1#ifndef __BPF_SCM__
2#define __BPF_SCM__
3
4#include <sys/types.h>
5#include <sys/socket.h>
6
7#include "utils.h"
8#include "bpf_elf.h"
9
10#define BPF_SCM_AUX_VER		1
11#define BPF_SCM_MAX_FDS		ELF_MAX_MAPS
12#define BPF_SCM_MSG_SIZE	1024
13
14struct bpf_elf_st {
15	dev_t st_dev;
16	ino_t st_ino;
17};
18
19struct bpf_map_aux {
20	unsigned short uds_ver;
21	unsigned short num_ent;
22	char obj_name[64];
23	struct bpf_elf_st obj_st;
24	struct bpf_elf_map ent[BPF_SCM_MAX_FDS];
25};
26
27struct bpf_map_set_msg {
28	struct msghdr hdr;
29	struct iovec iov;
30	char msg_buf[BPF_SCM_MSG_SIZE];
31	struct bpf_map_aux aux;
32};
33
34static inline int *bpf_map_set_init(struct bpf_map_set_msg *msg,
35				    struct sockaddr_un *addr,
36				    unsigned int addr_len)
37{
38	const unsigned int cmsg_ctl_len = sizeof(int) * BPF_SCM_MAX_FDS;
39	struct cmsghdr *cmsg;
40
41	msg->iov.iov_base = &msg->aux;
42	msg->iov.iov_len = sizeof(msg->aux);
43
44	msg->hdr.msg_iov = &msg->iov;
45	msg->hdr.msg_iovlen = 1;
46
47	msg->hdr.msg_name = (struct sockaddr *)addr;
48	msg->hdr.msg_namelen = addr_len;
49
50	BUILD_BUG_ON(sizeof(msg->msg_buf) < cmsg_ctl_len);
51	msg->hdr.msg_control = &msg->msg_buf;
52	msg->hdr.msg_controllen	= cmsg_ctl_len;
53
54	cmsg = CMSG_FIRSTHDR(&msg->hdr);
55	cmsg->cmsg_len = msg->hdr.msg_controllen;
56	cmsg->cmsg_level = SOL_SOCKET;
57	cmsg->cmsg_type	= SCM_RIGHTS;
58
59	return (int *)CMSG_DATA(cmsg);
60}
61
62static inline void bpf_map_set_init_single(struct bpf_map_set_msg *msg,
63					   int num)
64{
65	struct cmsghdr *cmsg;
66
67	msg->hdr.msg_controllen = CMSG_LEN(sizeof(int) * num);
68	msg->iov.iov_len = offsetof(struct bpf_map_aux, ent) +
69			   sizeof(struct bpf_elf_map) * num;
70
71	cmsg = CMSG_FIRSTHDR(&msg->hdr);
72	cmsg->cmsg_len = msg->hdr.msg_controllen;
73}
74
75#endif /* __BPF_SCM__ */
76