hyp/hypd/configuration/configuration.go

76 lines
2.8 KiB
Go

package configuration
import (
"encoding/json"
"fmt"
"os"
)
type HypdConfiguration struct {
NetworkInterface string `json:"networkInterface"` // The network interface that the eBPF program attaches to
PreSharedKeyDirectory string `json:"preSharedKeyDirectory"` // hypd will load all *.secret files from this directory
SuccessAction string `json:"successAction"` // The action to take for a successful knock, each argument is a separate string
TimeoutSeconds int `json:"timeoutSeconds"` // If > 0, once a knock sequence has been successful this value will count down and when it reaches 0, it will perform the TimeoutAction on the client
TimeoutAction string `json:"timeoutAction"` // The action to take after TimeoutSeconds has elapsed. only applicable if TimeoutSeconds is > 0, each argument is a separate string
}
// LoadConfiguration opens and parses the configuration file into a HypdConfiguration struct
// If a configFilePath is not specified, it will search in common locations
func LoadConfiguration(configFilePath string) (*HypdConfiguration, error) {
if configFilePath == "" {
commonLocations := []string{"hypdconfig.json",
"~/.hypdconfig.json",
"~/.config/hyp/hypdConfig.json",
"/etc/hyp/hypdConfig.json",
"/usr/local/etc/hyp/hypdConfig.json",
}
for _, loc := range commonLocations {
if _, err := os.Stat(loc); err == nil {
configFilePath = loc
break
}
}
}
// if it's still not found after checking common locations, load default config
if configFilePath == "" {
fmt.Println("no configuration file found. You can generate one with ./hypd generate defaultconfig | tee hypdconfig.json")
return DefaultConfig(), nil
}
// Otherwise if a config is specified, try to load it and error if it fails.
// I think it's better to error here if a config was intended and failed
// rather than failing back to default
b, err := os.ReadFile(configFilePath)
if err != nil {
return nil, fmt.Errorf("failed to read config file '%s': %w", configFilePath, err)
}
hypdConfiguration := &HypdConfiguration{}
err = json.Unmarshal(b, hypdConfiguration)
if err != nil {
return nil, fmt.Errorf("failed to unmarshal config file json to HypdConfiguration (is the config file malformed?): %w", err)
}
return hypdConfiguration, nil
}
func DefaultConfig() *HypdConfiguration {
var ifaceString string
iface, err := getDefaultNIC()
if err == nil {
ifaceString = iface.Name
} else {
ifaceString = "enp0s3" // fallback to fixed value
}
return &HypdConfiguration{
NetworkInterface: ifaceString,
PreSharedKeyDirectory: "./secrets/",
SuccessAction: "iptables -A INPUT -p tcp -s %s --dport 22 -j ACCEPT",
TimeoutSeconds: 1440,
TimeoutAction: "iptables -D INPUT -p tcp -s %s --dport 22 -j ACCEPT",
}
}