| 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.hpp" |
| 11 | #include "common/macros.hpp" |
| 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.hpp" |
| 22 | #include <common/defaults.hpp> |
| 23 | #include <common/error.hpp> |
| 24 | #include <common/hashtable/hashtable.hpp> |
| 25 | #include <common/hashtable/utils.hpp> |
| 26 | #include <common/tracker.hpp> |
| 27 | #include <lttng/lttng-error.h> |
| 28 | |
| 29 | struct process_attr_tracker { |
| 30 | enum lttng_tracking_policy policy; |
| 31 | struct cds_lfht *inclusion_set_ht; |
| 32 | }; |
| 33 | |
| 34 | namespace { |
| 35 | struct process_attr_tracker_value_node { |
| 36 | struct process_attr_value *value; |
| 37 | struct cds_lfht_node inclusion_set_ht_node; |
| 38 | struct rcu_head rcu_head; |
| 39 | }; |
| 40 | } /* namespace */ |
| 41 | |
| 42 | static void process_attr_tracker_value_node_rcu_free(struct rcu_head *rcu_head) |
| 43 | { |
| 44 | struct process_attr_tracker_value_node *node = lttng::utils::container_of( |
| 45 | rcu_head, &process_attr_tracker_value_node::rcu_head); |
| 46 | |
| 47 | free(node); |
| 48 | } |
| 49 | |
| 50 | struct process_attr_tracker *process_attr_tracker_create(void) |
| 51 | { |
| 52 | struct process_attr_tracker *tracker; |
| 53 | |
| 54 | tracker = zmalloc<process_attr_tracker>(); |
| 55 | if (!tracker) { |
| 56 | return NULL; |
| 57 | } |
| 58 | |
| 59 | (void) process_attr_tracker_set_tracking_policy( |
| 60 | tracker, LTTNG_TRACKING_POLICY_INCLUDE_ALL); |
| 61 | |
| 62 | tracker->inclusion_set_ht = cds_lfht_new(DEFAULT_HT_SIZE, 1, 0, |
| 63 | CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL); |
| 64 | if (!tracker->inclusion_set_ht) { |
| 65 | goto error; |
| 66 | } |
| 67 | |
| 68 | return tracker; |
| 69 | error: |
| 70 | process_attr_tracker_destroy(tracker); |
| 71 | return NULL; |
| 72 | } |
| 73 | |
| 74 | static void process_attr_tracker_remove_value_node( |
| 75 | struct process_attr_tracker *tracker, |
| 76 | struct process_attr_tracker_value_node *value_node) |
| 77 | { |
| 78 | cds_lfht_del(tracker->inclusion_set_ht, |
| 79 | &value_node->inclusion_set_ht_node); |
| 80 | process_attr_value_destroy(value_node->value); |
| 81 | call_rcu(&value_node->rcu_head, |
| 82 | process_attr_tracker_value_node_rcu_free); |
| 83 | } |
| 84 | |
| 85 | static void process_attr_tracker_clear_inclusion_set( |
| 86 | struct process_attr_tracker *tracker) |
| 87 | { |
| 88 | int ret; |
| 89 | struct lttng_ht_iter iter; |
| 90 | struct process_attr_tracker_value_node *value_node; |
| 91 | |
| 92 | if (!tracker->inclusion_set_ht) { |
| 93 | return; |
| 94 | } |
| 95 | |
| 96 | rcu_read_lock(); |
| 97 | cds_lfht_for_each_entry (tracker->inclusion_set_ht, &iter.iter, |
| 98 | value_node, inclusion_set_ht_node) { |
| 99 | process_attr_tracker_remove_value_node(tracker, value_node); |
| 100 | } |
| 101 | rcu_read_unlock(); |
| 102 | ret = cds_lfht_destroy(tracker->inclusion_set_ht, NULL); |
| 103 | LTTNG_ASSERT(ret == 0); |
| 104 | tracker->inclusion_set_ht = NULL; |
| 105 | } |
| 106 | |
| 107 | static int process_attr_tracker_create_inclusion_set( |
| 108 | struct process_attr_tracker *tracker) |
| 109 | { |
| 110 | LTTNG_ASSERT(!tracker->inclusion_set_ht); |
| 111 | tracker->inclusion_set_ht = cds_lfht_new(DEFAULT_HT_SIZE, 1, 0, |
| 112 | CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL); |
| 113 | return tracker->inclusion_set_ht ? 0 : -1; |
| 114 | } |
| 115 | |
| 116 | void process_attr_tracker_destroy(struct process_attr_tracker *tracker) |
| 117 | { |
| 118 | if (!tracker) { |
| 119 | return; |
| 120 | } |
| 121 | |
| 122 | process_attr_tracker_clear_inclusion_set(tracker); |
| 123 | free(tracker); |
| 124 | } |
| 125 | |
| 126 | enum lttng_tracking_policy process_attr_tracker_get_tracking_policy( |
| 127 | const struct process_attr_tracker *tracker) |
| 128 | { |
| 129 | return tracker->policy; |
| 130 | } |
| 131 | |
| 132 | int process_attr_tracker_set_tracking_policy( |
| 133 | struct process_attr_tracker *tracker, |
| 134 | enum lttng_tracking_policy tracking_policy) |
| 135 | { |
| 136 | int ret = 0; |
| 137 | |
| 138 | if (tracker->policy == tracking_policy) { |
| 139 | goto end; |
| 140 | } |
| 141 | |
| 142 | process_attr_tracker_clear_inclusion_set(tracker); |
| 143 | ret = process_attr_tracker_create_inclusion_set(tracker); |
| 144 | if (ret) { |
| 145 | goto end; |
| 146 | } |
| 147 | tracker->policy = tracking_policy; |
| 148 | end: |
| 149 | return ret; |
| 150 | } |
| 151 | |
| 152 | static int match_inclusion_set_value( |
| 153 | struct cds_lfht_node *node, const void *key) |
| 154 | { |
| 155 | const struct process_attr_value *value_key = (process_attr_value *) key; |
| 156 | const struct process_attr_tracker_value_node *value_node = |
| 157 | caa_container_of(node, |
| 158 | struct process_attr_tracker_value_node, |
| 159 | inclusion_set_ht_node); |
| 160 | |
| 161 | return process_attr_tracker_value_equal(value_node->value, value_key); |
| 162 | } |
| 163 | |
| 164 | static struct process_attr_tracker_value_node *process_attr_tracker_lookup( |
| 165 | const struct process_attr_tracker *tracker, |
| 166 | const struct process_attr_value *value) |
| 167 | { |
| 168 | struct cds_lfht_iter iter; |
| 169 | struct cds_lfht_node *node; |
| 170 | |
| 171 | LTTNG_ASSERT(tracker->policy == LTTNG_TRACKING_POLICY_INCLUDE_SET); |
| 172 | |
| 173 | rcu_read_lock(); |
| 174 | cds_lfht_lookup(tracker->inclusion_set_ht, |
| 175 | process_attr_value_hash(value), |
| 176 | match_inclusion_set_value, value, &iter); |
| 177 | node = cds_lfht_iter_get_node(&iter); |
| 178 | rcu_read_unlock(); |
| 179 | |
| 180 | return node ? lttng::utils::container_of(node, |
| 181 | &process_attr_tracker_value_node::inclusion_set_ht_node) : |
| 182 | NULL; |
| 183 | } |
| 184 | |
| 185 | /* Protected by session mutex held by caller. */ |
| 186 | enum process_attr_tracker_status process_attr_tracker_inclusion_set_add_value( |
| 187 | struct process_attr_tracker *tracker, |
| 188 | const struct process_attr_value *value) |
| 189 | { |
| 190 | enum process_attr_tracker_status status = |
| 191 | PROCESS_ATTR_TRACKER_STATUS_OK; |
| 192 | struct process_attr_value *value_copy = NULL; |
| 193 | struct process_attr_tracker_value_node *value_node = NULL; |
| 194 | |
| 195 | rcu_read_lock(); |
| 196 | if (tracker->policy != LTTNG_TRACKING_POLICY_INCLUDE_SET) { |
| 197 | status = PROCESS_ATTR_TRACKER_STATUS_INVALID_TRACKING_POLICY; |
| 198 | goto end; |
| 199 | } |
| 200 | |
| 201 | if (process_attr_tracker_lookup(tracker, value)) { |
| 202 | status = PROCESS_ATTR_TRACKER_STATUS_EXISTS; |
| 203 | goto end; |
| 204 | } |
| 205 | |
| 206 | value_node = zmalloc<process_attr_tracker_value_node>(); |
| 207 | if (!value_node) { |
| 208 | status = PROCESS_ATTR_TRACKER_STATUS_ERROR; |
| 209 | goto end; |
| 210 | } |
| 211 | |
| 212 | value_copy = process_attr_value_copy(value); |
| 213 | if (!value_copy) { |
| 214 | status = PROCESS_ATTR_TRACKER_STATUS_ERROR; |
| 215 | goto end; |
| 216 | } |
| 217 | |
| 218 | value_node->value = value_copy; |
| 219 | cds_lfht_add(tracker->inclusion_set_ht, |
| 220 | process_attr_value_hash(value_copy), |
| 221 | &value_node->inclusion_set_ht_node); |
| 222 | value_copy = NULL; |
| 223 | value_node = NULL; |
| 224 | end: |
| 225 | if (value_copy) { |
| 226 | process_attr_value_destroy(value_copy); |
| 227 | } |
| 228 | if (value_node) { |
| 229 | free(value_node); |
| 230 | } |
| 231 | rcu_read_unlock(); |
| 232 | return status; |
| 233 | } |
| 234 | |
| 235 | /* Protected by session mutex held by caller. */ |
| 236 | enum process_attr_tracker_status |
| 237 | process_attr_tracker_inclusion_set_remove_value( |
| 238 | struct process_attr_tracker *tracker, |
| 239 | const struct process_attr_value *value) |
| 240 | { |
| 241 | struct process_attr_tracker_value_node *value_node; |
| 242 | enum process_attr_tracker_status status = |
| 243 | PROCESS_ATTR_TRACKER_STATUS_OK; |
| 244 | |
| 245 | rcu_read_lock(); |
| 246 | if (tracker->policy != LTTNG_TRACKING_POLICY_INCLUDE_SET) { |
| 247 | status = PROCESS_ATTR_TRACKER_STATUS_INVALID_TRACKING_POLICY; |
| 248 | goto end; |
| 249 | } |
| 250 | |
| 251 | value_node = process_attr_tracker_lookup(tracker, value); |
| 252 | if (!value_node) { |
| 253 | status = PROCESS_ATTR_TRACKER_STATUS_MISSING; |
| 254 | goto end; |
| 255 | } |
| 256 | |
| 257 | process_attr_tracker_remove_value_node(tracker, value_node); |
| 258 | end: |
| 259 | rcu_read_unlock(); |
| 260 | return status; |
| 261 | } |
| 262 | |
| 263 | enum process_attr_tracker_status process_attr_tracker_get_inclusion_set( |
| 264 | const struct process_attr_tracker *tracker, |
| 265 | struct lttng_process_attr_values **_values) |
| 266 | { |
| 267 | struct lttng_ht_iter iter; |
| 268 | struct process_attr_tracker_value_node *value_node; |
| 269 | enum process_attr_tracker_status status = |
| 270 | PROCESS_ATTR_TRACKER_STATUS_OK; |
| 271 | struct lttng_process_attr_values *values; |
| 272 | struct process_attr_value *new_value = NULL; |
| 273 | |
| 274 | values = lttng_process_attr_values_create(); |
| 275 | if (!values) { |
| 276 | status = PROCESS_ATTR_TRACKER_STATUS_ERROR; |
| 277 | goto error; |
| 278 | } |
| 279 | |
| 280 | if (tracker->policy != LTTNG_TRACKING_POLICY_INCLUDE_SET) { |
| 281 | status = PROCESS_ATTR_TRACKER_STATUS_INVALID_TRACKING_POLICY; |
| 282 | goto error; |
| 283 | } |
| 284 | |
| 285 | rcu_read_lock(); |
| 286 | cds_lfht_for_each_entry (tracker->inclusion_set_ht, &iter.iter, |
| 287 | value_node, inclusion_set_ht_node) { |
| 288 | int ret; |
| 289 | |
| 290 | new_value = process_attr_value_copy(value_node->value); |
| 291 | if (!new_value) { |
| 292 | status = PROCESS_ATTR_TRACKER_STATUS_ERROR; |
| 293 | goto error_unlock; |
| 294 | } |
| 295 | |
| 296 | ret = lttng_dynamic_pointer_array_add_pointer( |
| 297 | &values->array, new_value); |
| 298 | if (ret) { |
| 299 | status = PROCESS_ATTR_TRACKER_STATUS_ERROR; |
| 300 | goto error_unlock; |
| 301 | } |
| 302 | |
| 303 | new_value = NULL; |
| 304 | } |
| 305 | rcu_read_unlock(); |
| 306 | *_values = values; |
| 307 | return status; |
| 308 | error_unlock: |
| 309 | rcu_read_unlock(); |
| 310 | error: |
| 311 | lttng_process_attr_values_destroy(values); |
| 312 | process_attr_value_destroy(new_value); |
| 313 | return status; |
| 314 | } |