| 1 | /* |
| 2 | * Copyright (C) 2018 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
| 3 | * Copyright (C) 2020 Jérémie Galarneau <jeremie.galarneau@efficios.com> |
| 4 | * |
| 5 | * SPDX-License-Identifier: GPL-2.0-only |
| 6 | * |
| 7 | */ |
| 8 | |
| 9 | #include "lttng/tracker.h" |
| 10 | #include "common/dynamic-array.h" |
| 11 | #include "common/macros.h" |
| 12 | #define _LGPL_SOURCE |
| 13 | #include <grp.h> |
| 14 | #include <pwd.h> |
| 15 | #include <sys/types.h> |
| 16 | #include <unistd.h> |
| 17 | #include <urcu.h> |
| 18 | #include <urcu/list.h> |
| 19 | #include <urcu/rculfhash.h> |
| 20 | |
| 21 | #include "tracker.h" |
| 22 | #include <common/defaults.h> |
| 23 | #include <common/error.h> |
| 24 | #include <common/hashtable/hashtable.h> |
| 25 | #include <common/hashtable/utils.h> |
| 26 | #include <common/tracker.h> |
| 27 | #include <lttng/lttng-error.h> |
| 28 | |
| 29 | struct process_attr_tracker_value_node { |
| 30 | struct process_attr_value *value; |
| 31 | struct cds_lfht_node inclusion_set_ht_node; |
| 32 | struct rcu_head rcu_head; |
| 33 | }; |
| 34 | |
| 35 | struct process_attr_tracker { |
| 36 | enum lttng_tracking_policy policy; |
| 37 | struct cds_lfht *inclusion_set_ht; |
| 38 | }; |
| 39 | |
| 40 | static void process_attr_tracker_value_node_rcu_free(struct rcu_head *rcu_head) |
| 41 | { |
| 42 | struct process_attr_tracker_value_node *node = |
| 43 | container_of(rcu_head, typeof(*node), rcu_head); |
| 44 | |
| 45 | free(node); |
| 46 | } |
| 47 | |
| 48 | struct process_attr_tracker *process_attr_tracker_create(void) |
| 49 | { |
| 50 | struct process_attr_tracker *tracker; |
| 51 | |
| 52 | tracker = zmalloc(sizeof(*tracker)); |
| 53 | if (!tracker) { |
| 54 | return NULL; |
| 55 | } |
| 56 | |
| 57 | (void) process_attr_tracker_set_tracking_policy( |
| 58 | tracker, LTTNG_TRACKING_POLICY_INCLUDE_ALL); |
| 59 | |
| 60 | tracker->inclusion_set_ht = cds_lfht_new(DEFAULT_HT_SIZE, 1, 0, |
| 61 | CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL); |
| 62 | if (!tracker->inclusion_set_ht) { |
| 63 | goto error; |
| 64 | } |
| 65 | |
| 66 | return tracker; |
| 67 | error: |
| 68 | process_attr_tracker_destroy(tracker); |
| 69 | return NULL; |
| 70 | } |
| 71 | |
| 72 | static void process_attr_tracker_remove_value_node( |
| 73 | struct process_attr_tracker *tracker, |
| 74 | struct process_attr_tracker_value_node *value_node) |
| 75 | { |
| 76 | cds_lfht_del(tracker->inclusion_set_ht, |
| 77 | &value_node->inclusion_set_ht_node); |
| 78 | process_attr_value_destroy(value_node->value); |
| 79 | call_rcu(&value_node->rcu_head, |
| 80 | process_attr_tracker_value_node_rcu_free); |
| 81 | } |
| 82 | |
| 83 | static void process_attr_tracker_clear_inclusion_set( |
| 84 | struct process_attr_tracker *tracker) |
| 85 | { |
| 86 | int ret; |
| 87 | struct lttng_ht_iter iter; |
| 88 | struct process_attr_tracker_value_node *value_node; |
| 89 | |
| 90 | if (!tracker->inclusion_set_ht) { |
| 91 | return; |
| 92 | } |
| 93 | |
| 94 | rcu_read_lock(); |
| 95 | cds_lfht_for_each_entry (tracker->inclusion_set_ht, &iter.iter, |
| 96 | value_node, inclusion_set_ht_node) { |
| 97 | process_attr_tracker_remove_value_node(tracker, value_node); |
| 98 | } |
| 99 | rcu_read_unlock(); |
| 100 | ret = cds_lfht_destroy(tracker->inclusion_set_ht, NULL); |
| 101 | assert(ret == 0); |
| 102 | tracker->inclusion_set_ht = NULL; |
| 103 | } |
| 104 | |
| 105 | static int process_attr_tracker_create_inclusion_set( |
| 106 | struct process_attr_tracker *tracker) |
| 107 | { |
| 108 | assert(!tracker->inclusion_set_ht); |
| 109 | tracker->inclusion_set_ht = cds_lfht_new(DEFAULT_HT_SIZE, 1, 0, |
| 110 | CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL); |
| 111 | return tracker->inclusion_set_ht ? 0 : -1; |
| 112 | } |
| 113 | |
| 114 | void process_attr_tracker_destroy(struct process_attr_tracker *tracker) |
| 115 | { |
| 116 | if (!tracker) { |
| 117 | return; |
| 118 | } |
| 119 | |
| 120 | process_attr_tracker_clear_inclusion_set(tracker); |
| 121 | free(tracker); |
| 122 | } |
| 123 | |
| 124 | enum lttng_tracking_policy process_attr_tracker_get_tracking_policy( |
| 125 | const struct process_attr_tracker *tracker) |
| 126 | { |
| 127 | return tracker->policy; |
| 128 | } |
| 129 | |
| 130 | int process_attr_tracker_set_tracking_policy( |
| 131 | struct process_attr_tracker *tracker, |
| 132 | enum lttng_tracking_policy tracking_policy) |
| 133 | { |
| 134 | int ret = 0; |
| 135 | |
| 136 | if (tracker->policy == tracking_policy) { |
| 137 | goto end; |
| 138 | } |
| 139 | |
| 140 | process_attr_tracker_clear_inclusion_set(tracker); |
| 141 | ret = process_attr_tracker_create_inclusion_set(tracker); |
| 142 | if (ret) { |
| 143 | goto end; |
| 144 | } |
| 145 | tracker->policy = tracking_policy; |
| 146 | end: |
| 147 | return ret; |
| 148 | } |
| 149 | |
| 150 | static int match_inclusion_set_value( |
| 151 | struct cds_lfht_node *node, const void *key) |
| 152 | { |
| 153 | const struct process_attr_value *value_key = key; |
| 154 | const struct process_attr_tracker_value_node *value_node = |
| 155 | caa_container_of(node, |
| 156 | struct process_attr_tracker_value_node, |
| 157 | inclusion_set_ht_node); |
| 158 | |
| 159 | return process_attr_tracker_value_equal(value_node->value, value_key); |
| 160 | } |
| 161 | |
| 162 | static struct process_attr_tracker_value_node *process_attr_tracker_lookup( |
| 163 | const struct process_attr_tracker *tracker, |
| 164 | const struct process_attr_value *value) |
| 165 | { |
| 166 | struct cds_lfht_iter iter; |
| 167 | struct cds_lfht_node *node; |
| 168 | |
| 169 | assert(tracker->policy == LTTNG_TRACKING_POLICY_INCLUDE_SET); |
| 170 | |
| 171 | rcu_read_lock(); |
| 172 | cds_lfht_lookup(tracker->inclusion_set_ht, |
| 173 | process_attr_value_hash(value), |
| 174 | match_inclusion_set_value, value, &iter); |
| 175 | node = cds_lfht_iter_get_node(&iter); |
| 176 | rcu_read_unlock(); |
| 177 | |
| 178 | return node ? container_of(node, struct process_attr_tracker_value_node, |
| 179 | inclusion_set_ht_node) : |
| 180 | NULL; |
| 181 | } |
| 182 | |
| 183 | /* Protected by session mutex held by caller. */ |
| 184 | enum process_attr_tracker_status process_attr_tracker_inclusion_set_add_value( |
| 185 | struct process_attr_tracker *tracker, |
| 186 | const struct process_attr_value *value) |
| 187 | { |
| 188 | enum process_attr_tracker_status status = |
| 189 | PROCESS_ATTR_TRACKER_STATUS_OK; |
| 190 | struct process_attr_value *value_copy = NULL; |
| 191 | struct process_attr_tracker_value_node *value_node = NULL; |
| 192 | |
| 193 | rcu_read_lock(); |
| 194 | if (tracker->policy != LTTNG_TRACKING_POLICY_INCLUDE_SET) { |
| 195 | status = PROCESS_ATTR_TRACKER_STATUS_INVALID_TRACKING_POLICY; |
| 196 | goto end; |
| 197 | } |
| 198 | |
| 199 | if (process_attr_tracker_lookup(tracker, value)) { |
| 200 | status = PROCESS_ATTR_TRACKER_STATUS_EXISTS; |
| 201 | goto end; |
| 202 | } |
| 203 | |
| 204 | value_node = zmalloc(sizeof(*value_node)); |
| 205 | if (!value_node) { |
| 206 | status = PROCESS_ATTR_TRACKER_STATUS_ERROR; |
| 207 | goto end; |
| 208 | } |
| 209 | |
| 210 | value_copy = process_attr_value_copy(value); |
| 211 | if (!value_copy) { |
| 212 | status = PROCESS_ATTR_TRACKER_STATUS_ERROR; |
| 213 | goto end; |
| 214 | } |
| 215 | |
| 216 | value_node->value = value_copy; |
| 217 | cds_lfht_add(tracker->inclusion_set_ht, |
| 218 | process_attr_value_hash(value_copy), |
| 219 | &value_node->inclusion_set_ht_node); |
| 220 | value_copy = NULL; |
| 221 | value_node = NULL; |
| 222 | end: |
| 223 | if (value_copy) { |
| 224 | process_attr_value_destroy(value_copy); |
| 225 | } |
| 226 | if (value_node) { |
| 227 | free(value_node); |
| 228 | } |
| 229 | rcu_read_unlock(); |
| 230 | return status; |
| 231 | } |
| 232 | |
| 233 | /* Protected by session mutex held by caller. */ |
| 234 | enum process_attr_tracker_status |
| 235 | process_attr_tracker_inclusion_set_remove_value( |
| 236 | struct process_attr_tracker *tracker, |
| 237 | const struct process_attr_value *value) |
| 238 | { |
| 239 | struct process_attr_tracker_value_node *value_node; |
| 240 | enum process_attr_tracker_status status = |
| 241 | PROCESS_ATTR_TRACKER_STATUS_OK; |
| 242 | |
| 243 | rcu_read_lock(); |
| 244 | if (tracker->policy != LTTNG_TRACKING_POLICY_INCLUDE_SET) { |
| 245 | status = PROCESS_ATTR_TRACKER_STATUS_INVALID_TRACKING_POLICY; |
| 246 | goto end; |
| 247 | } |
| 248 | |
| 249 | value_node = process_attr_tracker_lookup(tracker, value); |
| 250 | if (!value_node) { |
| 251 | status = PROCESS_ATTR_TRACKER_STATUS_MISSING; |
| 252 | goto end; |
| 253 | } |
| 254 | |
| 255 | process_attr_tracker_remove_value_node(tracker, value_node); |
| 256 | end: |
| 257 | rcu_read_unlock(); |
| 258 | return status; |
| 259 | } |
| 260 | |
| 261 | enum process_attr_tracker_status process_attr_tracker_get_inclusion_set( |
| 262 | const struct process_attr_tracker *tracker, |
| 263 | struct lttng_process_attr_values **_values) |
| 264 | { |
| 265 | struct lttng_ht_iter iter; |
| 266 | struct process_attr_tracker_value_node *value_node; |
| 267 | enum process_attr_tracker_status status = |
| 268 | PROCESS_ATTR_TRACKER_STATUS_OK; |
| 269 | struct lttng_process_attr_values *values; |
| 270 | struct process_attr_value *new_value = NULL; |
| 271 | |
| 272 | values = lttng_process_attr_values_create(); |
| 273 | if (!values) { |
| 274 | status = PROCESS_ATTR_TRACKER_STATUS_ERROR; |
| 275 | goto error; |
| 276 | } |
| 277 | |
| 278 | if (tracker->policy != LTTNG_TRACKING_POLICY_INCLUDE_SET) { |
| 279 | status = PROCESS_ATTR_TRACKER_STATUS_INVALID_TRACKING_POLICY; |
| 280 | goto error; |
| 281 | } |
| 282 | |
| 283 | rcu_read_lock(); |
| 284 | cds_lfht_for_each_entry (tracker->inclusion_set_ht, &iter.iter, |
| 285 | value_node, inclusion_set_ht_node) { |
| 286 | int ret; |
| 287 | |
| 288 | new_value = process_attr_value_copy(value_node->value); |
| 289 | if (!new_value) { |
| 290 | status = PROCESS_ATTR_TRACKER_STATUS_ERROR; |
| 291 | goto error_unlock; |
| 292 | } |
| 293 | |
| 294 | ret = lttng_dynamic_pointer_array_add_pointer( |
| 295 | &values->array, new_value); |
| 296 | if (ret) { |
| 297 | status = PROCESS_ATTR_TRACKER_STATUS_ERROR; |
| 298 | goto error_unlock; |
| 299 | } |
| 300 | |
| 301 | new_value = NULL; |
| 302 | } |
| 303 | rcu_read_unlock(); |
| 304 | *_values = values; |
| 305 | return status; |
| 306 | error_unlock: |
| 307 | rcu_read_unlock(); |
| 308 | error: |
| 309 | lttng_process_attr_values_destroy(values); |
| 310 | process_attr_value_destroy(new_value); |
| 311 | return status; |
| 312 | } |