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/* -*- coding: utf-8 -*- */
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/* -*- coding: utf-8; mode: c; mode: orgtbl -*- */
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* Mandos plugin runner - Run Mandos plugins
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* Copyright © 2008 Teddy Hogeborn & Björn Påhlsson
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* Copyright © 2008,2009 Teddy Hogeborn
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* Copyright © 2008,2009 Björn Påhlsson
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* This program is free software: you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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#define _GNU_SOURCE /* TEMP_FAILURE_RETRY(), getline(),
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asprintf(), O_CLOEXEC */
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#include <stddef.h> /* size_t, NULL */
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#include <stdlib.h> /* malloc(), exit(), EXIT_FAILURE,
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EXIT_SUCCESS, realloc() */
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#include <stdbool.h> /* bool, true, false */
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#include <stdio.h> /* perror, fileno(), fprintf(),
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stderr, STDOUT_FILENO */
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#include <sys/types.h> /* DIR, opendir(), stat(), struct
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#include <sys/types.h> /* DIR, fdopendir(), stat(), struct
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stat, waitpid(), WIFEXITED(),
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WEXITSTATUS(), wait(), pid_t,
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uid_t, gid_t, getuid(), getgid(),
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#include <sys/select.h> /* fd_set, select(), FD_ZERO(),
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FD_SET(), FD_ISSET(), FD_CLR */
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#include <sys/wait.h> /* wait(), waitpid(), WIFEXITED(),
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WEXITSTATUS(), WTERMSIG(),
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#include <sys/stat.h> /* struct stat, stat(), S_ISREG() */
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#include <iso646.h> /* and, or, not */
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#include <dirent.h> /* DIR, struct dirent, opendir(),
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#include <dirent.h> /* DIR, struct dirent, fdopendir(),
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readdir(), closedir(), dirfd() */
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#include <unistd.h> /* struct stat, stat(), S_ISREG(),
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fcntl(), setuid(), setgid(),
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#include <fcntl.h> /* fcntl(), F_GETFD, F_SETFD,
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#include <string.h> /* strsep, strlen(), asprintf() */
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#include <string.h> /* strsep, strlen(), asprintf(),
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#include <errno.h> /* errno */
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#include <argp.h> /* struct argp_option, struct
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argp_state, struct argp,
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#include <signal.h> /* struct sigaction, sigemptyset(),
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sigaddset(), sigaction(),
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sigprocmask(), SIG_BLOCK, SIGCHLD,
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SIG_UNBLOCK, kill() */
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SIG_UNBLOCK, kill(), sig_atomic_t
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#include <errno.h> /* errno, EBADF */
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#include <inttypes.h> /* intmax_t, PRIdMAX, strtoimax() */
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#define BUFFER_SIZE 256
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or if none is found, creates a new one */
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static plugin *getplugin(char *name){
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/* Check for exiting plugin with that name */
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for (plugin *p = plugin_list; p != NULL; p = p->next){
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if ((p->name == name)
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or (p->name and name and (strcmp(p->name, name) == 0))){
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for(plugin *p = plugin_list; p != NULL; p = p->next){
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or (p->name and name and (strcmp(p->name, name) == 0))){
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/* Create a new plugin */
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plugin *new_plugin = malloc(sizeof(plugin));
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if (new_plugin == NULL){
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plugin *new_plugin = NULL;
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new_plugin = malloc(sizeof(plugin));
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} while(new_plugin == NULL and errno == EINTR);
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if(new_plugin == NULL){
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char *copy_name = NULL;
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if(name != NULL){
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copy_name = strdup(name);
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copy_name = strdup(name);
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} while(copy_name == NULL and errno == EINTR);
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if(copy_name == NULL){
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*new_plugin = (plugin) { .name = copy_name,
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.next = plugin_list };
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*new_plugin = (plugin){ .name = copy_name,
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.next = plugin_list };
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new_plugin->argv = malloc(sizeof(char *) * 2);
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if (new_plugin->argv == NULL){
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new_plugin->argv = malloc(sizeof(char *) * 2);
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} while(new_plugin->argv == NULL and errno == EINTR);
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if(new_plugin->argv == NULL){
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free(new_plugin);
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new_plugin->argv[0] = copy_name;
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new_plugin->argv[1] = NULL;
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new_plugin->environ = malloc(sizeof(char *));
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new_plugin->environ = malloc(sizeof(char *));
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} while(new_plugin->environ == NULL and errno == EINTR);
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if(new_plugin->environ == NULL){
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free(new_plugin->argv);
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static bool add_to_char_array(const char *new, char ***array,
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/* Resize the pointed-to array to hold one more pointer */
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*array = realloc(*array, sizeof(char *)
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* (size_t) ((*len) + 2));
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*array = realloc(*array, sizeof(char *)
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* (size_t) ((*len) + 2));
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} while(*array == NULL and errno == EINTR);
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/* Malloc check */
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if(*array == NULL){
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/* Make a copy of the new string */
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char *copy = strdup(new);
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} while(copy == NULL and errno == EINTR);
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if(copy == NULL){
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if(strncmp(*e, def, namelen + 1) == 0){
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/* It already exists */
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char *new = realloc(*e, strlen(def) + 1);
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new = realloc(*e, strlen(def) + 1);
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} while(new == NULL and errno == EINTR);
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* Based on the example in the GNU LibC manual chapter 13.13 "File
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* Descriptor Flags".
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* *Note File Descriptor Flags:(libc)Descriptor Flags.
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| [[info:libc:Descriptor%20Flags][File Descriptor Flags]] |
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static int set_cloexec_flag(int fd){
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int ret = fcntl(fd, F_GETFD, 0);
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int ret = (int)TEMP_FAILURE_RETRY(fcntl(fd, F_GETFD, 0));
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/* If reading the flags failed, return error indication now. */
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/* Store modified flag word in the descriptor. */
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return fcntl(fd, F_SETFD, ret | FD_CLOEXEC);
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return (int)TEMP_FAILURE_RETRY(fcntl(fd, F_SETFD,
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/* Mark processes as completed when they exit, and save their exit
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static void handle_sigchld(__attribute__((unused)) int sig){
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int old_errno = errno;
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plugin *proc = plugin_list;
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error_t parse_opt (int key, char *arg, __attribute__((unused))
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struct argp_state *state) {
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error_t parse_opt(int key, char *arg, __attribute__((unused))
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struct argp_state *state){
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case 'g': /* --global-options */
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while((p = strsep(&arg, ",")) != NULL){
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while((plugin_option = strsep(&arg, ",")) != NULL){
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if(plugin_option[0] == '\0'){
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if(not add_argument(getplugin(NULL), p)){
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if(not add_argument(getplugin(NULL), plugin_option)){
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perror("add_argument");
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return ARGP_ERR_UNKNOWN;
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case 'o': /* --options-for */
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char *p_name = strsep(&arg, ":");
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if(p_name[0] == '\0' or arg == NULL){
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char *opt = strsep(&arg, ":");
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if(opt[0] == '\0' or opt == NULL){
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while((p = strsep(&opt, ",")) != NULL){
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if(not add_argument(getplugin(p_name), p)){
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char *plugin_name = strsep(&arg, ":");
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if(plugin_name[0] == '\0'){
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while((plugin_option = strsep(&arg, ",")) != NULL){
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if(not add_argument(getplugin(plugin_name), plugin_option)){
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perror("add_argument");
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return ARGP_ERR_UNKNOWN;
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plugindir = strdup(arg);
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if(plugindir == NULL){
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perror("strdup");
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case 129: /* --config-file */
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/* This is already done by parse_opt_config_file() */
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case 130: /* --userid */
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uid = (uid_t)strtol(arg, NULL, 10);
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tmpmax = strtoimax(arg, &tmp, 10);
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if(errno != 0 or tmp == arg or *tmp != '\0'
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or tmpmax != (uid_t)tmpmax){
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fprintf(stderr, "Bad user ID number: \"%s\", using %"
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PRIdMAX "\n", arg, (intmax_t)uid);
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case 131: /* --groupid */
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gid = (gid_t)strtol(arg, NULL, 10);
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tmpmax = strtoimax(arg, &tmp, 10);
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if(errno != 0 or tmp == arg or *tmp != '\0'
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or tmpmax != (gid_t)tmpmax){
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fprintf(stderr, "Bad group ID number: \"%s\", using %"
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PRIdMAX "\n", arg, (intmax_t)gid);
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case 132: /* --debug */
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* When adding more options before this line, remember to also add a
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* "case" to the "parse_opt_config_file" function below.
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case ARGP_KEY_ARG:
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/* Cryptsetup always passes an argument, which is an empty
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string if "none" was specified in /etc/crypttab. So if
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/* This option parser is the same as parse_opt() above, except it
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ignores everything but the --config-file option. */
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error_t parse_opt_config_file (int key, char *arg,
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__attribute__((unused))
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struct argp_state *state) {
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error_t parse_opt_config_file(int key, char *arg,
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__attribute__((unused))
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struct argp_state *state){
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case 'g': /* --global-options */
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case 'G': /* --global-env */
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case 'o': /* --options-for */
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.doc = "Mandos plugin runner -- Run plugins" };
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/* Parse using the parse_opt_config_file in order to get the custom
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/* Parse using parse_opt_config_file() in order to get the custom
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config file location, if any. */
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ret = argp_parse (&argp, argc, argv, ARGP_IN_ORDER, 0, NULL);
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if (ret == ARGP_ERR_UNKNOWN){
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ret = argp_parse(&argp, argc, argv, ARGP_IN_ORDER, 0, NULL);
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if(ret == ARGP_ERR_UNKNOWN){
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fprintf(stderr, "Unknown error while parsing arguments\n");
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exitstatus = EXIT_FAILURE;
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argp.parser = parse_opt;
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/* Open the configfile if available */
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if (argfile == NULL){
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conffp = fopen(AFILE, "r");
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conffp = fopen(argfile, "r");
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if(conffp != NULL){
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char *org_line = NULL;
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char *p, *arg, *new_arg, *line;
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const char whitespace_delims[] = " \r\t\f\v\n";
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const char comment_delim[] = "#";
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custom_argv = malloc(sizeof(char*) * 2);
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if(custom_argv == NULL){
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custom_argv[custom_argc-1] = new_arg;
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custom_argv[custom_argc] = NULL;
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custom_argv[custom_argc] = NULL;
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ret = fclose(conffp);
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} while(ret == EOF and errno == EINTR);
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exitstatus = EXIT_FAILURE;
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/* Check for harmful errors and go to fallback. Other errors might
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not affect opening plugins */
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if (errno == EMFILE or errno == ENFILE or errno == ENOMEM){
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if(errno == EMFILE or errno == ENFILE or errno == ENOMEM){
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exitstatus = EXIT_FAILURE;
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/* If there was any arguments from configuration file,
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pass them to parser as command arguments */
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if(custom_argv != NULL){
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ret = argp_parse (&argp, custom_argc, custom_argv, ARGP_IN_ORDER,
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if (ret == ARGP_ERR_UNKNOWN){
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ret = argp_parse(&argp, custom_argc, custom_argv, ARGP_IN_ORDER,
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if(ret == ARGP_ERR_UNKNOWN){
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fprintf(stderr, "Unknown error while parsing arguments\n");
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exitstatus = EXIT_FAILURE;
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/* Parse actual command line arguments, to let them override the
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ret = argp_parse (&argp, argc, argv, ARGP_IN_ORDER, 0, NULL);
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if (ret == ARGP_ERR_UNKNOWN){
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ret = argp_parse(&argp, argc, argv, ARGP_IN_ORDER, 0, NULL);
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if(ret == ARGP_ERR_UNKNOWN){
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fprintf(stderr, "Unknown error while parsing arguments\n");
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exitstatus = EXIT_FAILURE;
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for(char **a = p->argv; *a != NULL; a++){
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fprintf(stderr, "\tArg: %s\n", *a);
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fprintf(stderr, "...and %u environment variables\n", p->envc);
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fprintf(stderr, "...and %d environment variables\n", p->envc);
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for(char **a = p->environ; *a != NULL; a++){
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fprintf(stderr, "\t%s\n", *a);
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/* Strip permissions down to nobody */
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ret = setuid(uid);
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perror("setuid");
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if (plugindir == NULL){
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dir = opendir(plugindir);
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perror("Could not open plugin dir");
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exitstatus = EXIT_FAILURE;
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/* Set the FD_CLOEXEC flag on the directory, if possible */
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/* Open plugin directory with close_on_exec flag */
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int dir_fd = dirfd(dir);
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ret = set_cloexec_flag(dir_fd);
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perror("set_cloexec_flag");
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exitstatus = EXIT_FAILURE;
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if(plugindir == NULL){
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dir_fd = open(PDIR, O_RDONLY |
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#else /* not O_CLOEXEC */
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#endif /* not O_CLOEXEC */
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dir_fd = open(plugindir, O_RDONLY |
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#else /* not O_CLOEXEC */
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#endif /* not O_CLOEXEC */
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perror("Could not open plugin dir");
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exitstatus = EXIT_FAILURE;
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/* Set the FD_CLOEXEC flag on the directory */
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ret = set_cloexec_flag(dir_fd);
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perror("set_cloexec_flag");
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TEMP_FAILURE_RETRY(close(dir_fd));
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exitstatus = EXIT_FAILURE;
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#endif /* O_CLOEXEC */
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dir = fdopendir(dir_fd);
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perror("Could not open plugin dir");
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TEMP_FAILURE_RETRY(close(dir_fd));
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exitstatus = EXIT_FAILURE;
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if(plugindir == NULL){
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ret = asprintf(&filename, PDIR "/%s", dirst->d_name);
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ret = (int)TEMP_FAILURE_RETRY(asprintf(&filename, PDIR "/%s",
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ret = asprintf(&filename, "%s/%s", plugindir, dirst->d_name);
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ret = (int)TEMP_FAILURE_RETRY(asprintf(&filename, "%s/%s",
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perror("asprintf");
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ret = stat(filename, &st);
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ret = (int)TEMP_FAILURE_RETRY(stat(filename, &st));
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/* Ignore non-executable files */
757
if (not S_ISREG(st.st_mode) or (access(filename, X_OK) != 0)){
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if(not S_ISREG(st.st_mode)
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or (TEMP_FAILURE_RETRY(access(filename, X_OK)) != 0)){
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fprintf(stderr, "Ignoring plugin dir entry \"%s\""
760
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" with bad type or mode\n", filename);
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/* Block SIGCHLD until process is safely in process list */
829
ret = sigprocmask (SIG_BLOCK, &sigchld_action.sa_mask, NULL);
906
ret = (int)TEMP_FAILURE_RETRY(sigprocmask(SIG_BLOCK,
907
&sigchld_action.sa_mask,
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perror("sigprocmask");
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exitstatus = EXIT_FAILURE;
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/* Starting a new process to be watched */
918
} while(pid == -1 and errno == EINTR);
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exitstatus = EXIT_FAILURE;
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/* Parent process */
880
close(pipefd[1]); /* Close unused write end of pipe */
962
TEMP_FAILURE_RETRY(close(pipefd[1])); /* Close unused write end of
882
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plugin *new_plugin = getplugin(dirst->d_name);
883
if (new_plugin == NULL){
966
if(new_plugin == NULL){
884
967
perror("getplugin");
885
ret = sigprocmask (SIG_UNBLOCK, &sigchld_action.sa_mask, NULL);
968
ret = (int)(TEMP_FAILURE_RETRY
969
(sigprocmask(SIG_UNBLOCK, &sigchld_action.sa_mask,
887
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perror("sigprocmask");
896
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/* Unblock SIGCHLD so signal handler can be run if this process
897
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has already completed */
898
ret = sigprocmask (SIG_UNBLOCK, &sigchld_action.sa_mask, NULL);
983
ret = (int)TEMP_FAILURE_RETRY(sigprocmask(SIG_UNBLOCK,
984
&sigchld_action.sa_mask,
900
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perror("sigprocmask");
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exitstatus = EXIT_FAILURE;
905
FD_SET(new_plugin->fd, &rfds_all);
992
FD_SET(new_plugin->fd, &rfds_all); /* Spurious warning from
907
if (maxfd < new_plugin->fd){
995
if(maxfd < new_plugin->fd){
908
996
maxfd = new_plugin->fd;
1000
TEMP_FAILURE_RETRY(closedir(dir));
1002
free_plugin(getplugin(NULL));
915
1004
for(plugin *p = plugin_list; p != NULL; p = p->next){
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1005
if(p->pid != 0){
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1016
while(plugin_list){
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1017
fd_set rfds = rfds_all;
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1018
int select_ret = select(maxfd+1, &rfds, NULL, NULL, NULL);
930
if (select_ret == -1){
1019
if(select_ret == -1 and errno != EINTR){
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1020
perror("select");
932
1021
exitstatus = EXIT_FAILURE;
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from one of them */
937
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for(plugin *proc = plugin_list; proc != NULL;){
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1027
/* Is this process completely done? */
939
if(proc->eof and proc->completed){
1028
if(proc->completed and proc->eof){
940
1029
/* Only accept the plugin output if it exited cleanly */
941
1030
if(not WIFEXITED(proc->status)
942
1031
or WEXITSTATUS(proc->status) != 0){
943
1032
/* Bad exit by plugin */
946
1035
if(WIFEXITED(proc->status)){
947
fprintf(stderr, "Plugin %u exited with status %d\n",
948
(unsigned int) (proc->pid),
1036
fprintf(stderr, "Plugin %s [%" PRIdMAX "] exited with"
1037
" status %d\n", proc->name,
1038
(intmax_t) (proc->pid),
949
1039
WEXITSTATUS(proc->status));
950
} else if(WIFSIGNALED(proc->status)) {
951
fprintf(stderr, "Plugin %u killed by signal %d\n",
952
(unsigned int) (proc->pid),
953
WTERMSIG(proc->status));
1040
} else if(WIFSIGNALED(proc->status)){
1041
fprintf(stderr, "Plugin %s [%" PRIdMAX "] killed by"
1042
" signal %d: %s\n", proc->name,
1043
(intmax_t) (proc->pid),
1044
WTERMSIG(proc->status),
1045
strsignal(WTERMSIG(proc->status)));
954
1046
} else if(WCOREDUMP(proc->status)){
955
fprintf(stderr, "Plugin %d dumped core\n",
956
(unsigned int) (proc->pid));
1047
fprintf(stderr, "Plugin %s [%" PRIdMAX "] dumped"
1048
" core\n", proc->name, (intmax_t) (proc->pid));
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1052
/* Remove the plugin */
961
FD_CLR(proc->fd, &rfds_all);
1053
FD_CLR(proc->fd, &rfds_all); /* Spurious warning from
963
1056
/* Block signal while modifying process_list */
964
ret = sigprocmask(SIG_BLOCK, &sigchld_action.sa_mask, NULL);
1057
ret = (int)TEMP_FAILURE_RETRY(sigprocmask
1059
&sigchld_action.sa_mask,
966
1062
perror("sigprocmask");
967
1063
exitstatus = EXIT_FAILURE;
973
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proc = next_plugin;
975
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/* We are done modifying process list, so unblock signal */
976
ret = sigprocmask (SIG_UNBLOCK, &sigchld_action.sa_mask,
1072
ret = (int)(TEMP_FAILURE_RETRY
1073
(sigprocmask(SIG_UNBLOCK,
1074
&sigchld_action.sa_mask, NULL)));
979
1076
perror("sigprocmask");
980
1077
exitstatus = EXIT_FAILURE;
1002
1099
/* This process has not completed. Does it have any output? */
1003
if(proc->eof or not FD_ISSET(proc->fd, &rfds)){
1100
if(proc->eof or not FD_ISSET(proc->fd, &rfds)){ /* Spurious
1004
1103
/* This process had nothing to say at this time */
1005
1104
proc = proc->next;
1009
1108
if(proc->buffer_length + BUFFER_SIZE > proc->buffer_size){
1010
1109
proc->buffer = realloc(proc->buffer, proc->buffer_size
1011
1110
+ (size_t) BUFFER_SIZE);
1012
if (proc->buffer == NULL){
1111
if(proc->buffer == NULL){
1013
1112
perror("malloc");
1014
1113
exitstatus = EXIT_FAILURE;
1017
1116
proc->buffer_size += BUFFER_SIZE;
1019
1118
/* Read from the process */
1020
ret = read(proc->fd, proc->buffer + proc->buffer_length,
1119
sret = TEMP_FAILURE_RETRY(read(proc->fd,
1121
+ proc->buffer_length,
1023
1124
/* Read error from this process; ignore the error */
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1125
proc = proc->next;
1029
1130
proc->eof = true;
1031
proc->buffer_length += (size_t) ret;
1132
proc->buffer_length += (size_t) sret;
1039
1140
if(plugin_list == NULL or exitstatus != EXIT_SUCCESS){