SecuritySNACCRuntime/c-examples/any/README

   1 (RCS control information is at the end of this file.)
   2
   3
   4 C ANY example README
   5 ------------------
   6
   7 This example shows how the snacc compiler handles the ANY DEFINED BY
   8 type in C.  ANY types (not ANY DEFINED BY) require the modifications
   9 to the generated code.  Type "make" to build this example.
  10
  11 This directory should have the following files in it:
  12
  13         README
  14         genber.c
  15         example.c
  16         makefile
  17
  18 There are 3 programs generated by the makefile:
  19
  20         genber - builds a BER value of the AnyTestType and writes it
  21                  to a file called "att.ber"
  22
  23         def    - takes file name of an AnyTestType value.  Decodes the
  24                  file and re-encodes it to stdout.  Uses definite
  25                  lengths for constructed values.
  26
  27         indef  - takes file name of an AnyTestType value.  Decodes the
  28                  file and re-encodes it to stdout.  Uses indefinite
  29                  lengths for constructed values.
  30
  31
  32 These files use the code generated by snacc from the
  33 snacc/asn1specs/any.asn1 file. (see the makefile)
  34
  35 Look at genber.c to see how values can be built and printed.
  36
  37 Look at the generated code in any_test.c and any_test.h to see how the
  38 any hash table is built.
  39
  40
  41 try the following commands in your c-shell:
  42
  43 %1 genber                   # generate the att.ber file
  44 %2 indef att.ber > tmp.ber  # decode att.ber an re-encode into tmp.ber
  45 %3 def tmp.ber > tmp2.ber   # decode tmp.ber an re-encode into tmp2.ber
  46 %4 diff att.ber tmp2.ber    # compare .ber files (should be the same)
  47
  48 When you are finished with the example type "make clean"  to remove
  49 the binaries and generated code.
  50
  51
  52
  53 Things To Note
  54 --------------
  55
  56 Snacc ASN.1 comment commands
  57
  58 In the snacc/asn1specs/any.asn1 file, the AnyTestType has a special
  59 "--snacc" ASN.1 comment after ::= to give snacc some extra information
  60 about the AnyTestType.
  61
  62 AnyTestType ::= --snacc isPdu:"TRUE" -- SEQUENCE { ... etc. ... }
  63
  64 The "isPdu" flag tells snacc that the AnyTestType is a PDU type that
  65 you will be calling the encoding and decoding routines directly
  66 from your code.  This causes snacc to generate the "BEncAnyTestType"
  67 and "BDecAnyTestType" routines in addition to the standard
  68 "BEncAnyTestTypeContent" and "BDecAnyTestTypeContent".
  69
  70 The Content encoding and decoding routines only deal with the content
  71 of the type, ignoring all of the tag and length pairs on the given
  72 type (in this case the UNIVERSAL (CONSTRUCTED) 16 tag and the length
  73 for the SEQUENCE).  The "BEncAnyTestType" and "BDecAnyTestType"
  74 routines do encode the SEQUENCE tag and its length.  This design is
  75 motivated by IMPLICIT tagging.
  76
  77 The compiler generated routines generally only call the content
  78 oriented routines except in the case of ANY and ANY DEFINED BY types.
  79 For ANY and ANY DEFINED BY types the PDU form of the rouine is called
  80 since the tags are not known by the containing type.
  81
  82
  83 SNMP OBJECT-TYPE Macro
  84
  85 The SNMP OBJECT-TYPE macro is used to define the id to type mapping
  86 for ANY DEFINED BY types.  The macro has been modified to accept both
  87 INTEGERs and OBJECT IDENTIFIERs as values (see
  88 snacc/asn1specs/any.asn1).  This macro can be used with other
  89 protocols to define the id to type mapping.
  90
  91 Two hash tables are used to hold the id to type mappings. One for
  92 INTEGER to type mappings and the other for OBJECT IDENTIFIER to type
  93 mappings.  You must explicitly initialize the hash tables by calling
  94 generated init routines once at the beginning of your program.  Each
  95 module that has OBJECT-TYPE macros in it will generate an
  96 "InitAny<module name>" routine.  You must call every init routine to
  97 add all the mappings to the hash table(s).
  98
  99 #-------------------------------------------------------------------------------
 100 # $Header: /cvs/Darwin/src/live/Security/SecuritySNACCRuntime/c-examples/any/README,v 1.1.1.1 2001/05/18 23:14:07 mb Exp $
 101 # $Log: README,v $
 102 # Revision 1.1.1.1  2001/05/18 23:14:07  mb
 103 # Move from private repository to open source repository
 104 #
 105 # Revision 1.1.1.1  1999/03/16 18:06:08  aram
 106 # Originals from SMIME Free Library.
 107 #
 108 # Revision 1.2  1997/02/16 20:26:14  rj
 109 # check-in of a few cosmetic changes
 110 #
 111 # Revision 1.1  1994/08/31  08:46:17  rj
 112 # first check-in. for a list of changes to the snacc-1.1 distribution please refer to the ChangeLog.
 113 #