Skip to content
Snippets Groups Projects
tftp.c 33 KiB
Newer Older
/***************************************************************************
 *                                  _   _ ____  _
 *  Project                     ___| | | |  _ \| |
 *                             / __| | | | |_) | |
 *                            | (__| |_| |  _ <| |___
 *                             \___|\___/|_| \_\_____|
 *
 * Copyright (C) 1998 - 2009, 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 <stdarg.h>
#include <stdlib.h>
#include <ctype.h>

#if defined(WIN32)
#include <time.h>
#include <io.h>
#else
#ifdef HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif
#include <netinet/in.h>
Gisle Vanem's avatar
Gisle Vanem committed
#endif
#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

#ifdef HAVE_SYS_PARAM_H
#include <sys/param.h>
#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 "curl_memory.h"
#include "select.h"

/* The last #include file should be: */
#include "memdebug.h"

/* RFC2348 allows the block size to be negotiated */
#define TFTP_BLKSIZE_DEFAULT 512
#define TFTP_BLKSIZE_MIN 8
#define TFTP_BLKSIZE_MAX 65464
#define TFTP_OPTION_BLKSIZE "blksize"
#define TFTP_OPTION_TSIZE "tsize"
#define TFTP_OPTION_INTERVAL "interval"
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,  /* This will never be triggered by this code */

  /* The remaining error codes are internal to curl */
  TFTP_ERR_NONE = -100,
  TFTP_ERR_TIMEOUT,
  TFTP_ERR_NORESPONSE
} tftp_error_t;

typedef struct tftp_packet {
} 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;
  time_t          start_time;
  time_t          max_time;
  unsigned short  block;
  struct Curl_sockaddr_storage   local_addr;
  struct Curl_sockaddr_storage   remote_addr;
  curl_socklen_t  remote_addrlen;
  size_t          sbytes;
  size_t          blksize;
  int             requested_blksize;
  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) ;
static CURLcode tftp_connect(struct connectdata *conn, bool *done);
static CURLcode tftp_disconnect(struct connectdata *conn);
static CURLcode tftp_do(struct connectdata *conn, bool *done);
static CURLcode tftp_done(struct connectdata *conn,
static CURLcode tftp_setup_connection(struct connectdata * conn);


/*
 * TFTP protocol handler.
 */

const struct Curl_handler Curl_handler_tftp = {
  "TFTP",                               /* scheme */
  tftp_setup_connection,                /* setup_connection */
  tftp_do,                              /* do_it */
  tftp_done,                            /* done */
  ZERO_NULL,                            /* do_more */
  ZERO_NULL,                            /* connecting */
  ZERO_NULL,                            /* doing */
  ZERO_NULL,                            /* proto_getsock */
  ZERO_NULL,                            /* doing_getsock */
  PORT_TFTP,                            /* defport */
  PROT_TFTP                             /* protocol */
};


/**********************************************************
 *
 * 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
 *
 *
 **********************************************************/
static CURLcode tftp_set_timeouts(tftp_state_data_t *state)
  bool start = (bool)(state->state == TFTP_STATE_START);
  timeout_ms = Curl_timeleft(state->conn, NULL, start);

  if(timeout_ms < 0) {
    /* time-out, bail out, go home */
    failf(state->conn->data, "Connection time-out");
    return CURLE_OPERATION_TIMEDOUT;
  }

    maxtime = (time_t)(timeout_ms + 500) / 1000;
    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;

    if(state->retry_max < 1)
      /* avoid division by zero below */
      state->retry_max = 1;

    /* 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;
    if(timeout_ms > 0)
      maxtime = (time_t)(timeout_ms + 500) / 1000;
    else
      maxtime = 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(state->conn->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)
{
Yang Tse's avatar
Yang Tse committed
  packet->data[0] = (unsigned char)(num >> 8);
  packet->data[1] = (unsigned char)(num & 0xff);
}


static void setpacketblock(tftp_packet_t *packet, unsigned short num)
{
Yang Tse's avatar
Yang Tse committed
  packet->data[2] = (unsigned char)(num >> 8);
  packet->data[3] = (unsigned char)(num & 0xff);
Dan Fandrich's avatar
Dan Fandrich committed
static unsigned short getrpacketevent(const tftp_packet_t *packet)
Yang Tse's avatar
Yang Tse committed
  return (unsigned short)((packet->data[0] << 8) | packet->data[1]);
Dan Fandrich's avatar
Dan Fandrich committed
static unsigned short getrpacketblock(const tftp_packet_t *packet)
Yang Tse's avatar
Yang Tse committed
  return (unsigned short)((packet->data[2] << 8) | packet->data[3]);
static size_t Curl_strnlen(const char *string, size_t maxlen)
{
  const char *end = memchr (string, '\0', maxlen);
  return end ? (size_t) (end - string) : maxlen;
}

static const char *tftp_option_get(const char *buf, size_t len,
                                   const char **option, const char **value)
{
  size_t loc;

  loc = Curl_strnlen( buf, len );
  loc++; /* NULL term */

  if (loc >= len)
    return NULL;
  *option = buf;

  loc += Curl_strnlen( buf+loc, len-loc );
  loc++; /* NULL term */

  if (loc > len)
    return NULL;
  *value = &buf[strlen(*option) + 1];

  return &buf[loc];
}

static CURLcode tftp_parse_option_ack(tftp_state_data_t *state,
                                      const char *ptr, int len)
{
  const char *tmp = ptr;
  struct SessionHandle *data = state->conn->data;

  /* if OACK doesn't contain blksize option, the default (512) must be used */
  state->blksize = TFTP_BLKSIZE_DEFAULT;

  while (tmp < ptr + len) {
    const char *option, *value;

    tmp = tftp_option_get(tmp, ptr + len - tmp, &option, &value);
    if(tmp == NULL) {
      failf(data, "Malformed ACK packet, rejecting");
      return CURLE_TFTP_ILLEGAL;
    }

    infof(data, "got option=(%s) value=(%s)\n", option, value);

    if(checkprefix(option, TFTP_OPTION_BLKSIZE)) {
      int blksize;

      blksize = (int)strtol( value, NULL, 10 );

      if(!blksize) {
        failf(data, "invalid blocksize value in OACK packet");
        return CURLE_TFTP_ILLEGAL;
      }
      else if(blksize > TFTP_BLKSIZE_MAX) {
        failf(data, "%s (%d)", "blksize is larger than max supported",
                TFTP_BLKSIZE_MAX);
        return CURLE_TFTP_ILLEGAL;
      }
      else if(blksize < TFTP_BLKSIZE_MIN) {
        failf(data, "%s (%d)", "blksize is smaller than min supported",
                TFTP_BLKSIZE_MIN);
        return CURLE_TFTP_ILLEGAL;
      }
      else if (blksize > state->requested_blksize) {
        /* could realloc pkt buffers here, but the spec doesn't call out
         * support for the server requesting a bigger blksize than the client
         * requests */
        failf(data, "%s (%d)",
                "server requested blksize larger than allocated", blksize);
        return CURLE_TFTP_ILLEGAL;
      }

      state->blksize = blksize;
      infof(data, "%s (%d) %s (%d)\n", "blksize parsed from OACK",
        state->blksize, "requested", state->requested_blksize);
    }
    else if(checkprefix(option, TFTP_OPTION_TSIZE)) {
      long tsize = 0;

      tsize = strtol( value, NULL, 10 );
      if(!tsize) {
        failf(data, "invalid tsize value in OACK packet");
        return CURLE_TFTP_ILLEGAL;
      }
      Curl_pgrsSetDownloadSize(data, tsize);
      infof(data, "%s (%d)\n", "tsize parsed from OACK", tsize);
    }
  }

  return CURLE_OK;
}

static size_t tftp_option_add(tftp_state_data_t *state, size_t csize,
                              char *buf, const char *option)
{
  if( ( strlen(option) + csize + 1U ) > state->blksize )
        return 0;
  strcpy(buf, option);
  return( strlen(option) + 1 );
}

static CURLcode tftp_connect_for_tx(tftp_state_data_t *state, tftp_event_t event)
#ifndef CURL_DISABLE_VERBOSE_STRINGS
  struct SessionHandle *data = state->conn->data;

  infof(data, "%s\n", "Connected for transmit");
  state->state = TFTP_STATE_TX;
  res = tftp_set_timeouts(state);
static CURLcode tftp_connect_for_rx(tftp_state_data_t *state, tftp_event_t event)
#ifndef CURL_DISABLE_VERBOSE_STRINGS
  struct SessionHandle *data = state->conn->data;

  infof(data, "%s\n", "Connected for receive");
  state->state = TFTP_STATE_RX;
  res = tftp_set_timeouts(state);
static CURLcode tftp_send_first(tftp_state_data_t *state, tftp_event_t event)
  struct SessionHandle *data = state->conn->data;
  CURLcode res = CURLE_OK;

  /* Set ascii mode if -B flag was used */
Loading
Loading full blame...