
The Xprint Module

Elena-Ramona Modroiu

   Asipto

   Copyright © 2003 FhG FOKUS
     _________________________________________________________________

   Table of Contents

   1. Admin Guide

        1. Overview
        2. Implemented Specifiers
        3. Parameters

              3.1. buf_size (integer)

        4. Functions

              4.1. xplog(level, format) 
              4.2. xpdbg(format) 

   2. Developer Guide

        1. Module API

              1.1. Functions

                    1.1.1. int xbind(xl_api_t *xl_api) 
                    1.1.2. int xparse(char *s, xl_elog_p *el) 
                    1.1.3. int shm_xparse(char *s, xl_elog_p *el) 
                    1.1.4. int xparse2(char *s, xl_elog_p *el,
                            xl_parse_cb cb) 

                    1.1.5. int shm_xparse2(char *s, xl_elog_p *el,
                            xl_parse_cb cb) 

                    1.1.6. xfree(xl_elog_p el) 
                    1.1.7. shm_xfree(xl_elog_p el) 
                    1.1.8. int xprint(struct sip_msg* msg, xl_elog_p el,
                            char *buf, int *len) 

                    1.1.9. str *xnulstr() 

   List of Examples

   1.1. Set buf_size parameter
   1.2. xplog usage
   1.3. xpdbg usage

Chapter 1. Admin Guide

   Table of Contents

   1. Overview
   2. Implemented Specifiers
   3. Parameters

        3.1. buf_size (integer)

   4. Functions

        4.1. xplog(level, format) 
        4.2. xpdbg(format) 

1. Overview

   IMPORTANT:  this  is  former xlog module from SIP Express Router (SER)
   kept  because it is used by other modules via API to get the value for
   strings  with  specifiers.  If  you  want  to  print log messages from
   configuration file, use the real module named 'xlog'.

   This  module  provides  the possibility to print user formatted log or
   debug  messages from SER scripts, similar to printf function but now a
   specifier  is  replaced  with  a  part  of the SIP request. Section 2,
   "Implemented Specifiers" shows what can be printed out.

2. Implemented Specifiers

     * %% : '%'
     * %br : request's first branch
     * %bR : request's all branches
     * %ci : call-id
     * %cs : cseq
     * %ct : contact header
     * %Cxy  :  color  printing based on escape sequences (x - foreground
       color,  y  - background color). The values for colors: x - default
       color  of the terminal; s - Black; r - Red; g - Green; y - Yellow;
       b - Blue; p - Purple; c - Cyan; w - White
     * %ds : destination set
     * %fu : 'From' uri
     * %ft : 'From' tag
     * %Hn  :  host's  hostname  (if system hostname is FQDN, part before
       first .)
     * %Hd : host's domain (if system hosntame is FQDN, part behind first
       .)
     * %Hf : host's FQDN hostname
     * %Hi : host's IP address
     * %mb : whole SIP message buffer
     * %mf : flags set for current SIP request
     * %mi : SIP message id
     * %ml : SIP message length
     * %mx : SIP message id (in hex notation)
     * %nh : message's next hop
     * %pp : process id (pid)
     * %px : process id (pid) (in hex notation)
     * %rm : request's method
     * %ru : request's r-uri
     * %rr : reply's reason
     * %rs : reply's status
     * %rt : 'Refer-To' uri
     * %Ri  :  IP  address  of  the  interface where the request has been
       received
     * %Rp : received port
     * %si : IP source address
     * %sp : source port
     * %tu : 'To' uri
     * %tt : 'To' tag
     * %Ts : unix time stamp
     * %Tf : string formatted time
     * %Tx : unix time stamp (in hex notation)
     * %ua : User agent header field
     * %uq : unique id (per SER's process) - to make really unique id use
       %uq-%px-%mx or %uq-%px-%Tx
     * %{name[N]}  :  print  the  body  of  the  Nth header identified by
       'name'.  If  [N]  is  omitted then the body of the first header is
       printed.  The  first  header  is got when N=0, for the second N=1,
       a.s.o.  To  print  the  last header of that type, use -1, no other
       negative  values  are  supported  now. No white spaces are allowed
       inside  the specifier (before }, before or after {, [, ] symbols).
       When N='*', all headers of that type are printed.
       The  module should identify most of compact header names (the ones
       recognized by ser which should be all at this moment), if not, the
       compact form has to be specified explicitely. It is recommended to
       use  dedicated  specifiers  for  headers (e.g., %ua for user agent
       header), if they are available -- they are faster.
     * %<name[N]> : print the value of AVP optionally %indexed by the [N]
       value It uses AVPs subindexing, e.g. if you don't specify subindex
       and there are more AVPs with the same name, the result is NULL. To
       specify  first  AVP  use  [1], negative values are indexes counted
       backward through the list.
     * %@select.framework[N].value  : print the value of select framework
       call.  For  detailed  info  what  calls  are  available see select
       framework documentation (and modules documentation, as modules can
       extend select framework calls).
     * %| or %(space) : end of %@select.framework identifier. If you need
       to  concatenate  select  framework call and another non-whitespace
       literal,  you  need  to  explicitelly  set  the  end of the select
       framework identifier.
       E.g.  %@ruri.user%|@%@ruri.host  converts all featured request uri
       into user@host form only.

3. Parameters

   3.1. buf_size (integer)

3.1. buf_size (integer)

   Maximum size of the log message.

   Default value is 4096.

   Example 1.1. Set buf_size parameter
...
modparam("xprint", "buf_size", 8192)
...

4. Functions

   4.1. xplog(level, format) 
   4.2. xpdbg(format) 

4.1.  xplog(level, format)

   Print a formated message using LOG function.

   Meaning of the parameters is as follows:
     * level - The level that will be used in LOG function. It can be:
          + L_ALERT
          + L_CRIT
          + L_ERR
          + L_WARN
          + L_NOTICE
          + L_INFO
          + L_DBG
       What really matters is the third letter of the value.
     * format - The formatted string to be printed.

   Example 1.2. xplog usage
...
xplog("L_ERR", "time [%Tf] method <%rm> r-uri <%ru> 2nd via <%{via[1]}>\n");
...

4.2.  xpdbg(format)

   Print a formatted message using DBG function.

   Meaning of the parameters is as follows:
     * format - The formatted string to be printed.

   Example 1.3. xpdbg usage
...
xpdbg("time [%Tf] method <%rm> r-uri <%ru>\n");
...

Chapter 2. Developer Guide

   Table of Contents

   1. Module API

        1.1. Functions

              1.1.1. int xbind(xl_api_t *xl_api) 
              1.1.2. int xparse(char *s, xl_elog_p *el) 
              1.1.3. int shm_xparse(char *s, xl_elog_p *el) 
              1.1.4. int xparse2(char *s, xl_elog_p *el, xl_parse_cb cb) 
              1.1.5. int shm_xparse2(char *s, xl_elog_p *el, xl_parse_cb
                      cb) 

              1.1.6. xfree(xl_elog_p el) 
              1.1.7. shm_xfree(xl_elog_p el) 
              1.1.8. int xprint(struct sip_msg* msg, xl_elog_p el, char
                      *buf, int *len) 

              1.1.9. str *xnulstr() 

1. Module API

   1.1. Functions

        1.1.1. int xbind(xl_api_t *xl_api) 
        1.1.2. int xparse(char *s, xl_elog_p *el) 
        1.1.3. int shm_xparse(char *s, xl_elog_p *el) 
        1.1.4. int xparse2(char *s, xl_elog_p *el, xl_parse_cb cb) 
        1.1.5. int shm_xparse2(char *s, xl_elog_p *el, xl_parse_cb cb) 
        1.1.6. xfree(xl_elog_p el) 
        1.1.7. shm_xfree(xl_elog_p el) 
        1.1.8. int xprint(struct sip_msg* msg, xl_elog_p el, char *buf,
                int *len) 

        1.1.9. str *xnulstr() 

1.1. Functions

1.1.1.  int xbind(xl_api_t *xl_api)

   Bind to the xprint module API.

   Meaning of the parameters is as follows:
     * xl_api  -  structure that the xprint module functions are bind to.
       The    functions    can    be    executed    as   xl_api.xparse(),
       xl_api.xprint()...

   Return value: 0 - success, <0 - error.

1.1.2.  int xparse(char *s, xl_elog_p *el)

   Parse an xl-formatted string in private memory.

   Meaning of the parameters is as follows:
     * s - string to be parsed.
     * el - returned xl-lib list.

   Return value: 0 - success, <0 - error.

1.1.3.  int shm_xparse(char *s, xl_elog_p *el)

   Parse  an  xl-formatted string in shared memory. See xparse() function
   for details.

1.1.4.  int xparse2(char *s, xl_elog_p *el, xl_parse_cb cb)

   Parse  an xl-formatted string in private memory. This function is able
   to  identify  regular  expression back references, for example \1, \2,
   \3...  When  a back reference is found the callback function is called
   that  is  supposed to farther parse the back reference and fill in the
   xl_elog structure.

   Meaning of the parameters is as follows:
     * s - string to be parsed.
     * el - returned xl-lib list.
     * cb  -  callback  function  for parsing the regular expression back
       references.

   The  prototype of the callback function is: typedef int (*xl_parse_cb)
   (str *s, int shm, xl_elog_p el);

   Parameters of the callback function:
     * s  -  regular  expression back reference to be parsed (without the
       leading '\' character).
     * shm - indicates whether or not shared memory needs to be used. (1:
       shared memory, 0: private memory)
     * el - pointer to the xl-lib list item that is supposed to be filled
       in.

   Return value: 0 - success, <0 - error.

1.1.5.  int shm_xparse2(char *s, xl_elog_p *el, xl_parse_cb cb)

   Parse  an  xl-formatted  string  in  shared  memory supporting regular
   expression back references. See xparse2() function for details.

1.1.6.  xfree(xl_elog_p el)

   Free the xl-lib list allocated by xparse() or xparse2().

   Meaning of the parameters is as follows:
     * el - xl-lib list to be freed.

1.1.7.  shm_xfree(xl_elog_p el)

   Free the xl-lib list allocated by shm_xparse() or shm_xparse2().

   Meaning of the parameters is as follows:
     * el - xl-lib list to be freed.

1.1.8.  int xprint(struct sip_msg* msg, xl_elog_p el, char *buf, int *len)

   Evaluate the xl-formatted string and print the result into a buffer.

   Meaning of the parameters is as follows:
     * msg - SIP message pointer.
     * el - xl-lib list to be evaluated.
     * buf - pre-allocated buffer that is filled in with the result.
     * len  -  length  of  the printed string. len needs to be set to the
       maximum length of the result buffer before calling this function.

   Return value: 0 - success, <0 - error.

1.1.9.  str *xnulstr()

   Return the string "<null>".
