Textopsx Module

Andrei Pelinescu-Onciul

FhG FOKUS

Daniel-Constantin Mierla

asipto.com

Table of Contents

1. Admin Guide
1. Overview
2. Functions
2.1. msg_apply_changes()
2.2. change_reply_status(code, reason)
2.3. remove_body()
2.4. keep_hf([regexp])
2.5. fnmatch(value, expr [, flags])
2.6. append_hf_value(hf, hvalue)
2.7. insert_hf_value(hf, hvalue)
2.8. remove_hf_value(hf_par)
2.9. remove_hf_value2(hf_par)
2.10. assign_hf_value(hf, hvalue)
2.11. assign_hf_value2(hf, hvalue)
2.12. include_hf_value(hf, hvalue)
2.13. exclude_hf_value(hf, hvalue)
2.14. hf_value_exists(hf, hvalue)
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. remove_body() usage
1.4. keep_hf() usage
1.5. fnmatch() usage
1.6. append_hf_value usage
1.7. insert_hf_value usage
1.8. remove_hf_value usage
1.9. remove_hf_value2 usage
1.10. assign_hf_value usage
1.11. assign_hf_value2 usage
1.12. include_hf_value usage
1.13. exclude_hf_value usage
1.14. hf_value_exists usage
1.15. @hf_value select usage

Chapter 1. Admin Guide

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).

2. Functions

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 If parsing of the new content is failing, the function stops executions of the config file (the internal structure is no longer valid for config processing, like it happens when a broken message is received from network).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.  remove_body()

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

This function can be used from ANY_ROUTE.

Example 1.3. remove_body() usage

...
remove_body();
...

2.4.  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 1.4. keep_hf() usage

...
keep_hf("User-Agent");
...

2.5.  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 1.5. fnmatch() usage

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

2.6.  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.

  • hvalue - Value to be added, config var formatting supported.

Example 1.6. 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 not exists add new header
...

2.7.  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 value behing last value use appenf_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.

  • hvalue - Value to be added, config var formatting supported.

Example 1.7. 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
...

2.8.  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.

Example 1.8. 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
...

2.9.  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.

Example 1.9. 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_header("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
...

2.10.  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.

  • hvalue - Value to be assigned, config var formatting supported. If value is empty then no equal sign apears in param.

Example 1.10. 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)
...

2.11.  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.

  • hvalue - Value to be assigned, config var formatting supported. If value is empty then no equal sign apears in param.

Example 1.11. 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)
...

2.12.  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 1.12. include_hf_value usage

...
include_hf_value("Supported", "path");
...

2.13.  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 1.13. exclude_hf_value usage

...
exclude_hf_value("Supported", "100rel");
...

2.14.  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 1.14. hf_value_exists usage

...
if (hf_value_exists("Supported", "100rel")) {

}

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

}
...

3. Selects

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 requred 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 1.15. @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.