| /* |
| * This is a module which is used for logging packets to userspace via |
| * nfetlink. |
| * |
| * (C) 2005 by Harald Welte <laforge@netfilter.org> |
| * (C) 2006-2012 Patrick McHardy <kaber@trash.net> |
| * |
| * 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. |
| */ |
| |
| #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| |
| #include <linux/module.h> |
| #include <linux/skbuff.h> |
| #include <linux/if_arp.h> |
| #include <linux/init.h> |
| #include <linux/ip.h> |
| #include <linux/ipv6.h> |
| #include <linux/netdevice.h> |
| #include <linux/netfilter.h> |
| #include <linux/netfilter_bridge.h> |
| #include <net/netlink.h> |
| #include <linux/netfilter/nfnetlink.h> |
| #include <linux/netfilter/nfnetlink_log.h> |
| #include <linux/netfilter/nf_conntrack_common.h> |
| #include <linux/spinlock.h> |
| #include <linux/sysctl.h> |
| #include <linux/proc_fs.h> |
| #include <linux/security.h> |
| #include <linux/list.h> |
| #include <linux/slab.h> |
| #include <net/sock.h> |
| #include <net/netfilter/nf_log.h> |
| #include <net/netns/generic.h> |
| #include <net/netfilter/nfnetlink_log.h> |
| |
| #include <linux/atomic.h> |
| |
| #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) |
| #include "../bridge/br_private.h" |
| #endif |
| |
| #define NFULNL_NLBUFSIZ_DEFAULT NLMSG_GOODSIZE |
| #define NFULNL_TIMEOUT_DEFAULT 100 /* every second */ |
| #define NFULNL_QTHRESH_DEFAULT 100 /* 100 packets */ |
| /* max packet size is limited by 16-bit struct nfattr nfa_len field */ |
| #define NFULNL_COPY_RANGE_MAX (0xFFFF - NLA_HDRLEN) |
| |
| #define PRINTR(x, args...) do { if (net_ratelimit()) \ |
| printk(x, ## args); } while (0); |
| |
| 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 timer_list timer; |
| struct net *net; |
| struct user_namespace *peer_user_ns; /* User namespace of the peer process */ |
| u32 peer_portid; /* PORTID 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_int32_t seq; /* instance-local sequential counter */ |
| u_int16_t group_num; /* number of this queue */ |
| u_int16_t flags; |
| u_int8_t copy_mode; |
| struct rcu_head rcu; |
| }; |
| |
| #define INSTANCE_BUCKETS 16 |
| |
| static int nfnl_log_net_id __read_mostly; |
| |
| struct nfnl_log_net { |
| spinlock_t instances_lock; |
| struct hlist_head instance_table[INSTANCE_BUCKETS]; |
| atomic_t global_seq; |
| }; |
| |
| static struct nfnl_log_net *nfnl_log_pernet(struct net *net) |
| { |
| return net_generic(net, nfnl_log_net_id); |
| } |
| |
| static inline u_int8_t instance_hashfn(u_int16_t group_num) |
| { |
| return ((group_num & 0xff) % INSTANCE_BUCKETS); |
| } |
| |
| static struct nfulnl_instance * |
| __instance_lookup(struct nfnl_log_net *log, u_int16_t group_num) |
| { |
| struct hlist_head *head; |
| struct nfulnl_instance *inst; |
| |
| head = &log->instance_table[instance_hashfn(group_num)]; |
| hlist_for_each_entry_rcu(inst, 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(struct nfnl_log_net *log, u_int16_t group_num) |
| { |
| struct nfulnl_instance *inst; |
| |
| rcu_read_lock_bh(); |
| inst = __instance_lookup(log, group_num); |
| if (inst && !atomic_inc_not_zero(&inst->use)) |
| inst = NULL; |
| rcu_read_unlock_bh(); |
| |
| return inst; |
| } |
| |
| static void nfulnl_instance_free_rcu(struct rcu_head *head) |
| { |
| struct nfulnl_instance *inst = |
| container_of(head, struct nfulnl_instance, rcu); |
| |
| put_net(inst->net); |
| kfree(inst); |
| module_put(THIS_MODULE); |
| } |
| |
| static void |
| instance_put(struct nfulnl_instance *inst) |
| { |
| if (inst && atomic_dec_and_test(&inst->use)) |
| call_rcu_bh(&inst->rcu, nfulnl_instance_free_rcu); |
| } |
| |
| static void nfulnl_timer(unsigned long data); |
| |
| static struct nfulnl_instance * |
| instance_create(struct net *net, u_int16_t group_num, |
| u32 portid, struct user_namespace *user_ns) |
| { |
| struct nfulnl_instance *inst; |
| struct nfnl_log_net *log = nfnl_log_pernet(net); |
| int err; |
| |
| spin_lock_bh(&log->instances_lock); |
| if (__instance_lookup(log, group_num)) { |
| err = -EEXIST; |
| goto out_unlock; |
| } |
| |
| inst = kzalloc(sizeof(*inst), GFP_ATOMIC); |
| if (!inst) { |
| err = -ENOMEM; |
| goto out_unlock; |
| } |
| |
| if (!try_module_get(THIS_MODULE)) { |
| kfree(inst); |
| err = -EAGAIN; |
| goto out_unlock; |
| } |
| |
| INIT_HLIST_NODE(&inst->hlist); |
| spin_lock_init(&inst->lock); |
| /* needs to be two, since we _put() after creation */ |
| atomic_set(&inst->use, 2); |
| |
| setup_timer(&inst->timer, nfulnl_timer, (unsigned long)inst); |
| |
| inst->net = get_net(net); |
| inst->peer_user_ns = user_ns; |
| inst->peer_portid = portid; |
| 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 = NFULNL_COPY_RANGE_MAX; |
| |
| hlist_add_head_rcu(&inst->hlist, |
| &log->instance_table[instance_hashfn(group_num)]); |
| |
| |
| spin_unlock_bh(&log->instances_lock); |
| |
| return inst; |
| |
| out_unlock: |
| spin_unlock_bh(&log->instances_lock); |
| return ERR_PTR(err); |
| } |
| |
| static void __nfulnl_flush(struct nfulnl_instance *inst); |
| |
| /* called with BH disabled */ |
| static void |
| __instance_destroy(struct nfulnl_instance *inst) |
| { |
| /* first pull it out of the global list */ |
| hlist_del_rcu(&inst->hlist); |
| |
| /* then flush all pending packets from skb */ |
| |
| spin_lock(&inst->lock); |
| |
| /* lockless readers wont be able to use us */ |
| inst->copy_mode = NFULNL_COPY_DISABLED; |
| |
| if (inst->skb) |
| __nfulnl_flush(inst); |
| spin_unlock(&inst->lock); |
| |
| /* and finally put the refcount */ |
| instance_put(inst); |
| } |
| |
| static inline void |
| instance_destroy(struct nfnl_log_net *log, |
| struct nfulnl_instance *inst) |
| { |
| spin_lock_bh(&log->instances_lock); |
| __instance_destroy(inst); |
| spin_unlock_bh(&log->instances_lock); |
| } |
| |
| 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; |
| if (range == 0) |
| range = NFULNL_COPY_RANGE_MAX; |
| inst->copy_range = min_t(unsigned int, |
| range, NFULNL_COPY_RANGE_MAX); |
| 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 int |
| nfulnl_set_flags(struct nfulnl_instance *inst, u_int16_t flags) |
| { |
| spin_lock_bh(&inst->lock); |
| inst->flags = flags; |
| spin_unlock_bh(&inst->lock); |
| |
| return 0; |
| } |
| |
| static struct sk_buff * |
| nfulnl_alloc_skb(struct net *net, u32 peer_portid, unsigned int inst_size, |
| unsigned int pkt_size) |
| { |
| struct sk_buff *skb; |
| unsigned int n; |
| |
| /* alloc skb which should be big enough for a whole multipart |
| * message. WARNING: has to be <= 128k due to slab restrictions */ |
| |
| n = max(inst_size, pkt_size); |
| skb = nfnetlink_alloc_skb(net, n, peer_portid, GFP_ATOMIC); |
| if (!skb) { |
| if (n > pkt_size) { |
| /* try to allocate only as much as we need for current |
| * packet */ |
| |
| skb = nfnetlink_alloc_skb(net, pkt_size, |
| peer_portid, GFP_ATOMIC); |
| } |
| } |
| |
| return skb; |
| } |
| |
| static void |
| __nfulnl_send(struct nfulnl_instance *inst) |
| { |
| if (inst->qlen > 1) { |
| struct nlmsghdr *nlh = nlmsg_put(inst->skb, 0, 0, |
| NLMSG_DONE, |
| sizeof(struct nfgenmsg), |
| 0); |
| if (WARN_ONCE(!nlh, "bad nlskb size: %u, tailroom %d\n", |
| inst->skb->len, skb_tailroom(inst->skb))) { |
| kfree_skb(inst->skb); |
| goto out; |
| } |
| } |
| nfnetlink_unicast(inst->skb, inst->net, inst->peer_portid, |
| MSG_DONTWAIT); |
| out: |
| inst->qlen = 0; |
| inst->skb = NULL; |
| } |
| |
| static void |
| __nfulnl_flush(struct nfulnl_instance *inst) |
| { |
| /* timer holds a reference */ |
| if (del_timer(&inst->timer)) |
| instance_put(inst); |
| if (inst->skb) |
| __nfulnl_send(inst); |
| } |
| |
| static void |
| nfulnl_timer(unsigned long data) |
| { |
| struct nfulnl_instance *inst = (struct nfulnl_instance *)data; |
| |
| spin_lock_bh(&inst->lock); |
| if (inst->skb) |
| __nfulnl_send(inst); |
| spin_unlock_bh(&inst->lock); |
| instance_put(inst); |
| } |
| |
| /* This is an inline function, we don't really care about a long |
| * list of arguments */ |
| static inline int |
| __build_packet_message(struct nfnl_log_net *log, |
| struct nfulnl_instance *inst, |
| const struct sk_buff *skb, |
| unsigned int data_len, |
| u_int8_t pf, |
| unsigned int hooknum, |
| const struct net_device *indev, |
| const struct net_device *outdev, |
| const char *prefix, unsigned int plen, |
| const struct nfnl_ct_hook *nfnl_ct, |
| struct nf_conn *ct, enum ip_conntrack_info ctinfo) |
| { |
| struct nfulnl_msg_packet_hdr pmsg; |
| struct nlmsghdr *nlh; |
| struct nfgenmsg *nfmsg; |
| sk_buff_data_t old_tail = inst->skb->tail; |
| struct sock *sk; |
| const unsigned char *hwhdrp; |
| |
| nlh = nlmsg_put(inst->skb, 0, 0, |
| NFNL_SUBSYS_ULOG << 8 | NFULNL_MSG_PACKET, |
| sizeof(struct nfgenmsg), 0); |
| if (!nlh) |
| return -1; |
| nfmsg = nlmsg_data(nlh); |
| nfmsg->nfgen_family = pf; |
| nfmsg->version = NFNETLINK_V0; |
| nfmsg->res_id = htons(inst->group_num); |
| |
| memset(&pmsg, 0, sizeof(pmsg)); |
| pmsg.hw_protocol = skb->protocol; |
| pmsg.hook = hooknum; |
| |
| if (nla_put(inst->skb, NFULA_PACKET_HDR, sizeof(pmsg), &pmsg)) |
| goto nla_put_failure; |
| |
| if (prefix && |
| nla_put(inst->skb, NFULA_PREFIX, plen, prefix)) |
| goto nla_put_failure; |
| |
| if (indev) { |
| #if !IS_ENABLED(CONFIG_BRIDGE_NETFILTER) |
| if (nla_put_be32(inst->skb, NFULA_IFINDEX_INDEV, |
| htonl(indev->ifindex))) |
| goto nla_put_failure; |
| #else |
| if (pf == PF_BRIDGE) { |
| /* Case 1: outdev is physical input device, we need to |
| * look for bridge group (when called from |
| * netfilter_bridge) */ |
| if (nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSINDEV, |
| htonl(indev->ifindex)) || |
| /* this is the bridge group "brX" */ |
| /* rcu_read_lock()ed by nf_hook_slow or nf_log_packet */ |
| nla_put_be32(inst->skb, NFULA_IFINDEX_INDEV, |
| htonl(br_port_get_rcu(indev)->br->dev->ifindex))) |
| goto nla_put_failure; |
| } else { |
| struct net_device *physindev; |
| |
| /* Case 2: indev is bridge group, we need to look for |
| * physical device (when called from ipv4) */ |
| if (nla_put_be32(inst->skb, NFULA_IFINDEX_INDEV, |
| htonl(indev->ifindex))) |
| goto nla_put_failure; |
| |
| physindev = nf_bridge_get_physindev(skb); |
| if (physindev && |
| nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSINDEV, |
| htonl(physindev->ifindex))) |
| goto nla_put_failure; |
| } |
| #endif |
| } |
| |
| if (outdev) { |
| #if !IS_ENABLED(CONFIG_BRIDGE_NETFILTER) |
| if (nla_put_be32(inst->skb, NFULA_IFINDEX_OUTDEV, |
| htonl(outdev->ifindex))) |
| goto nla_put_failure; |
| #else |
| if (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(inst->skb, NFULA_IFINDEX_PHYSOUTDEV, |
| htonl(outdev->ifindex)) || |
| /* this is the bridge group "brX" */ |
| /* rcu_read_lock()ed by nf_hook_slow or nf_log_packet */ |
| nla_put_be32(inst->skb, NFULA_IFINDEX_OUTDEV, |
| htonl(br_port_get_rcu(outdev)->br->dev->ifindex))) |
| goto nla_put_failure; |
| } else { |
| struct net_device *physoutdev; |
| |
| /* Case 2: indev is a bridge group, we need to look |
| * for physical device (when called from ipv4) */ |
| if (nla_put_be32(inst->skb, NFULA_IFINDEX_OUTDEV, |
| htonl(outdev->ifindex))) |
| goto nla_put_failure; |
| |
| physoutdev = nf_bridge_get_physoutdev(skb); |
| if (physoutdev && |
| nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSOUTDEV, |
| htonl(physoutdev->ifindex))) |
| goto nla_put_failure; |
| } |
| #endif |
| } |
| |
| if (skb->mark && |
| nla_put_be32(inst->skb, NFULA_MARK, htonl(skb->mark))) |
| goto nla_put_failure; |
| |
| if (indev && skb->dev && |
| skb->mac_header != skb->network_header) { |
| struct nfulnl_msg_packet_hw phw; |
| int len; |
| |
| memset(&phw, 0, sizeof(phw)); |
| len = dev_parse_header(skb, phw.hw_addr); |
| if (len > 0) { |
| phw.hw_addrlen = htons(len); |
| if (nla_put(inst->skb, NFULA_HWADDR, sizeof(phw), &phw)) |
| goto nla_put_failure; |
| } |
| } |
| |
| if (indev && skb_mac_header_was_set(skb)) { |
| if (nla_put_be16(inst->skb, NFULA_HWTYPE, htons(skb->dev->type)) || |
| nla_put_be16(inst->skb, NFULA_HWLEN, |
| htons(skb->dev->hard_header_len))) |
| goto nla_put_failure; |
| |
| hwhdrp = skb_mac_header(skb); |
| |
| if (skb->dev->type == ARPHRD_SIT) |
| hwhdrp -= ETH_HLEN; |
| |
| if (hwhdrp >= skb->head && |
| nla_put(inst->skb, NFULA_HWHEADER, |
| skb->dev->hard_header_len, hwhdrp)) |
| goto nla_put_failure; |
| } |
| |
| if (skb->tstamp.tv64) { |
| struct nfulnl_msg_packet_timestamp ts; |
| struct timespec64 kts = ktime_to_timespec64(skb->tstamp); |
| ts.sec = cpu_to_be64(kts.tv_sec); |
| ts.usec = cpu_to_be64(kts.tv_nsec / NSEC_PER_USEC); |
| |
| if (nla_put(inst->skb, NFULA_TIMESTAMP, sizeof(ts), &ts)) |
| goto nla_put_failure; |
| } |
| |
| /* UID */ |
| sk = skb->sk; |
| if (sk && sk_fullsock(sk)) { |
| read_lock_bh(&sk->sk_callback_lock); |
| if (sk->sk_socket && sk->sk_socket->file) { |
| struct file *file = sk->sk_socket->file; |
| const struct cred *cred = file->f_cred; |
| struct user_namespace *user_ns = inst->peer_user_ns; |
| __be32 uid = htonl(from_kuid_munged(user_ns, cred->fsuid)); |
| __be32 gid = htonl(from_kgid_munged(user_ns, cred->fsgid)); |
| read_unlock_bh(&sk->sk_callback_lock); |
| if (nla_put_be32(inst->skb, NFULA_UID, uid) || |
| nla_put_be32(inst->skb, NFULA_GID, gid)) |
| goto nla_put_failure; |
| } else |
| read_unlock_bh(&sk->sk_callback_lock); |
| } |
| |
| /* local sequence number */ |
| if ((inst->flags & NFULNL_CFG_F_SEQ) && |
| nla_put_be32(inst->skb, NFULA_SEQ, htonl(inst->seq++))) |
| goto nla_put_failure; |
| |
| /* global sequence number */ |
| if ((inst->flags & NFULNL_CFG_F_SEQ_GLOBAL) && |
| nla_put_be32(inst->skb, NFULA_SEQ_GLOBAL, |
| htonl(atomic_inc_return(&log->global_seq)))) |
| goto nla_put_failure; |
| |
| if (ct && nfnl_ct->build(inst->skb, ct, ctinfo, |
| NFULA_CT, NFULA_CT_INFO) < 0) |
| goto nla_put_failure; |
| |
| if (data_len) { |
| struct nlattr *nla; |
| int size = nla_attr_size(data_len); |
| |
| if (skb_tailroom(inst->skb) < nla_total_size(data_len)) |
| goto nla_put_failure; |
| |
| nla = (struct nlattr *)skb_put(inst->skb, nla_total_size(data_len)); |
| nla->nla_type = NFULA_PAYLOAD; |
| nla->nla_len = size; |
| |
| if (skb_copy_bits(skb, 0, nla_data(nla), data_len)) |
| BUG(); |
| } |
| |
| nlh->nlmsg_len = inst->skb->tail - old_tail; |
| return 0; |
| |
| nla_put_failure: |
| PRINTR(KERN_ERR "nfnetlink_log: error creating log nlmsg\n"); |
| return -1; |
| } |
| |
| 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 */ |
| void |
| nfulnl_log_packet(struct net *net, |
| u_int8_t 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) |
| { |
| size_t size; |
| unsigned int data_len; |
| struct nfulnl_instance *inst; |
| const struct nf_loginfo *li; |
| unsigned int qthreshold; |
| unsigned int plen; |
| struct nfnl_log_net *log = nfnl_log_pernet(net); |
| const struct nfnl_ct_hook *nfnl_ct = NULL; |
| struct nf_conn *ct = NULL; |
| enum ip_conntrack_info uninitialized_var(ctinfo); |
| |
| if (li_user && li_user->type == NF_LOG_TYPE_ULOG) |
| li = li_user; |
| else |
| li = &default_loginfo; |
| |
| inst = instance_lookup_get(log, li->u.ulog.group); |
| if (!inst) |
| return; |
| |
| plen = 0; |
| if (prefix) |
| plen = strlen(prefix) + 1; |
| |
| /* 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_total_size(sizeof(struct nfgenmsg)) |
| + nla_total_size(sizeof(struct nfulnl_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(u_int32_t)) /* uid */ |
| + nla_total_size(sizeof(u_int32_t)) /* gid */ |
| + nla_total_size(plen) /* prefix */ |
| + nla_total_size(sizeof(struct nfulnl_msg_packet_hw)) |
| + nla_total_size(sizeof(struct nfulnl_msg_packet_timestamp)) |
| + nla_total_size(sizeof(struct nfgenmsg)); /* NLMSG_DONE */ |
| |
| if (in && skb_mac_header_was_set(skb)) { |
| size += nla_total_size(skb->dev->hard_header_len) |
| + nla_total_size(sizeof(u_int16_t)) /* hwtype */ |
| + nla_total_size(sizeof(u_int16_t)); /* hwlen */ |
| } |
| |
| spin_lock_bh(&inst->lock); |
| |
| if (inst->flags & NFULNL_CFG_F_SEQ) |
| size += nla_total_size(sizeof(u_int32_t)); |
| if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL) |
| size += nla_total_size(sizeof(u_int32_t)); |
| if (inst->flags & NFULNL_CFG_F_CONNTRACK) { |
| nfnl_ct = rcu_dereference(nfnl_ct_hook); |
| if (nfnl_ct != NULL) { |
| ct = nfnl_ct->get_ct(skb, &ctinfo); |
| if (ct != NULL) |
| size += nfnl_ct->build_size(ct); |
| } |
| } |
| |
| qthreshold = inst->qthreshold; |
| /* per-rule qthreshold overrides per-instance */ |
| if (li->u.ulog.qthreshold) |
| 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 > skb->len) |
| data_len = skb->len; |
| else |
| data_len = inst->copy_range; |
| |
| size += nla_total_size(data_len); |
| break; |
| |
| case NFULNL_COPY_DISABLED: |
| default: |
| goto unlock_and_release; |
| } |
| |
| if (inst->skb && 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. */ |
| __nfulnl_flush(inst); |
| } |
| |
| if (!inst->skb) { |
| inst->skb = nfulnl_alloc_skb(net, inst->peer_portid, |
| inst->nlbufsiz, size); |
| if (!inst->skb) |
| goto alloc_failure; |
| } |
| |
| inst->qlen++; |
| |
| __build_packet_message(log, inst, skb, data_len, pf, |
| hooknum, in, out, prefix, plen, |
| nfnl_ct, ct, ctinfo); |
| |
| if (inst->qlen >= qthreshold) |
| __nfulnl_flush(inst); |
| /* timer_pending always called within inst->lock, so there |
| * is no chance of a race here */ |
| else if (!timer_pending(&inst->timer)) { |
| instance_get(inst); |
| inst->timer.expires = jiffies + (inst->flushtimeout*HZ/100); |
| add_timer(&inst->timer); |
| } |
| |
| unlock_and_release: |
| spin_unlock_bh(&inst->lock); |
| instance_put(inst); |
| return; |
| |
| alloc_failure: |
| /* FIXME: statistics */ |
| goto unlock_and_release; |
| } |
| EXPORT_SYMBOL_GPL(nfulnl_log_packet); |
| |
| static int |
| nfulnl_rcv_nl_event(struct notifier_block *this, |
| unsigned long event, void *ptr) |
| { |
| struct netlink_notify *n = ptr; |
| struct nfnl_log_net *log = nfnl_log_pernet(n->net); |
| |
| if (event == NETLINK_URELEASE && n->protocol == NETLINK_NETFILTER) { |
| int i; |
| |
| /* destroy all instances for this portid */ |
| spin_lock_bh(&log->instances_lock); |
| for (i = 0; i < INSTANCE_BUCKETS; i++) { |
| struct hlist_node *t2; |
| struct nfulnl_instance *inst; |
| struct hlist_head *head = &log->instance_table[i]; |
| |
| hlist_for_each_entry_safe(inst, t2, head, hlist) { |
| if (n->portid == inst->peer_portid) |
| __instance_destroy(inst); |
| } |
| } |
| spin_unlock_bh(&log->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, |
| const struct nlmsghdr *nlh, |
| const struct nlattr * const nfqa[]) |
| { |
| return -ENOTSUPP; |
| } |
| |
| static struct nf_logger nfulnl_logger __read_mostly = { |
| .name = "nfnetlink_log", |
| .type = NF_LOG_TYPE_ULOG, |
| .logfn = &nfulnl_log_packet, |
| .me = THIS_MODULE, |
| }; |
| |
| static const struct nla_policy nfula_cfg_policy[NFULA_CFG_MAX+1] = { |
| [NFULA_CFG_CMD] = { .len = sizeof(struct nfulnl_msg_config_cmd) }, |
| [NFULA_CFG_MODE] = { .len = sizeof(struct nfulnl_msg_config_mode) }, |
| [NFULA_CFG_TIMEOUT] = { .type = NLA_U32 }, |
| [NFULA_CFG_QTHRESH] = { .type = NLA_U32 }, |
| [NFULA_CFG_NLBUFSIZ] = { .type = NLA_U32 }, |
| [NFULA_CFG_FLAGS] = { .type = NLA_U16 }, |
| }; |
| |
| static int |
| nfulnl_recv_config(struct sock *ctnl, struct sk_buff *skb, |
| const struct nlmsghdr *nlh, |
| const struct nlattr * const nfula[]) |
| { |
| struct nfgenmsg *nfmsg = nlmsg_data(nlh); |
| u_int16_t group_num = ntohs(nfmsg->res_id); |
| struct nfulnl_instance *inst; |
| struct nfulnl_msg_config_cmd *cmd = NULL; |
| struct net *net = sock_net(ctnl); |
| struct nfnl_log_net *log = nfnl_log_pernet(net); |
| int ret = 0; |
| u16 flags = 0; |
| |
| if (nfula[NFULA_CFG_CMD]) { |
| u_int8_t pf = nfmsg->nfgen_family; |
| cmd = nla_data(nfula[NFULA_CFG_CMD]); |
| |
| /* Commands without queue context */ |
| switch (cmd->command) { |
| case NFULNL_CFG_CMD_PF_BIND: |
| return nf_log_bind_pf(net, pf, &nfulnl_logger); |
| case NFULNL_CFG_CMD_PF_UNBIND: |
| nf_log_unbind_pf(net, pf); |
| return 0; |
| } |
| } |
| |
| inst = instance_lookup_get(log, group_num); |
| if (inst && inst->peer_portid != NETLINK_CB(skb).portid) { |
| ret = -EPERM; |
| goto out_put; |
| } |
| |
| /* Check if we support these flags in first place, dependencies should |
| * be there too not to break atomicity. |
| */ |
| if (nfula[NFULA_CFG_FLAGS]) { |
| flags = ntohs(nla_get_be16(nfula[NFULA_CFG_FLAGS])); |
| |
| if ((flags & NFULNL_CFG_F_CONNTRACK) && |
| !rcu_access_pointer(nfnl_ct_hook)) { |
| #ifdef CONFIG_MODULES |
| nfnl_unlock(NFNL_SUBSYS_ULOG); |
| request_module("ip_conntrack_netlink"); |
| nfnl_lock(NFNL_SUBSYS_ULOG); |
| if (rcu_access_pointer(nfnl_ct_hook)) { |
| ret = -EAGAIN; |
| goto out_put; |
| } |
| #endif |
| ret = -EOPNOTSUPP; |
| goto out_put; |
| } |
| } |
| |
| if (cmd != NULL) { |
| switch (cmd->command) { |
| case NFULNL_CFG_CMD_BIND: |
| if (inst) { |
| ret = -EBUSY; |
| goto out_put; |
| } |
| |
| inst = instance_create(net, group_num, |
| NETLINK_CB(skb).portid, |
| sk_user_ns(NETLINK_CB(skb).sk)); |
| if (IS_ERR(inst)) { |
| ret = PTR_ERR(inst); |
| goto out; |
| } |
| break; |
| case NFULNL_CFG_CMD_UNBIND: |
| if (!inst) { |
| ret = -ENODEV; |
| goto out; |
| } |
| |
| instance_destroy(log, inst); |
| goto out_put; |
| default: |
| ret = -ENOTSUPP; |
| break; |
| } |
| } else if (!inst) { |
| ret = -ENODEV; |
| goto out; |
| } |
| |
| if (nfula[NFULA_CFG_MODE]) { |
| struct nfulnl_msg_config_mode *params = |
| nla_data(nfula[NFULA_CFG_MODE]); |
| |
| nfulnl_set_mode(inst, params->copy_mode, |
| ntohl(params->copy_range)); |
| } |
| |
| if (nfula[NFULA_CFG_TIMEOUT]) { |
| __be32 timeout = nla_get_be32(nfula[NFULA_CFG_TIMEOUT]); |
| |
| nfulnl_set_timeout(inst, ntohl(timeout)); |
| } |
| |
| if (nfula[NFULA_CFG_NLBUFSIZ]) { |
| __be32 nlbufsiz = nla_get_be32(nfula[NFULA_CFG_NLBUFSIZ]); |
| |
| nfulnl_set_nlbufsiz(inst, ntohl(nlbufsiz)); |
| } |
| |
| if (nfula[NFULA_CFG_QTHRESH]) { |
| __be32 qthresh = nla_get_be32(nfula[NFULA_CFG_QTHRESH]); |
| |
| nfulnl_set_qthresh(inst, ntohl(qthresh)); |
| } |
| |
| if (nfula[NFULA_CFG_FLAGS]) |
| nfulnl_set_flags(inst, flags); |
| |
| out_put: |
| instance_put(inst); |
| out: |
| return ret; |
| } |
| |
| static const struct nfnl_callback nfulnl_cb[NFULNL_MSG_MAX] = { |
| [NFULNL_MSG_PACKET] = { .call = nfulnl_recv_unsupp, |
| .attr_count = NFULA_MAX, }, |
| [NFULNL_MSG_CONFIG] = { .call = nfulnl_recv_config, |
| .attr_count = NFULA_CFG_MAX, |
| .policy = nfula_cfg_policy }, |
| }; |
| |
| static const 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 { |
| struct seq_net_private p; |
| unsigned int bucket; |
| }; |
| |
| static struct hlist_node *get_first(struct net *net, struct iter_state *st) |
| { |
| struct nfnl_log_net *log; |
| if (!st) |
| return NULL; |
| |
| log = nfnl_log_pernet(net); |
| |
| for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) { |
| struct hlist_head *head = &log->instance_table[st->bucket]; |
| |
| if (!hlist_empty(head)) |
| return rcu_dereference_bh(hlist_first_rcu(head)); |
| } |
| return NULL; |
| } |
| |
| static struct hlist_node *get_next(struct net *net, struct iter_state *st, |
| struct hlist_node *h) |
| { |
| h = rcu_dereference_bh(hlist_next_rcu(h)); |
| while (!h) { |
| struct nfnl_log_net *log; |
| struct hlist_head *head; |
| |
| if (++st->bucket >= INSTANCE_BUCKETS) |
| return NULL; |
| |
| log = nfnl_log_pernet(net); |
| head = &log->instance_table[st->bucket]; |
| h = rcu_dereference_bh(hlist_first_rcu(head)); |
| } |
| return h; |
| } |
| |
| static struct hlist_node *get_idx(struct net *net, struct iter_state *st, |
| loff_t pos) |
| { |
| struct hlist_node *head; |
| head = get_first(net, st); |
| |
| if (head) |
| while (pos && (head = get_next(net, st, head))) |
| pos--; |
| return pos ? NULL : head; |
| } |
| |
| static void *seq_start(struct seq_file *s, loff_t *pos) |
| __acquires(rcu_bh) |
| { |
| rcu_read_lock_bh(); |
| return get_idx(seq_file_net(s), s->private, *pos); |
| } |
| |
| static void *seq_next(struct seq_file *s, void *v, loff_t *pos) |
| { |
| (*pos)++; |
| return get_next(seq_file_net(s), s->private, v); |
| } |
| |
| static void seq_stop(struct seq_file *s, void *v) |
| __releases(rcu_bh) |
| { |
| rcu_read_unlock_bh(); |
| } |
| |
| static int seq_show(struct seq_file *s, void *v) |
| { |
| const struct nfulnl_instance *inst = v; |
| |
| seq_printf(s, "%5u %6u %5u %1u %5u %6u %2u\n", |
| inst->group_num, |
| inst->peer_portid, inst->qlen, |
| inst->copy_mode, inst->copy_range, |
| inst->flushtimeout, atomic_read(&inst->use)); |
| |
| return 0; |
| } |
| |
| static const 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) |
| { |
| return seq_open_net(inode, file, &nful_seq_ops, |
| sizeof(struct iter_state)); |
| } |
| |
| static const struct file_operations nful_file_ops = { |
| .owner = THIS_MODULE, |
| .open = nful_open, |
| .read = seq_read, |
| .llseek = seq_lseek, |
| .release = seq_release_net, |
| }; |
| |
| #endif /* PROC_FS */ |
| |
| static int __net_init nfnl_log_net_init(struct net *net) |
| { |
| unsigned int i; |
| struct nfnl_log_net *log = nfnl_log_pernet(net); |
| |
| for (i = 0; i < INSTANCE_BUCKETS; i++) |
| INIT_HLIST_HEAD(&log->instance_table[i]); |
| spin_lock_init(&log->instances_lock); |
| |
| #ifdef CONFIG_PROC_FS |
| if (!proc_create("nfnetlink_log", 0440, |
| net->nf.proc_netfilter, &nful_file_ops)) |
| return -ENOMEM; |
| #endif |
| return 0; |
| } |
| |
| static void __net_exit nfnl_log_net_exit(struct net *net) |
| { |
| #ifdef CONFIG_PROC_FS |
| remove_proc_entry("nfnetlink_log", net->nf.proc_netfilter); |
| #endif |
| nf_log_unset(net, &nfulnl_logger); |
| } |
| |
| static struct pernet_operations nfnl_log_net_ops = { |
| .init = nfnl_log_net_init, |
| .exit = nfnl_log_net_exit, |
| .id = &nfnl_log_net_id, |
| .size = sizeof(struct nfnl_log_net), |
| }; |
| |
| static int __init nfnetlink_log_init(void) |
| { |
| int status; |
| |
| status = register_pernet_subsys(&nfnl_log_net_ops); |
| if (status < 0) { |
| pr_err("failed to register pernet ops\n"); |
| goto out; |
| } |
| |
| netlink_register_notifier(&nfulnl_rtnl_notifier); |
| status = nfnetlink_subsys_register(&nfulnl_subsys); |
| if (status < 0) { |
| pr_err("failed to create netlink socket\n"); |
| goto cleanup_netlink_notifier; |
| } |
| |
| status = nf_log_register(NFPROTO_UNSPEC, &nfulnl_logger); |
| if (status < 0) { |
| pr_err("failed to register logger\n"); |
| goto cleanup_subsys; |
| } |
| |
| return status; |
| |
| cleanup_subsys: |
| nfnetlink_subsys_unregister(&nfulnl_subsys); |
| cleanup_netlink_notifier: |
| netlink_unregister_notifier(&nfulnl_rtnl_notifier); |
| unregister_pernet_subsys(&nfnl_log_net_ops); |
| out: |
| return status; |
| } |
| |
| static void __exit nfnetlink_log_fini(void) |
| { |
| nf_log_unregister(&nfulnl_logger); |
| nfnetlink_subsys_unregister(&nfulnl_subsys); |
| netlink_unregister_notifier(&nfulnl_rtnl_notifier); |
| unregister_pernet_subsys(&nfnl_log_net_ops); |
| } |
| |
| MODULE_DESCRIPTION("netfilter userspace logging"); |
| MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>"); |
| MODULE_LICENSE("GPL"); |
| MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_ULOG); |
| MODULE_ALIAS_NF_LOGGER(AF_INET, 1); |
| MODULE_ALIAS_NF_LOGGER(AF_INET6, 1); |
| MODULE_ALIAS_NF_LOGGER(AF_BRIDGE, 1); |
| |
| module_init(nfnetlink_log_init); |
| module_exit(nfnetlink_log_fini); |