--- /dev/null
+/* libltt
+ *
+ * Linux Trace Toolkit Netlink Control Library
+ *
+ * Controls the ltt-control kernel module through debugfs.
+ *
+ * Copyright 2005 -
+ * Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
+ *
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <liblttctl/lttctl.h>
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+#include <dirent.h>
+#include <limits.h>
+#include <fcntl.h>
+#include <stdlib.h>
+
+#define MAX_CHANNEL (256)
+
+static char debugfsmntdir[PATH_MAX];
+
+static int initdebugfsmntdir(void)
+{
+ return getdebugfsmntdir(debugfsmntdir);
+}
+
+/*
+ * This function must called posterior to initdebugfsmntdir(),
+ * because it need to use debugfsmntdir[] which is inited in initdebugfsmntdir()
+ */
+static int initmodule(void)
+{
+ char controldirname[PATH_MAX];
+ DIR *dir;
+ int tryload_done = 0;
+
+ sprintf(controldirname, "%s/ltt/control/", debugfsmntdir);
+
+check_again:
+ /*
+ * Check ltt control's debugfs dir
+ *
+ * We don't check is ltt-trace-control module exist, because it maybe
+ * compiled into kernel.
+ */
+ dir = opendir(controldirname);
+ if (dir) {
+ closedir(dir);
+ return 0;
+ }
+
+ if (!tryload_done) {
+ system("modprobe ltt-trace-control");
+ tryload_done = 1;
+ goto check_again;
+ }
+
+ return -ENOENT;
+}
+
+int lttctl_init(void)
+{
+ int ret;
+
+
+ ret = initdebugfsmntdir();
+ if (ret) {
+ fprintf(stderr, "Get debugfs mount point failed\n");
+ return ret;
+ }
+
+ ret = initmodule();
+ if (ret) {
+ fprintf(stderr, "Control module seems not work\n");
+ return ret;
+ }
+
+ return 0;
+}
+
+int lttctl_destroy(void)
+{
+ return 0;
+}
+
+static int lttctl_sendop(const char *fname, const char *op)
+{
+ int fd;
+
+ if (!fname) {
+ fprintf(stderr, "%s: args invalid\n", __func__);
+ return 1;
+ }
+
+ fd = open(fname, O_WRONLY);
+ if (fd == -1) {
+ fprintf(stderr, "%s: open %s failed: %s\n", __func__, fname,
+ strerror(errno));
+ return errno;
+ }
+
+ if (write(fd, op, strlen(op)) == -1) {
+ int ret = errno;
+ fprintf(stderr, "%s: write %s to %s failed: %s\n", __func__, op,
+ fname, strerror(errno));
+ close(fd);
+ return ret;
+ }
+
+ close(fd);
+
+ return 0;
+}
+
+/*
+ * check is trace exist(check debugfsmntdir too)
+ * expect:
+ * 0: expect that trace not exist
+ * !0: expect that trace exist
+ *
+ * ret:
+ * 0: check pass
+ * -(EEXIST | ENOENT): check failed
+ * -ERRNO: error happened (no check)
+ */
+static int lttctl_check_trace(const char *name, int expect)
+{
+ char tracedirname[PATH_MAX];
+ DIR *dir;
+ int exist;
+
+ if (!name) {
+ fprintf(stderr, "%s: args invalid\n", __func__);
+ return -EINVAL;
+ }
+
+ if (!debugfsmntdir[0]) {
+ fprintf(stderr, "%s: debugfsmntdir not valid\n", __func__);
+ return -EINVAL;
+ }
+
+ sprintf(tracedirname, "%s/ltt/control/%s", debugfsmntdir, name);
+
+ dir = opendir(tracedirname);
+ if (dir) {
+ exist = 1;
+ } else {
+ if (errno != ENOENT) {
+ fprintf(stderr, "%s: %s\n", __func__, strerror(errno));
+ return -EINVAL;
+ }
+ exist = 0;
+ }
+
+ closedir(dir);
+
+ if (!expect != !exist) {
+ if (exist)
+ {
+ fprintf(stderr, "Trace %s already exist\n", name);
+ return -EEXIST;
+ }
+ else
+ {
+ fprintf(stderr, "Trace %s not exist\n", name);
+ return -ENOENT;
+ }
+
+ }
+
+ return 0;
+}
+
+/*
+ * get channel list of a trace
+ * don't include metadata channel when metadata is 0
+ *
+ * return number of channel on success
+ * return negative number on fail
+ * Caller must free channellist.
+ */
+static int lttctl_get_channellist(const char *tracename,
+ char ***channellist, int metadata)
+{
+ char tracedirname[PATH_MAX];
+ struct dirent *dirent;
+ DIR *dir;
+ char **list = NULL, **old_list;
+ int nr_chan = 0;
+
+ sprintf(tracedirname, "%s/ltt/control/%s/channel", debugfsmntdir,
+ tracename);
+
+ dir = opendir(tracedirname);
+ if (!dir) {
+ nr_chan = -ENOENT;
+ goto error;
+ }
+
+ for (;;) {
+ dirent = readdir(dir);
+ if (!dirent)
+ break;
+ if (!strcmp(dirent->d_name, ".")
+ || !strcmp(dirent->d_name, ".."))
+ continue;
+ if (!metadata && !strcmp(dirent->d_name, "metadata"))
+ continue;
+ old_list = list;
+ list = malloc(sizeof(char *) * ++nr_chan);
+ memcpy(list, old_list, sizeof(*list) * (nr_chan - 1));
+ free(old_list);
+ list[nr_chan - 1] = strdup(dirent->d_name);
+ }
+
+ closedir(dir);
+
+ *channellist = list;
+ return nr_chan;
+error:
+ free(list);
+ *channellist = NULL;
+ return nr_chan;
+}
+
+static void lttctl_free_channellist(char **channellist, int n_channel)
+{
+ int i = 0;
+ for(; i < n_channel; ++i)
+ free(channellist[i]);
+ free(channellist);
+}
+
+int lttctl_setup_trace(const char *name)
+{
+ int ret;
+ char ctlfname[PATH_MAX];
+
+ if (!name) {
+ fprintf(stderr, "%s: args invalid\n", __func__);
+ ret = -EINVAL;
+ goto arg_error;
+ }
+
+ ret = lttctl_check_trace(name, 0);
+ if (ret)
+ goto arg_error;
+
+ sprintf(ctlfname, "%s/ltt/setup_trace", debugfsmntdir);
+
+ ret = lttctl_sendop(ctlfname, name);
+ if (ret) {
+ fprintf(stderr, "Setup trace failed\n");
+ goto op_err;
+ }
+
+ return 0;
+
+op_err:
+arg_error:
+ return ret;
+}
+
+int lttctl_destroy_trace(const char *name)
+{
+ int ret;
+ char ctlfname[PATH_MAX];
+
+ if (!name) {
+ fprintf(stderr, "%s: args invalid\n", __func__);
+ ret = -EINVAL;
+ goto arg_error;
+ }
+
+ ret = lttctl_check_trace(name, 1);
+ if (ret)
+ goto arg_error;
+
+ sprintf(ctlfname, "%s/ltt/destroy_trace", debugfsmntdir);
+
+ ret = lttctl_sendop(ctlfname, name);
+ if (ret) {
+ fprintf(stderr, "Destroy trace failed\n");
+ goto op_err;
+ }
+
+ return 0;
+
+op_err:
+arg_error:
+ return ret;
+}
+
+int lttctl_alloc_trace(const char *name)
+{
+ int ret;
+ char ctlfname[PATH_MAX];
+
+ if (!name) {
+ fprintf(stderr, "%s: args invalid\n", __func__);
+ ret = -EINVAL;
+ goto arg_error;
+ }
+
+ ret = lttctl_check_trace(name, 1);
+ if (ret)
+ goto arg_error;
+
+ sprintf(ctlfname, "%s/ltt/control/%s/alloc", debugfsmntdir, name);
+
+ ret = lttctl_sendop(ctlfname, "1");
+ if (ret) {
+ fprintf(stderr, "Allocate trace failed\n");
+ goto op_err;
+ }
+
+ return 0;
+
+op_err:
+arg_error:
+ return ret;
+}
+
+int lttctl_start(const char *name)
+{
+ int ret;
+ char ctlfname[PATH_MAX];
+
+ if (!name) {
+ fprintf(stderr, "%s: args invalid\n", __func__);
+ ret = -EINVAL;
+ goto arg_error;
+ }
+
+ ret = lttctl_check_trace(name, 1);
+ if (ret)
+ goto arg_error;
+
+ sprintf(ctlfname, "%s/ltt/control/%s/enabled", debugfsmntdir, name);
+
+ ret = lttctl_sendop(ctlfname, "1");
+ if (ret) {
+ fprintf(stderr, "Start trace failed\n");
+ goto op_err;
+ }
+
+ return 0;
+
+op_err:
+arg_error:
+ return ret;
+}
+
+int lttctl_pause(const char *name)
+{
+ int ret;
+ char ctlfname[PATH_MAX];
+
+ if (!name) {
+ fprintf(stderr, "%s: args invalid\n", __func__);
+ ret = -EINVAL;
+ goto arg_error;
+ }
+
+ ret = lttctl_check_trace(name, 1);
+ if (ret)
+ goto arg_error;
+
+ sprintf(ctlfname, "%s/ltt/control/%s/enabled", debugfsmntdir, name);
+
+ ret = lttctl_sendop(ctlfname, "0");
+ if (ret) {
+ fprintf(stderr, "Pause trace failed\n");
+ goto op_err;
+ }
+
+ return 0;
+
+op_err:
+arg_error:
+ return ret;
+}
+
+int lttctl_set_trans(const char *name, const char *trans)
+{
+ int ret;
+ char ctlfname[PATH_MAX];
+
+ if (!name) {
+ fprintf(stderr, "%s: args invalid\n", __func__);
+ ret = -EINVAL;
+ goto arg_error;
+ }
+
+ ret = lttctl_check_trace(name, 1);
+ if (ret)
+ goto arg_error;
+
+ sprintf(ctlfname, "%s/ltt/control/%s/trans", debugfsmntdir, name);
+
+ ret = lttctl_sendop(ctlfname, trans);
+ if (ret) {
+ fprintf(stderr, "Set transport failed\n");
+ goto op_err;
+ }
+
+ return 0;
+
+op_err:
+arg_error:
+ return ret;
+}
+
+static int __lttctl_set_channel_enable(const char *name, const char *channel,
+ int enable)
+{
+ int ret;
+ char ctlfname[PATH_MAX];
+
+ sprintf(ctlfname, "%s/ltt/control/%s/channel/%s/enable", debugfsmntdir,
+ name, channel);
+
+ ret = lttctl_sendop(ctlfname, enable ? "1" : "0");
+ if (ret)
+ fprintf(stderr, "Set channel's enable mode failed\n");
+
+ return ret;
+}
+int lttctl_set_channel_enable(const char *name, const char *channel,
+ int enable)
+{
+ int ret;
+ char **channellist;
+ int n_channel;
+
+ if (!name || !channel) {
+ fprintf(stderr, "%s: args invalid\n", __func__);
+ ret = -EINVAL;
+ goto arg_error;
+ }
+
+ ret = lttctl_check_trace(name, 1);
+ if (ret)
+ goto arg_error;
+
+ if (strcmp(channel, "all")) {
+ ret = __lttctl_set_channel_enable(name, channel, enable);
+ if (ret)
+ goto op_err;
+ } else {
+ /* Don't allow set enable state for metadata channel */
+ n_channel = lttctl_get_channellist(name, &channellist, 0);
+ if (n_channel < 0) {
+ fprintf(stderr, "%s: lttctl_get_channellist failed\n",
+ __func__);
+ ret = -ENOENT;
+ goto op_err;
+ }
+
+ for (; n_channel > 0; n_channel--) {
+ ret = __lttctl_set_channel_enable(name,
+ channellist[n_channel - 1], enable);
+ if (ret)
+ goto op_err_clean;
+ }
+ lttctl_free_channellist(channellist, n_channel);
+ }
+
+ return 0;
+
+op_err_clean:
+ lttctl_free_channellist(channellist, n_channel);
+op_err:
+arg_error:
+ return ret;
+}
+
+static int __lttctl_set_channel_overwrite(const char *name, const char *channel,
+ int overwrite)
+{
+ int ret;
+ char ctlfname[PATH_MAX];
+
+ sprintf(ctlfname, "%s/ltt/control/%s/channel/%s/overwrite",
+ debugfsmntdir, name, channel);
+
+ ret = lttctl_sendop(ctlfname, overwrite ? "1" : "0");
+ if (ret)
+ fprintf(stderr, "Set channel's overwrite mode failed\n");
+
+ return ret;
+}
+int lttctl_set_channel_overwrite(const char *name, const char *channel,
+ int overwrite)
+{
+ int ret;
+ char **channellist;
+ int n_channel;
+
+ if (!name || !channel) {
+ fprintf(stderr, "%s: args invalid\n", __func__);
+ ret = -EINVAL;
+ goto arg_error;
+ }
+
+ ret = lttctl_check_trace(name, 1);
+ if (ret)
+ goto arg_error;
+
+ if (strcmp(channel, "all")) {
+ ret = __lttctl_set_channel_overwrite(name, channel, overwrite);
+ if (ret)
+ goto op_err;
+ } else {
+ /* Don't allow set overwrite for metadata channel */
+ n_channel = lttctl_get_channellist(name, &channellist, 0);
+ if (n_channel < 0) {
+ fprintf(stderr, "%s: lttctl_get_channellist failed\n",
+ __func__);
+ ret = -ENOENT;
+ goto op_err;
+ }
+
+ for (; n_channel > 0; n_channel--) {
+ ret = __lttctl_set_channel_overwrite(name,
+ channellist[n_channel - 1], overwrite);
+ if (ret)
+ goto op_err_clean;
+ }
+ lttctl_free_channellist(channellist, n_channel);
+ }
+
+ return 0;
+
+op_err_clean:
+ lttctl_free_channellist(channellist, n_channel);
+op_err:
+arg_error:
+ return ret;
+}
+
+static int __lttctl_set_channel_subbuf_num(const char *name,
+ const char *channel, unsigned subbuf_num)
+{
+ int ret;
+ char ctlfname[PATH_MAX];
+ char opstr[32];
+
+ sprintf(ctlfname, "%s/ltt/control/%s/channel/%s/subbuf_num",
+ debugfsmntdir, name, channel);
+
+ sprintf(opstr, "%u", subbuf_num);
+
+ ret = lttctl_sendop(ctlfname, opstr);
+ if (ret)
+ fprintf(stderr, "Set channel's subbuf number failed\n");
+
+ return ret;
+}
+int lttctl_set_channel_subbuf_num(const char *name, const char *channel,
+ unsigned subbuf_num)
+{
+ int ret;
+ char **channellist;
+ int n_channel;
+
+ if (!name || !channel) {
+ fprintf(stderr, "%s: args invalid\n", __func__);
+ ret = -EINVAL;
+ goto arg_error;
+ }
+
+ ret = lttctl_check_trace(name, 1);
+ if (ret)
+ goto arg_error;
+
+ if (strcmp(channel, "all")) {
+ ret = __lttctl_set_channel_subbuf_num(name, channel,
+ subbuf_num);
+ if (ret)
+ goto op_err;
+ } else {
+ /* allow set subbuf_num for metadata channel */
+ n_channel = lttctl_get_channellist(name, &channellist, 1);
+ if (n_channel < 0) {
+ fprintf(stderr, "%s: lttctl_get_channellist failed\n",
+ __func__);
+ ret = -ENOENT;
+ goto op_err;
+ }
+
+ for (; n_channel > 0; n_channel--) {
+ ret = __lttctl_set_channel_subbuf_num(name,
+ channellist[n_channel - 1], subbuf_num);
+ if (ret)
+ goto op_err_clean;
+ }
+ lttctl_free_channellist(channellist, n_channel);
+ }
+
+ return 0;
+
+op_err_clean:
+ lttctl_free_channellist(channellist, n_channel);
+op_err:
+arg_error:
+ return ret;
+}
+
+static int __lttctl_set_channel_subbuf_size(const char *name,
+ const char *channel, unsigned subbuf_size)
+{
+ int ret;
+ char ctlfname[PATH_MAX];
+ char opstr[32];
+
+ sprintf(ctlfname, "%s/ltt/control/%s/channel/%s/subbuf_size",
+ debugfsmntdir, name, channel);
+
+ sprintf(opstr, "%u", subbuf_size);
+
+ ret = lttctl_sendop(ctlfname, opstr);
+ if (ret)
+ fprintf(stderr, "Set channel's subbuf size failed\n");
+}
+int lttctl_set_channel_subbuf_size(const char *name, const char *channel,
+ unsigned subbuf_size)
+{
+ int ret;
+ char **channellist;
+ int n_channel;
+
+ if (!name || !channel) {
+ fprintf(stderr, "%s: args invalid\n", __func__);
+ ret = -EINVAL;
+ goto arg_error;
+ }
+
+ ret = lttctl_check_trace(name, 1);
+ if (ret)
+ goto arg_error;
+
+ if (strcmp(channel, "all")) {
+ ret = __lttctl_set_channel_subbuf_size(name, channel,
+ subbuf_size);
+ if (ret)
+ goto op_err;
+ } else {
+ /* allow set subbuf_size for metadata channel */
+ n_channel = lttctl_get_channellist(name, &channellist, 1);
+ if (n_channel < 0) {
+ fprintf(stderr, "%s: lttctl_get_channellist failed\n",
+ __func__);
+ ret = -ENOENT;
+ goto op_err;
+ }
+
+ for (; n_channel > 0; n_channel--) {
+ ret = __lttctl_set_channel_subbuf_size(name,
+ channellist[n_channel - 1], subbuf_size);
+ if (ret)
+ goto op_err_clean;
+ }
+ lttctl_free_channellist(channellist, n_channel);
+ }
+
+ return 0;
+
+op_err_clean:
+ lttctl_free_channellist(channellist, n_channel);
+op_err:
+arg_error:
+ return ret;
+}
+
+int getdebugfsmntdir(char *mntdir)
+{
+ char mnt_dir[PATH_MAX];
+ char mnt_type[PATH_MAX];
+ int trymount_done = 0;
+
+ FILE *fp = fopen("/proc/mounts", "r");
+ if (!fp)
+ return -EINVAL;
+
+find_again:
+ while (1) {
+ if (fscanf(fp, "%*s %s %s %*s %*s %*s", mnt_dir, mnt_type) <= 0)
+ break;
+
+ if (!strcmp(mnt_type, "debugfs")) {
+ strcpy(mntdir, mnt_dir);
+ return 0;
+ }
+ }
+
+ if (!trymount_done) {
+ mount("debugfs", "/sys/kernel/debug/", "debugfs", 0, NULL);
+ trymount_done = 1;
+ goto find_again;
+ }
+
+ return -ENOENT;
+}
projects / ltt-control.git / blobdiff