diff options
Diffstat (limited to 'Utilities/cmcurl/lib/content_encoding.c')
| -rw-r--r-- | Utilities/cmcurl/lib/content_encoding.c | 1013 |
1 files changed, 1013 insertions, 0 deletions
diff --git a/Utilities/cmcurl/lib/content_encoding.c b/Utilities/cmcurl/lib/content_encoding.c new file mode 100644 index 0000000..46bef0c --- /dev/null +++ b/Utilities/cmcurl/lib/content_encoding.c @@ -0,0 +1,1013 @@ +/*************************************************************************** + * _ _ ____ _ + * Project ___| | | | _ \| | + * / __| | | | |_) | | + * | (__| |_| | _ <| |___ + * \___|\___/|_| \_\_____| + * + * Copyright (C) 1998 - 2017, Daniel Stenberg, <daniel@haxx.se>, et al. + * + * This software is licensed as described in the file COPYING, which + * you should have received as part of this distribution. The terms + * are also available at https://curl.haxx.se/docs/copyright.html. + * + * 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 COPYING file. + * + * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY + * KIND, either express or implied. + * + ***************************************************************************/ + +#include "curl_setup.h" + +#include "urldata.h" +#include <curl/curl.h> +#include <stddef.h> + +#ifdef HAVE_ZLIB_H +#include <zlib.h> +#ifdef __SYMBIAN32__ +/* zlib pollutes the namespace with this definition */ +#undef WIN32 +#endif +#endif + +#ifdef HAVE_BROTLI +#include <brotli/decode.h> +#endif + +#include "sendf.h" +#include "http.h" +#include "content_encoding.h" +#include "strdup.h" +#include "strcase.h" +#include "curl_memory.h" +#include "memdebug.h" + +#define CONTENT_ENCODING_DEFAULT "identity" + +#ifndef CURL_DISABLE_HTTP + +#define DSIZ CURL_MAX_WRITE_SIZE /* buffer size for decompressed data */ + + +#ifdef HAVE_LIBZ + +/* Comment this out if zlib is always going to be at least ver. 1.2.0.4 + (doing so will reduce code size slightly). */ +#define OLD_ZLIB_SUPPORT 1 + +#define GZIP_MAGIC_0 0x1f +#define GZIP_MAGIC_1 0x8b + +/* gzip flag byte */ +#define ASCII_FLAG 0x01 /* bit 0 set: file probably ascii text */ +#define HEAD_CRC 0x02 /* bit 1 set: header CRC present */ +#define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */ +#define ORIG_NAME 0x08 /* bit 3 set: original file name present */ +#define COMMENT 0x10 /* bit 4 set: file comment present */ +#define RESERVED 0xE0 /* bits 5..7: reserved */ + +typedef enum { + ZLIB_UNINIT, /* uninitialized */ + ZLIB_INIT, /* initialized */ + ZLIB_INFLATING, /* Inflating started. */ + ZLIB_GZIP_HEADER, /* reading gzip header */ + ZLIB_GZIP_TRAILER, /* reading gzip trailer */ + ZLIB_GZIP_INFLATING, /* inflating gzip stream */ + ZLIB_INIT_GZIP /* initialized in transparent gzip mode */ +} zlibInitState; + +/* Writer parameters. */ +typedef struct { + zlibInitState zlib_init; /* zlib init state */ + uInt trailerlen; /* Remaining trailer byte count. */ + z_stream z; /* State structure for zlib. */ +} zlib_params; + + +static voidpf +zalloc_cb(voidpf opaque, unsigned int items, unsigned int size) +{ + (void) opaque; + /* not a typo, keep it calloc() */ + return (voidpf) calloc(items, size); +} + +static void +zfree_cb(voidpf opaque, voidpf ptr) +{ + (void) opaque; + free(ptr); +} + +static CURLcode +process_zlib_error(struct connectdata *conn, z_stream *z) +{ + struct Curl_easy *data = conn->data; + if(z->msg) + failf(data, "Error while processing content unencoding: %s", + z->msg); + else + failf(data, "Error while processing content unencoding: " + "Unknown failure within decompression software."); + + return CURLE_BAD_CONTENT_ENCODING; +} + +static CURLcode +exit_zlib(struct connectdata *conn, + z_stream *z, zlibInitState *zlib_init, CURLcode result) +{ + if(*zlib_init == ZLIB_GZIP_HEADER) + Curl_safefree(z->next_in); + + if(*zlib_init != ZLIB_UNINIT) { + if(inflateEnd(z) != Z_OK && result == CURLE_OK) + result = process_zlib_error(conn, z); + *zlib_init = ZLIB_UNINIT; + } + + return result; +} + +static CURLcode process_trailer(struct connectdata *conn, zlib_params *zp) +{ + z_stream *z = &zp->z; + CURLcode result = CURLE_OK; + uInt len = z->avail_in < zp->trailerlen? z->avail_in: zp->trailerlen; + + /* Consume expected trailer bytes. Terminate stream if exhausted. + Issue an error if unexpected bytes follow. */ + + zp->trailerlen -= len; + z->avail_in -= len; + z->next_in += len; + if(z->avail_in) + result = CURLE_WRITE_ERROR; + if(result || !zp->trailerlen) + result = exit_zlib(conn, z, &zp->zlib_init, result); + else { + /* Only occurs for gzip with zlib < 1.2.0.4. */ + zp->zlib_init = ZLIB_GZIP_TRAILER; + } + return result; +} + +static CURLcode inflate_stream(struct connectdata *conn, + contenc_writer *writer, zlibInitState started) +{ + zlib_params *zp = (zlib_params *) &writer->params; + z_stream *z = &zp->z; /* zlib state structure */ + uInt nread = z->avail_in; + Bytef *orig_in = z->next_in; + int status; /* zlib status */ + bool done = FALSE; + CURLcode result = CURLE_OK; /* Curl_client_write status */ + char *decomp; /* Put the decompressed data here. */ + + /* Check state. */ + if(zp->zlib_init != ZLIB_INIT && + zp->zlib_init != ZLIB_INFLATING && + zp->zlib_init != ZLIB_INIT_GZIP && + zp->zlib_init != ZLIB_GZIP_INFLATING) + return exit_zlib(conn, z, &zp->zlib_init, CURLE_WRITE_ERROR); + + /* Dynamically allocate a buffer for decompression because it's uncommonly + large to hold on the stack */ + decomp = malloc(DSIZ); + if(decomp == NULL) + return exit_zlib(conn, z, &zp->zlib_init, CURLE_OUT_OF_MEMORY); + + /* because the buffer size is fixed, iteratively decompress and transfer to + the client via downstream_write function. */ + while(!done) { + done = TRUE; + + /* (re)set buffer for decompressed output for every iteration */ + z->next_out = (Bytef *) decomp; + z->avail_out = DSIZ; + + status = inflate(z, Z_BLOCK); + + /* Flush output data if some. */ + if(z->avail_out != DSIZ) { + if(status == Z_OK || status == Z_STREAM_END) { + zp->zlib_init = started; /* Data started. */ + result = Curl_unencode_write(conn, writer->downstream, decomp, + DSIZ - z->avail_out); + if(result) { + exit_zlib(conn, z, &zp->zlib_init, result); + break; + } + } + } + + /* Dispatch by inflate() status. */ + switch(status) { + case Z_OK: + /* Always loop: there may be unflushed latched data in zlib state. */ + done = FALSE; + break; + case Z_BUF_ERROR: + /* No more data to flush: just exit loop. */ + break; + case Z_STREAM_END: + result = process_trailer(conn, zp); + break; + case Z_DATA_ERROR: + /* some servers seem to not generate zlib headers, so this is an attempt + to fix and continue anyway */ + if(zp->zlib_init == ZLIB_INIT) { + /* Do not use inflateReset2(): only available since zlib 1.2.3.4. */ + (void) inflateEnd(z); /* don't care about the return code */ + if(inflateInit2(z, -MAX_WBITS) == Z_OK) { + z->next_in = orig_in; + z->avail_in = nread; + zp->zlib_init = ZLIB_INFLATING; + done = FALSE; + break; + } + zp->zlib_init = ZLIB_UNINIT; /* inflateEnd() already called. */ + } + /* FALLTHROUGH */ + default: + result = exit_zlib(conn, z, &zp->zlib_init, process_zlib_error(conn, z)); + break; + } + } + free(decomp); + + /* We're about to leave this call so the `nread' data bytes won't be seen + again. If we are in a state that would wrongly allow restart in raw mode + at the next call, assume output has already started. */ + if(nread && zp->zlib_init == ZLIB_INIT) + zp->zlib_init = started; /* Cannot restart anymore. */ + + return result; +} + + +/* Deflate handler. */ +static CURLcode deflate_init_writer(struct connectdata *conn, + contenc_writer *writer) +{ + zlib_params *zp = (zlib_params *) &writer->params; + z_stream *z = &zp->z; /* zlib state structure */ + + if(!writer->downstream) + return CURLE_WRITE_ERROR; + + /* Initialize zlib */ + z->zalloc = (alloc_func) zalloc_cb; + z->zfree = (free_func) zfree_cb; + + if(inflateInit(z) != Z_OK) + return process_zlib_error(conn, z); + zp->zlib_init = ZLIB_INIT; + return CURLE_OK; +} + +static CURLcode deflate_unencode_write(struct connectdata *conn, + contenc_writer *writer, + const char *buf, size_t nbytes) +{ + zlib_params *zp = (zlib_params *) &writer->params; + z_stream *z = &zp->z; /* zlib state structure */ + + /* Set the compressed input when this function is called */ + z->next_in = (Bytef *) buf; + z->avail_in = (uInt) nbytes; + + /* Now uncompress the data */ + return inflate_stream(conn, writer, ZLIB_INFLATING); +} + +static void deflate_close_writer(struct connectdata *conn, + contenc_writer *writer) +{ + zlib_params *zp = (zlib_params *) &writer->params; + z_stream *z = &zp->z; /* zlib state structure */ + + exit_zlib(conn, z, &zp->zlib_init, CURLE_OK); +} + +static const content_encoding deflate_encoding = { + "deflate", + NULL, + deflate_init_writer, + deflate_unencode_write, + deflate_close_writer, + sizeof(zlib_params) +}; + + +/* Gzip handler. */ +static CURLcode gzip_init_writer(struct connectdata *conn, + contenc_writer *writer) +{ + zlib_params *zp = (zlib_params *) &writer->params; + z_stream *z = &zp->z; /* zlib state structure */ + + if(!writer->downstream) + return CURLE_WRITE_ERROR; + + /* Initialize zlib */ + z->zalloc = (alloc_func) zalloc_cb; + z->zfree = (free_func) zfree_cb; + + if(strcmp(zlibVersion(), "1.2.0.4") >= 0) { + /* zlib ver. >= 1.2.0.4 supports transparent gzip decompressing */ + if(inflateInit2(z, MAX_WBITS + 32) != Z_OK) { + return process_zlib_error(conn, z); + } + zp->zlib_init = ZLIB_INIT_GZIP; /* Transparent gzip decompress state */ + } + else { + /* we must parse the gzip header and trailer ourselves */ + if(inflateInit2(z, -MAX_WBITS) != Z_OK) { + return process_zlib_error(conn, z); + } + zp->trailerlen = 8; /* A CRC-32 and a 32-bit input size (RFC 1952, 2.2) */ + zp->zlib_init = ZLIB_INIT; /* Initial call state */ + } + + return CURLE_OK; +} + +#ifdef OLD_ZLIB_SUPPORT +/* Skip over the gzip header */ +static enum { + GZIP_OK, + GZIP_BAD, + GZIP_UNDERFLOW +} check_gzip_header(unsigned char const *data, ssize_t len, ssize_t *headerlen) +{ + int method, flags; + const ssize_t totallen = len; + + /* The shortest header is 10 bytes */ + if(len < 10) + return GZIP_UNDERFLOW; + + if((data[0] != GZIP_MAGIC_0) || (data[1] != GZIP_MAGIC_1)) + return GZIP_BAD; + + method = data[2]; + flags = data[3]; + + if(method != Z_DEFLATED || (flags & RESERVED) != 0) { + /* Can't handle this compression method or unknown flag */ + return GZIP_BAD; + } + + /* Skip over time, xflags, OS code and all previous bytes */ + len -= 10; + data += 10; + + if(flags & EXTRA_FIELD) { + ssize_t extra_len; + + if(len < 2) + return GZIP_UNDERFLOW; + + extra_len = (data[1] << 8) | data[0]; + + if(len < (extra_len + 2)) + return GZIP_UNDERFLOW; + + len -= (extra_len + 2); + data += (extra_len + 2); + } + + if(flags & ORIG_NAME) { + /* Skip over NUL-terminated file name */ + while(len && *data) { + --len; + ++data; + } + if(!len || *data) + return GZIP_UNDERFLOW; + + /* Skip over the NUL */ + --len; + ++data; + } + + if(flags & COMMENT) { + /* Skip over NUL-terminated comment */ + while(len && *data) { + --len; + ++data; + } + if(!len || *data) + return GZIP_UNDERFLOW; + + /* Skip over the NUL */ + --len; + } + + if(flags & HEAD_CRC) { + if(len < 2) + return GZIP_UNDERFLOW; + + len -= 2; + } + + *headerlen = totallen - len; + return GZIP_OK; +} +#endif + +static CURLcode gzip_unencode_write(struct connectdata *conn, + contenc_writer *writer, + const char *buf, size_t nbytes) +{ + zlib_params *zp = (zlib_params *) &writer->params; + z_stream *z = &zp->z; /* zlib state structure */ + + if(zp->zlib_init == ZLIB_INIT_GZIP) { + /* Let zlib handle the gzip decompression entirely */ + z->next_in = (Bytef *) buf; + z->avail_in = (uInt) nbytes; + /* Now uncompress the data */ + return inflate_stream(conn, writer, ZLIB_INIT_GZIP); + } + +#ifndef OLD_ZLIB_SUPPORT + /* Support for old zlib versions is compiled away and we are running with + an old version, so return an error. */ + return exit_zlib(conn, z, &zp->zlib_init, CURLE_WRITE_ERROR); + +#else + /* This next mess is to get around the potential case where there isn't + * enough data passed in to skip over the gzip header. If that happens, we + * malloc a block and copy what we have then wait for the next call. If + * there still isn't enough (this is definitely a worst-case scenario), we + * make the block bigger, copy the next part in and keep waiting. + * + * This is only required with zlib versions < 1.2.0.4 as newer versions + * can handle the gzip header themselves. + */ + + switch(zp->zlib_init) { + /* Skip over gzip header? */ + case ZLIB_INIT: + { + /* Initial call state */ + ssize_t hlen; + + switch(check_gzip_header((unsigned char *) buf, nbytes, &hlen)) { + case GZIP_OK: + z->next_in = (Bytef *) buf + hlen; + z->avail_in = (uInt) (nbytes - hlen); + zp->zlib_init = ZLIB_GZIP_INFLATING; /* Inflating stream state */ + break; + + case GZIP_UNDERFLOW: + /* We need more data so we can find the end of the gzip header. It's + * possible that the memory block we malloc here will never be freed if + * the transfer abruptly aborts after this point. Since it's unlikely + * that circumstances will be right for this code path to be followed in + * the first place, and it's even more unlikely for a transfer to fail + * immediately afterwards, it should seldom be a problem. + */ + z->avail_in = (uInt) nbytes; + z->next_in = malloc(z->avail_in); + if(z->next_in == NULL) { + return exit_zlib(conn, z, &zp->zlib_init, CURLE_OUT_OF_MEMORY); + } + memcpy(z->next_in, buf, z->avail_in); + zp->zlib_init = ZLIB_GZIP_HEADER; /* Need more gzip header data state */ + /* We don't have any data to inflate yet */ + return CURLE_OK; + + case GZIP_BAD: + default: + return exit_zlib(conn, z, &zp->zlib_init, process_zlib_error(conn, z)); + } + + } + break; + + case ZLIB_GZIP_HEADER: + { + /* Need more gzip header data state */ + ssize_t hlen; + z->avail_in += (uInt) nbytes; + z->next_in = Curl_saferealloc(z->next_in, z->avail_in); + if(z->next_in == NULL) { + return exit_zlib(conn, z, &zp->zlib_init, CURLE_OUT_OF_MEMORY); + } + /* Append the new block of data to the previous one */ + memcpy(z->next_in + z->avail_in - nbytes, buf, nbytes); + + switch(check_gzip_header(z->next_in, z->avail_in, &hlen)) { + case GZIP_OK: + /* This is the zlib stream data */ + free(z->next_in); + /* Don't point into the malloced block since we just freed it */ + z->next_in = (Bytef *) buf + hlen + nbytes - z->avail_in; + z->avail_in = (uInt) (z->avail_in - hlen); + zp->zlib_init = ZLIB_GZIP_INFLATING; /* Inflating stream state */ + break; + + case GZIP_UNDERFLOW: + /* We still don't have any data to inflate! */ + return CURLE_OK; + + case GZIP_BAD: + default: + return exit_zlib(conn, z, &zp->zlib_init, process_zlib_error(conn, z)); + } + + } + break; + + case ZLIB_GZIP_TRAILER: + z->next_in = (Bytef *) buf; + z->avail_in = (uInt) nbytes; + return process_trailer(conn, zp); + + case ZLIB_GZIP_INFLATING: + default: + /* Inflating stream state */ + z->next_in = (Bytef *) buf; + z->avail_in = (uInt) nbytes; + break; + } + + if(z->avail_in == 0) { + /* We don't have any data to inflate; wait until next time */ + return CURLE_OK; + } + + /* We've parsed the header, now uncompress the data */ + return inflate_stream(conn, writer, ZLIB_GZIP_INFLATING); +#endif +} + +static void gzip_close_writer(struct connectdata *conn, + contenc_writer *writer) +{ + zlib_params *zp = (zlib_params *) &writer->params; + z_stream *z = &zp->z; /* zlib state structure */ + + exit_zlib(conn, z, &zp->zlib_init, CURLE_OK); +} + +static const content_encoding gzip_encoding = { + "gzip", + "x-gzip", + gzip_init_writer, + gzip_unencode_write, + gzip_close_writer, + sizeof(zlib_params) +}; + +#endif /* HAVE_LIBZ */ + + +#ifdef HAVE_BROTLI + +/* Writer parameters. */ +typedef struct { + BrotliDecoderState *br; /* State structure for brotli. */ +} brotli_params; + + +static CURLcode brotli_map_error(BrotliDecoderErrorCode be) +{ + switch(be) { + case BROTLI_DECODER_ERROR_FORMAT_EXUBERANT_NIBBLE: + case BROTLI_DECODER_ERROR_FORMAT_EXUBERANT_META_NIBBLE: + case BROTLI_DECODER_ERROR_FORMAT_SIMPLE_HUFFMAN_ALPHABET: + case BROTLI_DECODER_ERROR_FORMAT_SIMPLE_HUFFMAN_SAME: + case BROTLI_DECODER_ERROR_FORMAT_CL_SPACE: + case BROTLI_DECODER_ERROR_FORMAT_HUFFMAN_SPACE: + case BROTLI_DECODER_ERROR_FORMAT_CONTEXT_MAP_REPEAT: + case BROTLI_DECODER_ERROR_FORMAT_BLOCK_LENGTH_1: + case BROTLI_DECODER_ERROR_FORMAT_BLOCK_LENGTH_2: + case BROTLI_DECODER_ERROR_FORMAT_TRANSFORM: + case BROTLI_DECODER_ERROR_FORMAT_DICTIONARY: + case BROTLI_DECODER_ERROR_FORMAT_WINDOW_BITS: + case BROTLI_DECODER_ERROR_FORMAT_PADDING_1: + case BROTLI_DECODER_ERROR_FORMAT_PADDING_2: +#ifdef BROTLI_DECODER_ERROR_COMPOUND_DICTIONARY + case BROTLI_DECODER_ERROR_COMPOUND_DICTIONARY: +#endif +#ifdef BROTLI_DECODER_ERROR_DICTIONARY_NOT_SET + case BROTLI_DECODER_ERROR_DICTIONARY_NOT_SET: +#endif + case BROTLI_DECODER_ERROR_INVALID_ARGUMENTS: + return CURLE_BAD_CONTENT_ENCODING; + case BROTLI_DECODER_ERROR_ALLOC_CONTEXT_MODES: + case BROTLI_DECODER_ERROR_ALLOC_TREE_GROUPS: + case BROTLI_DECODER_ERROR_ALLOC_CONTEXT_MAP: + case BROTLI_DECODER_ERROR_ALLOC_RING_BUFFER_1: + case BROTLI_DECODER_ERROR_ALLOC_RING_BUFFER_2: + case BROTLI_DECODER_ERROR_ALLOC_BLOCK_TYPE_TREES: + return CURLE_OUT_OF_MEMORY; + default: + break; + } + return CURLE_WRITE_ERROR; +} + +static CURLcode brotli_init_writer(struct connectdata *conn, + contenc_writer *writer) +{ + brotli_params *bp = (brotli_params *) &writer->params; + + (void) conn; + + if(!writer->downstream) + return CURLE_WRITE_ERROR; + + bp->br = BrotliDecoderCreateInstance(NULL, NULL, NULL); + return bp->br? CURLE_OK: CURLE_OUT_OF_MEMORY; +} + +static CURLcode brotli_unencode_write(struct connectdata *conn, + contenc_writer *writer, + const char *buf, size_t nbytes) +{ + brotli_params *bp = (brotli_params *) &writer->params; + const uint8_t *src = (const uint8_t *) buf; + char *decomp; + uint8_t *dst; + size_t dstleft; + CURLcode result = CURLE_OK; + BrotliDecoderResult r = BROTLI_DECODER_RESULT_NEEDS_MORE_OUTPUT; + + if(!bp->br) + return CURLE_WRITE_ERROR; /* Stream already ended. */ + + decomp = malloc(DSIZ); + if(!decomp) + return CURLE_OUT_OF_MEMORY; + + while((nbytes || r == BROTLI_DECODER_RESULT_NEEDS_MORE_OUTPUT) && + result == CURLE_OK) { + dst = (uint8_t *) decomp; + dstleft = DSIZ; + r = BrotliDecoderDecompressStream(bp->br, + &nbytes, &src, &dstleft, &dst, NULL); + result = Curl_unencode_write(conn, writer->downstream, + decomp, DSIZ - dstleft); + if(result) + break; + switch(r) { + case BROTLI_DECODER_RESULT_NEEDS_MORE_OUTPUT: + case BROTLI_DECODER_RESULT_NEEDS_MORE_INPUT: + break; + case BROTLI_DECODER_RESULT_SUCCESS: + BrotliDecoderDestroyInstance(bp->br); + bp->br = NULL; + if(nbytes) + result = CURLE_WRITE_ERROR; + break; + default: + result = brotli_map_error(BrotliDecoderGetErrorCode(bp->br)); + break; + } + } + free(decomp); + return result; +} + +static void brotli_close_writer(struct connectdata *conn, + contenc_writer *writer) +{ + brotli_params *bp = (brotli_params *) &writer->params; + + (void) conn; + + if(bp->br) { + BrotliDecoderDestroyInstance(bp->br); + bp->br = NULL; + } +} + +static const content_encoding brotli_encoding = { + "br", + NULL, + brotli_init_writer, + brotli_unencode_write, + brotli_close_writer, + sizeof(brotli_params) +}; +#endif + + +/* Identity handler. */ +static CURLcode identity_init_writer(struct connectdata *conn, + contenc_writer *writer) +{ + (void) conn; + return writer->downstream? CURLE_OK: CURLE_WRITE_ERROR; +} + +static CURLcode identity_unencode_write(struct connectdata *conn, + contenc_writer *writer, + const char *buf, size_t nbytes) +{ + return Curl_unencode_write(conn, writer->downstream, buf, nbytes); +} + +static void identity_close_writer(struct connectdata *conn, + contenc_writer *writer) +{ + (void) conn; + (void) writer; +} + +static const content_encoding identity_encoding = { + "identity", + NULL, + identity_init_writer, + identity_unencode_write, + identity_close_writer, + 0 +}; + + +/* supported content encodings table. */ +static const content_encoding * const encodings[] = { + &identity_encoding, +#ifdef HAVE_LIBZ + &deflate_encoding, + &gzip_encoding, +#endif +#ifdef HAVE_BROTLI + &brotli_encoding, +#endif + NULL +}; + + +/* Return a list of comma-separated names of supported encodings. */ +char *Curl_all_content_encodings(void) +{ + size_t len = 0; + const content_encoding * const *cep; + const content_encoding *ce; + char *ace; + char *p; + + for(cep = encodings; *cep; cep++) { + ce = *cep; + if(!strcasecompare(ce->name, CONTENT_ENCODING_DEFAULT)) + len += strlen(ce->name) + 2; + } + + if(!len) + return strdup(CONTENT_ENCODING_DEFAULT); + + ace = malloc(len); + if(ace) { + p = ace; + for(cep = encodings; *cep; cep++) { + ce = *cep; + if(!strcasecompare(ce->name, CONTENT_ENCODING_DEFAULT)) { + strcpy(p, ce->name); + p += strlen(p); + *p++ = ','; + *p++ = ' '; + } + } + p[-2] = '\0'; + } + + return ace; +} + + +/* Real client writer: no downstream. */ +static CURLcode client_init_writer(struct connectdata *conn, + contenc_writer *writer) +{ + (void) conn; + return writer->downstream? CURLE_WRITE_ERROR: CURLE_OK; +} + +static CURLcode client_unencode_write(struct connectdata *conn, + contenc_writer *writer, + const char *buf, size_t nbytes) +{ + struct Curl_easy *data = conn->data; + struct SingleRequest *k = &data->req; + + (void) writer; + + if(!nbytes || k->ignorebody) + return CURLE_OK; + + return Curl_client_write(conn, CLIENTWRITE_BODY, (char *) buf, nbytes); +} + +static void client_close_writer(struct connectdata *conn, + contenc_writer *writer) +{ + (void) conn; + (void) writer; +} + +static const content_encoding client_encoding = { + NULL, + NULL, + client_init_writer, + client_unencode_write, + client_close_writer, + 0 +}; + + +/* Deferred error dummy writer. */ +static CURLcode error_init_writer(struct connectdata *conn, + contenc_writer *writer) +{ + (void) conn; + return writer->downstream? CURLE_OK: CURLE_WRITE_ERROR; +} + +static CURLcode error_unencode_write(struct connectdata *conn, + contenc_writer *writer, + const char *buf, size_t nbytes) +{ + char *all = Curl_all_content_encodings(); + + (void) writer; + (void) buf; + (void) nbytes; + + if(!all) + return CURLE_OUT_OF_MEMORY; + failf(conn->data, "Unrecognized content encoding type. " + "libcurl understands %s content encodings.", all); + free(all); + return CURLE_BAD_CONTENT_ENCODING; +} + +static void error_close_writer(struct connectdata *conn, + contenc_writer *writer) +{ + (void) conn; + (void) writer; +} + +static const content_encoding error_encoding = { + NULL, + NULL, + error_init_writer, + error_unencode_write, + error_close_writer, + 0 +}; + +/* Create an unencoding writer stage using the given handler. */ +static contenc_writer *new_unencoding_writer(struct connectdata *conn, + const content_encoding *handler, + contenc_writer *downstream) +{ + size_t sz = offsetof(contenc_writer, params) + handler->paramsize; + contenc_writer *writer = (contenc_writer *) malloc(sz); + + if(writer) { + memset(writer, 0, sz); + writer->handler = handler; + writer->downstream = downstream; + if(handler->init_writer(conn, writer)) { + free(writer); + writer = NULL; + } + } + + return writer; +} + +/* Write data using an unencoding writer stack. */ +CURLcode Curl_unencode_write(struct connectdata *conn, contenc_writer *writer, + const char *buf, size_t nbytes) +{ + if(!nbytes) + return CURLE_OK; + return writer->handler->unencode_write(conn, writer, buf, nbytes); +} + +/* Close and clean-up the connection's writer stack. */ +void Curl_unencode_cleanup(struct connectdata *conn) +{ + struct Curl_easy *data = conn->data; + struct SingleRequest *k = &data->req; + contenc_writer *writer = k->writer_stack; + + while(writer) { + k->writer_stack = writer->downstream; + writer->handler->close_writer(conn, writer); + free(writer); + writer = k->writer_stack; + } +} + +/* Find the content encoding by name. */ +static const content_encoding *find_encoding(const char *name, size_t len) +{ + const content_encoding * const *cep; + const content_encoding *ce; + + for(cep = encodings; *cep; cep++) { + ce = *cep; + if((strncasecompare(name, ce->name, len) && !ce->name[len]) || + (ce->alias && strncasecompare(name, ce->alias, len) && !ce->alias[len])) + return ce; + } + return NULL; +} + +/* Set-up the unencoding stack from the Content-Encoding header value. + * See RFC 7231 section 3.1.2.2. */ +CURLcode Curl_build_unencoding_stack(struct connectdata *conn, + const char *enclist, int maybechunked) +{ + struct Curl_easy *data = conn->data; + struct SingleRequest *k = &data->req; + + do { + const char *name; + size_t namelen; + + /* Parse a single encoding name. */ + while(ISSPACE(*enclist) || *enclist == ',') + enclist++; + + name = enclist; + + for(namelen = 0; *enclist && *enclist != ','; enclist++) + if(!ISSPACE(*enclist)) + namelen = enclist - name + 1; + + /* Special case: chunked encoding is handled at the reader level. */ + if(maybechunked && namelen == 7 && strncasecompare(name, "chunked", 7)) { + k->chunk = TRUE; /* chunks coming our way. */ + Curl_httpchunk_init(conn); /* init our chunky engine. */ + } + else if(namelen) { + const content_encoding *encoding = find_encoding(name, namelen); + contenc_writer *writer; + + if(!k->writer_stack) { + k->writer_stack = new_unencoding_writer(conn, &client_encoding, NULL); + + if(!k->writer_stack) + return CURLE_OUT_OF_MEMORY; + } + + if(!encoding) + encoding = &error_encoding; /* Defer error at stack use. */ + + /* Stack the unencoding stage. */ + writer = new_unencoding_writer(conn, encoding, k->writer_stack); + if(!writer) + return CURLE_OUT_OF_MEMORY; + k->writer_stack = writer; + } + } while(*enclist); + + return CURLE_OK; +} + +#else +/* Stubs for builds without HTTP. */ +CURLcode Curl_build_unencoding_stack(struct connectdata *conn, + const char *enclist, int maybechunked) +{ + (void) conn; + (void) enclist; + (void) maybechunked; + return CURLE_NOT_BUILT_IN; +} + +CURLcode Curl_unencode_write(struct connectdata *conn, contenc_writer *writer, + const char *buf, size_t nbytes) +{ + (void) conn; + (void) writer; + (void) buf; + (void) nbytes; + return CURLE_NOT_BUILT_IN; +} + +void Curl_unencode_cleanup(struct connectdata *conn) +{ + (void) conn; +} + +char *Curl_all_content_encodings(void) +{ + return strdup(CONTENT_ENCODING_DEFAULT); /* Satisfy caller. */ +} + +#endif /* CURL_DISABLE_HTTP */ |