diff options
| author | Stefan Brüns <stefan.bruens@rwth-aachen.de> | 2015-08-27 23:53:26 +0200 |
|---|---|---|
| committer | Joe Hershberger <joe.hershberger@ni.com> | 2015-10-28 14:54:19 -0500 |
| commit | 867d6ae2c9cec6a0f6f3a7472cf8397693f6cc35 (patch) | |
| tree | 238c0d27100c8607d163908b8bec130e011beb50 | |
| parent | 829533287afbc2aff2b8c65eb0cbf8f8ee887ae2 (diff) | |
net: reject Bootp/DHCP packets with bad OP value
Rename check_packet to check_reply_packet to make its function more
obvious.
The check for DHCP_* values is completely off, as it should
compare against DHCP option 53 (Message Type). Only valid value for
any Bootp/DHCP reply is BOOTREPLY.
Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
| -rw-r--r-- | net/bootp.c | 13 |
1 files changed, 5 insertions, 8 deletions
diff --git a/net/bootp.c b/net/bootp.c index fbdc7cb3a3..3fac7f3b3a 100644 --- a/net/bootp.c +++ b/net/bootp.c @@ -109,7 +109,8 @@ static bool bootp_match_id(ulong id) return false; } -static int check_packet(uchar *pkt, unsigned dest, unsigned src, unsigned len) +static int check_reply_packet(uchar *pkt, unsigned dest, unsigned src, + unsigned len) { struct bootp_hdr *bp = (struct bootp_hdr *)pkt; int retval = 0; @@ -118,11 +119,7 @@ static int check_packet(uchar *pkt, unsigned dest, unsigned src, unsigned len) retval = -1; else if (len < sizeof(struct bootp_hdr) - OPT_FIELD_SIZE) retval = -2; - else if (bp->bp_op != OP_BOOTREQUEST && - bp->bp_op != OP_BOOTREPLY && - bp->bp_op != DHCP_OFFER && - bp->bp_op != DHCP_ACK && - bp->bp_op != DHCP_NAK) + else if (bp->bp_op != OP_BOOTREPLY) retval = -3; else if (bp->bp_htype != HWT_ETHER) retval = -4; @@ -343,7 +340,7 @@ static void bootp_handler(uchar *pkt, unsigned dest, struct in_addr sip, bp = (struct bootp_hdr *)pkt; /* Filter out pkts we don't want */ - if (check_packet(pkt, dest, src, len)) + if (check_reply_packet(pkt, dest, src, len)) return; /* @@ -960,7 +957,7 @@ static void dhcp_handler(uchar *pkt, unsigned dest, struct in_addr sip, src, dest, len, dhcp_state); /* Filter out pkts we don't want */ - if (check_packet(pkt, dest, src, len)) + if (check_reply_packet(pkt, dest, src, len)) return; debug("DHCPHandler: got DHCP packet: (src=%d, dst=%d, len=%d) state: " |