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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 © 2007-2008 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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#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, popen(), fileno(),
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fprintf(), stderr, STDOUT_FILENO */
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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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stat, waitpid(), WIFEXITED(),
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WEXITSTATUS(), wait(), pid_t,
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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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fcntl(), setuid(), setgid(),
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F_GETFD, F_SETFD, FD_CLOEXEC,
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access(), pipe(), fork(), close()
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dup2, STDOUT_FILENO, _exit(),
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dup2(), STDOUT_FILENO, _exit(),
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execv(), write(), read(),
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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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#define PDIR "/lib/mandos/plugins.d"
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#define AFILE "/conf/conf.d/mandos/plugin-runner.conf"
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const char *argp_program_version = "plugin-runner 1.0";
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const char *argp_program_version = "plugin-runner " VERSION;
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const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";
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typedef struct plugin{
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char *name; /* can be NULL or any plugin name */
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size_t buffer_size;
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size_t buffer_length;
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volatile bool completed;
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volatile sig_atomic_t completed;
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struct plugin *next;
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static plugin *plugin_list = NULL;
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/* Gets a existing plugin based on name,
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/* Gets an existing plugin based on name,
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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->argv = malloc(sizeof(char *) * 2);
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if (new_plugin->argv == NULL){
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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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} 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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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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size_t namelen = (size_t)(strchrnul(def, '=') - def);
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/* Search for this environment variable */
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for(char **e = p->environ; *e != NULL; e++){
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if(strncmp(*e, def, namelen+1) == 0){
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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));
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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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static int set_cloexec_flag(int fd){
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int ret = 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 TEMP_FAILURE_RETRY(fcntl(fd, F_SETFD, ret | FD_CLOEXEC));
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/* Mark processes as completed when they exit, and save their exit
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void handle_sigchld(__attribute__((unused)) int sig){
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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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proc->status = status;
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proc->completed = true;
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/* Prints out a password to stdout */
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bool print_out_password(const char *buffer, size_t length){
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static bool print_out_password(const char *buffer, size_t length){
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if(length>0 and buffer[length-1] == '\n'){
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for(size_t written = 0; written < length; written += (size_t)ret){
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ret = TEMP_FAILURE_RETRY(write(STDOUT_FILENO, buffer + written,
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length - written));
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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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char *envdef = strdup(arg);
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if(not add_environment(getplugin(NULL), envdef, true)){
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perror("add_environment");
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if(not add_environment(getplugin(NULL), arg, true)){
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perror("add_environment");
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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'){
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char *opt = strsep(&arg, ":");
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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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perror("add_argument");
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return ARGP_ERR_UNKNOWN;
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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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if(envdef == NULL){
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char *p_name = strndup(arg, (size_t) (envdef-arg));
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if(not add_environment(getplugin(p_name), envdef, true)){
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if(not add_environment(getplugin(arg), envdef+1, true)){
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perror("add_environment");
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case 'd': /* --disable */
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plugin *p = getplugin(arg);
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return ARGP_ERR_UNKNOWN;
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case 128: /* --plugin-dir */
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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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fprintf(stderr, "Ignoring unknown argument \"%s\"\n", 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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argument was empty, we ignore it silently. */
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fprintf(stderr, "Ignoring unknown argument \"%s\"\n", arg);
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case ARGP_KEY_END:
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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);
633
if (ret == ARGP_ERR_UNKNOWN){
669
ret = argp_parse(&argp, argc, argv, ARGP_IN_ORDER, 0, NULL);
670
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);
750
ret = asprintf(&filename, "%s/%s", plugindir, dirst->d_name);
790
if(plugindir == NULL){
791
ret = TEMP_FAILURE_RETRY(asprintf(&filename, PDIR "/%s",
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ret = TEMP_FAILURE_RETRY(asprintf(&filename, "%s/%s", plugindir,
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perror("asprintf");
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ret = stat(filename, &st);
802
ret = TEMP_FAILURE_RETRY(stat(filename, &st));
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/* Ignore non-executable files */
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if (not S_ISREG(st.st_mode) or (access(filename, X_OK) != 0)){
810
if(not S_ISREG(st.st_mode)
811
or (TEMP_FAILURE_RETRY(access(filename, X_OK)) != 0)){
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fprintf(stderr, "Ignoring plugin dir entry \"%s\""
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814
" with bad type or mode\n", filename);
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/* Block SIGCHLD until process is safely in process list */
836
ret = sigprocmask (SIG_BLOCK, &sigchld_action.sa_mask, NULL);
883
ret = TEMP_FAILURE_RETRY(sigprocmask(SIG_BLOCK,
884
&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 */
895
} while(pid == -1 and errno == EINTR);
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exitstatus = EXIT_FAILURE;
930
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free_plugin_list();
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/* Main loop while running plugins exist */
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while(plugin_list){
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993
fd_set rfds = rfds_all;
937
994
int select_ret = select(maxfd+1, &rfds, NULL, NULL, NULL);
938
if (select_ret == -1){
995
if(select_ret == -1 and errno != EINTR){
939
996
perror("select");
940
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exitstatus = EXIT_FAILURE;
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1000
/* OK, now either a process completed, or something can be read
944
1001
from one of them */
945
for(plugin *proc = plugin_list; proc != NULL; proc = proc->next){
1002
for(plugin *proc = plugin_list; proc != NULL;){
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1003
/* Is this process completely done? */
947
if(proc->eof and proc->completed){
1004
if(proc->completed and proc->eof){
948
1005
/* Only accept the plugin output if it exited cleanly */
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1006
if(not WIFEXITED(proc->status)
950
1007
or WEXITSTATUS(proc->status) != 0){
951
1008
/* Bad exit by plugin */
954
1011
if(WIFEXITED(proc->status)){
955
fprintf(stderr, "Plugin %u exited with status %d\n",
956
(unsigned int) (proc->pid),
1012
fprintf(stderr, "Plugin %s [%" PRIdMAX "] exited with"
1013
" status %d\n", proc->name,
1014
(intmax_t) (proc->pid),
957
1015
WEXITSTATUS(proc->status));
958
} else if(WIFSIGNALED(proc->status)) {
959
fprintf(stderr, "Plugin %u killed by signal %d\n",
960
(unsigned int) (proc->pid),
961
WTERMSIG(proc->status));
1016
} else if(WIFSIGNALED(proc->status)){
1017
fprintf(stderr, "Plugin %s [%" PRIdMAX "] killed by"
1018
" signal %d: %s\n", proc->name,
1019
(intmax_t) (proc->pid),
1020
WTERMSIG(proc->status),
1021
strsignal(WTERMSIG(proc->status)));
962
1022
} else if(WCOREDUMP(proc->status)){
963
fprintf(stderr, "Plugin %d dumped core\n",
964
(unsigned int) (proc->pid));
1023
fprintf(stderr, "Plugin %s [%" PRIdMAX "] dumped"
1024
" core\n", proc->name, (intmax_t) (proc->pid));
968
1028
/* Remove the plugin */
969
1029
FD_CLR(proc->fd, &rfds_all);
971
1031
/* Block signal while modifying process_list */
972
ret = sigprocmask(SIG_BLOCK, &sigchld_action.sa_mask, NULL);
1032
ret = TEMP_FAILURE_RETRY(sigprocmask(SIG_BLOCK,
1033
&sigchld_action.sa_mask,
974
1036
perror("sigprocmask");
975
1037
exitstatus = EXIT_FAILURE;
1041
plugin *next_plugin = proc->next;
978
1042
free_plugin(proc);
979
1045
/* We are done modifying process list, so unblock signal */
980
ret = sigprocmask (SIG_UNBLOCK, &sigchld_action.sa_mask,
1046
ret = TEMP_FAILURE_RETRY(sigprocmask(SIG_UNBLOCK,
1047
&sigchld_action.sa_mask,
983
1050
perror("sigprocmask");
984
1051
exitstatus = EXIT_FAILURE;
1005
1073
/* This process has not completed. Does it have any output? */
1006
1074
if(proc->eof or not FD_ISSET(proc->fd, &rfds)){
1007
1075
/* This process had nothing to say at this time */
1010
1079
/* Before reading, make the process' data buffer large enough */
1011
1080
if(proc->buffer_length + BUFFER_SIZE > proc->buffer_size){
1012
1081
proc->buffer = realloc(proc->buffer, proc->buffer_size
1013
1082
+ (size_t) BUFFER_SIZE);
1014
if (proc->buffer == NULL){
1083
if(proc->buffer == NULL){
1015
1084
perror("malloc");
1016
1085
exitstatus = EXIT_FAILURE;
1019
1088
proc->buffer_size += BUFFER_SIZE;
1021
1090
/* Read from the process */
1022
ret = read(proc->fd, proc->buffer + proc->buffer_length,
1091
sret = TEMP_FAILURE_RETRY(read(proc->fd,
1093
+ proc->buffer_length,
1025
1096
/* Read error from this process; ignore the error */
1030
1102
proc->eof = true;
1032
proc->buffer_length += (size_t) ret;
1104
proc->buffer_length += (size_t) sret;
1040
1112
if(plugin_list == NULL or exitstatus != EXIT_SUCCESS){
1044
1116
fprintf(stderr, "Going to fallback mode using getpass(3)\n");
1045
1117
char *passwordbuffer = getpass("Password: ");
1046
bret = print_out_password(passwordbuffer, strlen(passwordbuffer));
1118
size_t len = strlen(passwordbuffer);
1119
/* Strip trailing newline */
1120
if(len > 0 and passwordbuffer[len-1] == '\n'){
1121
passwordbuffer[len-1] = '\0'; /* not strictly necessary */
1124
bret = print_out_password(passwordbuffer, len);
1048
1126
perror("print_out_password");
1049
1127
exitstatus = EXIT_FAILURE;