21
21
* Contact the authors at <mandos@fukt.bsnet.se>.
24
#include <stdio.h> /* popen(), fileno(), fprintf(),
25
stderr, STDOUT_FILENO */
24
#define _GNU_SOURCE /* TEMP_FAILURE_RETRY() */
26
#include <stddef.h> /* size_t, NULL */
27
#include <stdlib.h> /* malloc(), exit(), EXIT_FAILURE,
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EXIT_SUCCESS, realloc() */
29
#include <stdbool.h> /* bool, true, false */
30
#include <stdio.h> /* perror, popen(), fileno(),
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fprintf(), stderr, STDOUT_FILENO */
32
#include <sys/types.h> /* DIR, opendir(), stat(), struct
33
stat, waitpid(), WIFEXITED(),
34
WEXITSTATUS(), wait(), pid_t,
35
uid_t, gid_t, getuid(), getgid(),
37
#include <sys/select.h> /* fd_set, select(), FD_ZERO(),
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FD_SET(), FD_ISSET(), FD_CLR */
39
#include <sys/wait.h> /* wait(), waitpid(), WIFEXITED(),
41
#include <sys/stat.h> /* struct stat, stat(), S_ISREG() */
26
42
#include <iso646.h> /* and, or, not */
27
#include <sys/types.h> /* DIR, opendir(), stat(), struct stat,
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waitpid(), WIFEXITED(),
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WEXITSTATUS(), wait() */
30
#include <sys/wait.h> /* wait() */
31
43
#include <dirent.h> /* DIR, struct dirent, opendir(),
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readdir(), closedir() */
33
#include <sys/stat.h> /* struct stat, stat(), S_ISREG() */
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readdir(), closedir(), dirfd() */
34
45
#include <unistd.h> /* struct stat, stat(), S_ISREG(),
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#include <fcntl.h> /* fcntl() */
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#include <stddef.h> /* NULL */
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#include <stdlib.h> /* EXIT_FAILURE */
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#include <sys/select.h> /* fd_set, select(), FD_ZERO(),
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FD_SET(), FD_ISSET() */
41
#include <string.h> /* strlen(), strcpy(), strcat() */
42
#include <stdbool.h> /* true */
43
#include <sys/wait.h> /* waitpid(), WIFEXITED(),
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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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execv(), write(), read(),
52
#include <fcntl.h> /* fcntl(), F_GETFD, F_SETFD,
54
#include <string.h> /* strtok, strlen(), strcpy(),
45
56
#include <errno.h> /* errno */
46
#include <argp.h> /* struct argp_option,
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struct argp_state, struct argp,
57
#include <argp.h> /* struct argp_option, struct
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argp_state, struct argp,
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argp_parse(), ARGP_ERR_UNKNOWN,
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ARGP_KEY_END, ARGP_KEY_ARG, error_t */
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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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#include <errno.h> /* errno, EBADF */
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#define BUFFER_SIZE 256
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const char *argp_program_version = "plugin-runner 1.0";
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const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";
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131
p->argv[p->argc] = NULL;
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#define BUFFER_SIZE 256
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const char *argp_program_version =
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"plugbasedclient 0.9";
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const char *argp_program_bug_address =
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"<mandos@fukt.bsnet.se>";
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* Based on the example in the GNU LibC manual chapter 13.13 "File
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* *Note File Descriptor Flags:(libc)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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/* 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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process *process_list = NULL;
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/* Mark a process as completed when it exits, and save its exit
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void handle_sigchld(__attribute__((unused)) int sig){
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process *proc = process_list;
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pid_t pid = wait(&status);
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while(proc != NULL and proc->pid != pid){
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/* Process not found in process list */
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proc->status = status;
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proc->completed = true;
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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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188
int main(int argc, char *argv[]){
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const char *plugindir = "/conf/conf.d/mandos/plugins.d";
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const char *plugindir = "/lib/mandos/plugins.d";
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size_t d_name_len;
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struct dirent *dirst;
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int ret, maxfd = 0;
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process *process_list = NULL;
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198
bool debug = false;
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int exitstatus = EXIT_SUCCESS;
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struct sigaction old_sigchld_action;
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struct sigaction sigchld_action = { .sa_handler = handle_sigchld,
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.sa_flags = SA_NOCLDSTOP };
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char *plus_options = NULL;
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char **plus_argv = NULL;
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/* Establish a signal handler */
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sigemptyset(&sigchld_action.sa_mask);
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ret = sigaddset(&sigchld_action.sa_mask, SIGCHLD);
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ret = sigaction(SIGCHLD, &sigchld_action, &old_sigchld_action);
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/* The options we understand. */
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struct argp_option options[] = {
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302
plugin *plugin_list = NULL;
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struct argp argp = { .options = options, .parser = parse_opt,
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.args_doc = "[+PLUS_SEPARATED_OPTIONS]",
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.doc = "Mandos plugin runner -- Run plugins" };
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argp_parse (&argp, argc, argv, 0, 0, &plugin_list);
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ret = argp_parse (&argp, argc, argv, 0, 0, &plugin_list);
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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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/* This is a mangled argument in the form of
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"+--option+--other-option=parameter+--yet-another-option", etc */
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/* Make new argc and argv vars, and call argp_parse() again. */
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plus_options++; /* skip the first '+' character */
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const char delims[] = "+";
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plus_argv = malloc(sizeof(char*) * 2);
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if(plus_argv == NULL){
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exitstatus = EXIT_FAILURE;
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plus_argv[0] = argv[0];
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arg = strtok(plus_options, delims); /* Get first argument */
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plus_argv = realloc(plus_argv, sizeof(char *)
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* ((unsigned int) new_argc + 1));
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if(plus_argv == NULL){
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exitstatus = EXIT_FAILURE;
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plus_argv[new_argc-1] = arg;
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plus_argv[new_argc] = NULL;
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arg = strtok(NULL, delims); /* Get next argument */
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ret = argp_parse (&argp, new_argc, plus_argv, 0, 0, &plugin_list);
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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(plugin *p = plugin_list; p != NULL; p=p->next){
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fprintf(stderr, "Plugin: %s has %d arguments\n",
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p->name ? p->name : "Global", p->argc);
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p->name ? p->name : "Global", p->argc - 1);
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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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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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/* Set the FD_CLOEXEC flag on the directory */
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ret = fcntl (fd, F_GETFD, 0);
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perror("fcntl F_GETFD");
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ret = fcntl(fd, F_SETFD, FD_CLOEXEC | ret);
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perror("fcntl F_SETFD");
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fprintf(stderr, "Can not open directory\n");
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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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FD_ZERO(&rfds_all);
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char *filename = malloc(d_name_len + strlen(plugindir) + 2);
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if (filename == NULL){
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perror("malloc");
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exitstatus =EXIT_FAILURE;
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strcpy(filename, plugindir);
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strcat(filename, "/");
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strcat(filename, dirst->d_name);
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strcpy(filename, plugindir); /* Spurious warning */
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strcat(filename, "/"); /* Spurious warning */
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strcat(filename, dirst->d_name); /* Spurious warning */
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ret = stat(filename, &st);
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if (not S_ISREG(st.st_mode) or (access(filename, X_OK) != 0)){
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fprintf(stderr, "Ignoring plugin dir entry name \"%s\""
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fprintf(stderr, "Ignoring plugin dir entry \"%s\""
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" with bad type or mode\n", filename);
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if(getplugin(dirst->d_name, &plugin_list)->disabled){
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fprintf(stderr, "Ignoring disabled plugin \"%s\"",
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fprintf(stderr, "Ignoring disabled plugin \"%s\"\n",
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// Starting a new process to be watched
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plugin *p = getplugin(dirst->d_name, &plugin_list);
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/* Add global arguments to argument list for this plugin */
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plugin *g = getplugin(NULL, &plugin_list);
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for(char **a = g->argv + 1; *a != NULL; a++){
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ret = pipe(pipefd);
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exitstatus = EXIT_FAILURE;
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ret = set_cloexec_flag(pipefd[0]);
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perror("set_cloexec_flag");
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exitstatus = EXIT_FAILURE;
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ret = set_cloexec_flag(pipefd[1]);
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perror("set_cloexec_flag");
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exitstatus = EXIT_FAILURE;
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/* Block SIGCHLD until process is safely in process list */
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ret = sigprocmask (SIG_BLOCK, &sigchld_action.sa_mask, NULL);
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perror("sigprocmask");
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exitstatus = EXIT_FAILURE;
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// Starting a new process to be watched
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pid_t pid = fork();
525
exitstatus = EXIT_FAILURE;
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/* this is the child process */
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close(pipefd[0]); /* close unused read end of pipe */
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dup2(pipefd[1], STDOUT_FILENO); /* replace our stdout */
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ret = sigaction(SIGCHLD, &old_sigchld_action, NULL);
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ret = sigprocmask (SIG_UNBLOCK, &sigchld_action.sa_mask, NULL);
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perror("sigprocmask");
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ret = dup2(pipefd[1], STDOUT_FILENO); /* replace our stdout */
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plugin *p = getplugin(dirst->d_name, &plugin_list);
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plugin *g = getplugin(NULL, &plugin_list);
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for(char **a = g->argv + 1; *a != NULL; a++){
548
/* If dir has no file descriptor, we could not set FD_CLOEXEC
549
above and must now close it manually here. */
337
552
if(execv(filename, p->argv) < 0){
340
554
_exit(EXIT_FAILURE);
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560
close(pipefd[1]); /* close unused write end of pipe */
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561
process *new_process = malloc(sizeof(process));
346
562
if (new_process == NULL){
347
563
perror("malloc");
348
exitstatus = EXIT_FAILURE;
352
new_process->fd = pipefd[0];
353
new_process->buffer = malloc(BUFFER_SIZE);
354
if (new_process->buffer == NULL){
356
exitstatus = EXIT_FAILURE;
359
new_process->buffer_size = BUFFER_SIZE;
360
new_process->buffer_length = 0;
564
ret = sigprocmask (SIG_UNBLOCK, &sigchld_action.sa_mask, NULL);
566
perror("sigprocmask");
568
exitstatus = EXIT_FAILURE;
572
*new_process = (struct process){ .pid = pid,
574
.next = process_list };
576
process_list = new_process;
577
/* Unblock SIGCHLD so signal handler can be run if this process
578
has already completed */
579
ret = sigprocmask (SIG_UNBLOCK, &sigchld_action.sa_mask, NULL);
581
perror("sigprocmask");
582
exitstatus = EXIT_FAILURE;
361
586
FD_SET(new_process->fd, &rfds_all);
363
588
if (maxfd < new_process->fd){
364
589
maxfd = new_process->fd;
368
new_process->next = process_list;
369
process_list = new_process;
594
/* Free the plugin list */
595
for(plugin *next; plugin_list != NULL; plugin_list = next){
596
next = plugin_list->next;
597
free(plugin_list->argv);
374
if (process_list != NULL){
376
fd_set rfds = rfds_all;
377
int select_ret = select(maxfd+1, &rfds, NULL, NULL, NULL);
378
if (select_ret == -1){
382
for(process *process_itr = process_list; process_itr != NULL;
383
process_itr = process_itr->next){
384
if(FD_ISSET(process_itr->fd, &rfds)){
385
if(process_itr->buffer_length + BUFFER_SIZE
386
> process_itr->buffer_size){
387
process_itr->buffer = realloc(process_itr->buffer,
388
process_itr->buffer_size
389
+ (size_t) BUFFER_SIZE);
390
if (process_itr->buffer == NULL){
394
process_itr->buffer_size += BUFFER_SIZE;
396
ret = read(process_itr->fd, process_itr->buffer
397
+ process_itr->buffer_length, BUFFER_SIZE);
399
/* Read error from this process; ignore it */
402
process_itr->buffer_length += (size_t) ret;
405
/* wait for process exit */
407
waitpid(process_itr->pid, &status, 0);
408
if(WIFEXITED(status) and WEXITSTATUS(status) == 0){
409
for(size_t written = 0;
410
written < process_itr->buffer_length;){
411
ret = write(STDOUT_FILENO,
412
process_itr->buffer + written,
413
process_itr->buffer_length - written);
418
written += (size_t)ret;
422
FD_CLR(process_itr->fd, &rfds_all);
604
if (process_list == NULL){
605
fprintf(stderr, "No plugin processes started. Incorrect plugin"
610
fd_set rfds = rfds_all;
611
int select_ret = select(maxfd+1, &rfds, NULL, NULL, NULL);
612
if (select_ret == -1){
614
exitstatus = EXIT_FAILURE;
617
/* OK, now either a process completed, or something can be read
619
for(process *proc = process_list; proc ; proc = proc->next){
620
/* Is this process completely done? */
621
if(proc->eof and proc->completed){
622
/* Only accept the plugin output if it exited cleanly */
623
if(not WIFEXITED(proc->status)
624
or WEXITSTATUS(proc->status) != 0){
625
/* Bad exit by plugin */
627
if(WIFEXITED(proc->status)){
628
fprintf(stderr, "Plugin %u exited with status %d\n",
629
(unsigned int) (proc->pid),
630
WEXITSTATUS(proc->status));
631
} else if(WIFSIGNALED(proc->status)) {
632
fprintf(stderr, "Plugin %u killed by signal %d\n",
633
(unsigned int) (proc->pid),
634
WTERMSIG(proc->status));
635
} else if(WCOREDUMP(proc->status)){
636
fprintf(stderr, "Plugin %d dumped core\n",
637
(unsigned int) (proc->pid));
640
/* Remove the plugin */
641
FD_CLR(proc->fd, &rfds_all);
642
/* Block signal while modifying process_list */
643
ret = sigprocmask (SIG_BLOCK, &sigchld_action.sa_mask, NULL);
645
perror("sigprocmask");
646
exitstatus = EXIT_FAILURE;
649
/* Delete this process entry from the list */
650
if(process_list == proc){
651
/* First one - simple */
652
process_list = proc->next;
654
/* Second one or later */
655
for(process *p = process_list; p != NULL; p = p->next){
657
p->next = proc->next;
662
/* We are done modifying process list, so unblock signal */
663
ret = sigprocmask (SIG_UNBLOCK, &sigchld_action.sa_mask,
666
perror("sigprocmask");
670
/* We deleted this process from the list, so we can't go
671
proc->next. Therefore, start over from the beginning of
675
/* This process exited nicely, so print its buffer */
677
bool bret = print_out_password(proc->buffer, proc->buffer_length);
679
perror("print_out_password");
680
exitstatus = EXIT_FAILURE;
684
/* This process has not completed. Does it have any output? */
685
if(proc->eof or not FD_ISSET(proc->fd, &rfds)){
686
/* This process had nothing to say at this time */
689
/* Before reading, make the process' data buffer large enough */
690
if(proc->buffer_length + BUFFER_SIZE > proc->buffer_size){
691
proc->buffer = realloc(proc->buffer, proc->buffer_size
692
+ (size_t) BUFFER_SIZE);
693
if (proc->buffer == NULL){
695
exitstatus = EXIT_FAILURE;
698
proc->buffer_size += BUFFER_SIZE;
700
/* Read from the process */
701
ret = read(proc->fd, proc->buffer + proc->buffer_length,
704
/* Read error from this process; ignore the error */
711
proc->buffer_length += (size_t) ret;
432
for(process *process_itr = process_list; process_itr != NULL;
433
process_itr = process_itr->next){
434
close(process_itr->fd);
435
kill(process_itr->pid, SIGTERM);
436
free(process_itr->buffer);
719
if(process_list == NULL or exitstatus != EXIT_SUCCESS){
720
/* Fallback if all plugins failed, none are found or an error occured */
722
fprintf(stderr, "Going to fallback mode using getpass(3)\n");
723
char *passwordbuffer = getpass("Password: ");
724
bret = print_out_password(passwordbuffer, strlen(passwordbuffer));
726
perror("print_out_password");
727
exitstatus = EXIT_FAILURE;
732
/* Restore old signal handler */
733
sigaction(SIGCHLD, &old_sigchld_action, NULL);
737
/* Free the plugin list */
738
for(plugin *next; plugin_list != NULL; plugin_list = next){
739
next = plugin_list->next;
740
free(plugin_list->argv);
748
/* Free the process list and kill the processes */
749
for(process *next; process_list != NULL; process_list = next){
750
next = process_list->next;
751
close(process_list->fd);
752
ret = kill(process_list->pid, SIGTERM);
753
if(ret == -1 and errno != ESRCH){
754
/* set-uid proccesses migth not get closed */
757
free(process_list->buffer);
761
/* Wait for any remaining child processes to terminate */
449
769
return exitstatus;