1 files changed, 164 insertions, 0 deletions

diff --git a/main/session.c b/main/session.c
new file mode 100644
index 0000000..6d9c334
--- /dev/null
+++ b/main/session.c
@@ -0,0 +1,164 @@
+#include "session.h"
+#include "firewall.h"
+#include "dns_server.h"
+#include "esp_log.h"
+#include "freertos/FreeRTOS.h"
+#include "freertos/task.h"
+#include <string.h>
+
+#define SPENT_SECRETS_MAX 100
+
+static const char *TAG = "session";
+static session_t s_sessions[SESSION_MAX_CLIENTS];
+static int s_session_count = 0;
+
+static char s_spent_secrets[SPENT_SECRETS_MAX][65];
+static int s_spent_count = 0;
+
+static int64_t get_time_ms(void)
+{
+    return (int64_t)xTaskGetTickCount() * portTICK_PERIOD_MS;
+}
+
+esp_err_t session_manager_init(void)
+{
+    memset(s_sessions, 0, sizeof(s_sessions));
+    s_session_count = 0;
+    s_spent_count = 0;
+    ESP_LOGI(TAG, "Session manager initialized");
+    return ESP_OK;
+}
+
+session_t *session_create(uint32_t client_ip, uint64_t allotment_ms,
+                          const char *spent_secrets[], int secret_count)
+{
+    session_t *existing = session_find_by_ip(client_ip);
+    if (existing) {
+        session_extend(existing, allotment_ms);
+        for (int i = 0; i < secret_count && s_spent_count < SPENT_SECRETS_MAX; i++) {
+            strncpy(s_spent_secrets[s_spent_count], spent_secrets[i], 64);
+            s_spent_secrets[s_spent_count][64] = '\0';
+            s_spent_count++;
+        }
+        return existing;
+    }
+
+    if (s_session_count >= SESSION_MAX_CLIENTS) {
+        for (int i = 0; i < SESSION_MAX_CLIENTS; i++) {
+            if (!s_sessions[i].active || session_is_expired(&s_sessions[i])) {
+                session_revoke(&s_sessions[i]);
+                break;
+            }
+        }
+    }
+
+    for (int i = 0; i < SESSION_MAX_CLIENTS; i++) {
+        if (!s_sessions[i].active) {
+            s_sessions[i].client_ip = client_ip;
+            s_sessions[i].allotment_ms = allotment_ms;
+            s_sessions[i].start_time_ms = get_time_ms();
+            s_sessions[i].active = true;
+            s_sessions[i].spent_secret_count = 0;
+
+            for (int j = 0; j < secret_count && j < 5; j++) {
+                strncpy(s_sessions[i].spent_secrets[s_sessions[i].spent_secret_count],
+                        spent_secrets[j], 64);
+                s_sessions[i].spent_secrets[s_sessions[i].spent_secret_count][64] = '\0';
+                s_sessions[i].spent_secret_count++;
+            }
+
+            for (int j = 0; j < secret_count && s_spent_count < SPENT_SECRETS_MAX; j++) {
+                strncpy(s_spent_secrets[s_spent_count], spent_secrets[j], 64);
+                s_spent_secrets[s_spent_count][64] = '\0';
+                s_spent_count++;
+            }
+
+            s_session_count++;
+            firewall_grant_access(client_ip);
+
+            esp_ip4_addr_t ip = { .addr = client_ip };
+            ESP_LOGI(TAG, "Session created: " IPSTR " allotment=%llums", IP2STR(&ip),
+                     (unsigned long long)allotment_ms);
+            return &s_sessions[i];
+        }
+    }
+
+    ESP_LOGW(TAG, "No free session slots");
+    return NULL;
+}
+
+session_t *session_find_by_ip(uint32_t client_ip)
+{
+    for (int i = 0; i < SESSION_MAX_CLIENTS; i++) {
+        if (s_sessions[i].active && s_sessions[i].client_ip == client_ip) {
+            return &s_sessions[i];
+        }
+    }
+    return NULL;
+}
+
+void session_extend(session_t *session, uint64_t additional_ms)
+{
+    if (!session || !session->active) return;
+    session->allotment_ms += additional_ms;
+    esp_ip4_addr_t ip = { .addr = session->client_ip };
+    ESP_LOGI(TAG, "Session extended: " IPSTR " +%llums (total=%llu)", IP2STR(&ip),
+             (unsigned long long)additional_ms, (unsigned long long)session->allotment_ms);
+}
+
+bool session_is_expired(const session_t *session)
+{
+    if (!session || !session->active) return true;
+    int64_t elapsed = get_time_ms() - session->start_time_ms;
+    return elapsed >= (int64_t)session->allotment_ms;
+}
+
+bool session_is_secret_spent(const char *secret)
+{
+    for (int i = 0; i < s_spent_count; i++) {
+        if (strncmp(s_spent_secrets[i], secret, 64) == 0) return true;
+    }
+    return false;
+}
+
+void session_check_expiry(void)
+{
+    for (int i = 0; i < SESSION_MAX_CLIENTS; i++) {
+        if (s_sessions[i].active && session_is_expired(&s_sessions[i])) {
+            esp_ip4_addr_t ip = { .addr = s_sessions[i].client_ip };
+            ESP_LOGI(TAG, "Session expired: " IPSTR, IP2STR(&ip));
+            session_revoke(&s_sessions[i]);
+        }
+    }
+}
+
+void session_revoke(session_t *session)
+{
+    if (!session || !session->active) return;
+    firewall_revoke_access(session->client_ip);
+    session->active = false;
+    s_session_count--;
+}
+
+void session_revoke_all(void)
+{
+    for (int i = 0; i < SESSION_MAX_CLIENTS; i++) {
+        if (s_sessions[i].active) {
+            session_revoke(&s_sessions[i]);
+        }
+    }
+}
+
+int session_active_count(void)
+{
+    int count = 0;
+    for (int i = 0; i < SESSION_MAX_CLIENTS; i++) {
+        if (s_sessions[i].active) count++;
+    }
+    return count;
+}
+
+void session_tick(void)
+{
+    session_check_expiry();
+}