[hackers] [sdhcp] [PATCH] Request mask, router and DNS server options

From: Michael Forney <mforney_AT_mforney.org>
Date: Sat, 10 Aug 2019 13:03:32 -0700

I've run into a DHCP server that doesn't send these unless they are
requested.

---
 sdhcp.c | 2 ++
 1 file changed, 2 insertions(+)
diff --git a/sdhcp.c b/sdhcp.c
index 1fcf5e6..7e3f7f5 100644
--- a/sdhcp.c
+++ b/sdhcp.c
_AT_@ -267,6 +267,7 @@ hnoptput(unsigned char *p, int opt, uint32_t data, size_t len)
 static void
 dhcpsend(int type, int how)
 {
+	static unsigned char params[] = { OBmask, OBrouter, OBdnsserver };
 	unsigned char *ip, *p;
 
 	memset(&bp, 0, sizeof(bp));
_AT_@ -290,6 +291,7 @@ dhcpsend(int type, int how)
 		/* memcpy(bp.ciaddr, client, sizeof bp.ciaddr); */
 		p = optput(p, ODipaddr, client, sizeof(client));
 		p = optput(p, ODserverid, server, sizeof(server));
+		p = optput(p, ODparams, params, sizeof(params));
 		break;
 	case DHCPrelease:
 		memcpy(bp.ciaddr, client, sizeof(client));
-- 
2.20.1

Received on Sat Aug 10 2019 - 22:03:32 CEST