| #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; |
| } |
| |