denyhosts/clamscan/libclamav/text.c

/*
 *  Copyright (C) 2013-2022 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
 *  Copyright (C) 2007-2013 Sourcefire, Inc.
 *
 *  Authors: Nigel Horne
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License version 2 as
 *  published by the Free Software Foundation.
 *
 *  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., 51 Franklin Street, Fifth Floor, Boston,
 *  MA 02110-1301, USA.
 *
 * $Log: text.c,v $
 * Revision 1.25  2007/02/12 20:46:09  njh
 * Various tidy
 *
 * Revision 1.24  2006/09/13 20:53:50  njh
 * Added debug
 *
 * Revision 1.23  2006/07/14 12:13:08  njh
 * Typo
 *
 * Revision 1.22  2006/07/01 21:03:36  njh
 * Better use of destroy mode
 *
 * Revision 1.21  2006/07/01 16:17:35  njh
 * Added destroy flag
 *
 * Revision 1.20  2006/07/01 03:47:50  njh
 * Don't loop if binhex runs out of memory
 *
 * Revision 1.19  2006/05/19 11:02:12  njh
 * Just include mbox.h
 *
 * Revision 1.18  2006/05/04 10:37:03  nigelhorne
 * Speed up scanning of clean files
 *
 * Revision 1.17  2006/05/03 09:36:40  nigelhorne
 * Pass full ctx into the mbox code
 *
 * Revision 1.16  2006/04/09 19:59:28  kojm
 * update GPL headers with new address for FSF
 *
 * Revision 1.15  2005/03/10 08:50:49  nigelhorne
 * Tidy
 *
 * Revision 1.14  2005/01/19 05:31:55  nigelhorne
 * Added textIterate
 *
 * Revision 1.13  2004/12/08 19:03:41  nigelhorne
 * Fix compilation error on Solaris
 *
 * Revision 1.12  2004/12/04 16:03:55  nigelhorne
 * Text/plain now handled as no encoding
 *
 * Revision 1.11  2004/11/27 21:54:26  nigelhorne
 * Tidy
 *
 * Revision 1.10  2004/08/22 10:34:24  nigelhorne
 * Use fileblob
 *
 * Revision 1.9  2004/08/21 11:57:57  nigelhorne
 * Use line.[ch]
 *
 * Revision 1.8  2004/07/20 14:35:29  nigelhorne
 * Some MYDOOM.I were getting through
 *
 * Revision 1.7  2004/06/22 04:08:02  nigelhorne
 * Optimise empty lines
 *
 * Revision 1.6  2004/05/05 09:37:52  nigelhorne
 * Removed textClean - not needed in clamAV
 *
 * Revision 1.5  2004/03/25 22:40:46  nigelhorne
 * Removed even more calls to realloc and some duplicated code
 *
 * Revision 1.4  2004/02/26 13:26:34  nigelhorne
 * Handle spaces at the end of uuencoded lines
 *
 */

#if HAVE_CONFIG_H
#include "clamav-config.h"
#endif

#include <stdlib.h>
#ifdef C_DARWIN
#include <sys/types.h>
#include <sys/malloc.h>
#else
#ifdef HAVE_MALLOC_H /* tk: FreeBSD-CURRENT doesn't support malloc.h */
#ifndef C_BSD        /* BSD now uses stdlib.h */
#include <malloc.h>
#endif
#endif
#endif
#include <string.h>
#include <ctype.h>
#include <assert.h>
#include <stdio.h>

#include "clamav.h"
#include "others.h"

#include "mbox.h"

static text *textCopy(const text *t_head);
static text *textAdd(text *t_head, const text *t);
static void addToFileblob(const line_t *line, void *arg);
static void getLength(const line_t *line, void *arg);
static void addToBlob(const line_t *line, void *arg);
static void *textIterate(text *t_text, void (*cb)(const line_t *line, void *arg), void *arg, int destroy);

void textDestroy(text *t_head)
{
    while (t_head) {
        text *t_next = t_head->t_next;
        if (t_head->t_line) {
            lineUnlink(t_head->t_line);
            t_head->t_line = NULL;
        }
        free(t_head);
        t_head = t_next;
    }
}

/* Clone the current object */
static text *
textCopy(const text *t_head)
{
    text *first = NULL, *last = NULL;

    while (t_head) {
        if (first == NULL)
            last = first = (text *)cli_malloc(sizeof(text));
        else {
            last->t_next = (text *)cli_malloc(sizeof(text));
            last         = last->t_next;
        }

        if (last == NULL) {
            cli_errmsg("textCopy: Unable to allocate memory to clone object\n");
            if (first)
                textDestroy(first);
            return NULL;
        }

        last->t_next = NULL;

        if (t_head->t_line)
            last->t_line = lineLink(t_head->t_line);
        else
            last->t_line = NULL;

        t_head = t_head->t_next;
    }

    if (first)
        last->t_next = NULL;

    return first;
}

/* Add a copy of a text to the end of the current object */
static text *
textAdd(text *t_head, const text *t)
{
    text *ret;
    int count;

    if (t_head == NULL) {
        if (t == NULL) {
            cli_errmsg("textAdd fails sanity check\n");
            return NULL;
        }
        return textCopy(t);
    }

    if (t == NULL)
        return t_head;

    ret = t_head;

    count = 0;
    while (t_head->t_next) {
        count++;
        t_head = t_head->t_next;
    }

    cli_dbgmsg("textAdd: count = %d\n", count);

    while (t) {
        t_head->t_next = (text *)cli_malloc(sizeof(text));
        t_head         = t_head->t_next;

        assert(t_head != NULL);

        if (t->t_line)
            t_head->t_line = lineLink(t->t_line);
        else
            t_head->t_line = NULL;

        t = t->t_next;
    }

    t_head->t_next = NULL;

    return ret;
}

/*
 * Add a message's content to the end of the current object
 */
text *
textAddMessage(text *aText, message *aMessage)
{
    assert(aMessage != NULL);

    if (messageGetEncoding(aMessage) == NOENCODING)
        return textAdd(aText, messageGetBody(aMessage));
    else {
        text *anotherText = messageToText(aMessage);

        if (aText) {
            text *newHead = textMove(aText, anotherText);
            free(anotherText);
            return newHead;
        }
        return anotherText;
    }
}

/*
 * Put the contents of the given text at the end of the current object.
 * The given text emptied; it can be used again if needed, though be warned that
 * it will have an empty line at the start.
 */
text *
textMove(text *t_head, text *t)
{
    text *ret;

    if (t_head == NULL) {
        if (t == NULL) {
            cli_errmsg("textMove fails sanity check\n");
            return NULL;
        }
        t_head = (text *)cli_malloc(sizeof(text));
        if (t_head == NULL) {
            cli_errmsg("textMove: Unable to allocate memory for head\n");
            return NULL;
        }
        t_head->t_line = t->t_line;
        t_head->t_next = t->t_next;
        t->t_line      = NULL;
        t->t_next      = NULL;
        return t_head;
    }

    if (t == NULL)
        return t_head;

    ret = t_head;

    while (t_head->t_next)
        t_head = t_head->t_next;

    /*
	 * Move the first line manually so that the caller is left clean but
	 * empty, the rest is moved by a simple pointer reassignment
	 */
    t_head->t_next = (text *)cli_malloc(sizeof(text));
    if (t_head->t_next == NULL) {
        cli_errmsg("textMove: Unable to allocate memory for head->next\n");
        return NULL;
    }
    t_head = t_head->t_next;

    assert(t_head != NULL);

    if (t->t_line) {
        t_head->t_line = t->t_line;
        t->t_line      = NULL;
    } else
        t_head->t_line = NULL;

    t_head->t_next = t->t_next;
    t->t_next      = NULL;

    return ret;
}

/*
 * Transfer the contents of the text into a blob
 * The caller must free the returned blob if b is NULL
 */
blob *
textToBlob(text *t, blob *b, int destroy)
{
    size_t s;
    blob *bin;

    if (t == NULL)
        return NULL;

    s = 0;

    (void)textIterate(t, getLength, &s, 0);

    if (s == 0)
        return b;

    /*
	 * copy b. If b is NULL and an error occurs we know we need to free
	 *	before returning
	 */
    bin = b;
    if (b == NULL) {
        b = blobCreate();

        if (b == NULL)
            return NULL;
    }

    if (blobGrow(b, s) != CL_SUCCESS) {
        cli_warnmsg("Couldn't grow the blob: we may be low on memory\n");
#if 0
		if(!destroy) {
			if(bin == NULL)
				blobDestroy(b);
			return NULL;
		}
		/*
		 * We may be able to recover enough memory as we destroy to
		 * create the blob
		 */
#else
        if (bin == NULL)
            blobDestroy(b);
        return NULL;
#endif
    }

    (void)textIterate(t, addToBlob, b, destroy);

    if (destroy && t->t_next) {
        textDestroy(t->t_next);
        t->t_next = NULL;
    }

    blobClose(b);

    return b;
}

fileblob *
textToFileblob(text *t, fileblob *fb, int destroy)
{
    assert(fb != NULL);
    assert(t != NULL);

    if (fb == NULL) {
        cli_dbgmsg("textToFileBlob, destroy = %d\n", destroy);
        fb = fileblobCreate();

        if (fb == NULL)
            return NULL;
    } else {
        cli_dbgmsg("textToFileBlob to %s, destroy = %d\n",
                   fileblobGetFilename(fb), destroy);

        fb->ctx = NULL; /* no need to scan */
    }

    fb = textIterate(t, addToFileblob, fb, destroy);
    if (destroy && t->t_next) {
        textDestroy(t->t_next);
        t->t_next = NULL;
    }
    return fb;
}

static void
getLength(const line_t *line, void *arg)
{
    size_t *length = (size_t *)arg;

    if (line)
        *length += strlen(lineGetData(line)) + 1;
    else
        (*length)++;
}

static void
addToBlob(const line_t *line, void *arg)
{
    blob *b = (blob *)arg;

    if (line) {
        const char *l = lineGetData(line);

        blobAddData(b, (const unsigned char *)l, strlen(l));
    }
    blobAddData(b, (const unsigned char *)"\n", 1);
}

static void
addToFileblob(const line_t *line, void *arg)
{
    fileblob *fb = (fileblob *)arg;

    if (line) {
        const char *l = lineGetData(line);

        fileblobAddData(fb, (const unsigned char *)l, strlen(l));
    }
    fileblobAddData(fb, (const unsigned char *)"\n", 1);
}

static void *
textIterate(text *t_text, void (*cb)(const line_t *item, void *arg), void *arg, int destroy)
{
    /*
	 * Have two loops rather than one, so that we're not checking the
	 * value of "destroy" lots and lots of times
	 */
#if 0
	while(t_text) {
		(*cb)(t_text->t_line, arg);

		if(destroy && t_text->t_line) {
			lineUnlink(t_text->t_line);
			t_text->t_line = NULL;
		}

		t_text = t_text->t_next;
	}
#else
    if (destroy)
        while (t_text) {
            (*cb)(t_text->t_line, arg);

            if (t_text->t_line) {
                lineUnlink(t_text->t_line);
                t_text->t_line = NULL;
            }

            t_text = t_text->t_next;
        }
    else
        while (t_text) {
            (*cb)(t_text->t_line, arg);

            t_text = t_text->t_next;
        }
#endif
    return arg;
}