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  • /***************************************************************************
     *                                  _   _ ____  _
     *  Project                     ___| | | |  _ \| |
     *                             / __| | | | |_) | |
     *                            | (__| |_| |  _ <| |___
     *                             \___|\___/|_| \_\_____|
     *
    
     * Copyright (C) 1998 - 2006, Daniel Stenberg, <daniel@haxx.se>, et al.
    
     *
     * This software is licensed as described in the file COPYING, which
     * you should have received as part of this distribution. The terms
     * are also available at http://curl.haxx.se/docs/copyright.html.
     *
     * You may opt to use, copy, modify, merge, publish, distribute and/or sell
     * copies of the Software, and permit persons to whom the Software is
     * furnished to do so, under the terms of the COPYING file.
     *
     * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
     * KIND, either express or implied.
     *
     * $Id$
     ***************************************************************************/
    
    #include "setup.h"
    
    #ifndef CURL_DISABLE_TFTP
    /* -- WIN32 approved -- */
    #include <stdio.h>
    #include <string.h>
    #include <stdarg.h>
    #include <stdlib.h>
    #include <ctype.h>
    #ifdef HAVE_SYS_TYPES_H
    #include <sys/types.h>
    #endif
    #ifdef HAVE_SYS_STAT_H
    #include <sys/stat.h>
    #endif
    
    #if defined(WIN32)
    #include <time.h>
    #include <io.h>
    #else
    #ifdef HAVE_SYS_SOCKET_H
    #include <sys/socket.h>
    #endif
    #include <netinet/in.h>
    #include <sys/time.h>
    #ifdef HAVE_UNISTD_H
    #include <unistd.h>
    #endif
    #include <netdb.h>
    #ifdef HAVE_ARPA_INET_H
    #include <arpa/inet.h>
    #endif
    #ifdef HAVE_NET_IF_H
    #include <net/if.h>
    #endif
    #include <sys/ioctl.h>
    #include <signal.h>
    
    #ifdef HAVE_SYS_PARAM_H
    #include <sys/param.h>
    #endif
    
    
    #endif
    
    #include "urldata.h"
    #include <curl/curl.h>
    #include "transfer.h"
    #include "sendf.h"
    #include "tftp.h"
    #include "progress.h"
    
    #include "connect.h"
    #include "strerror.h"
    
    #include "sockaddr.h" /* required for Curl_sockaddr_storage */
    
    
    #define _MPRINTF_REPLACE /* use our functions only */
    #include <curl/mprintf.h>
    
    #include "memory.h"
    #include "select.h"
    
    /* The last #include file should be: */
    #include "memdebug.h"
    
    
    /* RFC2348 allows the block size to be negotiated, but we don't support that */
    #define TFTP_BLOCKSIZE 512
    
    
    typedef enum {
      TFTP_MODE_NETASCII=0,
      TFTP_MODE_OCTET
    } tftp_mode_t;
    
    typedef enum {
      TFTP_STATE_START=0,
      TFTP_STATE_RX,
      TFTP_STATE_TX,
      TFTP_STATE_FIN
    } tftp_state_t;
    
    typedef enum {
      TFTP_EVENT_INIT=0,
      TFTP_EVENT_RRQ = 1,
      TFTP_EVENT_WRQ = 2,
      TFTP_EVENT_DATA = 3,
      TFTP_EVENT_ACK = 4,
      TFTP_EVENT_ERROR = 5,
      TFTP_EVENT_TIMEOUT
    } tftp_event_t;
    
    typedef enum {
      TFTP_ERR_UNDEF=0,
      TFTP_ERR_NOTFOUND,
      TFTP_ERR_PERM,
      TFTP_ERR_DISKFULL,
      TFTP_ERR_ILLEGAL,
      TFTP_ERR_UNKNOWNID,
      TFTP_ERR_EXISTS,
      TFTP_ERR_NOSUCHUSER,
      TFTP_ERR_TIMEOUT,
      TFTP_ERR_NORESPONSE
    } tftp_error_t;
    
    typedef struct tftp_packet {
    
      unsigned char data[2 + 2 + TFTP_BLOCKSIZE];
    
    } tftp_packet_t;
    
    typedef struct tftp_state_data {
      tftp_state_t    state;
      tftp_mode_t     mode;
      tftp_error_t    error;
      struct connectdata      *conn;
    
      curl_socket_t   sockfd;
    
      int             retries;
      int             retry_time;
      int             retry_max;
      time_t          start_time;
      time_t          max_time;
      unsigned short  block;
    
      struct Curl_sockaddr_storage   local_addr;
    
      struct Curl_sockaddr_storage   remote_addr;
    
      socklen_t       remote_addrlen;
      int             rbytes;
      int             sbytes;
      tftp_packet_t   rpacket;
      tftp_packet_t   spacket;
    } tftp_state_data_t;
    
    
    /* Forward declarations */
    
    static CURLcode tftp_rx(tftp_state_data_t *state, tftp_event_t event) ;
    static CURLcode tftp_tx(tftp_state_data_t *state, tftp_event_t event) ;
    
    void tftp_set_timeouts(tftp_state_data_t *state) ;
    
    /**********************************************************
     *
     * tftp_set_timeouts -
     *
     * Set timeouts based on state machine state.
     * Use user provided connect timeouts until DATA or ACK
     * packet is received, then use user-provided transfer timeouts
     *
     *
     **********************************************************/
    void tftp_set_timeouts(tftp_state_data_t *state)
    {
    
      struct SessionHandle *data = state->conn->data;
    
    
      time(&state->start_time);
      if(state->state == TFTP_STATE_START) {
        /* Compute drop-dead time */
    
        maxtime = (time_t)(data->set.connecttimeout?data->set.connecttimeout:30);
    
        state->max_time = state->start_time+maxtime;
    
        /* Set per-block timeout to total */
        timeout = maxtime ;
    
        /* Average restart after 5 seconds */
        state->retry_max = timeout/5;
    
        /* Compute the re-start interval to suit the timeout */
        state->retry_time = timeout/state->retry_max;
    
        if(state->retry_time<1)
          state->retry_time=1;
    
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        maxtime = (time_t)(data->set.timeout?data->set.timeout:3600);
    
        state->max_time = state->start_time+maxtime;
    
        /* Set per-block timeout to 10% of total */
        timeout = maxtime/10 ;
    
        /* Average reposting an ACK after 15 seconds */
        state->retry_max = timeout/15;
      }
      /* But bound the total number  */
    
      if(state->retry_max<3)
        state->retry_max=3;
    
      if(state->retry_max>50)
        state->retry_max=50;
    
    
      /* Compute the re-ACK interval to suit the timeout */
      state->retry_time = timeout/state->retry_max;
    
      if(state->retry_time<1)
        state->retry_time=1;
    
    
      infof(data, "set timeouts for state %d; Total %d, retry %d maxtry %d\n",
            state->state, (state->max_time-state->start_time),
            state->retry_time, state->retry_max);
    }
    
    /**********************************************************
     *
     * tftp_set_send_first
     *
     * Event handler for the START state
     *
     **********************************************************/
    
    
    static void setpacketevent(tftp_packet_t *packet, unsigned short num)
    {
    
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      packet->data[0] = (unsigned char)(num >> 8);
      packet->data[1] = (unsigned char)(num & 0xff);
    
    }
    
    
    static void setpacketblock(tftp_packet_t *packet, unsigned short num)
    {
    
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      packet->data[2] = (unsigned char)(num >> 8);
      packet->data[3] = (unsigned char)(num & 0xff);
    
    }
    
    static unsigned short getrpacketevent(tftp_packet_t *packet)
    {
    
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      return (unsigned short)((packet->data[0] << 8) | packet->data[1]);
    
    }
    
    static unsigned short getrpacketblock(tftp_packet_t *packet)
    {
    
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      return (unsigned short)((packet->data[2] << 8) | packet->data[3]);
    
    static CURLcode tftp_send_first(tftp_state_data_t *state, tftp_event_t event)
    
    
      /* As RFC3617 describes the separator slash is not actually part of the file
         name so we skip the always-present first letter of the path string. */
      char *filename = &state->conn->path[1];
    
      struct SessionHandle *data = state->conn->data;
    
      CURLcode res = CURLE_OK;
    
    
      /* Set ascii mode if -B flag was used */
    
        mode = "netascii";
    
      switch(event) {
    
      case TFTP_EVENT_INIT:    /* Send the first packet out */
      case TFTP_EVENT_TIMEOUT: /* Resend the first packet out */
        /* Increment the retry counter, quit if over the limit */
        state->retries++;
        if(state->retries>state->retry_max) {
          state->error = TFTP_ERR_NORESPONSE;
          state->state = TFTP_STATE_FIN;
    
        }
    
        if(data->set.upload) {
          /* If we are uploading, send an WRQ */
    
          setpacketevent(&state->spacket, TFTP_EVENT_WRQ);
    
          filename = curl_easy_unescape(data, filename, 0, NULL);
    
          state->conn->upload_fromhere = (char *)&state->spacket.data[4];
    
          if(data->set.infilesize != -1)
    
            Curl_pgrsSetUploadSize(data, data->set.infilesize);
        }
        else {
          /* If we are downloading, send an RRQ */
    
          setpacketevent(&state->spacket, TFTP_EVENT_RRQ);
    
        snprintf((char *)&state->spacket.data[2],
    
                 "%s%c%s%c", filename, '\0',  mode, '\0');
    
        sbytes = 4 + (int)strlen(filename) + (int)strlen(mode);
    
        sbytes = sendto(state->sockfd, (void *)&state->spacket,
                        sbytes, 0,
    
                        state->conn->ip_addr->ai_addr,
                        state->conn->ip_addr->ai_addrlen);
        if(sbytes < 0) {
    
          failf(data, "%s\n", Curl_strerror(state->conn, Curl_sockerrno()));
    
        }
        break;
    
      case TFTP_EVENT_ACK: /* Connected for transmit */
        infof(data, "%s\n", "Connected for transmit");
        state->state = TFTP_STATE_TX;
        tftp_set_timeouts(state);
    
    
      case TFTP_EVENT_DATA: /* connected for receive */
        infof(data, "%s\n", "Connected for receive");
        state->state = TFTP_STATE_RX;
        tftp_set_timeouts(state);
    
    
      case TFTP_EVENT_ERROR:
        state->state = TFTP_STATE_FIN;
        break;
    
      default:
        failf(state->conn->data, "tftp_send_first: internal error\n");
        break;
      }
    
    }
    
    /**********************************************************
     *
     * tftp_rx
     *
     * Event handler for the RX state
     *
     **********************************************************/
    
    static CURLcode tftp_rx(tftp_state_data_t *state, tftp_event_t event)
    
      struct SessionHandle *data = state->conn->data;
    
    
      switch(event) {
    
      case TFTP_EVENT_DATA:
    
        /* Is this the block we expect? */
    
        rblock = getrpacketblock(&state->rpacket);
    
        if ((state->block+1) != rblock) {
          /* No, log it, up the retry count and fail if over the limit */
    
                "Received unexpected DATA packet block %d\n", rblock);
          state->retries++;
          if (state->retries>state->retry_max) {
    
            failf(data, "tftp_rx: giving up waiting for block %d\n",
    
          }
        }
        /* This is the expected block.  Reset counters and ACK it. */
    
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        state->block = (unsigned short)rblock;
    
        setpacketevent(&state->spacket, TFTP_EVENT_ACK);
        setpacketblock(&state->spacket, state->block);
        sbytes = sendto(state->sockfd, (void *)state->spacket.data,
    
                        (struct sockaddr *)&state->remote_addr,
                        state->remote_addrlen);
    
          failf(data, "%s\n", Curl_strerror(state->conn, Curl_sockerrno()));
    
        /* Check if completed (That is, a less than full packet is received) */
    
        if (state->rbytes < (int)sizeof(state->spacket)){
          state->state = TFTP_STATE_FIN;
        }
        else {
          state->state = TFTP_STATE_RX;
        }
        break;
    
      case TFTP_EVENT_TIMEOUT:
        /* Increment the retry count and fail if over the limit */
        state->retries++;
    
              "Timeout waiting for block %d ACK.  Retries = %d\n", state->retries);
        if(state->retries > state->retry_max) {
          state->error = TFTP_ERR_TIMEOUT;
          state->state = TFTP_STATE_FIN;
    
          sbytes = sendto(state->sockfd, (void *)&state->spacket,
    
                          (struct sockaddr *)&state->remote_addr,
                          state->remote_addrlen);
    
          /* Check all sbytes were sent */
          if(sbytes<0) {
    
            failf(data, "%s\n", Curl_strerror(state->conn, Curl_sockerrno()));
    
          }
        }
        break;
    
      case TFTP_EVENT_ERROR:
        state->state = TFTP_STATE_FIN;
        break;
    
      default:
    
        failf(data, "%s\n", "tftp_rx: internal error");
    
      Curl_pgrsSetDownloadCounter(data,
    
                                  (curl_off_t) state->block*TFTP_BLOCKSIZE);
    
    }
    
    /**********************************************************
     *
     * tftp_tx
     *
     * Event handler for the TX state
     *
     **********************************************************/
    
    static CURLcode tftp_tx(tftp_state_data_t *state, tftp_event_t event)
    
      struct SessionHandle *data = state->conn->data;
    
    
      switch(event) {
    
      case TFTP_EVENT_ACK:
        /* Ack the packet */
    
        rblock = getrpacketblock(&state->rpacket);
    
    
        if(rblock != state->block) {
          /* This isn't the expected block.  Log it and up the retry counter */
    
          infof(data, "Received ACK for block %d, expecting %d\n",
    
                rblock, state->block);
          state->retries++;
          /* Bail out if over the maximum */
          if(state->retries>state->retry_max) {
    
            failf(data, "tftp_tx: giving up waiting for block %d ack",
    
            /* Re-send the data packet */
            sbytes = sendto(state->sockfd, (void *)&state->spacket,
                            4+state->sbytes, SEND_4TH_ARG,
                            (struct sockaddr *)&state->remote_addr,
                            state->remote_addrlen);
            /* Check all sbytes were sent */
            if(sbytes<0) {
              failf(data, "%s\n", Curl_strerror(state->conn, Curl_sockerrno()));
    
        }
        /* This is the expected packet.  Reset the counters and send the next
           block */
        state->block++;
        state->retries = 0;
    
        setpacketevent(&state->spacket, TFTP_EVENT_DATA);
        setpacketblock(&state->spacket, state->block);
    
        if(state->block > 1 && state->sbytes < TFTP_BLOCKSIZE) {
    
        res = Curl_fillreadbuffer(state->conn, TFTP_BLOCKSIZE, &state->sbytes);
        if(res)
          return res;
    
        sbytes = sendto(state->sockfd, (void *)state->spacket.data,
    
                        4+state->sbytes, SEND_4TH_ARG,
    
                        (struct sockaddr *)&state->remote_addr,
                        state->remote_addrlen);
    
        /* Check all sbytes were sent */
        if(sbytes<0) {
    
          failf(data, "%s\n", Curl_strerror(state->conn, Curl_sockerrno()));
    
        }
        break;
    
      case TFTP_EVENT_TIMEOUT:
        /* Increment the retry counter and log the timeout */
        state->retries++;
    
        infof(data, "Timeout waiting for block %d ACK. "
    
              " Retries = %d\n", state->retries);
        /* Decide if we've had enough */
        if(state->retries > state->retry_max) {
          state->error = TFTP_ERR_TIMEOUT;
          state->state = TFTP_STATE_FIN;
        } else {
          /* Re-send the data packet */
    
          sbytes = sendto(state->sockfd, (void *)&state->spacket,
    
                          4+state->sbytes, SEND_4TH_ARG,
    
                          (struct sockaddr *)&state->remote_addr,
                          state->remote_addrlen);
    
          /* Check all sbytes were sent */
          if(sbytes<0) {
    
            failf(data, "%s\n", Curl_strerror(state->conn, Curl_sockerrno()));
    
          }
        }
        break;
    
      case TFTP_EVENT_ERROR:
        state->state = TFTP_STATE_FIN;
        break;
    
      default:
    
        failf(data, "%s\n", "tftp_tx: internal error");
    
      Curl_pgrsSetUploadCounter(data, (curl_off_t) state->block*TFTP_BLOCKSIZE);
    
    }
    
    /**********************************************************
     *
     * tftp_state_machine
     *
     * The tftp state machine event dispatcher
     *
     **********************************************************/
    static CURLcode tftp_state_machine(tftp_state_data_t *state,
                                       tftp_event_t event)
    {
    
      struct SessionHandle *data = state->conn->data;
    
      switch(state->state) {
      case TFTP_STATE_START:
    
        DEBUGF(infof(data, "TFTP_STATE_START\n"));
    
        res = tftp_send_first(state, event);
    
        DEBUGF(infof(data, "TFTP_STATE_RX\n"));
    
        DEBUGF(infof(data, "TFTP_STATE_TX\n"));
    
        infof(data, "%s\n", "TFTP finished");
    
        DEBUGF(infof(data, "STATE: %d\n", state->state));
        failf(data, "%s\n", "Internal state machine error");
    
    }
    
    
    /**********************************************************
     *
     * Curl_tftp_connect
     *
     * The connect callback
     *
     **********************************************************/
    CURLcode Curl_tftp_connect(struct connectdata *conn, bool *done)
    {
      CURLcode code;
      tftp_state_data_t     *state;
      int rc;
    
    
      state = conn->proto.tftp = calloc(sizeof(tftp_state_data_t), 1);
      if(!state)
    
        return CURLE_OUT_OF_MEMORY;
    
    
      state->conn = conn;
      state->sockfd = state->conn->sock[FIRSTSOCKET];
      state->state = TFTP_STATE_START;
    
    
      ((struct sockaddr *)&state->local_addr)->sa_family =
    
      /* Bind to any interface, random UDP port.
       *
       * We once used the size of the local_addr struct as the third argument for
       * bind() to better work with IPv6 or whatever size the struct could have,
       * but we learned that at least Tru64, AIX and IRIX *requires* the size of
       * that argument to match the exact size of a 'sockaddr_in' struct when
       * running IPv4-only.
       *
       * Therefore we use the size from the address we connected to, which we
       * assume uses the same IP version and thus hopefully this works for both
       * IPv4 and IPv6...
       */
    
      rc = bind(state->sockfd, (struct sockaddr *)&state->local_addr,
    
        failf(conn->data, "bind() failed; %s\n",
    
              Curl_strerror(conn, Curl_sockerrno()));
    
        return CURLE_COULDNT_CONNECT;
      }
    
    
      Curl_pgrsStartNow(conn->data);
    
      *done = TRUE;
      code = CURLE_OK;
      return(code);
    }
    
    /**********************************************************
     *
     * Curl_tftp_done
     *
     * The done callback
     *
     **********************************************************/
    CURLcode Curl_tftp_done(struct connectdata *conn, CURLcode status)
    {
      (void)status; /* unused */
    
      free(conn->proto.tftp);
      conn->proto.tftp = NULL;
      Curl_pgrsDone(conn);
    
      return CURLE_OK;
    }
    
    
    /**********************************************************
     *
     * Curl_tftp
     *
     * The do callback
     *
     * This callback handles the entire TFTP transfer
     *
     **********************************************************/
    
    CURLcode Curl_tftp(struct connectdata *conn, bool *done)
    {
      struct SessionHandle  *data = conn->data;
      tftp_state_data_t     *state = (tftp_state_data_t *)(conn->proto.tftp);
      tftp_event_t          event;
      CURLcode              code;
      int                   rc;
    
      socklen_t             fromlen;
      int                   check_time = 0;
    
      (void)done; /* prevent compiler warning */
    
      /* Run the TFTP State Machine */
      for(tftp_state_machine(state, TFTP_EVENT_INIT);
          state->state != TFTP_STATE_FIN;
          tftp_state_machine(state, event) ) {
    
        /* Wait until ready to read or timeout occurs */
    
        rc=Curl_select(state->sockfd, CURL_SOCKET_BAD, state->retry_time * 1000);
    
          int error = Curl_sockerrno();
    
          failf(data, "%s\n", Curl_strerror(conn, error));
    
          event = TFTP_EVENT_ERROR;
        }
        else if (rc==0) {
          /* A timeout occured */
          event = TFTP_EVENT_TIMEOUT;
    
          /* Force a look at transfer timeouts */
          check_time = 0;
    
        }
        else {
    
          /* Receive the packet */
          fromlen=sizeof(fromaddr);
          state->rbytes = recvfrom(state->sockfd,
                                   (void *)&state->rpacket, sizeof(state->rpacket),
    
                                   0, (struct sockaddr *)&fromaddr, &fromlen);
    
          if(state->remote_addrlen==0) {
            memcpy(&state->remote_addr, &fromaddr, fromlen);
            state->remote_addrlen = fromlen;
          }
    
    
          /* Sanity check packet length */
    
            failf(conn->data, "Received too short packet\n");
            /* Not a timeout, but how best to handle it? */
            event = TFTP_EVENT_TIMEOUT;
    
          }
          else {
    
            /* The event is given by the TFTP packet time */
            event = (tftp_event_t)getrpacketevent(&state->rpacket);
    
            switch(event) {
            case TFTP_EVENT_DATA:
              /* Don't pass to the client empty or retransmitted packets */
              if (state->rbytes > 4 &&
                  ((state->block+1) == getrpacketblock(&state->rpacket))) {
    
                code = Curl_client_write(conn, CLIENTWRITE_BODY,
    
                                         (char *)&state->rpacket.data[4],
                                         state->rbytes-4);
                if(code)
                  return code;
              }
              break;
            case TFTP_EVENT_ERROR:
              state->error = (tftp_error_t)getrpacketblock(&state->rpacket);
              infof(conn->data, "%s\n", (char *)&state->rpacket.data[4]);
              break;
            case TFTP_EVENT_ACK:
              break;
            case TFTP_EVENT_RRQ:
            case TFTP_EVENT_WRQ:
            default:
              failf(conn->data, "%s\n", "Internal error: Unexpected packet");
              break;
            }
    
            /* Update the progress meter */
    
            if(Curl_pgrsUpdate(conn))
              return CURLE_ABORTED_BY_CALLBACK;
    
        }
    
        /* Check for transfer timeout every 10 blocks, or after timeout */
        if(check_time%10==0) {
          time_t current;
          time(&current);
          if(current>state->max_time) {
    
            DEBUGF(infof(data, "timeout: %d > %d\n",
                         current, state->max_time));
    
            state->error = TFTP_ERR_TIMEOUT;
            state->state = TFTP_STATE_FIN;
          }
        }
    
      }
    
      /* Tell curl we're done */
    
      code = Curl_Transfer(conn, -1, -1, FALSE, NULL, -1, NULL);
      if(code)
        return code;
    
    
      /* If we have encountered an error */
      if(state->error) {
    
        /* Translate internal error codes to curl error codes */
        switch(state->error) {
        case TFTP_ERR_NOTFOUND:
          code = CURLE_TFTP_NOTFOUND;
          break;
        case TFTP_ERR_PERM:
          code = CURLE_TFTP_PERM;
          break;
        case TFTP_ERR_DISKFULL:
          code = CURLE_TFTP_DISKFULL;
          break;
        case TFTP_ERR_ILLEGAL:
          code = CURLE_TFTP_ILLEGAL;
          break;
        case TFTP_ERR_UNKNOWNID:
          code = CURLE_TFTP_UNKNOWNID;
          break;
        case TFTP_ERR_EXISTS:
          code = CURLE_TFTP_EXISTS;
          break;
        case TFTP_ERR_NOSUCHUSER:
          code = CURLE_TFTP_NOSUCHUSER;
          break;
        case TFTP_ERR_TIMEOUT:
          code = CURLE_OPERATION_TIMEOUTED;
          break;
        case TFTP_ERR_NORESPONSE:
          code = CURLE_COULDNT_CONNECT;
          break;
        default:
          code= CURLE_ABORTED_BY_CALLBACK;
          break;
        }
      }
      else
        code = CURLE_OK;
      return code;
    }
    #endif