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
   5  * modify it under the terms of the GNU General Public License
   6  * as published by the Free Software Foundation; only version 2
   7  * of the License.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  17  */
  18
  19 #define _GNU_SOURCE
  20 #include <popt.h>
  21 #include <stdio.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24 #include <sys/stat.h>
  25 #include <sys/types.h>
  26 #include <unistd.h>
  27 #include <inttypes.h>
  28
  29 #include "../cmd.h"
  30 #include "../conf.h"
  31 #include "../utils.h"
  32
  33 static char *opt_channels;
  34 static int opt_kernel;
  35 static char *opt_cmd_name;
  36 static char *opt_session_name;
  37 static int opt_userspace;
  38 static char *opt_cmd_name;
  39 static pid_t opt_pid;
  40 static struct lttng_channel chan;
  41
  42 enum {
  43         OPT_HELP = 1,
  44         OPT_DISCARD,
  45         OPT_OVERWRITE,
  46         OPT_SUBBUF_SIZE,
  47         OPT_NUM_SUBBUF,
  48         OPT_SWITCH_TIMER,
  49         OPT_READ_TIMER,
  50         OPT_USERSPACE,
  51 };
  52
  53 static struct lttng_handle *handle;
  54
  55 static struct poptOption long_options[] = {
  56         /* longName, shortName, argInfo, argPtr, value, descrip, argDesc */
  57         {"help",           'h', POPT_ARG_NONE, 0, OPT_HELP, 0, 0},
  58         {"session",        's', POPT_ARG_STRING, &opt_session_name, 0, 0, 0},
  59         {"kernel",         'k', POPT_ARG_VAL, &opt_kernel, 1, 0, 0},
  60         {"userspace",      'u', POPT_ARG_STRING | POPT_ARGFLAG_OPTIONAL, &opt_cmd_name, OPT_USERSPACE, 0, 0},
  61         {"pid",            'p', POPT_ARG_INT, &opt_pid, 0, 0, 0},
  62         {"discard",        0,   POPT_ARG_NONE, 0, OPT_DISCARD, 0, 0},
  63         {"overwrite",      0,   POPT_ARG_NONE, 0, OPT_OVERWRITE, 0, 0},
  64         {"subbuf-size",    0,   POPT_ARG_DOUBLE, 0, OPT_SUBBUF_SIZE, 0, 0},
  65         {"num-subbuf",     0,   POPT_ARG_INT, 0, OPT_NUM_SUBBUF, 0, 0},
  66         {"switch-timer",   0,   POPT_ARG_INT, 0, OPT_SWITCH_TIMER, 0, 0},
  67         {"read-timer",     0,   POPT_ARG_INT, 0, OPT_READ_TIMER, 0, 0},
  68         {0, 0, 0, 0, 0, 0, 0}
  69 };
  70
  71 /*
  72  * usage
  73  */
  74 static void usage(FILE *ofp)
  75 {
  76         fprintf(ofp, "usage: lttng enable-channel NAME[,NAME2,...] [options] [channel_options]\n");
  77         fprintf(ofp, "\n");
  78         fprintf(ofp, "  -h, --help               Show this help\n");
  79         fprintf(ofp, "  -s, --session            Apply on session name\n");
  80         fprintf(ofp, "  -k, --kernel             Apply on the kernel tracer\n");
  81         fprintf(ofp, "  -u, --userspace [CMD]    Apply for the user-space tracer\n");
  82         fprintf(ofp, "                           If no CMD, the domain used is UST global\n");
  83         fprintf(ofp, "                           or else the domain is UST EXEC_NAME\n");
  84         fprintf(ofp, "  -p, --pid PID            If -u, apply to specific PID (domain: UST PID)\n");
  85         fprintf(ofp, "\n");
  86         fprintf(ofp, "Channel options:\n");
  87         fprintf(ofp, "      --discard            Discard event when buffers are full%s\n",
  88                 DEFAULT_CHANNEL_OVERWRITE ? "" : " (default)");
  89         fprintf(ofp, "      --overwrite          Flight recorder mode%s\n",
  90                 DEFAULT_CHANNEL_OVERWRITE ? " (default)" : "");
  91         fprintf(ofp, "      --subbuf-size        Subbuffer size in bytes\n");
  92         fprintf(ofp, "                               (default: %u, kernel default: %u)\n",
  93                 DEFAULT_CHANNEL_SUBBUF_SIZE,
  94                 DEFAULT_KERNEL_CHANNEL_SUBBUF_SIZE);
  95         fprintf(ofp, "      --num-subbuf         Number of subbufers\n");
  96         fprintf(ofp, "                               (default: %u, kernel default: %u)\n",
  97                 DEFAULT_CHANNEL_SUBBUF_NUM,
  98                 DEFAULT_KERNEL_CHANNEL_SUBBUF_NUM);
  99         fprintf(ofp, "      --switch-timer       Switch timer interval in usec (default: %u)\n",
 100                 DEFAULT_CHANNEL_SWITCH_TIMER);
 101         fprintf(ofp, "      --read-timer         Read timer interval in usec (default: %u)\n",
 102                 DEFAULT_CHANNEL_READ_TIMER);
 103         fprintf(ofp, "\n");
 104 }
 105
 106 /*
 107  * Set default attributes depending on those already defined from the command
 108  * line.
 109  */
 110 static void set_default_attr(struct lttng_domain *dom)
 111 {
 112         struct lttng_channel_attr default_attr;
 113
 114         /* Set attributes */
 115         lttng_channel_set_default_attr(dom, &default_attr);
 116
 117         if (chan.attr.overwrite == -1) {
 118                 chan.attr.overwrite = default_attr.overwrite;
 119         }
 120         if (chan.attr.subbuf_size == -1) {
 121                 chan.attr.subbuf_size = default_attr.subbuf_size;
 122         }
 123         if (chan.attr.num_subbuf == -1) {
 124                 chan.attr.num_subbuf = default_attr.num_subbuf;
 125         }
 126         if (chan.attr.switch_timer_interval == -1) {
 127                 chan.attr.switch_timer_interval = default_attr.switch_timer_interval;
 128         }
 129         if (chan.attr.read_timer_interval == -1) {
 130                 chan.attr.read_timer_interval = default_attr.read_timer_interval;
 131         }
 132         if (chan.attr.output == -1) {
 133                 chan.attr.output = default_attr.output;
 134         }
 135 }
 136
 137 /*
 138  * Adding channel using the lttng API.
 139  */
 140 static int enable_channel(char *session_name)
 141 {
 142         int ret = CMD_SUCCESS;
 143         char *channel_name;
 144         struct lttng_domain dom;
 145
 146         if (opt_kernel) {
 147                 dom.type = LTTNG_DOMAIN_KERNEL;
 148         } else if (opt_pid != 0) {
 149                 dom.type = LTTNG_DOMAIN_UST_PID;
 150                 dom.attr.pid = opt_pid;
 151                 DBG("PID %d set to lttng handle", opt_pid);
 152         } else if (opt_userspace && opt_cmd_name == NULL) {
 153                 dom.type = LTTNG_DOMAIN_UST;
 154         } else if (opt_userspace && opt_cmd_name != NULL) {
 155                 dom.type = LTTNG_DOMAIN_UST_EXEC_NAME;
 156                 strncpy(dom.attr.exec_name, opt_cmd_name, NAME_MAX);
 157         } else {
 158                 ERR("Please specify a tracer (-k/--kernel or -u/--userspace)");
 159                 ret = CMD_NOT_IMPLEMENTED;
 160                 goto error;
 161         }
 162
 163         set_default_attr(&dom);
 164
 165         handle = lttng_create_handle(session_name, &dom);
 166         if (handle == NULL) {
 167                 ret = -1;
 168                 goto error;
 169         }
 170
 171         /* Strip channel list (format: chan1,chan2,...) */
 172         channel_name = strtok(opt_channels, ",");
 173         while (channel_name != NULL) {
 174                 /* Copy channel name and normalize it */
 175                 strncpy(chan.name, channel_name, NAME_MAX);
 176                 chan.name[NAME_MAX - 1] = '\0';
 177
 178                 DBG("Enabling channel %s", channel_name);
 179
 180                 ret = lttng_enable_channel(handle, &chan);
 181                 if (ret < 0) {
 182                         goto error;
 183                 } else {
 184                         MSG("Channel enabled %s for session %s",
 185                                         channel_name, session_name);
 186                 }
 187
 188                 /* Next event */
 189                 channel_name = strtok(NULL, ",");
 190         }
 191
 192 error:
 193         lttng_destroy_handle(handle);
 194
 195         return ret;
 196 }
 197
 198 /*
 199  * Default value for channel configuration.
 200  */
 201 static void init_channel_config(void)
 202 {
 203         /*
 204          * Put -1 everywhere so we can identify those set by the command line and
 205          * those needed to be set by the default values.
 206          */
 207         memset(&chan.attr, -1, sizeof(chan.attr));
 208 }
 209
 210 /*
 211  * Add channel to trace session
 212  */
 213 int cmd_enable_channels(int argc, const char **argv)
 214 {
 215         int opt, ret;
 216         static poptContext pc;
 217         char *session_name = NULL;
 218
 219         init_channel_config();
 220
 221         pc = poptGetContext(NULL, argc, argv, long_options, 0);
 222         poptReadDefaultConfig(pc, 0);
 223
 224         while ((opt = poptGetNextOpt(pc)) != -1) {
 225                 switch (opt) {
 226                 case OPT_HELP:
 227                         usage(stderr);
 228                         ret = CMD_SUCCESS;
 229                         goto end;
 230                 case OPT_DISCARD:
 231                         chan.attr.overwrite = 0;
 232                         DBG("Channel set to discard");
 233                         break;
 234                 case OPT_OVERWRITE:
 235                         chan.attr.overwrite = 1;
 236                         DBG("Channel set to overwrite");
 237                         break;
 238                 case OPT_SUBBUF_SIZE:
 239                         chan.attr.subbuf_size = atol(poptGetOptArg(pc));
 240                         DBG("Channel subbuf size set to %" PRIu64, chan.attr.subbuf_size);
 241                         break;
 242                 case OPT_NUM_SUBBUF:
 243                         chan.attr.num_subbuf = atoi(poptGetOptArg(pc));
 244                         DBG("Channel subbuf num set to %" PRIu64, chan.attr.num_subbuf);
 245                         break;
 246                 case OPT_SWITCH_TIMER:
 247                         chan.attr.switch_timer_interval = atoi(poptGetOptArg(pc));
 248                         DBG("Channel switch timer interval set to %d", chan.attr.switch_timer_interval);
 249                         break;
 250                 case OPT_READ_TIMER:
 251                         chan.attr.read_timer_interval = atoi(poptGetOptArg(pc));
 252                         DBG("Channel read timer interval set to %d", chan.attr.read_timer_interval);
 253                         break;
 254                 case OPT_USERSPACE:
 255                         opt_userspace = 1;
 256                         break;
 257                 default:
 258                         usage(stderr);
 259                         ret = CMD_UNDEFINED;
 260                         goto end;
 261                 }
 262         }
 263
 264         opt_channels = (char*) poptGetArg(pc);
 265         if (opt_channels == NULL) {
 266                 ERR("Missing channel name.\n");
 267                 usage(stderr);
 268                 ret = CMD_SUCCESS;
 269                 goto end;
 270         }
 271
 272         if (!opt_session_name) {
 273                 session_name = get_session_name();
 274                 if (session_name == NULL) {
 275                         ret = -1;
 276                         goto end;
 277                 }
 278         } else {
 279                 session_name = opt_session_name;
 280         }
 281
 282         ret = enable_channel(session_name);
 283
 284 end:
 285         return ret;
 286 }