BINDRESVPORT(3) | Library Functions Manual | BINDRESVPORT(3) |
bindresvport
, bindresvport_sa
—
#include <sys/types.h>
#include <rpc/rpc.h>
int
bindresvport
(int
sd, struct sockaddr_in
*sin);
int
bindresvport_sa
(int
sd, struct sockaddr
*sa);
bindresvport
() and
bindresvport_sa
() are used to bind a socket descriptor
to a reserved privileged IP port, that is, a port number in the range 0-1023.
The routine returns 0 if it is successful, otherwise -1 is returned and
errno set to reflect the cause of the error.
If sin is a pointer to a struct sockaddr_in then the appropriate fields in the structure should be defined. Note that sin->sin_family must be initialized to the address family of the socket, passed by sd. If sin->sin_port is ‘0’ then a port (in the range 600-1023) will be chosen, and if bind(2) is successful, the sin->sin_port will be updated to contain the allocated port.
If sin is the NULL
pointer, a port will be allocated (as above). However, there is no way for
bindresvport
() to return the allocated port in this
case. getsockname(2) can
be used to determine the assigned port.
Only root can bind to a privileged port; this call will fail for any other users.
Function prototype of bindresvport
() is
biased to AF_INET
socket.
bindresvport_sa
() acts exactly the same, with more
neutral function prototype. Note that both functions behave exactly the
same, and both support AF_INET6
sockets as well as
AF_INET
sockets.
EPFNOSUPPORT
]bindresvport
() may also fail and set
errno for any of the errors specified for the calls
bind(2),
getsockopt(2), or
setsockopt(2).
January 27, 2007 | NetBSD 9.2 |