diff options
Diffstat (limited to 'net/netfilter/nfnetlink_log.c')
| -rw-r--r-- | net/netfilter/nfnetlink_log.c | 1055 |
1 files changed, 1055 insertions, 0 deletions
diff --git a/net/netfilter/nfnetlink_log.c b/net/netfilter/nfnetlink_log.c new file mode 100644 index 000000000000..ff5601ceedcb --- /dev/null +++ b/net/netfilter/nfnetlink_log.c @@ -0,0 +1,1055 @@ +/* + * This is a module which is used for logging packets to userspace via + * nfetlink. + * + * (C) 2005 by Harald Welte <laforge@netfilter.org> + * + * Based on the old ipv4-only ipt_ULOG.c: + * (C) 2000-2004 by Harald Welte <laforge@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/ip.h> +#include <linux/ipv6.h> +#include <linux/netdevice.h> +#include <linux/netfilter.h> +#include <linux/netlink.h> +#include <linux/netfilter/nfnetlink.h> +#include <linux/netfilter/nfnetlink_log.h> +#include <linux/spinlock.h> +#include <linux/sysctl.h> +#include <linux/proc_fs.h> +#include <linux/security.h> +#include <linux/list.h> +#include <linux/jhash.h> +#include <linux/random.h> +#include <net/sock.h> + +#include <asm/atomic.h> + +#ifdef CONFIG_BRIDGE_NETFILTER +#include "../bridge/br_private.h" +#endif + +#define NFULNL_NLBUFSIZ_DEFAULT 4096 +#define NFULNL_TIMEOUT_DEFAULT 100 /* every second */ +#define NFULNL_QTHRESH_DEFAULT 100 /* 100 packets */ + +#define PRINTR(x, args...) do { if (net_ratelimit()) \ + printk(x, ## args); } while (0); + +#if 0 +#define UDEBUG(x, args ...) printk(KERN_DEBUG "%s(%d):%s(): " x, \ + __FILE__, __LINE__, __FUNCTION__, \ + ## args) +#else +#define UDEBUG(x, ...) +#endif + +struct nfulnl_instance { + struct hlist_node hlist; /* global list of instances */ + spinlock_t lock; + atomic_t use; /* use count */ + + unsigned int qlen; /* number of nlmsgs in skb */ + struct sk_buff *skb; /* pre-allocatd skb */ + struct nlmsghdr *lastnlh; /* netlink header of last msg in skb */ + struct timer_list timer; + int peer_pid; /* PID of the peer process */ + + /* configurable parameters */ + unsigned int flushtimeout; /* timeout until queue flush */ + unsigned int nlbufsiz; /* netlink buffer allocation size */ + unsigned int qthreshold; /* threshold of the queue */ + u_int32_t copy_range; + u_int16_t group_num; /* number of this queue */ + u_int8_t copy_mode; +}; + +static DEFINE_RWLOCK(instances_lock); + +#define INSTANCE_BUCKETS 16 +static struct hlist_head instance_table[INSTANCE_BUCKETS]; +static unsigned int hash_init; + +static inline u_int8_t instance_hashfn(u_int16_t group_num) +{ + return ((group_num & 0xff) % INSTANCE_BUCKETS); +} + +static struct nfulnl_instance * +__instance_lookup(u_int16_t group_num) +{ + struct hlist_head *head; + struct hlist_node *pos; + struct nfulnl_instance *inst; + + UDEBUG("entering (group_num=%u)\n", group_num); + + head = &instance_table[instance_hashfn(group_num)]; + hlist_for_each_entry(inst, pos, head, hlist) { + if (inst->group_num == group_num) + return inst; + } + return NULL; +} + +static inline void +instance_get(struct nfulnl_instance *inst) +{ + atomic_inc(&inst->use); +} + +static struct nfulnl_instance * +instance_lookup_get(u_int16_t group_num) +{ + struct nfulnl_instance *inst; + + read_lock_bh(&instances_lock); + inst = __instance_lookup(group_num); + if (inst) + instance_get(inst); + read_unlock_bh(&instances_lock); + + return inst; +} + +static void +instance_put(struct nfulnl_instance *inst) +{ + if (inst && atomic_dec_and_test(&inst->use)) { + UDEBUG("kfree(inst=%p)\n", inst); + kfree(inst); + } +} + +static void nfulnl_timer(unsigned long data); + +static struct nfulnl_instance * +instance_create(u_int16_t group_num, int pid) +{ + struct nfulnl_instance *inst; + + UDEBUG("entering (group_num=%u, pid=%d)\n", group_num, + pid); + + write_lock_bh(&instances_lock); + if (__instance_lookup(group_num)) { + inst = NULL; + UDEBUG("aborting, instance already exists\n"); + goto out_unlock; + } + + inst = kmalloc(sizeof(*inst), GFP_ATOMIC); + if (!inst) + goto out_unlock; + + memset(inst, 0, sizeof(*inst)); + INIT_HLIST_NODE(&inst->hlist); + inst->lock = SPIN_LOCK_UNLOCKED; + /* needs to be two, since we _put() after creation */ + atomic_set(&inst->use, 2); + + init_timer(&inst->timer); + inst->timer.function = nfulnl_timer; + inst->timer.data = (unsigned long)inst; + /* don't start timer yet. (re)start it with every packet */ + + inst->peer_pid = pid; + inst->group_num = group_num; + + inst->qthreshold = NFULNL_QTHRESH_DEFAULT; + inst->flushtimeout = NFULNL_TIMEOUT_DEFAULT; + inst->nlbufsiz = NFULNL_NLBUFSIZ_DEFAULT; + inst->copy_mode = NFULNL_COPY_PACKET; + inst->copy_range = 0xffff; + + if (!try_module_get(THIS_MODULE)) + goto out_free; + + hlist_add_head(&inst->hlist, + &instance_table[instance_hashfn(group_num)]); + + UDEBUG("newly added node: %p, next=%p\n", &inst->hlist, + inst->hlist.next); + + write_unlock_bh(&instances_lock); + + return inst; + +out_free: + instance_put(inst); +out_unlock: + write_unlock_bh(&instances_lock); + return NULL; +} + +static int __nfulnl_send(struct nfulnl_instance *inst); + +static void +_instance_destroy2(struct nfulnl_instance *inst, int lock) +{ + /* first pull it out of the global list */ + if (lock) + write_lock_bh(&instances_lock); + + UDEBUG("removing instance %p (queuenum=%u) from hash\n", + inst, inst->group_num); + + hlist_del(&inst->hlist); + + if (lock) + write_unlock_bh(&instances_lock); + + /* then flush all pending packets from skb */ + + spin_lock_bh(&inst->lock); + if (inst->skb) { + if (inst->qlen) + __nfulnl_send(inst); + if (inst->skb) { + kfree_skb(inst->skb); + inst->skb = NULL; + } + } + spin_unlock_bh(&inst->lock); + + /* and finally put the refcount */ + instance_put(inst); + + module_put(THIS_MODULE); +} + +static inline void +__instance_destroy(struct nfulnl_instance *inst) +{ + _instance_destroy2(inst, 0); +} + +static inline void +instance_destroy(struct nfulnl_instance *inst) +{ + _instance_destroy2(inst, 1); +} + +static int +nfulnl_set_mode(struct nfulnl_instance *inst, u_int8_t mode, + unsigned int range) +{ + int status = 0; + + spin_lock_bh(&inst->lock); + + switch (mode) { + case NFULNL_COPY_NONE: + case NFULNL_COPY_META: + inst->copy_mode = mode; + inst->copy_range = 0; + break; + + case NFULNL_COPY_PACKET: + inst->copy_mode = mode; + /* we're using struct nfattr which has 16bit nfa_len */ + if (range > 0xffff) + inst->copy_range = 0xffff; + else + inst->copy_range = range; + break; + + default: + status = -EINVAL; + break; + } + + spin_unlock_bh(&inst->lock); + + return status; +} + +static int +nfulnl_set_nlbufsiz(struct nfulnl_instance *inst, u_int32_t nlbufsiz) +{ + int status; + + spin_lock_bh(&inst->lock); + if (nlbufsiz < NFULNL_NLBUFSIZ_DEFAULT) + status = -ERANGE; + else if (nlbufsiz > 131072) + status = -ERANGE; + else { + inst->nlbufsiz = nlbufsiz; + status = 0; + } + spin_unlock_bh(&inst->lock); + + return status; +} + +static int +nfulnl_set_timeout(struct nfulnl_instance *inst, u_int32_t timeout) +{ + spin_lock_bh(&inst->lock); + inst->flushtimeout = timeout; + spin_unlock_bh(&inst->lock); + + return 0; +} + +static int +nfulnl_set_qthresh(struct nfulnl_instance *inst, u_int32_t qthresh) +{ + spin_lock_bh(&inst->lock); + inst->qthreshold = qthresh; + spin_unlock_bh(&inst->lock); + + return 0; +} + +static struct sk_buff *nfulnl_alloc_skb(unsigned int inst_size, + unsigned int pkt_size) +{ + struct sk_buff *skb; + + UDEBUG("entered (%u, %u)\n", inst_size, pkt_size); + + /* alloc skb which should be big enough for a whole multipart + * message. WARNING: has to be <= 128k due to slab restrictions */ + + skb = alloc_skb(inst_size, GFP_ATOMIC); + if (!skb) { + PRINTR("nfnetlink_log: can't alloc whole buffer (%u bytes)\n", + inst_size); + + /* try to allocate only as much as we need for current + * packet */ + + skb = alloc_skb(pkt_size, GFP_ATOMIC); + if (!skb) + PRINTR("nfnetlink_log: can't even alloc %u bytes\n", + pkt_size); + } + + return skb; +} + +static int +__nfulnl_send(struct nfulnl_instance *inst) +{ + int status; + + if (timer_pending(&inst->timer)) + del_timer(&inst->timer); + + if (inst->qlen > 1) + inst->lastnlh->nlmsg_type = NLMSG_DONE; + + status = nfnetlink_unicast(inst->skb, inst->peer_pid, MSG_DONTWAIT); + if (status < 0) { + UDEBUG("netlink_unicast() failed\n"); + /* FIXME: statistics */ + } + + inst->qlen = 0; + inst->skb = NULL; + inst->lastnlh = NULL; + + return status; +} + +static void nfulnl_timer(unsigned long data) +{ + struct nfulnl_instance *inst = (struct nfulnl_instance *)data; + + UDEBUG("timer function called, flushing buffer\n"); + + spin_lock_bh(&inst->lock); + __nfulnl_send(inst); + instance_put(inst); + spin_unlock_bh(&inst->lock); +} + +static inline int +__build_packet_message(struct nfulnl_instance *inst, + const struct sk_buff *skb, + unsigned int data_len, + unsigned int pf, + unsigned int hooknum, + const struct net_device *indev, + const struct net_device *outdev, + const struct nf_loginfo *li, + const char *prefix) +{ + unsigned char *old_tail; + struct nfulnl_msg_packet_hdr pmsg; + struct nlmsghdr *nlh; + struct nfgenmsg *nfmsg; + u_int32_t tmp_uint; + + UDEBUG("entered\n"); + + old_tail = inst->skb->tail; + nlh = NLMSG_PUT(inst->skb, 0, 0, + NFNL_SUBSYS_ULOG << 8 | NFULNL_MSG_PACKET, + sizeof(struct nfgenmsg)); + nfmsg = NLMSG_DATA(nlh); + nfmsg->nfgen_family = pf; + nfmsg->version = NFNETLINK_V0; + nfmsg->res_id = htons(inst->group_num); + + pmsg.hw_protocol = htons(skb->protocol); + pmsg.hook = hooknum; + + NFA_PUT(inst->skb, NFULA_PACKET_HDR, sizeof(pmsg), &pmsg); + + if (prefix) { + int slen = strlen(prefix); + if (slen > NFULNL_PREFIXLEN) + slen = NFULNL_PREFIXLEN; + NFA_PUT(inst->skb, NFULA_PREFIX, slen, prefix); + } + + if (indev) { + tmp_uint = htonl(indev->ifindex); +#ifndef CONFIG_BRIDGE_NETFILTER + NFA_PUT(inst->skb, NFULA_IFINDEX_INDEV, sizeof(tmp_uint), + &tmp_uint); +#else + if (pf == PF_BRIDGE) { + /* Case 1: outdev is physical input device, we need to + * look for bridge group (when called from + * netfilter_bridge) */ + NFA_PUT(inst->skb, NFULA_IFINDEX_PHYSINDEV, + sizeof(tmp_uint), &tmp_uint); + /* this is the bridge group "brX" */ + tmp_uint = htonl(indev->br_port->br->dev->ifindex); + NFA_PUT(inst->skb, NFULA_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(inst->skb, NFULA_IFINDEX_INDEV, + sizeof(tmp_uint), &tmp_uint); + if (skb->nf_bridge && skb->nf_bridge->physindev) { + tmp_uint = + htonl(skb->nf_bridge->physindev->ifindex); + NFA_PUT(inst->skb, NFULA_IFINDEX_PHYSINDEV, + sizeof(tmp_uint), &tmp_uint); + } + } +#endif + } + + if (outdev) { + tmp_uint = htonl(outdev->ifindex); +#ifndef CONFIG_BRIDGE_NETFILTER + NFA_PUT(inst->skb, NFULA_IFINDEX_OUTDEV, sizeof(tmp_uint), + &tmp_uint); +#else + if (pf == PF_BRIDGE) { + /* Case 1: outdev is physical output device, we need to + * look for bridge group (when called from + * netfilter_bridge) */ + NFA_PUT(inst->skb, NFULA_IFINDEX_PHYSOUTDEV, + sizeof(tmp_uint), &tmp_uint); + /* this is the bridge group "brX" */ + tmp_uint = htonl(outdev->br_port->br->dev->ifindex); + NFA_PUT(inst->skb, NFULA_IFINDEX_OUTDEV, + sizeof(tmp_uint), &tmp_uint); + } else { + /* Case 2: indev is a bridge group, we need to look + * for physical device (when called from ipv4) */ + NFA_PUT(inst->skb, NFULA_IFINDEX_OUTDEV, + sizeof(tmp_uint), &tmp_uint); + if (skb->nf_bridge) { + tmp_uint = + htonl(skb->nf_bridge->physoutdev->ifindex); + NFA_PUT(inst->skb, NFULA_IFINDEX_PHYSOUTDEV, + sizeof(tmp_uint), &tmp_uint); + } + } +#endif + } + + if (skb->nfmark) { + tmp_uint = htonl(skb->nfmark); + NFA_PUT(inst->skb, NFULA_MARK, sizeof(tmp_uint), &tmp_uint); + } + + if (indev && skb->dev && skb->dev->hard_header_parse) { + struct nfulnl_msg_packet_hw phw; + + phw.hw_addrlen = + skb->dev->hard_header_parse((struct sk_buff *)skb, + phw.hw_addr); + phw.hw_addrlen = htons(phw.hw_addrlen); + NFA_PUT(inst->skb, NFULA_HWADDR, sizeof(phw), &phw); + } + + if (skb->tstamp.off_sec) { + struct nfulnl_msg_packet_timestamp ts; + + ts.sec = cpu_to_be64(skb_tv_base.tv_sec + skb->tstamp.off_sec); + ts.usec = cpu_to_be64(skb_tv_base.tv_usec + skb->tstamp.off_usec); + + NFA_PUT(inst->skb, NFULA_TIMESTAMP, sizeof(ts), &ts); + } + + /* UID */ + if (skb->sk) { + read_lock_bh(&skb->sk->sk_callback_lock); + if (skb->sk->sk_socket && skb->sk->sk_socket->file) { + u_int32_t uid = htonl(skb->sk->sk_socket->file->f_uid); + /* need to unlock here since NFA_PUT may goto */ + read_unlock_bh(&skb->sk->sk_callback_lock); + NFA_PUT(inst->skb, NFULA_UID, sizeof(uid), &uid); + } else + read_unlock_bh(&skb->sk->sk_callback_lock); + } + + if (data_len) { + struct nfattr *nfa; + int size = NFA_LENGTH(data_len); + + if (skb_tailroom(inst->skb) < (int)NFA_SPACE(data_len)) { + printk(KERN_WARNING "nfnetlink_log: no tailroom!\n"); + goto nlmsg_failure; + } + + nfa = (struct nfattr *)skb_put(inst->skb, NFA_ALIGN(size)); + nfa->nfa_type = NFULA_PAYLOAD; + nfa->nfa_len = size; + + if (skb_copy_bits(skb, 0, NFA_DATA(nfa), data_len)) + BUG(); + } + + nlh->nlmsg_len = inst->skb->tail - old_tail; + return 0; + +nlmsg_failure: + UDEBUG("nlmsg_failure\n"); +nfattr_failure: + PRINTR(KERN_ERR "nfnetlink_log: error creating log nlmsg\n"); + return -1; +} + +#define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0) + +static struct nf_loginfo default_loginfo = { + .type = NF_LOG_TYPE_ULOG, + .u = { + .ulog = { + .copy_len = 0xffff, + .group = 0, + .qthreshold = 1, + }, + }, +}; + +/* log handler for internal netfilter logging api */ +static void +nfulnl_log_packet(unsigned int pf, + unsigned int hooknum, + const struct sk_buff *skb, + const struct net_device *in, + const struct net_device *out, + const struct nf_loginfo *li_user, + const char *prefix) +{ + unsigned int size, data_len; + struct nfulnl_instance *inst; + const struct nf_loginfo *li; + unsigned int qthreshold; + unsigned int nlbufsiz; + + if (li_user && li_user->type == NF_LOG_TYPE_ULOG) + li = li_user; + else + li = &default_loginfo; + + inst = instance_lookup_get(li->u.ulog.group); + if (!inst) + inst = instance_lookup_get(0); + if (!inst) { + PRINTR("nfnetlink_log: trying to log packet, " + "but no instance for group %u\n", li->u.ulog.group); + return; + } + + /* all macros expand to constant values at compile time */ + /* FIXME: do we want to make the size calculation conditional based on + * what is actually present? way more branches and checks, but more + * memory efficient... */ + size = NLMSG_SPACE(sizeof(struct nfgenmsg)) + + NFA_SPACE(sizeof(struct nfulnl_msg_packet_hdr)) + + NFA_SPACE(sizeof(u_int32_t)) /* ifindex */ + + NFA_SPACE(sizeof(u_int32_t)) /* ifindex */ +#ifdef CONFIG_BRIDGE_NETFILTER + + NFA_SPACE(sizeof(u_int32_t)) /* ifindex */ + + NFA_SPACE(sizeof(u_int32_t)) /* ifindex */ +#endif + + NFA_SPACE(sizeof(u_int32_t)) /* mark */ + + NFA_SPACE(sizeof(u_int32_t)) /* uid */ + + NFA_SPACE(NFULNL_PREFIXLEN) /* prefix */ + + NFA_SPACE(sizeof(struct nfulnl_msg_packet_hw)) + + NFA_SPACE(sizeof(struct nfulnl_msg_packet_timestamp)); + + UDEBUG("initial size=%u\n", size); + + spin_lock_bh(&inst->lock); + + qthreshold = inst->qthreshold; + /* per-rule qthreshold overrides per-instance */ + if (qthreshold > li->u.ulog.qthreshold) + qthreshold = li->u.ulog.qthreshold; + + switch (inst->copy_mode) { + case NFULNL_COPY_META: + case NFULNL_COPY_NONE: + data_len = 0; + break; + + case NFULNL_COPY_PACKET: + if (inst->copy_range == 0 + || inst->copy_range > skb->len) + data_len = skb->len; + else + data_len = inst->copy_range; + + size += NFA_SPACE(data_len); + UDEBUG("copy_packet, therefore size now %u\n", size); + break; + + default: + spin_unlock_bh(&inst->lock); + instance_put(inst); + return; + } + + if (size > inst->nlbufsiz) + nlbufsiz = size; + else + nlbufsiz = inst->nlbufsiz; + + if (!inst->skb) { + if (!(inst->skb = nfulnl_alloc_skb(nlbufsiz, size))) { + UDEBUG("error in nfulnl_alloc_skb(%u, %u)\n", + inst->nlbufsiz, size); + goto alloc_failure; + } + } else if (inst->qlen >= qthreshold || + size > skb_tailroom(inst->skb)) { + /* either the queue len is too high or we don't have + * enough room in the skb left. flush to userspace. */ + UDEBUG("flushing old skb\n"); + + __nfulnl_send(inst); + + if (!(inst->skb = nfulnl_alloc_skb(nlbufsiz, size))) { + UDEBUG("error in nfulnl_alloc_skb(%u, %u)\n", + inst->nlbufsiz, size); + goto alloc_failure; + } + } + + UDEBUG("qlen %d, qthreshold %d\n", inst->qlen, qthreshold); + inst->qlen++; + + __build_packet_message(inst, skb, data_len, pf, + hooknum, in, out, li, prefix); + + /* timer_pending always called within inst->lock, so there + * is no chance of a race here */ + if (!timer_pending(&inst->timer)) { + instance_get(inst); + inst->timer.expires = jiffies + (inst->flushtimeout*HZ/100); + add_timer(&inst->timer); + } + spin_unlock_bh(&inst->lock); + + return; + +alloc_failure: + spin_unlock_bh(&inst->lock); + instance_put(inst); + UDEBUG("error allocating skb\n"); + /* FIXME: statistics */ +} + +static int +nfulnl_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 nfulnl_instance *inst; + struct hlist_head *head = &instance_table[i]; + + hlist_for_each_entry_safe(inst, tmp, t2, head, hlist) { + UDEBUG("node = %p\n", inst); + if (n->pid == inst->peer_pid) + __instance_destroy(inst); + } + } + write_unlock_bh(&instances_lock); + } + return NOTIFY_DONE; +} + +static struct notifier_block nfulnl_rtnl_notifier = { + .notifier_call = nfulnl_rcv_nl_event, +}; + +static int +nfulnl_recv_unsupp(struct sock *ctnl, struct sk_buff *skb, + struct nlmsghdr *nlh, struct nfattr *nfqa[], int *errp) +{ + return -ENOTSUPP; +} + +static struct nf_logger nfulnl_logger = { + .name = "nfnetlink_log", + .logfn = &nfulnl_log_packet, + .me = THIS_MODULE, +}; + +static const int nfula_min[NFULA_MAX] = { + [NFULA_PACKET_HDR-1] = sizeof(struct nfulnl_msg_packet_hdr), + [NFULA_MARK-1] = sizeof(u_int32_t), + [NFULA_TIMESTAMP-1] = sizeof(struct nfulnl_msg_packet_timestamp), + [NFULA_IFINDEX_INDEV-1] = sizeof(u_int32_t), + [NFULA_IFINDEX_OUTDEV-1]= sizeof(u_int32_t), + [NFULA_HWADDR-1] = sizeof(struct nfulnl_msg_packet_hw), + [NFULA_PAYLOAD-1] = 0, + [NFULA_PREFIX-1] = 0, + [NFULA_UID-1] = sizeof(u_int32_t), +}; + +static const int nfula_cfg_min[NFULA_CFG_MAX] = { + [NFULA_CFG_CMD-1] = sizeof(struct nfulnl_msg_config_cmd), + [NFULA_CFG_MODE-1] = sizeof(struct nfulnl_msg_config_mode), + [NFULA_CFG_TIMEOUT-1] = sizeof(u_int32_t), + [NFULA_CFG_QTHRESH-1] = sizeof(u_int32_t), + [NFULA_CFG_NLBUFSIZ-1] = sizeof(u_int32_t), +}; + +static int +nfulnl_recv_config(struct sock *ctnl, struct sk_buff *skb, + struct nlmsghdr *nlh, struct nfattr *nfula[], int *errp) +{ + struct nfgenmsg *nfmsg = NLMSG_DATA(nlh); + u_int16_t group_num = ntohs(nfmsg->res_id); + struct nfulnl_instance *inst; + int ret = 0; + + UDEBUG("entering for msg %u\n", NFNL_MSG_TYPE(nlh->nlmsg_type)); + + if (nfattr_bad_size(nfula, NFULA_CFG_MAX, nfula_cfg_min)) { + UDEBUG("bad attribute size\n"); + return -EINVAL; + } + + inst = instance_lookup_get(group_num); + if (nfula[NFULA_CFG_CMD-1]) { + u_int8_t pf = nfmsg->nfgen_family; + struct nfulnl_msg_config_cmd *cmd; + cmd = NFA_DATA(nfula[NFULA_CFG_CMD-1]); + UDEBUG("found CFG_CMD for\n"); + + switch (cmd->command) { + case NFULNL_CFG_CMD_BIND: + if (inst) { + ret = -EBUSY; + goto out_put; + } + + inst = instance_create(group_num, + NETLINK_CB(skb).pid); + if (!inst) { + ret = -EINVAL; + goto out_put; + } + break; + case NFULNL_CFG_CMD_UNBIND: + if (!inst) { + ret = -ENODEV; + goto out_put; + } + + if (inst->peer_pid != NETLINK_CB(skb).pid) { + ret = -EPERM; + goto out_put; + } + + instance_destroy(inst); + break; + case NFULNL_CFG_CMD_PF_BIND: + UDEBUG("registering log handler for pf=%u\n", pf); + ret = nf_log_register(pf, &nfulnl_logger); + break; + case NFULNL_CFG_CMD_PF_UNBIND: + UDEBUG("unregistering log handler for pf=%u\n", pf); + /* This is a bug and a feature. We cannot unregister + * other handlers, like nfnetlink_inst can */ + nf_log_unregister_pf(pf); + break; + default: + ret = -EINVAL; + break; + } + } else { + if (!inst) { + UDEBUG("no config command, and no instance for " + "group=%u pid=%u =>ENOENT\n", + group_num, NETLINK_CB(skb).pid); + ret = -ENOENT; + goto out_put; + } + + if (inst->peer_pid != NETLINK_CB(skb).pid) { + UDEBUG("no config command, and wrong pid\n"); + ret = -EPERM; + goto out_put; + } + } + + if (nfula[NFULA_CFG_MODE-1]) { + struct nfulnl_msg_config_mode *params; + params = NFA_DATA(nfula[NFULA_CFG_MODE-1]); + + nfulnl_set_mode(inst, params->copy_mode, + ntohs(params->copy_range)); + } + + if (nfula[NFULA_CFG_TIMEOUT-1]) { + u_int32_t timeout = + *(u_int32_t *)NFA_DATA(nfula[NFULA_CFG_TIMEOUT-1]); + + nfulnl_set_timeout(inst, ntohl(timeout)); + } + + if (nfula[NFULA_CFG_NLBUFSIZ-1]) { + u_int32_t nlbufsiz = + *(u_int32_t *)NFA_DATA(nfula[NFULA_CFG_NLBUFSIZ-1]); + + nfulnl_set_nlbufsiz(inst, ntohl(nlbufsiz)); + } + + if (nfula[NFULA_CFG_QTHRESH-1]) { + u_int32_t qthresh = + *(u_int16_t *)NFA_DATA(nfula[NFULA_CFG_QTHRESH-1]); + + nfulnl_set_qthresh(inst, ntohl(qthresh)); + } + +out_put: + instance_put(inst); + return ret; +} + +static struct nfnl_callback nfulnl_cb[NFULNL_MSG_MAX] = { + [NFULNL_MSG_PACKET] = { .call = nfulnl_recv_unsupp, + .attr_count = NFULA_MAX, + .cap_required = CAP_NET_ADMIN, }, + [NFULNL_MSG_CONFIG] = { .call = nfulnl_recv_config, + .attr_count = NFULA_CFG_MAX, + .cap_required = CAP_NET_ADMIN }, +}; + +static struct nfnetlink_subsystem nfulnl_subsys = { + .name = "log", + .subsys_id = NFNL_SUBSYS_ULOG, + .cb_count = NFULNL_MSG_MAX, + .cb = nfulnl_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 nfulnl_instance *inst = v; + + return seq_printf(s, "%5d %6d %5d %1d %5d %6d %2d\n", + inst->group_num, + inst->peer_pid, inst->qlen, + inst->copy_mode, inst->copy_range, + inst->flushtimeout, atomic_read(&inst->use)); +} + +static struct seq_operations nful_seq_ops = { + .start = seq_start, + .next = seq_next, + .stop = seq_stop, + .show = seq_show, +}; + +static int nful_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, &nful_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 nful_file_ops = { + .owner = THIS_MODULE, + .open = nful_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_nful; +#endif + + if (!init) + goto cleanup; + + for (i = 0; i < INSTANCE_BUCKETS; i++) + INIT_HLIST_HEAD(&instance_table[i]); + + /* it's not really all that important to have a random value, so + * we can do this from the init function, even if there hasn't + * been that much entropy yet */ + get_random_bytes(&hash_init, sizeof(hash_init)); + + netlink_register_notifier(&nfulnl_rtnl_notifier); + status = nfnetlink_subsys_register(&nfulnl_subsys); + if (status < 0) { + printk(KERN_ERR "log: failed to create netlink socket\n"); + goto cleanup_netlink_notifier; + } + +#ifdef CONFIG_PROC_FS + proc_nful = create_proc_entry("nfnetlink_log", 0440, + proc_net_netfilter); + if (!proc_nful) + goto cleanup_subsys; + proc_nful->proc_fops = &nful_file_ops; +#endif + + return status; + +cleanup: + nf_log_unregister_logger(&nfulnl_logger); +#ifdef CONFIG_PROC_FS + remove_proc_entry("nfnetlink_log", proc_net_netfilter); +cleanup_subsys: +#endif + nfnetlink_subsys_unregister(&nfulnl_subsys); +cleanup_netlink_notifier: + netlink_unregister_notifier(&nfulnl_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 userspace logging"); +MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_ULOG); + +module_init(init); +module_exit(fini); |