/*
   Bacula(R) - The Network Backup Solution

   Copyright (C) 2000-2020 Kern Sibbald

   The original author of Bacula is Kern Sibbald, with contributions
   from many others, a complete list can be found in the file AUTHORS.

   You may use this file and others of this release according to the
   license defined in the LICENSE file, which includes the Affero General
   Public License, v3.0 ("AGPLv3") and some additional permissions and
   terms pursuant to its AGPLv3 Section 7.

   This notice must be preserved when any source code is
   conveyed and/or propagated.

   Bacula(R) is a registered trademark of Kern Sibbald.
*/
/*
 * Hello routines for Storage daemon.
 *
 * This file contains all the code relating to reading and writing of
 *  all Hello commands between the daemons.
 *
 *   Written by Kern Sibbald, June 2014
 *
 */


#include "bacula.h"
#include "stored.h"

extern STORES *me;               /* our Global resource */

const int dbglvl = 50;

static char hello_sd[]  = "Hello Bacula SD: Start Job %s %d %d tlspsk=%d\n";

static char Sorry[]     = "3999 No go\n";
static char OK_hello[]  = "3000 OK Hello %d\n";

/* We store caps in a special structure to update JCR
 * only after the auth phase
 */
class caps_fd {
public:
   int32_t  fd_dedup;
   int32_t  fd_rehydration;
   caps_fd() :
      fd_dedup(0),
      fd_rehydration(0)
      {};
   bool scan(const char *msg) {
      return sscanf(msg, "fdcaps: dedup=%ld rehydration=%ld",
                    &fd_dedup, &fd_rehydration) == 2;
   }
   /* Set variable that we got in JCR */
   void set(JCR *jcr) {
      jcr->fd_dedup = fd_dedup;
      jcr->fd_rehydration = fd_rehydration;
   };
};

static bool recv_fdcaps(JCR *jcr, BSOCK *cl, caps_fd *caps);
static bool send_sdcaps(JCR *jcr, BSOCK *cl);
static bool recv_sdcaps(JCR *jcr, BSOCK *cl);
static bool send_fdcaps(JCR *jcr, BSOCK *cl);


/*********************************************************************
 *
 *  Validate hello from the Director.
 *
 * Returns: true  if Hello is good.
 *          false if Hello is bad.
 */
bool validate_dir_hello(JCR* jcr)
{
   POOLMEM *dirname;
   DIRRES *director = NULL;
   int dir_version = 0;
   BSOCK *dir = jcr->dir_bsock;

   if (dir->msglen < 25 || dir->msglen > 500) {
      Dmsg2(dbglvl, "Bad Hello command from Director at %s. Len=%d.\n",
            dir->who(), dir->msglen);
      Qmsg2(jcr, M_SECURITY, 0, _("Bad Hello command from Director at %s. Len=%d.\n"),
            dir->who(), dir->msglen);
      sleep(5);
      return false;
   }
   dirname = get_pool_memory(PM_MESSAGE);
   dirname = check_pool_memory_size(dirname, dir->msglen);
   dir->tlspsk_remote = 0;
   if (scan_string(dir->msg, "Hello SD: Bacula Director %127s calling %d tlspsk=%d",
         dirname, &dir_version, &dir->tlspsk_remote) != 3 &&
       scan_string(dir->msg, "Hello SD: Bacula Director %127s calling %d",
          dirname, &dir_version) != 2 &&
       scan_string(dir->msg, "Hello SD: Bacula Director %127s calling",
          dirname) != 1) {
      dir->msg[100] = 0;
      Dmsg2(dbglvl, "Bad Hello command from Director at %s: %s\n",
            dir->who(), dir->msg);
      Qmsg2(jcr, M_SECURITY, 0, _("Bad Hello command from Director at %s: %s\n"),
            dir->who(), dir->msg);
      free_pool_memory(dirname);
      sleep(5);
      return false;
   }

   if (dir_version >= 1 && me->comm_compression) {
      dir->set_compress();
   } else {
      dir->clear_compress();
      Dmsg0(050, "**** No SD compression to Dir\n");
   }
   director = NULL;
   unbash_spaces(dirname);
   foreach_res(director, R_DIRECTOR) {
      if (strcasecmp(director->hdr.name, dirname) == 0) {
         break;
      }
   }
   if (!director) {
      Dmsg2(dbglvl, "Connection from unknown Director %s at %s rejected.\n",
            dirname, dir->who());
      Qmsg2(jcr, M_SECURITY, 0, _("Connection from unknown Director %s at %s rejected.\n"
            "Please see " MANUAL_AUTH_URL " for help.\n"),
            dirname, dir->who());
      free_pool_memory(dirname);
      sleep(5);
      return false;
   }
   jcr->director = director;
   free_pool_memory(dirname);
   return true;
}

/*
 * After receiving a connection (in dircmd.c) if it is
 *   from the File daemon, this routine is called.
 */
void handle_client_connection(BSOCK *fd)
{
   JCR *jcr;
   int fd_version = 0;
   int sd_version = 0;
   char job_name[500];
   caps_fd fdcaps;
   /*
    * Do a sanity check on the message received
    */
   if (fd->msglen < 25 || fd->msglen > (int)sizeof(job_name)) {
      Pmsg1(000, "<filed: %s", fd->msg);
      Qmsg2(NULL, M_SECURITY, 0, _("Invalid connection from %s. Len=%d\n"), fd->who(), fd->msglen);
      bmicrosleep(5, 0);   /* make user wait 5 seconds */
      fd->destroy();
      return;
   }

   Dmsg1(dbglvl, "authenticate: %s", fd->msg);
   /*
    * See if this is a File daemon connection. If so
    *   call FD handler.
    */
   fd->tlspsk_remote = 0;
   if (scan_string(fd->msg, "Hello Bacula SD: Start Job %127s %d %d tlspsk=%d", job_name, &fd_version, &sd_version, &fd->tlspsk_remote) != 4 &&
       scan_string(fd->msg, "Hello Bacula SD: Start Job %127s %d %d", job_name, &fd_version, &sd_version) != 3 &&
       scan_string(fd->msg, "Hello Bacula SD: Start Job %127s %d tlspsk=%d", job_name, &fd_version, &fd->tlspsk_remote) != 3 &&
       scan_string(fd->msg, "Hello Bacula SD: Start Job %127s %d", job_name, &fd_version) != 2 &&
       scan_string(fd->msg, "Hello FD: Bacula Storage calling Start Job %127s %d", job_name, &sd_version) != 2 &&
       scan_string(fd->msg, "Hello Start Job %127s", job_name) != 1) {
      Qmsg2(NULL, M_SECURITY, 0, _("Invalid Hello from %s. Len=%d\n"), fd->who(), fd->msglen);
      sleep(5);
      fd->destroy();
      return;
   }

   if (!(jcr=get_jcr_by_full_name(job_name))) {
      Qmsg1(NULL, M_SECURITY, 0, _("Client connect failed: Job name not found: %s\n"), job_name);
      Dmsg1(3, "**** Job \"%s\" not found.\n", job_name);
      sleep(5);
      fd->destroy();
      return;
   }

   /* After this point, we can use bail_out */
   Dmsg1(100, "Found Client Job %s\n", job_name);
   if (jcr->authenticated) {
      Jmsg3(jcr, M_SECURITY, 0, _("A Client \"%s\" tried to authenticate for Job %s, "
                                 "but the Job is already authenticated with \"%s\".\n"),
            fd->who(), jcr->Job, jcr->file_bsock?jcr->file_bsock->who():"N/A");
      Dmsg2(050, "Hey!!!! JobId %u Job %s already authenticated.\n",
         (uint32_t)jcr->JobId, jcr->Job);
      goto bail_out;
   }

   fd->set_jcr(jcr);
   Dmsg2(050, "fd_version=%d sd_version=%d\n", fd_version, sd_version);

   /* Turn on compression for newer FDs, except for community version */
   if ((fd_version >= 9 || sd_version >= 1) && fd_version != 213 && me->comm_compression) {
      fd->set_compress();             /* set compression allowed */
   } else {
      fd->clear_compress();
      Dmsg0(050, "*** No SD compression to FD\n");
   }

   /* The community version 213 doesn't send caps, the 215 version might do it  */
   if (fd_version >= 12 && fd_version != 213 && fd_version != 214) {
      /* Send and get capabilities */
      if (!send_sdcaps(jcr, fd)) {
         goto bail_out;
      }
      if (!recv_fdcaps(jcr, fd, &fdcaps)) {
         goto bail_out;
      }
   }

   /*
    * Authenticate the Client (FD or SD)
    */
   jcr->lock_auth();     /* Ensure that only one thread is dealing with auth */
   if (jcr->authenticated) {
      Jmsg2(jcr, M_SECURITY, 0, _("A Client \"%s\" tried to authenticate for Job %s, "
                                 "but the job is already authenticated.\n"),
            fd->who(), jcr->Job);

   } else if (!authenticate_filed(jcr, fd, fd_version)) {
      Dmsg1(50, "Authentication failed Job %s\n", jcr->Job);
      /* Job not yet started, we can cancel */
      Jmsg(jcr, M_SECURITY, 0, _("Unable to authenticate File daemon\n"));

   } else {
      Dmsg2(050, "OK Authentication jid=%u Job %s\n", (uint32_t)jcr->JobId, jcr->Job);
      jcr->file_bsock = fd;
      jcr->FDVersion = fd_version;
      jcr->SDVersion = sd_version;
      fdcaps.set(jcr);
      jcr->authenticated = true;

      if (sd_version > 0) {
         jcr->sd_client = true;
      }
   }
   jcr->unlock_auth();

   if (!jcr->authenticated) {
      jcr->setJobStatus(JS_ErrorTerminated);
   }

   Dmsg4(050, "=== Auth %s, unblock Job %s jid=%d sd_ver=%d\n",
         jcr->authenticated?"OK":"KO", job_name, jcr->JobId, sd_version);

bail_out:
   /* file_bsock might be NULL or a previous BSOCK */
   if (jcr->file_bsock != fd) {
      fd->destroy();
   }
   pthread_cond_signal(&jcr->job_start_wait); /* wake waiting job */
   free_jcr(jcr);
   if (!jcr->authenticated) {
      sleep(5);
   }
   return;
}


bool is_client_connection(BSOCK *bs)
{
   return
      scan_string(bs->msg, "Hello Bacula SD: Start Job ") == 0 ||
      scan_string(bs->msg, "Hello FD: Bacula Storage calling Start Job ") == 0 ||
      scan_string(bs->msg, "Hello Start Job ") == 0;
}

/*
 * If sd_calls_client, we must read the client's response to
 *   the hello we previously sent.
 */
bool read_client_hello(JCR *jcr)
{
   int i;
   int stat;
   int fd_version = 0;
   int sd_version = 0;
   BSOCK *cl = jcr->file_bsock;
   char job_name[500];
   caps_fd fdcaps;

   /* We connected to Client, so finish work */
   if (!cl) {
      Jmsg0(jcr, M_FATAL, 0, _("Client socket not open. Could not connect to Client.\n"));
      Dmsg0(050, "Client socket not open. Could not connect to Client.\n");
      return false;
   }
   /* Get response to Hello command sent earlier */
   Dmsg0(050, "Read Hello command from Client\n");
   for (i=0; i<60; i++) {
      stat = cl->recv();
      if (stat <= 0) {
         bmicrosleep(1, 0);
      } else {
         break;
      }
   }
   if (stat <= 0) {
      berrno be;
      Jmsg1(jcr, M_FATAL, 0, _("Recv request to Client failed. ERR=%s\n"),
         be.bstrerror());
      Dmsg1(050, _("Recv request to Client failed. ERR=%s\n"), be.bstrerror());
      return false;
   }
   Dmsg1(dbglvl, "authenticate: %s", cl->msg);
   cl->tlspsk_remote = 0;
   if (scan_string(cl->msg, "Hello Bacula SD: Start Job %127s %d %d tlspsk=%d", job_name, &fd_version, &sd_version, &cl->tlspsk_remote) != 4 &&
       scan_string(cl->msg, "Hello Bacula SD: Start Job %127s %d tlspsk=%d", job_name, &fd_version, &cl->tlspsk_remote) != 3 &&
       scan_string(cl->msg, "Hello Bacula SD: Start Job %127s %d %d", job_name, &fd_version, &sd_version) != 3 &&
       scan_string(cl->msg, "Hello Bacula SD: Start Job %127s %d", job_name, &fd_version) != 2) {
      Jmsg1(jcr, M_FATAL, 0, _("Bad Hello from Client: %s.\n"), cl->msg);
      Dmsg1(050, _("Bad Hello from Client: %s.\n"), cl->msg);
      return false;
   }

   unbash_spaces(job_name);
   jcr->FDVersion = fd_version;
   jcr->SDVersion = sd_version;
   Dmsg1(050, "FDVersion=%d\n", fd_version);
   /* Turn on compression for newer FDs, except for Community version */
   if (jcr->FDVersion >= 9 && jcr->FDVersion != 213 && me->comm_compression) {
      cl->set_compress();             /* set compression allowed */
   } else {
      cl->clear_compress();
      Dmsg0(050, "*** No SD compression to FD\n");
   }

   /* The community version 213 doesn't have caps */
   if (fd_version >= 12 && fd_version != 213 && fd_version != 214) {
      /* Send and get capabilities */
      if (!send_sdcaps(jcr, cl)) {
         return false;
      }
      if (!recv_fdcaps(jcr, cl, &fdcaps)) {
         return false;
      }
      fdcaps.set(jcr);
   }
   return true;
}

/*
 * Send Hello OK to DIR or FD
 */
bool send_hello_ok(BSOCK *bs)
{
   return bs->fsend(OK_hello, SD_VERSION);
}

bool send_sorry(BSOCK *bs)
{
   return bs->fsend(Sorry);
}

/*
 * We are acting as a client, so send Hello to the SD.
 */
bool send_hello_sd(JCR *jcr, char *Job, int tlspsk)
{
   bool rtn;
   BSOCK *sd = jcr->store_bsock;

   bash_spaces(Job);
   rtn = sd->fsend(hello_sd, Job, FD_VERSION, SD_VERSION, tlspsk);
   unbash_spaces(Job);
   Dmsg1(100, "Send to SD: %s\n", sd->msg);
   if (!rtn) {
      return false;
   }

   /* Receive and send capabilities */
   if (!recv_sdcaps(jcr, sd)) {
      return false;
   }
   if (!send_fdcaps(jcr, sd)) {
      return false;
   }
   return true;
}

/*
 * We are SD so send Hello to client
 *  Note: later the Client will send us a Hello.
 */
bool send_hello_client(JCR *jcr, char *Job)
{
   bool rtn;
   BSOCK *cl = jcr->file_bsock;

   bash_spaces(Job);
   // This is a "dummy" hello, just to connect to the waiting FD job
   // No need of a TLS-PSK field here, the FD will send the "real" TLS-PSK field
   rtn = cl->fsend("Hello FD: Bacula Storage calling Start Job %s %d\n", Job, SD_VERSION);
   unbash_spaces(Job);
   if (!rtn) {
      return false;
   }
   return rtn;
}

/*
 * Capabilities Exchange
 *
 * Immediately after the Hello is sent/received by the SD, the SD sends
 *  its capabilities to the client (FD), and the client responds by
 *  sending its capabilities.
 */
static bool send_sdcaps(JCR *jcr, BSOCK *cl)
{
   int stat;
   int32_t dedup = 0;
   int32_t hash = DEDUP_DEFAULT_HASH_ID;
   uint32_t block_size = DEDUP_IDEAL_BLOCK_SIZE;
   uint32_t min_block_size = DEDUP_MIN_BLOCK_SIZE;
   uint32_t max_block_size = DEDUP_MAX_BLOCK_SIZE;

   /* Set dedup, if SD is dedup enabled and device is dedup type */
   if (jcr->dcr) {
      dedup = jcr->dcr->dev->dev_type==B_DEDUP_DEV;
   }
   Dmsg5(200, ">Send sdcaps: dedup=%ld hash=%ld dedup_block=%lu min_dedup_block=%lu max_dedup_block=%lu\n",
        dedup, hash, block_size, min_block_size, max_block_size);
   stat = cl->fsend("sdcaps: dedup=%ld hash=%ld dedup_block=%lu min_dedup_block=%lu max_dedup_block=%lu\n",
      dedup, hash, block_size, min_block_size, max_block_size);
   if (!stat) {
      berrno be;
      Jmsg1(jcr, M_FATAL, 0, _("Send caps to Client failed. ERR=%s\n"),
         be.bstrerror());
      Dmsg1(050, _("Send caps to Client failed. ERR=%s\n"), be.bstrerror());
      return false;
   }
   return true;
}

static bool recv_fdcaps(JCR *jcr, BSOCK *cl, caps_fd *caps)
{
   int stat;

   stat = cl->recv();
   if (stat <= 0) {
      berrno be;
      Jmsg1(jcr, M_FATAL, 0, _("Recv caps from Client failed. ERR=%s\n"),
         be.bstrerror());
      Dmsg1(050, _("Recv caps from Client failed. ERR=%s\n"), be.bstrerror());
      return false;
   }
   if (!caps->scan(cl->msg)) {
      Jmsg1(jcr, M_FATAL, 0, _("Recv bad caps from Client: %s.\n"), cl->msg);
      Dmsg1(050, _("Recv bad caps from Client %s\n"), cl->msg);
      return false;
   }
   return true;
}

/* ======================== */


/*
 * Note: for the following two subroutines, during copy/migration
 *  jobs, we are acting as a File daemon.
 */
static bool send_fdcaps(JCR *jcr, BSOCK *sd)
{
   int dedup = 0;
   if (jcr->dcr->device->dev_type == B_DEDUP_DEV) {
      dedup = 1;
   }
   return sd->fsend("fdcaps: dedup=%d rehydration=%d\n", dedup, dedup);
}

/* Result not used */
static bool recv_sdcaps(JCR *jcr, BSOCK *sd)
{
   int stat;
   int32_t dedup = 0;
   int32_t hash = 0;
   int32_t block_size = 0;
   int32_t min_block_size = 0;
   int32_t max_block_size = 0;


   stat = sd->recv();
   if (stat <= 0) {
      berrno be;
      Jmsg1(jcr, M_FATAL, 0, _("Recv caps from SD failed. ERR=%s\n"),
         be.bstrerror());
      Dmsg1(050, _("Recv caps from SD failed. ERR=%s\n"), be.bstrerror());
      return false;
   }

   if (sscanf(sd->msg, "sdcaps: dedup=%ld hash=%ld dedup_block=%ld min_dedup_block=%ld max_dedup_block=%ld",
        &dedup, &hash, &block_size, &min_block_size, &max_block_size) != 5) {
      Jmsg1(jcr, M_FATAL, 0, _("Bad caps from SD: %s.\n"), sd->msg);
      Dmsg1(050, _("Bad caps from SD: %s\n"), sd->msg);
      return false;
   }
   Dmsg5(200, "sdcaps: dedup=%ld hash=%ld dedup_block=%ld min_dedup_block=%ld max_dedup_block=%ld\n",
        dedup, hash, block_size, min_block_size, max_block_size);
   return true;
}