Commit fda4fde2 authored by Julian Wiedmann's avatar Julian Wiedmann Committed by Jakub Kicinski
Browse files

net: ip_tunnel: clean up endianness conversions 



sparse complains about some harmless endianness issues:

> net/ipv4/ip_tunnel_core.c:225:43: warning: cast to restricted __be16
> net/ipv4/ip_tunnel_core.c:225:43: warning: incorrect type in initializer (different base types)
> net/ipv4/ip_tunnel_core.c:225:43:    expected restricted __be16 [usertype] mtu
> net/ipv4/ip_tunnel_core.c:225:43:    got unsigned short [usertype]

iptunnel_pmtud_build_icmp() uses the wrong flavour of byte-order conversion
when storing the MTU into the ICMPv4 packet. Use htons(), just like
iptunnel_pmtud_build_icmpv6() does.

> net/ipv4/ip_tunnel_core.c:248:35: warning: cast from restricted __be16
> net/ipv4/ip_tunnel_core.c:248:35: warning: incorrect type in argument 3 (different base types)
> net/ipv4/ip_tunnel_core.c:248:35:    expected unsigned short type
> net/ipv4/ip_tunnel_core.c:248:35:    got restricted __be16 [usertype]
> net/ipv4/ip_tunnel_core.c:341:35: warning: cast from restricted __be16
> net/ipv4/ip_tunnel_core.c:341:35: warning: incorrect type in argument 3 (different base types)
> net/ipv4/ip_tunnel_core.c:341:35:    expected unsigned short type
> net/ipv4/ip_tunnel_core.c:341:35:    got restricted __be16 [usertype]

eth_header() wants the Ethertype in host-order, use the correct flavour of
byte-order conversion.

> net/ipv4/ip_tunnel_core.c:600:45: warning: restricted __be16 degrades to integer
> net/ipv4/ip_tunnel_core.c:609:30: warning: incorrect type in assignment (different base types)
> net/ipv4/ip_tunnel_core.c:609:30:    expected int type
> net/ipv4/ip_tunnel_core.c:609:30:    got restricted __be16 [usertype]
> net/ipv4/ip_tunnel_core.c:619:30: warning: incorrect type in assignment (different base types)
> net/ipv4/ip_tunnel_core.c:619:30:    expected int type
> net/ipv4/ip_tunnel_core.c:619:30:    got restricted __be16 [usertype]
> net/ipv4/ip_tunnel_core.c:629:30: warning: incorrect type in assignment (different base types)
> net/ipv4/ip_tunnel_core.c:629:30:    expected int type
> net/ipv4/ip_tunnel_core.c:629:30:    got restricted __be16 [usertype]

The TUNNEL_* types are big-endian, so adjust the type of the local
variable in ip_tun_parse_opts().

Signed-off-by: default avatarJulian Wiedmann <jwi@linux.ibm.com>
Link: https://lore.kernel.org/r/20210107144008.25777-1-jwi@linux.ibm.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent f67b4ff2

net/ipv4/ip_tunnel_core.c

+5 −4
Original line number Diff line number Diff line
@@ -222,7 +222,7 @@ static int iptunnel_pmtud_build_icmp(struct sk_buff *skb, int mtu) 
		.code			= ICMP_FRAG_NEEDED,

		.checksum		= 0,

		.un.frag.__unused	= 0,

		.un.frag.mtu		= ntohs(mtu),

		.un.frag.mtu		= htons(mtu),

	};

	icmph->checksum = ip_compute_csum(icmph, len);

	skb_reset_transport_header(skb);
@@ -245,7 +245,7 @@ static int iptunnel_pmtud_build_icmp(struct sk_buff *skb, int mtu) 


	skb->ip_summed = CHECKSUM_NONE;



	eth_header(skb, skb->dev, htons(eh.h_proto), eh.h_source, eh.h_dest, 0);

	eth_header(skb, skb->dev, ntohs(eh.h_proto), eh.h_source, eh.h_dest, 0);

	skb_reset_mac_header(skb);



	return skb->len;
@@ -338,7 +338,7 @@ static int iptunnel_pmtud_build_icmpv6(struct sk_buff *skb, int mtu) 


	skb->ip_summed = CHECKSUM_NONE;



	eth_header(skb, skb->dev, htons(eh.h_proto), eh.h_source, eh.h_dest, 0);

	eth_header(skb, skb->dev, ntohs(eh.h_proto), eh.h_source, eh.h_dest, 0);

	skb_reset_mac_header(skb);



	return skb->len;
@@ -583,8 +583,9 @@ static int ip_tun_parse_opts_erspan(struct nlattr *attr, 
static int ip_tun_parse_opts(struct nlattr *attr, struct ip_tunnel_info *info,

			     struct netlink_ext_ack *extack)

{

	int err, rem, opt_len, opts_len = 0, type = 0;

	int err, rem, opt_len, opts_len = 0;

	struct nlattr *nla;

	__be16 type = 0;



	if (!attr)

		return 0;