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gerrit.osmocom.org / asn1c / refs/heads/aper
commit539d484434be91eeab55e0eff3ce63cfe3a2453a[log] [tgz]
authorroux <roux@mycompany.com>Sat Apr 30 16:03:12 2016 +0200
committerHarald Welte <laforge@gnumonks.org>Sat Apr 30 17:37:56 2016 +0200
treec3a2c6bad6693eef1b6999232012546a7025c616
parent50823b81391418465f378a73aa4a3e92af6d0f27 [diff]
Fix a bug in asn1c PER code when skipping unknown extension

Basically when skiping an unknown extension, asn1c did read 24 bits per
24 bits and later on failed if the remaining bits (up to 23) were
superior to 8.  The patch reads 1 bit per 1 bit.

(imported from openairinterface5g/openair2/RRC/LITE/MESSAGES/asn1c/asn1cpatch.p0)
1 file changed
tree: c3a2c6bad6693eef1b6999232012546a7025c616
  1. asn1c/
  2. doc/
  3. examples/
  4. libasn1compiler/
  5. libasn1fix/
  6. libasn1parser/
  7. libasn1print/
  8. m4/
  9. skeletons/
  10. tests/
  11. .gitignore
  12. .travis.yml
  13. asn1c.spec.in
  14. AUTHORS
  15. BUGS
  16. ChangeLog
  17. config.sub
  18. configure.ac
  19. COPYING
  20. depcomp
  21. FAQ
  22. INSTALL
  23. Makefile.am
  24. MANIFEST
  25. README.md
  26. stamp-h.in
  27. TODO
README.md

Installation

If you haven't installed the asn1c yet, read the INSTALL file for a short installation guide.

Documentation

For the list of asn1c command line options, see asn1c -h or man asn1c.

The comprehensive documentation on this compiler is in asn1c-usage.pdf.

If you are building the compiler from the sources, the PDFs reside in the ./doc directory. Normally the file is installed together with the README.md file you're reading right now.

Please also read the FAQ file.

An excellent book on ASN.1 is written by Olivier Dubuisson: "ASN.1 Communication between heterogeneous systems", ISBN:0-12-6333361-0.

Quick start

(also check out asn1c-quick.pdf)

After building [and installing] the compiler (see INSTALL), you may use the asn1c command to compile the ASN.1 specification:

asn1c <module.asn1>                         # Compile module

If several specifications contain interdependencies, all of them must be specified:

asn1c <module1.asn1> <module2.asn1> ...     # Compile interdependent modules

If you are building the asn1c from the sources, the ./examples directory contains several ASN.1 modules and a script to extract the ASN.1 modules from RFC documents. Refer to the README file in that directory. To compile the X.509 PKI module:

./asn1c/asn1c -P ./examples/rfc3280-*.asn1  # Compile-n-print

In this example, -P option is used to instruct the compiler to print the compiled text on the standard output instead of creating multiple .c and .h files for every ASN.1 type found inside the specified ASN.1 modules. This is useful for debugging and test automation.

The compiler -E and -EF options are used for testing the parser and the semantic fixer, respectively. These options will instruct the compiler to dump out the parsed (and fixed) ASN.1 specification as it was "understood" by the compiler. It might be useful for checking whether a particular syntactic construction is properly supported by the compiler.

asn1c -EF <module-to-test.asn1>     # Check semantic validity

Model of operation

The asn1c compiler works by processing the ASN.1 module specifications in several stages:

  1. In the first stage, the ASN.1 file is parsed. (Parsing produces an ASN.1 syntax tree for the subsequent levels)
  2. In the second stage, the syntax tree is "fixed". (Fixing is a process of checking the tree for semantic errors, accompanied by the tree transformation into the canonical form)
  3. In the third stage, the syntax tree is compiled into the target language.

There are several command-line options reserved for printing the results after each stage of operation:

<parser> => print                                       (-E)
<parser> => <fixer> => print                            (-E -F)
<parser> => <fixer> => <compiler> => print              (-P)
<parser> => <fixer> => <compiler> => save-compiled      [default]

-- Lev Walkin vlm@lionet.info