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Diffstat (limited to 'lib/zlib_inflate/inflate.c')
| -rw-r--r-- | lib/zlib_inflate/inflate.c | 786 |
1 files changed, 786 insertions, 0 deletions
diff --git a/lib/zlib_inflate/inflate.c b/lib/zlib_inflate/inflate.c new file mode 100644 index 000000000..58a733b10 --- /dev/null +++ b/lib/zlib_inflate/inflate.c @@ -0,0 +1,786 @@ +/* inflate.c -- zlib decompression + * Copyright (C) 1995-2005 Mark Adler + * For conditions of distribution and use, see copyright notice in zlib.h + * + * Based on zlib 1.2.3 but modified for the Linux Kernel by + * Richard Purdie <richard@openedhand.com> + * + * Changes mainly for static instead of dynamic memory allocation + * + */ + +#include <linux/zutil.h> +#include "inftrees.h" +#include "inflate.h" +#include "inffast.h" +#include "infutil.h" + +int zlib_inflate_workspacesize(void) +{ + return sizeof(struct inflate_workspace); +} + +int zlib_inflateReset(z_streamp strm) +{ + struct inflate_state *state; + + if (strm == NULL || strm->state == NULL) return Z_STREAM_ERROR; + state = (struct inflate_state *)strm->state; + strm->total_in = strm->total_out = state->total = 0; + strm->msg = NULL; + strm->adler = 1; /* to support ill-conceived Java test suite */ + state->mode = HEAD; + state->last = 0; + state->havedict = 0; + state->dmax = 32768U; + state->hold = 0; + state->bits = 0; + state->lencode = state->distcode = state->next = state->codes; + + /* Initialise Window */ + state->wsize = 1U << state->wbits; + state->write = 0; + state->whave = 0; + + return Z_OK; +} + +int zlib_inflateInit2(z_streamp strm, int windowBits) +{ + struct inflate_state *state; + + if (strm == NULL) return Z_STREAM_ERROR; + strm->msg = NULL; /* in case we return an error */ + + state = &WS(strm)->inflate_state; + strm->state = (struct internal_state *)state; + + if (windowBits < 0) { + state->wrap = 0; + windowBits = -windowBits; + } + else { + state->wrap = (windowBits >> 4) + 1; + } + if (windowBits < 8 || windowBits > 15) { + return Z_STREAM_ERROR; + } + state->wbits = (unsigned)windowBits; + state->window = &WS(strm)->working_window[0]; + + return zlib_inflateReset(strm); +} + +/* + Return state with length and distance decoding tables and index sizes set to + fixed code decoding. This returns fixed tables from inffixed.h. + */ +static void zlib_fixedtables(struct inflate_state *state) +{ +# include "inffixed.h" + state->lencode = lenfix; + state->lenbits = 9; + state->distcode = distfix; + state->distbits = 5; +} + + +/* + Update the window with the last wsize (normally 32K) bytes written before + returning. This is only called when a window is already in use, or when + output has been written during this inflate call, but the end of the deflate + stream has not been reached yet. It is also called to window dictionary data + when a dictionary is loaded. + + Providing output buffers larger than 32K to inflate() should provide a speed + advantage, since only the last 32K of output is copied to the sliding window + upon return from inflate(), and since all distances after the first 32K of + output will fall in the output data, making match copies simpler and faster. + The advantage may be dependent on the size of the processor's data caches. + */ +static void zlib_updatewindow(z_streamp strm, unsigned out) +{ + struct inflate_state *state; + unsigned copy, dist; + + state = (struct inflate_state *)strm->state; + + /* copy state->wsize or less output bytes into the circular window */ + copy = out - strm->avail_out; + if (copy >= state->wsize) { + memcpy(state->window, strm->next_out - state->wsize, state->wsize); + state->write = 0; + state->whave = state->wsize; + } + else { + dist = state->wsize - state->write; + if (dist > copy) dist = copy; + memcpy(state->window + state->write, strm->next_out - copy, dist); + copy -= dist; + if (copy) { + memcpy(state->window, strm->next_out - copy, copy); + state->write = copy; + state->whave = state->wsize; + } + else { + state->write += dist; + if (state->write == state->wsize) state->write = 0; + if (state->whave < state->wsize) state->whave += dist; + } + } +} + + +/* + * At the end of a Deflate-compressed PPP packet, we expect to have seen + * a `stored' block type value but not the (zero) length bytes. + */ +/* + Returns true if inflate is currently at the end of a block generated by + Z_SYNC_FLUSH or Z_FULL_FLUSH. This function is used by one PPP + implementation to provide an additional safety check. PPP uses + Z_SYNC_FLUSH but removes the length bytes of the resulting empty stored + block. When decompressing, PPP checks that at the end of input packet, + inflate is waiting for these length bytes. + */ +static int zlib_inflateSyncPacket(z_streamp strm) +{ + struct inflate_state *state; + + if (strm == NULL || strm->state == NULL) return Z_STREAM_ERROR; + state = (struct inflate_state *)strm->state; + + if (state->mode == STORED && state->bits == 0) { + state->mode = TYPE; + return Z_OK; + } + return Z_DATA_ERROR; +} + +/* Macros for inflate(): */ + +/* check function to use adler32() for zlib or crc32() for gzip */ +#define UPDATE(check, buf, len) zlib_adler32(check, buf, len) + +/* Load registers with state in inflate() for speed */ +#define LOAD() \ + do { \ + put = strm->next_out; \ + left = strm->avail_out; \ + next = strm->next_in; \ + have = strm->avail_in; \ + hold = state->hold; \ + bits = state->bits; \ + } while (0) + +/* Restore state from registers in inflate() */ +#define RESTORE() \ + do { \ + strm->next_out = put; \ + strm->avail_out = left; \ + strm->next_in = next; \ + strm->avail_in = have; \ + state->hold = hold; \ + state->bits = bits; \ + } while (0) + +/* Clear the input bit accumulator */ +#define INITBITS() \ + do { \ + hold = 0; \ + bits = 0; \ + } while (0) + +/* Get a byte of input into the bit accumulator, or return from inflate() + if there is no input available. */ +#define PULLBYTE() \ + do { \ + if (have == 0) goto inf_leave; \ + have--; \ + hold += (unsigned long)(*next++) << bits; \ + bits += 8; \ + } while (0) + +/* Assure that there are at least n bits in the bit accumulator. If there is + not enough available input to do that, then return from inflate(). */ +#define NEEDBITS(n) \ + do { \ + while (bits < (unsigned)(n)) \ + PULLBYTE(); \ + } while (0) + +/* Return the low n bits of the bit accumulator (n < 16) */ +#define BITS(n) \ + ((unsigned)hold & ((1U << (n)) - 1)) + +/* Remove n bits from the bit accumulator */ +#define DROPBITS(n) \ + do { \ + hold >>= (n); \ + bits -= (unsigned)(n); \ + } while (0) + +/* Remove zero to seven bits as needed to go to a byte boundary */ +#define BYTEBITS() \ + do { \ + hold >>= bits & 7; \ + bits -= bits & 7; \ + } while (0) + +/* Reverse the bytes in a 32-bit value */ +#define REVERSE(q) \ + ((((q) >> 24) & 0xff) + (((q) >> 8) & 0xff00) + \ + (((q) & 0xff00) << 8) + (((q) & 0xff) << 24)) + +/* + inflate() uses a state machine to process as much input data and generate as + much output data as possible before returning. The state machine is + structured roughly as follows: + + for (;;) switch (state) { + ... + case STATEn: + if (not enough input data or output space to make progress) + return; + ... make progress ... + state = STATEm; + break; + ... + } + + so when inflate() is called again, the same case is attempted again, and + if the appropriate resources are provided, the machine proceeds to the + next state. The NEEDBITS() macro is usually the way the state evaluates + whether it can proceed or should return. NEEDBITS() does the return if + the requested bits are not available. The typical use of the BITS macros + is: + + NEEDBITS(n); + ... do something with BITS(n) ... + DROPBITS(n); + + where NEEDBITS(n) either returns from inflate() if there isn't enough + input left to load n bits into the accumulator, or it continues. BITS(n) + gives the low n bits in the accumulator. When done, DROPBITS(n) drops + the low n bits off the accumulator. INITBITS() clears the accumulator + and sets the number of available bits to zero. BYTEBITS() discards just + enough bits to put the accumulator on a byte boundary. After BYTEBITS() + and a NEEDBITS(8), then BITS(8) would return the next byte in the stream. + + NEEDBITS(n) uses PULLBYTE() to get an available byte of input, or to return + if there is no input available. The decoding of variable length codes uses + PULLBYTE() directly in order to pull just enough bytes to decode the next + code, and no more. + + Some states loop until they get enough input, making sure that enough + state information is maintained to continue the loop where it left off + if NEEDBITS() returns in the loop. For example, want, need, and keep + would all have to actually be part of the saved state in case NEEDBITS() + returns: + + case STATEw: + while (want < need) { + NEEDBITS(n); + keep[want++] = BITS(n); + DROPBITS(n); + } + state = STATEx; + case STATEx: + + As shown above, if the next state is also the next case, then the break + is omitted. + + A state may also return if there is not enough output space available to + complete that state. Those states are copying stored data, writing a + literal byte, and copying a matching string. + + When returning, a "goto inf_leave" is used to update the total counters, + update the check value, and determine whether any progress has been made + during that inflate() call in order to return the proper return code. + Progress is defined as a change in either strm->avail_in or strm->avail_out. + When there is a window, goto inf_leave will update the window with the last + output written. If a goto inf_leave occurs in the middle of decompression + and there is no window currently, goto inf_leave will create one and copy + output to the window for the next call of inflate(). + + In this implementation, the flush parameter of inflate() only affects the + return code (per zlib.h). inflate() always writes as much as possible to + strm->next_out, given the space available and the provided input--the effect + documented in zlib.h of Z_SYNC_FLUSH. Furthermore, inflate() always defers + the allocation of and copying into a sliding window until necessary, which + provides the effect documented in zlib.h for Z_FINISH when the entire input + stream available. So the only thing the flush parameter actually does is: + when flush is set to Z_FINISH, inflate() cannot return Z_OK. Instead it + will return Z_BUF_ERROR if it has not reached the end of the stream. + */ + +int zlib_inflate(z_streamp strm, int flush) +{ + struct inflate_state *state; + const unsigned char *next; /* next input */ + unsigned char *put; /* next output */ + unsigned have, left; /* available input and output */ + unsigned long hold; /* bit buffer */ + unsigned bits; /* bits in bit buffer */ + unsigned in, out; /* save starting available input and output */ + unsigned copy; /* number of stored or match bytes to copy */ + unsigned char *from; /* where to copy match bytes from */ + code this; /* current decoding table entry */ + code last; /* parent table entry */ + unsigned len; /* length to copy for repeats, bits to drop */ + int ret; /* return code */ + static const unsigned short order[19] = /* permutation of code lengths */ + {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15}; + + /* Do not check for strm->next_out == NULL here as ppc zImage + inflates to strm->next_out = 0 */ + + if (strm == NULL || strm->state == NULL || + (strm->next_in == NULL && strm->avail_in != 0)) + return Z_STREAM_ERROR; + + state = (struct inflate_state *)strm->state; + + if (state->mode == TYPE) state->mode = TYPEDO; /* skip check */ + LOAD(); + in = have; + out = left; + ret = Z_OK; + for (;;) + switch (state->mode) { + case HEAD: + if (state->wrap == 0) { + state->mode = TYPEDO; + break; + } + NEEDBITS(16); + if ( + ((BITS(8) << 8) + (hold >> 8)) % 31) { + strm->msg = (char *)"incorrect header check"; + state->mode = BAD; + break; + } + if (BITS(4) != Z_DEFLATED) { + strm->msg = (char *)"unknown compression method"; + state->mode = BAD; + break; + } + DROPBITS(4); + len = BITS(4) + 8; + if (len > state->wbits) { + strm->msg = (char *)"invalid window size"; + state->mode = BAD; + break; + } + state->dmax = 1U << len; + strm->adler = state->check = zlib_adler32(0L, NULL, 0); + state->mode = hold & 0x200 ? DICTID : TYPE; + INITBITS(); + break; + case DICTID: + NEEDBITS(32); + strm->adler = state->check = REVERSE(hold); + INITBITS(); + state->mode = DICT; + case DICT: + if (state->havedict == 0) { + RESTORE(); + return Z_NEED_DICT; + } + strm->adler = state->check = zlib_adler32(0L, NULL, 0); + state->mode = TYPE; + case TYPE: + if (flush == Z_BLOCK) goto inf_leave; + case TYPEDO: + if (state->last) { + BYTEBITS(); + state->mode = CHECK; + break; + } + NEEDBITS(3); + state->last = BITS(1); + DROPBITS(1); + switch (BITS(2)) { + case 0: /* stored block */ + state->mode = STORED; + break; + case 1: /* fixed block */ + zlib_fixedtables(state); + state->mode = LEN; /* decode codes */ + break; + case 2: /* dynamic block */ + state->mode = TABLE; + break; + case 3: + strm->msg = (char *)"invalid block type"; + state->mode = BAD; + } + DROPBITS(2); + break; + case STORED: + BYTEBITS(); /* go to byte boundary */ + NEEDBITS(32); + if ((hold & 0xffff) != ((hold >> 16) ^ 0xffff)) { + strm->msg = (char *)"invalid stored block lengths"; + state->mode = BAD; + break; + } + state->length = (unsigned)hold & 0xffff; + INITBITS(); + state->mode = COPY; + case COPY: + copy = state->length; + if (copy) { + if (copy > have) copy = have; + if (copy > left) copy = left; + if (copy == 0) goto inf_leave; + memcpy(put, next, copy); + have -= copy; + next += copy; + left -= copy; + put += copy; + state->length -= copy; + break; + } + state->mode = TYPE; + break; + case TABLE: + NEEDBITS(14); + state->nlen = BITS(5) + 257; + DROPBITS(5); + state->ndist = BITS(5) + 1; + DROPBITS(5); + state->ncode = BITS(4) + 4; + DROPBITS(4); +#ifndef PKZIP_BUG_WORKAROUND + if (state->nlen > 286 || state->ndist > 30) { + strm->msg = (char *)"too many length or distance symbols"; + state->mode = BAD; + break; + } +#endif + state->have = 0; + state->mode = LENLENS; + case LENLENS: + while (state->have < state->ncode) { + NEEDBITS(3); + state->lens[order[state->have++]] = (unsigned short)BITS(3); + DROPBITS(3); + } + while (state->have < 19) + state->lens[order[state->have++]] = 0; + state->next = state->codes; + state->lencode = (code const *)(state->next); + state->lenbits = 7; + ret = zlib_inflate_table(CODES, state->lens, 19, &(state->next), + &(state->lenbits), state->work); + if (ret) { + strm->msg = (char *)"invalid code lengths set"; + state->mode = BAD; + break; + } + state->have = 0; + state->mode = CODELENS; + case CODELENS: + while (state->have < state->nlen + state->ndist) { + for (;;) { + this = state->lencode[BITS(state->lenbits)]; + if ((unsigned)(this.bits) <= bits) break; + PULLBYTE(); + } + if (this.val < 16) { + NEEDBITS(this.bits); + DROPBITS(this.bits); + state->lens[state->have++] = this.val; + } + else { + if (this.val == 16) { + NEEDBITS(this.bits + 2); + DROPBITS(this.bits); + if (state->have == 0) { + strm->msg = (char *)"invalid bit length repeat"; + state->mode = BAD; + break; + } + len = state->lens[state->have - 1]; + copy = 3 + BITS(2); + DROPBITS(2); + } + else if (this.val == 17) { + NEEDBITS(this.bits + 3); + DROPBITS(this.bits); + len = 0; + copy = 3 + BITS(3); + DROPBITS(3); + } + else { + NEEDBITS(this.bits + 7); + DROPBITS(this.bits); + len = 0; + copy = 11 + BITS(7); + DROPBITS(7); + } + if (state->have + copy > state->nlen + state->ndist) { + strm->msg = (char *)"invalid bit length repeat"; + state->mode = BAD; + break; + } + while (copy--) + state->lens[state->have++] = (unsigned short)len; + } + } + + /* handle error breaks in while */ + if (state->mode == BAD) break; + + /* build code tables */ + state->next = state->codes; + state->lencode = (code const *)(state->next); + state->lenbits = 9; + ret = zlib_inflate_table(LENS, state->lens, state->nlen, &(state->next), + &(state->lenbits), state->work); + if (ret) { + strm->msg = (char *)"invalid literal/lengths set"; + state->mode = BAD; + break; + } + state->distcode = (code const *)(state->next); + state->distbits = 6; + ret = zlib_inflate_table(DISTS, state->lens + state->nlen, state->ndist, + &(state->next), &(state->distbits), state->work); + if (ret) { + strm->msg = (char *)"invalid distances set"; + state->mode = BAD; + break; + } + state->mode = LEN; + case LEN: + if (have >= 6 && left >= 258) { + RESTORE(); + inflate_fast(strm, out); + LOAD(); + break; + } + for (;;) { + this = state->lencode[BITS(state->lenbits)]; + if ((unsigned)(this.bits) <= bits) break; + PULLBYTE(); + } + if (this.op && (this.op & 0xf0) == 0) { + last = this; + for (;;) { + this = state->lencode[last.val + + (BITS(last.bits + last.op) >> last.bits)]; + if ((unsigned)(last.bits + this.bits) <= bits) break; + PULLBYTE(); + } + DROPBITS(last.bits); + } + DROPBITS(this.bits); + state->length = (unsigned)this.val; + if ((int)(this.op) == 0) { + state->mode = LIT; + break; + } + if (this.op & 32) { + state->mode = TYPE; + break; + } + if (this.op & 64) { + strm->msg = (char *)"invalid literal/length code"; + state->mode = BAD; + break; + } + state->extra = (unsigned)(this.op) & 15; + state->mode = LENEXT; + case LENEXT: + if (state->extra) { + NEEDBITS(state->extra); + state->length += BITS(state->extra); + DROPBITS(state->extra); + } + state->mode = DIST; + case DIST: + for (;;) { + this = state->distcode[BITS(state->distbits)]; + if ((unsigned)(this.bits) <= bits) break; + PULLBYTE(); + } + if ((this.op & 0xf0) == 0) { + last = this; + for (;;) { + this = state->distcode[last.val + + (BITS(last.bits + last.op) >> last.bits)]; + if ((unsigned)(last.bits + this.bits) <= bits) break; + PULLBYTE(); + } + DROPBITS(last.bits); + } + DROPBITS(this.bits); + if (this.op & 64) { + strm->msg = (char *)"invalid distance code"; + state->mode = BAD; + break; + } + state->offset = (unsigned)this.val; + state->extra = (unsigned)(this.op) & 15; + state->mode = DISTEXT; + case DISTEXT: + if (state->extra) { + NEEDBITS(state->extra); + state->offset += BITS(state->extra); + DROPBITS(state->extra); + } +#ifdef INFLATE_STRICT + if (state->offset > state->dmax) { + strm->msg = (char *)"invalid distance too far back"; + state->mode = BAD; + break; + } +#endif + if (state->offset > state->whave + out - left) { + strm->msg = (char *)"invalid distance too far back"; + state->mode = BAD; + break; + } + state->mode = MATCH; + case MATCH: + if (left == 0) goto inf_leave; + copy = out - left; + if (state->offset > copy) { /* copy from window */ + copy = state->offset - copy; + if (copy > state->write) { + copy -= state->write; + from = state->window + (state->wsize - copy); + } + else + from = state->window + (state->write - copy); + if (copy > state->length) copy = state->length; + } + else { /* copy from output */ + from = put - state->offset; + copy = state->length; + } + if (copy > left) copy = left; + left -= copy; + state->length -= copy; + do { + *put++ = *from++; + } while (--copy); + if (state->length == 0) state->mode = LEN; + break; + case LIT: + if (left == 0) goto inf_leave; + *put++ = (unsigned char)(state->length); + left--; + state->mode = LEN; + break; + case CHECK: + if (state->wrap) { + NEEDBITS(32); + out -= left; + strm->total_out += out; + state->total += out; + if (out) + strm->adler = state->check = + UPDATE(state->check, put - out, out); + out = left; + if (( + REVERSE(hold)) != state->check) { + strm->msg = (char *)"incorrect data check"; + state->mode = BAD; + break; + } + INITBITS(); + } + state->mode = DONE; + case DONE: + ret = Z_STREAM_END; + goto inf_leave; + case BAD: + ret = Z_DATA_ERROR; + goto inf_leave; + case MEM: + return Z_MEM_ERROR; + case SYNC: + default: + return Z_STREAM_ERROR; + } + + /* + Return from inflate(), updating the total counts and the check value. + If there was no progress during the inflate() call, return a buffer + error. Call zlib_updatewindow() to create and/or update the window state. + */ + inf_leave: + RESTORE(); + if (state->wsize || (state->mode < CHECK && out != strm->avail_out)) + zlib_updatewindow(strm, out); + + in -= strm->avail_in; + out -= strm->avail_out; + strm->total_in += in; + strm->total_out += out; + state->total += out; + if (state->wrap && out) + strm->adler = state->check = + UPDATE(state->check, strm->next_out - out, out); + + strm->data_type = state->bits + (state->last ? 64 : 0) + + (state->mode == TYPE ? 128 : 0); + + if (flush == Z_PACKET_FLUSH && ret == Z_OK && + strm->avail_out != 0 && strm->avail_in == 0) + return zlib_inflateSyncPacket(strm); + + if (((in == 0 && out == 0) || flush == Z_FINISH) && ret == Z_OK) + ret = Z_BUF_ERROR; + + return ret; +} + +int zlib_inflateEnd(z_streamp strm) +{ + if (strm == NULL || strm->state == NULL) + return Z_STREAM_ERROR; + return Z_OK; +} + +/* + * This subroutine adds the data at next_in/avail_in to the output history + * without performing any output. The output buffer must be "caught up"; + * i.e. no pending output but this should always be the case. The state must + * be waiting on the start of a block (i.e. mode == TYPE or HEAD). On exit, + * the output will also be caught up, and the checksum will have been updated + * if need be. + */ +int zlib_inflateIncomp(z_stream *z) +{ + struct inflate_state *state = (struct inflate_state *)z->state; + Byte *saved_no = z->next_out; + uInt saved_ao = z->avail_out; + + if (state->mode != TYPE && state->mode != HEAD) + return Z_DATA_ERROR; + + /* Setup some variables to allow misuse of updateWindow */ + z->avail_out = 0; + z->next_out = (unsigned char*)z->next_in + z->avail_in; + + zlib_updatewindow(z, z->avail_in); + + /* Restore saved variables */ + z->avail_out = saved_ao; + z->next_out = saved_no; + + z->adler = state->check = + UPDATE(state->check, z->next_in, z->avail_in); + + z->total_out += z->avail_in; + z->total_in += z->avail_in; + z->next_in += z->avail_in; + state->total += z->avail_in; + z->avail_in = 0; + + return Z_OK; +} |