Inline some ICMP helpers into their use modules

src/apps/ipv4/echo.lua

@@ -16,12 +16,16 @@ local engine = require("core.app")
 local receive, transmit = link.receive, link.transmit
 local wr16, rd32, wr32 = lwutil.wr16, lwutil.rd32, lwutil.wr32
 local get_ihl_from_offset = lwutil.get_ihl_from_offset
+local is_ipv4 = lwutil.is_ipv4
 local htons = lib.htons
 
 local ehs = constants.ethernet_header_size
+local proto_icmp = constants.proto_icmp
+local o_ipv4_proto = constants.ethernet_header_size + constants.o_ipv4_proto
 local o_ipv4_ver_and_ihl = ehs + constants.o_ipv4_ver_and_ihl
 local o_ipv4_checksum = ehs + constants.o_ipv4_checksum
 local o_icmpv4_msg_type_sans_ihl = ehs + constants.o_icmpv4_msg_type
+local o_icmpv4_msg_code_sans_ihl = ehs + constants.o_icmpv4_msg_code
 local o_icmpv4_checksum_sans_ihl = ehs + constants.o_icmpv4_checksum
 local icmpv4_echo_request = constants.icmpv4_echo_request
 local icmpv4_echo_reply = constants.icmpv4_echo_reply
@@ -41,13 +45,27 @@ function ICMPEcho:new(conf)
    return setmetatable({addresses = addresses}, {__index = ICMPEcho})
 end
 
+local function is_icmpv4(pkt)
+   return is_ipv4(pkt) and pkt.data[o_ipv4_proto] == proto_icmp
+end
+
+local function is_icmpv4_echo_request(pkt)
+   if is_icmpv4(pkt) then
+      local ihl = get_ihl_from_offset(pkt, o_ipv4_ver_and_ihl)
+      return pkt.data[o_icmpv4_msg_type_sans_ihl + ihl] == icmpv4_echo_request
+         and pkt.data[o_icmpv4_msg_code_sans_ihl + ihl] == 0
+   else
+      return false
+   end
+end
+
 function ICMPEcho:push()
    local l_in, l_out, l_reply = self.input.south, self.output.north, self.output.south
 
    for _ = 1, link.nreadable(l_in) do
       local out, pkt = l_out, receive(l_in)
 
-      if icmp.is_icmpv4_message(pkt, icmpv4_echo_request, 0) then
+      if is_icmpv4_echo_request(pkt) then
          local pkt_ipv4 = ipv4:new_from_mem(pkt.data + ehs,
                                             pkt.length - ehs)
          local pkt_ipv4_dst = rd32(pkt_ipv4:dst())

src/apps/ipv6/echo.lua

@@ -25,8 +25,10 @@ local ipv6_fixed_header_size = constants.ipv6_fixed_header_size
 
 local proto_icmpv6 = constants.proto_icmpv6
 local ethernet_header_size = constants.ethernet_header_size
+local o_ipv6_next_header = ethernet_header_size + constants.o_ipv6_next_header
 local o_icmpv6_header = ethernet_header_size + ipv6_fixed_header_size
 local o_icmpv6_msg_type = o_icmpv6_header + constants.o_icmpv6_msg_type
+local o_icmpv6_msg_code = o_icmpv6_header + constants.o_icmpv6_msg_code
 local o_icmpv6_checksum = o_icmpv6_header + constants.o_icmpv6_checksum
 local icmpv6_echo_request = constants.icmpv6_echo_request
 local icmpv6_echo_reply = constants.icmpv6_echo_reply
@@ -47,13 +49,24 @@ function ICMPEcho:new(conf)
    return setmetatable({addresses = addresses}, {__index = ICMPEcho})
 end
 
+local function is_icmpv6(pkt)
+   return is_ipv6(pkt) and pkt.data[o_ipv6_next_header] == proto_icmpv6
+end
+
+
+local function is_icmpv6_echo_request(pkt)
+   return is_icmpv6(pkt)
+      and pkt.data[o_icmpv6_msg_type] == icmpv6_echo_request
+      and pkt.data[o_icmpv6_msg_code] == 0
+end
+
 function ICMPEcho:push()
    local l_in, l_out, l_reply = self.input.south, self.output.north, self.output.south
 
    for _ = 1, link.nreadable(l_in) do
       local out, pkt = l_out, receive(l_in)
 
-      if icmp.is_icmpv6_message(pkt, icmpv6_echo_request, 0) then
+      if is_icmpv6_echo_request(pkt) then
          local pkt_ipv6 = ipv6:new_from_mem(pkt.data + ethernet_header_size,
                                             pkt.length - ethernet_header_size)
          local pkt_ipv6_dst = ffi.string(pkt_ipv6:dst(), 16)

src/apps/lwaftr/icmp.lua

@@ -16,20 +16,10 @@ local lib = require("core.lib")
 local band, bnot = bit.band, bit.bnot
 local C = ffi.C
 local wr16, wr32 = lwutil.wr16, lwutil.wr32
-local is_ipv4, is_ipv6 = lwutil.is_ipv4, lwutil.is_ipv6
 local get_ihl_from_offset = lwutil.get_ihl_from_offset
 local htons, ntohs = lib.htons, lib.ntohs
 local write_eth_header = lwheader.write_eth_header
 
-local proto_icmp = constants.proto_icmp
-local proto_icmpv6 = constants.proto_icmpv6
-local o_ipv4_proto = constants.ethernet_header_size + constants.o_ipv4_proto
-local o_ipv4_ver_and_ihl = constants.ethernet_header_size + constants.o_ipv4_ver_and_ihl
-local o_icmpv4_msg_type_sans_ihl = constants.ethernet_header_size + constants.o_icmpv4_msg_type
-local o_icmpv4_msg_code_sans_ihl = constants.ethernet_header_size + constants.o_icmpv4_msg_code
-local o_ipv6_next_header = constants.ethernet_header_size + constants.o_ipv6_next_header
-local o_icmpv6_msg_type = constants.ethernet_header_size + constants.ipv6_fixed_header_size + constants.o_icmpv6_msg_type
-local o_icmpv6_msg_code = constants.ethernet_header_size + constants.ipv6_fixed_header_size + constants.o_icmpv6_msg_code
 local ehs = constants.ethernet_header_size
 
 local function calculate_payload_size(dst_pkt, initial_pkt, max_size, config)
@@ -106,20 +96,6 @@ function new_icmpv4_packet(from_ip, to_ip, initial_pkt, config)
    return new_pkt
 end
 
-function is_icmpv4(pkt)
-   return is_ipv4(pkt) and pkt.data[o_ipv4_proto] == proto_icmp
-end
-
-function is_icmpv4_message(pkt, msg_type, msg_code)
-   if is_icmpv4(pkt) then
-      local ihl = get_ihl_from_offset(pkt, o_ipv4_ver_and_ihl)
-      return pkt.data[o_icmpv4_msg_type_sans_ihl + ihl] == msg_type
-         and pkt.data[o_icmpv4_msg_code_sans_ihl + ihl] == msg_code
-   else
-      return false
-   end
-end
-
 function new_icmpv6_packet(from_ip, to_ip, initial_pkt, config)
    local new_pkt = packet.allocate()
    local dgram = to_datagram(new_pkt)
@@ -144,12 +120,3 @@ function new_icmpv6_packet(from_ip, to_ip, initial_pkt, config)
    ipv6_header:free()
    return new_pkt
 end
-
-function is_icmpv6(pkt)
-   return is_ipv6(pkt) and pkt.data[o_ipv6_next_header] == proto_icmpv6
-end
-
-
-function is_icmpv6_message(pkt, msg_type, msg_code)
-   return is_icmpv6(pkt) and pkt.data[o_icmpv6_msg_type] == msg_type and pkt.data[o_icmpv6_msg_code] == msg_code
-end