src/bin/lttng/commands/remove_trigger.c

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