func (a *AsPathPrependAction) apply(path *table.Path) *table.Path {
var asn uint32
if a.useLeftMost {
asns := path.GetAsSeqList()
if len(asns) == 0 {
log.WithFields(log.Fields{
"Topic": "Policy",
"Type": "AsPathPrepend Action",
}).Error("aspath length is zero.")
return path
}
asn = asns[0]
log.WithFields(log.Fields{
"Topic": "Policy",
"Type": "AsPathPrepend Action",
"LastAs": asn,
"Repeat": a.repeat,
}).Debug("use last AS.")
} else {
asn = a.asn
}
path.PrependAsn(asn, a.repeat)
return path
}
// compare AS_PATH in the message's AS_PATH attribute with
// the one in condition.
func (c *AsPathCondition) evaluate(path *table.Path) bool {
aspath := path.GetAsSeqList()
if len(aspath) == 0 {
return false
}
matched := false
for _, member := range c.AsPathList {
switch member.postiion {
case AS_FROM:
matched = aspath[0] == member.asn
case AS_ANY:
for _, n := range aspath {
if n == member.asn {
matched = true
break
}
}
case AS_ORIGIN:
matched = aspath[len(aspath)-1] == member.asn
case AS_ONLY:
matched = len(aspath) == 1 && aspath[0] == member.asn
}
if matched {
log.WithFields(log.Fields{
"Topic": "Policy",
"Condition": "aspath length",
"ASN": member.asn,
"Position": member.postiion,
}).Debug("condition matched")
return true
}
}
return false
}