C++ (Cpp) icmp_error_message Exemples

Exemple #1

Fichier : ip_conntrack_proto_icmp.c Projet : KrisChaplin/LRT2x4_v1.0.2.06_GPL_source

/* Small and modified version of icmp_rcv */
static int
icmp_error(struct sk_buff *skb, enum ip_conntrack_info *ctinfo,
	   unsigned int hooknum)
{
	struct icmphdr _ih, *icmph;

	/* Not enough header? */
	icmph = skb_header_pointer(skb, skb->nh.iph->ihl*4, sizeof(_ih), &_ih);
	if (icmph == NULL) {
		if (LOG_INVALID(IPPROTO_ICMP))
			nf_log_packet(PF_INET, 0, skb, NULL, NULL, NULL,
				      "ip_ct_icmp: short packet ");
		return -NF_ACCEPT;
	}

	/* See ip_conntrack_proto_tcp.c */
	if (hooknum != NF_IP_PRE_ROUTING)
		goto checksum_skipped;

	switch (skb->ip_summed) {
	case CHECKSUM_HW:
		if (!(u16)csum_fold(skb->csum)) 
			break;
		/* fall through */
	case CHECKSUM_NONE:
		skb->csum = 0;
		if (__skb_checksum_complete(skb)) {
			if (LOG_INVALID(IPPROTO_ICMP))
				nf_log_packet(PF_INET, 0, skb, NULL, NULL, NULL,
					      "ip_ct_icmp: bad ICMP checksum ");
			return -NF_ACCEPT;
		}
	}

checksum_skipped:
	/*
	 *	18 is the highest 'known' ICMP type. Anything else is a mystery
	 *
	 *	RFC 1122: 3.2.2  Unknown ICMP messages types MUST be silently
	 *		  discarded.
	 */
	if (icmph->type > NR_ICMP_TYPES) {
		if (LOG_INVALID(IPPROTO_ICMP))
			nf_log_packet(PF_INET, 0, skb, NULL, NULL, NULL,
				      "ip_ct_icmp: invalid ICMP type ");
		return -NF_ACCEPT;
	}

	/* Need to track icmp error message? */
	if (icmph->type != ICMP_DEST_UNREACH
	    && icmph->type != ICMP_SOURCE_QUENCH
	    && icmph->type != ICMP_TIME_EXCEEDED
	    && icmph->type != ICMP_PARAMETERPROB
	    && icmph->type != ICMP_REDIRECT)
		return NF_ACCEPT;

	return icmp_error_message(skb, ctinfo, hooknum);
}

Exemple #2

Fichier : nf_conntrack_proto_icmp.c Projet : Chingliu/Reading-and-comprehense-linux-Kernel-network-protocol-stack

/* Small and modified version of icmp_rcv */
static int
icmp_error(struct net *net, struct nf_conn *tmpl,
	   struct sk_buff *skb, unsigned int dataoff,
	   enum ip_conntrack_info *ctinfo, u_int8_t pf, unsigned int hooknum)
{
	const struct icmphdr *icmph;
	struct icmphdr _ih;

	/* Not enough header? */
	icmph = skb_header_pointer(skb, ip_hdrlen(skb), sizeof(_ih), &_ih);
	if (icmph == NULL) {
		if (LOG_INVALID(net, IPPROTO_ICMP))
			nf_log_packet(PF_INET, 0, skb, NULL, NULL, NULL,
				      "nf_ct_icmp: short packet ");
		return -NF_ACCEPT;
	}

	/* See ip_conntrack_proto_tcp.c */
	if (net->ct.sysctl_checksum && hooknum == NF_INET_PRE_ROUTING &&
	    nf_ip_checksum(skb, hooknum, dataoff, 0)) {
		if (LOG_INVALID(net, IPPROTO_ICMP))
			nf_log_packet(PF_INET, 0, skb, NULL, NULL, NULL,
				      "nf_ct_icmp: bad HW ICMP checksum ");
		return -NF_ACCEPT;
	}

	/*
	 *	18 is the highest 'known' ICMP type. Anything else is a mystery
	 *
	 *	RFC 1122: 3.2.2  Unknown ICMP messages types MUST be silently
	 *		  discarded.
	 */
	if (icmph->type > NR_ICMP_TYPES) {
		if (LOG_INVALID(net, IPPROTO_ICMP))
			nf_log_packet(PF_INET, 0, skb, NULL, NULL, NULL,
				      "nf_ct_icmp: invalid ICMP type ");
		return -NF_ACCEPT;
	}

	/* Need to track icmp error message? */
	if (icmph->type != ICMP_DEST_UNREACH &&
	    icmph->type != ICMP_SOURCE_QUENCH &&
	    icmph->type != ICMP_TIME_EXCEEDED &&
	    icmph->type != ICMP_PARAMETERPROB &&
	    icmph->type != ICMP_REDIRECT)
		return NF_ACCEPT;

	return icmp_error_message(net, tmpl, skb, ctinfo, hooknum);
}