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