Commit 50f37fc2 authored by Geert Uytterhoeven's avatar Geert Uytterhoeven Committed by Jakub Kicinski
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ipv4: ip_gre: Fix set but not used warning in ipgre_err() if IPv4-only 



if CONFIG_NET_IPGRE is enabled, but CONFIG_IPV6 is disabled:

    net/ipv4/ip_gre.c: In function ‘ipgre_err’:
    net/ipv4/ip_gre.c:144:22: error: variable ‘data_len’ set but not used [-Werror=unused-but-set-variable]
      144 |         unsigned int data_len = 0;
	  |                      ^~~~~~~~

Fix this by moving all data_len processing inside the IPV6-only section
that uses its result.

Reported-by: default avatarkernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202501121007.2GofXmh5-lkp@intel.com/


Signed-off-by: default avatarGeert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: default avatarSimon Horman <horms@kernel.org>
Link: https://patch.msgid.link/d09113cfe2bfaca02f3dddf832fb5f48dd20958b.1738704881.git.geert@linux-m68k.org


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent faac69a4

net/ipv4/ip_gre.c

+10 −6
Original line number Diff line number Diff line
@@ -141,7 +141,6 @@ static int ipgre_err(struct sk_buff *skb, u32 info, 
	const struct iphdr *iph;

	const int type = icmp_hdr(skb)->type;

	const int code = icmp_hdr(skb)->code;

	unsigned int data_len = 0;

	struct ip_tunnel *t;



	if (tpi->proto == htons(ETH_P_TEB))
@@ -182,7 +181,6 @@ static int ipgre_err(struct sk_buff *skb, u32 info, 
	case ICMP_TIME_EXCEEDED:

		if (code != ICMP_EXC_TTL)

			return 0;

		data_len = icmp_hdr(skb)->un.reserved[1] * 4; /* RFC 4884 4.1 */

		break;



	case ICMP_REDIRECT:
@@ -190,10 +188,16 @@ static int ipgre_err(struct sk_buff *skb, u32 info, 
	}



#if IS_ENABLED(CONFIG_IPV6)

	if (tpi->proto == htons(ETH_P_IPV6) &&

	    !ip6_err_gen_icmpv6_unreach(skb, iph->ihl * 4 + tpi->hdr_len,

	if (tpi->proto == htons(ETH_P_IPV6)) {

		unsigned int data_len = 0;



		if (type == ICMP_TIME_EXCEEDED)

			data_len = icmp_hdr(skb)->un.reserved[1] * 4; /* RFC 4884 4.1 */



		if (!ip6_err_gen_icmpv6_unreach(skb, iph->ihl * 4 + tpi->hdr_len,

						type, data_len))

			return 0;

	}

#endif



	if (t->parms.iph.daddr == 0 ||