Merge PR snabbco#37 (ICMP support) into master

.travis.yml

@@ -9,4 +9,6 @@ before_script:
 
 script:
  - make -j
- - (cd src && sudo ./snabb snsh program/vita/test.snabb IMIX 1e6 3)
+ - (cd src && sudo program/vita/selftest.snabb)
+ - (cd src && sudo program/vita/conftest.snabb)
+ - (cd src && sudo program/vita/test.snabb IMIX 1e6 3)

src/apps/test/match.lua

@@ -30,7 +30,10 @@ function Match:push ()
       elseif cmp.length ~= p.length
          or C.memcmp(cmp.data, p.data, cmp.length) ~= 0 then
          if not self.fuzzy then
-            table.insert(self.errs, "Mismatch:\n"..dump(cmp).."\n"..dump(p))
+            table.insert(self.errs,
+                         "Mismatch at packet #"..(self.seen+1)..":\n"
+                            ..dump(cmp).."\n"
+                            ..dump(p))
          end
       else
          self.seen = self.seen + 1

src/lib/protocol/README.md

@@ -197,6 +197,14 @@ Computes and sets the IPv4 header checksum. Its called automatically by
 Predicate methods to test if *ip* is equal to the source or destination
 addresses individually.
 
+— Method **ipv4:swap**
+
+Swaps the source and destination addresses.
+
+— Method **ipv4:is_fragment**
+
+Returns true if the header denotes an IP fragment and false otherwise.
+
 — Function **ipv4:pton** *string*
 
 Returns the binary representation of IPv4 address denoted by *string*.

src/lib/protocol/ipv4.lua

@@ -8,6 +8,8 @@ local header = require("lib.protocol.header")
 local ipsum = require("lib.checksum").ipsum
 local htons, ntohs, htonl, ntohl =
    lib.htons, lib.ntohs, lib.htonl, lib.ntohl
+local band, lshift, rshift, bnot =
+   bit.band, bit.lshift, bit.rshift, bit.bnot
 
 -- TODO: generalize
 local AF_INET = 2
@@ -31,10 +33,10 @@ local ipv4 = subClass(header)
 ipv4._name = "ipv4"
 ipv4._ulp = {
    class_map = {
+       [1] = "lib.protocol.icmp.header",
        [6] = "lib.protocol.tcp",
       [17] = "lib.protocol.udp",
       [47] = "lib.protocol.gre",
-      [58] = "lib.protocol.icmp.header",
    },
    method    = 'protocol' }
 ipv4:init(
@@ -62,7 +64,7 @@ function ipv4:new (config)
    o:ihl(o:sizeof() / 4)
    o:dscp(config.dscp or 0)
    o:ecn(config.ecn or 0)
-   o:total_length(o:sizeof()) -- default to header only
+   o:total_length(config.total_length or o:sizeof()) -- default to header only
    o:id(config.id or 0)
    o:flags(config.flags or 0)
    o:frag_off(config.frag_off or 0)
@@ -139,6 +141,10 @@ function ipv4:frag_off (frag_off)
    return lib.bitfield(16, self:header(), 'frag_off', 3, 13, frag_off)
 end
 
+function ipv4:is_fragment ()
+   return self:frag_off() ~= 0 or band(self:flags(), 0x01) == 1
+end
+
 function ipv4:ttl (ttl)
    if ttl ~= nil then
       self:header().ttl = ttl
@@ -147,6 +153,25 @@ function ipv4:ttl (ttl)
    end
 end
 
+-- Adopted from lwAFTR with love
+function ipv4:ttl_decrement ()
+   local old_ttl = self:ttl()
+   local new_ttl = band(old_ttl - 1, 0xff)
+   self:ttl(new_ttl)
+   local chksum = bnot(ntohs(self:header().checksum))
+   -- Now fix up the checksum. The ttl field is the first byte in the
+   -- 16-bit big-endian word, so the difference to the overall sum is
+   -- multiplied by 0xff.
+   chksum = chksum + lshift(new_ttl - old_ttl, 8)
+   -- Now do the one's complement 16-bit addition of the 16-bit words of
+   -- the checksum, which necessarily is a 32-bit value.  Two carry
+   -- iterations will suffice.
+   chksum = band(chksum, 0xffff) + rshift(chksum, 16)
+   chksum = band(chksum, 0xffff) + rshift(chksum, 16)
+   self:header().checksum = htons(bnot(chksum))
+   return new_ttl
+end
+
 function ipv4:protocol (protocol)
    if protocol ~= nil then
       self:header().protocol = protocol
@@ -174,8 +199,12 @@ function ipv4:src (ip)
    end
 end
 
+local function ip_eq (x, y)
+   return ffi.cast("uint32_t *", x)[0] == ffi.cast("uint32_t *", y)[0]
+end
+
 function ipv4:src_eq (ip)
-   return C.memcmp(ip, self:header().src_ip, ipv4_addr_t_size) == 0
+   return ip_eq(ip, self:header().src_ip, ipv4_addr_t_size)
 end
 
 function ipv4:dst (ip)
@@ -187,7 +216,7 @@ function ipv4:dst (ip)
 end
 
 function ipv4:dst_eq (ip)
-   return C.memcmp(ip, self:header().dst_ip, ipv4_addr_t_size) == 0
+   return ip_eq(ip, self:header().dst_ip, ipv4_addr_t_size)
 end
 
 -- override the default equality method
@@ -199,6 +228,14 @@ function ipv4:eq (other)
          self:src_eq(other:src()) and self:dst_eq(other:dst())
 end
 
+function ipv4:swap ()
+   local tmp = ipv4_addr_t()
+   local h = self:header()
+   ffi.copy(tmp, h.src_ip, ipv4_addr_t_size)
+   ffi.copy(h.dst_ip, h.src_ip, ipv4_addr_t_size)
+   ffi.copy(h.src_ip, tmp, ipv4_addr_t_size)
+end
+
 -- Return a pseudo header for checksum calculation in a upper-layer
 -- protocol (e.g. icmp).  Note that the payload length and next-header
 -- values in the pseudo-header refer to the effective upper-layer

src/program/vita/README.config

@@ -14,7 +14,6 @@ CONFIGURATION SYNTAX
   interface:=
     macaddr <hwaddr>;
     [ vlan <tag>; ]
-    [ mtu <size>; ]
     pciaddr <busaddr>;
 
   route:=
@@ -23,6 +22,7 @@ CONFIGURATION SYNTAX
     gw_ip4 <ipv4addr>;
     preshared_key <string>;
     spi <spi>;
+    [ private_mtu <size>; ]
 
 NOTES
 
@@ -32,10 +32,10 @@ NOTES
   Vita nodes.
 
   Each interface is identified by a Linux PCI bus address, and assigned an
-  Ethernet (MAC) address. Optionally, the MTU can be specified in bytes, and a
-  IEEE 802.1Q VLAN Identifier can be set. Given that the underlying hardware
-  device supports VMDq, it is possible to pass the same PCI bus address for
-  both interfaces to have them share a single physical port.
+  Ethernet (MAC) address. Optionally, a IEEE 802.1Q VLAN Identifier can be set.
+  Given that the underlying hardware device supports VMDq, it is possible to
+  pass the same PCI bus address for both interfaces to have them share a single
+  physical port.
 
   Each route is given a unique, human readable identifier that must satisfy the
   pattern [a-zA-Z0-9_]+ (i.e., one or more alphanumeric ASCII and underscore
@@ -48,13 +48,20 @@ NOTES
   associating encrypted traffic for a given route. Like the pre-shared key, the
   SPI must be the same for both ends of a route.
 
+  Optionally, the private MTU can be specified in bytes. The default and
+  maximum permitted value is 8937. Since Vita performs neither fragmentation
+  nor reassembly it may be necessary to adjust the next-hop MTU accordingly.
+  Note that packets leaving the public interface will have an added packet size
+  overhead due to encapsulation (up to 57 bytes for IPv4 and up to 77 bytes for
+  IPv6.)
+
   While the default configuration should be generally applicable, the
   negotiation timeout and lifetime of Security Associations (SA) can be
   specified in seconds.
 
 EXAMPLE
 
-  private_interface { macaddr 52:54:00:00:00:00; mtu 1280; pciaddr 0c:00.0; }
+  private_interface { macaddr 52:54:00:00:00:00; pciaddr 0c:00.0; }
   public_interface { macaddr 52:54:00:00:00:FF; pciaddr 0c:00.1; }
 
   private_ip4 192.168.10.10;
@@ -76,7 +83,9 @@ EXAMPLE
     net_cidr4 192.168.30.0/24;
     gw_ip4 203.0.113.3;
     preshared_key CF0BDD7A058BE55C12B7F2AA30D23FF01BDF8BE6571F2019ED7F7EBD3DA97B47;
-    spi 1002;
+    spi 1223;
   }
 
+  private_mtu 1280;
+
   sa_ttl 86400;

src/program/vita/conftest.snabb

@@ -11,21 +11,26 @@ local S = require("syscall")
 local confpath = shm.root.."/"..shm.resolve("group/testconf")
 
 local function commit_conf (conf)
-   local f = assert(io.open(confpath, "w"), "Unable to open file: "..confpath)
-   yang.print_config_for_schema(vita.schemata['esp-gateway'], conf, f)
-   f:close()
+   vita.save_config(vita.schemata['esp-gateway'], confpath, conf)
 end
 
+worker.set_exit_on_worker_death(true)
+
 worker.start(
    "PublicRouterLoopback",
    ([[require("program.vita.vita").public_router_loopback_worker(%q)]])
       :format(confpath)
 )
+worker.start(
+   "Exchange",
+   ([[require("program.vita.vita").exchange_worker(%q)]])
+      :format(confpath)
+)
 S.sleep(1)
 
 local conf0 = {
-   private_interface = { macaddr = "52:54:00:00:00:00" },
-   public_interface = { macaddr = "52:54:00:00:00:FF" },
+   private_interface = { pciaddr = "00:00.0", macaddr = "52:54:00:00:00:00" },
+   public_interface = { pciaddr = "00:00.0", macaddr = "52:54:00:00:00:FF" },
    private_ip4 = "192.168.10.1",
    public_ip4 = "203.0.113.1",
    private_nexthop_ip4 = "192.168.10.1",
@@ -37,8 +42,8 @@ commit_conf(conf0)
 S.sleep(3)
 
 local conf1 = {
-   private_interface = { macaddr = "52:54:00:00:00:00" },
-   public_interface = { macaddr = "52:54:00:00:00:FF" },
+   private_interface = { pciaddr = "00:00.0", macaddr = "52:54:00:00:00:00" },
+   public_interface = { pciaddr = "00:00.0", macaddr = "52:54:00:00:00:FF" },
    private_ip4 = "192.168.10.1",
    public_ip4 = "203.0.113.1",
    private_nexthop_ip4 = "192.168.10.1",
@@ -61,8 +66,8 @@ commit_conf(conf1)
 S.sleep(3)
 
 local conf2 = {
-   private_interface = { macaddr = "52:54:00:00:00:00" },
-   public_interface = { macaddr = "52:54:00:00:00:FF" },
+   private_interface = { pciaddr = "00:00.0", macaddr = "52:54:00:00:00:00" },
+   public_interface = { pciaddr = "00:00.0", macaddr = "52:54:00:00:00:FF" },
    private_ip4 = "192.168.10.1",
    public_ip4 = "203.0.113.1",
    private_nexthop_ip4 = "192.168.10.1",
@@ -81,8 +86,8 @@ commit_conf(conf2)
 S.sleep(3)
 
 local conf3 = {
-   private_interface = { macaddr = "52:54:00:00:00:00" },
-   public_interface = { macaddr = "52:54:00:00:00:FF" },
+   private_interface = { pciaddr = "00:00.0", macaddr = "52:54:00:00:00:00" },
+   public_interface = { pciaddr = "00:00.0", macaddr = "52:54:00:00:00:FF" },
    private_ip4 = "192.168.10.1",
    public_ip4 = "203.0.113.1",
    private_nexthop_ip4 = "192.168.10.1",
@@ -101,8 +106,8 @@ commit_conf(conf3)
 S.sleep(3)
 
 local conf4 = {
-   private_interface = { macaddr = "52:54:00:00:00:00" },
-   public_interface = { macaddr = "52:54:00:00:00:FF" },
+   private_interface = { pciaddr = "00:00.0", macaddr = "52:54:00:00:00:00" },
+   public_interface = { pciaddr = "00:00.0", macaddr = "52:54:00:00:00:FF" },
    private_ip4 = "192.168.10.1",
    public_ip4 = "203.0.113.2",
    private_nexthop_ip4 = "192.168.10.1",
@@ -121,8 +126,8 @@ commit_conf(conf4)
 S.sleep(3)
 
 local conf5 = {
-   private_interface = { macaddr = "52:54:00:00:00:00" },
-   public_interface = { macaddr = "52:54:00:00:00:FF" },
+   private_interface = { pciaddr = "00:00.0", macaddr = "52:54:00:00:00:00" },
+   public_interface = { pciaddr = "00:00.0", macaddr = "52:54:00:00:00:FF" },
    private_ip4 = "192.168.10.1",
    public_ip4 = "203.0.113.2",
    private_nexthop_ip4 = "192.168.10.1",
@@ -141,8 +146,8 @@ commit_conf(conf5)
 S.sleep(3)
 
 local conf6 = {
-   private_interface = { macaddr = "52:54:00:00:00:00" },
-   public_interface = { macaddr = "52:54:00:00:00:FF" },
+   private_interface = { pciaddr = "00:00.0", macaddr = "52:54:00:00:00:00" },
+   public_interface = { pciaddr = "00:00.0", macaddr = "52:54:00:00:00:FF" },
    private_ip4 = "192.168.10.1",
    public_ip4 = "203.0.113.2",
    private_nexthop_ip4 = "192.168.10.1",