... unless it is listed in 55.
Many clients expect option 53 at the beginning.
mTCP has this code:
if ( resp->options[0] != 53 ) {
TRACE_WARN(( "Dhcp: first option was not a Dhcp msg type\n" ));
return;
}
wattcp32 has this:
static int DHCP_is_ack (void)
{
const BYTE *opt = (const BYTE*) &dhcp_in.dh_opt[4];
return (opt[0] == DHCP_OPT_MSG_TYPE && opt[1] == 1 && opt[2] ==
DHCP_ACK);
}
static int DHCP_is_nack (void)
{
const BYTE *opt = (const BYTE*) &dhcp_in.dh_opt[4];
return (opt[0] == DHCP_OPT_MSG_TYPE && opt[1] == 1 && opt[2] ==
DHCP_NAK);
}
Link: https://bugs.passt.top/show_bug.cgi?id=77
Signed-off-by: Stas Sergeev <stsp2(a)yandex.ru>
---
dhcp.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/dhcp.c b/dhcp.c
index 46c258e..eed1b4a 100644
--- a/dhcp.c
+++ b/dhcp.c
@@ -149,6 +149,12 @@ static int fill(struct msg *m)
for (o = 0; o < 255; o++)
opts[o].sent = 0;
+ /* Some clients (wattcp32, mTCP, maybe some other) expect
+ * options 53 at the beginning of the list.
+ * Put it there explicitly, unless requested via option 55.
+ */
+ if (!memchr(opts[55].c, 53, opts[55].clen))
+ fill_one(m, 53, &offset);
for (i = 0; i < opts[55].clen; i++) {
o = opts[55].c[i];
if (opts[o].slen)
--
2.40.1