// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net>
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* Copyright (c) 2012-2014 Pablo Neira Ayuso <pablo@netfilter.org>
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*
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* Development of this code funded by Astaro AG (http://www.astaro.com/)
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*/
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#include <linux/audit.h>
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/netlink.h>
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#include <linux/netfilter.h>
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#include <linux/netfilter/nf_tables.h>
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#include <net/ipv6.h>
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#include <net/ip.h>
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#include <net/netfilter/nf_tables.h>
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#include <net/netfilter/nf_log.h>
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#include <linux/netdevice.h>
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static const char *nft_log_null_prefix = "";
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struct nft_log {
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struct nf_loginfo loginfo;
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char *prefix;
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};
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static bool audit_ip4(struct audit_buffer *ab, struct sk_buff *skb)
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{
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struct iphdr _iph;
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const struct iphdr *ih;
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ih = skb_header_pointer(skb, skb_network_offset(skb), sizeof(_iph), &_iph);
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if (!ih)
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return false;
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audit_log_format(ab, " saddr=%pI4 daddr=%pI4 proto=%hhu",
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&ih->saddr, &ih->daddr, ih->protocol);
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return true;
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}
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static bool audit_ip6(struct audit_buffer *ab, struct sk_buff *skb)
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{
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struct ipv6hdr _ip6h;
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const struct ipv6hdr *ih;
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u8 nexthdr;
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__be16 frag_off;
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ih = skb_header_pointer(skb, skb_network_offset(skb), sizeof(_ip6h), &_ip6h);
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if (!ih)
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return false;
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nexthdr = ih->nexthdr;
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ipv6_skip_exthdr(skb, skb_network_offset(skb) + sizeof(_ip6h), &nexthdr, &frag_off);
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audit_log_format(ab, " saddr=%pI6c daddr=%pI6c proto=%hhu",
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&ih->saddr, &ih->daddr, nexthdr);
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return true;
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}
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static void nft_log_eval_audit(const struct nft_pktinfo *pkt)
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{
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struct sk_buff *skb = pkt->skb;
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struct audit_buffer *ab;
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int fam = -1;
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if (!audit_enabled)
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return;
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ab = audit_log_start(NULL, GFP_ATOMIC, AUDIT_NETFILTER_PKT);
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if (!ab)
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return;
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audit_log_format(ab, "mark=%#x", skb->mark);
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switch (nft_pf(pkt)) {
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case NFPROTO_BRIDGE:
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switch (eth_hdr(skb)->h_proto) {
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case htons(ETH_P_IP):
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fam = audit_ip4(ab, skb) ? NFPROTO_IPV4 : -1;
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break;
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case htons(ETH_P_IPV6):
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fam = audit_ip6(ab, skb) ? NFPROTO_IPV6 : -1;
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break;
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}
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break;
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case NFPROTO_IPV4:
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fam = audit_ip4(ab, skb) ? NFPROTO_IPV4 : -1;
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break;
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case NFPROTO_IPV6:
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fam = audit_ip6(ab, skb) ? NFPROTO_IPV6 : -1;
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break;
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}
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if (fam == -1)
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audit_log_format(ab, " saddr=? daddr=? proto=-1");
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audit_log_end(ab);
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}
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static void nft_log_eval(const struct nft_expr *expr,
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struct nft_regs *regs,
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const struct nft_pktinfo *pkt)
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{
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const struct nft_log *priv = nft_expr_priv(expr);
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if (priv->loginfo.type == NF_LOG_TYPE_LOG &&
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priv->loginfo.u.log.level == NFT_LOGLEVEL_AUDIT) {
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nft_log_eval_audit(pkt);
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return;
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}
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nf_log_packet(nft_net(pkt), nft_pf(pkt), nft_hook(pkt), pkt->skb,
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nft_in(pkt), nft_out(pkt), &priv->loginfo, "%s",
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priv->prefix);
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}
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static const struct nla_policy nft_log_policy[NFTA_LOG_MAX + 1] = {
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[NFTA_LOG_GROUP] = { .type = NLA_U16 },
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[NFTA_LOG_PREFIX] = { .type = NLA_STRING,
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.len = NF_LOG_PREFIXLEN - 1 },
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[NFTA_LOG_SNAPLEN] = { .type = NLA_U32 },
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[NFTA_LOG_QTHRESHOLD] = { .type = NLA_U16 },
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[NFTA_LOG_LEVEL] = { .type = NLA_U32 },
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[NFTA_LOG_FLAGS] = { .type = NLA_U32 },
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};
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static int nft_log_init(const struct nft_ctx *ctx,
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const struct nft_expr *expr,
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const struct nlattr * const tb[])
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{
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struct nft_log *priv = nft_expr_priv(expr);
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struct nf_loginfo *li = &priv->loginfo;
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const struct nlattr *nla;
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int err;
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li->type = NF_LOG_TYPE_LOG;
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if (tb[NFTA_LOG_LEVEL] != NULL &&
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tb[NFTA_LOG_GROUP] != NULL)
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return -EINVAL;
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if (tb[NFTA_LOG_GROUP] != NULL) {
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li->type = NF_LOG_TYPE_ULOG;
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if (tb[NFTA_LOG_FLAGS] != NULL)
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return -EINVAL;
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}
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nla = tb[NFTA_LOG_PREFIX];
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if (nla != NULL) {
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priv->prefix = kmalloc(nla_len(nla) + 1, GFP_KERNEL);
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if (priv->prefix == NULL)
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return -ENOMEM;
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nla_strlcpy(priv->prefix, nla, nla_len(nla) + 1);
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} else {
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priv->prefix = (char *)nft_log_null_prefix;
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}
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switch (li->type) {
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case NF_LOG_TYPE_LOG:
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if (tb[NFTA_LOG_LEVEL] != NULL) {
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li->u.log.level =
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ntohl(nla_get_be32(tb[NFTA_LOG_LEVEL]));
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} else {
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li->u.log.level = NFT_LOGLEVEL_WARNING;
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}
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if (li->u.log.level > NFT_LOGLEVEL_AUDIT) {
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err = -EINVAL;
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goto err1;
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}
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if (tb[NFTA_LOG_FLAGS] != NULL) {
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li->u.log.logflags =
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ntohl(nla_get_be32(tb[NFTA_LOG_FLAGS]));
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if (li->u.log.logflags & ~NF_LOG_MASK) {
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err = -EINVAL;
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goto err1;
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}
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}
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break;
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case NF_LOG_TYPE_ULOG:
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li->u.ulog.group = ntohs(nla_get_be16(tb[NFTA_LOG_GROUP]));
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if (tb[NFTA_LOG_SNAPLEN] != NULL) {
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li->u.ulog.flags |= NF_LOG_F_COPY_LEN;
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li->u.ulog.copy_len =
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ntohl(nla_get_be32(tb[NFTA_LOG_SNAPLEN]));
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}
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if (tb[NFTA_LOG_QTHRESHOLD] != NULL) {
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li->u.ulog.qthreshold =
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ntohs(nla_get_be16(tb[NFTA_LOG_QTHRESHOLD]));
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}
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break;
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}
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if (li->u.log.level == NFT_LOGLEVEL_AUDIT)
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return 0;
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err = nf_logger_find_get(ctx->family, li->type);
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if (err < 0)
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goto err1;
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return 0;
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err1:
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if (priv->prefix != nft_log_null_prefix)
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kfree(priv->prefix);
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return err;
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}
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static void nft_log_destroy(const struct nft_ctx *ctx,
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const struct nft_expr *expr)
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{
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struct nft_log *priv = nft_expr_priv(expr);
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struct nf_loginfo *li = &priv->loginfo;
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if (priv->prefix != nft_log_null_prefix)
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kfree(priv->prefix);
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if (li->u.log.level == NFT_LOGLEVEL_AUDIT)
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return;
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nf_logger_put(ctx->family, li->type);
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}
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static int nft_log_dump(struct sk_buff *skb, const struct nft_expr *expr)
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{
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const struct nft_log *priv = nft_expr_priv(expr);
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const struct nf_loginfo *li = &priv->loginfo;
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if (priv->prefix != nft_log_null_prefix)
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if (nla_put_string(skb, NFTA_LOG_PREFIX, priv->prefix))
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goto nla_put_failure;
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switch (li->type) {
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case NF_LOG_TYPE_LOG:
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if (nla_put_be32(skb, NFTA_LOG_LEVEL, htonl(li->u.log.level)))
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goto nla_put_failure;
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if (li->u.log.logflags) {
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if (nla_put_be32(skb, NFTA_LOG_FLAGS,
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htonl(li->u.log.logflags)))
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goto nla_put_failure;
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}
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break;
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case NF_LOG_TYPE_ULOG:
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if (nla_put_be16(skb, NFTA_LOG_GROUP, htons(li->u.ulog.group)))
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goto nla_put_failure;
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if (li->u.ulog.flags & NF_LOG_F_COPY_LEN) {
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if (nla_put_be32(skb, NFTA_LOG_SNAPLEN,
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htonl(li->u.ulog.copy_len)))
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goto nla_put_failure;
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}
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if (li->u.ulog.qthreshold) {
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if (nla_put_be16(skb, NFTA_LOG_QTHRESHOLD,
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htons(li->u.ulog.qthreshold)))
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goto nla_put_failure;
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}
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break;
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}
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return 0;
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nla_put_failure:
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return -1;
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}
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static struct nft_expr_type nft_log_type;
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static const struct nft_expr_ops nft_log_ops = {
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.type = &nft_log_type,
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.size = NFT_EXPR_SIZE(sizeof(struct nft_log)),
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.eval = nft_log_eval,
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.init = nft_log_init,
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.destroy = nft_log_destroy,
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.dump = nft_log_dump,
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};
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static struct nft_expr_type nft_log_type __read_mostly = {
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.name = "log",
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.ops = &nft_log_ops,
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.policy = nft_log_policy,
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.maxattr = NFTA_LOG_MAX,
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.owner = THIS_MODULE,
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};
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static int __init nft_log_module_init(void)
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{
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return nft_register_expr(&nft_log_type);
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}
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static void __exit nft_log_module_exit(void)
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{
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nft_unregister_expr(&nft_log_type);
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}
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module_init(nft_log_module_init);
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module_exit(nft_log_module_exit);
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
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MODULE_ALIAS_NFT_EXPR("log");
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MODULE_DESCRIPTION("Netfilter nf_tables log module");
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