Daniel Borkmann | 6256f8c | 2015-04-01 17:57:44 +0200 | [diff] [blame] | 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 | |
| 14 | struct bpf_elf_st { |
| 15 | dev_t st_dev; |
| 16 | ino_t st_ino; |
| 17 | }; |
| 18 | |
| 19 | struct 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 | |
| 27 | struct 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 | |
| 34 | static 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 | |
| 62 | static 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__ */ |