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nsds_util.c File Reference

Utility / common routines for the NSDS driver and DAQ. More...

#include "nsds_util.h"
#include "flog.h"
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <errno.h>
#include <stdlib.h>
#include <stdio.h>
#include <math.h>
#include <unistd.h>
#include <stdint.h>
#include <string.h>
#include <signal.h>
#include <time.h>
#include <sys/time.h>

Go to the source code of this file.

Functions
char *	gen_timestamp (void)
	Generate an ISO 8601-compliant timestamp.
int	tcp_socket_make (const uint16_t SRV_PORT, const int QUEUE_LENGTH)
	Create server socket, ready for accept().
int	tcp_nl_write (const int socket, const char *buf)
	Send a string, appending a newline character.
int	tcp_nl_read (const uint16_t socket, char *buf, const time_t timeout)
	Read until EOL or MAX_CMD_LEN bytes.
int	tcp_connect (const char *server, const uint16_t port)
	Routine, after Comer, for opening a TCP connection.
socket_wait_ret	tcp_socket_wait (const int socket, const time_t timeout)
	Function to wait on a socket, with or without timeout.
char *	tcp_peername (const int socket)
	Function to return a string w/name of connected peer.
int	tcp_connect_retry (const char *host, const uint16_t port, const time_t retry_delay, const time_t end_time, const char *description)
	Loop until can open client connection.
void	tcp_close (const int socket_fd)
	Shutdown and close TCP socket.
Variables
bool	control_break
	Global boolean set by signal handler to force exit.

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Detailed Description

Utility / common routines for the NSDS driver and DAQ.

Author:

Paul Hubbard

Date:

9/5/02

Note:

Requires the flog message library as of 9/24/02

Definition in file nsds_util.c.

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Function Documentation

char* gen_timestamp (  void    )

Generate an ISO 8601-compliant timestamp. Note: Not threadsafe! Requires gettimeofday call Return values: Ptr  to static buffer with timestamp string Date: 9/19/02 This is, frankly, a hack. It generates a UTC-format ISO8601 timestamp, with 5-digit fractional seconds. Its for the fake_daq program, so that it can spew psuedo data. The format, however, should be correct. Definition at line 46 of file nsds_util.c. Referenced by daq_thread_main().

void tcp_close (  const int    socket_fd )

Shutdown and close TCP socket. Does shutdown (read/write) and then close if fd > 0 Parameters: socket_fd  File descriptor of socket Definition at line 620 of file nsds_util.c. Referenced by daq_main_loop(), and main_loop().

int tcp_connect (  const char *    server, const uint16_t    port )

Routine, after Comer, for opening a TCP connection. --------------------------------------------------------------------- Note: hardwired to use TCP, stream mode Assumes Server ready and able to answer connections TCP/IP available Not multithreaded - gethostbyname is NOT reentrant! Parameters: server  Ptr to string of server name port  Port number on server Return values: 0  if no errors, !=0 on any error. Date: 4/00, modified 8/28/02 Definition at line 359 of file nsds_util.c. Referenced by tcp_connect_retry().

int tcp_connect_retry (  const char *    host, const uint16_t    port, const time_t    retry_delay, const time_t    end_time, const char *    description )

Loop until can open client connection. Parameters: host  Hostname port  Port number retry_delay  Time, in seconds, to sleep between attempts end_time  If >0, when we give up description  String to print to screen Return values: If  > 0, socket FD <=  0, error or timeout Retry, every N seconds, to open a connection. Used to provide robustness against network failures; non-blocking. Definition at line 562 of file nsds_util.c. References tcp_connect(). Referenced by main_loop().

int tcp_nl_read (  const uint16_t    socket, char *    buf, const time_t    timeout )

Read until EOL or MAX_CMD_LEN bytes. --------------------------------------------------------------------- Read from TCP into static buffer until get newline or exceed buffer length. All messages are newline-delimted, so this is used all over the place to read commands and data. Yeah, yeah, I know already. Needs dynamic buffers, or sizing, or code that Sucks Less. Note: Removes newline and terminates string with 0x00 Date: 8/28/02 Parameters: socket  tcp socket buf  Buffer, of >= MAX_CMD_LEN bytes timeout  If > 0, uses this as timeout. 0 waits forever. Return values: Number  of bytes read, < 0 on an error, 0 if timed out Definition at line 246 of file nsds_util.c. References MAX_CMD_LEN, socket_wait_ret, and tcp_socket_wait(). Referenced by cmd_handler(), and daq_do_work().

int tcp_nl_write (  const int    socket, const char *    buf )

Send a string, appending a newline character. --------------------------------------------------------------------- Date: 8/29/02 Return values: Number  of bytes written, not counting newline! Parameters: socket  Socket/fd buf  C string to send Note: Forces a sync to flush at the end of the send Very simple, writes a buffer and appends a newline. Definition at line 194 of file nsds_util.c. Referenced by cmd_handler(), daq_do_work(), daq_thread_main(), and tcp_send_driverids().

char* tcp_peername (  const int    socket )

Function to return a string w/name of connected peer. Note: Non-reentrant, uses static buffer Does a DNS lookup on the peer, returns their name or (if DNS fails) their IP address as a dotted-decimal string. Quite handy. Definition at line 510 of file nsds_util.c. Referenced by daq_main_loop(), and main_loop().

int tcp_socket_make (  const uint16_t    SRV_PORT, const int    QUEUE_LENGTH )

Create server socket, ready for accept(). --------------------------------------------------------------------- Note: Borrowed from FNAL server code Date: 8/27/02 Return values: >  0 (Socket, OK) <=0  (Error) Parameters: SRV_PORT  Port to create QUEUE_LENGTH  TCP queue length, passed to listen() Does the low-level work of setting up a listen socket, very careful about possible errors and socket options. Produced socket is ready for accept() calls. Definition at line 100 of file nsds_util.c. References QUEUE_LENGTH, and SRV_PORT. Referenced by daq_main_loop().

socket_wait_ret tcp_socket_wait (  const int    socket, const time_t    timeout )

Function to wait on a socket, with or without timeout. Blocking or non-blocking wait until a socket is ready for reading. Used in functions that cannot wait forever, as well as ones that can. Note: Also copied from FNAL code Negative or zero timeout means blocking wait; might wanna change this to a bool param? Return values: socket_wait_ret  enumerated type Parameters: socket  file descriptor timeout  Timeout, in seconds Definition at line 437 of file nsds_util.c. References socket_wait_ret. Referenced by tcp_nl_read().

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Variable Documentation

bool control_break

Global boolean set by signal handler to force exit. Definition at line 30 of file nsds_util.c. Referenced by daq_main_loop(), daq_thread_main(), main(), and sighandler().

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