From 37f5c2d4654580aa9d1195490d4a911b9b079acb Mon Sep 17 00:00:00 2001
From: "Matthias P. Braendli" <matthias.braendli@mpb.li>
Date: Mon, 26 Dec 2016 22:20:35 +0100
Subject: EDI: Handle RFU bits and add some sanity checks

---
 lib/edi/ETIDecoder.cpp | 36 ++++++++++++++++++++++++++++++------
 lib/edi/ETIDecoder.hpp |  2 ++
 lib/edi/ETIWriter.cpp  | 13 +++++++++++--
 lib/edi/ETIWriter.hpp  |  5 +++++
 4 files changed, 48 insertions(+), 8 deletions(-)

(limited to 'lib/edi')

diff --git a/lib/edi/ETIDecoder.cpp b/lib/edi/ETIDecoder.cpp
index 36e49fa..c79054b 100644
--- a/lib/edi/ETIDecoder.cpp
+++ b/lib/edi/ETIDecoder.cpp
@@ -154,9 +154,18 @@ decode_state_t ETIDecoder::decode_afpacket(
     // read length from packet
     uint32_t taglength = read_32b(input_data.begin() + 2);
     uint16_t seq = read_16b(input_data.begin() + 6);
+    if (m_last_seq + 1 != seq) {
+        etiLog.level(warn) << "EDI AF Packet sequence error";
+    }
+    m_last_seq = seq;
 
     bool has_crc = (input_data[8] & 0x80) ? true : false;
-    uint8_t revision = input_data[8] & 0x7F;
+    uint8_t major_revision = (input_data[8] & 0x70) >> 4;
+    uint8_t minor_revision = input_data[8] & 0x0F;
+    if (major_revision != 1 or minor_revision != 0) {
+        throw invalid_argument("EDI AF Packet has wrong revision " +
+                to_string(major_revision) + "." + to_string(minor_revision));
+    }
     uint8_t pt = input_data[9];
     if (pt != 'T') {
         // only support Tag
@@ -298,9 +307,13 @@ bool ETIDecoder::decode_deti(const vector<uint8_t> &value)
 
     fc.mid = (etiHeader >> 22) & 0x03;
     fc.fp = (etiHeader >> 19) & 0x07;
-    bool rfa = (etiHeader >> 17) & 0x1;
+    uint8_t rfa = (etiHeader >> 17) & 0x3;
+    if (rfa != 0) {
+        etiLog.log(warn, "EDI deti TAG: rfa non-zero");
+    }
+
     bool rfu = (etiHeader >> 16) & 0x1;
-    uint16_t mnsc = etiHeader & 0xFFFF;
+    uint16_t mnsc = rfu ? 0xFFFF : etiHeader & 0xFFFF;
 
     const size_t fic_length_words = (fc.ficf ? (fc.mid == 3 ? 32 : 24) : 0);
     const size_t fic_length = 4 * fic_length_words;
@@ -311,9 +324,10 @@ bool ETIDecoder::decode_deti(const vector<uint8_t> &value)
         (rfudf ? 3 : 0);
 
     if (value.size() != expected_length) {
-        etiLog.log(warn, "     Assertion error: value.size() != expected_length: %zu %zu\n",
-                value.size(), expected_length);
-        assert(false);
+        throw std::logic_error("EDI deti: Assertion error:"
+                "value.size() != expected_length: " +
+               to_string(value.size()) + " " +
+               to_string(expected_length));
     }
 
     m_eti_writer.update_err(stat);
@@ -352,6 +366,13 @@ bool ETIDecoder::decode_deti(const vector<uint8_t> &value)
     if (rfudf) {
         uint32_t rfud = read_24b(value.begin() + i);
 
+        // high 16 bits: RFU in LIDATA EOH
+        // low 8 bits: RFU in TIST (not supported)
+        m_eti_writer.update_rfu(rfud >> 8);
+        if ((rfud & 0xFF) != 0xFF) {
+            etiLog.level(warn) << "EDI: RFU in TIST not supported";
+        }
+
         i += 3;
     }
 
@@ -370,6 +391,9 @@ bool ETIDecoder::decode_estn(const vector<uint8_t> &value, uint8_t n)
     stc.sad = (sstc >> 8) & 0x3FF;
     stc.tpl = (sstc >> 2) & 0x3F;
     uint8_t rfa = sstc & 0x3;
+    if (rfa != 0) {
+        etiLog.level(warn) << "EDI: rfa field in ESTn tag non-null";
+    }
 
     copy(   value.begin() + 3,
             value.end(),
diff --git a/lib/edi/ETIDecoder.hpp b/lib/edi/ETIDecoder.hpp
index e0c7218..cec284f 100644
--- a/lib/edi/ETIDecoder.hpp
+++ b/lib/edi/ETIDecoder.hpp
@@ -68,6 +68,8 @@ class ETIDecoder {
 
         PFT::PFT m_pft;
 
+        uint16_t m_last_seq;
+
         std::vector<uint8_t> m_input_data;
 };
 
diff --git a/lib/edi/ETIWriter.cpp b/lib/edi/ETIWriter.cpp
index 0eb3feb..bd051dd 100644
--- a/lib/edi/ETIWriter.cpp
+++ b/lib/edi/ETIWriter.cpp
@@ -117,6 +117,15 @@ void ETIWriter::update_mnsc(uint16_t mnsc)
     m_mnsc = mnsc;
 }
 
+void ETIWriter::update_rfu(uint16_t rfu)
+{
+    if (not m_proto_valid) {
+        throw std::logic_error("Cannot update RFU before protocol");
+    }
+
+    m_rfu = rfu;
+}
+
 void ETIWriter::add_subchannel(const eti_stc_data& stc)
 {
     if (not m_proto_valid) {
@@ -242,8 +251,8 @@ void ETIWriter::assemble()
     eti.push_back(mst_crc & 0xFF);
 
     // RFU
-    eti.push_back(0xff);
-    eti.push_back(0xff);
+    eti.push_back(m_rfu >> 8);
+    eti.push_back(m_rfu);
 
     // TIST
     eti.push_back(m_fc.tsta >> 24);
diff --git a/lib/edi/ETIWriter.hpp b/lib/edi/ETIWriter.hpp
index 001f537..aa907fc 100644
--- a/lib/edi/ETIWriter.hpp
+++ b/lib/edi/ETIWriter.hpp
@@ -79,6 +79,8 @@ class ETIWriter {
 
         void update_mnsc(uint16_t mnsc);
 
+        void update_rfu(uint16_t rfu);
+
         void add_subchannel(const eti_stc_data& stc);
 
         // Tell the ETIWriter that the AFPacket is complete
@@ -109,6 +111,9 @@ class ETIWriter {
         uint32_t m_seconds;
 
         uint16_t m_mnsc = 0xffff;
+
+        // 16 bits: RFU field in EOH
+        uint16_t m_rfu = 0xffff;
 };
 
 }
-- 
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