X-Git-Url: https://git.ozlabs.org/?p=ppp.git;a=blobdiff_plain;f=linux%2Fppp_deflate.c;fp=linux%2Fppp_deflate.c;h=255592af29c92a01bbf5d764e6361c59537e9210;hp=0000000000000000000000000000000000000000;hb=6589bd3bbe86761cc41767a1400a69bbc985788a;hpb=43047c8a5e7896451e966a0051ed48fe66b4561c diff --git a/linux/ppp_deflate.c b/linux/ppp_deflate.c new file mode 100644 index 0000000..255592a --- /dev/null +++ b/linux/ppp_deflate.c @@ -0,0 +1,783 @@ +/* + * ==FILEVERSION 960302== + * + * ppp_deflate.c - interface the zlib procedures for Deflate compression + * and decompression (as used by gzip) to the PPP code. + * This version is for use with Linux kernel 1.3.X. + * + * Copyright (c) 1994 The Australian National University. + * All rights reserved. + * + * Permission to use, copy, modify, and distribute this software and its + * documentation is hereby granted, provided that the above copyright + * notice appears in all copies. This software is provided without any + * warranty, express or implied. The Australian National University + * makes no representations about the suitability of this software for + * any purpose. + * + * IN NO EVENT SHALL THE AUSTRALIAN NATIONAL UNIVERSITY BE LIABLE TO ANY + * PARTY FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES + * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF + * THE AUSTRALIAN NATIONAL UNIVERSITY HAS BEEN ADVISED OF THE POSSIBILITY + * OF SUCH DAMAGE. + * + * THE AUSTRALIAN NATIONAL UNIVERSITY SPECIFICALLY DISCLAIMS ANY WARRANTIES, + * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY + * AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS + * ON AN "AS IS" BASIS, AND THE AUSTRALIAN NATIONAL UNIVERSITY HAS NO + * OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, + * OR MODIFICATIONS. + * + * From: deflate.c,v 1.1 1996/01/18 03:17:48 paulus Exp + */ + +#include + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include /* to get the struct task_struct */ +#include /* used in new tty drivers */ +#include /* used in new tty drivers */ + +#include +#include +#include + +#include + +#include +#include +#include +#include +#include + +#include + +#ifdef NEW_SKBUFF +#include +#endif + +#include +#include +#include + +#undef PACKETPTR +#define PACKETPTR 1 +#include +#undef PACKETPTR + +#include "zlib.c" + +/* + * State for a Deflate (de)compressor. + */ +struct ppp_deflate_state { + int seqno; + int w_size; + int unit; + int mru; + int debug; + z_stream strm; + struct compstat stats; +}; + +#define DEFLATE_OVHD 2 /* Deflate overhead/packet */ + +static void *zalloc __P((void *, unsigned int items, unsigned int size)); +static void zfree __P((void *, void *ptr, unsigned int nb)); +static void *z_comp_alloc __P((unsigned char *options, int opt_len)); +static void *z_decomp_alloc __P((unsigned char *options, int opt_len)); +static void z_comp_free __P((void *state)); +static void z_decomp_free __P((void *state)); +static int z_comp_init __P((void *state, unsigned char *options, + int opt_len, + int unit, int hdrlen, int debug)); +static int z_decomp_init __P((void *state, unsigned char *options, + int opt_len, + int unit, int hdrlen, int mru, int debug)); +static int z_compress __P((void *state, unsigned char *rptr, + unsigned char *obuf, + int isize, int osize)); +static void z_incomp __P((void *state, unsigned char *ibuf, int icnt)); +static int z_decompress __P((void *state, unsigned char *ibuf, + int isize, unsigned char *obuf, int osize)); +static void z_comp_reset __P((void *state)); +static void z_decomp_reset __P((void *state)); +static void z_comp_stats __P((void *state, struct compstat *stats)); + +/* + * This is a small set of memory allocation routines. I created them so + * that all memory allocation from the kernel takes place at the + * z_(de)comp_alloc and z_(de)comp_free routines. This eliminates worry + * about calling valloc() from within an interrupt. + * + * The free list is a single linked list sorted by memory address. + * The zfree() function re-combines any segments it can. + */ +typedef struct memchunk { + unsigned int m_size; + struct memchunk *m_next; +} MemChunk; + +typedef struct { + void *memHead; + MemChunk *freePool; +} MemPool; + +static int memPoolAlloc __P((void *arg, unsigned int size)); +static void memPoolFree __P((void *arg)); + +static int +memPoolAlloc(arg, size) +void *arg; +unsigned int size; +{ + MemPool **memPool = arg; + MemChunk *freePool; + + if ((*memPool = kmalloc(sizeof(MemPool), GFP_KERNEL)) == NULL) { + printk(KERN_DEBUG "Unable to allocate Memory Head\n"); + return 0; + } + + if (((*memPool)->memHead = (void *)vmalloc(size)) == NULL) { + printk(KERN_DEBUG "Unable to allocate Memory Pool\n"); + kfree(*memPool); + return 0; + } + freePool = (*memPool)->freePool = (*memPool)->memHead; + freePool->m_size = size; + freePool->m_next = 0; + + return 1; +} + +static void +memPoolFree(arg) +void *arg; +{ + MemPool **memPool = arg; + + if (*memPool) { + vfree((*memPool)->memHead); + kfree(*memPool); + *memPool = NULL; + } +} + +#ifdef POOLDGB +static void showFreeList __P((MemChunk *)); + +static void +showFreeList(freePool) +MemChunk *freePool; +{ + MemChunk *node; + + for (node = freePool; node; node = node->m_next) + printk(KERN_DEBUG "{%x,%d}->", node, node->m_size); + printk(KERN_DEBUG "\n"); +} +#endif + +/* + * Space allocation and freeing routines for use by zlib routines. + */ +void +zfree(arg, ptr, nbytes) + void *arg; + void *ptr; + unsigned int nbytes; +{ + MemPool *memPool = (MemPool *)arg; + MemChunk *mprev = 0, *node; + MemChunk *new = (void *)(((unsigned char *)ptr) - sizeof(MemChunk)); + + if (!memPool->freePool) { + new->m_next = 0; + memPool->freePool = new; + } else { + /* + * Find where this new chunk fits in the free list. + */ + for (node = memPool->freePool; node && new > node; node = node->m_next) + mprev = node; + /* + * Re-combine with the following free chunk if possible. + */ + if ((((unsigned char *)new) + new->m_size) == (unsigned char *)node) { + new->m_size += node->m_size; + new->m_next = node->m_next; + if (mprev) { + if ((((unsigned char *)mprev) + mprev->m_size) == (unsigned char *)new) { + mprev->m_size += new->m_size; + mprev->m_next = new->m_next; + } else + mprev->m_next = new; + } else + memPool->freePool = new; + /* + * Re-combine with the previous free chunk if possible. + */ + } else if (mprev && (((unsigned char *)mprev) + mprev->m_size) == + (unsigned char *)new) { + mprev->m_size += new->m_size; + if ((((unsigned char *)mprev) + mprev->m_size) == (unsigned char *)node) { + mprev->m_size += node->m_size; + mprev->m_next = node->m_next; + } else + mprev->m_next = node; + /* + * No luck re-combining, just insert the new chunk into the list. + */ + } else { + if (mprev) + mprev->m_next = new; + else + memPool->freePool = new; + new->m_next = node; + } + } +} + +void * +zalloc(arg, items, size) + void *arg; + unsigned int items, size; +{ + MemPool *memPool = (MemPool *)arg; + MemChunk *mprev = 0, *node; + + size *= items; + size += sizeof(MemChunk); + if (size & 0x3) + size = (size + 7) & ~3; + for (node = memPool->freePool; node; node = node->m_next) { + if (size == node->m_size) { + if (mprev) + mprev->m_next = node->m_next; + else + memPool->freePool = node->m_next; + return (void *)(((unsigned char *)node)+sizeof(MemChunk)); + } else if (node->m_size > (size + sizeof(MemChunk) + 7)) { + MemChunk *new; + + new = (void *)(((unsigned char *)node) + size); + new->m_size = node->m_size - size; + new->m_next = node->m_next; + if (mprev) + mprev->m_next = new; + else + memPool->freePool = new; + + node->m_size = size; + + return (void *)(((unsigned char *)node)+sizeof(MemChunk)); + break; + } + mprev = node; + } + printk(KERN_DEBUG + "zalloc(%d)... Out of memory in Pool!\n", size - sizeof(MemChunk)); + return NULL; +} + +static void +z_comp_free(arg) + void *arg; +{ + struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg; + + if (state) { + deflateEnd(&state->strm); + memPoolFree(&state->strm.opaque); + kfree(state); + MOD_DEC_USE_COUNT; + } +} + +/* + * Allocate space for a compressor. + */ +static void * +z_comp_alloc(options, opt_len) + unsigned char *options; + int opt_len; +{ + struct ppp_deflate_state *state; + int w_size; + + if (opt_len != CILEN_DEFLATE || options[0] != CI_DEFLATE + || options[1] != CILEN_DEFLATE + || DEFLATE_METHOD(options[2]) != DEFLATE_METHOD_VAL + || options[3] != DEFLATE_CHK_SEQUENCE) + return NULL; + w_size = DEFLATE_SIZE(options[2]); + if (w_size < DEFLATE_MIN_SIZE || w_size > DEFLATE_MAX_SIZE) + return NULL; + + state = (struct ppp_deflate_state *) kmalloc(sizeof(*state), GFP_KERNEL); + if (state == NULL) + return NULL; + + MOD_INC_USE_COUNT; + memset (state, 0, sizeof (struct ppp_deflate_state)); + state->strm.next_in = NULL; + state->strm.zalloc = zalloc; + state->strm.zfree = zfree; + state->w_size = w_size; + + if (!memPoolAlloc(&state->strm.opaque, 0x50000)) { + z_comp_free(state); + return NULL; + } + + if (deflateInit2(&state->strm, Z_DEFAULT_COMPRESSION, DEFLATE_METHOD_VAL, + -w_size, 8, Z_DEFAULT_STRATEGY, DEFLATE_OVHD+2) != Z_OK) { + z_comp_free(state); + return NULL; + } + return (void *) state; +} + +static int +z_comp_init(arg, options, opt_len, unit, hdrlen, debug) + void *arg; + unsigned char *options; + int opt_len, unit, hdrlen, debug; +{ + struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg; + + if (opt_len < CILEN_DEFLATE || options[0] != CI_DEFLATE + || options[1] != CILEN_DEFLATE + || DEFLATE_METHOD(options[2]) != DEFLATE_METHOD_VAL + || DEFLATE_SIZE(options[2]) != state->w_size + || options[3] != DEFLATE_CHK_SEQUENCE) + return 0; + + state->seqno = 0; + state->unit = unit; + state->debug = debug; + + deflateReset(&state->strm); + + return 1; +} + +static void +z_comp_reset(arg) + void *arg; +{ + struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg; + state->seqno = 0; + deflateReset(&state->strm); +} + +int +z_compress(arg, rptr, obuf, isize, osize) + void *arg; + unsigned char *rptr; /* uncompressed packet (in) */ + unsigned char *obuf; /* compressed packet (out) */ + int isize, osize; +{ + struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg; + int r, proto, off, olen; + unsigned char *wptr; + + /* + * Check that the protocol is in the range we handle. + */ + proto = PPP_PROTOCOL(rptr); + if (proto > 0x3fff || proto == 0xfd || proto == 0xfb) + return isize; + + /* Don't generate compressed packets which are larger than + the uncompressed packet. */ + if (osize > isize) + osize = isize; + + wptr = obuf; + + /* + * Copy over the PPP header and store the 2-byte sequence number. + */ + wptr[0] = PPP_ADDRESS(rptr); + wptr[1] = PPP_CONTROL(rptr); + wptr[2] = PPP_COMP >> 8; + wptr[3] = PPP_COMP; + wptr += PPP_HDRLEN; + wptr[0] = state->seqno >> 8; + wptr[1] = state->seqno; + wptr += 2; + state->strm.next_out = wptr; + state->strm.avail_out = osize - (PPP_HDRLEN + 2); + ++state->seqno; + + off = (proto > 0xff) ? 2 : 3; /* skip 1st proto byte if 0 */ + rptr += off; + state->strm.next_in = rptr; + state->strm.avail_in = (isize - off); + + olen = 0; + for (;;) { + r = deflate(&state->strm, Z_PACKET_FLUSH); + if (r != Z_OK) { + printk(KERN_DEBUG "z_compress: deflate returned %d (%s)\n", + r, (state->strm.msg? state->strm.msg: "")); + break; + } + if (state->strm.avail_out == 0) { + olen += osize; + state->strm.next_out = NULL; + state->strm.avail_out = 1000000; + } else { + break; /* all done */ + } + } + if (olen < osize) + olen += osize - state->strm.avail_out; + + /* + * See if we managed to reduce the size of the packet. + * If the compressor just gave us a single zero byte, it means + * the packet was incompressible. + */ + if (olen < isize && !(olen == PPP_HDRLEN + 3 && *wptr == 0)) { + state->stats.comp_bytes += olen; + state->stats.comp_packets++; + } else { + state->stats.inc_bytes += isize; + state->stats.inc_packets++; + olen = 0; + } + state->stats.unc_bytes += isize; + state->stats.unc_packets++; + + return olen; +} + +static void +z_comp_stats(arg, stats) + void *arg; + struct compstat *stats; +{ + struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg; + + *stats = state->stats; +} + +static void +z_decomp_free(arg) + void *arg; +{ + struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg; + + if (state) { + inflateEnd(&state->strm); + memPoolFree(&state->strm.opaque); + kfree(state); + MOD_DEC_USE_COUNT; + } +} + +/* + * Allocate space for a decompressor. + */ +static void * +z_decomp_alloc(options, opt_len) + unsigned char *options; + int opt_len; +{ + struct ppp_deflate_state *state; + int w_size; + + if (opt_len != CILEN_DEFLATE || options[0] != CI_DEFLATE + || options[1] != CILEN_DEFLATE + || DEFLATE_METHOD(options[2]) != DEFLATE_METHOD_VAL + || options[3] != DEFLATE_CHK_SEQUENCE) + return NULL; + w_size = DEFLATE_SIZE(options[2]); + if (w_size < DEFLATE_MIN_SIZE || w_size > DEFLATE_MAX_SIZE) + return NULL; + + state = (struct ppp_deflate_state *) kmalloc(sizeof(*state), GFP_KERNEL); + if (state == NULL) + return NULL; + + MOD_INC_USE_COUNT; + memset (state, 0, sizeof (struct ppp_deflate_state)); + state->w_size = w_size; + state->strm.next_out = NULL; + state->strm.zalloc = zalloc; + state->strm.zfree = zfree; + + if (!memPoolAlloc(&state->strm.opaque, 0x10000)) { + z_decomp_free(state); + return NULL; + } + + if (inflateInit2(&state->strm, -w_size) != Z_OK) { + z_decomp_free(state); + return NULL; + } + return (void *) state; +} + +static int +z_decomp_init(arg, options, opt_len, unit, hdrlen, mru, debug) + void *arg; + unsigned char *options; + int opt_len, unit, hdrlen, mru, debug; +{ + struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg; + + if (opt_len < CILEN_DEFLATE || options[0] != CI_DEFLATE + || options[1] != CILEN_DEFLATE + || DEFLATE_METHOD(options[2]) != DEFLATE_METHOD_VAL + || DEFLATE_SIZE(options[2]) != state->w_size + || options[3] != DEFLATE_CHK_SEQUENCE) + return 0; + + state->seqno = 0; + state->unit = unit; + state->debug = debug; + state->mru = mru; + + inflateReset(&state->strm); + + return 1; +} + +static void +z_decomp_reset(arg) + void *arg; +{ + struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg; + + state->seqno = 0; + inflateReset(&state->strm); +} + +/* + * Decompress a Deflate-compressed packet. + * + * Because of patent problems, we return DECOMP_ERROR for errors + * found by inspecting the input data and for system problems, but + * DECOMP_FATALERROR for any errors which could possibly be said to + * be being detected "after" decompression. For DECOMP_ERROR, + * we can issue a CCP reset-request; for DECOMP_FATALERROR, we may be + * infringing a patent of Motorola's if we do, so we take CCP down + * instead. + * + * Given that the frame has the correct sequence number and a good FCS, + * errors such as invalid codes in the input most likely indicate a + * bug, so we return DECOMP_FATALERROR for them in order to turn off + * compression, even though they are detected by inspecting the input. + */ +int +z_decompress(arg, ibuf, isize, obuf, osize) + void *arg; + unsigned char *ibuf; + int isize; + unsigned char *obuf; + int osize; +{ + struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg; + int olen, seq, i, r, decode_proto; + unsigned char hdr[PPP_HDRLEN + DEFLATE_OVHD]; + unsigned char *rptr, *wptr; + + rptr = ibuf; + wptr = obuf; + for (i = 0; i < PPP_HDRLEN + DEFLATE_OVHD; ++i) + hdr[i] = *rptr++; + + /* Check the sequence number. */ + seq = (hdr[PPP_HDRLEN] << 8) + hdr[PPP_HDRLEN+1]; + if (seq != state->seqno) { + if (state->debug) + printk(KERN_DEBUG "z_decompress%d: bad seq # %d, expected %d\n", + state->unit, seq, state->seqno); + return DECOMP_ERROR; + } + ++state->seqno; + + /* + * Fill in the first part of the PPP header. The protocol field + * comes from the decompressed data. + */ + wptr[0] = PPP_ADDRESS(hdr); + wptr[1] = PPP_CONTROL(hdr); + wptr[2] = 0; + + /* + * Set up to call inflate. We set avail_out to 1 initially so we can + * look at the first byte of the output and decide whether we have + * a 1-byte or 2-byte protocol field. + */ + state->strm.next_in = rptr; + state->strm.avail_in = isize - (PPP_HDRLEN + DEFLATE_OVHD); + state->strm.next_out = wptr + 3; + state->strm.avail_out = 1; + decode_proto = 1; + + /* + * Call inflate, supplying more input or output as needed. + */ + for (;;) { + r = inflate(&state->strm, Z_PACKET_FLUSH); + if (r != Z_OK) { + if (state->debug) + printk(KERN_DEBUG "z_decompress%d: inflate returned %d (%s)\n", + state->unit, r, (state->strm.msg? state->strm.msg: "")); + return DECOMP_FATALERROR; + } + if (state->strm.avail_out != 0) + break; /* all done */ + if (state->strm.avail_out == 0) { + if (decode_proto) { + state->strm.avail_out = osize - PPP_HDRLEN; + if ((wptr[3] & 1) == 0) { + /* 2-byte protocol field */ + wptr[2] = wptr[3]; + --state->strm.next_out; + ++state->strm.avail_out; + } + decode_proto = 0; + } else { + if (state->debug) + printk(KERN_DEBUG "z_decompress%d: ran out of mru\n", + state->unit); + return DECOMP_FATALERROR; + } + } + } + + if (decode_proto) + return DECOMP_ERROR; + + olen = (osize - state->strm.avail_out); + + state->stats.unc_bytes += olen; + state->stats.unc_packets++; + state->stats.comp_bytes += isize; + state->stats.comp_packets++; + + return olen; +} + +/* + * Incompressible data has arrived - add it to the history. + */ +static void +z_incomp(arg, ibuf, icnt) + void *arg; + unsigned char *ibuf; + int icnt; +{ + struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg; + unsigned char *rptr = ibuf; + int proto, r; + + /* + * Check that the protocol is one we handle. + */ + proto = PPP_PROTOCOL(rptr); + if (proto > 0x3fff || proto == 0xfd || proto == 0xfb) + return; + + ++state->seqno; + + /* + * Iterate through the message blocks, adding the characters in them + * to the decompressor's history. For the first block, we start + * at the either the 1st or 2nd byte of the protocol field, + * depending on whether the protocol value is compressible. + */ + state->strm.next_in = rptr + 3; + state->strm.avail_in = icnt - 3; + if (proto > 0xff) { + --state->strm.next_in; + ++state->strm.avail_in; + } + + r = inflateIncomp(&state->strm); + if (r != Z_OK) { + /* gak! */ + if (state->debug) { + printk(KERN_DEBUG "z_incomp%d: inflateIncomp returned %d (%s)\n", + state->unit, r, (state->strm.msg? state->strm.msg: "")); + } + return; + } + + /* + * Update stats. + */ + state->stats.inc_bytes += icnt; + state->stats.inc_packets++; + state->stats.unc_bytes += icnt; + state->stats.unc_packets++; +} + +/************************************************************* + * Module interface table + *************************************************************/ + +/* These are in ppp.c */ +extern int ppp_register_compressor (struct compressor *cp); +extern void ppp_unregister_compressor (struct compressor *cp); + +/* + * Procedures exported to if_ppp.c. + */ +struct compressor ppp_deflate = { + CI_DEFLATE, /* compress_proto */ + z_comp_alloc, /* comp_alloc */ + z_comp_free, /* comp_free */ + z_comp_init, /* comp_init */ + z_comp_reset, /* comp_reset */ + z_compress, /* compress */ + z_comp_stats, /* comp_stat */ + z_decomp_alloc, /* decomp_alloc */ + z_decomp_free, /* decomp_free */ + z_decomp_init, /* decomp_init */ + z_decomp_reset, /* decomp_reset */ + z_decompress, /* decompress */ + z_incomp, /* incomp */ + z_comp_stats, /* decomp_stat */ +}; + +/************************************************************* + * Module support routines + *************************************************************/ + +int +init_module(void) +{ + int answer = ppp_register_compressor (&ppp_deflate); + if (answer == 0) + printk (KERN_INFO + "PPP Deflate Compression module registered\n"); + return answer; +} + +void +cleanup_module(void) +{ + if (MOD_IN_USE) + printk (KERN_INFO + "Deflate Compression module busy, remove delayed\n"); + else + ppp_unregister_compressor (&ppp_deflate); +}