GNUnet  0.10.x
Macros | Functions
plugin_block_dns.c File Reference

block plugin for advertising a DNS exit service More...

#include "platform.h"
#include "gnunet_block_plugin.h"
#include "block_dns.h"
#include "gnunet_signatures.h"
#include "gnunet_block_group_lib.h"
Include dependency graph for plugin_block_dns.c:

Go to the source code of this file.

Macros

#define BLOOMFILTER_K   16
 Number of bits we set per entry in the bloomfilter. More...
 

Functions

static struct GNUNET_BLOCK_Groupblock_plugin_dns_create_group (void *cls, enum GNUNET_BLOCK_Type type, uint32_t nonce, const void *raw_data, size_t raw_data_size, va_list va)
 Create a new block group. More...
 
static enum GNUNET_BLOCK_EvaluationResult block_plugin_dns_evaluate (void *cls, struct GNUNET_BLOCK_Context *ctx, enum GNUNET_BLOCK_Type type, struct GNUNET_BLOCK_Group *bg, enum GNUNET_BLOCK_EvaluationOptions eo, const struct GNUNET_HashCode *query, const void *xquery, size_t xquery_size, const void *reply_block, size_t reply_block_size)
 Function called to validate a reply or a request. More...
 
static int block_plugin_dns_get_key (void *cls, enum GNUNET_BLOCK_Type type, const void *block, size_t block_size, struct GNUNET_HashCode *key)
 Function called to obtain the key for a block. More...
 
void * libgnunet_plugin_block_dns_init (void *cls)
 Entry point for the plugin. More...
 
void * libgnunet_plugin_block_dns_done (void *cls)
 Exit point from the plugin. More...
 

Detailed Description

block plugin for advertising a DNS exit service

Author
Christian Grothoff

Note that this plugin might more belong with EXIT and PT as those two are using this type of block. Still, this might be a natural enough place for people to find the code...

Definition in file plugin_block_dns.c.

Macro Definition Documentation

◆ BLOOMFILTER_K

#define BLOOMFILTER_K   16

Number of bits we set per entry in the bloomfilter.

Do not change!

Definition at line 41 of file plugin_block_dns.c.

Referenced by block_plugin_dns_create_group().

Function Documentation

◆ block_plugin_dns_create_group()

static struct GNUNET_BLOCK_Group* block_plugin_dns_create_group ( void *  cls,
enum GNUNET_BLOCK_Type  type,
uint32_t  nonce,
const void *  raw_data,
size_t  raw_data_size,
va_list  va 
)
static

Create a new block group.

Parameters
ctxblock context in which the block group is created
typetype of the block for which we are creating the group
noncerandom value used to seed the group creation
raw_dataoptional serialized prior state of the group, NULL if unavailable/fresh
raw_data_sizenumber of bytes in raw_data, 0 if unavailable/fresh
vavariable arguments specific to type
Returns
block group handle, NULL if block groups are not supported by this type of block (this is not an error)

Definition at line 57 of file plugin_block_dns.c.

References BLOOMFILTER_K, GNUNET_BLOCK_GROUP_bf_create(), GNUNET_BLOCK_GROUP_compute_bloomfilter_size(), and GNUNET_break.

Referenced by libgnunet_plugin_block_dns_init().

63 {
64  unsigned int bf_size;
65  const char *guard;
66 
67  guard = va_arg (va, const char *);
68  if (0 == strcmp (guard,
69  "seen-set-size"))
70  bf_size = GNUNET_BLOCK_GROUP_compute_bloomfilter_size (va_arg (va, unsigned int),
72  else if (0 == strcmp (guard,
73  "filter-size"))
74  bf_size = va_arg (va, unsigned int);
75  else
76  {
77  GNUNET_break (0);
78  bf_size = 8;
79  }
80  GNUNET_break (NULL == va_arg (va, const char *));
81  return GNUNET_BLOCK_GROUP_bf_create (cls,
82  bf_size,
84  type,
85  nonce,
86  raw_data,
87  raw_data_size);
88 }
struct GNUNET_BLOCK_Group * GNUNET_BLOCK_GROUP_bf_create(void *cls, size_t bf_size, unsigned int bf_k, enum GNUNET_BLOCK_Type type, uint32_t nonce, const void *raw_data, size_t raw_data_size)
Create a new block group that filters duplicates using a Bloom filter.
Definition: bg_bf.c:175
size_t GNUNET_BLOCK_GROUP_compute_bloomfilter_size(unsigned int entry_count, unsigned int k)
How many bytes should a bloomfilter be if we have already seen entry_count responses? Sized so that do not have to re-size the filter too often (to keep it cheap).
Definition: bg_bf.c:250
#define GNUNET_break(cond)
Use this for internal assertion violations that are not fatal (can be handled) but should not occur...
#define BLOOMFILTER_K
Number of bits we set per entry in the bloomfilter.
enum GNUNET_TESTBED_UnderlayLinkModelType type
the type of this model
Here is the call graph for this function:
Here is the caller graph for this function:

◆ block_plugin_dns_evaluate()

static enum GNUNET_BLOCK_EvaluationResult block_plugin_dns_evaluate ( void *  cls,
struct GNUNET_BLOCK_Context ctx,
enum GNUNET_BLOCK_Type  type,
struct GNUNET_BLOCK_Group bg,
enum GNUNET_BLOCK_EvaluationOptions  eo,
const struct GNUNET_HashCode query,
const void *  xquery,
size_t  xquery_size,
const void *  reply_block,
size_t  reply_block_size 
)
static

Function called to validate a reply or a request.

For request evaluation, simply pass "NULL" for the reply_block.

Parameters
clsclosure
ctxblock context
typeblock type
bggroup to evaluate against
eocontrol flags
queryoriginal query (hash)
xqueryextended query data (can be NULL, depending on type)
xquery_sizenumber of bytes in xquery
reply_blockresponse to validate
reply_block_sizenumber of bytes in reply_block
Returns
characterization of result

Definition at line 108 of file plugin_block_dns.c.

References GNUNET_DNS_Advertisement::expiration_time, GNUNET_BLOCK_EVALUATION_OK_DUPLICATE, GNUNET_BLOCK_EVALUATION_OK_MORE, GNUNET_BLOCK_EVALUATION_REQUEST_INVALID, GNUNET_BLOCK_EVALUATION_REQUEST_VALID, GNUNET_BLOCK_EVALUATION_RESULT_INVALID, GNUNET_BLOCK_EVALUATION_TYPE_NOT_SUPPORTED, GNUNET_BLOCK_GROUP_bf_test_and_set(), GNUNET_BLOCK_TYPE_DNS, GNUNET_break_op, GNUNET_CRYPTO_eddsa_verify(), GNUNET_CRYPTO_hash(), GNUNET_ERROR_TYPE_DEBUG, GNUNET_log, GNUNET_OK, GNUNET_SIGNATURE_PURPOSE_DNS_RECORD, GNUNET_TIME_absolute_get_remaining(), GNUNET_TIME_absolute_ntoh(), GNUNET_YES, GNUNET_DNS_Advertisement::peer, GNUNET_PeerIdentity::public_key, GNUNET_DNS_Advertisement::purpose, GNUNET_TIME_Relative::rel_value_us, GNUNET_DNS_Advertisement::signature, and GNUNET_CRYPTO_EccSignaturePurpose::size.

Referenced by libgnunet_plugin_block_dns_init().

118 {
119  const struct GNUNET_DNS_Advertisement *ad;
120  struct GNUNET_HashCode phash;
121 
122  switch (type)
123  {
125  if (0 != xquery_size)
127 
128  if (NULL == reply_block)
130 
131  if (sizeof (struct GNUNET_DNS_Advertisement) != reply_block_size)
132  {
133  GNUNET_break_op (0);
135  }
136  ad = reply_block;
137 
138  if (ntohl (ad->purpose.size) !=
139  sizeof (struct GNUNET_DNS_Advertisement) -
140  sizeof (struct GNUNET_CRYPTO_EddsaSignature))
141  {
142  GNUNET_break_op (0);
144  }
145  if (0 ==
148  {
150  "DNS advertisement has expired\n");
152  }
153  if (GNUNET_OK !=
155  &ad->purpose,
156  &ad->signature,
157  &ad->peer.public_key))
158  {
159  GNUNET_break_op (0);
161  }
162  GNUNET_CRYPTO_hash (reply_block,
163  reply_block_size,
164  &phash);
165  if (GNUNET_YES ==
167  &phash))
170  default:
172  }
173 }
Block does not match query (invalid result)
struct GNUNET_TIME_Absolute GNUNET_TIME_absolute_ntoh(struct GNUNET_TIME_AbsoluteNBO a)
Convert absolute time from network byte order.
Definition: time.c:670
This is the structure describing an DNS exit service.
Definition: block_dns.h:40
uint64_t rel_value_us
The actual value.
#define GNUNET_SIGNATURE_PURPOSE_DNS_RECORD
Signature of an GNUNET_DNS_Advertisement.
#define GNUNET_OK
Named constants for return values.
Definition: gnunet_common.h:78
struct GNUNET_CRYPTO_EddsaSignature signature
Signature of the peer affirming that it is offering the service.
Definition: block_dns.h:45
struct GNUNET_CRYPTO_EccSignaturePurpose purpose
Beginning of signed portion of the record, signs everything until the end of the struct.
Definition: block_dns.h:51
Block for storing DNS exit service advertisements.
int GNUNET_CRYPTO_eddsa_verify(uint32_t purpose, const struct GNUNET_CRYPTO_EccSignaturePurpose *validate, const struct GNUNET_CRYPTO_EddsaSignature *sig, const struct GNUNET_CRYPTO_EddsaPublicKey *pub)
Verify EdDSA signature.
Definition: crypto_ecc.c:1116
Valid result, but suppressed because it is a duplicate.
#define GNUNET_break_op(cond)
Use this for assertion violations caused by other peers (i.e.
void GNUNET_CRYPTO_hash(const void *block, size_t size, struct GNUNET_HashCode *ret)
Compute hash of a given block.
Definition: crypto_hash.c:44
uint32_t size
How many bytes does this signature sign? (including this purpose header); in network byte order (!)...
A 512-bit hashcode.
struct GNUNET_PeerIdentity peer
The peer providing this service.
Definition: block_dns.h:61
Valid result, and there may be more.
an ECC signature using EdDSA.
Specified block type not supported by this plugin.
Query format does not match block type (invalid query).
#define GNUNET_log(kind,...)
struct GNUNET_TIME_Relative GNUNET_TIME_absolute_get_remaining(struct GNUNET_TIME_Absolute future)
Given a timestamp in the future, how much time remains until then?
Definition: time.c:331
enum GNUNET_TESTBED_UnderlayLinkModelType type
the type of this model
#define GNUNET_YES
Definition: gnunet_common.h:80
struct GNUNET_TIME_AbsoluteNBO expiration_time
When does this signature expire?
Definition: block_dns.h:56
int GNUNET_BLOCK_GROUP_bf_test_and_set(struct GNUNET_BLOCK_Group *bg, const struct GNUNET_HashCode *hc)
Test if hc is contained in the Bloom filter of bg.
Definition: bg_bf.c:214
Query is valid, no reply given.
struct GNUNET_CRYPTO_EddsaPublicKey public_key
Here is the call graph for this function:
Here is the caller graph for this function:

◆ block_plugin_dns_get_key()

static int block_plugin_dns_get_key ( void *  cls,
enum GNUNET_BLOCK_Type  type,
const void *  block,
size_t  block_size,
struct GNUNET_HashCode key 
)
static

Function called to obtain the key for a block.

Parameters
clsclosure
typeblock type
blockblock to get the key for
block_sizenumber of bytes in block
keyset to the key (query) for the given block
Returns
GNUNET_OK on success, GNUNET_SYSERR if type not supported (or if extracting a key from a block of this type does not work)

Definition at line 188 of file plugin_block_dns.c.

References GNUNET_SYSERR.

Referenced by libgnunet_plugin_block_dns_init().

193 {
194  /* we cannot extract a key from a block of this type */
195  return GNUNET_SYSERR;
196 }
#define GNUNET_SYSERR
Definition: gnunet_common.h:79
Here is the caller graph for this function:

◆ libgnunet_plugin_block_dns_init()

void* libgnunet_plugin_block_dns_init ( void *  cls)

Entry point for the plugin.

Definition at line 203 of file plugin_block_dns.c.

References block_plugin_dns_create_group(), block_plugin_dns_evaluate(), block_plugin_dns_get_key(), GNUNET_BLOCK_PluginFunctions::create_group, GNUNET_BLOCK_PluginFunctions::evaluate, GNUNET_BLOCK_PluginFunctions::get_key, GNUNET_BLOCK_TYPE_ANY, GNUNET_BLOCK_TYPE_DNS, GNUNET_new, and GNUNET_BLOCK_PluginFunctions::types.

204 {
205  static enum GNUNET_BLOCK_Type types[] =
206  {
208  GNUNET_BLOCK_TYPE_ANY /* end of list */
209  };
210  struct GNUNET_BLOCK_PluginFunctions *api;
211 
216  api->types = types;
217  return api;
218 }
enum GNUNET_BLOCK_Type * types
0-terminated array of block types supported by this plugin.
static enum GNUNET_BLOCK_EvaluationResult block_plugin_dns_evaluate(void *cls, struct GNUNET_BLOCK_Context *ctx, enum GNUNET_BLOCK_Type type, struct GNUNET_BLOCK_Group *bg, enum GNUNET_BLOCK_EvaluationOptions eo, const struct GNUNET_HashCode *query, const void *xquery, size_t xquery_size, const void *reply_block, size_t reply_block_size)
Function called to validate a reply or a request.
Any type of block, used as a wildcard when searching.
static struct GNUNET_BLOCK_Group * block_plugin_dns_create_group(void *cls, enum GNUNET_BLOCK_Type type, uint32_t nonce, const void *raw_data, size_t raw_data_size, va_list va)
Create a new block group.
GNUNET_BLOCK_EvaluationFunction evaluate
Main function of a block plugin.
GNUNET_BLOCK_Type
Blocks in the datastore and the datacache must have a unique type.
Each plugin is required to return a pointer to a struct of this type as the return value from its ent...
static int block_plugin_dns_get_key(void *cls, enum GNUNET_BLOCK_Type type, const void *block, size_t block_size, struct GNUNET_HashCode *key)
Function called to obtain the key for a block.
#define GNUNET_new(type)
Allocate a struct or union of the given type.
Block for storing DNS exit service advertisements.
GNUNET_BLOCK_GroupCreateFunction create_group
Create a block group to process a bunch of blocks in a shared context (i.e.
GNUNET_BLOCK_GetKeyFunction get_key
Obtain the key for a given block (if possible).
Here is the call graph for this function:

◆ libgnunet_plugin_block_dns_done()

void* libgnunet_plugin_block_dns_done ( void *  cls)

Exit point from the plugin.

Definition at line 225 of file plugin_block_dns.c.

References GNUNET_BLOCK_PluginFunctions::cls, and GNUNET_free.

226 {
227  struct GNUNET_BLOCK_PluginFunctions *api = cls;
228 
229  GNUNET_free (api);
230  return NULL;
231 }
Each plugin is required to return a pointer to a struct of this type as the return value from its ent...
void * cls
Closure for all of the callbacks.
#define GNUNET_free(ptr)
Wrapper around free.