build: Refactor CMake back to in-tree CMakeListsbe

This moves the build definitions back to src/ subdirectories
(CMakeLists.txt per component). Configuration and dependencies are
kept out of tree. Configuration options are bundled into cmake/config/
modules. Dependencies are grouped by component (system/, crypt/, eth/,
coverage/, etc.). It now consistently uses target-based commands
(target_include_directories, target_link_libraries) instead of global
include_directories(). Proper PRIVATE/PUBLIC visibility for executable
link libraries. CONFIG_OUROBOROS_DEBUG now properly set based on being
a valid debug config (not just checking the string name).

It also adds OuroborosTargets export for find_package() support and
CMake package config files (OuroborosConfig.cmake) for easier
integration with CMake projects.

The build logic now follows more idiomatic CMake practices with
configuration separated from target definitions.

Signed-off-by: Dimitri Staessens <dimitri@ouroboros.rocks>
Signed-off-by: Sander Vrijders <sander@ouroboros.rocks>

1 files changed, 94 insertions, 0 deletions

diff --git a/cmake/config/lib.cmake b/cmake/config/lib.cmake
new file mode 100644
index 00000000..287f30dc
--- /dev/null
+++ b/cmake/config/lib.cmake
@@ -0,0 +1,94 @@
+# Library configuration options for Ouroboros
+# Options affecting libouroboros-common, libouroboros-dev, libouroboros-irm
+
+# Flow limits
+set(SYS_MAX_FLOWS 10240 CACHE STRING
+  "Maximum number of total flows for this system")
+set(PROG_MAX_FLOWS 4096 CACHE STRING
+  "Maximum number of flows in an application")
+set(PROG_RES_FDS 64 CACHE STRING
+  "Number of reserved flow descriptors per application")
+set(PROG_MAX_FQUEUES 32 CACHE STRING
+  "Maximum number of flow sets per application")
+
+# Threading
+if(NOT APPLE)
+  set(PTHREAD_COND_CLOCK "CLOCK_MONOTONIC" CACHE STRING
+    "Clock to use for condition variable timing")
+else()
+  set(PTHREAD_COND_CLOCK "CLOCK_REALTIME" CACHE INTERNAL
+    "Clock to use for condition variable timing")
+endif()
+
+# Timeouts
+set(SOCKET_TIMEOUT 500 CACHE STRING
+  "Default timeout for responses from IPCPs (ms)")
+
+# QoS settings
+set(QOS_DISABLE_CRC TRUE CACHE BOOL
+  "Ignores ber setting on all QoS cubes")
+
+# Delta-t protocol timers
+set(DELTA_T_MPL 60 CACHE STRING
+  "Maximum packet lifetime (s)")
+set(DELTA_T_ACK 10 CACHE STRING
+  "Maximum time to acknowledge a packet (s)")
+set(DELTA_T_RTX 120 CACHE STRING
+  "Maximum time to retransmit a packet (s)")
+
+# FRCT configuration
+set(FRCT_REORDER_QUEUE_SIZE 256 CACHE STRING
+  "Size of the reordering queue, must be a power of 2")
+set(FRCT_START_WINDOW 64 CACHE STRING
+  "Start window, must be a power of 2")
+set(FRCT_LINUX_RTT_ESTIMATOR TRUE CACHE BOOL
+  "Use Linux RTT estimator formula instead of the TCP RFC formula")
+set(FRCT_RTO_MDEV_MULTIPLIER 2 CACHE STRING
+  "Multiplier for deviation term in the RTO: RTO = sRTT + (mdev << X)")
+set(FRCT_RTO_INC_FACTOR 0 CACHE STRING
+  "Divisor for RTO increase after timeout: RTO += RTX >> X, 0: Karn/Partridge")
+set(FRCT_RTO_MIN 250 CACHE STRING
+  "Minimum Retransmission Timeout (RTO) for FRCT (us)")
+set(FRCT_TICK_TIME 5000 CACHE STRING
+  "Tick time for FRCT activity (retransmission, acknowledgments) (us)")
+
+# Retransmission (RXM) configuration
+set(RXM_BUFFER_ON_HEAP FALSE CACHE BOOL
+  "Store packets for retransmission on the heap instead of in packet buffer")
+set(RXM_BLOCKING TRUE CACHE BOOL
+  "Use blocking writes for retransmission")
+set(RXM_MIN_RESOLUTION 20 CACHE STRING
+  "Minimum retransmission delay (ns), as a power to 2")
+set(RXM_WHEEL_MULTIPLIER 4 CACHE STRING
+  "Factor for retransmission wheel levels as a power to 2")
+set(RXM_WHEEL_LEVELS 3 CACHE STRING
+  "Number of levels in the retransmission wheel")
+set(RXM_WHEEL_SLOTS_PER_LEVEL 256 CACHE STRING
+  "Number of slots per level in the retransmission wheel, must be a power of 2")
+
+# Acknowledgment wheel configuration
+set(ACK_WHEEL_SLOTS 256 CACHE STRING
+  "Number of slots in the acknowledgment wheel, must be a power of 2")
+set(ACK_WHEEL_RESOLUTION 18 CACHE STRING
+  "Minimum acknowledgment delay (ns), as a power to 2")
+
+# Thread pool manager (TPM) debugging
+set(TPM_DEBUG_REPORT_INTERVAL 0 CACHE STRING
+  "Interval at wich the TPM will report long running threads (s), 0 disables")
+set(TPM_DEBUG_ABORT_TIMEOUT 0 CACHE STRING
+  "TPM abort process after a thread reaches this timeout (s), 0 disables")
+
+# Encryption
+set(KEY_ROTATION_BIT 20 CACHE STRING
+  "Bit position in packet counter that triggers key rotation (default 20 = every 2^20 packets)")
+
+# Flow statistics (requires FUSE)
+if(HAVE_FUSE)
+  set(PROC_FLOW_STATS TRUE CACHE BOOL
+    "Enable flow statistics tracking for application flows")
+  if(PROC_FLOW_STATS)
+    message(STATUS "Application flow statistics enabled")
+  else()
+    message(STATUS "Application flow statistics disabled")
+  endif()
+endif()