CMSG_ALIGN
#define CMSG_SPACE(len) (sizeof(struct cmsghdr) + CMSG_ALIGN(len))
__ptr = (struct cmsghdr*)(((unsigned char *) __cmsg) + CMSG_ALIGN(__cmsg->cmsg_len));
tmp = CMSG_ALIGN(tmp);
if ((char *)kcmsg_base + kcmlen - (char *)kcmsg < CMSG_ALIGN(tmp))
tmp = CMSG_ALIGN(tmp);
*p += CMSG_ALIGN(ipv6_optlen(*dest));
tot_len += CMSG_ALIGN(ipv6_optlen(opt->hopopt));
tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst0opt));
tot_len += CMSG_ALIGN(ipv6_optlen(opt->srcrt));
tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst1opt));
tot_len += CMSG_ALIGN(ipv6_optlen(newopt));
olen = optlen - CMSG_ALIGN(sizeof(*freq));
CMSG_ALIGN(sizeof(*freq)), olen))
CMSG_ALIGN(sizeof(struct cmsghdr)));
#define CMSG_SPACE(len) (sizeof(struct cmsghdr) + CMSG_ALIGN(len))
__ptr = (struct cmsghdr*)(((unsigned char *) __cmsg) + CMSG_ALIGN(__cmsg->cmsg_len));