shithub: mc

Download patch

ref: 0332d1906fe2722d135ecff3466142f2d4703c11
parent: 073546effee37340cd682778536bb84a77110cad
parent: 7fe8f299454bc2238a549e7dad31c0956aed26a9
author: Ori Bernstein <[email protected]>
date: Tue Oct 29 15:07:22 EDT 2013 

Merge branch 'master' of git+ssh://git.eigenstate.org/git/ori/mc


--- a/libstd/resolve.myr
+++ b/libstd/resolve.myr
@@ -1,7 +1,9 @@
 use "alloc.use"
+use "die.use"
 use "endian.use"
 use "error.use"
 use "fmt.use"
+use "slcp.use"
 use "sys.use"
 use "types.use"
 
@@ -25,6 +27,16 @@
 	const resolve	: (host : byte[:]	-> hostinfo#)
 ;;
 
+type dnshdr = struct
+	id	: uint16
+	/* {qr:1|op:4|aa:1|tc:1|rd:1|ra:1|z:3|rcode:4} */
+	flags	: uint16  
+	qdcnt	: uint16
+	ancnt	: uint16
+	nscnt	: uint16
+	arcnt	: uint16
+;;
+
 const resolve = {host : byte[:]
 	var hinf
 
@@ -54,7 +66,7 @@
 	var s
 	var status
 	
-	s = socket(Afinet, Sockstream, 0)
+	s = socket(Afinet, Sockdgram, 0)
 	if s < 0
 		put("Warning: Failed to open socket: %l\n", s)
 		-> -1
@@ -72,8 +84,96 @@
 }
 
 const dnsquery = {srv, host
+	tquery(srv, host)
+	rquery(srv)
 	put("Unimplemented query: srv=%z, host=%s\n", srv, host)
 	-> false
+}
+
+const Qr : uint16 = 1 << 0
+const Aa : uint16 = 1 << 4
+const Tc : uint16 = 1 << 5
+const Rd : uint16 = 1 << 6
+const Ra : uint16 = 1 << 7
+
+var nextid = 0
+const tquery = {srv, host
+	var pkt : byte[512] /* big enough */
+	var off
+
+	/* header */
+	off = 0
+	off += pack16(pkt[:], off, nextid++)	/* id */
+	off += pack16(pkt[:], off, Qr|Ra|Rd)	/* flags */
+	off += pack16(pkt[:], off, 1)	/* qdcount */
+	off += pack16(pkt[:], off, 0)	/* ancount */
+	off += pack16(pkt[:], off, 0)	/* nscount */
+	off += pack16(pkt[:], off, 0)	/* arcount */
+
+	/* query */
+	off += packname(pkt[:], off, host)	/* host */
+	off += pack16(pkt[:], off, 0x1) /* qtype: a record */
+	off += pack16(pkt[:], off, 0x1) /* qclass: inet4 */
+
+	write(srv, pkt[:off])
+}
+
+const rquery = {srv
+	var pktbuf : byte[1024]
+	var n
+
+	n = read(srv, pktbuf[:])
+	if n < 0
+		put("Warning: Failed to read from %z: %i\n", srv, n)
+	;;
+	put("pkt: [len = %z]: %s\n", n, pktbuf[:n])
+}
+
+const pack16 = {buf, off, v
+	buf[off]	= (v & 0xff00) >> 8 castto(byte)
+	buf[off+1]	= (v & 0x00ff) castto(byte)
+	-> sizeof(uint16) /* we always write one uint16 */
+}
+
+/*
+const unpack16 = {buf, off
+	var v
+
+	v = (buf[off] castto(uint16)) << 8
+	v |= (buf[off + 1] castto(uint16))
+	-> (v, sizeof(uint16))
+}
+*/
+
+const packname = {buf, off, host
+	var i
+	var start
+	var seglen
+	var lastseg
+
+	start = off
+	lastseg = 0
+	for i = 0; i < host.len; i++
+		if host[i] == ('.' castto(byte))
+			off += addseg(buf, off, host[lastseg:lastseg+seglen])
+			lastseg = seglen + 1
+			seglen = 0
+		;;
+		seglen++
+	;;
+	if host[host.len - 1] != ('.' castto(byte))
+		off += addseg(buf, off, host[lastseg:lastseg + seglen])
+	;;
+	off += addseg(buf, off, "") /* null terminating segment */
+	put("size: %z\n", off - start)
+	-> off - start
+}
+
+const addseg = {buf, off, str
+	put("Adding seg %s\n", str)
+	buf[0] = str.len castto(byte)
+	slcp(buf[off + 1 : off + str.len + 1], str)
+	-> str.len
 }
 
 const valid = {host : byte[:]