Manpage of BINDRESVPORT

BINDRESVPORT

Section: Linux Programmer's Manual (3)
Updated: 2015-03-02
Index
 

NAME

bindresvport - bind a socket to a privileged IP port  

SYNOPSIS

#include <sys/types.h>#include <netinet/in.h>int bindresvport(int sockfd, struct sockaddr_in *sin);
 

DESCRIPTION

bindresvport() is used to bind the socket referred to by the file descriptor sockfdto a privileged anonymous IP port, that is, a port number arbitrarily selected from the range 512 to 1023.

If the bind(2) performed by bindresvport() is successful, and sinis not NULL, then sin->sin_portreturns the port number actually allocated.

sincan be NULL, in which case sin->sin_familyis implicitly taken to be AF_INET. However, in this case, bindresvport() has no way to return the port number actually allocated. (This information can later be obtained using getsockname(2).)  

RETURN VALUE

bindresvport() returns 0 on success; otherwise -1 is returned and errnoset to indicate the cause of the error.  

ERRORS

bindresvport() can fail for any of the same reasons as bind(2). In addition, the following errors may occur:
EACCES
The caller did not have superuser privilege (to be precise: the CAP_NET_BIND_SERVICEcapability is required).
EADDRINUSE
All privileged ports are in use.
EAFNOSUPPORT (EPFNOSUPPORT in glibc 2.7 and earlier)
sinis not NULL and sin->sin_familyis not AF_INET.
 

ATTRIBUTES

For an explanation of the terms used in this section, see attributes(7).
InterfaceAttributeValue
bindresvport() Thread safetyglibc >= 2.17: MT-Safe
glibc < 2.17: MT-Unsafe

The bindresvport() function uses a static variable that was not protected by a lock before glibc 2.17, rendering the function MT-Unsafe.  

CONFORMING TO

Not in POSIX.1. Present on the BSDs, Solaris, and many other systems.  

NOTES

Unlike some bindresvport() implementations, the glibc implementation ignores any value that the caller supplies in sin->sin_port.  

SEE ALSO

bind(2), getsockname(2)


 

Index

NAME
SYNOPSIS
DESCRIPTION
RETURN VALUE
ERRORS
ATTRIBUTES
CONFORMING TO
NOTES
SEE ALSO

This document was created by man2html, using the manual pages.
Time: 22:28:00 GMT, June 20, 2016