ftp.c

linux下的网络下载工具prozilla的源码

/*
   FTP support. Copyright (C) 2000 Kalum Somaratna 
  
   This program is free software; you can redistribute it and/or modify it
   under the terms of the GNU General Public License as published by the Free 
   Software Foundation; either version 2 of the License, or (at your option)
   any later version.
  
   This program is distributed in the hope that it will be useful, but
   WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 
   or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
   for more details.
   
   You should have received a copy of the GNU General Public License along
   with this program; if not, write to the Free Software Foundation, Inc.,
   675 Mass Ave, Cambridge, MA 02139, USA.  
 */

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

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <time.h>
#include <errno.h>
#include <ctype.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <signal.h>
#include <setjmp.h>
#include <assert.h>
#include "main.h"
#include "connect.h"
#include "misc.h"
#include "url.h"
#include "ftp.h"
#include "netrc.h"
#include "runtime.h"
#include "debug.h"

#define UNIMPLEMENTED_CMD(a)          ((a == 500) || (a == 502) || (a == 504))

/*
 * return the numeric response of the ftp server by reading the first 3
 * characters in the buffer 
 */
int get_ftp_return(const char *ftp_buffer)
{
    char code[4];

    strncpy(code, ftp_buffer, 3);
    code[3] = '\0';
    return atoi(code);

}

int ftp_check_msg(int sock, char *szBuffer, int len)
{
    int ret;

    if ((ret = krecv(sock, szBuffer, len, MSG_PEEK, rt.timeout)) == -1)
    {
	message("Error checking for ftp data-: %s", strerror(errno));
	return ret;
    }

    return ret;
}


int ftp_read_msg(int sock, char *szBuffer, int len)
{
    int ret;

    if ((ret = krecv(sock, szBuffer, len, 0, rt.timeout)) == -1)
    {
	message("Error Receiving ftp  data-: %s", strerror(errno));
	return ret;
    }

    return ret;
}

uerr_t ftp_send_msg(int sock, char *szBuffer, int len)
{
    if (ksend(sock, szBuffer, len, 0, rt.timeout) == -1)
    {
	message("Error Sending ftp  data-: %s", strerror(errno));
	return FTPERR;
    }

    return FTPOK;
}


uerr_t ftp_get_line(int control_sock, char *buffer)
{
    int iLen, iBuffLen = 0, ret = 0;
    char *szPtr = buffer, ch = 0;

    while ((iBuffLen < FTP_BUFFER_SIZE) &&
	   ((ret = ftp_check_msg(control_sock, &ch, 1)) > 0))
    {
	iLen = ftp_read_msg(control_sock, &ch, 1);
	if (iLen != 1)
	{
	    return FTPERR;
	}
	iBuffLen += iLen;
	*szPtr = ch;
	szPtr += iLen;
	if (ch == '\n')
	    break;		/*
				 * we have a line: return 
				 */
    }
    /*
     * Check for error returned in ftp_check_message 
     */
    if (ret == -1)
	return FTPERR;

    *(szPtr + 1) = '\0';
    return FTPOK;
}


uerr_t ftp_get_reply(int sock, char *szBuffer)
{
    int cont = 0;
    int code;
    char * tmp = alloca(FTP_BUFFER_SIZE);

    memset(szBuffer, 0, FTP_BUFFER_SIZE);

    if (ftp_get_line(sock, szBuffer) != FTPOK)
    {
	return FTPERR;
    }

    debug_prz("message =%s\n", szBuffer);

    if (!isdigit(*szBuffer))
	return FTPERR;

    if (*szBuffer == '\0')
	return FTPERR;

    code = get_ftp_return(szBuffer);

    if (szBuffer[3] == '-')
	cont = 1;
    else
	cont = 0;

    (void) strtok_r(szBuffer, "\r\n",&tmp);

    while (cont)
    {
	if (ftp_get_line(sock, szBuffer) != FTPOK)
	{
	    return FTPERR;
	}
	debug_prz("message =%s\n", szBuffer);

	/* Server closed the connection */
	if (*szBuffer == '\0')
	    return FTPERR;

	if ((get_ftp_return(szBuffer) == code) && (szBuffer[3] == ' '))
	    cont = 0;

	(void) strtok_r(szBuffer, "\r\n", &tmp);
    }
    return FTPOK;
}


uerr_t ftp_ascii(int sock)
{
    char szBuffer[FTP_BUFFER_SIZE];
    uerr_t err;

    snprintf(szBuffer, sizeof(szBuffer), "TYPE A\r\n");

    err = ftp_send_msg(sock, szBuffer, strlen(szBuffer));
    if (err != FTPOK)
    {
	return err;
    }

    err = ftp_get_reply(sock, szBuffer);

    if (err != FTPOK)
    {
	return err;
    }

    if (*szBuffer != '2')
    {
	return FTPUNKNOWNTYPE;
    }

    return FTPOK;
}

uerr_t ftp_binary(int sock)
{
    char szBuffer[FTP_BUFFER_SIZE];
    uerr_t err;

    snprintf(szBuffer, sizeof(szBuffer), "TYPE I\r\n");
    err = ftp_send_msg(sock, szBuffer, strlen(szBuffer));
    if (err != FTPOK)
    {
	return err;
    }

    err = ftp_get_reply(sock, szBuffer);
    if (err != FTPOK)
    {
	return err;
    }

    if (*szBuffer != '2')
    {
	return FTPUNKNOWNTYPE;
    }

    return FTPOK;
}


uerr_t ftp_port(int sock, char *command)
{
    char szBuffer[FTP_BUFFER_SIZE];
    uerr_t err;

    strcpy(szBuffer, command);
    err = ftp_send_msg(sock, szBuffer, strlen(szBuffer));
    if (err != FTPOK)
    {
	return err;
    }

    err = ftp_get_reply(sock, szBuffer);

    if (err != FTPOK)
    {
	return err;
    }

    if (*szBuffer != '2')
    {
	return FTPPORTERR;
    }

    return FTPOK;

}


uerr_t ftp_list(int sock, char *file)
{
    char szBuffer[FTP_BUFFER_SIZE];
    uerr_t err;

    if (snprintf(szBuffer, sizeof(szBuffer),
		 "LIST %s\r\n",
		 file) >= sizeof(szBuffer))
    {
        return NOTENOUGHMEM; /* FIXME: Better error */
    }
    err = ftp_send_msg(sock, szBuffer, strlen(szBuffer));
    if (err != FTPOK)
    {
	return err;
    }

    err = ftp_get_reply(sock, szBuffer);

    if (err != FTPOK)
    {
	return err;
    }

    if (*szBuffer == '5')
    {
	return FTPNSFOD;
    }

    if (*szBuffer != '1')
    {
	return FTPERR;
    }
    return FTPOK;
}

uerr_t ftp_retr(int sock, char *file)
{
    char szBuffer[FTP_BUFFER_SIZE];
    uerr_t err;

    if (snprintf(szBuffer, sizeof(szBuffer),
		 "RETR %s\r\n",
		 file) >= sizeof(szBuffer))
    {
        return NOTENOUGHMEM; /* FIXME: Better error */
    }
    err = ftp_send_msg(sock, szBuffer, strlen(szBuffer));
    if (err != FTPOK)
    {
	return err;
    }

    err = ftp_get_reply(sock, szBuffer);

    if (err != FTPOK)
    {
	return err;
    }

    if (*szBuffer == '5')
    {
	return FTPNSFOD;
    }

    if (*szBuffer != '1')
    {
	return FTPERR;
    }
    return FTPOK;

}

/*
 * does the PASV command 
 */

uerr_t ftp_pasv(int sock, unsigned char *addr)
{
    char szBuffer[FTP_BUFFER_SIZE];
    uerr_t err;
    unsigned char *p;
    int i;

    snprintf(szBuffer, sizeof(szBuffer), "%s", "PASV\r\n");
    err = ftp_send_msg(sock, szBuffer, strlen(szBuffer));
    if (err != FTPOK)
    {
	return err;
    }

    err = ftp_get_reply(sock, szBuffer);

    debug_prz("FTP PASV Header =%s\n", szBuffer);

    if (err != FTPOK)
    {
	return err;
    }
    if (*szBuffer != '2')
    {
	return FTPNOPASV;
    }
    /*
     * parse it 
     */
    p = (unsigned char *) szBuffer;
    for (p += 4; *p && !isdigit(*p); p++);
    if (!*p)
	return FTPINVPASV;

    for (i = 0; i < 6; i++)
    {
	addr[i] = 0;
	for (; isdigit(*p); p++)
	    addr[i] = (*p - '0') + 10 * addr[i];
	if (*p == ',')
	    p++;
	else if (i < 5)
	{
	    return FTPINVPASV;
	}
    }
    return FTPOK;
}

uerr_t ftp_rest(int sock, off_t bytes)
{
    char szBuffer[FTP_BUFFER_SIZE];
    uerr_t err;

    if (snprintf(szBuffer, sizeof(szBuffer),
		 "REST %Ld\r\n", (long long)
		 bytes) >= sizeof(szBuffer))
    {
        return NOTENOUGHMEM; /* FIXME: Better error */
    }
    err = ftp_send_msg(sock, szBuffer, strlen(szBuffer));
    if (err != FTPOK)
    {
	return err;
    }
    err = (ftp_get_reply(sock, szBuffer));
    if (err != FTPOK)
    {
	return err;
    }
    if (*szBuffer != '3')
    {

	return FTPRESTFAIL;
    }

    return FTPOK;
}

/*
 * CWD command 
 */
uerr_t ftp_cwd(int sock, char *dir)
{
    char szBuffer[FTP_BUFFER_SIZE];
    uerr_t err;

    if (snprintf(szBuffer, sizeof(szBuffer),
		 "CWD %s\r\n",
		 dir) >= sizeof(szBuffer))
    {
        return NOTENOUGHMEM; /* FIXME: Better error */
    }
    err = ftp_send_msg(sock, szBuffer, strlen(szBuffer));
    if (err != FTPOK)
    {
	return err;
    }

    err = (ftp_get_reply(sock, szBuffer));
    if (err != FTPOK)
    {
	return err;
    }


    /*
     * check and see whether the CWD succeeded 
     */
    if (*szBuffer == '5')
    {
	return FTPNSFOD;
    }

    if (*szBuffer != '2')
    {
	return CWDFAIL;
    }

    /*
     * all ok 
     */
    return FTPOK;
}


/*
 *  Returns the Current working directory in dir 
 */
uerr_t ftp_pwd(int sock, char *dir)
{
    char szBuffer[FTP_BUFFER_SIZE];
    uerr_t err;
    char *r, *l;

    snprintf(szBuffer, sizeof(szBuffer), "PWD\r\n");
    err = ftp_send_msg(sock, szBuffer, strlen(szBuffer));
    if (err != FTPOK)
    {
	return err;
    }

    err = (ftp_get_reply(sock, szBuffer));
    if (err != FTPOK)
    {
	return err;
    }

    /*
     * check and see wether the PWD succeeded 
     */
    if (*szBuffer == '5')
    {
	return FTPPWDERR;
    }

    if (*szBuffer != '2')
    {
	return PWDFAIL;
    }

    if ((r = strrchr(szBuffer, '"')) != NULL)
    {
	l = strchr(szBuffer, '"');
	if ((l != NULL) && (l != r))
	{
	    *r = '\0';
	    ++l;
	    strcpy(dir, l);
	    *r = '"';
	}
    } else
    {
	if ((r = strchr(szBuffer, ' ')) != NULL)
	{
	    *r = '\0';