Copyright © 2004, 2005, 2006 FhG FOKUS, iptelorg GmbH
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set_iattr(attribute,value)
flags2attr("$avp")
set_sattr(attribute,value)
print_attr($attribute)
attr2uri($attribute[,uri-part])
attr_exists(attribute)
attr_equals(attribute, value)
attr_equals_xl(attribute, xl_format)
dump_attrs()
xlset_attr($attribute, xl_format)
xlfix_attr($attribute)
insert_attr_hf(name)
insert_attr_hf(header_name, $avp_name)
append_attr_hf(name)
append_attr_hf(header_name, $avp_name)
replace_attr_hf(name)
replace_attr_hf(header_name, $avp_name)
attr_to_reply(name)
attr_to_reply(header_name, $avp_name)
attr_destination($avp_name)
xlset_destination(xl_format)
subst_attr($avp_name, subst_re)
del_attr($avp_name)
hdr_body2attrs(headername, prefix)
hdr_body2attrs2(headername, prefix)
This module contains several functions that can be used to manipulate the contents of AVPs (Attribute-Value pairs). The AVPs are variables attached to the SIP message being processed. Each variable has its name and value. AVPs can be used to store arbitrary data or as a means of inter-module comminication.
You may also want to check the avpops module which is more flexible and contains more functions. In future SER releases the avp module will be probably deprecated in favor of avpops module.
Create an AVP of type integer.
Meaning of the parameter is as follows:
attribute - The name of the AVP to be created.
value - Integer value of the AVP.
Store the current state of SER flags into the sepcified avp.
Create an AVP of type string.
Meaning of the parameter is as follows:
attribute - The name of the AVP to be created.
value - String value of the AVP.
Print the value of an AVP to syslog.
Meaning of the parameter is as follows:
attribute - The name of the AVP.
Rewrite the whole Request-URI of the message being processed with
the value of an AVP, or if an uri-part is specified,
rewrite only that specific part.
Meaning of the parameter is as follows:
$attribute - The name of the AVP.
uri-part - The name of the part of the uri that will be rewritten. The supported values are: "prefix", "uri", "username", "user", "usernamepassword", "userpass", "domain", "host", "domainport", "hostport", "port", "strip", "strip_tail". "prefix" will add the AVP as a prefix to the username (equivalent to prefix("string")), "strip" and "strip_tail" expect a number in the AVP and they will remove the specified number of characters from the beginning, respective the end of the username part of the uri. The rest of the uri-part values names are self-explaining.
Test for the existence of AVP with given name. The function returns 1 if given AVP exists and -1 if not.
Meaning of the parameter is as follows:
attribute - The name of the AVP.
Example 4. attr_exists usage
...
if (attr_exists("saved_ruri")) {
attr2uri("saved_uri");
} else {
rewriteuri("sip:a@iptel.org");
};
...
Test whether an AVP with given name and value exists. The function returns 1 if the AVP with given name and value exists and -1 if not. The value of the AVP is compared string-wise. The comparison is case sensitive.
Meaning of the parameter is as follows:
attribute - The name of the AVP.
value - The AVP value to look for.
Test whether an AVP with given name and value exists. The function returns 1 if the AVP with given name and value exists and -1 if not. The value of the AVP is compared string-wise to the result of xlog formatting call. The comparison is case sensitive.
Meaning of the parameter is as follows:
attribute - The name of the AVP.
xl_format - The xlog formatting string, result of which is looked for in AVP.
Note: You must ensure, that the xlog module is loaded to be able to use this function.
Example 5. attr_equals_xl usage
...
if (attr_equals_xl("my_avp", "%ct")) {
# my_avp has value equal to current Contact header field
} else {
# my_avp was different
}
...
Dumps all AVPs in user lists to the debug output (with level INFO).
The function does not require any parameters.
Creates new AVP identified by attribute and assigns the result string of xlog formatting rules as its value.
Meaning of the parameter is as follows:
$attribute - The name of the AVP.
xl_format - String used for xlog formatting. For detailed info see documentation of xlog module.
Note: You must ensure, that the xlog module is loaded to be able to use this function.
Fixes an xl formatted attribute value to pure string.
Meaning of the parameter is as follows:
$attribute - The name of the AVP.
Inserts new header into the request, which is beeing forwarded. The AVP name is the name of the header field.
If you need to insert header with name which differs from the AVP name use insert_attr_hf(header_name, $avp_name) instead.
Inserting means putting the header to the beginning of the request, before any others.
Meaning of the parameter is as follows:
name - The name of the header field which is inserted into forwarded request as well as name of AVP which's value is put as the header field value.
Inserts new header into the request, which is beeing forwarded.
Inserting means putting the header to the beginning of the request, before any others.
Meaning of the parameter is as follows:
header_name - The name of the header field which is inserted into forwarded request.
$avp_name - The name of AVP which's value is put as the header field value.
Example 6. insert_attr_hf usage
...
set_sattr("my_route","<sip:user@host:port;lr>");
insert_attr_hf("Route", "$my_route");
...
Appends new header into the request, which is beeing forwarded. The AVP name is the name of the header field.
If you need to append header with name which differs from the AVP name use append_attr_hf(header_name, $avp_name) instead.
Appending means putting the header to the end of the request, after any others.
Meaning of the parameter is as follows:
name - The name of the header field which is appended into forwarded request as well as name of AVP which's value is put as the header field value.
Appends new header into the request, which is beeing forwarded.
Appending means putting the header to the end of the request, after any others.
Meaning of the parameter is as follows:
header_name - The name of the header field which is appended into forwarded request.
$avp_name - The name of AVP which's value is put as the header field value.
Replaces header in the request, which is beeing forwarded. The AVP name is the same as the name of the header field.
If you need to replace header with name which differs from the AVP name use replace_attr_hf(header_name, $avp_name) instead.
Replacing means removing all the headers with specified name and appending new one at the end, with the value from AVP.
Meaning of the parameter is as follows:
name - The name of the header field which is replaced in forwarded request as well as name of AVP which's value is put as the header field value.
Replaces header in the request, which is beeing forwarded.
Replacing means removing all the headers with specified name and appending new one at the end, with the value from AVP.
Meaning of the parameter is as follows:
header_name - The name of the header field which is replaced in forwarded request.
$avp_name - The name of AVP which's value is put as the header field value.
Appends new header into the reply at the request time processing. The AVP name is the name of the header field.
If you need to append header with name which differs from the AVP name use attr_to_reply(header_name, $avp_name) instead.
If you need to append headers during reply processing you can use insert_attr_hf and append_attr_hf. This function stores data and waits for the reply being created.
Meaning of the parameter is as follows:
name - The name of the header field which is appended into reply as well as name of AVP which's value is put as the header field value.
Appends new header into the reply at the request time processing.
Meaning of the parameter is as follows:
header_name - The name of the header field which is appended into reply.
$avp_name - The name of AVP which's value is put as the header field value.
Example 7. attr_to_reply usage
...
xlset_attr("$my_route","<sip:%Hf:5080;lr>";
attr_to_reply("P-Hint-Route", "my_route");
...
Sets the destination of the forwarded request to the value of AVP, which must be either a SIP URI or a string in nameaddr format (e.g. "Foo Bar" <sip:uri>).
Meaning of the parameter is as follows:
$avp_name - The name of AVP which's value is used for further request forwarding.
Example 8. attr_destination usage
...
xlset_attr("$my_route","<sip:%<next_host>:%<next_port>;myparam=a123;lr>");
insert_attr_hf("Route", "$my_route");
attr_destination("$my_route");
t_relay();
...
Sets the destination of the forwarded request to the value of result of xlog formatted string. Either SIP URI or nameaddr format is allowed.
Meaning of the parameter is as follows:
xl_format - xlog module formatting string, the result is used for request forwarding.
Note: You must ensure, that the xlog module is loaded to be able to use this function.
Example 9. xlset_destination usage
...
xlset_destination("%<next_host>:%<next_port>");
t_relay();
...
The value of the AVP identified by $avp_name name is matched and substitued according to the subst_re sed like expression. Result of the substitution is then stored in the original AVP.
Meaning of the parameter is as follows:
$avp_name - Name of the AVP which will be used for the substitution.
subst_re - SED like match&replace regullar expression.
The AVP identified by $avp_name name is deleted.
Meaning of the parameter is as follows:
$avp_name - Name of the AVP which will be deleted.
Example 11. del_attr usage
...
failure_route[1] {
if (status=~4[0-9][0-9]) {
if (attr_exists("backup_gw") {
append_branch;
attr_destination("backup_gw");
del_attr("backup_gw");
t_relay();
}
}
...
Function parses a header body content scans for fld1=val1,fld2=val2,... and creates bunch of avps prefixfld1:= val1, prefixfld2:= val2, .... If possible stores values as integers.
Meaning of the parameter is as follows:
headername - The header name, which will be scanned for the name=value pairs.
If you want to create only AVPs with integer value use "/i" postfix to the header name.
If you want to create only AVPs with string value use "/s" postfix to the header name.
prefix - The prefix, which is added before the name parsed from the header body.
Function parses a header body content scans for fld1=val1,val2;fld2=val3,... and creates bunch of avps prefixfld1#1:= val1, prefixfld1#2:= val2, prefixfld2:=val3 .... If possible stores values as integers.
Meaning of the parameter is as follows:
headername - The header name, which will be scanned for the name=value pairs.
If you want to create only AVPs with integer value use "/i" postfix to the header name.
If you want to create only AVPs with string value use "/s" postfix to the header name.
prefix - The prefix, which is added before the name parsed from the header body.
Example 12. hdr_body2attrs and hdr_body2attrs2 usage
if (method=="BYE") {
# QoS reporting
if (search("^User-Agent: AVM FRITZ!Box Fon*")) {
hdr_body2attrs2("X-RTP-Stat/i", "QoS_");
xlog("L_INFO", "QoS: %Ts, %fu, %tu, %ci, %{User-Agent}, %{X-RTP-Stat}\n");
} else if (search("^User-Agent: Sipura/*")) {
hdr_body2attrs("P-RTP-Stat/i", "QoS_");
xlog("L_INFO", "QoS: %Ts, %fu, %tu, %ci, %{User-Agent}, %{P-RTP-Stat}\n");
}
}
# AVP QoS_xx now contain the values from appropriate header
# e.g. QoS_JI is jitter
Defines size of internal buffer for all xlog formatting calls. If you don't use xlog formatting calls, you can set it to 0 to preserve some memory, if you get errors while formatting due to buffer size, you can enlarge it.
Default value is 256.