diff options
Diffstat (limited to 'libcurl/src/lib/content_encoding.c')
| -rw-r--r-- | libcurl/src/lib/content_encoding.c | 435 |
1 files changed, 435 insertions, 0 deletions
diff --git a/libcurl/src/lib/content_encoding.c b/libcurl/src/lib/content_encoding.c new file mode 100644 index 0000000..0da02c8 --- /dev/null +++ b/libcurl/src/lib/content_encoding.c @@ -0,0 +1,435 @@ +/***************************************************************************
+ * _ _ ____ _
+ * Project ___| | | | _ \| |
+ * / __| | | | |_) | |
+ * | (__| |_| | _ <| |___
+ * \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 1998 - 2011, 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 http://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"
+
+#ifdef HAVE_LIBZ
+
+#include "urldata.h"
+#include <curl/curl.h>
+#include "sendf.h"
+#include "content_encoding.h"
+#include "curl_memory.h"
+
+#include "memdebug.h"
+
+/* 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 DSIZ CURL_MAX_WRITE_SIZE /* buffer size for decompressed data */
+
+#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 */
+
+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 SessionHandle *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(z_stream *z, zlibInitState *zlib_init, CURLcode result)
+{
+ inflateEnd(z);
+ *zlib_init = ZLIB_UNINIT;
+ return result;
+}
+
+static CURLcode
+inflate_stream(struct connectdata *conn,
+ struct SingleRequest *k)
+{
+ int allow_restart = 1;
+ z_stream *z = &k->z; /* zlib state structure */
+ uInt nread = z->avail_in;
+ Bytef *orig_in = z->next_in;
+ int status; /* zlib status */
+ CURLcode result = CURLE_OK; /* Curl_client_write status */
+ char *decomp; /* Put the decompressed data here. */
+
+ /* 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(z, &k->zlib_init, CURLE_OUT_OF_MEMORY);
+ }
+
+ /* because the buffer size is fixed, iteratively decompress and transfer to
+ the client via client_write. */
+ for(;;) {
+ /* (re)set buffer for decompressed output for every iteration */
+ z->next_out = (Bytef *)decomp;
+ z->avail_out = DSIZ;
+
+ status = inflate(z, Z_SYNC_FLUSH);
+ if(status == Z_OK || status == Z_STREAM_END) {
+ allow_restart = 0;
+ if((DSIZ - z->avail_out) && (!k->ignorebody)) {
+ result = Curl_client_write(conn, CLIENTWRITE_BODY, decomp,
+ DSIZ - z->avail_out);
+ /* if !CURLE_OK, clean up, return */
+ if(result) {
+ free(decomp);
+ return exit_zlib(z, &k->zlib_init, result);
+ }
+ }
+
+ /* Done? clean up, return */
+ if(status == Z_STREAM_END) {
+ free(decomp);
+ if(inflateEnd(z) == Z_OK)
+ return exit_zlib(z, &k->zlib_init, result);
+ else
+ return exit_zlib(z, &k->zlib_init, process_zlib_error(conn, z));
+ }
+
+ /* Done with these bytes, exit */
+
+ /* status is always Z_OK at this point! */
+ if(z->avail_in == 0) {
+ free(decomp);
+ return result;
+ }
+ }
+ else if(allow_restart && status == Z_DATA_ERROR) {
+ /* some servers seem to not generate zlib headers, so this is an attempt
+ to fix and continue anyway */
+
+ (void) inflateEnd(z); /* don't care about the return code */
+ if(inflateInit2(z, -MAX_WBITS) != Z_OK) {
+ free(decomp);
+ return exit_zlib(z, &k->zlib_init, process_zlib_error(conn, z));
+ }
+ z->next_in = orig_in;
+ z->avail_in = nread;
+ allow_restart = 0;
+ continue;
+ }
+ else { /* Error; exit loop, handle below */
+ free(decomp);
+ return exit_zlib(z, &k->zlib_init, process_zlib_error(conn, z));
+ }
+ }
+ /* Will never get here */
+}
+
+CURL_STATIC CURLcode
+Curl_unencode_deflate_write(struct connectdata *conn,
+ struct SingleRequest *k,
+ ssize_t nread)
+{
+ z_stream *z = &k->z; /* zlib state structure */
+
+ /* Initialize zlib? */
+ if(k->zlib_init == ZLIB_UNINIT) {
+ memset(z, 0, sizeof(z_stream));
+ z->zalloc = (alloc_func)zalloc_cb;
+ z->zfree = (free_func)zfree_cb;
+
+ if(inflateInit(z) != Z_OK)
+ return process_zlib_error(conn, z);
+ k->zlib_init = ZLIB_INIT;
+ }
+
+ /* Set the compressed input when this function is called */
+ z->next_in = (Bytef *)k->str;
+ z->avail_in = (uInt)nread;
+
+ /* Now uncompress the data */
+ return inflate_stream(conn, k);
+}
+
+#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
+
+CURL_STATIC CURLcode
+Curl_unencode_gzip_write(struct connectdata *conn,
+ struct SingleRequest *k,
+ ssize_t nread)
+{
+ z_stream *z = &k->z; /* zlib state structure */
+
+ /* Initialize zlib? */
+ if(k->zlib_init == ZLIB_UNINIT) {
+ memset(z, 0, sizeof(z_stream));
+ 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);
+ }
+ k->zlib_init = ZLIB_INIT_GZIP; /* Transparent gzip decompress state */
+ }
+ else {
+ /* we must parse the gzip header ourselves */
+ if(inflateInit2(z, -MAX_WBITS) != Z_OK) {
+ return process_zlib_error(conn, z);
+ }
+ k->zlib_init = ZLIB_INIT; /* Initial call state */
+ }
+ }
+
+ if(k->zlib_init == ZLIB_INIT_GZIP) {
+ /* Let zlib handle the gzip decompression entirely */
+ z->next_in = (Bytef *)k->str;
+ z->avail_in = (uInt)nread;
+ /* Now uncompress the data */
+ return inflate_stream(conn, k);
+ }
+
+#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(z, &k->zlib_init, CURLE_FUNCTION_NOT_FOUND);
+
+#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 (k->zlib_init) {
+ /* Skip over gzip header? */
+ case ZLIB_INIT:
+ {
+ /* Initial call state */
+ ssize_t hlen;
+
+ switch (check_gzip_header((unsigned char *)k->str, nread, &hlen)) {
+ case GZIP_OK:
+ z->next_in = (Bytef *)k->str + hlen;
+ z->avail_in = (uInt)(nread - hlen);
+ k->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)nread;
+ z->next_in = malloc(z->avail_in);
+ if(z->next_in == NULL) {
+ return exit_zlib(z, &k->zlib_init, CURLE_OUT_OF_MEMORY);
+ }
+ memcpy(z->next_in, k->str, z->avail_in);
+ k->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(z, &k->zlib_init, process_zlib_error(conn, z));
+ }
+
+ }
+ break;
+
+ case ZLIB_GZIP_HEADER:
+ {
+ /* Need more gzip header data state */
+ ssize_t hlen;
+ unsigned char *oldblock = z->next_in;
+
+ z->avail_in += (uInt)nread;
+ z->next_in = realloc(z->next_in, z->avail_in);
+ if(z->next_in == NULL) {
+ free(oldblock);
+ return exit_zlib(z, &k->zlib_init, CURLE_OUT_OF_MEMORY);
+ }
+ /* Append the new block of data to the previous one */
+ memcpy(z->next_in + z->avail_in - nread, k->str, nread);
+
+ 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 *)k->str + hlen + nread - z->avail_in;
+ z->avail_in = (uInt)(z->avail_in - hlen);
+ k->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:
+ free(z->next_in);
+ return exit_zlib(z, &k->zlib_init, process_zlib_error(conn, z));
+ }
+
+ }
+ break;
+
+ case ZLIB_GZIP_INFLATING:
+ default:
+ /* Inflating stream state */
+ z->next_in = (Bytef *)k->str;
+ z->avail_in = (uInt)nread;
+ 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, k);
+#endif
+}
+
+CURL_STATIC void Curl_unencode_cleanup(struct connectdata *conn)
+{
+ struct SessionHandle *data = conn->data;
+ struct SingleRequest *k = &data->req;
+ z_stream *z = &k->z;
+ if(k->zlib_init != ZLIB_UNINIT)
+ (void) exit_zlib(z, &k->zlib_init, CURLE_OK);
+}
+
+#endif /* HAVE_LIBZ */
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