remarkable-linux/net/ipv6/netfilter/nf_log_ipv6.c
Pablo Neira Ayuso fab4085f4e netfilter: log: nf_log_packet() as real unified interface
Before this patch, the nf_loginfo parameter specified the logging
configuration in case the specified default logger was loaded. This
patch updates the semantics of the nf_loginfo parameter in
nf_log_packet() which now indicates the logger that you explicitly
want to use.

Thus, nf_log_packet() is exposed as an unified interface which
internally routes the log message to the corresponding logger type
by family.

The module dependencies are expressed by the new nf_logger_find_get()
and nf_logger_put() functions which bump the logger module refcount.
Thus, you can not remove logger modules that are used by rules anymore.

Another important effect of this change is that the family specific
module is only loaded when required. Therefore, xt_LOG and nft_log
will just trigger the autoload of the nf_log_{ip,ip6} modules
according to the family.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2014-06-27 13:20:13 +02:00

418 lines
9.6 KiB
C

/* (C) 1999-2001 Paul `Rusty' Russell
* (C) 2002-2004 Netfilter Core Team <coreteam@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/spinlock.h>
#include <linux/skbuff.h>
#include <linux/if_arp.h>
#include <linux/ip.h>
#include <net/ipv6.h>
#include <net/icmp.h>
#include <net/udp.h>
#include <net/tcp.h>
#include <net/route.h>
#include <linux/netfilter.h>
#include <linux/netfilter_ipv6/ip6_tables.h>
#include <linux/netfilter/xt_LOG.h>
#include <net/netfilter/nf_log.h>
static struct nf_loginfo default_loginfo = {
.type = NF_LOG_TYPE_LOG,
.u = {
.log = {
.level = 5,
.logflags = NF_LOG_MASK,
},
},
};
/* One level of recursion won't kill us */
static void dump_ipv6_packet(struct nf_log_buf *m,
const struct nf_loginfo *info,
const struct sk_buff *skb, unsigned int ip6hoff,
int recurse)
{
u_int8_t currenthdr;
int fragment;
struct ipv6hdr _ip6h;
const struct ipv6hdr *ih;
unsigned int ptr;
unsigned int hdrlen = 0;
unsigned int logflags;
if (info->type == NF_LOG_TYPE_LOG)
logflags = info->u.log.logflags;
else
logflags = NF_LOG_MASK;
ih = skb_header_pointer(skb, ip6hoff, sizeof(_ip6h), &_ip6h);
if (ih == NULL) {
nf_log_buf_add(m, "TRUNCATED");
return;
}
/* Max length: 88 "SRC=0000.0000.0000.0000.0000.0000.0000.0000 DST=0000.0000.0000.0000.0000.0000.0000.0000 " */
nf_log_buf_add(m, "SRC=%pI6 DST=%pI6 ", &ih->saddr, &ih->daddr);
/* Max length: 44 "LEN=65535 TC=255 HOPLIMIT=255 FLOWLBL=FFFFF " */
nf_log_buf_add(m, "LEN=%Zu TC=%u HOPLIMIT=%u FLOWLBL=%u ",
ntohs(ih->payload_len) + sizeof(struct ipv6hdr),
(ntohl(*(__be32 *)ih) & 0x0ff00000) >> 20,
ih->hop_limit,
(ntohl(*(__be32 *)ih) & 0x000fffff));
fragment = 0;
ptr = ip6hoff + sizeof(struct ipv6hdr);
currenthdr = ih->nexthdr;
while (currenthdr != NEXTHDR_NONE && ip6t_ext_hdr(currenthdr)) {
struct ipv6_opt_hdr _hdr;
const struct ipv6_opt_hdr *hp;
hp = skb_header_pointer(skb, ptr, sizeof(_hdr), &_hdr);
if (hp == NULL) {
nf_log_buf_add(m, "TRUNCATED");
return;
}
/* Max length: 48 "OPT (...) " */
if (logflags & XT_LOG_IPOPT)
nf_log_buf_add(m, "OPT ( ");
switch (currenthdr) {
case IPPROTO_FRAGMENT: {
struct frag_hdr _fhdr;
const struct frag_hdr *fh;
nf_log_buf_add(m, "FRAG:");
fh = skb_header_pointer(skb, ptr, sizeof(_fhdr),
&_fhdr);
if (fh == NULL) {
nf_log_buf_add(m, "TRUNCATED ");
return;
}
/* Max length: 6 "65535 " */
nf_log_buf_add(m, "%u ", ntohs(fh->frag_off) & 0xFFF8);
/* Max length: 11 "INCOMPLETE " */
if (fh->frag_off & htons(0x0001))
nf_log_buf_add(m, "INCOMPLETE ");
nf_log_buf_add(m, "ID:%08x ",
ntohl(fh->identification));
if (ntohs(fh->frag_off) & 0xFFF8)
fragment = 1;
hdrlen = 8;
break;
}
case IPPROTO_DSTOPTS:
case IPPROTO_ROUTING:
case IPPROTO_HOPOPTS:
if (fragment) {
if (logflags & XT_LOG_IPOPT)
nf_log_buf_add(m, ")");
return;
}
hdrlen = ipv6_optlen(hp);
break;
/* Max Length */
case IPPROTO_AH:
if (logflags & XT_LOG_IPOPT) {
struct ip_auth_hdr _ahdr;
const struct ip_auth_hdr *ah;
/* Max length: 3 "AH " */
nf_log_buf_add(m, "AH ");
if (fragment) {
nf_log_buf_add(m, ")");
return;
}
ah = skb_header_pointer(skb, ptr, sizeof(_ahdr),
&_ahdr);
if (ah == NULL) {
/*
* Max length: 26 "INCOMPLETE [65535
* bytes] )"
*/
nf_log_buf_add(m, "INCOMPLETE [%u bytes] )",
skb->len - ptr);
return;
}
/* Length: 15 "SPI=0xF1234567 */
nf_log_buf_add(m, "SPI=0x%x ", ntohl(ah->spi));
}
hdrlen = (hp->hdrlen+2)<<2;
break;
case IPPROTO_ESP:
if (logflags & XT_LOG_IPOPT) {
struct ip_esp_hdr _esph;
const struct ip_esp_hdr *eh;
/* Max length: 4 "ESP " */
nf_log_buf_add(m, "ESP ");
if (fragment) {
nf_log_buf_add(m, ")");
return;
}
/*
* Max length: 26 "INCOMPLETE [65535 bytes] )"
*/
eh = skb_header_pointer(skb, ptr, sizeof(_esph),
&_esph);
if (eh == NULL) {
nf_log_buf_add(m, "INCOMPLETE [%u bytes] )",
skb->len - ptr);
return;
}
/* Length: 16 "SPI=0xF1234567 )" */
nf_log_buf_add(m, "SPI=0x%x )",
ntohl(eh->spi));
}
return;
default:
/* Max length: 20 "Unknown Ext Hdr 255" */
nf_log_buf_add(m, "Unknown Ext Hdr %u", currenthdr);
return;
}
if (logflags & XT_LOG_IPOPT)
nf_log_buf_add(m, ") ");
currenthdr = hp->nexthdr;
ptr += hdrlen;
}
switch (currenthdr) {
case IPPROTO_TCP:
if (nf_log_dump_tcp_header(m, skb, currenthdr, fragment,
ptr, logflags))
return;
break;
case IPPROTO_UDP:
case IPPROTO_UDPLITE:
if (nf_log_dump_udp_header(m, skb, currenthdr, fragment, ptr))
return;
break;
case IPPROTO_ICMPV6: {
struct icmp6hdr _icmp6h;
const struct icmp6hdr *ic;
/* Max length: 13 "PROTO=ICMPv6 " */
nf_log_buf_add(m, "PROTO=ICMPv6 ");
if (fragment)
break;
/* Max length: 25 "INCOMPLETE [65535 bytes] " */
ic = skb_header_pointer(skb, ptr, sizeof(_icmp6h), &_icmp6h);
if (ic == NULL) {
nf_log_buf_add(m, "INCOMPLETE [%u bytes] ",
skb->len - ptr);
return;
}
/* Max length: 18 "TYPE=255 CODE=255 " */
nf_log_buf_add(m, "TYPE=%u CODE=%u ",
ic->icmp6_type, ic->icmp6_code);
switch (ic->icmp6_type) {
case ICMPV6_ECHO_REQUEST:
case ICMPV6_ECHO_REPLY:
/* Max length: 19 "ID=65535 SEQ=65535 " */
nf_log_buf_add(m, "ID=%u SEQ=%u ",
ntohs(ic->icmp6_identifier),
ntohs(ic->icmp6_sequence));
break;
case ICMPV6_MGM_QUERY:
case ICMPV6_MGM_REPORT:
case ICMPV6_MGM_REDUCTION:
break;
case ICMPV6_PARAMPROB:
/* Max length: 17 "POINTER=ffffffff " */
nf_log_buf_add(m, "POINTER=%08x ",
ntohl(ic->icmp6_pointer));
/* Fall through */
case ICMPV6_DEST_UNREACH:
case ICMPV6_PKT_TOOBIG:
case ICMPV6_TIME_EXCEED:
/* Max length: 3+maxlen */
if (recurse) {
nf_log_buf_add(m, "[");
dump_ipv6_packet(m, info, skb,
ptr + sizeof(_icmp6h), 0);
nf_log_buf_add(m, "] ");
}
/* Max length: 10 "MTU=65535 " */
if (ic->icmp6_type == ICMPV6_PKT_TOOBIG) {
nf_log_buf_add(m, "MTU=%u ",
ntohl(ic->icmp6_mtu));
}
}
break;
}
/* Max length: 10 "PROTO=255 " */
default:
nf_log_buf_add(m, "PROTO=%u ", currenthdr);
}
/* Max length: 15 "UID=4294967295 " */
if ((logflags & XT_LOG_UID) && recurse)
nf_log_dump_sk_uid_gid(m, skb->sk);
/* Max length: 16 "MARK=0xFFFFFFFF " */
if (recurse && skb->mark)
nf_log_buf_add(m, "MARK=0x%x ", skb->mark);
}
static void dump_ipv6_mac_header(struct nf_log_buf *m,
const struct nf_loginfo *info,
const struct sk_buff *skb)
{
struct net_device *dev = skb->dev;
unsigned int logflags = 0;
if (info->type == NF_LOG_TYPE_LOG)
logflags = info->u.log.logflags;
if (!(logflags & XT_LOG_MACDECODE))
goto fallback;
switch (dev->type) {
case ARPHRD_ETHER:
nf_log_buf_add(m, "MACSRC=%pM MACDST=%pM MACPROTO=%04x ",
eth_hdr(skb)->h_source, eth_hdr(skb)->h_dest,
ntohs(eth_hdr(skb)->h_proto));
return;
default:
break;
}
fallback:
nf_log_buf_add(m, "MAC=");
if (dev->hard_header_len &&
skb->mac_header != skb->network_header) {
const unsigned char *p = skb_mac_header(skb);
unsigned int len = dev->hard_header_len;
unsigned int i;
if (dev->type == ARPHRD_SIT) {
p -= ETH_HLEN;
if (p < skb->head)
p = NULL;
}
if (p != NULL) {
nf_log_buf_add(m, "%02x", *p++);
for (i = 1; i < len; i++)
nf_log_buf_add(m, ":%02x", *p++);
}
nf_log_buf_add(m, " ");
if (dev->type == ARPHRD_SIT) {
const struct iphdr *iph =
(struct iphdr *)skb_mac_header(skb);
nf_log_buf_add(m, "TUNNEL=%pI4->%pI4 ", &iph->saddr,
&iph->daddr);
}
} else {
nf_log_buf_add(m, " ");
}
}
static void nf_log_ip6_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 *loginfo,
const char *prefix)
{
struct nf_log_buf *m;
/* FIXME: Disabled from containers until syslog ns is supported */
if (!net_eq(net, &init_net))
return;
m = nf_log_buf_open();
if (!loginfo)
loginfo = &default_loginfo;
nf_log_dump_packet_common(m, pf, hooknum, skb, in, out,
loginfo, prefix);
if (in != NULL)
dump_ipv6_mac_header(m, loginfo, skb);
dump_ipv6_packet(m, loginfo, skb, skb_network_offset(skb), 1);
nf_log_buf_close(m);
}
static struct nf_logger nf_ip6_logger __read_mostly = {
.name = "nf_log_ipv6",
.type = NF_LOG_TYPE_LOG,
.logfn = nf_log_ip6_packet,
.me = THIS_MODULE,
};
static int __net_init nf_log_ipv6_net_init(struct net *net)
{
nf_log_set(net, NFPROTO_IPV6, &nf_ip6_logger);
return 0;
}
static void __net_exit nf_log_ipv6_net_exit(struct net *net)
{
nf_log_unset(net, &nf_ip6_logger);
}
static struct pernet_operations nf_log_ipv6_net_ops = {
.init = nf_log_ipv6_net_init,
.exit = nf_log_ipv6_net_exit,
};
static int __init nf_log_ipv6_init(void)
{
int ret;
ret = register_pernet_subsys(&nf_log_ipv6_net_ops);
if (ret < 0)
return ret;
nf_log_register(NFPROTO_IPV6, &nf_ip6_logger);
return 0;
}
static void __exit nf_log_ipv6_exit(void)
{
unregister_pernet_subsys(&nf_log_ipv6_net_ops);
nf_log_unregister(&nf_ip6_logger);
}
module_init(nf_log_ipv6_init);
module_exit(nf_log_ipv6_exit);
MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
MODULE_DESCRIPTION("Netfilter IPv4 packet logging");
MODULE_LICENSE("GPL");
MODULE_ALIAS_NF_LOGGER(AF_INET6, 0);