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mirror of git://git.gnupg.org/gnupg.git synced 2024-11-04 20:38:50 +01:00
gnupg/g10/exec.c
David Shaw 3e6d5d7c77 More comments about when to use IDEA in keygen.c
When key signing with multiple keys at the same time, make sure each key
gets the sigclass prompt
Close the iobuf and FILE before trying to reap the child process to
encourage the child to exit
Disable cache-on-close of the fd iobuf (shouldn't all fd iobufs not be
cached?)
2002-01-27 05:56:35 +00:00

494 lines
10 KiB
C

/* exec.c - generic call-a-program code
* Copyright (C) 2001 Free Software Foundation, Inc.
*
* This file is part of GnuPG.
*
* GnuPG 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 2 of the License, or
* (at your option) any later version.
*
* GnuPG 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 this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
*/
#include <config.h>
#include <stdlib.h>
#include <stdarg.h>
#include <stdio.h>
#include <sys/stat.h>
#include <sys/types.h>
#ifndef EXEC_TEMPFILE_ONLY
#include <sys/wait.h>
#endif
#ifdef HAVE_DOSISH_SYSTEM
#include <windows.h>
#endif
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include "options.h"
#include "memory.h"
#include "i18n.h"
#include "iobuf.h"
#include "util.h"
#include "exec.h"
#ifndef HAVE_MKDTEMP
char *mkdtemp(char *template);
#endif
/* Makes a temp directory and filenames */
static int make_tempdir(struct exec_info *info)
{
char *tmp=opt.temp_dir;
/* Make up the temp dir and files in case we need them */
if(tmp==NULL)
{
tmp=getenv("TMPDIR");
if(tmp==NULL)
{
tmp=getenv("TMP");
if(tmp==NULL)
{
#ifdef __riscos__
tmp="<Wimp$ScrapDir>";
#elif defined (__MINGW32__) || defined (__CYGWIN32__)
tmp=m_alloc(256);
if(GetTempPath(256,tmp)==0)
strcpy(tmp,"c:\temp");
else
{
int len=strlen(tmp);
/* GetTempPath may return with \ on the end */
while(len>0 && tmp[len-1]=='\\')
{
tmp[len-1]='\0';
len--;
}
}
#else
tmp="/tmp";
#endif
}
}
}
info->tempdir=m_alloc(strlen(tmp)+1+10+1);
sprintf(info->tempdir,"%s" DIRSEP_S "gpg-XXXXXX",tmp);
#if defined (__MINGW32__) || defined (__CYGWIN32__)
m_free(tmp);
#endif
if(mkdtemp(info->tempdir)==NULL)
log_error(_("%s: can't create directory: %s\n"),
info->tempdir,strerror(errno));
else
{
info->madedir=1;
info->tempfile_in=m_alloc(strlen(info->tempdir)+1+10+1);
sprintf(info->tempfile_in,"%s" DIRSEP_S "datain" EXTSEP_S "%s",
info->tempdir,info->binary?"bin":"txt");
if(!info->writeonly)
{
info->tempfile_out=m_alloc(strlen(info->tempdir)+1+11+1);
sprintf(info->tempfile_out,"%s" DIRSEP_S "dataout" EXTSEP_S "%s",
info->tempdir,info->binary?"bin":"txt");
}
}
return info->madedir?0:G10ERR_GENERAL;
}
/* Expands %i and %o in the args to the full temp files within the
temp directory. */
static int expand_args(struct exec_info *info,const char *args_in)
{
const char *ch=args_in;
int size,len;
info->use_temp_files=0;
info->keep_temp_files=0;
size=100;
info->command=m_alloc(size);
len=0;
info->command[0]='\0';
while(*ch!='\0')
{
if(*ch=='%')
{
char *append=NULL;
ch++;
switch(*ch)
{
case 'O':
info->keep_temp_files=1;
/* fall through */
case 'o': /* out */
if(!info->madedir)
{
if(make_tempdir(info))
goto fail;
}
append=info->tempfile_out;
info->use_temp_files=1;
break;
case 'I':
info->keep_temp_files=1;
/* fall through */
case 'i': /* in */
if(!info->madedir)
{
if(make_tempdir(info))
goto fail;
}
append=info->tempfile_in;
info->use_temp_files=1;
break;
case '%':
append="%";
break;
}
if(append)
{
while(strlen(append)+len>size-1)
{
size+=100;
info->command=m_realloc(info->command,size);
}
strcat(info->command,append);
len+=strlen(append);
}
}
else
{
if(len==size-1) /* leave room for the \0 */
{
size+=100;
info->command=m_realloc(info->command,size);
}
info->command[len++]=*ch;
info->command[len]='\0';
}
ch++;
}
/* printf("args expanded to \"%s\"\n",info->command); */
return 0;
fail:
m_free(info->command);
info->command=NULL;
return G10ERR_GENERAL;
}
/* Either handles the tempfile creation, or the fork/exec. If it
returns ok, then info->tochild is a FILE * that can be written to.
The rules are: if there are no args, then it's a fork/exec/pipe.
If there are args, but no tempfiles, then it's a fork/exec/pipe via
shell -c. If there are tempfiles, then it's a system. */
int exec_write(struct exec_info **info,const char *program,
const char *args_in,int writeonly,int binary)
{
int ret=G10ERR_GENERAL;
if(opt.exec_disable && !opt.no_perm_warn)
{
log_info(_("external program calls are disabled due to unsafe "
"options file permissions\n"));
return ret;
}
#if defined(HAVE_GETUID) && defined(HAVE_GETEUID)
/* There should be no way to get to this spot while still carrying
setuid privs. Just in case, bomb out if we are. */
if(getuid()!=geteuid())
BUG();
#endif
if(program==NULL && args_in==NULL)
BUG();
*info=m_alloc_clear(sizeof(struct exec_info));
(*info)->binary=binary;
(*info)->writeonly=writeonly;
/* Expand the args, if any */
if(args_in && expand_args(*info,args_in))
goto fail;
#ifdef EXEC_TEMPFILE_ONLY
if(!(*info)->use_temp_files)
{
log_error(_("this platform requires temp files when calling external "
"programs\n"));
goto fail;
}
#else /* !EXEC_TEMPFILE_ONLY */
/* If there are no args, or there are args, but no temp files, we
can use fork/exec/pipe */
if(args_in==NULL || (*info)->use_temp_files==0)
{
int to[2],from[2];
if(pipe(to)==-1)
goto fail;
if(pipe(from)==-1)
{
close(to[0]);
close(to[1]);
goto fail;
}
if(((*info)->child=fork())==-1)
{
close(to[0]);
close(to[1]);
close(from[0]);
close(from[1]);
goto fail;
}
if((*info)->child==0)
{
char *shell=getenv("SHELL");
if(shell==NULL)
shell="/bin/sh";
/* I'm the child */
/* If the program isn't going to respond back, they get to
keep their stdout/stderr */
if(!(*info)->writeonly)
{
/* implied close of STDERR */
if(dup2(STDOUT_FILENO,STDERR_FILENO)==-1)
_exit(1);
/* implied close of STDOUT */
close(from[0]);
if(dup2(from[1],STDOUT_FILENO)==-1)
_exit(1);
}
/* implied close of STDIN */
close(to[1]);
if(dup2(to[0],STDIN_FILENO)==-1)
_exit(1);
if(args_in==NULL)
{
/* fprintf(stderr,"execing: %s\n",program); */
execlp(program,program,NULL);
}
else
{
/* fprintf(stderr,"execing: %s -c %s\n",shell,(*info)->command); */
execlp(shell,shell,"-c",(*info)->command,NULL);
}
/* If we get this far the exec failed. Clean up and return. */
log_error(_("unable to execute %s \"%s\": %s\n"),
args_in==NULL?"program":"shell",
args_in==NULL?program:shell,
strerror(errno));
if(errno==ENOENT)
_exit(127);
_exit(1);
}
/* I'm the parent */
close(to[0]);
(*info)->tochild=fdopen(to[1],binary?"wb":"w");
if((*info)->tochild==NULL)
{
close(to[1]);
ret=G10ERR_WRITE_FILE;
goto fail;
}
close(from[1]);
(*info)->fromchild=iobuf_fdopen(from[0],"r");
if((*info)->fromchild==NULL)
{
close(from[0]);
ret=G10ERR_READ_FILE;
goto fail;
}
/* fd iobufs are cached?! */
iobuf_ioctl((*info)->fromchild,3,1,NULL);
return 0;
}
#endif /* !EXEC_TEMPFILE_ONLY */
/* It's not fork/exec/pipe, so create a temp file */
(*info)->tochild=fopen((*info)->tempfile_in,binary?"wb":"w");
if((*info)->tochild==NULL)
{
log_error(_("%s: can't create: %s\n"),
(*info)->tempfile_in,strerror(errno));
ret=G10ERR_WRITE_FILE;
goto fail;
}
ret=0;
fail:
return ret;
}
int exec_read(struct exec_info *info)
{
int ret=G10ERR_GENERAL;
fclose(info->tochild);
info->tochild=NULL;
if(info->use_temp_files)
{
/* printf("system command is %s\n",info->command); */
info->progreturn=system(info->command);
if(info->progreturn==-1)
{
log_error(_("system error while calling external program: %s\n"),
strerror(errno));
info->progreturn=127;
goto fail;
}
else
{
#ifdef WEXITSTATUS
info->progreturn=WEXITSTATUS(info->progreturn);
#else
info->progreturn/=256;
#endif
}
/* 127 is the magic value returned from system() to indicate
that the shell could not be executed, or from /bin/sh to
indicate that the program could not be executed. */
if(info->progreturn==127)
{
log_error(_("unable to execute external program\n"));
goto fail;
}
if(!info->writeonly)
{
info->fromchild=iobuf_open(info->tempfile_out);
if(info->fromchild==NULL)
{
log_error(_("unable to read external program response: %s\n"),
strerror(errno));
ret=G10ERR_READ_FILE;
goto fail;
}
/* Do not cache this iobuf on close */
iobuf_ioctl(info->fromchild,3,1,NULL);
}
}
ret=0;
fail:
return ret;
}
int exec_finish(struct exec_info *info)
{
int ret=info->progreturn;
if(info->fromchild)
iobuf_close(info->fromchild);
if(info->tochild)
fclose(info->tochild);
#ifndef EXEC_TEMPFILE_ONLY
if(info->child>0)
{
if(waitpid(info->child,&info->progreturn,0)!=0 &&
WIFEXITED(info->progreturn))
ret=WEXITSTATUS(info->progreturn);
else
ret=127;
}
#endif
if(info->madedir && !info->keep_temp_files)
{
if(info->tempfile_in)
{
if(unlink(info->tempfile_in)==-1)
log_info(_("Warning: unable to remove tempfile (%s) \"%s\": %s\n"),
"in",info->tempfile_in,strerror(errno));
}
if(info->tempfile_out)
{
if(unlink(info->tempfile_out)==-1)
log_info(_("Warning: unable to remove tempfile (%s) \"%s\": %s\n"),
"out",info->tempfile_out,strerror(errno));
}
if(rmdir(info->tempdir)==-1)
log_info(_("Warning: unable to remove temp directory \"%s\": %s\n"),
info->tempdir,strerror(errno));
}
m_free(info->command);
m_free(info->tempdir);
m_free(info->tempfile_in);
m_free(info->tempfile_out);
m_free(info);
return ret;
}