From c56eb57316ac0094aa2b5b805762d239a18f0c63 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Stefan=20Br=C3=BCns?= Date: Fri, 28 Aug 2015 10:15:54 +0200 Subject: [PATCH] net: Fix parsing of Bootp/DHCP option 0 (Pad) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Pad has no len byte, so the normal parsing code fails. Signed-off-by: Stefan Brüns Acked-by: Joe Hershberger --- net/bootp.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/net/bootp.c b/net/bootp.c index 93eff87246..1316f00dd8 100644 --- a/net/bootp.c +++ b/net/bootp.c @@ -776,6 +776,9 @@ static void dhcp_process_options(uchar *popt, struct bootp_hdr *bp) while (popt < end && *popt != 0xff) { oplen = *(popt + 1); switch (*popt) { + case 0: + oplen = -1; /* Pad omits len byte */ + break; case 1: net_copy_ip(&net_netmask, (popt + 2)); break; @@ -879,7 +882,13 @@ static int dhcp_message_type(unsigned char *popt) while (*popt != 0xff) { if (*popt == 53) /* DHCP Message Type */ return *(popt + 2); - popt += *(popt + 1) + 2; /* Scan through all options */ + if (*popt == 0) { + /* Pad */ + popt += 1; + } else { + /* Scan through all options */ + popt += *(popt + 1) + 2; + } } return -1; }