netfilter: nf_log_ipv4: rename to nf_log_syslog

Netfilter has multiple log modules:
 nf_log_arp
 nf_log_bridge
 nf_log_ipv4
 nf_log_ipv6
 nf_log_netdev
 nfnetlink_log
 nf_log_common

With the exception of nfnetlink_log (packet is sent to userspace for
dissection/logging), all of them log to the kernel ringbuffer.

This is the first part of a series to merge all modules except
nfnetlink_log into a single module: nf_log_syslog.

This allows to reduce code.  After the series, only two log modules remain:
nfnetlink_log and nf_log_syslog. The latter provides the same
functionality as the old per-af log modules.

This renames nf_log_ipv4 to nf_log_syslog.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

3 files changed, 4 insertions, 397 deletions

diff --git a/net/ipv4/netfilter/Kconfig b/net/ipv4/netfilter/Kconfig
index a2f4f894be2b..aadb98e43fb1 100644
--- a/net/ipv4/netfilter/Kconfig
+++ b/net/ipv4/netfilter/Kconfig
@@ -81,7 +81,10 @@ config NF_LOG_ARP
 config NF_LOG_IPV4
 	tristate "IPv4 packet logging"
 	default m if NETFILTER_ADVANCED=n
-	select NF_LOG_COMMON
+	select NF_LOG_SYSLOG
+	help
+	This is a backwards-compat option for the user's convenience
+	(e.g. when running oldconfig). It selects CONFIG_NF_LOG_SYSLOG.
 
 config NF_REJECT_IPV4
 	tristate "IPv4 packet rejection"
diff --git a/net/ipv4/netfilter/Makefile b/net/ipv4/netfilter/Makefile
index 7c497c78105f..abd133048b42 100644
--- a/net/ipv4/netfilter/Makefile
+++ b/net/ipv4/netfilter/Makefile
@@ -11,7 +11,6 @@ obj-$(CONFIG_NF_TPROXY_IPV4) += nf_tproxy_ipv4.o
 
 # logging
 obj-$(CONFIG_NF_LOG_ARP) += nf_log_arp.o
-obj-$(CONFIG_NF_LOG_IPV4) += nf_log_ipv4.o
 
 # reject
 obj-$(CONFIG_NF_REJECT_IPV4) += nf_reject_ipv4.o
diff --git a/net/ipv4/netfilter/nf_log_ipv4.c b/net/ipv4/netfilter/nf_log_ipv4.c
deleted file mode 100644
index d07583fac8f8..000000000000
--- a/net/ipv4/netfilter/nf_log_ipv4.c
+++ /dev/null
@@ -1,395 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-/* (C) 1999-2001 Paul `Rusty' Russell
- * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
- */
-
-#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
-
-#include <linux/kernel.h>
-#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 const struct nf_loginfo default_loginfo = {
-	.type	= NF_LOG_TYPE_LOG,
-	.u = {
-		.log = {
-			.level	  = LOGLEVEL_NOTICE,
-			.logflags = NF_LOG_DEFAULT_MASK,
-		},
-	},
-};
-
-/* One level of recursion won't kill us */
-static void dump_ipv4_packet(struct net *net, 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_DEFAULT_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 & NF_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);
-			fallthrough;
-		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(net, 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 & NF_LOG_UID) && !iphoff)
-		nf_log_dump_sk_uid_gid(net, 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 & NF_LOG_MACDECODE))
-		goto fallback;
-
-	switch (dev->type) {
-	case ARPHRD_ETHER:
-		nf_log_buf_add(m, "MACSRC=%pM MACDST=%pM ",
-			       eth_hdr(skb)->h_source, eth_hdr(skb)->h_dest);
-		nf_log_dump_vlan(m, skb);
-		nf_log_buf_add(m, "MACPROTO=%04x ",
-			       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, " ");
-}
-
-static 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) && !sysctl_nf_log_all_netns)
-		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(net, m, loginfo, skb, 0);
-
-	nf_log_buf_close(m);
-}
-
-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)
-{
-	return nf_log_set(net, NFPROTO_IPV4, &nf_ip_logger);
-}
-
-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;
-
-	ret = nf_log_register(NFPROTO_IPV4, &nf_ip_logger);
-	if (ret < 0) {
-		pr_err("failed to register logger\n");
-		goto err1;
-	}
-
-	return 0;
-
-err1:
-	unregister_pernet_subsys(&nf_log_ipv4_net_ops);
-	return ret;
-}
-
-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");
-MODULE_ALIAS_NF_LOGGER(AF_INET, 0);