1 // SPDX-License-Identifier: GPL-2.0 2 #define _GNU_SOURCE 3 #include <sys/uio.h> 4 #include <errno.h> 5 #include <stdio.h> 6 #include <sys/socket.h> 7 #include <fcntl.h> 8 #include <unistd.h> 9 #include "../../include/uapi/linux/bpf.h" 10 #include <asm/unistd.h> 11 #include "msgfmt.h" 12 13 int debug_fd; 14 15 static int handle_get_cmd(struct mbox_request *cmd) 16 { 17 switch (cmd->cmd) { 18 case 0: 19 return 0; 20 default: 21 break; 22 } 23 return -ENOPROTOOPT; 24 } 25 26 static int handle_set_cmd(struct mbox_request *cmd) 27 { 28 return -ENOPROTOOPT; 29 } 30 31 static void loop(void) 32 { 33 while (1) { 34 struct mbox_request req; 35 struct mbox_reply reply; 36 int n; 37 38 n = read(0, &req, sizeof(req)); 39 if (n != sizeof(req)) { 40 dprintf(debug_fd, "invalid request %d\n", n); 41 return; 42 } 43 44 reply.status = req.is_set ? 45 handle_set_cmd(&req) : 46 handle_get_cmd(&req); 47 48 n = write(1, &reply, sizeof(reply)); 49 if (n != sizeof(reply)) { 50 dprintf(debug_fd, "reply failed %d\n", n); 51 return; 52 } 53 } 54 } 55 56 int main(void) 57 { 58 debug_fd = open("/dev/kmsg", 00000002); 59 dprintf(debug_fd, "Started bpfilter\n"); 60 loop(); 61 close(debug_fd); 62 return 0; 63 } 64