path: root/mail/em-inline-filter.c

/*
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) version 3.
 *
 * 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with the program; if not, see <http://www.gnu.org/licenses/>  
 *
 *
 * Authors:
 *      Michael Zucchi <notzed@ximian.com>
 *
 * Copyright (C) 1999-2008 Novell, Inc. (www.novell.com)
 *
 */

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

#include <string.h>

#include "em-inline-filter.h"
#include <camel/camel-mime-part.h>
#include <camel/camel-multipart.h>
#include <camel/camel-stream-mem.h>

#include "em-utils.h"
#include "em-format/em-format.h"

#define d(x)

static void em_inline_filter_class_init (EMInlineFilterClass *klass);
static void em_inline_filter_init (CamelObject *object);
static void em_inline_filter_finalize (CamelObject *object);

static void emif_filter(CamelMimeFilter *f, char *in, size_t len, size_t prespace, char **out, size_t *outlen, size_t *outprespace);
static void emif_complete(CamelMimeFilter *f, char *in, size_t len, size_t prespace, char **out, size_t *outlen, size_t *outprespace);
static void emif_reset(CamelMimeFilter *f);

static CamelMimeFilterClass *parent_class = NULL;

CamelType
em_inline_filter_get_type (void)
{
    static CamelType type = CAMEL_INVALID_TYPE;

    if (type == CAMEL_INVALID_TYPE) {
        parent_class = (CamelMimeFilterClass *)camel_mime_filter_get_type();

        type = camel_type_register(camel_mime_filter_get_type(),
                       "EMInlineFilter",
                       sizeof (EMInlineFilter),
                       sizeof (EMInlineFilterClass),
                       (CamelObjectClassInitFunc) em_inline_filter_class_init,
                       NULL,
                       (CamelObjectInitFunc) em_inline_filter_init,
                       (CamelObjectFinalizeFunc) em_inline_filter_finalize);
    }

    return type;
}

static void
em_inline_filter_class_init (EMInlineFilterClass *klass)
{
    ((CamelMimeFilterClass *)klass)->filter = emif_filter;
    ((CamelMimeFilterClass *)klass)->complete = emif_complete;
    ((CamelMimeFilterClass *)klass)->reset = emif_reset;
}

static void
em_inline_filter_init (CamelObject *object)
{
    EMInlineFilter *emif = (EMInlineFilter *)object;

    emif->data = g_byte_array_new();
}


static void
em_inline_filter_finalize (CamelObject *object)
{
    EMInlineFilter *emif = (EMInlineFilter *)object;

    if (emif->base_type)
        camel_content_type_unref(emif->base_type);

    emif_reset((CamelMimeFilter *)emif);
    g_byte_array_free(emif->data, TRUE);
    g_free(emif->filename);
}

enum {
    EMIF_PLAIN,
    EMIF_UUENC,
    EMIF_BINHEX,
    EMIF_POSTSCRIPT,
    EMIF_PGPSIGNED,
    EMIF_PGPENCRYPTED
};

static const struct {
    const char *type;
    const char *subtype;
    CamelTransferEncoding encoding;
    guint plain:1;
} emif_types[] = {
    { "text",        "plain",                 CAMEL_TRANSFER_ENCODING_DEFAULT,  1, },
    { "application", "octet-stream",          CAMEL_TRANSFER_ENCODING_UUENCODE, 0, },
    { "application", "mac-binhex40",          CAMEL_TRANSFER_ENCODING_7BIT,     0, },
    { "application", "postscript",            CAMEL_TRANSFER_ENCODING_7BIT,     0, },
    { "application", "x-inlinepgp-signed",    CAMEL_TRANSFER_ENCODING_DEFAULT,  0, },
    { "application", "x-inlinepgp-encrypted", CAMEL_TRANSFER_ENCODING_DEFAULT,  0, },
};

static void
emif_add_part(EMInlineFilter *emif, const char *data, int len)
{
    CamelTransferEncoding encoding;
    CamelContentType *content_type;
    CamelDataWrapper *dw;
    const char *mimetype;
    CamelMimePart *part;
    CamelStream *mem;
    char *type;

    if (emif->state == EMIF_PLAIN || emif->state == EMIF_PGPSIGNED || emif->state == EMIF_PGPENCRYPTED)
        encoding = emif->base_encoding;
    else
        encoding = emif_types[emif->state].encoding;

    g_byte_array_append(emif->data, (unsigned char *)data, len);
    /* check the part will actually have content */
    if (emif->data->len <= 0) {
        return;
    }
    mem = camel_stream_mem_new_with_byte_array(emif->data);
    emif->data = g_byte_array_new();

    dw = camel_data_wrapper_new();
    camel_data_wrapper_construct_from_stream(dw, mem);
    camel_object_unref(mem);

    if (emif_types[emif->state].plain && emif->base_type) {
        camel_content_type_ref (emif->base_type);
        content_type = emif->base_type;
    } else {
        /* we want to preserve all params */
        type = camel_content_type_format (emif->base_type);
        content_type = camel_content_type_decode (type);
        g_free (type);

        g_free (content_type->type);
        g_free (content_type->subtype);
        content_type->type = g_strdup (emif_types[emif->state].type);
        content_type->subtype = g_strdup (emif_types[emif->state].subtype);
    }

    camel_data_wrapper_set_mime_type_field (dw, content_type);
    camel_content_type_unref (content_type);
    dw->encoding = encoding;

    part = camel_mime_part_new();
    camel_medium_set_content_object((CamelMedium *)part, dw);
    camel_mime_part_set_encoding(part, encoding);
    camel_object_unref(dw);

    if (emif->filename)
        camel_mime_part_set_filename(part, emif->filename);

    /* pre-snoop the mime type of unknown objects, and poke and hack it into place */
    if (camel_content_type_is(dw->mime_type, "application", "octet-stream")
        && (mimetype = em_format_snoop_type(part))
        && strcmp(mimetype, "application/octet-stream") != 0) {
        camel_data_wrapper_set_mime_type(dw, mimetype);
        camel_mime_part_set_content_type(part, mimetype);
        if (emif->filename)
            camel_mime_part_set_filename(part, emif->filename);
    }

    g_free(emif->filename);
    emif->filename = NULL;

    emif->parts = g_slist_append(emif->parts, part);
}

static int
emif_scan(CamelMimeFilter *f, char *in, size_t len, int final)
{
    EMInlineFilter *emif = (EMInlineFilter *)f;
    char *inptr = in, *inend = in+len;
    char *data_start = in;
    char *start = in;

    while (inptr < inend) {
        start = inptr;

        while (inptr < inend && *inptr != '\n')
            inptr++;

        if (inptr == inend) {
            if (!final) {
                camel_mime_filter_backup(f, start, inend-start);
                inend = start;
            }
            break;
        }

        *inptr++ = 0;

        switch(emif->state) {
        case EMIF_PLAIN:
            /* This could use some funky plugin shit, but this'll do for now */
            if (strncmp(start, "begin ", 6) == 0
                && start[6] >= '0' && start[6] <= '7') {
                int i = 7;
                char *name;

                while (start[i] >='0' && start[i] <='7')
                    i++;

                inptr[-1] = '\n';

                if (start[i++] != ' ')
                    break;

                emif_add_part(emif, data_start, start-data_start);

                name = g_strndup(start+i, inptr-start-i-1);
                emif->filename = camel_header_decode_string(name, emif->base_type?camel_content_type_param(emif->base_type, "charset"):NULL);
                g_free(name);
                data_start = start;
                emif->state = EMIF_UUENC;
            } else if (strncmp(start, "(This file must be converted with BinHex 4.0)", 45) == 0) {
                inptr[-1] = '\n';
                emif_add_part(emif, data_start, start-data_start);
                data_start = start;
                emif->state = EMIF_BINHEX;
            } else if (strncmp(start, "%!PS-Adobe-", 11) == 0) {
                inptr[-1] = '\n';
                emif_add_part(emif, data_start, start-data_start);
                data_start = start;
                emif->state = EMIF_POSTSCRIPT;
            } else if (strncmp(start, "-----BEGIN PGP SIGNED MESSAGE-----", 34) == 0) {
                inptr[-1] = '\n';
                emif_add_part(emif, data_start, start-data_start);
                data_start = start;
                emif->state = EMIF_PGPSIGNED;
            } else if (strncmp(start, "-----BEGIN PGP MESSAGE-----", 27) == 0) {
                inptr[-1] = '\n';
                emif_add_part(emif, data_start, start-data_start);
                data_start = start;
                emif->state = EMIF_PGPENCRYPTED;
            }

            break;
        case EMIF_UUENC:
            if (strcmp(start, "end") == 0) {
                inptr[-1] = '\n';
                emif_add_part(emif, data_start, inptr-data_start);
                data_start = inptr;
                emif->state = EMIF_PLAIN;
            } else {
                int linelen;

                /* check the length byte matches the data, if not, output what we have and re-scan this line */
                len = ((start[0] - ' ') & 077);
                linelen = inptr-start-1;
                while (linelen > 0 && (start[linelen] == '\r' || start[linelen] == '\n'))
                    linelen--;
                linelen--;
                linelen /= 4;
                linelen *= 3;
                if (!(len == linelen || len == linelen-1 || len == linelen-2)) {
                    inptr[-1] = '\n';
                    emif_add_part(emif, data_start, start-data_start);
                    data_start = start;
                    inptr = start;
                    emif->state = EMIF_PLAIN;
                    continue;
                }
            }
            break;
        case EMIF_BINHEX:
            if (inptr > (start+1) && inptr[-2] == ':') {
                inptr[-1] = '\n';
                emif_add_part(emif, data_start, inptr-data_start);
                data_start = inptr;
                emif->state = EMIF_PLAIN;
            }
            break;
        case EMIF_POSTSCRIPT:
            if (strcmp(start, "%%EOF") == 0) {
                inptr[-1] = '\n';
                emif_add_part(emif, data_start, inptr-data_start);
                data_start = inptr;
                emif->state = EMIF_PLAIN;
            }
            break;
        case EMIF_PGPSIGNED:
            if (strcmp(start, "-----END PGP SIGNATURE-----") == 0) {
                inptr[-1] = '\n';
                emif_add_part(emif, data_start, inptr-data_start);
                data_start = inptr;
                emif->state = EMIF_PLAIN;
            }
            break;
        case EMIF_PGPENCRYPTED:
            if (strcmp(start, "-----END PGP MESSAGE-----") == 0) {
                inptr[-1] = '\n';
                emif_add_part(emif, data_start, inptr-data_start);
                data_start = inptr;
                emif->state = EMIF_PLAIN;
            }
            break;
        }

        inptr[-1] = '\n';
    }

    if (final) {
        emif_add_part(emif, data_start, inend-data_start);
    } else {
        g_byte_array_append(emif->data, (unsigned char *)data_start, inend-data_start);
    }

    return 0;
}

static void
emif_filter(CamelMimeFilter *f, char *in, size_t len, size_t prespace, char **out, size_t *outlen, size_t *outprespace)
{
    emif_scan(f, in, len, FALSE);

    *out = in;
    *outlen = len;
    *outprespace = prespace;
}

static void
emif_complete(CamelMimeFilter *f, char *in, size_t len, size_t prespace, char **out, size_t *outlen, size_t *outprespace)
{
    emif_scan(f, in, len, TRUE);

    *out = in;
    *outlen = len;
    *outprespace = prespace;
}

static void
emif_reset(CamelMimeFilter *f)
{
    EMInlineFilter *emif = (EMInlineFilter *)f;
    GSList *l;

    l = emif->parts;
    while (l) {
        GSList *n = l->next;

        camel_object_unref(l->data);
        g_slist_free_1(l);

        l = n;
    }
    emif->parts = NULL;
    g_byte_array_set_size(emif->data, 0);
}

/**
 * em_inline_filter_new:
 * @base_encoding: The base transfer-encoding of the
 * raw data being processed.
 * @base_type: The base content-type of the raw data, should always be
 * text/plain.
 *
 * Create a filter which will scan a (text) stream for
 * embedded parts.  You can then retrieve the contents
 * as a CamelMultipart object.
 *
 * Return value:
 **/
EMInlineFilter *
em_inline_filter_new(CamelTransferEncoding base_encoding, CamelContentType *base_type)
{
    EMInlineFilter *emif;

    emif = (EMInlineFilter *)camel_object_new(em_inline_filter_get_type());
    emif->base_encoding = base_encoding;
    if (base_type) {
        emif->base_type = base_type;
        camel_content_type_ref(emif->base_type);
    }

    return emif;
}

CamelMultipart *
em_inline_filter_get_multipart(EMInlineFilter *emif)
{
    GSList *l = emif->parts;
    CamelMultipart *mp;

    mp = camel_multipart_new();
    while (l) {
        camel_multipart_add_part(mp, l->data);
        l = l->next;
    }

    return mp;
}