ping: add hostname resolution

2 files changed, 35 insertions, 1 deletions

diff --git a/main.nim b/main.nim
index 04a81f1..be77427 100644
--- a/main.nim
+++ b/main.nim
@@ -70,7 +70,7 @@ proc main() =
     of "max": max = parseInt(val)
 
     of "ping":
-      let targetIp = parseIpAddress(val)
+      let targetIp = resolve(val)
       let mon = initPingMonitor(targetIp, procIdent())
       probe = (timeout: Duration) => mon.ping(timeout).inMilliseconds.int
 
diff --git a/ping.nim b/ping.nim
index c99da96..b09d5f1 100644
--- a/ping.nim
+++ b/ping.nim
@@ -167,6 +167,40 @@ proc receiveReply(sock: Socket, timeout: Duration): seq[uint8] =
   stripIPHeader(ipAddr.family, cast[seq[uint8]](buffer))
 
 
+func toIpAddress(info: ptr AddrInfo): IpAddress =
+  case info.ai_family:
+  of posix.AF_INET6:
+    let sockAddr = cast[ptr posix.SockAddr_in6](info.ai_addr)[]
+    IpAddress(
+      family: IPv6,
+      address_v6: cast[array[0..15, uint8]](sockAddr.sin6_addr.s6_addr),
+    )
+  of posix.AF_INET:
+    let sockAddr = cast[ptr posix.SockAddr_in](info.ai_addr)[]
+    IpAddress(
+      family: IPv4,
+      address_v4: cast[array[0..3, uint8]](sockAddr.sin_addr.s_addr),
+    )
+  else:
+    raise newException(ValueError, "Invalid address info")
+
+func splitDomainHostname(target: string): (Domain, string) =
+  let parts = target.split('/', 1)
+  case parts[0]:
+  of "6": (AF_INET6, parts[1])
+  of "4": (AF_INET, parts[1])
+  else: (AF_UNSPEC, target)
+
+proc resolve*(target: string): IpAddress =
+  try:
+    parseIpAddress(target)
+  except ValueError:
+    let (domain, hostname) = splitDomainHostname(target)
+    let addrInfo = getAddrInfo(hostname, Port 0, domain)
+    defer: freeAddrInfo(addrInfo)
+    addrInfo.toIpAddress
+
+
 type PingMonitor = ref object
   socket: Socket
   target: IpAddress