Initial revision
diff --git a/skeletons/constr_CHOICE.c b/skeletons/constr_CHOICE.c
new file mode 100644
index 0000000..2cfac3b
--- /dev/null
+++ b/skeletons/constr_CHOICE.c
@@ -0,0 +1,627 @@
+/*-
+ * Copyright (c) 2003, 2004 Lev Walkin <vlm@lionet.info>. All rights reserved.
+ * Redistribution and modifications are permitted subject to BSD license.
+ */
+#include <constr_CHOICE.h>
+#include <netinet/in.h> /* for ntohl */
+#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<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)
+
+/*
+ * Return a standardized complex structure.
+ */
+#define RETURN(_code) do { \
+ rval.code = _code; \
+ rval.consumed = consumed_myself;\
+ return rval; \
+ } while(0)
+
+/*
+ * See the definitions.
+ */
+static inline int _fetch_present_idx(const void *struct_ptr, int off, int size);
+static inline void _set_present_idx(void *sptr, int offset, int size, int pres);
+
+/*
+ * Tags are canonically sorted in the tag to member table.
+ */
+static int
+_search4tag(const void *ap, const void *bp) {
+ const asn1_CHOICE_tag2member_t *a = ap;
+ const asn1_CHOICE_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)
+ 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 CHOICE type.
+ */
+ber_dec_rval_t
+CHOICE_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_CHOICE_specifics_t *specs = sd->specifics;
+ asn1_CHOICE_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 */
+ ssize_t tag_len; /* Length of TLV's T */
+ //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 */
+
+ ASN_DEBUG("Decoding %s as CHOICE", 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.
+ */
+
+ if(tag_mode || sd->tags_count) {
+ 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) {
+ /* ?Substracted below! */
+ ctx->left += rval.consumed;
+ }
+ ADVANCE(rval.consumed);
+ } else {
+ ctx->left = -1;
+ }
+
+ NEXT_PHASE(ctx);
+
+ ASN_DEBUG("Structure consumes %ld bytes, buffer %ld",
+ (long)ctx->left, (long)size);
+
+ /* Fall through */
+ case 1:
+ /*
+ * Fetch the T from TLV.
+ */
+ tag_len = ber_fetch_tag(ptr, LEFT, &tlv_tag);
+ ASN_DEBUG("In %s CHOICE tag length %d", sd->name, (int)tag_len);
+ switch(tag_len) {
+ case 0: if(!SIZE_VIOLATION) RETURN(RC_WMORE);
+ /* Fall through */
+ case -1: RETURN(RC_FAIL);
+ }
+
+ do {
+ asn1_CHOICE_tag2member_t *t2m;
+ asn1_CHOICE_tag2member_t key;
+
+ key.el_tag = tlv_tag;
+ t2m = bsearch(&key, specs->tag2el, specs->tag2el_count,
+ sizeof(specs->tag2el[0]), _search4tag);
+ if(t2m) {
+ /*
+ * Found the element corresponding to the tag.
+ */
+ NEXT_PHASE(ctx);
+ ctx->step = t2m->el_no;
+ break;
+ } else if(specs->extensible == 0) {
+ ASN_DEBUG("Unexpected tag %s "
+ "in non-extensible CHOICE %s",
+ ber_tlv_tag_string(tlv_tag), sd->name);
+ RETURN(RC_FAIL);
+ } else {
+ /* Skip this tag */
+ ssize_t skip;
+
+ ASN_DEBUG("Skipping unknown tag %s",
+ ber_tlv_tag_string(tlv_tag));
+
+ skip = ber_skip_length(
+ BER_TLV_CONSTRUCTED(ptr),
+ ptr + tag_len, LEFT - tag_len);
+
+ switch(skip) {
+ case 0: if(!SIZE_VIOLATION) RETURN(RC_WMORE);
+ /* Fall through */
+ case -1: RETURN(RC_FAIL);
+ }
+
+ ADVANCE(skip + tag_len);
+ RETURN(RC_OK);
+ }
+ } while(0);
+
+ case 2:
+ /*
+ * PHASE 2.
+ * Read in the element.
+ */
+ do {
+ asn1_CHOICE_element_t *elm; /* CHOICE's element */
+ void *memb_ptr; /* Pointer to the member */
+ void *memb_ptr2; /* Pointer to that pointer */
+
+ elm = &elements[ctx->step];
+
+ /*
+ * 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(elm->optional) {
+ /* Optional member, hereby, a simple pointer */
+ memb_ptr2 = (char *)st + elm->memb_offset;
+ } else {
+ /*
+ * A pointer to a pointer
+ * holding the start of the structure
+ */
+ memb_ptr = (char *)st + elm->memb_offset;
+ memb_ptr2 = &memb_ptr;
+ }
+ /*
+ * Invoke the member fetch routine according to member's type
+ */
+ rval = elm->type->ber_decoder(
+ (void *)elm->type,
+ memb_ptr2, ptr, LEFT,
+ elm->tag_mode);
+ switch(rval.code) {
+ case RC_OK:
+ _set_present_idx(st, specs->pres_offset,
+ specs->pres_size, ctx->step + 1);
+ break;
+ case RC_WMORE: /* More data expected */
+ if(!SIZE_VIOLATION) {
+ ADVANCE(rval.consumed);
+ RETURN(RC_WMORE);
+ }
+ RETURN(RC_FAIL);
+ case RC_FAIL: /* Fatal error */
+ RETURN(rval.code);
+ } /* switch(rval) */
+
+ ADVANCE(rval.consumed);
+ } while(0);
+
+ NEXT_PHASE(ctx);
+
+ /* Fall through */
+ case 3:
+ ASN_DEBUG("CHOICE %s Leftover: %ld, size = %ld, tm=%d, tc=%d",
+ sd->name, (long)ctx->left, (long)size,
+ tag_mode, sd->tags_count);
+
+ if(ctx->left > 0) {
+ /*
+ * The type must be fully decoded
+ * by the CHOICE member-specific decoder.
+ */
+ RETURN(RC_FAIL);
+ }
+
+ if(ctx->left == -1
+ && !(tag_mode || sd->tags_count)) {
+ /*
+ * This is an untagged CHOICE.
+ * It doesn't contain nothing
+ * except for the member itself, including all its tags.
+ * The decoding is completed.
+ */
+ NEXT_PHASE(ctx);
+ break;
+ }
+
+ /*
+ * Read in the "end of data chunks"'s.
+ */
+ while(ctx->left < 0) {
+ ssize_t tl;
+
+ 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);
+ }
+
+ /*
+ * Expected <0><0>...
+ */
+ if(((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>.
+ */
+ continue;
+ }
+ } else {
+ ASN_DEBUG("Unexpected continuation in %s",
+ sd->name);
+ RETURN(RC_FAIL);
+ }
+
+ ADVANCE(2);
+ ctx->left++;
+ }
+
+ NEXT_PHASE(ctx);
+ case 4:
+ /* No meaningful work here */
+ break;
+ }
+
+ RETURN(RC_OK);
+}
+
+der_enc_rval_t
+CHOICE_encode_der(asn1_TYPE_descriptor_t *sd,
+ void *struct_ptr,
+ int tag_mode, ber_tlv_tag_t tag,
+ asn_app_consume_bytes_f *cb, void *app_key) {
+ asn1_CHOICE_specifics_t *specs = sd->specifics;
+ asn1_CHOICE_element_t *elm; /* CHOICE element */
+ der_enc_rval_t erval;
+ void *memb_ptr;
+ size_t computed_size = 0;
+ int present;
+
+ ASN_DEBUG("%s %s as CHOICE",
+ cb?"Encoding":"Estimating", sd->name);
+
+ present = _fetch_present_idx(struct_ptr,
+ specs->pres_offset, specs->pres_size);
+
+ /*
+ * If the structure was not initialized, it cannot be encoded:
+ * can't deduce what to encode in the choice type.
+ */
+ if(present <= 0 || present > specs->elements_count) {
+ if(present == 0 && specs->elements_count == 0) {
+ /* The CHOICE is empty?! */
+ erval.encoded = 0;
+ return erval;
+ }
+ erval.encoded = -1;
+ erval.failed_type = sd;
+ erval.structure_ptr = struct_ptr;
+ return erval;
+ }
+
+ /*
+ * Seek over the present member of the structure.
+ */
+ elm = &specs->elements[present-1];
+ if(elm->optional) {
+ memb_ptr = *(void **)((char *)struct_ptr + elm->memb_offset);
+ if(memb_ptr == 0) {
+ erval.encoded = 0;
+ return erval;
+ }
+ } else {
+ memb_ptr = (void *)((char *)struct_ptr + elm->memb_offset);
+ }
+
+ /*
+ * If the CHOICE itself is tagged EXPLICIT:
+ * T ::= [2] EXPLICIT CHOICE { ... }
+ * Then emit the appropriate tags.
+ */
+ if(tag_mode == 1 || sd->tags_count) {
+ /*
+ * For this, we need to pre-compute the member.
+ */
+ ssize_t ret;
+
+ /* Encode member with its tag */
+ erval = elm->type->der_encoder(elm->type, memb_ptr,
+ elm->tag_mode, elm->tag, 0, 0);
+ if(erval.encoded == -1)
+ return erval;
+
+ /* Encode CHOICE with parent or my own tag */
+ ret = der_write_tags(sd, erval.encoded, tag_mode, tag,
+ cb, app_key);
+ if(ret == -1) {
+ erval.encoded = -1;
+ erval.failed_type = sd;
+ erval.structure_ptr = struct_ptr;
+ return erval;
+ }
+ computed_size += ret;
+ }
+
+ /*
+ * Encode the single underlying member.
+ */
+ erval = elm->type->der_encoder(elm->type, memb_ptr,
+ elm->tag_mode, elm->tag, cb, app_key);
+ if(erval.encoded == -1)
+ return erval;
+
+ ASN_DEBUG("Encoded CHOICE member in %ld bytes (+%ld)",
+ (long)erval.encoded, (long)computed_size);
+
+ erval.encoded += computed_size;
+
+ return erval;
+}
+
+ber_tlv_tag_t
+CHOICE_outmost_tag(asn1_TYPE_descriptor_t *td, const void *ptr, int tag_mode, ber_tlv_tag_t tag) {
+ asn1_CHOICE_specifics_t *specs = td->specifics;
+ int present;
+
+ assert(tag_mode == 0);
+ assert(tag == 0);
+
+ /*
+ * Figure out which CHOICE element is encoded.
+ */
+ present = _fetch_present_idx(ptr, specs->pres_offset, specs->pres_size);
+
+ if(present > 0 || present <= specs->elements_count) {
+ asn1_CHOICE_element_t *elm = &specs->elements[present-1];
+ void *memb_ptr;
+
+ if(elm->optional) {
+ memb_ptr = *(void **)((char *)ptr + elm->memb_offset);
+ } else {
+ memb_ptr = (void *)((char *)ptr + elm->memb_offset);
+ }
+
+ return asn1_TYPE_outmost_tag(elm->type, memb_ptr,
+ elm->tag_mode, elm->tag);
+ } else {
+ return -1;
+ }
+}
+
+int
+CHOICE_constraint(asn1_TYPE_descriptor_t *td, const void *sptr,
+ asn_app_consume_bytes_f *app_errlog, void *app_key) {
+ asn1_CHOICE_specifics_t *specs = td->specifics;
+ int present;
+
+ if(!sptr) {
+ _ASN_ERRLOG("%s: value not given", td->name);
+ return -1;
+ }
+
+ /*
+ * Figure out which CHOICE element is encoded.
+ */
+ present = _fetch_present_idx(sptr, specs->pres_offset,specs->pres_size);
+ if(present > 0 && present <= specs->elements_count) {
+ asn1_CHOICE_element_t *elm = &specs->elements[present-1];
+ const void *memb_ptr;
+
+ if(elm->optional) {
+ memb_ptr = *(const void * const *)((const char *)sptr + elm->memb_offset);
+ if(!memb_ptr) return 0;
+ } else {
+ memb_ptr = (const void *)((const char *)sptr + elm->memb_offset);
+ }
+
+ return elm->type->check_constraints(elm->type, memb_ptr,
+ app_errlog, app_key);
+ } else {
+ _ASN_ERRLOG("%s: no CHOICE element given", td->name);
+ return -1;
+ }
+}
+
+int
+CHOICE_print(asn1_TYPE_descriptor_t *td, const void *sptr, int ilevel,
+ asn_app_consume_bytes_f *cb, void *app_key) {
+ asn1_CHOICE_specifics_t *specs = td->specifics;
+ int present;
+
+ if(!sptr) return cb("<absent>", 8, app_key);
+
+ /*
+ * Figure out which CHOICE element is encoded.
+ */
+ present = _fetch_present_idx(sptr, specs->pres_offset,specs->pres_size);
+
+ /*
+ * Free that element.
+ */
+ if(present > 0 && present <= specs->elements_count) {
+ asn1_CHOICE_element_t *elm = &specs->elements[present-1];
+ const void *memb_ptr;
+
+ if(elm->optional) {
+ memb_ptr = *(const void * const *)((const char *)sptr + elm->memb_offset);
+ if(!memb_ptr) return cb("<absent>", 8, app_key);
+ } else {
+ memb_ptr = (const void *)((const char *)sptr + elm->memb_offset);
+ }
+
+ /* Print member's name and stuff */
+ if(cb(elm->name, strlen(elm->name), app_key)
+ || cb(": ", 2, app_key))
+ return -1;
+
+ return elm->type->print_struct(elm->type, memb_ptr, ilevel,
+ cb, app_key);
+ } else {
+ return cb("<absent>", 8, app_key);
+ }
+}
+
+void
+CHOICE_free(asn1_TYPE_descriptor_t *td, void *ptr, int contents_only) {
+ asn1_CHOICE_specifics_t *specs = td->specifics;
+ int present;
+
+ if(!td || !ptr)
+ return;
+
+ ASN_DEBUG("Freeing %s as CHOICE", td->name);
+
+ /*
+ * Figure out which CHOICE element is encoded.
+ */
+ present = _fetch_present_idx(ptr, specs->pres_offset, specs->pres_size);
+
+ /*
+ * Free that element.
+ */
+ if(present > 0 && present <= specs->elements_count) {
+ asn1_CHOICE_element_t *elm = &specs->elements[present-1];
+ void *memb_ptr;
+
+ if(elm->optional) {
+ memb_ptr = *(void **)((char *)ptr + elm->memb_offset);
+ if(memb_ptr)
+ elm->type->free_struct(elm->type, memb_ptr, 0);
+ } else {
+ memb_ptr = (void *)((char *)ptr + elm->memb_offset);
+ elm->type->free_struct(elm->type, memb_ptr, 1);
+ }
+ }
+
+ if(!contents_only) {
+ FREEMEM(ptr);
+ }
+}
+
+
+/*
+ * The following functions functions offer protection against -fshort-enums,
+ * compatible with little- and big-endian machines.
+ * If assertion is triggered, either disable -fshort-enums, or add an entry
+ * here with the ->pres_size of your target stracture.
+ * Unless the target structure is packed, the ".present" member
+ * is guaranteed to be aligned properly. ASN.1 compiler itself does not
+ * produce packed code.
+ */
+static inline int
+_fetch_present_idx(const void *struct_ptr, int pres_offset, int pres_size) {
+ const void *present_ptr;
+ int present;
+
+ present_ptr = ((const char *)struct_ptr) + pres_offset;
+
+ switch(pres_size) {
+ case sizeof(int): present = *(const int *)present_ptr; break;
+ case sizeof(short): present = *(const short *)present_ptr; break;
+ case sizeof(char): present = *(const char *)present_ptr; break;
+ default:
+ /* ANSI C mandates enum to be equivalent to integer */
+ assert(pres_size != sizeof(int));
+ return 0; /* If not aborted, pass back safe value */
+ }
+
+ return present;
+}
+
+static inline void
+_set_present_idx(void *struct_ptr, int pres_offset, int pres_size, int present) {
+ void *present_ptr;
+ present_ptr = ((char *)struct_ptr) + pres_offset;
+
+ switch(pres_size) {
+ case sizeof(int): *(int *)present_ptr = present; break;
+ case sizeof(short): *(short *)present_ptr = present; break;
+ case sizeof(char): *(char *)present_ptr = present; break;
+ default:
+ /* ANSI C mandates enum to be equivalent to integer */
+ assert(pres_size != sizeof(int));
+ }
+}