ftpparse.c

linux下的网络下载工具prozilla的源码

/* ftpparse.c, ftpparse.h: library for parsing FTP LIST responses
D. J. Bernstein, [e-mail]
19970712 (doc updated 19970810)
Commercial use is fine, if you let me know what programs you're using this in.

Currently covered:
EPLF.
UNIX ls, with or without gid.
Microsoft FTP Service.
Windows NT FTP Server.
VMS.
WFTPD (DOS).
NetPresenz (Mac).
NetWare.

Definitely not covered: 
Long VMS filenames, with information split across two lines.
NCSA Telnet FTP server. Has LIST = NLST (and bad NLST for directories).

Written for maximum portability, but tested only under UNIX so far.
*/

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

#include <sys/types.h>
#include <time.h>
#include "ftpparse.h"

static long totai(year, month, mday)
long year;
long month;
long mday;
{
    /*
     * adapted from datetime_untai() 
     */
    /*
     * about 100x faster than typical mktime() 
     */
    long result;
    if (month >= 2)
	month -= 2;
    else
    {
	month += 10;
	--year;
    }
    result = (mday - 1) * 10 + 5 + 306 * month;
    result /= 10;
    if (result == 365)
    {
	year -= 3;
	result = 1460;
    } else
	result += 365 * (year % 4);
    year /= 4;
    result += 1461 * (year % 25);
    year /= 25;
    if (result == 36524)
    {
	year -= 3;
	result = 146096;
    } else
    {
	result += 36524 * (year % 4);
    }
    year /= 4;
    result += 146097 * (year - 5);
    result += 11017;
    return result * 86400;
}

static int flagneedbase = 1;
static time_t base;		/*
				 * time() value on this OS at the beginning of 1970 TAI 
				 */
static long now;		/*
				 * current time 
				 */
static int flagneedcurrentyear = 1;
static long currentyear;	/*
				 * approximation to current year 
				 */

static void initbase()
{
    struct tm *t;
    if (!flagneedbase)
	return;

    base = 0;
    t = gmtime(&base);
    base =
	-(totai(t->tm_year + 1900, t->tm_mon, t->tm_mday) +
	  t->tm_hour * 3600 + t->tm_min * 60 + t->tm_sec);
    /*
     * time_t is assumed to be measured in TAI seconds. 
     */
    /*
     * base may be slightly off if time_t is measured in UTC seconds. 
     */
    /*
     * Typical software naively claims to use UTC but actually uses TAI. 
     */
    flagneedbase = 0;
}

static void initnow()
{
    long day;
    long year;

    initbase();
    now = time((time_t *) 0) - base;

    if (flagneedcurrentyear)
    {
	/*
	 * adapted from datetime_tai() 
	 */
	day = now / 86400;
	if ((now % 86400) < 0)
	    --day;
	day -= 11017;
	year = 5 + day / 146097;
	day = day % 146097;
	if (day < 0)
	{
	    day += 146097;
	    --year;
	}
	year *= 4;
	if (day == 146096)
	{
	    year += 3;
	    day = 36524;
	} else
	{
	    year += day / 36524;
	    day %= 36524;
	}
	year *= 25;
	year += day / 1461;
	day %= 1461;
	year *= 4;
	if (day == 1460)
	{
	    year += 3;
	    day = 365;
	} else
	{
	    year += day / 365;
	    day %= 365;
	}
	day *= 10;
	if ((day + 5) / 306 >= 10)
	    ++year;
	currentyear = year;
	flagneedcurrentyear = 0;
    }
}

/* UNIX ls does not show the year for dates in the last six months. */
/* So we have to guess the year. */
/* Apparently NetWare uses ``twelve months'' instead of ``six months''; ugh. */
/* Some versions of ls also fail to show the year for future dates. */
static long guesstai(month, mday)
long month;
long mday;
{
    long year;
    long t;

    initnow();

    for (year = currentyear - 1; year < currentyear + 100; ++year)
    {
	t = totai(year, month, mday);
	if (now - t < 350 * 86400)
	    return t;
    }
/* Added by Grendel */
    return 0;
}

static int check(buf, monthname)
char *buf;
char *monthname;
{
    if ((buf[0] != monthname[0]) && (buf[0] != monthname[0] - 32))
	return 0;
    if ((buf[1] != monthname[1]) && (buf[1] != monthname[1] - 32))
	return 0;
    if ((buf[2] != monthname[2]) && (buf[2] != monthname[2] - 32))
	return 0;
    return 1;
}

static char *months[12] = {
    "jan", "feb", "mar", "apr", "may", "jun", "jul", "aug", "sep", "oct",
    "nov", "dec"
};

static int getmonth(buf, len)
char *buf;
int len;
{
    int i;
    if (len == 3)
	for (i = 0; i < 12; ++i)
	    if (check(buf, months[i]))
		return i;
    return -1;
}

static long getlong(buf, len)
char *buf;
int len;
{
    long u = 0;
    while (len-- > 0)
	u = u * 10 + (*buf++ - '0');
    return u;
}

static long long getlonglong(buf, len)
char *buf;
int len;
{
    long long u = 0;
    while (len-- > 0)
	u = u * 10 + (*buf++ - '0');
    return u;
}

int ftpparse(fp, buf, len)
struct ftpparse *fp;
char *buf;
int len;
{
    int i;
    int j;
    int state;
    off_t size = -1;
    long year;
    long month = -1;
    long mday = -1;
    long hour;
    long minute;

    fp->name = 0;
    fp->namelen = 0;
    fp->flagtrycwd = 0;
    fp->flagtryretr = 0;
    fp->sizetype = FTPPARSE_SIZE_UNKNOWN;
    fp->size = 0;
    fp->mtimetype = FTPPARSE_MTIME_UNKNOWN;
    fp->mtime = 0;
    fp->idtype = FTPPARSE_ID_UNKNOWN;
    fp->id = 0;
    fp->idlen = 0;

    if (len < 2)		/*
				 * an empty name in EPLF, with no info, could be 2 chars 
				 */
	return 0;

    switch (*buf)
    {
	/*
	 * see http://pobox.com/~djb/proto/eplf.txt 
	 */
	/*
	 * "+i8388621.29609,m824255902,/,\tdev" 
	 */
	/*
	 * "+i8388621.44468,m839956783,r,s10376,\tRFCEPLF" 
	 */
    case '+':
	i = 1;
	for (j = 1; j < len; ++j)
	{
	    if (buf[j] == 9)
	    {
		fp->name = buf + j + 1;
		fp->namelen = len - j - 1;
		return 1;
	    }
	    if (buf[j] == ',')
	    {
		switch (buf[i])
		{
		case '/':
		    fp->flagtrycwd = 1;
		    break;
		case 'r':
		    fp->flagtryretr = 1;
		    break;
		case 's':
		    fp->sizetype = FTPPARSE_SIZE_BINARY;
		    fp->size = getlonglong(buf + i + 1, j - i - 1);
		    break;
		case 'm':
		    fp->mtimetype = FTPPARSE_MTIME_LOCAL;
		    initbase();
		    fp->mtime = base + getlong(buf + i + 1, j - i - 1);
		    break;
		case 'i':
		    fp->idtype = FTPPARSE_ID_FULL;
		    fp->id = buf + i + 1;
		    fp->idlen = j - i - 1;
		}
		i = j + 1;
	    }
	}
	return 0;

	/*
	 * UNIX-style listing, without inum and without blocks 
	 */
	/*
	 * "-rw-r--r--   1 root     other        531 Jan 29 03:26 README" 
	 */
	/*
	 * "dr-xr-xr-x   2 root     other        512 Apr  8  1994 etc" 
	 */
	/*
	 * "dr-xr-xr-x   2 root     512 Apr  8  1994 etc" 
	 */
	/*
	 * "lrwxrwxrwx   1 root     other          7 Jan 25 00:17 bin -> usr/bin" 
	 */
	/*
	 * Also produced by Microsoft's FTP servers for Windows: 
	 */
	/*
	 * "----------   1 owner    group         1803128 Jul 10 10:18 ls-lR.Z" 
	 */
	/*
	 * "d---------   1 owner    group               0 May  9 19:45 Softlib" 
	 */
	/*
	 * Also WFTPD for MSDOS: 
	 */
	/*
	 * "-rwxrwxrwx   1 noone    nogroup      322 Aug 19  1996 message.ftp" 
	 */
	/*
	 * Also NetWare: 
	 */
	/*
	 * "d [R----F--] supervisor            512       Jan 16 18:53    login" 
	 */
	/*
	 * "- [R----F--] rhesus             214059       Oct 20 15:27    cx.exe" 
	 */
	/*
	 * Also NetPresenz for the Mac: 
	 */
	/*
	 * "-------r--         326  1391972  1392298 Nov 22  1995 MegaPhone.sit" 
	 */
	/*
	 * "drwxrwxr-x               folder        2 May 10  1996 network" 
	 */
    case 'b':
    case 'c':
    case 'd':
    case 'l':
    case 'p':
    case 's':
    case '-':

	if (*buf == 'd')
	    fp->flagtrycwd = 1;
	if (*buf == '-')
	    fp->flagtryretr = 1;
	if (*buf == 'l')
	    fp->flagtrycwd = fp->flagtryretr = 1;

	state = 1;
	i = 0;
	for (j = 1; j < len; ++j)
	    if ((buf[j] == ' ') && (buf[j - 1] != ' '))
	    {
		switch (state)
		{
		case 1:	/*
				   * skipping perm 
				 */
		    state = 2;
		    break;
		case 2:	/*
				   * skipping nlink 
				 */
		    state = 3;
		    if ((j - i == 6) && (buf[i] == 'f'))	/*
								 * for NetPresenz 
								 */
			state = 4;
		    break;
		case 3:	/*
				   * skipping uid 
				 */
		    state = 4;
		    break;
		case 4:	/*
				   * getting tentative size 
				 */
		    size = getlonglong(buf + i, j - i);
		    state = 5;
		    break;
		case 5:	/*
				   * searching for month, otherwise getting tentative size 
				 */
		    month = getmonth(buf + i, j - i);
		    if (month >= 0)
			state = 6;
		    else
			size = getlonglong(buf + i, j - i);
		    break;
		case 6:	/*
				   * have size and month 
				 */
		    mday = getlong(buf + i, j - i);
		    state = 7;
		    break;
		case 7:	/*
				   * have size, month, mday 
				 */
		    if ((j - i == 4) && (buf[i + 1] == ':'))
		    {
			hour = getlong(buf + i, 1);
			minute = getlong(buf + i + 2, 2);
			fp->mtimetype = FTPPARSE_MTIME_REMOTEMINUTE;
			initbase();
			fp->mtime =
			    base + guesstai(month,
					    mday) + hour * 3600 +
			    minute * 60;
		    } else if ((j - i == 5) && (buf[i + 2] == ':'))
		    {
			hour = getlong(buf + i, 2);
			minute = getlong(buf + i + 3, 2);
			fp->mtimetype = FTPPARSE_MTIME_REMOTEMINUTE;
			initbase();
			fp->mtime =
			    base + guesstai(month,
					    mday) + hour * 3600 +
			    minute * 60;
		    } else if (j - i >= 4)
		    {
			year = getlong(buf + i, j - i);
			fp->mtimetype = FTPPARSE_MTIME_REMOTEDAY;
			initbase();
			fp->mtime = base + totai(year, month, mday);
		    } else
			return 0;
		    fp->name = buf + j + 1;
		    fp->namelen = len - j - 1;
		    state = 8;
		    break;
		case 8:	/*
				   * twiddling thumbs 
				 */
		    break;
		}
		i = j + 1;
		while ((i < len) && (buf[i] == ' '))
		    ++i;
	    }

	if (state != 8)
	    return 0;

	fp->size = size;
	fp->sizetype = FTPPARSE_SIZE_ASCII;

	if (*buf == 'l')
	    for (i = 0; i + 3 < fp->namelen; ++i)
		if (fp->name[i] == ' ')
		    if (fp->name[i + 1] == '-')
			if (fp->name[i + 2] == '>')
			    if (fp->name[i + 3] == ' ')
			    {
				fp->namelen = i;
				break;
			    }

	/*
	 * eliminate extra NetWare spaces 
	 */
	if ((buf[1] == ' ') || (buf[1] == '['))
	    if (fp->namelen > 3)
		if (fp->name[0] == ' ')
		    if (fp->name[1] == ' ')
			if (fp->name[2] == ' ')
			{
			    fp->name += 3;
			    fp->namelen -= 3;
			}

	return 1;
    }

    /*
     * MultiNet (some spaces removed from examples) 
     */
    /*
     * "00README.TXT;1      2 30-DEC-1996 17:44 [SYSTEM] (RWED,RWED,RE,RE)" 
     */
    /*
     * "CORE.DIR;1          1  8-SEP-1996 16:09 [SYSTEM] (RWE,RWE,RE,RE)" 
     */
    /*
     * and non-MutliNet VMS: 
     */
    /*
     * "CII-MANUAL.TEX;1  213/216  29-JAN-1996 03:33:12  [ANONYMOU,ANONYMOUS]   (RWED,RWED,,)" 
     */
    for (i = 0; i < len; ++i)
	if (buf[i] == ';')
	    break;
    if (i < len)
    {
	fp->name = buf;
	fp->namelen = i;
	if (i > 4)
	    if (buf[i - 4] == '.')
		if (buf[i - 3] == 'D')
		    if (buf[i - 2] == 'I')
			if (buf[i - 1] == 'R')
			{
			    fp->namelen -= 4;
			    fp->flagtrycwd = 1;
			}
	if (!fp->flagtrycwd)
	    fp->flagtryretr = 1;
	while (buf[i] != ' ')
	    if (++i == len)
		return 0;
	while (buf[i] == ' ')
	    if (++i == len)
		return 0;
	while (buf[i] != ' ')
	    if (++i == len)
		return 0;
	while (buf[i] == ' ')
	    if (++i == len)
		return 0;
	j = i;
	while (buf[j] != '-')
	    if (++j == len)
		return 0;
	mday = getlong(buf + i, j - i);
	while (buf[j] == '-')
	    if (++j == len)
		return 0;
	i = j;
	while (buf[j] != '-')
	    if (++j == len)
		return 0;
	month = getmonth(buf + i, j - i);
	if (month < 0)
	    return 0;
	while (buf[j] == '-')
	    if (++j == len)
		return 0;
	i = j;
	while (buf[j] != ' ')
	    if (++j == len)
		return 0;
	year = getlong(buf + i, j - i);
	while (buf[j] == ' ')
	    if (++j == len)
		return 0;
	i = j;
	while (buf[j] != ':')
	    if (++j == len)
		return 0;
	hour = getlong(buf + i, j - i);
	while (buf[j] == ':')
	    if (++j == len)
		return 0;
	i = j;
	while ((buf[j] != ':') && (buf[j] != ' '))
	    if (++j == len)
		return 0;
	minute = getlong(buf + i, j - i);

	fp->mtimetype = FTPPARSE_MTIME_REMOTEMINUTE;
	initbase();
	fp->mtime =
	    base + totai(year, month, mday) + hour * 3600 + minute * 60;

	return 1;
    }

    /*
     * Some useless lines, safely ignored: 
     */
    /*
     * "Total of 11 Files, 10966 Blocks." (VMS) 
     */
    /*
     * "total 14786" (UNIX) 
     */
    /*
     * "DISK$ANONFTP:[ANONYMOUS]" (VMS) 
     */
    /*
     * "Directory DISK$PCSA:[ANONYM]" (VMS) 
     */

    return 0;
}