/mandos/release

To get this branch, use:
bzr branch http://bzr.recompile.se/loggerhead/mandos/release
237.1.2 by Teddy Hogeborn
Further steps towards a D-Bus server interface, plus minor syntax
1
/*  -*- coding: utf-8 -*- */
2
/*
237.2.24 by Teddy Hogeborn
* plugins.d/askpass-fifo.c: Fix name in header.
3
 * Splashy - Read a password from splashy and output it
237.1.2 by Teddy Hogeborn
Further steps towards a D-Bus server interface, plus minor syntax
4
 * 
237.2.9 by Teddy Hogeborn
* README: Update copyright year; add "2009".
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 * Copyright © 2008,2009 Teddy Hogeborn
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 * Copyright © 2008,2009 Björn Påhlsson
237.1.2 by Teddy Hogeborn
Further steps towards a D-Bus server interface, plus minor syntax
7
 * 
8
 * This program is free software: you can redistribute it and/or
9
 * modify it under the terms of the GNU General Public License as
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 * published by the Free Software Foundation, either version 3 of the
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 * License, or (at your option) any later version.
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 * 
13
 * This program is distributed in the hope that it will be useful, but
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 * WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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 * General Public License for more details.
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 * 
18
 * You should have received a copy of the GNU General Public License
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 * along with this program.  If not, see
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 * <http://www.gnu.org/licenses/>.
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 * 
22
 * Contact the authors at <https://www.fukt.bsnet.se/~belorn/> and
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 * <https://www.fukt.bsnet.se/~teddy/>.
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 */
25
205 by Teddy Hogeborn
* Makefile (PLUGINS, uninstall-client,
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#define _GNU_SOURCE		/* asprintf() */
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#include <signal.h>		/* sig_atomic_t, struct sigaction,
223 by Teddy Hogeborn
* .bzrignore (plugins.d/askpass-fifo): Added.
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				   sigemptyset(), sigaddset(), SIGINT,
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				   SIGHUP, SIGTERM, sigaction,
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				   SIG_IGN, kill(), SIGKILL */
205 by Teddy Hogeborn
* Makefile (PLUGINS, uninstall-client,
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#include <stddef.h>		/* NULL */
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#include <stdlib.h>		/* getenv() */
237.2.74 by Teddy Hogeborn
Overflows are not detected by sscanf(), so stop using it:
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#include <stdio.h>		/* asprintf(), perror() */
237.2.27 by Teddy Hogeborn
* plugin-runner.c (main): Use "sscanf" instead of "strtol"; using the
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#include <stdlib.h>		/* EXIT_FAILURE, free(),
223 by Teddy Hogeborn
* .bzrignore (plugins.d/askpass-fifo): Added.
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				   EXIT_SUCCESS */
205 by Teddy Hogeborn
* Makefile (PLUGINS, uninstall-client,
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#include <sys/types.h>		/* pid_t, DIR, struct dirent,
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				   ssize_t */
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#include <dirent.h>		/* opendir(), readdir(), closedir() */
237.2.74 by Teddy Hogeborn
Overflows are not detected by sscanf(), so stop using it:
39
#include <inttypes.h>		/* intmax_t, strtoimax() */
223 by Teddy Hogeborn
* .bzrignore (plugins.d/askpass-fifo): Added.
40
#include <sys/stat.h>		/* struct stat, lstat(), S_ISLNK */
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#include <iso646.h>		/* not, or, and */
205 by Teddy Hogeborn
* Makefile (PLUGINS, uninstall-client,
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#include <unistd.h>		/* readlink(), fork(), execl(),
223 by Teddy Hogeborn
* .bzrignore (plugins.d/askpass-fifo): Added.
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				   sleep(), dup2() STDERR_FILENO,
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				   STDOUT_FILENO, _exit() */
205 by Teddy Hogeborn
* Makefile (PLUGINS, uninstall-client,
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#include <string.h>		/* memcmp() */
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#include <errno.h>		/* errno */
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#include <sys/wait.h>		/* waitpid(), WIFEXITED(),
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				   WEXITSTATUS() */
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sig_atomic_t interrupted_by_signal = 0;
237.2.125 by Teddy Hogeborn
* plugin-runner.c (getplugin, add_environment, main): Handle EINTR
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int signal_received;
205 by Teddy Hogeborn
* Makefile (PLUGINS, uninstall-client,
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237.2.125 by Teddy Hogeborn
* plugin-runner.c (getplugin, add_environment, main): Handle EINTR
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static void termination_handler(int signum){
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  if(interrupted_by_signal){
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    return;
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  }
205 by Teddy Hogeborn
* Makefile (PLUGINS, uninstall-client,
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  interrupted_by_signal = 1;
237.2.125 by Teddy Hogeborn
* plugin-runner.c (getplugin, add_environment, main): Handle EINTR
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  signal_received = signum;
205 by Teddy Hogeborn
* Makefile (PLUGINS, uninstall-client,
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}
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208 by Teddy Hogeborn
* Makefile (PLUGINS): Added "plugins.d/usplash".
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int main(__attribute__((unused))int argc,
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	 __attribute__((unused))char **argv){
205 by Teddy Hogeborn
* Makefile (PLUGINS, uninstall-client,
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  int ret = 0;
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  /* Create prompt string */
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  char *prompt = NULL;
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  {
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    const char *const cryptsource = getenv("cryptsource");
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    const char *const crypttarget = getenv("crypttarget");
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    const char *const prompt_start = "getpass "
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      "Enter passphrase to unlock the disk";
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    if(cryptsource == NULL){
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      if(crypttarget == NULL){
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	ret = asprintf(&prompt, "%s: ", prompt_start);
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      } else {
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	ret = asprintf(&prompt, "%s (%s): ", prompt_start,
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		       crypttarget);
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      }
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    } else {
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      if(crypttarget == NULL){
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	ret = asprintf(&prompt, "%s %s: ", prompt_start, cryptsource);
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      } else {
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	ret = asprintf(&prompt, "%s %s (%s): ", prompt_start,
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		       cryptsource, crypttarget);
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      }
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    }
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    if(ret == -1){
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      return EXIT_FAILURE;
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    }
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  }
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93
  /* Find splashy process */
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  pid_t splashy_pid = 0;
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  {
96
    const char splashy_name[] = "/sbin/splashy";
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    DIR *proc_dir = opendir("/proc");
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    if(proc_dir == NULL){
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      free(prompt);
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      perror("opendir");
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      return EXIT_FAILURE;
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    }
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    for(struct dirent *proc_ent = readdir(proc_dir);
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	proc_ent != NULL;
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	proc_ent = readdir(proc_dir)){
237.2.27 by Teddy Hogeborn
* plugin-runner.c (main): Use "sscanf" instead of "strtol"; using the
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      pid_t pid;
237.2.31 by Teddy Hogeborn
Fixes for sscanf usage:
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      {
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	intmax_t tmpmax;
237.2.74 by Teddy Hogeborn
Overflows are not detected by sscanf(), so stop using it:
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	char *tmp;
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	errno = 0;
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	tmpmax = strtoimax(proc_ent->d_name, &tmp, 10);
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	if(errno != 0 or tmp == proc_ent->d_name or *tmp != '\0'
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	   or tmpmax != (pid_t)tmpmax){
237.2.31 by Teddy Hogeborn
Fixes for sscanf usage:
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	  /* Not a process */
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	  continue;
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	}
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	pid = (pid_t)tmpmax;
205 by Teddy Hogeborn
* Makefile (PLUGINS, uninstall-client,
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      }
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      /* Find the executable name by doing readlink() on the
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	 /proc/<pid>/exe link */
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      char exe_target[sizeof(splashy_name)];
208 by Teddy Hogeborn
* Makefile (PLUGINS): Added "plugins.d/usplash".
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      ssize_t sret;
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      {
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	char *exe_link;
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	ret = asprintf(&exe_link, "/proc/%s/exe", proc_ent->d_name);
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	if(ret == -1){
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	  perror("asprintf");
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	  free(prompt);
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	  closedir(proc_dir);
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	  return EXIT_FAILURE;
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	}
223 by Teddy Hogeborn
* .bzrignore (plugins.d/askpass-fifo): Added.
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133
	/* Check that it refers to a symlink owned by root:root */
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	struct stat exe_stat;
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	ret = lstat(exe_link, &exe_stat);
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	if(ret == -1){
237.2.25 by Teddy Hogeborn
* plugins.d/splashy.c (main): Do not abort if a process vanishes while
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	  if(errno == ENOENT){
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	    free(exe_link);
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	    continue;
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	  }
223 by Teddy Hogeborn
* .bzrignore (plugins.d/askpass-fifo): Added.
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	  perror("lstat");
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	  free(exe_link);
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	  free(prompt);
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	  closedir(proc_dir);
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	  return EXIT_FAILURE;
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	}
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	if(not S_ISLNK(exe_stat.st_mode)
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	   or exe_stat.st_uid != 0
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	   or exe_stat.st_gid != 0){
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	  free(exe_link);
151
	  continue;
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	}
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208 by Teddy Hogeborn
* Makefile (PLUGINS): Added "plugins.d/usplash".
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	sret = readlink(exe_link, exe_target, sizeof(exe_target));
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	free(exe_link);
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      }
205 by Teddy Hogeborn
* Makefile (PLUGINS, uninstall-client,
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      if((sret == ((ssize_t)sizeof(exe_target)-1))
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	 and (memcmp(splashy_name, exe_target,
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		     sizeof(exe_target)-1) == 0)){
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	splashy_pid = pid;
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	break;
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      }
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    }
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    closedir(proc_dir);
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  }
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  if(splashy_pid == 0){
167
    free(prompt);
168
    return EXIT_FAILURE;
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  }
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171
  /* Set up the signal handler */
172
  {
173
    struct sigaction old_action,
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      new_action = { .sa_handler = termination_handler,
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		     .sa_flags = 0 };
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    sigemptyset(&new_action.sa_mask);
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    sigaddset(&new_action.sa_mask, SIGINT);
237.2.125 by Teddy Hogeborn
* plugin-runner.c (getplugin, add_environment, main): Handle EINTR
178
    if(ret == -1){
179
      perror("sigaddset");
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      free(prompt);
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      return EXIT_FAILURE;
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    }
205 by Teddy Hogeborn
* Makefile (PLUGINS, uninstall-client,
183
    sigaddset(&new_action.sa_mask, SIGHUP);
237.2.125 by Teddy Hogeborn
* plugin-runner.c (getplugin, add_environment, main): Handle EINTR
184
    if(ret == -1){
185
      perror("sigaddset");
186
      free(prompt);
187
      return EXIT_FAILURE;
188
    }
205 by Teddy Hogeborn
* Makefile (PLUGINS, uninstall-client,
189
    sigaddset(&new_action.sa_mask, SIGTERM);
237.2.125 by Teddy Hogeborn
* plugin-runner.c (getplugin, add_environment, main): Handle EINTR
190
    if(ret == -1){
191
      perror("sigaddset");
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      free(prompt);
193
      return EXIT_FAILURE;
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    }
205 by Teddy Hogeborn
* Makefile (PLUGINS, uninstall-client,
195
    ret = sigaction(SIGINT, NULL, &old_action);
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    if(ret == -1){
197
      perror("sigaction");
198
      free(prompt);
199
      return EXIT_FAILURE;
200
    }
223 by Teddy Hogeborn
* .bzrignore (plugins.d/askpass-fifo): Added.
201
    if(old_action.sa_handler != SIG_IGN){
205 by Teddy Hogeborn
* Makefile (PLUGINS, uninstall-client,
202
      ret = sigaction(SIGINT, &new_action, NULL);
203
      if(ret == -1){
204
	perror("sigaction");
205
	free(prompt);
206
	return EXIT_FAILURE;
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      }
208
    }
209
    ret = sigaction(SIGHUP, NULL, &old_action);
210
    if(ret == -1){
211
      perror("sigaction");
212
      free(prompt);
213
      return EXIT_FAILURE;
214
    }
223 by Teddy Hogeborn
* .bzrignore (plugins.d/askpass-fifo): Added.
215
    if(old_action.sa_handler != SIG_IGN){
205 by Teddy Hogeborn
* Makefile (PLUGINS, uninstall-client,
216
      ret = sigaction(SIGHUP, &new_action, NULL);
217
      if(ret == -1){
218
	perror("sigaction");
219
	free(prompt);
220
	return EXIT_FAILURE;
221
      }
222
    }
223
    ret = sigaction(SIGTERM, NULL, &old_action);
224
    if(ret == -1){
225
      perror("sigaction");
226
      free(prompt);
227
      return EXIT_FAILURE;
228
    }
223 by Teddy Hogeborn
* .bzrignore (plugins.d/askpass-fifo): Added.
229
    if(old_action.sa_handler != SIG_IGN){
205 by Teddy Hogeborn
* Makefile (PLUGINS, uninstall-client,
230
      ret = sigaction(SIGTERM, &new_action, NULL);
231
      if(ret == -1){
232
	perror("sigaction");
233
	free(prompt);
234
	return EXIT_FAILURE;
235
      }
236
    }
237
  }
238
  
239
  /* Fork off the splashy command to prompt for password */
240
  pid_t splashy_command_pid = 0;
241
  if(not interrupted_by_signal){
242
    splashy_command_pid = fork();
243
    if(splashy_command_pid == -1){
244
      if(not interrupted_by_signal){
245
	perror("fork");
246
      }
247
      return EXIT_FAILURE;
248
    }
249
    /* Child */
250
    if(splashy_command_pid == 0){
251
      const char splashy_command[] = "/sbin/splashy_update";
252
      ret = execl(splashy_command, splashy_command, prompt,
253
		  (char *)NULL);
223 by Teddy Hogeborn
* .bzrignore (plugins.d/askpass-fifo): Added.
254
      if(not interrupted_by_signal){
205 by Teddy Hogeborn
* Makefile (PLUGINS, uninstall-client,
255
	perror("execl");
256
      }
257
      free(prompt);
223 by Teddy Hogeborn
* .bzrignore (plugins.d/askpass-fifo): Added.
258
      _exit(EXIT_FAILURE);
205 by Teddy Hogeborn
* Makefile (PLUGINS, uninstall-client,
259
    }
260
  }
261
  
262
  /* Parent */
263
  free(prompt);
264
  
265
  /* Wait for command to complete */
223 by Teddy Hogeborn
* .bzrignore (plugins.d/askpass-fifo): Added.
266
  if(not interrupted_by_signal and splashy_command_pid != 0){
267
    int status;
268
    ret = waitpid(splashy_command_pid, &status, 0);
269
    if(ret == -1){
270
      if(errno != EINTR){
271
	perror("waitpid");
272
      }
273
      if(errno == ECHILD){
274
	splashy_command_pid = 0;
275
      }
276
    } else {
277
      /* The child process has exited */
278
      splashy_command_pid = 0;
279
      if(not interrupted_by_signal and WIFEXITED(status)
280
	 and WEXITSTATUS(status)==0){
281
	return EXIT_SUCCESS;
282
      }
205 by Teddy Hogeborn
* Makefile (PLUGINS, uninstall-client,
283
    }
284
  }
285
  kill(splashy_pid, SIGTERM);
223 by Teddy Hogeborn
* .bzrignore (plugins.d/askpass-fifo): Added.
286
  if(interrupted_by_signal and splashy_command_pid != 0){
205 by Teddy Hogeborn
* Makefile (PLUGINS, uninstall-client,
287
    kill(splashy_command_pid, SIGTERM);
288
  }
223 by Teddy Hogeborn
* .bzrignore (plugins.d/askpass-fifo): Added.
289
  sleep(2);
290
  while(kill(splashy_pid, 0) == 0){
291
    kill(splashy_pid, SIGKILL);
292
    sleep(1);
293
  }
205 by Teddy Hogeborn
* Makefile (PLUGINS, uninstall-client,
294
  pid_t new_splashy_pid = fork();
295
  if(new_splashy_pid == 0){
207 by Teddy Hogeborn
* plugins.d/splashy.c (main): Bug fix: free "exe_link".
296
    /* Child; will become new splashy process */
223 by Teddy Hogeborn
* .bzrignore (plugins.d/askpass-fifo): Added.
297
    
298
    /* Make the effective user ID (root) the only user ID instead of
237.2.28 by Teddy Hogeborn
* plugin-runner.c (main): Bug fix; do not accept a "d" character after
299
       the real user ID (_mandos) */
223 by Teddy Hogeborn
* .bzrignore (plugins.d/askpass-fifo): Added.
300
    ret = setuid(geteuid());
301
    if(ret == -1){
302
      perror("setuid");
205 by Teddy Hogeborn
* Makefile (PLUGINS, uninstall-client,
303
    }
223 by Teddy Hogeborn
* .bzrignore (plugins.d/askpass-fifo): Added.
304
    
305
    setsid();
306
    ret = chdir("/");
307
/*     if(fork() != 0){ */
308
/*       _exit(EXIT_SUCCESS); */
309
/*     } */
205 by Teddy Hogeborn
* Makefile (PLUGINS, uninstall-client,
310
    ret = dup2(STDERR_FILENO, STDOUT_FILENO); /* replace our stdout */
311
    if(ret == -1){
312
      perror("dup2");
313
      _exit(EXIT_FAILURE);
314
    }
223 by Teddy Hogeborn
* .bzrignore (plugins.d/askpass-fifo): Added.
315
    
205 by Teddy Hogeborn
* Makefile (PLUGINS, uninstall-client,
316
    execl("/sbin/splashy", "/sbin/splashy", "boot", (char *)NULL);
223 by Teddy Hogeborn
* .bzrignore (plugins.d/askpass-fifo): Added.
317
    if(not interrupted_by_signal){
318
      perror("execl");
319
    }
320
    _exit(EXIT_FAILURE);
205 by Teddy Hogeborn
* Makefile (PLUGINS, uninstall-client,
321
  }
322
  
323
  return EXIT_FAILURE;
324
}