diff options
Diffstat (limited to 'net/netfilter/nfnetlink_queue.c')
| -rw-r--r-- | net/netfilter/nfnetlink_queue.c | 1132 |
1 files changed, 1132 insertions, 0 deletions
diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c new file mode 100644 index 0000000000000..e3a5285329af5 --- /dev/null +++ b/net/netfilter/nfnetlink_queue.c @@ -0,0 +1,1132 @@ +/* + * This is a module which is used for queueing packets and communicating with + * userspace via nfetlink. + * + * (C) 2005 by Harald Welte <laforge@netfilter.org> + * + * 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/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/nfnetlink.h> +#include <linux/netfilter/nfnetlink_queue.h> +#include <linux/list.h> +#include <net/sock.h> + +#include <asm/atomic.h> + +#ifdef CONFIG_BRIDGE_NETFILTER +#include "../bridge/br_private.h" +#endif + +#define NFQNL_QMAX_DEFAULT 1024 + +#if 0 +#define QDEBUG(x, args ...) printk(KERN_DEBUG "%s(%d):%s(): " x, \ + __FILE__, __LINE__, __FUNCTION__, \ + ## args) +#else +#define QDEBUG(x, ...) +#endif + +struct nfqnl_queue_entry { + struct list_head list; + struct nf_info *info; + struct sk_buff *skb; + unsigned int id; +}; + +struct nfqnl_instance { + struct hlist_node hlist; /* global list of queues */ + atomic_t use; + + int peer_pid; + unsigned int queue_maxlen; + unsigned int copy_range; + unsigned int queue_total; + unsigned int queue_dropped; + unsigned int queue_user_dropped; + + atomic_t id_sequence; /* 'sequence' of pkt ids */ + + u_int16_t queue_num; /* number of this queue */ + u_int8_t copy_mode; + + spinlock_t lock; + + struct list_head queue_list; /* packets in queue */ +}; + +typedef int (*nfqnl_cmpfn)(struct nfqnl_queue_entry *, unsigned long); + +static DEFINE_RWLOCK(instances_lock); + +u_int64_t htonll(u_int64_t in) +{ + u_int64_t out; + int i; + + for (i = 0; i < sizeof(u_int64_t); i++) + ((u_int8_t *)&out)[sizeof(u_int64_t)-1] = ((u_int8_t *)&in)[i]; + + return out; +} + +#define INSTANCE_BUCKETS 16 +static struct hlist_head instance_table[INSTANCE_BUCKETS]; + +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(u_int16_t queue_num) +{ + struct hlist_head *head; + struct hlist_node *pos; + struct nfqnl_instance *inst; + + head = &instance_table[instance_hashfn(queue_num)]; + hlist_for_each_entry(inst, pos, head, hlist) { + if (inst->queue_num == queue_num) + return inst; + } + return NULL; +} + +static struct nfqnl_instance * +instance_lookup_get(u_int16_t queue_num) +{ + struct nfqnl_instance *inst; + + read_lock_bh(&instances_lock); + inst = __instance_lookup(queue_num); + if (inst) + atomic_inc(&inst->use); + read_unlock_bh(&instances_lock); + + return inst; +} + +static void +instance_put(struct nfqnl_instance *inst) +{ + if (inst && atomic_dec_and_test(&inst->use)) { + QDEBUG("kfree(inst=%p)\n", inst); + kfree(inst); + } +} + +static struct nfqnl_instance * +instance_create(u_int16_t queue_num, int pid) +{ + struct nfqnl_instance *inst; + + QDEBUG("entering for queue_num=%u, pid=%d\n", queue_num, pid); + + write_lock_bh(&instances_lock); + if (__instance_lookup(queue_num)) { + inst = NULL; + QDEBUG("aborting, instance already exists\n"); + goto out_unlock; + } + + inst = kmalloc(sizeof(*inst), GFP_ATOMIC); + if (!inst) + goto out_unlock; + + memset(inst, 0, sizeof(*inst)); + inst->queue_num = queue_num; + inst->peer_pid = pid; + inst->queue_maxlen = NFQNL_QMAX_DEFAULT; + inst->copy_range = 0xfffff; + inst->copy_mode = NFQNL_COPY_NONE; + atomic_set(&inst->id_sequence, 0); + /* needs to be two, since we _put() after creation */ + atomic_set(&inst->use, 2); + inst->lock = SPIN_LOCK_UNLOCKED; + INIT_LIST_HEAD(&inst->queue_list); + + if (!try_module_get(THIS_MODULE)) + goto out_free; + + hlist_add_head(&inst->hlist, + &instance_table[instance_hashfn(queue_num)]); + + write_unlock_bh(&instances_lock); + + QDEBUG("successfully created new instance\n"); + + return inst; + +out_free: + kfree(inst); +out_unlock: + write_unlock_bh(&instances_lock); + return NULL; +} + +static void nfqnl_flush(struct nfqnl_instance *queue, int verdict); + +static void +_instance_destroy2(struct nfqnl_instance *inst, int lock) +{ + /* first pull it out of the global list */ + if (lock) + write_lock_bh(&instances_lock); + + QDEBUG("removing instance %p (queuenum=%u) from hash\n", + inst, inst->queue_num); + hlist_del(&inst->hlist); + + if (lock) + write_unlock_bh(&instances_lock); + + /* then flush all pending skbs from the queue */ + nfqnl_flush(inst, NF_DROP); + + /* and finally put the refcount */ + instance_put(inst); + + module_put(THIS_MODULE); +} + +static inline void +__instance_destroy(struct nfqnl_instance *inst) +{ + _instance_destroy2(inst, 0); +} + +static inline void +instance_destroy(struct nfqnl_instance *inst) +{ + _instance_destroy2(inst, 1); +} + + + +static void +issue_verdict(struct nfqnl_queue_entry *entry, int verdict) +{ + QDEBUG("entering for entry %p, verdict %u\n", entry, verdict); + + /* TCP input path (and probably other bits) assume to be called + * from softirq context, not from syscall, like issue_verdict is + * called. TCP input path deadlocks with locks taken from timer + * softirq, e.g. We therefore emulate this by local_bh_disable() */ + + local_bh_disable(); + nf_reinject(entry->skb, entry->info, verdict); + local_bh_enable(); + + kfree(entry); +} + +static inline void +__enqueue_entry(struct nfqnl_instance *queue, + struct nfqnl_queue_entry *entry) +{ + list_add(&entry->list, &queue->queue_list); + queue->queue_total++; +} + +/* + * Find and return a queued entry matched by cmpfn, or return the last + * entry if cmpfn is NULL. + */ +static inline struct nfqnl_queue_entry * +__find_entry(struct nfqnl_instance *queue, nfqnl_cmpfn cmpfn, + unsigned long data) +{ + struct list_head *p; + + list_for_each_prev(p, &queue->queue_list) { + struct nfqnl_queue_entry *entry = (struct nfqnl_queue_entry *)p; + + if (!cmpfn || cmpfn(entry, data)) + return entry; + } + return NULL; +} + +static inline void +__dequeue_entry(struct nfqnl_instance *q, struct nfqnl_queue_entry *entry) +{ + list_del(&entry->list); + q->queue_total--; +} + +static inline struct nfqnl_queue_entry * +__find_dequeue_entry(struct nfqnl_instance *queue, + nfqnl_cmpfn cmpfn, unsigned long data) +{ + struct nfqnl_queue_entry *entry; + + entry = __find_entry(queue, cmpfn, data); + if (entry == NULL) + return NULL; + + __dequeue_entry(queue, entry); + return entry; +} + + +static inline void +__nfqnl_flush(struct nfqnl_instance *queue, int verdict) +{ + struct nfqnl_queue_entry *entry; + + while ((entry = __find_dequeue_entry(queue, NULL, 0))) + issue_verdict(entry, verdict); +} + +static inline int +__nfqnl_set_mode(struct nfqnl_instance *queue, + unsigned char mode, unsigned int range) +{ + int status = 0; + + 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; + /* we're using struct nfattr which has 16bit nfa_len */ + if (range > 0xffff) + queue->copy_range = 0xffff; + else + queue->copy_range = range; + break; + + default: + status = -EINVAL; + + } + return status; +} + +static struct nfqnl_queue_entry * +find_dequeue_entry(struct nfqnl_instance *queue, + nfqnl_cmpfn cmpfn, unsigned long data) +{ + struct nfqnl_queue_entry *entry; + + spin_lock_bh(&queue->lock); + entry = __find_dequeue_entry(queue, cmpfn, data); + spin_unlock_bh(&queue->lock); + + return entry; +} + +static void +nfqnl_flush(struct nfqnl_instance *queue, int verdict) +{ + spin_lock_bh(&queue->lock); + __nfqnl_flush(queue, verdict); + spin_unlock_bh(&queue->lock); +} + +static struct sk_buff * +nfqnl_build_packet_message(struct nfqnl_instance *queue, + struct nfqnl_queue_entry *entry, int *errp) +{ + unsigned char *old_tail; + size_t size; + size_t data_len = 0; + struct sk_buff *skb; + struct nfqnl_msg_packet_hdr pmsg; + struct nlmsghdr *nlh; + struct nfgenmsg *nfmsg; + unsigned int tmp_uint; + + QDEBUG("entered\n"); + + /* all macros expand to constant values at compile time */ + size = NLMSG_SPACE(sizeof(struct nfqnl_msg_packet_hdr)) + + NLMSG_SPACE(sizeof(u_int32_t)) /* ifindex */ + + NLMSG_SPACE(sizeof(u_int32_t)) /* ifindex */ +#ifdef CONFIG_BRIDGE_NETFILTER + + NLMSG_SPACE(sizeof(u_int32_t)) /* ifindex */ + + NLMSG_SPACE(sizeof(u_int32_t)) /* ifindex */ +#endif + + NLMSG_SPACE(sizeof(u_int32_t)) /* mark */ + + NLMSG_SPACE(sizeof(struct nfqnl_msg_packet_hw)) + + NLMSG_SPACE(sizeof(struct nfqnl_msg_packet_timestamp)); + + spin_lock_bh(&queue->lock); + + switch (queue->copy_mode) { + case NFQNL_COPY_META: + case NFQNL_COPY_NONE: + data_len = 0; + break; + + case NFQNL_COPY_PACKET: + if (queue->copy_range == 0 + || queue->copy_range > entry->skb->len) + data_len = entry->skb->len; + else + data_len = queue->copy_range; + + size += NLMSG_SPACE(data_len); + break; + + default: + *errp = -EINVAL; + spin_unlock_bh(&queue->lock); + return NULL; + } + + spin_unlock_bh(&queue->lock); + + skb = alloc_skb(size, GFP_ATOMIC); + if (!skb) + goto nlmsg_failure; + + old_tail= skb->tail; + nlh = NLMSG_PUT(skb, 0, 0, + NFNL_SUBSYS_QUEUE << 8 | NFQNL_MSG_PACKET, + sizeof(struct nfgenmsg)); + nfmsg = NLMSG_DATA(nlh); + nfmsg->nfgen_family = entry->info->pf; + nfmsg->version = NFNETLINK_V0; + nfmsg->res_id = htons(queue->queue_num); + + pmsg.packet_id = htonl(entry->id); + pmsg.hw_protocol = htons(entry->skb->protocol); + pmsg.hook = entry->info->hook; + + NFA_PUT(skb, NFQA_PACKET_HDR, sizeof(pmsg), &pmsg); + + if (entry->info->indev) { + tmp_uint = htonl(entry->info->indev->ifindex); +#ifndef CONFIG_BRIDGE_NETFILTER + NFA_PUT(skb, NFQA_IFINDEX_INDEV, sizeof(tmp_uint), &tmp_uint); +#else + if (entry->info->pf == PF_BRIDGE) { + /* Case 1: indev is physical input device, we need to + * look for bridge group (when called from + * netfilter_bridge) */ + NFA_PUT(skb, NFQA_IFINDEX_PHYSINDEV, sizeof(tmp_uint), + &tmp_uint); + /* this is the bridge group "brX" */ + tmp_uint = htonl(entry->info->indev->br_port->br->dev->ifindex); + NFA_PUT(skb, NFQA_IFINDEX_INDEV, sizeof(tmp_uint), + &tmp_uint); + } else { + /* Case 2: indev is bridge group, we need to look for + * physical device (when called from ipv4) */ + NFA_PUT(skb, NFQA_IFINDEX_INDEV, sizeof(tmp_uint), + &tmp_uint); + if (entry->skb->nf_bridge + && entry->skb->nf_bridge->physindev) { + tmp_uint = htonl(entry->skb->nf_bridge->physindev->ifindex); + NFA_PUT(skb, NFQA_IFINDEX_PHYSINDEV, + sizeof(tmp_uint), &tmp_uint); + } + } +#endif + } + + if (entry->info->outdev) { + tmp_uint = htonl(entry->info->outdev->ifindex); +#ifndef CONFIG_BRIDGE_NETFILTER + NFA_PUT(skb, NFQA_IFINDEX_OUTDEV, sizeof(tmp_uint), &tmp_uint); +#else + if (entry->info->pf == PF_BRIDGE) { + /* Case 1: outdev is physical output device, we need to + * look for bridge group (when called from + * netfilter_bridge) */ + NFA_PUT(skb, NFQA_IFINDEX_PHYSOUTDEV, sizeof(tmp_uint), + &tmp_uint); + /* this is the bridge group "brX" */ + tmp_uint = htonl(entry->info->outdev->br_port->br->dev->ifindex); + NFA_PUT(skb, NFQA_IFINDEX_OUTDEV, sizeof(tmp_uint), + &tmp_uint); + } else { + /* Case 2: outdev is bridge group, we need to look for + * physical output device (when called from ipv4) */ + NFA_PUT(skb, NFQA_IFINDEX_OUTDEV, sizeof(tmp_uint), + &tmp_uint); + if (entry->skb->nf_bridge + && entry->skb->nf_bridge->physoutdev) { + tmp_uint = htonl(entry->skb->nf_bridge->physoutdev->ifindex); + NFA_PUT(skb, NFQA_IFINDEX_PHYSOUTDEV, + sizeof(tmp_uint), &tmp_uint); + } + } +#endif + } + + if (entry->skb->nfmark) { + tmp_uint = htonl(entry->skb->nfmark); + NFA_PUT(skb, NFQA_MARK, sizeof(u_int32_t), &tmp_uint); + } + + if (entry->info->indev && entry->skb->dev + && entry->skb->dev->hard_header_parse) { + struct nfqnl_msg_packet_hw phw; + + phw.hw_addrlen = + entry->skb->dev->hard_header_parse(entry->skb, + phw.hw_addr); + phw.hw_addrlen = htons(phw.hw_addrlen); + NFA_PUT(skb, NFQA_HWADDR, sizeof(phw), &phw); + } + + if (entry->skb->tstamp.off_sec) { + struct nfqnl_msg_packet_timestamp ts; + + ts.sec = htonll(skb_tv_base.tv_sec + entry->skb->tstamp.off_sec); + ts.usec = htonll(skb_tv_base.tv_usec + entry->skb->tstamp.off_usec); + + NFA_PUT(skb, NFQA_TIMESTAMP, sizeof(ts), &ts); + } + + if (data_len) { + struct nfattr *nfa; + int size = NFA_LENGTH(data_len); + + if (skb_tailroom(skb) < (int)NFA_SPACE(data_len)) { + printk(KERN_WARNING "nf_queue: no tailroom!\n"); + goto nlmsg_failure; + } + + nfa = (struct nfattr *)skb_put(skb, NFA_ALIGN(size)); + nfa->nfa_type = NFQA_PAYLOAD; + nfa->nfa_len = size; + + if (skb_copy_bits(entry->skb, 0, NFA_DATA(nfa), data_len)) + BUG(); + } + + nlh->nlmsg_len = skb->tail - old_tail; + return skb; + +nlmsg_failure: +nfattr_failure: + if (skb) + kfree_skb(skb); + *errp = -EINVAL; + if (net_ratelimit()) + printk(KERN_ERR "nf_queue: error creating packet message\n"); + return NULL; +} + +static int +nfqnl_enqueue_packet(struct sk_buff *skb, struct nf_info *info, + unsigned int queuenum, void *data) +{ + int status = -EINVAL; + struct sk_buff *nskb; + struct nfqnl_instance *queue; + struct nfqnl_queue_entry *entry; + + QDEBUG("entered\n"); + + queue = instance_lookup_get(queuenum); + if (!queue) { + QDEBUG("no queue instance matching\n"); + return -EINVAL; + } + + if (queue->copy_mode == NFQNL_COPY_NONE) { + QDEBUG("mode COPY_NONE, aborting\n"); + status = -EAGAIN; + goto err_out_put; + } + + entry = kmalloc(sizeof(*entry), GFP_ATOMIC); + if (entry == NULL) { + if (net_ratelimit()) + printk(KERN_ERR + "nf_queue: OOM in nfqnl_enqueue_packet()\n"); + status = -ENOMEM; + goto err_out_put; + } + + entry->info = info; + entry->skb = skb; + entry->id = atomic_inc_return(&queue->id_sequence); + + nskb = nfqnl_build_packet_message(queue, entry, &status); + if (nskb == NULL) + goto err_out_free; + + spin_lock_bh(&queue->lock); + + if (!queue->peer_pid) + goto err_out_free_nskb; + + if (queue->queue_total >= queue->queue_maxlen) { + queue->queue_dropped++; + status = -ENOSPC; + if (net_ratelimit()) + printk(KERN_WARNING "ip_queue: full at %d entries, " + "dropping packets(s). Dropped: %d\n", + queue->queue_total, queue->queue_dropped); + goto err_out_free_nskb; + } + + /* nfnetlink_unicast will either free the nskb or add it to a socket */ + status = nfnetlink_unicast(nskb, queue->peer_pid, MSG_DONTWAIT); + if (status < 0) { + queue->queue_user_dropped++; + goto err_out_unlock; + } + + __enqueue_entry(queue, entry); + + spin_unlock_bh(&queue->lock); + instance_put(queue); + return status; + +err_out_free_nskb: + kfree_skb(nskb); + +err_out_unlock: + spin_unlock_bh(&queue->lock); + +err_out_free: + kfree(entry); +err_out_put: + instance_put(queue); + return status; +} + +static int +nfqnl_mangle(void *data, int data_len, struct nfqnl_queue_entry *e) +{ + int diff; + + diff = data_len - e->skb->len; + if (diff < 0) + skb_trim(e->skb, data_len); + else if (diff > 0) { + if (data_len > 0xFFFF) + return -EINVAL; + if (diff > skb_tailroom(e->skb)) { + struct sk_buff *newskb; + + newskb = skb_copy_expand(e->skb, + skb_headroom(e->skb), + diff, + GFP_ATOMIC); + if (newskb == NULL) { + printk(KERN_WARNING "ip_queue: OOM " + "in mangle, dropping packet\n"); + return -ENOMEM; + } + if (e->skb->sk) + skb_set_owner_w(newskb, e->skb->sk); + kfree_skb(e->skb); + e->skb = newskb; + } + skb_put(e->skb, diff); + } + if (!skb_make_writable(&e->skb, data_len)) + return -ENOMEM; + memcpy(e->skb->data, data, data_len); + + return 0; +} + +static inline int +id_cmp(struct nfqnl_queue_entry *e, unsigned long id) +{ + return (id == e->id); +} + +static int +nfqnl_set_mode(struct nfqnl_instance *queue, + unsigned char mode, unsigned int range) +{ + int status; + + spin_lock_bh(&queue->lock); + status = __nfqnl_set_mode(queue, mode, range); + spin_unlock_bh(&queue->lock); + + return status; +} + +static int +dev_cmp(struct nfqnl_queue_entry *entry, unsigned long ifindex) +{ + if (entry->info->indev) + if (entry->info->indev->ifindex == ifindex) + return 1; + + if (entry->info->outdev) + if (entry->info->outdev->ifindex == ifindex) + return 1; + + return 0; +} + +/* drop all packets with either indev or outdev == ifindex from all queue + * instances */ +static void +nfqnl_dev_drop(int ifindex) +{ + int i; + + QDEBUG("entering for ifindex %u\n", ifindex); + + /* this only looks like we have to hold the readlock for a way too long + * time, issue_verdict(), nf_reinject(), ... - but we always only + * issue NF_DROP, which is processed directly in nf_reinject() */ + read_lock_bh(&instances_lock); + + for (i = 0; i < INSTANCE_BUCKETS; i++) { + struct hlist_node *tmp; + struct nfqnl_instance *inst; + struct hlist_head *head = &instance_table[i]; + + hlist_for_each_entry(inst, tmp, head, hlist) { + struct nfqnl_queue_entry *entry; + while ((entry = find_dequeue_entry(inst, dev_cmp, + ifindex)) != NULL) + issue_verdict(entry, NF_DROP); + } + } + + read_unlock_bh(&instances_lock); +} + +#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 = ptr; + + /* Drop any packets associated with the downed device */ + if (event == NETDEV_DOWN) + nfqnl_dev_drop(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; + + if (event == NETLINK_URELEASE && + n->protocol == NETLINK_NETFILTER && n->pid) { + int i; + + /* destroy all instances for this pid */ + write_lock_bh(&instances_lock); + for (i = 0; i < INSTANCE_BUCKETS; i++) { + struct hlist_node *tmp, *t2; + struct nfqnl_instance *inst; + struct hlist_head *head = &instance_table[i]; + + hlist_for_each_entry_safe(inst, tmp, t2, head, hlist) { + if (n->pid == inst->peer_pid) + __instance_destroy(inst); + } + } + write_unlock_bh(&instances_lock); + } + return NOTIFY_DONE; +} + +static struct notifier_block nfqnl_rtnl_notifier = { + .notifier_call = nfqnl_rcv_nl_event, +}; + +static const int nfqa_verdict_min[NFQA_MAX] = { + [NFQA_VERDICT_HDR-1] = sizeof(struct nfqnl_msg_verdict_hdr), + [NFQA_MARK-1] = sizeof(u_int32_t), + [NFQA_PAYLOAD-1] = 0, +}; + +static int +nfqnl_recv_verdict(struct sock *ctnl, struct sk_buff *skb, + struct nlmsghdr *nlh, struct nfattr *nfqa[], int *errp) +{ + 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 nfqnl_queue_entry *entry; + int err; + + if (nfattr_bad_size(nfqa, NFQA_MAX, nfqa_verdict_min)) { + QDEBUG("bad attribute size\n"); + return -EINVAL; + } + + queue = instance_lookup_get(queue_num); + if (!queue) + return -ENODEV; + + if (queue->peer_pid != NETLINK_CB(skb).pid) { + err = -EPERM; + goto err_out_put; + } + + if (!nfqa[NFQA_VERDICT_HDR-1]) { + err = -EINVAL; + goto err_out_put; + } + + vhdr = NFA_DATA(nfqa[NFQA_VERDICT_HDR-1]); + verdict = ntohl(vhdr->verdict); + + if ((verdict & NF_VERDICT_MASK) > NF_MAX_VERDICT) { + err = -EINVAL; + goto err_out_put; + } + + entry = find_dequeue_entry(queue, id_cmp, ntohl(vhdr->id)); + if (entry == NULL) { + err = -ENOENT; + goto err_out_put; + } + + if (nfqa[NFQA_PAYLOAD-1]) { + if (nfqnl_mangle(NFA_DATA(nfqa[NFQA_PAYLOAD-1]), + NFA_PAYLOAD(nfqa[NFQA_PAYLOAD-1]), entry) < 0) + verdict = NF_DROP; + } + + if (nfqa[NFQA_MARK-1]) + skb->nfmark = ntohl(*(u_int32_t *)NFA_DATA(nfqa[NFQA_MARK-1])); + + issue_verdict(entry, verdict); + instance_put(queue); + return 0; + +err_out_put: + instance_put(queue); + return err; +} + +static int +nfqnl_recv_unsupp(struct sock *ctnl, struct sk_buff *skb, + struct nlmsghdr *nlh, struct nfattr *nfqa[], int *errp) +{ + return -ENOTSUPP; +} + +static const int nfqa_cfg_min[NFQA_CFG_MAX] = { + [NFQA_CFG_CMD-1] = sizeof(struct nfqnl_msg_config_cmd), + [NFQA_CFG_PARAMS-1] = sizeof(struct nfqnl_msg_config_params), +}; + +static struct nf_queue_handler nfqh = { + .name = "nf_queue", + .outfn = &nfqnl_enqueue_packet, +}; + +static int +nfqnl_recv_config(struct sock *ctnl, struct sk_buff *skb, + struct nlmsghdr *nlh, struct nfattr *nfqa[], int *errp) +{ + struct nfgenmsg *nfmsg = NLMSG_DATA(nlh); + u_int16_t queue_num = ntohs(nfmsg->res_id); + struct nfqnl_instance *queue; + int ret = 0; + + QDEBUG("entering for msg %u\n", NFNL_MSG_TYPE(nlh->nlmsg_type)); + + if (nfattr_bad_size(nfqa, NFQA_CFG_MAX, nfqa_cfg_min)) { + QDEBUG("bad attribute size\n"); + return -EINVAL; + } + + queue = instance_lookup_get(queue_num); + if (nfqa[NFQA_CFG_CMD-1]) { + struct nfqnl_msg_config_cmd *cmd; + cmd = NFA_DATA(nfqa[NFQA_CFG_CMD-1]); + QDEBUG("found CFG_CMD\n"); + + switch (cmd->command) { + case NFQNL_CFG_CMD_BIND: + if (queue) + return -EBUSY; + + queue = instance_create(queue_num, NETLINK_CB(skb).pid); + if (!queue) + return -EINVAL; + break; + case NFQNL_CFG_CMD_UNBIND: + if (!queue) + return -ENODEV; + + if (queue->peer_pid != NETLINK_CB(skb).pid) { + ret = -EPERM; + goto out_put; + } + + instance_destroy(queue); + break; + case NFQNL_CFG_CMD_PF_BIND: + QDEBUG("registering queue handler for pf=%u\n", + ntohs(cmd->pf)); + ret = nf_register_queue_handler(ntohs(cmd->pf), &nfqh); + break; + case NFQNL_CFG_CMD_PF_UNBIND: + QDEBUG("unregistering queue handler for pf=%u\n", + ntohs(cmd->pf)); + /* This is a bug and a feature. We can unregister + * other handlers(!) */ + ret = nf_unregister_queue_handler(ntohs(cmd->pf)); + break; + default: + ret = -EINVAL; + break; + } + } else { + if (!queue) { + QDEBUG("no config command, and no instance ENOENT\n"); + ret = -ENOENT; + goto out_put; + } + + if (queue->peer_pid != NETLINK_CB(skb).pid) { + QDEBUG("no config command, and wrong pid\n"); + ret = -EPERM; + goto out_put; + } + } + + if (nfqa[NFQA_CFG_PARAMS-1]) { + struct nfqnl_msg_config_params *params; + params = NFA_DATA(nfqa[NFQA_CFG_PARAMS-1]); + + nfqnl_set_mode(queue, params->copy_mode, + ntohl(params->copy_range)); + } + +out_put: + instance_put(queue); + return ret; +} + +static struct nfnl_callback nfqnl_cb[NFQNL_MSG_MAX] = { + [NFQNL_MSG_PACKET] = { .call = nfqnl_recv_unsupp, + .attr_count = NFQA_MAX, + .cap_required = CAP_NET_ADMIN }, + [NFQNL_MSG_VERDICT] = { .call = nfqnl_recv_verdict, + .attr_count = NFQA_MAX, + .cap_required = CAP_NET_ADMIN }, + [NFQNL_MSG_CONFIG] = { .call = nfqnl_recv_config, + .attr_count = NFQA_CFG_MAX, + .cap_required = CAP_NET_ADMIN }, +}; + +static 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 { + unsigned int bucket; +}; + +static struct hlist_node *get_first(struct seq_file *seq) +{ + struct iter_state *st = seq->private; + + if (!st) + return NULL; + + for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) { + if (!hlist_empty(&instance_table[st->bucket])) + return 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; + + h = h->next; + while (!h) { + if (++st->bucket >= INSTANCE_BUCKETS) + return NULL; + + h = 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 *seq, loff_t *pos) +{ + read_lock_bh(&instances_lock); + return get_idx(seq, *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) +{ + read_unlock_bh(&instances_lock); +} + +static int seq_show(struct seq_file *s, void *v) +{ + const struct nfqnl_instance *inst = v; + + return seq_printf(s, "%5d %6d %5d %1d %5d %5d %5d %8d %2d\n", + inst->queue_num, + inst->peer_pid, inst->queue_total, + inst->copy_mode, inst->copy_range, + inst->queue_dropped, inst->queue_user_dropped, + atomic_read(&inst->id_sequence), + atomic_read(&inst->use)); +} + +static 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) +{ + struct seq_file *seq; + struct iter_state *is; + int ret; + + is = kmalloc(sizeof(*is), GFP_KERNEL); + if (!is) + return -ENOMEM; + memset(is, 0, sizeof(*is)); + ret = seq_open(file, &nfqnl_seq_ops); + if (ret < 0) + goto out_free; + seq = file->private_data; + seq->private = is; + return ret; +out_free: + kfree(is); + return ret; +} + +static struct file_operations nfqnl_file_ops = { + .owner = THIS_MODULE, + .open = nfqnl_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release_private, +}; + +#endif /* PROC_FS */ + +static int +init_or_cleanup(int init) +{ + int i, status = -ENOMEM; +#ifdef CONFIG_PROC_FS + struct proc_dir_entry *proc_nfqueue; +#endif + + if (!init) + goto cleanup; + + for (i = 0; i < INSTANCE_BUCKETS; i++) + INIT_HLIST_HEAD(&instance_table[i]); + + netlink_register_notifier(&nfqnl_rtnl_notifier); + status = nfnetlink_subsys_register(&nfqnl_subsys); + if (status < 0) { + printk(KERN_ERR "nf_queue: failed to create netlink socket\n"); + goto cleanup_netlink_notifier; + } + +#ifdef CONFIG_PROC_FS + proc_nfqueue = create_proc_entry("nfnetlink_queue", 0440, + proc_net_netfilter); + if (!proc_nfqueue) + goto cleanup_subsys; + proc_nfqueue->proc_fops = &nfqnl_file_ops; +#endif + + register_netdevice_notifier(&nfqnl_dev_notifier); + + return status; + +cleanup: + nf_unregister_queue_handlers(&nfqh); + unregister_netdevice_notifier(&nfqnl_dev_notifier); +#ifdef CONFIG_PROC_FS + remove_proc_entry("nfnetlink_queue", proc_net_netfilter); +cleanup_subsys: +#endif + nfnetlink_subsys_unregister(&nfqnl_subsys); +cleanup_netlink_notifier: + netlink_unregister_notifier(&nfqnl_rtnl_notifier); + return status; +} + +static int __init init(void) +{ + + return init_or_cleanup(1); +} + +static void __exit fini(void) +{ + init_or_cleanup(0); +} + +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(init); +module_exit(fini); |