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-rw-r--r--g10/exec.c443
1 files changed, 443 insertions, 0 deletions
diff --git a/g10/exec.c b/g10/exec.c
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index 000000000..1685cb6cb
--- /dev/null
+++ b/g10/exec.c
@@ -0,0 +1,443 @@
+/* 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>
+#include <sys/wait.h>
+#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)
+{
+ const 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>";
+#else
+ tmp="/tmp";
+#endif
+ }
+ }
+ }
+
+ info->tempdir=m_alloc(strlen(tmp)+1+10+1);
+
+ sprintf(info->tempdir,"%s" DIRSEP_S "gpg-XXXXXX",tmp);
+
+ 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");
+
+ 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
+ bash -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;
+ }
+
+ 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;
+ }
+
+ return 0;
+
+ fail:
+ exec_finish(*info);
+ 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));
+ goto fail;
+ }
+
+ info->progreturn=WEXITSTATUS(info->progreturn);
+
+ 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;
+ }
+ }
+ }
+
+ return 0;
+
+ fail:
+ exec_finish(info);
+ return ret;
+}
+
+int exec_finish(struct exec_info *info)
+{
+ int ret=info->progreturn;
+
+#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->fromchild)
+ iobuf_close(info->fromchild);
+
+ if(info->tochild)
+ fclose(info->tochild);
+
+ if(info->madedir && !info->keep_temp_files)
+ {
+ if(info->tempfile_in)
+ unlink(info->tempfile_in);
+
+ if(info->tempfile_out)
+ unlink(info->tempfile_out);
+
+ rmdir(info->tempdir);
+ }
+
+ m_free(info->command);
+ m_free(info->tempdir);
+ m_free(info->tempfile_in);
+ m_free(info->tempfile_out);
+ m_free(info);
+
+ return ret;
+}
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