GNUnet  0.10.x
Data Structures | Macros | Functions
json_mhd.c File Reference

functions to parse JSON snippets we receive via MHD More...

#include "platform.h"
#include "gnunet_json_lib.h"
#include <zlib.h>
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Go to the source code of this file.

Data Structures

struct  Buffer
 Buffer for POST requests. More...
 

Macros

#define REQUEST_BUFFER_INITIAL   (2 * 1024)
 Initial size for POST request buffers. More...
 

Functions

static int buffer_init (struct Buffer *buf, const void *data, size_t data_size, size_t alloc_size, size_t max_size)
 Initialize a buffer. More...
 
static void buffer_deinit (struct Buffer *buf)
 Free the data in a buffer. More...
 
static int buffer_append (struct Buffer *buf, const void *data, size_t data_size, size_t max_size)
 Append data to a buffer, growing the buffer if necessary. More...
 
static enum GNUNET_JSON_PostResult inflate_data (struct Buffer *buf)
 Decompress data in buf. More...
 
enum GNUNET_JSON_PostResult GNUNET_JSON_post_parser (size_t buffer_max, struct MHD_Connection *connection, void **con_cls, const char *upload_data, size_t *upload_data_size, json_t **json)
 Process a POST request containing a JSON object. More...
 
void GNUNET_JSON_post_parser_cleanup (void *con_cls)
 Function called whenever we are done with a request to clean up our state. More...
 

Detailed Description

functions to parse JSON snippets we receive via MHD

Author
Florian Dold
Benedikt Mueller
Christian Grothoff

Definition in file json_mhd.c.

Macro Definition Documentation

◆ REQUEST_BUFFER_INITIAL

#define REQUEST_BUFFER_INITIAL   (2 * 1024)

Initial size for POST request buffers.

Should be big enough to usually not require a reallocation, but not so big that it hurts in terms of memory use.

Definition at line 37 of file json_mhd.c.

Referenced by GNUNET_JSON_post_parser().

Function Documentation

◆ buffer_init()

static int buffer_init ( struct Buffer buf,
const void *  data,
size_t  data_size,
size_t  alloc_size,
size_t  max_size 
)
static

Initialize a buffer.

Parameters
bufthe buffer to initialize
datathe initial data
data_sizesize of the initial data
alloc_sizesize of the buffer
max_sizemaximum size that the buffer can grow to
Returns
a GNUnet result code

Definition at line 77 of file json_mhd.c.

References Buffer::alloc, Buffer::data, data_size, Buffer::fill, GNUNET_malloc, GNUNET_memcpy, GNUNET_OK, GNUNET_SYSERR, Buffer::max, and max_size.

Referenced by GNUNET_JSON_post_parser().

82 {
83  if ((data_size > max_size) || (alloc_size > max_size))
84  return GNUNET_SYSERR;
85  if (data_size > alloc_size)
86  alloc_size = data_size;
87  buf->data = GNUNET_malloc(alloc_size);
88  buf->alloc = alloc_size;
90  buf->fill = data_size;
91  buf->max = max_size;
92  return GNUNET_OK;
93 }
size_t alloc
Number of allocated bytes in buffer.
Definition: json_mhd.c:57
#define GNUNET_memcpy(dst, src, n)
Call memcpy() but check for n being 0 first.
#define GNUNET_OK
Named constants for return values.
Definition: gnunet_common.h:75
size_t fill
Number of valid bytes in buffer.
Definition: json_mhd.c:52
size_t max
Maximum buffer size allowed.
Definition: json_mhd.c:62
char * data
Allocated memory.
Definition: json_mhd.c:47
#define GNUNET_SYSERR
Definition: gnunet_common.h:76
static size_t max_size
The maximal size the extended sampler elements should grow to.
uint32_t data
The data value.
static size_t data_size
Number of bytes in data.
#define GNUNET_malloc(size)
Wrapper around malloc.
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◆ buffer_deinit()

static void buffer_deinit ( struct Buffer buf)
static

Free the data in a buffer.

Does not free the buffer object itself.

Parameters
bufbuffer to de-initialize

Definition at line 103 of file json_mhd.c.

References Buffer::data, and GNUNET_free.

Referenced by GNUNET_JSON_post_parser(), and GNUNET_JSON_post_parser_cleanup().

104 {
105  GNUNET_free(buf->data);
106  buf->data = NULL;
107 }
char * data
Allocated memory.
Definition: json_mhd.c:47
#define GNUNET_free(ptr)
Wrapper around free.
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◆ buffer_append()

static int buffer_append ( struct Buffer buf,
const void *  data,
size_t  data_size,
size_t  max_size 
)
static

Append data to a buffer, growing the buffer if necessary.

Parameters
bufthe buffer to append to
datathe data to append
data_sizethe size of data
max_sizemaximum size that the buffer can grow to
Returns
GNUNET_OK on success, GNUNET_NO if the buffer can't accomodate for the new data

Definition at line 121 of file json_mhd.c.

References Buffer::alloc, Buffer::data, data_size, Buffer::fill, GNUNET_free, GNUNET_malloc, GNUNET_memcpy, GNUNET_NO, and GNUNET_OK.

Referenced by GNUNET_JSON_post_parser().

125 {
126  if (buf->fill + data_size > max_size)
127  return GNUNET_NO;
128  if (buf->fill + data_size > buf->alloc)
129  {
130  char *new_buf;
131  size_t new_size = buf->alloc;
132  while (new_size < buf->fill + data_size)
133  new_size += 2;
134  if (new_size > max_size)
135  return GNUNET_NO;
136  new_buf = GNUNET_malloc(new_size);
137  GNUNET_memcpy(new_buf, buf->data, buf->fill);
138  GNUNET_free(buf->data);
139  buf->data = new_buf;
140  buf->alloc = new_size;
141  }
142  GNUNET_memcpy(buf->data + buf->fill, data, data_size);
143  buf->fill += data_size;
144  return GNUNET_OK;
145 }
size_t alloc
Number of allocated bytes in buffer.
Definition: json_mhd.c:57
#define GNUNET_memcpy(dst, src, n)
Call memcpy() but check for n being 0 first.
#define GNUNET_NO
Definition: gnunet_common.h:78
#define GNUNET_OK
Named constants for return values.
Definition: gnunet_common.h:75
size_t fill
Number of valid bytes in buffer.
Definition: json_mhd.c:52
char * data
Allocated memory.
Definition: json_mhd.c:47
static size_t max_size
The maximal size the extended sampler elements should grow to.
uint32_t data
The data value.
static size_t data_size
Number of bytes in data.
#define GNUNET_malloc(size)
Wrapper around malloc.
#define GNUNET_free(ptr)
Wrapper around free.
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◆ inflate_data()

static enum GNUNET_JSON_PostResult inflate_data ( struct Buffer buf)
static

Decompress data in buf.

Parameters
bufinput data to inflate
Returns
result code indicating the status of the operation

Definition at line 155 of file json_mhd.c.

References Buffer::alloc, Buffer::data, Buffer::fill, GNUNET_break, GNUNET_break_op, GNUNET_free, GNUNET_JSON_PR_JSON_INVALID, GNUNET_JSON_PR_OUT_OF_MEMORY, GNUNET_JSON_PR_SUCCESS, GNUNET_malloc, GNUNET_MIN, GNUNET_realloc, Buffer::max, and ret.

Referenced by GNUNET_JSON_post_parser().

156 {
157  z_stream z;
158  char *tmp;
159  size_t tmp_size;
160  int ret;
161 
162  memset(&z, 0, sizeof(z));
163  z.next_in = (Bytef *)buf->data;
164  z.avail_in = buf->fill;
165  tmp_size = GNUNET_MIN(buf->max, buf->fill * 4);
166  tmp = GNUNET_malloc(tmp_size);
167  z.next_out = (Bytef *)tmp;
168  z.avail_out = tmp_size;
169  ret = inflateInit(&z);
170  switch (ret)
171  {
172  case Z_MEM_ERROR:
173  GNUNET_break(0);
175 
176  case Z_STREAM_ERROR:
177  GNUNET_break_op(0);
179 
180  case Z_OK:
181  break;
182  }
183  while (1)
184  {
185  ret = inflate(&z, 0);
186  switch (ret)
187  {
188  case Z_MEM_ERROR:
189  GNUNET_break(0);
190  GNUNET_break(Z_OK == inflateEnd(&z));
191  GNUNET_free(tmp);
193 
194  case Z_DATA_ERROR:
195  GNUNET_break(0);
196  GNUNET_break(Z_OK == inflateEnd(&z));
197  GNUNET_free(tmp);
199 
200  case Z_NEED_DICT:
201  GNUNET_break(0);
202  GNUNET_break(Z_OK == inflateEnd(&z));
203  GNUNET_free(tmp);
205 
206  case Z_OK:
207  if ((0 < z.avail_out) && (0 == z.avail_in))
208  {
209  /* truncated input stream */
210  GNUNET_break(0);
211  GNUNET_break(Z_OK == inflateEnd(&z));
212  GNUNET_free(tmp);
214  }
215  if (0 < z.avail_out)
216  continue; /* just call it again */
217  /* output buffer full, can we grow it? */
218  if (tmp_size == buf->max)
219  {
220  /* already at max */
221  GNUNET_break(0);
222  GNUNET_break(Z_OK == inflateEnd(&z));
223  GNUNET_free(tmp);
225  }
226  if (tmp_size * 2 < tmp_size)
227  tmp_size = buf->max;
228  else
229  tmp_size = GNUNET_MIN(buf->max, tmp_size * 2);
230  tmp = GNUNET_realloc(tmp, tmp_size);
231  z.next_out = (Bytef *)&tmp[z.total_out];
232  continue;
233 
234  case Z_STREAM_END:
235  /* decompression successful, make 'tmp' the new 'data' */
236  GNUNET_free(buf->data);
237  buf->data = tmp;
238  buf->alloc = tmp_size;
239  buf->fill = z.total_out;
240  GNUNET_break(Z_OK == inflateEnd(&z));
241  return GNUNET_JSON_PR_SUCCESS; /* at least for now */
242  }
243  } /* while (1) */
244 }
JSON parsing failed.
size_t alloc
Number of allocated bytes in buffer.
Definition: json_mhd.c:57
static int ret
Final status code.
Definition: gnunet-arm.c:89
size_t fill
Number of valid bytes in buffer.
Definition: json_mhd.c:52
#define GNUNET_break(cond)
Use this for internal assertion violations that are not fatal (can be handled) but should not occur...
Parsing successful, JSON result is in *json.
#define GNUNET_break_op(cond)
Use this for assertion violations caused by other peers (i.e.
#define GNUNET_realloc(ptr, size)
Wrapper around realloc.
#define GNUNET_MIN(a, b)
Definition: gnunet_common.h:80
Sorry, memory allocation (malloc()) failed.
size_t max
Maximum buffer size allowed.
Definition: json_mhd.c:62
char * data
Allocated memory.
Definition: json_mhd.c:47
#define GNUNET_malloc(size)
Wrapper around malloc.
#define GNUNET_free(ptr)
Wrapper around free.
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◆ GNUNET_JSON_post_parser()

enum GNUNET_JSON_PostResult GNUNET_JSON_post_parser ( size_t  buffer_max,
struct MHD_Connection *  connection,
void **  con_cls,
const char *  upload_data,
size_t *  upload_data_size,
json_t **  json 
)

Process a POST request containing a JSON object.

This function realizes an MHD POST processor that will (incrementally) process JSON data uploaded to the HTTP server. It will store the required state in the con_cls, which must be cleaned up using #GNUNET_JSON_post_parser_callback().

Parameters
buffer_maxmaximum allowed size for the buffer
connectionMHD connection handle (for meta data about the upload)
con_clsthe closure (will point to a struct Buffer *)
upload_datathe POST data
upload_data_sizenumber of bytes in upload_data
jsonthe JSON object for a completed request
Returns
result code indicating the status of the operation

Definition at line 263 of file json_mhd.c.

References buffer_append(), buffer_deinit(), buffer_init(), Buffer::data, Buffer::fill, GNUNET_ERROR_TYPE_WARNING, GNUNET_free, GNUNET_JSON_PR_CONTINUE, GNUNET_JSON_PR_JSON_INVALID, GNUNET_JSON_PR_OUT_OF_MEMORY, GNUNET_JSON_PR_REQUEST_TOO_LARGE, GNUNET_JSON_PR_SUCCESS, GNUNET_log, GNUNET_new, GNUNET_OK, inflate_data(), REQUEST_BUFFER_INITIAL, and ret.

269 {
270  struct Buffer *r = *con_cls;
271  const char *ce;
272  int ret;
273 
274  *json = NULL;
275  if (NULL == *con_cls)
276  {
277  /* We are seeing a fresh POST request. */
278  r = GNUNET_new(struct Buffer);
279  if (GNUNET_OK != buffer_init(r,
280  upload_data,
281  *upload_data_size,
283  buffer_max))
284  {
285  *con_cls = NULL;
286  buffer_deinit(r);
287  GNUNET_free(r);
289  }
290  /* everything OK, wait for more POST data */
291  *upload_data_size = 0;
292  *con_cls = r;
294  }
295  if (0 != *upload_data_size)
296  {
297  /* We are seeing an old request with more data available. */
298 
299  if (GNUNET_OK !=
300  buffer_append(r, upload_data, *upload_data_size, buffer_max))
301  {
302  /* Request too long */
303  *con_cls = NULL;
304  buffer_deinit(r);
305  GNUNET_free(r);
307  }
308  /* everything OK, wait for more POST data */
309  *upload_data_size = 0;
311  }
312 
313  /* We have seen the whole request. */
314  ce = MHD_lookup_connection_value(connection,
315  MHD_HEADER_KIND,
316  MHD_HTTP_HEADER_CONTENT_ENCODING);
317  if ((NULL != ce) && (0 == strcasecmp("deflate", ce)))
318  {
319  ret = inflate_data(r);
320  if (GNUNET_JSON_PR_SUCCESS != ret)
321  {
322  buffer_deinit(r);
323  GNUNET_free(r);
324  *con_cls = NULL;
325  return ret;
326  }
327  }
328 
329  *json = json_loadb(r->data, r->fill, 0, NULL);
330  if (NULL == *json)
331  {
333  "Failed to parse JSON request body\n");
334  buffer_deinit(r);
335  GNUNET_free(r);
336  *con_cls = NULL;
338  }
339  buffer_deinit(r);
340  GNUNET_free(r);
341  *con_cls = NULL;
342 
343  return GNUNET_JSON_PR_SUCCESS;
344 }
JSON parsing failed.
static enum GNUNET_JSON_PostResult inflate_data(struct Buffer *buf)
Decompress data in buf.
Definition: json_mhd.c:155
Buffer for POST requests.
Definition: json_mhd.c:43
#define GNUNET_OK
Named constants for return values.
Definition: gnunet_common.h:75
#define GNUNET_new(type)
Allocate a struct or union of the given type.
static int ret
Final status code.
Definition: gnunet-arm.c:89
size_t fill
Number of valid bytes in buffer.
Definition: json_mhd.c:52
Parsing successful, JSON result is in *json.
static int buffer_init(struct Buffer *buf, const void *data, size_t data_size, size_t alloc_size, size_t max_size)
Initialize a buffer.
Definition: json_mhd.c:77
Sorry, memory allocation (malloc()) failed.
Request size exceeded buffer_max argument.
static int buffer_append(struct Buffer *buf, const void *data, size_t data_size, size_t max_size)
Append data to a buffer, growing the buffer if necessary.
Definition: json_mhd.c:121
char * data
Allocated memory.
Definition: json_mhd.c:47
#define REQUEST_BUFFER_INITIAL
Initial size for POST request buffers.
Definition: json_mhd.c:37
Parsing continues, call again soon!
#define GNUNET_log(kind,...)
static void buffer_deinit(struct Buffer *buf)
Free the data in a buffer.
Definition: json_mhd.c:103
#define GNUNET_free(ptr)
Wrapper around free.
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◆ GNUNET_JSON_post_parser_cleanup()

void GNUNET_JSON_post_parser_cleanup ( void *  con_cls)

Function called whenever we are done with a request to clean up our state.

Parameters
con_clsvalue as it was left by GNUNET_JSON_post_parser(), to be cleaned up

Definition at line 355 of file json_mhd.c.

References buffer_deinit(), and GNUNET_free.

356 {
357  struct Buffer *r = con_cls;
358 
359  if (NULL != r)
360  {
361  buffer_deinit(r);
362  GNUNET_free(r);
363  }
364 }
Buffer for POST requests.
Definition: json_mhd.c:43
static void buffer_deinit(struct Buffer *buf)
Free the data in a buffer.
Definition: json_mhd.c:103
#define GNUNET_free(ptr)
Wrapper around free.
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