X-Git-Url: https://gerrit.o-ran-sc.org/r/gitweb?p=sim%2Fe2-interface.git;a=blobdiff_plain;f=e2sim%2Fasn1c%2Fconstr_SET_OF_ber.c;fp=e2sim%2Fasn1c%2Fconstr_SET_OF_ber.c;h=4187e2999975438f259987b6cd09eb0c35891149;hp=0000000000000000000000000000000000000000;hb=f5900596513e4359fc839ba361da085674e90b68;hpb=215d350dbe06a4c7ee370815f26128a7f7e160cb diff --git a/e2sim/asn1c/constr_SET_OF_ber.c b/e2sim/asn1c/constr_SET_OF_ber.c new file mode 100644 index 0000000..4187e29 --- /dev/null +++ b/e2sim/asn1c/constr_SET_OF_ber.c @@ -0,0 +1,355 @@ +/* + * Copyright (c) 2017 Lev Walkin . + * All rights reserved. + * Redistribution and modifications are permitted subject to BSD license. + */ +#include +#include +#include + +/* + * 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:(size_t)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 's L, even if the buffer size allows + * reading more data. + * For example, consider the buffer containing the following TLVs: + * ... + * 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. + */ +#undef ADVANCE +#define ADVANCE(num_bytes) \ + do { \ + size_t num = num_bytes; \ + ptr = ((const char *)ptr) + num; \ + size -= num; \ + if(ctx->left >= 0) \ + ctx->left -= num; \ + consumed_myself += num; \ + } while(0) + +/* + * Switch to the next phase of parsing. + */ +#undef NEXT_PHASE +#define NEXT_PHASE(ctx) \ + do { \ + ctx->phase++; \ + ctx->step = 0; \ + } while(0) +#undef PHASE_OUT +#define PHASE_OUT(ctx) \ + do { \ + ctx->phase = 10; \ + } while(0) + +/* + * Return a standardized complex structure. + */ +#undef RETURN +#define RETURN(_code) \ + do { \ + rval.code = _code; \ + rval.consumed = consumed_myself; \ + return rval; \ + } while(0) + +/* + * The decoder of the SET OF type. + */ +asn_dec_rval_t +SET_OF_decode_ber(const asn_codec_ctx_t *opt_codec_ctx, + const asn_TYPE_descriptor_t *td, void **struct_ptr, + const void *ptr, size_t size, int tag_mode) { + /* + * Bring closer parts of structure description. + */ + const asn_SET_OF_specifics_t *specs = (const asn_SET_OF_specifics_t *)td->specifics; + const asn_TYPE_member_t *elm = td->elements; /* Single one */ + + /* + * Parts of the structure being constructed. + */ + void *st = *struct_ptr; /* Target structure. */ + asn_struct_ctx_t *ctx; /* Decoder context */ + + ber_tlv_tag_t tlv_tag; /* T from TLV */ + asn_dec_rval_t rval; /* Return code from subparsers */ + + ssize_t consumed_myself = 0; /* Consumed bytes from ptr */ + + ASN_DEBUG("Decoding %s as SET OF", td->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 = (asn_struct_ctx_t *)((char *)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(opt_codec_ctx, td, ctx, ptr, size, + tag_mode, 1, &ctx->left, 0); + if(rval.code != RC_OK) { + ASN_DEBUG("%s tagging check failed: %d", + td->name, rval.code); + return rval; + } + + if(ctx->left >= 0) + ctx->left += rval.consumed; /* ?Subtracted below! */ + ADVANCE(rval.consumed); + + ASN_DEBUG("Structure consumes %ld bytes, " + "buffer %ld", (long)ctx->left, (long)size); + + NEXT_PHASE(ctx); + /* Fall through */ + case 1: + /* + * PHASE 1. + * From the place where we've left it previously, + * try to decode the next item. + */ + for(;; ctx->step = 0) { + ssize_t tag_len; /* Length of TLV's T */ + + if(ctx->step & 1) + goto microphase2; + + /* + * MICROPHASE 1: Synchronize decoding. + */ + + if(ctx->left == 0) { + ASN_DEBUG("End of SET OF %s", td->name); + /* + * No more things to decode. + * Exit out of here. + */ + PHASE_OUT(ctx); + RETURN(RC_OK); + } + + /* + * Fetch the T from TLV. + */ + tag_len = ber_fetch_tag(ptr, LEFT, &tlv_tag); + switch(tag_len) { + case 0: if(!SIZE_VIOLATION) RETURN(RC_WMORE); + /* Fall through */ + case -1: RETURN(RC_FAIL); + } + + if(ctx->left < 0 && ((const uint8_t *)ptr)[0] == 0) { + if(LEFT < 2) { + if(SIZE_VIOLATION) + RETURN(RC_FAIL); + else + RETURN(RC_WMORE); + } else if(((const uint8_t *)ptr)[1] == 0) { + /* + * Found the terminator of the + * indefinite length structure. + */ + break; + } + } + + /* Outmost tag may be unknown and cannot be fetched/compared */ + if(elm->tag != (ber_tlv_tag_t)-1) { + if(BER_TAGS_EQUAL(tlv_tag, elm->tag)) { + /* + * The new list member of expected type has arrived. + */ + } else { + ASN_DEBUG("Unexpected tag %s fixed SET OF %s", + ber_tlv_tag_string(tlv_tag), td->name); + ASN_DEBUG("%s SET OF has tag %s", + td->name, ber_tlv_tag_string(elm->tag)); + RETURN(RC_FAIL); + } + } + + /* + * MICROPHASE 2: Invoke the member-specific decoder. + */ + ctx->step |= 1; /* Confirm entering next microphase */ + microphase2: + + /* + * Invoke the member fetch routine according to member's type + */ + rval = elm->type->op->ber_decoder(opt_codec_ctx, + elm->type, &ctx->ptr, + ptr, LEFT, 0); + ASN_DEBUG("In %s SET OF %s code %d consumed %d", + td->name, elm->type->name, + rval.code, (int)rval.consumed); + switch(rval.code) { + case RC_OK: + { + asn_anonymous_set_ *list = _A_SET_FROM_VOID(st); + if(ASN_SET_ADD(list, ctx->ptr) != 0) + RETURN(RC_FAIL); + else + ctx->ptr = 0; + } + break; + case RC_WMORE: /* More data expected */ + if(!SIZE_VIOLATION) { + ADVANCE(rval.consumed); + RETURN(RC_WMORE); + } + /* Fall through */ + case RC_FAIL: /* Fatal error */ + ASN_STRUCT_FREE(*elm->type, ctx->ptr); + ctx->ptr = 0; + RETURN(RC_FAIL); + } /* switch(rval) */ + + ADVANCE(rval.consumed); + } /* for(all list members) */ + + NEXT_PHASE(ctx); + case 2: + /* + * Read in all "end of content" TLVs. + */ + while(ctx->left < 0) { + if(LEFT < 2) { + if(LEFT > 0 && ((const char *)ptr)[0] != 0) { + /* Unexpected tag */ + RETURN(RC_FAIL); + } else { + RETURN(RC_WMORE); + } + } + if(((const char *)ptr)[0] == 0 + && ((const char *)ptr)[1] == 0) { + ADVANCE(2); + ctx->left++; + } else { + RETURN(RC_FAIL); + } + } + + PHASE_OUT(ctx); + } + + RETURN(RC_OK); +} + +/* + * The DER encoder of the SET OF type. + */ +asn_enc_rval_t +SET_OF_encode_der(const asn_TYPE_descriptor_t *td, const void *sptr, + int tag_mode, ber_tlv_tag_t tag, asn_app_consume_bytes_f *cb, + void *app_key) { + const asn_TYPE_member_t *elm = td->elements; + const asn_anonymous_set_ *list = _A_CSET_FROM_VOID(sptr); + size_t computed_size = 0; + ssize_t encoding_size = 0; + struct _el_buffer *encoded_els; + int edx; + + ASN_DEBUG("Estimating size for SET OF %s", td->name); + + /* + * Gather the length of the underlying members sequence. + */ + for(edx = 0; edx < list->count; edx++) { + void *memb_ptr = list->array[edx]; + asn_enc_rval_t erval = {0,0,0}; + + if(!memb_ptr) ASN__ENCODE_FAILED; + + erval = + elm->type->op->der_encoder(elm->type, memb_ptr, 0, elm->tag, 0, 0); + if(erval.encoded == -1) return erval; + computed_size += erval.encoded; + } + + /* + * Encode the TLV for the sequence itself. + */ + encoding_size = + der_write_tags(td, computed_size, tag_mode, 1, tag, cb, app_key); + if(encoding_size < 0) { + ASN__ENCODE_FAILED; + } + computed_size += encoding_size; + + if(!cb || list->count == 0) { + asn_enc_rval_t erval = {0,0,0}; + erval.encoded = computed_size; + ASN__ENCODED_OK(erval); + } + + ASN_DEBUG("Encoding members of %s SET OF", td->name); + + /* + * DER mandates dynamic sorting of the SET OF elements + * according to their encodings. Build an array of the + * encoded elements. + */ + encoded_els = SET_OF__encode_sorted(elm, list, SOES_DER); + + /* + * Report encoded elements to the application. + * Dispose of temporary sorted members table. + */ + for(edx = 0; edx < list->count; edx++) { + struct _el_buffer *encoded_el = &encoded_els[edx]; + /* Report encoded chunks to the application */ + if(cb(encoded_el->buf, encoded_el->length, app_key) < 0) { + break; + } else { + encoding_size += encoded_el->length; + } + } + + SET_OF__encode_sorted_free(encoded_els, list->count); + + if(edx == list->count) { + asn_enc_rval_t erval = {0,0,0}; + assert(computed_size == (size_t)encoding_size); + erval.encoded = computed_size; + ASN__ENCODED_OK(erval); + } else { + ASN__ENCODE_FAILED; + } +}