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