src/bin/lttng/utils.c

   1 /*
   2  * Copyright (c)  2011 David Goulet <david.goulet@polymtl.ca>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License, version 2 only,
   6  * as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along
  14  * with this program; if not, write to the Free Software Foundation, Inc.,
  15  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  16  */
  17
  18 #define _GNU_SOURCE
  19 #define _LGPL_SOURCE
  20 #include <assert.h>
  21 #include <stdlib.h>
  22 #include <ctype.h>
  23 #include <limits.h>
  24 #include <sys/types.h>
  25 #include <sys/socket.h>
  26 #include <signal.h>
  27 #include <netinet/in.h>
  28 #include <arpa/inet.h>
  29
  30 #include <common/error.h>
  31 #include <common/utils.h>
  32
  33 #include "conf.h"
  34 #include "utils.h"
  35 #include "command.h"
  36
  37 static const char *str_kernel = "Kernel";
  38 static const char *str_ust = "UST";
  39 static const char *str_jul = "JUL";
  40 static const char *str_log4j = "LOG4J";
  41 static const char *str_python = "Python";
  42
  43 /*
  44  *  get_session_name
  45  *
  46  *  Return allocated string with the session name found in the config
  47  *  directory.
  48  */
  49 char *get_session_name(void)
  50 {
  51         char *path, *session_name = NULL;
  52
  53         /* Get path to config file */
  54         path = utils_get_home_dir();
  55         if (path == NULL) {
  56                 goto error;
  57         }
  58
  59         /* Get session name from config */
  60         session_name = config_read_session_name(path);
  61         if (session_name == NULL) {
  62                 goto error;
  63         }
  64
  65         DBG2("Config file path found: %s", path);
  66         DBG("Session name found: %s", session_name);
  67         return session_name;
  68
  69 error:
  70         return NULL;
  71 }
  72
  73 /*
  74  *  list_commands
  75  *
  76  *  List commands line by line. This is mostly for bash auto completion and to
  77  *  avoid difficult parsing.
  78  */
  79 void list_commands(struct cmd_struct *commands, FILE *ofp)
  80 {
  81         int i = 0;
  82         struct cmd_struct *cmd = NULL;
  83
  84         cmd = &commands[i];
  85         while (cmd->name != NULL) {
  86                 fprintf(ofp, "%s\n", cmd->name);
  87                 i++;
  88                 cmd = &commands[i];
  89         }
  90 }
  91
  92 /*
  93  * list_cmd_options
  94  *
  95  * Prints a simple list of the options available to a command. This is intended
  96  * to be easily parsed for bash completion.
  97  */
  98 void list_cmd_options(FILE *ofp, struct poptOption *options)
  99 {
 100         int i;
 101         struct poptOption *option = NULL;
 102
 103         for (i = 0; options[i].longName != NULL; i++) {
 104                 option = &options[i];
 105
 106                 fprintf(ofp, "--%s\n", option->longName);
 107
 108                 if (isprint(option->shortName)) {
 109                         fprintf(ofp, "-%c\n", option->shortName);
 110                 }
 111         }
 112 }
 113
 114 /*
 115  * fls: returns the position of the most significant bit.
 116  * Returns 0 if no bit is set, else returns the position of the most
 117  * significant bit (from 1 to 32 on 32-bit, from 1 to 64 on 64-bit).
 118  */
 119 #if defined(__i386) || defined(__x86_64)
 120 static inline
 121 unsigned int fls_u32(uint32_t x)
 122 {
 123         int r;
 124
 125         asm("bsrl %1,%0\n\t"
 126             "jnz 1f\n\t"
 127             "movl $-1,%0\n\t"
 128             "1:\n\t"
 129             : "=r" (r) : "rm" (x));
 130         return r + 1;
 131 }
 132 #define HAS_FLS_U32
 133 #endif
 134
 135 #if defined(__x86_64)
 136 static inline
 137 unsigned int fls_u64(uint64_t x)
 138 {
 139         long r;
 140
 141         asm("bsrq %1,%0\n\t"
 142             "jnz 1f\n\t"
 143             "movq $-1,%0\n\t"
 144             "1:\n\t"
 145             : "=r" (r) : "rm" (x));
 146         return r + 1;
 147 }
 148 #define HAS_FLS_U64
 149 #endif
 150
 151 #ifndef HAS_FLS_U64
 152 static __attribute__((unused))
 153 unsigned int fls_u64(uint64_t x)
 154 {
 155         unsigned int r = 64;
 156
 157         if (!x)
 158                 return 0;
 159
 160         if (!(x & 0xFFFFFFFF00000000ULL)) {
 161                 x <<= 32;
 162                 r -= 32;
 163         }
 164         if (!(x & 0xFFFF000000000000ULL)) {
 165                 x <<= 16;
 166                 r -= 16;
 167         }
 168         if (!(x & 0xFF00000000000000ULL)) {
 169                 x <<= 8;
 170                 r -= 8;
 171         }
 172         if (!(x & 0xF000000000000000ULL)) {
 173                 x <<= 4;
 174                 r -= 4;
 175         }
 176         if (!(x & 0xC000000000000000ULL)) {
 177                 x <<= 2;
 178                 r -= 2;
 179         }
 180         if (!(x & 0x8000000000000000ULL)) {
 181                 x <<= 1;
 182                 r -= 1;
 183         }
 184         return r;
 185 }
 186 #endif
 187
 188 #ifndef HAS_FLS_U32
 189 static __attribute__((unused))
 190 unsigned int fls_u32(uint32_t x)
 191 {
 192         unsigned int r = 32;
 193
 194         if (!x)
 195                 return 0;
 196         if (!(x & 0xFFFF0000U)) {
 197                 x <<= 16;
 198                 r -= 16;
 199         }
 200         if (!(x & 0xFF000000U)) {
 201                 x <<= 8;
 202                 r -= 8;
 203         }
 204         if (!(x & 0xF0000000U)) {
 205                 x <<= 4;
 206                 r -= 4;
 207         }
 208         if (!(x & 0xC0000000U)) {
 209                 x <<= 2;
 210                 r -= 2;
 211         }
 212         if (!(x & 0x80000000U)) {
 213                 x <<= 1;
 214                 r -= 1;
 215         }
 216         return r;
 217 }
 218 #endif
 219
 220 static
 221 unsigned int fls_ulong(unsigned long x)
 222 {
 223 #if (CAA_BITS_PER_LONG == 32)
 224         return fls_u32(x);
 225 #else
 226         return fls_u64(x);
 227 #endif
 228 }
 229
 230 /*
 231  * Return the minimum order for which x <= (1UL << order).
 232  * Return -1 if x is 0.
 233  */
 234 int get_count_order_u32(uint32_t x)
 235 {
 236         if (!x)
 237                 return -1;
 238
 239         return fls_u32(x - 1);
 240 }
 241
 242 /*
 243  * Return the minimum order for which x <= (1UL << order).
 244  * Return -1 if x is 0.
 245  */
 246 int get_count_order_u64(uint64_t x)
 247 {
 248         if (!x)
 249                 return -1;
 250
 251         return fls_u64(x - 1);
 252 }
 253
 254 /*
 255  * Return the minimum order for which x <= (1UL << order).
 256  * Return -1 if x is 0.
 257  */
 258 int get_count_order_ulong(unsigned long x)
 259 {
 260         if (!x)
 261                 return -1;
 262
 263         return fls_ulong(x - 1);
 264 }
 265
 266 const char *get_domain_str(enum lttng_domain_type domain)
 267 {
 268         const char *str_dom;
 269
 270         switch (domain) {
 271         case LTTNG_DOMAIN_KERNEL:
 272                 str_dom = str_kernel;
 273                 break;
 274         case LTTNG_DOMAIN_UST:
 275                 str_dom = str_ust;
 276                 break;
 277         case LTTNG_DOMAIN_JUL:
 278                 str_dom = str_jul;
 279                 break;
 280         case LTTNG_DOMAIN_LOG4J:
 281                 str_dom = str_log4j;
 282                 break;
 283         case LTTNG_DOMAIN_PYTHON:
 284                 str_dom = str_python;
 285                 break;
 286         default:
 287                 /* Should not have an unknown domain or else define it. */
 288                 assert(0);
 289         }
 290
 291         return str_dom;
 292 }
 293
 294 /*
 295  * Spawn a lttng relayd daemon by forking and execv.
 296  */
 297 int spawn_relayd(const char *pathname, int port)
 298 {
 299         int ret = 0;
 300         pid_t pid;
 301         char url[255];
 302
 303         if (!port) {
 304                 port = DEFAULT_NETWORK_VIEWER_PORT;
 305         }
 306
 307         ret = snprintf(url, sizeof(url), "tcp://localhost:%d", port);
 308         if (ret < 0) {
 309                 goto end;
 310         }
 311
 312         MSG("Spawning a relayd daemon");
 313         pid = fork();
 314         if (pid == 0) {
 315                 /*
 316                  * Spawn session daemon and tell
 317                  * it to signal us when ready.
 318                  */
 319                 execlp(pathname, "lttng-relayd", "-L", url, NULL);
 320                 /* execlp only returns if error happened */
 321                 if (errno == ENOENT) {
 322                         ERR("No relayd found. Use --relayd-path.");
 323                 } else {
 324                         PERROR("execlp");
 325                 }
 326                 kill(getppid(), SIGTERM);       /* wake parent */
 327                 exit(EXIT_FAILURE);
 328         } else if (pid > 0) {
 329                 goto end;
 330         } else {
 331                 PERROR("fork");
 332                 ret = -1;
 333                 goto end;
 334         }
 335
 336 end:
 337         return ret;
 338 }
 339
 340 /*
 341  * Check if relayd is alive.
 342  *
 343  * Return 1 if found else 0 if NOT found. Negative value on error.
 344  */
 345 int check_relayd(void)
 346 {
 347         int ret, fd;
 348         struct sockaddr_in sin;
 349
 350         fd = socket(AF_INET, SOCK_STREAM, 0);
 351         if (fd < 0) {
 352                 PERROR("socket check relayd");
 353                 ret = -1;
 354                 goto error_socket;
 355         }
 356
 357         sin.sin_family = AF_INET;
 358         sin.sin_port = htons(DEFAULT_NETWORK_VIEWER_PORT);
 359         ret = inet_pton(sin.sin_family, "127.0.0.1", &sin.sin_addr);
 360         if (ret < 1) {
 361                 PERROR("inet_pton check relayd");
 362                 ret = -1;
 363                 goto error;
 364         }
 365
 366         /*
 367          * A successful connect means the relayd exists thus returning 0 else a
 368          * negative value means it does NOT exists.
 369          */
 370         ret = connect(fd, &sin, sizeof(sin));
 371         if (ret < 0) {
 372                 /* Not found. */
 373                 ret = 0;
 374         } else {
 375                 /* Already spawned. */
 376                 ret = 1;
 377         }
 378
 379 error:
 380         if (close(fd) < 0) {
 381                 PERROR("close relayd fd");
 382         }
 383 error_socket:
 384         return ret;
 385 }