/*
 * Cisco router simulation platform.
 * Copyright (c) 2006 Christophe Fillot (cf@utc.fr)
 *
 * Hypervisor routines.
 */

/* By default, Cygwin supports only 64 FDs with select()! */
#ifdef __CYGWIN__
#define FD_SETSIZE 1024
#endif

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <signal.h>
#include <fcntl.h>
#include <errno.h>
#include <assert.h>
#include <stdarg.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <pthread.h>

#include "utils.h"
#include "parser.h"
#include "net.h"
#include "registry.h"
#include "cpu.h"
#include "vm.h"
#include "dynamips.h"
#include "dev_c7200.h"
#include "dev_c3600.h"
#include "dev_c2691.h"
#include "dev_c3725.h"
#include "dev_c3745.h"
#include "dev_c2600.h"
#include "hypervisor.h"
#include "net_io.h"
#include "net_io_bridge.h"
#include "frame_relay.h"
#include "atm.h"

#define DEBUG_TOKEN  0

/* Hypervisor modules */
static hypervisor_module_t *module_list = NULL;
static volatile int hypervisor_running = 0;

/* Hypervisor connection list */
static hypervisor_conn_t *hypervisor_conn_list = NULL;

/* Show hypervisor version */
static int cmd_version(hypervisor_conn_t *conn,int argc,char *argv[])
{
   hypervisor_send_reply(conn,HSC_INFO_OK,1,"%s",sw_version);
   return(0);
}

/* Parser test */
static int cmd_parser_test(hypervisor_conn_t *conn,int argc,char *argv[])
{
   int i;

   for(i=0;i<argc;i++)
      hypervisor_send_reply(conn,HSC_INFO_MSG,0,
                            "arg %d (len %u): \"%s\"",
                            i,strlen(argv[i]),argv[i]);

   hypervisor_send_reply(conn,HSC_INFO_OK,1,"OK");
   return(0);
}

/* Show hypervisor module list */
static int cmd_mod_list(hypervisor_conn_t *conn,int argc,char *argv[])
{
   hypervisor_module_t *m;

   for(m=module_list;m;m=m->next)
      hypervisor_send_reply(conn,HSC_INFO_MSG,0,"%s",m->name);

   hypervisor_send_reply(conn,HSC_INFO_OK,1,"OK");
   return(0);
}

/* Show module command list */
static int cmd_modcmd_list(hypervisor_conn_t *conn,int argc,char *argv[])
{
   hypervisor_module_t *m;
   hypervisor_cmd_t *cmd;

   if (!(m = hypervisor_find_module(argv[0]))) {
      hypervisor_send_reply(conn,HSC_ERR_UNK_MODULE,1,"unknown module '%s'",
                            argv[0]);
      return(-1);
   }

   for(cmd=m->cmd_list;cmd;cmd=cmd->next)
      hypervisor_send_reply(conn,HSC_INFO_MSG,0,"%s (min/max args: %d/%d)",
                            cmd->name,cmd->min_param,cmd->max_param);

   hypervisor_send_reply(conn,HSC_INFO_OK,1,"OK");
   return(0);
}

/* Set working directory */
static int cmd_set_working_dir(hypervisor_conn_t *conn,int argc,char *argv[])
{
   if (chdir(argv[0]) == -1) {
      hypervisor_send_reply(conn,HSC_ERR_INV_PARAM,1,
                            "chdir: %s",strerror(errno));
   } else {
      hypervisor_send_reply(conn,HSC_INFO_OK,1,"OK");
   }
   return(0);
}

/* Save the hypervisor configuration in the specified file */
static int cmd_save_config(hypervisor_conn_t *conn,int argc,char *argv[])
{
   FILE *fd;

   if (!(fd = fopen(argv[0],"w"))) {
      hypervisor_send_reply(conn,HSC_ERR_FILE,1,"fopen: %s",strerror(errno));
      return(-1);
   }

   /* Save configuration for all objects */
   netio_save_config_all(fd);
   frsw_save_config_all(fd);
   atmsw_save_config_all(fd);
   netio_bridge_save_config_all(fd);
   c7200_save_config_all(fd);
   c3600_save_config_all(fd);
   c2691_save_config_all(fd);
   c3725_save_config_all(fd);
   c3745_save_config_all(fd);
   c2600_save_config_all(fd);

   hypervisor_send_reply(conn,HSC_INFO_OK,1,"OK");
   return(0);
}

/* Reset hypervisor (delete all objects) */
static int cmd_reset(hypervisor_conn_t *conn,int argc,char *argv[])
{
   dynamips_reset();
   hypervisor_send_reply(conn,HSC_INFO_OK,1,"OK");
   return(0);
}

/* Close connection */
static int cmd_close(hypervisor_conn_t *conn,int argc,char *argv[])
{
   hypervisor_send_reply(conn,HSC_INFO_OK,1,"OK");
   conn->active = FALSE;
   return(0);
}

/* Stop hypervisor */
static int cmd_stop(hypervisor_conn_t *conn,int argc,char *argv[])
{
   hypervisor_send_reply(conn,HSC_INFO_OK,1,"OK");
   hypervisor_running = FALSE;
   return(0);
}

/* Hypervisor commands */
static hypervisor_cmd_t hypervisor_cmd_array[] = {
   { "version", 0, 0, cmd_version, NULL },
   { "parser_test", 0, 10, cmd_parser_test, NULL },
   { "module_list", 0, 0, cmd_mod_list, NULL },
   { "cmd_list", 1, 1, cmd_modcmd_list, NULL },
   { "working_dir", 1, 1, cmd_set_working_dir, NULL },
   { "save_config", 1, 1, cmd_save_config, NULL },
   { "reset", 0, 0, cmd_reset, NULL },
   { "close", 0, 0, cmd_close, NULL },
   { "stop", 0, 0, cmd_stop, NULL },
   { NULL, -1, -1, NULL, NULL },
};

/* Send a reply */
int hypervisor_send_reply(hypervisor_conn_t *conn,int code,int done,
                          char *format,...)
{
   va_list ap;
   size_t n = 0;

   if (conn != NULL) {
      va_start(ap,format);
      n += fprintf(conn->out,"%3d%s",code,(done)?"-":" ");
      n += vfprintf(conn->out,format,ap);
      n += fprintf(conn->out,"\r\n");
      fflush(conn->out);
      va_end(ap);
   }

   return(n);
}

/* Find a module */
hypervisor_module_t *hypervisor_find_module(char *name)
{
   hypervisor_module_t *m;

   for(m=module_list;m;m=m->next)
      if (!strcmp(m->name,name))
         return m;

   return NULL;
}

/* Find a command in a module */
hypervisor_cmd_t *hypervisor_find_cmd(hypervisor_module_t *module,char *name)
{                                      
   hypervisor_cmd_t *cmd;
   
   for(cmd=module->cmd_list;cmd;cmd=cmd->next)
      if (!strcmp(cmd->name,name))
         return cmd;

   return NULL;
}

/* Find an object in the registry */
void *hypervisor_find_object(hypervisor_conn_t *conn,char *name,int obj_type)
{
   void *p;

   if (!(p = registry_find(name,obj_type))) {
      hypervisor_send_reply(conn,HSC_ERR_UNK_OBJ,1,
                            "unable to find object '%s'",name);
      return NULL;
   }

   return p;
}

/* Find a VM in the registry */
void *hypervisor_find_vm(hypervisor_conn_t *conn,char *name,int vm_type)
{
   vm_instance_t *vm;

   if (!(vm = vm_acquire(name))) {
      hypervisor_send_reply(conn,HSC_ERR_UNK_OBJ,1,
                            "unable to find VM '%s'",name);
      return NULL;
   }

   if (vm->type != vm_type) {
      vm_release(vm);
      hypervisor_send_reply(conn,HSC_ERR_BAD_OBJ,1,
                            "VM '%s' is not a VM type %d",
                            name,vm_type);
      return NULL;
   }

   return vm;
}

/* Register a module */
hypervisor_module_t *hypervisor_register_module(char *name)
{
   hypervisor_module_t *m;

   if (hypervisor_find_module(name) != NULL) {
      fprintf(stderr,"Hypervisor: module '%s' already exists.\n",name);
      return NULL;
   }
   
   if (!(m = malloc(sizeof(*m)))) {
      fprintf(stderr,"Hypervisor: unable to register new module.\n");
      return NULL;
   }

   m->name = name;
   m->cmd_list = NULL;

   m->next = module_list;
   module_list = m;
   return m;
}

/* Register a list of commands */
int hypervisor_register_cmd_list(hypervisor_module_t *module,
                                 hypervisor_cmd_t *cmd_list)
{
   hypervisor_cmd_t *cmd = cmd_list;

   while(cmd->next != NULL)
      cmd = cmd->next;

   cmd->next = module->cmd_list;
   module->cmd_list = cmd_list;
   return(0);
}

/* Register an array of commands */
int hypervisor_register_cmd_array(hypervisor_module_t *module,
                                  hypervisor_cmd_t *cmd_array)
{
   hypervisor_cmd_t *cmd;

   for(cmd=cmd_array;cmd->name!=NULL;cmd++) {
      cmd->next = module->cmd_list;
      module->cmd_list = cmd;
   }

   return(0);
}

/* Locate the module and execute command */
static int hypervisor_exec_cmd(hypervisor_conn_t *conn,
                               char *mod_name,char *cmd_name,
                               int argc,char *argv[])
{
   hypervisor_module_t *module;
   hypervisor_cmd_t *cmd;

   if (!(module = hypervisor_find_module(mod_name))) {
      hypervisor_send_reply(conn,HSC_ERR_UNK_MODULE,1,"Unknown module '%s'",
                            mod_name);
      return(-1);
   }

   if (!(cmd = hypervisor_find_cmd(module,cmd_name))) {
      hypervisor_send_reply(conn,HSC_ERR_UNK_CMD,1,"Unknown command '%s'",
                            cmd_name);
      return(-1);
   }

   if ((argc < cmd->min_param) || (argc > cmd->max_param))  {
      hypervisor_send_reply(conn,HSC_ERR_BAD_PARAM,1,
                            "Bad number of parameters (%d with min/max=%d/%d)",
                            argc,cmd->min_param,cmd->max_param);
      return(-1);
   }

   return(cmd->handler(conn,argc,argv));
}

/* Thread for servicing connections */
static void *hypervisor_thread(void *arg)
{   
   hypervisor_conn_t *conn = arg;
   char buffer[512],**tokens;
   parser_context_t ctx;
   int res;
   
   tokens = NULL;
   parser_context_init(&ctx);

   while(conn->active) {
      if (!fgets(buffer,sizeof(buffer),conn->in))
         break;
   
      if (!*buffer)
         continue;

      /* Tokenize command line */
      res = parser_scan_buffer(&ctx,buffer,strlen(buffer));

      if (res != 0) {   
         tokens = NULL;

         if (ctx.error != 0) {
            hypervisor_send_reply(conn,HSC_ERR_PARSING,1,"Parse error: %s",
                                  parser_strerror(&ctx));
            goto free_tokens;
         }

         if (ctx.tok_count < 2) {
            hypervisor_send_reply(conn,HSC_ERR_PARSING,1,
                                  "At least a module and a command "
                                  "must be specified");
            goto free_tokens;
         }

         /* Map token list to an array */
         tokens = parser_map_array(&ctx);
      
         if (!tokens) {
            hypervisor_send_reply(conn,HSC_ERR_PARSING,1,"No memory");
            goto free_tokens;
         }

         /* Execute command */
         //m_log("hypervisor_exec","%s\n",buffer);
         hypervisor_exec_cmd(conn,tokens[0],tokens[1],ctx.
                             tok_count-2,&tokens[2]);
      
      free_tokens:
         free(tokens);
         tokens = NULL;
         parser_context_free(&ctx);
      }
   }

   free(tokens);
   parser_context_free(&ctx);
   return NULL;
}

static void sigpipe_handler(int sig)
{
   printf("SIGPIPE received.\n");
}

/* Initialize hypervisor */
int hypervisor_init(void)
{
   hypervisor_module_t *module;

   module = hypervisor_register_module("hypervisor");
   assert(module != NULL);

   hypervisor_register_cmd_array(module,hypervisor_cmd_array);
   return(0);
}

/* Remove a connection from the list */
static void hypervisor_remove_conn(hypervisor_conn_t *conn)
{
   if (conn->pprev != NULL) {
      if (conn->next)
         conn->next->pprev = conn->pprev;

      *(conn->pprev) = conn->next;
   }
}

/* Close a connection */
static void hypervisor_close_conn(hypervisor_conn_t *conn)
{
   if (conn != NULL) {
      conn->active = FALSE;      
      shutdown(conn->client_fd,2);
      pthread_join(conn->tid,NULL);

      fclose(conn->in);
      fclose(conn->out);

      shutdown(conn->client_fd,2);
      close(conn->client_fd);

      hypervisor_remove_conn(conn);
      free(conn);
   }
}

/* Close connections (dead or all) */
static void hypervisor_close_conn_list(int dead_status)
{
   hypervisor_conn_t *conn,*next;
   
   for(conn=hypervisor_conn_list;conn;conn=next) {
      next = conn->next;

      if (dead_status && conn->active)
         continue;

      hypervisor_close_conn(conn);
   }
}

/* Add a new connection to the list */
static void hypervisor_add_conn(hypervisor_conn_t *conn)
{
   conn->next = hypervisor_conn_list;
   conn->pprev = &hypervisor_conn_list;

   if (hypervisor_conn_list != NULL)
      hypervisor_conn_list->pprev = &conn->next;

   hypervisor_conn_list = conn;
}

/* Create a new connection */
static hypervisor_conn_t *hypervisor_create_conn(int client_fd)
{
   hypervisor_conn_t *conn;

   if (!(conn = malloc(sizeof(*conn))))
      goto err_malloc;

   memset(conn,0,sizeof(*conn));
   conn->active    = TRUE;
   conn->client_fd = client_fd;

   /* Open input buffered stream */
   if (!(conn->in = fdopen(client_fd,"r"))) {
      perror("hypervisor_create_conn: fdopen/in");
      goto err_fd_in;
   }

   /* Open output buffered stream */
   if (!(conn->out = fdopen(client_fd,"w"))) {
      perror("hypervisor_create_conn: fdopen/out");
      goto err_fd_out;
   }

   /* Set line buffering */
   setlinebuf(conn->in);
   setlinebuf(conn->out);
  
   /* Create the managing thread */
   if (pthread_create(&conn->tid,NULL,hypervisor_thread,conn) != 0)
      goto err_thread;

   /* Add it to the connection list */
   hypervisor_add_conn(conn);
   return conn;

 err_thread:
   fclose(conn->out);
 err_fd_out:
   fclose(conn->in);
 err_fd_in:
   free(conn);
 err_malloc:
   return NULL;
}

/* Stop hypervisor from sighandler */
int hypervisor_stopsig(void)
{
   hypervisor_running = FALSE;
   return(0);
}

/* Hypervisor TCP server */
int hypervisor_tcp_server(char* ip_address,int tcp_port)
{
   int fd_array[HYPERVISOR_MAX_FD];
   struct sockaddr_storage remote_addr;
   socklen_t remote_len;
   int i,res,clnt,fd_count,fd_max;
   struct timeval tv;
   fd_set fds;

   /* Initialize all hypervisor modules */
   hypervisor_init();
   hypervisor_nio_init();
   hypervisor_nio_bridge_init();
   hypervisor_frsw_init();
   hypervisor_atmsw_init();
   hypervisor_ethsw_init();
   hypervisor_vm_init();
   hypervisor_vm_debug_init();
   hypervisor_c7200_init();
   hypervisor_c3600_init();
   hypervisor_c2691_init();
   hypervisor_c3725_init();
   hypervisor_c3745_init();
   hypervisor_c2600_init();

   signal(SIGPIPE,sigpipe_handler);

   if (!tcp_port)
      tcp_port = HYPERVISOR_TCP_PORT;

   fd_count = ip_listen(ip_address,tcp_port,SOCK_STREAM,HYPERVISOR_MAX_FD,fd_array);

   if (fd_count <= 0) {
      fprintf(stderr,"Hypervisor: unable to create TCP sockets.\n");
      return(-1);
   }

   /* Start accepting connections */
   printf("Hypervisor TCP control server started (port %d).\n",tcp_port);
   hypervisor_running = TRUE;

   while(hypervisor_running) {
      FD_ZERO(&fds);
      fd_max = -1;

      for(i=0;i<fd_count;i++)
         if (fd_array[i] != -1) {
            FD_SET(fd_array[i],&fds);
            if (fd_array[i] > fd_max)
               fd_max = fd_array[i];
         }

      /* Wait for incoming connections */
      tv.tv_sec  = 0;
      tv.tv_usec = 500 * 1000;  /* 500 ms */
      res = select(fd_max+1,&fds,NULL,NULL,&tv);

      if (res == -1) {
         if (errno == EINTR)
            continue;
         else
            perror("hypervisor_tcp_server: select");
      }

      /* Accept connections on signaled sockets */
      for(i=0;i<fd_count;i++) {
         if (fd_array[i] == -1)
            continue;
         
         if (!FD_ISSET(fd_array[i],&fds))
            continue;

         remote_len = sizeof(remote_addr);
         clnt = accept(fd_array[i],(struct sockaddr *)&remote_addr,
                       &remote_len);

         if (clnt < 0) {
            perror("hypervisor_tcp_server: accept");
            continue;
         }
            
         /* create a new connection and start a thread to handle it */
         if (!hypervisor_create_conn(clnt)) {
            fprintf(stderr,"hypervisor_tcp_server: unable to create new "
                    "connection for FD %d\n",clnt);
            close(clnt);
         }
      }

      /* Walk through the connection list to eliminate dead connections */
      hypervisor_close_conn_list(TRUE);
   }   

   /* Close all control sockets */
   printf("Hypervisor: closing control sockets.\n");
   for(i=0;i<fd_count;i++) {
      if (fd_array[i] != -1) {
         shutdown(fd_array[i],2);
         close(fd_array[i]);
      }
   }

   /* Close all remote client connections */
   printf("Hypervisor: closing remote client connections.\n");
   hypervisor_close_conn_list(FALSE);
   return(0);
}