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 = nullptr;
  66         const struct argpar_item *argpar_item = nullptr;
  67         const char *name = nullptr;
  68         int i;
  69         struct lttng_triggers *triggers = nullptr;
  70         unsigned int triggers_count;
  71         enum lttng_trigger_status trigger_status;
  72         const struct lttng_trigger *trigger_to_remove = nullptr;
  73         char *owner_uid = nullptr;
  74         long long uid;
  75         struct mi_writer *mi_writer = nullptr;
  76         const char **args;
  77
  78         if (lttng_opt_mi) {
  79                 mi_writer = mi_lttng_writer_create(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(mi_writer, mi_lttng_element_command_output);
  95                 if (ret) {
  96                         ret = CMD_ERROR;
  97                         goto error;
  98                 }
  99         }
 100
 101         args = argv + 1;
 102
 103         argpar_iter = argpar_iter_create(argc - 1, args, 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 =
 113                         parse_next_item(argpar_iter, &argpar_item, 1, args, true, nullptr, nullptr);
 114                 if (status == PARSE_NEXT_ITEM_STATUS_ERROR ||
 115                     status == PARSE_NEXT_ITEM_STATUS_ERROR_MEMORY) {
 116                         goto error;
 117                 } else if (status == PARSE_NEXT_ITEM_STATUS_END) {
 118                         break;
 119                 }
 120
 121                 assert(status == PARSE_NEXT_ITEM_STATUS_OK);
 122
 123                 if (argpar_item_type(argpar_item) == ARGPAR_ITEM_TYPE_OPT) {
 124                         const struct argpar_opt_descr *descr = argpar_item_opt_descr(argpar_item);
 125                         const char *arg = argpar_item_opt_arg(argpar_item);
 126
 127                         switch (descr->id) {
 128                         case OPT_HELP:
 129                                 SHOW_HELP();
 130                                 ret = 0;
 131                                 goto end;
 132                         case OPT_LIST_OPTIONS:
 133                                 list_cmd_options_argpar(stdout, remove_trigger_options);
 134                                 ret = 0;
 135                                 goto end;
 136                         case OPT_OWNER_UID:
 137                         {
 138                                 if (!assign_string(&owner_uid, arg, "--owner-uid")) {
 139                                         goto error;
 140                                 }
 141                                 break;
 142                         }
 143                         default:
 144                                 abort();
 145                         }
 146                 } else {
 147                         const char *arg = argpar_item_non_opt_arg(argpar_item);
 148
 149                         if (name) {
 150                                 ERR("Unexpected argument '%s'", arg);
 151                                 goto error;
 152                         }
 153
 154                         name = arg;
 155                 }
 156         }
 157
 158         if (!name) {
 159                 ERR("Missing `name` argument.");
 160                 goto error;
 161         }
 162
 163         if (owner_uid) {
 164                 char *end;
 165
 166                 errno = 0;
 167                 uid = strtol(owner_uid, &end, 10);
 168                 if (end == owner_uid || *end != '\0' || errno != 0) {
 169                         ERR("Failed to parse `%s` as an integer.", owner_uid);
 170                 }
 171         } else {
 172                 uid = geteuid();
 173         }
 174
 175         ret = lttng_list_triggers(&triggers);
 176         if (ret != LTTNG_OK) {
 177                 ERR("Failed to get the list of triggers.");
 178                 goto error;
 179         }
 180
 181         trigger_status = lttng_triggers_get_count(triggers, &triggers_count);
 182         LTTNG_ASSERT(trigger_status == LTTNG_TRIGGER_STATUS_OK);
 183
 184         for (i = 0; i < triggers_count; i++) {
 185                 const struct lttng_trigger *trigger;
 186                 const char *trigger_name;
 187                 uid_t trigger_uid;
 188
 189                 trigger = lttng_triggers_get_at_index(triggers, i);
 190                 trigger_status = lttng_trigger_get_name(trigger, &trigger_name);
 191                 switch (trigger_status) {
 192                 case LTTNG_TRIGGER_STATUS_OK:
 193                         break;
 194                 case LTTNG_TRIGGER_STATUS_UNSET:
 195                         /* Don't compare against anonymous triggers. */
 196                         continue;
 197                 default:
 198                         abort();
 199                 }
 200
 201                 trigger_status = lttng_trigger_get_owner_uid(trigger, &trigger_uid);
 202                 LTTNG_ASSERT(trigger_status == LTTNG_TRIGGER_STATUS_OK);
 203
 204                 if (trigger_uid == uid && strcmp(trigger_name, name) == 0) {
 205                         trigger_to_remove = trigger;
 206                         break;
 207                 }
 208         }
 209
 210         if (!trigger_to_remove) {
 211                 ERR("Couldn't find trigger with name `%s`.", name);
 212                 goto error;
 213         }
 214
 215         ret = lttng_unregister_trigger(trigger_to_remove);
 216         if (ret != 0) {
 217                 ERR("Failed to unregister trigger `%s`.", name);
 218                 goto error;
 219         }
 220
 221         if (lttng_opt_mi) {
 222                 ret_code = lttng_trigger_mi_serialize(trigger_to_remove, mi_writer, nullptr);
 223                 if (ret_code != LTTNG_OK) {
 224                         goto error;
 225                 }
 226         }
 227         MSG("Removed trigger `%s`.", name);
 228
 229         ret = 0;
 230         goto end;
 231
 232 error:
 233         ret = 1;
 234
 235 end:
 236         /* Mi closing. */
 237         if (lttng_opt_mi && mi_writer) {
 238                 /* Close output element. */
 239                 int mi_ret = mi_lttng_writer_close_element(mi_writer);
 240                 if (mi_ret) {
 241                         ret = 1;
 242                         goto cleanup;
 243                 }
 244
 245                 mi_ret = mi_lttng_writer_write_element_bool(
 246                         mi_writer, mi_lttng_element_command_success, ret ? 0 : 1);
 247                 if (mi_ret) {
 248                         ret = 1;
 249                         goto cleanup;
 250                 }
 251
 252                 /* Command element close. */
 253                 mi_ret = mi_lttng_writer_command_close(mi_writer);
 254                 if (mi_ret) {
 255                         ret = 1;
 256                         goto cleanup;
 257                 }
 258         }
 259
 260 cleanup:
 261         argpar_item_destroy(argpar_item);
 262         argpar_iter_destroy(argpar_iter);
 263         lttng_triggers_destroy(triggers);
 264         free(owner_uid);
 265
 266         if (mi_writer && mi_lttng_writer_destroy(mi_writer)) {
 267                 /* Preserve original error code. */
 268                 ret = ret ? ret : CMD_ERROR;
 269         }
 270         return ret;
 271 }