_bridge)
+ __skb_push(skb, skb->network_header - skb->mac_header);
+}
+
+static void nf_bridge_adjust_segmented_data(struct sk_buff *skb)
+{
+ if (skb->nf_bridge)
+ __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->next = NULL;
+
+ 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 = dev_net(entry->state.in ?
+ entry->state.in : entry->state.out);
+ struct nfnl_queue_net *q = nfnl_queue_pernet(net);
+
+ /* rcu_read_lock()ed by nf_hook_slow() */
+ 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 -ECANCELED 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) {
+ printk(KERN_WARNING "nf_queue: OOM "
+ "in mangle, dropping packet\n");
+ 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 (entry->state.in)
+ if (entry->state.in->ifindex == ifindex)
+ return 1;
+ if (entry->state.out)
+ if (entry->state.out->ifindex == ifindex)
+ return 1;
+#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
+ if (entry->skb->nf_bridge) {
+ 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
+ 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();
+}
+
+#define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
+
+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 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_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 },
+};
+
+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 sock *ctnl, struct sk_buff *skb,
+ const struct nlmsghdr *nlh,
+ const struct nlattr * const nfqa[])
+{
+ 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 net *net = sock_net(ctnl);
+ 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]));
+ nf_reinject(entry, verdict);
+ }
+ return 0;
+}
+
+static int
+nfqnl_recv_verdict(struct sock *ctnl, struct sk_buff *skb,
+ const struct nlmsghdr *nlh,
+ const struct nlattr * const nfqa[])
+{
+ 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 nf_conn *ct = NULL;
+
+ struct net *net = sock_net(ctnl);
+ struct nfnl_queue_net *q = nfnl_queue_pernet(net);
+
+ queue = instance_lookup(q, queue_num);
+ if (!queue)
+ 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;
+
+ if (nfqa[NFQA_CT]) {
+ ct = nfqnl_ct_parse(entry->skb, nfqa[NFQA_CT], &ctinfo);
+ if (ct && nfqa[NFQA_EXP]) {
+ nfqnl_attach_expect(ct, nfqa[NFQA_EXP],
+ NETLINK_CB(skb).portid,
+ nlmsg_report(nlh));
+ }
+ }
+
+ 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)
+ nfqnl_ct_seq_adjust(entry->skb, ct, ctinfo, diff);
+ }
+
+ if (nfqa[NFQA_MARK])
+ entry->skb->mark = ntohl(nla_get_be32(nfqa[NFQA_MARK]));
+
+ nf_reinject(entry, verdict);
+ return 0;
+}
+
+static int
+nfqnl_recv_unsupp(struct sock *ctnl, struct sk_buff *skb,
+ const struct nlmsghdr *nlh,
+ const struct nlattr * const nfqa[])
+{
+ 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) },
+};
+
+static const struct nf_queue_handler nfqh = {
+ .outfn = &nfqnl_enqueue_packet,
+};
+
+static int
+nfqnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
+ const struct nlmsghdr *nlh,
+ const struct nlattr * const nfqa[])
+{
+ 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 net *net = sock_net(ctnl);
+ struct nfnl_queue_net *q = nfnl_queue_pernet(net);
+ 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;
+ }
+ }
+
+ 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);
+ break;
+ case NFQNL_CFG_CMD_PF_BIND:
+ case NFQNL_CFG_CMD_PF_UNBIND:
+ break;
+ default:
+ ret = -ENOTSUPP;
+ break;
+ }
+ }
+
+ if (nfqa[NFQA_CFG_PARAMS]) {
+ struct nfqnl_msg_config_params *params;
+
+ if (!queue) {
+ ret = -ENODEV;
+ goto err_out_unlock;
+ }
+ 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;
+
+ if (!queue) {
+ ret = -ENODEV;
+ goto err_out_unlock;
+ }
+ 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]) {
+ __u32 flags, mask;
+
+ if (!queue) {
+ ret = -ENODEV;
+ goto err_out_unlock;
+ }
+
+ if (!nfqa[NFQA_CFG_MASK]) {
+ /* A mask is needed to specify which flags are being
+ * changed.
+ */
+ ret = -EINVAL;
+ goto err_out_unlock;
+ }
+
+ flags = ntohl(nla_get_be32(nfqa[NFQA_CFG_FLAGS]));
+ mask = ntohl(nla_get_be32(nfqa[NFQA_CFG_MASK]));
+
+ if (flags >= NFQA_CFG_F_MAX) {
+ ret = -EOPNOTSUPP;
+ goto err_out_unlock;
+ }
+
+ 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 seq_has_overflowed(s);
+}
+
+static const struct seq_operations nfqnl_seq_ops = {
+ .start = seq_start,
+ .next = seq_next,
+ .stop = seq_stop,
+ .show = seq_show,
+};
+
+static int nfqnl_open(struct inode *inode, struct file *file)
+{
+ return seq_open_net(inode, file, &nfqnl_seq_ops,
+ sizeof(struct iter_state));
+}
+
+static const struct file_operations nfqnl_file_ops = {
+ .owner = THIS_MODULE,
+ .open = nfqnl_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release_net,
+};
+
+#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("nfnetlink_queue", 0440,
+ net->nf.proc_netfilter, &nfqnl_file_ops))
+ return -ENOMEM;
+#endif
+ return 0;
+}
+
+static void __net_exit nfnl_queue_net_exit(struct net *net)
+{
+#ifdef CONFIG_PROC_FS
+ remove_proc_entry("nfnetlink_queue", net->nf.proc_netfilter);
+#endif
+}
+
+static struct pernet_operations nfnl_queue_net_ops = {
+ .init = nfnl_queue_net_init,
+ .exit = nfnl_queue_net_exit,
+ .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("nf_queue: 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("nf_queue: failed to create netlink socket\n");
+ goto cleanup_netlink_notifier;
+ }
+
+ register_netdevice_notifier(&nfqnl_dev_notifier);
+ nf_register_queue_handler(&nfqh);
+ return status;
+
+cleanup_netlink_notifier:
+ netlink_unregister_notifier(&nfqnl_rtnl_notifier);
+out:
+ return status;
+}
+
+static void __exit nfnetlink_queue_fini(void)
+{
+ nf_unregister_queue_handler();
+ 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 <laforge@netfilter.org>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_QUEUE);
+
+module_init(nfnetlink_queue_init);
+module_exit(nfnetlink_queue_fini);
Code Review / kvmfornfv.git / blobdiff