c3a82ca0a6
more weird kinds of a.out than anyone can argue for. This code failed to load the first 28K of the text-segment, in the case where the first page of the a.out contains only the a.out-header, and the text is still at 0x0. Thanks Steven !
1491 lines
47 KiB
C
1491 lines
47 KiB
C
/*
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* Parts of this file are not covered by:
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* ----------------------------------------------------------------------------
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* "THE BEER-WARE LICENSE" (Revision 42):
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* <phk@login.dknet.dk> wrote this file. As long as you retain this notice you
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* can do whatever you want with this stuff. If we meet some day, and you think
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* this stuff is worth it, you can buy me a beer in return. Poul-Henning Kamp
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* ----------------------------------------------------------------------------
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*
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* $Id: imgact_gzip.c,v 1.5 1994/10/05 00:58:33 phk Exp $
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*
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* This module handles execution of a.out files which have been run through
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* "gzip -9".
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*
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* For now you need to use exactly this command to compress the binaries:
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*
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* gzip -9 -v < /bin/sh > /tmp/sh
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*
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* TODO:
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* text-segments should be made R/O after being filled
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* is the vm-stuff safe ?
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* should handle the entire header of gzip'ed stuff.
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* inflate isn't quite reentrant yet...
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* error-handling is a mess...
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* so is the rest...
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*/
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/resourcevar.h>
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#include <sys/exec.h>
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#include <sys/mman.h>
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#include <sys/malloc.h>
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#include <sys/imgact.h>
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#include <sys/imgact_aout.h>
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#include <sys/kernel.h>
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#include <sys/sysent.h>
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#include <vm/vm.h>
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#include <vm/vm_kern.h>
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#define WSIZE 0x8000
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struct gzip {
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struct image_params *ip;
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struct exec a_out;
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int error;
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int where;
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u_char *inbuf;
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u_long offset;
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u_long output;
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u_long len;
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int idx;
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u_long virtual_offset, file_offset, file_end, bss_size;
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unsigned gz_wp;
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u_char *gz_slide;
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};
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int inflate __P((struct gzip *));
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extern struct sysentvec aout_sysvec;
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#define slide (gz->gz_slide)
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#define wp (gz->gz_wp)
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int
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exec_gzip_imgact(iparams)
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struct image_params *iparams;
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{
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int error,error2=0;
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u_char *p = (u_char *) iparams->image_header;
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struct gzip *gz;
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/* If these four are not OK, it isn't a gzip file */
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if (p[0] != 0x1f) return -1; /* 0 Simply magic */
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if (p[1] != 0x8b) return -1; /* 1 Simply magic */
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if (p[2] != 0x08) return -1; /* 2 Compression method */
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if (p[9] != 0x03) return -1; /* 9 OS compressed on */
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/* If this one contains anything but a comment or a filename
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* marker, we don't want to chew on it
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*/
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if (p[3] & ~(0x18)) return ENOEXEC; /* 3 Flags */
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/* These are of no use to us */
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/* 4-7 Timestamp */
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/* 8 Extra flags */
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gz = malloc(sizeof *gz,M_GZIP,M_NOWAIT);
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if (!gz)
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return ENOMEM;
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bzero(gz,sizeof *gz); /* waste of time ? */
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error = vm_allocate(kernel_map, &gz->gz_slide, WSIZE, TRUE);
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if (error) {
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free(gz,M_GZIP);
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return error;
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}
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gz->ip = iparams;
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gz->error = ENOEXEC;
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gz->idx = 10;
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if (p[3] & 0x08) { /* skip a filename */
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while (p[gz->idx++])
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if (gz->idx >= PAGE_SIZE)
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goto done;
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}
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if (p[3] & 0x10) { /* skip a comment */
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while (p[gz->idx++])
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if (gz->idx >= PAGE_SIZE)
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goto done;
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}
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gz->len = gz->ip->attr->va_size;
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gz->error = 0;
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error = inflate(gz);
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if (gz->inbuf) {
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error2 =
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vm_deallocate(kernel_map, (vm_offset_t)gz->inbuf, PAGE_SIZE);
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}
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if (gz->error || error || error2) {
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printf("Output=%lu ",gz->output);
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printf("Inflate_error=%d gz->error=%d error2=%d where=%d\n",
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error,gz->error,error2,gz->where);
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if (gz->error)
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goto done;
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if (error) {
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gz->error = ENOEXEC;
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goto done;
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}
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if (error2) {
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gz->error = error2;
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goto done;
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}
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}
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done:
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error = gz->error;
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vm_deallocate(kernel_map, gz->gz_slide, WSIZE);
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free(gz,M_GZIP);
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return error;
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}
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int
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do_aout_hdr(struct gzip *gz)
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{
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int error;
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struct vmspace *vmspace = gz->ip->proc->p_vmspace;
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u_long vmaddr;
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/*
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* Set file/virtual offset based on a.out variant.
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* We do two cases: host byte order and network byte order
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* (for NetBSD compatibility)
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*/
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switch ((int)(gz->a_out.a_magic & 0xffff)) {
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case ZMAGIC:
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gz->virtual_offset = 0;
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if (gz->a_out.a_text) {
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gz->file_offset = NBPG;
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} else {
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/* Bill's "screwball mode" */
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gz->file_offset = 0;
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}
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break;
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case QMAGIC:
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gz->virtual_offset = NBPG;
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gz->file_offset = 0;
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break;
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default:
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/* NetBSD compatibility */
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switch ((int)(ntohl(gz->a_out.a_magic) & 0xffff)) {
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case ZMAGIC:
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case QMAGIC:
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gz->virtual_offset = NBPG;
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gz->file_offset = 0;
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break;
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default:
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gz->where = __LINE__;
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return (-1);
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}
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}
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gz->bss_size = roundup(gz->a_out.a_bss, NBPG);
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/*
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* Check various fields in header for validity/bounds.
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*/
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if (/* entry point must lay with text region */
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gz->a_out.a_entry < gz->virtual_offset ||
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gz->a_out.a_entry >= gz->virtual_offset + gz->a_out.a_text ||
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/* text and data size must each be page rounded */
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gz->a_out.a_text % NBPG ||
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gz->a_out.a_data % NBPG) {
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gz->where = __LINE__;
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return (-1);
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}
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/*
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* text/data/bss must not exceed limits
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*/
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if (/* text can't exceed maximum text size */
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gz->a_out.a_text > MAXTSIZ ||
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/* data + bss can't exceed maximum data size */
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gz->a_out.a_data + gz->bss_size > MAXDSIZ ||
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/* data + bss can't exceed rlimit */
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gz->a_out.a_data + gz->bss_size >
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gz->ip->proc->p_rlimit[RLIMIT_DATA].rlim_cur) {
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gz->where = __LINE__;
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return (ENOMEM);
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}
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/* Find out how far we should go */
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gz->file_end = gz->file_offset + gz->a_out.a_text + gz->a_out.a_data;
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/* copy in arguments and/or environment from old process */
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error = exec_extract_strings(gz->ip);
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if (error) {
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gz->where = __LINE__;
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return (error);
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}
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/*
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* Destroy old process VM and create a new one (with a new stack)
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*/
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exec_new_vmspace(gz->ip);
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vmaddr = gz->virtual_offset;
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error = vm_mmap(&vmspace->vm_map, /* map */
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&vmaddr, /* address */
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gz->a_out.a_text, /* size */
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VM_PROT_READ | VM_PROT_EXECUTE | VM_PROT_WRITE, /* protection */
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VM_PROT_READ | VM_PROT_EXECUTE | VM_PROT_WRITE,
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MAP_ANON | MAP_FIXED, /* flags */
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0, /* vnode */
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0); /* offset */
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if (error) {
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gz->where = __LINE__;
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return (error);
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}
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vmaddr = gz->virtual_offset + gz->a_out.a_text;
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/*
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* Map data read/write (if text is 0, assume text is in data area
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* [Bill's screwball mode])
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*/
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error = vm_mmap(&vmspace->vm_map,
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&vmaddr,
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gz->a_out.a_data,
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VM_PROT_READ | VM_PROT_WRITE | (gz->a_out.a_text ? 0 : VM_PROT_EXECUTE),
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VM_PROT_ALL, MAP_ANON | MAP_FIXED,
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0,
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0);
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if (error) {
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gz->where = __LINE__;
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return (error);
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}
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/*
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* Allocate demand-zeroed area for uninitialized data
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* "bss" = 'block started by symbol' - named after the IBM 7090
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* instruction of the same name.
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*/
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vmaddr = gz->virtual_offset + gz->a_out.a_text + gz->a_out.a_data;
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error = vm_allocate(&vmspace->vm_map, &vmaddr, gz->bss_size, FALSE);
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if (error) {
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gz->where = __LINE__;
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return (error);
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}
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/* Fill in process VM information */
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vmspace->vm_tsize = gz->a_out.a_text >> PAGE_SHIFT;
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vmspace->vm_dsize = (gz->a_out.a_data + gz->bss_size) >> PAGE_SHIFT;
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vmspace->vm_taddr = (caddr_t) gz->virtual_offset;
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vmspace->vm_daddr = (caddr_t) gz->virtual_offset + gz->a_out.a_text;
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/* Fill in image_params */
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gz->ip->interpreted = 0;
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gz->ip->entry_addr = gz->a_out.a_entry;
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gz->ip->proc->p_sysent = &aout_sysvec;
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return 0;
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}
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/*
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* Tell kern_execve.c about it, with a little help from the linker.
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* Since `const' objects end up in the text segment, TEXT_SET is the
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* correct directive to use.
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*/
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static const struct execsw gzip_execsw = { exec_gzip_imgact, "gzip" };
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TEXT_SET(execsw_set, gzip_execsw);
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/* Stuff to make inflate() work */
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# define uch u_char
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# define ush u_short
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# define ulg u_long
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# define memzero(dest,len) bzero(dest,len)
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# define NOMEMCPY
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#define FPRINTF printf
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#define EOF -1
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#define CHECK_EOF
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static int
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NextByte(struct gzip *gz)
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{
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int error;
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if(gz->idx >= gz->len) {
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gz->where = __LINE__;
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return EOF;
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}
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if((!gz->inbuf) || gz->idx >= (gz->offset+PAGE_SIZE)) {
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if(gz->inbuf) {
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error = vm_deallocate(kernel_map,
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(vm_offset_t)gz->inbuf, PAGE_SIZE);
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if(error) {
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gz->where = __LINE__;
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gz->error = error;
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return EOF;
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}
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}
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gz->offset += PAGE_SIZE;
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error = vm_mmap(kernel_map, /* map */
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(vm_offset_t *)&gz->inbuf, /* address */
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PAGE_SIZE, /* size */
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VM_PROT_READ, /* protection */
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VM_PROT_READ, /* max protection */
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0, /* flags */
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(caddr_t)gz->ip->vnodep, /* vnode */
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gz->offset); /* offset */
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if(error) {
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gz->where = __LINE__;
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gz->error = error;
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return EOF;
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}
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}
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return gz->inbuf[(gz->idx++) - gz->offset];
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}
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|
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#define NEXTBYTE NextByte(gz)
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|
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static int
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Flush(struct gzip *gz,u_long siz)
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{
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u_char *p = slide,*q;
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int i;
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/* First, find a a.out-header */
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if(gz->output < sizeof gz->a_out) {
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q = (u_char*) &gz->a_out;
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i = min(siz,sizeof gz->a_out - gz->output);
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bcopy(p,q+gz->output,i);
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gz->output += i;
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p += i;
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siz -= i;
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if(gz->output == sizeof gz->a_out) {
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i = do_aout_hdr(gz);
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if (i == -1) {
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gz->where = __LINE__;
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gz->error = ENOEXEC;
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return ENOEXEC;
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} else if (i) {
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gz->where = __LINE__;
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gz->error = i;
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return ENOEXEC;
|
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}
|
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if(gz->file_offset < sizeof gz->a_out) {
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q = (u_char*) gz->virtual_offset + gz->output - gz->file_offset;
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bcopy(&gz->a_out,q,sizeof gz->a_out - gz->file_offset);
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}
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}
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}
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/* Skip over zero-padded first PAGE if needed */
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if(gz->output < gz->file_offset && (gz->output+siz) > gz->file_offset) {
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i = min(siz, gz->file_offset - gz->output);
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gz->output += i;
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p += i;
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siz -= i;
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}
|
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if(gz->output >= gz->file_offset && gz->output < gz->file_end) {
|
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i = min(siz, gz->file_end - gz->output);
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q = (u_char*) gz->virtual_offset + gz->output - gz->file_offset;
|
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bcopy(p,q,i);
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gz->output += i;
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p += i;
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siz -= i;
|
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}
|
|
gz->output += siz;
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return 0;
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}
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|
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#define FLUSH(x,y) {int foo = Flush(x,y); if (foo) return foo;}
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static
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void *
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myalloc(u_long size)
|
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{
|
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return malloc(size, M_GZIP, M_NOWAIT);
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|
}
|
|
#define malloc myalloc
|
|
|
|
static
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|
void
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|
myfree(void * ptr)
|
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{
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free(ptr,M_GZIP);
|
|
}
|
|
#define free myfree
|
|
|
|
static int qflag;
|
|
#define Trace(x) /* */
|
|
|
|
|
|
/* This came from unzip-5.12. I have changed it to pass a "gz" pointer
|
|
* around, thus hopefully making it re-entrant. Poul-Henningi
|
|
*/
|
|
|
|
/* inflate.c -- put in the public domain by Mark Adler
|
|
version c14o, 23 August 1994 */
|
|
|
|
/* You can do whatever you like with this source file, though I would
|
|
prefer that if you modify it and redistribute it that you include
|
|
comments to that effect with your name and the date. Thank you.
|
|
|
|
History:
|
|
vers date who what
|
|
---- --------- -------------- ------------------------------------
|
|
a ~~ Feb 92 M. Adler used full (large, one-step) lookup table
|
|
b1 21 Mar 92 M. Adler first version with partial lookup tables
|
|
b2 21 Mar 92 M. Adler fixed bug in fixed-code blocks
|
|
b3 22 Mar 92 M. Adler sped up match copies, cleaned up some
|
|
b4 25 Mar 92 M. Adler added prototypes; removed window[] (now
|
|
is the responsibility of unzip.h--also
|
|
changed name to slide[]), so needs diffs
|
|
for unzip.c and unzip.h (this allows
|
|
compiling in the small model on MSDOS);
|
|
fixed cast of q in huft_build();
|
|
b5 26 Mar 92 M. Adler got rid of unintended macro recursion.
|
|
b6 27 Mar 92 M. Adler got rid of nextbyte() routine. fixed
|
|
bug in inflate_fixed().
|
|
c1 30 Mar 92 M. Adler removed lbits, dbits environment variables.
|
|
changed BMAX to 16 for explode. Removed
|
|
OUTB usage, and replaced it with flush()--
|
|
this was a 20% speed improvement! Added
|
|
an explode.c (to replace unimplod.c) that
|
|
uses the huft routines here. Removed
|
|
register union.
|
|
c2 4 Apr 92 M. Adler fixed bug for file sizes a multiple of 32k.
|
|
c3 10 Apr 92 M. Adler reduced memory of code tables made by
|
|
huft_build significantly (factor of two to
|
|
three).
|
|
c4 15 Apr 92 M. Adler added NOMEMCPY do kill use of memcpy().
|
|
worked around a Turbo C optimization bug.
|
|
c5 21 Apr 92 M. Adler added the WSIZE #define to allow reducing
|
|
the 32K window size for specialized
|
|
applications.
|
|
c6 31 May 92 M. Adler added some typecasts to eliminate warnings
|
|
c7 27 Jun 92 G. Roelofs added some more typecasts (444: MSC bug).
|
|
c8 5 Oct 92 J-l. Gailly added ifdef'd code to deal with PKZIP bug.
|
|
c9 9 Oct 92 M. Adler removed a memory error message (~line 416).
|
|
c10 17 Oct 92 G. Roelofs changed ULONG/UWORD/byte to ulg/ush/uch,
|
|
removed old inflate, renamed inflate_entry
|
|
to inflate, added Mark's fix to a comment.
|
|
c10.5 14 Dec 92 M. Adler fix up error messages for incomplete trees.
|
|
c11 2 Jan 93 M. Adler fixed bug in detection of incomplete
|
|
tables, and removed assumption that EOB is
|
|
the longest code (bad assumption).
|
|
c12 3 Jan 93 M. Adler make tables for fixed blocks only once.
|
|
c13 5 Jan 93 M. Adler allow all zero length codes (pkzip 2.04c
|
|
outputs one zero length code for an empty
|
|
distance tree).
|
|
c14 12 Mar 93 M. Adler made inflate.c standalone with the
|
|
introduction of inflate.h.
|
|
c14b 16 Jul 93 G. Roelofs added (unsigned) typecast to w at 470.
|
|
c14c 19 Jul 93 J. Bush changed v[N_MAX], l[288], ll[28x+3x] arrays
|
|
to static for Amiga.
|
|
c14d 13 Aug 93 J-l. Gailly de-complicatified Mark's c[*p++]++ thing.
|
|
c14e 8 Oct 93 G. Roelofs changed memset() to memzero().
|
|
c14f 22 Oct 93 G. Roelofs renamed quietflg to qflag; made Trace()
|
|
conditional; added inflate_free().
|
|
c14g 28 Oct 93 G. Roelofs changed l/(lx+1) macro to pointer (Cray bug)
|
|
c14h 7 Dec 93 C. Ghisler huft_build() optimizations.
|
|
c14i 9 Jan 94 A. Verheijen set fixed_t{d,l} to NULL after freeing;
|
|
G. Roelofs check NEXTBYTE macro for EOF.
|
|
c14j 23 Jan 94 G. Roelofs removed Ghisler "optimizations"; ifdef'd
|
|
EOF check.
|
|
c14k 27 Feb 94 G. Roelofs added some typecasts to avoid warnings.
|
|
c14l 9 Apr 94 G. Roelofs fixed split comments on preprocessor lines
|
|
to avoid bug in Encore compiler.
|
|
c14m 7 Jul 94 P. Kienitz modified to allow assembler version of
|
|
inflate_codes() (define ASM_INFLATECODES)
|
|
c14n 22 Jul 94 G. Roelofs changed fprintf to FPRINTF for DLL versions
|
|
c14o 23 Aug 94 C. Spieler added a newline to a debug statement;
|
|
G. Roelofs added another typecast to avoid MSC warning
|
|
*/
|
|
|
|
|
|
/*
|
|
Inflate deflated (PKZIP's method 8 compressed) data. The compression
|
|
method searches for as much of the current string of bytes (up to a
|
|
length of 258) in the previous 32K bytes. If it doesn't find any
|
|
matches (of at least length 3), it codes the next byte. Otherwise, it
|
|
codes the length of the matched string and its distance backwards from
|
|
the current position. There is a single Huffman code that codes both
|
|
single bytes (called "literals") and match lengths. A second Huffman
|
|
code codes the distance information, which follows a length code. Each
|
|
length or distance code actually represents a base value and a number
|
|
of "extra" (sometimes zero) bits to get to add to the base value. At
|
|
the end of each deflated block is a special end-of-block (EOB) literal/
|
|
length code. The decoding process is basically: get a literal/length
|
|
code; if EOB then done; if a literal, emit the decoded byte; if a
|
|
length then get the distance and emit the referred-to bytes from the
|
|
sliding window of previously emitted data.
|
|
|
|
There are (currently) three kinds of inflate blocks: stored, fixed, and
|
|
dynamic. The compressor outputs a chunk of data at a time and decides
|
|
which method to use on a chunk-by-chunk basis. A chunk might typically
|
|
be 32K to 64K, uncompressed. If the chunk is uncompressible, then the
|
|
"stored" method is used. In this case, the bytes are simply stored as
|
|
is, eight bits per byte, with none of the above coding. The bytes are
|
|
preceded by a count, since there is no longer an EOB code.
|
|
|
|
If the data is compressible, then either the fixed or dynamic methods
|
|
are used. In the dynamic method, the compressed data is preceded by
|
|
an encoding of the literal/length and distance Huffman codes that are
|
|
to be used to decode this block. The representation is itself Huffman
|
|
coded, and so is preceded by a description of that code. These code
|
|
descriptions take up a little space, and so for small blocks, there is
|
|
a predefined set of codes, called the fixed codes. The fixed method is
|
|
used if the block ends up smaller that way (usually for quite small
|
|
chunks); otherwise the dynamic method is used. In the latter case, the
|
|
codes are customized to the probabilities in the current block and so
|
|
can code it much better than the pre-determined fixed codes can.
|
|
|
|
The Huffman codes themselves are decoded using a mutli-level table
|
|
lookup, in order to maximize the speed of decoding plus the speed of
|
|
building the decoding tables. See the comments below that precede the
|
|
lbits and dbits tuning parameters.
|
|
*/
|
|
|
|
|
|
/*
|
|
Notes beyond the 1.93a appnote.txt:
|
|
|
|
1. Distance pointers never point before the beginning of the output
|
|
stream.
|
|
2. Distance pointers can point back across blocks, up to 32k away.
|
|
3. There is an implied maximum of 7 bits for the bit length table and
|
|
15 bits for the actual data.
|
|
4. If only one code exists, then it is encoded using one bit. (Zero
|
|
would be more efficient, but perhaps a little confusing.) If two
|
|
codes exist, they are coded using one bit each (0 and 1).
|
|
5. There is no way of sending zero distance codes--a dummy must be
|
|
sent if there are none. (History: a pre 2.0 version of PKZIP would
|
|
store blocks with no distance codes, but this was discovered to be
|
|
too harsh a criterion.) Valid only for 1.93a. 2.04c does allow
|
|
zero distance codes, which is sent as one code of zero bits in
|
|
length.
|
|
6. There are up to 286 literal/length codes. Code 256 represents the
|
|
end-of-block. Note however that the static length tree defines
|
|
288 codes just to fill out the Huffman codes. Codes 286 and 287
|
|
cannot be used though, since there is no length base or extra bits
|
|
defined for them. Similarily, there are up to 30 distance codes.
|
|
However, static trees define 32 codes (all 5 bits) to fill out the
|
|
Huffman codes, but the last two had better not show up in the data.
|
|
7. Unzip can check dynamic Huffman blocks for complete code sets.
|
|
The exception is that a single code would not be complete (see #4).
|
|
8. The five bits following the block type is really the number of
|
|
literal codes sent minus 257.
|
|
9. Length codes 8,16,16 are interpreted as 13 length codes of 8 bits
|
|
(1+6+6). Therefore, to output three times the length, you output
|
|
three codes (1+1+1), whereas to output four times the same length,
|
|
you only need two codes (1+3). Hmm.
|
|
10. In the tree reconstruction algorithm, Code = Code + Increment
|
|
only if BitLength(i) is not zero. (Pretty obvious.)
|
|
11. Correction: 4 Bits: # of Bit Length codes - 4 (4 - 19)
|
|
12. Note: length code 284 can represent 227-258, but length code 285
|
|
really is 258. The last length deserves its own, short code
|
|
since it gets used a lot in very redundant files. The length
|
|
258 is special since 258 - 3 (the min match length) is 255.
|
|
13. The literal/length and distance code bit lengths are read as a
|
|
single stream of lengths. It is possible (and advantageous) for
|
|
a repeat code (16, 17, or 18) to go across the boundary between
|
|
the two sets of lengths.
|
|
*/
|
|
|
|
|
|
#define PKZIP_BUG_WORKAROUND /* PKZIP 1.93a problem--live with it */
|
|
|
|
/*
|
|
inflate.h must supply the uch slide[WSIZE] array and the NEXTBYTE,
|
|
FLUSH() and memzero macros. If the window size is not 32K, it
|
|
should also define WSIZE. If INFMOD is defined, it can include
|
|
compiled functions to support the NEXTBYTE and/or FLUSH() macros.
|
|
There are defaults for NEXTBYTE and FLUSH() below for use as
|
|
examples of what those functions need to do. Normally, you would
|
|
also want FLUSH() to compute a crc on the data. inflate.h also
|
|
needs to provide these typedefs:
|
|
|
|
typedef unsigned char uch;
|
|
typedef unsigned short ush;
|
|
typedef unsigned long ulg;
|
|
|
|
This module uses the external functions malloc() and free() (and
|
|
probably memset() or bzero() in the memzero() macro). Their
|
|
prototypes are normally found in <string.h> and <stdlib.h>.
|
|
*/
|
|
#define INFMOD /* tell inflate.h to include code to be compiled */
|
|
|
|
/* Huffman code lookup table entry--this entry is four bytes for machines
|
|
that have 16-bit pointers (e.g. PC's in the small or medium model).
|
|
Valid extra bits are 0..13. e == 15 is EOB (end of block), e == 16
|
|
means that v is a literal, 16 < e < 32 means that v is a pointer to
|
|
the next table, which codes e - 16 bits, and lastly e == 99 indicates
|
|
an unused code. If a code with e == 99 is looked up, this implies an
|
|
error in the data. */
|
|
struct huft {
|
|
uch e; /* number of extra bits or operation */
|
|
uch b; /* number of bits in this code or subcode */
|
|
union {
|
|
ush n; /* literal, length base, or distance base */
|
|
struct huft *t; /* pointer to next level of table */
|
|
} v;
|
|
};
|
|
|
|
|
|
/* Function prototypes */
|
|
#ifndef OF
|
|
# ifdef __STDC__
|
|
# define OF(a) a
|
|
# else /* !__STDC__ */
|
|
# define OF(a) ()
|
|
# endif /* ?__STDC__ */
|
|
#endif
|
|
int huft_build OF((struct gzip *,unsigned *, unsigned, unsigned, ush *, ush *,
|
|
struct huft **, int *));
|
|
int huft_free OF((struct gzip *,struct huft *));
|
|
int inflate_codes OF((struct gzip *,struct huft *, struct huft *, int, int));
|
|
int inflate_stored OF((struct gzip *));
|
|
int inflate_fixed OF((struct gzip *));
|
|
int inflate_dynamic OF((struct gzip *));
|
|
int inflate_block OF((struct gzip *,int *));
|
|
int inflate_free OF((struct gzip *));
|
|
|
|
|
|
/* The inflate algorithm uses a sliding 32K byte window on the uncompressed
|
|
stream to find repeated byte strings. This is implemented here as a
|
|
circular buffer. The index is updated simply by incrementing and then
|
|
and'ing with 0x7fff (32K-1). */
|
|
/* It is left to other modules to supply the 32K area. It is assumed
|
|
to be usable as if it were declared "uch slide[32768];" or as just
|
|
"uch *slide;" and then malloc'ed in the latter case. The definition
|
|
must be in unzip.h, included above. */
|
|
|
|
|
|
/* Tables for deflate from PKZIP's appnote.txt. */
|
|
static unsigned border[] = { /* Order of the bit length code lengths */
|
|
16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
|
|
static ush cplens[] = { /* Copy lengths for literal codes 257..285 */
|
|
3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31,
|
|
35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0};
|
|
/* note: see note #13 above about the 258 in this list. */
|
|
static ush cplext[] = { /* Extra bits for literal codes 257..285 */
|
|
0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2,
|
|
3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0, 99, 99}; /* 99==invalid */
|
|
static ush cpdist[] = { /* Copy offsets for distance codes 0..29 */
|
|
1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,
|
|
257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145,
|
|
8193, 12289, 16385, 24577};
|
|
static ush cpdext[] = { /* Extra bits for distance codes */
|
|
0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6,
|
|
7, 7, 8, 8, 9, 9, 10, 10, 11, 11,
|
|
12, 12, 13, 13};
|
|
|
|
/* And'ing with mask[n] masks the lower n bits */
|
|
ush mask[] = {
|
|
0x0000,
|
|
0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
|
|
0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff
|
|
};
|
|
|
|
|
|
/* Macros for inflate() bit peeking and grabbing.
|
|
The usage is:
|
|
|
|
NEEDBITS(j)
|
|
x = b & mask[j];
|
|
DUMPBITS(j)
|
|
|
|
where NEEDBITS makes sure that b has at least j bits in it, and
|
|
DUMPBITS removes the bits from b. The macros use the variable k
|
|
for the number of bits in b. Normally, b and k are register
|
|
variables for speed, and are initialized at the begining of a
|
|
routine that uses these macros from a global bit buffer and count.
|
|
|
|
In order to not ask for more bits than there are in the compressed
|
|
stream, the Huffman tables are constructed to only ask for just
|
|
enough bits to make up the end-of-block code (value 256). Then no
|
|
bytes need to be "returned" to the buffer at the end of the last
|
|
block. See the huft_build() routine.
|
|
*/
|
|
|
|
ulg bb; /* bit buffer */
|
|
unsigned bk; /* bits in bit buffer */
|
|
|
|
#ifndef CHECK_EOF
|
|
# define NEEDBITS(n) {while(k<(n)){b|=((ulg)NEXTBYTE)<<k;k+=8;}}
|
|
#else
|
|
# define NEEDBITS(n) {while(k<(n)){int c=NEXTBYTE;if(c==EOF)return 1;\
|
|
b|=((ulg)c)<<k;k+=8;}}
|
|
#endif /* Piet Plomp: change "return 1" to "break" */
|
|
|
|
#define DUMPBITS(n) {b>>=(n);k-=(n);}
|
|
|
|
|
|
/*
|
|
Huffman code decoding is performed using a multi-level table lookup.
|
|
The fastest way to decode is to simply build a lookup table whose
|
|
size is determined by the longest code. However, the time it takes
|
|
to build this table can also be a factor if the data being decoded
|
|
is not very long. The most common codes are necessarily the
|
|
shortest codes, so those codes dominate the decoding time, and hence
|
|
the speed. The idea is you can have a shorter table that decodes the
|
|
shorter, more probable codes, and then point to subsidiary tables for
|
|
the longer codes. The time it costs to decode the longer codes is
|
|
then traded against the time it takes to make longer tables.
|
|
|
|
This results of this trade are in the variables lbits and dbits
|
|
below. lbits is the number of bits the first level table for literal/
|
|
length codes can decode in one step, and dbits is the same thing for
|
|
the distance codes. Subsequent tables are also less than or equal to
|
|
those sizes. These values may be adjusted either when all of the
|
|
codes are shorter than that, in which case the longest code length in
|
|
bits is used, or when the shortest code is *longer* than the requested
|
|
table size, in which case the length of the shortest code in bits is
|
|
used.
|
|
|
|
There are two different values for the two tables, since they code a
|
|
different number of possibilities each. The literal/length table
|
|
codes 286 possible values, or in a flat code, a little over eight
|
|
bits. The distance table codes 30 possible values, or a little less
|
|
than five bits, flat. The optimum values for speed end up being
|
|
about one bit more than those, so lbits is 8+1 and dbits is 5+1.
|
|
The optimum values may differ though from machine to machine, and
|
|
possibly even between compilers. Your mileage may vary.
|
|
*/
|
|
|
|
|
|
int lbits = 9; /* bits in base literal/length lookup table */
|
|
int dbits = 6; /* bits in base distance lookup table */
|
|
|
|
|
|
/* If BMAX needs to be larger than 16, then h and x[] should be ulg. */
|
|
#define BMAX 16 /* maximum bit length of any code (16 for explode) */
|
|
#define N_MAX 288 /* maximum number of codes in any set */
|
|
|
|
|
|
unsigned hufts; /* track memory usage */
|
|
|
|
|
|
int huft_build(gz,b, n, s, d, e, t, m)
|
|
struct gzip *gz;
|
|
unsigned *b; /* code lengths in bits (all assumed <= BMAX) */
|
|
unsigned n; /* number of codes (assumed <= N_MAX) */
|
|
unsigned s; /* number of simple-valued codes (0..s-1) */
|
|
ush *d; /* list of base values for non-simple codes */
|
|
ush *e; /* list of extra bits for non-simple codes */
|
|
struct huft **t; /* result: starting table */
|
|
int *m; /* maximum lookup bits, returns actual */
|
|
/* Given a list of code lengths and a maximum table size, make a set of
|
|
tables to decode that set of codes. Return zero on success, one if
|
|
the given code set is incomplete (the tables are still built in this
|
|
case), two if the input is invalid (all zero length codes or an
|
|
oversubscribed set of lengths), and three if not enough memory.
|
|
The code with value 256 is special, and the tables are constructed
|
|
so that no bits beyond that code are fetched when that code is
|
|
decoded. */
|
|
{
|
|
unsigned a; /* counter for codes of length k */
|
|
unsigned c[BMAX+1]; /* bit length count table */
|
|
unsigned el; /* length of EOB code (value 256) */
|
|
unsigned f; /* i repeats in table every f entries */
|
|
int g; /* maximum code length */
|
|
int h; /* table level */
|
|
register unsigned i; /* counter, current code */
|
|
register unsigned j; /* counter */
|
|
register int k; /* number of bits in current code */
|
|
int lx[BMAX+1]; /* memory for l[-1..BMAX-1] */
|
|
int *l = lx+1; /* stack of bits per table */
|
|
register unsigned *p; /* pointer into c[], b[], or v[] */
|
|
register struct huft *q; /* points to current table */
|
|
struct huft r; /* table entry for structure assignment */
|
|
struct huft *u[BMAX]; /* table stack */
|
|
static unsigned v[N_MAX]; /* values in order of bit length */
|
|
register int w; /* bits before this table == (l * h) */
|
|
unsigned x[BMAX+1]; /* bit offsets, then code stack */
|
|
unsigned *xp; /* pointer into x */
|
|
int y; /* number of dummy codes added */
|
|
unsigned z; /* number of entries in current table */
|
|
|
|
|
|
/* Generate counts for each bit length */
|
|
el = n > 256 ? b[256] : BMAX; /* set length of EOB code, if any */
|
|
memzero((char *)c, sizeof(c));
|
|
p = b; i = n;
|
|
do {
|
|
c[*p]++; p++; /* assume all entries <= BMAX */
|
|
} while (--i);
|
|
if (c[0] == n) /* null input--all zero length codes */
|
|
{
|
|
*t = (struct huft *)NULL;
|
|
*m = 0;
|
|
return 0;
|
|
}
|
|
|
|
|
|
/* Find minimum and maximum length, bound *m by those */
|
|
for (j = 1; j <= BMAX; j++)
|
|
if (c[j])
|
|
break;
|
|
k = j; /* minimum code length */
|
|
if ((unsigned)*m < j)
|
|
*m = j;
|
|
for (i = BMAX; i; i--)
|
|
if (c[i])
|
|
break;
|
|
g = i; /* maximum code length */
|
|
if ((unsigned)*m > i)
|
|
*m = i;
|
|
|
|
|
|
/* Adjust last length count to fill out codes, if needed */
|
|
for (y = 1 << j; j < i; j++, y <<= 1)
|
|
if ((y -= c[j]) < 0)
|
|
return 2; /* bad input: more codes than bits */
|
|
if ((y -= c[i]) < 0)
|
|
return 2;
|
|
c[i] += y;
|
|
|
|
|
|
/* Generate starting offsets into the value table for each length */
|
|
x[1] = j = 0;
|
|
p = c + 1; xp = x + 2;
|
|
while (--i) { /* note that i == g from above */
|
|
*xp++ = (j += *p++);
|
|
}
|
|
|
|
|
|
/* Make a table of values in order of bit lengths */
|
|
p = b; i = 0;
|
|
do {
|
|
if ((j = *p++) != 0)
|
|
v[x[j]++] = i;
|
|
} while (++i < n);
|
|
|
|
|
|
/* Generate the Huffman codes and for each, make the table entries */
|
|
x[0] = i = 0; /* first Huffman code is zero */
|
|
p = v; /* grab values in bit order */
|
|
h = -1; /* no tables yet--level -1 */
|
|
w = l[-1] = 0; /* no bits decoded yet */
|
|
u[0] = (struct huft *)NULL; /* just to keep compilers happy */
|
|
q = (struct huft *)NULL; /* ditto */
|
|
z = 0; /* ditto */
|
|
|
|
/* go through the bit lengths (k already is bits in shortest code) */
|
|
for (; k <= g; k++)
|
|
{
|
|
a = c[k];
|
|
while (a--)
|
|
{
|
|
/* here i is the Huffman code of length k bits for value *p */
|
|
/* make tables up to required level */
|
|
while (k > w + l[h])
|
|
{
|
|
w += l[h++]; /* add bits already decoded */
|
|
|
|
/* compute minimum size table less than or equal to *m bits */
|
|
z = (z = g - w) > (unsigned)*m ? *m : z; /* upper limit */
|
|
if ((f = 1 << (j = k - w)) > a + 1) /* try a k-w bit table */
|
|
{ /* too few codes for k-w bit table */
|
|
f -= a + 1; /* deduct codes from patterns left */
|
|
xp = c + k;
|
|
while (++j < z) /* try smaller tables up to z bits */
|
|
{
|
|
if ((f <<= 1) <= *++xp)
|
|
break; /* enough codes to use up j bits */
|
|
f -= *xp; /* else deduct codes from patterns */
|
|
}
|
|
}
|
|
if ((unsigned)w + j > el && (unsigned)w < el)
|
|
j = el - w; /* make EOB code end at table */
|
|
z = 1 << j; /* table entries for j-bit table */
|
|
l[h] = j; /* set table size in stack */
|
|
|
|
/* allocate and link in new table */
|
|
if ((q = (struct huft *)malloc((z + 1)*sizeof(struct huft))) ==
|
|
(struct huft *)NULL)
|
|
{
|
|
if (h)
|
|
huft_free(gz,u[0]);
|
|
return 3; /* not enough memory */
|
|
}
|
|
hufts += z + 1; /* track memory usage */
|
|
*t = q + 1; /* link to list for huft_free() */
|
|
*(t = &(q->v.t)) = (struct huft *)NULL;
|
|
u[h] = ++q; /* table starts after link */
|
|
|
|
/* connect to last table, if there is one */
|
|
if (h)
|
|
{
|
|
x[h] = i; /* save pattern for backing up */
|
|
r.b = (uch)l[h-1]; /* bits to dump before this table */
|
|
r.e = (uch)(16 + j); /* bits in this table */
|
|
r.v.t = q; /* pointer to this table */
|
|
j = (i & ((1 << w) - 1)) >> (w - l[h-1]);
|
|
u[h-1][j] = r; /* connect to last table */
|
|
}
|
|
}
|
|
|
|
/* set up table entry in r */
|
|
r.b = (uch)(k - w);
|
|
if (p >= v + n)
|
|
r.e = 99; /* out of values--invalid code */
|
|
else if (*p < s)
|
|
{
|
|
r.e = (uch)(*p < 256 ? 16 : 15); /* 256 is end-of-block code */
|
|
r.v.n = *p++; /* simple code is just the value */
|
|
}
|
|
else
|
|
{
|
|
r.e = (uch)e[*p - s]; /* non-simple--look up in lists */
|
|
r.v.n = d[*p++ - s];
|
|
}
|
|
|
|
/* fill code-like entries with r */
|
|
f = 1 << (k - w);
|
|
for (j = i >> w; j < z; j += f)
|
|
q[j] = r;
|
|
|
|
/* backwards increment the k-bit code i */
|
|
for (j = 1 << (k - 1); i & j; j >>= 1)
|
|
i ^= j;
|
|
i ^= j;
|
|
|
|
/* backup over finished tables */
|
|
while ((i & ((1 << w) - 1)) != x[h])
|
|
w -= l[--h]; /* don't need to update q */
|
|
}
|
|
}
|
|
|
|
|
|
/* return actual size of base table */
|
|
*m = l[0];
|
|
|
|
|
|
/* Return true (1) if we were given an incomplete table */
|
|
return y != 0 && g != 1;
|
|
}
|
|
|
|
|
|
|
|
int huft_free(gz,t)
|
|
struct gzip *gz;
|
|
struct huft *t; /* table to free */
|
|
/* Free the malloc'ed tables built by huft_build(), which makes a linked
|
|
list of the tables it made, with the links in a dummy first entry of
|
|
each table. */
|
|
{
|
|
register struct huft *p, *q;
|
|
|
|
|
|
/* Go through linked list, freeing from the malloced (t[-1]) address. */
|
|
p = t;
|
|
while (p != (struct huft *)NULL)
|
|
{
|
|
q = (--p)->v.t;
|
|
free(p);
|
|
p = q;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
|
|
|
|
#ifdef ASM_INFLATECODES
|
|
# define inflate_codes(tl,td,bl,bd) flate_codes(tl,td,bl,bd,(uch *)slide)
|
|
int flate_codes OF((struct huft *, struct huft *, int, int, uch *));
|
|
|
|
#else
|
|
|
|
int inflate_codes(gz,tl, td, bl, bd)
|
|
struct gzip *gz;
|
|
struct huft *tl, *td; /* literal/length and distance decoder tables */
|
|
int bl, bd; /* number of bits decoded by tl[] and td[] */
|
|
/* inflate (decompress) the codes in a deflated (compressed) block.
|
|
Return an error code or zero if it all goes ok. */
|
|
{
|
|
register unsigned e; /* table entry flag/number of extra bits */
|
|
unsigned n, d; /* length and index for copy */
|
|
unsigned w; /* current window position */
|
|
struct huft *t; /* pointer to table entry */
|
|
unsigned ml, md; /* masks for bl and bd bits */
|
|
register ulg b; /* bit buffer */
|
|
register unsigned k; /* number of bits in bit buffer */
|
|
|
|
|
|
/* make local copies of globals */
|
|
b = bb; /* initialize bit buffer */
|
|
k = bk;
|
|
w = wp; /* initialize window position */
|
|
|
|
|
|
/* inflate the coded data */
|
|
ml = mask[bl]; /* precompute masks for speed */
|
|
md = mask[bd];
|
|
while (1) /* do until end of block */
|
|
{
|
|
NEEDBITS((unsigned)bl)
|
|
if ((e = (t = tl + ((unsigned)b & ml))->e) > 16)
|
|
do {
|
|
if (e == 99)
|
|
return 1;
|
|
DUMPBITS(t->b)
|
|
e -= 16;
|
|
NEEDBITS(e)
|
|
} while ((e = (t = t->v.t + ((unsigned)b & mask[e]))->e) > 16);
|
|
DUMPBITS(t->b)
|
|
if (e == 16) /* then it's a literal */
|
|
{
|
|
slide[w++] = (uch)t->v.n;
|
|
if (w == WSIZE)
|
|
{
|
|
FLUSH(gz,w);
|
|
w = 0;
|
|
}
|
|
}
|
|
else /* it's an EOB or a length */
|
|
{
|
|
/* exit if end of block */
|
|
if (e == 15)
|
|
break;
|
|
|
|
/* get length of block to copy */
|
|
NEEDBITS(e)
|
|
n = t->v.n + ((unsigned)b & mask[e]);
|
|
DUMPBITS(e);
|
|
|
|
/* decode distance of block to copy */
|
|
NEEDBITS((unsigned)bd)
|
|
if ((e = (t = td + ((unsigned)b & md))->e) > 16)
|
|
do {
|
|
if (e == 99)
|
|
return 1;
|
|
DUMPBITS(t->b)
|
|
e -= 16;
|
|
NEEDBITS(e)
|
|
} while ((e = (t = t->v.t + ((unsigned)b & mask[e]))->e) > 16);
|
|
DUMPBITS(t->b)
|
|
NEEDBITS(e)
|
|
d = w - t->v.n - ((unsigned)b & mask[e]);
|
|
DUMPBITS(e)
|
|
|
|
/* do the copy */
|
|
do {
|
|
n -= (e = (e = WSIZE - ((d &= WSIZE-1) > w ? d : w)) > n ? n : e);
|
|
#ifndef NOMEMCPY
|
|
if (w - d >= e) /* (this test assumes unsigned comparison) */
|
|
{
|
|
memcpy(slide + w, slide + d, e);
|
|
w += e;
|
|
d += e;
|
|
}
|
|
else /* do it slow to avoid memcpy() overlap */
|
|
#endif /* !NOMEMCPY */
|
|
do {
|
|
slide[w++] = slide[d++];
|
|
} while (--e);
|
|
if (w == WSIZE)
|
|
{
|
|
FLUSH(gz,w);
|
|
w = 0;
|
|
}
|
|
} while (n);
|
|
}
|
|
}
|
|
|
|
|
|
/* restore the globals from the locals */
|
|
wp = w; /* restore global window pointer */
|
|
bb = b; /* restore global bit buffer */
|
|
bk = k;
|
|
|
|
|
|
/* done */
|
|
return 0;
|
|
}
|
|
|
|
#endif /* ASM_INFLATECODES */
|
|
|
|
|
|
|
|
int inflate_stored(gz)
|
|
struct gzip *gz;
|
|
/* "decompress" an inflated type 0 (stored) block. */
|
|
{
|
|
unsigned n; /* number of bytes in block */
|
|
unsigned w; /* current window position */
|
|
register ulg b; /* bit buffer */
|
|
register unsigned k; /* number of bits in bit buffer */
|
|
|
|
|
|
/* make local copies of globals */
|
|
Trace((stderr, "\nstored block"));
|
|
b = bb; /* initialize bit buffer */
|
|
k = bk;
|
|
w = wp; /* initialize window position */
|
|
|
|
|
|
/* go to byte boundary */
|
|
n = k & 7;
|
|
DUMPBITS(n);
|
|
|
|
|
|
/* get the length and its complement */
|
|
NEEDBITS(16)
|
|
n = ((unsigned)b & 0xffff);
|
|
DUMPBITS(16)
|
|
NEEDBITS(16)
|
|
if (n != (unsigned)((~b) & 0xffff))
|
|
return 1; /* error in compressed data */
|
|
DUMPBITS(16)
|
|
|
|
|
|
/* read and output the compressed data */
|
|
while (n--)
|
|
{
|
|
NEEDBITS(8)
|
|
slide[w++] = (uch)b;
|
|
if (w == WSIZE)
|
|
{
|
|
FLUSH(gz,w);
|
|
w = 0;
|
|
}
|
|
DUMPBITS(8)
|
|
}
|
|
|
|
|
|
/* restore the globals from the locals */
|
|
wp = w; /* restore global window pointer */
|
|
bb = b; /* restore global bit buffer */
|
|
bk = k;
|
|
return 0;
|
|
}
|
|
|
|
|
|
/* Globals for literal tables (built once) */
|
|
struct huft *fixed_tl = (struct huft *)NULL;
|
|
struct huft *fixed_td;
|
|
int fixed_bl, fixed_bd;
|
|
|
|
int inflate_fixed(gz)
|
|
struct gzip *gz;
|
|
/* decompress an inflated type 1 (fixed Huffman codes) block. We should
|
|
either replace this with a custom decoder, or at least precompute the
|
|
Huffman tables. */
|
|
{
|
|
/* if first time, set up tables for fixed blocks */
|
|
Trace((stderr, "\nliteral block"));
|
|
if (fixed_tl == (struct huft *)NULL)
|
|
{
|
|
int i; /* temporary variable */
|
|
static unsigned l[288]; /* length list for huft_build */
|
|
|
|
/* literal table */
|
|
for (i = 0; i < 144; i++)
|
|
l[i] = 8;
|
|
for (; i < 256; i++)
|
|
l[i] = 9;
|
|
for (; i < 280; i++)
|
|
l[i] = 7;
|
|
for (; i < 288; i++) /* make a complete, but wrong code set */
|
|
l[i] = 8;
|
|
fixed_bl = 7;
|
|
if ((i = huft_build(gz,l, 288, 257, cplens, cplext,
|
|
&fixed_tl, &fixed_bl)) != 0)
|
|
{
|
|
fixed_tl = (struct huft *)NULL;
|
|
return i;
|
|
}
|
|
|
|
/* distance table */
|
|
for (i = 0; i < 30; i++) /* make an incomplete code set */
|
|
l[i] = 5;
|
|
fixed_bd = 5;
|
|
if ((i = huft_build(gz,l, 30, 0, cpdist, cpdext, &fixed_td, &fixed_bd)) > 1)
|
|
{
|
|
huft_free(gz,fixed_tl);
|
|
fixed_tl = (struct huft *)NULL;
|
|
return i;
|
|
}
|
|
}
|
|
|
|
|
|
/* decompress until an end-of-block code */
|
|
return inflate_codes(gz,fixed_tl, fixed_td, fixed_bl, fixed_bd) != 0;
|
|
}
|
|
|
|
|
|
|
|
int inflate_dynamic(gz)
|
|
struct gzip *gz;
|
|
/* decompress an inflated type 2 (dynamic Huffman codes) block. */
|
|
{
|
|
int i; /* temporary variables */
|
|
unsigned j;
|
|
unsigned l; /* last length */
|
|
unsigned m; /* mask for bit lengths table */
|
|
unsigned n; /* number of lengths to get */
|
|
struct huft *tl; /* literal/length code table */
|
|
struct huft *td; /* distance code table */
|
|
int bl; /* lookup bits for tl */
|
|
int bd; /* lookup bits for td */
|
|
unsigned nb; /* number of bit length codes */
|
|
unsigned nl; /* number of literal/length codes */
|
|
unsigned nd; /* number of distance codes */
|
|
#ifdef PKZIP_BUG_WORKAROUND
|
|
static unsigned ll[288+32]; /* literal/length and distance code lengths */
|
|
#else
|
|
static unsigned ll[286+30]; /* literal/length and distance code lengths */
|
|
#endif
|
|
register ulg b; /* bit buffer */
|
|
register unsigned k; /* number of bits in bit buffer */
|
|
|
|
|
|
/* make local bit buffer */
|
|
Trace((stderr, "\ndynamic block"));
|
|
b = bb;
|
|
k = bk;
|
|
|
|
|
|
/* read in table lengths */
|
|
NEEDBITS(5)
|
|
nl = 257 + ((unsigned)b & 0x1f); /* number of literal/length codes */
|
|
DUMPBITS(5)
|
|
NEEDBITS(5)
|
|
nd = 1 + ((unsigned)b & 0x1f); /* number of distance codes */
|
|
DUMPBITS(5)
|
|
NEEDBITS(4)
|
|
nb = 4 + ((unsigned)b & 0xf); /* number of bit length codes */
|
|
DUMPBITS(4)
|
|
#ifdef PKZIP_BUG_WORKAROUND
|
|
if (nl > 288 || nd > 32)
|
|
#else
|
|
if (nl > 286 || nd > 30)
|
|
#endif
|
|
return 1; /* bad lengths */
|
|
|
|
|
|
/* read in bit-length-code lengths */
|
|
for (j = 0; j < nb; j++)
|
|
{
|
|
NEEDBITS(3)
|
|
ll[border[j]] = (unsigned)b & 7;
|
|
DUMPBITS(3)
|
|
}
|
|
for (; j < 19; j++)
|
|
ll[border[j]] = 0;
|
|
|
|
|
|
/* build decoding table for trees--single level, 7 bit lookup */
|
|
bl = 7;
|
|
if ((i = huft_build(gz,ll, 19, 19, NULL, NULL, &tl, &bl)) != 0)
|
|
{
|
|
if (i == 1)
|
|
huft_free(gz,tl);
|
|
return i; /* incomplete code set */
|
|
}
|
|
|
|
|
|
/* read in literal and distance code lengths */
|
|
n = nl + nd;
|
|
m = mask[bl];
|
|
i = l = 0;
|
|
while ((unsigned)i < n)
|
|
{
|
|
NEEDBITS((unsigned)bl)
|
|
j = (td = tl + ((unsigned)b & m))->b;
|
|
DUMPBITS(j)
|
|
j = td->v.n;
|
|
if (j < 16) /* length of code in bits (0..15) */
|
|
ll[i++] = l = j; /* save last length in l */
|
|
else if (j == 16) /* repeat last length 3 to 6 times */
|
|
{
|
|
NEEDBITS(2)
|
|
j = 3 + ((unsigned)b & 3);
|
|
DUMPBITS(2)
|
|
if ((unsigned)i + j > n)
|
|
return 1;
|
|
while (j--)
|
|
ll[i++] = l;
|
|
}
|
|
else if (j == 17) /* 3 to 10 zero length codes */
|
|
{
|
|
NEEDBITS(3)
|
|
j = 3 + ((unsigned)b & 7);
|
|
DUMPBITS(3)
|
|
if ((unsigned)i + j > n)
|
|
return 1;
|
|
while (j--)
|
|
ll[i++] = 0;
|
|
l = 0;
|
|
}
|
|
else /* j == 18: 11 to 138 zero length codes */
|
|
{
|
|
NEEDBITS(7)
|
|
j = 11 + ((unsigned)b & 0x7f);
|
|
DUMPBITS(7)
|
|
if ((unsigned)i + j > n)
|
|
return 1;
|
|
while (j--)
|
|
ll[i++] = 0;
|
|
l = 0;
|
|
}
|
|
}
|
|
|
|
|
|
/* free decoding table for trees */
|
|
huft_free(gz,tl);
|
|
|
|
|
|
/* restore the global bit buffer */
|
|
bb = b;
|
|
bk = k;
|
|
|
|
|
|
/* build the decoding tables for literal/length and distance codes */
|
|
bl = lbits;
|
|
if ((i = huft_build(gz,ll, nl, 257, cplens, cplext, &tl, &bl)) != 0)
|
|
{
|
|
if (i == 1 && !qflag) {
|
|
FPRINTF( "(incomplete l-tree) ");
|
|
huft_free(gz,tl);
|
|
}
|
|
return i; /* incomplete code set */
|
|
}
|
|
bd = dbits;
|
|
if ((i = huft_build(gz,ll + nl, nd, 0, cpdist, cpdext, &td, &bd)) != 0)
|
|
{
|
|
if (i == 1 && !qflag) {
|
|
FPRINTF( "(incomplete d-tree) ");
|
|
#ifdef PKZIP_BUG_WORKAROUND
|
|
i = 0;
|
|
}
|
|
#else
|
|
huft_free(gz,td);
|
|
}
|
|
huft_free(gz,tl);
|
|
return i; /* incomplete code set */
|
|
#endif
|
|
}
|
|
|
|
|
|
/* decompress until an end-of-block code */
|
|
if (inflate_codes(gz,tl, td, bl, bd))
|
|
return 1;
|
|
|
|
|
|
/* free the decoding tables, return */
|
|
huft_free(gz,tl);
|
|
huft_free(gz,td);
|
|
return 0;
|
|
}
|
|
|
|
|
|
|
|
int inflate_block(gz,e)
|
|
struct gzip *gz;
|
|
int *e; /* last block flag */
|
|
/* decompress an inflated block */
|
|
{
|
|
unsigned t; /* block type */
|
|
register ulg b; /* bit buffer */
|
|
register unsigned k; /* number of bits in bit buffer */
|
|
|
|
|
|
/* make local bit buffer */
|
|
b = bb;
|
|
k = bk;
|
|
|
|
|
|
/* read in last block bit */
|
|
NEEDBITS(1)
|
|
*e = (int)b & 1;
|
|
DUMPBITS(1)
|
|
|
|
|
|
/* read in block type */
|
|
NEEDBITS(2)
|
|
t = (unsigned)b & 3;
|
|
DUMPBITS(2)
|
|
|
|
|
|
/* restore the global bit buffer */
|
|
bb = b;
|
|
bk = k;
|
|
|
|
|
|
/* inflate that block type */
|
|
if (t == 2)
|
|
return inflate_dynamic(gz);
|
|
if (t == 0)
|
|
return inflate_stored(gz);
|
|
if (t == 1)
|
|
return inflate_fixed(gz);
|
|
|
|
|
|
/* bad block type */
|
|
return 2;
|
|
}
|
|
|
|
|
|
|
|
int inflate(gz)
|
|
struct gzip *gz;
|
|
/* decompress an inflated entry */
|
|
{
|
|
int e; /* last block flag */
|
|
int r; /* result code */
|
|
unsigned h; /* maximum struct huft's malloc'ed */
|
|
|
|
|
|
/* initialize window, bit buffer */
|
|
wp = 0;
|
|
bk = 0;
|
|
bb = 0;
|
|
|
|
|
|
/* decompress until the last block */
|
|
h = 0;
|
|
do {
|
|
hufts = 0;
|
|
if ((r = inflate_block(gz,&e)) != 0)
|
|
return r;
|
|
if (hufts > h)
|
|
h = hufts;
|
|
} while (!e);
|
|
|
|
|
|
/* flush out slide */
|
|
FLUSH(gz,wp);
|
|
|
|
|
|
/* return success */
|
|
Trace((stderr, "\n%u bytes in Huffman tables (%d/entry)\n",
|
|
h * sizeof(struct huft), sizeof(struct huft)));
|
|
return 0;
|
|
}
|
|
|
|
|
|
|
|
int inflate_free(gz)
|
|
struct gzip *gz;
|
|
{
|
|
if (fixed_tl != (struct huft *)NULL)
|
|
{
|
|
huft_free(gz,fixed_td);
|
|
huft_free(gz,fixed_tl);
|
|
fixed_td = fixed_tl = (struct huft *)NULL;
|
|
}
|
|
return 0;
|
|
}
|