README

Textopsx Module

Andrei Pelinescu-Onciul

   FhG FOKUS

Daniel-Constantin Mierla

   asipto.com
   <miconda@gmail.com>

   Copyright © 2003 FhG FOKUS
     __________________________________________________________________

   Table of Contents

   1. Admin Guide

        1. Overview
        2. Functions

              2.1. msg_apply_changes()
              2.2. change_reply_status(code, reason)
              2.3. change_reply_status_code(vcode)
              2.4. remove_body()
              2.5. keep_hf([regexp])
              2.6. fnmatch(value, expr [, flags])
              2.7. append_hf_value(hf, hvalue)
              2.8. insert_hf_value(hf, hvalue)
              2.9. remove_hf_value(hf_par)
              2.10. remove_hf_value2(hf_par)
              2.11. assign_hf_value(hf, hvalue)
              2.12. assign_hf_value2(hf, hvalue)
              2.13. include_hf_value(hf, hvalue)
              2.14. exclude_hf_value(hf, hvalue)
              2.15. hf_value_exists(hf, hvalue)
              2.16. hf_iterator_start(iname)
              2.17. hf_iterator_end(iname)
              2.18. textopsx.f.hf_iterator_next(iname)
              2.19. hf_iterator_rm(iname)

        3. Selects

              3.1. @hf_value
              3.2. @hf_value2
              3.3. @hf_value_exists

   List of Examples

   1.1. msg_apply_changes() usage
   1.2. change_reply_status usage
   1.3. change_reply_status_code usage
   1.4. remove_body() usage
   1.5. keep_hf() usage
   1.6. fnmatch() usage
   1.7. append_hf_value usage
   1.8. insert_hf_value usage
   1.9. remove_hf_value usage
   1.10. remove_hf_value2 usage
   1.11. assign_hf_value usage
   1.12. assign_hf_value2 usage
   1.13. include_hf_value usage
   1.14. exclude_hf_value usage
   1.15. hf_value_exists usage
   1.16. hf_iterator_start usage
   1.17. hf_iterator_end usage
   1.18. hf_iterator_next usage
   1.19. hf_iterator_rm usage
   1.20. @hf_value select usage

Chapter 1. Admin Guide

   Table of Contents

   1. Overview
   2. Functions

        2.1. msg_apply_changes()
        2.2. change_reply_status(code, reason)
        2.3. change_reply_status_code(vcode)
        2.4. remove_body()
        2.5. keep_hf([regexp])
        2.6. fnmatch(value, expr [, flags])
        2.7. append_hf_value(hf, hvalue)
        2.8. insert_hf_value(hf, hvalue)
        2.9. remove_hf_value(hf_par)
        2.10. remove_hf_value2(hf_par)
        2.11. assign_hf_value(hf, hvalue)
        2.12. assign_hf_value2(hf, hvalue)
        2.13. include_hf_value(hf, hvalue)
        2.14. exclude_hf_value(hf, hvalue)
        2.15. hf_value_exists(hf, hvalue)
        2.16. hf_iterator_start(iname)
        2.17. hf_iterator_end(iname)
        2.18. textopsx.f.hf_iterator_next(iname)
        2.19. hf_iterator_rm(iname)

   3. Selects

        3.1. @hf_value
        3.2. @hf_value2
        3.3. @hf_value_exists

1. Overview

   This module implements functions for SIP message text operations in
   routing block configurations. It adds new features similar to the
   textops module (textops eXtentions).

   Note: If you add or remove message parts (header, body etc..) it may be
   required to execute msg_apply_changes() from this module if there are
   other operations done on the SIP message later on.

2. Functions

   2.1. msg_apply_changes()
   2.2. change_reply_status(code, reason)
   2.3. change_reply_status_code(vcode)
   2.4. remove_body()
   2.5. keep_hf([regexp])
   2.6. fnmatch(value, expr [, flags])
   2.7. append_hf_value(hf, hvalue)
   2.8. insert_hf_value(hf, hvalue)
   2.9. remove_hf_value(hf_par)
   2.10. remove_hf_value2(hf_par)
   2.11. assign_hf_value(hf, hvalue)
   2.12. assign_hf_value2(hf, hvalue)
   2.13. include_hf_value(hf, hvalue)
   2.14. exclude_hf_value(hf, hvalue)
   2.15. hf_value_exists(hf, hvalue)
   2.16. hf_iterator_start(iname)
   2.17. hf_iterator_end(iname)
   2.18. textopsx.f.hf_iterator_next(iname)
   2.19. hf_iterator_rm(iname)

2.1.  msg_apply_changes()

   Use this function to apply changes performed on SIP message content. Be
   careful when using this function; due to special handling of changes to
   the SIP message buffer so far, using this function might change the
   behaviour of your config. Do test your config properly!

   The function returns true (1) on success. If it is failure before the
   new content is build, the function returns false (-1), the old content
   is still in place. If parsing of the new content is failing, the
   function stops executions of the config file (the internal structure is
   no longer valid for config processing, like it happens when a broken
   message is received from network).

   This function can be used from REQUEST_ROUTE or core REPLY_ROUTE.

   Note: It must be used before the transaction is created in
   request_route and not inside the onreply_route[name] executed by tm
   module. Also, do not use after resuming a suspended request or reply,
   at that moment the transaction is already created.

   Example 1.1. msg_apply_changes() usage
...
append_hf("My-Header: yes\r\n");
if(msg_apply_changes())
{
    # msg buffer has a new content
    if(is_present_hf("My-Header"))
    {
        # will get here always
    }
}
...

2.2.  change_reply_status(code, reason)

   Intercept a SIP reply (in an onreply_route) and change its status code
   and reason phrase prior to forwarding it.

   Meaning of the parameters is as follows:
     * code - Status code.
     * reason - Reason phrase.

   This function can be used from ONREPLY_ROUTE.

   Example 1.2. change_reply_status usage
...
reply_route {
    if (status == "603") {
        change_reply_status(404, "Not Found");
        exit;
    }
}
...

2.3.  change_reply_status_code(vcode)

   Change the status code for a SIP reply .

   Meaning of the parameters is as follows:
     * vcode - the new status code.

   This function can be used from ONREPLY_ROUTE.

   Example 1.3. change_reply_status_code usage
...
reply_route {
    if (status == "604") {
        change_reply_status_code("404");
        exit;
    }
}
...

2.4.  remove_body()

   Use this function to remove the body of SIP requests or replies.

   This function can be used from ANY_ROUTE.

   Example 1.4. remove_body() usage
...
remove_body();
...

2.5.  keep_hf([regexp])

   Remove headers that don't match the regular expression regexp. Several
   header are ignored always (thus not removed): Via, From, To, Call-ID,
   CSeq, Content-Length, Content-Type, Max-Forwards, Contact, Route,
   Record-Route -- these can be removed one by one with remove_hf(). If
   regexp is missing, then only the headers listed above are kept, the
   rest are removed.

   This function can be used from ANY_ROUTE.

   Example 1.5. keep_hf() usage
...
keep_hf("User-Agent");
...

2.6.  fnmatch(value, expr [, flags])

   Match the value against the expr using shell-style pattern for file
   name matching (see man page for C function fnmatch()). It is known to
   be faster and use less-memory than regular expressions.

   Parameter 'flags' is optional and can be 'i' to do case insensitive
   matching.

   This function can be used from ANY_ROUTE.

   Example 1.6. fnmatch() usage
...
if(fnmatch("$rU", "123*"))
{
    ...
}
...

2.7.  append_hf_value(hf, hvalue)

   Append new header value after an existing header, if no index acquired
   append at the end of list. Note that a header may consist of comma
   delimited list of values.

   Meaning of the parameters is as follows:
     * hf - Header field to be appended. Format: HFNAME [ [IDX] ]. If
       index is not specified new header is inserted at the end of
       message. The index 1 correxponds to the first header.
     * hvalue - Value to be added, config var formatting supported.

   Example 1.7. append_hf_value usage
...
append_hf_value("foo", "gogo;stamp=$Ts")   # add new header
append_hf_value("foo[1]", "gogo")  # add new value behind first value
append_hf_value("foo[-1]", "$var(Bar)") # try add value to the last header, if n
ot exists add new header
...

2.8.  insert_hf_value(hf, hvalue)

   Insert new header value before an existing header, if no index acquired
   insert before first hf header. Note that a header may consist of comma
   delimited list of values. To insert a value behind the last value use
   append_hf_value.

   Meaning of the parameters is as follows:
     * hf - Header field to be appended. Format: HFNAME [ [IDX] ]. If
       index is not specified new header is inserted at the top of
       message. The index 1 correxponds to the first header.
     * hvalue - Value to be added, config var formatting supported.

   Example 1.8. insert_hf_value usage
...
insert_hf_value("foo[2]", "gogo")
insert_hf_value("foo", "$avp(foo)")   # add new header at the top of list
insert_hf_value("foo[1]", "gogo") # try add to the first header
...

2.9.  remove_hf_value(hf_par)

   Remove the header value from existing header, Note that a header may
   consist of comma delimited list of values.

   Meaning of the parameters is as follows:
     * hf_par - Header field/param to be removed. Format: HFNAME [ [IDX] ]
       [. PARAM ] If asterisk is specified as index then all values are
       affected. The index 1 correxponds to the first header.

   Example 1.9. remove_hf_value usage
...
remove_hf_value("foo")  # remove foo[1]
remove_hf_value("foo[*]")  # remove all foo's headers
remove_hf_value("foo[-1]") # last foo
remove_hf_value("foo.bar")  # delete parameter
remove_hf_value("foo[*].bar") # for each foo delete bar parameters
...

2.10.  remove_hf_value2(hf_par)

   Remove specified header or parameter. It is expected header in
   Authorization format (comma delimiters are not treated as multi-value
   delimiters).

   Meaning of the parameters is as follows:
     * hf_par - Header/param to be removed. Format: HFNAME [ [IDX] ] [.
       PARAM ] If asterisk is specified as index then all values are
       affected. The index 1 correxponds to the first header.

   Example 1.10. remove_hf_value2 usage
...
remove_hf_value2("foo")  # remove foo[1]
remove_hf_value2("foo[*]")  # remove all foo's headers, the same as remove_hf_he
ader("foo[*]");
remove_hf_value2("foo[-1]") # last foo
remove_hf_value2("foo.bar")  # delete parameter
remove_hf_value2("foo[*].bar") # for each foo delete bar parameters
...

2.11.  assign_hf_value(hf, hvalue)

   Assign value to specified header value / param.

   Meaning of the parameters is as follows:
     * hf_para - Header field value / param to be appended. Format: HFNAME
       [ [IDX] ] [. PARAM] If asterisk is specified as index then all
       values are affected. The index 1 correxponds to the first header.
     * hvalue - Value to be assigned, config var formatting supported. If
       value is empty then no equal sign appears in param.

   Example 1.11. assign_hf_value usage
...
assign_hf_value("foo", "gogo")  # foo[1]
assign_hf_value("foo[-1]", "gogo")  # foo[last_foo]

assign_hf_value("foo.bar", "")
assign_hf_value("foo[3].bar", "")
assign_hf_value("foo[*]", "")  # remove all foo's, empty value remains
assign_hf_value("foo[*].bar", "")  # set empty value (ex. lr)
...

2.12.  assign_hf_value2(hf, hvalue)

   Assign value to specified header. It is expected header in
   Authorization format (comma delimiters are not treated as multi-value
   delimiters).

   Meaning of the parameters is as follows:
     * hf_para - Header field value / param to be appended. Format: HFNAME
       [ [IDX] ] [. PARAM] If asterisk is specified as index then all
       values are affected. The index 1 correxponds to the first header.
     * hvalue - Value to be assigned, config var formatting supported. If
       value is empty then no equal sign appears in param.

   Example 1.12. assign_hf_value2 usage
...
assign_hf_value2("Authorization.integrity-protected", "\"yes\"")
assign_hf_value2("foo[-1]", "gogo")  # foo[last_foo]
assign_hf_value2("foo[*].bar", "")  # set empty value (ex. lr)
...

2.13.  include_hf_value(hf, hvalue)

   Add value in set if not exists, eg. "Supported: path,100rel".

   Meaning of the parameters is as follows:
     * hf - Header field name to be affected.
     * hvalue - config var formatting supported.

   Example 1.13. include_hf_value usage
...
include_hf_value("Supported", "path");
...

2.14.  exclude_hf_value(hf, hvalue)

   Remove value from set if exists, eg. "Supported: path,100rel".

   Meaning of the parameters is as follows:
     * hf - Header field name to be affected.
     * hvalue - config formatting supported.

   Example 1.14. exclude_hf_value usage
...
exclude_hf_value("Supported", "100rel");
...

2.15.  hf_value_exists(hf, hvalue)

   Check if value exists in set. Alternate select
   @hf_value_exists.HF.VALUE may be used. It returns one or zero.

   Meaning of the parameters is as follows:
     * hf - Header field name to be affected. Underscores are treated as
       dashes.
     * hvalue - config var formatting supported.

   Example 1.15. hf_value_exists usage
...
if (hf_value_exists("Supported", "100rel")) {

}

if (@hf_value_exists.supported.path == "1") {

}
...

2.16.  hf_iterator_start(iname)

   Start an iterator for headers in the current SIP message. The parameter
   iname is used to identify the iterator. There can be up to 4 iterators
   at the same time, with different name.

   The parameter can be a dynamic string with variables.

   This function can be used from ANY_ROUTE.

   Example 1.16. hf_iterator_start usage
...
hf_iterator_start("i1");
...

2.17.  hf_iterator_end(iname)

   Close the iterator identified by iname parameter. The iname value must
   be the same used for sht_iterator_start().

   The parameter can be dynamic string with variables.

   This function can be used from ANY_ROUTE.

   Example 1.17. hf_iterator_end usage
...
hf_iterator_end("i1");
...

2.18.  textopsx.f.hf_iterator_next(iname)

   Move the iterator to the next header. It must be called also after
   sht_iterator_start() to get the first header.

   The return code is false when there is no other header in the list.

   The item name and value are accessible via variables: $hfitname(iname)
   and $hfitbody(iname).

   The parameter can be dynamic string with variables.

   This function can be used from ANY_ROUTE.

   Example 1.18. hf_iterator_next usage
...
    hf_iterator_start("i1");
    while(hf_iterator_next("i1")) {
        xlog("hdr[$hfitname(i1)] is: $hfitbody(i1)\n");
    }
    hf_iterator_end("i1");
...

2.19.  hf_iterator_rm(iname)

   Remove the header at the current iterator position.

   The parameter can be dynamic string with variables.

   This function can be used from ANY_ROUTE.

   Example 1.19. hf_iterator_rm usage
...
    hf_iterator_start("i1");
    while(hf_iterator_next("i1")) {
        if($hfitname(i1)=="My-Header") {
            hf_iterator_rm("i1");
        }
    }
    hf_iterator_end("i1");
...

3. Selects

   3.1. @hf_value
   3.2. @hf_value2
   3.3. @hf_value_exists

3.1. @hf_value

   Get value of required header-value or param. Note that functions called
   'value2' works with Authorization-like headers where comma is not
   treated as value delimiter. Formats: @hf_value.HFNAME[IDX] # idx value,
   negative value counts from bottom @hf_value.HFNAME.PARAM_NAME
   @hf_value.HFNAME[IDX].PARAM_NAME @hf_value.HFNAME.p.PARAM_NAME # or
   .param., useful if required called "uri", "p", "param"
   @hf_value.HFNAME[IDX].p.PARAM_NAME # dtto @hf_value.HFNAME[IDX].uri #
   (< & > excluded) @hf_value.HFNAME[*] # return comma delimited list of
   all values (combines headers) @hf_value.HFNAME # the same as above [*]
   but may be parsed by cfg.y @hf_value.HFNAME[*].uri # return comma
   delimited list of uris (< & > excluded) @hf_value.HFNAME.uri # the same
   as above [*] but may be parsed by cfg.y @hf_value.HFNAME[IDX].name #
   returns name part, quotes excluded @hf_value.HFNAME.name # returns name
   part of the first value @hf_value2.HFNAME # returns value of first
   header @hf_value2.HFNAME[IDX] # returns value of idx's header
   @hf_value2.HFNAME.PARAM_NAME @hf_value2.HFNAME[IDX].PARAM_NAME
   @hf_value.HFNAME[IDX].uri # return URI, quotes excluded
   @hf_value.HFNAME.p.uri # returns param named uri, not URI itself
   @hf_value.HFNAME.p.name # returns param named name, not name itself
   @hf_value.HFNAME[IDX].uri.name # any sel_any_uri nested features may be
   used @hf_value.HFNAME[IDX].nameaddr.name # select_any_nameaddr

   Meaning of the parameters is as follows:
     * HFNAME - Header field name. Underscores are treated as dashes.
     * IDX - Value index, negative value counts from bottom
     * PARAM_NAME - name of parameter

   Example 1.20. @hf_value select usage
...
$a = @hf_value.my_header[1].my_param;
xplog("L_ERR", "$sel(@hf_value.via[-1]), $sel(@hf_value.from.tag)\n");
$b = @hf_value.p_associated_uri;

xplog("L_ERR", "Route uris: '$sel(@hf_value.route[*].uri)'\n");
$rr = @hf_value.route.uri;

$prt = @hf_value2.authorization.integrity_protected;
...

3.2. @hf_value2

   TBA.

3.3. @hf_value_exists

   TBA.