tests: net: dhcpv4: client: Verify that Pad option is handled

Add Pad option to the DHCP packets generated by the fake server, to
verify the client processes them correctly.

Signed-off-by: Robert Lubos <robert.lubos@nordicsemi.no>

Author: rlubos

tests/net/dhcpv4/client/src/main.c

@@ -37,7 +37,7 @@ LOG_MODULE_REGISTER(net_test, CONFIG_NET_DHCPV4_LOG_LEVEL);
 #include "net_private.h"
 
 /* Sample DHCP offer (420 bytes) */
-static const unsigned char offer[420] = {
+static const unsigned char offer[] = {
 0x02, 0x01, 0x06, 0x00, 0x00, 0x00,
 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 0x00, 0x00, 0x0a, 0xed, 0x48, 0x9e, 0x0a, 0xb8,
@@ -70,6 +70,8 @@ static const unsigned char offer[420] = {
 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 /* Magic cookie: DHCP */
 0x63, 0x82, 0x53, 0x63,
+/* [0] Pad option */
+0x00,
 /* [53] DHCP Message Type: OFFER */
 0x35, 0x01, 0x02,
 /* [1] Subnet Mask: 255.255.255.0 */
@@ -124,7 +126,7 @@ static const unsigned char offer[420] = {
 };
 
 /* Sample DHCPv4 ACK */
-static const unsigned char ack[420] = {
+static const unsigned char ack[] = {
 0x02, 0x01, 0x06, 0x00, 0x00, 0x00, 0x00, 0x00,
 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 0x0a, 0xed, 0x48, 0x9e, 0x00, 0x00, 0x00, 0x00,
@@ -157,6 +159,8 @@ static const unsigned char ack[420] = {
 0x00, 0x00, 0x00, 0x00,
 /* Magic cookie: DHCP */
 0x63, 0x82, 0x53, 0x63,
+/* [0] Pad option */
+0x00,
 /* [53] DHCP Message Type: ACK */
 0x35, 0x01, 0x05,
 /* [58] Renewal Time Value: (21600s) 6 hours */