Changeset 29c8666

Timestamp:

11/05/08 16:46:04 (13 years ago)

Author:

Perry Lorier <perry@…>

Branches:

4.0.1-hotfixes, cachetimestamps, develop, dpdk-ndag, etsilive, getfragoff, help, libtrace4, master, ndag_format, pfring, rc-4.0.1, rc-4.0.2, rc-4.0.3, rc-4.0.4, ringdecrementfix, ringperformance, ringtimestampfixes

Children:

edb844c

Parents:

13fd6e1

Message:

Deal with PoS traces better

Location:

lib

Files:

• format_legacy.c (modified) (1 diff)
• linktypes.c (modified) (3 diffs)
• protocols_l2.c (modified) (3 diffs)

lib/format_legacy.c

@@ -311 +311 @@
 static libtrace_linktype_t legacypos_get_link_type(
                 const libtrace_packet_t *packet) {
-        /* This code used to look for (0x0F|0x8F 0x00) frames
-         * and return TRACE_TYPE_HDLC_POS, otherwise return PPP.
-         * However the PPP frames were being decoded using HDLC_POS semantics
-         * so when we fixed PPP, this all broke.  I've changed this to always
-         * assume HDLC_POS.  If we ever find a trace that does raw PPP over
-         * HDLC_POS then this should be changed to detect that it's PPP and 
-         * do the right thing.  I suspect this is due to an original confusion
-         * as to how exactly POS works.
-         *  -- Perry Lorier (2008-10-14)
+        /* POS can be PPP over HDLC (DLT_PPP_SERIAL), or it can be
+         * just straight PPP.  Sigh.
+         *
+         * Ref: RFC 1549
+         *      - Perry Lorier (2008-11-04)
          */
-        return TRACE_TYPE_HDLC_POS;
+        if (((char *)packet->payload)[0] == '\xFF'
+                && ((char*)packet->payload)[1] == '\x03')
+                return TRACE_TYPE_POS;
+        else 
+                return TRACE_TYPE_PPP;
 }
 

lib/linktypes.c

@@ -44 +44 @@
                 case TRACE_DLT_ATM_RFC1483: return TRACE_TYPE_LLCSNAP;
                 case TRACE_DLT_PPP: return TRACE_TYPE_PPP;
+                case TRACE_DLT_PPP_SERIAL: return TRACE_TYPE_POS;
                 /* Unhandled */
                 case TRACE_DLT_NULL:    /* Raw IP frame with a BSD specific
@@ -70 +71 @@
                 case TRACE_TYPE_PPP:    return TRACE_DLT_PPP;
                 case TRACE_TYPE_HDLC_POS: return TRACE_DLT_C_HDLC;
+                /* Theres more than one type of PPP.  Who knew? */
+                case TRACE_TYPE_POS:    return TRACE_DLT_PPP_SERIAL; 
+
                 /* Below here are unsupported conversions */
                 /* Dispite hints to the contrary, there is no DLT
@@ -84 +88 @@
                 case TRACE_TYPE_80211_PRISM:    
                 /* Probably == PPP */
-                case TRACE_TYPE_POS:
                 /* TODO: We haven't researched these yet */
                 case TRACE_TYPE_AAL5:

lib/protocols_l2.c

@@ -223 +223 @@
 
         if (type) {
-                *type=ntohs(chdlc->ethertype);
+                switch(ntohs(chdlc->ethertype)) {
+                        case 0x0021: /* IP */
+                                *type = 0x0800;
+                                break;
+                        default:
+                                printf("Unknown chdlc type: %04x\n",ntohs(chdlc->ethertype));
+                                *type = 0; /* Unknown */
+                }
         }
 
@@ -307 +314 @@
 {
         void *l;
+        assert(linktype != -1);
         switch(linktype) {
                 /* Packet Metadata headers, not layer2 headers */
@@ -350 +358 @@
                         return trace_get_payload_from_chdlc(link,ethertype,
                                         remaining);
+                case TRACE_TYPE_POS:
+                        return trace_get_payload_from_chdlc(link,ethertype,
+                                        remaining);
                 /* TODO: Unsupported */
-                case TRACE_TYPE_POS:
                 case TRACE_TYPE_AAL5:
                         return NULL;