72 lines
1.9 KiB
Go
72 lines
1.9 KiB
Go
package dhcp
|
|
|
|
import (
|
|
"fmt"
|
|
"net"
|
|
"os"
|
|
"path/filepath"
|
|
"strings"
|
|
|
|
"git.g3e.fr/syonad/two/internal/metadata"
|
|
)
|
|
|
|
func GenerateConfig(c Config) (string, map[string]string, error) {
|
|
if c.InterfaceIP == nil {
|
|
return "", nil, fmt.Errorf("interface ip is required: guests would have no route to the metadata server")
|
|
}
|
|
mask := fmt.Sprintf("%d.%d.%d.%d", c.Network.Mask[0], c.Network.Mask[1], c.Network.Mask[2], c.Network.Mask[3])
|
|
|
|
var sb strings.Builder
|
|
fmt.Fprintf(&sb, "no-resolv\n")
|
|
fmt.Fprintf(&sb, "dhcp-range=%s,static,%s,12h\n", c.Network.IP.String(), mask)
|
|
fmt.Fprintf(&sb, "dhcp-option=121,%s\n", strings.Join(classlessRoutes(c), ","))
|
|
if c.DefaultGateway != nil {
|
|
fmt.Fprintf(&sb, "dhcp-option=3,%s\n", c.DefaultGateway.String())
|
|
} else {
|
|
fmt.Fprintf(&sb, "dhcp-option=3\n")
|
|
}
|
|
fmt.Fprintf(&sb, "dhcp-option=6,1.1.1.1,8.8.8.8\n\n")
|
|
|
|
entries := make(map[string]string)
|
|
i := 0
|
|
for ip := cloneIP(c.Network.IP); c.Network.Contains(ip); incrementIP(ip) {
|
|
mac := fmt.Sprintf("00:22:33:%02X:%02X:%02X", (i>>16)&0xFF, (i>>8)&0xFF, i&0xFF)
|
|
fmt.Fprintf(&sb, "dhcp-host=%s,%s\n", mac, ip)
|
|
entries[ip.String()] = mac
|
|
i++
|
|
}
|
|
|
|
outPath := filepath.Join(c.ConfDir, c.Name+".conf")
|
|
if err := os.MkdirAll(c.ConfDir, 0755); err != nil {
|
|
return "", nil, err
|
|
}
|
|
return outPath, entries, os.WriteFile(outPath, []byte(sb.String()), 0644)
|
|
}
|
|
|
|
func classlessRoutes(c Config) []string {
|
|
nextHop := c.InterfaceIP.String()
|
|
|
|
routes := []string{metadata.ServiceIP + "/32," + nextHop}
|
|
if c.VPCRoute != nil {
|
|
routes = append(routes, c.VPCRoute.String()+","+nextHop)
|
|
}
|
|
if c.DefaultGateway != nil {
|
|
routes = append(routes, "0.0.0.0/0,"+c.DefaultGateway.String())
|
|
}
|
|
return routes
|
|
}
|
|
|
|
func incrementIP(ip net.IP) {
|
|
for j := len(ip) - 1; j >= 0; j-- {
|
|
ip[j]++
|
|
if ip[j] != 0 {
|
|
break
|
|
}
|
|
}
|
|
}
|
|
|
|
func cloneIP(ip net.IP) net.IP {
|
|
clone := make(net.IP, len(ip))
|
|
copy(clone, ip)
|
|
return clone
|
|
}
|