zlib 1.2.3.5v1.2.3.5

1 files changed, 632 insertions, 0 deletions

diff --git a/gzread.c b/gzread.c
new file mode 100644
index 0000000..836c57c
--- /dev/null
+++ b/gzread.c
@@ -0,0 +1,632 @@
+/* gzread.c -- zlib functions for reading gzip files
+ * Copyright (C) 2004, 2005, 2010 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+#ifndef OLD_GZIO
+
+#include "gzguts.h"
+
+/* Local functions */
+local int gz_load OF((gz_statep, unsigned char *, unsigned, unsigned *));
+local int gz_avail OF((gz_statep));
+local int gz_next4 OF((gz_statep, unsigned long *));
+local int gz_head OF((gz_statep));
+local int gz_decomp OF((gz_statep));
+local int gz_make OF((gz_statep));
+local int gz_skip OF((gz_statep, z_off_t));
+
+/* Use read() to load a buffer -- return -1 on error, otherwise 0.  Read from
+   state->fd, and update state->eof, state->err, and state->msg as appropriate.
+   This function needs to loop on read(), since read() is not guaranteed to
+   read the number of bytes requested, depending on the type of descriptor. */
+local int gz_load(state, buf, len, have)
+    gz_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) {
+        gz_error(state, Z_ERRNO, zstrerror());
+        return -1;
+    }
+    if (ret == 0)
+        state->eof = 1;
+    return 0;
+}
+
+/* Load up input buffer and set eof flag if last data loaded -- return -1 on
+   error, 0 otherwise.  Note that the eof flag is set when the end of the input
+   file is reached, even though there may be unused data in the buffer.  Once
+   that data has been used, no more attempts will be made to read the file.
+   gz_avail() assumes that strm->avail_in == 0. */
+local int gz_avail(state)
+    gz_statep state;
+{
+    z_streamp strm = &(state->strm);
+
+    if (state->err != Z_OK)
+        return -1;
+    if (state->eof == 0) {
+        if (gz_load(state, state->in, state->size, &(strm->avail_in)) == -1)
+            return -1;
+        strm->next_in = state->in;
+    }
+    return 0;
+}
+
+/* Get next byte from input, or -1 if end or error. */
+#define NEXT() ((strm->avail_in == 0 && gz_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. */
+local int gz_next4(state, ret)
+    gz_statep state;
+    unsigned long *ret;
+{
+    int ch;
+    unsigned long val;
+    z_streamp strm = &(state->strm);
+
+    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;
+}
+
+/* Look for gzip header, set up for inflate or copy.  state->have must be zero.
+   If this is the first time in, allocate required memory.  state->how will be
+   left unchanged if there is no more input data available, will be set to 1 if
+   there is no gzip header and direct copying will be performned, or it will be
+   set to 2 for decompression, and the gzip header will be skipped so that the
+   next available input data is the raw deflate stream.  If direct copying,
+   then leftover input data from the input buffer will be copied to the output
+   buffer.  In that case, all further file reads will be directly to either the
+   output buffer or a user buffer.  If decompressing, the inflate state and the
+   check value will be initialized.  gz_head() will return 0 on success or -1
+   on failure.  Failures may include read errors or gzip header errors. */
+local int gz_head(state)
+    gz_statep state;
+{
+    z_streamp strm = &(state->strm);
+    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);
+            gz_error(state, Z_MEM_ERROR, "out of memory");
+            return -1;
+        }
+        state->size = state->want;
+
+        /* allocate inflate memory */
+        state->strm.zalloc = Z_NULL;
+        state->strm.zfree = Z_NULL;
+        state->strm.opaque = Z_NULL;
+        state->strm.avail_in = 0;
+        state->strm.next_in = Z_NULL;
+        if (inflateInit2(&(state->strm), -15) != Z_OK) {    /* raw inflate */
+            free(state->out);
+            free(state->in);
+            state->size = 0;
+            gz_error(state, Z_MEM_ERROR, "out of memory");
+            return -1;
+        }
+    }
+
+    /* get some data in the input buffer */
+    if (strm->avail_in == 0) {
+        if (gz_avail(state) == -1)
+            return -1;
+        if (strm->avail_in == 0)
+            return 0;
+    }
+
+    /* 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 && gz_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 */
+                gz_error(state, Z_DATA_ERROR, "unknown compression method");
+                return -1;
+            }
+            flags = NEXT();
+            if (flags & 0xe0) {     /* reserved flag bits */
+                gz_error(state, Z_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();
+            }
+
+            /* set up for decompression */
+            inflateReset(strm);
+            strm->adler = crc32(0L, Z_NULL, 0);
+            state->how = 2;
+            return 0;
+        }
+        else {
+            /* not a gzip file -- save first byte (31) and fall to raw i/o */
+            state->out[0] = 31;
+            state->have = 1;
+        }
+    }
+
+    /* 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 */
+    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 = 1;
+    return 0;
+}
+
+/* Decompress from input to the provided next_out and avail_out in the state.
+   If the end of the compressed data is reached, then verify the gzip trailer
+   check value and length (modulo 2^32).  state->have and state->next are
+   set to point to the just decompressed data, and the crc is updated.  If the
+   trailer is verified, state->how is reset to zero to look for the next gzip
+   stream or raw data, once state->have is depleted. Returns 0 on success, -1
+   on failure.  Failures may include invalid compressed data or a failed gzip
+   trailer verification. */
+local int gz_decomp(state)
+    gz_statep state;
+{
+    int ret;
+    unsigned had;
+    unsigned long crc, len;
+    z_streamp strm = &(state->strm);
+
+    /* fill output buffer up to end of deflate stream */
+    had = strm->avail_out;
+    do {
+        /* get more input for inflate() */
+        if (strm->avail_in == 0 && gz_avail(state) == -1)
+            return -1;
+        if (strm->avail_in == 0) {
+            gz_error(state, Z_DATA_ERROR, "unexpected end of file");
+            return -1;
+        }
+
+        /* decompress and handle errors */
+        ret = inflate(strm, Z_NO_FLUSH);
+        if (ret == Z_STREAM_ERROR || ret == Z_NEED_DICT) {
+            gz_error(state, Z_STREAM_ERROR,
+                      "internal error: inflate stream corrupt");
+            return -1;
+        }
+        if (ret == Z_MEM_ERROR) {
+            gz_error(state, Z_MEM_ERROR, "out of memory");
+            return -1;
+        }
+        if (ret == Z_DATA_ERROR) {              /* deflate stream invalid */
+            gz_error(state, Z_DATA_ERROR,
+                      strm->msg == NULL ? "compressed data error" : strm->msg);
+            return -1;
+        }
+    } while (strm->avail_out && ret != Z_STREAM_END);
+
+    /* update available output and crc check value */
+    state->have = had - strm->avail_out;
+    state->next = strm->next_out - state->have;
+    strm->adler = crc32(strm->adler, state->next, state->have);
+
+    /* check gzip trailer if at end of deflate stream */
+    if (ret == Z_STREAM_END) {
+        if (gz_next4(state, &crc) == -1 || gz_next4(state, &len) == -1) {
+            gz_error(state, Z_DATA_ERROR, "unexpected end of file");
+            return -1;
+        }
+        if (crc != strm->adler) {
+            gz_error(state, Z_DATA_ERROR, "incorrect data check");
+            return -1;
+        }
+        if (len != (strm->total_out & 0xffffffffL)) {
+            gz_error(state, Z_DATA_ERROR, "incorrect length check");
+            return -1;
+        }
+        state->how = 0;         /* ready for next stream, once have is 0 */
+    }
+
+    /* good decompression */
+    return 0;
+}
+
+/* Make data and put in the output buffer.  Assumes that state->have == 0.
+   Data is either copied from the input file or decompressed from the input
+   file depending on state->how.  If state->how is zero, then a gzip header is
+   looked for (and skipped if found) to determine wither to copy or decompress.
+   Returns -1 on error, otherwise 0.  gz_make() will leave state->have non-zero
+   unless the end of the input file has been reached and all data has been
+   processed. */
+local int gz_make(state)
+    gz_statep state;
+{
+    z_streamp strm = &(state->strm);
+
+    if (state->how == 0) {              /* look for gzip header */
+        if (gz_head(state) == -1)
+            return -1;
+        if (state->have)                /* got some data from gz_head() */
+            return 0;
+    }
+    if (state->how == 1) {              /* straight copy */
+        if (gz_load(state, state->out, state->size << 1, &(state->have)) == -1)
+            return -1;
+        state->next = state->out;
+    }
+    else if (state->how == 2) {         /* decompress */
+        strm->avail_out = state->size << 1;
+        strm->next_out = state->out;
+        if (gz_decomp(state) == -1)
+            return -1;
+    }
+    return 0;
+}
+
+/* Skip len uncompressed bytes of output.  Return -1 on error, 0 on success. */
+local int gz_skip(state, len)
+    gz_statep state;
+    z_off_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 = 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 (gz_make(state) == -1)
+                return -1;
+        }
+    return 0;
+}
+
+/* -- see zlib.h -- */
+int ZEXPORT gzread(file, buf, len)
+    gzFile file;
+    voidp buf;
+    unsigned len;
+{
+    unsigned got, n;
+    gz_statep state;
+    z_streamp strm;
+
+    /* get internal structure */
+    if (file == NULL)
+        return -1;
+    state = (gz_statep)file;
+    strm = &(state->strm);
+
+    /* check that we're reading and that there's no error */
+    if (state->mode != GZ_READ || state->err != Z_OK)
+        return -1;
+
+    /* process a skip request */
+    if (state->seek) {
+        state->seek = 0;
+        if (gz_skip(state, state->skip) == -1)
+            return -1;
+    }
+
+    /* get len bytes to buf, or less than len if at the end */
+    got = 0;
+    while (len) {
+
+        /* 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 == 0 || len < (state->size << 1)) {
+            /* get more output, looking for header if required */
+            if (gz_make(state) == -1)
+                return -1;
+            continue;       /* no progress yet -- go back to memcpy() above */
+        }
+
+        /* large len -- read directly into user buffer */
+        else if (state->how == 1) {          /* read directly */
+            if (gz_load(state, buf, len, &n) == -1)
+                return -1;
+        }
+
+        /* large len -- decompress directly into user buffer */
+        else {  /* state->how == 2 */
+            strm->avail_out = len;
+            strm->next_out = buf;
+            if (gz_decomp(state) == -1)
+                return -1;
+            n = state->have;
+            state->have = 0;
+        }
+
+        /* update progress */
+        len -= n;
+        buf += n;
+        got += n;
+        state->pos += n;
+    }
+
+    /* return number of bytes read into user buffer */
+    return (int)got;        /* len had better fit in int -- interface flaw */
+}
+
+/* -- see zlib.h -- */
+int ZEXPORT gzgetc(file)
+    gzFile file;
+{
+    int ret;
+    unsigned char buf[1];
+    gz_statep state;
+
+    /* get internal structure */
+    if (file == NULL)
+        return -1;
+    state = (gz_statep)file;
+
+    /* check that we're reading and that there's no error */
+    if (state->mode != GZ_READ || state->err != Z_OK)
+        return -1;
+
+    /* try output buffer */
+    if (state->have) {
+        state->have--;
+        state->pos++;
+        return *(state->next)++;
+    }
+
+    /* nothing there -- try gzread() */
+    ret = gzread(file, buf, 1);
+    return ret < 1 ? -1 : buf[0];
+}
+
+/* -- see zlib.h -- */
+int ZEXPORT gzungetc(c, file)
+    int c;
+    gzFile file;
+{
+    gz_statep state;
+
+    /* get internal structure */
+    if (file == NULL)
+        return -1;
+    state = (gz_statep)file;
+
+    /* check that we're reading and that there's no error */
+    if (state->mode != GZ_READ || state->err != Z_OK)
+        return -1;
+
+    /* process a skip request */
+    if (state->seek) {
+        state->seek = 0;
+        if (gz_skip(state, state->skip) == -1)
+            return -1;
+    }
+
+    /* can't push EOF */
+    if (c < 0)
+        return -1;
+
+    /* if output buffer empty, put byte at end (allows more pushing) */
+    if (state->have == 0) {
+        state->have = 1;
+        state->next = state->out + (state->size << 1) - 1;
+        state->next[0] = c;
+        state->pos--;
+        return c;
+    }
+
+    /* if no room, give up (must have already done a gz_ungetc()) */
+    if (state->have == (state->size << 1))
+        return -1;
+
+    /* slide output data if needed and insert byte before existing data */
+    if (state->next == state->out) {
+        unsigned char *src = state->out + state->have;
+        unsigned char *dest = state->out + (state->size << 1);
+        while (src > state->out)
+            *--dest = *--src;
+        state->next = dest;
+    }
+    state->have++;
+    state->next--;
+    state->next[0] = c;
+    state->pos--;
+    return c;
+}
+
+/* -- see zlib.h -- */
+char * ZEXPORT gzgets(file, buf, len)
+    gzFile file;
+    char *buf;
+    int len;
+{
+    unsigned left, n;
+    char *str;
+    unsigned char *eol;
+    gz_statep state;
+
+    /* get internal structure */
+    if (file == NULL)
+        return NULL;
+    state = (gz_statep)file;
+
+    /* check that we're reading and that there's no error */
+    if (state->mode != GZ_READ || state->err != Z_OK)
+        return NULL;
+
+    /* process a skip request */
+    if (state->seek) {
+        state->seek = 0;
+        if (gz_skip(state, state->skip) == -1)
+            return NULL;
+    }
+
+    /* check for a dumb length */
+    if (len < 2)
+        return NULL;
+
+    /* copy output bytes up to new line or len - 1, whichever comes first --
+       append a terminating zero to the string (we don't check for a zero in
+       the contents, let the user worry about that) */
+    str = buf;
+    left = (unsigned)len - 1;
+    do {
+        /* assure that something is in the output buffer */
+        if (state->have == 0) {
+            if (gz_make(state) == -1)
+                return NULL;            /* error */
+            if (state->have == 0) {     /* end of file */
+                if (buf == str)         /* got bupkus */
+                    return NULL;
+                break;                  /* got something -- return it */
+            }
+        }
+
+        /* look for end-of-line in current output buffer */
+        n = state->have > left ? left : state->have;
+        eol = memchr(state->next, '\n', n);
+        if (eol != NULL)
+            n = (eol - state->next) + 1;
+
+        /* copy through end-of-line, or remainder if not found */
+        memcpy(buf, state->next, n);
+        state->have -= n;
+        state->next += n;
+        state->pos += n;
+        left -= n;
+        buf += n;
+    } while (left && eol == NULL);
+
+    /* found end-of-line or out of space -- terminate string and return it */
+    buf[0] = 0;
+    return str;
+}
+
+/* -- see zlib.h -- */
+int ZEXPORT gzdirect(file)
+    gzFile file;
+{
+    gz_statep state;
+
+    /* get internal structure */
+    if (file == NULL)
+        return 0;
+    state = (gz_statep)file;
+
+    /* check that we're reading */
+    if (state->mode != GZ_READ)
+        return 0;
+
+    /* return true if reading without decompression */
+    return state->how == 1;
+}
+
+/* -- see zlib.h -- */
+int ZEXPORT gzclose_r(file)
+    gzFile file;
+{
+    gz_statep state;
+
+    /* get internal structure */
+    if (file == NULL)
+        return Z_STREAM_ERROR;
+    state = (gz_statep)file;
+
+    /* check that we're reading */
+    if (state->mode != GZ_READ)
+        return Z_STREAM_ERROR;
+
+    /* free memory and close file */
+    if (state->size) {
+        inflateEnd(&(state->strm));
+        free(state->out);
+        free(state->in);
+    }
+    gz_error(state, Z_OK, NULL);
+    close(state->fd);
+    free(state);
+    return Z_OK;
+}
+
+#endif /* !OLD_GZIO */