tftpd.c

THIS IS HTTP CURL Example

      (sock, SOL_SOCKET, SO_REUSEADDR, (const void *) &flag,
       sizeof(int)) < 0) {
    perror("setsockopt(SO_REUSEADDR)");
  }

#ifdef ENABLE_IPV6
  if(!use_ipv6) {
#endif
    me.sin_family = AF_INET;
    me.sin_addr.s_addr = INADDR_ANY;
    me.sin_port = htons(port);
    rc = bind(sock, (struct sockaddr *) &me, sizeof(me));
#ifdef ENABLE_IPV6
  }
  else {
    memset(&me6, 0, sizeof(struct sockaddr_in6));
    me6.sin6_family = AF_INET6;
    me6.sin6_addr = in6addr_any;
    me6.sin6_port = htons(port);
    rc = bind(sock, (struct sockaddr *) &me6, sizeof(me6));
  }
#endif /* ENABLE_IPV6 */
  if(rc < 0) {
    perror("binding stream socket");
    logmsg("Error binding socket");
    return 1;
  }

  pidfile = fopen(pidname, "w");
  if(pidfile) {
    fprintf(pidfile, "%d\n", (int)getpid());
    fclose(pidfile);
  }
  else {
    error = ERRNO;
    logmsg("fopen() failed with error: %d %s", error, strerror(error));
    logmsg("Error opening file: %s", pidname);
    logmsg("Couldn't write pid file");
  }

  logmsg("Running IPv%d version on port UDP/%d",
#ifdef ENABLE_IPV6
         (use_ipv6?6:4)
#else
         4
#endif
         , port );

  do {
    fromlen = sizeof(from);
    n = recvfrom(sock, buf, sizeof (buf), 0,
                 (struct sockaddr *)&from, &fromlen);
    if (n < 0) {
      logmsg("recvfrom:\n");
      return 3;
    }

    from.sin_family = AF_INET;

    peer = socket(AF_INET, SOCK_DGRAM, 0);
    if (peer < 0) {
      logmsg("socket:\n");
      return 2;
    }

    if (connect(peer, (struct sockaddr *)&from, sizeof(from)) < 0) {
      logmsg("connect: fail\n");
      return 1;
    }
    maxtimeout = 5*TIMEOUT;

    tp = (struct tftphdr *)buf;
    tp->th_opcode = ntohs(tp->th_opcode);
    if (tp->th_opcode == RRQ || tp->th_opcode == WRQ) {
      memset(&test, 0, sizeof(test));
      if (tftp(&test, tp, n) < 0)
        break;
      if(test.buffer)
        free(test.buffer);
    }
    sclose(peer);
  } while(1);
  return 0;
}

struct formats {
  const char *f_mode;
  int f_convert;
} formats[] = {
  { "netascii",   1 },
  { "octet",      0 },
  { NULL,         0 }
};

/*
 * Handle initial connection protocol.
 */
static int tftp(struct testcase *test, struct tftphdr *tp, int size)
{
  char *cp;
  int first = 1, ecode;
  struct formats *pf;
  char *filename, *mode = NULL;
  int error;
  FILE *server;

  /* Open request dump file. */
  server = fopen(REQUEST_DUMP, "ab");
  if(!server) {
    error = ERRNO;
    logmsg("fopen() failed with error: %d %s", error, strerror(error));
    logmsg("Error opening file: %s", REQUEST_DUMP);
    return -1;
  }

  /* store input protocol */
  fprintf(server, "opcode: %x\n", tp->th_opcode);

  cp = (char *)&tp->th_stuff;
  filename = cp;
again:
  while (cp < buf + size) {
    if (*cp == '\0')
      break;
    cp++;
  }
  if (*cp) {
    nak(EBADOP);
    fclose(server);
    return 3;
  }
  if (first) {
    mode = ++cp;
    first = 0;
    goto again;
  }
  /* store input protocol */
  fprintf(server, "filename: %s\n", filename);

  for (cp = mode; *cp; cp++)
    if(ISUPPER(*cp))
      *cp = (char)tolower((int)*cp);

  /* store input protocol */
  fprintf(server, "mode: %s\n", mode);
  fclose(server);

  for (pf = formats; pf->f_mode; pf++)
    if (strcmp(pf->f_mode, mode) == 0)
      break;
  if (!pf->f_mode) {
    nak(EBADOP);
    return 2;
  }
  ecode = validate_access(test, filename, tp->th_opcode);
  if (ecode) {
    nak(ecode);
    return 1;
  }
  if (tp->th_opcode == WRQ)
    recvtftp(test, pf);
  else
    sendtftp(test, pf);

  return 0;
}

/*
 * Validate file access.
 */
static int validate_access(struct testcase *test,
                           const char *filename, int mode)
{
  char *ptr;
  long testno, partno;
  int error;
  char partbuf[80]="data";

  logmsg("trying to get file: %s mode %x", filename, mode);

  if(!strncmp("verifiedserver", filename, 15)) {
    char weare[128];
    size_t count = sprintf(weare, "WE ROOLZ: %d\r\n", (int)getpid());

    logmsg("Are-we-friendly question received");
    test->buffer = strdup(weare);
    test->rptr = test->buffer; /* set read pointer */
    test->bufsize = count;    /* set total count */
    test->rcount = count;     /* set data left to read */
    return 0; /* fine */
  }

  /* find the last slash */
  ptr = strrchr(filename, '/');

  if(ptr) {
    char *file;

    ptr++; /* skip the slash */

    /* skip all non-numericals following the slash */
    while(*ptr && !ISDIGIT(*ptr))
      ptr++;

    /* get the number */
    testno = strtol(ptr, &ptr, 10);

    if(testno > 10000) {
      partno = testno % 10000;
      testno /= 10000;
    }
    else
      partno = 0;


    logmsg("requested test number %ld part %ld", testno, partno);

    test->num = testno;

    file = test2file(testno);

    if(0 != partno)
      sprintf(partbuf, "data%ld", partno);

    if(file) {
      FILE *stream=fopen(file, "rb");
      if(!stream) {
        error = ERRNO;
        logmsg("fopen() failed with error: %d %s", error, strerror(error));
        logmsg("Error opening file: %s", file);
        logmsg("Couldn't open test file: %s", file);
        return EACCESS;
      }
      else {
        size_t count;
        test->buffer = (char *)spitout(stream, "reply", partbuf, &count);
        fclose(stream);
        if(test->buffer) {
          test->rptr = test->buffer; /* set read pointer */
          test->bufsize = count;    /* set total count */
          test->rcount = count;     /* set data left to read */
        }
        else
          return EACCESS;
      }

    }
    else
      return EACCESS;
  }
  else {
    logmsg("no slash found in path");
    return EACCESS; /* failure */
  }

  return 0;
}

int timeout;
#ifdef HAVE_SIGSETJMP
sigjmp_buf timeoutbuf;
#endif

static void timer(int signum)
{
  (void)signum;

  logmsg("alarm!");

  timeout += rexmtval;
  if (timeout >= maxtimeout)
    exit(1);
#ifdef HAVE_SIGSETJMP
  siglongjmp(timeoutbuf, 1);
#endif
}

/*
 * Send the requested file.
 */
static void sendtftp(struct testcase *test, struct formats *pf)
{
  struct tftphdr *dp;
  struct tftphdr *ap;    /* ack packet */
  unsigned short block = 1;
  int size;
  ssize_t n;
#if defined(HAVE_ALARM) && defined(SIGALRM)
  mysignal(SIGALRM, timer);
#endif
  dp = r_init();
  ap = (struct tftphdr *)ackbuf;
  do {
    size = readit(test, &dp, pf->f_convert);
    if (size < 0) {
      nak(ERRNO + 100);
      return;
    }
    dp->th_opcode = htons((u_short)DATA);
    dp->th_block = htons((u_short)block);
    timeout = 0;
#ifdef HAVE_SIGSETJMP
    (void) sigsetjmp(timeoutbuf, 1);
#endif
    send_data:
    if (swrite(peer, dp, size + 4) != size + 4) {
      logmsg("write\n");
      return;
    }
    read_ahead(test, pf->f_convert);
    for ( ; ; ) {
#ifdef HAVE_ALARM
      alarm(rexmtval);        /* read the ack */
#endif
      n = sread(peer, ackbuf, sizeof (ackbuf));
#ifdef HAVE_ALARM
      alarm(0);
#endif
      if (n < 0) {
        logmsg("read: fail\n");
        return;
      }
      ap->th_opcode = ntohs((u_short)ap->th_opcode);
      ap->th_block = ntohs((u_short)ap->th_block);

      if (ap->th_opcode == ERROR) {
        logmsg("got ERROR");
        return;
      }

      if (ap->th_opcode == ACK) {
        if (ap->th_block == block) {
          break;
        }
        /* Re-synchronize with the other side */
        (void) synchnet(peer);
        if (ap->th_block == (block -1)) {
          goto send_data;
        }
      }

    }
    block++;
  } while (size == SEGSIZE);
}

static void justtimeout(int signum)
{
  (void)signum;
}


/*
 * Receive a file.
 */
static void recvtftp(struct testcase *test, struct formats *pf)
{
  struct tftphdr *dp;
  struct tftphdr *ap;    /* ack buffer */
  unsigned short block = 0;
  ssize_t n, size;
#if defined(HAVE_ALARM) && defined(SIGALRM)
  mysignal(SIGALRM, timer);
#endif
  dp = w_init();
  ap = (struct tftphdr *)ackbuf;
  do {
    timeout = 0;
    ap->th_opcode = htons((u_short)ACK);
    ap->th_block = htons((u_short)block);
    block++;
#ifdef HAVE_SIGSETJMP
    (void) sigsetjmp(timeoutbuf, 1);
#endif
send_ack:
    if (swrite(peer, ackbuf, 4) != 4) {
      logmsg("write: fail\n");
      goto abort;
    }
    write_behind(test, pf->f_convert);
    for ( ; ; ) {
#ifdef HAVE_ALARM
      alarm(rexmtval);
#endif
      n = sread(peer, dp, PKTSIZE);
#ifdef HAVE_ALARM
      alarm(0);
#endif
      if (n < 0) {                       /* really? */
        logmsg("read: fail\n");
        goto abort;
      }
      dp->th_opcode = ntohs((u_short)dp->th_opcode);
      dp->th_block = ntohs((u_short)dp->th_block);
      if (dp->th_opcode == ERROR)
        goto abort;
      if (dp->th_opcode == DATA) {
        if (dp->th_block == block) {
          break;                         /* normal */
        }
        /* Re-synchronize with the other side */
        (void) synchnet(peer);
        if (dp->th_block == (block-1))
          goto send_ack;                 /* rexmit */
      }
    }

    size = writeit(test, &dp, (int)(n - 4), pf->f_convert);
    if (size != (n-4)) {                 /* ahem */
      if (size < 0)
        nak(ERRNO + 100);
      else
        nak(ENOSPACE);
      goto abort;
    }
  } while (size == SEGSIZE);
  write_behind(test, pf->f_convert);

  ap->th_opcode = htons((u_short)ACK);   /* send the "final" ack */
  ap->th_block = htons((u_short)(block));
  (void) swrite(peer, ackbuf, 4);
#if defined(HAVE_ALARM) && defined(SIGALRM)
  mysignal(SIGALRM, justtimeout);        /* just abort read on timeout */
  alarm(rexmtval);
#endif
  n = sread(peer, buf, sizeof(buf));     /* normally times out and quits */
#ifdef HAVE_ALARM
  alarm(0);
#endif
  if (n >= 4 &&                          /* if read some data */
      dp->th_opcode == DATA &&           /* and got a data block */
      block == dp->th_block) {           /* then my last ack was lost */
    (void) swrite(peer, ackbuf, 4);      /* resend final ack */
  }
abort:
  return;
}

struct errmsg {
  int e_code;
  const char *e_msg;
} errmsgs[] = {
  { EUNDEF,       "Undefined error code" },
  { ENOTFOUND,    "File not found" },
  { EACCESS,      "Access violation" },
  { ENOSPACE,     "Disk full or allocation exceeded" },
  { EBADOP,       "Illegal TFTP operation" },
  { EBADID,       "Unknown transfer ID" },
  { EEXISTS,      "File already exists" },
  { ENOUSER,      "No such user" },
  { -1,           0 }
};

/*
 * Send a nak packet (error message).  Error code passed in is one of the
 * standard TFTP codes, or a UNIX errno offset by 100.
 */
static void nak(int error)
{
  struct tftphdr *tp;
  int length;
  struct errmsg *pe;

  tp = (struct tftphdr *)buf;
  tp->th_opcode = htons((u_short)ERROR);
  tp->th_code = htons((u_short)error);
  for (pe = errmsgs; pe->e_code >= 0; pe++)
    if (pe->e_code == error)
      break;
  if (pe->e_code < 0) {
    pe->e_msg = strerror(error - 100);
    tp->th_code = EUNDEF;   /* set 'undef' errorcode */
  }
  strcpy(tp->th_msg, pe->e_msg);
  length = (int)strlen(pe->e_msg);
  tp->th_msg[length] = '\0';
  length += 5;
  if (swrite(peer, buf, length) != length)
    logmsg("nak: fail\n");
}