lib/librte_telemetry/telemetry.c

   1 /* SPDX-License-Identifier: BSD-3-Clause
   2  * Copyright(c) 2020 Intel Corporation
   3  */
   4
   5 #include <unistd.h>
   6 #include <pthread.h>
   7 #include <sys/socket.h>
   8 #include <sys/un.h>
   9 #include <dlfcn.h>
  10
  11 /* we won't link against libbsd, so just always use DPDKs-specific strlcpy */
  12 #undef RTE_USE_LIBBSD
  13 #include <rte_string_fns.h>
  14 #include <rte_common.h>
  15 #include <rte_spinlock.h>
  16 #include <rte_version.h>
  17 #include <rte_option.h>
  18
  19 #include "rte_telemetry.h"
  20 #include "telemetry_json.h"
  21 #include "telemetry_data.h"
  22 #include "rte_telemetry_legacy.h"
  23
  24 #define MAX_CMD_LEN 56
  25 #define MAX_HELP_LEN 64
  26 #define MAX_OUTPUT_LEN (1024 * 16)
  27
  28 static void *
  29 client_handler(void *socket);
  30
  31 struct cmd_callback {
  32         char cmd[MAX_CMD_LEN];
  33         telemetry_cb fn;
  34         char help[MAX_HELP_LEN];
  35 };
  36
  37 struct socket {
  38         int sock;
  39         char path[sizeof(((struct sockaddr_un *)0)->sun_path)];
  40         handler fn;
  41 };
  42 static struct socket v2_socket; /* socket for v2 telemetry */
  43 static struct socket v1_socket; /* socket for v1 telemetry */
  44 static char telemetry_log_error[1024]; /* Will contain error on init failure */
  45 /* list of command callbacks, with one command registered by default */
  46 static struct cmd_callback callbacks[TELEMETRY_MAX_CALLBACKS];
  47 static int num_callbacks; /* How many commands are registered */
  48 /* Used when accessing or modifying list of command callbacks */
  49 static rte_spinlock_t callback_sl = RTE_SPINLOCK_INITIALIZER;
  50
  51 int
  52 rte_telemetry_register_cmd(const char *cmd, telemetry_cb fn, const char *help)
  53 {
  54         int i = 0;
  55
  56         if (strlen(cmd) >= MAX_CMD_LEN || fn == NULL || cmd[0] != '/'
  57                         || strlen(help) >= MAX_HELP_LEN)
  58                 return -EINVAL;
  59         if (num_callbacks >= TELEMETRY_MAX_CALLBACKS)
  60                 return -ENOENT;
  61
  62         rte_spinlock_lock(&callback_sl);
  63         while (i < num_callbacks && strcmp(cmd, callbacks[i].cmd) > 0)
  64                 i++;
  65         if (i != num_callbacks)
  66                 /* Move elements to keep the list alphabetical */
  67                 memmove(callbacks + i + 1, callbacks + i,
  68                         sizeof(struct cmd_callback) * (num_callbacks - i));
  69
  70         strlcpy(callbacks[i].cmd, cmd, MAX_CMD_LEN);
  71         callbacks[i].fn = fn;
  72         strlcpy(callbacks[i].help, help, MAX_HELP_LEN);
  73         num_callbacks++;
  74         rte_spinlock_unlock(&callback_sl);
  75
  76         return 0;
  77 }
  78
  79 static int
  80 list_commands(const char *cmd __rte_unused, const char *params __rte_unused,
  81                 struct rte_tel_data *d)
  82 {
  83         int i;
  84
  85         rte_tel_data_start_array(d, RTE_TEL_STRING_VAL);
  86         for (i = 0; i < num_callbacks; i++)
  87                 rte_tel_data_add_array_string(d, callbacks[i].cmd);
  88         return 0;
  89 }
  90
  91 static int
  92 json_info(const char *cmd __rte_unused, const char *params __rte_unused,
  93                 struct rte_tel_data *d)
  94 {
  95         rte_tel_data_start_dict(d);
  96         rte_tel_data_add_dict_string(d, "version", rte_version());
  97         rte_tel_data_add_dict_int(d, "pid", getpid());
  98         rte_tel_data_add_dict_int(d, "max_output_len", MAX_OUTPUT_LEN);
  99         return 0;
 100 }
 101
 102 static int
 103 command_help(const char *cmd __rte_unused, const char *params,
 104                 struct rte_tel_data *d)
 105 {
 106         int i;
 107
 108         if (!params)
 109                 return -1;
 110         rte_tel_data_start_dict(d);
 111         rte_spinlock_lock(&callback_sl);
 112         for (i = 0; i < num_callbacks; i++)
 113                 if (strcmp(params, callbacks[i].cmd) == 0) {
 114                         rte_tel_data_add_dict_string(d, params,
 115                                         callbacks[i].help);
 116                         break;
 117                 }
 118         rte_spinlock_unlock(&callback_sl);
 119         if (i == num_callbacks)
 120                 return -1;
 121         return 0;
 122 }
 123
 124 static void
 125 output_json(const char *cmd, const struct rte_tel_data *d, int s)
 126 {
 127         char out_buf[MAX_OUTPUT_LEN];
 128
 129         char *cb_data_buf;
 130         size_t buf_len, prefix_used, used = 0;
 131         unsigned int i;
 132
 133         RTE_BUILD_BUG_ON(sizeof(out_buf) < MAX_CMD_LEN +
 134                         RTE_TEL_MAX_SINGLE_STRING_LEN + 10);
 135         switch (d->type) {
 136         case RTE_TEL_NULL:
 137                 used = snprintf(out_buf, sizeof(out_buf), "{\"%.*s\":null}",
 138                                 MAX_CMD_LEN, cmd ? cmd : "none");
 139                 break;
 140         case RTE_TEL_STRING:
 141                 used = snprintf(out_buf, sizeof(out_buf), "{\"%.*s\":\"%.*s\"}",
 142                                 MAX_CMD_LEN, cmd,
 143                                 RTE_TEL_MAX_SINGLE_STRING_LEN, d->data.str);
 144                 break;
 145         case RTE_TEL_DICT:
 146                 prefix_used = snprintf(out_buf, sizeof(out_buf), "{\"%.*s\":",
 147                                 MAX_CMD_LEN, cmd);
 148                 cb_data_buf = &out_buf[prefix_used];
 149                 buf_len = sizeof(out_buf) - prefix_used - 1; /* space for '}' */
 150
 151                 used = rte_tel_json_empty_obj(cb_data_buf, buf_len, 0);
 152                 for (i = 0; i < d->data_len; i++) {
 153                         const struct tel_dict_entry *v = &d->data.dict[i];
 154                         switch (v->type) {
 155                         case RTE_TEL_STRING_VAL:
 156                                 used = rte_tel_json_add_obj_str(cb_data_buf,
 157                                                 buf_len, used,
 158                                                 v->name, v->value.sval);
 159                                 break;
 160                         case RTE_TEL_INT_VAL:
 161                                 used = rte_tel_json_add_obj_int(cb_data_buf,
 162                                                 buf_len, used,
 163                                                 v->name, v->value.ival);
 164                                 break;
 165                         case RTE_TEL_U64_VAL:
 166                                 used = rte_tel_json_add_obj_u64(cb_data_buf,
 167                                                 buf_len, used,
 168                                                 v->name, v->value.u64val);
 169                                 break;
 170                         }
 171                 }
 172                 used += prefix_used;
 173                 used += strlcat(out_buf + used, "}", sizeof(out_buf) - used);
 174                 break;
 175         case RTE_TEL_ARRAY_STRING:
 176         case RTE_TEL_ARRAY_INT:
 177         case RTE_TEL_ARRAY_U64:
 178                 prefix_used = snprintf(out_buf, sizeof(out_buf), "{\"%.*s\":",
 179                                 MAX_CMD_LEN, cmd);
 180                 cb_data_buf = &out_buf[prefix_used];
 181                 buf_len = sizeof(out_buf) - prefix_used - 1; /* space for '}' */
 182
 183                 used = rte_tel_json_empty_array(cb_data_buf, buf_len, 0);
 184                 for (i = 0; i < d->data_len; i++)
 185                         if (d->type == RTE_TEL_ARRAY_STRING)
 186                                 used = rte_tel_json_add_array_string(
 187                                                 cb_data_buf,
 188                                                 buf_len, used,
 189                                                 d->data.array[i].sval);
 190                         else if (d->type == RTE_TEL_ARRAY_INT)
 191                                 used = rte_tel_json_add_array_int(cb_data_buf,
 192                                                 buf_len, used,
 193                                                 d->data.array[i].ival);
 194                         else if (d->type == RTE_TEL_ARRAY_U64)
 195                                 used = rte_tel_json_add_array_u64(cb_data_buf,
 196                                                 buf_len, used,
 197                                                 d->data.array[i].u64val);
 198                 used += prefix_used;
 199                 used += strlcat(out_buf + used, "}", sizeof(out_buf) - used);
 200                 break;
 201         }
 202         if (write(s, out_buf, used) < 0)
 203                 perror("Error writing to socket");
 204 }
 205
 206 static void
 207 perform_command(telemetry_cb fn, const char *cmd, const char *param, int s)
 208 {
 209         struct rte_tel_data data;
 210
 211         int ret = fn(cmd, param, &data);
 212         if (ret < 0) {
 213                 char out_buf[MAX_CMD_LEN + 10];
 214                 int used = snprintf(out_buf, sizeof(out_buf), "{\"%.*s\":null}",
 215                                 MAX_CMD_LEN, cmd ? cmd : "none");
 216                 if (write(s, out_buf, used) < 0)
 217                         perror("Error writing to socket");
 218                 return;
 219         }
 220         output_json(cmd, &data, s);
 221 }
 222
 223 static int
 224 unknown_command(const char *cmd __rte_unused, const char *params __rte_unused,
 225                 struct rte_tel_data *d)
 226 {
 227         return d->type = RTE_TEL_NULL;
 228 }
 229
 230 static void *
 231 client_handler(void *sock_id)
 232 {
 233         int s = (int)(uintptr_t)sock_id;
 234         char buffer[1024];
 235         char info_str[1024];
 236         snprintf(info_str, sizeof(info_str),
 237                         "{\"version\":\"%s\",\"pid\":%d,\"max_output_len\":%d}",
 238                         rte_version(), getpid(), MAX_OUTPUT_LEN);
 239         if (write(s, info_str, strlen(info_str)) < 0) {
 240                 close(s);
 241                 return NULL;
 242         }
 243
 244         /* receive data is not null terminated */
 245         int bytes = read(s, buffer, sizeof(buffer) - 1);
 246         while (bytes > 0) {
 247                 buffer[bytes] = 0;
 248                 const char *cmd = strtok(buffer, ",");
 249                 const char *param = strtok(NULL, ",");
 250                 telemetry_cb fn = unknown_command;
 251                 int i;
 252
 253                 if (cmd && strlen(cmd) < MAX_CMD_LEN) {
 254                         rte_spinlock_lock(&callback_sl);
 255                         for (i = 0; i < num_callbacks; i++)
 256                                 if (strcmp(cmd, callbacks[i].cmd) == 0) {
 257                                         fn = callbacks[i].fn;
 258                                         break;
 259                                 }
 260                         rte_spinlock_unlock(&callback_sl);
 261                 }
 262                 perform_command(fn, cmd, param, s);
 263
 264                 bytes = read(s, buffer, sizeof(buffer) - 1);
 265         }
 266         close(s);
 267         return NULL;
 268 }
 269
 270 static void *
 271 socket_listener(void *socket)
 272 {
 273         while (1) {
 274                 pthread_t th;
 275                 struct socket *s = (struct socket *)socket;
 276                 int s_accepted = accept(s->sock, NULL, NULL);
 277                 if (s_accepted < 0) {
 278                         snprintf(telemetry_log_error,
 279                                         sizeof(telemetry_log_error),
 280                                         "Error with accept, telemetry thread quitting\n");
 281                         return NULL;
 282                 }
 283                 pthread_create(&th, NULL, s->fn, (void *)(uintptr_t)s_accepted);
 284                 pthread_detach(th);
 285         }
 286         return NULL;
 287 }
 288
 289 static inline char *
 290 get_socket_path(const char *runtime_dir, const int version)
 291 {
 292         static char path[PATH_MAX];
 293         snprintf(path, sizeof(path), "%s/dpdk_telemetry.v%d",
 294                         strlen(runtime_dir) ? runtime_dir : "/tmp", version);
 295         return path;
 296 }
 297
 298 static void
 299 unlink_sockets(void)
 300 {
 301         if (v2_socket.path[0])
 302                 unlink(v2_socket.path);
 303         if (v1_socket.path[0])
 304                 unlink(v1_socket.path);
 305 }
 306
 307 static int
 308 create_socket(char *path)
 309 {
 310         int sock = socket(AF_UNIX, SOCK_SEQPACKET, 0);
 311         if (sock < 0) {
 312                 snprintf(telemetry_log_error, sizeof(telemetry_log_error),
 313                                 "Error with socket creation, %s",
 314                                 strerror(errno));
 315                 return -1;
 316         }
 317
 318         struct sockaddr_un sun = {.sun_family = AF_UNIX};
 319         strlcpy(sun.sun_path, path, sizeof(sun.sun_path));
 320         unlink(sun.sun_path);
 321         if (bind(sock, (void *) &sun, sizeof(sun)) < 0) {
 322                 snprintf(telemetry_log_error, sizeof(telemetry_log_error),
 323                                 "Error binding socket: %s",
 324                                 strerror(errno));
 325                 sun.sun_path[0] = 0;
 326                 goto error;
 327         }
 328
 329         if (listen(sock, 1) < 0) {
 330                 snprintf(telemetry_log_error, sizeof(telemetry_log_error),
 331                                 "Error calling listen for socket: %s",
 332                                 strerror(errno));
 333                 goto error;
 334         }
 335
 336         return sock;
 337
 338 error:
 339         close(sock);
 340         unlink_sockets();
 341         return -1;
 342 }
 343
 344 static int
 345 telemetry_legacy_init(const char *runtime_dir)
 346 {
 347         pthread_t t_old;
 348
 349         if (num_legacy_callbacks == 1) {
 350                 snprintf(telemetry_log_error, sizeof(telemetry_log_error),
 351                          "No legacy callbacks, legacy socket not created");
 352                 return -1;
 353         }
 354
 355         v1_socket.fn = legacy_client_handler;
 356         if ((size_t) snprintf(v1_socket.path, sizeof(v1_socket.path),
 357                         "%s/telemetry", runtime_dir)
 358                         >= sizeof(v1_socket.path)) {
 359                 snprintf(telemetry_log_error, sizeof(telemetry_log_error),
 360                                 "Error with socket binding, path too long");
 361                 return -1;
 362         }
 363         v1_socket.sock = create_socket(v1_socket.path);
 364         if (v1_socket.sock < 0)
 365                 return -1;
 366         pthread_create(&t_old, NULL, socket_listener, &v1_socket);
 367
 368         return 0;
 369 }
 370
 371 static int
 372 telemetry_v2_init(const char *runtime_dir)
 373 {
 374         pthread_t t_new;
 375
 376         rte_telemetry_register_cmd("/", list_commands,
 377                         "Returns list of available commands, Takes no parameters");
 378         rte_telemetry_register_cmd("/info", json_info,
 379                         "Returns DPDK Telemetry information. Takes no parameters");
 380         rte_telemetry_register_cmd("/help", command_help,
 381                         "Returns help text for a command. Parameters: string command");
 382         v2_socket.fn = client_handler;
 383         if (strlcpy(v2_socket.path, get_socket_path(runtime_dir, 2),
 384                         sizeof(v2_socket.path)) >= sizeof(v2_socket.path)) {
 385                 snprintf(telemetry_log_error, sizeof(telemetry_log_error),
 386                                 "Error with socket binding, path too long");
 387                 return -1;
 388         }
 389
 390         v2_socket.sock = create_socket(v2_socket.path);
 391         if (v2_socket.sock < 0)
 392                 return -1;
 393         pthread_create(&t_new, NULL, socket_listener, &v2_socket);
 394         atexit(unlink_sockets);
 395
 396         return 0;
 397 }
 398
 399 int32_t
 400 rte_telemetry_init(void)
 401 {
 402         const char *error_str;
 403         if (telemetry_v2_init(rte_eal_get_runtime_dir()) != 0) {
 404                 error_str = telemetry_log_error;
 405                 printf("Error initialising telemetry - %s", error_str);
 406                 return -1;
 407         }
 408         if (telemetry_legacy_init(rte_eal_get_runtime_dir()) != 0) {
 409                 error_str = telemetry_log_error;
 410                 printf("No telemetry legacy support- %s", error_str);
 411         }
 412         return 0;
 413 }
 414
 415 static struct rte_option option = {
 416         .name = "telemetry",
 417         .usage = "Enable telemetry backend",
 418         .cb = &rte_telemetry_init,
 419         .enabled = 0
 420 };
 421
 422 RTE_INIT(telemetry_register_op) {
 423         rte_option_register(&option);
 424 }