BINDRESVPORT(3) BSD Programmer's Manual BINDRESVPORT(3)
bindresvport, bindresvport_sa - bind a socket to a privileged IP port
#include <sys/types.h>
#include <netinet/in.h>
int
bindresvport(int sd, struct sockaddr_in *sin);
int
bindresvport_sa(int sd, struct sockaddr *sa);
The bindresvport() and bindresvport_sa() functions are used to bind a
socket descriptor to a privileged IP port, that is, a port number in the
range 0-1023. The bindresvport() function operates solely on AF_INET
sockets, whereas the bindresvport_sa() function is capable of binding
both AF_INET and AF_INET6 sockets.
Only the superuser may bind to a privileged port; these functions will
fail for any other user.
sd should be a socket descriptor that was returned by a call to
socket(2).
If sin is not the NULL pointer, sin->sin_family must be initialized to
the address family of the socket sd. If the value of sin->sin_port is
non-zero, bindresvport() will attempt to use the specified port. Other-
wise, a free port in the range 600-1023 will be chosen and, if the
bind(2) succeeds, sin->sin_port will be updated with the port that was
assigned.
If sin is the NULL pointer, a free port in the range 600-1023 will be
chosen (as above), but in this case there is no way for bindresvport() to
communicate to the caller which port was assigned.
bindresvport() returns 0 if it is successful, otherwise -1 is returned
and errno set to reflect the cause of the error.
The bindresvport() function fails if:
[EBADF] sd is not a valid descriptor.
[ENOTSOCK] sd is not a socket.
[EADDRNOTAVAIL]
The specified address is not available from the local
machine.
[EADDRINUSE] The specified address is already in use.
[EINVAL] The socket is already bound to an address.
[EINVAL] The family of the socket and that requested in sa-
>sa_family are not equivalent.
[EACCES] The requested address is protected, and the current user
has inadequate permission to access it.
[EFAULT] The name parameter is not in a valid part of the user ad-
dress space.
[ENOBUFS] Insufficient resources were available in the system to per-
form the operation.
[EPFNOSUPPORT]
The protocol family has not been configured into the sys-
tem, no implementation for it exists, or address family did
not match between arguments.
bind(2), socket(2), rresvport(3), rresvport_af(3)
MirBSD #10-current August 9, 1997 1