tftpd.c

THIS IS HTTP CURL Example

/***************************************************************************
 *                                  _   _ ____  _
 *  Project                     ___| | | |  _ \| |
 *                             / __| | | | |_) | |
 *                            | (__| |_| |  _ <| |___
 *                             \___|\___/|_| \_\_____|
 *
 * $Id: tftpd.c,v 1.30 2007-11-15 13:20:18 yangtse Exp $
 *
 * Trivial file transfer protocol server.
 *
 * This code includes many modifications by Jim Guyton <guyton@rand-unix>
 *
 * This source file was started based on netkit-tftpd 0.17
 * Heavily modified for curl's test suite
 */

/*
 * Copyright (c) 1983 Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include "setup.h" /* portability help from the lib directory */
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#ifdef HAVE_SYS_IOCTL_H
#include <sys/ioctl.h>
#endif
#ifdef HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif

#include <signal.h>

#ifdef HAVE_FCNTL_H
#include <fcntl.h>
#endif
#ifdef HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif
#ifdef HAVE_NETINET_IN_H
#include <netinet/in.h>
#endif
#ifdef HAVE_ARPA_TFTP_H
#include <arpa/tftp.h>
#else
#include "tftp.h"
#endif
#ifdef HAVE_NETDB_H
#include <netdb.h>
#endif
#ifdef HAVE_SYS_FILIO_H
/* FIONREAD on Solaris 7 */
#include <sys/filio.h>
#endif

#include <setjmp.h>
#include <stdio.h>
#include <errno.h>
#include <ctype.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#ifdef HAVE_PWD_H
#include <pwd.h>
#endif

#define ENABLE_CURLX_PRINTF
/* make the curlx header define all printf() functions to use the curlx_*
   versions instead */
#include "curlx.h" /* from the private lib dir */
#include "getpart.h"
#include "util.h"

/* include memdebug.h last */
#include "memdebug.h"

struct testcase {
  char *buffer;   /* holds the file data to send to the client */
  size_t bufsize; /* size of the data in buffer */
  char *rptr;     /* read pointer into the buffer */
  size_t rcount;  /* amount of data left to read of the file */
  long num;       /* test case number */
  int ofile;      /* file descriptor for output file when uploading to us */
};

static int synchnet(curl_socket_t);
static struct tftphdr *r_init(void);
static struct tftphdr *w_init(void);
static int readit(struct testcase *test, struct tftphdr **dpp, int convert);
static int writeit(struct testcase *test, struct tftphdr **dpp, int ct,
                   int convert);
static void mysignal(int, void (*func)(int));


#define TIMEOUT         5

#define PKTSIZE SEGSIZE+4

struct formats;
static int tftp(struct testcase *test, struct tftphdr *tp, int size);
static void nak(int error);
static void sendtftp(struct testcase *test, struct formats *pf);
static void recvtftp(struct testcase *test, struct formats *pf);
static int validate_access(struct testcase *test, const char *, int);

static curl_socket_t peer;
static int rexmtval = TIMEOUT;
static int maxtimeout = 5*TIMEOUT;

static char buf[PKTSIZE];
static char ackbuf[PKTSIZE];
static struct sockaddr_in from;
static socklen_t fromlen;

struct bf {
  int counter;            /* size of data in buffer, or flag */
  char buf[PKTSIZE];      /* room for data packet */
} bfs[2];

                                /* Values for bf.counter  */
#define BF_ALLOC -3             /* alloc'd but not yet filled */
#define BF_FREE  -2             /* free */
/* [-1 .. SEGSIZE] = size of data in the data buffer */

static int nextone;     /* index of next buffer to use */
static int current;     /* index of buffer in use */

                        /* control flags for crlf conversions */
int newline = 0;        /* fillbuf: in middle of newline expansion */
int prevchar = -1;      /* putbuf: previous char (cr check) */

static void read_ahead(struct testcase *test,
                       int convert /* if true, convert to ascii */);
static ssize_t write_behind(struct testcase *test, int convert);
static struct tftphdr *rw_init(int);
static struct tftphdr *w_init(void) { return rw_init(0); } /* write-behind */
static struct tftphdr *r_init(void) { return rw_init(1); } /* read-ahead */

static struct tftphdr *
rw_init(int x)              /* init for either read-ahead or write-behind */
{                           /* zero for write-behind, one for read-head */
  newline = 0;            /* init crlf flag */
  prevchar = -1;
  bfs[0].counter =  BF_ALLOC;     /* pass out the first buffer */
  current = 0;
  bfs[1].counter = BF_FREE;
  nextone = x;                    /* ahead or behind? */
  return (struct tftphdr *)bfs[0].buf;
}


/* Have emptied current buffer by sending to net and getting ack.
   Free it and return next buffer filled with data.
 */
static int readit(struct testcase *test, struct tftphdr **dpp,
           int convert /* if true, convert to ascii */)
{
  struct bf *b;

  bfs[current].counter = BF_FREE; /* free old one */
  current = !current;             /* "incr" current */

  b = &bfs[current];              /* look at new buffer */
  if (b->counter == BF_FREE)      /* if it's empty */
    read_ahead(test, convert);      /* fill it */

  *dpp = (struct tftphdr *)b->buf;        /* set caller's ptr */
  return b->counter;
}

#undef MIN /* some systems have this defined already, some don't */
#define MIN(x,y) ((x)<(y)?(x):(y));

/*
 * fill the input buffer, doing ascii conversions if requested
 * conversions are  lf -> cr,lf  and cr -> cr, nul
 */
static void read_ahead(struct testcase *test,
                       int convert /* if true, convert to ascii */)
{
  int i;
  char *p;
  int c;
  struct bf *b;
  struct tftphdr *dp;

  b = &bfs[nextone];              /* look at "next" buffer */
  if (b->counter != BF_FREE)      /* nop if not free */
    return;
  nextone = !nextone;             /* "incr" next buffer ptr */

  dp = (struct tftphdr *)b->buf;

  if (convert == 0) {
    /* The former file reading code did this:
       b->counter = read(fileno(file), dp->th_data, SEGSIZE); */
    size_t copy_n = MIN(SEGSIZE, test->rcount);
    memcpy(dp->th_data, test->rptr, copy_n);

    /* decrease amount, advance pointer */
    test->rcount -= copy_n;
    test->rptr += copy_n;
    b->counter = (int)copy_n;
    return;
  }

  p = dp->th_data;
  for (i = 0 ; i < SEGSIZE; i++) {
    if (newline) {
      if (prevchar == '\n')
        c = '\n';       /* lf to cr,lf */
      else
        c = '\0';       /* cr to cr,nul */
      newline = 0;
    }
    else {
      if(test->rcount) {
        c=test->rptr[0];
        test->rptr++;
        test->rcount--;
      }
      else
        break;
      if (c == '\n' || c == '\r') {
        prevchar = c;
        c = '\r';
        newline = 1;
      }
    }
    *p++ = (char)c;
  }
  b->counter = (int)(p - dp->th_data);
}

/* Update count associated with the buffer, get new buffer from the queue.
   Calls write_behind only if next buffer not available.
 */
static int writeit(struct testcase *test, struct tftphdr **dpp,
                   int ct, int convert)
{
  bfs[current].counter = ct;      /* set size of data to write */
  current = !current;             /* switch to other buffer */
  if (bfs[current].counter != BF_FREE)     /* if not free */
    write_behind(test, convert);     /* flush it */
  bfs[current].counter = BF_ALLOC;        /* mark as alloc'd */
  *dpp =  (struct tftphdr *)bfs[current].buf;
  return ct;                      /* this is a lie of course */
}

/*
 * Output a buffer to a file, converting from netascii if requested.
 * CR,NUL -> CR  and CR,LF => LF.
 * Note spec is undefined if we get CR as last byte of file or a
 * CR followed by anything else.  In this case we leave it alone.
 */
static ssize_t write_behind(struct testcase *test, int convert)
{
  char *writebuf;
  int count;
  int ct;
  char *p;
  int c;                          /* current character */
  struct bf *b;
  struct tftphdr *dp;

  b = &bfs[nextone];
  if (b->counter < -1)            /* anything to flush? */
    return 0;                     /* just nop if nothing to do */

  if(!test->ofile) {
    char outfile[256];
    snprintf(outfile, sizeof(outfile), "log/upload.%ld", test->num);
    test->ofile=open(outfile, O_CREAT|O_RDWR, 0777);
    if(test->ofile == -1) {
      logmsg("Couldn't create and/or open file %s for upload!", outfile);
      return -1; /* failure! */
    }
  }

  count = b->counter;             /* remember byte count */
  b->counter = BF_FREE;           /* reset flag */
  dp = (struct tftphdr *)b->buf;
  nextone = !nextone;             /* incr for next time */
  writebuf = dp->th_data;

  if (count <= 0)
    return -1;                    /* nak logic? */

  if (convert == 0)
    return write(test->ofile, writebuf, count);

  p = writebuf;
  ct = count;
  while (ct--) {                  /* loop over the buffer */
    c = *p++;                     /* pick up a character */
    if (prevchar == '\r') {       /* if prev char was cr */
      if (c == '\n')              /* if have cr,lf then just */
        lseek(test->ofile, -1, SEEK_CUR); /* smash lf on top of the cr */
      else
        if (c == '\0')            /* if have cr,nul then */
          goto skipit;            /* just skip over the putc */
      /* else just fall through and allow it */
    }
    /* formerly
       putc(c, file); */
    write(test->ofile, &c, 1);
    skipit:
    prevchar = c;
  }
  return count;
}


/* When an error has occurred, it is possible that the two sides are out of
 * synch.  Ie: that what I think is the other side's response to packet N is
 * really their response to packet N-1.
 *
 * So, to try to prevent that, we flush all the input queued up for us on the
 * network connection on our host.
 *
 * We return the number of packets we flushed (mostly for reporting when trace
 * is active).
 */

static int synchnet(curl_socket_t f /* socket to flush */)
{

#if defined(HAVE_IOCTLSOCKET)
  unsigned long i;
#else
  int i;
#endif
  int j = 0;
  char rbuf[PKTSIZE];
  struct sockaddr_in fromaddr;
  socklen_t fromaddrlen;

  while (1) {
#if defined(HAVE_IOCTLSOCKET)
    (void) ioctlsocket(f, FIONREAD, &i);
#else
    (void) ioctl(f, FIONREAD, &i);
#endif
    if (i) {
      j++;
      fromaddrlen = sizeof fromaddr;
      (void) recvfrom(f, rbuf, sizeof (rbuf), 0,
                      (struct sockaddr *)&fromaddr, &fromaddrlen);
    }
    else
      break;
  }
  return j;
}

#if defined(HAVE_ALARM) && defined(SIGALRM)
/*
 * Like signal(), but with well-defined semantics.
 */
static void mysignal(int sig, void (*handler)(int))
{
  struct sigaction sa;
  memset(&sa, 0, sizeof(sa));
  sa.sa_handler = handler;
  sigaction(sig, &sa, NULL);
}
#endif

#ifndef DEFAULT_LOGFILE
#define DEFAULT_LOGFILE "log/tftpd.log"
#endif

#define DEFAULT_PORT 8999 /* UDP */
const char *serverlogfile = DEFAULT_LOGFILE;

#define REQUEST_DUMP  "log/server.input"

char use_ipv6=FALSE;

int main(int argc, char **argv)
{
  struct sockaddr_in me;
#ifdef ENABLE_IPV6
  struct sockaddr_in6 me6;
#endif /* ENABLE_IPV6 */

  struct tftphdr *tp;
  int n = 0;
  int arg = 1;
  FILE *pidfile;
  char *pidname= (char *)".tftpd.pid";
  unsigned short port = DEFAULT_PORT;
  curl_socket_t sock;
  int flag;
  int rc;
  int error;
  struct testcase test;

  while(argc>arg) {
    if(!strcmp("--version", argv[arg])) {
      printf("tftpd IPv4%s\n",
#ifdef ENABLE_IPV6
             "/IPv6"
#else
             ""
#endif
             );
      return 0;
    }
    else if(!strcmp("--pidfile", argv[arg])) {
      arg++;
      if(argc>arg)
        pidname = argv[arg++];
    }
    else if(!strcmp("--ipv6", argv[arg])) {
#ifdef ENABLE_IPV6
      use_ipv6=TRUE;
#endif
      arg++;
    }
    else if(argc>arg) {

      if(atoi(argv[arg]))
        port = (unsigned short)atoi(argv[arg++]);

      if(argc>arg)
        path = argv[arg++];
    }
  }

#ifdef WIN32
  win32_init();
  atexit(win32_cleanup);
#endif

#ifdef ENABLE_IPV6
  if(!use_ipv6)
#endif
    sock = socket(AF_INET, SOCK_DGRAM, 0);
#ifdef ENABLE_IPV6
  else
    sock = socket(AF_INET6, SOCK_DGRAM, 0);
#endif

  if (sock < 0) {
    perror("opening stream socket");
    logmsg("Error opening socket");
    return 1;
  }

  flag = 1;
  if (setsockopt