From: Roy Marples <roy@marples.name>
Date: Mon, 20 Apr 2020 21:18:41 +0000 (+0100)
Subject: DHCP: Avoid mis-aligned BOOTP structure
X-Git-Tag: v9.0.2~3
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=504992bdff47a6efeda0503022d333f7c0c63025;p=thirdparty%2Fdhcpcd.git

DHCP: Avoid mis-aligned BOOTP structure

This was caused by the recent change to pass back the frame header.
---

diff --git a/src/dhcp.c b/src/dhcp.c
index 879ce3e5..3fd72f85 100644
--- a/src/dhcp.c
+++ b/src/dhcp.c
@@ -3494,8 +3494,9 @@ dhcp_packet(struct interface *ifp, uint8_t *data, size_t len)
 			    __func__, ifp->name);
 			return;
 		}
-		data += fl;
 		len -= fl;
+		/* Move the data to avoid alignment errors. */
+		memmove(data, data + fl, len);
 	}
 
 	/* Validate filter. */