main.c

linux下tftp客气端的源码实现

/*
 * Copyright (c) 1983, 1993
 *	The 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.
 * 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.
 */

#ifndef lint
static char     copyright[] = "@(#) Copyright (c) 1983, 1993\n\
	The Regents of the University of California.  All rights reserved.\n";
#endif /* not lint */

#ifndef lint
static char     sccsid[] = "@(#)main.c	8.1 (Berkeley) 6/6/93";
#endif /* not lint */

/* Many bug fixes are from Jim Guyton <guyton@rand-unix> */

/*
 * TFTP User Program -- Command Interface.
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <sys/types.h>
#include <sys/socket.h>
#include <sys/file.h>

#include <netinet/in.h>

#include <arpa/inet.h>

#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <netdb.h>
#include <setjmp.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "xalloc.h"
#include "extern.h"

#define	TIMEOUT		5	/* secs between rexmt's */

struct sockaddr_in peeraddr;
int             f;
short           port;
int             trace;
int             verbose;
int             connected;
char            mode[32];
char            line[200];
int             margc;
char           *margv[20];
char           *prompt = "tftp";
jmp_buf         toplevel;
void            intr ();
struct servent *sp;

void get        (int, char **);
void help       (int, char **);
void modecmd    (int, char **);
void put        (int, char **);
void quit       (int, char **);
void setascii   (int, char **);
void setbinary  (int, char **);
void setpeer    (int, char **);
void setrexmt   (int, char **);
void settimeout (int, char **);
void settrace   (int, char **);
void setverbose (int, char **);
void status     (int, char **);

static void command (void);

static void getusage (char *);
static void makeargv (void);
static void putusage (char *);
static void settftpmode (char *);

#define HELPINDENT (sizeof("connect"))

struct cmd
{
  char           *name;
  char           *help;
  void            (*handler) (int, char **);
};

char            vhelp[] = "toggle verbose mode";
char            thelp[] = "toggle packet tracing";
char            chelp[] = "connect to remote tftp";
char            qhelp[] = "exit tftp";
char            hhelp[] = "print help information";
char            shelp[] = "send file";
char            rhelp[] = "receive file";
char            mhelp[] = "set file transfer mode";
char            sthelp[] = "show current status";
char            xhelp[] = "set per-packet retransmission timeout";
char            ihelp[] = "set total retransmission timeout";
char            ashelp[] = "set mode to netascii";
char            bnhelp[] = "set mode to octet";

struct cmd      cmdtab[] = {
  {"connect", chelp, setpeer},
  {"mode", mhelp, modecmd},
  {"put", shelp, put},
  {"get", rhelp, get},
  {"quit", qhelp, quit},
  {"verbose", vhelp, setverbose},
  {"trace", thelp, settrace},
  {"status", sthelp, status},
  {"binary", bnhelp, setbinary},
  {"ascii", ashelp, setascii},
  {"rexmt", xhelp, setrexmt},
  {"timeout", ihelp, settimeout},
  {"?", hhelp, help},
  {0}
};

struct cmd     *getcmd ();
char           *tail ();

char *program_name;

int
main (int argc, char *argv[])
{
  struct sockaddr_in sin;

  program_name = argv[0];

  sp = getservbyname ("tftp", "udp");
  if (sp == 0)
    {
      fprintf (stderr, "tftp: udp/tftp: unknown service\n");
      exit (1);
    }
  f = socket (AF_INET, SOCK_DGRAM, 0);
  if (f < 0)
    {
      perror ("tftp: socket");
      exit (3);
    }
  memset (&sin, 0, sizeof (sin));
  sin.sin_family = AF_INET;
  if (bind (f, (struct sockaddr *) &sin, sizeof (sin)) < 0)
    {
      perror ("tftp: bind");
      exit (1);
    }
  strcpy (mode, "netascii");
  signal (SIGINT, intr);
  if (argc > 1)
    {
      if (setjmp (toplevel) != 0)
	exit (0);
      setpeer (argc, argv);
    }
  if (setjmp (toplevel) != 0)
    putchar ('\n');
  command ();
}

char *hostname;

#define RESOLVE_OK            0
#define RESOLVE_FAIL         -1
#define RESOLVE_NOT_RESOLVED  1 

/* Resolve NAME. Fill in peeraddr, hostname and set connected on success.
   Return value: RESOLVE_OK success
                 RESOLVE_FAIL error
		 RESOLVE_NOT_RESOLVED name is not resolved and ALLOW_NULL
		 is true */
static int
resolve_name (char *name, int allow_null)
{
  struct hostent *hp = gethostbyname (name);
  if (hp == NULL)
    {
      if (allow_null)
	return RESOLVE_NOT_RESOLVED;
      fprintf (stderr, "tftp: %s: ", name);
      herror ((char *) NULL);
      return RESOLVE_FAIL;
    }
  else if (hp->h_length != sizeof peeraddr.sin_addr)
    {
      fprintf (stderr, "tftp: resolving %s returns unexpected length", name);
      return RESOLVE_FAIL;
    }
  memcpy (&peeraddr.sin_addr, hp->h_addr, hp->h_length);
  peeraddr.sin_family = hp->h_addrtype;
  connected = 1;
  free (hostname);
  hostname = xstrdup (hp->h_name);
  return RESOLVE_OK;
}

/* Prompt for more arguments from the user with PROMPT, putting the results
   into ARGC & ARGV, with an initial argument of ARG0.  Global variables
   LINE, MARGC, and MARGV are changed.  */
static void
get_args (char *arg0, char *prompt, int *argc, char ***argv)
{
  size_t arg0_len = strlen (arg0);

  strcpy (line, arg0);
  strcat (line, " ");

  printf ("%s", prompt);
  fgets (line + arg0_len + 1, sizeof line - arg0_len - 1, stdin);

  makeargv ();
  *argc = margc;
  *argv = margv;
}

void
setpeer (int argc, char *argv[])
{
  if (argc < 2)
    get_args ("Connect", "(to) ", &argc, &argv);

  if (argc < 2 || argc > 3)
    {
      printf ("usage: %s host-name [port]\n", argv[0]);
      return;
    }
  
  switch (resolve_name (argv[1], 1))
    {
    case RESOLVE_OK:
      break;

    case RESOLVE_FAIL:
      return;
      
    case RESOLVE_NOT_RESOLVED: 
      peeraddr.sin_family = AF_INET;
      peeraddr.sin_addr.s_addr = inet_addr (argv[1]);
      if (peeraddr.sin_addr.s_addr == -1)
	{
	  connected = 0;
	  printf ("%s: unknown host\n", argv[1]);
	  return;
	}
      hostname = xstrdup (argv[1]);
    }
  
  port = sp->s_port;
  if (argc == 3)
    {
      port = atoi (argv[2]);
      if (port < 0)
	{
	  printf ("%s: bad port number\n", argv[2]);
	  connected = 0;
	  return;
	}
      port = htons (port);
    }
  connected = 1;
}

struct modes
{
  char           *m_name;
  char           *m_mode;
}
modes[] =
{
  {"ascii", "netascii"},
  {"netascii", "netascii"},
  {"binary", "octet"},
  {"image", "octet"},
  {"octet", "octet"},
/*      { "mail",       "mail" },       */
  {0, 0}
};

void
modecmd (int argc, char *argv[])
{
  register struct modes *p;
  char *sep;

  if (argc < 2)
    {
      printf ("Using %s mode to transfer files.\n", mode);
      return;
    }
  if (argc == 2)
    {
      for (p = modes; p->m_name; p++)
	if (strcmp (argv[1], p->m_name) == 0)
	  break;
      if (p->m_name)
	{
	  settftpmode (p->m_mode);
	  return;
	}
      printf ("%s: unknown mode\n", argv[1]);
      /* drop through and print usage message */
    }

  printf ("usage: %s [", argv[0]);
  sep = " ";
  for (p = modes; p->m_name; p++)
    {
      printf ("%s%s", sep, p->m_name);
      if (*sep == ' ')
	sep = " | ";
    }
  printf (" ]\n");
  return;
}

void
setbinary (int argc, char *argv[])
{
  settftpmode ("octet");
}

void
setascii (int argc, char *argv[])
{
  settftpmode ("netascii");
}

static void
settftpmode (char *newmode)
{
  strcpy (mode, newmode);
  if (verbose)
    printf ("mode set to %s\n", mode);
}

/*
 * Send file(s).
 */
void
put (int argc, char *argv[])
{
  int             fd;
  register int    n;
  register char  *cp, *targ;

  if (argc < 2)
    get_args ("send", "(file) ", &argc, &argv);

  if (argc < 2)