| 1 | #define _GNU_SOURCE /* See feature_test_macros(7) */ |
| 2 | #include <stdlib.h> |
| 3 | #include <unistd.h> |
| 4 | #include <sys/types.h> |
| 5 | #include <stdio.h> |
| 6 | #include <stdint.h> |
| 7 | #include <inttypes.h> |
| 8 | |
| 9 | #define event_list "lttng_statedump_start,lttng_statedump_end," \ |
| 10 | "lttng_statedump_process_state,lttng_statedump_file_descriptor," \ |
| 11 | "lttng_statedump_vm_map,lttng_statedump_network_interface," \ |
| 12 | "lttng_statedump_interrupt,sched_process_free," \ |
| 13 | "sched_switch,sched_process_fork" |
| 14 | #define context_list "-t pid -t procname -t tid -t ppid " |
| 15 | |
| 16 | static |
| 17 | int check_or_start_sessiond() |
| 18 | { |
| 19 | int ret; |
| 20 | int sudo = 0; |
| 21 | |
| 22 | ret = system("pgrep -u root lttng-sessiond >/dev/null"); |
| 23 | if (ret == 0) |
| 24 | goto end; |
| 25 | |
| 26 | if (getuid() != 0) { |
| 27 | fprintf(stderr, "Trying to start lttng-sessiond with sudo\n"); |
| 28 | ret = system("sudo -l lttng-sessiond >/dev/null"); |
| 29 | if (ret < 0) { |
| 30 | fprintf(stderr, "[error] You are not root and not " |
| 31 | "allowed by sudo to start lttng-sessiond\n"); |
| 32 | ret = -1; |
| 33 | goto end; |
| 34 | } |
| 35 | sudo = 1; |
| 36 | } |
| 37 | |
| 38 | if (sudo) |
| 39 | ret = system("sudo lttng-sessiond -d"); |
| 40 | else |
| 41 | ret = system("lttng-sessiond -d"); |
| 42 | |
| 43 | if (ret != 0) { |
| 44 | fprintf(stderr, "Error starting lttng-sessiond as root\n"); |
| 45 | ret = -1; |
| 46 | goto end; |
| 47 | } |
| 48 | |
| 49 | end: |
| 50 | return ret; |
| 51 | } |
| 52 | |
| 53 | static |
| 54 | int check_or_start_relayd() |
| 55 | { |
| 56 | int ret; |
| 57 | |
| 58 | ret = system("pgrep lttng-relayd >/dev/null"); |
| 59 | if (ret == 0) |
| 60 | goto end; |
| 61 | |
| 62 | ret = system("lttng-relayd -d"); |
| 63 | if (ret != 0) { |
| 64 | fprintf(stderr, "Error starting lttng-relayd\n"); |
| 65 | ret = -1; |
| 66 | goto end; |
| 67 | } |
| 68 | |
| 69 | end: |
| 70 | return ret; |
| 71 | } |
| 72 | |
| 73 | /* |
| 74 | * Return 0 if in tracing group or root, 1 if sudo is needed (and working), |
| 75 | * a negative value on error. |
| 76 | */ |
| 77 | static |
| 78 | int check_tracing_group() |
| 79 | { |
| 80 | int ret; |
| 81 | |
| 82 | ret = getuid(); |
| 83 | if (ret == 0) |
| 84 | goto end; |
| 85 | |
| 86 | ret = system("groups|grep tracing >/dev/null"); |
| 87 | if (ret == 0) { |
| 88 | goto end; |
| 89 | } |
| 90 | |
| 91 | ret = system("sudo lttng --version >/dev/null"); |
| 92 | if (ret != 0) { |
| 93 | fprintf(stderr, "Error executing lttng with sudo, you need to " |
| 94 | "be root or in the \"tracing\" group to start " |
| 95 | "kernel tracing\n"); |
| 96 | ret = -1; |
| 97 | goto end; |
| 98 | } else { |
| 99 | ret = 1; |
| 100 | } |
| 101 | |
| 102 | end: |
| 103 | return ret; |
| 104 | } |
| 105 | |
| 106 | static |
| 107 | int check_lttng_modules(int sudo) |
| 108 | { |
| 109 | int ret; |
| 110 | |
| 111 | if (sudo) { |
| 112 | ret = system("sudo lttng list -k | grep sched_switch >/dev/null"); |
| 113 | } else { |
| 114 | ret = system("lttng list -k | grep sched_switch >/dev/null"); |
| 115 | } |
| 116 | if (ret != 0) { |
| 117 | fprintf(stderr, "Error listing kernel events, " |
| 118 | "lttng-modules might not be installed\n"); |
| 119 | goto end; |
| 120 | } |
| 121 | |
| 122 | end: |
| 123 | return ret; |
| 124 | } |
| 125 | |
| 126 | static |
| 127 | int check_requirements(int *sudo) |
| 128 | { |
| 129 | int ret; |
| 130 | |
| 131 | ret = check_or_start_sessiond(); |
| 132 | if (ret < 0) |
| 133 | goto end; |
| 134 | ret = check_or_start_relayd(); |
| 135 | if (ret < 0) |
| 136 | goto end; |
| 137 | ret = check_tracing_group(); |
| 138 | if (ret < 0) |
| 139 | goto end; |
| 140 | else if (ret == 1) |
| 141 | *sudo = 1; |
| 142 | |
| 143 | ret = check_lttng_modules(*sudo); |
| 144 | if (ret < 0) |
| 145 | goto end; |
| 146 | end: |
| 147 | return ret; |
| 148 | } |
| 149 | |
| 150 | /* |
| 151 | * Allocate a random string, must be freed by the caller. |
| 152 | */ |
| 153 | static |
| 154 | char *random_session_name() |
| 155 | { |
| 156 | uint64_t id; |
| 157 | char *str = NULL; |
| 158 | int ret; |
| 159 | |
| 160 | FILE *f = fopen( "/dev/urandom", "r"); |
| 161 | if (!f) { |
| 162 | perror("fopen"); |
| 163 | goto end; |
| 164 | } |
| 165 | |
| 166 | ret = fread(&id, 1, sizeof(uint64_t), f); |
| 167 | if (ret < sizeof(id)) { |
| 168 | perror("fread"); |
| 169 | goto end; |
| 170 | } |
| 171 | |
| 172 | ret = asprintf(&str, "lttngtop-%" PRIu64, id); |
| 173 | if (ret < 0) { |
| 174 | fprintf(stderr, "Error allocating session name"); |
| 175 | str = NULL; |
| 176 | goto end; |
| 177 | } |
| 178 | |
| 179 | ret = fclose(f); |
| 180 | if (ret != 0) { |
| 181 | perror("fclose"); |
| 182 | goto end; |
| 183 | } |
| 184 | |
| 185 | end: |
| 186 | return str; |
| 187 | } |
| 188 | |
| 189 | static |
| 190 | int check_session_name(char *name, int sudo) |
| 191 | { |
| 192 | int ret; |
| 193 | char cmd[1024]; |
| 194 | |
| 195 | ret = sprintf(cmd, "%s lttng list | grep %s >/dev/null", |
| 196 | (sudo) ? "sudo" : " ", name); |
| 197 | if (ret < 0) { |
| 198 | fprintf(stderr, "Allocating cmd\n"); |
| 199 | goto end; |
| 200 | } |
| 201 | |
| 202 | ret = (system(cmd)); |
| 203 | if (ret == 0) { |
| 204 | fprintf(stderr, "Error: session %s already exist, either we " |
| 205 | "are not random enough or something is " |
| 206 | "really wrong\n", name); |
| 207 | ret = -1; |
| 208 | goto end; |
| 209 | } |
| 210 | |
| 211 | end: |
| 212 | return ret; |
| 213 | } |
| 214 | |
| 215 | static |
| 216 | int local_session(char *name, int sudo) |
| 217 | { |
| 218 | int ret; |
| 219 | char cmd[1024]; |
| 220 | |
| 221 | ret = sprintf(cmd, "%s lttng create %s >/dev/null", |
| 222 | (sudo) ? "sudo" : " ", name); |
| 223 | if (ret < 0) { |
| 224 | fprintf(stderr, "Allocating cmd\n"); |
| 225 | goto end; |
| 226 | } |
| 227 | ret = (system(cmd)); |
| 228 | if (ret != 0) { |
| 229 | fprintf(stderr, "Error: creating the session\n"); |
| 230 | ret = -1; |
| 231 | goto end; |
| 232 | } |
| 233 | |
| 234 | end: |
| 235 | return ret; |
| 236 | } |
| 237 | |
| 238 | static |
| 239 | int enable_event(char *name, int sudo) |
| 240 | { |
| 241 | int ret; |
| 242 | char cmd[1024]; |
| 243 | |
| 244 | ret = sprintf(cmd, "%s lttng enable-event -s %s -k %s >/dev/null", |
| 245 | (sudo) ? "sudo" : " ", name, event_list); |
| 246 | if (ret < 0) { |
| 247 | fprintf(stderr, "Allocating cmd\n"); |
| 248 | goto end; |
| 249 | } |
| 250 | |
| 251 | ret = (system(cmd)); |
| 252 | if (ret != 0) { |
| 253 | fprintf(stderr, "Error: enabling events\n"); |
| 254 | ret = -1; |
| 255 | goto end; |
| 256 | } |
| 257 | |
| 258 | end: |
| 259 | return ret; |
| 260 | } |
| 261 | |
| 262 | static |
| 263 | int add_contexts(char *name, int sudo) |
| 264 | { |
| 265 | int ret; |
| 266 | char cmd[1024]; |
| 267 | |
| 268 | ret = sprintf(cmd, "%s lttng add-context -s %s -k %s >/dev/null", |
| 269 | (sudo) ? "sudo" : " ", name, context_list); |
| 270 | if (ret < 0) { |
| 271 | fprintf(stderr, "allocating cmd\n"); |
| 272 | goto end; |
| 273 | } |
| 274 | |
| 275 | ret = (system(cmd)); |
| 276 | if (ret != 0) { |
| 277 | fprintf(stderr, "error: adding contexts\n"); |
| 278 | ret = -1; |
| 279 | goto end; |
| 280 | } |
| 281 | |
| 282 | end: |
| 283 | return ret; |
| 284 | } |
| 285 | |
| 286 | static |
| 287 | int start(char *name, int sudo) |
| 288 | { |
| 289 | int ret; |
| 290 | char cmd[1024]; |
| 291 | |
| 292 | ret = sprintf(cmd, "%s lttng start %s >/dev/null", |
| 293 | (sudo) ? "sudo" : " ", name); |
| 294 | if (ret < 0) { |
| 295 | fprintf(stderr, "allocating cmd\n"); |
| 296 | goto end; |
| 297 | } |
| 298 | |
| 299 | ret = (system(cmd)); |
| 300 | if (ret != 0) { |
| 301 | fprintf(stderr, "error: starting the session %s\n", name); |
| 302 | ret = -1; |
| 303 | goto end; |
| 304 | } |
| 305 | |
| 306 | ret = sprintf(cmd, "%s lttng list|grep %s|cut -d'(' -f2|cut -d ')' -f1", |
| 307 | (sudo) ? "sudo" : " ", name); |
| 308 | if (ret < 0) { |
| 309 | fprintf(stderr, "allocating cmd\n"); |
| 310 | goto end; |
| 311 | } |
| 312 | fprintf(stderr, "Local session started in "); |
| 313 | ret = (system(cmd)); |
| 314 | if (ret != 0) { |
| 315 | fprintf(stderr, "error: listing the sessions\n"); |
| 316 | ret = -1; |
| 317 | goto end; |
| 318 | } |
| 319 | |
| 320 | end: |
| 321 | return ret; |
| 322 | } |
| 323 | |
| 324 | static |
| 325 | int destroy(char *name, int sudo) |
| 326 | { |
| 327 | int ret; |
| 328 | char cmd[1024]; |
| 329 | |
| 330 | ret = sprintf(cmd, "%s lttng destroy %s >/dev/null", |
| 331 | (sudo) ? "sudo" : " ", name); |
| 332 | if (ret < 0) { |
| 333 | fprintf(stderr, "allocating cmd\n"); |
| 334 | goto end; |
| 335 | } |
| 336 | |
| 337 | ret = (system(cmd)); |
| 338 | if (ret != 0) { |
| 339 | fprintf(stderr, "error: destroying the session %s\n", name); |
| 340 | ret = -1; |
| 341 | goto end; |
| 342 | } |
| 343 | |
| 344 | end: |
| 345 | return ret; |
| 346 | } |
| 347 | |
| 348 | int create_local_session() |
| 349 | { |
| 350 | int ret; |
| 351 | char *name; |
| 352 | int sudo = 0; |
| 353 | |
| 354 | ret = check_requirements(&sudo); |
| 355 | |
| 356 | name = random_session_name(); |
| 357 | if (!name) { |
| 358 | ret = -1; |
| 359 | goto end; |
| 360 | } |
| 361 | |
| 362 | ret = check_session_name(name, sudo); |
| 363 | if (ret < 0) { |
| 364 | goto end_free; |
| 365 | } |
| 366 | |
| 367 | ret = local_session(name, sudo); |
| 368 | if (ret < 0) { |
| 369 | goto end_free; |
| 370 | } |
| 371 | |
| 372 | ret = enable_event(name, sudo); |
| 373 | if (ret < 0) { |
| 374 | goto end_free; |
| 375 | } |
| 376 | |
| 377 | ret = add_contexts(name, sudo); |
| 378 | if (ret < 0) { |
| 379 | goto end_free; |
| 380 | } |
| 381 | |
| 382 | ret = start(name, sudo); |
| 383 | if (ret < 0) { |
| 384 | goto end_free; |
| 385 | } |
| 386 | |
| 387 | end_free: |
| 388 | free(name); |
| 389 | end: |
| 390 | return ret; |
| 391 | } |
| 392 | |
| 393 | int destroy_local_session(char *name, int sudo) |
| 394 | { |
| 395 | return destroy(name, sudo); |
| 396 | } |
| 397 | |
| 398 | /* |
| 399 | int create_live_local_session(); |
| 400 | int destroy_live_local_session(); |
| 401 | */ |