1BINDRESVPORT(3) Linux Programmer's Manual BINDRESVPORT(3)
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6 bindresvport - bind a socket to a privileged IP port
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9 #include <sys/types.h>
10 #include <netinet/in.h>
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12 int bindresvport(int sockfd, struct sockaddr_in *sin);
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15 bindresvport() is used to bind a socket descriptor to a privileged
16 anonymous IP port, that is, a port number arbitrarily selected from the
17 range 512 to 1023.
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19 If the bind(2) performed by bindresvport() is successful, and sin is
20 not NULL, then sin->sin_port returns the port number actually allo‐
21 cated.
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23 sin can be NULL, in which case sin->sin_family is implicitly taken to
24 be AF_INET. However, in this case, bindresvport() has no way to return
25 the port number actually allocated. (This information can later be
26 obtained using getsockname(2).)
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29 bindresvport() returns 0 on success; otherwise -1 is returned and errno
30 set to indicate the cause of the error.
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33 bindresvport() can fail for any of the same reasons as bind(2). In
34 addition, the following errors may occur:
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36 EACCES The caller did not have superuser privilege (to be precise: the
37 CAP_NET_BIND_SERVICE capability is required).
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39 EADDRINUSE
40 All privileged ports are in use.
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42 EAFNOSUPPORT (EPFNOSUPPORT in glibc 2.7 and earlier)
43 sin is not NULL and sin->sin_family is not AF_INET.
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46 Not in POSIX.1-2001. Present on the BSDs, Solaris, and many other sys‐
47 tems.
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50 Unlike some bindresvport() implementations, the glibc implementation
51 ignores any value that the caller supplies in sin->sin_port.
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54 bind(2), getsockname(2)
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57 This page is part of release 3.22 of the Linux man-pages project. A
58 description of the project, and information about reporting bugs, can
59 be found at http://www.kernel.org/doc/man-pages/.
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63 2008-12-03 BINDRESVPORT(3)