gpg: photoid: Move functions from exec.c.

* g10/exec.c (w32_system): Expose to public.
(exec_write, exec_read, exec_finish, make_tempdir, expand_args): Move
to photoid.c.
* g10/exec.h: Likewise.
* g10/photoid.c (exec_write, exec_read, exec_finish, make_tempdir)
(expand_args): Move here.

Signed-off-by: NIIBE Yutaka <[email protected]>

1 files changed, 546 insertions, 0 deletions

diff --git a/g10/photoid.c b/g10/photoid.c
index 6d7ef7cba..a68f43465 100644
--- a/g10/photoid.c
+++ b/g10/photoid.c
@@ -21,6 +21,7 @@
 #include <errno.h>
 #include <stdio.h>
 #include <string.h>
+#include <unistd.h>
 #ifdef _WIN32
 # ifdef HAVE_WINSOCK2_H
 #  include <winsock2.h>
@@ -295,6 +296,551 @@ get_default_photo_command(void)
 }
 #endif
 
+#ifndef DISABLE_PHOTO_VIEWER
+struct exec_info
+{
+  int progreturn;
+  struct
+  {
+    unsigned int binary:1;
+    unsigned int writeonly:1;
+    unsigned int madedir:1;
+    unsigned int use_temp_files:1;
+    unsigned int keep_temp_files:1;
+  } flags;
+  pid_t child;
+  FILE *tochild;
+  iobuf_t fromchild;
+  char *command,*name,*tempdir,*tempfile_in,*tempfile_out;
+};
+
+#ifdef NO_EXEC
+static int
+exec_write(struct exec_info **info,const char *program,
+	       const char *args_in,const char *name,int writeonly,int binary)
+{
+  log_error(_("no remote program execution supported\n"));
+  return GPG_ERR_GENERAL;
+}
+
+static int
+exec_read(struct exec_info *info) { return GPG_ERR_GENERAL; }
+
+static int
+exec_finish(struct exec_info *info) { return GPG_ERR_GENERAL; }
+
+#else /* ! NO_EXEC */
+#include <stdlib.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#ifndef EXEC_TEMPFILE_ONLY
+#include <sys/wait.h>
+#endif
+#include <fcntl.h>
+#include <errno.h>
+
+#include "../common/membuf.h"
+#include "../common/sysutils.h"
+
+/* Makes a temp directory and filenames */
+static int
+make_tempdir(struct exec_info *info)
+{
+  char *tmp=opt.temp_dir,*namein=info->name,*nameout;
+
+  if(!namein)
+    namein=info->flags.binary?"tempin" EXTSEP_S "bin":"tempin" EXTSEP_S "txt";
+
+  nameout=info->flags.binary?"tempout" EXTSEP_S "bin":"tempout" EXTSEP_S "txt";
+
+  /* Make up the temp dir and files in case we need them */
+
+  if(tmp==NULL)
+    {
+#if defined (_WIN32)
+      int err;
+
+      tmp=xmalloc(MAX_PATH+2);
+      err=GetTempPath(MAX_PATH+1,tmp);
+      if(err==0 || err>MAX_PATH+1)
+	strcpy(tmp,"c:\\windows\\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 /* More unixish systems */
+      tmp=getenv("TMPDIR");
+      if(tmp==NULL)
+	{
+	  tmp=getenv("TMP");
+	  if(tmp==NULL)
+	    {
+#ifdef __riscos__
+	      tmp="<Wimp$ScrapDir>.GnuPG";
+	      mkdir(tmp,0700); /* Error checks occur later on */
+#else
+	      tmp="/tmp";
+#endif
+	    }
+	}
+#endif
+    }
+
+  info->tempdir=xmalloc(strlen(tmp)+strlen(DIRSEP_S)+10+1);
+
+  sprintf(info->tempdir,"%s" DIRSEP_S "gpg-XXXXXX",tmp);
+
+#if defined (_WIN32)
+  xfree(tmp);
+#endif
+
+  if (!gnupg_mkdtemp(info->tempdir))
+    log_error(_("can't create directory '%s': %s\n"),
+	      info->tempdir,strerror(errno));
+  else
+    {
+      info->flags.madedir=1;
+
+      info->tempfile_in=xmalloc(strlen(info->tempdir)+
+				strlen(DIRSEP_S)+strlen(namein)+1);
+      sprintf(info->tempfile_in,"%s" DIRSEP_S "%s",info->tempdir,namein);
+
+      if(!info->flags.writeonly)
+	{
+	  info->tempfile_out=xmalloc(strlen(info->tempdir)+
+				     strlen(DIRSEP_S)+strlen(nameout)+1);
+	  sprintf(info->tempfile_out,"%s" DIRSEP_S "%s",info->tempdir,nameout);
+	}
+    }
+
+  return info->flags.madedir? 0 : GPG_ERR_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;
+  membuf_t command;
+
+  info->flags.use_temp_files=0;
+  info->flags.keep_temp_files=0;
+
+  if(DBG_EXTPROG)
+    log_debug("expanding string \"%s\"\n",args_in);
+
+  init_membuf (&command, 100);
+
+  while(*ch!='\0')
+    {
+      if(*ch=='%')
+	{
+	  char *append=NULL;
+
+	  ch++;
+
+	  switch(*ch)
+	    {
+	    case 'O':
+	      info->flags.keep_temp_files=1;
+	      /* fall through */
+
+	    case 'o': /* out */
+	      if(!info->flags.madedir)
+		{
+		  if(make_tempdir(info))
+		    goto fail;
+		}
+	      append=info->tempfile_out;
+	      info->flags.use_temp_files=1;
+	      break;
+
+	    case 'I':
+	      info->flags.keep_temp_files=1;
+	      /* fall through */
+
+	    case 'i': /* in */
+	      if(!info->flags.madedir)
+		{
+		  if(make_tempdir(info))
+		    goto fail;
+		}
+	      append=info->tempfile_in;
+	      info->flags.use_temp_files=1;
+	      break;
+
+	    case '%':
+	      append="%";
+	      break;
+	    }
+
+	  if(append)
+            put_membuf_str (&command, append);
+	}
+      else
+        put_membuf (&command, ch, 1);
+
+      ch++;
+    }
+
+  put_membuf (&command, "", 1);  /* Terminate string.  */
+
+  info->command = get_membuf (&command, NULL);
+  if (!info->command)
+    return gpg_error_from_syserror ();
+
+  if(DBG_EXTPROG)
+    log_debug("args expanded to \"%s\", use %u, keep %u\n",info->command,
+	      info->flags.use_temp_files,info->flags.keep_temp_files);
+
+  return 0;
+
+ fail:
+  xfree (get_membuf (&command, NULL));
+  return GPG_ERR_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. */
+
+static int
+exec_write(struct exec_info **info,const char *program,
+           const char *args_in,const char *name,int writeonly,int binary)
+{
+  int ret = GPG_ERR_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=xmalloc_clear(sizeof(struct exec_info));
+
+  if(name)
+    (*info)->name=xstrdup(name);
+  (*info)->flags.binary=binary;
+  (*info)->flags.writeonly=writeonly;
+
+  /* Expand the args, if any */
+  if(args_in && expand_args(*info,args_in))
+    goto fail;
+
+#ifdef EXEC_TEMPFILE_ONLY
+  if(!(*info)->flags.use_temp_files)
+    {
+      log_error(_("this platform requires temporary 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)->flags.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)->flags.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)
+	    {
+	      if(DBG_EXTPROG)
+		log_debug("execlp: %s\n",program);
+
+	      execlp(program,program,(void *)NULL);
+	    }
+	  else
+	    {
+	      if(DBG_EXTPROG)
+		log_debug("execlp: %s -c %s\n",shell,(*info)->command);
+
+	      execlp(shell,shell,"-c",(*info)->command,(void *)NULL);
+	    }
+
+	  /* If we get this far the exec failed.  Clean up and return. */
+
+	  if(args_in==NULL)
+	    log_error(_("unable to execute program '%s': %s\n"),
+		      program,strerror(errno));
+	  else
+	    log_error(_("unable to execute shell '%s': %s\n"),
+		      shell,strerror(errno));
+
+	  /* This mimics the POSIX sh behavior - 127 means "not found"
+             from the shell. */
+	  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)
+	{
+          ret = gpg_error_from_syserror ();
+	  close(to[1]);
+	  goto fail;
+	}
+
+      close(from[1]);
+
+      (*info)->fromchild=iobuf_fdopen(from[0],"r");
+      if((*info)->fromchild==NULL)
+	{
+          ret = gpg_error_from_syserror ();
+	  close(from[0]);
+	  goto fail;
+	}
+
+      /* fd iobufs are cached! */
+      iobuf_ioctl((*info)->fromchild, IOBUF_IOCTL_NO_CACHE, 1, NULL);
+
+      return 0;
+    }
+#endif /* !EXEC_TEMPFILE_ONLY */
+
+  if(DBG_EXTPROG)
+    log_debug("using temp file '%s'\n",(*info)->tempfile_in);
+
+  /* It's not fork/exec/pipe, so create a temp file */
+  if( is_secured_filename ((*info)->tempfile_in) )
+    {
+      (*info)->tochild = NULL;
+      gpg_err_set_errno (EPERM);
+    }
+  else
+    (*info)->tochild=fopen((*info)->tempfile_in,binary?"wb":"w");
+  if((*info)->tochild==NULL)
+    {
+      ret = gpg_error_from_syserror ();
+      log_error(_("can't create '%s': %s\n"),
+		(*info)->tempfile_in,strerror(errno));
+      goto fail;
+    }
+
+  ret=0;
+
+ fail:
+  if (ret)
+    {
+      xfree (*info);
+      *info = NULL;
+    }
+  return ret;
+}
+
+static int
+exec_read(struct exec_info *info)
+{
+  int ret = GPG_ERR_GENERAL;
+
+  fclose(info->tochild);
+  info->tochild=NULL;
+
+  if(info->flags.use_temp_files)
+    {
+      if(DBG_EXTPROG)
+	log_debug ("running command: %s\n",info->command);
+
+#if defined (_WIN32)
+      info->progreturn=w32_system(info->command);
+#else
+      info->progreturn=system(info->command);
+#endif
+
+      if(info->progreturn==-1)
+	{
+	  log_error(_("system error while calling external program: %s\n"),
+		    strerror(errno));
+	  info->progreturn=127;
+	  goto fail;
+	}
+
+#if defined(WIFEXITED) && defined(WEXITSTATUS)
+      if(WIFEXITED(info->progreturn))
+	info->progreturn=WEXITSTATUS(info->progreturn);
+      else
+	{
+	  log_error(_("unnatural exit of external program\n"));
+	  info->progreturn=127;
+	  goto fail;
+	}
+#else
+      /* If we don't have the macros, do the best we can. */
+      info->progreturn = (info->progreturn & 0xff00) >> 8;
+#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->flags.writeonly)
+	{
+	  info->fromchild=iobuf_open(info->tempfile_out);
+          if (info->fromchild
+              && is_secured_file (iobuf_get_fd (info->fromchild)))
+            {
+              iobuf_close (info->fromchild);
+              info->fromchild = NULL;
+              gpg_err_set_errno (EPERM);
+            }
+	  if(info->fromchild==NULL)
+	    {
+              ret = gpg_error_from_syserror ();
+	      log_error(_("unable to read external program response: %s\n"),
+			strerror(errno));
+	      goto fail;
+	    }
+
+	  /* Do not cache this iobuf on close */
+	  iobuf_ioctl(info->fromchild, IOBUF_IOCTL_NO_CACHE, 1, NULL);
+	}
+    }
+
+  ret=0;
+
+ fail:
+  return ret;
+}
+
+static 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
+	{
+	  log_error(_("unnatural exit of external program\n"));
+	  ret=127;
+	}
+    }
+#endif
+
+  if(info->flags.madedir && !info->flags.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));
+    }
+
+  xfree(info->command);
+  xfree(info->name);
+  xfree(info->tempdir);
+  xfree(info->tempfile_in);
+  xfree(info->tempfile_out);
+  xfree(info);
+
+  return ret;
+}
+#endif
+#endif
+
 
 void
 show_photos (ctrl_t ctrl, const struct user_attribute *attrs, int count,