Fix loopback interface. Add new tests, remove deprecated tests.

.github/workflows/linux.yml

@@ -90,6 +90,18 @@ jobs:
           set -euo pipefail
           timeout --preserve-status 2m sudo LD_PRELOAD=$PWD/libwolfip.so ping -c 5 10.10.10.1
 
+      - name: Rebuild libwolfip.so with loopback enabled
+        run: |
+          set -euo pipefail
+          rm -f libwolfip.so build/pie/wolfip.o
+          make libwolfip.so EXTRA_CFLAGS="-DWOLFIP_ENABLE_LOOPBACK=1"
+
+      - name: Testing ICMP loopback smoke (no TUN/TAP)
+        timeout-minutes: 2
+        run: |
+          set -euo pipefail
+          timeout --preserve-status 2m sudo LD_PRELOAD=$PWD/libwolfip.so ping -4 -n -c 5 127.0.0.1
+
       - name: Install check
         run: |
           sudo apt-get install -y check

Makefile

@@ -1,6 +1,7 @@
 CC?=gcc
 CFLAGS:=-Wall -Werror -Wextra -I. -D_GNU_SOURCE
 CFLAGS+=-g -ggdb -Wdeclaration-after-statement
+CFLAGS+=$(EXTRA_CFLAGS)
 LDFLAGS+=-pthread
 # additional debug flags:
 #   CFLAGS+=-DDEBUG_TAP

src/test/test_wolfguard_loopback.c

@@ -16,11 +16,19 @@
 #endif
 
 #undef  WOLFIP_MAX_INTERFACES
-#define WOLFIP_MAX_INTERFACES 2
+#define WOLFIP_MAX_INTERFACES 3
 
 #include "check.h"
 #include "../../config.h"
 
+#if WOLFIP_ENABLE_LOOPBACK
+#define TEST_PHYS_IF 1U
+#define TEST_WG_IF   2U
+#else
+#define TEST_PHYS_IF 0U
+#define TEST_WG_IF   1U
+#endif
+
 /* Override after config.h */
 #undef  MAX_UDPSOCKETS
 #define MAX_UDPSOCKETS 8
@@ -205,47 +213,47 @@ static void setup_loopback_stacks(uint64_t *now)
     /* ---- Stack A ---- */
     wolfIP_init(&stack_a);
 
-    /* Physical interface (non_ethernet, index 0) */
-    ll = wolfIP_getdev_ex(&stack_a, 0);
+    /* Physical interface (non_ethernet, index TEST_PHYS_IF). */
+    ll = wolfIP_getdev_ex(&stack_a, TEST_PHYS_IF);
     ll->non_ethernet = 1;
     ll->poll = phys_a_poll;
     ll->send = phys_a_send;
     strncpy(ll->ifname, "eth_a", sizeof(ll->ifname) - 1);
 
-    wolfIP_ipconfig_set(&stack_a, MAKE_IP4(192,168,1,1),
-                        MAKE_IP4(255,255,255,0), 0);
+    wolfIP_ipconfig_set_ex(&stack_a, TEST_PHYS_IF, MAKE_IP4(192,168,1,1),
+                           MAKE_IP4(255,255,255,0), 0);
 
     /* wolfGuard on interface 1 (wg0) */
-    ck_assert_int_eq(wolfguard_init(&wg_dev_a, &stack_a, 1, 51820), 0);
+    ck_assert_int_eq(wolfguard_init(&wg_dev_a, &stack_a, TEST_WG_IF, 51820), 0);
 
     /* Generate and set keys for A */
     wc_RNG_GenerateBlock(&test_rng, priv_a, WG_PRIVATE_KEY_LEN);
     ck_assert_int_eq(wolfguard_set_private_key(&wg_dev_a, priv_a), 0);
 
-    wolfIP_ipconfig_set_ex(&stack_a, 1, MAKE_IP4(10,0,0,1),
+    wolfIP_ipconfig_set_ex(&stack_a, TEST_WG_IF, MAKE_IP4(10,0,0,1),
                            MAKE_IP4(255,255,255,0), 0);
 
     /* Stack B */
     wolfIP_init(&stack_b);
 
-    /* Physical interface (non_ethernet, index 0) */
-    ll = wolfIP_getdev_ex(&stack_b, 0);
+    /* Physical interface (non_ethernet, index TEST_PHYS_IF). */
+    ll = wolfIP_getdev_ex(&stack_b, TEST_PHYS_IF);
     ll->non_ethernet = 1;
     ll->poll = phys_b_poll;
     ll->send = phys_b_send;
     strncpy(ll->ifname, "eth_b", sizeof(ll->ifname) - 1);
 
-    wolfIP_ipconfig_set(&stack_b, MAKE_IP4(192,168,1,2),
-                        MAKE_IP4(255,255,255,0), 0);
+    wolfIP_ipconfig_set_ex(&stack_b, TEST_PHYS_IF, MAKE_IP4(192,168,1,2),
+                           MAKE_IP4(255,255,255,0), 0);
 
     /* wolfGuard on interface 1 (wg0) */
-    ck_assert_int_eq(wolfguard_init(&wg_dev_b, &stack_b, 1, 51820), 0);
+    ck_assert_int_eq(wolfguard_init(&wg_dev_b, &stack_b, TEST_WG_IF, 51820), 0);
 
     /* Generate and set keys for B */
     wc_RNG_GenerateBlock(&test_rng, priv_b, WG_PRIVATE_KEY_LEN);
     ck_assert_int_eq(wolfguard_set_private_key(&wg_dev_b, priv_b), 0);
 
-    wolfIP_ipconfig_set_ex(&stack_b, 1, MAKE_IP4(10,0,0,2),
+    wolfIP_ipconfig_set_ex(&stack_b, TEST_WG_IF, MAKE_IP4(10,0,0,2),
                            MAKE_IP4(255,255,255,0), 0);
 
     /* Add peers (A knows B, B knows A) */
@@ -798,50 +806,50 @@ START_TEST(test_multi_peer)
 
     /* Stack A (hub, 2 peers) */
     wolfIP_init(&stack_a);
-    ll = wolfIP_getdev_ex(&stack_a, 0);
+    ll = wolfIP_getdev_ex(&stack_a, TEST_PHYS_IF);
     ll->non_ethernet = 1;
     ll->poll = phys_a_poll_multi;
     ll->send = phys_a_send_multi;
     strncpy(ll->ifname, "eth_a", sizeof(ll->ifname) - 1);
-    wolfIP_ipconfig_set(&stack_a, MAKE_IP4(192,168,1,1),
-                        MAKE_IP4(255,255,255,0), 0);
+    wolfIP_ipconfig_set_ex(&stack_a, TEST_PHYS_IF, MAKE_IP4(192,168,1,1),
+                           MAKE_IP4(255,255,255,0), 0);
 
-    ck_assert_int_eq(wolfguard_init(&wg_dev_a, &stack_a, 1, 51820), 0);
+    ck_assert_int_eq(wolfguard_init(&wg_dev_a, &stack_a, TEST_WG_IF, 51820), 0);
     wc_RNG_GenerateBlock(&test_rng, priv_a, WG_PRIVATE_KEY_LEN);
     ck_assert_int_eq(wolfguard_set_private_key(&wg_dev_a, priv_a), 0);
-    wolfIP_ipconfig_set_ex(&stack_a, 1, MAKE_IP4(10,0,0,1),
+    wolfIP_ipconfig_set_ex(&stack_a, TEST_WG_IF, MAKE_IP4(10,0,0,1),
                            MAKE_IP4(255,0,0,0), 0);
 
     /* Stack B */
     wolfIP_init(&stack_b);
-    ll = wolfIP_getdev_ex(&stack_b, 0);
+    ll = wolfIP_getdev_ex(&stack_b, TEST_PHYS_IF);
     ll->non_ethernet = 1;
     ll->poll = phys_b_poll;
     ll->send = phys_b_send;
     strncpy(ll->ifname, "eth_b", sizeof(ll->ifname) - 1);
-    wolfIP_ipconfig_set(&stack_b, MAKE_IP4(192,168,1,2),
-                        MAKE_IP4(255,255,255,0), 0);
+    wolfIP_ipconfig_set_ex(&stack_b, TEST_PHYS_IF, MAKE_IP4(192,168,1,2),
+                           MAKE_IP4(255,255,255,0), 0);
 
-    ck_assert_int_eq(wolfguard_init(&wg_dev_b, &stack_b, 1, 51820), 0);
+    ck_assert_int_eq(wolfguard_init(&wg_dev_b, &stack_b, TEST_WG_IF, 51820), 0);
     wc_RNG_GenerateBlock(&test_rng, priv_b, WG_PRIVATE_KEY_LEN);
     ck_assert_int_eq(wolfguard_set_private_key(&wg_dev_b, priv_b), 0);
-    wolfIP_ipconfig_set_ex(&stack_b, 1, MAKE_IP4(10,0,1,1),
+    wolfIP_ipconfig_set_ex(&stack_b, TEST_WG_IF, MAKE_IP4(10,0,1,1),
                            MAKE_IP4(255,255,255,0), 0);
 
     /* Stack C */
     wolfIP_init(&stack_c);
-    ll = wolfIP_getdev_ex(&stack_c, 0);
+    ll = wolfIP_getdev_ex(&stack_c, TEST_PHYS_IF);
     ll->non_ethernet = 1;
     ll->poll = phys_c_poll;
     ll->send = phys_c_send;
     strncpy(ll->ifname, "eth_c", sizeof(ll->ifname) - 1);
-    wolfIP_ipconfig_set(&stack_c, MAKE_IP4(192,168,1,3),
-                        MAKE_IP4(255,255,255,0), 0);
+    wolfIP_ipconfig_set_ex(&stack_c, TEST_PHYS_IF, MAKE_IP4(192,168,1,3),
+                           MAKE_IP4(255,255,255,0), 0);
 
-    ck_assert_int_eq(wolfguard_init(&wg_dev_c, &stack_c, 1, 51820), 0);
+    ck_assert_int_eq(wolfguard_init(&wg_dev_c, &stack_c, TEST_WG_IF, 51820), 0);
     wc_RNG_GenerateBlock(&test_rng, priv_c, WG_PRIVATE_KEY_LEN);
     ck_assert_int_eq(wolfguard_set_private_key(&wg_dev_c, priv_c), 0);
-    wolfIP_ipconfig_set_ex(&stack_c, 1, MAKE_IP4(10,0,2,1),
+    wolfIP_ipconfig_set_ex(&stack_c, TEST_WG_IF, MAKE_IP4(10,0,2,1),
                            MAKE_IP4(255,255,255,0), 0);
 
     /* Add peers */

src/test/unit/unit.c

@@ -115,8 +115,10 @@ Suite *wolf_suite(void)
 #if WOLFIP_ENABLE_LOOPBACK
     tcase_add_test(tc_utils, test_wolfip_loopback_defaults);
     tcase_add_test(tc_utils, test_wolfip_loopback_send_paths);
+    tcase_add_test(tc_utils, test_wolfip_loopback_poll_paths);
+    tcase_add_test(tc_utils, test_wolfip_loopback_poll_keeps_pending_on_short_buffer);
     tcase_add_test(tc_utils, test_wolfip_loopback_send_drops_oversize);
-    tcase_add_test(tc_utils, test_wolfip_loopback_send_null_container);
+    tcase_add_test(tc_utils, test_wolfip_loopback_send_queue_full_returns_eagain);
     tcase_add_test(tc_utils, test_wolfip_loopback_send_rejects_null_args);
 #endif
     tcase_add_test(tc_utils, test_wolfip_send_port_unreachable_ignores_missing_link_sender);
@@ -770,7 +772,13 @@ Suite *wolf_suite(void)
     tcase_add_test(tc_proto, test_regression_syn_on_established_not_silently_processed);
     tcase_add_test(tc_proto, test_regression_syn_on_last_ack_not_silently_processed);
     tcase_add_test(tc_proto, test_regression_full_txbuf_still_sends_pure_ack);
-    tcase_add_test(tc_proto, test_regression_loopback_immediate_pure_ack_uses_loopback_ll);
+    tcase_add_test(tc_proto, test_regression_loopback_pure_ack_uses_deferred_buffer_until_poll);
+    tcase_add_test(tc_proto, test_regression_loopback_pure_ack_drain_allows_next_send_cycle);
+    tcase_add_test(tc_proto, test_regression_loopback_pure_ack_immediate_propagates_eagain_when_queue_full);
+    tcase_add_test(tc_proto, test_regression_loopback_udp_tx_backpressure_retries_after_queue_drain);
+    tcase_add_test(tc_proto, test_regression_ll_send_frame_returns_wolfip_error_codes);
+    tcase_add_test(tc_proto, test_regression_loopback_ack_retry_pending_requeued_on_poll);
+    tcase_add_test(tc_proto, test_regression_loopback_queue_full_pure_ack_backpressure_retry);
     tcase_add_test(tc_proto, test_regression_tcp_tx_desc_payload_len_keeps_descriptor_layout_sanity);
     tcase_add_test(tc_proto, test_regression_fast_recovery_cwnd_ssthresh_rfc5681);
     tcase_add_test(tc_proto, test_regression_paws_rejects_stale_timestamp);

src/test/unit/unit_esp.c

@@ -28,6 +28,7 @@
 #undef  WOLFIP_MAX_INTERFACES
 #define WOLFIP_MAX_INTERFACES 1
 #undef  WOLFIP_ENABLE_LOOPBACK
+#define WOLFIP_ENABLE_LOOPBACK 0
 
 #include "check.h"
 #include "../../../config.h"