AVPops Module

AVPops (AVP-operations) modules implements a set of script functions which allow access and manipulation of user AVPs (preferences) and pseudo-variables. AVPs are a powerful tool for implementing services/preferences per user/domain. Now they are usable directly from configuration script. Functions for interfacing DB resources (loading/storing/removing), functions for swapping information between AVPs and SIP messages, function for testing/checking the value of an AVP.

An up-to-date tutorial providing more information (detailed explanations and commented examples) can be found on Voice Sistem documentation web page at http://voice-system.ro/docs/avpops .

1.2. Dependencies

1.2.1. OpenSER Modules

The following modules must be loaded before this module:

Optionally a database module

1.2.2. External Libraries or Applications

The following libraries or applications must be installed before running OpenSER with this module loaded:

None

1.3. AVP naming format

The format of the parameters specifying an AVP in functions exported by this module is: $avp(avp_flags:avp_name) or $avp(avp_alias).

avp_flags = type_flags [script_flags]; type_flags = 'I' | 'i' | 'S' | 's'; script_flags = 0..255
'I' or 'i' means that the type of avp name is integer (ID)
'S' or 's' means that the type of avp name is string
The type flag is mandatory.
script_flags must be an 8 bit unsigned number, therefore can be set up to 8 flags. If no script flag is provided, the name will match all AVPs, regardless they have or not a script flag set (preserves the compatibility with the old naming schema).
avp_name = string | integer
string - might be any alphanumeric string, wich contain following characters: [a-z] [A-Z] [0-9] '_'
integer - might be an unsigned integer, greater than zero, up to 2^16-1
avp_alias = string
string - might be any alphanumeric string, wich contain following characters: [a-z] [A-Z] [0-9] '_'

Example 1-1. AVP naming examples

...
$avp(i:11) - the AVP identified by integer 11
$avp(s:foo) - the AVP identified by the string 'foo'
$avp(bar) - the AVP identified by the AVP alias 'bar'
$avp(i3:123) - the AVP identified by the integer 123 which has script flags 1
    and 2 set
...

1.4. Exported Parameters

1.4.1. `avp_url` (string)

DB URL for database connection.

This parameter is optional, it's default value being NULL.

Example 1-2. Set avp_url parameter

...
modparam("avpops","avp_url","mysql://user:passwd@host/database")
...

1.4.2. `db_url` (string)

This parameter has the same meaning as "avp_url" parameter.

1.4.3. `avp_table` (string)

DB table to be used.

This parameter is optional, it's default value being NULL.

Example 1-3. Set avp_table parameter

...
modparam("avpops","avp_table","avptable")
...

1.4.4. `avp_aliases` (string)

Contains a multiple definition of aliases for AVP names.

This parameter is optional.

Example 1-4. Set avp_aliases parameter

...
modparam("avpops","avp_aliases","uuid=I:660;email=s:email_addr;fwd=i:753")
...

1.4.5. `use_domain` (integer)

If the domain part of the an URI should be used for identifying an AVP in DB operations.

Default value is 0 (no).

Example 1-5. Set use_domain parameter

...
modparam("avpops","use_domain",1)
...

1.4.6. `uuid_column` (string)

Name of column containing the uuid (unique user id).

Default value is "uuid".

Example 1-6. Set uuid_column parameter

...
modparam("avpops","uuid_column","uuid")
...

1.4.7. `username_column` (string)

Name of column containing the username.

Default value is "username".

Example 1-7. Set username_column parameter

...
modparam("avpops","username_column","username")
...

1.4.8. `domain_column` (string)

Name of column containing the domain name.

Default value is "domain".

Example 1-8. Set domain_column parameter

...
modparam("avpops","domain_column","domain")
...

1.4.9. `attribute_column` (string)

Name of column containing the attribute name (AVP name).

Default value is "attribute".

Example 1-9. Set attribute_column parameter

...
modparam("avpops","attribute_column","attribute")
...

1.4.10. `value_column` (string)

Name of column containing the AVP value.

Default value is "value".

Example 1-10. Set value_column parameter

...
modparam("avpops","value_column","value")
...

1.4.11. `type_column` (string)

Name of column containing the AVP type.

Default value is "type".

Example 1-11. Set type_column parameter

...
modparam("avpops","type_column","type")
...

1.4.12. `db_scheme` (string)

Definition of a DB schemeto be used for non-standard access to Database information.

Default value is "NULL".

Example 1-12. Set db_scheme parameter

...
modparam("avpops","db_scheme",
"scheme1:table=subscriber;uuid_column=uuid;value_column=first_name")
...

1.5. Exported Functions

1.5.1. `avp_db_load(source,name)`

Loads from DB into memory the AVPs corresponding to the given source. If given, it sets the script flags for loaded AVPs.

Meaning of the parameters is as follows:

source - what info is used for identifying the AVPs. Parameter syntax:
- source = (pvar|str_value) ['/'('username'|'domain'|'uri'|'uuid')])
- pvar = any pseudo variable defined in OpenSER. If the pvar is $ru (request uri), $fu (from uri), $tu (to uri) or $ou (original uri), then the implicit flag is 'uri'. Otherwise, the implicit flag is 'uuid'.
name - which AVPs will be loaded from DB into memory. Parameter syntax is:
- name = avp_spec['/'(table_name|'$'db_scheme)]
- avp_spec = matching_flags|$avp(avp_name)|$avp(avp_alias)
- matching_flags = 'a' | 'A' | 'i' | 'I' | 's' | 'S' [script_flags]
  'a' or 'A' means matching any of AVP name types ('i' and 's'), the rest have the meaning descriped in 'AVP naming format' chapter.

This function can be used from REQUEST_ROUTE, FAILURE_ROUTE, BRANCH_ROUTE.

Example 1-13. avp_db_load usage

...
avp_db_load("$fu","$(i:678)");
avp_db_load("$ru/domain","i:/domain_preferences");
avp_db_load("$uuid","$avp(s:404fwd)/fwd_table");
avp_db_load("$ru","$avp(i1:123)/$some_scheme");
...

1.5.2. `avp_db_store(source,name)`

Stores to DB the AVPs corresponding to the given source.

The meaning and usage of the parameters are identical as for avp_db_load(source,name) function. Please refer to its description.

This function can be used from REQUEST_ROUTE, FAILURE_ROUTE, BRANCH_ROUTE.

Example 1-14. avp_db_store usage

...
avp_db_store("$tu","$avp(i:678)");
avp_db_store("$ru/username","$avp(email)");
...

1.5.3. `avp_db_delete(source,name)`

Deletes from DB the AVPs corresponding to the given source.

The meaning and usage of the parameters are identical as for avp_db_load(source,name) function. Please refer to its description.

This function can be used from REQUEST_ROUTE, FAILURE_ROUTE, BRANCH_ROUTE.

Example 1-15. avp_db_delete usage

...
avp_db_delete("$tu","$avp(i:678)");
avp_db_delete("$ru/username","$avp(email)");
avp_db_delete("$uuid","$avp(s:404fwd)/fwd_table");
...

1.5.4. `avp_db_query(query[,dest])`

Make a database query and store the result in AVPs.

The meaning and usage of the parameters:

query - must be a valid SQL query. The parameter can contain pseudo-variables.
dest - a list with AVP names where to store the result. The format is "$avp(name1);$avp(name2);...". If this parameter is ommited, the result is stored in "$avp(i:1);$avp(i:2);...". If the result gives many rows, then multiple AVPs with corresponding name will be added.

This function can be used from REQUEST_ROUTE, FAILURE_ROUTE, BRANCH_ROUTE.

Example 1-16. avp_db_query usage

...
avp_db_query("select password, ha1 from subscriber where username='$tu'",
	"$avp(i:678);$avp(i:679)");
avp_db_query("delete from subscriber");
...

1.5.5. `avp_write(value,name)`

The function writes some value (given) or some information from the SIP message into a new AVP.

Meaning of the parameters is as follows:

value - the value to be written into the AVP. Parameter syntax:
- value = (variable) | (fix_value)
- variable = pvar ['/'('username'|'domain')])
- pvar = any pseudo-variable defined in OpenSER
- fix_value = 'i:'integer | 's:'string | string
Integer values can be given in hexadecimal using notation 'i:0xhex_number' (e.g.,: 'i:0xabcd');
name - the name of the new written AVP. Parameter syntax is:
- name = avp_name | avp_alias

This function can be used from REQUEST_ROUTE, FAILURE_ROUTE, BRANCH_ROUTE.

Example 1-17. avp_write usage

...
avp_write("$tu","$avp(i:678)");
avp_write("$ru/username","$avp(email)");
avp_write("$si","$avp(s:ip)");
avp_write("$du","$avp(s:next_hop)");
avp_write("$hdr(call-id)","$avp(i:11)");
avp_write("i:333","$avp(i:6)");
...

1.5.6. `avp_delete(name)`

Deletes from memory the AVPs with name or, if empty, all AVPs.

Meaning of the parameters is as follows:

name - which AVPs will be deleted from memory. Parameter syntax is:
- name = (matching_flags|avp_name|avp_alias)['/'flag]
- matching_flags = please refer to avp_db_load() function
- flag = 'g'|'G'

This function can be used from REQUEST_ROUTE, FAILURE_ROUTE, BRANCH_ROUTE.

Example 1-18. avp_delete usage

...
avp_delete("$avp(i:678)/g");
avp_delete("$avp(email)");
avp_delete("i");
avp_delete("a3");
...

1.5.7. `avp_pushto(destination,name)`

Pushes the value of AVP(s) into the SIP message.

Meaning of the parameters is as follows:

destination - as what will be the AVP value pushed into SIP message. Parameter syntax:
- destination = '$ru' ['/'('username'|'domain')] | '$du' | '$br'
- $ru '['/'('username'|'domain')] - write the AVP in the request URI or in username/domain part of it
- $du - write the AVP in 'dst_uri' field
- $br - write the AVP directly as a new branch (does not affect RURI)
name - which AVP(s)/pseudo-variable should be pushed into the SIP message. Parameter syntax is:
- name = ( avp_name | avp_alias | pvar_name )['/'flags]
- flags = 'g' - effective only with AVPs

This function can be used from REQUEST_ROUTE, FAILURE_ROUTE, BRANCH_ROUTE.

Example 1-19. avp_pushto usage

...
avp_pushto("$ru/domain","$fd");
avp_pushto("$ru","$avp(i:678)");
avp_pushto("$ru/domain","$avp(s:backup_domains)/g");
avp_pushto("$du","$avp(i:679)");
avp_pushto("$br","$avp(i:680)");
...

1.5.8. `avp_check(name,op_value)`

Checks the value of the AVP(s) against an operator and value.

Meaning of the parameters is as follows:

name - which AVP(s) should be checked. Parameter syntax is:
- name = ( pseudo-variable )
op_value - define the operator, the value and flags for checking. Parameter syntax is:
- op_value = operator '/' value ['/'flags]
- operator = 'eq' | 'ne' | 'lt' | 'le' | 'gt' | 'ge' | 're' | 'fm' | 'and' | 'or' | 'xor'
- value = pseudo-variable | fix_value
- fix_value = 'i:'integer | 's:'string | string
- flags = 'g' | 'G' | 'i' | 'I'
Operator meaning:
- eq - equal
- ne - not equal
- lt - less than
- le - less or equal
- gt - greater than
- ge - greater or equal
- re - regexp (regular exression match)
- fm - fast match (see: man fnmatch)
- and - bitwise 'and'
- or - bitwise 'or'
- xor - bitwise 'xor'
Integer values can be given in hexadecimal using notation: 'i:0xhex_number' (e.g.,: 'i:0xabcd');

This function can be used from REQUEST_ROUTE, FAILURE_ROUTE, BRANCH_ROUTE.

Example 1-20. avp_check usage

...
avp_check("$avp(i:678)", "lt/i:345/g");
avp_check("$fd","eq/$td/I");
avp_check("$avp(s:foo)","gt/$avp($bar)/g");
avp_check("$avp(s:foo)","re/sip:.*@bar.net/g");
avp_check("$avp(s:foo)","fm/$avp(fm_avp)/g");
...

1.5.9. `avp_copy(old_name,new_name)`

Copy / move an avp under a new name.

Meaning of the parameters is as follows:

name1 - which AVP(s) should be copied/moved. Parameter syntax is:
- name = ( avp_name | avp_alias )
name2 - the new name of the copied/moved AVP(s). Parameter syntax is:
- name = ( avp_name | avp_alias ) ['/'flags]
- flags = 'g' | 'G' | 'd' | 'D' | 'n' | 'N' | 's' | 'S'

This function can be used from REQUEST_ROUTE, FAILURE_ROUTE, BRANCH_ROUTE.

Example 1-21. avp_copy usage

...
avp_copy("$avp(i:678)", "$avp(s:345)/g");
avp_copy("$avp(old)","$avp(new)/gd");
...

1.5.10. `avp_printf(dest, format)`

Prints the formatted string 'format' in the AVP 'dest'. The 'format' parameter can include any pseudo-variable defined in OpenSER. The list with all pseudo-variables in OpenSER can be found at: http://openser.org/docs/pseudo-variables-1.1.x.html.

Meaning of the parameters is as follows:

dest - in which AVP should be stored the result. Parameter syntax is:
- name = ( avp_name | avp_alias )
format - the formatted string to be printed in 'dest' AVP.

This function can be used from REQUEST_ROUTE, FAILURE_ROUTE, BRANCH_ROUTE.

Example 1-22. avp_printf usage

...
avp_printf("$avp(i:20)", "This is a $rm request with call-id $hdr(call-id)");
...

1.5.11. `avp_subst(avps, subst)`

Perl/sed-like subst applied to AVPs having string value.

Meaning of the parameters is as follows:

avps - source AVP, destination AVP and flags. Parameter syntax is:
- avps = src_avp [ '/' dst_avp [ '/' flags ] ]
- src_avp = ( avp_name | avp_alias )
- dst_avp = ( avp_name | avp_alias ) - if dst_avp is missing then the value of src_avp will be replaced
- flags = ( d | D | g | G ) -- (d, D - delete source avp; g, G - apply to all avps matching src_avp name)
subst - perl/sed-like reqular expression. Parameter syntax is:
- subst = "/regexp/replacement/flags"
- regexp - regular expression
- replacement - replacement string, can include pseudo-variables and \1, ..., \9 for matching tokens, \0 for whole matching text
- flags = 'g' | 'G' | 'i' | 'i' (g, G - replace all matching tokens; i, I - match ignore case)

This function can be used from REQUEST_ROUTE, FAILURE_ROUTE, BRANCH_ROUTE.

Example 1-23. avp_subst usage

...
# if avp i:678 has a string value in e-mail format, replace the
# domain part with the value of domain part from R-URI
avp_subst("$avp(i:678)", "/(.*)@(.*)/\1@$rd/");

# if any avp i:678 has a string value in e-mail format, replace the
# domain part with the value of domain part from R-URI
# and place the result in avp i:679
avp_subst("$avp(i:678)/$avp(i:679)/g", "/(.*)@(.*)/\1@$rd/");
...

IMPORTANT NOTE: if the replacement string includes src_avp or dst_avp you will get something that you may not expect. In case you have many src_avp and you make the substitution to be applied to all of them, after the first src_avp is processed, it will be added in avp list and next processing will use it.

1.5.12. `avp_op(name,op_value)`

Different integer operations with avps.

Meaning of the parameters is as follows:

name - 'source_avp/destination_avp' - which AVP(s) should be processed and where to store the result. If 'destination_avp' is missing, same name as 'source_avp' is used to store the result.
Parameter syntax is:
- name = ( source_avp[/destination_avp] )
  source_avp = ( avp_name | avp_alias )
  destination_avp = ( avp_name | avp_alias )
op_value - define the operation, the value and flags. Parameter syntax is:
- op_value = operator '/' value ['/'flags]
- operator = 'add' | 'sub' | 'mul' | 'div' | 'mod' | 'and' | 'or' | 'xor' | 'not'
- value = pseudo-variable | fix_value
- fix_value = 'i:'integer
- flags = 'g' | 'G' | 'd' | 'D'
Integer values can be given in hexadecimal using notation 'i:0xhex_number' (e.g.,: 'i:0xabcd');

This function can be used from REQUEST_ROUTE, FAILURE_ROUTE, BRANCH_ROUTE.

Example 1-24. avp_op usage

...
avp_op("$avp(i:678)", "add/i:345/g");
avp_op("$avp(number)","sub/$avp(number2)/d");
...

1.5.13. `is_avp_set(name)`

Check if any AVP with name is set.

Meaning of the parameters is as follows:

name - name of AVP to look for. Parameter syntax is:
- name = avp_name|avp_alias [ '/' flags ])
  flags = ('e'|'s'|'n') - e = empty value; s = value string; n = value number (int)

This function can be used from REQUEST_ROUTE, FAILURE_ROUTE, BRANCH_ROUTE.

Example 1-25. is_avp_set usage

...
if(is_avp_set("$avp(i:678)"))
    log("AVP with integer id 678 exists\n");
...

1.5.14. `avp_print()`

Prints the list with all the AVPs from memory. This is only a helper/debug function.

This function can be used from REQUEST_ROUTE, FAILURE_ROUTE, BRANCH_ROUTE.

Example 1-26. avp_print usage

...
avp_print();
...

Chapter 2. Developer's Guide

The module does not provide any API to use in other OpenSER modules.

Chapter 3. Frequently Asked Questions

3.1. Where can I find more documentation about this module?
3.2. Where can I post a question about this module?
3.3. How can I report a bug?

3.1. Where can I find more documentation about this module?

An up-to-date tutorial providing more information (detailed explanations and commneted examples) can be found on Voice Sistem documentation web page at http://voice-system.ro/docs/avpops .

3.2. Where can I post a question about this module?

Sent an email to <team@openser.org> or, if you want to keep the mail private, send it to <ramona@voice-system.ro>.

Remember: first at all, check if your question was already answered on one of OpenSER mailing lists:

User Mailing List - http://openser.org/cgi-bin/mailman/listinfo/users
Developer Mailing List - http://openser.org/cgi-bin/mailman/listinfo/devel

3.3. How can I report a bug?

Accumulate as much as possible information (OpenSER version, openser -V output, your OS (uname -a), OpenSER logs, network dumps, core dump files, configuration file) and send a mail to <team@openser.org>.