Resolve #1091 Require default feature for ICMP echo request auto reply

Cargo.toml

@@ -97,14 +97,17 @@ defmt = ["dep:defmt", "heapless/defmt"]
 
 "async" = []
 
+# Automatically reply on an ICMP echo request
+"auto-icmp-echo-reply" = []
+
 default = [
   "std", "log", # needed for `cargo test --no-default-features --features default` :/
   "medium-ethernet", "medium-ip", "medium-ieee802154",
   "phy-raw_socket", "phy-tuntap_interface",
   "proto-ipv4",  "proto-dhcpv4", "proto-ipv6", "proto-dns",
   "proto-ipv4-fragmentation", "proto-sixlowpan-fragmentation",
   "socket-raw", "socket-icmp", "socket-udp", "socket-tcp", "socket-dhcpv4", "socket-dns", "socket-mdns",
-  "packetmeta-id", "async", "multicast"
+  "packetmeta-id", "async", "multicast", "auto-icmp-echo-reply"
 ]
 
 # Private features

README.md

@@ -86,7 +86,7 @@ The IGMPv1 and IGMPv2 protocols are supported, and IPv4 multicast is available.
 The ICMPv4 protocol is supported, and ICMP sockets are available.
 
   * ICMPv4 header checksum is supported.
-  * ICMPv4 echo replies are generated in response to echo requests.
+  * ICMPv4 echo replies are generated in response to echo requests by default.
   * ICMP sockets can listen to ICMPv4 Port Unreachable messages, or any ICMPv4 messages with
     a given IPv4 identifier field.
   * ICMPv4 protocol unreachable messages are **not** passed to higher layers when received.
@@ -97,7 +97,7 @@ The ICMPv4 protocol is supported, and ICMP sockets are available.
 The ICMPv6 protocol is supported, and ICMP sockets are available.
 
   * ICMPv6 header checksum is supported.
-  * ICMPv6 echo replies are generated in response to echo requests.
+  * ICMPv6 echo replies are generated in response to echo requests by default.
   * ICMPv6 protocol unreachable messages are **not** passed to higher layers when received.
 
 #### NDISC

ci.sh

@@ -21,17 +21,17 @@ FEATURES_TEST=(
     "std,medium-ethernet,proto-ipv4,multicast,socket-raw,socket-dns"
     "std,medium-ethernet,proto-ipv4,socket-udp,socket-tcp,socket-dns"
     "std,medium-ethernet,proto-ipv4,proto-dhcpv4,socket-udp"
-    "std,medium-ethernet,medium-ip,medium-ieee802154,proto-ipv6,multicast,proto-rpl,socket-udp,socket-dns"
+    "std,medium-ethernet,medium-ip,medium-ieee802154,proto-ipv6,multicast,proto-rpl,socket-udp,socket-dns,auto-icmp-echo-reply"
     "std,medium-ethernet,proto-ipv6,socket-tcp"
     "std,medium-ethernet,medium-ip,proto-ipv4,socket-icmp,socket-tcp"
     "std,medium-ip,proto-ipv6,socket-icmp,socket-tcp"
-    "std,medium-ieee802154,proto-sixlowpan,socket-udp"
-    "std,medium-ieee802154,proto-sixlowpan,proto-sixlowpan-fragmentation,socket-udp"
-    "std,medium-ieee802154,proto-rpl,proto-sixlowpan,proto-sixlowpan-fragmentation,socket-udp"
+    "std,medium-ieee802154,proto-sixlowpan,socket-udp,auto-icmp-echo-reply"
+    "std,medium-ieee802154,proto-sixlowpan,proto-sixlowpan-fragmentation,socket-udp,auto-icmp-echo-reply"
+    "std,medium-ieee802154,proto-rpl,proto-sixlowpan,proto-sixlowpan-fragmentation,socket-udp,auto-icmp-echo-reply"
     "std,medium-ip,proto-ipv4,proto-ipv6,socket-tcp,socket-udp"
-    "std,medium-ethernet,medium-ip,medium-ieee802154,proto-ipv4,proto-ipv6,multicast,proto-rpl,socket-raw,socket-udp,socket-tcp,socket-icmp,socket-dns,async"
+    "std,medium-ethernet,medium-ip,medium-ieee802154,proto-ipv4,proto-ipv6,multicast,proto-rpl,socket-raw,socket-udp,socket-tcp,socket-icmp,socket-dns,async,auto-icmp-echo-reply"
     "std,medium-ip,proto-ipv4,proto-ipv6,multicast,socket-raw,socket-udp,socket-tcp,socket-icmp,socket-dns,async"
-    "std,medium-ieee802154,medium-ip,proto-ipv4,socket-raw"
+    "std,medium-ieee802154,medium-ip,proto-ipv4,socket-raw,auto-icmp-echo-reply"
     "std,medium-ethernet,proto-ipv4,proto-ipsec,socket-raw"
 )
 
@@ -43,7 +43,7 @@ FEATURES_CHECK=(
     "medium-ip,medium-ethernet,medium-ieee802154,proto-ipv6,proto-ipv6,multicast,proto-dhcpv4,proto-ipsec,socket-raw,socket-udp,socket-tcp,socket-icmp,socket-dns,async"
     "defmt,medium-ip,medium-ethernet,proto-ipv6,proto-ipv6,multicast,proto-dhcpv4,socket-raw,socket-udp,socket-tcp,socket-icmp,socket-dns,async"
     "defmt,alloc,medium-ip,medium-ethernet,proto-ipv6,proto-ipv6,multicast,proto-dhcpv4,socket-raw,socket-udp,socket-tcp,socket-icmp,socket-dns,async"
-    "medium-ieee802154,proto-sixlowpan,socket-dns"
+    "medium-ieee802154,proto-sixlowpan,socket-dns,auto-icmp-echo-reply"
 )
 
 test() {

src/iface/interface/ipv4.rs

@@ -345,7 +345,7 @@ impl InterfaceInner {
 
         match icmp_repr {
             // Respond to echo requests.
-            #[cfg(feature = "proto-ipv4")]
+            #[cfg(all(feature = "proto-ipv4", feature = "auto-icmp-echo-reply"))]
             Icmpv4Repr::EchoRequest {
                 ident,
                 seq_no,
@@ -368,6 +368,7 @@ impl InterfaceInner {
             _ if handled_by_icmp_socket => None,
 
             // FIXME: do something correct here?
+            // By doing nothing, this arm handles the case when auto echo replies are disabled.
             _ => None,
         }
     }

src/iface/interface/ipv6.rs

@@ -398,6 +398,7 @@ impl InterfaceInner {
 
         match icmp_repr {
             // Respond to echo requests.
+            #[cfg(feature = "auto-icmp-echo-reply")]
             Icmpv6Repr::EchoRequest {
                 ident,
                 seq_no,
@@ -441,6 +442,7 @@ impl InterfaceInner {
             _ if handled_by_icmp_socket => None,
 
             // FIXME: do something correct here?
+            // By doing nothing, this arm handles the case when auto echo replies are disabled.
             _ => None,
         }
     }

src/iface/interface/tests/ipv4.rs

@@ -381,9 +381,9 @@ fn test_icmp_error_port_unreachable(#[case] medium: Medium) {
 
 #[rstest]
 #[case(Medium::Ip)]
-#[cfg(feature = "medium-ip")]
+#[cfg(all(feature = "medium-ip", feature = "auto-icmp-echo-reply"))]
 #[case(Medium::Ethernet)]
-#[cfg(feature = "medium-ethernet")]
+#[cfg(all(feature = "medium-ethernet", feature = "auto-icmp-echo-reply"))]
 fn test_handle_ipv4_broadcast(#[case] medium: Medium) {
     use crate::wire::{Icmpv4Packet, Icmpv4Repr};
 
@@ -626,9 +626,17 @@ fn test_arp_flush_after_update_ip(#[case] medium: Medium) {
 
 #[rstest]
 #[case(Medium::Ip)]
-#[cfg(all(feature = "socket-icmp", feature = "medium-ip"))]
+#[cfg(all(
+    feature = "socket-icmp",
+    feature = "medium-ip",
+    feature = "auto-icmp-echo-reply",
+))]
 #[case(Medium::Ethernet)]
-#[cfg(all(feature = "socket-icmp", feature = "medium-ethernet"))]
+#[cfg(all(
+    feature = "socket-icmp",
+    feature = "medium-ethernet",
+    feature = "auto-icmp-echo-reply",
+))]
 fn test_icmpv4_socket(#[case] medium: Medium) {
     use crate::wire::Icmpv4Packet;