diff options
| -rw-r--r-- | sys/conf/files | 1 | ||||
| -rw-r--r-- | sys/kern/imgact_gzip.c | 1220 | ||||
| -rw-r--r-- | sys/kern/inflate.c | 1228 | ||||
| -rw-r--r-- | sys/sys/inflate.h | 81 |
4 files changed, 1319 insertions, 1211 deletions
diff --git a/sys/conf/files b/sys/conf/files index 405ced6..ead2914 100644 --- a/sys/conf/files +++ b/sys/conf/files @@ -37,6 +37,7 @@ kdb/kdb_sym.c optional kadb kdb/kdb_trap.c optional kadb kern/imgact_aout.c standard kern/imgact_gzip.c optional gzip +kern/inflate.c optional gzip kern/imgact_shell.c standard kern/init_main.c standard kern/init_sysent.c standard diff --git a/sys/kern/imgact_gzip.c b/sys/kern/imgact_gzip.c index a9a6d3a..270daae 100644 --- a/sys/kern/imgact_gzip.c +++ b/sys/kern/imgact_gzip.c @@ -7,7 +7,7 @@ * this stuff is worth it, you can buy me a beer in return. Poul-Henning Kamp * ---------------------------------------------------------------------------- * - * $Id: imgact_gzip.c,v 1.5 1994/10/05 00:58:33 phk Exp $ + * $Id: imgact_gzip.c,v 1.4 1994/10/04 06:51:42 phk Exp $ * * This module handles execution of a.out files which have been run through * "gzip -9". @@ -23,12 +23,14 @@ * inflate isn't quite reentrant yet... * error-handling is a mess... * so is the rest... + * tidy up unnecesary includes */ #include <sys/param.h> #include <sys/systm.h> #include <sys/resourcevar.h> #include <sys/exec.h> +#include <sys/inflate.h> #include <sys/mman.h> #include <sys/malloc.h> #include <sys/imgact.h> @@ -39,30 +41,8 @@ #include <vm/vm.h> #include <vm/vm_kern.h> -#define WSIZE 0x8000 - -struct gzip { - struct image_params *ip; - struct exec a_out; - int error; - int where; - u_char *inbuf; - u_long offset; - u_long output; - u_long len; - int idx; - u_long virtual_offset, file_offset, file_end, bss_size; - unsigned gz_wp; - u_char *gz_slide; -}; - -int inflate __P((struct gzip *)); - extern struct sysentvec aout_sysvec; -#define slide (gz->gz_slide) -#define wp (gz->gz_wp) - int exec_gzip_imgact(iparams) struct image_params *iparams; @@ -70,6 +50,7 @@ exec_gzip_imgact(iparams) int error,error2=0; u_char *p = (u_char *) iparams->image_header; struct gzip *gz; + struct gz_global gz_glbl; /* If these four are not OK, it isn't a gzip file */ if (p[0] != 0x1f) return -1; /* 0 Simply magic */ @@ -91,10 +72,10 @@ exec_gzip_imgact(iparams) return ENOMEM; bzero(gz,sizeof *gz); /* waste of time ? */ - error = vm_allocate(kernel_map, &gz->gz_slide, WSIZE, TRUE); - if (error) { + gz->gz_slide = malloc(WSIZE,M_TEMP,M_NOWAIT); + if (!gz->gz_slide) { free(gz,M_GZIP); - return error; + return ENOMEM; } gz->ip = iparams; @@ -117,7 +98,7 @@ exec_gzip_imgact(iparams) gz->error = 0; - error = inflate(gz); + error = inflate(gz, &gz_glbl); if (gz->inbuf) { error2 = @@ -142,7 +123,7 @@ exec_gzip_imgact(iparams) done: error = gz->error; - vm_deallocate(kernel_map, gz->gz_slide, WSIZE); + free(gz->gz_slide,M_TEMP); free(gz,M_GZIP); return error; } @@ -305,1186 +286,3 @@ do_aout_hdr(struct gzip *gz) static const struct execsw gzip_execsw = { exec_gzip_imgact, "gzip" }; TEXT_SET(execsw_set, gzip_execsw); -/* Stuff to make inflate() work */ -# define uch u_char -# define ush u_short -# define ulg u_long -# define memzero(dest,len) bzero(dest,len) -# define NOMEMCPY -#define FPRINTF printf - -#define EOF -1 -#define CHECK_EOF -static int -NextByte(struct gzip *gz) -{ - int error; - - if(gz->idx >= gz->len) { - gz->where = __LINE__; - return EOF; - } - - if((!gz->inbuf) || gz->idx >= (gz->offset+PAGE_SIZE)) { - if(gz->inbuf) { - error = vm_deallocate(kernel_map, - (vm_offset_t)gz->inbuf, PAGE_SIZE); - if(error) { - gz->where = __LINE__; - gz->error = error; - return EOF; - } - } - - gz->offset += PAGE_SIZE; - - error = vm_mmap(kernel_map, /* map */ - (vm_offset_t *)&gz->inbuf, /* address */ - PAGE_SIZE, /* size */ - VM_PROT_READ, /* protection */ - VM_PROT_READ, /* max protection */ - 0, /* flags */ - (caddr_t)gz->ip->vnodep, /* vnode */ - gz->offset); /* offset */ - if(error) { - gz->where = __LINE__; - gz->error = error; - return EOF; - } - - } - return gz->inbuf[(gz->idx++) - gz->offset]; -} - -#define NEXTBYTE NextByte(gz) - -static int -Flush(struct gzip *gz,u_long siz) -{ - u_char *p = slide,*q; - int i; - - /* First, find a a.out-header */ - if(gz->output < sizeof gz->a_out) { - q = (u_char*) &gz->a_out; - i = min(siz,sizeof gz->a_out - gz->output); - bcopy(p,q+gz->output,i); - gz->output += i; - p += i; - siz -= i; - if(gz->output == sizeof gz->a_out) { - i = do_aout_hdr(gz); - if (i == -1) { - gz->where = __LINE__; - gz->error = ENOEXEC; - return ENOEXEC; - } else if (i) { - gz->where = __LINE__; - gz->error = i; - return ENOEXEC; - } - if(gz->file_offset < sizeof gz->a_out) { - q = (u_char*) gz->virtual_offset + gz->output - gz->file_offset; - bcopy(&gz->a_out,q,sizeof gz->a_out - gz->file_offset); - } - } - } - /* Skip over zero-padded first PAGE if needed */ - if(gz->output < gz->file_offset && (gz->output+siz) > gz->file_offset) { - i = min(siz, gz->file_offset - gz->output); - gz->output += i; - p += i; - siz -= i; - } - if(gz->output >= gz->file_offset && gz->output < gz->file_end) { - i = min(siz, gz->file_end - gz->output); - q = (u_char*) gz->virtual_offset + gz->output - gz->file_offset; - bcopy(p,q,i); - gz->output += i; - p += i; - siz -= i; - } - gz->output += siz; - return 0; -} - -#define FLUSH(x,y) {int foo = Flush(x,y); if (foo) return foo;} -static -void * -myalloc(u_long size) -{ - return malloc(size, M_GZIP, M_NOWAIT); -} -#define malloc myalloc - -static -void -myfree(void * ptr) -{ - 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; -} diff --git a/sys/kern/inflate.c b/sys/kern/inflate.c new file mode 100644 index 0000000..f68fab8 --- /dev/null +++ b/sys/kern/inflate.c @@ -0,0 +1,1228 @@ +/* + * Parts of this file are not covered by: + * ---------------------------------------------------------------------------- + * "THE BEER-WARE LICENSE" (Revision 42): + * <phk@login.dknet.dk> wrote this file. As long as you retain this notice you + * can do whatever you want with this stuff. If we meet some day, and you think + * this stuff is worth it, you can buy me a beer in return. Poul-Henning Kamp + * ---------------------------------------------------------------------------- + * + * $Id: imgact_gzip.c,v 1.4 1994/10/04 06:51:42 phk Exp $ + * + * This module handles execution of a.out files which have been run through + * "gzip -9". + * + * For now you need to use exactly this command to compress the binaries: + * + * gzip -9 -v < /bin/sh > /tmp/sh + * + * TODO: + * text-segments should be made R/O after being filled + * is the vm-stuff safe ? + * should handle the entire header of gzip'ed stuff. + * inflate isn't quite reentrant yet... + * error-handling is a mess... + * so is the rest... + */ + +#include <sys/param.h> +#include <sys/systm.h> +#include <sys/resourcevar.h> +#include <sys/exec.h> +#include <sys/inflate.h> +#include <sys/mman.h> +#include <sys/malloc.h> +#include <sys/imgact.h> +#include <sys/imgact_aout.h> +#include <sys/kernel.h> +#include <sys/sysent.h> + +#include <vm/vm.h> +#include <vm/vm_kern.h> + +/* Stuff to make inflate() work */ +# define uch u_char +# define ush u_short +# define ulg u_long +# define memzero(dest,len) bzero(dest,len) +# define NOMEMCPY +#define FPRINTF printf + +#define EOF -1 +#define CHECK_EOF +static int +NextByte(struct gzip *gz) +{ + int error; + + if(gz->idx >= gz->len) { + gz->where = __LINE__; + return EOF; + } + + if((!gz->inbuf) || gz->idx >= (gz->offset+PAGE_SIZE)) { + if(gz->inbuf) { + error = vm_deallocate(kernel_map, + (vm_offset_t)gz->inbuf, PAGE_SIZE); + if(error) { + gz->where = __LINE__; + gz->error = error; + return EOF; + } + } + + gz->offset += PAGE_SIZE; + + error = vm_mmap(kernel_map, /* map */ + (vm_offset_t *)&gz->inbuf, /* address */ + PAGE_SIZE, /* size */ + VM_PROT_READ, /* protection */ + VM_PROT_READ, /* max protection */ + 0, /* flags */ + (caddr_t)gz->ip->vnodep, /* vnode */ + gz->offset); /* offset */ + if(error) { + gz->where = __LINE__; + gz->error = error; + return EOF; + } + + } + return gz->inbuf[(gz->idx++) - gz->offset]; +} + +#define NEXTBYTE NextByte(gz) + +static int +Flush(struct gzip *gz,u_long siz) +{ + u_char *p = slide,*q; + int i; + + /* First, find a a.out-header */ + if(gz->output < sizeof gz->a_out) { + q = (u_char*) &gz->a_out; + i = min(siz,sizeof gz->a_out - gz->output); + bcopy(p,q+gz->output,i); + gz->output += i; + p += i; + siz -= i; + if(gz->output == sizeof gz->a_out) { + i = do_aout_hdr(gz); + if (i == -1) { + gz->where = __LINE__; + gz->error = ENOEXEC; + return ENOEXEC; + } else if (i) { + gz->where = __LINE__; + gz->error = i; + return ENOEXEC; + } + if(gz->file_offset < sizeof gz->a_out) { + q = (u_char*) gz->virtual_offset + gz->output - gz->file_offset; + bcopy(&gz->a_out,q,sizeof gz->a_out - gz->file_offset); + } + } + } + /* Skip over zero-padded first PAGE if needed */ + if(gz->output < gz->file_offset && (gz->output+siz) > gz->file_offset) { + i = min(siz, gz->file_offset - gz->output); + gz->output += i; + p += i; + siz -= i; + } + if(gz->output >= gz->file_offset && gz->output < gz->file_end) { + i = min(siz, gz->file_end - gz->output); + q = (u_char*) gz->virtual_offset + gz->output - gz->file_offset; + bcopy(p,q,i); + gz->output += i; + p += i; + siz -= i; + } + gz->output += siz; + return 0; +} + +#define FLUSH(x,y) {int foo = Flush(x,y); if (foo) return foo;} +static +void * +myalloc(u_long size) +{ + return malloc(size, M_GZIP, M_NOWAIT); +} +#define malloc myalloc + +static +void +myfree(void * ptr) +{ + free(ptr,M_GZIP); +} +#define free myfree + +static const int qflag = 0; +#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 +static int huft_build OF((struct gzip *,unsigned *, unsigned, unsigned, const ush *, const ush *, + struct huft **, int *)); +static int huft_free OF((struct gzip *,struct huft *)); +static int inflate_codes OF((struct gzip *,struct huft *, struct huft *, int, int)); +static int inflate_stored OF((struct gzip *)); +static int inflate_fixed OF((struct gzip *)); +static int inflate_dynamic OF((struct gzip *)); +static int inflate_block OF((struct gzip *,int *)); +static 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 const 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 const 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 const 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 const 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 const 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 */ +const 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. + */ + +/* !!! XXX !!! */ +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. + */ + + +const int lbits = 9; /* bits in base literal/length lookup table */ +const 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 */ + +/* !!! XXX !!! */ +unsigned hufts; /* track memory usage */ + + +static 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) */ +const ush *d; /* list of base values for non-simple codes */ +const 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; +} + + + +static 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 + +static 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 */ + + + +static 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) */ +/* !!! XXX !!! */ +struct huft *fixed_tl = (struct huft *)NULL; +struct huft *fixed_td; +int fixed_bl, fixed_bd; + +static 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; +} + + + +static 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; +} + + + +static 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, glbl) +struct gzip *gz; +struct gz_global * glbl; +/* 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; +} + + + +static 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; +} diff --git a/sys/sys/inflate.h b/sys/sys/inflate.h new file mode 100644 index 0000000..2415cdd --- /dev/null +++ b/sys/sys/inflate.h @@ -0,0 +1,81 @@ +/* + * Parts of this file are not covered by: + * ---------------------------------------------------------------------------- + * "THE BEER-WARE LICENSE" (Revision 42): + * <phk@login.dknet.dk> wrote this file. As long as you retain this notice you + * can do whatever you want with this stuff. If we meet some day, and you think + * this stuff is worth it, you can buy me a beer in return. Poul-Henning Kamp + * ---------------------------------------------------------------------------- + * + * $Id: imgact_gzip.c,v 1.4 1994/10/04 06:51:42 phk Exp $ + * + * This module handles execution of a.out files which have been run through + * "gzip -9". + * + * For now you need to use exactly this command to compress the binaries: + * + * gzip -9 -v < /bin/sh > /tmp/sh + * + * TODO: + * text-segments should be made R/O after being filled + * is the vm-stuff safe ? + * should handle the entire header of gzip'ed stuff. + * inflate isn't quite reentrant yet... + * error-handling is a mess... + * so is the rest... + * tidy up unnecessary includes + */ + + +#ifndef _SYS_INFLATE_H_ +#define _SYS_INFLATE_H_ + +#ifdef KERNEL + +#include <sys/param.h> +#include <sys/systm.h> +#include <sys/resourcevar.h> +#include <sys/exec.h> +#include <sys/mman.h> +#include <sys/malloc.h> +#include <sys/imgact.h> +#include <sys/imgact_aout.h> +#include <sys/kernel.h> +#include <sys/sysent.h> + +#include <vm/vm.h> +#include <vm/vm_kern.h> + +#define WSIZE 0x8000 + +struct gzip { + struct image_params *ip; + struct exec a_out; + int error; + int where; + u_char *inbuf; + u_long offset; + u_long output; + u_long len; + int idx; + u_long virtual_offset, file_offset, file_end, bss_size; + unsigned gz_wp; + u_char *gz_slide; +}; + +/* + * Global variables used by inflate and friends. + * This structure is used in order to make inflate() reentrant. + */ +struct gz_global { + int foo; +}; + +int inflate __P((struct gzip *, struct gz_global *)); + +#define slide (gz->gz_slide) +#define wp (gz->gz_wp) + +#endif /* KERNEL */ + +#endif /* ! _SYS_INFLATE_H_ */ |
