cnet's core Application Programming Interface

Most core functions return the integer 0 on success and the integer -1 on failure. The most recent error status is reflected in the global variable cnet_errno. All values of cnet_errno will be instances of the enumerated type CnetError. Functions do not set the value of cnet_errno to ER_OK if their execution was successful.

Note that these functions' names are prefixed with CNET_. Errors may be reported to stderr with CNET_perror() and their error message string accessed from cnet_errstr[(int)cnet_errno].

Application Layer functions

• overview
• CNET_read_application,  CNET_write_application,  CNET_enable_application,  and CNET_disable_application

Physical Layer functions

• overview
• CNET_write_physical,  CNET_write_physical_reliable,  CNET_write_direct,  CNET_read_physical, 
• CNET_carrier_sense,  CNET_set_nicaddr,  CNET_parse_nicaddr,  and CNET_format_nicaddr

WLAN and mobile node functions

• overview
• CNET_get_wlaninfo,  CNET_set_wlaninfo,  CNET_set_wlan_model,  CNET_get_wlanstate,  CNET_set_wlanstate,  CNET_set_wlancolour,  CNET_wlan_arrival,  CNET_get_position,  CNET_set_position,  and CNET_get_mapscale

Event handling functions

• CNET_set_handler , CNET_get_handler
• CNET_unused_debug_event,  CNET_unused_timer_event

Checksum and CRC functions

• CNET_IP_checksum,  CNET_ccitt,  CNET_crc16,  and CNET_crc32

Timer functions

• overview
• CNET_start_timer,  CNET_stop_timer,  and CNET_timer_data

Tracing functions

• overview
• CNET_trace,  CNET_trace_name,  CNET_set_trace,  and CNET_get_trace

Node and per-link statistics

• CNET_get_nodestats and CNET_get_linkstats

Formatting 64-bit integers

• CNET_format64,  CNET_set_commas,  and CNET_get_commas

Pseudo-random number generation

• CNET_srand,  CNET_rand,  CNET_newrand,  and CNET_nextrand

Miscellaneous functions

• CNET_vflag, and CNET_Wflag
• CNET_check_version,  CNET_read_keyboard,  CNET_set_debug_string,  CNET_set_LED,  CNET_set_time_of_day 
• CNET_getvar,  CNET_shmem,  CNET_shmem2 
• TCLTK,  TCLTK_interp, and CNET_set_outputfile

API restrictions

• Calls to the functions:

      CNET_write_application,
      CNET_read_application,
      CNET_enable_application,
      CNET_disable_application and
      CNET_set_handler(EV_APPLICATIONLAYER,...) and
      CNET_set_handler(EV_KEYBOARDREADY,...)
  

  are only valid if called from a node of type NT_HOST or NT_MOBILE.

• Function calls to either the Application or Physical Layers are invalid when cnet is not running. This can occur when the node is rebooting, when the simulation is running under a windowing system, is paused, and a node's debug button is selected.

• Calls to the function:

      CNET_set_position

  are only valid if called from a node of node type NT_MOBILE.

• Calls to the functions:

      CNET_get_wlaninfo,
      CNET_set_wlaninfo
      CNET_wlan_arrival
  

  are only valid for links of type LT_WLAN.

• Calls to the functions:

      CNET_set_nicaddr
  

  are only valid for links of type LT_LAN or LT_WLAN. Furthermore, you cannot set the attributes of link 0, the LOOPBACK link, nor set a NIC address to either the zero address, 00:00:00:00:00:00, or the broadcast address, ff:ff:ff:ff:ff:ff.