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.hpp"
   9 #include "common/argpar/argpar.h"
  10 #include "common/argpar-utils/argpar-utils.hpp"
  11 #include "common/mi-lttng.hpp"
  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, NULL);
 116                 if (status == PARSE_NEXT_ITEM_STATUS_ERROR ||
 117                                 status == PARSE_NEXT_ITEM_STATUS_ERROR_MEMORY) {
 118                         goto error;
 119                 } else if (status == PARSE_NEXT_ITEM_STATUS_END) {
 120                         break;
 121                 }
 122
 123                 assert(status == PARSE_NEXT_ITEM_STATUS_OK);
 124
 125                 if (argpar_item_type(argpar_item) == ARGPAR_ITEM_TYPE_OPT) {
 126                         const struct argpar_opt_descr *descr =
 127                                 argpar_item_opt_descr(argpar_item);
 128                         const char *arg = argpar_item_opt_arg(argpar_item);
 129
 130                         switch (descr->id) {
 131                         case OPT_HELP:
 132                                 SHOW_HELP();
 133                                 ret = 0;
 134                                 goto end;
 135                         case OPT_LIST_OPTIONS:
 136                                 list_cmd_options_argpar(stdout,
 137                                         remove_trigger_options);
 138                                 ret = 0;
 139                                 goto end;
 140                         case OPT_OWNER_UID:
 141                         {
 142                                 if (!assign_string(&owner_uid, arg,
 143                                                 "--owner-uid")) {
 144                                         goto error;
 145                                 }
 146                                 break;
 147                         }
 148                         default:
 149                                 abort();
 150                         }
 151                 } else {
 152                         const char *arg = argpar_item_non_opt_arg(argpar_item);
 153
 154                         if (name) {
 155                                 ERR("Unexpected argument '%s'", arg);
 156                                 goto error;
 157                         }
 158
 159                         name = arg;
 160                 }
 161         }
 162
 163         if (!name) {
 164                 ERR("Missing `name` argument.");
 165                 goto error;
 166         }
 167
 168         if (owner_uid) {
 169                 char *end;
 170
 171                 errno = 0;
 172                 uid = strtol(owner_uid, &end, 10);
 173                 if (end == owner_uid || *end != '\0' || errno != 0) {
 174                         ERR("Failed to parse `%s` as an integer.", owner_uid);
 175                 }
 176         } else {
 177                 uid = geteuid();
 178         }
 179
 180         ret = lttng_list_triggers(&triggers);
 181         if (ret != LTTNG_OK) {
 182                 ERR("Failed to get the list of triggers.");
 183                 goto error;
 184         }
 185
 186         trigger_status = lttng_triggers_get_count(triggers, &triggers_count);
 187         LTTNG_ASSERT(trigger_status == LTTNG_TRIGGER_STATUS_OK);
 188
 189         for (i = 0; i < triggers_count; i++) {
 190                 const struct lttng_trigger *trigger;
 191                 const char *trigger_name;
 192                 uid_t trigger_uid;
 193
 194                 trigger = lttng_triggers_get_at_index(triggers, i);
 195                 trigger_status = lttng_trigger_get_name(trigger, &trigger_name);
 196                 switch (trigger_status) {
 197                 case LTTNG_TRIGGER_STATUS_OK:
 198                         break;
 199                 case LTTNG_TRIGGER_STATUS_UNSET:
 200                         /* Don't compare against anonymous triggers. */
 201                         continue;
 202                 default:
 203                         abort();
 204                 }
 205
 206                 trigger_status = lttng_trigger_get_owner_uid(
 207                                 trigger, &trigger_uid);
 208                 LTTNG_ASSERT(trigger_status == LTTNG_TRIGGER_STATUS_OK);
 209
 210                 if (trigger_uid == uid && strcmp(trigger_name, name) == 0) {
 211                         trigger_to_remove = trigger;
 212                         break;
 213                 }
 214         }
 215
 216         if (!trigger_to_remove) {
 217                 ERR("Couldn't find trigger with name `%s`.", name);
 218                 goto error;
 219         }
 220
 221         ret = lttng_unregister_trigger(trigger_to_remove);
 222         if (ret != 0) {
 223                 ERR("Failed to unregister trigger `%s`.", name);
 224                 goto error;
 225         }
 226
 227         if (lttng_opt_mi) {
 228                 ret_code = lttng_trigger_mi_serialize(
 229                                 trigger_to_remove, mi_writer, NULL);
 230                 if (ret_code != LTTNG_OK) {
 231                         goto error;
 232                 }
 233         }
 234         MSG("Removed trigger `%s`.", name);
 235
 236         ret = 0;
 237         goto end;
 238
 239 error:
 240         ret = 1;
 241
 242 end:
 243         /* Mi closing. */
 244         if (lttng_opt_mi && mi_writer) {
 245                 /* Close output element. */
 246                 int mi_ret = mi_lttng_writer_close_element(mi_writer);
 247                 if (mi_ret) {
 248                         ret = 1;
 249                         goto cleanup;
 250                 }
 251
 252                 mi_ret = mi_lttng_writer_write_element_bool(mi_writer,
 253                                 mi_lttng_element_command_success, ret ? 0 : 1);
 254                 if (mi_ret) {
 255                         ret = 1;
 256                         goto cleanup;
 257                 }
 258
 259                 /* Command element close. */
 260                 mi_ret = mi_lttng_writer_command_close(mi_writer);
 261                 if (mi_ret) {
 262                         ret = 1;
 263                         goto cleanup;
 264                 }
 265         }
 266
 267 cleanup:
 268         argpar_item_destroy(argpar_item);
 269         argpar_iter_destroy(argpar_iter);
 270         lttng_triggers_destroy(triggers);
 271         free(owner_uid);
 272
 273         if (mi_writer && mi_lttng_writer_destroy(mi_writer)) {
 274                 /* Preserve original error code. */
 275                 ret = ret ? ret : CMD_ERROR;
 276         }
 277         return ret;
 278 }