ip,ip6: remove the builtin ICMP echo API

The grcli ping and traceroute commands are gone, and nothing else ever
called GR_IP4_ICMP_SEND, GR_IP4_ICMP_RECV or their IPv6 counterparts.
What they drove goes with them: the session pool that held a reply until
a client came to collect it, the two icmp_local_send nodes that built the
echo requests, and the parsers that walked an error message looking for
one of our own probes.

The punt callback loses its session lookup and hands everything to the
kernel. It keeps the drain check the pool used to do: a message that came
in on an interface being removed is dropped rather than quietly delivered
on the VRF loopback, which is where it would land once the addresses of
that interface are gone.

Deciding whether a message is well formed no longer happens here. The
input nodes do it, so what reaches the callback has already been checked
against RFC 792 and RFC 4443, and the errno the parsers used to carry is
not needed to tell a malformed message from one that is simply not ours.

icmp_output stays, icmp_input and ip_error both feed it, so grout still
answers echo requests and still emits the time exceeded that traceroute
walks through.

Signed-off-by: Maxime Leroy <maxime@leroys.fr>

Author: maxime-leroy

README.md

@@ -164,14 +164,12 @@ graph                Show packet processing graph info (requires interfaces to b
 interface            Interfaces.
 logging              Ingress/egress packet logging.
 nexthop              Nexthops.
-ping                 Send ICMPv6 echo requests and wait for replies.
 quit                 Exit the CLI.
 route                Routing tables.
 router-advert        IPv6 router advertisements.
 snat44               Dynamic source NAT44.
 stats                Packet processing statistics.
 trace                Packet tracing.
-traceroute           Discover IPv6 intermediate gateways.
 tunsrc               SRv6 source address.
 grout# interface show
 NAME  ID   FLAGS       MODE  DOMAIN  TYPE  INFO
@@ -218,7 +216,6 @@ graph               (Show packet processing graph info (requires interfaces to b
 interface           (Interfaces.)
 logging             (Ingress/egress packet logging.)
 nexthop             (Nexthops.)
-ping                (Send ICMPv6 echo requests and wait for replies.)
 quit                (Exit the CLI.)
 route               (Routing tables.)
 router-advert       (IPv6 router advertisements.)
@@ -228,7 +225,6 @@ snat44              (Dynamic source NAT44.)
 stats               (Packet processing statistics.)
 --trace-commands    (Print executed commands.)
 trace               (Packet tracing.)
-traceroute          (Discover IPv6 intermediate gateways.)
 tunsrc              (SRv6 source address.)
 -x                  (Print executed commands.)
 [root@grout]$ grcli stats <TAB><TAB>

api/gr_api.h

@@ -11,7 +11,7 @@
 #include <stdlib.h>
 
 // Must be bumped when making non-backward compatible changes in API headers
-#define GR_API_VERSION 11
+#define GR_API_VERSION 12
 
 // API request header.
 struct gr_api_request {

docs/graph.svg

@@ -4,7 +4,6 @@
 src += files(
   'bond.c',
   'ctlplane.c',
-  'icmp_session.c',
   'graph.c',
   'group_nexthop.c',
   'iface.c',

modules/infra/control/icmp_session.c

@@ -35,8 +35,6 @@ enum gr_ip4_requests : uint32_t {
 	GR_IP4_ADDR_DEL,
 	GR_IP4_ADDR_LIST,
 	GR_IP4_ADDR_FLUSH,
-	GR_IP4_ICMP_SEND,
-	GR_IP4_ICMP_RECV,
 	GR_IP4_FIB_DEFAULT_SET,
 	GR_IP4_FIB_INFO_LIST,
 };
@@ -117,37 +115,6 @@ struct gr_ip4_addr_flush_req {
 
 GR_REQ(GR_IP4_ADDR_FLUSH, struct gr_ip4_addr_flush_req, struct gr_empty);
 
-// icmp ////////////////////////////////////////////////////////////////////////
-
-// Send an ICMP echo request (ping).
-struct gr_ip4_icmp_send_req {
-	ip4_addr_t addr;
-	uint16_t vrf;
-	uint16_t ident;
-	uint16_t seq_num;
-	uint8_t ttl;
-};
-
-GR_REQ(GR_IP4_ICMP_SEND, struct gr_ip4_icmp_send_req, struct gr_empty);
-
-// Receive an ICMP echo reply (ping response) or error.
-struct gr_ip4_icmp_recv_req {
-	uint16_t ident;
-	uint16_t seq_num;
-};
-
-struct gr_ip4_icmp_recv_resp {
-	uint8_t type;
-	uint8_t code;
-	uint8_t ttl;
-	uint16_t ident;
-	uint16_t seq_num;
-	ip4_addr_t src_addr;
-	gr_clock_ns_t response_time;
-};
-
-GR_REQ(GR_IP4_ICMP_RECV, struct gr_ip4_icmp_recv_req, struct gr_ip4_icmp_recv_resp);
-
 // fib info ////////////////////////////////////////////////////////////////////
 
 // FIB status for a VRF.