| /* ----------------------------------------------------------------------- * |
| * |
| * Copyright 2003-2008 H. Peter Anvin - All Rights Reserved |
| * |
| * Permission is hereby granted, free of charge, to any person |
| * obtaining a copy of this software and associated documentation |
| * files (the "Software"), to deal in the Software without |
| * restriction, including without limitation the rights to use, |
| * copy, modify, merge, publish, distribute, sublicense, and/or |
| * sell copies of the Software, and to permit persons to whom |
| * the Software is furnished to do so, subject to the following |
| * conditions: |
| * |
| * The above copyright notice and this permission notice shall |
| * be included in all copies or substantial portions of the Software. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, |
| * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES |
| * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND |
| * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT |
| * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, |
| * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING |
| * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR |
| * OTHER DEALINGS IN THE SOFTWARE. |
| * |
| * ----------------------------------------------------------------------- */ |
| |
| #include <errno.h> |
| #include <string.h> |
| #include <unistd.h> |
| #include <fcntl.h> |
| #include <stdlib.h> |
| #include <syslinux/zio.h> |
| |
| #include "file.h" |
| #include "zlib.h" |
| |
| /* |
| * zopen.c |
| * |
| * Open an ordinary file, possibly compressed; if so, insert |
| * an appropriate decompressor. |
| */ |
| |
| int __file_get_block(struct file_info *fp); |
| int __file_close(struct file_info *fp); |
| |
| static ssize_t gzip_file_read(struct file_info *, void *, size_t); |
| static int gzip_file_close(struct file_info *); |
| |
| static const struct input_dev gzip_file_dev = { |
| .dev_magic = __DEV_MAGIC, |
| .flags = __DEV_FILE | __DEV_INPUT, |
| .fileflags = O_RDONLY, |
| .read = gzip_file_read, |
| .close = gzip_file_close, |
| .open = NULL, |
| }; |
| |
| static int gzip_file_init(struct file_info *fp) |
| { |
| z_streamp zs = calloc(1, sizeof(z_stream)); |
| |
| if (!zs) |
| return -1; |
| |
| fp->i.pvt = zs; |
| |
| zs->next_in = (void *)fp->i.datap; |
| zs->avail_in = fp->i.nbytes; |
| |
| if (inflateInit2(zs, 15 + 32) != Z_OK) { |
| errno = EIO; |
| return -1; |
| } |
| |
| fp->iop = &gzip_file_dev; |
| fp->i.fd.size = -1; /* Unknown */ |
| |
| return 0; |
| } |
| |
| static ssize_t gzip_file_read(struct file_info *fp, void *ptr, size_t n) |
| { |
| z_streamp zs = fp->i.pvt; |
| int rv; |
| ssize_t bytes; |
| ssize_t nout = 0; |
| unsigned char *p = ptr; |
| |
| while (n) { |
| zs->next_out = p; |
| zs->avail_out = n; |
| |
| if (!zs->avail_in && fp->i.fd.handle) { |
| if (__file_get_block(fp)) |
| return nout ? nout : -1; |
| |
| zs->next_in = (void *)fp->i.datap; |
| zs->avail_in = fp->i.nbytes; |
| } |
| |
| rv = inflate(zs, Z_SYNC_FLUSH); |
| |
| bytes = n - zs->avail_out; |
| nout += bytes; |
| p += bytes; |
| n -= bytes; |
| |
| switch (rv) { |
| case Z_DATA_ERROR: |
| case Z_NEED_DICT: |
| case Z_BUF_ERROR: |
| case Z_STREAM_ERROR: |
| default: |
| errno = EIO; |
| return nout ? nout : -1; |
| case Z_MEM_ERROR: |
| errno = ENOMEM; |
| return nout ? nout : -1; |
| case Z_STREAM_END: |
| return nout; |
| case Z_OK: |
| break; |
| } |
| } |
| |
| return nout; |
| } |
| |
| static int gzip_file_close(struct file_info *fp) |
| { |
| z_streamp zs = fp->i.pvt; |
| |
| inflateEnd(zs); |
| free(zs); |
| return __file_close(fp); |
| } |
| |
| int zopen(const char *pathname, int flags, ...) |
| { |
| int fd, rv; |
| struct file_info *fp; |
| |
| /* We don't actually give a hoot about the creation bits... */ |
| fd = open(pathname, flags, 0); |
| |
| if (fd < 0) |
| return -1; |
| |
| fp = &__file_info[fd]; |
| |
| /* Need to get the first block into the buffer, but not consumed */ |
| if (__file_get_block(fp)) |
| goto err; |
| |
| if (fp->i.nbytes >= 14 && |
| (uint8_t) fp->i.buf[0] == 037 && |
| (uint8_t) fp->i.buf[1] == 0213 && /* gzip */ |
| fp->i.buf[2] == 8) /* deflate */ |
| rv = gzip_file_init(fp); |
| else |
| rv = 0; /* Plain file */ |
| |
| if (!rv) |
| return fd; |
| |
| err: |
| close(fd); |
| return -1; |
| } |