| /*- |
| * 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> |
| #include <assert.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<(size_t)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 && (size_t)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)) |
| |
| |
| /* |
| * Tags are canonically sorted in the tag2element map. |
| */ |
| static int |
| _t2e_cmp(const void *ap, const void *bp) { |
| const asn1_TYPE_tag2member_t *a = ap; |
| const asn1_TYPE_tag2member_t *b = bp; |
| int a_class = BER_TAG_CLASS(a->el_tag); |
| int b_class = BER_TAG_CLASS(b->el_tag); |
| |
| if(a_class == b_class) { |
| ber_tlv_tag_t a_value = BER_TAG_VALUE(a->el_tag); |
| ber_tlv_tag_t b_value = BER_TAG_VALUE(b->el_tag); |
| |
| if(a_value == b_value) { |
| if(a->el_no > b->el_no) |
| return 1; |
| /* |
| * Important: we do not check |
| * for a->el_no <= b->el_no! |
| */ |
| return 0; |
| } else if(a_value < b_value) |
| return -1; |
| else |
| return 1; |
| } else if(a_class < b_class) { |
| return -1; |
| } else { |
| return 1; |
| } |
| } |
| |
| |
| /* |
| * 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 use_bsearch; |
| 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. |
| */ |
| use_bsearch = 0; |
| opt_edx_end = edx + elements[edx].optional + 1; |
| if(opt_edx_end > specs->elements_count) |
| opt_edx_end = specs->elements_count; /* Cap */ |
| else if(opt_edx_end - edx > 8) { |
| /* Limit the scope of linear search... */ |
| opt_edx_end = edx + 8; |
| use_bsearch = 1; |
| /* ... and resort to bsearch() */ |
| } |
| 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 = 1 + 2 * edx; /* Remember! */ |
| goto microphase2; |
| } else if(elements[n].tag == (ber_tlv_tag_t)-1) { |
| use_bsearch = 1; |
| break; |
| } |
| } |
| if(use_bsearch) { |
| /* |
| * Resorch to a binary search over |
| * sorted array of tags. |
| */ |
| asn1_TYPE_tag2member_t *t2m; |
| asn1_TYPE_tag2member_t key; |
| key.el_tag = tlv_tag; |
| key.el_no = edx; |
| t2m = bsearch(&key, specs->tag2el, specs->tag2el_count, |
| sizeof(specs->tag2el[0]), _t2e_cmp); |
| if(t2m) { |
| asn1_TYPE_tag2member_t *best = 0; |
| asn1_TYPE_tag2member_t *t2m_f, *t2m_l; |
| int edx_max = edx + elements[edx].optional; |
| /* |
| * Rewind to the first element with that tag, |
| * `cause bsearch() does not guarantee order. |
| */ |
| t2m_f = t2m + t2m->toff_first; |
| t2m_l = t2m + t2m->toff_last; |
| for(t2m = t2m_f; t2m <= t2m_l; t2m++) { |
| if(t2m->el_no > edx_max) break; |
| if(t2m->el_no < edx) continue; |
| best = t2m; |
| } |
| if(best) { |
| edx = best->el_no; |
| ctx->step = 1 + 2 * edx; |
| goto microphase2; |
| } |
| } |
| n = opt_edx_end; |
| } |
| 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)%s", |
| ber_tlv_tag_string(elements[edx].tag), |
| elements[edx].name, |
| 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 *)((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; |
| } |