1
/* -*- coding: utf-8 -*- */
1
/* -*- coding: utf-8; mode: c; mode: orgtbl -*- */
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3
* 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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/* Refuse to add an existing variable */
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if(strncmp(*e, def, namelen + 1) == 0){
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/* It already exists */
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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 = (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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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){
279
static bool print_out_password(const char *buffer, size_t length){
250
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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{ .name = "global-options", .key = 'g',
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.arg = "OPTION[,OPTION[,...]]",
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.doc = "Options passed to all plugins" },
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{ .name = "global-env", .key = 'e',
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{ .name = "global-env", .key = 'G',
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.arg = "VAR=value",
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.doc = "Environment variable passed to all plugins" },
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{ .name = "options-for", .key = 'o',
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.arg = "PLUGIN:OPTION[,OPTION[,...]]",
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.doc = "Options passed only to specified plugin" },
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{ .name = "env-for", .key = 'f',
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{ .name = "env-for", .key = 'E',
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.arg = "PLUGIN:ENV=value",
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.doc = "Environment variable passed to specified plugin" },
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{ .name = "disable", .key = 'd',
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.doc = "Disable a specific plugin", .group = 1 },
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{ .name = "enable", .key = 'e',
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.doc = "Enable a specific plugin", .group = 1 },
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{ .name = "plugin-dir", .key = 128,
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.arg = "DIRECTORY",
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.doc = "Specify a different plugin directory", .group = 2 },
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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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/* Get the INPUT argument from `argp_parse', which we know is a
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pointer to our plugin list pointer. */
400
error_t parse_opt(int key, char *arg, __attribute__((unused))
401
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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413
perror("add_argument");
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return ARGP_ERR_UNKNOWN;
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case 'e': /* --global-env */
419
case 'G': /* --global-env */
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char *envdef = strdup(arg);
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if(not add_environment(getplugin(NULL), envdef)){
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perror("add_environment");
423
if(not add_environment(getplugin(NULL), arg, true)){
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perror("add_environment");
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427
case 'o': /* --options-for */
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char *p_name = strsep(&arg, ":");
404
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)){
418
perror("add_argument");
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return ARGP_ERR_UNKNOWN;
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char *plugin_name = strsep(&arg, ":");
430
if(plugin_name[0] == '\0'){
434
while((plugin_option = strsep(&arg, ",")) != NULL){
435
if(not add_argument(getplugin(plugin_name), plugin_option)){
436
perror("add_argument");
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return ARGP_ERR_UNKNOWN;
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case 'f': /* --env-for */
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case 'E': /* --env-for */
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p->disabled = true;
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case 'e': /* --enable */
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plugin *p = getplugin(arg);
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return ARGP_ERR_UNKNOWN;
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475
case 128: /* --plugin-dir */
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plugindir = strdup(arg);
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if(plugindir == NULL){
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perror("strdup");
459
case 129: /* --config-file */
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case 129: /* --config-file */
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/* This is already done by parse_opt_config_file() */
485
case 130: /* --userid */
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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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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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/* Cryptsetup always passes an argument, which is an empty
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string if "none" was specified in /etc/crypttab. So if
517
argument was empty, we ignore it silently. */
519
fprintf(stderr, "Ignoring unknown argument \"%s\"\n", arg);
525
return ARGP_ERR_UNKNOWN;
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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. */
532
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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case 'E': /* --env-for */
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case 'd': /* --disable */
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case 'e': /* --enable */
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case 128: /* --plugin-dir */
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case 129: /* --config-file */
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argfile = strdup(arg);
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if(argfile == NULL){
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perror("strdup");
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case 130: /* --userid */
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uid = (uid_t)strtol(arg, NULL, 10);
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case 131: /* --groupid */
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gid = (gid_t)strtol(arg, NULL, 10);
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case 132: /* --debug */
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case ARGP_KEY_ARG:
475
fprintf(stderr, "Ignoring unknown argument \"%s\"\n", arg);
477
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case ARGP_KEY_END:
485
struct argp argp = { .options = options, .parser = parse_opt,
486
.args_doc = "[+PLUS_SEPARATED_OPTIONS]",
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struct argp argp = { .options = options,
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.parser = parse_opt_config_file,
487
566
.doc = "Mandos plugin runner -- Run plugins" };
489
ret = argp_parse (&argp, argc, argv, 0, 0, NULL);
490
if (ret == ARGP_ERR_UNKNOWN){
568
/* Parse using parse_opt_config_file() in order to get the custom
569
config file location, if any. */
570
ret = argp_parse(&argp, argc, argv, ARGP_IN_ORDER, 0, NULL);
571
if(ret == ARGP_ERR_UNKNOWN){
491
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fprintf(stderr, "Unknown error while parsing arguments\n");
492
573
exitstatus = EXIT_FAILURE;
496
/* Opens the configfile if aviable */
497
if (argfile == NULL){
577
/* Reset to the normal argument parser */
578
argp.parser = parse_opt;
580
/* Open the configfile if available */
498
582
conffp = fopen(AFILE, "r");
500
584
conffp = fopen(argfile, "r");
502
586
if(conffp != NULL){
503
587
char *org_line = NULL;
504
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char *p, *arg, *new_arg, *line;
507
590
const char whitespace_delims[] = " \r\t\f\v\n";
508
591
const char comment_delim[] = "#";
511
594
custom_argv = malloc(sizeof(char*) * 2);
512
595
if(custom_argv == NULL){
551
634
custom_argv[custom_argc-1] = new_arg;
552
custom_argv[custom_argc] = NULL;
635
custom_argv[custom_argc] = NULL;
639
ret = fclose(conffp);
640
} while(ret == EOF and errno == EINTR);
643
exitstatus = EXIT_FAILURE;
557
648
/* Check for harmful errors and go to fallback. Other errors might
558
649
not affect opening plugins */
559
if (errno == EMFILE or errno == ENFILE or errno == ENOMEM){
650
if(errno == EMFILE or errno == ENFILE or errno == ENOMEM){
561
652
exitstatus = EXIT_FAILURE;
565
656
/* If there was any arguments from configuration file,
566
657
pass them to parser as command arguments */
567
658
if(custom_argv != NULL){
568
ret = argp_parse (&argp, custom_argc, custom_argv, 0, 0, NULL);
569
if (ret == ARGP_ERR_UNKNOWN){
659
ret = argp_parse(&argp, custom_argc, custom_argv, ARGP_IN_ORDER,
661
if(ret == ARGP_ERR_UNKNOWN){
570
662
fprintf(stderr, "Unknown error while parsing arguments\n");
571
663
exitstatus = EXIT_FAILURE;
668
/* Parse actual command line arguments, to let them override the
670
ret = argp_parse(&argp, argc, argv, ARGP_IN_ORDER, 0, NULL);
671
if(ret == ARGP_ERR_UNKNOWN){
672
fprintf(stderr, "Unknown error while parsing arguments\n");
673
exitstatus = EXIT_FAILURE;
577
678
for(plugin *p = plugin_list; p != NULL; p=p->next){
578
679
fprintf(stderr, "Plugin: %s has %d arguments\n",
580
681
for(char **a = p->argv; *a != NULL; a++){
581
682
fprintf(stderr, "\tArg: %s\n", *a);
583
fprintf(stderr, "...and %u environment variables\n", p->envc);
684
fprintf(stderr, "...and %d environment variables\n", p->envc);
584
685
for(char **a = p->environ; *a != NULL; a++){
585
686
fprintf(stderr, "\t%s\n", *a);
590
691
/* Strip permissions down to nobody */
591
696
ret = setuid(uid);
593
698
perror("setuid");
600
if (plugindir == NULL){
701
if(plugindir == NULL){
601
702
dir = opendir(PDIR);
603
704
dir = opendir(plugindir);
687
ret = asprintf(&filename, "%s/%s", plugindir, dirst->d_name);
791
if(plugindir == NULL){
792
ret = (int)TEMP_FAILURE_RETRY(asprintf(&filename, PDIR "/%s",
795
ret = (int)TEMP_FAILURE_RETRY(asprintf(&filename, "%s/%s",
689
800
perror("asprintf");
693
ret = stat(filename, &st);
804
ret = (int)TEMP_FAILURE_RETRY(stat(filename, &st));
700
811
/* Ignore non-executable files */
701
if (not S_ISREG(st.st_mode) or (access(filename, X_OK) != 0)){
812
if(not S_ISREG(st.st_mode)
813
or (TEMP_FAILURE_RETRY(access(filename, X_OK)) != 0)){
703
815
fprintf(stderr, "Ignoring plugin dir entry \"%s\""
704
816
" with bad type or mode\n", filename);
744
856
if(p->environ[0] != NULL){
745
857
for(char **e = environ; *e != NULL; e++){
746
char *copy = strdup(*e);
751
if(not add_environment(p, copy)){
858
if(not add_environment(p, *e, false)){
752
859
perror("add_environment");
865
ret = (int)TEMP_FAILURE_RETRY(pipe(pipefd));
761
868
exitstatus = EXIT_FAILURE;
777
884
/* Block SIGCHLD until process is safely in process list */
778
ret = sigprocmask (SIG_BLOCK, &sigchld_action.sa_mask, NULL);
885
ret = (int)TEMP_FAILURE_RETRY(sigprocmask(SIG_BLOCK,
886
&sigchld_action.sa_mask,
780
889
perror("sigprocmask");
781
890
exitstatus = EXIT_FAILURE;
784
// Starting a new process to be watched
893
/* Starting a new process to be watched */
897
} while(pid == -1 and errno == EINTR);
788
900
exitstatus = EXIT_FAILURE;
828
940
/* Parent process */
829
close(pipefd[1]); /* Close unused write end of pipe */
941
TEMP_FAILURE_RETRY(close(pipefd[1])); /* Close unused write end of
831
944
plugin *new_plugin = getplugin(dirst->d_name);
832
if (new_plugin == NULL){
945
if(new_plugin == NULL){
833
946
perror("getplugin");
834
ret = sigprocmask (SIG_UNBLOCK, &sigchld_action.sa_mask, NULL);
947
ret = (int)(TEMP_FAILURE_RETRY
948
(sigprocmask(SIG_UNBLOCK, &sigchld_action.sa_mask,
836
951
perror("sigprocmask");
872
989
free_plugin_list();
876
993
/* Main loop while running plugins exist */
877
994
while(plugin_list){
878
995
fd_set rfds = rfds_all;
879
996
int select_ret = select(maxfd+1, &rfds, NULL, NULL, NULL);
880
if (select_ret == -1){
997
if(select_ret == -1 and errno != EINTR){
881
998
perror("select");
882
999
exitstatus = EXIT_FAILURE;
885
1002
/* OK, now either a process completed, or something can be read
886
1003
from one of them */
887
for(plugin *proc = plugin_list; proc != NULL; proc = proc->next){
1004
for(plugin *proc = plugin_list; proc != NULL;){
888
1005
/* Is this process completely done? */
889
if(proc->eof and proc->completed){
1006
if(proc->completed and proc->eof){
890
1007
/* Only accept the plugin output if it exited cleanly */
891
1008
if(not WIFEXITED(proc->status)
892
1009
or WEXITSTATUS(proc->status) != 0){
893
1010
/* Bad exit by plugin */
896
1013
if(WIFEXITED(proc->status)){
897
fprintf(stderr, "Plugin %u exited with status %d\n",
898
(unsigned int) (proc->pid),
1014
fprintf(stderr, "Plugin %s [%" PRIdMAX "] exited with"
1015
" status %d\n", proc->name,
1016
(intmax_t) (proc->pid),
899
1017
WEXITSTATUS(proc->status));
900
} else if(WIFSIGNALED(proc->status)) {
901
fprintf(stderr, "Plugin %u killed by signal %d\n",
902
(unsigned int) (proc->pid),
903
WTERMSIG(proc->status));
1018
} else if(WIFSIGNALED(proc->status)){
1019
fprintf(stderr, "Plugin %s [%" PRIdMAX "] killed by"
1020
" signal %d: %s\n", proc->name,
1021
(intmax_t) (proc->pid),
1022
WTERMSIG(proc->status),
1023
strsignal(WTERMSIG(proc->status)));
904
1024
} else if(WCOREDUMP(proc->status)){
905
fprintf(stderr, "Plugin %d dumped core\n",
906
(unsigned int) (proc->pid));
1025
fprintf(stderr, "Plugin %s [%" PRIdMAX "] dumped"
1026
" core\n", proc->name, (intmax_t) (proc->pid));
910
1030
/* Remove the plugin */
911
1031
FD_CLR(proc->fd, &rfds_all);
913
1033
/* Block signal while modifying process_list */
914
ret = sigprocmask(SIG_BLOCK, &sigchld_action.sa_mask, NULL);
1034
ret = (int)TEMP_FAILURE_RETRY(sigprocmask
1036
&sigchld_action.sa_mask,
916
1039
perror("sigprocmask");
917
1040
exitstatus = EXIT_FAILURE;
1044
plugin *next_plugin = proc->next;
920
1045
free_plugin(proc);
921
1048
/* We are done modifying process list, so unblock signal */
922
ret = sigprocmask (SIG_UNBLOCK, &sigchld_action.sa_mask,
1049
ret = (int)(TEMP_FAILURE_RETRY
1050
(sigprocmask(SIG_UNBLOCK,
1051
&sigchld_action.sa_mask, NULL)));
925
1053
perror("sigprocmask");
926
1054
exitstatus = EXIT_FAILURE;
947
1076
/* This process has not completed. Does it have any output? */
948
1077
if(proc->eof or not FD_ISSET(proc->fd, &rfds)){
949
1078
/* This process had nothing to say at this time */
952
1082
/* Before reading, make the process' data buffer large enough */
953
1083
if(proc->buffer_length + BUFFER_SIZE > proc->buffer_size){
954
1084
proc->buffer = realloc(proc->buffer, proc->buffer_size
955
1085
+ (size_t) BUFFER_SIZE);
956
if (proc->buffer == NULL){
1086
if(proc->buffer == NULL){
957
1087
perror("malloc");
958
1088
exitstatus = EXIT_FAILURE;
961
1091
proc->buffer_size += BUFFER_SIZE;
963
1093
/* Read from the process */
964
ret = read(proc->fd, proc->buffer + proc->buffer_length,
1094
sret = TEMP_FAILURE_RETRY(read(proc->fd,
1096
+ proc->buffer_length,
967
1099
/* Read error from this process; ignore the error */
972
1105
proc->eof = true;
974
proc->buffer_length += (size_t) ret;
1107
proc->buffer_length += (size_t) sret;
982
1115
if(plugin_list == NULL or exitstatus != EXIT_SUCCESS){
986
1119
fprintf(stderr, "Going to fallback mode using getpass(3)\n");
987
1120
char *passwordbuffer = getpass("Password: ");
988
bret = print_out_password(passwordbuffer, strlen(passwordbuffer));
1121
size_t len = strlen(passwordbuffer);
1122
/* Strip trailing newline */
1123
if(len > 0 and passwordbuffer[len-1] == '\n'){
1124
passwordbuffer[len-1] = '\0'; /* not strictly necessary */
1127
bret = print_out_password(passwordbuffer, len);
990
1129
perror("print_out_password");
991
1130
exitstatus = EXIT_FAILURE;