/* SPDX-License-Identifier: GPL-2.0 */

#ifndef __BPF_SCM__

#define __BPF_SCM__

#include <sys/types.h>

#include <sys/socket.h>

#include <sys/un.h>

#include "utils.h"

#include "bpf_elf.h"

#define BPF_SCM_AUX_VER		1

#define BPF_SCM_MAX_FDS		ELF_MAX_MAPS

#define BPF_SCM_MSG_SIZE	1024

struct bpf_elf_st {

	dev_t st_dev;

	ino_t st_ino;

};

struct bpf_map_aux {

	unsigned short uds_ver;

	unsigned short num_ent;

	char obj_name[64];

	struct bpf_elf_st obj_st;

	struct bpf_elf_map ent[BPF_SCM_MAX_FDS];

};

struct bpf_map_set_msg {

	struct msghdr hdr;

	struct iovec iov;

	char msg_buf[BPF_SCM_MSG_SIZE];

	struct bpf_map_aux aux;

};

static inline int *bpf_map_set_init(struct bpf_map_set_msg *msg,

				    struct sockaddr_un *addr,

				    unsigned int addr_len)

{

	const unsigned int cmsg_ctl_len = sizeof(int) * BPF_SCM_MAX_FDS;

	struct cmsghdr *cmsg;

	msg->iov.iov_base = &msg->aux;

	msg->iov.iov_len = sizeof(msg->aux);

	msg->hdr.msg_iov = &msg->iov;

	msg->hdr.msg_iovlen = 1;

	msg->hdr.msg_name = (struct sockaddr *)addr;

	msg->hdr.msg_namelen = addr_len;

	BUILD_BUG_ON(sizeof(msg->msg_buf) < cmsg_ctl_len);

	msg->hdr.msg_control = &msg->msg_buf;

	msg->hdr.msg_controllen	= cmsg_ctl_len;

	cmsg = CMSG_FIRSTHDR(&msg->hdr);

	cmsg->cmsg_len = msg->hdr.msg_controllen;

	cmsg->cmsg_level = SOL_SOCKET;

	cmsg->cmsg_type	= SCM_RIGHTS;

	return (int *)CMSG_DATA(cmsg);

}

static inline void bpf_map_set_init_single(struct bpf_map_set_msg *msg,

					   int num)

{

	struct cmsghdr *cmsg;

	msg->hdr.msg_controllen = CMSG_LEN(sizeof(int) * num);

	msg->iov.iov_len = offsetof(struct bpf_map_aux, ent) +

			   sizeof(struct bpf_elf_map) * num;

	cmsg = CMSG_FIRSTHDR(&msg->hdr);

	cmsg->cmsg_len = msg->hdr.msg_controllen;

}

#endif /* __BPF_SCM__ */