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/*
* Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013 Nicira, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at:
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <config.h>
#include "unixctl.h"
#include <errno.h>
#include <unistd.h>
#include "coverage.h"
#include "dirs.h"
#include "dynamic-string.h"
#include "json.h"
#include "jsonrpc.h"
#include "list.h"
#include "poll-loop.h"
#include "shash.h"
#include "stream.h"
#include "stream-provider.h"
#include "svec.h"
#include "vlog.h"
VLOG_DEFINE_THIS_MODULE(unixctl);
COVERAGE_DEFINE(unixctl_received);
COVERAGE_DEFINE(unixctl_replied);
struct unixctl_command {
const char *usage;
int min_args, max_args;
unixctl_cb_func *cb;
void *aux;
};
struct unixctl_conn {
struct list node;
struct jsonrpc *rpc;
/* Only one request can be in progress at a time. While the request is
* being processed, 'request_id' is populated, otherwise it is null. */
struct json *request_id; /* ID of the currently active request. */
};
/* Server for control connection. */
struct unixctl_server {
struct pstream *listener;
struct list conns;
};
static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(5, 5);
static struct shash commands = SHASH_INITIALIZER(&commands);
static void
unixctl_help(struct unixctl_conn *conn, int argc OVS_UNUSED,
const char *argv[] OVS_UNUSED, void *aux OVS_UNUSED)
{
struct ds ds = DS_EMPTY_INITIALIZER;
const struct shash_node **nodes = shash_sort(&commands);
size_t i;
ds_put_cstr(&ds, "The available commands are:\n");
for (i = 0; i < shash_count(&commands); i++) {
const struct shash_node *node = nodes[i];
const struct unixctl_command *command = node->data;
ds_put_format(&ds, " %-23s %s\n", node->name, command->usage);
}
free(nodes);
unixctl_command_reply(conn, ds_cstr(&ds));
ds_destroy(&ds);
}
static void
unixctl_version(struct unixctl_conn *conn, int argc OVS_UNUSED,
const char *argv[] OVS_UNUSED, void *aux OVS_UNUSED)
{
unixctl_command_reply(conn, get_program_version());
}
/* Registers a unixctl command with the given 'name'. 'usage' describes the
* arguments to the command; it is used only for presentation to the user in
* "help" output.
*
* 'cb' is called when the command is received. It is passed an array
* containing the command name and arguments, plus a copy of 'aux'. Normally
* 'cb' should reply by calling unixctl_command_reply() or
* unixctl_command_reply_error() before it returns, but if the command cannot
* be handled immediately then it can defer the reply until later. A given
* connection can only process a single request at a time, so a reply must be
* made eventually to avoid blocking that connection. */
void
unixctl_command_register(const char *name, const char *usage,
int min_args, int max_args,
unixctl_cb_func *cb, void *aux)
{
struct unixctl_command *command;
struct unixctl_command *lookup = shash_find_data(&commands, name);
ovs_assert(!lookup || lookup->cb == cb);
if (lookup) {
return;
}
command = xmalloc(sizeof *command);
command->usage = usage;
command->min_args = min_args;
command->max_args = max_args;
command->cb = cb;
command->aux = aux;
shash_add(&commands, name, command);
}
static void
unixctl_command_reply__(struct unixctl_conn *conn,
bool success, const char *body)
{
struct json *body_json;
struct jsonrpc_msg *reply;
COVERAGE_INC(unixctl_replied);
ovs_assert(conn->request_id);
if (!body) {
body = "";
}
if (body[0] && body[strlen(body) - 1] != '\n') {
body_json = json_string_create_nocopy(xasprintf("%s\n", body));
} else {
body_json = json_string_create(body);
}
if (success) {
reply = jsonrpc_create_reply(body_json, conn->request_id);
} else {
reply = jsonrpc_create_error(body_json, conn->request_id);
}
/* If jsonrpc_send() returns an error, the run loop will take care of the
* problem eventually. */
jsonrpc_send(conn->rpc, reply);
json_destroy(conn->request_id);
conn->request_id = NULL;
}
/* Replies to the active unixctl connection 'conn'. 'result' is sent to the
* client indicating the command was processed successfully. Only one call to
* unixctl_command_reply() or unixctl_command_reply_error() may be made per
* request. */
void
unixctl_command_reply(struct unixctl_conn *conn, const char *result)
{
unixctl_command_reply__(conn, true, result);
}
/* Replies to the active unixctl connection 'conn'. 'error' is sent to the
* client indicating an error occurred processing the command. Only one call to
* unixctl_command_reply() or unixctl_command_reply_error() may be made per
* request. */
void
unixctl_command_reply_error(struct unixctl_conn *conn, const char *error)
{
unixctl_command_reply__(conn, false, error);
}
/* Creates a unixctl server listening on 'path', which for POSIX may be:
*
* - NULL, in which case <rundir>/<program>.<pid>.ctl is used.
*
* - A name that does not start with '/', in which case it is put in
* <rundir>.
*
* - An absolute path (starting with '/') that gives the exact name of
* the Unix domain socket to listen on.
*
* For Windows, a kernel assigned TCP port is used and written in 'path'
* which may be:
*
* - NULL, in which case <rundir>/<program>.ctl is used.
*
* - An absolute path that gives the name of the file.
*
* For both POSIX and Windows, if the path is "none", the function will
* return successfully but no socket will actually be created.
*
* A program that (optionally) daemonizes itself should call this function
* *after* daemonization, so that the socket name contains the pid of the
* daemon instead of the pid of the program that exited. (Otherwise,
* "ovs-appctl --target=<program>" will fail.)
*
* Returns 0 if successful, otherwise a positive errno value. If successful,
* sets '*serverp' to the new unixctl_server (or to NULL if 'path' was "none"),
* otherwise to NULL. */
int
unixctl_server_create(const char *path, struct unixctl_server **serverp)
{
struct unixctl_server *server;
struct pstream *listener;
char *punix_path;
int error;
*serverp = NULL;
if (path && !strcmp(path, "none")) {
return 0;
}
if (path) {
char *abs_path;
#ifndef _WIN32
abs_path = abs_file_name(ovs_rundir(), path);
#else
abs_path = strdup(path);
#endif
punix_path = xasprintf("punix:%s", abs_path);
free(abs_path);
} else {
#ifndef _WIN32
punix_path = xasprintf("punix:%s/%s.%ld.ctl", ovs_rundir(),
program_name, (long int) getpid());
#else
punix_path = xasprintf("punix:%s/%s.ctl", ovs_rundir(), program_name);
#endif
}
error = pstream_open(punix_path, &listener, 0);
if (error) {
ovs_error(error, "could not initialize control socket %s", punix_path);
goto exit;
}
unixctl_command_register("help", "", 0, 0, unixctl_help, NULL);
unixctl_command_register("version", "", 0, 0, unixctl_version, NULL);
server = xmalloc(sizeof *server);
server->listener = listener;
list_init(&server->conns);
*serverp = server;
exit:
free(punix_path);
return error;
}
static void
process_command(struct unixctl_conn *conn, struct jsonrpc_msg *request)
{
char *error = NULL;
struct unixctl_command *command;
struct json_array *params;
COVERAGE_INC(unixctl_received);
conn->request_id = json_clone(request->id);
params = json_array(request->params);
command = shash_find_data(&commands, request->method);
if (!command) {
error = xasprintf("\"%s\" is not a valid command", request->method);
} else if (params->n < command->min_args) {
error = xasprintf("\"%s\" command requires at least %d arguments",
request->method, command->min_args);
} else if (params->n > command->max_args) {
error = xasprintf("\"%s\" command takes at most %d arguments",
request->method, command->max_args);
} else {
struct svec argv = SVEC_EMPTY_INITIALIZER;
int i;
svec_add(&argv, request->method);
for (i = 0; i < params->n; i++) {
if (params->elems[i]->type != JSON_STRING) {
error = xasprintf("\"%s\" command has non-string argument",
request->method);
break;
}
svec_add(&argv, json_string(params->elems[i]));
}
svec_terminate(&argv);
if (!error) {
command->cb(conn, argv.n, (const char **) argv.names,
command->aux);
}
svec_destroy(&argv);
}
if (error) {
unixctl_command_reply_error(conn, error);
free(error);
}
}
static int
run_connection(struct unixctl_conn *conn)
{
int error, i;
jsonrpc_run(conn->rpc);
error = jsonrpc_get_status(conn->rpc);
if (error || jsonrpc_get_backlog(conn->rpc)) {
return error;
}
for (i = 0; i < 10; i++) {
struct jsonrpc_msg *msg;
if (error || conn->request_id) {
break;
}
jsonrpc_recv(conn->rpc, &msg);
if (msg) {
if (msg->type == JSONRPC_REQUEST) {
process_command(conn, msg);
} else {
VLOG_WARN_RL(&rl, "%s: received unexpected %s message",
jsonrpc_get_name(conn->rpc),
jsonrpc_msg_type_to_string(msg->type));
error = EINVAL;
}
jsonrpc_msg_destroy(msg);
}
error = error ? error : jsonrpc_get_status(conn->rpc);
}
return error;
}
static void
kill_connection(struct unixctl_conn *conn)
{
list_remove(&conn->node);
jsonrpc_close(conn->rpc);
json_destroy(conn->request_id);
free(conn);
}
void
unixctl_server_run(struct unixctl_server *server)
{
struct unixctl_conn *conn, *next;
int i;
if (!server) {
return;
}
for (i = 0; i < 10; i++) {
struct stream *stream;
int error;
error = pstream_accept(server->listener, &stream);
if (!error) {
struct unixctl_conn *conn = xzalloc(sizeof *conn);
list_push_back(&server->conns, &conn->node);
conn->rpc = jsonrpc_open(stream);
} else if (error == EAGAIN) {
break;
} else {
VLOG_WARN_RL(&rl, "%s: accept failed: %s",
pstream_get_name(server->listener),
ovs_strerror(error));
}
}
LIST_FOR_EACH_SAFE (conn, next, node, &server->conns) {
int error = run_connection(conn);
if (error && error != EAGAIN) {
kill_connection(conn);
}
}
}
void
unixctl_server_wait(struct unixctl_server *server)
{
struct unixctl_conn *conn;
if (!server) {
return;
}
pstream_wait(server->listener);
LIST_FOR_EACH (conn, node, &server->conns) {
jsonrpc_wait(conn->rpc);
if (!jsonrpc_get_backlog(conn->rpc)) {
jsonrpc_recv_wait(conn->rpc);
}
}
}
/* Destroys 'server' and stops listening for connections. */
void
unixctl_server_destroy(struct unixctl_server *server)
{
if (server) {
struct unixctl_conn *conn, *next;
LIST_FOR_EACH_SAFE (conn, next, node, &server->conns) {
kill_connection(conn);
}
pstream_close(server->listener);
free(server);
}
}
/* On POSIX based systems, connects to a unixctl server socket. 'path' should
* be the name of a unixctl server socket. If it does not start with '/', it
* will be prefixed with the rundir (e.g. /usr/local/var/run/openvswitch).
*
* On Windows, connects to a localhost TCP port as written inside 'path'.
* 'path' should be an absolute path of the file.
*
* Returns 0 if successful, otherwise a positive errno value. If successful,
* sets '*client' to the new jsonrpc, otherwise to NULL. */
int
unixctl_client_create(const char *path, struct jsonrpc **client)
{
char *abs_path, *unix_path;
struct stream *stream;
int error;
#ifdef _WIN32
abs_path = strdup(path);
#else
abs_path = abs_file_name(ovs_rundir(), path);
#endif
unix_path = xasprintf("unix:%s", abs_path);
*client = NULL;
error = stream_open_block(stream_open(unix_path, &stream, DSCP_DEFAULT),
&stream);
free(unix_path);
free(abs_path);
if (error) {
VLOG_WARN("failed to connect to %s", path);
return error;
}
*client = jsonrpc_open(stream);
return 0;
}
/* Executes 'command' on the server with an argument vector 'argv' containing
* 'argc' elements. If successfully communicated with the server, returns 0
* and sets '*result', or '*err' (not both) to the result or error the server
* returned. Otherwise, sets '*result' and '*err' to NULL and returns a
* positive errno value. The caller is responsible for freeing '*result' or
* '*err' if not NULL. */
int
unixctl_client_transact(struct jsonrpc *client, const char *command, int argc,
char *argv[], char **result, char **err)
{
struct jsonrpc_msg *request, *reply;
struct json **json_args, *params;
int error, i;
*result = NULL;
*err = NULL;
json_args = xmalloc(argc * sizeof *json_args);
for (i = 0; i < argc; i++) {
json_args[i] = json_string_create(argv[i]);
}
params = json_array_create(json_args, argc);
request = jsonrpc_create_request(command, params, NULL);
error = jsonrpc_transact_block(client, request, &reply);
if (error) {
VLOG_WARN("error communicating with %s: %s", jsonrpc_get_name(client),
ovs_retval_to_string(error));
return error;
}
if (reply->error) {
if (reply->error->type == JSON_STRING) {
*err = xstrdup(json_string(reply->error));
} else {
VLOG_WARN("%s: unexpected error type in JSON RPC reply: %s",
jsonrpc_get_name(client),
json_type_to_string(reply->error->type));
error = EINVAL;
}
} else if (reply->result) {
if (reply->result->type == JSON_STRING) {
*result = xstrdup(json_string(reply->result));
} else {
VLOG_WARN("%s: unexpected result type in JSON rpc reply: %s",
jsonrpc_get_name(client),
json_type_to_string(reply->result->type));
error = EINVAL;
}
}
jsonrpc_msg_destroy(reply);
return error;
}
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