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-rw-r--r--net/netfilter/nfnetlink_log.c1209
1 files changed, 1209 insertions, 0 deletions
diff --git a/net/netfilter/nfnetlink_log.c b/net/netfilter/nfnetlink_log.c
new file mode 100644
index 000000000..200a82a8f
--- /dev/null
+++ b/net/netfilter/nfnetlink_log.c
@@ -0,0 +1,1209 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * 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>
+ */
+
+#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 <linux/atomic.h>
+#include <linux/refcount.h>
+
+
+#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
+#include "../bridge/br_private.h"
+#endif
+
+#if IS_ENABLED(CONFIG_NF_CONNTRACK)
+#include <net/netfilter/nf_conntrack.h>
+#endif
+
+#define NFULNL_COPY_DISABLED 0xff
+#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;
+ refcount_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;
+ netns_tracker ns_tracker;
+ 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 unsigned 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)
+{
+ refcount_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 && !refcount_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_track(inst->net, &inst->ns_tracker);
+ kfree(inst);
+ module_put(THIS_MODULE);
+}
+
+static void
+instance_put(struct nfulnl_instance *inst)
+{
+ if (inst && refcount_dec_and_test(&inst->use))
+ call_rcu(&inst->rcu, nfulnl_instance_free_rcu);
+}
+
+static void nfulnl_timer(struct timer_list *t);
+
+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 */
+ refcount_set(&inst->use, 2);
+
+ timer_setup(&inst->timer, nfulnl_timer, 0);
+
+ inst->net = get_net_track(net, &inst->ns_tracker, GFP_ATOMIC);
+ 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 void
+nfulnl_set_timeout(struct nfulnl_instance *inst, u_int32_t timeout)
+{
+ spin_lock_bh(&inst->lock);
+ inst->flushtimeout = timeout;
+ spin_unlock_bh(&inst->lock);
+}
+
+static void
+nfulnl_set_qthresh(struct nfulnl_instance *inst, u_int32_t qthresh)
+{
+ spin_lock_bh(&inst->lock);
+ inst->qthreshold = qthresh;
+ spin_unlock_bh(&inst->lock);
+}
+
+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 = alloc_skb(n, GFP_ATOMIC | __GFP_NOWARN);
+ if (!skb) {
+ if (n > pkt_size) {
+ /* try to allocate only as much as we need for current
+ * packet */
+
+ skb = alloc_skb(pkt_size, 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);
+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(struct timer_list *t)
+{
+ struct nfulnl_instance *inst = from_timer(inst, t, timer);
+
+ spin_lock_bh(&inst->lock);
+ if (inst->skb)
+ __nfulnl_send(inst);
+ spin_unlock_bh(&inst->lock);
+ instance_put(inst);
+}
+
+static u32 nfulnl_get_bridge_size(const struct sk_buff *skb)
+{
+ u32 size = 0;
+
+ if (!skb_mac_header_was_set(skb))
+ return 0;
+
+ if (skb_vlan_tag_present(skb)) {
+ size += nla_total_size(0); /* nested */
+ size += nla_total_size(sizeof(u16)); /* id */
+ size += nla_total_size(sizeof(u16)); /* tag */
+ }
+
+ if (skb->network_header > skb->mac_header)
+ size += nla_total_size(skb->network_header - skb->mac_header);
+
+ return size;
+}
+
+static int nfulnl_put_bridge(struct nfulnl_instance *inst, const struct sk_buff *skb)
+{
+ if (!skb_mac_header_was_set(skb))
+ return 0;
+
+ if (skb_vlan_tag_present(skb)) {
+ struct nlattr *nest;
+
+ nest = nla_nest_start(inst->skb, NFULA_VLAN);
+ if (!nest)
+ goto nla_put_failure;
+
+ if (nla_put_be16(inst->skb, NFULA_VLAN_TCI, htons(skb->vlan_tci)) ||
+ nla_put_be16(inst->skb, NFULA_VLAN_PROTO, skb->vlan_proto))
+ goto nla_put_failure;
+
+ nla_nest_end(inst->skb, nest);
+ }
+
+ if (skb->mac_header < skb->network_header) {
+ int len = (int)(skb->network_header - skb->mac_header);
+
+ if (nla_put(inst->skb, NFULA_L2HDR, len, skb_mac_header(skb)))
+ goto nla_put_failure;
+ }
+
+ return 0;
+
+nla_put_failure:
+ return -1;
+}
+
+/* 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;
+ sk_buff_data_t old_tail = inst->skb->tail;
+ struct sock *sk;
+ const unsigned char *hwhdrp;
+ ktime_t tstamp;
+
+ nlh = nfnl_msg_put(inst->skb, 0, 0,
+ nfnl_msg_type(NFNL_SUBSYS_ULOG, NFULNL_MSG_PACKET),
+ 0, pf, NFNETLINK_V0, htons(inst->group_num));
+ if (!nlh)
+ return -1;
+
+ 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_thresh 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 {
+ int physinif;
+
+ /* 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;
+
+ physinif = nf_bridge_get_physinif(skb);
+ if (physinif &&
+ nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSINDEV,
+ htonl(physinif)))
+ 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_thresh 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_was_set(skb) &&
+ skb_mac_header_len(skb) != 0) {
+ 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;
+ }
+
+ tstamp = skb_tstamp_cond(skb, false);
+ if (hooknum <= NF_INET_FORWARD && tstamp) {
+ struct nfulnl_msg_packet_timestamp ts;
+ struct timespec64 kts = ktime_to_timespec64(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 ((pf == NFPROTO_NETDEV || pf == NFPROTO_BRIDGE) &&
+ nfulnl_put_bridge(inst, skb) < 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 = 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 const 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(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 = 0;
+ struct nfnl_log_net *log = nfnl_log_pernet(net);
+ const struct nfnl_ct_hook *nfnl_ct = NULL;
+ enum ip_conntrack_info ctinfo = 0;
+ struct nf_conn *ct = NULL;
+
+ 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;
+
+ 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 IS_ENABLED(CONFIG_NF_CONNTRACK)
+ if (inst->flags & NFULNL_CFG_F_CONNTRACK) {
+ nfnl_ct = rcu_dereference(nfnl_ct_hook);
+ if (nfnl_ct != NULL) {
+ ct = nf_ct_get(skb, &ctinfo);
+ if (ct != NULL)
+ size += nfnl_ct->build_size(ct);
+ }
+ }
+#endif
+ if (pf == NFPROTO_NETDEV || pf == NFPROTO_BRIDGE)
+ size += nfulnl_get_bridge_size(skb);
+
+ 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:
+ data_len = inst->copy_range;
+ if ((li->u.ulog.flags & NF_LOG_F_COPY_LEN) &&
+ (li->u.ulog.copy_len < data_len))
+ data_len = li->u.ulog.copy_len;
+
+ if (data_len > skb->len)
+ data_len = skb->len;
+
+ 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;
+}
+
+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 sk_buff *skb, const struct nfnl_info *info,
+ const struct nlattr * const nfula[])
+{
+ 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 sk_buff *skb, const struct nfnl_info *info,
+ const struct nlattr * const nfula[])
+{
+ struct nfnl_log_net *log = nfnl_log_pernet(info->net);
+ u_int16_t group_num = ntohs(info->nfmsg->res_id);
+ struct nfulnl_msg_config_cmd *cmd = NULL;
+ struct nfulnl_instance *inst;
+ u16 flags = 0;
+ int ret = 0;
+
+ if (nfula[NFULA_CFG_CMD]) {
+ u_int8_t pf = info->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(info->net, pf, &nfulnl_logger);
+ case NFULNL_CFG_CMD_PF_UNBIND:
+ nf_log_unbind_pf(info->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(info->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;
+ goto out_put;
+ }
+ } 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,
+ .type = NFNL_CB_MUTEX,
+ .attr_count = NFULA_MAX,
+ },
+ [NFULNL_MSG_CONFIG] = {
+ .call = nfulnl_recv_config,
+ .type = NFNL_CB_MUTEX,
+ .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, refcount_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,
+};
+#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);
+#ifdef CONFIG_PROC_FS
+ struct proc_dir_entry *proc;
+ kuid_t root_uid;
+ kgid_t root_gid;
+#endif
+
+ for (i = 0; i < INSTANCE_BUCKETS; i++)
+ INIT_HLIST_HEAD(&log->instance_table[i]);
+ spin_lock_init(&log->instances_lock);
+
+#ifdef CONFIG_PROC_FS
+ proc = proc_create_net("nfnetlink_log", 0440, net->nf.proc_netfilter,
+ &nful_seq_ops, sizeof(struct iter_state));
+ if (!proc)
+ return -ENOMEM;
+
+ root_uid = make_kuid(net->user_ns, 0);
+ root_gid = make_kgid(net->user_ns, 0);
+ if (uid_valid(root_uid) && gid_valid(root_gid))
+ proc_set_user(proc, root_uid, root_gid);
+#endif
+ return 0;
+}
+
+static void __net_exit nfnl_log_net_exit(struct net *net)
+{
+ struct nfnl_log_net *log = nfnl_log_pernet(net);
+ unsigned int i;
+
+#ifdef CONFIG_PROC_FS
+ remove_proc_entry("nfnetlink_log", net->nf.proc_netfilter);
+#endif
+ nf_log_unset(net, &nfulnl_logger);
+ for (i = 0; i < INSTANCE_BUCKETS; i++)
+ WARN_ON_ONCE(!hlist_empty(&log->instance_table[i]));
+}
+
+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)
+{
+ nfnetlink_subsys_unregister(&nfulnl_subsys);
+ netlink_unregister_notifier(&nfulnl_rtnl_notifier);
+ unregister_pernet_subsys(&nfnl_log_net_ops);
+ nf_log_unregister(&nfulnl_logger);
+}
+
+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_ALIAS_NF_LOGGER(3, 1); /* NFPROTO_ARP */
+MODULE_ALIAS_NF_LOGGER(5, 1); /* NFPROTO_NETDEV */
+
+module_init(nfnetlink_log_init);
+module_exit(nfnetlink_log_fini);
generated by cgit v1.2.3 (git 2.39.1) at 2024-06-09 06:42:33 +0000