[ovs-discuss] installing datapath-dkms deb package fails on 3.13.0-83-generic kernel

[Zoltán Balogh]

Hi,

Recently, I upgraded to Linux kernel version 3.13.0-83-generic from version 3.13.0-79-generic. Then I rebuilt the debian packages and tried to install them. Installing the datapath-dkms package failed. 

make -C /lib/modules/3.13.0-83-generic/build M=/var/lib/dkms/openvswitch/2.5.0.dpdk2.2/build/datapath/linux modules
make[1]: Entering directory `/usr/src/linux-headers-3.13.0-83-generic'
  CC [M]  /var/lib/dkms/openvswitch/2.5.0.dpdk2.2/build/datapath/linux/actions.o
/var/lib/dkms/openvswitch/2.5.0.dpdk2.2/build/datapath/linux/actions.c: In function 'ovs_fragment':
/var/lib/dkms/openvswitch/2.5.0.dpdk2.2/build/datapath/linux/actions.c:730:3: warning: passing argument 1 of 'v6ops->fragment' from incompatible pointer type [enabled by default]
   v6ops->fragment(skb->sk, skb, ovs_vport_output);
   ^
/var/lib/dkms/openvswitch/2.5.0.dpdk2.2/build/datapath/linux/actions.c:730:3: note: expected 'struct sk_buff *' but argument is of type 'struct sock *'
/var/lib/dkms/openvswitch/2.5.0.dpdk2.2/build/datapath/linux/actions.c:730:3: warning: passing argument 2 of 'v6ops->fragment' from incompatible pointer type [enabled by default]
/var/lib/dkms/openvswitch/2.5.0.dpdk2.2/build/datapath/linux/actions.c:730:3: note: expected 'int (*)(struct sk_buff *)' but argument is of type 'struct sk_buff *'
/var/lib/dkms/openvswitch/2.5.0.dpdk2.2/build/datapath/linux/actions.c:730:3: error: too many arguments to function 'v6ops->fragment'
make[2]: *** [/var/lib/dkms/openvswitch/2.5.0.dpdk2.2/build/datapath/linux/actions.o] Error 1
make[1]: *** [_module_/var/lib/dkms/openvswitch/2.5.0.dpdk2.2/build/datapath/linux] Error 2
make[1]: Leaving directory `/usr/src/linux-headers-3.13.0-83-generic'
make: *** [default] Error 2
make: Leaving directory `/var/lib/dkms/openvswitch/2.5.0.dpdk2.2/build/datapath/linux'

I compared the include/linux/netfilter_ipv6.h files of  the two kernel sources:

diff /usr/src/linux-headers-3.13.0-83-generic/include/linux/netfilter_ipv6.h /usr/src/linux-headers-3.13.0-79-generic/include/linux/netfilter_ipv6.h 
28d27
<       int (*fragment)(struct sk_buff *skb, int (*output)(struct sk_buff *));

It seems the new struct member fragment was introduced in nf_ipv6_ops in version 3.13.0-83-general:

/*
 * Hook functions for ipv6 to allow xt_* modules to be built-in even
 * if IPv6 is a module.
 */
struct nf_ipv6_ops {
	int (*chk_addr)(struct net *net, const struct in6_addr *addr,
			const struct net_device *dev, int strict);
	int (*fragment)(struct sk_buff *skb, int (*output)(struct sk_buff *));
};

While the ovs code defines fragment with three arguments in netfilter_ipv6.h and ip6_route.h:

#ifndef HAVE_NF_IPV6_OPS_FRAGMENT
/* Try to minimise changes required to the actions.c code for calling IPv6
 * fragmentation. We can keep the fragment() API mostly the same, except that
 * the callback parameter needs to be in the form that older kernels accept.
 * We don't backport the other ipv6_ops as they're currently unused by OVS. */
struct ovs_nf_ipv6_ops {
	int (*fragment)(struct sock *sk, struct sk_buff *skb,
			int (*output)(OVS_VPORT_OUTPUT_PARAMS));
};
#define nf_ipv6_ops ovs_nf_ipv6_ops

#if defined(OVS_FRAGMENT_BACKPORT)
static struct ovs_nf_ipv6_ops ovs_ipv6_ops = {
	.fragment = ip6_fragment,
};

static inline struct ovs_nf_ipv6_ops *ovs_nf_get_ipv6_ops(void)
{
	return &ovs_ipv6_ops;
}
#else /* !OVS_FRAGMENT_BACKPORT */
static inline const struct ovs_nf_ipv6_ops *ovs_nf_get_ipv6_ops(void)
{
	return NULL;
}
#endif
#define nf_get_ipv6_ops ovs_nf_get_ipv6_ops

---

#ifndef HAVE_NF_IPV6_OPS_FRAGMENT
#ifdef OVS_FRAGMENT_BACKPORT
int rpl_ip6_fragment(struct sock *sk, struct sk_buff *skb,
		     int (*output)(OVS_VPORT_OUTPUT_PARAMS));
#else
static inline int rpl_ip6_fragment(struct sock *sk, struct sk_buff *skb,
				   int (*output)(struct sk_buff *))
{
	kfree_skb(skb);
	return -ENOTSUPP;
}
#endif /* OVS_FRAGMENT_BACKPORT */
#define ip6_fragment rpl_ip6_fragment
#endif /* HAVE_NF_IPV6_OPS_FRAGMENT */

Best regards,
Zoltán