5ce6b04ce9
First, log prefix will be truncated to NF_LOG_PREFIXLEN-1, i.e. 127,
at nf_log_packet(), so the extra part is useless.
Second, after adding a log rule with a very very long prefix, we will
fail to dump the nft rules after this _special_ one, but acctually,
they do exist. For example:
# name_65000=$(printf "%0.sQ" {1..65000})
# nft add rule filter output log prefix "$name_65000"
# nft add rule filter output counter
# nft add rule filter output counter
# nft list chain filter output
table ip filter {
chain output {
type filter hook output priority 0; policy accept;
}
}
So now, restrict the log prefix length to NF_LOG_PREFIXLEN-1.
Fixes: 96518518cc
("netfilter: add nftables")
Signed-off-by: Liping Zhang <zlpnobody@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
214 lines
5.3 KiB
C
214 lines
5.3 KiB
C
/*
|
|
* Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net>
|
|
* Copyright (c) 2012-2014 Pablo Neira Ayuso <pablo@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.
|
|
*
|
|
* Development of this code funded by Astaro AG (http://www.astaro.com/)
|
|
*/
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/init.h>
|
|
#include <linux/module.h>
|
|
#include <linux/netlink.h>
|
|
#include <linux/netfilter.h>
|
|
#include <linux/netfilter/nf_tables.h>
|
|
#include <net/netfilter/nf_tables.h>
|
|
#include <net/netfilter/nf_log.h>
|
|
#include <linux/netdevice.h>
|
|
|
|
static const char *nft_log_null_prefix = "";
|
|
|
|
struct nft_log {
|
|
struct nf_loginfo loginfo;
|
|
char *prefix;
|
|
};
|
|
|
|
static void nft_log_eval(const struct nft_expr *expr,
|
|
struct nft_regs *regs,
|
|
const struct nft_pktinfo *pkt)
|
|
{
|
|
const struct nft_log *priv = nft_expr_priv(expr);
|
|
|
|
nf_log_packet(nft_net(pkt), nft_pf(pkt), nft_hook(pkt), pkt->skb,
|
|
nft_in(pkt), nft_out(pkt), &priv->loginfo, "%s",
|
|
priv->prefix);
|
|
}
|
|
|
|
static const struct nla_policy nft_log_policy[NFTA_LOG_MAX + 1] = {
|
|
[NFTA_LOG_GROUP] = { .type = NLA_U16 },
|
|
[NFTA_LOG_PREFIX] = { .type = NLA_STRING,
|
|
.len = NF_LOG_PREFIXLEN - 1 },
|
|
[NFTA_LOG_SNAPLEN] = { .type = NLA_U32 },
|
|
[NFTA_LOG_QTHRESHOLD] = { .type = NLA_U16 },
|
|
[NFTA_LOG_LEVEL] = { .type = NLA_U32 },
|
|
[NFTA_LOG_FLAGS] = { .type = NLA_U32 },
|
|
};
|
|
|
|
static int nft_log_init(const struct nft_ctx *ctx,
|
|
const struct nft_expr *expr,
|
|
const struct nlattr * const tb[])
|
|
{
|
|
struct nft_log *priv = nft_expr_priv(expr);
|
|
struct nf_loginfo *li = &priv->loginfo;
|
|
const struct nlattr *nla;
|
|
int err;
|
|
|
|
li->type = NF_LOG_TYPE_LOG;
|
|
if (tb[NFTA_LOG_LEVEL] != NULL &&
|
|
tb[NFTA_LOG_GROUP] != NULL)
|
|
return -EINVAL;
|
|
if (tb[NFTA_LOG_GROUP] != NULL) {
|
|
li->type = NF_LOG_TYPE_ULOG;
|
|
if (tb[NFTA_LOG_FLAGS] != NULL)
|
|
return -EINVAL;
|
|
}
|
|
|
|
nla = tb[NFTA_LOG_PREFIX];
|
|
if (nla != NULL) {
|
|
priv->prefix = kmalloc(nla_len(nla) + 1, GFP_KERNEL);
|
|
if (priv->prefix == NULL)
|
|
return -ENOMEM;
|
|
nla_strlcpy(priv->prefix, nla, nla_len(nla) + 1);
|
|
} else {
|
|
priv->prefix = (char *)nft_log_null_prefix;
|
|
}
|
|
|
|
switch (li->type) {
|
|
case NF_LOG_TYPE_LOG:
|
|
if (tb[NFTA_LOG_LEVEL] != NULL) {
|
|
li->u.log.level =
|
|
ntohl(nla_get_be32(tb[NFTA_LOG_LEVEL]));
|
|
} else {
|
|
li->u.log.level = LOGLEVEL_WARNING;
|
|
}
|
|
if (li->u.log.level > LOGLEVEL_DEBUG) {
|
|
err = -EINVAL;
|
|
goto err1;
|
|
}
|
|
|
|
if (tb[NFTA_LOG_FLAGS] != NULL) {
|
|
li->u.log.logflags =
|
|
ntohl(nla_get_be32(tb[NFTA_LOG_FLAGS]));
|
|
if (li->u.log.logflags & ~NF_LOG_MASK) {
|
|
err = -EINVAL;
|
|
goto err1;
|
|
}
|
|
}
|
|
break;
|
|
case NF_LOG_TYPE_ULOG:
|
|
li->u.ulog.group = ntohs(nla_get_be16(tb[NFTA_LOG_GROUP]));
|
|
if (tb[NFTA_LOG_SNAPLEN] != NULL) {
|
|
li->u.ulog.flags |= NF_LOG_F_COPY_LEN;
|
|
li->u.ulog.copy_len =
|
|
ntohl(nla_get_be32(tb[NFTA_LOG_SNAPLEN]));
|
|
}
|
|
if (tb[NFTA_LOG_QTHRESHOLD] != NULL) {
|
|
li->u.ulog.qthreshold =
|
|
ntohs(nla_get_be16(tb[NFTA_LOG_QTHRESHOLD]));
|
|
}
|
|
break;
|
|
}
|
|
|
|
err = nf_logger_find_get(ctx->afi->family, li->type);
|
|
if (err < 0)
|
|
goto err1;
|
|
|
|
return 0;
|
|
|
|
err1:
|
|
if (priv->prefix != nft_log_null_prefix)
|
|
kfree(priv->prefix);
|
|
return err;
|
|
}
|
|
|
|
static void nft_log_destroy(const struct nft_ctx *ctx,
|
|
const struct nft_expr *expr)
|
|
{
|
|
struct nft_log *priv = nft_expr_priv(expr);
|
|
struct nf_loginfo *li = &priv->loginfo;
|
|
|
|
if (priv->prefix != nft_log_null_prefix)
|
|
kfree(priv->prefix);
|
|
|
|
nf_logger_put(ctx->afi->family, li->type);
|
|
}
|
|
|
|
static int nft_log_dump(struct sk_buff *skb, const struct nft_expr *expr)
|
|
{
|
|
const struct nft_log *priv = nft_expr_priv(expr);
|
|
const struct nf_loginfo *li = &priv->loginfo;
|
|
|
|
if (priv->prefix != nft_log_null_prefix)
|
|
if (nla_put_string(skb, NFTA_LOG_PREFIX, priv->prefix))
|
|
goto nla_put_failure;
|
|
switch (li->type) {
|
|
case NF_LOG_TYPE_LOG:
|
|
if (nla_put_be32(skb, NFTA_LOG_LEVEL, htonl(li->u.log.level)))
|
|
goto nla_put_failure;
|
|
|
|
if (li->u.log.logflags) {
|
|
if (nla_put_be32(skb, NFTA_LOG_FLAGS,
|
|
htonl(li->u.log.logflags)))
|
|
goto nla_put_failure;
|
|
}
|
|
break;
|
|
case NF_LOG_TYPE_ULOG:
|
|
if (nla_put_be16(skb, NFTA_LOG_GROUP, htons(li->u.ulog.group)))
|
|
goto nla_put_failure;
|
|
|
|
if (li->u.ulog.flags & NF_LOG_F_COPY_LEN) {
|
|
if (nla_put_be32(skb, NFTA_LOG_SNAPLEN,
|
|
htonl(li->u.ulog.copy_len)))
|
|
goto nla_put_failure;
|
|
}
|
|
if (li->u.ulog.qthreshold) {
|
|
if (nla_put_be16(skb, NFTA_LOG_QTHRESHOLD,
|
|
htons(li->u.ulog.qthreshold)))
|
|
goto nla_put_failure;
|
|
}
|
|
break;
|
|
}
|
|
return 0;
|
|
|
|
nla_put_failure:
|
|
return -1;
|
|
}
|
|
|
|
static struct nft_expr_type nft_log_type;
|
|
static const struct nft_expr_ops nft_log_ops = {
|
|
.type = &nft_log_type,
|
|
.size = NFT_EXPR_SIZE(sizeof(struct nft_log)),
|
|
.eval = nft_log_eval,
|
|
.init = nft_log_init,
|
|
.destroy = nft_log_destroy,
|
|
.dump = nft_log_dump,
|
|
};
|
|
|
|
static struct nft_expr_type nft_log_type __read_mostly = {
|
|
.name = "log",
|
|
.ops = &nft_log_ops,
|
|
.policy = nft_log_policy,
|
|
.maxattr = NFTA_LOG_MAX,
|
|
.owner = THIS_MODULE,
|
|
};
|
|
|
|
static int __init nft_log_module_init(void)
|
|
{
|
|
return nft_register_expr(&nft_log_type);
|
|
}
|
|
|
|
static void __exit nft_log_module_exit(void)
|
|
{
|
|
nft_unregister_expr(&nft_log_type);
|
|
}
|
|
|
|
module_init(nft_log_module_init);
|
|
module_exit(nft_log_module_exit);
|
|
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
|
|
MODULE_ALIAS_NFT_EXPR("log");
|