]> The Tcpdump Group git mirrors - tcpdump/blobdiff - print-openflow.c
OpenFlow: Fix a compiler error on Windows. [skip travis]
[tcpdump] / print-openflow.c
index 8825ae3d5c8714a72fc559536f00d59ebf0bf55c..2b821880ac3c9910dce8b41abf41bf4b86fac46d 100644 (file)
  * POSSIBILITY OF SUCH DAMAGE.
  */
 
-#define NETDISSECT_REWORKED
+/* \summary: version-independent OpenFlow printer */
+
 #ifdef HAVE_CONFIG_H
-#include "config.h"
+#include <config.h>
 #endif
 
-#include <tcpdump-stdinc.h>
+#include "netdissect-stdinc.h"
 
-#include "interface.h"
+#define ND_LONGJMP_FROM_TCHECK
+#include "netdissect.h"
 #include "extract.h"
 #include "openflow.h"
 #include "oui.h"
 
-static const char tstr[] = " [|openflow]";
-static const char cstr[] = " (corrupt)";
 
 #define OF_VER_1_0    0x01
+#define OF_VER_1_1    0x02
+#define OF_VER_1_2    0x03
+#define OF_VER_1_3    0x04
+#define OF_VER_1_4    0x05
+#define OF_VER_1_5    0x06
+
+static const struct tok ofver_str[] = {
+       { OF_VER_1_0,   "1.0" },
+       { OF_VER_1_1,   "1.1" },
+       { OF_VER_1_2,   "1.2" },
+       { OF_VER_1_3,   "1.3" },
+       { OF_VER_1_4,   "1.4" },
+       { OF_VER_1_5,   "1.5" },
+       { 0, NULL }
+};
 
 const struct tok onf_exp_str[] = {
        { ONF_EXP_ONF,               "ONF Extensions"                                  },
@@ -66,77 +81,113 @@ of_vendor_name(const uint32_t vendor)
        return tok2str(table, "unknown", vendor);
 }
 
-static void
-of_header_print(netdissect_options *ndo, const uint8_t version, const uint8_t type,
-                      const uint16_t length, const uint32_t xid)
-{
-       ND_PRINT((ndo, "\n\tversion unknown (0x%02x), type 0x%02x, length %u, xid 0x%08x",
-              version, type, length, xid));
-}
-
-/* Print a single OpenFlow message. */
-static const u_char *
-of_header_body_print(netdissect_options *ndo, const u_char *cp, const u_char *ep)
+void
+of_data_print(netdissect_options *ndo,
+              const u_char *cp, const u_int len)
 {
-       uint8_t version, type;
-       uint16_t length;
-       uint32_t xid;
-
-       if (ep < cp + OF_HEADER_LEN)
-               goto corrupt;
-       /* version */
-       ND_TCHECK2(*cp, 1);
-       version = *cp;
-       cp += 1;
-       /* type */
-       ND_TCHECK2(*cp, 1);
-       type = *cp;
-       cp += 1;
-       /* length */
-       ND_TCHECK2(*cp, 2);
-       length = EXTRACT_16BITS(cp);
-       cp += 2;
-       /* xid */
-       ND_TCHECK2(*cp, 4);
-       xid = EXTRACT_32BITS(cp);
-       cp += 4;
-       /* Message length includes the header length and a message always includes
-        * the basic header. A message length underrun fails decoding of the rest of
-        * the current packet. At the same time, try decoding as much of the current
-        * message as possible even when it does not end within the current TCP
-        * segment. */
-       if (length < OF_HEADER_LEN) {
-               of_header_print(ndo, version, type, length, xid);
-               goto corrupt;
-       }
-       /* Decode known protocol versions further without printing the header (the
-        * type decoding is version-specific. */
-       switch (version) {
-       case OF_VER_1_0:
-               return of10_header_body_print(ndo, cp, ep, type, length, xid);
-       default:
-               of_header_print(ndo, version, type, length, xid);
-               ND_TCHECK2(*cp, length - OF_HEADER_LEN);
-               return cp + length - OF_HEADER_LEN; /* done with current message */
-       }
-
-corrupt: /* fail current packet */
-       ND_PRINT((ndo, "%s", cstr));
-       ND_TCHECK2(*cp, ep - cp);
-       return ep;
-trunc:
-       ND_PRINT((ndo, "%s", tstr));
-       return ep;
+       if (len == 0)
+               return;
+       /* data */
+       ND_PRINT("\n\t data (%u octets)", len);
+       if (ndo->ndo_vflag >= 2)
+               hex_and_ascii_print(ndo, "\n\t  ", cp, len);
+       else
+               ND_TCHECK_LEN(cp, len);
 }
 
 /* Print a TCP segment worth of OpenFlow messages presuming the segment begins
  * on a message boundary. */
 void
-openflow_print(netdissect_options *ndo, const u_char *cp, const u_int len)
+openflow_print(netdissect_options *ndo, const u_char *cp, u_int len)
 {
-       const u_char *ep = cp + len;
+       ndo->ndo_protocol = "openflow";
+       ND_PRINT(": OpenFlow");
+       while (len) {
+               /* Print a single OpenFlow message. */
+               uint8_t version, type;
+               uint16_t length;
+               void (*decoder)(struct netdissect_options *,
+                               const u_char *, uint16_t, const uint8_t) = NULL;
+
+               /* version */
+               version = GET_U_1(cp);
+               OF_FWD(1);
+               ND_PRINT("\n\tversion %s",
+                        tok2str(ofver_str, "unknown (0x%02x)", version));
+               /* type */
+               if (len < 1)
+                       goto partial_header;
+               type = GET_U_1(cp);
+               OF_FWD(1);
+               switch (version) {
+               case OF_VER_1_0:
+                       ND_PRINT(", type %s", of10_msgtype_str(type));
+                       decoder = of10_message_print;
+                       break;
+               case OF_VER_1_3:
+                       ND_PRINT(", type %s", of13_msgtype_str(type));
+                       decoder = of13_message_print;
+                       break;
+               default:
+                       ND_PRINT(", type unknown (0x%02x)", type);
+               }
+               /* length */
+               if (len < 2)
+                       goto partial_header;
+               length = GET_BE_U_2(cp);
+               OF_FWD(2);
+               ND_PRINT(", length %u%s", length,
+                        length < OF_HEADER_FIXLEN ? " (too short!)" : "");
+               /* xid */
+               if (len < 4)
+                       goto partial_header;
+               ND_PRINT(", xid 0x%08x", GET_BE_U_4(cp));
+               OF_FWD(4);
+
+               /*
+                * When a TCP packet can contain several protocol messages,
+                * and at the same time a protocol message can span several
+                * TCP packets, decoding an incomplete message at the end of
+                * a TCP packet requires attention to detail in this loop.
+                *
+                * Message length includes the header length and a message
+                * always includes the basic header. A message length underrun
+                * fails decoding of the rest of the current packet. At the
+                * same time, try decoding as much of the current message as
+                * possible even when it does not end within the current TCP
+                * segment.
+                *
+                * Specifically, to try to process the message body in this
+                * iteration do NOT require the header "length" to be small
+                * enough for the full declared OpenFlow message to fit into
+                * the remainder of the declared TCP segment, same as the full
+                * declared TCP segment is not required to fit into the
+                * captured packet buffer.
+                *
+                * But DO require the same at the end of this iteration to
+                * decrement "len" and to proceed to the next iteration.
+                * (Ideally the declared TCP payload end will be at or after
+                * the captured packet buffer end, but stay safe even when
+                * that's somehow not the case.)
+                */
+               if (length < OF_HEADER_FIXLEN)
+                       goto invalid;
+
+               if (decoder != NULL)
+                       decoder(ndo, cp, length - OF_HEADER_FIXLEN, type);
+               else
+                       ND_TCHECK_LEN(cp, length - OF_HEADER_FIXLEN);
+               if (length - OF_HEADER_FIXLEN > len)
+                       break;
+               OF_FWD(length - OF_HEADER_FIXLEN);
+       } /* while (len) */
+       return;
 
-       ND_PRINT((ndo, ": OpenFlow"));
-       while (cp < ep)
-               cp = of_header_body_print(ndo, cp, ep);
+partial_header:
+       ND_PRINT(" (end of TCP payload)");
+       ND_TCHECK_LEN(cp, len);
+       return;
+invalid: /* fail the current packet */
+       nd_print_invalid(ndo);
+       ND_TCHECK_LEN(cp, len);
 }