xzlib.c 24.2 KB
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/**
 * xzlib.c: front end for the transparent suport of lzma compression
 *          at the I/O layer, based on an example file from lzma project
 *
 * See Copyright for the status of this software.
 *
 * Anders F Bjorklund <afb@users.sourceforge.net>
 */
#define IN_LIBXML
#include "libxml.h"
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#ifdef LIBXML_LZMA_ENABLED
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#include <string.h>
#ifdef HAVE_ERRNO_H
#include <errno.h>
#endif


#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#ifdef HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif
#ifdef HAVE_FCNTL_H
#include <fcntl.h>
#endif
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif
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#ifdef LIBXML_ZLIB_ENABLED
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#include <zlib.h>
#endif
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#ifdef LIBXML_LZMA_ENABLED
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#include <lzma.h>
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#endif
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#include "xzlib.h"
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#include <libxml/xmlmemory.h>
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/* values for xz_state how */
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#define LOOK 0                  /* look for a gzip/lzma header */
#define COPY 1                  /* copy input directly */
#define GZIP 2                  /* decompress a gzip stream */
#define LZMA 3                  /* decompress a lzma stream */
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/* internal lzma file state data structure */
typedef struct {
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    int mode;                   /* see lzma modes above */
    int fd;                     /* file descriptor */
    char *path;                 /* path or fd for error messages */
    uint64_t pos;               /* current position in uncompressed data */
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    unsigned int size;          /* buffer size, zero if not allocated yet */
    unsigned int want;          /* requested buffer size, default is BUFSIZ */
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    unsigned char *in;          /* input buffer */
    unsigned char *out;         /* output buffer (double-sized when reading) */
    unsigned char *next;        /* next output data to deliver or write */
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    unsigned int have;          /* amount of output data unused at next */
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    int eof;                    /* true if end of input file reached */
    uint64_t start;             /* where the lzma data started, for rewinding */
    uint64_t raw;               /* where the raw data started, for seeking */
    int how;                    /* 0: get header, 1: copy, 2: decompress */
    int direct;                 /* true if last read direct, false if lzma */
    /* seek request */
    uint64_t skip;              /* amount to skip (already rewound if backwards) */
    int seek;                   /* true if seek request pending */
    /* error information */
    int err;                    /* error code */
    char *msg;                  /* error message */
    /* lzma stream */
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    int init;                   /* is the iniflate stream initialized */
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    lzma_stream strm;           /* stream structure in-place (not a pointer) */
    char padding1[32];          /* padding allowing to cope with possible
                                   extensions of above structure without
				   too much side effect */
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#ifdef LIBXML_ZLIB_ENABLED
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    /* zlib inflate or deflate stream */
    z_stream zstrm;             /* stream structure in-place (not a pointer) */
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#endif
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    char padding2[32];          /* padding allowing to cope with possible
                                   extensions of above structure without
				   too much side effect */
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} xz_state, *xz_statep;

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static void
xz_error(xz_statep state, int err, const char *msg)
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{
    /* free previously allocated message and clear */
    if (state->msg != NULL) {
        if (state->err != LZMA_MEM_ERROR)
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            xmlFree(state->msg);
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        state->msg = NULL;
    }

    /* set error code, and if no message, then done */
    state->err = err;
    if (msg == NULL)
        return;

    /* for an out of memory error, save as static string */
    if (err == LZMA_MEM_ERROR) {
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        state->msg = (char *) msg;
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        return;
    }

    /* construct error message with path */
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    if ((state->msg =
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         xmlMalloc(strlen(state->path) + strlen(msg) + 3)) == NULL) {
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        state->err = LZMA_MEM_ERROR;
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        state->msg = (char *) "out of memory";
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        return;
    }
    strcpy(state->msg, state->path);
    strcat(state->msg, ": ");
    strcat(state->msg, msg);
    return;
}

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static void
xz_reset(xz_statep state)
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{
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    state->have = 0;            /* no output data available */
    state->eof = 0;             /* not at end of file */
    state->how = LOOK;          /* look for gzip header */
    state->direct = 1;          /* default for empty file */
    state->seek = 0;            /* no seek request pending */
    xz_error(state, LZMA_OK, NULL);     /* clear error */
    state->pos = 0;             /* no uncompressed data yet */
    state->strm.avail_in = 0;   /* no input data yet */
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#ifdef LIBXML_ZLIB_ENABLED
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    state->zstrm.avail_in = 0;  /* no input data yet */
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#endif
}

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static xzFile
xz_open(const char *path, int fd, const char *mode ATTRIBUTE_UNUSED)
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{
    xz_statep state;

    /* allocate xzFile structure to return */
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    state = xmlMalloc(sizeof(xz_state));
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    if (state == NULL)
        return NULL;
    state->size = 0;            /* no buffers allocated yet */
    state->want = BUFSIZ;       /* requested buffer size */
    state->msg = NULL;          /* no error message yet */
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    state->init = 0;            /* initialization of zlib data */
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    /* save the path name for error messages */
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    state->path = xmlMalloc(strlen(path) + 1);
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    if (state->path == NULL) {
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        xmlFree(state);
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        return NULL;
    }
    strcpy(state->path, path);

    /* open the file with the appropriate mode (or just use fd) */
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    state->fd = fd != -1 ? fd : open(path,
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#ifdef O_LARGEFILE
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                                     O_LARGEFILE |
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#endif
#ifdef O_BINARY
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                                     O_BINARY |
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#endif
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                                     O_RDONLY, 0666);
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    if (state->fd == -1) {
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        xmlFree(state->path);
        xmlFree(state);
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        return NULL;
    }

    /* save the current position for rewinding (only if reading) */
    state->start = lseek(state->fd, 0, SEEK_CUR);
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    if (state->start == (uint64_t) - 1)
        state->start = 0;
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    /* initialize stream */
    xz_reset(state);

    /* return stream */
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    return (xzFile) state;
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}

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static int
xz_compressed(xzFile f) {
    xz_statep state;

    if (f == NULL)
        return(-1);
    state = (xz_statep) f;
    if (state->init <= 0)
        return(-1);

    switch (state->how) {
        case COPY:
	    return(0);
	case GZIP:
	case LZMA:
	    return(1);
    }
    return(-1);
}

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xzFile
__libxml2_xzopen(const char *path, const char *mode)
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{
    return xz_open(path, -1, mode);
}

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int
__libxml2_xzcompressed(xzFile f) {
    return xz_compressed(f);
}

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xzFile
__libxml2_xzdopen(int fd, const char *mode)
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{
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    char *path;                 /* identifier for error messages */
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    xzFile xz;

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    if (fd == -1 || (path = xmlMalloc(7 + 3 * sizeof(int))) == NULL)
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        return NULL;
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    sprintf(path, "<fd:%d>", fd);       /* for debugging */
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    xz = xz_open(path, fd, mode);
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    xmlFree(path);
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    return xz;
}

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static int
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xz_load(xz_statep state, unsigned char *buf, unsigned int len,
        unsigned int *have)
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{
    int ret;

    *have = 0;
    do {
        ret = read(state->fd, buf + *have, len - *have);
        if (ret <= 0)
            break;
        *have += ret;
    } while (*have < len);
    if (ret < 0) {
        xz_error(state, -1, strerror(errno));
        return -1;
    }
    if (ret == 0)
        state->eof = 1;
    return 0;
}

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static int
xz_avail(xz_statep state)
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{
    lzma_stream *strm = &(state->strm);

    if (state->err != LZMA_OK)
        return -1;
    if (state->eof == 0) {
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        /* avail_in is size_t, which is not necessary sizeof(unsigned) */
        unsigned tmp = strm->avail_in;

        if (xz_load(state, state->in, state->size, &tmp) == -1) {
            strm->avail_in = tmp;
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            return -1;
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        }
        strm->avail_in = tmp;
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        strm->next_in = state->in;
    }
    return 0;
}

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#ifdef LIBXML_ZLIB_ENABLED
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static int
xz_avail_zstrm(xz_statep state)
{
    int ret;
    state->strm.avail_in = state->zstrm.avail_in;
    state->strm.next_in = state->zstrm.next_in;
    ret = xz_avail(state);
    state->zstrm.avail_in = (uInt) state->strm.avail_in;
    state->zstrm.next_in = (Bytef *) state->strm.next_in;
    return ret;
}
#endif

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static int
is_format_xz(xz_statep state)
{
    lzma_stream *strm = &(state->strm);

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    return strm->avail_in >= 6 && memcmp(state->in, "\3757zXZ", 6) == 0;
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}

static int
is_format_lzma(xz_statep state)
{
    lzma_stream *strm = &(state->strm);

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    lzma_filter filter;
    lzma_options_lzma *opt;
    uint32_t dict_size;
    uint64_t uncompressed_size;
    size_t i;

    if (strm->avail_in < 13)
        return 0;

    filter.id = LZMA_FILTER_LZMA1;
    if (lzma_properties_decode(&filter, NULL, state->in, 5) != LZMA_OK)
        return 0;

    opt = filter.options;
    dict_size = opt->dict_size;
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    free(opt); /* we can't use xmlFree on a string returned by zlib */
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    /* A hack to ditch tons of false positives: We allow only dictionary
     * sizes that are 2^n or 2^n + 2^(n-1) or UINT32_MAX. LZMA_Alone
     * created only files with 2^n, but accepts any dictionary size.
     * If someone complains, this will be reconsidered.
     */
    if (dict_size != UINT32_MAX) {
        uint32_t d = dict_size - 1;

        d |= d >> 2;
        d |= d >> 3;
        d |= d >> 4;
        d |= d >> 8;
        d |= d >> 16;
        ++d;
        if (d != dict_size || dict_size == 0)
            return 0;
    }

    /* Another hack to ditch false positives: Assume that if the
     * uncompressed size is known, it must be less than 256 GiB.
     * Again, if someone complains, this will be reconsidered.
     */
    uncompressed_size = 0;
    for (i = 0; i < 8; ++i)
        uncompressed_size |= (uint64_t) (state->in[5 + i]) << (i * 8);

    if (uncompressed_size != UINT64_MAX
        && uncompressed_size > (UINT64_C(1) << 38))
        return 0;

    return 1;
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}

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#ifdef LIBXML_ZLIB_ENABLED
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/* Get next byte from input, or -1 if end or error. */
#define NEXT() ((strm->avail_in == 0 && xz_avail(state) == -1) ? -1 : \
                (strm->avail_in == 0 ? -1 : \
                 (strm->avail_in--, *(strm->next_in)++)))
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/* Same thing, but from zstrm */
#define NEXTZ() ((strm->avail_in == 0 && xz_avail_zstrm(state) == -1) ? -1 : \
                (strm->avail_in == 0 ? -1 : \
                 (strm->avail_in--, *(strm->next_in)++)))
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/* Get a four-byte little-endian integer and return 0 on success and the value
   in *ret.  Otherwise -1 is returned and *ret is not modified. */
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static int
gz_next4(xz_statep state, unsigned long *ret)
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{
    int ch;
    unsigned long val;
    z_streamp strm = &(state->zstrm);

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    val = NEXTZ();
    val += (unsigned) NEXTZ() << 8;
    val += (unsigned long) NEXTZ() << 16;
    ch = NEXTZ();
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    if (ch == -1)
        return -1;
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    val += (unsigned long) ch << 24;
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    *ret = val;
    return 0;
}
#endif

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static int
xz_head(xz_statep state)
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{
    lzma_stream *strm = &(state->strm);
    lzma_stream init = LZMA_STREAM_INIT;
    int flags;
    unsigned len;

    /* allocate read buffers and inflate memory */
    if (state->size == 0) {
        /* allocate buffers */
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        state->in = xmlMalloc(state->want);
        state->out = xmlMalloc(state->want << 1);
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        if (state->in == NULL || state->out == NULL) {
            if (state->out != NULL)
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                xmlFree(state->out);
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            if (state->in != NULL)
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                xmlFree(state->in);
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            xz_error(state, LZMA_MEM_ERROR, "out of memory");
            return -1;
        }
        state->size = state->want;

        /* allocate decoder memory */
        state->strm = init;
        state->strm.avail_in = 0;
        state->strm.next_in = NULL;
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        if (lzma_auto_decoder(&state->strm, 100000000, 0) != LZMA_OK) {
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            xmlFree(state->out);
            xmlFree(state->in);
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            state->size = 0;
            xz_error(state, LZMA_MEM_ERROR, "out of memory");
            return -1;
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        }
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#ifdef LIBXML_ZLIB_ENABLED
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        /* allocate inflate memory */
        state->zstrm.zalloc = Z_NULL;
        state->zstrm.zfree = Z_NULL;
        state->zstrm.opaque = Z_NULL;
        state->zstrm.avail_in = 0;
        state->zstrm.next_in = Z_NULL;
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        if (state->init == 0) {
            if (inflateInit2(&(state->zstrm), -15) != Z_OK) {/* raw inflate */
                xmlFree(state->out);
                xmlFree(state->in);
                state->size = 0;
                xz_error(state, LZMA_MEM_ERROR, "out of memory");
                return -1;
            }
            state->init = 1;
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        }
#endif
    }

    /* get some data in the input buffer */
    if (strm->avail_in == 0) {
        if (xz_avail(state) == -1)
            return -1;
        if (strm->avail_in == 0)
            return 0;
    }

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    /* look for the xz magic header bytes */
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    if (is_format_xz(state) || is_format_lzma(state)) {
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        state->how = LZMA;
        state->direct = 0;
        return 0;
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    }
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#ifdef LIBXML_ZLIB_ENABLED
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    /* look for the gzip magic header bytes 31 and 139 */
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    if (strm->next_in[0] == 31) {
        strm->avail_in--;
        strm->next_in++;
        if (strm->avail_in == 0 && xz_avail(state) == -1)
            return -1;
        if (strm->avail_in && strm->next_in[0] == 139) {
            /* we have a gzip header, woo hoo! */
            strm->avail_in--;
            strm->next_in++;

            /* skip rest of header */
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            if (NEXT() != 8) {  /* compression method */
                xz_error(state, LZMA_DATA_ERROR,
                         "unknown compression method");
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                return -1;
            }
            flags = NEXT();
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            if (flags & 0xe0) { /* reserved flag bits */
                xz_error(state, LZMA_DATA_ERROR,
                         "unknown header flags set");
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                return -1;
            }
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            NEXT();             /* modification time */
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            NEXT();
            NEXT();
            NEXT();
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            NEXT();             /* extra flags */
            NEXT();             /* operating system */
            if (flags & 4) {    /* extra field */
                len = (unsigned) NEXT();
                len += (unsigned) NEXT() << 8;
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                while (len--)
                    if (NEXT() < 0)
                        break;
            }
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            if (flags & 8)      /* file name */
                while (NEXT() > 0) ;
            if (flags & 16)     /* comment */
                while (NEXT() > 0) ;
            if (flags & 2) {    /* header crc */
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                NEXT();
                NEXT();
            }
            /* an unexpected end of file is not checked for here -- it will be
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             * noticed on the first request for uncompressed data */
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            /* set up for decompression */
            inflateReset(&state->zstrm);
            state->zstrm.adler = crc32(0L, Z_NULL, 0);
            state->how = GZIP;
            state->direct = 0;
            return 0;
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        } else {
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            /* not a gzip file -- save first byte (31) and fall to raw i/o */
            state->out[0] = 31;
            state->have = 1;
        }
    }
#endif

    /* doing raw i/o, save start of raw data for seeking, copy any leftover
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     * input to output -- this assumes that the output buffer is larger than
     * the input buffer, which also assures space for gzungetc() */
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    state->raw = state->pos;
    state->next = state->out;
    if (strm->avail_in) {
        memcpy(state->next + state->have, strm->next_in, strm->avail_in);
        state->have += strm->avail_in;
        strm->avail_in = 0;
    }
    state->how = COPY;
    state->direct = 1;
    return 0;
}

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static int
xz_decomp(xz_statep state)
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{
    int ret;
    unsigned had;
    unsigned long crc, len;
    lzma_stream *strm = &(state->strm);

    lzma_action action = LZMA_RUN;

    /* fill output buffer up to end of deflate stream */
    had = strm->avail_out;
    do {
        /* get more input for inflate() */
        if (strm->avail_in == 0 && xz_avail(state) == -1)
            return -1;
        if (strm->avail_in == 0) {
            xz_error(state, LZMA_DATA_ERROR, "unexpected end of file");
            return -1;
        }
        if (state->eof)
            action = LZMA_FINISH;
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        /* decompress and handle errors */
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#ifdef LIBXML_ZLIB_ENABLED
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        if (state->how == GZIP) {
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            state->zstrm.avail_in = (uInt) state->strm.avail_in;
            state->zstrm.next_in = (Bytef *) state->strm.next_in;
            state->zstrm.avail_out = (uInt) state->strm.avail_out;
            state->zstrm.next_out = (Bytef *) state->strm.next_out;
            ret = inflate(&state->zstrm, Z_NO_FLUSH);
            if (ret == Z_STREAM_ERROR || ret == Z_NEED_DICT) {
                xz_error(state, Z_STREAM_ERROR,
                         "internal error: inflate stream corrupt");
                return -1;
            }
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            /*
             * FIXME: Remapping a couple of error codes and falling through
             * to the LZMA error handling looks fragile.
             */
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            if (ret == Z_MEM_ERROR)
                ret = LZMA_MEM_ERROR;
            if (ret == Z_DATA_ERROR)
                ret = LZMA_DATA_ERROR;
            if (ret == Z_STREAM_END)
                ret = LZMA_STREAM_END;
            state->strm.avail_in = state->zstrm.avail_in;
            state->strm.next_in = state->zstrm.next_in;
            state->strm.avail_out = state->zstrm.avail_out;
            state->strm.next_out = state->zstrm.next_out;
        } else                  /* state->how == LZMA */
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#endif
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            ret = lzma_code(strm, action);
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        if (ret == LZMA_MEM_ERROR) {
            xz_error(state, LZMA_MEM_ERROR, "out of memory");
            return -1;
        }
        if (ret == LZMA_DATA_ERROR) {
            xz_error(state, LZMA_DATA_ERROR, "compressed data error");
            return -1;
        }
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        if (ret == LZMA_PROG_ERROR) {
            xz_error(state, LZMA_PROG_ERROR, "compression error");
            return -1;
        }
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        if ((state->how != GZIP) &&
            (ret != LZMA_OK) && (ret != LZMA_STREAM_END)) {
            xz_error(state, ret, "lzma error");
            return -1;
        }
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    } while (strm->avail_out && ret != LZMA_STREAM_END);

    /* update available output and crc check value */
    state->have = had - strm->avail_out;
    state->next = strm->next_out - state->have;
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#ifdef LIBXML_ZLIB_ENABLED
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    state->zstrm.adler =
        crc32(state->zstrm.adler, state->next, state->have);
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#endif

    if (ret == LZMA_STREAM_END) {
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#ifdef LIBXML_ZLIB_ENABLED
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        if (state->how == GZIP) {
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            if (gz_next4(state, &crc) == -1 || gz_next4(state, &len) == -1) {
                xz_error(state, LZMA_DATA_ERROR, "unexpected end of file");
                return -1;
            }
            if (crc != state->zstrm.adler) {
                xz_error(state, LZMA_DATA_ERROR, "incorrect data check");
                return -1;
            }
            if (len != (state->zstrm.total_out & 0xffffffffL)) {
                xz_error(state, LZMA_DATA_ERROR, "incorrect length check");
                return -1;
            }
            state->strm.avail_in = 0;
            state->strm.next_in = NULL;
            state->strm.avail_out = 0;
            state->strm.next_out = NULL;
        } else
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#endif
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        if (strm->avail_in != 0 || !state->eof) {
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            xz_error(state, LZMA_DATA_ERROR, "trailing garbage");
            return -1;
        }
        state->how = LOOK;      /* ready for next stream, once have is 0 (leave
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                                 * state->direct unchanged to remember how) */
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    }

    /* good decompression */
    return 0;
}

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static int
xz_make(xz_statep state)
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{
    lzma_stream *strm = &(state->strm);

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    if (state->how == LOOK) {   /* look for lzma / gzip header */
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        if (xz_head(state) == -1)
            return -1;
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        if (state->have)        /* got some data from xz_head() */
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            return 0;
    }
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    if (state->how == COPY) {   /* straight copy */
        if (xz_load(state, state->out, state->size << 1, &(state->have)) ==
            -1)
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            return -1;
        state->next = state->out;
658
    } else if (state->how == LZMA || state->how == GZIP) {      /* decompress */
659 660 661 662 663 664 665 666
        strm->avail_out = state->size << 1;
        strm->next_out = state->out;
        if (xz_decomp(state) == -1)
            return -1;
    }
    return 0;
}

667 668
static int
xz_skip(xz_statep state, uint64_t len)
669 670 671 672 673 674 675
{
    unsigned n;

    /* skip over len bytes or reach end-of-file, whichever comes first */
    while (len)
        /* skip over whatever is in output buffer */
        if (state->have) {
676 677
            n = (uint64_t) state->have > len ?
                (unsigned) len : state->have;
678 679 680 681 682 683
            state->have -= n;
            state->next += n;
            state->pos += n;
            len -= n;
        }

684
    /* output buffer empty -- return if we're at the end of the input */
685 686 687
        else if (state->eof && state->strm.avail_in == 0)
            break;

688
    /* need more data to skip -- load up output buffer */
689 690 691 692 693 694 695 696
        else {
            /* get more output, looking for header if required */
            if (xz_make(state) == -1)
                return -1;
        }
    return 0;
}

697 698
int
__libxml2_xzread(xzFile file, void *buf, unsigned len)
699 700 701 702 703 704 705 706
{
    unsigned got, n;
    xz_statep state;
    lzma_stream *strm;

    /* get internal structure */
    if (file == NULL)
        return -1;
707
    state = (xz_statep) file;
708 709 710 711 712 713 714
    strm = &(state->strm);

    /* check that we're reading and that there's no error */
    if (state->err != LZMA_OK)
        return -1;

    /* since an int is returned, make sure len fits in one, otherwise return
715 716 717 718
     * with an error (this avoids the flaw in the interface) */
    if ((int) len < 0) {
        xz_error(state, LZMA_BUF_ERROR,
                 "requested length does not fit in int");
719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748
        return -1;
    }

    /* if len is zero, avoid unnecessary operations */
    if (len == 0)
        return 0;

    /* process a skip request */
    if (state->seek) {
        state->seek = 0;
        if (xz_skip(state, state->skip) == -1)
            return -1;
    }

    /* get len bytes to buf, or less than len if at the end */
    got = 0;
    do {
        /* first just try copying data from the output buffer */
        if (state->have) {
            n = state->have > len ? len : state->have;
            memcpy(buf, state->next, n);
            state->next += n;
            state->have -= n;
        }

        /* output buffer empty -- return if we're at the end of the input */
        else if (state->eof && strm->avail_in == 0)
            break;

        /* need output data -- for small len or new stream load up our output
749
         * buffer */
750 751 752 753
        else if (state->how == LOOK || len < (state->size << 1)) {
            /* get more output, looking for header if required */
            if (xz_make(state) == -1)
                return -1;
754
            continue;           /* no progress yet -- go back to memcpy() above */
755
            /* the copy above assures that we will leave with space in the
756
             * output buffer, allowing at least one gzungetc() to succeed */
757 758 759
        }

        /* large len -- read directly into user buffer */
760
        else if (state->how == COPY) {  /* read directly */
761 762 763 764 765
            if (xz_load(state, buf, len, &n) == -1)
                return -1;
        }

        /* large len -- decompress directly into user buffer */
766
        else {                  /* state->how == LZMA */
767 768 769 770 771 772 773 774 775 776
            strm->avail_out = len;
            strm->next_out = buf;
            if (xz_decomp(state) == -1)
                return -1;
            n = state->have;
            state->have = 0;
        }

        /* update progress */
        len -= n;
777
        buf = (char *) buf + n;
778 779 780 781 782
        got += n;
        state->pos += n;
    } while (len);

    /* return number of bytes read into user buffer (will fit in int) */
783
    return (int) got;
784 785
}

786 787
int
__libxml2_xzclose(xzFile file)
788 789 790 791 792 793 794
{
    int ret;
    xz_statep state;

    /* get internal structure */
    if (file == NULL)
        return LZMA_DATA_ERROR;
795
    state = (xz_statep) file;
796 797 798 799

    /* free memory and close file */
    if (state->size) {
        lzma_end(&(state->strm));
800
#ifdef LIBXML_ZLIB_ENABLED
801 802 803
        if (state->init == 1)
            inflateEnd(&(state->zstrm));
        state->init = 0;
804
#endif
805 806
        xmlFree(state->out);
        xmlFree(state->in);
807
    }
808
    xmlFree(state->path);
809 810
    if ((state->msg != NULL) && (state->err != LZMA_MEM_ERROR))
        xmlFree(state->msg);
811
    ret = close(state->fd);
812
    xmlFree(state);
813 814
    return ret ? ret : LZMA_OK;
}
815
#endif /* LIBXML_LZMA_ENABLED */