/*
* Adding channel using the lttng API.
*/
static int enable_channel(char *session_name)
{
struct lttng_channel *channel = NULL;
int ret = CMD_SUCCESS, warn = 0, error = 0, success = 0;
char *channel_name;
struct lttng_domain dom;
memset(&dom, 0, sizeof(dom));
/* Validate options. */
if (opt_kernel) {
if (opt_blocking_timeout.set) {
ERR("Retry timeout option not supported for kernel domain (-k)");
ret = CMD_ERROR;
goto error;
}
}
/* Create lttng domain */
if (opt_kernel) {
dom.type = LTTNG_DOMAIN_KERNEL;
dom.buf_type = LTTNG_BUFFER_GLOBAL;
if (opt_buffer_uid || opt_buffer_pid) {
ERR("Buffer type not supported for domain -k");
ret = CMD_ERROR;
goto error;
}
} else if (opt_userspace) {
dom.type = LTTNG_DOMAIN_UST;
if (opt_buffer_pid) {
dom.buf_type = LTTNG_BUFFER_PER_PID;
} else {
if (opt_buffer_global) {
ERR("Buffer type not supported for domain -u");
ret = CMD_ERROR;
goto error;
}
dom.buf_type = LTTNG_BUFFER_PER_UID;
}
} else {
/* Checked by the caller. */
assert(0);
}
set_default_attr(&dom);
if (chan_opts.attr.tracefile_size == 0 && chan_opts.attr.tracefile_count) {
ERR("Missing option --tracefile-size. "
"A file count without a size won't do anything.");
ret = CMD_ERROR;
goto error;
}
if ((chan_opts.attr.tracefile_size > 0) &&
(chan_opts.attr.tracefile_size < chan_opts.attr.subbuf_size)) {
WARN("Tracefile size rounded up from (%" PRIu64 ") to subbuffer size (%" PRIu64 ")",
chan_opts.attr.tracefile_size, chan_opts.attr.subbuf_size);
chan_opts.attr.tracefile_size = chan_opts.attr.subbuf_size;
}
/* Setting channel output */
if (opt_output) {
if (!strncmp(output_mmap, opt_output, strlen(output_mmap))) {
chan_opts.attr.output = LTTNG_EVENT_MMAP;
} else if (!strncmp(output_splice, opt_output, strlen(output_splice))) {
chan_opts.attr.output = LTTNG_EVENT_SPLICE;
} else {
ERR("Unknown output type %s. Possible values are: %s, %s\n",
opt_output, output_mmap, output_splice);
ret = CMD_ERROR;
goto error;
}
}
handle = lttng_create_handle(session_name, &dom);
if (handle == NULL) {
ret = -1;
goto error;
}
/* Mi open channels element */
if (lttng_opt_mi) {
assert(writer);
ret = mi_lttng_channels_open(writer);
if (ret) {
ret = CMD_ERROR;
goto error;
}
}
/* Strip channel list (format: chan1,chan2,...) */
channel_name = strtok(opt_channels, ",");
while (channel_name != NULL) {
void *extended_ptr;
/* Validate channel name's length */
if (strlen(channel_name) >= sizeof(chan_opts.name)) {
ERR("Channel name is too long (max. %zu characters)",
sizeof(chan_opts.name) - 1);
error = 1;
goto skip_enable;
}
/*
* A dynamically-allocated channel is used in order to allow
* the configuration of extended attributes (post-2.9).
*/
channel = lttng_channel_create(&dom);
if (!channel) {
ERR("Unable to create channel object");
error = 1;
goto error;
}
/* Copy channel name */
strcpy(channel->name, channel_name);
channel->enabled = 1;
extended_ptr = channel->attr.extended.ptr;
memcpy(&channel->attr, &chan_opts.attr, sizeof(chan_opts.attr));
channel->attr.extended.ptr = extended_ptr;
if (opt_monitor_timer.set) {
ret = lttng_channel_set_monitor_timer_interval(channel,
opt_monitor_timer.interval);
if (ret) {
ERR("Failed to set the channel's monitor timer interval");
error = 1;
goto error;
}
}
if (opt_blocking_timeout.set) {
ret = lttng_channel_set_blocking_timeout(channel,
opt_blocking_timeout.value);
if (ret) {
ERR("Failed to set the channel's blocking timeout");
error = 1;
goto error;
}
}
DBG("Enabling channel %s", channel_name);
ret = lttng_enable_channel(handle, channel);
if (ret < 0) {
success = 0;
switch (-ret) {
case LTTNG_ERR_KERN_CHAN_EXIST:
case LTTNG_ERR_UST_CHAN_EXIST:
case LTTNG_ERR_CHAN_EXIST:
WARN("Channel %s: %s (session %s)", channel_name,
lttng_strerror(ret), session_name);
warn = 1;
break;
case LTTNG_ERR_INVALID_CHANNEL_NAME:
ERR("Invalid channel name: \"%s\". "
"Channel names may not start with '.', and "
"may not contain '/'.", channel_name);
error = 1;
break;
default:
ERR("Channel %s: %s (session %s)", channel_name,
lttng_strerror(ret), session_name);
error = 1;
break;
}
} else {
MSG("%s channel %s enabled for session %s",
get_domain_str(dom.type), channel_name, session_name);
success = 1;
}
skip_enable:
if (lttng_opt_mi) {
/* Mi print the channel element and leave it open */
ret = mi_lttng_channel(writer, channel, 1);
if (ret) {
ret = CMD_ERROR;
goto error;
}
/* Individual Success ? */
ret = mi_lttng_writer_write_element_bool(writer,
mi_lttng_element_command_success, success);
if (ret) {
ret = CMD_ERROR;
goto error;
}
/* Close channel element */
ret = mi_lttng_writer_close_element(writer);
if (ret) {
ret = CMD_ERROR;
goto error;
}
}
/* Next channel */
channel_name = strtok(NULL, ",");
lttng_channel_destroy(channel);
channel = NULL;
}
if (lttng_opt_mi) {
/* Close channels element */
ret = mi_lttng_writer_close_element(writer);
if (ret) {
ret = CMD_ERROR;
goto error;
}
}
ret = CMD_SUCCESS;
error:
if (channel) {
lttng_channel_destroy(channel);
}
/* If more important error happen bypass the warning */
if (!ret && warn) {
ret = CMD_WARNING;
}
/* If more important error happen bypass the warning */
if (!ret && error) {
ret = CMD_ERROR;
}
lttng_destroy_handle(handle);
return ret;
}
static
int lttng_abi_create_channel(struct file *session_file,
struct lttng_kernel_channel *chan_param,
enum channel_type channel_type)
{
struct lttng_session *session = session_file->private_data;
const struct file_operations *fops = NULL;
const char *transport_name;
struct lttng_channel *chan;
struct file *chan_file;
int chan_fd;
int ret = 0;
chan_fd = lttng_get_unused_fd();
if (chan_fd < 0) {
ret = chan_fd;
goto fd_error;
}
switch (channel_type) {
case PER_CPU_CHANNEL:
fops = <tng_channel_fops;
break;
case METADATA_CHANNEL:
fops = <tng_metadata_fops;
break;
}
chan_file = anon_inode_getfile("[lttng_channel]",
fops,
NULL, O_RDWR);
if (IS_ERR(chan_file)) {
ret = PTR_ERR(chan_file);
goto file_error;
}
switch (channel_type) {
case PER_CPU_CHANNEL:
if (chan_param->output == LTTNG_KERNEL_SPLICE) {
transport_name = chan_param->overwrite ?
"relay-overwrite" : "relay-discard";
} else if (chan_param->output == LTTNG_KERNEL_MMAP) {
transport_name = chan_param->overwrite ?
"relay-overwrite-mmap" : "relay-discard-mmap";
} else {
return -EINVAL;
}
break;
case METADATA_CHANNEL:
if (chan_param->output == LTTNG_KERNEL_SPLICE)
transport_name = "relay-metadata";
else if (chan_param->output == LTTNG_KERNEL_MMAP)
transport_name = "relay-metadata-mmap";
else
return -EINVAL;
break;
default:
transport_name = "<unknown>";
break;
}
if (atomic_long_add_unless(&session_file->f_count,
1, INT_MAX) == INT_MAX) {
goto refcount_error;
}
/*
* We tolerate no failure path after channel creation. It will stay
* invariant for the rest of the session.
*/
chan = lttng_channel_create(session, transport_name, NULL,
chan_param->subbuf_size,
chan_param->num_subbuf,
chan_param->switch_timer_interval,
chan_param->read_timer_interval,
channel_type);
if (!chan) {
ret = -EINVAL;
goto chan_error;
}
chan->file = chan_file;
chan_file->private_data = chan;
fd_install(chan_fd, chan_file);
return chan_fd;
chan_error:
atomic_long_dec(&session_file->f_count);
refcount_error:
fput(chan_file);
file_error:
put_unused_fd(chan_fd);
fd_error:
return ret;
}