path: root/camel/camel-mime-part-utils.c

/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8; fill-column: 160 -*- */
/* camel-mime-part-utils : Utility for mime parsing and so on
 *
 * Authors: Bertrand Guiheneuf <bertrand@helixcode.com>
 *      Michael Zucchi <notzed@ximian.com>
 *
 * Copyright 1999, 2000 Ximian, Inc. (www.ximian.com)
 *
 * 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, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
 * USA
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <stdio.h>
#include <string.h>
#include <unistd.h>

#include "string-utils.h"
#include "camel-mime-part-utils.h"
#include "camel-mime-message.h"
#include "camel-multipart.h"
#include "camel-seekable-substream.h"
#include "camel-stream-fs.h"
#include "camel-stream-filter.h"
#include "camel-stream-mem.h"
#include "camel-mime-filter-basic.h"
#include "camel-mime-filter-charset.h"
#include "camel-mime-filter-crlf.h"

#define d(x) /*(printf("%s(%d): ", __FILE__, __LINE__),(x))*/

static char *
extract_metatag_charset (GByteArray *buffer)
{
    /* example: <META http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> */
    const char *slashhead, *data;
    char *charset = NULL;
    
    data = buffer->data;
    
    slashhead = strstrcase (data, "</head");
    if (!slashhead)
        slashhead = data + buffer->len;
    
    /* Yea, this is ugly */
    while (data < slashhead) {
        struct _header_param *params;
        const char *meta, *metaend;
        const char *val;
        
        meta = strstrcase (data, "<meta");
        if (!meta)
            break;
        
        metaend = strchr (meta, '>');
        if (!metaend)
            metaend = slashhead;
        else
            metaend++;
        
        params = html_meta_param_list_decode (meta, metaend - meta);
        if (params) {
            val = header_param (params, "http-equiv");
            if (val && !g_strcasecmp (val, "Content-Type")) {
                struct _header_content_type *content_type;
                
                val = header_param (params, "content");
                content_type = header_content_type_decode (val);
                charset = g_strdup (header_content_type_param (content_type, "charset"));
                
                header_content_type_unref (content_type);
            }
            
            header_param_list_free (params);
            
            /* break as soon as we find a charset */
            if (charset)
                break;
        }
        
        data = metaend;
    }
    
    return charset;
}

/* simple data wrapper */
static void
simple_data_wrapper_construct_from_parser (CamelDataWrapper *dw, CamelMimeParser *mp)
{
    CamelMimeFilter *fdec = NULL, *fcrlf = NULL, *fch = NULL;
    int len, decid = -1, crlfid = -1, chrid = -1;
    struct _header_content_type *ct;
    CamelSeekableStream *seekable_source = NULL;
    CamelStream *source;
    GByteArray *buffer;
    off_t start = 0, end;
    char *encoding, *buf;
    
    d(printf("constructing data-wrapper\n"));
    
    /* Ok, try and be smart.  If we're storing a small message (typical) convert it,
       and store it in memory as we parse it ... if not, throw away the conversion
       and scan till the end ... */
    
    /* if we can't seek, dont have a stream/etc, then we must cache it */
    source = camel_mime_parser_stream (mp);
    if (source) {
        camel_object_ref ((CamelObject *)source);
        if (CAMEL_IS_SEEKABLE_STREAM (source)) {
            seekable_source = CAMEL_SEEKABLE_STREAM (source);
        }
    }
    
    /* first, work out conversion, if any, required, we dont care about what we dont know about */
    encoding = header_content_encoding_decode (camel_mime_parser_header (mp, "content-transfer-encoding", NULL));
    if (encoding) {
        if (!g_strcasecmp (encoding, "base64")) {
            d(printf("Adding base64 decoder ...\n"));
            fdec = (CamelMimeFilter *)camel_mime_filter_basic_new_type (CAMEL_MIME_FILTER_BASIC_BASE64_DEC);
            decid = camel_mime_parser_filter_add (mp, fdec);
        } else if (!strcasecmp(encoding, "quoted-printable")) {
            d(printf("Adding quoted-printable decoder ...\n"));
            fdec = (CamelMimeFilter *)camel_mime_filter_basic_new_type (CAMEL_MIME_FILTER_BASIC_QP_DEC);
            decid = camel_mime_parser_filter_add (mp, fdec);
        }
        g_free (encoding);
    }
    
    /* If we're doing text, we also need to do CRLF->LF and may have to convert it to UTF8 as well. */
    ct = camel_mime_parser_content_type (mp);
    if (header_content_type_is (ct, "text", "*")) {
        const char *charset = header_content_type_param (ct, "charset");
        char *acharset = NULL;  /* to be alloca'd on demand */
        
        if (fdec) {
            d(printf("Adding CRLF conversion filter\n"));
            fcrlf = (CamelMimeFilter *)camel_mime_filter_crlf_new (CAMEL_MIME_FILTER_CRLF_DECODE,
                                           CAMEL_MIME_FILTER_CRLF_MODE_CRLF_ONLY);
            crlfid = camel_mime_parser_filter_add (mp, fcrlf);
        }
        
        /* Possible Lame Mailer Alert... check the META tags for a charset */
        if (!charset && header_content_type_is (ct, "text", "html")) {
            GByteArray *bytes;
            const char *buf;
            off_t offset;
            int len;
            
            offset = camel_mime_parser_tell (mp);
            /* if we can't find the charset within the first 2k, we ain't gonna find it */
            len = camel_mime_parser_read (mp, &buf, 2048);
            camel_mime_parser_seek (mp, offset, SEEK_SET);
            
            /* we only do this because we need it to be null terminated */
            bytes = g_byte_array_new ();
            g_byte_array_append (bytes, buf, len);
            g_byte_array_append (bytes, "", 1);
            
            acharset = extract_metatag_charset (bytes);
            charset = acharset;
            g_byte_array_free (bytes, TRUE);
        }
        
        /* if the charset is not us-ascii or utf-8, then we need to convert to utf-8 */
        if (charset && !(g_strcasecmp (charset, "us-ascii") == 0 || g_strcasecmp (charset, "utf-8") == 0)) {
            d(printf("Adding conversion filter from %s to UTF-8\n", charset));
            fch = (CamelMimeFilter *)camel_mime_filter_charset_new_convert (charset, "UTF-8");
            if (fch) {
                chrid = camel_mime_parser_filter_add (mp, (CamelMimeFilter *)fch);
            } else {
                g_warning ("Cannot convert '%s' to 'UTF-8', message display may be corrupt", charset);
            }
        }
        
        g_free (acharset);
    }
    
    buffer = g_byte_array_new ();
    
    if (seekable_source /* !cache */) {
        start = camel_mime_parser_tell (mp) + seekable_source->bound_start;
    }
    
    while (camel_mime_parser_step (mp, &buf, &len) != HSCAN_BODY_END) {
        d(printf("appending o/p data: %d: %.*s\n", len, len, buf));
        if (buffer) {
            if (buffer->len > 20480 && seekable_source) {
                /* is this a 'big' message?  Yes?  We dont want to convert it all then. */
                camel_mime_parser_filter_remove (mp, decid);
                camel_mime_parser_filter_remove (mp, chrid);
                decid = -1;
                chrid = -1;
                g_byte_array_free (buffer, TRUE);
                buffer = NULL;
            } else {
                g_byte_array_append (buffer, buf, len);
            }
        }
    }
    
    if (buffer) {
        CamelStream *mem;
        
        d(printf("Small message part, kept in memory!\n"));
        
        mem = camel_stream_mem_new_with_byte_array (buffer);
        camel_data_wrapper_construct_from_stream (dw, mem);
        camel_object_unref ((CamelObject *)mem);
    } else {
        CamelStream *sub;
        CamelStreamFilter *filter;
        
        d(printf("Big message part, left on disk ...\n"));
        
        end = camel_mime_parser_tell (mp) + seekable_source->bound_start;
        sub = camel_seekable_substream_new_with_seekable_stream_and_bounds (seekable_source, start, end);
        if (fdec || fch) {
            filter = camel_stream_filter_new_with_stream (sub);
            if (fdec) {
                camel_mime_filter_reset (fdec);
                camel_stream_filter_add (filter, fdec);
            }
            if (fcrlf) {
                camel_mime_filter_reset (fcrlf);
                camel_stream_filter_add (filter, fcrlf);
            }
            if (fch) {
                camel_mime_filter_reset (fch);
                camel_stream_filter_add (filter, fch);
            }
            camel_data_wrapper_construct_from_stream (dw, (CamelStream *)filter);
            camel_object_unref ((CamelObject *)filter);
        } else {
            camel_data_wrapper_construct_from_stream (dw, sub);
        }
        camel_object_unref ((CamelObject *)sub);
    }
    
    camel_mime_parser_filter_remove (mp, decid);
    camel_mime_parser_filter_remove (mp, crlfid);
    camel_mime_parser_filter_remove (mp, chrid);
    
    if (fdec)
        camel_object_unref ((CamelObject *)fdec);
    if (fcrlf)
        camel_object_unref ((CamelObject *)fcrlf);
    if (fch)
        camel_object_unref ((CamelObject *)fch);
    if (source)
        camel_object_unref ((CamelObject *)source);
}

/* This replaces the data wrapper repository ... and/or could be replaced by it? */
void
camel_mime_part_construct_content_from_parser (CamelMimePart *dw, CamelMimeParser *mp)
{
    CamelDataWrapper *content = NULL;
    char *buf;
    int len;
    
    switch (camel_mime_parser_state (mp)) {
    case HSCAN_HEADER:
        d(printf("Creating body part\n"));
        content = camel_data_wrapper_new ();
        simple_data_wrapper_construct_from_parser (content, mp);
        break;
    case HSCAN_MESSAGE:
        d(printf("Creating message part\n"));
        content = (CamelDataWrapper *) camel_mime_message_new ();
        camel_mime_part_construct_from_parser ((CamelMimePart *)content, mp);
        break;
    case HSCAN_MULTIPART: {
        CamelDataWrapper *bodypart;
        
#ifndef NO_WARNINGS
#warning This should use a camel-mime-multipart
#endif
        d(printf("Creating multi-part\n"));
        content = (CamelDataWrapper *)camel_multipart_new ();
        
        /* FIXME: use the real boundary? */
        camel_multipart_set_boundary ((CamelMultipart *)content, NULL);
        while (camel_mime_parser_step (mp, &buf, &len) != HSCAN_MULTIPART_END) {
            camel_mime_parser_unstep (mp);
            bodypart = (CamelDataWrapper *)camel_mime_part_new ();
            camel_mime_part_construct_from_parser ((CamelMimePart *)bodypart, mp);
            camel_multipart_add_part ((CamelMultipart *)content, (CamelMimePart *)bodypart);
            camel_object_unref ((CamelObject *)bodypart);
        }
        
        /* these are only return valid data in the MULTIPART_END state */
        camel_multipart_set_preface ((CamelMultipart *)content, camel_mime_parser_preface (mp));
        camel_multipart_set_postface ((CamelMultipart *)content, camel_mime_parser_postface (mp));
        
        d(printf("Created multi-part\n"));
        break; }
    default:
        g_warning("Invalid state encountered???: %d", camel_mime_parser_state (mp));
    }
    if (content) {
#ifndef NO_WARNINGS
#warning there just has got to be a better way ... to transfer the mime-type to the datawrapper
#endif
        /* would you believe you have to set this BEFORE you set the content object???  oh my god !!!! */
        camel_data_wrapper_set_mime_type_field (content, 
                            camel_mime_part_get_content_type ((CamelMimePart *)dw));
        camel_medium_set_content_object ((CamelMedium *)dw, content);
        camel_object_unref ((CamelObject *)content);
    }
}