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I
inet6_rthdr_getflags()
Get the flags for a segment in an IPv6 routing header

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        Append IPv6 hop-by-hop or destination options into ancillary data object
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        Search for IPv6 hop-by-hop and destination options
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        Initialize an ancillary data object that contains IPv6 hop-by-hop and destination options
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        Find the next IPv6 hop-by-hop or destination option
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        Determine how much space an IPv6 hop-by-hop or destination option requires
      - inet6_rthdr_add()
        Add an address to an IPv6 routing header
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        Get a pointer to an IPv6 address in the routing header
      - inet6_rthdr_getflags()
        Get the flags for a segment in an IPv6 routing header
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        Initialize an IPv6 routing header
      - inet6_rthdr_lasthop()
        Specify the Strict/Loose flag for the final hop of an IPv6 routing header
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        Reverse the list of addresses in an IPv6 router header
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        Count the segments in an IPv6 routing header
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        Determine the space required by an IPv6 routing header
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        Verify a client's ability to open or to create a resource
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        Default handler for _IO_CONNECT messages
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        Increment count and locking flags
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        Default handler for _IO_OPENFD messages
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        Support pathconf() requests
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        Default handler for _IO_PATHCONF messages
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        Default handler for _IO_READ messages
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        Verify a client's read access to a resource
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        Verify the attributes being used to read a link
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        Do permission checks for a _IO_CONNECT_RENAME message
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        Do permission checks for the _IO_SPACE message
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        Populate a stat structure
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        Default handler for _IO_STAT messages
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        Indicate if synchronization is needed
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        Default handler for _IO_SYNC messages
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        Verify permissions to sync
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        Update time stamps
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        Unblock OCBs
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        Default unblock handler
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        Verify that an entry can be unlinked
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        Default handler for the unlock_ocb callout
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        Update time stamps
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        Default handler for _IO_UTIME messages
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        Default handler for _IO_WRITE messages
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        Verify a client's write access to a resource
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        Arm a resource manager
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        Internet security protocol
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        Generate a readable string from an IPsec policy specification
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        Get the length of the IPsec policy
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        Generate an IPsec policy specification structure from a readable string
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        Error messages for IPsec policy manipulation library
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        Internet Protocol version 6
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        Test a character to see if it's alphanumeric
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        Test a character to see if it's a control character
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        Test a character to see if it's a decimal digit
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        Test the file type of a file descriptor
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        Determine if a number is finite
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        Test a character to see if it's any printable character except a space
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        Determine whether one floating-point number is greater than another
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        Determine whether one floating-point number is greater than or equal to another
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        Test for infinity
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        Determine whether one floating-point number is less than another
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        Determine whether one floating-point number is less than or equal to another
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        Determine whether one floating-point number is less than or greater than another
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        Test a character to see if it's a lowercase letter
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        Test for not-a-number (NaN)
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        Determine whether a floating-point number is normal
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        Determine whether two floating-point numbers are unordered
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        Convert an integer into a string, using a given base
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inet6_rthdr_getflags()

Get the flags for a segment in an IPv6 routing header

Synopsis:

#include <netinet/in.h>

int inet6_rthdr_getflags( const struct cmsghdr *cmsg, 
                          int index);

Arguments:

cmsg: A pointer to the ancillary data containing the routing header.
index: A value between 0 and the number returned by inet6_rthdr_segments().

Library:

libsocket

Use the -l socket option to qcc to link against this library.

Description:

This function returns the flags for the segment specified by index in the routing header described by cmsg. The index must have a value between 0 and the number returned by inet6_rthdr_segments().

Note:

Addresses are indexed starting at 1, and flags starting at 0. They're consistent with the terminology and figures in RFC2460.

Based on:

W. Stevens and M. Thomas, Advanced Sockets API for IPv6, RFC 2292, February 1998. Contains good examples.
S. Deering and R. Hinden, Internet Protocol, Version 6 (IPv6) Specification, RFC 2460, December 1998.

Returns:

IPV6_RTHDR_LOOSE or IPV6_RTHDR_STRICT for an IPv6 Type 0 routing header, or -1 if an error occurred.

Classification:


Safety:
Cancellation point	No
Interrupt handler	No
Signal handler	Yes
Thread	Yes

Page updated: March 12, 2026