dhcp: Add test for discover DHCP packet creation

Set a fake MAC address and emulate raw packet sending. When the buffer
containing the Discover message is received, check selected IP and
UDP headers and compute IP header and UDP message checksums. Also
send the DHCP message for option parsing and expect a successful
outcome.

diff --git a/Makefile.am b/Makefile.am
index 7c155141be904abc461675fb6730a933ec54fac8..5828ae19a3240a42edf6ada53df124bf3bb522a5 100644 (file)
--- a/Makefile.am
+++ b/Makefile.am
@@ -3880,6 +3880,8 @@ test_dhcp_client_SOURCES = \
        src/libsystemd-dhcp/dhcp-protocol.h \
        src/systemd/sd-dhcp-client.h \
        src/libsystemd-dhcp/dhcp-client.c \
+       src/libsystemd-dhcp/dhcp-internal.h \
+       src/libsystemd-dhcp/dhcp-option.c \
        src/libsystemd-dhcp/test-dhcp-client.c
 
 test_dhcp_client_LDADD = \

diff --git a/src/libsystemd-dhcp/test-dhcp-client.c b/src/libsystemd-dhcp/test-dhcp-client.c
index d097c7d43c5073590eaddb11148de7186445bfb9..fdcb6b1c495ce4b396d321061a9b21510c002cd1 100644 (file)
--- a/src/libsystemd-dhcp/test-dhcp-client.c
+++ b/src/libsystemd-dhcp/test-dhcp-client.c
@@ -24,9 +24,16 @@
 #include <errno.h>
 #include <stdio.h>
 
+#include "util.h"
+
 #include "dhcp-protocol.h"
+#include "dhcp-internal.h"
 #include "sd-dhcp-client.h"
 
+static struct ether_addr mac_addr = {
+        .ether_addr_octet = {'A', 'B', 'C', '1', '2', '3'}
+};
+
 static void test_request_basic(void)
 {
         sd_dhcp_client *client;
@@ -112,10 +119,83 @@ static void test_checksum(void)
         assert(client_checksum(&buf, 20) == *val);
 }
 
+static int check_options(uint8_t code, uint8_t len, const uint8_t *option,
+                void *user_data)
+{
+        return 0;
+}
+
+int dhcp_network_send_raw_packet(int index, const void *packet, size_t len)
+{
+        size_t size;
+        _cleanup_free_ DHCPPacket *discover;
+        uint16_t ip_check, udp_check;
+        int res;
+
+        assert(index == 42);
+        assert(packet);
+
+        size = sizeof(DHCPPacket) + 4;
+        assert(len > size);
+
+        discover = memdup(packet, len);
+
+        assert(memcmp(discover->dhcp.chaddr,
+                      &mac_addr.ether_addr_octet, 6) == 0);
+        assert(discover->ip.ttl == IPDEFTTL);
+        assert(discover->ip.protocol == IPPROTO_UDP);
+        assert(discover->ip.saddr == INADDR_ANY);
+        assert(discover->ip.daddr == INADDR_BROADCAST);
+        assert(discover->udp.source == ntohs(DHCP_PORT_CLIENT));
+        assert(discover->udp.dest == ntohs(DHCP_PORT_SERVER));
+
+        ip_check = discover->ip.check;
+
+        discover->ip.ttl = 0;
+        discover->ip.check = discover->udp.len;
+
+        udp_check = ~client_checksum(&discover->ip.ttl, len - 8);
+        assert(udp_check == 0xffff);
+
+        discover->ip.ttl = IPDEFTTL;
+        discover->ip.check = ip_check;
+
+        ip_check = ~client_checksum(&discover->ip, sizeof(discover->ip));
+        assert(ip_check == 0xffff);
+
+        size = len - sizeof(struct iphdr) - sizeof(struct udphdr);
+
+        res = dhcp_option_parse(&discover->dhcp, size, check_options, NULL);
+        if (res < 0)
+                return res;
+
+        return 575;
+}
+
+static void test_discover_message(void)
+{
+        sd_dhcp_client *client;
+        int res;
+
+        client = sd_dhcp_client_new();
+        assert(client);
+
+        assert(sd_dhcp_client_set_index(client, 42) >= 0);
+        assert(sd_dhcp_client_set_mac(client, &mac_addr) >= 0);
+
+        assert(sd_dhcp_client_set_request_option(client, 248) >= 0);
+
+        res = sd_dhcp_client_start(client);
+
+        assert(res == 0 || res == -EINPROGRESS);
+}
+
 int main(int argc, char *argv[])
 {
         test_request_basic();
         test_checksum();
 
+        test_discover_message();
+
         return 0;
 }