/net/ipv6/netfilter/ip6t_LOG.c
C | 504 lines | 377 code | 73 blank | 54 comment | 81 complexity | 7b162713cd68d9996529acec30811e8c MD5 | raw file
- /*
- * This is a module which is used for logging packets.
- */
- /* (C) 2001 Jan Rekorajski <baggins@pld.org.pl>
- * (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/moduleparam.h>
- #include <linux/skbuff.h>
- #include <linux/if_arp.h>
- #include <linux/ip.h>
- #include <linux/spinlock.h>
- #include <linux/icmpv6.h>
- #include <net/udp.h>
- #include <net/tcp.h>
- #include <net/ipv6.h>
- #include <linux/netfilter.h>
- #include <linux/netfilter/x_tables.h>
- #include <linux/netfilter_ipv6/ip6_tables.h>
- #include <net/netfilter/nf_log.h>
- MODULE_AUTHOR("Jan Rekorajski <baggins@pld.org.pl>");
- MODULE_DESCRIPTION("Xtables: IPv6 packet logging to syslog");
- MODULE_LICENSE("GPL");
- struct in_device;
- #include <net/route.h>
- #include <linux/netfilter_ipv6/ip6t_LOG.h>
- /* Use lock to serialize, so printks don't overlap */
- static DEFINE_SPINLOCK(log_lock);
- /* One level of recursion won't kill us */
- static void dump_packet(const struct nf_loginfo *info,
- const struct sk_buff *skb, unsigned int ip6hoff,
- int recurse)
- {
- u_int8_t currenthdr;
- int fragment;
- struct ipv6hdr _ip6h;
- const struct ipv6hdr *ih;
- unsigned int ptr;
- unsigned int hdrlen = 0;
- 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, ip6hoff, sizeof(_ip6h), &_ip6h);
- if (ih == NULL) {
- printk("TRUNCATED");
- return;
- }
- /* Max length: 88 "SRC=0000.0000.0000.0000.0000.0000.0000.0000 DST=0000.0000.0000.0000.0000.0000.0000.0000 " */
- printk("SRC=%pI6 DST=%pI6 ", &ih->saddr, &ih->daddr);
- /* Max length: 44 "LEN=65535 TC=255 HOPLIMIT=255 FLOWLBL=FFFFF " */
- printk("LEN=%Zu TC=%u HOPLIMIT=%u FLOWLBL=%u ",
- ntohs(ih->payload_len) + sizeof(struct ipv6hdr),
- (ntohl(*(__be32 *)ih) & 0x0ff00000) >> 20,
- ih->hop_limit,
- (ntohl(*(__be32 *)ih) & 0x000fffff));
- fragment = 0;
- ptr = ip6hoff + sizeof(struct ipv6hdr);
- currenthdr = ih->nexthdr;
- while (currenthdr != NEXTHDR_NONE && ip6t_ext_hdr(currenthdr)) {
- struct ipv6_opt_hdr _hdr;
- const struct ipv6_opt_hdr *hp;
- hp = skb_header_pointer(skb, ptr, sizeof(_hdr), &_hdr);
- if (hp == NULL) {
- printk("TRUNCATED");
- return;
- }
- /* Max length: 48 "OPT (...) " */
- if (logflags & IP6T_LOG_IPOPT)
- printk("OPT ( ");
- switch (currenthdr) {
- case IPPROTO_FRAGMENT: {
- struct frag_hdr _fhdr;
- const struct frag_hdr *fh;
- printk("FRAG:");
- fh = skb_header_pointer(skb, ptr, sizeof(_fhdr),
- &_fhdr);
- if (fh == NULL) {
- printk("TRUNCATED ");
- return;
- }
- /* Max length: 6 "65535 " */
- printk("%u ", ntohs(fh->frag_off) & 0xFFF8);
- /* Max length: 11 "INCOMPLETE " */
- if (fh->frag_off & htons(0x0001))
- printk("INCOMPLETE ");
- printk("ID:%08x ", ntohl(fh->identification));
- if (ntohs(fh->frag_off) & 0xFFF8)
- fragment = 1;
- hdrlen = 8;
- break;
- }
- case IPPROTO_DSTOPTS:
- case IPPROTO_ROUTING:
- case IPPROTO_HOPOPTS:
- if (fragment) {
- if (logflags & IP6T_LOG_IPOPT)
- printk(")");
- return;
- }
- hdrlen = ipv6_optlen(hp);
- break;
- /* Max Length */
- case IPPROTO_AH:
- if (logflags & IP6T_LOG_IPOPT) {
- struct ip_auth_hdr _ahdr;
- const struct ip_auth_hdr *ah;
- /* Max length: 3 "AH " */
- printk("AH ");
- if (fragment) {
- printk(")");
- return;
- }
- ah = skb_header_pointer(skb, ptr, sizeof(_ahdr),
- &_ahdr);
- if (ah == NULL) {
- /*
- * Max length: 26 "INCOMPLETE [65535
- * bytes] )"
- */
- printk("INCOMPLETE [%u bytes] )",
- skb->len - ptr);
- return;
- }
- /* Length: 15 "SPI=0xF1234567 */
- printk("SPI=0x%x ", ntohl(ah->spi));
- }
- hdrlen = (hp->hdrlen+2)<<2;
- break;
- case IPPROTO_ESP:
- if (logflags & IP6T_LOG_IPOPT) {
- struct ip_esp_hdr _esph;
- const struct ip_esp_hdr *eh;
- /* Max length: 4 "ESP " */
- printk("ESP ");
- if (fragment) {
- printk(")");
- return;
- }
- /*
- * Max length: 26 "INCOMPLETE [65535 bytes] )"
- */
- eh = skb_header_pointer(skb, ptr, sizeof(_esph),
- &_esph);
- if (eh == NULL) {
- printk("INCOMPLETE [%u bytes] )",
- skb->len - ptr);
- return;
- }
- /* Length: 16 "SPI=0xF1234567 )" */
- printk("SPI=0x%x )", ntohl(eh->spi) );
- }
- return;
- default:
- /* Max length: 20 "Unknown Ext Hdr 255" */
- printk("Unknown Ext Hdr %u", currenthdr);
- return;
- }
- if (logflags & IP6T_LOG_IPOPT)
- printk(") ");
- currenthdr = hp->nexthdr;
- ptr += hdrlen;
- }
- switch (currenthdr) {
- case IPPROTO_TCP: {
- struct tcphdr _tcph;
- const struct tcphdr *th;
- /* Max length: 10 "PROTO=TCP " */
- printk("PROTO=TCP ");
- if (fragment)
- break;
- /* Max length: 25 "INCOMPLETE [65535 bytes] " */
- th = skb_header_pointer(skb, ptr, sizeof(_tcph), &_tcph);
- if (th == NULL) {
- printk("INCOMPLETE [%u bytes] ", skb->len - ptr);
- return;
- }
- /* Max length: 20 "SPT=65535 DPT=65535 " */
- printk("SPT=%u DPT=%u ",
- ntohs(th->source), ntohs(th->dest));
- /* Max length: 30 "SEQ=4294967295 ACK=4294967295 " */
- if (logflags & IP6T_LOG_TCPSEQ)
- printk("SEQ=%u ACK=%u ",
- ntohl(th->seq), ntohl(th->ack_seq));
- /* Max length: 13 "WINDOW=65535 " */
- printk("WINDOW=%u ", ntohs(th->window));
- /* Max length: 9 "RES=0x3C " */
- printk("RES=0x%02x ", (u_int8_t)(ntohl(tcp_flag_word(th) & TCP_RESERVED_BITS) >> 22));
- /* Max length: 32 "CWR ECE URG ACK PSH RST SYN FIN " */
- if (th->cwr)
- printk("CWR ");
- if (th->ece)
- printk("ECE ");
- if (th->urg)
- printk("URG ");
- if (th->ack)
- printk("ACK ");
- if (th->psh)
- printk("PSH ");
- if (th->rst)
- printk("RST ");
- if (th->syn)
- printk("SYN ");
- if (th->fin)
- printk("FIN ");
- /* Max length: 11 "URGP=65535 " */
- printk("URGP=%u ", ntohs(th->urg_ptr));
- if ((logflags & IP6T_LOG_TCPOPT)
- && th->doff * 4 > sizeof(struct tcphdr)) {
- u_int8_t _opt[60 - sizeof(struct tcphdr)];
- const u_int8_t *op;
- unsigned int i;
- unsigned int optsize = th->doff * 4
- - sizeof(struct tcphdr);
- op = skb_header_pointer(skb,
- ptr + sizeof(struct tcphdr),
- optsize, _opt);
- if (op == NULL) {
- printk("OPT (TRUNCATED)");
- return;
- }
- /* Max length: 127 "OPT (" 15*4*2chars ") " */
- printk("OPT (");
- for (i =0; i < optsize; i++)
- printk("%02X", op[i]);
- printk(") ");
- }
- break;
- }
- case IPPROTO_UDP:
- case IPPROTO_UDPLITE: {
- struct udphdr _udph;
- const struct udphdr *uh;
- if (currenthdr == IPPROTO_UDP)
- /* Max length: 10 "PROTO=UDP " */
- printk("PROTO=UDP " );
- else /* Max length: 14 "PROTO=UDPLITE " */
- printk("PROTO=UDPLITE ");
- if (fragment)
- break;
- /* Max length: 25 "INCOMPLETE [65535 bytes] " */
- uh = skb_header_pointer(skb, ptr, sizeof(_udph), &_udph);
- if (uh == NULL) {
- printk("INCOMPLETE [%u bytes] ", skb->len - ptr);
- return;
- }
- /* Max length: 20 "SPT=65535 DPT=65535 " */
- printk("SPT=%u DPT=%u LEN=%u ",
- ntohs(uh->source), ntohs(uh->dest),
- ntohs(uh->len));
- break;
- }
- case IPPROTO_ICMPV6: {
- struct icmp6hdr _icmp6h;
- const struct icmp6hdr *ic;
- /* Max length: 13 "PROTO=ICMPv6 " */
- printk("PROTO=ICMPv6 ");
- if (fragment)
- break;
- /* Max length: 25 "INCOMPLETE [65535 bytes] " */
- ic = skb_header_pointer(skb, ptr, sizeof(_icmp6h), &_icmp6h);
- if (ic == NULL) {
- printk("INCOMPLETE [%u bytes] ", skb->len - ptr);
- return;
- }
- /* Max length: 18 "TYPE=255 CODE=255 " */
- printk("TYPE=%u CODE=%u ", ic->icmp6_type, ic->icmp6_code);
- switch (ic->icmp6_type) {
- case ICMPV6_ECHO_REQUEST:
- case ICMPV6_ECHO_REPLY:
- /* Max length: 19 "ID=65535 SEQ=65535 " */
- printk("ID=%u SEQ=%u ",
- ntohs(ic->icmp6_identifier),
- ntohs(ic->icmp6_sequence));
- break;
- case ICMPV6_MGM_QUERY:
- case ICMPV6_MGM_REPORT:
- case ICMPV6_MGM_REDUCTION:
- break;
- case ICMPV6_PARAMPROB:
- /* Max length: 17 "POINTER=ffffffff " */
- printk("POINTER=%08x ", ntohl(ic->icmp6_pointer));
- /* Fall through */
- case ICMPV6_DEST_UNREACH:
- case ICMPV6_PKT_TOOBIG:
- case ICMPV6_TIME_EXCEED:
- /* Max length: 3+maxlen */
- if (recurse) {
- printk("[");
- dump_packet(info, skb, ptr + sizeof(_icmp6h),
- 0);
- printk("] ");
- }
- /* Max length: 10 "MTU=65535 " */
- if (ic->icmp6_type == ICMPV6_PKT_TOOBIG)
- printk("MTU=%u ", ntohl(ic->icmp6_mtu));
- }
- break;
- }
- /* Max length: 10 "PROTO=255 " */
- default:
- printk("PROTO=%u ", currenthdr);
- }
- /* Max length: 15 "UID=4294967295 " */
- if ((logflags & IP6T_LOG_UID) && recurse && skb->sk) {
- read_lock_bh(&skb->sk->sk_callback_lock);
- if (skb->sk->sk_socket && skb->sk->sk_socket->file)
- printk("UID=%u GID=%u ",
- skb->sk->sk_socket->file->f_cred->fsuid,
- skb->sk->sk_socket->file->f_cred->fsgid);
- read_unlock_bh(&skb->sk->sk_callback_lock);
- }
- /* Max length: 16 "MARK=0xFFFFFFFF " */
- if (!recurse && skb->mark)
- printk("MARK=0x%x ", skb->mark);
- }
- static struct nf_loginfo default_loginfo = {
- .type = NF_LOG_TYPE_LOG,
- .u = {
- .log = {
- .level = 0,
- .logflags = NF_LOG_MASK,
- },
- },
- };
- static void
- ip6t_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)
- {
- if (!loginfo)
- loginfo = &default_loginfo;
- spin_lock_bh(&log_lock);
- printk("<%d>%sIN=%s OUT=%s ", loginfo->u.log.level,
- 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) {
- for (i = 0; i < len; i++)
- printk("%02x%s", p[i],
- i == len - 1 ? "" : ":");
- }
- 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(" ");
- }
- dump_packet(loginfo, skb, skb_network_offset(skb), 1);
- printk("\n");
- spin_unlock_bh(&log_lock);
- }
- static unsigned int
- log_tg6(struct sk_buff *skb, const struct xt_target_param *par)
- {
- const struct ip6t_log_info *loginfo = par->targinfo;
- struct nf_loginfo li;
- li.type = NF_LOG_TYPE_LOG;
- li.u.log.level = loginfo->level;
- li.u.log.logflags = loginfo->logflags;
- ip6t_log_packet(NFPROTO_IPV6, par->hooknum, skb, par->in, par->out,
- &li, loginfo->prefix);
- return XT_CONTINUE;
- }
- static bool log_tg6_check(const struct xt_tgchk_param *par)
- {
- const struct ip6t_log_info *loginfo = par->targinfo;
- if (loginfo->level >= 8) {
- pr_debug("LOG: level %u >= 8\n", loginfo->level);
- return false;
- }
- if (loginfo->prefix[sizeof(loginfo->prefix)-1] != '\0') {
- pr_debug("LOG: prefix term %i\n",
- loginfo->prefix[sizeof(loginfo->prefix)-1]);
- return false;
- }
- return true;
- }
- static struct xt_target log_tg6_reg __read_mostly = {
- .name = "LOG",
- .family = NFPROTO_IPV6,
- .target = log_tg6,
- .targetsize = sizeof(struct ip6t_log_info),
- .checkentry = log_tg6_check,
- .me = THIS_MODULE,
- };
- static struct nf_logger ip6t_logger __read_mostly = {
- .name = "ip6t_LOG",
- .logfn = &ip6t_log_packet,
- .me = THIS_MODULE,
- };
- static int __init log_tg6_init(void)
- {
- int ret;
- ret = xt_register_target(&log_tg6_reg);
- if (ret < 0)
- return ret;
- nf_log_register(NFPROTO_IPV6, &ip6t_logger);
- return 0;
- }
- static void __exit log_tg6_exit(void)
- {
- nf_log_unregister(&ip6t_logger);
- xt_unregister_target(&log_tg6_reg);
- }
- module_init(log_tg6_init);
- module_exit(log_tg6_exit);