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 #include <assert.h>
  20 #include <stdlib.h>
  21 #include <ctype.h>
  22 #include <limits.h>
  23 #include <sys/types.h>
  24 #include <sys/socket.h>
  25 #include <signal.h>
  26 #include <netinet/in.h>
  27 #include <arpa/inet.h>
  28
  29 #include <common/error.h>
  30 #include <common/utils.h>
  31
  32 #include "conf.h"
  33 #include "utils.h"
  34 #include "command.h"
  35
  36 static const char *str_kernel = "Kernel";
  37 static const char *str_ust = "UST";
  38 static const char *str_jul = "JUL";
  39 static const char *str_log4j = "LOG4J";
  40
  41 static
  42 char *_get_session_name(int quiet)
  43 {
  44         char *path, *session_name = NULL;
  45
  46         /* Get path to config file */
  47         path = utils_get_home_dir();
  48         if (path == NULL) {
  49                 goto error;
  50         }
  51
  52         /* Get session name from config */
  53         session_name = quiet ? config_read_session_name_quiet(path) :
  54                 config_read_session_name(path);
  55         if (session_name == NULL) {
  56                 goto error;
  57         }
  58
  59         DBG2("Config file path found: %s", path);
  60         DBG("Session name found: %s", session_name);
  61         return session_name;
  62
  63 error:
  64         return NULL;
  65 }
  66
  67 /*
  68  *  get_session_name
  69  *
  70  *  Return allocated string with the session name found in the config
  71  *  directory.
  72  */
  73 char *get_session_name(void)
  74 {
  75         return _get_session_name(0);
  76 }
  77
  78 /*
  79  *  get_session_name_quiet (no warnings/errors emitted)
  80  *
  81  *  Return allocated string with the session name found in the config
  82  *  directory.
  83  */
  84 char *get_session_name_quiet(void)
  85 {
  86         return _get_session_name(1);
  87 }
  88
  89 /*
  90  *  list_commands
  91  *
  92  *  List commands line by line. This is mostly for bash auto completion and to
  93  *  avoid difficult parsing.
  94  */
  95 void list_commands(struct cmd_struct *commands, FILE *ofp)
  96 {
  97         int i = 0;
  98         struct cmd_struct *cmd = NULL;
  99
 100         cmd = &commands[i];
 101         while (cmd->name != NULL) {
 102                 fprintf(ofp, "%s\n", cmd->name);
 103                 i++;
 104                 cmd = &commands[i];
 105         }
 106 }
 107
 108 /*
 109  * list_cmd_options
 110  *
 111  * Prints a simple list of the options available to a command. This is intended
 112  * to be easily parsed for bash completion.
 113  */
 114 void list_cmd_options(FILE *ofp, struct poptOption *options)
 115 {
 116         int i;
 117         struct poptOption *option = NULL;
 118
 119         for (i = 0; options[i].longName != NULL; i++) {
 120                 option = &options[i];
 121
 122                 fprintf(ofp, "--%s\n", option->longName);
 123
 124                 if (isprint(option->shortName)) {
 125                         fprintf(ofp, "-%c\n", option->shortName);
 126                 }
 127         }
 128 }
 129
 130 /*
 131  * fls: returns the position of the most significant bit.
 132  * Returns 0 if no bit is set, else returns the position of the most
 133  * significant bit (from 1 to 32 on 32-bit, from 1 to 64 on 64-bit).
 134  */
 135 #if defined(__i386) || defined(__x86_64)
 136 static inline
 137 unsigned int fls_u32(uint32_t x)
 138 {
 139         int r;
 140
 141         asm("bsrl %1,%0\n\t"
 142             "jnz 1f\n\t"
 143             "movl $-1,%0\n\t"
 144             "1:\n\t"
 145             : "=r" (r) : "rm" (x));
 146         return r + 1;
 147 }
 148 #define HAS_FLS_U32
 149 #endif
 150
 151 #if defined(__x86_64)
 152 static inline
 153 unsigned int fls_u64(uint64_t x)
 154 {
 155         long r;
 156
 157         asm("bsrq %1,%0\n\t"
 158             "jnz 1f\n\t"
 159             "movq $-1,%0\n\t"
 160             "1:\n\t"
 161             : "=r" (r) : "rm" (x));
 162         return r + 1;
 163 }
 164 #define HAS_FLS_U64
 165 #endif
 166
 167 #ifndef HAS_FLS_U64
 168 static __attribute__((unused))
 169 unsigned int fls_u64(uint64_t x)
 170 {
 171         unsigned int r = 64;
 172
 173         if (!x)
 174                 return 0;
 175
 176         if (!(x & 0xFFFFFFFF00000000ULL)) {
 177                 x <<= 32;
 178                 r -= 32;
 179         }
 180         if (!(x & 0xFFFF000000000000ULL)) {
 181                 x <<= 16;
 182                 r -= 16;
 183         }
 184         if (!(x & 0xFF00000000000000ULL)) {
 185                 x <<= 8;
 186                 r -= 8;
 187         }
 188         if (!(x & 0xF000000000000000ULL)) {
 189                 x <<= 4;
 190                 r -= 4;
 191         }
 192         if (!(x & 0xC000000000000000ULL)) {
 193                 x <<= 2;
 194                 r -= 2;
 195         }
 196         if (!(x & 0x8000000000000000ULL)) {
 197                 x <<= 1;
 198                 r -= 1;
 199         }
 200         return r;
 201 }
 202 #endif
 203
 204 #ifndef HAS_FLS_U32
 205 static __attribute__((unused))
 206 unsigned int fls_u32(uint32_t x)
 207 {
 208         unsigned int r = 32;
 209
 210         if (!x)
 211                 return 0;
 212         if (!(x & 0xFFFF0000U)) {
 213                 x <<= 16;
 214                 r -= 16;
 215         }
 216         if (!(x & 0xFF000000U)) {
 217                 x <<= 8;
 218                 r -= 8;
 219         }
 220         if (!(x & 0xF0000000U)) {
 221                 x <<= 4;
 222                 r -= 4;
 223         }
 224         if (!(x & 0xC0000000U)) {
 225                 x <<= 2;
 226                 r -= 2;
 227         }
 228         if (!(x & 0x80000000U)) {
 229                 x <<= 1;
 230                 r -= 1;
 231         }
 232         return r;
 233 }
 234 #endif
 235
 236 static
 237 unsigned int fls_ulong(unsigned long x)
 238 {
 239 #if (CAA_BITS_PER_LONG == 32)
 240         return fls_u32(x);
 241 #else
 242         return fls_u64(x);
 243 #endif
 244 }
 245
 246 /*
 247  * Return the minimum order for which x <= (1UL << order).
 248  * Return -1 if x is 0.
 249  */
 250 int get_count_order_u32(uint32_t x)
 251 {
 252         if (!x)
 253                 return -1;
 254
 255         return fls_u32(x - 1);
 256 }
 257
 258 /*
 259  * Return the minimum order for which x <= (1UL << order).
 260  * Return -1 if x is 0.
 261  */
 262 int get_count_order_u64(uint64_t x)
 263 {
 264         if (!x)
 265                 return -1;
 266
 267         return fls_u64(x - 1);
 268 }
 269
 270 /*
 271  * Return the minimum order for which x <= (1UL << order).
 272  * Return -1 if x is 0.
 273  */
 274 int get_count_order_ulong(unsigned long x)
 275 {
 276         if (!x)
 277                 return -1;
 278
 279         return fls_ulong(x - 1);
 280 }
 281
 282 const char *get_domain_str(enum lttng_domain_type domain)
 283 {
 284         const char *str_dom;
 285
 286         switch (domain) {
 287         case LTTNG_DOMAIN_KERNEL:
 288                 str_dom = str_kernel;
 289                 break;
 290         case LTTNG_DOMAIN_UST:
 291                 str_dom = str_ust;
 292                 break;
 293         case LTTNG_DOMAIN_JUL:
 294                 str_dom = str_jul;
 295                 break;
 296         case LTTNG_DOMAIN_LOG4J:
 297                 str_dom = str_log4j;
 298                 break;
 299         default:
 300                 /* Should not have an unknown domain or else define it. */
 301                 assert(0);
 302         }
 303
 304         return str_dom;
 305 }
 306
 307 /*
 308  * Spawn a lttng relayd daemon by forking and execv.
 309  */
 310 int spawn_relayd(const char *pathname, int port)
 311 {
 312         int ret = 0;
 313         pid_t pid;
 314         char url[255];
 315
 316         if (!port) {
 317                 port = DEFAULT_NETWORK_VIEWER_PORT;
 318         }
 319
 320         ret = snprintf(url, sizeof(url), "tcp://localhost:%d", port);
 321         if (ret < 0) {
 322                 goto end;
 323         }
 324
 325         MSG("Spawning a relayd daemon");
 326         pid = fork();
 327         if (pid == 0) {
 328                 /*
 329                  * Spawn session daemon and tell
 330                  * it to signal us when ready.
 331                  */
 332                 execlp(pathname, "lttng-relayd", "-L", url, NULL);
 333                 /* execlp only returns if error happened */
 334                 if (errno == ENOENT) {
 335                         ERR("No relayd found. Use --relayd-path.");
 336                 } else {
 337                         perror("execlp");
 338                 }
 339                 kill(getppid(), SIGTERM);       /* wake parent */
 340                 exit(EXIT_FAILURE);
 341         } else if (pid > 0) {
 342                 goto end;
 343         } else {
 344                 perror("fork");
 345                 ret = -1;
 346                 goto end;
 347         }
 348
 349 end:
 350         return ret;
 351 }
 352
 353 /*
 354  * Check if relayd is alive.
 355  *
 356  * Return 1 if found else 0 if NOT found. Negative value on error.
 357  */
 358 int check_relayd(void)
 359 {
 360         int ret, fd;
 361         struct sockaddr_in sin;
 362
 363         fd = socket(AF_INET, SOCK_STREAM, 0);
 364         if (fd < 0) {
 365                 perror("socket check relayd");
 366                 ret = -1;
 367                 goto error_socket;
 368         }
 369
 370         sin.sin_family = AF_INET;
 371         sin.sin_port = htons(DEFAULT_NETWORK_VIEWER_PORT);
 372         ret = inet_pton(sin.sin_family, "127.0.0.1", &sin.sin_addr);
 373         if (ret < 1) {
 374                 perror("inet_pton check relayd");
 375                 ret = -1;
 376                 goto error;
 377         }
 378
 379         /*
 380          * A successful connect means the relayd exists thus returning 0 else a
 381          * negative value means it does NOT exists.
 382          */
 383         ret = connect(fd, &sin, sizeof(sin));
 384         if (ret < 0) {
 385                 /* Not found. */
 386                 ret = 0;
 387         } else {
 388                 /* Already spawned. */
 389                 ret = 1;
 390         }
 391
 392 error:
 393         if (close(fd) < 0) {
 394                 perror("close relayd fd");
 395         }
 396 error_socket:
 397         return ret;
 398 }
 399
 400 int print_missing_or_multiple_domains(unsigned int sum)
 401 {
 402         int ret = 0;
 403
 404         if (sum == 0) {
 405                 ERR("Please specify a domain (-k/-u/-j).");
 406                 ret = -1;
 407         } else if (sum > 1) {
 408                 ERR("Multiple domains specified.");
 409                 ret = -1;
 410         }
 411
 412         return ret;
 413 }