ipv4ll: do not reset conflict counter on restart

Don't reset the conflict counter when trying a new pseudo random
address, so that after trying 10 addresses the londer timeout is used in
accordance with the RFC

Fixes #14299.

src/libsystemd-network/sd-ipv4acd.c

@@ -441,7 +441,7 @@ int sd_ipv4acd_is_running(sd_ipv4acd *acd) {
         return acd->state != IPV4ACD_STATE_INIT;
 }
 
-int sd_ipv4acd_start(sd_ipv4acd *acd) {
+int sd_ipv4acd_start(sd_ipv4acd *acd, bool reset_conflicts) {
         int r;
 
         assert_return(acd, -EINVAL);
@@ -458,7 +458,9 @@ int sd_ipv4acd_start(sd_ipv4acd *acd) {
         safe_close(acd->fd);
         acd->fd = r;
         acd->defend_window = 0;
-        acd->n_conflict = 0;
+
+        if (reset_conflicts)
+                acd->n_conflict = 0;
 
         r = sd_event_add_io(acd->event, &acd->receive_message_event_source, acd->fd, EPOLLIN, ipv4acd_on_packet, acd);
         if (r < 0)

src/libsystemd-network/sd-ipv4ll.c

@@ -241,7 +241,7 @@ static int ipv4ll_start_internal(sd_ipv4ll *ll, bool reset_generation) {
                 picked_address = true;
         }
 
-        r = sd_ipv4acd_start(ll->acd);
+        r = sd_ipv4acd_start(ll->acd, reset_generation);
         if (r < 0) {
 
                 /* We couldn't start? If so, let's forget the picked address again, the user might make a change and

src/libsystemd-network/test-acd.c

@@ -47,7 +47,7 @@ static int client_run(int ifindex, const struct in_addr *pa, const struct ether_
 
         log_info("starting IPv4ACD client");
 
-        assert_se(sd_ipv4acd_start(acd) >= 0);
+        assert_se(sd_ipv4acd_start(acd, true) >= 0);
 
         assert_se(sd_event_loop(e) >= 0);
 

src/network/networkd-address.c

@@ -670,7 +670,7 @@ int address_configure(
                         log_debug("Starting IPv4ACD client. Probing address %s", strna(pretty));
                 }
 
-                r = sd_ipv4acd_start(address->acd);
+                r = sd_ipv4acd_start(address->acd, true);
                 if (r < 0)
                         log_link_warning_errno(link, r, "Failed to start IPv4ACD client, ignoring: %m");
         }

src/systemd/sd-ipv4acd.h

@@ -20,6 +20,7 @@
 
 #include <net/ethernet.h>
 #include <netinet/in.h>
+#include <stdbool.h>
 
 #include "sd-event.h"
 
@@ -44,7 +45,7 @@ int sd_ipv4acd_set_mac(sd_ipv4acd *acd, const struct ether_addr *addr);
 int sd_ipv4acd_set_ifindex(sd_ipv4acd *acd, int interface_index);
 int sd_ipv4acd_set_address(sd_ipv4acd *acd, const struct in_addr *address);
 int sd_ipv4acd_is_running(sd_ipv4acd *acd);
-int sd_ipv4acd_start(sd_ipv4acd *acd);
+int sd_ipv4acd_start(sd_ipv4acd *acd, bool reset_conflicts);
 int sd_ipv4acd_stop(sd_ipv4acd *acd);
 sd_ipv4acd *sd_ipv4acd_ref(sd_ipv4acd *acd);
 sd_ipv4acd *sd_ipv4acd_unref(sd_ipv4acd *acd);