ATM: Modernize packet parsing style.

Enable ND_LONGJMP_FROM_TCHECK. In atm_if_print() remove the custom
guards for ndo_snapend; increment ndo_ll_hdr_len before calling the next
function, not after. In oam_print() use uint2tokary() instead of custom
props. Comment unused named constants out.

diff --git a/print-atm.c b/print-atm.c
index 79275d159fbbe58847f0bc39194cfe0ee88352ef..ce5b6afe98ed9532e254d073fb9b94af31c608dd 100644 (file)
--- a/print-atm.c
+++ b/print-atm.c
@@ -27,6 +27,7 @@
 
 #include "netdissect-stdinc.h"
 
+#define ND_LONGJMP_FROM_TCHECK
 #include "netdissect.h"
 #include "extract.h"
 #include "addrtoname.h"
@@ -113,6 +114,7 @@
 #define PROTO_POS       0      /* offset of protocol discriminator */
 #define CALL_REF_POS    2      /* offset of call reference value */
 #define MSG_TYPE_POS    5      /* offset of message type */
+#if 0
 #define MSG_LEN_POS     7      /* offset of mesage length */
 #define IE_BEGIN_POS    9      /* offset of first information element */
 
@@ -120,6 +122,7 @@
 #define TYPE_POS       0
 #define LEN_POS                2
 #define FIELD_BEGIN_POS 4
+#endif
 
 /* end of the original atmuni31.h */
 
@@ -193,23 +196,11 @@ static const struct tok oam_fm_loopback_indicator_values[] = {
     { 0, NULL }
 };
 
-static const struct tok *oam_functype_values[16] = {
-    NULL,
-    oam_fm_functype_values, /* 1 */
-    oam_pm_functype_values, /* 2 */
-    NULL,
-    NULL,
-    NULL,
-    NULL,
-    NULL,
-    oam_ad_functype_values, /* 8 */
-    NULL,
-    NULL,
-    NULL,
-    NULL,
-    NULL,
-    NULL,
-    NULL
+static const struct uint_tokary oam_celltype2tokary[] = {
+       { OAM_CELLTYPE_FM, oam_fm_functype_values },
+       { OAM_CELLTYPE_PM, oam_pm_functype_values },
+       { OAM_CELLTYPE_AD, oam_ad_functype_values },
+       /* uint2tokary() does not use array termination. */
 };
 
 /*
@@ -253,18 +244,13 @@ atm_if_print(netdissect_options *ndo,
        u_int hdrlen = 0;
 
        ndo->ndo_protocol = "atm";
-       if (caplen < 1) {
-               nd_print_trunc(ndo);
-               ndo->ndo_ll_hdr_len += caplen;
-               return;
-       }
 
         /* Cisco Style NLPID ? */
         if (GET_U_1(p) == LLC_UI) {
             if (ndo->ndo_eflag)
                 ND_PRINT("CNLPID ");
+            ndo->ndo_ll_hdr_len += 1;
             isoclns_print(ndo, p + 1, length - 1);
-            ndo->ndo_ll_hdr_len += hdrlen;
             return;
         }
 
@@ -272,11 +258,6 @@ atm_if_print(netdissect_options *ndo,
         * Must have at least a DSAP, an SSAP, and the first byte of the
         * control field.
         */
-       if (caplen < 3) {
-               nd_print_trunc(ndo);
-               ndo->ndo_ll_hdr_len += caplen;
-               return;
-       }
 
        /*
         * Extract the presumed LLC header into a variable, for quick
@@ -305,24 +286,21 @@ atm_if_print(netdissect_options *ndo,
                 * packets?  If so, could it be changed to use a
                 * new DLT_IEEE802_6 value if we added it?
                 */
-               if (caplen < 20) {
-                       nd_print_trunc(ndo);
-                       ndo->ndo_ll_hdr_len += caplen;
-                       return;
-               }
                if (ndo->ndo_eflag)
                        ND_PRINT("%08x%08x %08x%08x ",
                               GET_BE_U_4(p),
                               GET_BE_U_4(p + 4),
                               GET_BE_U_4(p + 8),
                               GET_BE_U_4(p + 12));
+               /* Always cover the full header. */
+               ND_TCHECK_LEN(p, 20);
                p += 20;
                length -= 20;
                caplen -= 20;
                hdrlen += 20;
        }
-       hdrlen += atm_llc_print(ndo, p, length, caplen);
        ndo->ndo_ll_hdr_len += hdrlen;
+       ndo->ndo_ll_hdr_len += atm_llc_print(ndo, p, length, caplen);
 }
 
 /*
@@ -452,6 +430,7 @@ oam_print(netdissect_options *ndo,
     uint32_t cell_header;
     uint16_t vpi, vci, cksum, cksum_shouldbe, idx;
     uint8_t  cell_type, func_type, payload, clp;
+    const struct tok *oam_functype_str;
 
     union {
         const struct oam_fm_loopback_t *oam_fm_loopback;
@@ -482,11 +461,12 @@ oam_print(netdissect_options *ndo,
            tok2str(oam_celltype_values, "unknown", cell_type),
            cell_type);
 
-    if (oam_functype_values[cell_type] == NULL)
+    oam_functype_str = uint2tokary(oam_celltype2tokary, cell_type);
+    if (oam_functype_str == NULL)
         ND_PRINT(", func-type unknown (%u)", func_type);
     else
         ND_PRINT(", func-type %s (%u)",
-               tok2str(oam_functype_values[cell_type],"none",func_type),
+               tok2str(oam_functype_str, "none", func_type),
                func_type);
 
     p += ATM_HDR_LEN_NOHEC + hec;
@@ -547,9 +527,4 @@ oam_print(netdissect_options *ndo,
     ND_PRINT("\n\tcksum 0x%03x (%scorrect)",
            cksum,
            cksum_shouldbe == 0 ? "" : "in");
-
-    return;
-
-trunc:
-    nd_print_trunc(ndo);
 }