ckufio.c

C语言核心协议的C语言源代码,用于早期网络通信

char *ckzv = "Unix file support, 4C(032) 19 Mar 86";

/* C K U F I O  --  Kermit file system support for Unix systems */

/*
 Author: Frank da Cruz (SY.FDC@CU20B),
 Columbia University Center for Computing Activities, January 1985.
 Copyright (C) 1985, Trustees of Columbia University in the City of New York.
 Permission is granted to any individual or institution to use, copy, or
 redistribute this software so long as it is not sold for profit, provided this
 copyright notice is retained. 
*/
/* Includes */

#include "ckcker.h"			/* Kermit definitions */
#include "ckcdeb.h"			/* Typedefs, debug formats, etc */
#include <ctype.h>			/* Character types */
#include <stdio.h>			/* Standard i/o */
#include <sys/types.h>			/* Data types */
#include <sys/dir.h>			/* Directory structure */
#include <sys/stat.h>			/* File status */
#include <pwd.h>			/* Password file for shell name */

/* Berkeley Unix Version 4.x */
/* 4.1bsd support added by Charles E Brooks, EDN-VAX */

#ifdef BSD4
#ifdef MAXNAMLEN
#define BSD42
char *ckzsys = " 4.2 BSD";
#else
#ifdef FT17
#define BSD41
char *ckzsys = " For:Pro Fortune 1.7";
#else
#define BSD41
char *ckzsys = " 4.1 BSD";
#endif
#endif
#endif

/* 2.9bsd support contributed by Bradley Smith, UCLA */
#ifdef BSD29
char *ckzsys = " 2.9 BSD";
#endif

/* Version 7 Unix  */
#ifdef V7
char *ckzsys = " Version 7 Unix";
#endif

/* DEC Professional-300 series with Venturcom Venix v1 */
#ifdef PROVX1
char *ckzsys = " DEC Pro-3xx/Venix v1";
#endif

/* NCR Tower support contributed by John Bray, Auburn, AL. */
/* Tower OS is like Sys III but with BSD features -- mostly follows BSD. */
#ifdef TOWER1
char *ckzsys = " NCR Tower 1632, OS 1.02";
#endif

/* Sys III/V, Xenix, PC/IX,... support by Herm Fischer, Litton Data Systems */
#ifdef UXIII
#ifdef XENIX
char *ckzsys = " Xenix/286";
#else
#ifdef PCIX
char *ckzsys = " PC/IX";
#else
#ifdef ISIII
char *ckzsys = " Interactive Systems Corp, System III";
#else
char *ckzsys = " AT&T System III/System V";
#endif
#endif
#endif
#endif

/* Definitions of some Unix system commands */

char *DIRCMD = "ls -l ";		/* For directory listing */
char *DELCMD = "rm -f ";		/* For file deletion */
char *TYPCMD = "cat ";			/* For typing a file */
char *PWDCMD = "pwd ";			/* For saying where I am */

#ifdef BSD4
char *SPACMD = "pwd ; quota ; df .";	/* Space/quota of current directory */
#else
char *SPACMD = "df ";
#endif

char *SPACM2 = "df ";			/* For space in specified directory */

#ifdef BSD4
char *WHOCMD = "finger ";		/* For seeing who's logged in */
#else
char *WHOCMD = "who ";			/* For seeing who's logged in */
#endif

/*
  Functions (n is one of the predefined file numbers from ckermi.h):

   zopeni(n,name)   -- Opens an existing file for input.
   zopeno(n,name)   -- Opens a new file for output.
   zclose(n)        -- Closes a file.
   zchin(n,&c)      -- Gets the next character from an input file.
   zsout(n,s)       -- Write a null-terminated string to output file, buffered.
   zsoutl(n,s)      -- Like zsout, but appends a line terminator.
   zsoutx(n,s,x)    -- Write x characters to output file, unbuffered.
   zchout(n,c)      -- Add a character to an output file, unbuffered.
   zchki(name)      -- Check if named file exists and is readable, return size.
   zchko(name)      -- Check if named file can be created.
   znewn(name,s)    -- Make a new unique file name based on the given name.
   zdelet(name)     -- Delete the named file.
   zxpand(string)   -- Expands the given wildcard string into a list of files.
   znext(string)    -- Returns the next file from the list in "string".
   zxcmd(cmd)       -- Execute the command in a lower fork.
   zclosf()         -- Close input file associated with zxcmd()'s lower fork.
   zrtol(n1,n2)     -- Convert remote filename into local form.
   zltor(n1,n2)     -- Convert local filename into remote form.
   zchdir(dirnam)   -- Change working directory.
   zhome()          -- Return pointer to home directory name string.
   zkself()         -- Kill self, log out own job.
 */


#ifdef FT17
#define PROVX1
#endif
#ifndef PROVX1
#include <sys/file.h>			/* File access */
#endif
#ifdef FT17
#undef PROVX1
#endif

/* Some systems define these in include files, others don't... */
#ifndef R_OK
#define R_OK 4				/* For access */
#endif

#ifndef W_OK
#define W_OK 2
#endif

#ifdef PROVX1
#define MAXNAMLEN DIRSIZ		/* Max file name length */
#endif

#ifdef UXIII
#include <fcntl.h>
#define MAXNAMLEN DIRSIZ
#endif

#ifndef O_RDONLY
#define O_RDONLY 000
#endif

#ifndef MAXNAMLEN
#define MAXNAMLEN 14			/* If still not defined... */
#endif

#ifdef PROVX1
#define MAXWLD 50			/* Maximum wildcard filenames */
#else
#ifdef BSD29
#define MAXWLD 50			/* Maximum wildcard filenames */
#else
#define MAXWLD 500
#endif
#endif

/* Declarations */

FILE *fp[ZNFILS] = { 			/* File pointers */
    NULL, NULL, NULL, NULL, NULL, NULL, NULL };

static int pid;	    			/* pid of child fork */
static int fcount;			/* Number of files in wild group */
static char nambuf[MAXNAMLEN+1];	/* Buffer for a filename */
char *malloc(), *getenv(), *strcpy();	/* System functions */
extern errno;				/* System error code */

static char *mtchs[MAXWLD],		/* Matches found for filename */
     **mtchptr;				/* Pointer to current match */

/*  Z K S E L F  --  Kill Self: log out own job, if possible.  */

zkself() {				/* For "bye", but no guarantee! */
#ifdef PROVX1
    return(kill(0,9));
#else
#ifdef V7
    return(kill(0,9));
#else
#ifdef TOWER1
    return(kill(0,9));
#else
#ifdef FT17
    return(kill(0,9));
#else
    return(kill(getppid(),1));
#endif
#endif
#endif
#endif
}

/*  Z O P E N I  --  Open an existing file for input. */

zopeni(n,name) int n; char *name; {
    debug(F111," zopeni",name,n);
    debug(F101,"  fp","",(int) fp[n]);
    if (chkfn(n) != 0) return(0);
    if (n == ZSYSFN) {			/* Input from a system function? */
        debug(F110," invoking zxcmd",name,0);
	return(zxcmd(name));		/* Try to fork the command */
    }
    if (n == ZSTDIO) {			/* Standard input? */
	if (isatty(0)) {
	    ermsg("Terminal input not allowed");
	    debug(F110,"zopeni: attempts input from unredirected stdin","",0);
	    return(0);
	}
	fp[ZIFILE] = stdin;
	return(1);
    }
    fp[n] = fopen(name,"r");		/* Real file. */
    debug(F111," zopeni", name, (int) fp[n]);
    if (fp[n] == NULL) perror("zopeni");
    return((fp[n] != NULL) ? 1 : 0);
}

/*  Z O P E N O  --  Open a new file for output.  */

zopeno(n,name) int n; char *name; {
    debug(F111," zopeno",name,n);
    if (chkfn(n) != 0) return(0);
    if ((n == ZCTERM) || (n == ZSTDIO)) {   /* Terminal or standard output */
	fp[ZOFILE] = stdout;
	debug(F101," fp[]=stdout", "", (int) fp[n]);
	return(1);
    }
    fp[n] = fopen(name,"w");		/* A real file, try to open */
    if (fp[n] == NULL) {
        perror("zopeno can't open");
    } else {
	chown(name, getuid(), getgid());     /* In case set[gu]id */
        if (n == ZDFILE) setbuf(fp[n],NULL); /* Debugging file unbuffered */
    }
    debug(F101, " fp[n]", "", (int) fp[n]);
    return((fp[n] != NULL) ? 1 : 0);
}

/*  Z C L O S E  --  Close the given file.  */

/*  Returns 0 if arg out of range, 1 if successful, -1 if close failed.  */

zclose(n) int n; {
    int x;
    if (chkfn(n) < 1) return(0);	/* Check range of n */
    if ((n == ZIFILE) && fp[ZSYSFN]) {	/* If system function */
    	x = zclosf();			/* do it specially */
    } else {
    	if ((fp[n] != stdout) && (fp[n] != stdin)) x = fclose(fp[n]);
	fp[n] = NULL;
    }
    return((x == EOF) ? -1 : 1);
}

/*  Z C H I N  --  Get a character from the input file.  */

/*  Returns -1 if EOF, 0 otherwise with character returned in argument  */

zchin(n,c) int n; char *c; {
    int a;
    if (chkfn(n) < 1) return(-1);
    a = getc(fp[n]);
    if (a == EOF) return(-1);
    *c = a & 0377;
    return(0);
}

/*  Z S O U T  --  Write a string to the given file, buffered.  */

zsout(n,s) int n; char *s; {
    if (chkfn(n) < 1) return(-1);
    fputs(s,fp[n]);
    return(0);
}

/*  Z S O U T L  --  Write string to file, with line terminator, buffered  */

zsoutl(n,s) int n; char *s; {
    if (chkfn(n) < 1) return(-1);
    fputs(s,fp[n]);
    fputs("\n",fp[n]);
    return(0);
}

/*  Z S O U T X  --  Write x characters to file, unbuffered.  */

zsoutx(n,s,x) int n, x; char *s; {
    if (chkfn(n) < 1) return(-1);
    return(write(fp[n]->_file,s,x));
}


/*  Z C H O U T  --  Add a character to the given file.  */

/*  Should return 0 or greater on success, -1 on failure (e.g. disk full)  */

zchout(n,c) int n; char c; {
    if (chkfn(n) < 1) return(-1);
    if (n == ZSFILE)
    	return(write(fp[n]->_file,&c,1)); /* Use unbuffered for session log */
    else {				/* Buffered for everything else */
	if (putc(c,fp[n]) == EOF)	/* If true, maybe there was an error */
	    return(ferror(fp[n]));	/* Check to make sure */
	else				/* Otherwise... */
	    return(0);			/* There was no error. */
    }
}

/*  C H K F N  --  Internal function to verify file number is ok  */

/*
 Returns:
  -1: File number n is out of range
   0: n is in range, but file is not open
   1: n in range and file is open
*/
chkfn(n) int n; {
    switch (n) {
	case ZCTERM:
	case ZSTDIO:
	case ZIFILE:
	case ZOFILE:
	case ZDFILE:
	case ZTFILE:
	case ZPFILE:
	case ZSFILE:
	case ZSYSFN: break;
	default:
	    debug(F101,"chkfn: file number out of range","",n);
	    fprintf(stderr,"?File number out of range - %d\n",n);
	    return(-1);
    }
    return( (fp[n] == NULL) ? 0 : 1 );
}

/*  Z C H K I  --  Check if input file exists and is readable  */

/*
  Returns:
   >= 0 if the file can be read (returns the size).
     -1 if file doesn't exist or can't be accessed,
     -2 if file exists but is not readable (e.g. a directory file).
     -3 if file exists but protected against read access.
*/
/*
 For Berkeley Unix, a file must be of type "regular" to be readable.
 Directory files, special files, and symbolic links are not readable.
*/
long
zchki(name) char *name; {
    struct stat buf;
    int x; long y;			 

    x = stat(name,&buf);
    if (x < 0) {
	debug(F111,"zchki stat fails",name,errno);
	return(-1);
    }
    x = buf.st_mode & S_IFMT;		/* Isolate file format field */
    if ((x != 0) && (x != S_IFREG)) {
	debug(F111,"zchki skipping:",name,x);
	return(-2);
    }
    debug(F111,"zchki stat ok:",name,x);

    if ((x = access(name,R_OK)) < 0) { 	/* Is the file accessible? */
	debug(F111," access failed:",name,x); /* No */
    	return(-3);			
    } else {
	y = buf.st_size;
	debug(F111," access ok:",name,(int) y); /* Yes */
	return( (y > -1) ? y : 0 );
    }
}

/*  Z C H K O  --  Check if output file can be created  */

/*
 Returns -1 if write permission for the file would be denied, 0 otherwise.
*/
zchko(name) char *name; {
    int i, x;
    char s[50], *sp;	

    sp = s;				/* Make a copy, get length */
    x = 0;
    while ((*sp++ = *name++) != '\0')
    	x++;
    if (x == 0) return(-1);		/* If no filename, fail. */

    debug(F101," length","",x);
    for (i = x; i > 0; i--)		/* Strip filename. */
	if (s[i-1] == '/') break;
    
    debug(F101," i","",i);
    if (i == 0)				/* If no path, use current directory */
    	strcpy(s,"./");			
    else				/* Otherwise, use given one. */
        s[i] = '\0';

    x = access(s,W_OK);			/* Check access of path. */
    if (x < 0) {
	debug(F111,"zchko access failed:",s,errno);
	return(-1);
    } else {
	debug(F111,"zchko access ok:",s,x);
	return(0);
    }
}

/*  Z D E L E T  --  Delete the named file.  */

zdelet(name) char *name; {
    unlink(name);
}


/*  Z R T O L  --  Convert remote filename into local form  */

/*  For UNIX, this means changing uppercase letters to lowercase.  */

zrtol(name,name2) char *name, *name2; {
    for ( ; *name != '\0'; name++) {
    	*name2++ = isupper(*name) ? tolower(*name) : *name;
    }
    *name2 = '\0';
    debug(F110,"zrtol:",name2,0);
}


/*  Z L T O R  --  Local TO Remote */

/*  Convert filename from local format to common (remote) form.  */

zltor(name,name2) char *name, *name2; {
    char work[100], *cp, *pp;
    int dc = 0;

    debug(F110,"zltor",name,0);
    pp = work;
    for (cp = name; *cp != '\0'; cp++) {	/* strip path name */
    	if (*cp == '/') {
	    dc = 0;
	    pp = work;
	}