vlm | 9de248e | 2004-10-20 15:50:55 +0000 | [diff] [blame] | 1 | |
| 2 | #include <asn_application.h> |
| 3 | #include <asn_internal.h> |
| 4 | #include <xer_support.h> /* XER/XML parsing support */ |
| 5 | #include <assert.h> |
| 6 | |
| 7 | |
| 8 | /* |
| 9 | * Decode the XER encoding of a given type. |
| 10 | */ |
| 11 | asn_dec_rval_t |
| 12 | xer_decode(asn_codec_ctx_t *opt_codec_ctx, asn_TYPE_descriptor_t *td, |
| 13 | void **struct_ptr, void *buffer, size_t size) { |
| 14 | asn_codec_ctx_t s_codec_ctx; |
| 15 | |
| 16 | /* |
| 17 | * Satisfy the requirement that the codec context |
| 18 | * must be allocated on the stack. |
| 19 | */ |
| 20 | if(opt_codec_ctx && opt_codec_ctx->max_stack_size) { |
| 21 | s_codec_ctx = *opt_codec_ctx; |
| 22 | opt_codec_ctx = &s_codec_ctx; |
| 23 | } |
| 24 | |
| 25 | /* |
| 26 | * Invoke type-specific decoder. |
| 27 | */ |
| 28 | return td->xer_decoder(opt_codec_ctx, td, struct_ptr, 0, buffer, size); |
| 29 | } |
| 30 | |
| 31 | |
| 32 | |
| 33 | struct xer__cb_arg { |
| 34 | pxml_chunk_type_e chunk_type; |
| 35 | size_t chunk_size; |
| 36 | void *chunk_buf; |
| 37 | int callback_not_invoked; |
| 38 | }; |
| 39 | |
| 40 | static int |
| 41 | xer__token_cb(pxml_chunk_type_e type, void *_chunk_data, size_t _chunk_size, void *key) { |
| 42 | struct xer__cb_arg *arg = (struct xer__cb_arg *)key; |
| 43 | arg->chunk_type = type; |
| 44 | arg->chunk_size = _chunk_size; |
| 45 | arg->chunk_buf = _chunk_data; |
| 46 | arg->callback_not_invoked = 0; |
| 47 | return -1; /* Terminate the XML parsing */ |
| 48 | } |
| 49 | |
| 50 | /* |
| 51 | * Fetch the next token from the XER/XML stream. |
| 52 | */ |
| 53 | ssize_t |
| 54 | xer_next_token(int *stateContext, void *buffer, size_t size, |
| 55 | pxer_chunk_type_e *ch_type) { |
| 56 | struct xer__cb_arg arg; |
| 57 | ssize_t ret; |
| 58 | |
| 59 | arg.callback_not_invoked = 1; |
| 60 | ret = pxml_parse(stateContext, buffer, size, xer__token_cb, &arg); |
| 61 | if(ret < 0) return -1; |
| 62 | if(arg.callback_not_invoked) { |
| 63 | assert(ret == 0); /* No data was consumed */ |
| 64 | return 0; /* Try again with more data */ |
| 65 | } else { |
| 66 | assert(arg.chunk_size); |
| 67 | assert(arg.chunk_buf == buffer); |
| 68 | } |
| 69 | |
| 70 | /* |
| 71 | * Translate the XML chunk types into more convenient ones. |
| 72 | */ |
| 73 | switch(arg.chunk_type) { |
| 74 | case PXML_TEXT: |
| 75 | *ch_type = PXER_TEXT; |
| 76 | break; |
| 77 | case PXML_TAG: return 0; /* Want more */ |
| 78 | case PXML_TAG_END: |
| 79 | *ch_type = PXER_TAG; |
| 80 | break; |
| 81 | case PXML_COMMENT: |
| 82 | case PXML_COMMENT_END: |
| 83 | *ch_type = PXER_COMMENT; |
| 84 | break; |
| 85 | } |
| 86 | |
| 87 | return arg.chunk_size; |
| 88 | } |
| 89 | |
| 90 | #define CSLASH 0x2f /* '/' */ |
| 91 | #define LANGLE 0x3c /* '<' */ |
| 92 | #define RANGLE 0x3e /* '>' */ |
| 93 | |
| 94 | xer_check_tag_e |
| 95 | xer_check_tag(const void *buf_ptr, int size, const char *need_tag) { |
| 96 | const char *buf = (const char *)buf_ptr; |
| 97 | const char *end; |
| 98 | xer_check_tag_e ct = XCT_OPENING; |
| 99 | |
| 100 | if(size < 2 || buf[0] != LANGLE || buf[size-1] != RANGLE) { |
| 101 | return XCT_BROKEN; |
| 102 | } |
| 103 | |
| 104 | /* |
| 105 | * Determine the tag class. |
| 106 | */ |
| 107 | if(buf[1] == CSLASH) { |
| 108 | buf += 2; /* advance past "</" */ |
| 109 | size -= 3; /* strip "</" and ">" */ |
| 110 | ct = XCT_CLOSING; |
| 111 | if(size > 0 && buf[size-1] == CSLASH) |
| 112 | return XCT_BROKEN; /* </abc/> */ |
| 113 | } else { |
| 114 | buf++; /* advance past "<" */ |
| 115 | size -= 2; /* strip "<" and ">" */ |
| 116 | if(size > 0 && buf[size-1] == CSLASH) { |
| 117 | ct = XCT_BOTH; |
| 118 | size--; /* One more, for "/" */ |
| 119 | } |
| 120 | } |
| 121 | |
| 122 | /* |
| 123 | * Determine the tag name. |
| 124 | */ |
| 125 | for(end = buf + size; buf < end; buf++, need_tag++) { |
| 126 | int b = *buf, n = *need_tag; |
| 127 | if(b != n) { |
| 128 | if(n == 0) { |
| 129 | switch(b) { |
| 130 | case 0x09: case 0x0a: case 0x0c: case 0x0d: |
| 131 | case 0x20: |
| 132 | /* "<abc def/>": whitespace is normal */ |
| 133 | return ct; |
| 134 | } |
| 135 | } |
| 136 | return XCT_UNEXPECTED; |
| 137 | } |
| 138 | if(b == 0) |
| 139 | return XCT_BROKEN; /* Embedded 0 in buf?! */ |
| 140 | } |
| 141 | if(*need_tag) return XCT_UNEXPECTED; |
| 142 | |
| 143 | return ct; |
| 144 | } |
| 145 | |
| 146 | |
| 147 | #undef ADVANCE |
| 148 | #define ADVANCE(num_bytes) do { \ |
| 149 | size_t num = (num_bytes); \ |
| 150 | buf_ptr = ((char *)buf_ptr) + num; \ |
| 151 | size -= num; \ |
| 152 | consumed_myself += num; \ |
| 153 | } while(0) |
| 154 | |
| 155 | #undef RETURN |
| 156 | #define RETURN(_code) do { \ |
| 157 | rval.code = _code; \ |
| 158 | rval.consumed = consumed_myself; \ |
| 159 | return rval; \ |
| 160 | } while(0) |
| 161 | |
| 162 | #define XER_GOT_BODY(chunk_buf, chunk_size) do { \ |
| 163 | ssize_t converted_size = body_receiver \ |
| 164 | (struct_ptr, chunk_buf, chunk_size, \ |
| 165 | (size_t)chunk_size < size); \ |
| 166 | if(converted_size == -1) RETURN(RC_FAIL); \ |
| 167 | chunk_size = converted_size; \ |
| 168 | } while(0) |
| 169 | #define XER_GOT_EMPTY() do { \ |
| 170 | ssize_t chunk_size = 0; \ |
| 171 | XER_GOT_BODY(0, chunk_size); \ |
| 172 | } while(0) |
| 173 | |
| 174 | /* |
| 175 | * Generalized function for decoding the primitive values. |
| 176 | */ |
| 177 | asn_dec_rval_t |
| 178 | xer_decode_general(asn_codec_ctx_t *opt_codec_ctx, |
| 179 | asn_struct_ctx_t *ctx, /* Type decoder context */ |
| 180 | void *struct_ptr, /* The structure must be already allocated */ |
| 181 | const char *xml_tag, /* Expected XML tag */ |
| 182 | void *buf_ptr, size_t size, |
| 183 | int (*opt_unexpected_tag_decoder) |
| 184 | (void *struct_ptr, void *chunk_buf, size_t chunk_size), |
| 185 | ssize_t (*body_receiver) |
| 186 | (void *struct_ptr, void *chunk_buf, size_t chunk_size, |
| 187 | int have_more) |
| 188 | ) { |
| 189 | |
| 190 | asn_dec_rval_t rval; |
| 191 | ssize_t consumed_myself = 0; |
| 192 | pxer_chunk_type_e ch_type; /* XER chunk type */ |
| 193 | int xer_state; /* XER low level parsing context */ |
| 194 | |
| 195 | (void)opt_codec_ctx; |
| 196 | |
| 197 | /* |
| 198 | * Phases of XER/XML processing: |
| 199 | * Phase 0: Check that the opening tag matches our expectations. |
| 200 | * Phase 1: Processing body and reacting on closing tag. |
| 201 | */ |
| 202 | if(ctx->phase > 1) RETURN(RC_FAIL); |
| 203 | for(xer_state = ctx->step;;) { |
| 204 | ssize_t ch_size; /* Chunk size */ |
| 205 | xer_check_tag_e tcv; /* Tag check value */ |
| 206 | |
| 207 | /* |
| 208 | * Get the next part of the XML stream. |
| 209 | */ |
| 210 | ch_size = xer_next_token(&xer_state, buf_ptr, size, &ch_type); |
| 211 | switch(ch_size) { |
| 212 | case -1: RETURN(RC_FAIL); |
| 213 | case 0: |
| 214 | ctx->step = xer_state; |
| 215 | RETURN(RC_WMORE); |
| 216 | default: |
| 217 | switch(ch_type) { |
| 218 | case PXER_COMMENT: /* Got XML comment */ |
| 219 | ADVANCE(ch_size); /* Skip silently */ |
| 220 | continue; |
| 221 | case PXER_TEXT: |
| 222 | if(ctx->phase == 0) { |
vlm | 7958f11 | 2004-10-21 05:44:11 +0000 | [diff] [blame] | 223 | /* |
| 224 | * We have to ignore whitespace here, |
| 225 | * but in order to be forward compatible |
| 226 | * with EXTENDED-XER (EMBED-VALUES, #25) |
| 227 | * any text is just ignored here. |
| 228 | */ |
| 229 | } else { |
| 230 | XER_GOT_BODY(buf_ptr, ch_size); |
vlm | 9de248e | 2004-10-20 15:50:55 +0000 | [diff] [blame] | 231 | } |
vlm | 9de248e | 2004-10-20 15:50:55 +0000 | [diff] [blame] | 232 | ADVANCE(ch_size); |
| 233 | continue; |
| 234 | case PXER_TAG: |
| 235 | break; /* Check the rest down there */ |
| 236 | } |
| 237 | } |
| 238 | |
| 239 | assert(ch_type == PXER_TAG && size); |
| 240 | |
| 241 | tcv = xer_check_tag(buf_ptr, ch_size, xml_tag); |
| 242 | if(ctx->phase == 0) { |
| 243 | /* |
| 244 | * Expecting the opening tag |
| 245 | * for the type being processed. |
| 246 | */ |
| 247 | switch(tcv) { |
| 248 | case XCT_BOTH: |
| 249 | /* Finished decoding of an empty element */ |
| 250 | XER_GOT_EMPTY(); |
| 251 | ADVANCE(ch_size); |
| 252 | ctx->phase = 2; /* Phase out */ |
| 253 | RETURN(RC_OK); |
| 254 | case XCT_OPENING: |
| 255 | ADVANCE(ch_size); |
| 256 | ctx->phase = 1; /* Processing body phase */ |
| 257 | continue; |
| 258 | default: |
| 259 | break; /* Unexpected tag */ |
| 260 | } |
| 261 | } else { |
| 262 | /* |
| 263 | * Waiting for the closing XML tag. |
| 264 | */ |
| 265 | switch(tcv) { |
| 266 | case XCT_CLOSING: |
| 267 | ADVANCE(ch_size); |
| 268 | ctx->phase = 2; /* Phase out */ |
| 269 | RETURN(RC_OK); |
| 270 | case XCT_UNEXPECTED: |
| 271 | /* |
| 272 | * Certain tags in the body may be expected. |
| 273 | */ |
| 274 | if(opt_unexpected_tag_decoder |
| 275 | && opt_unexpected_tag_decoder(struct_ptr, |
| 276 | buf_ptr, ch_size) == 0) { |
| 277 | /* Tag's processed fine */ |
| 278 | ADVANCE(ch_size); |
| 279 | continue; |
| 280 | } |
| 281 | /* Fall through */ |
| 282 | default: |
| 283 | break; |
| 284 | } |
| 285 | ASN_DEBUG("Unexpected XML tag"); |
| 286 | } |
| 287 | break; /* Dark and mysterious things have just happened */ |
| 288 | } |
| 289 | |
| 290 | RETURN(RC_FAIL); |
| 291 | } |
| 292 | |