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BINDRESVPORT(3) | Library Functions Manual | BINDRESVPORT(3) |
NAME¶
bindresvport
,
bindresvport_sa
—
bind a socket to a privileged IP port
SYNOPSIS¶
#include
<sys/types.h>
#include
<rpc/rpc.h>
int
bindresvport
(int
sd, struct
sockaddr_in *sin);
int
bindresvport_sa
(int
sd, struct
sockaddr *sa);
DESCRIPTION¶
Thebindresvport
() 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.
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
an anonymous 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, an anonymous port will be
allocated (as above). However, there is no way for
bindresvport
() to return the allocated port
in this case.
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. The
bindresvport_sa
() function 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.
RETURN VALUES¶
Thebindresvport
() function returns the
value 0 if successful; otherwise the value -1 is returned and
the global variable errno is set to indicate
the error.
ERRORS¶
- [
EPFNOSUPPORT
] - If second argument was supplied, and address family did not match between arguments.
bindresvport
() function may also fail and
set errno for any of the errors specified for
the calls bind(2),
getsockopt(2), or
setsockopt(2).
AVAILABILITY¶
Thebindresvport
() function is part of
libtirpc.
SEE ALSO¶
bind(2), getsockopt(2), setsockopt(2)November 22, 1987 | Debian |