sd-ipv4ll: Add an explicit stop state for IPv4LL

Add an explicit stop state for IPv4LL so that the user can stop the
IPv4LL client from the callback. When returning from the callback,
check also the stop state in order to halt any further protocol
processing.

1 files changed, 13 insertions, 6 deletions

diff --git a/src/libsystemd-network/sd-ipv4ll.c b/src/libsystemd-network/sd-ipv4ll.c
index 37cb802b63..72289b2baf 100644
--- a/src/libsystemd-network/sd-ipv4ll.c
+++ b/src/libsystemd-network/sd-ipv4ll.c
@@ -61,6 +61,7 @@ typedef enum IPv4LLState {
         IPV4LL_STATE_WAITING_ANNOUNCE,
         IPV4LL_STATE_ANNOUNCING,
         IPV4LL_STATE_RUNNING,
+        IPV4LL_STATE_STOPPED,
         _IPV4LL_STATE_MAX,
         _IPV4LL_STATE_INVALID = -1
 } IPv4LLState;
@@ -264,7 +265,7 @@ static void ipv4ll_run_state_machine(sd_ipv4ll *ll, IPv4LLTrigger trigger, void
                         log_ipv4ll(ll, "ANNOUNCE");
                         ll->claimed_address = ll->address;
                         ll = ipv4ll_client_notify(ll, IPV4LL_EVENT_BIND);
-                        if (!ll)
+                        if (!ll || ll->state == IPV4LL_STATE_STOPPED)
                                 goto out;
 
                         ll->conflict = 0;
@@ -311,7 +312,7 @@ static void ipv4ll_run_state_machine(sd_ipv4ll *ll, IPv4LLTrigger trigger, void
                 if (conflicted) {
                         log_ipv4ll(ll, "CONFLICT");
                         ll = ipv4ll_client_notify(ll, IPV4LL_EVENT_CONFLICT);
-                        if (!ll)
+                        if (!ll || ll->state == IPV4LL_STATE_STOPPED)
                                 goto out;
 
                         ll->claimed_address = 0;
@@ -382,7 +383,8 @@ static int ipv4ll_receive_message(sd_event_source *s, int fd,
 int sd_ipv4ll_set_index(sd_ipv4ll *ll, int interface_index) {
         assert_return(ll, -EINVAL);
         assert_return(interface_index >= -1, -EINVAL);
-        assert_return(ll->state == IPV4LL_STATE_INIT, -EBUSY);
+        assert_return(IN_SET(ll->state, IPV4LL_STATE_INIT,
+                             IPV4LL_STATE_STOPPED), -EBUSY);
 
         ll->index = interface_index;
 
@@ -398,7 +400,7 @@ int sd_ipv4ll_set_mac(sd_ipv4ll *ll, const struct ether_addr *addr) {
         if (memcmp(&ll->mac_addr, addr, ETH_ALEN) == 0)
                 return 0;
 
-        if (ll->state != IPV4LL_STATE_INIT) {
+        if (!IN_SET(ll->state, IPV4LL_STATE_INIT, IPV4LL_STATE_STOPPED)) {
                 log_ipv4ll(ll, "Changing MAC address on running IPv4LL "
                            "client, restarting");
                 ll = ipv4ll_stop(ll, IPV4LL_EVENT_STOP);
@@ -500,7 +502,7 @@ error:
 bool sd_ipv4ll_is_running(sd_ipv4ll *ll) {
         assert_return(ll, -EINVAL);
 
-        return ll->state != IPV4LL_STATE_INIT;
+        return !IN_SET(ll->state, IPV4LL_STATE_INIT, IPV4LL_STATE_STOPPED);
 }
 
 #define HASH_KEY SD_ID128_MAKE(df,04,22,98,3f,ad,14,52,f9,87,2e,d1,9c,70,e2,f2)
@@ -511,7 +513,10 @@ int sd_ipv4ll_start (sd_ipv4ll *ll) {
         assert_return(ll, -EINVAL);
         assert_return(ll->event, -EINVAL);
         assert_return(ll->index > 0, -EINVAL);
-        assert_return(ll->state == IPV4LL_STATE_INIT, -EBUSY);
+        assert_return(IN_SET(ll->state, IPV4LL_STATE_INIT,
+                             IPV4LL_STATE_STOPPED), -EBUSY);
+
+        ll->state = IPV4LL_STATE_INIT;
 
         r = arp_network_bind_raw_socket(ll->index, &ll->link);
 
@@ -572,6 +577,8 @@ out:
 
 int sd_ipv4ll_stop(sd_ipv4ll *ll) {
         ipv4ll_stop(ll, IPV4LL_EVENT_STOP);
+        if (ll)
+                ipv4ll_set_state(ll, IPV4LL_STATE_STOPPED, 1);
 
         return 0;
 }