E2Manager/asn1codec/e2ap_engine/asn_codecs_prim.c

   1
   2 /*-
   3  * Copyright (c) 2003, 2004 Lev Walkin <vlm@lionet.info>. All rights reserved.
   4  * Redistribution and modifications are permitted subject to BSD license.
   5  */
   6 #include <asn_internal.h>
   7 #include <asn_codecs_prim.h>
   8 #include <errno.h>
   9
  10 /*
  11  * Decode an always-primitive type.
  12  */
  13 asn_dec_rval_t
  14 ber_decode_primitive(const asn_codec_ctx_t *opt_codec_ctx,
  15                      const asn_TYPE_descriptor_t *td, void **sptr,
  16                      const void *buf_ptr, size_t size, int tag_mode) {
  17     ASN__PRIMITIVE_TYPE_t *st = (ASN__PRIMITIVE_TYPE_t *)*sptr;
  18         asn_dec_rval_t rval;
  19         ber_tlv_len_t length = 0; /* =0 to avoid [incorrect] warning. */
  20
  21         /*
  22          * If the structure is not there, allocate it.
  23          */
  24         if(st == NULL) {
  25                 st = (ASN__PRIMITIVE_TYPE_t *)CALLOC(1, sizeof(*st));
  26                 if(st == NULL) ASN__DECODE_FAILED;
  27                 *sptr = (void *)st;
  28         }
  29
  30         ASN_DEBUG("Decoding %s as plain primitive (tm=%d)",
  31                 td->name, tag_mode);
  32
  33         /*
  34          * Check tags and extract value length.
  35          */
  36         rval = ber_check_tags(opt_codec_ctx, td, 0, buf_ptr, size,
  37                         tag_mode, 0, &length, 0);
  38         if(rval.code != RC_OK)
  39                 return rval;
  40
  41         ASN_DEBUG("%s length is %d bytes", td->name, (int)length);
  42
  43         /*
  44          * Make sure we have this length.
  45          */
  46         buf_ptr = ((const char *)buf_ptr) + rval.consumed;
  47         size -= rval.consumed;
  48         if(length > (ber_tlv_len_t)size) {
  49                 rval.code = RC_WMORE;
  50                 rval.consumed = 0;
  51                 return rval;
  52         }
  53
  54         st->size = (int)length;
  55         /* The following better be optimized away. */
  56         if(sizeof(st->size) != sizeof(length)
  57                         && (ber_tlv_len_t)st->size != length) {
  58                 st->size = 0;
  59                 ASN__DECODE_FAILED;
  60         }
  61
  62         st->buf = (uint8_t *)MALLOC(length + 1);
  63         if(!st->buf) {
  64                 st->size = 0;
  65                 ASN__DECODE_FAILED;
  66         }
  67
  68         memcpy(st->buf, buf_ptr, length);
  69         st->buf[length] = '\0';         /* Just in case */
  70
  71         rval.code = RC_OK;
  72         rval.consumed += length;
  73
  74         ASN_DEBUG("Took %ld/%ld bytes to encode %s",
  75                 (long)rval.consumed,
  76                 (long)length, td->name);
  77
  78         return rval;
  79 }
  80
  81 /*
  82  * Encode an always-primitive type using DER.
  83  */
  84 asn_enc_rval_t
  85 der_encode_primitive(const asn_TYPE_descriptor_t *td, const void *sptr,
  86                      int tag_mode, ber_tlv_tag_t tag,
  87                      asn_app_consume_bytes_f *cb, void *app_key) {
  88         asn_enc_rval_t erval = {0,0,0};
  89         const ASN__PRIMITIVE_TYPE_t *st = (const ASN__PRIMITIVE_TYPE_t *)sptr;
  90
  91         ASN_DEBUG("%s %s as a primitive type (tm=%d)",
  92                 cb?"Encoding":"Estimating", td->name, tag_mode);
  93
  94         erval.encoded = der_write_tags(td, st->size, tag_mode, 0, tag,
  95                 cb, app_key);
  96         ASN_DEBUG("%s wrote tags %d", td->name, (int)erval.encoded);
  97         if(erval.encoded == -1) {
  98                 erval.failed_type = td;
  99                 erval.structure_ptr = sptr;
 100                 return erval;
 101         }
 102
 103         if(cb && st->buf) {
 104                 if(cb(st->buf, st->size, app_key) < 0) {
 105                         erval.encoded = -1;
 106                         erval.failed_type = td;
 107                         erval.structure_ptr = sptr;
 108                         return erval;
 109                 }
 110         } else {
 111                 assert(st->buf || st->size == 0);
 112         }
 113
 114         erval.encoded += st->size;
 115         ASN__ENCODED_OK(erval);
 116 }
 117
 118 void
 119 ASN__PRIMITIVE_TYPE_free(const asn_TYPE_descriptor_t *td, void *sptr,
 120                          enum asn_struct_free_method method) {
 121     ASN__PRIMITIVE_TYPE_t *st = (ASN__PRIMITIVE_TYPE_t *)sptr;
 122
 123         if(!td || !sptr)
 124                 return;
 125
 126         ASN_DEBUG("Freeing %s as a primitive type", td->name);
 127
 128         if(st->buf)
 129                 FREEMEM(st->buf);
 130
 131     switch(method) {
 132     case ASFM_FREE_EVERYTHING:
 133         FREEMEM(sptr);
 134         break;
 135     case ASFM_FREE_UNDERLYING:
 136         break;
 137     case ASFM_FREE_UNDERLYING_AND_RESET:
 138         memset(sptr, 0, sizeof(ASN__PRIMITIVE_TYPE_t));
 139         break;
 140     }
 141 }
 142
 143
 144 /*
 145  * Local internal type passed around as an argument.
 146  */
 147 struct xdp_arg_s {
 148     const asn_TYPE_descriptor_t *type_descriptor;
 149     void *struct_key;
 150         xer_primitive_body_decoder_f *prim_body_decoder;
 151         int decoded_something;
 152         int want_more;
 153 };
 154
 155 /*
 156  * Since some kinds of primitive values can be encoded using value-specific
 157  * tags (<MINUS-INFINITY>, <enum-element>, etc), the primitive decoder must
 158  * be supplied with such tags to parse them as needed.
 159  */
 160 static int
 161 xer_decode__unexpected_tag(void *key, const void *chunk_buf, size_t chunk_size) {
 162         struct xdp_arg_s *arg = (struct xdp_arg_s *)key;
 163         enum xer_pbd_rval bret;
 164
 165         /*
 166          * The chunk_buf is guaranteed to start at '<'.
 167          */
 168         assert(chunk_size && ((const char *)chunk_buf)[0] == 0x3c);
 169
 170         /*
 171          * Decoding was performed once already. Prohibit doing it again.
 172          */
 173         if(arg->decoded_something)
 174                 return -1;
 175
 176         bret = arg->prim_body_decoder(arg->type_descriptor,
 177                 arg->struct_key, chunk_buf, chunk_size);
 178         switch(bret) {
 179         case XPBD_SYSTEM_FAILURE:
 180         case XPBD_DECODER_LIMIT:
 181         case XPBD_BROKEN_ENCODING:
 182                 break;
 183         case XPBD_BODY_CONSUMED:
 184                 /* Tag decoded successfully */
 185                 arg->decoded_something = 1;
 186                 /* Fall through */
 187         case XPBD_NOT_BODY_IGNORE:      /* Safe to proceed further */
 188                 return 0;
 189         }
 190
 191         return -1;
 192 }
 193
 194 static ssize_t
 195 xer_decode__primitive_body(void *key, const void *chunk_buf, size_t chunk_size, int have_more) {
 196         struct xdp_arg_s *arg = (struct xdp_arg_s *)key;
 197         enum xer_pbd_rval bret;
 198         size_t lead_wsp_size;
 199
 200         if(arg->decoded_something) {
 201                 if(xer_whitespace_span(chunk_buf, chunk_size) == chunk_size) {
 202                         /*
 203                          * Example:
 204                          * "<INTEGER>123<!--/--> </INTEGER>"
 205                          *                      ^- chunk_buf position.
 206                          */
 207                         return chunk_size;
 208                 }
 209                 /*
 210                  * Decoding was done once already. Prohibit doing it again.
 211                  */
 212                 return -1;
 213         }
 214
 215         if(!have_more) {
 216                 /*
 217                  * If we've received something like "1", we can't really
 218                  * tell whether it is really `1` or `123`, until we know
 219                  * that there is no more data coming.
 220                  * The have_more argument will be set to 1 once something
 221                  * like this is available to the caller of this callback:
 222                  * "1<tag_start..."
 223                  */
 224                 arg->want_more = 1;
 225                 return -1;
 226         }
 227
 228         lead_wsp_size = xer_whitespace_span(chunk_buf, chunk_size);
 229         chunk_buf = (const char *)chunk_buf + lead_wsp_size;
 230         chunk_size -= lead_wsp_size;
 231
 232         bret = arg->prim_body_decoder(arg->type_descriptor,
 233                 arg->struct_key, chunk_buf, chunk_size);
 234         switch(bret) {
 235         case XPBD_SYSTEM_FAILURE:
 236         case XPBD_DECODER_LIMIT:
 237         case XPBD_BROKEN_ENCODING:
 238                 break;
 239         case XPBD_BODY_CONSUMED:
 240                 /* Tag decoded successfully */
 241                 arg->decoded_something = 1;
 242                 /* Fall through */
 243         case XPBD_NOT_BODY_IGNORE:      /* Safe to proceed further */
 244                 return lead_wsp_size + chunk_size;
 245         }
 246
 247         return -1;
 248 }
 249
 250
 251 asn_dec_rval_t
 252 xer_decode_primitive(const asn_codec_ctx_t *opt_codec_ctx,
 253                      const asn_TYPE_descriptor_t *td, void **sptr,
 254                      size_t struct_size, const char *opt_mname,
 255                      const void *buf_ptr, size_t size,
 256                      xer_primitive_body_decoder_f *prim_body_decoder) {
 257     const char *xml_tag = opt_mname ? opt_mname : td->xml_tag;
 258         asn_struct_ctx_t s_ctx;
 259         struct xdp_arg_s s_arg;
 260         asn_dec_rval_t rc;
 261
 262         /*
 263          * Create the structure if does not exist.
 264          */
 265         if(!*sptr) {
 266                 *sptr = CALLOC(1, struct_size);
 267                 if(!*sptr) ASN__DECODE_FAILED;
 268         }
 269
 270         memset(&s_ctx, 0, sizeof(s_ctx));
 271         s_arg.type_descriptor = td;
 272         s_arg.struct_key = *sptr;
 273         s_arg.prim_body_decoder = prim_body_decoder;
 274         s_arg.decoded_something = 0;
 275         s_arg.want_more = 0;
 276
 277         rc = xer_decode_general(opt_codec_ctx, &s_ctx, &s_arg,
 278                 xml_tag, buf_ptr, size,
 279                 xer_decode__unexpected_tag, xer_decode__primitive_body);
 280         switch(rc.code) {
 281         case RC_OK:
 282                 if(!s_arg.decoded_something) {
 283                         char ch;
 284                         ASN_DEBUG("Primitive body is not recognized, "
 285                                 "supplying empty one");
 286                         /*
 287                          * Decoding opportunity has come and gone.
 288                          * Where's the result?
 289                          * Try to feed with empty body, see if it eats it.
 290                          */
 291                         if(prim_body_decoder(s_arg.type_descriptor,
 292                                 s_arg.struct_key, &ch, 0)
 293                                         != XPBD_BODY_CONSUMED) {
 294                                 /*
 295                                  * This decoder does not like empty stuff.
 296                                  */
 297                                 ASN__DECODE_FAILED;
 298                         }
 299                 }
 300                 break;
 301         case RC_WMORE:
 302                 /*
 303                  * Redo the whole thing later.
 304                  * We don't have a context to save intermediate parsing state.
 305                  */
 306                 rc.consumed = 0;
 307                 break;
 308         case RC_FAIL:
 309                 rc.consumed = 0;
 310                 if(s_arg.want_more)
 311                         rc.code = RC_WMORE;
 312                 else
 313                         ASN__DECODE_FAILED;
 314                 break;
 315         }
 316         return rc;
 317 }
 318