func extractCommunity(args []string) ([]string, bgp.PathAttributeInterface, error) {
for idx, arg := range args {
if arg == "community" && len(args) > (idx+1) {
elems := strings.Split(args[idx+1], ",")
comms := make([]uint32, 0, 1)
for _, elem := range elems {
c, err := table.ParseCommunity(elem)
if err != nil {
return nil, nil, err
}
comms = append(comms, c)
}
args = append(args[:idx], args[idx+2:]...)
return args, bgp.NewPathAttributeCommunities(comms), nil
}
}
return args, nil, nil
}
// RemoveCommunities removes specific communities.
// If the length of communites is 0, it does nothing.
// If all communities are removed, it removes Communities path attribute itself.
func (path *Path) RemoveCommunities(communities []uint32) int {
if len(communities) == 0 {
// do nothing
return 0
}
find := func(val uint32) bool {
for _, com := range communities {
if com == val {
return true
}
}
return false
}
count := 0
attr := path.getPathAttr(bgp.BGP_ATTR_TYPE_COMMUNITIES)
if attr != nil {
newList := make([]uint32, 0)
c := attr.(*bgp.PathAttributeCommunities)
for _, value := range c.Value {
if find(value) {
count += 1
} else {
newList = append(newList, value)
}
}
if len(newList) != 0 {
path.setPathAttr(bgp.NewPathAttributeCommunities(newList))
} else {
path.delPathAttr(bgp.BGP_ATTR_TYPE_COMMUNITIES)
}
}
return count
}
// SetCommunities adds or replaces communities with new ones.
// If the length of communities is 0 and doReplace is true, it clears communities.
func (path *Path) SetCommunities(communities []uint32, doReplace bool) {
if len(communities) == 0 && doReplace {
// clear communities
path.delPathAttr(bgp.BGP_ATTR_TYPE_COMMUNITIES)
return
}
newList := make([]uint32, 0)
attr := path.getPathAttr(bgp.BGP_ATTR_TYPE_COMMUNITIES)
if attr != nil {
c := attr.(*bgp.PathAttributeCommunities)
if doReplace {
newList = append(newList, communities...)
} else {
newList = append(newList, c.Value...)
newList = append(newList, communities...)
}
} else {
newList = append(newList, communities...)
}
path.setPathAttr(bgp.NewPathAttributeCommunities(newList))
}