关于openswan补丁

外零

xl2tpd[31300]: IPsec SAref does not work with L2TP kernel mode yet, enabling force userspace=yes
xl2tpd[31300]: setsockopt recvref[30]: Protocol not available
xl2tpd[31300]: Not looking for kernel support.
xl2tpd[31300]: open_controlfd: Unable to open /var/run/xl2tpd/l2tp-control for reading.

openswan的文档中并没有说一定要saref打上这个补丁，但是不管在xl2tpd中怎么配置，都会出现这样的问题。

内核2.6.32，
$uname -r
2.6.32-431.3.1.el6.i686

release centos 6.3

使用openswan-2.6.39/patches/kernel/2.6.32目录下的patch，然后重新编译内核的时候会出现以下问题

net/ipv4/ip_sockglue.c: In function ‘ip_cmsg_recv_ipsec_refinfo’:
net/ipv4/ip_sockglue.c:180: error: dereferencing pointer to incomplete type
net/ipv4/ip_sockglue.c:181: error: dereferencing pointer to incomplete type
net/ipv4/ip_sockglue.c: In function ‘ip_cmsg_send_ipsec_refinfo’:
net/ipv4/ip_sockglue.c:200: error: dereferencing pointer to incomplete type
net/ipv4/ip_sockglue.c:201: error: dereferencing pointer to incomplete type

查看代码 结构体 ipsec_secpath_saref_ops 未定义。
加上结构体定义：
struct ipsec_secpath_saref_ops {
        int (*set_ipc_saref)(struct ipcm_cookie *ipc, xfrm_sec_unique_t saref);
        void (*get_secpath_sarefs)(struct sec_path *sp,
                        xfrm_sec_unique_t *refme, xfrm_sec_unique_t *refhim);
};


net/ipv4/ip_sockglue.c:306: error: redefinition of ‘__kcrctab_ip_cmsg_send’
net/ipv4/ip_sockglue.c:258: note: previous definition of ‘__kcrctab_ip_cmsg_send’ was here

306和258行

EXPORT_SYMBOL(ip_cmsg_send);

重复。