122 lines
3.3 KiB
Go
122 lines
3.3 KiB
Go
package main
|
|
|
|
import (
|
|
"regexp"
|
|
"strings"
|
|
)
|
|
|
|
// The protocol name for each route (e.g. "ibgp_sea02") is encoded in the form:
|
|
//
|
|
// unicast [ibgp_sea02 2021-08-27 from fd86:bad:11b7:1::1] * (100/1015) [i]
|
|
var protocolNameRe = regexp.MustCompile(`\[(.*?) .*\]`)
|
|
|
|
// Try to split the output into one chunk for each route.
|
|
// Possible values are defined at https://gitlab.nic.cz/labs/bird/-/blob/v2.0.8/nest/rt-attr.c#L81-87
|
|
var routeSplitRe = regexp.MustCompile("(unicast|blackhole|unreachable|prohibited)")
|
|
|
|
var routeViaRe = regexp.MustCompile(`(?m)^\t(via .*?)$`)
|
|
var routeASPathRe = regexp.MustCompile(`(?m)^\tBGP\.as_path: (.*?)$`)
|
|
|
|
func makeEdgeAttrs(preferred bool) RouteAttrs {
|
|
result := RouteAttrs{
|
|
"fontsize": "12.0",
|
|
}
|
|
if preferred {
|
|
result["color"] = "red"
|
|
}
|
|
return result
|
|
}
|
|
|
|
func makePointAttrs(preferred bool) RouteAttrs {
|
|
result := RouteAttrs{}
|
|
if preferred {
|
|
result["color"] = "red"
|
|
}
|
|
return result
|
|
}
|
|
|
|
func birdRouteToGraph(servers []string, responses []string, target string) RouteGraph {
|
|
graph := makeRouteGraph()
|
|
|
|
graph.AddPoint(target, false, RouteAttrs{"color": "red", "shape": "diamond"})
|
|
|
|
for serverID, server := range servers {
|
|
response := responses[serverID]
|
|
if len(response) == 0 {
|
|
continue
|
|
}
|
|
graph.AddPoint(server, false, RouteAttrs{"color": "blue", "shape": "box"})
|
|
routes := routeSplitRe.Split(response, -1)
|
|
|
|
for routeIndex, route := range routes {
|
|
if routeIndex == 0 {
|
|
continue
|
|
}
|
|
|
|
var via string
|
|
var paths []string
|
|
var routePreferred bool = strings.Contains(route, "*")
|
|
// Track non-BGP routes in the output by their protocol name, but draw them altogether in one line
|
|
// so that there are no conflicts in the edge label
|
|
var protocolName string
|
|
|
|
if match := routeViaRe.FindStringSubmatch(route); len(match) >= 2 {
|
|
via = strings.TrimSpace(match[1])
|
|
}
|
|
|
|
if match := routeASPathRe.FindStringSubmatch(route); len(match) >= 2 {
|
|
pathString := strings.TrimSpace(match[1])
|
|
if len(pathString) > 0 {
|
|
paths = strings.Split(strings.TrimSpace(match[1]), " ")
|
|
for i := range paths {
|
|
paths[i] = strings.TrimPrefix(paths[i], "(")
|
|
paths[i] = strings.TrimSuffix(paths[i], ")")
|
|
}
|
|
}
|
|
}
|
|
|
|
if match := protocolNameRe.FindStringSubmatch(route); len(match) >= 2 {
|
|
protocolName = strings.TrimSpace(match[1])
|
|
if routePreferred {
|
|
protocolName = protocolName + "*"
|
|
}
|
|
}
|
|
|
|
if len(paths) == 0 {
|
|
graph.AddEdge(server, target, strings.TrimSpace(protocolName+"\n"+via), makeEdgeAttrs(routePreferred))
|
|
continue
|
|
}
|
|
|
|
// Edges between AS
|
|
for i := range paths {
|
|
var src string
|
|
var label string
|
|
// Only show nexthop information on the first hop
|
|
if i == 0 {
|
|
src = server
|
|
label = strings.TrimSpace(protocolName + "\n" + via)
|
|
} else {
|
|
src = paths[i-1]
|
|
label = ""
|
|
}
|
|
dst := paths[i]
|
|
|
|
graph.AddEdge(src, dst, label, makeEdgeAttrs(routePreferred))
|
|
// Only set color for next step, origin color is set to blue above
|
|
graph.AddPoint(dst, true, makePointAttrs(routePreferred))
|
|
}
|
|
|
|
// Last AS to destination
|
|
src := paths[len(paths)-1]
|
|
graph.AddEdge(src, target, "", makeEdgeAttrs(routePreferred))
|
|
}
|
|
}
|
|
|
|
return graph
|
|
}
|
|
|
|
func birdRouteToGraphviz(servers []string, responses []string, targetName string) string {
|
|
graph := birdRouteToGraph(servers, responses, targetName)
|
|
return graph.ToGraphviz()
|
|
}
|