test(fuzz): esp_netif/ping_sock/ip_addr stubs — un-break ADR-061 fuzz build after #954

csi_collector.c gained esp_netif.h / ping/ping_sock.h / lwip/ip_addr.h
includes for the #954 gateway self-ping; the host-fuzz stub env lacked
them, breaking the fuzz build on main since 5789351b7. Stubs return
no-gateway so the self-ping path early-outs (compiles + links, never
exercised — matches the fuzz threat model which targets frame
serialization, not the network stack).

Co-Authored-By: claude-flow <ruv@ruv.net>

firmware/esp32-csi-node/test/stubs/esp_netif.h

@@ -0,0 +1,48 @@
+/* Host-fuzzing stub for esp_netif.h (ADR-061).
+ *
+ * csi_collector.c's #954 self-ping needs the STA netif handle + gateway IP.
+ * In the fuzz environment there is no network stack: the handle lookup
+ * returns NULL, so csi_start_self_ping() takes its no-gateway early-out and
+ * the esp_ping path is never exercised (but must compile and link).
+ */
+#pragma once
+
+#include <stdint.h>
+#include <stdio.h>
+
+#include "esp_err.h"
+
+typedef struct esp_netif_obj esp_netif_t;
+
+typedef struct {
+    uint32_t addr;
+} esp_ip4_addr_t;
+
+typedef struct {
+    esp_ip4_addr_t ip;
+    esp_ip4_addr_t netmask;
+    esp_ip4_addr_t gw;
+} esp_netif_ip_info_t;
+
+static inline esp_netif_t *esp_netif_get_handle_from_ifkey(const char *if_key)
+{
+    (void)if_key;
+    return NULL; /* no netif in fuzz env -> self-ping early-out */
+}
+
+static inline esp_err_t esp_netif_get_ip_info(esp_netif_t *netif, esp_netif_ip_info_t *ip_info)
+{
+    (void)netif;
+    (void)ip_info;
+    return ESP_FAIL;
+}
+
+static inline char *esp_ip4addr_ntoa(const esp_ip4_addr_t *addr, char *buf, int buflen)
+{
+    if (buf != NULL && buflen > 0) {
+        snprintf(buf, (size_t)buflen, "%u.%u.%u.%u",
+                 (unsigned)(addr->addr & 0xff), (unsigned)((addr->addr >> 8) & 0xff),
+                 (unsigned)((addr->addr >> 16) & 0xff), (unsigned)((addr->addr >> 24) & 0xff));
+    }
+    return buf;
+}

firmware/esp32-csi-node/test/stubs/lwip/ip_addr.h

@@ -0,0 +1,20 @@
+/* Host-fuzzing stub for lwip/ip_addr.h (ADR-061). Minimal surface for the
+ * #954 self-ping block; never functionally exercised in the fuzz env. */
+#pragma once
+
+#include <stdint.h>
+
+typedef struct {
+    uint32_t addr;
+    uint8_t type;
+} ip_addr_t;
+
+static inline int ipaddr_aton(const char *cp, ip_addr_t *addr)
+{
+    (void)cp;
+    if (addr != NULL) {
+        addr->addr = 0;
+        addr->type = 0;
+    }
+    return 1;
+}

firmware/esp32-csi-node/test/stubs/ping/ping_sock.h

@@ -0,0 +1,79 @@
+/* Host-fuzzing stub for ping/ping_sock.h (ADR-061). The #954 self-ping is
+ * unreachable in the fuzz env (esp_netif stub returns no gateway), but the
+ * symbols must compile and link. */
+#pragma once
+
+#include <stdint.h>
+
+#include "esp_err.h"
+#include "lwip/ip_addr.h"
+
+typedef void *esp_ping_handle_t;
+
+typedef void (*esp_ping_cb_t)(esp_ping_handle_t hdl, void *args);
+
+typedef struct {
+    uint32_t count;
+    uint32_t interval_ms;
+    uint32_t timeout_ms;
+    uint32_t data_size;
+    uint8_t tos;
+    int ttl;
+    ip_addr_t target_addr;
+    uint32_t task_stack_size;
+    uint32_t task_prio;
+    uint32_t interface;
+} esp_ping_config_t;
+
+#define ESP_PING_COUNT_INFINITE (0)
+
+#define ESP_PING_DEFAULT_CONFIG()       \
+    {                                   \
+        .count = 5,                     \
+        .interval_ms = 1000,            \
+        .timeout_ms = 1000,             \
+        .data_size = 64,                \
+        .tos = 0,                       \
+        .ttl = 64,                      \
+        .target_addr = {0, 0},          \
+        .task_stack_size = 2048,        \
+        .task_prio = 2,                 \
+        .interface = 0,                 \
+    }
+
+typedef struct {
+    void *cb_args;
+    esp_ping_cb_t on_ping_success;
+    esp_ping_cb_t on_ping_timeout;
+    esp_ping_cb_t on_ping_end;
+} esp_ping_callbacks_t;
+
+static inline esp_err_t esp_ping_new_session(const esp_ping_config_t *config,
+                                             const esp_ping_callbacks_t *cbs,
+                                             esp_ping_handle_t *hdl_out)
+{
+    (void)config;
+    (void)cbs;
+    if (hdl_out != NULL) {
+        *hdl_out = (void *)0;
+    }
+    return ESP_FAIL; /* never starts a ping task in the fuzz env */
+}
+
+static inline esp_err_t esp_ping_start(esp_ping_handle_t hdl)
+{
+    (void)hdl;
+    return ESP_OK;
+}
+
+static inline esp_err_t esp_ping_stop(esp_ping_handle_t hdl)
+{
+    (void)hdl;
+    return ESP_OK;
+}
+
+static inline esp_err_t esp_ping_delete_session(esp_ping_handle_t hdl)
+{
+    (void)hdl;
+    return ESP_OK;
+}