GNUnet  0.18.1
Client library

Generic client-side communication with services. More...

Collaboration diagram for Client library:

Functions

int GNUNET_CLIENT_test (const struct GNUNET_CONFIGURATION_Handle *cfg, const char *service_name)
 Test if the port or UNIXPATH of the given service_name is in use and thus (most likely) the respective service is up. More...
 
struct GNUNET_MQ_HandleGNUNET_CLIENT_connect (const struct GNUNET_CONFIGURATION_Handle *cfg, const char *service_name, const struct GNUNET_MQ_MessageHandler *handlers, GNUNET_MQ_ErrorHandler error_handler, void *error_handler_cls)
 Create a message queue to connect to a GNUnet service. More...
 

Detailed Description

Generic client-side communication with services.

See also
Documentation

Function Documentation

◆ GNUNET_CLIENT_test()

int GNUNET_CLIENT_test ( const struct GNUNET_CONFIGURATION_Handle cfg,
const char *  service_name 
)

Test if the port or UNIXPATH of the given service_name is in use and thus (most likely) the respective service is up.

Parameters
cfgour configuration
service_namename of the service to connect to
Returns
GNUNET_YES if the service is (likely) up (or running remotely), GNUNET_NO if the service is (definitively) down, GNUNET_SYSERR if the configuration does not give us the necessary information about the service, or if we could not check (e.g. socket() failed)
Parameters
cfgour configuration
service_namename of the service to connect to
Returns
GNUNET_YES if the service is (likely) up, GNUNET_NO if the service is (definitively) down, GNUNET_SYSERR if the configuration does not give us the necessary information about the service, or if we could not check (e.g. socket() failed)

Definition at line 903 of file client.c.

905 {
906  char *hostname = NULL;
907  unsigned long long port;
908  int ret;
909 
910 #if AF_UNIX
911  {
912  char *unixpath = NULL;
913 
914  if (GNUNET_OK ==
916  service_name,
917  "UNIXPATH",
918  &unixpath))
919  {
920  if (0 == strlen (unixpath))
921  {
922  GNUNET_free (unixpath);
923  return GNUNET_SYSERR; /* empty string not OK */
924  }
925  if (0 == access (unixpath,
926  F_OK))
927  {
928  GNUNET_free (unixpath);
929  return GNUNET_OK; /* file exists, we assume service is running */
930  }
931  GNUNET_free (unixpath);
932  }
933  else if (GNUNET_OK ==
935  service_name,
936  "UNIXPATH"))
937  {
938  /* UNIXPATH specified but not a valid path! */
940  service_name,
941  "UNIXPATH",
942  _ ("not a valid filename"));
943  return GNUNET_SYSERR;
944  }
945  }
946 #endif
947 
948  if ( (GNUNET_OK !=
950  service_name,
951  "PORT",
952  &port)) ||
953  (port > 65535) ||
954  (0 == port) )
955  {
956  return GNUNET_SYSERR;
957  }
958  if (GNUNET_OK ==
960  service_name,
961  "HOSTNAME",
962  &hostname))
963  {
964  /* We always assume remotes are up */
965  ret = GNUNET_YES;
966  }
967  else
968  {
969  /* We look for evidence the service is up */
970  ret = GNUNET_NO;
971  }
972  if ( (NULL == hostname) ||
973  (0 == strcasecmp (hostname,
974  "localhost")) ||
975  (0 == strcasecmp (hostname,
976  "ip6-localnet")) )
977  {
978  /* service runs on loopback */
979  struct sockaddr_in v4;
980  struct sockaddr_in6 v6;
981  int sock;
982 
983  memset (&v4, 0, sizeof (v4));
984  memset (&v6, 0, sizeof (v6));
985  v4.sin_family = AF_INET;
986  v4.sin_port = htons ((uint16_t) port);
987 #if HAVE_SOCKADDR_IN_SUN_LEN
988  v4.sin_len = (u_char) sizeof(struct sockaddr_in);
989 #endif
990  GNUNET_assert (1 == inet_pton (AF_INET,
991  "127.0.0.1",
992  &v4.sin_addr));
993  ret = GNUNET_NO;
994  sock = socket (AF_INET,
995  SOCK_STREAM,
996  0);
997  if (-1 != sock)
998  {
999  if (0 != bind (sock,
1000  (struct sockaddr *) &v4,
1001  sizeof (v4)))
1002  {
1003  /* bind failed, so someone is listening! */
1004  ret = GNUNET_YES;
1005  }
1006  (void) close (sock);
1007  }
1008  else
1009  {
1011  "socket");
1012  if (GNUNET_NO == ret)
1013  ret = GNUNET_SYSERR;
1014  }
1015  v6.sin6_family = AF_INET6;
1016  v6.sin6_port = htons ((uint16_t) port);
1017 #if HAVE_SOCKADDR_IN_SUN_LEN
1018  v6.sin6_len = (u_char) sizeof(struct sockaddr_in6);
1019 #endif
1020  inet_pton (AF_INET6,
1021  "::1",
1022  &v6.sin6_addr);
1023  sock = socket (AF_INET6,
1024  SOCK_STREAM,
1025  0);
1026  if (-1 != sock)
1027  {
1028  if (0 != bind (sock,
1029  (struct sockaddr *) &v6,
1030  sizeof (v6)))
1031  {
1032  /* bind failed, so someone is listening! */
1033  ret = GNUNET_YES;
1034  }
1035  (void) close (sock);
1036  }
1037  else
1038  {
1040  "socket");
1041  /* not changing 'ret' intentionally here, as
1042  v4 succeeding and v6 failing just means we
1043  should use v4 */
1044  }
1045  }
1046  else
1047  {
1048  /* service running remotely */
1049  ret = GNUNET_OK;
1050  }
1052  return ret;
1053 }
static const struct GNUNET_CONFIGURATION_Handle * cfg
Configuration we are using.
Definition: gnunet-abd.c:36
static int ret
Return value of the commandline.
Definition: gnunet-abd.c:81
static uint16_t port
Port number.
Definition: gnunet-bcd.c:147
static char * hostname
Our hostname; we give this to all the peers we start.
static char * service_name
Option -s: service name (hash to get service descriptor)
Definition: gnunet-vpn.c:50
enum GNUNET_GenericReturnValue GNUNET_CONFIGURATION_get_value_filename(const struct GNUNET_CONFIGURATION_Handle *cfg, const char *section, const char *option, char **value)
Get a configuration value that should be the name of a file or directory.
enum GNUNET_GenericReturnValue GNUNET_CONFIGURATION_get_value_number(const struct GNUNET_CONFIGURATION_Handle *cfg, const char *section, const char *option, unsigned long long *number)
Get a configuration value that should be a number.
enum GNUNET_GenericReturnValue GNUNET_CONFIGURATION_get_value_string(const struct GNUNET_CONFIGURATION_Handle *cfg, const char *section, const char *option, char **value)
Get a configuration value that should be a string.
enum GNUNET_GenericReturnValue GNUNET_CONFIGURATION_have_value(const struct GNUNET_CONFIGURATION_Handle *cfg, const char *section, const char *option)
Test if we have a value for a particular option.
@ GNUNET_OK
@ GNUNET_YES
@ GNUNET_NO
@ GNUNET_SYSERR
#define GNUNET_assert(cond)
Use this for fatal errors that cannot be handled.
void GNUNET_log_config_invalid(enum GNUNET_ErrorType kind, const char *section, const char *option, const char *required)
Log error message about invalid configuration option value.
#define GNUNET_log_strerror(level, cmd)
Log an error message at log-level 'level' that indicates a failure of the command 'cmd' with the mess...
@ GNUNET_ERROR_TYPE_WARNING
@ GNUNET_ERROR_TYPE_ERROR
#define GNUNET_free(ptr)
Wrapper around free.
#define _(String)
GNU gettext support macro.
Definition: platform.h:177

References _, cfg, GNUNET_assert, GNUNET_CONFIGURATION_get_value_filename(), GNUNET_CONFIGURATION_get_value_number(), GNUNET_CONFIGURATION_get_value_string(), GNUNET_CONFIGURATION_have_value(), GNUNET_ERROR_TYPE_ERROR, GNUNET_ERROR_TYPE_WARNING, GNUNET_free, GNUNET_log_config_invalid(), GNUNET_log_strerror, GNUNET_NO, GNUNET_OK, GNUNET_SYSERR, GNUNET_YES, hostname, port, ret, and service_name.

Referenced by action_loop(), and run().

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◆ GNUNET_CLIENT_connect()

struct GNUNET_MQ_Handle* GNUNET_CLIENT_connect ( const struct GNUNET_CONFIGURATION_Handle cfg,
const char *  service_name,
const struct GNUNET_MQ_MessageHandler handlers,
GNUNET_MQ_ErrorHandler  error_handler,
void *  error_handler_cls 
)

Create a message queue to connect to a GNUnet service.

If handlers are specified, receive messages from the connection.

Parameters
cfgour configuration
service_namename of the service to connect to
handlershandlers for receiving messages, can be NULL
error_handlererror handler
error_handler_clsclosure for the error_handler
Returns
the message queue, NULL on error

Definition at line 1057 of file client.c.

1062 {
1063  struct ClientState *cstate;
1064 
1065  if (GNUNET_OK !=
1067  cfg))
1068  return NULL;
1069  cstate = GNUNET_new (struct ClientState);
1071  cstate->cfg = cfg;
1073  cstate);
1074  cstate->mst = GNUNET_MST_create (&recv_message,
1075  cstate);
1076  if (GNUNET_YES ==
1078  service_name,
1079  "PORT"))
1080  {
1081  if (! ((GNUNET_OK !=
1083  service_name,
1084  "PORT",
1085  &cstate->port)) ||
1086  (cstate->port > 65535) ||
1087  (GNUNET_OK !=
1089  service_name,
1090  "HOSTNAME",
1091  &cstate->hostname))) &&
1092  (0 == strlen (cstate->hostname)))
1093  {
1094  GNUNET_free (cstate->hostname);
1095  cstate->hostname = NULL;
1097  _ ("Need a non-empty hostname for service `%s'.\n"),
1098  service_name);
1099  }
1100  }
1104  cstate,
1105  handlers,
1106  error_handler,
1107  error_handler_cls);
1108  return cstate->mq;
1109 }
static void error_handler(void *cls, enum GNUNET_MQ_Error error)
We encountered an error handling the MQ to the ATS service.
static void connection_client_cancel_impl(struct GNUNET_MQ_Handle *mq, void *impl_state)
Cancel the currently sent message.
Definition: client.c:873
static void connection_client_send_impl(struct GNUNET_MQ_Handle *mq, const struct GNUNET_MessageHeader *msg, void *impl_state)
Implements the transmission functionality of a message queue.
Definition: client.c:841
static void start_connect(void *cls)
Try to connect to the service.
Definition: client.c:787
static enum GNUNET_GenericReturnValue recv_message(void *cls, const struct GNUNET_MessageHeader *msg)
We have received a full message, pass to the MQ dispatcher.
Definition: client.c:335
static void connection_client_destroy_impl(struct GNUNET_MQ_Handle *mq, void *impl_state)
Implement the destruction of a message queue.
Definition: client.c:386
static int test_service_configuration(const char *service_name, const struct GNUNET_CONFIGURATION_Handle *cfg)
Test whether the configuration has proper values for connection (UNIXPATH || (PORT && HOSTNAME)).
Definition: client.c:726
#define LOG(kind,...)
Definition: client.c:37
static struct GNUNET_CADET_MessageHandler handlers[]
Handlers, for diverse services.
#define GNUNET_strdup(a)
Wrapper around GNUNET_xstrdup_.
#define GNUNET_new(type)
Allocate a struct or union of the given type.
struct GNUNET_MQ_Handle * GNUNET_MQ_queue_for_callbacks(GNUNET_MQ_SendImpl send, GNUNET_MQ_DestroyImpl destroy, GNUNET_MQ_CancelImpl cancel, void *impl_state, const struct GNUNET_MQ_MessageHandler *handlers, GNUNET_MQ_ErrorHandler error_handler, void *cls)
Create a message queue for the specified handlers.
Definition: mq.c:469
struct GNUNET_SCHEDULER_Task * GNUNET_SCHEDULER_add_now(GNUNET_SCHEDULER_TaskCallback task, void *task_cls)
Schedule a new task to be run as soon as possible.
Definition: scheduler.c:1268
struct GNUNET_MessageStreamTokenizer * GNUNET_MST_create(GNUNET_MessageTokenizerCallback cb, void *cb_cls)
Create a message stream tokenizer.
Definition: mst.c:86
State we keep per client.
struct GNUNET_MQ_Handle * mq
MQ to talk to client.
const struct GNUNET_CONFIGURATION_Handle * cfg
Our configuration.
Definition: client.c:116
struct GNUNET_MessageStreamTokenizer * mst
Tokenizer for inbound messages.
Definition: client.c:163
struct GNUNET_SCHEDULER_Task * retry_task
Task for trying to connect to the service.
Definition: client.c:148
char * hostname
Hostname, if any.
Definition: client.c:138
unsigned long long port
TCP port (0 for disabled).
Definition: client.c:184
char * service_name
Name of the service we interact with.
Definition: client.c:133

References _, cfg, ClientState::cfg, connection_client_cancel_impl(), connection_client_destroy_impl(), connection_client_send_impl(), error_handler(), GNUNET_CONFIGURATION_get_value_number(), GNUNET_CONFIGURATION_get_value_string(), GNUNET_CONFIGURATION_have_value(), GNUNET_ERROR_TYPE_WARNING, GNUNET_free, GNUNET_MQ_queue_for_callbacks(), GNUNET_MST_create(), GNUNET_new, GNUNET_OK, GNUNET_SCHEDULER_add_now(), GNUNET_strdup, GNUNET_YES, handlers, ClientState::hostname, LOG, ClientState::mq, ClientState::mst, ClientState::port, recv_message(), ClientState::retry_task, ClientState::service_name, service_name, start_connect(), and test_service_configuration().

Referenced by addr_cb(), announce_reconnect(), connect_task(), create_internal(), create_loc_uri(), do_connect(), do_peer_connect(), do_plugin_connect(), do_reconnect(), GNUNET_CONSENSUS_create(), GNUNET_CONVERSATION_call_start(), GNUNET_DATASTORE_disconnect(), GNUNET_FS_get_indexed_files(), GNUNET_IDENTITY_ego_lookup(), GNUNET_IDENTITY_ego_lookup_by_suffix(), GNUNET_NAT_AUTO_autoconfig_start(), GNUNET_REVOCATION_query(), GNUNET_REVOCATION_revoke(), GNUNET_SCALARPRODUCT_accept_computation(), GNUNET_SCALARPRODUCT_start_computation(), GNUNET_SECRETSHARING_create_session(), GNUNET_SECRETSHARING_decrypt(), GNUNET_SETI_create(), GNUNET_SETU_create(), GNUNET_TESTBED_barrier_wait(), GNUNET_TESTBED_controller_connect(), GNUNET_TESTBED_LOGGER_connect(), GNUNET_TRANSPORT_address_to_string(), GNUNET_TRANSPORT_offer_hello(), hash_for_index_cb(), listen_connect(), reconnect(), reconnect_arm(), reconnect_arm_monitor(), reconnect_phone(), reconnect_task(), search_reconnect(), test_nat_punched(), try_connect(), try_reconnect(), and unindex_finish().

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