src/common/event-rule/event-rule.c

   1 /*
   2  * Copyright (C) 2019 Jonathan Rajotte
   3  * <jonathan.rajotte-julien@efficios.com>
   4  *
   5  * SPDX-License-Identifier: LGPL-2.1-only
   6  *
   7  */
   8
   9 #include <assert.h>
  10 #include <common/buffer-view.h>
  11 #include <common/dynamic-buffer.h>
  12 #include <common/error.h>
  13 #include <common/macros.h>
  14 #include <lttng/event-rule/event-rule-internal.h>
  15 #include <lttng/event-rule/kprobe-internal.h>
  16 #include <lttng/event-rule/kretprobe-internal.h>
  17 #include <lttng/event-rule/syscall-internal.h>
  18 #include <lttng/event-rule/tracepoint-internal.h>
  19 #include <lttng/event-rule/uprobe-internal.h>
  20 #include <stdbool.h>
  21
  22 enum lttng_event_rule_type lttng_event_rule_get_type(
  23                 const struct lttng_event_rule *event_rule)
  24 {
  25         return event_rule ? event_rule->type : LTTNG_EVENT_RULE_TYPE_UNKNOWN;
  26 }
  27
  28 LTTNG_HIDDEN
  29 enum lttng_domain_type lttng_event_rule_get_domain_type(
  30                 const struct lttng_event_rule *event_rule)
  31 {
  32         enum lttng_domain_type domain_type;
  33
  34         switch (lttng_event_rule_get_type(event_rule)) {
  35         case LTTNG_EVENT_RULE_TYPE_TRACEPOINT:
  36                 (void) lttng_event_rule_tracepoint_get_domain_type(event_rule, &domain_type);
  37                 break;
  38         case LTTNG_EVENT_RULE_TYPE_SYSCALL:
  39         case LTTNG_EVENT_RULE_TYPE_KPROBE:
  40         case LTTNG_EVENT_RULE_TYPE_KRETPROBE:
  41         case LTTNG_EVENT_RULE_TYPE_UPROBE:
  42                 domain_type = LTTNG_DOMAIN_KERNEL;
  43                 break;
  44         case LTTNG_EVENT_RULE_TYPE_UNKNOWN:
  45                 domain_type = LTTNG_DOMAIN_NONE;
  46                 break;
  47         }
  48
  49         return domain_type;
  50 }
  51
  52 static void lttng_event_rule_release(struct urcu_ref *ref)
  53 {
  54         struct lttng_event_rule *event_rule =
  55                         container_of(ref, typeof(*event_rule), ref);
  56
  57         assert(event_rule->destroy);
  58         event_rule->destroy(event_rule);
  59 }
  60
  61 void lttng_event_rule_destroy(struct lttng_event_rule *event_rule)
  62 {
  63         lttng_event_rule_put(event_rule);
  64 }
  65
  66 LTTNG_HIDDEN
  67 bool lttng_event_rule_validate(const struct lttng_event_rule *event_rule)
  68 {
  69         bool valid;
  70
  71         if (!event_rule) {
  72                 valid = false;
  73                 goto end;
  74         }
  75
  76         if (!event_rule->validate) {
  77                 /* Sub-class guarantees that it can never be invalid. */
  78                 valid = true;
  79                 goto end;
  80         }
  81
  82         valid = event_rule->validate(event_rule);
  83 end:
  84         return valid;
  85 }
  86
  87 LTTNG_HIDDEN
  88 int lttng_event_rule_serialize(const struct lttng_event_rule *event_rule,
  89                 struct lttng_dynamic_buffer *buf,
  90                 int *fd_to_send)
  91 {
  92         int ret;
  93         struct lttng_event_rule_comm event_rule_comm = {0};
  94
  95         if (!event_rule) {
  96                 ret = -1;
  97                 goto end;
  98         }
  99
 100         event_rule_comm.event_rule_type = (int8_t) event_rule->type;
 101
 102         ret = lttng_dynamic_buffer_append(
 103                         buf, &event_rule_comm, sizeof(event_rule_comm));
 104         if (ret) {
 105                 goto end;
 106         }
 107
 108         ret = event_rule->serialize(event_rule, buf, fd_to_send);
 109         if (ret) {
 110                 goto end;
 111         }
 112 end:
 113         return ret;
 114 }
 115
 116 LTTNG_HIDDEN
 117 bool lttng_event_rule_is_equal(const struct lttng_event_rule *a,
 118                 const struct lttng_event_rule *b)
 119 {
 120         bool is_equal = false;
 121
 122         if (!a || !b) {
 123                 goto end;
 124         }
 125
 126         if (a->type != b->type) {
 127                 goto end;
 128         }
 129
 130         if (a == b) {
 131                 is_equal = true;
 132                 goto end;
 133         }
 134
 135         is_equal = a->equal ? a->equal(a, b) : true;
 136 end:
 137         return is_equal;
 138 }
 139
 140 LTTNG_HIDDEN
 141 ssize_t lttng_event_rule_create_from_buffer(
 142                 const struct lttng_buffer_view *buffer,
 143                 struct lttng_event_rule **event_rule)
 144 {
 145         ssize_t ret, event_rule_size = 0;
 146         const struct lttng_event_rule_comm *event_rule_comm;
 147         event_rule_create_from_buffer_cb create_from_buffer = NULL;
 148
 149         if (!buffer || !event_rule) {
 150                 ret = -1;
 151                 goto end;
 152         }
 153
 154         DBG("Deserializing event_rule from buffer");
 155         event_rule_comm = (const struct lttng_event_rule_comm *) buffer->data;
 156         event_rule_size += sizeof(*event_rule_comm);
 157
 158         switch ((enum lttng_event_rule_type) event_rule_comm->event_rule_type) {
 159         case LTTNG_EVENT_RULE_TYPE_TRACEPOINT:
 160                 create_from_buffer =
 161                                 lttng_event_rule_tracepoint_create_from_buffer;
 162                 break;
 163         case LTTNG_EVENT_RULE_TYPE_KPROBE:
 164                 create_from_buffer = lttng_event_rule_kprobe_create_from_buffer;
 165                 break;
 166         case LTTNG_EVENT_RULE_TYPE_KRETPROBE:
 167                 create_from_buffer =
 168                                 lttng_event_rule_kretprobe_create_from_buffer;
 169                 break;
 170         case LTTNG_EVENT_RULE_TYPE_UPROBE:
 171                 create_from_buffer = lttng_event_rule_uprobe_create_from_buffer;
 172                 break;
 173         case LTTNG_EVENT_RULE_TYPE_SYSCALL:
 174                 create_from_buffer =
 175                                 lttng_event_rule_syscall_create_from_buffer;
 176                 break;
 177         default:
 178                 ERR("Attempted to create event rule of unknown type (%i)",
 179                                 (int) event_rule_comm->event_rule_type);
 180                 ret = -1;
 181                 goto end;
 182         }
 183
 184         if (create_from_buffer) {
 185                 const struct lttng_buffer_view view =
 186                                 lttng_buffer_view_from_view(buffer,
 187                                                 sizeof(*event_rule_comm), -1);
 188
 189                 ret = create_from_buffer(&view, event_rule);
 190                 if (ret < 0) {
 191                         goto end;
 192                 }
 193                 event_rule_size += ret;
 194
 195         } else {
 196                 abort();
 197         }
 198
 199         ret = event_rule_size;
 200 end:
 201         return ret;
 202 }
 203
 204 LTTNG_HIDDEN
 205 void lttng_event_rule_init(struct lttng_event_rule *event_rule,
 206                 enum lttng_event_rule_type type)
 207 {
 208         urcu_ref_init(&event_rule->ref);
 209         event_rule->type = type;
 210 }
 211
 212 LTTNG_HIDDEN
 213 bool lttng_event_rule_get(struct lttng_event_rule *event_rule)
 214 {
 215         return urcu_ref_get_unless_zero(&event_rule->ref);
 216 }
 217
 218 LTTNG_HIDDEN
 219 void lttng_event_rule_put(struct lttng_event_rule *event_rule)
 220 {
 221         if (!event_rule) {
 222                 return;
 223         }
 224         assert(event_rule->ref.refcount);
 225         urcu_ref_put(&event_rule->ref, lttng_event_rule_release);
 226 }
 227
 228 LTTNG_HIDDEN
 229 enum lttng_error_code lttng_event_rule_populate(
 230                 struct lttng_event_rule *rule, uid_t uid, gid_t gid)
 231 {
 232         assert(rule->populate);
 233         return rule->populate(rule, uid, gid);
 234 }
 235
 236 /* If not present return NULL
 237  * Caller DO NOT own the returned object
 238  */
 239 LTTNG_HIDDEN
 240 const char *lttng_event_rule_get_filter(const struct lttng_event_rule *rule)
 241 {
 242         assert(rule->get_filter);
 243         return rule->get_filter(rule);
 244 }
 245
 246 /* If not present return NULL
 247  * Caller DO NOT own the returned object
 248  */
 249 LTTNG_HIDDEN
 250 const struct lttng_bytecode *lttng_event_rule_get_filter_bytecode(
 251                 const struct lttng_event_rule *rule)
 252 {
 253         assert(rule->get_filter_bytecode);
 254         return rule->get_filter_bytecode(rule);
 255 }
 256
 257 /*
 258  * If not present return NULL
 259  * Caller OWN the returned object
 260  * TODO: should this be done another way?
 261  */
 262 LTTNG_HIDDEN
 263 struct lttng_event_exclusion *lttng_event_rule_generate_exclusions(
 264                 struct lttng_event_rule *rule)
 265 {
 266         assert(rule->generate_exclusions);
 267         return rule->generate_exclusions(rule);
 268 }
 269
 270 LTTNG_HIDDEN
 271 struct lttng_event *lttng_event_rule_generate_lttng_event(
 272                 const struct lttng_event_rule *rule)
 273 {
 274         assert(rule->generate_lttng_event);
 275         return rule->generate_lttng_event(rule);
 276 }
 277
 278 LTTNG_HIDDEN
 279 bool lttng_event_rule_is_agent(const struct lttng_event_rule *rule)
 280 {
 281         bool ret = false;
 282         enum lttng_domain_type type = lttng_event_rule_get_domain_type(rule);
 283
 284         switch (type) {
 285         case LTTNG_DOMAIN_JUL:
 286         case LTTNG_DOMAIN_LOG4J:
 287         case LTTNG_DOMAIN_PYTHON:
 288                 ret = true;
 289                 break;
 290         case LTTNG_DOMAIN_UST:
 291         case LTTNG_DOMAIN_KERNEL:
 292                 ret = false;
 293                 break;
 294         default:
 295                 assert(0);
 296         };
 297
 298         return ret;
 299 }
 300
 301 const char *lttng_event_rule_type_str(enum lttng_event_rule_type type)
 302 {
 303         switch (type) {
 304         case LTTNG_EVENT_RULE_TYPE_UNKNOWN:
 305                 return "unknown";
 306
 307         case LTTNG_EVENT_RULE_TYPE_TRACEPOINT:
 308                 return "tracepoint";
 309
 310         case LTTNG_EVENT_RULE_TYPE_SYSCALL:
 311                 return "syscall";
 312
 313         case LTTNG_EVENT_RULE_TYPE_KPROBE:
 314                 return "probe";
 315
 316         case LTTNG_EVENT_RULE_TYPE_KRETPROBE:
 317                 return "function";
 318
 319         case LTTNG_EVENT_RULE_TYPE_UPROBE:
 320                 return "userspace-probe";
 321
 322         default:
 323                 abort();
 324         }
 325 }