diff options
Diffstat (limited to 'plugin/hosts/hostsfile.go')
| -rw-r--r-- | plugin/hosts/hostsfile.go | 110 |
1 files changed, 70 insertions, 40 deletions
diff --git a/plugin/hosts/hostsfile.go b/plugin/hosts/hostsfile.go index 1cce850c3..5e0fd5bf6 100644 --- a/plugin/hosts/hostsfile.go +++ b/plugin/hosts/hostsfile.go @@ -32,6 +32,26 @@ func absDomainName(b string) string { return plugin.Name(b).Normalize() } +type options struct { + // automatically generate IP to Hostname PTR entries + // for host entries we parse + autoReverse bool + + // The TTL of the record we generate + ttl uint32 + + // The time between two reload of the configuration + reload time.Duration +} + +func newOptions() *options { + return &options{ + autoReverse: true, + ttl: 3600, + reload: durationOf5s, + } +} + type hostsMap struct { // Key for the list of literal IP addresses must be a host // name. It would be part of DNS labels, a FQDN or an absolute @@ -46,6 +66,11 @@ type hostsMap struct { byAddr map[string][]string } +const ( + durationOf0s = time.Duration(0) + durationOf5s = time.Duration(5 * time.Second) +) + func newHostsMap() *hostsMap { return &hostsMap{ byNameV4: make(map[string][]net.IP), @@ -90,6 +115,8 @@ type Hostsfile struct { // mtime and size are only read and modified by a single goroutine mtime time.Time size int64 + + options *options } // readHosts determines if the cached data needs to be updated based on the size and modification time of the hostsfile. @@ -106,7 +133,7 @@ func (h *Hostsfile) readHosts() { return } - newMap := h.parse(file, h.inline) + newMap := h.parse(file) log.Debugf("Parsed hosts file into %d entries", newMap.Len()) h.Lock() @@ -124,13 +151,12 @@ func (h *Hostsfile) initInline(inline []string) { return } - hmap := newHostsMap() - h.inline = h.parse(strings.NewReader(strings.Join(inline, "\n")), hmap) + h.inline = h.parse(strings.NewReader(strings.Join(inline, "\n"))) *h.hmap = *h.inline } // Parse reads the hostsfile and populates the byName and byAddr maps. -func (h *Hostsfile) parse(r io.Reader, override *hostsMap) *hostsMap { +func (h *Hostsfile) parse(r io.Reader) *hostsMap { hmap := newHostsMap() scanner := bufio.NewScanner(r) @@ -163,22 +189,22 @@ func (h *Hostsfile) parse(r io.Reader, override *hostsMap) *hostsMap { default: continue } + if !h.options.autoReverse { + continue + } hmap.byAddr[addr.String()] = append(hmap.byAddr[addr.String()], name) } } - if override == nil { - return hmap - } - - for name := range override.byNameV4 { - hmap.byNameV4[name] = append(hmap.byNameV4[name], override.byNameV4[name]...) + for name := range h.hmap.byNameV4 { + hmap.byNameV4[name] = append(hmap.byNameV4[name], h.hmap.byNameV4[name]...) } - for name := range override.byNameV4 { - hmap.byNameV6[name] = append(hmap.byNameV6[name], override.byNameV6[name]...) + for name := range h.hmap.byNameV4 { + hmap.byNameV6[name] = append(hmap.byNameV6[name], h.hmap.byNameV6[name]...) } - for addr := range override.byAddr { - hmap.byAddr[addr] = append(hmap.byAddr[addr], override.byAddr[addr]...) + + for addr := range h.hmap.byAddr { + hmap.byAddr[addr] = append(hmap.byAddr[addr], h.hmap.byAddr[addr]...) } return hmap @@ -199,32 +225,34 @@ func ipVersion(s string) int { return 0 } -// LookupStaticHostV4 looks up the IPv4 addresses for the given host from the hosts file. -func (h *Hostsfile) LookupStaticHostV4(host string) []net.IP { +// LookupStaticHost looks up the IP addresses for the given host from the hosts file. +func (h *Hostsfile) lookupStaticHost(hmapByName map[string][]net.IP, host string) []net.IP { + fqhost := absDomainName(host) + h.RLock() defer h.RUnlock() - if len(h.hmap.byNameV4) != 0 { - if ips, ok := h.hmap.byNameV4[absDomainName(host)]; ok { - ipsCp := make([]net.IP, len(ips)) - copy(ipsCp, ips) - return ipsCp - } + + if len(hmapByName) == 0 { + return nil } - return nil + + ips, ok := hmapByName[fqhost] + if !ok { + return nil + } + ipsCp := make([]net.IP, len(ips)) + copy(ipsCp, ips) + return ipsCp +} + +// LookupStaticHostV4 looks up the IPv4 addresses for the given host from the hosts file. +func (h *Hostsfile) LookupStaticHostV4(host string) []net.IP { + return h.lookupStaticHost(h.hmap.byNameV4, host) } // LookupStaticHostV6 looks up the IPv6 addresses for the given host from the hosts file. func (h *Hostsfile) LookupStaticHostV6(host string) []net.IP { - h.RLock() - defer h.RUnlock() - if len(h.hmap.byNameV6) != 0 { - if ips, ok := h.hmap.byNameV6[absDomainName(host)]; ok { - ipsCp := make([]net.IP, len(ips)) - copy(ipsCp, ips) - return ipsCp - } - } - return nil + return h.lookupStaticHost(h.hmap.byNameV6, host) } // LookupStaticAddr looks up the hosts for the given address from the hosts file. @@ -235,12 +263,14 @@ func (h *Hostsfile) LookupStaticAddr(addr string) []string { if addr == "" { return nil } - if len(h.hmap.byAddr) != 0 { - if hosts, ok := h.hmap.byAddr[addr]; ok { - hostsCp := make([]string, len(hosts)) - copy(hostsCp, hosts) - return hostsCp - } + if len(h.hmap.byAddr) == 0 { + return nil + } + hosts, ok := h.hmap.byAddr[addr] + if !ok { + return nil } - return nil + hostsCp := make([]string, len(hosts)) + copy(hostsCp, hosts) + return hostsCp } |