diff options
Diffstat (limited to 'skeletons/constr_SEQUENCE.c')
| -rw-r--r-- | skeletons/constr_SEQUENCE.c | 588 |
1 files changed, 588 insertions, 0 deletions
diff --git a/skeletons/constr_SEQUENCE.c b/skeletons/constr_SEQUENCE.c new file mode 100644 index 00000000..6704dd84 --- /dev/null +++ b/skeletons/constr_SEQUENCE.c @@ -0,0 +1,588 @@ +/*- + * Copyright (c) 2003, 2004 Lev Walkin <vlm@lionet.info>. All rights reserved. + * Redistribution and modifications are permitted subject to BSD license. + */ +#include <constr_SEQUENCE.h> + +/* + * Number of bytes left for this structure. + * (ctx->left) indicates the number of bytes _transferred_ for the structure. + * (size) contains the number of bytes in the buffer passed. + */ +#define LEFT ((size<ctx->left)?size:ctx->left) + +/* + * If the subprocessor function returns with an indication that it wants + * more data, it may well be a fatal decoding problem, because the + * size is constrained by the <TLV>'s L, even if the buffer size allows + * reading more data. + * For example, consider the buffer containing the following TLVs: + * <T:5><L:1><V> <T:6>... + * The TLV length clearly indicates that one byte is expected in V, but + * if the V processor returns with "want more data" even if the buffer + * contains way more data than the V processor have seen. + */ +#define SIZE_VIOLATION (ctx->left >= 0 && ctx->left <= size) + +/* + * This macro "eats" the part of the buffer which is definitely "consumed", + * i.e. was correctly converted into local representation or rightfully skipped. + */ +#define ADVANCE(num_bytes) do { \ + size_t num = num_bytes; \ + ptr += num; \ + size -= num; \ + if(ctx->left >= 0) \ + ctx->left -= num; \ + consumed_myself += num; \ + } while(0) + +/* + * Switch to the next phase of parsing. + */ +#define NEXT_PHASE(ctx) do { \ + ctx->phase++; \ + ctx->step = 0; \ + } while(0) +#define PHASE_OUT(ctx) do { ctx->phase = 10; } while(0) + +/* + * Return a standardized complex structure. + */ +#define RETURN(_code) do { \ + rval.code = _code; \ + rval.consumed = consumed_myself;\ + return rval; \ + } while(0) + +/* + * Check whether we are inside the extensions group. + */ +#define IN_EXTENSION_GROUP(specs, memb_idx) \ + ( ((memb_idx) > (specs)->ext_after) \ + &&((memb_idx) < (specs)->ext_before)) + +/* + * The decoder of the SEQUENCE type. + */ +ber_dec_rval_t +SEQUENCE_decode_ber(asn1_TYPE_descriptor_t *sd, + void **struct_ptr, void *ptr, size_t size, int tag_mode) { + /* + * Bring closer parts of structure description. + */ + asn1_SEQUENCE_specifics_t *specs = sd->specifics; + asn1_SEQUENCE_element_t *elements = specs->elements; + + /* + * Parts of the structure being constructed. + */ + void *st = *struct_ptr; /* Target structure. */ + ber_dec_ctx_t *ctx; /* Decoder context */ + + ber_tlv_tag_t tlv_tag; /* T from TLV */ + //ber_tlv_len_t tlv_len; /* L from TLV */ + ber_dec_rval_t rval; /* Return code from subparsers */ + + ssize_t consumed_myself = 0; /* Consumed bytes from ptr */ + int edx; /* SEQUENCE element's index */ + + ASN_DEBUG("Decoding %s as SEQUENCE", sd->name); + + /* + * Create the target structure if it is not present already. + */ + if(st == 0) { + st = *struct_ptr = CALLOC(1, specs->struct_size); + if(st == 0) { + RETURN(RC_FAIL); + } + } + + /* + * Restore parsing context. + */ + ctx = (st + specs->ctx_offset); + + /* + * Start to parse where left previously + */ + switch(ctx->phase) { + case 0: + /* + * PHASE 0. + * Check that the set of tags associated with given structure + * perfectly fits our expectations. + */ + + rval = ber_check_tags(sd, ctx, ptr, size, + tag_mode, &ctx->left, 0); + if(rval.code != RC_OK) { + ASN_DEBUG("%s tagging check failed: %d", + sd->name, rval.code); + consumed_myself += rval.consumed; + RETURN(rval.code); + } + + if(ctx->left >= 0) + ctx->left += rval.consumed; /* ?Substracted below! */ + ADVANCE(rval.consumed); + + NEXT_PHASE(ctx); + + ASN_DEBUG("Structure consumes %ld bytes, buffer %ld", + (long)ctx->left, (long)size); + + /* Fall through */ + case 1: + /* + * PHASE 1. + * From the place where we've left it previously, + * try to decode the next member from the list of + * this structure's elements. + * (ctx->step) stores the member being processed + * between invocations and the microphase {0,1} of parsing + * that member: + * step = (<member_number> * 2 + <microphase>). + */ + for(edx = (ctx->step >> 1); edx < specs->elements_count; + edx++, ctx->step = (ctx->step & ~1) + 2) { + void *memb_ptr; /* Pointer to the member */ + void *memb_ptr2; /* Pointer to that pointer */ + ssize_t tag_len; /* Length of TLV's T */ + int opt_edx_end; /* Next non-optional element */ + int n; + + if(ctx->step & 1) + goto microphase2; + + /* + * MICROPHASE 1: Synchronize decoding. + */ + ASN_DEBUG("In %s SEQUENCE left %d, edx=%d opt=%d ec=%d", + sd->name, (int)ctx->left, + edx, elements[edx].optional, specs->elements_count); + + if(ctx->left == 0 /* No more stuff is expected */ + && ( + /* Explicit OPTIONAL specification reaches the end */ + (edx + elements[edx].optional == specs->elements_count) + || + /* All extensions are optional */ + (IN_EXTENSION_GROUP(specs, edx) + && specs->ext_before > specs->elements_count) + ) + ) { + ASN_DEBUG("End of SEQUENCE %s", sd->name); + /* + * Found the legitimate end of the structure. + */ + PHASE_OUT(ctx); + RETURN(RC_OK); + } + + /* + * Fetch the T from TLV. + */ + tag_len = ber_fetch_tag(ptr, LEFT, &tlv_tag); + ASN_DEBUG("In %s SEQUENCE for %d %s next tag length %d", + sd->name, edx, elements[edx].name, (int)tag_len); + switch(tag_len) { + case 0: if(!SIZE_VIOLATION) RETURN(RC_WMORE); + /* Fall through */ + case -1: RETURN(RC_FAIL); + } + + /* + * Find the next available type with this tag. + */ + opt_edx_end = edx + elements[edx].optional + 1; + if(opt_edx_end > specs->elements_count) + opt_edx_end = specs->elements_count; /* Cap */ + for(n = edx; n < opt_edx_end; n++) { + if(BER_TAGS_EQUAL(tlv_tag, elements[n].tag)) { + /* + * Found element corresponding to the tag + * being looked at. + * Reposition over the right element. + */ + edx = n; + ctx->step = 2 * edx; /* Remember! */ + break; + } + } + if(n == opt_edx_end) { + /* + * If tag is unknown, it may be either + * an unknown (thus, incorrect) tag, + * or an extension (...), + * or an end of the indefinite-length structure. + */ + + if(!IN_EXTENSION_GROUP(specs, edx)) { + ASN_DEBUG("Unexpected tag %s", + ber_tlv_tag_string(tlv_tag)); + ASN_DEBUG("Expected tag %s%s", + ber_tlv_tag_string(elements[edx].tag), + elements[edx].optional + ?" or alternatives":""); + RETURN(RC_FAIL); + } + + if(ctx->left < 0 + && ((uint8_t *)ptr)[0] == 0) { + if(LEFT < 2) { + if(SIZE_VIOLATION) + RETURN(RC_FAIL); + else + RETURN(RC_WMORE); + } else if(((uint8_t *)ptr)[1] == 0) { + /* + * Yeah, baby! Found the terminator + * of the indefinite length structure. + */ + /* + * Proceed to the canonical + * finalization function. + * No advancing is necessary. + */ + goto phase3; + } + } else { + /* Skip this tag */ + ssize_t skip; + + skip = ber_skip_length( + BER_TLV_CONSTRUCTED(ptr), + ptr + tag_len, LEFT - tag_len); + ASN_DEBUG("Skip length %d in %s", + (int)skip, sd->name); + switch(skip) { + case 0: if(!SIZE_VIOLATION) RETURN(RC_WMORE); + /* Fall through */ + case -1: RETURN(RC_FAIL); + } + + ADVANCE(skip + tag_len); + ctx->step -= 2; + edx--; + continue; /* Try again with the next tag */ + } + } + + /* + * MICROPHASE 2: Invoke the member-specific decoder. + */ + ctx->step |= 1; /* Confirm entering next microphase */ + microphase2: + ASN_DEBUG("Inside SEQUENCE %s MF2", sd->name); + + /* + * Compute the position of the member inside a structure, + * and also a type of containment (it may be contained + * as pointer or using inline inclusion). + */ + if(elements[edx].optional) { + /* Optional member, hereby, a simple pointer */ + memb_ptr2 = (char *)st + elements[edx].memb_offset; + } else { + /* + * A pointer to a pointer + * holding the start of the structure + */ + memb_ptr = (char *)st + elements[edx].memb_offset; + memb_ptr2 = &memb_ptr; + } + /* + * Invoke the member fetch routine according to member's type + */ + rval = elements[edx].type->ber_decoder( + (void *)elements[edx].type, + memb_ptr2, ptr, LEFT, + elements[edx].tag_mode); + ASN_DEBUG("In %s SEQUENCE decoded %d %s in %d bytes code %d", + sd->name, edx, elements[edx].type->name, + (int)rval.consumed, rval.code); + switch(rval.code) { + case RC_OK: + break; + case RC_WMORE: /* More data expected */ + if(!SIZE_VIOLATION) { + ADVANCE(rval.consumed); + RETURN(RC_WMORE); + } + /* Fall through */ + case RC_FAIL: /* Fatal error */ + RETURN(RC_FAIL); + } /* switch(rval) */ + + ADVANCE(rval.consumed); + } /* for(all structure members) */ + + phase3: + ctx->phase = 3; + case 3: /* 00 and other tags expected */ + case 4: /* only 00's expected */ + + ASN_DEBUG("SEQUENCE %s Leftover: %ld, size = %ld", + sd->name, (long)ctx->left, (long)size); + + /* + * Skip everything until the end of the SEQUENCE. + */ + while(ctx->left) { + ssize_t tl, ll; + + tl = ber_fetch_tag(ptr, LEFT, &tlv_tag); + switch(tl) { + case 0: if(!SIZE_VIOLATION) RETURN(RC_WMORE); + /* Fall through */ + case -1: RETURN(RC_FAIL); + } + + /* + * If expected <0><0>... + */ + if(ctx->left < 0 + && ((uint8_t *)ptr)[0] == 0) { + if(LEFT < 2) { + if(SIZE_VIOLATION) + RETURN(RC_FAIL); + else + RETURN(RC_WMORE); + } else if(((uint8_t *)ptr)[1] == 0) { + /* + * Correctly finished with <0><0>. + */ + ADVANCE(2); + ctx->left++; + ctx->phase = 4; + continue; + } + } + + if(!IN_EXTENSION_GROUP(specs, specs->elements_count) + || ctx->phase == 4) { + ASN_DEBUG("Unexpected continuation " + "of a non-extensible type " + "%s (SEQUENCE): %s", + sd->name, + ber_tlv_tag_string(tlv_tag)); + RETURN(RC_FAIL); + } + + ll = ber_skip_length( + BER_TLV_CONSTRUCTED(ptr), + ptr + tl, LEFT - tl); + switch(ll) { + case 0: if(!SIZE_VIOLATION) RETURN(RC_WMORE); + /* Fall through */ + case -1: RETURN(RC_FAIL); + } + + ADVANCE(tl + ll); + } + + PHASE_OUT(ctx); + } + + RETURN(RC_OK); +} + +/* + * The DER encoder of the SEQUENCE type. + */ +der_enc_rval_t +SEQUENCE_encode_der(asn1_TYPE_descriptor_t *sd, + void *ptr, int tag_mode, ber_tlv_tag_t tag, + asn_app_consume_bytes_f *cb, void *app_key) { + asn1_SEQUENCE_specifics_t *specs = sd->specifics; + size_t computed_size = 0; + der_enc_rval_t erval; + ssize_t ret; + int edx; + + ASN_DEBUG("%s %s as SEQUENCE", + cb?"Encoding":"Estimating", sd->name); + + /* + * Gather the length of the underlying members sequence. + */ + for(edx = 0; edx < specs->elements_count; edx++) { + asn1_SEQUENCE_element_t *elm = &specs->elements[edx]; + void *memb_ptr; + if(elm->optional) { + memb_ptr = *(void **)((char *)ptr + elm->memb_offset); + if(!memb_ptr) continue; + } else { + memb_ptr = (void *)((char *)ptr + elm->memb_offset); + } + erval = elm->type->der_encoder(elm->type, memb_ptr, + elm->tag_mode, elm->tag, + 0, 0); + if(erval.encoded == -1) + return erval; + computed_size += erval.encoded; + ASN_DEBUG("Member %d %s estimated %ld bytes", + edx, elm->name, (long)erval.encoded); + } + + /* + * Encode the TLV for the sequence itself. + */ + ret = der_write_tags(sd, computed_size, tag_mode, tag, cb, app_key); + ASN_DEBUG("Wrote tags: %ld (+%ld)", (long)ret, (long)computed_size); + if(ret == -1) { + erval.encoded = -1; + erval.failed_type = sd; + erval.structure_ptr = ptr; + return erval; + } + erval.encoded = computed_size + ret; + + if(!cb) return erval; + + /* + * Encode all members. + */ + for(edx = 0; edx < specs->elements_count; edx++) { + asn1_SEQUENCE_element_t *elm = &specs->elements[edx]; + der_enc_rval_t tmperval; + void *memb_ptr; + + if(elm->optional) { + memb_ptr = *(void **)((char *)ptr + elm->memb_offset); + if(!memb_ptr) continue; + } else { + memb_ptr = (void *)((char *)ptr + elm->memb_offset); + } + tmperval = elm->type->der_encoder(elm->type, memb_ptr, + elm->tag_mode, elm->tag, + cb, app_key); + if(tmperval.encoded == -1) + return tmperval; + computed_size -= tmperval.encoded; + ASN_DEBUG("Member %d %s of SEQUENCE %s encoded in %d bytes", + edx, elm->name, sd->name, tmperval.encoded); + } + + if(computed_size != 0) { + /* + * Encoded size is not equal to the computed size. + */ + erval.encoded = -1; + erval.failed_type = sd; + erval.structure_ptr = ptr; + } + + return erval; +} + +int +SEQUENCE_print(asn1_TYPE_descriptor_t *td, const void *sptr, int ilevel, + asn_app_consume_bytes_f *cb, void *app_key) { + asn1_SEQUENCE_specifics_t *specs = td->specifics; + int edx; + int ret; + + if(!sptr) return cb("<absent>", 8, app_key); + + /* Dump preamble */ + if(cb(td->name, strlen(td->name), app_key) + || cb(" ::= {\n", 7, app_key)) + return -1; + + for(edx = 0; edx < specs->elements_count; edx++) { + asn1_SEQUENCE_element_t *elm = &specs->elements[edx]; + const void *memb_ptr; + + if(elm->optional) { + memb_ptr = *(const void * const *)((const char *)sptr + elm->memb_offset); + if(!memb_ptr) continue; + } else { + memb_ptr = (const void *)((const char *)sptr + elm->memb_offset); + } + + /* Indentation */ + for(ret = 0; ret < ilevel; ret++) cb(" ", 1, app_key); + + /* Print the member's name and stuff */ + if(cb(elm->name, strlen(elm->name), app_key) + || cb(": ", 2, app_key)) + return -1; + + /* Print the member itself */ + ret = elm->type->print_struct(elm->type, memb_ptr, ilevel + 4, + cb, app_key); + if(ret) return ret; + + /* Print out the terminator */ + ret = cb("\n", 1, app_key); + if(ret) return ret; + } + + /* Indentation */ + for(ret = 0; ret < ilevel - 4; ret++) cb(" ", 1, app_key); + + return cb("}", 1, app_key); +} + +void +SEQUENCE_free(asn1_TYPE_descriptor_t *td, void *sptr, int contents_only) { + asn1_SEQUENCE_specifics_t *specs = td->specifics; + int edx; + + if(!td || !sptr) + return; + + ASN_DEBUG("Freeing %s as SEQUENCE", td->name); + + for(edx = 0; edx < specs->elements_count; edx++) { + asn1_SEQUENCE_element_t *elm = &specs->elements[edx]; + void *memb_ptr; + if(elm->optional) { + memb_ptr = *(void **)((char *)sptr + elm->memb_offset); + if(memb_ptr) + elm->type->free_struct(elm->type, memb_ptr, 0); + } else { + memb_ptr = (void *)((char *)sptr + elm->memb_offset); + elm->type->free_struct(elm->type, memb_ptr, 1); + } + } + + if(!contents_only) { + FREEMEM(sptr); + } +} + +int +SEQUENCE_constraint(asn1_TYPE_descriptor_t *td, const void *sptr, + asn_app_consume_bytes_f *app_errlog, void *app_key) { + asn1_SEQUENCE_specifics_t *specs = td->specifics; + int edx; + + if(!sptr) { + _ASN_ERRLOG("%s: value not given", td->name); + return -1; + } + + /* + * Iterate over structure members and check their validity. + */ + for(edx = 0; edx < specs->elements_count; edx++) { + asn1_SEQUENCE_element_t *elm = &specs->elements[edx]; + const void *memb_ptr; + + if(elm->optional) { + memb_ptr = *(const void **)((const char *)sptr + elm->memb_offset); + if(!memb_ptr) continue; + } else { + memb_ptr = (const void *)((const char *)sptr + elm->memb_offset); + } + + return elm->type->check_constraints(elm->type, memb_ptr, + app_errlog, app_key); + } + + return 0; +} |