Add ARP decoding and bring the TUI up to -c/-a parity

ARP had zero treatment until now - its ethertype just fell through
summarize_packet's "not IPv4/IPv6" branch, on traffic that appears on
essentially every real LAN capture. Scoped to Ethernet/IPv4 addressing
(the case that covers virtually all real ARP traffic), with tcpdump's
own "who-has X tell Y" / "X is-at Y" phrasing rather than inventing
new wording. Live-verified by flushing this machine's real gateway
ARP entry and capturing the resulting request/reply on wlp1s0.

TUI -c/-a were being parsed into RenderOptions but silently did
nothing: run_tui()'s consumer thread had its own loop that never read
them, unlike plain-text mode's render_packet(). Fixed to match, and
caught a real bug while doing it - pushing up to two rows per packet
(summary + reassembly line) against a single pop_front() would let
the row deque grow past its cap under sustained -a activity; needed a
while loop instead. Verified under tmux against the same split-segment
HTTP scenario used to verify -a on the CLI and GUI.

1 files changed, 18 insertions, 3 deletions

diff --git a/src/main.cpp b/src/main.cpp
index 82b07a9..833af52 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -152,10 +152,25 @@ void run_tui(packeteer::CaptureSession& session, packeteer::CaptureQueue& queue,
                                                   packet->ts_usec, bytes, packet->original_len);
             }
 
+            if (opts.verbose_checksums) {
+                std::string status = packeteer::checksum_status(bytes, opts.datalink);
+                if (!status.empty()) line += "  " + status;
+            }
+            std::optional<std::string> reassembled;
+            if (opts.reassembler) {
+                reassembled = packeteer::reassembled_http_status(bytes, opts.datalink,
+                                                                   *opts.reassembler);
+            }
+
             {
                 std::lock_guard<std::mutex> lock(state_mutex);
                 rows.push_back(std::move(line));
-                if (rows.size() > kMaxRows) rows.pop_front();
+                if (reassembled) rows.push_back("  [" + *reassembled + "]");
+                // A while loop, not if: up to two rows can be pushed per
+                // packet now (the summary plus an optional reassembly
+                // line), so a single pop_front() would let the deque
+                // grow past kMaxRows under sustained -a activity.
+                while (rows.size() > kMaxRows) rows.pop_front();
                 ++packet_count;
             }
             screen.PostEvent(Event::Custom);
@@ -275,13 +290,13 @@ void print_usage(const char* argv0) {
         "Options:\n"
         "  -t, --tui       Launch the interactive TUI instead of plain-text output\n"
         "  -x              Show a hex dump under each summary (plain-text mode only)\n"
-        "  -c              Show IPv4/TCP/UDP checksum validity (plain-text mode only).\n"
+        "  -c              Show IPv4/TCP/UDP checksum validity (plain-text and TUI).\n"
         "                  Off by default: checksum offload means many outbound and\n"
         "                  loopback packets show as invalid even when nothing is\n"
         "                  actually wrong - the NIC computes the real checksum in\n"
         "                  hardware after most capture points already saw the packet.\n"
         "  -a              Reassemble TCP streams and re-run HTTP parsing on the\n"
-        "                  joined bytes (plain-text mode only), catching a\n"
+        "                  joined bytes (plain-text and TUI), catching a\n"
         "                  request/response split across multiple segments that\n"
         "                  single-packet HTTP dissection alone would miss. In-order\n"
         "                  segments only - out-of-order/retransmitted segments are\n"