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plugin-runner.c
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plugin-runner.c
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/* -*- coding: utf-8; mode: c; mode: orgtbl -*- */
/*
* Mandos plugin runner - Run Mandos plugins
*
* Copyright © 2008-2018 Teddy Hogeborn
* Copyright © 2008-2018 Björn Påhlsson
*
* This file is part of Mandos.
*
* Mandos is free software: you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* Mandos is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with Mandos. If not, see <http://www.gnu.org/licenses/>.
*
* Contact the authors at <[email protected]>.
*/
#define _GNU_SOURCE /* TEMP_FAILURE_RETRY(), getline(),
O_CLOEXEC, pipe2() */
#include <stddef.h> /* size_t, NULL */
#include <stdlib.h> /* malloc(), exit(), EXIT_SUCCESS,
realloc() */
#include <stdbool.h> /* bool, true, false */
#include <stdio.h> /* fileno(), fprintf(),
stderr, STDOUT_FILENO, fclose() */
#include <sys/types.h> /* fstat(), struct stat, waitpid(),
WIFEXITED(), WEXITSTATUS(), wait(),
pid_t, uid_t, gid_t, getuid(),
getgid() */
#include <sys/select.h> /* fd_set, select(), FD_ZERO(),
FD_SET(), FD_ISSET(), FD_CLR */
#include <sys/wait.h> /* wait(), waitpid(), WIFEXITED(),
WEXITSTATUS(), WTERMSIG() */
#include <sys/stat.h> /* struct stat, fstat(), S_ISREG() */
#include <iso646.h> /* and, or, not */
#include <dirent.h> /* struct dirent, scandirat() */
#include <unistd.h> /* fcntl(), F_GETFD, F_SETFD,
FD_CLOEXEC, write(), STDOUT_FILENO,
struct stat, fstat(), close(),
setgid(), setuid(), S_ISREG(),
faccessat() pipe2(), fork(),
_exit(), dup2(), fexecve(), read()
*/
#include <fcntl.h> /* fcntl(), F_GETFD, F_SETFD,
FD_CLOEXEC, openat(), scandirat(),
pipe2() */
#include <string.h> /* strsep, strlen(), strsignal(),
strcmp(), strncmp() */
#include <errno.h> /* errno */
#include <argp.h> /* struct argp_option, struct
argp_state, struct argp,
argp_parse(), ARGP_ERR_UNKNOWN,
ARGP_KEY_END, ARGP_KEY_ARG,
error_t */
#include <signal.h> /* struct sigaction, sigemptyset(),
sigaddset(), sigaction(),
sigprocmask(), SIG_BLOCK, SIGCHLD,
SIG_UNBLOCK, kill(), sig_atomic_t
*/
#include <errno.h> /* errno, EBADF */
#include <inttypes.h> /* intmax_t, PRIdMAX, strtoimax() */
#include <sysexits.h> /* EX_OSERR, EX_USAGE, EX_IOERR,
EX_CONFIG, EX_UNAVAILABLE, EX_OK */
#include <errno.h> /* errno */
#include <error.h> /* error() */
#include <fnmatch.h> /* fnmatch() */
#define BUFFER_SIZE 256
#define PDIR "/lib/mandos/plugins.d"
#define PHDIR "/lib/mandos/plugin-helpers"
#define AFILE "/conf/conf.d/mandos/plugin-runner.conf"
const char *argp_program_version = "plugin-runner " VERSION;
const char *argp_program_bug_address = "<[email protected]>";
typedef struct plugin{
char *name; /* can be NULL or any plugin name */
char **argv;
int argc;
char **environ;
int envc;
bool disabled;
/* Variables used for running processes*/
pid_t pid;
int fd;
char *buffer;
size_t buffer_size;
size_t buffer_length;
bool eof;
volatile sig_atomic_t completed;
int status;
struct plugin *next;
} plugin;
static plugin *plugin_list = NULL;
/* Gets an existing plugin based on name,
or if none is found, creates a new one */
__attribute__((warn_unused_result))
static plugin *getplugin(char *name){
/* Check for existing plugin with that name */
for(plugin *p = plugin_list; p != NULL; p = p->next){
if((p->name == name)
or (p->name and name and (strcmp(p->name, name) == 0))){
return p;
}
}
/* Create a new plugin */
plugin *new_plugin = NULL;
do {
new_plugin = malloc(sizeof(plugin));
} while(new_plugin == NULL and errno == EINTR);
if(new_plugin == NULL){
return NULL;
}
char *copy_name = NULL;
if(name != NULL){
do {
copy_name = strdup(name);
} while(copy_name == NULL and errno == EINTR);
if(copy_name == NULL){
int e = errno;
free(new_plugin);
errno = e;
return NULL;
}
}
*new_plugin = (plugin){ .name = copy_name,
.argc = 1,
.disabled = false,
.next = plugin_list };
do {
new_plugin->argv = malloc(sizeof(char *) * 2);
} while(new_plugin->argv == NULL and errno == EINTR);
if(new_plugin->argv == NULL){
int e = errno;
free(copy_name);
free(new_plugin);
errno = e;
return NULL;
}
new_plugin->argv[0] = copy_name;
new_plugin->argv[1] = NULL;
do {
new_plugin->environ = malloc(sizeof(char *));
} while(new_plugin->environ == NULL and errno == EINTR);
if(new_plugin->environ == NULL){
int e = errno;
free(copy_name);
free(new_plugin->argv);
free(new_plugin);
errno = e;
return NULL;
}
new_plugin->environ[0] = NULL;
/* Append the new plugin to the list */
plugin_list = new_plugin;
return new_plugin;
}
/* Helper function for add_argument and add_environment */
__attribute__((nonnull, warn_unused_result))
static bool add_to_char_array(const char *new, char ***array,
int *len){
/* Resize the pointed-to array to hold one more pointer */
char **new_array = NULL;
do {
new_array = realloc(*array, sizeof(char *)
* (size_t) ((*len) + 2));
} while(new_array == NULL and errno == EINTR);
/* Malloc check */
if(new_array == NULL){
return false;
}
*array = new_array;
/* Make a copy of the new string */
char *copy;
do {
copy = strdup(new);
} while(copy == NULL and errno == EINTR);
if(copy == NULL){
return false;
}
/* Insert the copy */
(*array)[*len] = copy;
(*len)++;
/* Add a new terminating NULL pointer to the last element */
(*array)[*len] = NULL;
return true;
}
/* Add to a plugin's argument vector */
__attribute__((nonnull(2), warn_unused_result))
static bool add_argument(plugin *p, const char *arg){
if(p == NULL){
return false;
}
return add_to_char_array(arg, &(p->argv), &(p->argc));
}
/* Add to a plugin's environment */
__attribute__((nonnull(2), warn_unused_result))
static bool add_environment(plugin *p, const char *def, bool replace){
if(p == NULL){
return false;
}
/* namelen = length of name of environment variable */
size_t namelen = (size_t)(strchrnul(def, '=') - def);
/* Search for this environment variable */
for(char **envdef = p->environ; *envdef != NULL; envdef++){
if(strncmp(*envdef, def, namelen + 1) == 0){
/* It already exists */
if(replace){
char *new_envdef;
do {
new_envdef = realloc(*envdef, strlen(def) + 1);
} while(new_envdef == NULL and errno == EINTR);
if(new_envdef == NULL){
return false;
}
*envdef = new_envdef;
strcpy(*envdef, def);
}
return true;
}
}
return add_to_char_array(def, &(p->environ), &(p->envc));
}
#ifndef O_CLOEXEC
/*
* Based on the example in the GNU LibC manual chapter 13.13 "File
* Descriptor Flags".
| [[info:libc:Descriptor%20Flags][File Descriptor Flags]] |
*/
__attribute__((warn_unused_result))
static int set_cloexec_flag(int fd){
int ret = (int)TEMP_FAILURE_RETRY(fcntl(fd, F_GETFD, 0));
/* If reading the flags failed, return error indication now. */
if(ret < 0){
return ret;
}
/* Store modified flag word in the descriptor. */
return (int)TEMP_FAILURE_RETRY(fcntl(fd, F_SETFD,
ret | FD_CLOEXEC));
}
#endif /* not O_CLOEXEC */
/* Mark processes as completed when they exit, and save their exit
status. */
static void handle_sigchld(__attribute__((unused)) int sig){
int old_errno = errno;
while(true){
plugin *proc = plugin_list;
int status;
pid_t pid = waitpid(-1, &status, WNOHANG);
if(pid == 0){
/* Only still running child processes */
break;
}
if(pid == -1){
if(errno == ECHILD){
/* No child processes */
break;
}
error(0, errno, "waitpid");
}
/* A child exited, find it in process_list */
while(proc != NULL and proc->pid != pid){
proc = proc->next;
}
if(proc == NULL){
/* Process not found in process list */
continue;
}
proc->status = status;
proc->completed = 1;
}
errno = old_errno;
}
/* Prints out a password to stdout */
__attribute__((nonnull, warn_unused_result))
static bool print_out_password(const char *buffer, size_t length){
ssize_t ret;
for(size_t written = 0; written < length; written += (size_t)ret){
ret = TEMP_FAILURE_RETRY(write(STDOUT_FILENO, buffer + written,
length - written));
if(ret < 0){
return false;
}
}
return true;
}
/* Removes and free a plugin from the plugin list */
__attribute__((nonnull))
static void free_plugin(plugin *plugin_node){
for(char **arg = plugin_node->argv; *arg != NULL; arg++){
free(*arg);
}
free(plugin_node->argv);
for(char **env = plugin_node->environ; *env != NULL; env++){
free(*env);
}
free(plugin_node->environ);
free(plugin_node->buffer);
/* Removes the plugin from the singly-linked list */
if(plugin_node == plugin_list){
/* First one - simple */
plugin_list = plugin_list->next;
} else {
/* Second one or later */
for(plugin *p = plugin_list; p != NULL; p = p->next){
if(p->next == plugin_node){
p->next = plugin_node->next;
break;
}
}
}
free(plugin_node);
}
static void free_plugin_list(void){
while(plugin_list != NULL){
free_plugin(plugin_list);
}
}
int main(int argc, char *argv[]){
char *plugindir = NULL;
char *pluginhelperdir = NULL;
char *argfile = NULL;
FILE *conffp;
struct dirent **direntries = NULL;
struct stat st;
fd_set rfds_all;
int ret, maxfd = 0;
ssize_t sret;
uid_t uid = 65534;
gid_t gid = 65534;
bool debug = false;
int exitstatus = EXIT_SUCCESS;
struct sigaction old_sigchld_action;
struct sigaction sigchld_action = { .sa_handler = handle_sigchld,
.sa_flags = SA_NOCLDSTOP };
char **custom_argv = NULL;
int custom_argc = 0;
int dir_fd = -1;
/* Establish a signal handler */
sigemptyset(&sigchld_action.sa_mask);
ret = sigaddset(&sigchld_action.sa_mask, SIGCHLD);
if(ret == -1){
error(0, errno, "sigaddset");
exitstatus = EX_OSERR;
goto fallback;
}
ret = sigaction(SIGCHLD, &sigchld_action, &old_sigchld_action);
if(ret == -1){
error(0, errno, "sigaction");
exitstatus = EX_OSERR;
goto fallback;
}
/* The options we understand. */
struct argp_option options[] = {
{ .name = "global-options", .key = 'g',
.arg = "OPTION[,OPTION[,...]]",
.doc = "Options passed to all plugins" },
{ .name = "global-env", .key = 'G',
.arg = "VAR=value",
.doc = "Environment variable passed to all plugins" },
{ .name = "options-for", .key = 'o',
.arg = "PLUGIN:OPTION[,OPTION[,...]]",
.doc = "Options passed only to specified plugin" },
{ .name = "env-for", .key = 'E',
.arg = "PLUGIN:ENV=value",
.doc = "Environment variable passed to specified plugin" },
{ .name = "disable", .key = 'd',
.arg = "PLUGIN",
.doc = "Disable a specific plugin", .group = 1 },
{ .name = "enable", .key = 'e',
.arg = "PLUGIN",
.doc = "Enable a specific plugin", .group = 1 },
{ .name = "plugin-dir", .key = 128,
.arg = "DIRECTORY",
.doc = "Specify a different plugin directory", .group = 2 },
{ .name = "config-file", .key = 129,
.arg = "FILE",
.doc = "Specify a different configuration file", .group = 2 },
{ .name = "userid", .key = 130,
.arg = "ID", .flags = 0,
.doc = "User ID the plugins will run as", .group = 3 },
{ .name = "groupid", .key = 131,
.arg = "ID", .flags = 0,
.doc = "Group ID the plugins will run as", .group = 3 },
{ .name = "debug", .key = 132,
.doc = "Debug mode", .group = 4 },
{ .name = "plugin-helper-dir", .key = 133,
.arg = "DIRECTORY",
.doc = "Specify a different plugin helper directory",
.group = 2 },
/*
* These reproduce what we would get without ARGP_NO_HELP
*/
{ .name = "help", .key = '?',
.doc = "Give this help list", .group = -1 },
{ .name = "usage", .key = -3,
.doc = "Give a short usage message", .group = -1 },
{ .name = "version", .key = 'V',
.doc = "Print program version", .group = -1 },
{ .name = NULL }
};
__attribute__((nonnull(3)))
error_t parse_opt(int key, char *arg, struct argp_state *state){
errno = 0;
switch(key){
char *tmp;
intmax_t tmp_id;
case 'g': /* --global-options */
{
char *plugin_option;
while((plugin_option = strsep(&arg, ",")) != NULL){
if(not add_argument(getplugin(NULL), plugin_option)){
break;
}
}
errno = 0;
}
break;
case 'G': /* --global-env */
if(add_environment(getplugin(NULL), arg, true)){
errno = 0;
}
break;
case 'o': /* --options-for */
{
char *option_list = strchr(arg, ':');
if(option_list == NULL){
argp_error(state, "No colon in \"%s\"", arg);
errno = EINVAL;
break;
}
*option_list = '\0';
option_list++;
if(arg[0] == '\0'){
argp_error(state, "Empty plugin name");
errno = EINVAL;
break;
}
char *option;
while((option = strsep(&option_list, ",")) != NULL){
if(not add_argument(getplugin(arg), option)){
break;
}
}
errno = 0;
}
break;
case 'E': /* --env-for */
{
char *envdef = strchr(arg, ':');
if(envdef == NULL){
argp_error(state, "No colon in \"%s\"", arg);
errno = EINVAL;
break;
}
*envdef = '\0';
envdef++;
if(arg[0] == '\0'){
argp_error(state, "Empty plugin name");
errno = EINVAL;
break;
}
if(add_environment(getplugin(arg), envdef, true)){
errno = 0;
}
}
break;
case 'd': /* --disable */
{
plugin *p = getplugin(arg);
if(p != NULL){
p->disabled = true;
errno = 0;
}
}
break;
case 'e': /* --enable */
{
plugin *p = getplugin(arg);
if(p != NULL){
p->disabled = false;
errno = 0;
}
}
break;
case 128: /* --plugin-dir */
free(plugindir);
plugindir = strdup(arg);
if(plugindir != NULL){
errno = 0;
}
break;
case 129: /* --config-file */
/* This is already done by parse_opt_config_file() */
break;
case 130: /* --userid */
tmp_id = strtoimax(arg, &tmp, 10);
if(errno != 0 or tmp == arg or *tmp != '\0'
or tmp_id != (uid_t)tmp_id){
argp_error(state, "Bad user ID number: \"%s\", using %"
PRIdMAX, arg, (intmax_t)uid);
break;
}
uid = (uid_t)tmp_id;
errno = 0;
break;
case 131: /* --groupid */
tmp_id = strtoimax(arg, &tmp, 10);
if(errno != 0 or tmp == arg or *tmp != '\0'
or tmp_id != (gid_t)tmp_id){
argp_error(state, "Bad group ID number: \"%s\", using %"
PRIdMAX, arg, (intmax_t)gid);
break;
}
gid = (gid_t)tmp_id;
errno = 0;
break;
case 132: /* --debug */
debug = true;
break;
case 133: /* --plugin-helper-dir */
free(pluginhelperdir);
pluginhelperdir = strdup(arg);
if(pluginhelperdir != NULL){
errno = 0;
}
break;
/*
* These reproduce what we would get without ARGP_NO_HELP
*/
case '?': /* --help */
state->flags &= ~(unsigned int)ARGP_NO_EXIT; /* force exit */
argp_state_help(state, state->out_stream, ARGP_HELP_STD_HELP);
case -3: /* --usage */
state->flags &= ~(unsigned int)ARGP_NO_EXIT; /* force exit */
argp_state_help(state, state->out_stream,
ARGP_HELP_USAGE | ARGP_HELP_EXIT_OK);
case 'V': /* --version */
fprintf(state->out_stream, "%s\n", argp_program_version);
exit(EXIT_SUCCESS);
break;
/*
* When adding more options before this line, remember to also add a
* "case" to the "parse_opt_config_file" function below.
*/
case ARGP_KEY_ARG:
/* Cryptsetup always passes an argument, which is an empty
string if "none" was specified in /etc/crypttab. So if
argument was empty, we ignore it silently. */
if(arg[0] == '\0'){
break;
}
/* FALLTHROUGH */
default:
return ARGP_ERR_UNKNOWN;
}
return errno; /* Set to 0 at start */
}
/* This option parser is the same as parse_opt() above, except it
ignores everything but the --config-file option. */
error_t parse_opt_config_file(int key, char *arg,
__attribute__((unused))
struct argp_state *state){
errno = 0;
switch(key){
case 'g': /* --global-options */
case 'G': /* --global-env */
case 'o': /* --options-for */
case 'E': /* --env-for */
case 'd': /* --disable */
case 'e': /* --enable */
case 128: /* --plugin-dir */
break;
case 129: /* --config-file */
free(argfile);
argfile = strdup(arg);
if(argfile != NULL){
errno = 0;
}
break;
case 130: /* --userid */
case 131: /* --groupid */
case 132: /* --debug */
case 133: /* --plugin-helper-dir */
case '?': /* --help */
case -3: /* --usage */
case 'V': /* --version */
case ARGP_KEY_ARG:
break;
default:
return ARGP_ERR_UNKNOWN;
}
return errno;
}
struct argp argp = { .options = options,
.parser = parse_opt_config_file,
.args_doc = "",
.doc = "Mandos plugin runner -- Run plugins" };
/* Parse using parse_opt_config_file() in order to get the custom
config file location, if any. */
ret = argp_parse(&argp, argc, argv,
ARGP_IN_ORDER | ARGP_NO_EXIT | ARGP_NO_HELP,
NULL, NULL);
switch(ret){
case 0:
break;
case ENOMEM:
default:
errno = ret;
error(0, errno, "argp_parse");
exitstatus = EX_OSERR;
goto fallback;
case EINVAL:
exitstatus = EX_USAGE;
goto fallback;
}
/* Reset to the normal argument parser */
argp.parser = parse_opt;
/* Open the configfile if available */
if(argfile == NULL){
conffp = fopen(AFILE, "r");
} else {
conffp = fopen(argfile, "r");
}
if(conffp != NULL){
char *org_line = NULL;
char *p, *arg, *new_arg, *line;
size_t size = 0;
const char whitespace_delims[] = " \r\t\f\v\n";
const char comment_delim[] = "#";
custom_argc = 1;
custom_argv = malloc(sizeof(char*) * 2);
if(custom_argv == NULL){
error(0, errno, "malloc");
exitstatus = EX_OSERR;
goto fallback;
}
custom_argv[0] = argv[0];
custom_argv[1] = NULL;
/* for each line in the config file, strip whitespace and ignore
commented text */
while(true){
sret = getline(&org_line, &size, conffp);
if(sret == -1){
break;
}
line = org_line;
arg = strsep(&line, comment_delim);
while((p = strsep(&arg, whitespace_delims)) != NULL){
if(p[0] == '\0'){
continue;
}
new_arg = strdup(p);
if(new_arg == NULL){
error(0, errno, "strdup");
exitstatus = EX_OSERR;
free(org_line);
goto fallback;
}
custom_argc += 1;
{
char **new_argv = realloc(custom_argv, sizeof(char *)
* ((size_t)custom_argc + 1));
if(new_argv == NULL){
error(0, errno, "realloc");
exitstatus = EX_OSERR;
free(new_arg);
free(org_line);
goto fallback;
} else {
custom_argv = new_argv;
}
}
custom_argv[custom_argc-1] = new_arg;
custom_argv[custom_argc] = NULL;
}
}
do {
ret = fclose(conffp);
} while(ret == EOF and errno == EINTR);
if(ret == EOF){
error(0, errno, "fclose");
exitstatus = EX_IOERR;
goto fallback;
}
free(org_line);
} else {
/* Check for harmful errors and go to fallback. Other errors might
not affect opening plugins */
if(errno == EMFILE or errno == ENFILE or errno == ENOMEM){
error(0, errno, "fopen");
exitstatus = EX_OSERR;
goto fallback;
}
}
/* If there were any arguments from the configuration file, pass
them to parser as command line arguments */
if(custom_argv != NULL){
ret = argp_parse(&argp, custom_argc, custom_argv,
ARGP_IN_ORDER | ARGP_NO_EXIT | ARGP_NO_HELP,
NULL, NULL);
switch(ret){
case 0:
break;
case ENOMEM:
default:
errno = ret;
error(0, errno, "argp_parse");
exitstatus = EX_OSERR;
goto fallback;
case EINVAL:
exitstatus = EX_CONFIG;
goto fallback;
}
}
/* Parse actual command line arguments, to let them override the
config file */
ret = argp_parse(&argp, argc, argv,
ARGP_IN_ORDER | ARGP_NO_EXIT | ARGP_NO_HELP,
NULL, NULL);
switch(ret){
case 0:
break;
case ENOMEM:
default:
errno = ret;
error(0, errno, "argp_parse");
exitstatus = EX_OSERR;
goto fallback;
case EINVAL:
exitstatus = EX_USAGE;
goto fallback;
}
{
char *pluginhelperenv;
bool bret = true;
ret = asprintf(&pluginhelperenv, "MANDOSPLUGINHELPERDIR=%s",
pluginhelperdir != NULL ? pluginhelperdir : PHDIR);
if(ret != -1){
bret = add_environment(getplugin(NULL), pluginhelperenv, true);
}
if(ret == -1 or not bret){
error(0, errno, "Failed to set MANDOSPLUGINHELPERDIR"
" environment variable to \"%s\" for all plugins\n",
pluginhelperdir != NULL ? pluginhelperdir : PHDIR);
}
if(ret != -1){
free(pluginhelperenv);
}
}
if(debug){
for(plugin *p = plugin_list; p != NULL; p = p->next){
fprintf(stderr, "Plugin: %s has %d arguments\n",
p->name ? p->name : "Global", p->argc - 1);
for(char **a = p->argv; *a != NULL; a++){
fprintf(stderr, "\tArg: %s\n", *a);
}
fprintf(stderr, "...and %d environment variables\n", p->envc);
for(char **a = p->environ; *a != NULL; a++){
fprintf(stderr, "\t%s\n", *a);
}
}
}
if(getuid() == 0){
/* Work around Debian bug #633582:
<https://bugs.debian.org/633582> */
int plugindir_fd = open(/* plugindir or */ PDIR, O_RDONLY);
if(plugindir_fd == -1){
if(errno != ENOENT){
error(0, errno, "open(\"" PDIR "\")");
}
} else {
ret = (int)TEMP_FAILURE_RETRY(fstat(plugindir_fd, &st));
if(ret == -1){
error(0, errno, "fstat");
} else {
if(S_ISDIR(st.st_mode) and st.st_uid == 0 and st.st_gid == 0){
ret = fchown(plugindir_fd, uid, gid);
if(ret == -1){
error(0, errno, "fchown");
}
}
}
close(plugindir_fd);
}
}
/* Lower permissions */
ret = setgid(gid);
if(ret == -1){
error(0, errno, "setgid");
}
ret = setuid(uid);
if(ret == -1){
error(0, errno, "setuid");
}
/* Open plugin directory with close_on_exec flag */
{
dir_fd = open(plugindir != NULL ? plugindir : PDIR, O_RDONLY |
#ifdef O_CLOEXEC
O_CLOEXEC
#else /* not O_CLOEXEC */
0
#endif /* not O_CLOEXEC */
);
if(dir_fd == -1){
error(0, errno, "Could not open plugin dir");
exitstatus = EX_UNAVAILABLE;
goto fallback;
}
#ifndef O_CLOEXEC
/* Set the FD_CLOEXEC flag on the directory */
ret = set_cloexec_flag(dir_fd);
if(ret < 0){
error(0, errno, "set_cloexec_flag");
exitstatus = EX_OSERR;
goto fallback;
}
#endif /* O_CLOEXEC */
}
int good_name(const struct dirent * const dirent){
const char * const patterns[] = { ".*", "#*#", "*~", "*.dpkg-new",
"*.dpkg-old", "*.dpkg-bak",
"*.dpkg-divert", NULL };
#ifdef __GNUC__
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wcast-qual"
#endif
for(const char **pat = (const char **)patterns;
*pat != NULL; pat++){
#ifdef __GNUC__
#pragma GCC diagnostic pop
#endif
if(fnmatch(*pat, dirent->d_name, FNM_FILE_NAME | FNM_PERIOD)
!= FNM_NOMATCH){
if(debug){
fprintf(stderr, "Ignoring plugin dir entry \"%s\""
" matching pattern %s\n", dirent->d_name, *pat);
}
return 0;
}
}
return 1;
}
int numplugins = scandirat(dir_fd, ".", &direntries, good_name,
alphasort);
if(numplugins == -1){
error(0, errno, "Could not scan plugin dir");
direntries = NULL;
exitstatus = EX_OSERR;
goto fallback;
}
FD_ZERO(&rfds_all);
/* Read and execute any executable in the plugin directory*/
for(int i = 0; i < numplugins; i++){
int plugin_fd = openat(dir_fd, direntries[i]->d_name, O_RDONLY);
if(plugin_fd == -1){
error(0, errno, "Could not open plugin");
free(direntries[i]);
continue;
}
ret = (int)TEMP_FAILURE_RETRY(fstat(plugin_fd, &st));
if(ret == -1){
error(0, errno, "stat");
close(plugin_fd);
free(direntries[i]);
continue;
}
/* Ignore non-executable files */
if(not S_ISREG(st.st_mode)
or (TEMP_FAILURE_RETRY(faccessat(dir_fd, direntries[i]->d_name,
X_OK, 0)) != 0)){
if(debug){
fprintf(stderr, "Ignoring plugin dir entry \"%s/%s\""
" with bad type or mode\n",
plugindir != NULL ? plugindir : PDIR,
direntries[i]->d_name);
}
close(plugin_fd);
free(direntries[i]);
continue;
}
plugin *p = getplugin(direntries[i]->d_name);
if(p == NULL){
error(0, errno, "getplugin");
close(plugin_fd);
free(direntries[i]);
continue;
}
if(p->disabled){
if(debug){
fprintf(stderr, "Ignoring disabled plugin \"%s\"\n",
direntries[i]->d_name);
}
close(plugin_fd);
free(direntries[i]);
continue;
}
{
/* Add global arguments to argument list for this plugin */
plugin *g = getplugin(NULL);
if(g != NULL){
for(char **a = g->argv + 1; *a != NULL; a++){
if(not add_argument(p, *a)){
error(0, errno, "add_argument");
}
}
/* Add global environment variables */
for(char **e = g->environ; *e != NULL; e++){
if(not add_environment(p, *e, false)){
error(0, errno, "add_environment");
}
}
}
}
/* If this plugin has any environment variables, we need to
duplicate the environment from this process, too. */
if(p->environ[0] != NULL){
for(char **e = environ; *e != NULL; e++){
if(not add_environment(p, *e, false)){
error(0, errno, "add_environment");
}
}
}
int pipefd[2];
#ifndef O_CLOEXEC
ret = (int)TEMP_FAILURE_RETRY(pipe(pipefd));
#else /* O_CLOEXEC */
ret = (int)TEMP_FAILURE_RETRY(pipe2(pipefd, O_CLOEXEC));
#endif /* O_CLOEXEC */
if(ret == -1){
error(0, errno, "pipe");
exitstatus = EX_OSERR;
free(direntries[i]);
goto fallback;
}
if(pipefd[0] >= FD_SETSIZE){
fprintf(stderr, "pipe()[0] (%d) >= FD_SETSIZE (%d)", pipefd[0],
FD_SETSIZE);
close(pipefd[0]);
close(pipefd[1]);
exitstatus = EX_OSERR;
free(direntries[i]);
goto fallback;