X-Git-Url: https://git.stg.codes/stg.git/blobdiff_plain/20d4dd0571e75d254444acf755a01b48a691c7c2..4271ab433cd55bbd2612292bcf39e4dc3d7274f1:/libs/smux/per_opentype.c diff --git a/libs/smux/per_opentype.c b/libs/smux/per_opentype.c new file mode 100644 index 00000000..404aa726 --- /dev/null +++ b/libs/smux/per_opentype.c @@ -0,0 +1,378 @@ +/* + * Copyright (c) 2007 Lev Walkin . All rights reserved. + * Redistribution and modifications are permitted subject to BSD license. + */ +#include +#include +#include +#include + +typedef struct uper_ugot_key { + asn_per_data_t oldpd; /* Old per data source */ + size_t unclaimed; + size_t ot_moved; /* Number of bits moved by OT processing */ + int repeat; +} uper_ugot_key; + +static int uper_ugot_refill(asn_per_data_t *pd); +static int per_skip_bits(asn_per_data_t *pd, int skip_nbits); +static asn_dec_rval_t uper_sot_suck(asn_codec_ctx_t *, asn_TYPE_descriptor_t *td, asn_per_constraints_t *constraints, void **sptr, asn_per_data_t *pd); + +/* + * Encode an "open type field". + * #10.1, #10.2 + */ +int +uper_open_type_put(asn_TYPE_descriptor_t *td, asn_per_constraints_t *constraints, void *sptr, asn_per_outp_t *po) { + void *buf; + void *bptr; + ssize_t size; + size_t toGo; + + ASN_DEBUG("Open type put %s ...", td->name); + + size = uper_encode_to_new_buffer(td, constraints, sptr, &buf); + if(size <= 0) return -1; + + for(bptr = buf, toGo = size; toGo;) { + ssize_t maySave = uper_put_length(po, toGo); + ASN_DEBUG("Prepending length %d to %s and allowing to save %d", + (int)size, td->name, (int)maySave); + if(maySave < 0) break; + if(per_put_many_bits(po, bptr, maySave * 8)) break; + bptr = (char *)bptr + maySave; + toGo -= maySave; + } + + FREEMEM(buf); + if(toGo) return -1; + + ASN_DEBUG("Open type put %s of length %ld + overhead (1byte?)", + td->name, (long)size); + + return 0; +} + +static asn_dec_rval_t +uper_open_type_get_simple(asn_codec_ctx_t *ctx, asn_TYPE_descriptor_t *td, + asn_per_constraints_t *constraints, void **sptr, asn_per_data_t *pd) { + asn_dec_rval_t rv; + ssize_t chunk_bytes; + int repeat; + uint8_t *buf = 0; + size_t bufLen = 0; + size_t bufSize = 0; + asn_per_data_t spd; + size_t padding; + + ASN__STACK_OVERFLOW_CHECK(ctx); + + ASN_DEBUG("Getting open type %s...", td->name); + + do { + chunk_bytes = uper_get_length(pd, -1, &repeat); + if(chunk_bytes < 0) { + FREEMEM(buf); + ASN__DECODE_STARVED; + } + if(bufLen + chunk_bytes > bufSize) { + void *ptr; + bufSize = chunk_bytes + (bufSize << 2); + ptr = REALLOC(buf, bufSize); + if(!ptr) { + FREEMEM(buf); + ASN__DECODE_FAILED; + } + buf = ptr; + } + if(per_get_many_bits(pd, buf + bufLen, 0, chunk_bytes << 3)) { + FREEMEM(buf); + ASN__DECODE_STARVED; + } + bufLen += chunk_bytes; + } while(repeat); + + ASN_DEBUG("Getting open type %s encoded in %ld bytes", td->name, + (long)bufLen); + + memset(&spd, 0, sizeof(spd)); + spd.buffer = buf; + spd.nbits = bufLen << 3; + + ASN_DEBUG_INDENT_ADD(+4); + rv = td->uper_decoder(ctx, td, constraints, sptr, &spd); + ASN_DEBUG_INDENT_ADD(-4); + + if(rv.code == RC_OK) { + /* Check padding validity */ + padding = spd.nbits - spd.nboff; + if ((padding < 8 || + /* X.691#10.1.3 */ + (spd.nboff == 0 && spd.nbits == 8 && spd.buffer == buf)) && + per_get_few_bits(&spd, padding) == 0) { + /* Everything is cool */ + FREEMEM(buf); + return rv; + } + FREEMEM(buf); + if(padding >= 8) { + ASN_DEBUG("Too large padding %d in open type", (int)padding); + ASN__DECODE_FAILED; + } else { + ASN_DEBUG("Non-zero padding"); + ASN__DECODE_FAILED; + } + } else { + FREEMEM(buf); + /* rv.code could be RC_WMORE, nonsense in this context */ + rv.code = RC_FAIL; /* Noone would give us more */ + } + + return rv; +} + +static asn_dec_rval_t GCC_NOTUSED +uper_open_type_get_complex(asn_codec_ctx_t *ctx, asn_TYPE_descriptor_t *td, + asn_per_constraints_t *constraints, void **sptr, asn_per_data_t *pd) { + uper_ugot_key arg; + asn_dec_rval_t rv; + ssize_t padding; + + ASN__STACK_OVERFLOW_CHECK(ctx); + + ASN_DEBUG("Getting open type %s from %s", td->name, + per_data_string(pd)); + arg.oldpd = *pd; + arg.unclaimed = 0; + arg.ot_moved = 0; + arg.repeat = 1; + pd->refill = uper_ugot_refill; + pd->refill_key = &arg; + pd->nbits = pd->nboff; /* 0 good bits at this point, will refill */ + pd->moved = 0; /* This now counts the open type size in bits */ + + ASN_DEBUG_INDENT_ADD(+4); + rv = td->uper_decoder(ctx, td, constraints, sptr, pd); + ASN_DEBUG_INDENT_ADD(-4); + +#define UPDRESTOREPD do { \ + /* buffer and nboff are valid, preserve them. */ \ + pd->nbits = arg.oldpd.nbits - (pd->moved - arg.ot_moved); \ + pd->moved = arg.oldpd.moved + (pd->moved - arg.ot_moved); \ + pd->refill = arg.oldpd.refill; \ + pd->refill_key = arg.oldpd.refill_key; \ + } while(0) + + if(rv.code != RC_OK) { + UPDRESTOREPD; + return rv; + } + + ASN_DEBUG("OpenType %s pd%s old%s unclaimed=%d, repeat=%d", td->name, + per_data_string(pd), + per_data_string(&arg.oldpd), + (int)arg.unclaimed, (int)arg.repeat); + + padding = pd->moved % 8; + if(padding) { + int32_t pvalue; + if(padding > 7) { + ASN_DEBUG("Too large padding %d in open type", + (int)padding); + rv.code = RC_FAIL; + UPDRESTOREPD; + return rv; + } + padding = 8 - padding; + ASN_DEBUG("Getting padding of %d bits", (int)padding); + pvalue = per_get_few_bits(pd, padding); + switch(pvalue) { + case -1: + ASN_DEBUG("Padding skip failed"); + UPDRESTOREPD; + ASN__DECODE_STARVED; + case 0: break; + default: + ASN_DEBUG("Non-blank padding (%d bits 0x%02x)", + (int)padding, (int)pvalue); + UPDRESTOREPD; + ASN__DECODE_FAILED; + } + } + if(pd->nboff != pd->nbits) { + ASN_DEBUG("Open type %s overhead pd%s old%s", td->name, + per_data_string(pd), per_data_string(&arg.oldpd)); + if(1) { + UPDRESTOREPD; + ASN__DECODE_FAILED; + } else { + arg.unclaimed += pd->nbits - pd->nboff; + } + } + + /* Adjust pd back so it points to original data */ + UPDRESTOREPD; + + /* Skip data not consumed by the decoder */ + if(arg.unclaimed) { + ASN_DEBUG("Getting unclaimed %d", (int)arg.unclaimed); + switch(per_skip_bits(pd, arg.unclaimed)) { + case -1: + ASN_DEBUG("Claim of %d failed", (int)arg.unclaimed); + ASN__DECODE_STARVED; + case 0: + ASN_DEBUG("Got claim of %d", (int)arg.unclaimed); + break; + default: + /* Padding must be blank */ + ASN_DEBUG("Non-blank unconsumed padding"); + ASN__DECODE_FAILED; + } + arg.unclaimed = 0; + } + + if(arg.repeat) { + ASN_DEBUG("Not consumed the whole thing"); + rv.code = RC_FAIL; + return rv; + } + + return rv; +} + + +asn_dec_rval_t +uper_open_type_get(asn_codec_ctx_t *ctx, asn_TYPE_descriptor_t *td, + asn_per_constraints_t *constraints, void **sptr, asn_per_data_t *pd) { + + return uper_open_type_get_simple(ctx, td, constraints, sptr, pd); +} + +int +uper_open_type_skip(asn_codec_ctx_t *ctx, asn_per_data_t *pd) { + asn_TYPE_descriptor_t s_td; + asn_dec_rval_t rv; + + s_td.name = ""; + s_td.uper_decoder = uper_sot_suck; + + rv = uper_open_type_get(ctx, &s_td, 0, 0, pd); + if(rv.code != RC_OK) + return -1; + else + return 0; +} + +/* + * Internal functions. + */ + +static asn_dec_rval_t +uper_sot_suck(asn_codec_ctx_t *ctx, asn_TYPE_descriptor_t *td, + asn_per_constraints_t *constraints, void **sptr, asn_per_data_t *pd) { + asn_dec_rval_t rv; + + (void)ctx; + (void)td; + (void)constraints; + (void)sptr; + + while(per_get_few_bits(pd, 24) >= 0); + + rv.code = RC_OK; + rv.consumed = pd->moved; + + return rv; +} + +static int +uper_ugot_refill(asn_per_data_t *pd) { + uper_ugot_key *arg = pd->refill_key; + ssize_t next_chunk_bytes, next_chunk_bits; + ssize_t avail; + + asn_per_data_t *oldpd = &arg->oldpd; + + ASN_DEBUG("REFILLING pd->moved=%ld, oldpd->moved=%ld", + (long)pd->moved, (long)oldpd->moved); + + /* Advance our position to where pd is */ + oldpd->buffer = pd->buffer; + oldpd->nboff = pd->nboff; + oldpd->nbits -= pd->moved - arg->ot_moved; + oldpd->moved += pd->moved - arg->ot_moved; + arg->ot_moved = pd->moved; + + if(arg->unclaimed) { + /* Refill the container */ + if(per_get_few_bits(oldpd, 1)) + return -1; + if(oldpd->nboff == 0) { + assert(0); + return -1; + } + pd->buffer = oldpd->buffer; + pd->nboff = oldpd->nboff - 1; + pd->nbits = oldpd->nbits; + ASN_DEBUG("UNCLAIMED <- return from (pd->moved=%ld)", + (long)pd->moved); + return 0; + } + + if(!arg->repeat) { + ASN_DEBUG("Want more but refill doesn't have it"); + return -1; + } + + next_chunk_bytes = uper_get_length(oldpd, -1, &arg->repeat); + ASN_DEBUG("Open type LENGTH %ld bytes at off %ld, repeat %ld", + (long)next_chunk_bytes, (long)oldpd->moved, (long)arg->repeat); + if(next_chunk_bytes < 0) return -1; + if(next_chunk_bytes == 0) { + pd->refill = 0; /* No more refills, naturally */ + assert(!arg->repeat); /* Implementation guarantee */ + } + next_chunk_bits = next_chunk_bytes << 3; + avail = oldpd->nbits - oldpd->nboff; + if(avail >= next_chunk_bits) { + pd->nbits = oldpd->nboff + next_chunk_bits; + arg->unclaimed = 0; + ASN_DEBUG("!+Parent frame %ld bits, alloting %ld [%ld..%ld] (%ld)", + (long)next_chunk_bits, (long)oldpd->moved, + (long)oldpd->nboff, (long)oldpd->nbits, + (long)(oldpd->nbits - oldpd->nboff)); + } else { + pd->nbits = oldpd->nbits; + arg->unclaimed = next_chunk_bits - avail; + ASN_DEBUG("!-Parent frame %ld, require %ld, will claim %ld", + (long)avail, (long)next_chunk_bits, + (long)arg->unclaimed); + } + pd->buffer = oldpd->buffer; + pd->nboff = oldpd->nboff; + ASN_DEBUG("Refilled pd%s old%s", + per_data_string(pd), per_data_string(oldpd)); + return 0; +} + +static int +per_skip_bits(asn_per_data_t *pd, int skip_nbits) { + int hasNonZeroBits = 0; + while(skip_nbits > 0) { + int skip; + + /* per_get_few_bits() is more efficient when nbits <= 24 */ + if(skip_nbits < 24) + skip = skip_nbits; + else + skip = 24; + skip_nbits -= skip; + + switch(per_get_few_bits(pd, skip)) { + case -1: return -1; /* Starving */ + case 0: continue; /* Skipped empty space */ + default: hasNonZeroBits = 1; continue; + } + } + return hasNonZeroBits; +}