1 files changed, 77 insertions, 0 deletions
diff --git a/include/bpf_scm.h b/include/bpf_scm.h
new file mode 100644
index 0000000..669f053
--- /dev/null
+++ b/include/bpf_scm.h
@@ -0,0 +1,77 @@
+/* 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__ */