rework the oam printer: add support for payload printing of OAM loopback cells

1 files changed, 134 insertions, 17 deletions

diff --git a/print-atm.c b/print-atm.c
index 1bbc8e08..b7a1c341 100644
--- a/print-atm.c
+++ b/print-atm.c
@@ -20,7 +20,7 @@
  */
 #ifndef lint
 static const char rcsid[] _U_ =
-    "@(#) $Header: /tcpdump/master/tcpdump/print-atm.c,v 1.44 2006-01-25 13:26:37 hannes Exp $ (LBL)";
+    "@(#) $Header: /tcpdump/master/tcpdump/print-atm.c,v 1.45 2006-02-08 01:43:00 hannes Exp $ (LBL)";
 #endif
 
 #ifdef HAVE_CONFIG_H
@@ -43,25 +43,40 @@ static const char rcsid[] _U_ =
 
 #include "ether.h"
 
+#define OAM_CRC10_MASK 0x3ff
+#define OAM_PAYLOAD_LEN 48
+#define OAM_FUNCTION_SPECIFIC_LEN 45 /* this excludes crc10 and cell-type/function-type */
+#define OAM_CELLTYPE_FUNCTYPE_LEN 1
+
 struct tok oam_f_values[] = {
     { OAMF4SC, "OAM F4 (segment)" },
     { OAMF4EC, "OAM F4 (end)" },
     { 0, NULL }
 };
 
+#define OAM_CELLTYPE_FM 0x1
+#define OAM_CELLTYPE_PM 0x2
+#define OAM_CELLTYPE_AD 0x8
+#define OAM_CELLTYPE_SM 0xf
+
 struct tok oam_celltype_values[] = {
-    { 0x1, "Fault Management" },
-    { 0x2, "Performance Management" },
-    { 0x8, "activate/deactivate" },
-    { 0xf, "System Management" },
+    { OAM_CELLTYPE_FM, "Fault Management" },
+    { OAM_CELLTYPE_PM, "Performance Management" },
+    { OAM_CELLTYPE_AD, "activate/deactivate" },
+    { OAM_CELLTYPE_SM, "System Management" },
     { 0, NULL }
 };
 
+#define OAM_FM_FUNCTYPE_AIS       0x0
+#define OAM_FM_FUNCTYPE_RDI       0x1
+#define OAM_FM_FUNCTYPE_CONTCHECK 0x4
+#define OAM_FM_FUNCTYPE_LOOPBACK  0x8
+
 struct tok oam_fm_functype_values[] = {
-    { 0x0, "AIS" },
-    { 0x1, "RDI" },
-    { 0x4, "Continuity Check" },
-    { 0x8, "Loopback" },
+    { OAM_FM_FUNCTYPE_AIS, "AIS" },
+    { OAM_FM_FUNCTYPE_RDI, "RDI" },
+    { OAM_FM_FUNCTYPE_CONTCHECK, "Continuity Check" },
+    { OAM_FM_FUNCTYPE_LOOPBACK, "Loopback" },
     { 0, NULL }
 };
 
@@ -78,6 +93,14 @@ struct tok oam_ad_functype_values[] = {
     { 0, NULL }
 };
 
+#define OAM_FM_LOOPBACK_INDICATOR_MASK 0x1
+
+struct tok oam_fm_loopback_indicator_values[] = {
+    { 0x0, "Reply" },
+    { 0x1, "Request" },
+    { 0, NULL }
+};
+
 static const struct tok *oam_functype_values[16] = {
     NULL,
     oam_fm_functype_values, /* 1 */
@@ -301,26 +324,87 @@ atm_print(u_int vpi, u_int vci, u_int traftype, const u_char *p, u_int length,
 	}
 }
 
+struct oam_fm_loopback_t {
+    u_int8_t loopback_indicator;
+    u_int8_t correlation_tag[4];
+    u_int8_t loopback_id[12];
+    u_int8_t source_id[12];
+    u_int8_t unused[16];
+};
+
+struct oam_fm_ais_rdi_t {
+    u_int8_t failure_type;
+    u_int8_t failure_location[16];
+    u_int8_t unused[28];
+};
+
+
+#define CRC10_POLYNOMIAL 0x633
+static u_int16_t crc10_table[256];
+
+static void
+gen_crc10_table(void)
+{   
+    register int i, j;
+    register u_int16_t accum;
+    
+    for ( i = 0;  i < 256;  i++ )
+    {
+        accum = ((unsigned short) i << 2);
+        for ( j = 0;  j < 8;  j++ )
+        {
+            if ((accum <<= 1) & 0x400) accum ^= CRC10_POLYNOMIAL;
+        }
+        crc10_table[i] = accum;
+    }
+    return;
+}
+
+static u_int16_t
+verify_crc10_cksum(u_int16_t accum, const u_char *p, int length)
+{
+    register int i;
+
+    for ( i = 0;  i < length;  i++ )
+    {
+        accum = ((accum << 8) & 0x3ff)
+            ^ crc10_table[( accum >> 2) & 0xff]
+            ^ *p++;
+    }
+    return accum;
+}
+
 int 
 oam_print (const u_char *p, u_int length, u_int hec) {
 
     u_int32_t cell_header;
-    u_int16_t cell_type, func_type,vpi,vci,payload,clp;
+    u_int16_t vpi, vci, cksum, cksum_shouldbe;
+    u_int8_t  cell_type, func_type, payload, clp;
+
+    union {
+        const struct oam_fm_loopback_t *oam_fm_loopback;
+        const struct oam_fm_ais_rdi_t *oam_fm_ais_rdi;
+    } oam_ptr;
+
 
     cell_header = EXTRACT_32BITS(p+hec);
-    cell_type = ((*(p+4+hec))>>4) & 0x0f;
-    func_type = *(p+4+hec) & 0x0f;
+    cell_type = ((*(p+ATM_HDR_LEN_NOHEC+hec))>>4) & 0x0f;
+    func_type = (*(p+ATM_HDR_LEN_NOHEC+hec)) & 0x0f;
 
     vpi = (cell_header>>20)&0xff;
     vci = (cell_header>>4)&0xffff;
     payload = (cell_header>>1)&0x7;
     clp = cell_header&0x1;
 
-    printf("%s, vpi %u, vci %u, payload %u, clp %u, ",
+    printf("%s, vpi %u, vci %u, payload %u, clp %u, length %u",
            tok2str(oam_f_values, "OAM F5", vci),
-           vpi, vci, payload, clp);
+           vpi, vci, payload, clp, length);
+
+    if (!vflag) {
+        return 1;
+    }
 
-    printf("cell-type %s (%u)",
+    printf("\n\tcell-type %s (%u)",
            tok2str(oam_celltype_values, "unknown", cell_type),
            cell_type);
 
@@ -328,9 +412,42 @@ oam_print (const u_char *p, u_int length, u_int hec) {
         printf(", func-type unknown (%u)", func_type);
     else
         printf(", func-type %s (%u)",
-               bittok2str(oam_functype_values[cell_type],"none",func_type),
+               tok2str(oam_functype_values[cell_type],"none",func_type),
                func_type);
 
-    printf(", length %u",length);
+    p += ATM_HDR_LEN_NOHEC + hec;
+
+    switch (cell_type << 4 | func_type) {
+    case (OAM_CELLTYPE_FM << 4 | OAM_FM_FUNCTYPE_LOOPBACK):
+        oam_ptr.oam_fm_loopback = (const struct oam_fm_loopback_t *)(p + OAM_CELLTYPE_FUNCTYPE_LEN);
+        printf("\n\tLoopback-Indicator %s, Correlation-Tag 0x%08x",
+               tok2str(oam_fm_loopback_indicator_values,
+                       "Unknown",
+                       oam_ptr.oam_fm_loopback->loopback_indicator & OAM_FM_LOOPBACK_INDICATOR_MASK),
+               EXTRACT_LE_32BITS(&oam_ptr.oam_fm_loopback->correlation_tag));
+        printf("\n\tLocation-ID ");
+        safeputs((const char *)&oam_ptr.oam_fm_loopback->loopback_id,
+                 sizeof(oam_ptr.oam_fm_loopback->loopback_id));
+        printf("\n\tSource-ID   ");
+        safeputs((const char *)&oam_ptr.oam_fm_loopback->source_id,
+                 sizeof(oam_ptr.oam_fm_loopback->source_id));
+        break;
+    default:
+        break;
+    }
+
+    /* crc10 checksum verification */
+    gen_crc10_table();
+    cksum = EXTRACT_16BITS(p + OAM_CELLTYPE_FUNCTYPE_LEN + OAM_FUNCTION_SPECIFIC_LEN) & OAM_CRC10_MASK;
+    cksum_shouldbe = verify_crc10_cksum(0, p, OAM_PAYLOAD_LEN);
+    
+    printf("\n\tcksum 0x%03x", cksum);
+
+    if (cksum_shouldbe == 0) {
+        printf(" (correct)");
+    } else {
+        printf(" (incorrect (-> 0x%03x))", cksum_shouldbe);
+    }
+
     return 1;
 }