src/bin/lttng/commands/remove_trigger.cpp

   1 /*
   2  * Copyright (C) 2021 Simon Marchi <simon.marchi@efficios.com>
   3  *
   4  * SPDX-License-Identifier: GPL-2.0-only
   5  *
   6  */
   7
   8 #include "../command.h"
   9 #include "common/argpar/argpar.h"
  10 #include "common/argpar-utils/argpar-utils.h"
  11 #include "common/mi-lttng.h"
  12 #include <lttng/lttng.h>
  13 #include <stdio.h>
  14
  15 #ifdef LTTNG_EMBED_HELP
  16 static const char help_msg[] =
  17 #include <lttng-remove-trigger.1.h>
  18 ;
  19 #endif
  20
  21 enum {
  22         OPT_HELP,
  23         OPT_LIST_OPTIONS,
  24         OPT_OWNER_UID,
  25 };
  26
  27 static const
  28 struct argpar_opt_descr remove_trigger_options[] = {
  29         { OPT_HELP, 'h', "help", false },
  30         { OPT_LIST_OPTIONS, '\0', "list-options", false },
  31         { OPT_OWNER_UID, '\0', "owner-uid", true },
  32         ARGPAR_OPT_DESCR_SENTINEL,
  33 };
  34
  35 static
  36 bool assign_string(char **dest, const char *src, const char *opt_name)
  37 {
  38         bool ret;
  39
  40         if (*dest) {
  41                 ERR("Duplicate option '%s' given.", opt_name);
  42                 goto error;
  43         }
  44
  45         *dest = strdup(src);
  46         if (!*dest) {
  47                 ERR("Failed to allocate '%s' string.", opt_name);
  48                 goto error;
  49         }
  50
  51         ret = true;
  52         goto end;
  53
  54 error:
  55         ret = false;
  56
  57 end:
  58         return ret;
  59 }
  60
  61 int cmd_remove_trigger(int argc, const char **argv)
  62 {
  63         enum lttng_error_code ret_code;
  64         int ret;
  65         struct argpar_iter *argpar_iter = NULL;
  66         const struct argpar_item *argpar_item = NULL;
  67         const char *name = NULL;
  68         int i;
  69         struct lttng_triggers *triggers = NULL;
  70         unsigned int triggers_count;
  71         enum lttng_trigger_status trigger_status;
  72         const struct lttng_trigger *trigger_to_remove = NULL;
  73         char *owner_uid = NULL;
  74         long long uid;
  75         struct mi_writer *mi_writer = NULL;
  76
  77         if (lttng_opt_mi) {
  78                 mi_writer = mi_lttng_writer_create(
  79                                 fileno(stdout), lttng_opt_mi);
  80                 if (!mi_writer) {
  81                         ret = CMD_ERROR;
  82                         goto error;
  83                 }
  84
  85                 /* Open command element. */
  86                 ret = mi_lttng_writer_command_open(mi_writer,
  87                                 mi_lttng_element_command_remove_trigger);
  88                 if (ret) {
  89                         ret = CMD_ERROR;
  90                         goto error;
  91                 }
  92
  93                 /* Open output element. */
  94                 ret = mi_lttng_writer_open_element(
  95                                 mi_writer, mi_lttng_element_command_output);
  96                 if (ret) {
  97                         ret = CMD_ERROR;
  98                         goto error;
  99                 }
 100         }
 101
 102         argc--;
 103         argv++;
 104
 105         argpar_iter = argpar_iter_create(argc, argv, remove_trigger_options);
 106         if (!argpar_iter) {
 107                 ERR("Failed to allocate an argpar iter.");
 108                 goto error;
 109         }
 110
 111         while (true) {
 112                 enum parse_next_item_status status;
 113
 114                 status = parse_next_item(argpar_iter, &argpar_item, 1, argv,
 115                         true, NULL);
 116                 if (status == PARSE_NEXT_ITEM_STATUS_ERROR) {
 117                         goto error;
 118                 } else if (status == PARSE_NEXT_ITEM_STATUS_END) {
 119                         break;
 120                 }
 121
 122                 assert(status == PARSE_NEXT_ITEM_STATUS_OK);
 123
 124                 if (argpar_item_type(argpar_item) == ARGPAR_ITEM_TYPE_OPT) {
 125                         const struct argpar_opt_descr *descr =
 126                                 argpar_item_opt_descr(argpar_item);
 127                         const char *arg = argpar_item_opt_arg(argpar_item);
 128
 129                         switch (descr->id) {
 130                         case OPT_HELP:
 131                                 SHOW_HELP();
 132                                 ret = 0;
 133                                 goto end;
 134                         case OPT_LIST_OPTIONS:
 135                                 list_cmd_options_argpar(stdout,
 136                                         remove_trigger_options);
 137                                 ret = 0;
 138                                 goto end;
 139                         case OPT_OWNER_UID:
 140                         {
 141                                 if (!assign_string(&owner_uid, arg,
 142                                                 "--owner-uid")) {
 143                                         goto error;
 144                                 }
 145                                 break;
 146                         }
 147                         default:
 148                                 abort();
 149                         }
 150                 } else {
 151                         const char *arg = argpar_item_non_opt_arg(argpar_item);
 152
 153                         if (name) {
 154                                 ERR("Unexpected argument '%s'", arg);
 155                                 goto error;
 156                         }
 157
 158                         name = arg;
 159                 }
 160         }
 161
 162         if (!name) {
 163                 ERR("Missing `name` argument.");
 164                 goto error;
 165         }
 166
 167         if (owner_uid) {
 168                 char *end;
 169
 170                 errno = 0;
 171                 uid = strtol(owner_uid, &end, 10);
 172                 if (end == owner_uid || *end != '\0' || errno != 0) {
 173                         ERR("Failed to parse `%s` as an integer.", owner_uid);
 174                 }
 175         } else {
 176                 uid = geteuid();
 177         }
 178
 179         ret = lttng_list_triggers(&triggers);
 180         if (ret != LTTNG_OK) {
 181                 ERR("Failed to get the list of triggers.");
 182                 goto error;
 183         }
 184
 185         trigger_status = lttng_triggers_get_count(triggers, &triggers_count);
 186         LTTNG_ASSERT(trigger_status == LTTNG_TRIGGER_STATUS_OK);
 187
 188         for (i = 0; i < triggers_count; i++) {
 189                 const struct lttng_trigger *trigger;
 190                 const char *trigger_name;
 191                 uid_t trigger_uid;
 192
 193                 trigger = lttng_triggers_get_at_index(triggers, i);
 194                 trigger_status = lttng_trigger_get_name(trigger, &trigger_name);
 195                 switch (trigger_status) {
 196                 case LTTNG_TRIGGER_STATUS_OK:
 197                         break;
 198                 case LTTNG_TRIGGER_STATUS_UNSET:
 199                         /* Don't compare against anonymous triggers. */
 200                         continue;
 201                 default:
 202                         abort();
 203                 }
 204
 205                 trigger_status = lttng_trigger_get_owner_uid(
 206                                 trigger, &trigger_uid);
 207                 LTTNG_ASSERT(trigger_status == LTTNG_TRIGGER_STATUS_OK);
 208
 209                 if (trigger_uid == uid && strcmp(trigger_name, name) == 0) {
 210                         trigger_to_remove = trigger;
 211                         break;
 212                 }
 213         }
 214
 215         if (!trigger_to_remove) {
 216                 ERR("Couldn't find trigger with name `%s`.", name);
 217                 goto error;
 218         }
 219
 220         ret = lttng_unregister_trigger(trigger_to_remove);
 221         if (ret != 0) {
 222                 ERR("Failed to unregister trigger `%s`.", name);
 223                 goto error;
 224         }
 225
 226         if (lttng_opt_mi) {
 227                 ret_code = lttng_trigger_mi_serialize(
 228                                 trigger_to_remove, mi_writer, NULL);
 229                 if (ret_code != LTTNG_OK) {
 230                         goto error;
 231                 }
 232         }
 233         MSG("Removed trigger `%s`.", name);
 234
 235         ret = 0;
 236         goto end;
 237
 238 error:
 239         ret = 1;
 240
 241 end:
 242         /* Mi closing. */
 243         if (lttng_opt_mi && mi_writer) {
 244                 /* Close output element. */
 245                 int mi_ret = mi_lttng_writer_close_element(mi_writer);
 246                 if (mi_ret) {
 247                         ret = 1;
 248                         goto cleanup;
 249                 }
 250
 251                 mi_ret = mi_lttng_writer_write_element_bool(mi_writer,
 252                                 mi_lttng_element_command_success, ret ? 0 : 1);
 253                 if (mi_ret) {
 254                         ret = 1;
 255                         goto cleanup;
 256                 }
 257
 258                 /* Command element close. */
 259                 mi_ret = mi_lttng_writer_command_close(mi_writer);
 260                 if (mi_ret) {
 261                         ret = 1;
 262                         goto cleanup;
 263                 }
 264         }
 265
 266 cleanup:
 267         argpar_item_destroy(argpar_item);
 268         argpar_iter_destroy(argpar_iter);
 269         lttng_triggers_destroy(triggers);
 270         free(owner_uid);
 271
 272         if (mi_writer && mi_lttng_writer_destroy(mi_writer)) {
 273                 /* Preserve original error code. */
 274                 ret = ret ? ret : CMD_ERROR;
 275         }
 276         return ret;
 277 }