diff options
| -rw-r--r-- | eater.c | 86 |
1 files changed, 52 insertions, 34 deletions
@@ -16,6 +16,7 @@ #include <string.h> #include <fcntl.h> #include <unistd.h> +#include <argp.h> #include <sys/prctl.h> #include <sys/syscall.h> #include <sys/socket.h> @@ -26,27 +27,49 @@ extern char **environ; -static char *qemu_names[] = { - "kvm", - "qemu-kvm", -#ifdef ARCH - ( "qemu-system-" ARCH ), -#endif - "/usr/libexec/qemu-kvm", - NULL, +static char doc[] = + "Usage: seitan-eater: setain-eater -i <input file> -- program args1 args2..."; + +/* Eater options */ +static struct argp_option options[] = { { "input", 'i', "FILE", 0, + "BPF filter input file", 0 }, + { 0 } }; + +struct arguments { + char *input_file; + unsigned int program_index; }; -/** - * usage() - Print usage and exit - */ -void usage(void) +static error_t parse_opt(int key, char *arg, struct argp_state *state) { - fprintf(stderr, "Usage: seitan-eater [QEMU_ARG]...\n"); - fprintf(stderr, "\n"); + struct arguments *arguments = state->input; + + if (state->quoted == 0) + arguments->program_index = state->next + 1; + switch (key) { + case 'i': + if (state->quoted == 0) + arguments->input_file = arg; + break; + case ARGP_KEY_END: + if (arguments->input_file == NULL) + argp_error(state, "missing input file"); + if (state->argv[arguments->program_index] == NULL) + argp_error(state, "missing program"); + break; + } - exit(EXIT_FAILURE); + return 0; } +static struct argp argp = { .options = options, + .parser = parse_opt, + .args_doc = NULL, + .doc = doc, + .children = NULL, + .help_filter = NULL, + .argp_domain = NULL }; + static int seccomp(unsigned int operation, unsigned int flags, void *args) { return syscall(__NR_seccomp, operation, flags, args); @@ -55,40 +78,35 @@ static int seccomp(unsigned int operation, unsigned int flags, void *args) /** * main() - Entry point * @argc: Argument count - * @argv: qemu arguments + * @argv: Seitan-eater and program arguments * * Return: 0 once interrupted, non-zero on failure */ int main(int argc, char **argv) { - int fd = open("bpf.out", O_CLOEXEC | O_RDONLY); struct sock_filter filter[1024]; + struct arguments arguments; struct sock_fprog prog; - char **name; size_t n; + int fd; - (void)argc; - + argp_parse(&argp, argc, argv, 0, 0, &arguments); + fd = open(arguments.input_file, O_CLOEXEC | O_RDONLY); n = read(fd, filter, sizeof(filter)); close(fd); prog.filter = filter; prog.len = (unsigned short)(n / sizeof(filter[0])); prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); - fd = seccomp(SECCOMP_SET_MODE_FILTER, - SECCOMP_FILTER_FLAG_NEW_LISTENER, &prog); - - connect(0, NULL, 0); /* Wait for seitan to unblock this */ - - for (name = qemu_names; *name; name++) { - argv[0] = *name; - execvpe(*name, argv, environ); - if (errno != ENOENT) { - perror("execvpe"); - usage(); - } - } + fd = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_NEW_LISTENER, + &prog); - perror("execvpe"); + connect(0, NULL, 0); /* Wait for seitan to unblock this */ + execvpe(argv[arguments.program_index], &argv[arguments.program_index], + environ); + if (errno != ENOENT) { + perror("execvpe"); + exit(EXIT_FAILURE); + } return EXIT_FAILURE; } |