move xz/lzma helpers to separate included files
diff --git a/xzlib.c b/xzlib.c
new file mode 100644
index 0000000..ba3dbf3
--- /dev/null
+++ b/xzlib.c
@@ -0,0 +1,681 @@
+#include "xzlib.h"
+
+/* values for xz_state how */
+#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 */
+
+/* internal lzma file state data structure */
+typedef struct {
+ 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 */
+ unsigned size; /* buffer size, zero if not allocated yet */
+ unsigned want; /* requested buffer size, default is BUFSIZ */
+ unsigned char *in; /* input buffer */
+ unsigned char *out; /* output buffer (double-sized when reading) */
+ unsigned char *next; /* next output data to deliver or write */
+ unsigned have; /* amount of output data unused at next */
+ 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 */
+ lzma_stream strm; /* stream structure in-place (not a pointer) */
+#ifdef HAVE_ZLIB_H
+ /* zlib inflate or deflate stream */
+ z_stream zstrm; /* stream structure in-place (not a pointer) */
+#endif
+} xz_state, *xz_statep;
+
+static void xz_error(xz_statep state, int err, const char *msg)
+{
+ /* free previously allocated message and clear */
+ if (state->msg != NULL) {
+ if (state->err != LZMA_MEM_ERROR)
+ free(state->msg);
+ 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) {
+ state->msg = (char *)msg;
+ return;
+ }
+
+ /* construct error message with path */
+ if ((state->msg = malloc(strlen(state->path) + strlen(msg) + 3)) == NULL) {
+ state->err = LZMA_MEM_ERROR;
+ state->msg = (char *)"out of memory";
+ return;
+ }
+ strcpy(state->msg, state->path);
+ strcat(state->msg, ": ");
+ strcat(state->msg, msg);
+ return;
+}
+
+static void xz_reset(xz_statep state)
+{
+ 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 */
+#ifdef HAVE_ZLIB_H
+ state->zstrm.avail_in = 0; /* no input data yet */
+#endif
+}
+
+static xzFile xz_open(const char *path, int fd, const char *mode ATTRIBUTE_UNUSED)
+{
+ xz_statep state;
+
+ /* allocate xzFile structure to return */
+ state = malloc(sizeof(xz_state));
+ 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 */
+
+ /* save the path name for error messages */
+ state->path = malloc(strlen(path) + 1);
+ if (state->path == NULL) {
+ free(state);
+ return NULL;
+ }
+ strcpy(state->path, path);
+
+ /* open the file with the appropriate mode (or just use fd) */
+ state->fd = fd != -1 ? fd :
+ open(path,
+#ifdef O_LARGEFILE
+ O_LARGEFILE |
+#endif
+#ifdef O_BINARY
+ O_BINARY |
+#endif
+ O_RDONLY,
+ 0666);
+ if (state->fd == -1) {
+ free(state->path);
+ free(state);
+ return NULL;
+ }
+
+ /* save the current position for rewinding (only if reading) */
+ state->start = lseek(state->fd, 0, SEEK_CUR);
+ if (state->start == (uint64_t) -1) state->start = 0;
+
+ /* initialize stream */
+ xz_reset(state);
+
+ /* return stream */
+ return (xzFile)state;
+}
+
+xzFile xzopen(const char *path, const char *mode)
+{
+ return xz_open(path, -1, mode);
+}
+
+xzFile xzdopen(int fd, const char *mode)
+{
+ char *path; /* identifier for error messages */
+ xzFile xz;
+
+ if (fd == -1 || (path = malloc(7 + 3 * sizeof(int))) == NULL)
+ return NULL;
+ sprintf(path, "<fd:%d>", fd); /* for debugging */
+ xz = xz_open(path, fd, mode);
+ free(path);
+ return xz;
+}
+
+static int xz_load(xz_statep state, unsigned char *buf, unsigned len, unsigned *have)
+{
+ 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;
+}
+
+static int xz_avail(xz_statep state)
+{
+ lzma_stream *strm = &(state->strm);
+
+ if (state->err != LZMA_OK)
+ return -1;
+ if (state->eof == 0) {
+ if (xz_load(state, state->in, state->size,
+ (unsigned *)&(strm->avail_in)) == -1)
+ return -1;
+ strm->next_in = state->in;
+ }
+ return 0;
+}
+
+static int
+is_format_xz(xz_statep state)
+{
+ lzma_stream *strm = &(state->strm);
+
+ return strm->avail_in >= 6 && memcmp(state->in, "\3757zXZ", 6) == 0;
+}
+
+static int
+is_format_lzma(xz_statep state)
+{
+ lzma_stream *strm = &(state->strm);
+
+ 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;
+ free(opt);
+
+ /* 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;
+}
+
+#ifdef HAVE_ZLIB_H
+/* 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)++)))
+
+/* 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. */
+static int gz_next4(xz_statep state, unsigned long *ret)
+{
+ int ch;
+ unsigned long val;
+ z_streamp strm = &(state->zstrm);
+
+ val = NEXT();
+ val += (unsigned)NEXT() << 8;
+ val += (unsigned long)NEXT() << 16;
+ ch = NEXT();
+ if (ch == -1)
+ return -1;
+ val += (unsigned long)ch << 24;
+ *ret = val;
+ return 0;
+}
+#endif
+
+static int xz_head(xz_statep state)
+{
+ 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 */
+ state->in = malloc(state->want);
+ state->out = malloc(state->want << 1);
+ if (state->in == NULL || state->out == NULL) {
+ if (state->out != NULL)
+ free(state->out);
+ if (state->in != NULL)
+ free(state->in);
+ 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;
+ if (lzma_auto_decoder(&state->strm, UINT64_MAX, 0) != LZMA_OK) {
+ free(state->out);
+ free(state->in);
+ state->size = 0;
+ xz_error(state, LZMA_MEM_ERROR, "out of memory");
+ return -1;
+ }
+
+#ifdef HAVE_ZLIB_H
+ /* 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;
+ if (inflateInit2(&(state->zstrm), -15) != Z_OK) { /* raw inflate */
+ free(state->out);
+ free(state->in);
+ state->size = 0;
+ xz_error(state, LZMA_MEM_ERROR, "out of memory");
+ return -1;
+ }
+#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;
+ }
+
+ /* look for the xz magic header bytes */
+ if (is_format_xz(state) || is_format_lzma(state)) {
+ state->how = LZMA;
+ state->direct = 0;
+ return 0;
+ }
+
+#ifdef HAVE_ZLIB_H
+ /* look for the gzip magic header bytes 31 and 139 */
+ 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 */
+ if (NEXT() != 8) { /* compression method */
+ xz_error(state, LZMA_DATA_ERROR, "unknown compression method");
+ return -1;
+ }
+ flags = NEXT();
+ if (flags & 0xe0) { /* reserved flag bits */
+ xz_error(state, LZMA_DATA_ERROR, "unknown header flags set");
+ return -1;
+ }
+ NEXT(); /* modification time */
+ NEXT();
+ NEXT();
+ NEXT();
+ NEXT(); /* extra flags */
+ NEXT(); /* operating system */
+ if (flags & 4) { /* extra field */
+ len = (unsigned)NEXT();
+ len += (unsigned)NEXT() << 8;
+ while (len--)
+ if (NEXT() < 0)
+ break;
+ }
+ if (flags & 8) /* file name */
+ while (NEXT() > 0)
+ ;
+ if (flags & 16) /* comment */
+ while (NEXT() > 0)
+ ;
+ if (flags & 2) { /* header crc */
+ NEXT();
+ NEXT();
+ }
+ /* an unexpected end of file is not checked for here -- it will be
+ noticed on the first request for uncompressed data */
+
+ /* set up for decompression */
+ inflateReset(&state->zstrm);
+ state->zstrm.adler = crc32(0L, Z_NULL, 0);
+ state->how = GZIP;
+ state->direct = 0;
+ return 0;
+ }
+ else {
+ /* 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
+ input to output -- this assumes that the output buffer is larger than
+ the input buffer, which also assures space for gzungetc() */
+ 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;
+}
+
+static int xz_decomp(xz_statep state)
+{
+ 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;
+
+ /* decompress and handle errors */
+#ifdef HAVE_ZLIB_H
+ if (state->how == GZIP) {
+ 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;
+ }
+ 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 */
+#endif
+ ret = lzma_code(strm, action);
+ 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;
+ }
+ } 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;
+#ifdef HAVE_ZLIB_H
+ state->zstrm.adler = crc32(state->zstrm.adler, state->next, state->have);
+#endif
+
+ if (ret == LZMA_STREAM_END) {
+#ifdef HAVE_ZLIB_H
+ if (state->how == GZIP) {
+ 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
+#endif
+ if ( strm->avail_in != 0 || !state->eof) {
+ xz_error(state, LZMA_DATA_ERROR, "trailing garbage");
+ return -1;
+ }
+ state->how = LOOK; /* ready for next stream, once have is 0 (leave
+ state->direct unchanged to remember how) */
+ }
+
+ /* good decompression */
+ return 0;
+}
+
+static int xz_make(xz_statep state)
+{
+ lzma_stream *strm = &(state->strm);
+
+ if (state->how == LOOK) { /* look for lzma / gzip header */
+ if (xz_head(state) == -1)
+ return -1;
+ if (state->have) /* got some data from xz_head() */
+ return 0;
+ }
+ if (state->how == COPY) { /* straight copy */
+ if (xz_load(state, state->out, state->size << 1, &(state->have)) == -1)
+ return -1;
+ state->next = state->out;
+ }
+ else if (state->how == LZMA || state->how == GZIP) { /* decompress */
+ strm->avail_out = state->size << 1;
+ strm->next_out = state->out;
+ if (xz_decomp(state) == -1)
+ return -1;
+ }
+ return 0;
+}
+
+static int xz_skip(xz_statep state, uint64_t len)
+{
+ 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) {
+ n = (uint64_t)state->have > len ?
+ (unsigned)len : state->have;
+ state->have -= n;
+ state->next += n;
+ state->pos += n;
+ len -= n;
+ }
+
+ /* output buffer empty -- return if we're at the end of the input */
+ else if (state->eof && state->strm.avail_in == 0)
+ break;
+
+ /* need more data to skip -- load up output buffer */
+ else {
+ /* get more output, looking for header if required */
+ if (xz_make(state) == -1)
+ return -1;
+ }
+ return 0;
+}
+
+int xzread(xzFile file, void *buf, unsigned len)
+{
+ unsigned got, n;
+ xz_statep state;
+ lzma_stream *strm;
+
+ /* get internal structure */
+ if (file == NULL)
+ return -1;
+ state = (xz_statep)file;
+ 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
+ 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");
+ 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
+ buffer */
+ else if (state->how == LOOK || len < (state->size << 1)) {
+ /* get more output, looking for header if required */
+ if (xz_make(state) == -1)
+ return -1;
+ continue; /* no progress yet -- go back to memcpy() above */
+ /* the copy above assures that we will leave with space in the
+ output buffer, allowing at least one gzungetc() to succeed */
+ }
+
+ /* large len -- read directly into user buffer */
+ else if (state->how == COPY) { /* read directly */
+ if (xz_load(state, buf, len, &n) == -1)
+ return -1;
+ }
+
+ /* large len -- decompress directly into user buffer */
+ else { /* state->how == LZMA */
+ 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;
+ buf = (char *)buf + n;
+ got += n;
+ state->pos += n;
+ } while (len);
+
+ /* return number of bytes read into user buffer (will fit in int) */
+ return (int)got;
+}
+
+int xzclose(xzFile file)
+{
+ int ret;
+ xz_statep state;
+
+ /* get internal structure */
+ if (file == NULL)
+ return LZMA_DATA_ERROR;
+ state = (xz_statep)file;
+
+ /* free memory and close file */
+ if (state->size) {
+ lzma_end(&(state->strm));
+#ifdef HAVE_LIBZ_H
+ inflateEnd(&(state->zstrm));
+#endif
+ free(state->out);
+ free(state->in);
+ }
+ free(state->path);
+ ret = close(state->fd);
+ free(state);
+ return ret ? ret : LZMA_OK;
+}
+