err.no Git - linux-2.6/blob - net/bridge/netfilter/ebt_log.c

   1 /*
   2  *  ebt_log
   3  *
   4  *      Authors:
   5  *      Bart De Schuymer <bdschuym@pandora.be>
   6  *      Harald Welte <laforge@netfilter.org>
   7  *
   8  *  April, 2002
   9  *
  10  */
  11
  12 #include <linux/in.h>
  13 #include <linux/netfilter_bridge/ebtables.h>
  14 #include <linux/netfilter_bridge/ebt_log.h>
  15 #include <linux/netfilter.h>
  16 #include <linux/module.h>
  17 #include <linux/ip.h>
  18 #include <linux/if_arp.h>
  19 #include <linux/spinlock.h>
  20
  21 static DEFINE_SPINLOCK(ebt_log_lock);
  22
  23 static int ebt_log_check(const char *tablename, unsigned int hookmask,
  24    const struct ebt_entry *e, void *data, unsigned int datalen)
  25 {
  26         struct ebt_log_info *info = (struct ebt_log_info *)data;
  27
  28         if (datalen != EBT_ALIGN(sizeof(struct ebt_log_info)))
  29                 return -EINVAL;
  30         if (info->bitmask & ~EBT_LOG_MASK)
  31                 return -EINVAL;
  32         if (info->loglevel >= 8)
  33                 return -EINVAL;
  34         info->prefix[EBT_LOG_PREFIX_SIZE - 1] = '\0';
  35         return 0;
  36 }
  37
  38 struct tcpudphdr
  39 {
  40         uint16_t src;
  41         uint16_t dst;
  42 };
  43
  44 struct arppayload
  45 {
  46         unsigned char mac_src[ETH_ALEN];
  47         unsigned char ip_src[4];
  48         unsigned char mac_dst[ETH_ALEN];
  49         unsigned char ip_dst[4];
  50 };
  51
  52 static void print_MAC(unsigned char *p)
  53 {
  54         int i;
  55
  56         for (i = 0; i < ETH_ALEN; i++, p++)
  57                 printk("%02x%c", *p, i == ETH_ALEN - 1 ? ' ':':');
  58 }
  59
  60 #define myNIPQUAD(a) a[0], a[1], a[2], a[3]
  61 static void
  62 ebt_log_packet(unsigned int pf, unsigned int hooknum,
  63    const struct sk_buff *skb, const struct net_device *in,
  64    const struct net_device *out, const struct nf_loginfo *loginfo,
  65    const char *prefix)
  66 {
  67         unsigned int bitmask;
  68
  69         spin_lock_bh(&ebt_log_lock);
  70         printk("<%c>%s IN=%s OUT=%s MAC source = ", '0' + loginfo->u.log.level,
  71                prefix, in ? in->name : "", out ? out->name : "");
  72
  73         print_MAC(eth_hdr(skb)->h_source);
  74         printk("MAC dest = ");
  75         print_MAC(eth_hdr(skb)->h_dest);
  76
  77         printk("proto = 0x%04x", ntohs(eth_hdr(skb)->h_proto));
  78
  79         if (loginfo->type == NF_LOG_TYPE_LOG)
  80                 bitmask = loginfo->u.log.logflags;
  81         else
  82                 bitmask = NF_LOG_MASK;
  83
  84         if ((bitmask & EBT_LOG_IP) && eth_hdr(skb)->h_proto ==
  85            htons(ETH_P_IP)){
  86                 struct iphdr _iph, *ih;
  87
  88                 ih = skb_header_pointer(skb, 0, sizeof(_iph), &_iph);
  89                 if (ih == NULL) {
  90                         printk(" INCOMPLETE IP header");
  91                         goto out;
  92                 }
  93                 printk(" IP SRC=%u.%u.%u.%u IP DST=%u.%u.%u.%u, IP "
  94                        "tos=0x%02X, IP proto=%d", NIPQUAD(ih->saddr),
  95                        NIPQUAD(ih->daddr), ih->tos, ih->protocol);
  96                 if (ih->protocol == IPPROTO_TCP ||
  97                     ih->protocol == IPPROTO_UDP) {
  98                         struct tcpudphdr _ports, *pptr;
  99
 100                         pptr = skb_header_pointer(skb, ih->ihl*4,
 101                                                   sizeof(_ports), &_ports);
 102                         if (pptr == NULL) {
 103                                 printk(" INCOMPLETE TCP/UDP header");
 104                                 goto out;
 105                         }
 106                         printk(" SPT=%u DPT=%u", ntohs(pptr->src),
 107                            ntohs(pptr->dst));
 108                 }
 109                 goto out;
 110         }
 111
 112         if ((bitmask & EBT_LOG_ARP) &&
 113             ((eth_hdr(skb)->h_proto == htons(ETH_P_ARP)) ||
 114              (eth_hdr(skb)->h_proto == htons(ETH_P_RARP)))) {
 115                 struct arphdr _arph, *ah;
 116
 117                 ah = skb_header_pointer(skb, 0, sizeof(_arph), &_arph);
 118                 if (ah == NULL) {
 119                         printk(" INCOMPLETE ARP header");
 120                         goto out;
 121                 }
 122                 printk(" ARP HTYPE=%d, PTYPE=0x%04x, OPCODE=%d",
 123                        ntohs(ah->ar_hrd), ntohs(ah->ar_pro),
 124                        ntohs(ah->ar_op));
 125
 126                 /* If it's for Ethernet and the lengths are OK,
 127                  * then log the ARP payload */
 128                 if (ah->ar_hrd == htons(1) &&
 129                     ah->ar_hln == ETH_ALEN &&
 130                     ah->ar_pln == sizeof(uint32_t)) {
 131                         struct arppayload _arpp, *ap;
 132
 133                         ap = skb_header_pointer(skb, sizeof(_arph),
 134                                                 sizeof(_arpp), &_arpp);
 135                         if (ap == NULL) {
 136                                 printk(" INCOMPLETE ARP payload");
 137                                 goto out;
 138                         }
 139                         printk(" ARP MAC SRC=");
 140                         print_MAC(ap->mac_src);
 141                         printk(" ARP IP SRC=%u.%u.%u.%u",
 142                                myNIPQUAD(ap->ip_src));
 143                         printk(" ARP MAC DST=");
 144                         print_MAC(ap->mac_dst);
 145                         printk(" ARP IP DST=%u.%u.%u.%u",
 146                                myNIPQUAD(ap->ip_dst));
 147                 }
 148         }
 149 out:
 150         printk("\n");
 151         spin_unlock_bh(&ebt_log_lock);
 152
 153 }
 154
 155 static void ebt_log(const struct sk_buff *skb, unsigned int hooknr,
 156    const struct net_device *in, const struct net_device *out,
 157    const void *data, unsigned int datalen)
 158 {
 159         struct ebt_log_info *info = (struct ebt_log_info *)data;
 160         struct nf_loginfo li;
 161
 162         li.type = NF_LOG_TYPE_LOG;
 163         li.u.log.level = info->loglevel;
 164         li.u.log.logflags = info->bitmask;
 165
 166         nf_log_packet(PF_BRIDGE, hooknr, skb, in, out, &li, info->prefix);
 167 }
 168
 169 static struct ebt_watcher log =
 170 {
 171         .name           = EBT_LOG_WATCHER,
 172         .watcher        = ebt_log,
 173         .check          = ebt_log_check,
 174         .me             = THIS_MODULE,
 175 };
 176
 177 static struct nf_logger ebt_log_logger = {
 178         .name           = "ebt_log",
 179         .logfn          = &ebt_log_packet,
 180         .me             = THIS_MODULE,
 181 };
 182
 183 static int __init init(void)
 184 {
 185         int ret;
 186
 187         ret = ebt_register_watcher(&log);
 188         if (ret < 0)
 189                 return ret;
 190         if (nf_log_register(PF_BRIDGE, &ebt_log_logger) < 0) {
 191                 printk(KERN_WARNING "ebt_log: not logging via system console "
 192                        "since somebody else already registered for PF_INET\n");
 193                 /* we cannot make module load fail here, since otherwise
 194                  * ebtables userspace would abort */
 195         }
 196
 197         return 0;
 198 }
 199
 200 static void __exit fini(void)
 201 {
 202         nf_log_unregister_logger(&ebt_log_logger);
 203         ebt_unregister_watcher(&log);
 204 }
 205
 206 module_init(init);
 207 module_exit(fini);
 208 MODULE_LICENSE("GPL");