Subject: Bind to local iface: bug or feautre.
To: None <tech-net@NetBSD.ORG>
From: Jesus M. Gonzalez <>
List: tech-net
Date: 11/25/1996 14:05:31

	NetBSD returns an error when binding an UDP address where
the host address matchs a local iface (instead of the more used
INADDR_ANY). I'm not familar with the networking code,
and I'm not sure if this is a bug or a feature... Could somebody
tell me, so that I send-pr it if it is a bug?


PS: Next, the code which causes EADDRNOTAVAIL. I think it should just
work. Was tested on NetBSD-1.1/i386 and NetBSD-1.2/i386.

#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <stdio.h>

  int sock, length;
  struct sockaddr_in name;
  char buf[1024];

  /* Create socket from which to read. */
  sock = socket(AF_INET, SOCK_DGRAM, 0);
  if (sock < 0) {
    perror("opening datagram socket");
  /* Create name with wildcards. */
  name.sin_family = AF_INET;
  name.sin_addr.s_addr = inet_addr(""); /* Here your addr */
  name.sin_port = 0;
  if (bind(sock, (struct sockaddr *) &name, sizeof(name))) {
    perror("binding datagram socket");
  /* Find assigned port value and print it out. */
  length = sizeof(name);
  if (getsockname(sock, (struct sockaddr *) &name, &length)) {
    perror("getting socket name");

Jesus M. Gonzalez Barahona         | addr.:  c/ Butarque, 15
Grupo de Sistemas y Comunicaciones |         28911 Leganes, Spain
Departamento de Informatica        | tel: +34 1 624 94 58
Universidad Carlos III de Madrid   | fax: +34 1 624 94 30
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