[funini.com] -> [kei@sodan] -> Kernel Reading

root/net/bridge/netfilter/ebt_log.c

/* [<][>][^][v][top][bottom][index][help] */

DEFINITIONS

This source file includes following definitions.
  1. ebt_log_tg_check
  2. print_MAC
  3. print_ports
  4. ebt_log_packet
  5. ebt_log_tg
  6. ebt_log_init
  7. ebt_log_fini

/*
 *  ebt_log
 *
 *      Authors:
 *      Bart De Schuymer <bdschuym@pandora.be>
 *      Harald Welte <laforge@netfilter.org>
 *
 *  April, 2002
 *
 */
#include <linux/module.h>
#include <linux/ip.h>
#include <linux/in.h>
#include <linux/if_arp.h>
#include <linux/spinlock.h>
#include <net/netfilter/nf_log.h>
#include <linux/ipv6.h>
#include <net/ipv6.h>
#include <linux/in6.h>
#include <linux/netfilter/x_tables.h>
#include <linux/netfilter_bridge/ebtables.h>
#include <linux/netfilter_bridge/ebt_log.h>
#include <linux/netfilter.h>

static DEFINE_SPINLOCK(ebt_log_lock);

static bool ebt_log_tg_check(const struct xt_tgchk_param *par)
{
        struct ebt_log_info *info = par->targinfo;

        if (info->bitmask & ~EBT_LOG_MASK)
                return false;
        if (info->loglevel >= 8)
                return false;
        info->prefix[EBT_LOG_PREFIX_SIZE - 1] = '\0';
        return true;
}

struct tcpudphdr
{
        __be16 src;
        __be16 dst;
};

struct arppayload
{
        unsigned char mac_src[ETH_ALEN];
        unsigned char ip_src[4];
        unsigned char mac_dst[ETH_ALEN];
        unsigned char ip_dst[4];
};

static void print_MAC(const unsigned char *p)
{
        int i;

        for (i = 0; i < ETH_ALEN; i++, p++)
                printk("%02x%c", *p, i == ETH_ALEN - 1 ? ' ':':');
}

static void
print_ports(const struct sk_buff *skb, uint8_t protocol, int offset)
{
        if (protocol == IPPROTO_TCP ||
            protocol == IPPROTO_UDP ||
            protocol == IPPROTO_UDPLITE ||
            protocol == IPPROTO_SCTP ||
            protocol == IPPROTO_DCCP) {
                const struct tcpudphdr *pptr;
                struct tcpudphdr _ports;

                pptr = skb_header_pointer(skb, offset,
                                          sizeof(_ports), &_ports);
                if (pptr == NULL) {
                        printk(" INCOMPLETE TCP/UDP header");
                        return;
                }
                printk(" SPT=%u DPT=%u", ntohs(pptr->src), ntohs(pptr->dst));
        }
}

#define myNIPQUAD(a) a[0], a[1], a[2], a[3]
static void
ebt_log_packet(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)
{
        unsigned int bitmask;

        spin_lock_bh(&ebt_log_lock);
        printk("<%c>%s IN=%s OUT=%s MAC source = ", '0' + loginfo->u.log.level,
               prefix, in ? in->name : "", out ? out->name : "");

        print_MAC(eth_hdr(skb)->h_source);
        printk("MAC dest = ");
        print_MAC(eth_hdr(skb)->h_dest);

        printk("proto = 0x%04x", ntohs(eth_hdr(skb)->h_proto));

        if (loginfo->type == NF_LOG_TYPE_LOG)
                bitmask = loginfo->u.log.logflags;
        else
                bitmask = NF_LOG_MASK;

        if ((bitmask & EBT_LOG_IP) && eth_hdr(skb)->h_proto ==
           htons(ETH_P_IP)){
                const struct iphdr *ih;
                struct iphdr _iph;

                ih = skb_header_pointer(skb, 0, sizeof(_iph), &_iph);
                if (ih == NULL) {
                        printk(" INCOMPLETE IP header");
                        goto out;
                }
                printk(" IP SRC=%u.%u.%u.%u IP DST=%u.%u.%u.%u, IP "
                       "tos=0x%02X, IP proto=%d", NIPQUAD(ih->saddr),
                       NIPQUAD(ih->daddr), ih->tos, ih->protocol);
                print_ports(skb, ih->protocol, ih->ihl*4);
                goto out;
        }

#if defined(CONFIG_BRIDGE_EBT_IP6) || defined(CONFIG_BRIDGE_EBT_IP6_MODULE)
        if ((bitmask & EBT_LOG_IP6) && eth_hdr(skb)->h_proto ==
           htons(ETH_P_IPV6)) {
                const struct ipv6hdr *ih;
                struct ipv6hdr _iph;
                uint8_t nexthdr;
                int offset_ph;

                ih = skb_header_pointer(skb, 0, sizeof(_iph), &_iph);
                if (ih == NULL) {
                        printk(" INCOMPLETE IPv6 header");
                        goto out;
                }
                printk(" IPv6 SRC=%x:%x:%x:%x:%x:%x:%x:%x "
                       "IPv6 DST=%x:%x:%x:%x:%x:%x:%x:%x, IPv6 "
                       "priority=0x%01X, Next Header=%d", NIP6(ih->saddr),
                       NIP6(ih->daddr), ih->priority, ih->nexthdr);
                nexthdr = ih->nexthdr;
                offset_ph = ipv6_skip_exthdr(skb, sizeof(_iph), &nexthdr);
                if (offset_ph == -1)
                        goto out;
                print_ports(skb, nexthdr, offset_ph);
                goto out;
        }
#endif

        if ((bitmask & EBT_LOG_ARP) &&
            ((eth_hdr(skb)->h_proto == htons(ETH_P_ARP)) ||
             (eth_hdr(skb)->h_proto == htons(ETH_P_RARP)))) {
                const struct arphdr *ah;
                struct arphdr _arph;

                ah = skb_header_pointer(skb, 0, sizeof(_arph), &_arph);
                if (ah == NULL) {
                        printk(" INCOMPLETE ARP header");
                        goto out;
                }
                printk(" ARP HTYPE=%d, PTYPE=0x%04x, OPCODE=%d",
                       ntohs(ah->ar_hrd), ntohs(ah->ar_pro),
                       ntohs(ah->ar_op));

                /* If it's for Ethernet and the lengths are OK,
                 * then log the ARP payload */
                if (ah->ar_hrd == htons(1) &&
                    ah->ar_hln == ETH_ALEN &&
                    ah->ar_pln == sizeof(__be32)) {
                        const struct arppayload *ap;
                        struct arppayload _arpp;

                        ap = skb_header_pointer(skb, sizeof(_arph),
                                                sizeof(_arpp), &_arpp);
                        if (ap == NULL) {
                                printk(" INCOMPLETE ARP payload");
                                goto out;
                        }
                        printk(" ARP MAC SRC=");
                        print_MAC(ap->mac_src);
                        printk(" ARP IP SRC=%u.%u.%u.%u",
                               myNIPQUAD(ap->ip_src));
                        printk(" ARP MAC DST=");
                        print_MAC(ap->mac_dst);
                        printk(" ARP IP DST=%u.%u.%u.%u",
                               myNIPQUAD(ap->ip_dst));
                }
        }
out:
        printk("\n");
        spin_unlock_bh(&ebt_log_lock);

}

static unsigned int
ebt_log_tg(struct sk_buff *skb, const struct xt_target_param *par)
{
        const struct ebt_log_info *info = par->targinfo;
        struct nf_loginfo li;

        li.type = NF_LOG_TYPE_LOG;
        li.u.log.level = info->loglevel;
        li.u.log.logflags = info->bitmask;

        if (info->bitmask & EBT_LOG_NFLOG)
                nf_log_packet(NFPROTO_BRIDGE, par->hooknum, skb, par->in,
                              par->out, &li, "%s", info->prefix);
        else
                ebt_log_packet(NFPROTO_BRIDGE, par->hooknum, skb, par->in,
                               par->out, &li, info->prefix);
        return EBT_CONTINUE;
}

static struct xt_target ebt_log_tg_reg __read_mostly = {
        .name           = "log",
        .revision       = 0,
        .family         = NFPROTO_BRIDGE,
        .target         = ebt_log_tg,
        .checkentry     = ebt_log_tg_check,
        .targetsize     = XT_ALIGN(sizeof(struct ebt_log_info)),
        .me             = THIS_MODULE,
};

static const struct nf_logger ebt_log_logger = {
        .name           = "ebt_log",
        .logfn          = &ebt_log_packet,
        .me             = THIS_MODULE,
};

static int __init ebt_log_init(void)
{
        int ret;

        ret = xt_register_target(&ebt_log_tg_reg);
        if (ret < 0)
                return ret;
        nf_log_register(NFPROTO_BRIDGE, &ebt_log_logger);
        return 0;
}

static void __exit ebt_log_fini(void)
{
        nf_log_unregister(&ebt_log_logger);
        xt_unregister_target(&ebt_log_tg_reg);
}

module_init(ebt_log_init);
module_exit(ebt_log_fini);
MODULE_DESCRIPTION("Ebtables: Packet logging to syslog");
MODULE_LICENSE("GPL");

/* [<][>][^][v][top][bottom][index][help] */

[funini.com] -> [kei@sodan] -> Kernel Reading