src/spawn/spawn_client.c
// SPDX-License-Identifier: GPL-3.0-or-later
#include "spawn.h"
static uv_process_t process;
static uv_pipe_t spawn_channel;
static uv_loop_t *loop;
uv_async_t spawn_async;
static char prot_buffer[MAX_COMMAND_LENGTH];
static unsigned prot_buffer_len = 0;
static void async_cb(uv_async_t *handle)
{
uv_stop(handle->loop);
}
static void after_pipe_write(uv_write_t* req, int status)
{
(void)status;
#ifdef SPAWN_DEBUG
netdata_log_info("CLIENT %s called status=%d", __func__, status);
#endif
void **data = req->data;
freez(data[0]);
freez(data[1]);
freez(data);
}
static void client_parse_spawn_protocol(unsigned source_len, char *source)
{
unsigned required_len;
struct spawn_prot_header *header;
struct spawn_prot_spawn_result *spawn_result;
struct spawn_prot_cmd_exit_status *exit_status;
struct spawn_cmd_info *cmdinfo;
while (source_len) {
required_len = sizeof(*header);
if (prot_buffer_len < required_len)
copy_to_prot_buffer(prot_buffer, &prot_buffer_len, required_len - prot_buffer_len, &source, &source_len);
if (prot_buffer_len < required_len)
return; /* Source buffer ran out */
header = (struct spawn_prot_header *)prot_buffer;
cmdinfo = (struct spawn_cmd_info *)header->handle;
fatal_assert(NULL != cmdinfo);
switch(header->opcode) {
case SPAWN_PROT_SPAWN_RESULT:
required_len += sizeof(*spawn_result);
if (prot_buffer_len < required_len)
copy_to_prot_buffer(prot_buffer, &prot_buffer_len, required_len - prot_buffer_len, &source, &source_len);
if (prot_buffer_len < required_len)
return; /* Source buffer ran out */
spawn_result = (struct spawn_prot_spawn_result *)(header + 1);
uv_mutex_lock(&cmdinfo->mutex);
cmdinfo->pid = spawn_result->exec_pid;
if (0 == cmdinfo->pid) { /* Failed to spawn */
#ifdef SPAWN_DEBUG
netdata_log_info("CLIENT %s SPAWN_PROT_SPAWN_RESULT failed to spawn.", __func__);
#endif
cmdinfo->flags |= SPAWN_CMD_FAILED_TO_SPAWN | SPAWN_CMD_DONE;
uv_cond_signal(&cmdinfo->cond);
} else {
cmdinfo->exec_run_timestamp = spawn_result->exec_run_timestamp;
cmdinfo->flags |= SPAWN_CMD_IN_PROGRESS;
#ifdef SPAWN_DEBUG
netdata_log_info("CLIENT %s SPAWN_PROT_SPAWN_RESULT in progress.", __func__);
#endif
}
uv_mutex_unlock(&cmdinfo->mutex);
prot_buffer_len = 0;
break;
case SPAWN_PROT_CMD_EXIT_STATUS:
required_len += sizeof(*exit_status);
if (prot_buffer_len < required_len)
copy_to_prot_buffer(prot_buffer, &prot_buffer_len, required_len - prot_buffer_len, &source, &source_len);
if (prot_buffer_len < required_len)
return; /* Source buffer ran out */
exit_status = (struct spawn_prot_cmd_exit_status *)(header + 1);
uv_mutex_lock(&cmdinfo->mutex);
cmdinfo->exit_status = exit_status->exec_exit_status;
#ifdef SPAWN_DEBUG
netdata_log_info("CLIENT %s SPAWN_PROT_CMD_EXIT_STATUS %d.", __func__, exit_status->exec_exit_status);
#endif
cmdinfo->flags |= SPAWN_CMD_DONE;
uv_cond_signal(&cmdinfo->cond);
uv_mutex_unlock(&cmdinfo->mutex);
prot_buffer_len = 0;
break;
default:
fatal_assert(0);
break;
}
}
}
static void on_pipe_read(uv_stream_t* pipe, ssize_t nread, const uv_buf_t* buf)
{
if (0 == nread) {
netdata_log_info("%s: Zero bytes read from spawn pipe.", __func__);
} else if (UV_EOF == nread) {
netdata_log_info("EOF found in spawn pipe.");
} else if (nread < 0) {
netdata_log_error("%s: %s", __func__, uv_strerror(nread));
}
if (nread < 0) { /* stop stream due to EOF or error */
(void)uv_read_stop((uv_stream_t *)pipe);
} else if (nread) {
#ifdef SPAWN_DEBUG
netdata_log_info("CLIENT %s read %u", __func__, (unsigned)nread);
#endif
client_parse_spawn_protocol(nread, buf->base);
}
if (buf && buf->len) {
freez(buf->base);
}
if (nread < 0) {
uv_close((uv_handle_t *)pipe, NULL);
}
}
static void on_read_alloc(uv_handle_t* handle,
size_t suggested_size,
uv_buf_t* buf)
{
(void)handle;
buf->base = mallocz(suggested_size);
buf->len = suggested_size;
}
static void spawn_process_cmd(struct spawn_cmd_info *cmdinfo)
{
int ret;
uv_buf_t *writebuf;
struct write_context *write_ctx;
void **data = callocz(2, sizeof(void *));
writebuf = callocz(3, sizeof(uv_buf_t));
write_ctx = callocz(1, sizeof(*write_ctx));
data[0] = write_ctx;
data[1] = writebuf;
write_ctx->write_req.data = data;
uv_mutex_lock(&cmdinfo->mutex);
cmdinfo->flags |= SPAWN_CMD_PROCESSED;
uv_mutex_unlock(&cmdinfo->mutex);
write_ctx->header.opcode = SPAWN_PROT_EXEC_CMD;
write_ctx->header.handle = cmdinfo;
write_ctx->payload.command_length = strlen(cmdinfo->command_to_run);
writebuf[0] = uv_buf_init((char *)&write_ctx->header, sizeof(write_ctx->header));
writebuf[1] = uv_buf_init((char *)&write_ctx->payload, sizeof(write_ctx->payload));
writebuf[2] = uv_buf_init((char *)cmdinfo->command_to_run, write_ctx->payload.command_length);
#ifdef SPAWN_DEBUG
netdata_log_info("CLIENT %s SPAWN_PROT_EXEC_CMD %u", __func__, (unsigned)cmdinfo->serial);
#endif
ret = uv_write(&write_ctx->write_req, (uv_stream_t *)&spawn_channel, writebuf, 3, after_pipe_write);
fatal_assert(ret == 0);
}
void spawn_client(void *arg)
{
uv_thread_set_name_np("DAEMON_SPAWN");
int ret;
struct completion *completion = (struct completion *)arg;
loop = mallocz(sizeof(uv_loop_t));
ret = uv_loop_init(loop);
if (ret) {
netdata_log_error("uv_loop_init(): %s", uv_strerror(ret));
spawn_thread_error = ret;
goto error_after_loop_init;
}
loop->data = NULL;
spawn_async.data = NULL;
ret = uv_async_init(loop, &spawn_async, async_cb);
if (ret) {
netdata_log_error("uv_async_init(): %s", uv_strerror(ret));
spawn_thread_error = ret;
goto error_after_async_init;
}
ret = uv_pipe_init(loop, &spawn_channel, 1);
if (ret) {
netdata_log_error("uv_pipe_init(): %s", uv_strerror(ret));
spawn_thread_error = ret;
goto error_after_pipe_init;
}
fatal_assert(spawn_channel.ipc);
ret = create_spawn_server(loop, &spawn_channel, &process);
if (ret) {
netdata_log_error("Failed to fork spawn server process.");
spawn_thread_error = ret;
goto error_after_spawn_server;
}
spawn_thread_error = 0;
spawn_thread_shutdown = 0;
/* wake up initialization thread */
completion_mark_complete(completion);
prot_buffer_len = 0;
ret = uv_read_start((uv_stream_t *)&spawn_channel, on_read_alloc, on_pipe_read);
fatal_assert(ret == 0);
while (spawn_thread_shutdown == 0) {
struct spawn_cmd_info *cmdinfo;
uv_run(loop, UV_RUN_DEFAULT);
while (NULL != (cmdinfo = spawn_get_unprocessed_cmd())) {
spawn_process_cmd(cmdinfo);
}
}
/* cleanup operations of the event loop */
netdata_log_info("Shutting down spawn client event loop.");
uv_close((uv_handle_t *)&spawn_channel, NULL);
uv_close((uv_handle_t *)&spawn_async, NULL);
uv_run(loop, UV_RUN_DEFAULT); /* flush all libuv handles */
netdata_log_info("Shutting down spawn client loop complete.");
fatal_assert(0 == uv_loop_close(loop));
return;
error_after_spawn_server:
uv_close((uv_handle_t *)&spawn_channel, NULL);
error_after_pipe_init:
uv_close((uv_handle_t *)&spawn_async, NULL);
error_after_async_init:
uv_run(loop, UV_RUN_DEFAULT); /* flush all libuv handles */
fatal_assert(0 == uv_loop_close(loop));
error_after_loop_init:
freez(loop);
/* wake up initialization thread */
completion_mark_complete(completion);
}