+#define HOST_STATISTICS_TIME_WINDOW 1 /* seconds */
+#define HOST_STATISTICS_MAX_REQUESTS 10 /* maximum number of requests per window */
+#define HOST_STATISTICS_MIN_REQUESTS 2 /* minimum number of requests per window */
+
+uint64_t host_statistics_time_window;
+
+static lck_mtx_t host_statistics_lck;
+static lck_grp_t* host_statistics_lck_grp;
+
+#define HOST_VM_INFO64_REV0 0
+#define HOST_VM_INFO64_REV1 1
+#define HOST_EXTMOD_INFO64_REV0 2
+#define HOST_LOAD_INFO_REV0 3
+#define HOST_VM_INFO_REV0 4
+#define HOST_VM_INFO_REV1 5
+#define HOST_VM_INFO_REV2 6
+#define HOST_CPU_LOAD_INFO_REV0 7
+#define HOST_EXPIRED_TASK_INFO_REV0 8
+#define HOST_EXPIRED_TASK_INFO_REV1 9
+#define NUM_HOST_INFO_DATA_TYPES 10
+
+static vm_statistics64_data_t host_vm_info64_rev0 = {};
+static vm_statistics64_data_t host_vm_info64_rev1 = {};
+static vm_extmod_statistics_data_t host_extmod_info64 = {};
+static host_load_info_data_t host_load_info = {};
+static vm_statistics_data_t host_vm_info_rev0 = {};
+static vm_statistics_data_t host_vm_info_rev1 = {};
+static vm_statistics_data_t host_vm_info_rev2 = {};
+static host_cpu_load_info_data_t host_cpu_load_info = {};
+static task_power_info_data_t host_expired_task_info = {};
+static task_power_info_v2_data_t host_expired_task_info2 = {};
+
+struct host_stats_cache {
+ uint64_t last_access;
+ uint64_t current_requests;
+ uint64_t max_requests;
+ uintptr_t data;
+ mach_msg_type_number_t count; //NOTE count is in sizeof(integer_t)
+};
+
+static struct host_stats_cache g_host_stats_cache[NUM_HOST_INFO_DATA_TYPES] = {
+ [HOST_VM_INFO64_REV0] = { .last_access = 0, .current_requests = 0, .max_requests = 0, .data = (uintptr_t)&host_vm_info64_rev0, .count = HOST_VM_INFO64_REV0_COUNT },
+ [HOST_VM_INFO64_REV1] = { .last_access = 0, .current_requests = 0, .max_requests = 0, .data = (uintptr_t)&host_vm_info64_rev1, .count = HOST_VM_INFO64_REV1_COUNT },
+ [HOST_EXTMOD_INFO64_REV0] = { .last_access = 0, .current_requests = 0, .max_requests = 0, .data = (uintptr_t)&host_extmod_info64, .count = HOST_EXTMOD_INFO64_COUNT },
+ [HOST_LOAD_INFO_REV0] = { .last_access = 0, .current_requests = 0, .max_requests = 0, .data = (uintptr_t)&host_load_info, .count = HOST_LOAD_INFO_COUNT },
+ [HOST_VM_INFO_REV0] = { .last_access = 0, .current_requests = 0, .max_requests = 0, .data = (uintptr_t)&host_vm_info_rev0, .count = HOST_VM_INFO_REV0_COUNT },
+ [HOST_VM_INFO_REV1] = { .last_access = 0, .current_requests = 0, .max_requests = 0, .data = (uintptr_t)&host_vm_info_rev1, .count = HOST_VM_INFO_REV1_COUNT },
+ [HOST_VM_INFO_REV2] = { .last_access = 0, .current_requests = 0, .max_requests = 0, .data = (uintptr_t)&host_vm_info_rev2, .count = HOST_VM_INFO_REV2_COUNT },
+ [HOST_CPU_LOAD_INFO_REV0] = { .last_access = 0, .current_requests = 0, .max_requests = 0, .data = (uintptr_t)&host_cpu_load_info, .count = HOST_CPU_LOAD_INFO_COUNT },
+ [HOST_EXPIRED_TASK_INFO_REV0] = { .last_access = 0, .current_requests = 0, .max_requests = 0, .data = (uintptr_t)&host_expired_task_info, .count = TASK_POWER_INFO_COUNT },
+ [HOST_EXPIRED_TASK_INFO_REV1] = { .last_access = 0, .current_requests = 0, .max_requests = 0, .data = (uintptr_t)&host_expired_task_info2, .count = TASK_POWER_INFO_V2_COUNT},
+};
+
+
+void
+host_statistics_init(void)
+{
+ host_statistics_lck_grp = lck_grp_alloc_init("host_statistics", LCK_GRP_ATTR_NULL);
+ lck_mtx_init(&host_statistics_lck, host_statistics_lck_grp, LCK_ATTR_NULL);
+ nanoseconds_to_absolutetime((HOST_STATISTICS_TIME_WINDOW * NSEC_PER_SEC), &host_statistics_time_window);
+}
+
+static void
+cache_host_statistics(int index, host_info64_t info)
+{
+ if (index < 0 || index >= NUM_HOST_INFO_DATA_TYPES) {
+ return;
+ }
+
+ task_t task = current_task();
+ if (task->t_flags & TF_PLATFORM) {
+ return;
+ }
+
+ memcpy((void *)g_host_stats_cache[index].data, info, g_host_stats_cache[index].count * sizeof(integer_t));
+ return;
+}
+
+static void
+get_cached_info(int index, host_info64_t info, mach_msg_type_number_t* count)
+{
+ if (index < 0 || index >= NUM_HOST_INFO_DATA_TYPES) {
+ *count = 0;
+ return;
+ }
+
+ *count = g_host_stats_cache[index].count;
+ memcpy(info, (void *)g_host_stats_cache[index].data, g_host_stats_cache[index].count * sizeof(integer_t));
+}
+
+static int
+get_host_info_data_index(bool is_stat64, host_flavor_t flavor, mach_msg_type_number_t* count, kern_return_t* ret)
+{
+ switch (flavor) {
+ case HOST_VM_INFO64:
+ if (!is_stat64) {
+ *ret = KERN_INVALID_ARGUMENT;
+ return -1;
+ }
+ if (*count < HOST_VM_INFO64_REV0_COUNT) {
+ *ret = KERN_FAILURE;
+ return -1;
+ }
+ if (*count >= HOST_VM_INFO64_REV1_COUNT) {
+ return HOST_VM_INFO64_REV1;
+ }
+ return HOST_VM_INFO64_REV0;
+
+ case HOST_EXTMOD_INFO64:
+ if (!is_stat64) {
+ *ret = KERN_INVALID_ARGUMENT;
+ return -1;
+ }
+ if (*count < HOST_EXTMOD_INFO64_COUNT) {
+ *ret = KERN_FAILURE;
+ return -1;
+ }
+ return HOST_EXTMOD_INFO64_REV0;
+
+ case HOST_LOAD_INFO:
+ if (*count < HOST_LOAD_INFO_COUNT) {
+ *ret = KERN_FAILURE;
+ return -1;
+ }
+ return HOST_LOAD_INFO_REV0;
+
+ case HOST_VM_INFO:
+ if (*count < HOST_VM_INFO_REV0_COUNT) {
+ *ret = KERN_FAILURE;
+ return -1;
+ }
+ if (*count >= HOST_VM_INFO_REV2_COUNT) {
+ return HOST_VM_INFO_REV2;
+ }
+ if (*count >= HOST_VM_INFO_REV1_COUNT) {
+ return HOST_VM_INFO_REV1;
+ }
+ return HOST_VM_INFO_REV0;
+
+ case HOST_CPU_LOAD_INFO:
+ if (*count < HOST_CPU_LOAD_INFO_COUNT) {
+ *ret = KERN_FAILURE;
+ return -1;
+ }
+ return HOST_CPU_LOAD_INFO_REV0;
+
+ case HOST_EXPIRED_TASK_INFO:
+ if (*count < TASK_POWER_INFO_COUNT) {
+ *ret = KERN_FAILURE;
+ return -1;
+ }
+ if (*count >= TASK_POWER_INFO_V2_COUNT) {
+ return HOST_EXPIRED_TASK_INFO_REV1;
+ }
+ return HOST_EXPIRED_TASK_INFO_REV0;
+
+ default:
+ *ret = KERN_INVALID_ARGUMENT;
+ return -1;
+ }
+}
+
+static bool
+rate_limit_host_statistics(bool is_stat64, host_flavor_t flavor, host_info64_t info, mach_msg_type_number_t* count, kern_return_t* ret, int *pindex)
+{
+ task_t task = current_task();
+
+ assert(task != kernel_task);
+
+ *ret = KERN_SUCCESS;
+
+ /* Access control only for third party applications */
+ if (task->t_flags & TF_PLATFORM) {
+ return FALSE;
+ }
+
+ /* Rate limit to HOST_STATISTICS_MAX_REQUESTS queries for each HOST_STATISTICS_TIME_WINDOW window of time */
+ bool rate_limited = FALSE;
+ bool set_last_access = TRUE;
+
+ /* there is a cache for every flavor */
+ int index = get_host_info_data_index(is_stat64, flavor, count, ret);
+ if (index == -1) {
+ goto out;
+ }
+
+ *pindex = index;
+ lck_mtx_lock(&host_statistics_lck);
+ if (g_host_stats_cache[index].last_access > mach_continuous_time() - host_statistics_time_window) {
+ set_last_access = FALSE;
+ if (g_host_stats_cache[index].current_requests++ >= g_host_stats_cache[index].max_requests) {
+ rate_limited = TRUE;
+ get_cached_info(index, info, count);
+ }
+ }
+ if (set_last_access) {
+ g_host_stats_cache[index].current_requests = 1;
+ /*
+ * select a random number of requests (included between HOST_STATISTICS_MIN_REQUESTS and HOST_STATISTICS_MAX_REQUESTS)
+ * to let query host_statistics.
+ * In this way it is not possible to infer looking at when the a cached copy changes if host_statistics was called on
+ * the provious window.
+ */
+ g_host_stats_cache[index].max_requests = (mach_absolute_time() % (HOST_STATISTICS_MAX_REQUESTS - HOST_STATISTICS_MIN_REQUESTS + 1)) + HOST_STATISTICS_MIN_REQUESTS;
+ g_host_stats_cache[index].last_access = mach_continuous_time();
+ }
+ lck_mtx_unlock(&host_statistics_lck);
+out:
+ return rate_limited;
+}
+
+kern_return_t host_statistics64(host_t host, host_flavor_t flavor, host_info_t info, mach_msg_type_number_t * count);
+
projects / apple / xnu.git / blobdiff