diff options
| author | Guy Harris <guy@alum.mit.edu> | 1999-10-22 03:52:06 +0000 |
|---|---|---|
| committer | Guy Harris <guy@alum.mit.edu> | 1999-10-22 03:52:06 +0000 |
| commit | 2d16674a5ab27b7472aa9e7b7d2657848004bc3d (patch) | |
| tree | e4afe742e62adba0c9fce1d551b35a53bf881fbd /packet-ip.c | |
| parent | 25c3854517e6d88b1b3ad0e8f6b5436c47bbae2e (diff) | |
Check to make sure the header length is at least the minimum length for
an IP header.
svn path=/trunk/; revision=906
Diffstat (limited to 'packet-ip.c')
| -rw-r--r-- | packet-ip.c | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/packet-ip.c b/packet-ip.c index 2a7c1d2f74..c07d70884e 100644 --- a/packet-ip.c +++ b/packet-ip.c @@ -1,7 +1,7 @@ /* packet-ip.c * Routines for IP and miscellaneous IP protocol packet disassembly * - * $Id: packet-ip.c,v 1.56 1999/10/16 20:59:03 deniel Exp $ + * $Id: packet-ip.c,v 1.57 1999/10/22 03:52:06 guy Exp $ * * Ethereal - Network traffic analyzer * By Gerald Combs <gerald@zing.org> @@ -173,6 +173,9 @@ typedef struct _e_ip { guint32 ip_dst; } e_ip; +/* Minimum IP header length. */ +#define IPH_MIN_LEN 20 + /* IP flags. */ #define IP_CE 0x8000 /* Flag: "Congestion" */ #define IP_DF 0x4000 /* Flag: "Don't Fragment" */ @@ -679,7 +682,12 @@ dissect_ip(const u_char *pd, int offset, frame_data *fd, proto_tree *tree) { int advance; guint8 nxt; - /* To do: check for runts, errs, etc. */ + /* To do: check for errs, etc. */ + if (!BYTES_ARE_IN_FRAME(offset, IPH_MIN_LEN)) { + dissect_data(pd, offset, fd, tree); + return; + } + /* Avoids alignment problems on many architectures. */ memcpy(&iph, &pd[offset], sizeof(e_ip)); iph.ip_len = ntohs(iph.ip_len); @@ -698,6 +706,7 @@ dissect_ip(const u_char *pd, int offset, frame_data *fd, proto_tree *tree) { if (pi.captured_len > len) pi.captured_len = len; + /* XXX - check to make sure this is at least IPH_MIN_LEN. */ hlen = lo_nibble(iph.ip_v_hl) * 4; /* IP header length, in bytes */ switch (iph.ip_p) { |