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