handler.h File Reference

Decide how to display email content. More...

#include <iconv.h>
#include <stdbool.h>

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Functions
int	mutt_body_handler (struct Body *b, struct State *s)
	Handler for the Body of an email. More...
bool	mutt_can_decode (struct Body *b)
	Will decoding the attachment produce any output. More...
bool	mutt_prefer_as_attachment (struct Body *b)
	Do we want this part as an attachment? More...
void	mutt_decode_attachment (struct Body *b, struct State *s)
	Decode an email's attachment. More...
void	mutt_decode_base64 (struct State *s, size_t len, bool istext, iconv_t cd)
	Decode base64-encoded text. More...

Detailed Description

Decide how to display email content.

Authors

• Michael R. Elkins

Copyright

This program 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.

This program 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, see http://www.gnu.org/licenses/.

Definition in file handler.h.

Function Documentation

mutt_body_handler()

int mutt_body_handler	(	struct Body *	b,
		struct State *	s
	)

Handler for the Body of an email.

Parameters

b	Body of the email
s	State to work with

Return values

0	Success
-1	Error

Definition at line 1597 of file handler.c.

{
  if (!b || !s)
    return -1;
 
  bool plaintext = false;
  handler_t handler = NULL;
  handler_t encrypted_handler = NULL;
  int rc = 0;
  static unsigned short recurse_level = 0;
 
  const int oflags = s->flags;
  const bool is_attachment_display = (oflags & MUTT_DISPLAY_ATTACH);
 
  if (recurse_level >= MUTT_MIME_MAX_DEPTH)
  {
    mutt_debug(LL_DEBUG1, "recurse level too deep. giving up.\n");
    return 1;
  }
  recurse_level++;
 
  /* first determine which handler to use to process this part */
 
  if (is_autoview(b))
  {
    handler = autoview_handler;
    s->flags &= ~MUTT_CHARCONV;
  }
  else if (b->type == TYPE_TEXT)
  {
    if (mutt_istr_equal("plain", b->subtype))
    {
      const bool c_reflow_text = cs_subset_bool(NeoMutt->sub, "reflow_text");
      /* avoid copying this part twice since removing the transfer-encoding is
       * the only operation needed.  */
      if (((WithCrypto & APPLICATION_PGP) != 0) && mutt_is_application_pgp(b))
      {
        encrypted_handler = crypt_pgp_application_handler;
        handler = encrypted_handler;
      }
      else if (c_reflow_text &&
               mutt_istr_equal("flowed", mutt_param_get(&b->parameter, "format")))
      {
        handler = rfc3676_handler;
      }
      else
      {
        handler = text_plain_handler;
      }
    }
    else if (mutt_istr_equal("enriched", b->subtype))
      handler = text_enriched_handler;
    else /* text body type without a handler */
      plaintext = false;
  }
  else if (b->type == TYPE_MESSAGE)
  {
    if (mutt_is_message_type(b->type, b->subtype))
      handler = message_handler;
    else if (mutt_istr_equal("delivery-status", b->subtype))
      plaintext = true;
    else if (mutt_istr_equal("external-body", b->subtype))
      handler = external_body_handler;
  }
  else if (b->type == TYPE_MULTIPART)
  {
    const char *const c_show_multipart_alternative = cs_subset_string(NeoMutt->sub, "show_multipart_alternative");
    if (!mutt_str_equal("inline", c_show_multipart_alternative) &&
        mutt_istr_equal("alternative", b->subtype))
    {
      handler = alternative_handler;
    }
    else if (!mutt_str_equal("inline", c_show_multipart_alternative) &&
             mutt_istr_equal("multilingual", b->subtype))
    {
      handler = multilingual_handler;
    }
    else if ((WithCrypto != 0) && mutt_istr_equal("signed", b->subtype))
    {
      if (!mutt_param_get(&b->parameter, "protocol"))
        mutt_error(_("Error: multipart/signed has no protocol"));
      else if (s->flags & MUTT_VERIFY)
        handler = mutt_signed_handler;
    }
    else if (mutt_is_valid_multipart_pgp_encrypted(b))
    {
      encrypted_handler = valid_pgp_encrypted_handler;
      handler = encrypted_handler;
    }
    else if (mutt_is_malformed_multipart_pgp_encrypted(b))
    {
      encrypted_handler = malformed_pgp_encrypted_handler;
      handler = encrypted_handler;
    }
 
    if (!handler)
      handler = multipart_handler;
 
    if ((b->encoding != ENC_7BIT) && (b->encoding != ENC_8BIT) && (b->encoding != ENC_BINARY))
    {
      mutt_debug(LL_DEBUG1, "Bad encoding type %d for multipart entity, assuming 7 bit\n",
                 b->encoding);
      b->encoding = ENC_7BIT;
    }
  }
  else if ((WithCrypto != 0) && (b->type == TYPE_APPLICATION))
  {
    if (OptDontHandlePgpKeys && mutt_istr_equal("pgp-keys", b->subtype))
    {
      /* pass raw part through for key extraction */
      plaintext = true;
    }
    else if (((WithCrypto & APPLICATION_PGP) != 0) && mutt_is_application_pgp(b))
    {
      encrypted_handler = crypt_pgp_application_handler;
      handler = encrypted_handler;
    }
    else if (((WithCrypto & APPLICATION_SMIME) != 0) && mutt_is_application_smime(b))
    {
      encrypted_handler = crypt_smime_application_handler;
      handler = encrypted_handler;
    }
  }
 
  /* only respect disposition == attachment if we're not
   * displaying from the attachment menu (i.e. pager) */
  if ((plaintext || handler) && (is_attachment_display || !mutt_prefer_as_attachment(b)))
  {
    /* Prevent encrypted attachments from being included in replies
     * unless $include_encrypted is set. */
    const bool c_include_encrypted = cs_subset_bool(NeoMutt->sub, "include_encrypted");
    if ((s->flags & MUTT_REPLYING) && (s->flags & MUTT_FIRSTDONE) &&
        encrypted_handler && !c_include_encrypted)
    {
      goto cleanup;
    }
 
    rc = run_decode_and_handler(b, s, handler, plaintext);
  }
  /* print hint to use attachment menu for disposition == attachment
   * if we're not already being called from there */
  else if (s->flags & MUTT_DISPLAY)
  {
    const bool c_honor_disposition = cs_subset_bool(NeoMutt->sub, "honor_disposition");
    struct Buffer msg = mutt_buffer_make(256);
 
    if (!is_attachment_display)
    {
      char keystroke[128] = { 0 };
      if (km_expand_key(keystroke, sizeof(keystroke),
                        km_find_func(MENU_PAGER, OP_VIEW_ATTACHMENTS)))
      {
        if (c_honor_disposition && (b->disposition == DISP_ATTACH))
        {
          /* L10N: %s expands to a keystroke/key binding, e.g. 'v'.  */
          mutt_buffer_printf(&msg, _("[-- This is an attachment (use '%s' to view this part) --]\n"),
                             keystroke);
        }
        else
        {
          /* L10N: %s/%s is a MIME type, e.g. "text/plain".
             The last %s expands to a keystroke/key binding, e.g. 'v'. */
          mutt_buffer_printf(&msg, _("[-- %s/%s is unsupported (use '%s' to view this part) --]\n"),
                             TYPE(b), b->subtype, keystroke);
        }
      }
      else
      {
        if (c_honor_disposition && (b->disposition == DISP_ATTACH))
        {
          mutt_buffer_strcpy(&msg, _("[-- This is an attachment (need 'view-attachments' bound to key) --]\n"));
        }
        else
        {
          /* L10N: %s/%s is a MIME type, e.g. "text/plain". */
          mutt_buffer_printf(&msg, _("[-- %s/%s is unsupported (need 'view-attachments' bound to key) --]\n"),
                             TYPE(b), b->subtype);
        }
      }
    }
    else
    {
      if (c_honor_disposition && (b->disposition == DISP_ATTACH))
      {
        mutt_buffer_strcpy(&msg, _("[-- This is an attachment --]\n"));
      }
      else
      {
        /* L10N: %s/%s is a MIME type, e.g. "text/plain". */
        mutt_buffer_printf(&msg, _("[-- %s/%s is unsupported --]\n"), TYPE(b), b->subtype);
      }
    }
    state_mark_attach(s);
    state_printf(s, "%s", mutt_buffer_string(&msg));
    mutt_buffer_dealloc(&msg);
  }
 
cleanup:
  recurse_level--;
  s->flags = oflags | (s->flags & MUTT_FIRSTDONE);
  if (rc != 0)
  {
    mutt_debug(LL_DEBUG1, "Bailing on attachment of type %s/%s\n", TYPE(b),
               NONULL(b->subtype));
  }
 
  return rc;
}

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mutt_can_decode()

bool mutt_can_decode

(

struct Body *

b

)

Will decoding the attachment produce any output.

Parameters

b	Body of email to test

Return values

true	Decoding the attachment will produce output

Definition at line 1827 of file handler.c.

{
  if (is_autoview(b))
    return true;
  if (b->type == TYPE_TEXT)
    return true;
  if (b->type == TYPE_MESSAGE)
    return true;
  if (b->type == TYPE_MULTIPART)
  {
    if (WithCrypto)
    {
      if (mutt_istr_equal(b->subtype, "signed") || mutt_istr_equal(b->subtype, "encrypted"))
      {
        return true;
      }
    }
 
    for (struct Body *part = b->parts; part; part = part->next)
    {
      if (mutt_can_decode(part))
        return true;
    }
  }
  else if ((WithCrypto != 0) && (b->type == TYPE_APPLICATION))
  {
    if (((WithCrypto & APPLICATION_PGP) != 0) && mutt_is_application_pgp(b))
      return true;
    if (((WithCrypto & APPLICATION_SMIME) != 0) && mutt_is_application_smime(b))
      return true;
  }
 
  return false;
}

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mutt_prefer_as_attachment()

bool mutt_prefer_as_attachment

(

struct Body *

b

)

Do we want this part as an attachment?

Parameters

b	Body of email to test

Return values

true	We want this part as an attachment

Definition at line 1811 of file handler.c.

{
  if (!mutt_can_decode(b))
    return true;
 
  if (b->disposition != DISP_ATTACH)
    return false;
 
  return cs_subset_bool(NeoMutt->sub, "honor_disposition");
}

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mutt_decode_attachment()

void mutt_decode_attachment	(	struct Body *	b,
		struct State *	s
	)

Decode an email's attachment.

Parameters

b	Body of the email
s	State of text being processed

Definition at line 1867 of file handler.c.

{
  int istext = mutt_is_text_part(b) && (b->disposition == DISP_INLINE);
  iconv_t cd = (iconv_t) (-1);
 
  if (!mutt_file_seek(s->fp_in, b->offset, SEEK_SET))
  {
    return;
  }
 
  if (istext && (b->charset || (s->flags & MUTT_CHARCONV)))
  {
    const char *charset = b->charset;
    if (!charset)
    {
      const struct Slist *const c_assumed_charset = cs_subset_slist(NeoMutt->sub, "assumed_charset");
      charset = mutt_param_get(&b->parameter, "charset");
      if (!charset && c_assumed_charset)
        charset = mutt_ch_get_default_charset();
    }
    const char *const c_charset = cs_subset_string(NeoMutt->sub, "charset");
    if (charset && c_charset)
      cd = mutt_ch_iconv_open(c_charset, charset, MUTT_ICONV_HOOK_FROM);
  }
 
  switch (b->encoding)
  {
    case ENC_QUOTED_PRINTABLE:
      decode_quoted(s, b->length,
                    istext || (((WithCrypto & APPLICATION_PGP) != 0) &&
                               mutt_is_application_pgp(b)),
                    cd);
      break;
    case ENC_BASE64:
      mutt_decode_base64(s, b->length,
                         istext || (((WithCrypto & APPLICATION_PGP) != 0) &&
                                    mutt_is_application_pgp(b)),
                         cd);
      break;
    case ENC_UUENCODED:
      decode_uuencoded(s, b->length,
                       istext || (((WithCrypto & APPLICATION_PGP) != 0) &&
                                  mutt_is_application_pgp(b)),
                       cd);
      break;
    default:
      decode_xbit(s, b->length,
                  istext || (((WithCrypto & APPLICATION_PGP) != 0) &&
                             mutt_is_application_pgp(b)),
                  cd);
      break;
  }
 
  if (cd != (iconv_t) (-1))
    iconv_close(cd);
}

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mutt_decode_base64()

void mutt_decode_base64	(	struct State *	s,
		size_t	len,
		bool	istext,
		iconv_t	cd
	)

Decode base64-encoded text.

Parameters

s	State to work with
len	Length of text to decode
istext	Mime part is plain text
cd	Iconv conversion descriptor

Definition at line 1498 of file handler.c.

{
  char buf[5] = { 0 };
  int ch, i;
  bool cr = false;
  char bufi[BUFI_SIZE] = { 0 };
  size_t l = 0;
 
  buf[4] = '\0';
 
  if (istext)
    state_set_prefix(s);
 
  while (len > 0)
  {
    for (i = 0; (i < 4) && (len > 0); len--)
    {
      ch = fgetc(s->fp_in);
      if (ch == EOF)
        break;
      if ((ch >= 0) && (ch < 128) && ((base64val(ch) != -1) || (ch == '=')))
        buf[i++] = ch;
    }
    if (i != 4)
    {
      /* "i" may be zero if there is trailing whitespace, which is not an error */
      if (i != 0)
        mutt_debug(LL_DEBUG2, "didn't get a multiple of 4 chars\n");
      break;
    }
 
    const int c1 = base64val(buf[0]);
    const int c2 = base64val(buf[1]);
 
    /* first char */
    ch = (c1 << 2) | (c2 >> 4);
 
    if (cr && (ch != '\n'))
      bufi[l++] = '\r';
 
    cr = false;
 
    if (istext && (ch == '\r'))
      cr = true;
    else
      bufi[l++] = ch;
 
    /* second char */
    if (buf[2] == '=')
      break;
    const int c3 = base64val(buf[2]);
    ch = ((c2 & 0xf) << 4) | (c3 >> 2);
 
    if (cr && (ch != '\n'))
      bufi[l++] = '\r';
 
    cr = false;
 
    if (istext && (ch == '\r'))
      cr = true;
    else
      bufi[l++] = ch;
 
    /* third char */
    if (buf[3] == '=')
      break;
    const int c4 = base64val(buf[3]);
    ch = ((c3 & 0x3) << 6) | c4;
 
    if (cr && (ch != '\n'))
      bufi[l++] = '\r';
 
    cr = false;
 
    if (istext && (ch == '\r'))
      cr = true;
    else
      bufi[l++] = ch;
 
    if ((l + 8) >= sizeof(bufi))
      convert_to_state(cd, bufi, &l, s);
  }
 
  if (cr)
    bufi[l++] = '\r';
 
  convert_to_state(cd, bufi, &l, s);
  convert_to_state(cd, 0, 0, s);
 
  state_reset_prefix(s);
}

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