fix ipv4 checksum error in case of pkt_size>128 and field offset less than ip-header (fd.io issue - Miro)

4 files changed, 36 insertions, 6 deletions

diff --git a/src/stateless/cp/trex_stream.cpp b/src/stateless/cp/trex_stream.cpp
index fb0b35d5..05c14cba 100644
--- a/src/stateless/cp/trex_stream.cpp
+++ b/src/stateless/cp/trex_stream.cpp
@@ -62,7 +62,9 @@ TrexStream::vm_compile() {
     }
 
     /* compile */
+    m_vm.set_pkt(m_pkt.binary);
     m_vm.compile(m_pkt.len);
+    m_vm.set_pkt(0);
 
     /* create DP object */
     m_vm_dp = m_vm.generate_dp_object();
diff --git a/src/stateless/cp/trex_stream.h b/src/stateless/cp/trex_stream.h
index 2ab90c99..5240e96d 100644
--- a/src/stateless/cp/trex_stream.h
+++ b/src/stateless/cp/trex_stream.h
@@ -68,22 +68,26 @@ static inline uint16_t get_log2_size(uint16_t size){
  *        ==>62
  * 
  */
+
 static inline uint16_t calc_writable_mbuf_size(uint16_t max_offset_writable,
                                                uint16_t pkt_size){
 
-    if ( pkt_size<=64 ){
-        return (pkt_size);
-    }
     if (pkt_size<=128) {
         return (pkt_size);
     }
 
     //pkt_size> 128
+    // if reside is less than 64 keep it as a single packet
     uint16_t non_writable = pkt_size - (max_offset_writable +1) ;
     if ( non_writable<64 ) {
         return (pkt_size);
     }
-    return(max_offset_writable+1);
+
+    // keep the r/w at least 60 byte
+    if ((max_offset_writable+1)<=60) {
+        return 60;
+    }
+    return max_offset_writable+1;
 }
 
 
diff --git a/src/stateless/cp/trex_stream_vm.cpp b/src/stateless/cp/trex_stream_vm.cpp
index f83025dd..b0cadfb6 100644
--- a/src/stateless/cp/trex_stream_vm.cpp
+++ b/src/stateless/cp/trex_stream_vm.cpp
@@ -396,8 +396,6 @@ void StreamVm::build_program(){
         if (ins_type == StreamVmInstruction::itFIX_IPV4_CS) {
             StreamVmInstructionFixChecksumIpv4 *lpFix =(StreamVmInstructionFixChecksumIpv4 *)inst;
 
-            add_field_cnt(lpFix->m_pkt_offset +12);
-
             if ( (lpFix->m_pkt_offset + IPV4_HDR_LEN) > m_pkt_size  ) {
 
                 std::stringstream ss;
@@ -405,6 +403,26 @@ void StreamVm::build_program(){
                 err(ss.str());
             }
 
+            uint16_t offset_next_layer = IPV4_HDR_LEN;
+
+            if ( m_pkt ){
+                IPHeader * ipv4= (IPHeader *)(m_pkt+lpFix->m_pkt_offset);
+                offset_next_layer = ipv4->getSize();
+            }
+
+            if (offset_next_layer<IPV4_HDR_LEN) {
+                offset_next_layer=IPV4_HDR_LEN;
+            }
+
+            if ( (lpFix->m_pkt_offset + offset_next_layer) > m_pkt_size  ) {
+
+                std::stringstream ss;
+                ss << "instruction id '" << ins_id << "' fix ipv4 command offset  " << lpFix->m_pkt_offset << "plus "<<offset_next_layer<< " is too high relative to packet size  "<< m_pkt_size;
+                err(ss.str());
+            }
+            /* calculate this offset from the packet */
+            add_field_cnt(lpFix->m_pkt_offset + offset_next_layer);
+
             StreamDPOpIpv4Fix ipv_fix;
             ipv_fix.m_offset = lpFix->m_pkt_offset;
             ipv_fix.m_op = StreamDPVmInstructions::ditFIX_IPV4_CS;
diff --git a/src/stateless/cp/trex_stream_vm.h b/src/stateless/cp/trex_stream_vm.h
index 13504703..c16545d9 100644
--- a/src/stateless/cp/trex_stream_vm.h
+++ b/src/stateless/cp/trex_stream_vm.h
@@ -1408,6 +1408,7 @@ public:
 
         m_split_instr=NULL;
         m_is_compiled = false;
+        m_pkt=0;
     }
 
 
@@ -1511,6 +1512,10 @@ public:
     /* raise exception */
     void  err(const std::string &err);
 
+    void set_pkt(uint8_t *pkt){
+        m_pkt=pkt;
+    }
+
 
     /**
      * return a pointer to a flow var / client var 
@@ -1565,6 +1570,7 @@ private:
     StreamDPVmInstructions             m_instructions;
     
     StreamVmInstructionVar             *m_split_instr;
+    uint8_t                            *m_pkt;