netfilter: log: split family specific code to nf_log_{ip,ip6,common}.c files
The plain text logging is currently embedded into the xt_LOG target.
In order to be able to use the plain text logging from nft_log, as a
first step, this patch moves the family specific code to the following
files and Kconfig symbols:
1) net/ipv4/netfilter/nf_log_ip.c: CONFIG_NF_LOG_IPV4
2) net/ipv6/netfilter/nf_log_ip6.c: CONFIG_NF_LOG_IPV6
3) net/netfilter/nf_log_common.c: CONFIG_NF_LOG_COMMON
These new modules will be required by xt_LOG and nft_log. This patch
is based on original patch from Arturo Borrero Gonzalez.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
diff --git a/net/ipv4/netfilter/nf_log_ipv4.c b/net/ipv4/netfilter/nf_log_ipv4.c
new file mode 100644
index 0000000..7e69a40
--- /dev/null
+++ b/net/ipv4/netfilter/nf_log_ipv4.c
@@ -0,0 +1,385 @@
+/* (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/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_ipv4_packet(struct nf_log_buf *m,
+ const struct nf_loginfo *info,
+ const struct sk_buff *skb, unsigned int iphoff)
+{
+ struct iphdr _iph;
+ const struct iphdr *ih;
+ 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, iphoff, sizeof(_iph), &_iph);
+ if (ih == NULL) {
+ nf_log_buf_add(m, "TRUNCATED");
+ return;
+ }
+
+ /* Important fields:
+ * TOS, len, DF/MF, fragment offset, TTL, src, dst, options. */
+ /* Max length: 40 "SRC=255.255.255.255 DST=255.255.255.255 " */
+ nf_log_buf_add(m, "SRC=%pI4 DST=%pI4 ", &ih->saddr, &ih->daddr);
+
+ /* Max length: 46 "LEN=65535 TOS=0xFF PREC=0xFF TTL=255 ID=65535 " */
+ nf_log_buf_add(m, "LEN=%u TOS=0x%02X PREC=0x%02X TTL=%u ID=%u ",
+ ntohs(ih->tot_len), ih->tos & IPTOS_TOS_MASK,
+ ih->tos & IPTOS_PREC_MASK, ih->ttl, ntohs(ih->id));
+
+ /* Max length: 6 "CE DF MF " */
+ if (ntohs(ih->frag_off) & IP_CE)
+ nf_log_buf_add(m, "CE ");
+ if (ntohs(ih->frag_off) & IP_DF)
+ nf_log_buf_add(m, "DF ");
+ if (ntohs(ih->frag_off) & IP_MF)
+ nf_log_buf_add(m, "MF ");
+
+ /* Max length: 11 "FRAG:65535 " */
+ if (ntohs(ih->frag_off) & IP_OFFSET)
+ nf_log_buf_add(m, "FRAG:%u ", ntohs(ih->frag_off) & IP_OFFSET);
+
+ if ((logflags & XT_LOG_IPOPT) &&
+ ih->ihl * 4 > sizeof(struct iphdr)) {
+ const unsigned char *op;
+ unsigned char _opt[4 * 15 - sizeof(struct iphdr)];
+ unsigned int i, optsize;
+
+ optsize = ih->ihl * 4 - sizeof(struct iphdr);
+ op = skb_header_pointer(skb, iphoff+sizeof(_iph),
+ optsize, _opt);
+ if (op == NULL) {
+ nf_log_buf_add(m, "TRUNCATED");
+ return;
+ }
+
+ /* Max length: 127 "OPT (" 15*4*2chars ") " */
+ nf_log_buf_add(m, "OPT (");
+ for (i = 0; i < optsize; i++)
+ nf_log_buf_add(m, "%02X", op[i]);
+ nf_log_buf_add(m, ") ");
+ }
+
+ switch (ih->protocol) {
+ case IPPROTO_TCP:
+ if (nf_log_dump_tcp_header(m, skb, ih->protocol,
+ ntohs(ih->frag_off) & IP_OFFSET,
+ iphoff+ih->ihl*4, logflags))
+ return;
+ break;
+ case IPPROTO_UDP:
+ case IPPROTO_UDPLITE:
+ if (nf_log_dump_udp_header(m, skb, ih->protocol,
+ ntohs(ih->frag_off) & IP_OFFSET,
+ iphoff+ih->ihl*4))
+ return;
+ break;
+ case IPPROTO_ICMP: {
+ struct icmphdr _icmph;
+ const struct icmphdr *ich;
+ static const size_t required_len[NR_ICMP_TYPES+1]
+ = { [ICMP_ECHOREPLY] = 4,
+ [ICMP_DEST_UNREACH]
+ = 8 + sizeof(struct iphdr),
+ [ICMP_SOURCE_QUENCH]
+ = 8 + sizeof(struct iphdr),
+ [ICMP_REDIRECT]
+ = 8 + sizeof(struct iphdr),
+ [ICMP_ECHO] = 4,
+ [ICMP_TIME_EXCEEDED]
+ = 8 + sizeof(struct iphdr),
+ [ICMP_PARAMETERPROB]
+ = 8 + sizeof(struct iphdr),
+ [ICMP_TIMESTAMP] = 20,
+ [ICMP_TIMESTAMPREPLY] = 20,
+ [ICMP_ADDRESS] = 12,
+ [ICMP_ADDRESSREPLY] = 12 };
+
+ /* Max length: 11 "PROTO=ICMP " */
+ nf_log_buf_add(m, "PROTO=ICMP ");
+
+ if (ntohs(ih->frag_off) & IP_OFFSET)
+ break;
+
+ /* Max length: 25 "INCOMPLETE [65535 bytes] " */
+ ich = skb_header_pointer(skb, iphoff + ih->ihl * 4,
+ sizeof(_icmph), &_icmph);
+ if (ich == NULL) {
+ nf_log_buf_add(m, "INCOMPLETE [%u bytes] ",
+ skb->len - iphoff - ih->ihl*4);
+ break;
+ }
+
+ /* Max length: 18 "TYPE=255 CODE=255 " */
+ nf_log_buf_add(m, "TYPE=%u CODE=%u ", ich->type, ich->code);
+
+ /* Max length: 25 "INCOMPLETE [65535 bytes] " */
+ if (ich->type <= NR_ICMP_TYPES &&
+ required_len[ich->type] &&
+ skb->len-iphoff-ih->ihl*4 < required_len[ich->type]) {
+ nf_log_buf_add(m, "INCOMPLETE [%u bytes] ",
+ skb->len - iphoff - ih->ihl*4);
+ break;
+ }
+
+ switch (ich->type) {
+ case ICMP_ECHOREPLY:
+ case ICMP_ECHO:
+ /* Max length: 19 "ID=65535 SEQ=65535 " */
+ nf_log_buf_add(m, "ID=%u SEQ=%u ",
+ ntohs(ich->un.echo.id),
+ ntohs(ich->un.echo.sequence));
+ break;
+
+ case ICMP_PARAMETERPROB:
+ /* Max length: 14 "PARAMETER=255 " */
+ nf_log_buf_add(m, "PARAMETER=%u ",
+ ntohl(ich->un.gateway) >> 24);
+ break;
+ case ICMP_REDIRECT:
+ /* Max length: 24 "GATEWAY=255.255.255.255 " */
+ nf_log_buf_add(m, "GATEWAY=%pI4 ", &ich->un.gateway);
+ /* Fall through */
+ case ICMP_DEST_UNREACH:
+ case ICMP_SOURCE_QUENCH:
+ case ICMP_TIME_EXCEEDED:
+ /* Max length: 3+maxlen */
+ if (!iphoff) { /* Only recurse once. */
+ nf_log_buf_add(m, "[");
+ dump_ipv4_packet(m, info, skb,
+ iphoff + ih->ihl*4+sizeof(_icmph));
+ nf_log_buf_add(m, "] ");
+ }
+
+ /* Max length: 10 "MTU=65535 " */
+ if (ich->type == ICMP_DEST_UNREACH &&
+ ich->code == ICMP_FRAG_NEEDED) {
+ nf_log_buf_add(m, "MTU=%u ",
+ ntohs(ich->un.frag.mtu));
+ }
+ }
+ break;
+ }
+ /* Max Length */
+ case IPPROTO_AH: {
+ struct ip_auth_hdr _ahdr;
+ const struct ip_auth_hdr *ah;
+
+ if (ntohs(ih->frag_off) & IP_OFFSET)
+ break;
+
+ /* Max length: 9 "PROTO=AH " */
+ nf_log_buf_add(m, "PROTO=AH ");
+
+ /* Max length: 25 "INCOMPLETE [65535 bytes] " */
+ ah = skb_header_pointer(skb, iphoff+ih->ihl*4,
+ sizeof(_ahdr), &_ahdr);
+ if (ah == NULL) {
+ nf_log_buf_add(m, "INCOMPLETE [%u bytes] ",
+ skb->len - iphoff - ih->ihl*4);
+ break;
+ }
+
+ /* Length: 15 "SPI=0xF1234567 " */
+ nf_log_buf_add(m, "SPI=0x%x ", ntohl(ah->spi));
+ break;
+ }
+ case IPPROTO_ESP: {
+ struct ip_esp_hdr _esph;
+ const struct ip_esp_hdr *eh;
+
+ /* Max length: 10 "PROTO=ESP " */
+ nf_log_buf_add(m, "PROTO=ESP ");
+
+ if (ntohs(ih->frag_off) & IP_OFFSET)
+ break;
+
+ /* Max length: 25 "INCOMPLETE [65535 bytes] " */
+ eh = skb_header_pointer(skb, iphoff+ih->ihl*4,
+ sizeof(_esph), &_esph);
+ if (eh == NULL) {
+ nf_log_buf_add(m, "INCOMPLETE [%u bytes] ",
+ skb->len - iphoff - ih->ihl*4);
+ break;
+ }
+
+ /* Length: 15 "SPI=0xF1234567 " */
+ nf_log_buf_add(m, "SPI=0x%x ", ntohl(eh->spi));
+ break;
+ }
+ /* Max length: 10 "PROTO 255 " */
+ default:
+ nf_log_buf_add(m, "PROTO=%u ", ih->protocol);
+ }
+
+ /* Max length: 15 "UID=4294967295 " */
+ if ((logflags & XT_LOG_UID) && !iphoff)
+ nf_log_dump_sk_uid_gid(m, skb->sk);
+
+ /* Max length: 16 "MARK=0xFFFFFFFF " */
+ if (!iphoff && skb->mark)
+ nf_log_buf_add(m, "MARK=0x%x ", skb->mark);
+
+ /* Proto Max log string length */
+ /* IP: 40+46+6+11+127 = 230 */
+ /* TCP: 10+max(25,20+30+13+9+32+11+127) = 252 */
+ /* UDP: 10+max(25,20) = 35 */
+ /* UDPLITE: 14+max(25,20) = 39 */
+ /* ICMP: 11+max(25, 18+25+max(19,14,24+3+n+10,3+n+10)) = 91+n */
+ /* ESP: 10+max(25)+15 = 50 */
+ /* AH: 9+max(25)+15 = 49 */
+ /* unknown: 10 */
+
+ /* (ICMP allows recursion one level deep) */
+ /* maxlen = IP + ICMP + IP + max(TCP,UDP,ICMP,unknown) */
+ /* maxlen = 230+ 91 + 230 + 252 = 803 */
+}
+
+static void dump_ipv4_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 i;
+
+ nf_log_buf_add(m, "%02x", *p++);
+ for (i = 1; i < dev->hard_header_len; i++, p++)
+ nf_log_buf_add(m, ":%02x", *p);
+ }
+ nf_log_buf_add(m, " ");
+}
+
+void nf_log_ip_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_ipv4_mac_header(m, loginfo, skb);
+
+ dump_ipv4_packet(m, loginfo, skb, 0);
+
+ nf_log_buf_close(m);
+}
+EXPORT_SYMBOL_GPL(nf_log_ip_packet);
+
+static struct nf_logger nf_ip_logger __read_mostly = {
+ .name = "nf_log_ipv4",
+ .type = NF_LOG_TYPE_LOG,
+ .logfn = nf_log_ip_packet,
+ .me = THIS_MODULE,
+};
+
+static int __net_init nf_log_ipv4_net_init(struct net *net)
+{
+ nf_log_set(net, NFPROTO_IPV4, &nf_ip_logger);
+ return 0;
+}
+
+static void __net_exit nf_log_ipv4_net_exit(struct net *net)
+{
+ nf_log_unset(net, &nf_ip_logger);
+}
+
+static struct pernet_operations nf_log_ipv4_net_ops = {
+ .init = nf_log_ipv4_net_init,
+ .exit = nf_log_ipv4_net_exit,
+};
+
+static int __init nf_log_ipv4_init(void)
+{
+ int ret;
+
+ ret = register_pernet_subsys(&nf_log_ipv4_net_ops);
+ if (ret < 0)
+ return ret;
+
+ nf_log_register(NFPROTO_IPV4, &nf_ip_logger);
+ return 0;
+}
+
+static void __exit nf_log_ipv4_exit(void)
+{
+ unregister_pernet_subsys(&nf_log_ipv4_net_ops);
+ nf_log_unregister(&nf_ip_logger);
+}
+
+module_init(nf_log_ipv4_init);
+module_exit(nf_log_ipv4_exit);
+
+MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
+MODULE_DESCRIPTION("Netfilter IPv4 packet logging");
+MODULE_LICENSE("GPL");