Assigning an address explicitly

In this case, you call bind() as follows:

bind(s, name, namelen);

In the communications domain AF_INET, name comprises a 4-byte IPv4 address and a port number. name is passed in a variable of the type struct sockaddr_in (see section "sockaddr_in address structure of the AF_INET address family"). namelen contains the length of the data structure that defines the name.

In the communications domain AF_INET6, name comprises a 16-byte IPv6 address and a port number. name is passed in a variable of the type struct sockaddr_in6 (see section "sockaddr_in6 address structure of the AF_INET6 address family"). namelen contains the length of the data structure that defines the name.

In the communications domain AF_ISO, name comprises a network selector and a transport selector. name is passed in a variable of the type struct sockaddr_iso (see section "sockaddr_iso address structure for the AF_ISO address family"). namelen contains the length of the data structure that defines the name.

Assigning an address explicitly in the domains AF_INET and AF_INET6

Assigning an address explicitly in AF_INET

The following program extract illustrates how a name is assigned to a socket in the AF_INET domain.

#include <sys.types.h>
#include <netinet.in.h>
 ...
struct sockaddr_in sin;
int s;
...
sin.sin_family = AF_INET;
sin.sin_port = 0;
sin.sin_addr.s_addr = INADDR_ANY;
 ...
bind(s, &sin, sizeof sin);

  
Assigning an address explicitly in AF_INET6

#include <sys.types.h>
#include <netinet.in.h>
 ...
struct sockaddr_in6 sin6;
struct in6_addr in6addr_any = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
int s;
...
sin6.sin6_family = AF_INET6;
sin6.sin6_port = 0;
memcpy(sin6.sin6_addr.s6_addr,in6addr_any.s6_addr,16); 
 ...
bind(s, &sin6, sizeof sin6);

You must note the following when selecting the port number:

• Port numbers lower than PRIVPORT# (see the “BCAM Volume 1/2” manual) are reserved for privileged users (default: 2050).

• Certain port numbers are reserved for some standard applications:

  • Port number 3161 is used by the SNMP Basic Agent BS2000 is used for internal communications between the master agent and subagents (see the “SNMP Management for BS2000” manual).

  • Port number 1235 is required by the Domain Name Service (DNS) (see the “interNet Services” administration manual).

  • Note should be made of other well-known, registered, dynamic and/or private port numbers, which are documented on the IANA website at “http://www.iana.org/assignments/port-numbers”.

Assigning an address explicitly in the AF_ISO domain

The following program section illustrates how a name is assigned to a socket in the AF_ISO domain.

#include <sys.types.h>
#include <iso.h>
... ..
struct sockaddr_iso sin;
int s;
... ..
/* The statements which supply sin with a network selector
   and a transport selector must be inserted here.*/ 
... ..
bind(s, &sin, sizeof sin);