Ejemplo n.º 1
0
static void
ipt_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)
{
	struct sbuff *m;
	struct net *net = dev_net(in ? in : out);

	/* FIXME: Disabled from containers until syslog ns is supported */
	if (!net_eq(net, &init_net))
		return;

	m = sb_open();

	if (!loginfo)
		loginfo = &default_loginfo;

	log_packet_common(m, pf, hooknum, skb, in, out, loginfo, prefix);

	if (in != NULL)
		dump_ipv4_mac_header(m, loginfo, skb);

	dump_ipv4_packet(m, loginfo, skb, 0);

	sb_close(m);
}
Ejemplo n.º 2
0
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(m, loginfo, skb, 0);

	nf_log_buf_close(m);
}
Ejemplo n.º 3
0
static void
ipt_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)
{
	struct sbuff *m = sb_open();

	if (!loginfo)
		loginfo = &default_loginfo;

	log_packet_common(m, pf, hooknum, skb, in, out, loginfo, prefix);

	if (in != NULL)
		dump_ipv4_mac_header(m, loginfo, skb);

	dump_ipv4_packet(m, loginfo, skb, 0);

	sb_close(m);
}
Ejemplo n.º 4
0
/* One level of recursion won't kill us */
static void dump_ipv4_packet(struct sbuff *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_MASK;

	ih = skb_header_pointer(skb, iphoff, sizeof(_iph), &_iph);
	if (ih == NULL) {
		sb_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 " */
	sb_add(m, "SRC=%pI4 DST=%pI4 ",
	       &ih->saddr, &ih->daddr);

	/* Max length: 46 "LEN=65535 TOS=0xFF PREC=0xFF TTL=255 ID=65535 " */
	sb_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)
		sb_add(m, "CE ");
	if (ntohs(ih->frag_off) & IP_DF)
		sb_add(m, "DF ");
	if (ntohs(ih->frag_off) & IP_MF)
		sb_add(m, "MF ");

	/* Max length: 11 "FRAG:65535 " */
	if (ntohs(ih->frag_off) & IP_OFFSET)
		sb_add(m, "FRAG:%u ", ntohs(ih->frag_off) & IP_OFFSET);

	if ((logflags & XT_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) {
			sb_add(m, "TRUNCATED");
			return;
		}

		/* Max length: 127 "OPT (" 15*4*2chars ") " */
		sb_add(m, "OPT (");
		for (i = 0; i < optsize; i++)
			sb_add(m, "%02X", op[i]);
		sb_add(m, ") ");
	}

	switch (ih->protocol) {
	case IPPROTO_TCP:
		if (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 (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 " */
		sb_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) {
			sb_add(m, "INCOMPLETE [%u bytes] ",
			       skb->len - iphoff - ih->ihl*4);
			break;
		}

		/* Max length: 18 "TYPE=255 CODE=255 " */
		sb_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]) {
			sb_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 " */
			sb_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 " */
			sb_add(m, "PARAMETER=%u ",
			       ntohl(ich->un.gateway) >> 24);
			break;
		case ICMP_REDIRECT:
			/* Max length: 24 "GATEWAY=255.255.255.255 " */
			sb_add(m, "GATEWAY=%pI4 ", &ich->un.gateway);
			/* Fall through */
		case ICMP_DEST_UNREACH:
		case ICMP_SOURCE_QUENCH:
		case ICMP_TIME_EXCEEDED:
			/* Max length: 3+maxlen */
			if (!iphoff) { /* Only recurse once. */
				sb_add(m, "[");
				dump_ipv4_packet(m, info, skb,
					    iphoff + ih->ihl*4+sizeof(_icmph));
				sb_add(m, "] ");
			}

			/* Max length: 10 "MTU=65535 " */
			if (ich->type == ICMP_DEST_UNREACH &&
			    ich->code == ICMP_FRAG_NEEDED)
				sb_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 " */
		sb_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) {
			sb_add(m, "INCOMPLETE [%u bytes] ",
			       skb->len - iphoff - ih->ihl*4);
			break;
		}

		/* Length: 15 "SPI=0xF1234567 " */
		sb_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 " */
		sb_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) {
			sb_add(m, "INCOMPLETE [%u bytes] ",
			       skb->len - iphoff - ih->ihl*4);
			break;
		}

		/* Length: 15 "SPI=0xF1234567 " */
		sb_add(m, "SPI=0x%x ", ntohl(eh->spi));
		break;
	}
	/* Max length: 10 "PROTO 255 " */
	default:
		sb_add(m, "PROTO=%u ", ih->protocol);
	}

	/* Max length: 15 "UID=4294967295 " */
	if ((logflags & XT_LOG_UID) && !iphoff)
		dump_sk_uid_gid(m, skb->sk);

	/* Max length: 16 "MARK=0xFFFFFFFF " */
	if (!iphoff && skb->mark)
		sb_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 */
}