From 7eb9282cd0efac08b8377cbd5037ba297c77e3f7 Mon Sep 17 00:00:00 2001 From: Patrick McHardy Date: Mon, 28 Jun 2010 14:16:08 +0200 Subject: [PATCH] netfilter: ipt_LOG/ip6t_LOG: add option to print decoded MAC header The LOG targets print the entire MAC header as one long string, which is not readable very well: IN=eth0 OUT= MAC=00:15:f2:24:91:f8:00:1b:24:dc:61:e6:08:00 ... Add an option to decode known header formats (currently just ARPHRD_ETHER devices) in their individual fields: IN=eth0 OUT= MACSRC=00:1b:24:dc:61:e6 MACDST=00:15:f2:24:91:f8 MACPROTO=0800 ... IN=eth0 OUT= MACSRC=00:1b:24:dc:61:e6 MACDST=00:15:f2:24:91:f8 MACPROTO=86dd ... The option needs to be explicitly enabled by userspace to avoid breaking existing parsers. Signed-off-by: Patrick McHardy --- include/linux/netfilter_ipv4/ipt_LOG.h | 3 +- include/linux/netfilter_ipv6/ip6t_LOG.h | 3 +- net/ipv4/netfilter/ipt_LOG.c | 54 ++++++++++++----- net/ipv6/netfilter/ip6t_LOG.c | 81 ++++++++++++++++--------- 4 files changed, 97 insertions(+), 44 deletions(-) diff --git a/include/linux/netfilter_ipv4/ipt_LOG.h b/include/linux/netfilter_ipv4/ipt_LOG.h index 90fa6525ef9c..dcdbadf9fd4a 100644 --- a/include/linux/netfilter_ipv4/ipt_LOG.h +++ b/include/linux/netfilter_ipv4/ipt_LOG.h @@ -7,7 +7,8 @@ #define IPT_LOG_IPOPT 0x04 /* Log IP options */ #define IPT_LOG_UID 0x08 /* Log UID owning local socket */ #define IPT_LOG_NFLOG 0x10 /* Unsupported, don't reuse */ -#define IPT_LOG_MASK 0x1f +#define IPT_LOG_MACDECODE 0x20 /* Decode MAC header */ +#define IPT_LOG_MASK 0x2f struct ipt_log_info { unsigned char level; diff --git a/include/linux/netfilter_ipv6/ip6t_LOG.h b/include/linux/netfilter_ipv6/ip6t_LOG.h index 0d0119b0458c..9dd5579e02ec 100644 --- a/include/linux/netfilter_ipv6/ip6t_LOG.h +++ b/include/linux/netfilter_ipv6/ip6t_LOG.h @@ -7,7 +7,8 @@ #define IP6T_LOG_IPOPT 0x04 /* Log IP options */ #define IP6T_LOG_UID 0x08 /* Log UID owning local socket */ #define IP6T_LOG_NFLOG 0x10 /* Unsupported, don't use */ -#define IP6T_LOG_MASK 0x1f +#define IP6T_LOG_MACDECODE 0x20 /* Decode MAC header */ +#define IP6T_LOG_MASK 0x2f struct ip6t_log_info { unsigned char level; diff --git a/net/ipv4/netfilter/ipt_LOG.c b/net/ipv4/netfilter/ipt_LOG.c index 0a452a54adbe..915fc17d7ce2 100644 --- a/net/ipv4/netfilter/ipt_LOG.c +++ b/net/ipv4/netfilter/ipt_LOG.c @@ -13,6 +13,7 @@ #include #include #include +#include #include #include #include @@ -363,6 +364,42 @@ static void dump_packet(const struct nf_loginfo *info, /* maxlen = 230+ 91 + 230 + 252 = 803 */ } +static void dump_mac_header(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 & IPT_LOG_MACDECODE)) + goto fallback; + + switch (dev->type) { + case ARPHRD_ETHER: + printk("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: + printk("MAC="); + if (dev->hard_header_len && + skb->mac_header != skb->network_header) { + const unsigned char *p = skb_mac_header(skb); + unsigned int i; + + printk("%02x", *p++); + for (i = 1; i < dev->hard_header_len; i++, p++) + printk(":%02x", *p); + } + printk(" "); +} + static struct nf_loginfo default_loginfo = { .type = NF_LOG_TYPE_LOG, .u = { @@ -404,20 +441,9 @@ ipt_log_packet(u_int8_t pf, } #endif - if (in && !out) { - /* MAC logging for input chain only. */ - printk("MAC="); - if (skb->dev && skb->dev->hard_header_len && - skb->mac_header != skb->network_header) { - int i; - const unsigned char *p = skb_mac_header(skb); - - printk("%02x", *p++); - for (i = 1; i < skb->dev->hard_header_len; i++, p++) - printk(":%02x", *p); - } - printk(" "); - } + /* MAC logging for input path only. */ + if (in && !out) + dump_mac_header(loginfo, skb); dump_packet(loginfo, skb, 0); printk("\n"); diff --git a/net/ipv6/netfilter/ip6t_LOG.c b/net/ipv6/netfilter/ip6t_LOG.c index 4c7ddac7c62b..0a07ae7b933f 100644 --- a/net/ipv6/netfilter/ip6t_LOG.c +++ b/net/ipv6/netfilter/ip6t_LOG.c @@ -373,6 +373,56 @@ static void dump_packet(const struct nf_loginfo *info, printk("MARK=0x%x ", skb->mark); } +static void dump_mac_header(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 & IP6T_LOG_MACDECODE)) + goto fallback; + + switch (dev->type) { + case ARPHRD_ETHER: + printk("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: + printk("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) < skb->head) + p = NULL; + + if (p != NULL) { + printk("%02x", *p++); + for (i = 1; i < len; i++) + printk(":%02x", p[i]); + } + printk(" "); + + if (dev->type == ARPHRD_SIT) { + const struct iphdr *iph = + (struct iphdr *)skb_mac_header(skb); + printk("TUNNEL=%pI4->%pI4 ", &iph->saddr, &iph->daddr); + } + } else + printk(" "); +} + static struct nf_loginfo default_loginfo = { .type = NF_LOG_TYPE_LOG, .u = { @@ -400,35 +450,10 @@ ip6t_log_packet(u_int8_t pf, prefix, in ? in->name : "", out ? out->name : ""); - if (in && !out) { - unsigned int len; - /* MAC logging for input chain only. */ - printk("MAC="); - if (skb->dev && (len = skb->dev->hard_header_len) && - skb->mac_header != skb->network_header) { - const unsigned char *p = skb_mac_header(skb); - int i; - - if (skb->dev->type == ARPHRD_SIT && - (p -= ETH_HLEN) < skb->head) - p = NULL; - - if (p != NULL) { - printk("%02x", *p++); - for (i = 1; i < len; i++) - printk(":%02x", p[i]); - } - printk(" "); - if (skb->dev->type == ARPHRD_SIT) { - const struct iphdr *iph = - (struct iphdr *)skb_mac_header(skb); - printk("TUNNEL=%pI4->%pI4 ", - &iph->saddr, &iph->daddr); - } - } else - printk(" "); - } + /* MAC logging for input path only. */ + if (in && !out) + dump_mac_header(loginfo, skb); dump_packet(loginfo, skb, skb_network_offset(skb), 1); printk("\n"); -- 2.20.1