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/error.h>
  11 #include <common/macros.h>
  12 #include <common/payload.h>
  13 #include <common/payload-view.h>
  14 #include <lttng/event-rule/event-rule-internal.h>
  15 #include <lttng/event-rule/kprobe-internal.h>
  16 #include <lttng/event-rule/syscall-internal.h>
  17 #include <lttng/event-rule/uprobe-internal.h>
  18 #include <stdbool.h>
  19
  20 enum lttng_event_rule_type lttng_event_rule_get_type(
  21                 const struct lttng_event_rule *event_rule)
  22 {
  23         return event_rule ? event_rule->type : LTTNG_EVENT_RULE_TYPE_UNKNOWN;
  24 }
  25
  26 LTTNG_HIDDEN
  27 enum lttng_domain_type lttng_event_rule_get_domain_type(
  28                 const struct lttng_event_rule *event_rule)
  29 {
  30         enum lttng_domain_type domain_type = LTTNG_DOMAIN_NONE;
  31
  32         switch (lttng_event_rule_get_type(event_rule)) {
  33         case LTTNG_EVENT_RULE_TYPE_TRACEPOINT:
  34                 /* TODO */
  35                 domain_type = LTTNG_DOMAIN_NONE;
  36                 break;
  37         case LTTNG_EVENT_RULE_TYPE_SYSCALL:
  38         case LTTNG_EVENT_RULE_TYPE_KPROBE:
  39         case LTTNG_EVENT_RULE_TYPE_KRETPROBE:
  40         case LTTNG_EVENT_RULE_TYPE_UPROBE:
  41                 domain_type = LTTNG_DOMAIN_KERNEL;
  42                 break;
  43         case LTTNG_EVENT_RULE_TYPE_UNKNOWN:
  44                 domain_type = LTTNG_DOMAIN_NONE;
  45                 break;
  46         }
  47
  48         return domain_type;
  49 }
  50
  51 static void lttng_event_rule_release(struct urcu_ref *ref)
  52 {
  53         struct lttng_event_rule *event_rule =
  54                         container_of(ref, typeof(*event_rule), ref);
  55
  56         assert(event_rule->destroy);
  57         event_rule->destroy(event_rule);
  58 }
  59
  60 void lttng_event_rule_destroy(struct lttng_event_rule *event_rule)
  61 {
  62         lttng_event_rule_put(event_rule);
  63 }
  64
  65 LTTNG_HIDDEN
  66 bool lttng_event_rule_validate(const struct lttng_event_rule *event_rule)
  67 {
  68         bool valid;
  69
  70         if (!event_rule) {
  71                 valid = false;
  72                 goto end;
  73         }
  74
  75         if (!event_rule->validate) {
  76                 /* Sub-class guarantees that it can never be invalid. */
  77                 valid = true;
  78                 goto end;
  79         }
  80
  81         valid = event_rule->validate(event_rule);
  82 end:
  83         return valid;
  84 }
  85
  86 LTTNG_HIDDEN
  87 int lttng_event_rule_serialize(const struct lttng_event_rule *event_rule,
  88                 struct lttng_payload *payload)
  89 {
  90         int ret;
  91         struct lttng_event_rule_comm event_rule_comm = {};
  92
  93         if (!event_rule) {
  94                 ret = -1;
  95                 goto end;
  96         }
  97
  98         event_rule_comm.event_rule_type = (int8_t) event_rule->type;
  99
 100         ret = lttng_dynamic_buffer_append(
 101                         &payload->buffer, &event_rule_comm, sizeof(event_rule_comm));
 102         if (ret) {
 103                 goto end;
 104         }
 105
 106         ret = event_rule->serialize(event_rule, payload);
 107         if (ret) {
 108                 goto end;
 109         }
 110 end:
 111         return ret;
 112 }
 113
 114 LTTNG_HIDDEN
 115 bool lttng_event_rule_is_equal(const struct lttng_event_rule *a,
 116                 const struct lttng_event_rule *b)
 117 {
 118         bool is_equal = false;
 119
 120         if (!a || !b) {
 121                 goto end;
 122         }
 123
 124         if (a->type != b->type) {
 125                 goto end;
 126         }
 127
 128         if (a == b) {
 129                 is_equal = true;
 130                 goto end;
 131         }
 132
 133         is_equal = a->equal ? a->equal(a, b) : true;
 134 end:
 135         return is_equal;
 136 }
 137
 138 LTTNG_HIDDEN
 139 ssize_t lttng_event_rule_create_from_payload(
 140                 struct lttng_payload_view *view,
 141                 struct lttng_event_rule **event_rule)
 142 {
 143         ssize_t ret, consumed = 0;
 144         const struct lttng_event_rule_comm *event_rule_comm;
 145         event_rule_create_from_payload_cb create_from_payload = NULL;
 146
 147         if (!view || !event_rule) {
 148                 ret = -1;
 149                 goto end;
 150         }
 151
 152         DBG("Deserializing event_rule from payload.");
 153         event_rule_comm = (const struct lttng_event_rule_comm *) view->buffer.data;
 154         consumed += sizeof(*event_rule_comm);
 155
 156         switch ((enum lttng_event_rule_type) event_rule_comm->event_rule_type) {
 157         case LTTNG_EVENT_RULE_TYPE_TRACEPOINT:
 158                 /* TODO */
 159                 break;
 160         case LTTNG_EVENT_RULE_TYPE_KPROBE:
 161                 create_from_payload = lttng_event_rule_kprobe_create_from_payload;
 162                 break;
 163         case LTTNG_EVENT_RULE_TYPE_KRETPROBE:
 164                 /* TODO */
 165                 break;
 166         case LTTNG_EVENT_RULE_TYPE_UPROBE:
 167                 create_from_payload = lttng_event_rule_uprobe_create_from_payload;
 168                 break;
 169         case LTTNG_EVENT_RULE_TYPE_SYSCALL:
 170                 create_from_payload =
 171                                 lttng_event_rule_syscall_create_from_payload;
 172                 break;
 173         default:
 174                 ERR("Attempted to create event rule of unknown type (%i)",
 175                                 (int) event_rule_comm->event_rule_type);
 176                 ret = -1;
 177                 goto end;
 178         }
 179
 180         assert(create_from_payload);
 181
 182         {
 183                 struct lttng_payload_view child_view =
 184                                 lttng_payload_view_from_view(
 185                                                 view, consumed, -1);
 186
 187                 ret = create_from_payload(&child_view, event_rule);
 188                 if (ret < 0) {
 189                         goto end;
 190                 }
 191
 192                 consumed += ret;
 193         }
 194
 195         if (!lttng_event_rule_validate(*event_rule)) {
 196                 ret = -1;
 197                 goto end;
 198         }
 199
 200         ret = consumed;
 201 end:
 202         return ret;
 203 }
 204
 205 LTTNG_HIDDEN
 206 void lttng_event_rule_init(struct lttng_event_rule *event_rule,
 207                 enum lttng_event_rule_type type)
 208 {
 209         urcu_ref_init(&event_rule->ref);
 210         event_rule->type = type;
 211 }
 212
 213 LTTNG_HIDDEN
 214 bool lttng_event_rule_get(struct lttng_event_rule *event_rule)
 215 {
 216         return urcu_ref_get_unless_zero(&event_rule->ref);
 217 }
 218
 219 LTTNG_HIDDEN
 220 void lttng_event_rule_put(struct lttng_event_rule *event_rule)
 221 {
 222         if (!event_rule) {
 223                 return;
 224         }
 225
 226         assert(event_rule->ref.refcount);
 227         urcu_ref_put(&event_rule->ref, lttng_event_rule_release);
 228 }
 229
 230 LTTNG_HIDDEN
 231 enum lttng_error_code lttng_event_rule_generate_filter_bytecode(
 232                 struct lttng_event_rule *rule, uid_t uid, gid_t gid)
 233 {
 234         assert(rule->generate_filter_bytecode);
 235         return rule->generate_filter_bytecode(rule, uid, gid);
 236 }
 237
 238 LTTNG_HIDDEN
 239 const char *lttng_event_rule_get_filter(const struct lttng_event_rule *rule)
 240 {
 241         assert(rule->get_filter);
 242         return rule->get_filter(rule);
 243 }
 244
 245 LTTNG_HIDDEN
 246 const struct lttng_filter_bytecode *lttng_event_rule_get_filter_bytecode(
 247                 const struct lttng_event_rule *rule)
 248 {
 249         assert(rule->get_filter_bytecode);
 250         return rule->get_filter_bytecode(rule);
 251 }
 252
 253 LTTNG_HIDDEN
 254 struct lttng_event_exclusion *lttng_event_rule_generate_exclusions(
 255                 const struct lttng_event_rule *rule)
 256 {
 257         assert(rule->generate_exclusions);
 258         return rule->generate_exclusions(rule);
 259 }
 260
 261 LTTNG_HIDDEN
 262 const char *lttng_event_rule_type_str(enum lttng_event_rule_type type)
 263 {
 264         switch (type) {
 265         case LTTNG_EVENT_RULE_TYPE_UNKNOWN:
 266                 return "unknown";
 267         case LTTNG_EVENT_RULE_TYPE_TRACEPOINT:
 268                 return "tracepoint";
 269         case LTTNG_EVENT_RULE_TYPE_SYSCALL:
 270                 return "syscall";
 271         case LTTNG_EVENT_RULE_TYPE_KPROBE:
 272                 return "probe";
 273         case LTTNG_EVENT_RULE_TYPE_KRETPROBE:
 274                 return "function";
 275         case LTTNG_EVENT_RULE_TYPE_UPROBE:
 276                 return "userspace-probe";
 277         default:
 278                 abort();
 279         }
 280 }