/* Copyright (c) 2017 Facebook * * This program is free software; you can redistribute it and/or * modify it under the terms of version 2 of the GNU General Public * License as published by the Free Software Foundation. */ #include <stdio.h> #include <stdlib.h> #include <string.h> #include <linux/bpf.h> #include <bpf/bpf.h> #include "bpf_load.h" #include <unistd.h> #include <errno.h> #include <fcntl.h> #include <linux/unistd.h> static void usage(char *pname) { printf("USAGE:\n %s [-l] <cg-path> <prog filename>\n", pname); printf("\tLoad and attach a sock_ops program to the specified " "cgroup\n"); printf("\tIf \"-l\" is used, the program will continue to run\n"); printf("\tprinting the BPF log buffer\n"); printf("\tIf the specified filename does not end in \".o\", it\n"); printf("\tappends \"_kern.o\" to the name\n"); printf("\n"); printf(" %s -r <cg-path>\n", pname); printf("\tDetaches the currently attached sock_ops program\n"); printf("\tfrom the specified cgroup\n"); printf("\n"); exit(1); } int main(int argc, char **argv) { int logFlag = 0; int error = 0; char *cg_path; char fn[500]; char *prog; int cg_fd; if (argc < 3) usage(argv[0]); if (!strcmp(argv[1], "-r")) { cg_path = argv[2]; cg_fd = open(cg_path, O_DIRECTORY, O_RDONLY); error = bpf_prog_detach(cg_fd, BPF_CGROUP_SOCK_OPS); if (error) { printf("ERROR: bpf_prog_detach: %d (%s)\n", error, strerror(errno)); return 2; } return 0; } else if (!strcmp(argv[1], "-h")) { usage(argv[0]); } else if (!strcmp(argv[1], "-l")) { logFlag = 1; if (argc < 4) usage(argv[0]); } prog = argv[argc - 1]; cg_path = argv[argc - 2]; if (strlen(prog) > 480) { fprintf(stderr, "ERROR: program name too long (> 480 chars)\n"); return 3; } cg_fd = open(cg_path, O_DIRECTORY, O_RDONLY); if (!strcmp(prog + strlen(prog)-2, ".o")) strcpy(fn, prog); else sprintf(fn, "%s_kern.o", prog); if (logFlag) printf("loading bpf file:%s\n", fn); if (load_bpf_file(fn)) { printf("ERROR: load_bpf_file failed for: %s\n", fn); printf("%s", bpf_log_buf); return 4; } if (logFlag) printf("TCP BPF Loaded %s\n", fn); error = bpf_prog_attach(prog_fd[0], cg_fd, BPF_CGROUP_SOCK_OPS, 0); if (error) { printf("ERROR: bpf_prog_attach: %d (%s)\n", error, strerror(errno)); return 5; } else if (logFlag) { read_trace_pipe(); } return error; }