1libval_shim(3)                Programmer's Manual               libval_shim(3)
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NAME

6                             The Validator Shim Library
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DESCRIPTION

9       The validator shim library (libval_shim.so) is a shared library
10       designed to be dynamically loaded using the 'LD_PRELOAD' mechanism
11       (ld.so(8)) supported on linux and various other unix-like platforms.
12       The shim library implements wrappers for a number of DNS related
13       functions and in turn calls equivalent DNSSEC-aware validating
14       functions from libval(3), mapping the results to return codes
15       recognized by the original functions. In this way a wide variety of
16       applications can be made DNSSEC aware without code changes and
17       recompilation.
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19       The method of mapping return codes assumes that any 'untrusted' or
20       failure result from the libval(3) function is reflected as a failure to
21       the original calling function.
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23   Usage:
24       To load the library set LD_PRELOAD variable within the environment of
25       the the target application prior to execution:
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27   Validation Policy:
28       The validator shim library will create a policy context and cache it
29       for all subsequent libval(3) calls. A NULL policy label will be passed
30       to create the context. The policy is chosen according to rules defined
31       for libval(3).
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33       See dnsval.conf(1) for information on policy labels and definition.
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35   Logging:
36       Logging for the libval(3) functions may be enabled in the shim library
37       by setting an environment variable.
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39       See dt-validate(1) for specifics.
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NOTES

42   setuid/setgid programs
43       setuid and setgid root programs (e.g., ping(8)) do not honor the
44       LD_PRELOAD setting. These application may still use the LD_PRELOAD
45       mechanism when run directly from a root shell.
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48       Copyright 2004-2013 SPARTA, Inc.  All rights reserved.  See the COPYING
49       file included with the dnssec-tools package for details.
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AUTHORS

52       G. S. Marzot
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SEE ALSO

55       libsres(3), libval(3), dnsval.conf(1), gethostbyname(3)
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57       gethostbyaddr(3), getnameinfo(3), getaddrinfo(3), res_query(3)
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61perl v5.18.4                      2015-04-27                    libval_shim(3)
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