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