(Netplay) Refactor fork arguments (#14208)

network/netplay/netplay.h

@@ -36,6 +36,10 @@
 
 #include "../natt.h"
 
+#ifndef HAVE_DYNAMIC
+#define NETPLAY_FORK_MAX_ARGS 64
+#endif
+
 #define NETPLAY_NICK_LEN         32
 #define NETPLAY_HOST_STR_LEN     32
 #define NETPLAY_HOST_LONGSTR_LEN 256
@@ -59,8 +63,8 @@ enum rarch_netplay_ctl_state
    RARCH_NETPLAY_CTL_ENABLE_CLIENT,
    RARCH_NETPLAY_CTL_DISABLE,
 #ifndef HAVE_DYNAMIC
+   RARCH_NETPLAY_CTL_ADD_FORK_ARG,
    RARCH_NETPLAY_CTL_GET_FORK_ARGS,
-   RARCH_NETPLAY_CTL_SET_FORK_ARGS,
    RARCH_NETPLAY_CTL_CLEAR_FORK_ARGS,
 #endif
    RARCH_NETPLAY_CTL_REFRESH_CLIENT_INFO,
@@ -162,6 +166,14 @@ typedef struct mitm_server
    enum msg_hash_enums description;
 } mitm_server_t;
 
+#ifndef HAVE_DYNAMIC
+struct netplay_fork_args
+{
+   size_t size;
+   char   args[PATH_MAX_LENGTH];
+};
+#endif
+
 struct netplay_room
 {
    struct netplay_room *next;
@@ -230,6 +242,9 @@ struct netplay_chat_buffer
 
 typedef struct
 {
+#ifndef HAVE_DYNAMIC
+   struct netplay_fork_args fork_args;
+#endif
    /* NAT traversal info (if NAT traversal is used and serving) */
    struct nat_traversal_data nat_traversal_request;
 #ifdef HAVE_NETPLAYDISCOVERY
@@ -254,9 +269,6 @@ typedef struct
    unsigned server_port_deferred;
    char server_address_deferred[256];
    char server_session_deferred[32];
-#ifndef HAVE_DYNAMIC
-   char netplay_fork_args[PATH_MAX_LENGTH];
-#endif
    bool netplay_client_deferred;
    /* Only used before init_netplay */
    bool netplay_enabled;

network/netplay/netplay_frontend.c

@@ -8988,24 +8988,49 @@ bool netplay_driver_ctl(enum rarch_netplay_ctl_state state, void *data)
          break;
 
 #ifndef HAVE_DYNAMIC
-      case RARCH_NETPLAY_CTL_GET_FORK_ARGS:
+      case RARCH_NETPLAY_CTL_ADD_FORK_ARG:
-         if (data && !string_is_empty(net_st->netplay_fork_args))
+         if (data && net_st->fork_args.size < sizeof(net_st->fork_args.args))
-            strlcpy((char*)data, net_st->netplay_fork_args,
+         {
-               sizeof(net_st->netplay_fork_args));
+            size_t new_size = strlcpy(
+               net_st->fork_args.args + net_st->fork_args.size,
+               (const char*)data,
+               sizeof(net_st->fork_args.args) - net_st->fork_args.size);
+            new_size       += 1; /* NULL terminator */
+            new_size       += net_st->fork_args.size;
+            if (new_size > sizeof(net_st->fork_args.args))
+            {
+               ret = false;
+               break;
+            }
+            net_st->fork_args.size = new_size;
+         }
          else
             ret = false;
          break;
 
-      case RARCH_NETPLAY_CTL_SET_FORK_ARGS:
+      case RARCH_NETPLAY_CTL_GET_FORK_ARGS:
-         if (data)
+         if (data && net_st->fork_args.size)
-            strlcpy(net_st->netplay_fork_args, (const char*)data,
+         {
-               sizeof(net_st->netplay_fork_args));
+            size_t offset   = 0;
+            char  *args     = net_st->fork_args.args;
+            size_t args_sz  = net_st->fork_args.size;
+            char **args_cur = (char**)data;
+            char **args_end = &args_cur[NETPLAY_FORK_MAX_ARGS - 1];
+            for (; offset < args_sz && args_cur != args_end; args_cur++)
+            {
+               *args_cur = args + offset;
+               offset   += strlen(*args_cur) + 1;
+            }
+            /* Ensure that the final entry is NULL. */
+            *args_cur = NULL;
+         }
          else
             ret = false;
          break;
 
       case RARCH_NETPLAY_CTL_CLEAR_FORK_ARGS:
-         *net_st->netplay_fork_args = '\0';
+         net_st->fork_args.size  = 0;
+         *net_st->fork_args.args = '\0';
          break;
 #endif
 

tasks/task_netplay_find_content.c

@@ -451,31 +451,29 @@ finished:
 }
 
 #ifndef HAVE_DYNAMIC
-static void static_load(const char *core, const char *subsystem,
+static bool static_load(const char *core, const char *subsystem,
       const void *content, const char *hostname)
 {
-   char buf[512];
+#define ARG(arg) (void*)(arg)
-   char args[PATH_MAX_LENGTH];
-
-   path_set(RARCH_PATH_CORE, core);
-
    netplay_driver_ctl(RARCH_NETPLAY_CTL_CLEAR_FORK_ARGS, NULL);
 
    if (string_is_empty(hostname))
    {
-      strlcpy(args, "-H", sizeof(args));
+      if (!netplay_driver_ctl(RARCH_NETPLAY_CTL_ADD_FORK_ARG, ARG("-H")))
+         goto failure;
    }
    else
    {
-      strlcpy(args, "-C ", sizeof(args));
+      if (!netplay_driver_ctl(RARCH_NETPLAY_CTL_ADD_FORK_ARG, ARG("-C")) ||
-      strlcat(args, hostname, sizeof(args));
+            !netplay_driver_ctl(RARCH_NETPLAY_CTL_ADD_FORK_ARG, ARG(hostname)))
+         goto failure;
    }
 
    if (!string_is_empty(subsystem))
    {
-      snprintf(buf, sizeof(buf), "\"%s\"", subsystem);
+      if (!netplay_driver_ctl(RARCH_NETPLAY_CTL_ADD_FORK_ARG, ARG("--subsystem")) ||
-      strlcat(args, " --subsystem ", sizeof(args));
+            !netplay_driver_ctl(RARCH_NETPLAY_CTL_ADD_FORK_ARG, ARG(subsystem)))
-      strlcat(args, buf, sizeof(args));
+         goto failure;
 
       if (content)
       {
@@ -485,21 +483,35 @@ static void static_load(const char *core, const char *subsystem,
 
          for (i = 0; i < subsystem_content->size; i++)
          {
-            snprintf(buf, sizeof(buf), " \"%s\"",
+            if (!netplay_driver_ctl(RARCH_NETPLAY_CTL_ADD_FORK_ARG,
-               subsystem_content->elems[i].data);
+                  ARG(subsystem_content->elems[i].data)))
-            strlcat(args, buf, sizeof(args));
+               goto failure;
          }
       }
    }
    else if (content)
    {
-      snprintf(buf, sizeof(buf), " \"%s\"", (const char*)content);
+      if (!netplay_driver_ctl(RARCH_NETPLAY_CTL_ADD_FORK_ARG, ARG(content)))
-      strlcat(args, buf, sizeof(args));
+         goto failure;
    }
 
-   netplay_driver_ctl(RARCH_NETPLAY_CTL_SET_FORK_ARGS, args);
+   if (!frontend_driver_set_fork(FRONTEND_FORK_CORE_WITH_ARGS))
-   frontend_driver_set_fork(FRONTEND_FORK_CORE_WITH_ARGS);
+      goto failure;
+
+   path_set(RARCH_PATH_CORE, core);
+
    retroarch_ctl(RARCH_CTL_SET_SHUTDOWN, NULL);
+
+   return true;
+
+failure:
+   RARCH_ERR("[Lobby] Failed to fork RetroArch for netplay.\n");
+
+   netplay_driver_ctl(RARCH_NETPLAY_CTL_CLEAR_FORK_ARGS, NULL);
+
+   return false;
+
+#undef ARG
 }
 #endif
 
@@ -677,10 +689,9 @@ static void task_netplay_crc_scan_callback(retro_task_t *task,
                   content_set_subsystem_by_name(data->current.subsystem);
                }
 #else
-               static_load(data->core, data->current.subsystem, NULL,
+               if (static_load(data->core, data->current.subsystem, NULL,
-                  data->hostname);
+                     data->hostname))
 #endif
-
                runloop_msg_queue_push(
                   msg_hash_to_str(MENU_ENUM_LABEL_VALUE_NETPLAY_START_WHEN_LOADED),
                   1, 480, true, NULL,