1 /***************************************************************************
3 * Project ___| | | | _ \| |
5 * | (__| |_| | _ <| |___
6 * \___|\___/|_| \_\_____|
8 * Copyright (C) 1998 - 2018, Daniel Stenberg, <daniel@haxx.se>, et al.
10 * This software is licensed as described in the file COPYING, which
11 * you should have received as part of this distribution. The terms
12 * are also available at https://curl.haxx.se/docs/copyright.html.
14 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
15 * copies of the Software, and permit persons to whom the Software is
16 * furnished to do so, under the terms of the COPYING file.
18 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
19 * KIND, either express or implied.
21 ***************************************************************************/
23 #include "curl_setup.h"
25 #ifndef CURL_DISABLE_HTTP
27 #include "urldata.h" /* it includes http_chunks.h */
28 #include "sendf.h" /* for the client write stuff */
30 #include "content_encoding.h"
32 #include "non-ascii.h" /* for Curl_convert_to_network prototype */
33 #include "strtoofft.h"
36 /* The last #include files should be: */
37 #include "curl_memory.h"
41 * Chunk format (simplified):
43 * <HEX SIZE>[ chunk extension ] CRLF
46 * Highlights from RFC2616 section 3.6 say:
48 The chunked encoding modifies the body of a message in order to
49 transfer it as a series of chunks, each with its own size indicator,
50 followed by an OPTIONAL trailer containing entity-header fields. This
51 allows dynamically produced content to be transferred along with the
52 information necessary for the recipient to verify that it has
53 received the full message.
60 chunk = chunk-size [ chunk-extension ] CRLF
63 last-chunk = 1*("0") [ chunk-extension ] CRLF
65 chunk-extension= *( ";" chunk-ext-name [ "=" chunk-ext-val ] )
66 chunk-ext-name = token
67 chunk-ext-val = token | quoted-string
68 chunk-data = chunk-size(OCTET)
69 trailer = *(entity-header CRLF)
71 The chunk-size field is a string of hex digits indicating the size of
72 the chunk. The chunked encoding is ended by any chunk whose size is
73 zero, followed by the trailer, which is terminated by an empty line.
77 void Curl_httpchunk_init(struct connectdata *conn)
79 struct Curl_chunker *chunk = &conn->chunk;
80 chunk->hexindex = 0; /* start at 0 */
81 chunk->dataleft = 0; /* no data left yet! */
82 chunk->state = CHUNK_HEX; /* we get hex first! */
86 * chunk_read() returns a OK for normal operations, or a positive return code
87 * for errors. STOP means this sequence of chunks is complete. The 'wrote'
88 * argument is set to tell the caller how many bytes we actually passed to the
89 * client (for byte-counting and whatever).
91 * The states and the state-machine is further explained in the header file.
93 * This function always uses ASCII hex values to accommodate non-ASCII hosts.
94 * For example, 0x0d and 0x0a are used instead of '\r' and '\n'.
96 CHUNKcode Curl_httpchunk_read(struct connectdata *conn,
101 CURLcode result = CURLE_OK;
102 struct Curl_easy *data = conn->data;
103 struct Curl_chunker *ch = &conn->chunk;
104 struct SingleRequest *k = &data->req;
106 curl_off_t length = (curl_off_t)datalen;
107 size_t *wrote = (size_t *)wrotep;
109 *wrote = 0; /* nothing's written yet */
111 /* the original data is written to the client, but we go on with the
112 chunk read process, to properly calculate the content length*/
113 if(data->set.http_te_skip && !k->ignorebody) {
114 result = Curl_client_write(conn, CLIENTWRITE_BODY, datap, datalen);
116 return CHUNKE_WRITE_ERROR;
122 if(Curl_isxdigit(*datap)) {
123 if(ch->hexindex < MAXNUM_SIZE) {
124 ch->hexbuffer[ch->hexindex] = *datap;
130 return CHUNKE_TOO_LONG_HEX; /* longer hex than we support */
135 if(0 == ch->hexindex)
136 /* This is illegal data, we received junk where we expected
137 a hexadecimal digit. */
138 return CHUNKE_ILLEGAL_HEX;
140 /* length and datap are unmodified */
141 ch->hexbuffer[ch->hexindex] = 0;
143 /* convert to host encoding before calling strtoul */
144 result = Curl_convert_from_network(conn->data, ch->hexbuffer,
147 /* Curl_convert_from_network calls failf if unsuccessful */
148 /* Treat it as a bad hex character */
149 return CHUNKE_ILLEGAL_HEX;
152 if(curlx_strtoofft(ch->hexbuffer, &endptr, 16, &ch->datasize))
153 return CHUNKE_ILLEGAL_HEX;
154 ch->state = CHUNK_LF; /* now wait for the CRLF */
159 /* waiting for the LF after a chunk size */
161 /* we're now expecting data to come, unless size was zero! */
162 if(0 == ch->datasize) {
163 ch->state = CHUNK_TRAILER; /* now check for trailers */
167 ch->state = CHUNK_DATA;
175 /* We expect 'datasize' of data. We have 'length' right now, it can be
176 more or less than 'datasize'. Get the smallest piece.
178 piece = curlx_sotouz((ch->datasize >= length)?length:ch->datasize);
180 /* Write the data portion available */
181 if(!conn->data->set.http_te_skip && !k->ignorebody) {
182 if(!conn->data->set.http_ce_skip && k->writer_stack)
183 result = Curl_unencode_write(conn, k->writer_stack, datap, piece);
185 result = Curl_client_write(conn, CLIENTWRITE_BODY, datap, piece);
188 return CHUNKE_WRITE_ERROR;
192 ch->datasize -= piece; /* decrease amount left to expect */
193 datap += piece; /* move read pointer forward */
194 length -= piece; /* decrease space left in this round */
196 if(0 == ch->datasize)
197 /* end of data this round, we now expect a trailing CRLF */
198 ch->state = CHUNK_POSTLF;
203 /* The last one before we go back to hex state and start all over. */
204 Curl_httpchunk_init(conn); /* sets state back to CHUNK_HEX */
206 else if(*datap != 0x0d)
207 return CHUNKE_BAD_CHUNK;
213 if((*datap == 0x0d) || (*datap == 0x0a)) {
214 /* this is the end of a trailer, but if the trailer was zero bytes
215 there was no trailer and we move on */
218 /* we allocate trailer with 3 bytes extra room to fit this */
219 conn->trailer[conn->trlPos++] = 0x0d;
220 conn->trailer[conn->trlPos++] = 0x0a;
221 conn->trailer[conn->trlPos] = 0;
223 /* Convert to host encoding before calling Curl_client_write */
224 result = Curl_convert_from_network(conn->data, conn->trailer,
227 /* Curl_convert_from_network calls failf if unsuccessful */
228 /* Treat it as a bad chunk */
229 return CHUNKE_BAD_CHUNK;
231 if(!data->set.http_te_skip) {
232 result = Curl_client_write(conn, CLIENTWRITE_HEADER,
233 conn->trailer, conn->trlPos);
235 return CHUNKE_WRITE_ERROR;
238 ch->state = CHUNK_TRAILER_CR;
240 /* already on the LF */
244 /* no trailer, we're on the final CRLF pair */
245 ch->state = CHUNK_TRAILER_POSTCR;
246 break; /* don't advance the pointer */
250 /* conn->trailer is assumed to be freed in url.c on a
252 if(conn->trlPos >= conn->trlMax) {
253 /* we always allocate three extra bytes, just because when the full
254 header has been received we append CRLF\0 */
258 ptr = realloc(conn->trailer, conn->trlMax + 3);
262 ptr = malloc(conn->trlMax + 3);
265 return CHUNKE_OUT_OF_MEMORY;
268 conn->trailer[conn->trlPos++]=*datap;
274 case CHUNK_TRAILER_CR:
276 ch->state = CHUNK_TRAILER_POSTCR;
281 return CHUNKE_BAD_CHUNK;
284 case CHUNK_TRAILER_POSTCR:
285 /* We enter this state when a CR should arrive so we expect to
286 have to first pass a CR before we wait for LF */
287 if((*datap != 0x0d) && (*datap != 0x0a)) {
288 /* not a CR then it must be another header in the trailer */
289 ch->state = CHUNK_TRAILER;
297 /* now wait for the final LF */
298 ch->state = CHUNK_STOP;
305 /* Record the length of any data left in the end of the buffer
306 even if there's no more chunks to read */
307 ch->dataleft = curlx_sotouz(length);
309 return CHUNKE_STOP; /* return stop */
312 return CHUNKE_BAD_CHUNK;
318 const char *Curl_chunked_strerror(CHUNKcode code)
323 case CHUNKE_TOO_LONG_HEX:
324 return "Too long hexadecimal number";
325 case CHUNKE_ILLEGAL_HEX:
326 return "Illegal or missing hexadecimal sequence";
327 case CHUNKE_BAD_CHUNK:
328 return "Malformed encoding found";
329 case CHUNKE_WRITE_ERROR:
330 return "Write error";
331 case CHUNKE_BAD_ENCODING:
332 return "Bad content-encoding found";
333 case CHUNKE_OUT_OF_MEMORY:
334 return "Out of memory";
338 #endif /* CURL_DISABLE_HTTP */