mail: new options to read attachments from file descriptors

* mail/mail.c (default_encoding,default_content_type)
(content_name,content_filename): New statics.
(cli_attach): Use the value of --content-name option as the
content-type name parameter.
The "-" argument instructs the program to read attachment from
stdin (eqv --attach-fd=0)
(cli_attach_fd): New function.
(mail_options): New options: --content-name, --content-filename,
--attach-fd
* mail/mail.h (send_attach_file_default): Remove.
(send_attach_file): New proto.
* mail/send.c (atchinfo): New fields: id, name, source.
(atchinfo_free): Update.
(default_encoding,default_content_type): Remove globals.
(send_attach_file): Rewrite.
(send_attach_file_default): Remove.
(escape_list_attachments): Print attachment identifier instead
of the file name, which can be NULL.
(saveatt): Use mu_attachment_create and mu_attachment_copy_from_stream.

* NEWS: Update.
* doc/texinfo/programs.texi: Document the new options.

-GNU mailutils NEWS -- history of user-visible changes. 2016-12-17
+GNU mailutils NEWS -- history of user-visible changes. 2017-01-13
 Copyright (C) 2002-2017 Free Software Foundation, Inc.
 See the end of file for copying conditions.
 
@@ -7,6 +7,54 @@ Please send mailutils bug reports to <bug-mailutils@gnu.org>.
 
 Version 3.1.90 (Git)
 
+* mail
+
+** Modifying attachment name and filename
+
+Two new options are provided for modifying attachment name (a.k.a
+description), and file name:
+
+  --content-name=STRING
+     Sets the attachment name (description).  Technically speaking, it
+     is the "name" parameter in the Content-Type MIME header.
+     
+  --content-filename=NAME
+     Sets the file name (the "filename" parameter in the
+     Content-Description MIME header of the outgoing message.
+
+Both options affect only the next `--attach' or `--attach-fd' option.
+
+* Constructing attachments from command line
+
+The new option `--attach-fd=N' instructs mail to read attachment from
+file descriptor N.  By default, the attachments created using this
+option are unnamed, i.e. neither name parameter of the Content-Type
+header, nor the filename parameter of the Content-Disposition header
+are set.  Use the --content-name and --content-filename options to
+change these.
+
+The option `--attach-fd=0' causes attachment to be read from the
+standard input.  The option `--attach=-' has the same effect.  For
+obvious reasons, the interactive mode is suppressed in this case.
+
+The `--attach-fd' option is useful when calling `mail' from another
+program.
+
+Example:
+
+Suppose that the 'mail' binary is opened at file descriptor 5 and
+the mail.c file is opened at descriptor 6, the following command
+line sends them as attachments:
+
+  mail --encoding=base64 \
+       --content-type=application/octet-stream \
+       --content-name="the mail(1) binary" --content-filename="mail" \
+       --attach-fd=5 \
+       --encoding=binary\
+       --content-type=text/plain --content-name="mail.c source file"\
+       --content-filename=mail.c --attach-fd=6 \
+       root@example.org
+
 
 Version 3.1.1 - 2016-12-15
 

@@ -2915,6 +2915,7 @@ Configuration Files}, for a detailed description of their format.
 * Invoking Mail::            Command Line Options.
 * Specifying Messages::      How to Specify Message Sets.
 * Composing Mail::           Composing Mail.
+* Attachments::              Attaching Files.
 * Reading Mail::             Reading Mail.
 * Scripting::                Scripting.
 * Mail Variables::           How to Alter the Behavior of @command{mail}.
@@ -2938,9 +2939,22 @@ mail sending mode, otherwise it operates in mail reading mode.
 @table @option
 @item -A @var{file}
 @itemx --attach=@var{file}
-Attach @var{file} to the composed message.  The encoding and content
-type are controlled by the @option{--encoding} and
-@option{--content-type} options, correspondingly.
+Attach @var{file} to the composed message.  The encoding, content
+type, and content description are controlled by the
+@option{--encoding}, @option{--content-type}, and
+@option{--content-name} options, correspondingly.
+
+The option @option{--attach=-} instructs @command{mail} to read the
+file to be attached from the standard input.  Interactive shell is
+disabled in this case.
+
+@item --attach-fd=@var{fd}
+Read attachment body from the file descriptor @var{fd}.  The
+descriptor must be open for reading.  This option is useful when
+calling @command{mail} from another program.
+
+See the options @option{--encoding}, @option{--content-type}, 
+@option{--content-name}, and @option{--content-filename}.
 
 @item -a @var{header}:@var{value}
 @itemx --append=@var{header}:@var{value}
@@ -2950,6 +2964,14 @@ Append the given header to the composed message.
 This options sets the content type to be used by all subsequent
 @option{--attach} options.
 
+@item --content-filename=@var{name}
+Set the @samp{filename} parameter in the @samp{Content-Disposition}
+header for the next @option{--attach-fd} option.
+
+@item --content-name=@var{text}
+Set the @samp{name} parameter (description) in the @samp{Content-Type}
+header for the next @option{--attach} or @option{--attach-fd} option.
+
 @item -E @var{command}
 @itemx --exec=@var{command}
 Execute @var{command} before opening the mailbox.  Any number of
@@ -3412,6 +3434,115 @@ the old contents of your message.
 
 @c *********************************************************************
 
+@node Attachments
+@subsection Sending Attachments
+
+The simplest way to attach a file from command line is by using the
+@option{--attach} (@option{-A}) option.  Its argument specifies the
+file to attach.  For example, the following will attach the content
+of the file @file{archive.tar}:
+
+@example
+$ mail --attach=archive.tar
+@end example
+
+By default, the content type will be set to
+@samp{application/octet-stream}, and the attachment will be encoded
+using the @samp{base64} encoding.  To change the content type, use the
+@option{--content-type} option.  For example, to send an HTML
+attachment:
+
+@example
+$ mail --content-type=text/html --attach=in.html
+@end example
+
+The @option{--content-type} option affects all @option{--attach}
+options that follow it.  To change the content type, simply add
+another @option{--content-type} option.  For example, to send both
+the HTML file and the archive:
+
+@example
+$ mail --content-type=text/html --attach=in.html \
+       --content-type=application/x-tar --attach=archive.tar
+@end example
+
+Similarly, the encoding to use is set up by the @option{--encoding}
+option.  As well as @option{--content-type}, this option affects all
+attachments supplied after it in the command line, until changed by
+the eventual next appearance of the same option.  Extending the above
+example:
+
+@example
+$ mail --content-type=text/html --encoding=quoted-printable \
+       --attach=in.html \
+       --content-type=application/x-tar --encoding=base64 \
+       --attach=archive.tar
+@end example
+
+Each attachment can also be assigned a @dfn{description} and a
+@dfn{file name}.  Normally, these are the same as the file name
+supplied with the @option{--attach} option.  However, you can change
+either or both of them using the @option{--content-name} and
+@option{--content-filename}, correspondingly.  Both of these options
+affect only the next @option{--attach} (or @option{--attach-fd}, see
+below) option.
+
+All the examples above will enter the usual interactive shell,
+allowing you to compose the body of the message.  If that's not
+needed, the non-interactive use can be forced by redirecting
+@file{/dev/null} to the standard input, e.g.:
+
+@example
+$ mail --attach=archive.tar < /dev/null
+@end example
+
+This will normally produce a message saying:
+
+@example
+mail: Null message body; hope that's ok
+@end example
+
+To suppress this message, unset the @samp{nullbodymsg} variable,
+as shown in the example below:
+
+@example
+$ mail -E 'set nonullbodymsg' --attach=archive.tar < /dev/null
+@end example
+
+The option @option{--attach=-} forces @command{mail} to read the file
+to be attached from the standard input stream.  This option implies
+disables the interactive mode and sets @samp{nonullbodymsg}
+implicitly, so that the above example can be rewritten as:
+
+@example
+$ mail --attach=- < archive.tar
+@end example
+
+Special option is provided to facilitate the use of @command{mail}
+in scripts.  The @option{--attach-fd=@var{N}} instructs the program to
+read the data to be attached from the file descriptor @var{N}.  The
+above example is equivalent to:
+
+@example
+$ mail --attach-fd=0 < archive.tar
+@end example
+
+Attachments created using this option have neither filename not
+description set, so normally the use of @option{--content-name} and/or
+@option{--content-filename} is advised.
+
+@example
+$ mail --subject 'mail(1)' \
+       --content-name="The mail(1) binary" --content-filename="mail" \
+       --attach-fd 5 \
+       --encoding=binary --content-type=text/plain \
+       --content-name="mail.c source file" --content-filename=mail.c \
+       --attach-fd 6 gray@@example.org 5</usr/bin/mail \
+       6<mailutils/mail/mail.c
+@end example
+
+@c *********************************************************************
+
 @node Reading Mail
 @subsection Reading Mail
 

@@ -35,6 +35,11 @@ const char *program_version = "mail (" PACKAGE_STRING ")";
 int hint;
 char *file;
 char *user;
+
+char *default_encoding;
+char *default_content_type;
+char *content_name;
+char *content_filename;
 
 static void
 cli_f_option (struct mu_parseopt *po, struct mu_option *opt, char const *arg)
@@ -134,9 +139,45 @@ cli_append (struct mu_parseopt *po, struct mu_option *opt, char const *arg)
 static void
 cli_attach (struct mu_parseopt *po, struct mu_option *opt, char const *arg)
 {
+  int fd = -1;
+  
   hint |= HINT_SEND_MODE;
-  if (send_attach_file_default (arg))
+  if (strcmp (arg, "-") == 0)
+    {
+      arg = NULL;
+      fd = 0;
+    }
+  if (send_attach_file (fd, arg, content_filename, content_name,
+			default_content_type, default_encoding))
     exit (1);
+
+  free (content_name);
+  content_name = NULL;
+  free (content_filename);
+  content_filename = NULL;
+}
+
+static void
+cli_attach_fd (struct mu_parseopt *po, struct mu_option *opt, char const *arg)
+{
+  int rc, fd;
+  
+  hint |= HINT_SEND_MODE;
+  rc = mu_str_to_c (arg, mu_c_int, &fd, NULL);
+  if (rc)
+    {
+      mu_parseopt_error (po, _("%s: bad descriptor"), arg);
+      exit (po->po_exit_error);
+    }
+  
+  if (send_attach_file (fd, NULL, content_filename, content_name,
+			default_content_type, default_encoding))
+    exit (1);
+
+  free (content_name);
+  content_name = NULL;
+  free (content_filename);
+  content_filename = NULL;
 }
 
 static struct mu_option mail_options[] = {
@@ -212,10 +253,21 @@ static struct mu_option mail_options[] = {
     N_("set content type for subsequent --attach options"),
     mu_c_string, &default_content_type },
   
+  { "content-name", 0, N_("NAME"), MU_OPTION_DEFAULT,
+    N_("set the Content-Type name parameter for the next --attach option"),
+    mu_c_string, &content_name },
+  { "content-filename", 0, N_("NAME"), MU_OPTION_DEFAULT,
+    N_("set the Content-Disposition filename parameter for the next --attach option"),
+    mu_c_string, &content_filename },
+  
   { "attach",  'A', N_("FILE"), MU_OPTION_DEFAULT,
     N_("attach FILE"),
     mu_c_string, NULL, cli_attach },
 
+  { "attach-fd",  0, N_("FD"), MU_OPTION_DEFAULT,
+    N_("attach from file descriptor FD"),
+    mu_c_string, NULL, cli_attach_fd },
+
   MU_OPTION_END
 }, *options[] = { mail_options, NULL };
 

@@ -258,7 +258,11 @@ extern char *mail_expand_name (const char *name);
 
 extern void send_append_header (char const *text);
 extern void send_append_header2 (char const *name, char const *value, int mode);
-extern int send_attach_file_default (const char *name);
+extern int send_attach_file (int fd,
+			     const char *filename,
+			     const char *content_filename,
+			     const char *content_name,
+			     const char *content_type, const char *encoding);
 
 extern int escape_check_args (int argc, char **argv, int minargs, int maxargs);
 

@@ -134,55 +134,97 @@ mail_sendheader (int argc, char **argv)
 /* Attachments */
 struct atchinfo
 {
+  char *id;
   char *encoding;
   char *content_type;
+  char *name;
   char *filename;
+  mu_stream_t source;
 };
 
 static mu_list_t attlist;
 
-char *default_encoding;
-char *default_content_type;
-
 static void
 atchinfo_free (void *p)
 {
   struct atchinfo *ap = p;
+  free (ap->id);
   free (ap->encoding);
   free (ap->content_type);
+  free (ap->name);
   free (ap->filename);
+  mu_stream_destroy (&ap->source);
   free (ap);
 }
 
 int
-send_attach_file (const char *name,
+send_attach_file (int fd,
+		  const char *realname,
+		  const char *content_filename, const char *content_name,
 		  const char *content_type, const char *encoding)
 {
   int rc;
   struct stat st;
   struct atchinfo *aptr;
   mu_list_t list;
-  
-  if (stat (name, &st))
+  mu_stream_t stream = NULL;
+  char *id = NULL;
+
+  if (fd >= 0)
     {
-      if (errno == ENOENT)
+      rc = mu_fd_stream_create (&stream, NULL, fd, MU_STREAM_READ);
+      if (rc)
 	{
-	  mu_error (_("%s: file does not exist"), name);
+	  mu_error (_("can't open descriptor %d: %s"), fd, mu_strerror (rc));
 	  return 1;
 	}
-      else
+      mu_asprintf (&id, "fd %d", fd);
+      if (fd == 0)
 	{
-	  mu_error (_("%s: cannot stat: %s"), name, mu_strerror (errno));
-	  return 1;
+	  mu_stream_destroy (&mu_strin);
+	  mu_nullstream_create (&mu_strin, MU_STREAM_READ);
+	  mu_stream_ioctl (mu_strin, MU_IOCTL_NULLSTREAM,
+			   MU_IOCTL_NULLSTREAM_SET_PATTERN, NULL);
+	  util_do_command ("set nullbody nullbodymsg");
 	}
     }
-
-  if (!S_ISREG (st.st_mode))
+  else if (realname)
     {
-      mu_error (_("%s: not a regular file"), name);
-      return 1;
-    }
+      if (!content_filename)
+	content_filename = realname;
+      if (stat (realname, &st))
+	{
+	  if (errno == ENOENT)
+	    {
+	      mu_error (_("%s: file does not exist"), realname);
+	      return 1;
+	    }
+	  else
+	    {
+	      mu_error (_("%s: cannot stat: %s"), realname,
+			mu_strerror (errno));
+	      return 1;
+	    }
+	}
+      
+      if (!S_ISREG (st.st_mode))
+	{
+	  mu_error (_("%s: not a regular file"), realname);
+	  return 1;
+	}
 
+      rc = mu_mapfile_stream_create (&stream, realname, MU_STREAM_READ);
+      if (rc)
+	{
+	  mu_error (_("can't open file %s: %s"),
+		    realname, mu_strerror (rc));
+	  return 1;
+	}
+      mu_asprintf (&id, "\"%s\"", realname);
+    }
+  else
+    abort ();
+  
   if (!encoding)
     encoding = "base64";
   mu_filter_get_list (&list);
@@ -190,6 +232,8 @@ send_attach_file (const char *name,
   if (rc)
     {
       mu_error (_("unsupported encoding: %s"), encoding);
+      free (id);
+      mu_stream_destroy (&stream);
       return 1;
     }
   
@@ -205,11 +249,13 @@ send_attach_file (const char *name,
     }
   aptr = mu_alloc (sizeof (*aptr));
 
+  aptr->id = id;
   aptr->encoding = mu_strdup (encoding);  
   aptr->content_type = mu_strdup (content_type ?
-				  content_type :
-				    "application/octet-stream");
-  aptr->filename = mu_strdup (name);
+				  content_type : "application/octet-stream");
+  aptr->name = content_name ? mu_strdup (content_name) : NULL;
+  aptr->filename = content_filename ? mu_strdup (content_filename) : NULL;
+  aptr->source = stream;
   rc = mu_list_append (attlist, aptr);
   if (rc)
     {
@@ -220,12 +266,6 @@ send_attach_file (const char *name,
 }
 
 int
-send_attach_file_default (const char *name)
-{
-  return send_attach_file (name, default_content_type, default_encoding);
-}
-
-int
 escape_list_attachments (int argc, char **argv, compose_env_t *env)
 {
   mu_iterator_t itr;
@@ -246,7 +286,7 @@ escape_list_attachments (int argc, char **argv, compose_env_t *env)
 	continue;
 	  
       mu_printf ("%3d %-12s %-30s %-s\n",
-		 i, aptr->filename, aptr->content_type, aptr->encoding);
+		 i, aptr->id, aptr->content_type, aptr->encoding);
     }
   mu_iterator_destroy (&itr);
 
@@ -266,7 +306,8 @@ escape_attach (int argc, char **argv, compose_env_t *env)
     case 3:
       content_type = argv[2];
     case 2:
-      return send_attach_file (argv[1], content_type, encoding);
+      return send_attach_file (-1, argv[1], argv[1], argv[1],
+			       content_type, encoding);
     default:
       return escape_check_args (argc, argv, 2, 4);
     }
@@ -309,12 +350,20 @@ saveatt (void *item, void *data)
   int rc;
   size_t nparts;
   char *p;
-  
-  rc = mu_message_create_attachment (aptr->content_type, aptr->encoding,
-				     aptr->filename, &part);
+
+  rc = mu_attachment_create (&part, aptr->content_type, aptr->encoding,
+			     aptr->name, aptr->filename);
+  if (rc)
+    {
+      mu_error (_("can't create attachment %s: %s"),
+		aptr->id, mu_strerror (rc));
+      return 1;
+    }
+
+  rc = mu_attachment_copy_from_stream (part, aptr->source, aptr->encoding);
   if (rc)
     {
-      mu_error (_("cannot attach \"%s\": %s"), aptr->filename,
+      mu_error (_("cannot attach %s: %s"), aptr->filename,
 		mu_strerror (rc));
       return 1;
     }