src/bin/lttng/commands/enable_channels.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 <popt.h>
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <string.h>
  23 #include <sys/stat.h>
  24 #include <sys/types.h>
  25 #include <unistd.h>
  26 #include <inttypes.h>
  27
  28 #include "../command.h"
  29
  30 #include <src/common/sessiond-comm/sessiond-comm.h>
  31
  32 static char *opt_channels;
  33 static int opt_kernel;
  34 static char *opt_session_name;
  35 static int opt_userspace;
  36 static struct lttng_channel chan;
  37 static char *opt_output;
  38 #if 0
  39 /* Not implemented yet */
  40 static char *opt_cmd_name;
  41 static pid_t opt_pid;
  42 #endif
  43
  44 enum {
  45         OPT_HELP = 1,
  46         OPT_DISCARD,
  47         OPT_OVERWRITE,
  48         OPT_SUBBUF_SIZE,
  49         OPT_NUM_SUBBUF,
  50         OPT_SWITCH_TIMER,
  51         OPT_READ_TIMER,
  52         OPT_USERSPACE,
  53         OPT_LIST_OPTIONS,
  54 };
  55
  56 static struct lttng_handle *handle;
  57
  58 const char *output_mmap = "mmap";
  59 const char *output_splice = "splice";
  60
  61 static struct poptOption long_options[] = {
  62         /* longName, shortName, argInfo, argPtr, value, descrip, argDesc */
  63         {"help",           'h', POPT_ARG_NONE, 0, OPT_HELP, 0, 0},
  64         {"session",        's', POPT_ARG_STRING, &opt_session_name, 0, 0, 0},
  65         {"kernel",         'k', POPT_ARG_VAL, &opt_kernel, 1, 0, 0},
  66 #if 0
  67         /* Not implemented yet */
  68         {"userspace",      'u', POPT_ARG_STRING | POPT_ARGFLAG_OPTIONAL, &opt_cmd_name, OPT_USERSPACE, 0, 0},
  69         {"pid",            'p', POPT_ARG_INT, &opt_pid, 0, 0, 0},
  70 #else
  71         {"userspace",      'u', POPT_ARG_NONE, 0, OPT_USERSPACE, 0, 0},
  72 #endif
  73         {"discard",        0,   POPT_ARG_NONE, 0, OPT_DISCARD, 0, 0},
  74         {"overwrite",      0,   POPT_ARG_NONE, 0, OPT_OVERWRITE, 0, 0},
  75         {"subbuf-size",    0,   POPT_ARG_DOUBLE, 0, OPT_SUBBUF_SIZE, 0, 0},
  76         {"num-subbuf",     0,   POPT_ARG_INT, 0, OPT_NUM_SUBBUF, 0, 0},
  77         {"switch-timer",   0,   POPT_ARG_INT, 0, OPT_SWITCH_TIMER, 0, 0},
  78         {"read-timer",     0,   POPT_ARG_INT, 0, OPT_READ_TIMER, 0, 0},
  79         {"list-options",   0, POPT_ARG_NONE, NULL, OPT_LIST_OPTIONS, NULL, NULL},
  80         {"output",         0,   POPT_ARG_STRING, &opt_output, 0, 0, 0},
  81         {0, 0, 0, 0, 0, 0, 0}
  82 };
  83
  84 /*
  85  * usage
  86  */
  87 static void usage(FILE *ofp)
  88 {
  89         fprintf(ofp, "usage: lttng enable-channel NAME[,NAME2,...] [-u|-k] [OPTIONS]\n");
  90         fprintf(ofp, "\n");
  91         fprintf(ofp, "Options:\n");
  92         fprintf(ofp, "  -h, --help               Show this help\n");
  93         fprintf(ofp, "      --list-options       Simple listing of options\n");
  94         fprintf(ofp, "  -s, --session NAME       Apply to session name\n");
  95         fprintf(ofp, "  -k, --kernel             Apply to the kernel tracer\n");
  96         fprintf(ofp, "  -u, --userspace          Apply to the user-space tracer\n");
  97         fprintf(ofp, "\n");
  98         fprintf(ofp, "Channel options:\n");
  99         fprintf(ofp, "      --discard            Discard event when buffers are full%s\n",
 100                 DEFAULT_CHANNEL_OVERWRITE ? "" : " (default)");
 101         fprintf(ofp, "      --overwrite          Flight recorder mode%s\n",
 102                 DEFAULT_CHANNEL_OVERWRITE ? " (default)" : "");
 103         fprintf(ofp, "      --subbuf-size SIZE   Subbuffer size in bytes\n");
 104         fprintf(ofp, "                               (default: %zu, kernel default: %zu)\n",
 105                 default_get_channel_subbuf_size(),
 106                 default_get_kernel_channel_subbuf_size());
 107         fprintf(ofp, "                               Needs to be a power of 2 for\n");
 108         fprintf(ofp, "                               kernel and ust tracers\n");
 109         fprintf(ofp, "      --num-subbuf NUM     Number of subbufers\n");
 110         fprintf(ofp, "                               (default: %u)\n",
 111                 DEFAULT_CHANNEL_SUBBUF_NUM);
 112         fprintf(ofp, "                               Needs to be a power of 2 for\n");
 113         fprintf(ofp, "                               kernel and ust tracers\n");
 114         fprintf(ofp, "      --switch-timer USEC  Switch timer interval in usec (default: %u)\n",
 115                 DEFAULT_CHANNEL_SWITCH_TIMER);
 116         fprintf(ofp, "      --read-timer USEC    Read timer interval in usec (default: %u)\n",
 117                 DEFAULT_CHANNEL_READ_TIMER);
 118         fprintf(ofp, "      --output TYPE        Channel output type (Values: %s, %s)\n",
 119                         output_mmap, output_splice);
 120         fprintf(ofp, "\n");
 121 }
 122
 123 /*
 124  * Set default attributes depending on those already defined from the command
 125  * line.
 126  */
 127 static void set_default_attr(struct lttng_domain *dom)
 128 {
 129         struct lttng_channel_attr default_attr;
 130
 131         /* Set attributes */
 132         lttng_channel_set_default_attr(dom, &default_attr);
 133
 134         if (chan.attr.overwrite == -1) {
 135                 chan.attr.overwrite = default_attr.overwrite;
 136         }
 137         if (chan.attr.subbuf_size == -1) {
 138                 chan.attr.subbuf_size = default_attr.subbuf_size;
 139         }
 140         if (chan.attr.num_subbuf == -1) {
 141                 chan.attr.num_subbuf = default_attr.num_subbuf;
 142         }
 143         if (chan.attr.switch_timer_interval == -1) {
 144                 chan.attr.switch_timer_interval = default_attr.switch_timer_interval;
 145         }
 146         if (chan.attr.read_timer_interval == -1) {
 147                 chan.attr.read_timer_interval = default_attr.read_timer_interval;
 148         }
 149         if (chan.attr.output == -1) {
 150                 chan.attr.output = default_attr.output;
 151         }
 152 }
 153
 154 /*
 155  * Adding channel using the lttng API.
 156  */
 157 static int enable_channel(char *session_name)
 158 {
 159         int ret = CMD_SUCCESS, warn = 0;
 160         char *channel_name;
 161         struct lttng_domain dom;
 162
 163         memset(&dom, 0, sizeof(dom));
 164
 165         /* Create lttng domain */
 166         if (opt_kernel) {
 167                 dom.type = LTTNG_DOMAIN_KERNEL;
 168         } else if (opt_userspace) {
 169                 dom.type = LTTNG_DOMAIN_UST;
 170         } else {
 171                 ERR("Please specify a tracer (-k/--kernel or -u/--userspace)");
 172                 ret = CMD_ERROR;
 173                 goto error;
 174         }
 175
 176         set_default_attr(&dom);
 177
 178         /* Setting channel output */
 179         if (opt_output) {
 180                 if (!strncmp(output_mmap, opt_output, strlen(output_mmap))) {
 181                         chan.attr.output = LTTNG_EVENT_MMAP;
 182                 } else if (!strncmp(output_splice, opt_output, strlen(output_splice))) {
 183                         chan.attr.output = LTTNG_EVENT_SPLICE;
 184                 } else {
 185                         ERR("Unknown output type %s. Possible values are: %s, %s\n",
 186                                         opt_output, output_mmap, output_splice);
 187                         usage(stderr);
 188                         ret = CMD_ERROR;
 189                         goto error;
 190                 }
 191         }
 192
 193         handle = lttng_create_handle(session_name, &dom);
 194         if (handle == NULL) {
 195                 ret = -1;
 196                 goto error;
 197         }
 198
 199         /* Strip channel list (format: chan1,chan2,...) */
 200         channel_name = strtok(opt_channels, ",");
 201         while (channel_name != NULL) {
 202                 /* Copy channel name and normalize it */
 203                 strncpy(chan.name, channel_name, NAME_MAX);
 204                 chan.name[NAME_MAX - 1] = '\0';
 205
 206                 DBG("Enabling channel %s", channel_name);
 207
 208                 ret = lttng_enable_channel(handle, &chan);
 209                 if (ret < 0) {
 210                         switch (-ret) {
 211                         case LTTNG_ERR_KERN_CHAN_EXIST:
 212                         case LTTNG_ERR_UST_CHAN_EXIST:
 213                                 WARN("Channel %s: %s (session %s", channel_name,
 214                                                 lttng_strerror(ret), session_name);
 215                                 goto error;
 216                         default:
 217                                 ERR("Channel %s: %s (session %s)", channel_name,
 218                                                 lttng_strerror(ret), session_name);
 219                                 break;
 220                         }
 221                         warn = 1;
 222                 } else {
 223                         MSG("%s channel %s enabled for session %s",
 224                                         opt_kernel ? "Kernel" : "UST", channel_name,
 225                                         session_name);
 226                 }
 227
 228                 /* Next event */
 229                 channel_name = strtok(NULL, ",");
 230         }
 231
 232         ret = CMD_SUCCESS;
 233
 234 error:
 235         if (warn) {
 236                 ret = CMD_WARNING;
 237         }
 238
 239         lttng_destroy_handle(handle);
 240
 241         return ret;
 242 }
 243
 244 /*
 245  * Default value for channel configuration.
 246  */
 247 static void init_channel_config(void)
 248 {
 249         /*
 250          * Put -1 everywhere so we can identify those set by the command line and
 251          * those needed to be set by the default values.
 252          */
 253         memset(&chan.attr, -1, sizeof(chan.attr));
 254 }
 255
 256 /*
 257  * Add channel to trace session
 258  */
 259 int cmd_enable_channels(int argc, const char **argv)
 260 {
 261         int opt, ret = CMD_SUCCESS;
 262         static poptContext pc;
 263         char *session_name = NULL;
 264
 265         init_channel_config();
 266
 267         pc = poptGetContext(NULL, argc, argv, long_options, 0);
 268         poptReadDefaultConfig(pc, 0);
 269
 270         while ((opt = poptGetNextOpt(pc)) != -1) {
 271                 switch (opt) {
 272                 case OPT_HELP:
 273                         usage(stdout);
 274                         goto end;
 275                 case OPT_DISCARD:
 276                         chan.attr.overwrite = 0;
 277                         DBG("Channel set to discard");
 278                         break;
 279                 case OPT_OVERWRITE:
 280                         chan.attr.overwrite = 1;
 281                         DBG("Channel set to overwrite");
 282                         break;
 283                 case OPT_SUBBUF_SIZE:
 284                         /* TODO Replace atol with strtol and check for errors */
 285                         chan.attr.subbuf_size = atol(poptGetOptArg(pc));
 286                         DBG("Channel subbuf size set to %" PRIu64, chan.attr.subbuf_size);
 287                         break;
 288                 case OPT_NUM_SUBBUF:
 289                         /* TODO Replace atoi with strtol and check for errors */
 290                         chan.attr.num_subbuf = atoi(poptGetOptArg(pc));
 291                         DBG("Channel subbuf num set to %" PRIu64, chan.attr.num_subbuf);
 292                         break;
 293                 case OPT_SWITCH_TIMER:
 294                         /* TODO Replace atoi with strtol and check for errors */
 295                         chan.attr.switch_timer_interval = atoi(poptGetOptArg(pc));
 296                         DBG("Channel switch timer interval set to %d", chan.attr.switch_timer_interval);
 297                         break;
 298                 case OPT_READ_TIMER:
 299                         /* TODO Replace atoi with strtol and check for errors */
 300                         chan.attr.read_timer_interval = atoi(poptGetOptArg(pc));
 301                         DBG("Channel read timer interval set to %d", chan.attr.read_timer_interval);
 302                         break;
 303                 case OPT_USERSPACE:
 304                         opt_userspace = 1;
 305                         break;
 306                 case OPT_LIST_OPTIONS:
 307                         list_cmd_options(stdout, long_options);
 308                         goto end;
 309                 default:
 310                         usage(stderr);
 311                         ret = CMD_UNDEFINED;
 312                         goto end;
 313                 }
 314         }
 315
 316         opt_channels = (char*) poptGetArg(pc);
 317         if (opt_channels == NULL) {
 318                 ERR("Missing channel name.\n");
 319                 usage(stderr);
 320                 ret = CMD_ERROR;
 321                 goto end;
 322         }
 323
 324         if (!opt_session_name) {
 325                 session_name = get_session_name();
 326                 if (session_name == NULL) {
 327                         ret = CMD_ERROR;
 328                         goto end;
 329                 }
 330         } else {
 331                 session_name = opt_session_name;
 332         }
 333
 334         ret = enable_channel(session_name);
 335
 336 end:
 337         if (!opt_session_name && session_name) {
 338                 free(session_name);
 339         }
 340         poptFreeContext(pc);
 341         return ret;
 342 }