CMSG_ALIGN 85 include/linux/socket.h #define CMSG_DATA(cmsg) ((void *)((char *)(cmsg) + CMSG_ALIGN(sizeof(struct cmsghdr)))) CMSG_ALIGN 86 include/linux/socket.h #define CMSG_SPACE(len) (CMSG_ALIGN(sizeof(struct cmsghdr)) + CMSG_ALIGN(len)) CMSG_ALIGN 87 include/linux/socket.h #define CMSG_LEN(len) (CMSG_ALIGN(sizeof(struct cmsghdr)) + (len)) CMSG_ALIGN 116 include/linux/socket.h __ptr = (struct cmsghdr*)(((unsigned char *) __cmsg) + CMSG_ALIGN(__cmsg->cmsg_len));