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authorDaniel Stenberg <daniel@haxx.se>2001-03-07 23:28:22 +0000
committerDaniel Stenberg <daniel@haxx.se>2001-03-07 23:28:22 +0000
commit55b8ceac18339c7b7d95c9033667cd7431eb2fa7 (patch)
tree7d3218503c0798078db99166368534f3214f598e /lib
parentbcf448ee325ea681b476de2ece9433ef7137c01a (diff)
chunked transfer encoding support
Diffstat (limited to 'lib')
-rw-r--r--lib/http_chunks.c188
-rw-r--r--lib/http_chunks.h73
2 files changed, 261 insertions, 0 deletions
diff --git a/lib/http_chunks.c b/lib/http_chunks.c
new file mode 100644
index 000000000..d22de18d1
--- /dev/null
+++ b/lib/http_chunks.c
@@ -0,0 +1,188 @@
+/*****************************************************************************
+ * _ _ ____ _
+ * Project ___| | | | _ \| |
+ * / __| | | | |_) | |
+ * | (__| |_| | _ <| |___
+ * \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 2001, Daniel Stenberg, <daniel@haxx.se>, et al.
+ *
+ * In order to be useful for every potential user, curl and libcurl are
+ * dual-licensed under the MPL and the MIT/X-derivate licenses.
+ *
+ * You may opt to use, copy, modify, merge, publish, distribute and/or sell
+ * copies of the Software, and permit persons to whom the Software is
+ * furnished to do so, under the terms of the MPL or the MIT/X-derivate
+ * licenses. You may pick one of these licenses.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ * $Id$
+ *****************************************************************************/
+#include "setup.h"
+
+/* -- WIN32 approved -- */
+#include <stdio.h>
+#include <string.h>
+#include <stdarg.h>
+#include <stdlib.h>
+#include <ctype.h>
+
+#include "urldata.h" /* it includes http_chunks.h */
+#include "sendf.h" /* for the client write stuff */
+
+#define _MPRINTF_REPLACE /* use our functions only */
+#include <curl/mprintf.h>
+
+/* The last #include file should be: */
+#ifdef MALLOCDEBUG
+#include "memdebug.h"
+#endif
+
+/*
+ * Chunk format (simplified):
+ *
+ * <HEX SIZE>[ chunk extension ] CRLF
+ * <DATA>
+ *
+ * Highlights from RFC2616 section 3.6 say:
+
+ The chunked encoding modifies the body of a message in order to
+ transfer it as a series of chunks, each with its own size indicator,
+ followed by an OPTIONAL trailer containing entity-header fields. This
+ allows dynamically produced content to be transferred along with the
+ information necessary for the recipient to verify that it has
+ received the full message.
+
+ Chunked-Body = *chunk
+ last-chunk
+ trailer
+ CRLF
+
+ chunk = chunk-size [ chunk-extension ] CRLF
+ chunk-data CRLF
+ chunk-size = 1*HEX
+ last-chunk = 1*("0") [ chunk-extension ] CRLF
+
+ chunk-extension= *( ";" chunk-ext-name [ "=" chunk-ext-val ] )
+ chunk-ext-name = token
+ chunk-ext-val = token | quoted-string
+ chunk-data = chunk-size(OCTET)
+ trailer = *(entity-header CRLF)
+
+ The chunk-size field is a string of hex digits indicating the size of
+ the chunk. The chunked encoding is ended by any chunk whose size is
+ zero, followed by the trailer, which is terminated by an empty line.
+
+ */
+
+
+void Curl_httpchunk_init(struct connectdata *conn)
+{
+ struct Curl_chunker *chunk = &conn->proto.http->chunk;
+ chunk->hexindex=0; /* start at 0 */
+ chunk->state = CHUNK_HEX; /* we get hex first! */
+}
+
+/*
+ * chunk_read() returns a 0 for normal operations, or a positive return code
+ * for errors. A negative number means this sequence of chunks is complete,
+ * and that many ~bytes were NOT used at the end of the buffer passed in.
+ * The 'wrote' argument is set to tell the caller how many bytes we actually
+ * passed to the client (for byte-counting and whatever).
+ *
+ * The states and the state-machine is further explained in the header file.
+ */
+CHUNKcode Curl_httpchunk_read(struct connectdata *conn,
+ char *datap,
+ ssize_t length,
+ ssize_t *wrote)
+{
+ CURLcode result;
+ struct Curl_chunker *ch = &conn->proto.http->chunk;
+ int piece;
+ *wrote = 0; /* nothing yet */
+
+ while(length) {
+ switch(ch->state) {
+ case CHUNK_HEX:
+ if(isxdigit((int)*datap)) {
+ if(ch->hexindex < MAXNUM_SIZE) {
+ ch->hexbuffer[ch->hexindex] = *datap;
+ datap++;
+ length--;
+ ch->hexindex++;
+ }
+ else {
+ return 1; /* longer hex than we support */
+ }
+ }
+ else {
+ /* length and datap are unmodified */
+ ch->hexbuffer[ch->hexindex]=0;
+ ch->datasize=strtoul(ch->hexbuffer, NULL, 16);
+ ch->state = CHUNK_POSTHEX;
+ }
+ break;
+
+ case CHUNK_POSTHEX:
+ /* just a lame state waiting for CRLF to arrive */
+ if(*datap == '\r')
+ ch->state = CHUNK_CR;
+ length--;
+ datap++;
+ break;
+
+ case CHUNK_CR:
+ /* waiting for the LF */
+ if(*datap == '\n') {
+ /* we're now expecting data to come, unless size was zero! */
+ if(0 == ch->datasize) {
+ ch->state = CHUNK_STOP; /* stop reading! */
+ if(1 == length) {
+ /* This was the final byte, return right now */
+ return ~0;
+ }
+ }
+ else
+ ch->state = CHUNK_DATA;
+ }
+ else
+ /* previously we got a fake CR, go back to CR waiting! */
+ ch->state = CHUNK_CR;
+ datap++;
+ length--;
+ break;
+
+ case CHUNK_DATA:
+ /* we get pure and fine data
+
+ We expect another 'datasize' of data. We have 'length' right now,
+ it can be more or less than 'datasize'. Get the smallest piece.
+ */
+ piece = (ch->datasize >= length)?length:ch->datasize;
+
+ /* Write the data portion available */
+ result = Curl_client_write(conn->data, CLIENTWRITE_BODY, datap, piece);
+ if(result)
+ return CHUNKE_WRITE_ERROR;
+ *wrote += piece;
+
+ ch->datasize -= piece; /* decrease amount left to expect */
+ datap += piece; /* move read pointer forward */
+ length -= piece; /* decrease space left in this round */
+
+ if(0 == ch->datasize)
+ /* end of data this round, go back to get a new size */
+ Curl_httpchunk_init(conn);
+
+ break;
+ case CHUNK_STOP:
+ return ~length; /* return the data size left */
+ default:
+ return CHUNKE_STATE_ERROR;
+ }
+ }
+ return CHUNKE_OK;
+}
diff --git a/lib/http_chunks.h b/lib/http_chunks.h
new file mode 100644
index 000000000..5869b9173
--- /dev/null
+++ b/lib/http_chunks.h
@@ -0,0 +1,73 @@
+#ifndef __HTTP_CHUNKS_H
+#define __HTTP_CHUNKS_H
+/*****************************************************************************
+ * _ _ ____ _
+ * Project ___| | | | _ \| |
+ * / __| | | | |_) | |
+ * | (__| |_| | _ <| |___
+ * \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 2001, Daniel Stenberg, <daniel@haxx.se>, et al.
+ *
+ * In order to be useful for every potential user, curl and libcurl are
+ * dual-licensed under the MPL and the MIT/X-derivate licenses.
+ *
+ * You may opt to use, copy, modify, merge, publish, distribute and/or sell
+ * copies of the Software, and permit persons to whom the Software is
+ * furnished to do so, under the terms of the MPL or the MIT/X-derivate
+ * licenses. You may pick one of these licenses.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ * $Id$
+ *****************************************************************************/
+/*
+ * The longest possible hexadecimal number we support in a chunked transfer.
+ * Weird enoug, RFC2616 doesn't set a maximum size! Since we use strtoul()
+ * to convert it, we "only" support 2^32 bytes chunk data.
+ */
+#define MAXNUM_SIZE 16
+
+typedef enum {
+ CHUNK_LOST, /* never use */
+
+ /* In this we await and buffer all hexadecimal digits until we get one
+ that isn't a hexadecimal digit. When done, we go POSTHEX */
+ CHUNK_HEX,
+
+ /* We have received the hexadecimal digit and we eat all characters until
+ we get a CRLF pair. When we see a CR we go to the CR state. */
+ CHUNK_POSTHEX,
+
+ /* A single CR has been found and we should get a LF right away in this
+ state or we go back to POSTHEX. When LF is received, we go to DATA.
+ If the size given was zero, we set state to STOP and return. */
+ CHUNK_CR,
+
+ /* We eat the amount of data specified. When done, we move back to the
+ HEX state. */
+ CHUNK_DATA,
+
+ /* This is only used to really mark that we're out of the game */
+ CHUNK_STOP,
+
+ CHUNK_LAST /* never use */
+} ChunkyState;
+
+typedef enum {
+ CHUNKE_OK,
+ CHUNKE_TOO_LONG_HEX,
+ CHUNKE_WRITE_ERROR,
+ CHUNKE_STATE_ERROR,
+ CHUNKE_LAST
+} CHUNKcode;
+
+struct Curl_chunker {
+ char hexbuffer[ MAXNUM_SIZE + 1];
+ int hexindex;
+ ChunkyState state;
+ unsigned long datasize;
+};
+
+#endif