forked from mirrors/linux
		
	gre: Move utility functions to common headers
Several of the GRE functions defined in net/ipv4/ip_gre.c are usable
for IPv6 GRE implementation (that is they are protocol agnostic).
These include:
  - GRE flag handling functions are move to gre.h
  - GRE build_header is moved to gre.h and renamed gre_build_header
  - parse_gre_header is moved to gre_demux.c and renamed gre_parse_header
  - iptunnel_pull_header is taken out of gre_parse_header. This is now
    done by caller. The header length is returned from gre_parse_header
    in an int* argument.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
			
			
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					 3 changed files with 144 additions and 129 deletions
				
			
		|  | @ -25,4 +25,64 @@ int gre_del_protocol(const struct gre_protocol *proto, u8 version); | |||
| 
 | ||||
| struct net_device *gretap_fb_dev_create(struct net *net, const char *name, | ||||
| 				       u8 name_assign_type); | ||||
| int gre_parse_header(struct sk_buff *skb, struct tnl_ptk_info *tpi, | ||||
| 		     bool *csum_err, int *hdr_len); | ||||
| 
 | ||||
| static inline int gre_calc_hlen(__be16 o_flags) | ||||
| { | ||||
| 	int addend = 4; | ||||
| 
 | ||||
| 	if (o_flags & TUNNEL_CSUM) | ||||
| 		addend += 4; | ||||
| 	if (o_flags & TUNNEL_KEY) | ||||
| 		addend += 4; | ||||
| 	if (o_flags & TUNNEL_SEQ) | ||||
| 		addend += 4; | ||||
| 	return addend; | ||||
| } | ||||
| 
 | ||||
| static inline __be16 gre_flags_to_tnl_flags(__be16 flags) | ||||
| { | ||||
| 	__be16 tflags = 0; | ||||
| 
 | ||||
| 	if (flags & GRE_CSUM) | ||||
| 		tflags |= TUNNEL_CSUM; | ||||
| 	if (flags & GRE_ROUTING) | ||||
| 		tflags |= TUNNEL_ROUTING; | ||||
| 	if (flags & GRE_KEY) | ||||
| 		tflags |= TUNNEL_KEY; | ||||
| 	if (flags & GRE_SEQ) | ||||
| 		tflags |= TUNNEL_SEQ; | ||||
| 	if (flags & GRE_STRICT) | ||||
| 		tflags |= TUNNEL_STRICT; | ||||
| 	if (flags & GRE_REC) | ||||
| 		tflags |= TUNNEL_REC; | ||||
| 	if (flags & GRE_VERSION) | ||||
| 		tflags |= TUNNEL_VERSION; | ||||
| 
 | ||||
| 	return tflags; | ||||
| } | ||||
| 
 | ||||
| static inline __be16 gre_tnl_flags_to_gre_flags(__be16 tflags) | ||||
| { | ||||
| 	__be16 flags = 0; | ||||
| 
 | ||||
| 	if (tflags & TUNNEL_CSUM) | ||||
| 		flags |= GRE_CSUM; | ||||
| 	if (tflags & TUNNEL_ROUTING) | ||||
| 		flags |= GRE_ROUTING; | ||||
| 	if (tflags & TUNNEL_KEY) | ||||
| 		flags |= GRE_KEY; | ||||
| 	if (tflags & TUNNEL_SEQ) | ||||
| 		flags |= GRE_SEQ; | ||||
| 	if (tflags & TUNNEL_STRICT) | ||||
| 		flags |= GRE_STRICT; | ||||
| 	if (tflags & TUNNEL_REC) | ||||
| 		flags |= GRE_REC; | ||||
| 	if (tflags & TUNNEL_VERSION) | ||||
| 		flags |= GRE_VERSION; | ||||
| 
 | ||||
| 	return flags; | ||||
| } | ||||
| 
 | ||||
| #endif | ||||
|  |  | |||
|  | @ -60,6 +60,70 @@ int gre_del_protocol(const struct gre_protocol *proto, u8 version) | |||
| } | ||||
| EXPORT_SYMBOL_GPL(gre_del_protocol); | ||||
| 
 | ||||
| int gre_parse_header(struct sk_buff *skb, struct tnl_ptk_info *tpi, | ||||
| 		     bool *csum_err, int *ret_hdr_len) | ||||
| { | ||||
| 	const struct gre_base_hdr *greh; | ||||
| 	__be32 *options; | ||||
| 	int hdr_len; | ||||
| 
 | ||||
| 	if (unlikely(!pskb_may_pull(skb, sizeof(struct gre_base_hdr)))) | ||||
| 		return -EINVAL; | ||||
| 
 | ||||
| 	greh = (struct gre_base_hdr *)skb_transport_header(skb); | ||||
| 	if (unlikely(greh->flags & (GRE_VERSION | GRE_ROUTING))) | ||||
| 		return -EINVAL; | ||||
| 
 | ||||
| 	tpi->flags = gre_flags_to_tnl_flags(greh->flags); | ||||
| 	hdr_len = gre_calc_hlen(tpi->flags); | ||||
| 
 | ||||
| 	if (!pskb_may_pull(skb, hdr_len)) | ||||
| 		return -EINVAL; | ||||
| 
 | ||||
| 	greh = (struct gre_base_hdr *)skb_transport_header(skb); | ||||
| 	tpi->proto = greh->protocol; | ||||
| 
 | ||||
| 	options = (__be32 *)(greh + 1); | ||||
| 	if (greh->flags & GRE_CSUM) { | ||||
| 		if (skb_checksum_simple_validate(skb)) { | ||||
| 			*csum_err = true; | ||||
| 			return -EINVAL; | ||||
| 		} | ||||
| 
 | ||||
| 		skb_checksum_try_convert(skb, IPPROTO_GRE, 0, | ||||
| 					 null_compute_pseudo); | ||||
| 		options++; | ||||
| 	} | ||||
| 
 | ||||
| 	if (greh->flags & GRE_KEY) { | ||||
| 		tpi->key = *options; | ||||
| 		options++; | ||||
| 	} else { | ||||
| 		tpi->key = 0; | ||||
| 	} | ||||
| 	if (unlikely(greh->flags & GRE_SEQ)) { | ||||
| 		tpi->seq = *options; | ||||
| 		options++; | ||||
| 	} else { | ||||
| 		tpi->seq = 0; | ||||
| 	} | ||||
| 	/* WCCP version 1 and 2 protocol decoding.
 | ||||
| 	 * - Change protocol to IP | ||||
| 	 * - When dealing with WCCPv2, Skip extra 4 bytes in GRE header | ||||
| 	 */ | ||||
| 	if (greh->flags == 0 && tpi->proto == htons(ETH_P_WCCP)) { | ||||
| 		tpi->proto = htons(ETH_P_IP); | ||||
| 		if ((*(u8 *)options & 0xF0) != 0x40) { | ||||
| 			hdr_len += 4; | ||||
| 			if (!pskb_may_pull(skb, hdr_len)) | ||||
| 				return -EINVAL; | ||||
| 		} | ||||
| 	} | ||||
| 	*ret_hdr_len = hdr_len; | ||||
| 	return 0; | ||||
| } | ||||
| EXPORT_SYMBOL(gre_parse_header); | ||||
| 
 | ||||
| static int gre_rcv(struct sk_buff *skb) | ||||
| { | ||||
| 	const struct gre_protocol *proto; | ||||
|  |  | |||
|  | @ -122,125 +122,6 @@ static int ipgre_tunnel_init(struct net_device *dev); | |||
| static int ipgre_net_id __read_mostly; | ||||
| static int gre_tap_net_id __read_mostly; | ||||
| 
 | ||||
| static int ip_gre_calc_hlen(__be16 o_flags) | ||||
| { | ||||
| 	int addend = 4; | ||||
| 
 | ||||
| 	if (o_flags & TUNNEL_CSUM) | ||||
| 		addend += 4; | ||||
| 	if (o_flags & TUNNEL_KEY) | ||||
| 		addend += 4; | ||||
| 	if (o_flags & TUNNEL_SEQ) | ||||
| 		addend += 4; | ||||
| 	return addend; | ||||
| } | ||||
| 
 | ||||
| static __be16 gre_flags_to_tnl_flags(__be16 flags) | ||||
| { | ||||
| 	__be16 tflags = 0; | ||||
| 
 | ||||
| 	if (flags & GRE_CSUM) | ||||
| 		tflags |= TUNNEL_CSUM; | ||||
| 	if (flags & GRE_ROUTING) | ||||
| 		tflags |= TUNNEL_ROUTING; | ||||
| 	if (flags & GRE_KEY) | ||||
| 		tflags |= TUNNEL_KEY; | ||||
| 	if (flags & GRE_SEQ) | ||||
| 		tflags |= TUNNEL_SEQ; | ||||
| 	if (flags & GRE_STRICT) | ||||
| 		tflags |= TUNNEL_STRICT; | ||||
| 	if (flags & GRE_REC) | ||||
| 		tflags |= TUNNEL_REC; | ||||
| 	if (flags & GRE_VERSION) | ||||
| 		tflags |= TUNNEL_VERSION; | ||||
| 
 | ||||
| 	return tflags; | ||||
| } | ||||
| 
 | ||||
| static __be16 tnl_flags_to_gre_flags(__be16 tflags) | ||||
| { | ||||
| 	__be16 flags = 0; | ||||
| 
 | ||||
| 	if (tflags & TUNNEL_CSUM) | ||||
| 		flags |= GRE_CSUM; | ||||
| 	if (tflags & TUNNEL_ROUTING) | ||||
| 		flags |= GRE_ROUTING; | ||||
| 	if (tflags & TUNNEL_KEY) | ||||
| 		flags |= GRE_KEY; | ||||
| 	if (tflags & TUNNEL_SEQ) | ||||
| 		flags |= GRE_SEQ; | ||||
| 	if (tflags & TUNNEL_STRICT) | ||||
| 		flags |= GRE_STRICT; | ||||
| 	if (tflags & TUNNEL_REC) | ||||
| 		flags |= GRE_REC; | ||||
| 	if (tflags & TUNNEL_VERSION) | ||||
| 		flags |= GRE_VERSION; | ||||
| 
 | ||||
| 	return flags; | ||||
| } | ||||
| 
 | ||||
| static int parse_gre_header(struct sk_buff *skb, struct tnl_ptk_info *tpi, | ||||
| 			    bool *csum_err) | ||||
| { | ||||
| 	const struct gre_base_hdr *greh; | ||||
| 	__be32 *options; | ||||
| 	int hdr_len; | ||||
| 
 | ||||
| 	if (unlikely(!pskb_may_pull(skb, sizeof(struct gre_base_hdr)))) | ||||
| 		return -EINVAL; | ||||
| 
 | ||||
| 	greh = (struct gre_base_hdr *)skb_transport_header(skb); | ||||
| 	if (unlikely(greh->flags & (GRE_VERSION | GRE_ROUTING))) | ||||
| 		return -EINVAL; | ||||
| 
 | ||||
| 	tpi->flags = gre_flags_to_tnl_flags(greh->flags); | ||||
| 	hdr_len = ip_gre_calc_hlen(tpi->flags); | ||||
| 
 | ||||
| 	if (!pskb_may_pull(skb, hdr_len)) | ||||
| 		return -EINVAL; | ||||
| 
 | ||||
| 	greh = (struct gre_base_hdr *)skb_transport_header(skb); | ||||
| 	tpi->proto = greh->protocol; | ||||
| 
 | ||||
| 	options = (__be32 *)(greh + 1); | ||||
| 	if (greh->flags & GRE_CSUM) { | ||||
| 		if (skb_checksum_simple_validate(skb)) { | ||||
| 			*csum_err = true; | ||||
| 			return -EINVAL; | ||||
| 		} | ||||
| 
 | ||||
| 		skb_checksum_try_convert(skb, IPPROTO_GRE, 0, | ||||
| 					 null_compute_pseudo); | ||||
| 		options++; | ||||
| 	} | ||||
| 
 | ||||
| 	if (greh->flags & GRE_KEY) { | ||||
| 		tpi->key = *options; | ||||
| 		options++; | ||||
| 	} else { | ||||
| 		tpi->key = 0; | ||||
| 	} | ||||
| 	if (unlikely(greh->flags & GRE_SEQ)) { | ||||
| 		tpi->seq = *options; | ||||
| 		options++; | ||||
| 	} else { | ||||
| 		tpi->seq = 0; | ||||
| 	} | ||||
| 	/* WCCP version 1 and 2 protocol decoding.
 | ||||
| 	 * - Change protocol to IP | ||||
| 	 * - When dealing with WCCPv2, Skip extra 4 bytes in GRE header | ||||
| 	 */ | ||||
| 	if (greh->flags == 0 && tpi->proto == htons(ETH_P_WCCP)) { | ||||
| 		tpi->proto = htons(ETH_P_IP); | ||||
| 		if ((*(u8 *)options & 0xF0) != 0x40) { | ||||
| 			hdr_len += 4; | ||||
| 			if (!pskb_may_pull(skb, hdr_len)) | ||||
| 				return -EINVAL; | ||||
| 		} | ||||
| 	} | ||||
| 	return iptunnel_pull_header(skb, hdr_len, tpi->proto, false); | ||||
| } | ||||
| 
 | ||||
| static void ipgre_err(struct sk_buff *skb, u32 info, | ||||
| 		      const struct tnl_ptk_info *tpi) | ||||
| { | ||||
|  | @ -340,12 +221,16 @@ static void gre_err(struct sk_buff *skb, u32 info) | |||
| 	const int code = icmp_hdr(skb)->code; | ||||
| 	struct tnl_ptk_info tpi; | ||||
| 	bool csum_err = false; | ||||
| 	int hdr_len; | ||||
| 
 | ||||
| 	if (parse_gre_header(skb, &tpi, &csum_err)) { | ||||
| 	if (gre_parse_header(skb, &tpi, &csum_err, &hdr_len)) { | ||||
| 		if (!csum_err)		/* ignore csum errors. */ | ||||
| 			return; | ||||
| 	} | ||||
| 
 | ||||
| 	if (iptunnel_pull_header(skb, hdr_len, tpi.proto, false)) | ||||
| 		return; | ||||
| 
 | ||||
| 	if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) { | ||||
| 		ipv4_update_pmtu(skb, dev_net(skb->dev), info, | ||||
| 				 skb->dev->ifindex, 0, IPPROTO_GRE, 0); | ||||
|  | @ -419,6 +304,7 @@ static int gre_rcv(struct sk_buff *skb) | |||
| { | ||||
| 	struct tnl_ptk_info tpi; | ||||
| 	bool csum_err = false; | ||||
| 	int hdr_len; | ||||
| 
 | ||||
| #ifdef CONFIG_NET_IPGRE_BROADCAST | ||||
| 	if (ipv4_is_multicast(ip_hdr(skb)->daddr)) { | ||||
|  | @ -428,7 +314,10 @@ static int gre_rcv(struct sk_buff *skb) | |||
| 	} | ||||
| #endif | ||||
| 
 | ||||
| 	if (parse_gre_header(skb, &tpi, &csum_err) < 0) | ||||
| 	if (gre_parse_header(skb, &tpi, &csum_err, &hdr_len) < 0) | ||||
| 		goto drop; | ||||
| 
 | ||||
| 	if (iptunnel_pull_header(skb, hdr_len, tpi.proto, false)) | ||||
| 		goto drop; | ||||
| 
 | ||||
| 	if (ipgre_rcv(skb, &tpi) == PACKET_RCVD) | ||||
|  | @ -460,7 +349,7 @@ static void build_header(struct sk_buff *skb, int hdr_len, __be16 flags, | |||
| 
 | ||||
| 	skb_reset_transport_header(skb); | ||||
| 	greh = (struct gre_base_hdr *)skb->data; | ||||
| 	greh->flags = tnl_flags_to_gre_flags(flags); | ||||
| 	greh->flags = gre_tnl_flags_to_gre_flags(flags); | ||||
| 	greh->protocol = proto; | ||||
| 
 | ||||
| 	if (flags & (TUNNEL_KEY | TUNNEL_CSUM | TUNNEL_SEQ)) { | ||||
|  | @ -552,7 +441,7 @@ static void gre_fb_xmit(struct sk_buff *skb, struct net_device *dev) | |||
| 					  fl.saddr); | ||||
| 	} | ||||
| 
 | ||||
| 	tunnel_hlen = ip_gre_calc_hlen(key->tun_flags); | ||||
| 	tunnel_hlen = gre_calc_hlen(key->tun_flags); | ||||
| 
 | ||||
| 	min_headroom = LL_RESERVED_SPACE(rt->dst.dev) + rt->dst.header_len | ||||
| 			+ tunnel_hlen + sizeof(struct iphdr); | ||||
|  | @ -694,8 +583,8 @@ static int ipgre_tunnel_ioctl(struct net_device *dev, | |||
| 	if (err) | ||||
| 		return err; | ||||
| 
 | ||||
| 	p.i_flags = tnl_flags_to_gre_flags(p.i_flags); | ||||
| 	p.o_flags = tnl_flags_to_gre_flags(p.o_flags); | ||||
| 	p.i_flags = gre_tnl_flags_to_gre_flags(p.i_flags); | ||||
| 	p.o_flags = gre_tnl_flags_to_gre_flags(p.o_flags); | ||||
| 
 | ||||
| 	if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) | ||||
| 		return -EFAULT; | ||||
|  | @ -739,7 +628,7 @@ static int ipgre_header(struct sk_buff *skb, struct net_device *dev, | |||
| 
 | ||||
| 	iph = (struct iphdr *)skb_push(skb, t->hlen + sizeof(*iph)); | ||||
| 	greh = (struct gre_base_hdr *)(iph+1); | ||||
| 	greh->flags = tnl_flags_to_gre_flags(t->parms.o_flags); | ||||
| 	greh->flags = gre_tnl_flags_to_gre_flags(t->parms.o_flags); | ||||
| 	greh->protocol = htons(type); | ||||
| 
 | ||||
| 	memcpy(iph, &t->parms.iph, sizeof(struct iphdr)); | ||||
|  | @ -840,7 +729,7 @@ static void __gre_tunnel_init(struct net_device *dev) | |||
| 	int t_hlen; | ||||
| 
 | ||||
| 	tunnel = netdev_priv(dev); | ||||
| 	tunnel->tun_hlen = ip_gre_calc_hlen(tunnel->parms.o_flags); | ||||
| 	tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags); | ||||
| 	tunnel->parms.iph.protocol = IPPROTO_GRE; | ||||
| 
 | ||||
| 	tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen; | ||||
|  | @ -1155,8 +1044,10 @@ static int ipgre_fill_info(struct sk_buff *skb, const struct net_device *dev) | |||
| 	struct ip_tunnel_parm *p = &t->parms; | ||||
| 
 | ||||
| 	if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) || | ||||
| 	    nla_put_be16(skb, IFLA_GRE_IFLAGS, tnl_flags_to_gre_flags(p->i_flags)) || | ||||
| 	    nla_put_be16(skb, IFLA_GRE_OFLAGS, tnl_flags_to_gre_flags(p->o_flags)) || | ||||
| 	    nla_put_be16(skb, IFLA_GRE_IFLAGS, | ||||
| 			 gre_tnl_flags_to_gre_flags(p->i_flags)) || | ||||
| 	    nla_put_be16(skb, IFLA_GRE_OFLAGS, | ||||
| 			 gre_tnl_flags_to_gre_flags(p->o_flags)) || | ||||
| 	    nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) || | ||||
| 	    nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) || | ||||
| 	    nla_put_in_addr(skb, IFLA_GRE_LOCAL, p->iph.saddr) || | ||||
|  |  | |||
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