sd-dhcp-client: fix strict aliasing issue

diff --git a/src/libsystemd-network/sd-dhcp-client.c b/src/libsystemd-network/sd-dhcp-client.c
index 4224e0197cdfa6729dfcb57ba21e8bb95c82a4a5..a477cccecb934e8244420f3a1031eadd225644df 100644 (file)
--- a/src/libsystemd-network/sd-dhcp-client.c
+++ b/src/libsystemd-network/sd-dhcp-client.c
@@ -1469,7 +1469,7 @@ static int client_receive_message_udp(sd_event_source *s, int fd,
         _cleanup_free_ DHCPMessage *message = NULL;
         int buflen = 0, len, r;
         const struct ether_addr zero_mac = { { 0, 0, 0, 0, 0, 0 } };
         _cleanup_free_ DHCPMessage *message = NULL;
         int buflen = 0, len, r;
         const struct ether_addr zero_mac = { { 0, 0, 0, 0, 0, 0 } };

-        const struct ether_addr *expected_chaddr = NULL;
+        bool expect_chaddr;

         uint8_t expected_hlen = 0;
 
         assert(s);
         uint8_t expected_hlen = 0;
 
         assert(s);


@@ -1514,11 +1514,11 @@ static int client_receive_message_udp(sd_event_source *s, int fd,
 
         if (client->arp_type == ARPHRD_ETHER) {
                 expected_hlen = ETH_ALEN;
 
         if (client->arp_type == ARPHRD_ETHER) {
                 expected_hlen = ETH_ALEN;

-                expected_chaddr = (const struct ether_addr *) &client->mac_addr;
+                expect_chaddr = true;

         } else {
                /* Non-ethernet links expect zero chaddr */
                expected_hlen = 0;
         } else {
                /* Non-ethernet links expect zero chaddr */
                expected_hlen = 0;

-               expected_chaddr = &zero_mac;
+               expect_chaddr = false;

         }
 
         if (message->hlen != expected_hlen) {
         }
 
         if (message->hlen != expected_hlen) {


@@ -1526,7 +1526,10 @@ static int client_receive_message_udp(sd_event_source *s, int fd,
                 return 0;
         }
 
                 return 0;
         }
 

-        if (memcmp(&message->chaddr[0], expected_chaddr, ETH_ALEN)) {
+        if (memcmp(&message->chaddr[0], expect_chaddr ?
+                                          (void *)&client->mac_addr :
+                                          (void *)&zero_mac,
+                                        ETH_ALEN)) {

                 log_dhcp_client(client, "received chaddr does not match "
                                 "expected: ignoring");
                 return 0;
                 log_dhcp_client(client, "received chaddr does not match "
                                 "expected: ignoring");
                 return 0;