diff options
| author |   Artem Glazychev <glazychev@mts.ru> | 2024-07-17 16:48:45 +0700 |
|---|---|---|
| committer |   Matthew Smith <mgsmith@netgate.com> | 2024-10-23 13:44:09 +0000 |
| commit | 768c8d4ece46610de15644342a4f63e4ccd2c04f (patch) | |
| tree | 984db831c68ba960975a715a5938cef2c0921942 | |
| parent | 3bd4e47a9ae8eb53f2441aa82e6f18148ee69c2a (diff) | |
dhcp: fix buffer length after adding new option
The size of dhcp option should be o.length + 2 additional bytes of the header.
Incorrect offset results in an extra byte at the end of the packet:
...
0120 04 00 00 00 04 05 04 AC 10 04 01 FF 00
...
RFC2131 says the last should be the 'end' option (ff)
Type: fix
Change-Id: I056d755d29465aab8c1c55a0b930f65ece6fafce
Signed-off-by: Artem Glazychev <glazychev@mts.ru>
| -rw-r--r-- | src/plugins/dhcp/dhcp4_proxy_node.c | 3 | ||||
| -rw-r--r-- | test/test_dhcp.py | 3 |
2 files changed, 5 insertions, 1 deletions
diff --git a/src/plugins/dhcp/dhcp4_proxy_node.c b/src/plugins/dhcp/dhcp4_proxy_node.c index 2b49d49bb7f..740ae8043e0 100644 --- a/src/plugins/dhcp/dhcp4_proxy_node.c +++ b/src/plugins/dhcp/dhcp4_proxy_node.c @@ -321,7 +321,8 @@ dhcp_proxy_to_server_input (vlib_main_t * vm, o->length += id_len + 5; } - len = o->length + 3; + /* 2 bytes for option header 82+len */ + len = o->length + 2; b0->current_length += len; /* Fix IP header length and checksum */ old_l0 = ip0->length; diff --git a/test/test_dhcp.py b/test/test_dhcp.py index e668b7bd1c0..15af323454f 100644 --- a/test/test_dhcp.py +++ b/test/test_dhcp.py @@ -327,6 +327,9 @@ class TestDHCP(VppTestCase): is_discover = True self.assertTrue(is_discover) + # The last option must always be the 'end' option + self.assertEqual(dhcp.options[-1], "end") + data = self.validate_relay_options( pkt, src_intf, src_intf.local_ip4, vpn_id, fib_id, oui ) |