TCP - Lz4 single magic

CESNET · Mar 28, 2024 · ba33368 · ba33368
1 parent b1a60a2
commit ba33368
Showing 1 changed file with 6 additions and 10 deletions.
diff --git a/src/plugins/input/tcp/src/LZ4Decoder.cpp b/src/plugins/input/tcp/src/LZ4Decoder.cpp
@@ -30,17 +30,13 @@ namespace tcp_in {
 using namespace std;
 
 struct __attribute__((__packed__)) ipfix_compress_header {
-    uint32_t magic;
     uint16_t decompressed_size;
     uint16_t compressed_size;
 };
 
 struct __attribute__((__packed__)) ipfix_start_compress_header {
     uint32_t magic;
-    uint32_t zeros;
     uint32_t buffer_size;
-    uint16_t decompressed_size;
-    uint16_t compressed_size;
 };
 
 Lz4Decoder::Lz4Decoder(int fd) :
@@ -53,6 +49,7 @@ Lz4Decoder::Lz4Decoder(int fd) :
     m_compressed_size(0),
     m_decompressed_size(0)
 {
+    uint32_t magic = 0;
     if (!m_decoder) {
         throw runtime_error("LZ4 Decoder: Failed to create stream decoder");
     }
@@ -91,15 +88,17 @@ bool Lz4Decoder::read_header() {
         return false;
     }
 
-    auto hdr = reinterpret_cast<ipfix_compress_header *>(m_compressed.data());
-    if (hdr->compressed_size == 0 && hdr->decompressed_size == 0) {
-        return read_start_header();
+    if (m_decompressed.size() == 0) {
+        if (!read_start_header()) {
+            return false;
+        }
     }
 
     if (!read_until_n(CH_SIZE)) {
         return false;
     }
 
+    auto hdr = reinterpret_cast<ipfix_compress_header *>(m_compressed.data());
     m_compressed_size = ntohs(hdr->compressed_size);
     m_decompressed_size = ntohs(hdr->decompressed_size);
 
@@ -118,9 +117,6 @@ bool Lz4Decoder::read_start_header() {
     auto hdr = reinterpret_cast<ipfix_start_compress_header *>(m_compressed.data());
     auto new_buffer_size = ntohl(hdr->buffer_size);
 
-    m_compressed_size = ntohs(hdr->compressed_size);
-    m_decompressed_size = ntohs(hdr->decompressed_size);
-
     m_compressed.clear();
 
     reset_stream(new_buffer_size);