*
* This code is derived from the Stanford/CMU enet packet filter,
* (net/enet.c) distributed as part of 4.3BSD, and code contributed
- * to Berkeley by Steven McCanne and Van Jacobson both of Lawrence
+ * to Berkeley by Steven McCanne and Van Jacobson both of Lawrence
* Berkeley Laboratory.
*
* Redistribution and use in source and binary forms, with or without
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
- * @(#) $Header: /tcpdump/master/tcpdump/sll.h,v 1.1 2000-12-21 10:43:23 guy Exp $ (LBL)
+ * @(#) $Header: /tcpdump/master/tcpdump/sll.h,v 1.7.6.1 2008-05-30 01:38:21 guy Exp $ (LBL)
*/
/*
* specified by the previous value.
*
* All fields except for the link-layer address are in network byte order.
+ *
+ * DO NOT change the layout of this structure, or change any of the
+ * LINUX_SLL_ values below. If you must change the link-layer header
+ * for a "cooked" Linux capture, introduce a new DLT_ type (ask
+ * a value that collides with a value already being used), and use the
+ * new header in captures of that type, so that programs that can
+ * handle DLT_LINUX_SLL captures will continue to handle them correctly
+ * without any change, and so that capture files with different headers
+ * can be told apart and programs that read them can dissect the
+ * packets in them.
+ *
+ * This structure, and the #defines below, must be the same in the
+ * libpcap and tcpdump versions of "sll.h".
*/
/*
struct sll_header {
u_int16_t sll_pkttype; /* packet type */
- u_int16_t sll_protocol; /* protocol */
u_int16_t sll_hatype; /* link-layer address type */
u_int16_t sll_halen; /* link-layer address length */
u_int8_t sll_addr[SLL_ADDRLEN]; /* link-layer address */
+ u_int16_t sll_protocol; /* protocol */
};
/*
- * The LINUX_SLL_ values; they are defined here so that they're available
- * even on systems other than Linux, but they should be given the same
- * values as the corresponding PACKET_ values on Linux. (Let's hope
- * those values never change.)
+ * The LINUX_SLL_ values for "sll_pkttype"; these correspond to the
+ * PACKET_ values on Linux, but are defined here so that they're
+ * available even on systems other than Linux, and so that they
+ * don't change even if the PACKET_ values change.
*/
#define LINUX_SLL_HOST 0
#define LINUX_SLL_BROADCAST 1
#define LINUX_SLL_MULTICAST 2
#define LINUX_SLL_OTHERHOST 3
#define LINUX_SLL_OUTGOING 4
+
+/*
+ * The LINUX_SLL_ values for "sll_protocol"; these correspond to the
+ * ETH_P_ values on Linux, but are defined here so that they're
+ * available even on systems other than Linux. We assume, for now,
+ * that the ETH_P_ values won't change in Linux; if they do, then:
+ *
+ * if we don't translate them in "pcap-linux.c", capture files
+ * won't necessarily be readable if captured on a system that
+ * defines ETH_P_ values that don't match these values;
+ *
+ * if we do translate them in "pcap-linux.c", that makes life
+ * unpleasant for the BPF code generator, as the values you test
+ * for in the kernel aren't the values that you test for when
+ * reading a capture file, so the fixup code run on BPF programs
+ * handed to the kernel ends up having to do more work.
+ *
+ * Add other values here as necessary, for handling packet types that
+ * might show up on non-Ethernet, non-802.x networks. (Not all the ones
+ * in the Linux "if_ether.h" will, I suspect, actually show up in
+ * captures.)
+ */
+#define LINUX_SLL_P_802_3 0x0001 /* Novell 802.3 frames without 802.2 LLC header */
+#define LINUX_SLL_P_802_2 0x0004 /* 802.2 frames (not D/I/X Ethernet) */
projects / tcpdump / blobdiff