artdaq  v3_05_00
TCP_listen_fd.cc
1 // This file (TCP_listen_fd.cpp) was created by Ron Rechenmacher <ron@fnal.gov> on
2 // Apr 20, 2010. "TERMS AND CONDITIONS" governing this file are in the README
3 // or COPYING file. If you do not have such a file, one can be obtained by
4 // contacting Ron or Fermi Lab in Batavia IL, 60510, phone: 630-840-3000.
5 // $RCSfile: TCP_listen_fd.cpp,v $
6 // rev="$Revision: 1.3 $$Date: 2010/06/04 14:00:32 $";
7 
8 #define TRACE_NAME (app_name + "_TCP_listen_fd").c_str()
9 #include "artdaq/DAQdata/Globals.hh"
10 
11 #include <stdio.h> // printf
12 #include <stdlib.h> // exit
13 #include <strings.h> // bzero
14 #include <sys/socket.h> /* inet_aton, socket, bind, listen, accept */
15 #include <netinet/in.h> /* inet_aton, struct sockaddr_in */
16 #include <arpa/inet.h> /* inet_aton */
17 #include <netdb.h> /* gethostbyname */
18 #include <errno.h> // errno
19 
21 
22 int
23 TCP_listen_fd(int port, int rcvbuf)
24 {
25  int sts;
26  int listener_fd;
27  struct sockaddr_in sin;
28 
29  listener_fd = socket(PF_INET, SOCK_STREAM, 0); /* man TCP(7P) */
30  if (listener_fd == -1)
31  {
32  TLOG(TLVL_ERROR) << "Could not open listen socket! Exiting with code 1!";
33  perror("socket error");
34  exit(1);
35  }
36 
37  int opt = 1; // SO_REUSEADDR - man socket(7)
38  sts = setsockopt(listener_fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));
39  if (sts == -1)
40  {
41  TLOG(TLVL_ERROR) << "Could not set SO_REUSEADDR! Exiting with code 2!";
42  perror("setsockopt SO_REUSEADDR");
43  return (2);
44  }
45 
46  bzero((char *)&sin, sizeof(sin));
47  sin.sin_family = AF_INET;
48  sin.sin_port = htons(port);
49  sin.sin_addr.s_addr = INADDR_ANY;
50 
51  //printf( "bind..." );fflush(stdout);
52  sts = bind(listener_fd, (struct sockaddr *)&sin, sizeof(sin));
53  if (sts == -1)
54  {
55  TLOG(TLVL_ERROR) << "Could not bind socket for port " << port << "! Exiting with code 3!";
56  perror("bind error");
57  exit(3);
58  }
59  //printf( " OK\n" );
60 
61  int len = 0;
62  socklen_t arglen = sizeof(len);
63  sts = getsockopt(listener_fd, SOL_SOCKET, SO_RCVBUF, &len, &arglen);
64  TLOG(TLVL_INFO) << "RCVBUF initial: " << len << " sts/errno=" << sts << "/" << errno << " arglen=" << arglen << " rcvbuf=" << rcvbuf << " listener_fd=" << listener_fd;
65  if (rcvbuf > 0)
66  {
67  len = rcvbuf;
68  sts = setsockopt(listener_fd, SOL_SOCKET, SO_RCVBUF, &len, arglen);
69  if (sts == -1)
70  TLOG(TLVL_ERROR) << "Error with setsockopt SNDBUF " << errno;
71  len = 0;
72  sts = getsockopt(listener_fd, SOL_SOCKET, SO_RCVBUF, &len, &arglen);
73  if (len < (rcvbuf * 2))
74  TLOG(TLVL_WARNING) << "RCVBUF " << len << " not expected (" << rcvbuf << " sts/errno=" << sts << "/" << errno;
75  else
76  TLOG(TLVL_DEBUG) << "RCVBUF " << len << " sts/errno=" << sts << "/" << errno;
77  }
78 
79  //printf( "listen..." );fflush(stdout);
80  sts = listen(listener_fd, 5/*QLEN*/);
81  if (sts == -1)
82  {
83  perror("listen error");
84  exit(1);
85  }
86  //printf( " OK\n" );
87 
88  return (listener_fd);
89 } // TCP_listen_fd
int TCP_listen_fd(int port, int rcvbuf)
Create a TCP listening socket on the given port and INADDR_ANY, with the given receive buffer...