diff options
Diffstat (limited to 'lib/libstand/gzipfs.c')
| -rw-r--r-- | lib/libstand/gzipfs.c | 45 |
1 files changed, 30 insertions, 15 deletions
diff --git a/lib/libstand/gzipfs.c b/lib/libstand/gzipfs.c index 02195d80f4fd..9cc9ad9957f7 100644 --- a/lib/libstand/gzipfs.c +++ b/lib/libstand/gzipfs.c @@ -38,6 +38,7 @@ __FBSDID("$FreeBSD$"); struct z_file { int zf_rawfd; + off_t zf_dataoffset; z_stream zf_zstream; char zf_buf[Z_BUFSIZE]; }; @@ -98,11 +99,12 @@ zf_fill(struct z_file *zf) * Returns 0 if the header is OK, nonzero if not. */ static int -get_byte(struct z_file *zf) +get_byte(struct z_file *zf, off_t *curoffp) { if ((zf->zf_zstream.avail_in == 0) && (zf_fill(zf) == -1)) return(-1); zf->zf_zstream.avail_in--; + ++*curoffp; return(*(zf->zf_zstream.next_in)++); } @@ -124,36 +126,37 @@ check_header(struct z_file *zf) uInt len; int c; + zf->zf_dataoffset = 0; /* Check the gzip magic header */ for (len = 0; len < 2; len++) { - c = get_byte(zf); + c = get_byte(zf, &zf->zf_dataoffset); if (c != gz_magic[len]) { return(1); } } - method = get_byte(zf); - flags = get_byte(zf); + method = get_byte(zf, &zf->zf_dataoffset); + flags = get_byte(zf, &zf->zf_dataoffset); if (method != Z_DEFLATED || (flags & RESERVED) != 0) { return(1); } /* Discard time, xflags and OS code: */ - for (len = 0; len < 6; len++) (void)get_byte(zf); + for (len = 0; len < 6; len++) (void)get_byte(zf, &zf->zf_dataoffset); if ((flags & EXTRA_FIELD) != 0) { /* skip the extra field */ - len = (uInt)get_byte(zf); - len += ((uInt)get_byte(zf))<<8; + len = (uInt)get_byte(zf, &zf->zf_dataoffset); + len += ((uInt)get_byte(zf, &zf->zf_dataoffset))<<8; /* len is garbage if EOF but the loop below will quit anyway */ - while (len-- != 0 && get_byte(zf) != -1) ; + while (len-- != 0 && get_byte(zf, &zf->zf_dataoffset) != -1) ; } if ((flags & ORIG_NAME) != 0) { /* skip the original file name */ - while ((c = get_byte(zf)) != 0 && c != -1) ; + while ((c = get_byte(zf, &zf->zf_dataoffset)) != 0 && c != -1) ; } if ((flags & COMMENT) != 0) { /* skip the .gz file comment */ - while ((c = get_byte(zf)) != 0 && c != -1) ; + while ((c = get_byte(zf, &zf->zf_dataoffset)) != 0 && c != -1) ; } if ((flags & HEAD_CRC) != 0) { /* skip the header crc */ - for (len = 0; len < 2; len++) c = get_byte(zf); + for (len = 0; len < 2; len++) c = get_byte(zf, &zf->zf_dataoffset); } /* if there's data left, we're in business */ return((c == -1) ? 1 : 0); @@ -274,6 +277,20 @@ zf_read(struct open_file *f, void *buf, size_t size, size_t *resid) return(0); } +static int +zf_rewind(struct open_file *f) +{ + struct z_file *zf = (struct z_file *)f->f_fsdata; + + if (lseek(zf->zf_rawfd, zf->zf_dataoffset, SEEK_SET) == -1) + return -1; + zf->zf_zstream.avail_in = 0; + zf->zf_zstream.next_in = NULL; + (void)inflateReset(&zf->zf_zstream); + + return 0; +} + static off_t zf_seek(struct open_file *f, off_t offset, int where) { @@ -292,11 +309,9 @@ zf_seek(struct open_file *f, off_t offset, int where) target = -1; } - /* Can we get there from here? */ - if (target < zf->zf_zstream.total_out) { - errno = EOFFSET; + /* rewind if required */ + if (target < zf->zf_zstream.total_out && zf_rewind(f) != 0) return -1; - } /* skip forwards if required */ while (target > zf->zf_zstream.total_out) { |