Commit 178c49d9 authored by Willem de Bruijn's avatar Willem de Bruijn Committed by David S. Miller
Browse files

icmp: prepare rfc 4884 for ipv6 



The RFC 4884 spec is largely the same between IPv4 and IPv6.
Factor out the IPv4 specific parts in preparation for IPv6 support:

- icmp types supported

- icmp header size, and thus offset to original datagram start

- datagram length field offset in icmp(6)hdr.

- datagram length field word size: 4B for IPv4, 8B for IPv6.

Signed-off-by: default avatarWillem de Bruijn <willemb@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent c4e9e09f

include/linux/icmp.h

+2 −1
Original line number Diff line number Diff line
@@ -37,6 +37,7 @@ static inline bool icmp_is_err(int type) 
}



void ip_icmp_error_rfc4884(const struct sk_buff *skb,

			   struct sock_ee_data_rfc4884 *out);

			   struct sock_ee_data_rfc4884 *out,

			   int thlen, int off);



#endif	/* _LINUX_ICMP_H */

net/ipv4/icmp.c

+4 −13
Original line number Diff line number Diff line
@@ -1151,24 +1151,15 @@ static bool ip_icmp_error_rfc4884_validate(const struct sk_buff *skb, int off) 
}



void ip_icmp_error_rfc4884(const struct sk_buff *skb,

			   struct sock_ee_data_rfc4884 *out)

			   struct sock_ee_data_rfc4884 *out,

			   int thlen, int off)

{

	int hlen, off;



	switch (icmp_hdr(skb)->type) {

	case ICMP_DEST_UNREACH:

	case ICMP_TIME_EXCEEDED:

	case ICMP_PARAMETERPROB:

		break;

	default:

		return;

	}

	int hlen;



	/* original datagram headers: end of icmph to payload (skb->data) */

	hlen = -skb_transport_offset(skb) - sizeof(struct icmphdr);

	hlen = -skb_transport_offset(skb) - thlen;



	/* per rfc 4884: minimal datagram length of 128 bytes */

	off = icmp_hdr(skb)->un.reserved[1] * sizeof(u32);

	if (off < 128 || off < hlen)

		return;

net/ipv4/ip_sockglue.c

+13 −1
Original line number Diff line number Diff line
@@ -390,6 +390,18 @@ int ip_ra_control(struct sock *sk, unsigned char on, 
	return 0;

}



static void ipv4_icmp_error_rfc4884(const struct sk_buff *skb,

				    struct sock_ee_data_rfc4884 *out)

{

	switch (icmp_hdr(skb)->type) {

	case ICMP_DEST_UNREACH:

	case ICMP_TIME_EXCEEDED:

	case ICMP_PARAMETERPROB:

		ip_icmp_error_rfc4884(skb, out, sizeof(struct icmphdr),

				      icmp_hdr(skb)->un.reserved[1] * 4);

	}

}



void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err,

		   __be16 port, u32 info, u8 *payload)

{
@@ -413,7 +425,7 @@ void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err, 


	if (skb_pull(skb, payload - skb->data)) {

		if (inet_sk(sk)->recverr_rfc4884)

			ip_icmp_error_rfc4884(skb, &serr->ee.ee_rfc4884);

			ipv4_icmp_error_rfc4884(skb, &serr->ee.ee_rfc4884);



		skb_reset_transport_header(skb);

		if (sock_queue_err_skb(sk, skb) == 0)

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