diff options
author | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2015-08-05 17:04:01 -0300 |
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committer | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2015-08-05 17:04:01 -0300 |
commit | 57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch) | |
tree | 5e910f0e82173f4ef4f51111366a3f1299037a7b /net/netfilter/nfnetlink_queue_core.c |
Initial import
Diffstat (limited to 'net/netfilter/nfnetlink_queue_core.c')
-rw-r--r-- | net/netfilter/nfnetlink_queue_core.c | 1362 |
1 files changed, 1362 insertions, 0 deletions
diff --git a/net/netfilter/nfnetlink_queue_core.c b/net/netfilter/nfnetlink_queue_core.c new file mode 100644 index 000000000..11c7682fa --- /dev/null +++ b/net/netfilter/nfnetlink_queue_core.c @@ -0,0 +1,1362 @@ +/* + * 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); |