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(octal_to_mode): New function.

Browse Source 
(struct mode_change): New member mentioned.
(make_node_op_equals): New arg mentioned.  All callers changed.
(mode_compile): Keep track of which mode bits the user has explicitly
mentioned.
(mode_adjust): New arg DIR, so that we implement the X op correctly.
New arg PMODE_BITS, to keep track of which mode bits the user
mentioned; it treats S_ISUID and S_ISGID speciall.
All callers changed.
This commit is contained in:
Paul Eggert 2006-07-17 03:07:23 +00:00
parent 9a1ed6fbf9
commit 44ba013923
1 changed files with 75 additions and 42 deletions
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117
lib/modechange.c
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@ -1,7 +1,7 @@
/* modechange.c -- file mode manipulation
Copyright (C) 1989, 1990, 1997, 1998, 1999, 2001, 2003, 2004, 2005
Free Software Foundation, Inc.
Copyright (C) 1989, 1990, 1997, 1998, 1999, 2001, 2003, 2004, 2005,
2006 Free Software Foundation, Inc.
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
@ -51,6 +51,32 @@
#define XOTH 00001
#define ALLM 07777 /* all octal mode bits */
/* Convert OCTAL, which uses one of the traditional octal values, to
an internal mode_t value. */
static mode_t
octal_to_mode (unsigned int octal)
{
/* Help the compiler optimize the usual case where mode_t uses
the traditional octal representation. */
return ((S_ISUID == SUID && S_ISGID == SGID && S_ISVTX == SVTX
&& S_IRUSR == RUSR && S_IWUSR == WUSR && S_IXUSR == XUSR
&& S_IRGRP == RGRP && S_IWGRP == WGRP && S_IXGRP == XGRP
&& S_IROTH == ROTH && S_IWOTH == WOTH && S_IXOTH == XOTH)
? octal
: (mode_t) ((octal & SUID ? S_ISUID : 0)
| (octal & SGID ? S_ISGID : 0)
| (octal & SVTX ? S_ISVTX : 0)
| (octal & RUSR ? S_IRUSR : 0)
| (octal & WUSR ? S_IWUSR : 0)
| (octal & XUSR ? S_IXUSR : 0)
| (octal & RGRP ? S_IRGRP : 0)
| (octal & WGRP ? S_IWGRP : 0)
| (octal & XGRP ? S_IXGRP : 0)
| (octal & ROTH ? S_IROTH : 0)
| (octal & WOTH ? S_IWOTH : 0)
| (octal & XOTH ? S_IXOTH : 0)));
}
/* Special operations flags. */
enum
{
@ -78,19 +104,22 @@ struct mode_change
char flag; /* Special operations flag. */
mode_t affected; /* Set for u, g, o, or a. */
mode_t value; /* Bits to add/remove. */
mode_t mentioned; /* Bits explicitly mentioned. */
};
/* Return a mode_change array with the specified `=ddd'-style
mode change operation, where NEW_MODE is `ddd'. */
mode change operation, where NEW_MODE is `ddd' and MENTIONED
contains the bits explicitly mentioned in the mode are MENTIONED. */
static struct mode_change *
make_node_op_equals (mode_t new_mode)
make_node_op_equals (mode_t new_mode, mode_t mentioned)
{
struct mode_change *p = xmalloc (2 * sizeof *p);
p->op = '=';
p->flag = MODE_ORDINARY_CHANGE;
p->affected = CHMOD_MODE_BITS;
p->value = new_mode;
p->mentioned = mentioned;
p[1].flag = MODE_DONE;
return p;
}
@ -113,13 +142,14 @@ mode_compile (char const *mode_string)
if ('0' <= *mode_string && *mode_string < '8')
{
mode_t mode;
unsigned int octal_value = 0;
unsigned int octal_mode = 0;
unsigned int octal_mentioned = 0;
do
{
octal_value = 8 * octal_value + *mode_string++ - '0';
if (ALLM < octal_value)
octal_mode = 8 * octal_mode + *mode_string++ - '0';
octal_mentioned = 8 * octal_mentioned + 7;
if (ALLM < octal_mode)
return NULL;
}
while ('0' <= *mode_string && *mode_string < '8');
@ -127,27 +157,8 @@ mode_compile (char const *mode_string)
if (*mode_string)
return NULL;
/* Help the compiler optimize the usual case where mode_t uses
the traditional octal representation. */
mode = ((S_ISUID == SUID && S_ISGID == SGID && S_ISVTX == SVTX
&& S_IRUSR == RUSR && S_IWUSR == WUSR && S_IXUSR == XUSR
&& S_IRGRP == RGRP && S_IWGRP == WGRP && S_IXGRP == XGRP
&& S_IROTH == ROTH && S_IWOTH == WOTH && S_IXOTH == XOTH)
? octal_value
: (mode_t) ((octal_value & SUID ? S_ISUID : 0)
| (octal_value & SGID ? S_ISGID : 0)
| (octal_value & SVTX ? S_ISVTX : 0)
| (octal_value & RUSR ? S_IRUSR : 0)
| (octal_value & WUSR ? S_IWUSR : 0)
| (octal_value & XUSR ? S_IXUSR : 0)
| (octal_value & RGRP ? S_IRGRP : 0)
| (octal_value & WGRP ? S_IWGRP : 0)
| (octal_value & XGRP ? S_IXGRP : 0)
| (octal_value & ROTH ? S_IROTH : 0)
| (octal_value & WOTH ? S_IWOTH : 0)
| (octal_value & XOTH ? S_IXOTH : 0)));
return make_node_op_equals (mode);
return make_node_op_equals (octal_to_mode (octal_mode),
octal_to_mode (octal_mentioned & ALLM));
}
/* Allocate enough space to hold the result. */
@ -251,6 +262,7 @@ mode_compile (char const *mode_string)
change->flag = flag;
change->affected = affected;
change->value = value;
change->mentioned = (affected ? affected & value : value);
}
while (*mode_string == '=' || *mode_string == '+'
|| *mode_string == '-');
@ -280,25 +292,36 @@ mode_create_from_ref (const char *ref_file)
if (stat (ref_file, &ref_stats) != 0)
return NULL;
return make_node_op_equals (ref_stats.st_mode);
return make_node_op_equals (ref_stats.st_mode, CHMOD_MODE_BITS);
}
/* Return file mode OLDMODE, adjusted as indicated by the list of change
operations CHANGES, which are interpreted assuming the umask is
UMASK_VALUE. If OLDMODE is a directory, the type `X'
change affects it even if no execute bits were set in OLDMODE.
The returned value has the S_IFMT bits cleared. */
/* Return the file mode bits bits of OLDMODE (which is the mode of a
directory if DIR), assuming the umask is UMASK_VALUE, adjusted as
indicated by the list of change operations CHANGES. If DIR, the
type 'X' change affects the returned value even if no execute bits
were set in OLDMODE. If PMODE_BITS is not null, store into
*PMODE_BITS a mask denoting file mode bits that are affected by
CHANGES.
The returned value and *PMODE_BITS contain only file mode bits.
For example, they have the S_IFMT bits cleared on a standard
Unix-like host. */
mode_t
mode_adjust (mode_t oldmode, struct mode_change const *changes,
mode_t umask_value)
mode_adjust (mode_t oldmode, bool dir, mode_t umask_value,
struct mode_change const *changes, mode_t *pmode_bits)
{
/* The adjusted mode. */
mode_t newmode = oldmode & CHMOD_MODE_BITS;
/* File mode bits that CHANGES cares about. */
mode_t mode_bits = 0;
for (; changes->flag != MODE_DONE; changes++)
{
mode_t affected = changes->affected;
mode_t omit_change =
(dir ? S_ISUID | S_ISGID : 0) & ~ changes->mentioned;
mode_t value = changes->value;
switch (changes->flag)
@ -322,14 +345,15 @@ mode_adjust (mode_t oldmode, struct mode_change const *changes,
case MODE_X_IF_ANY_X:
/* Affect the execute bits if execute bits are already set
or if the file is a directory. */
if ((newmode & (S_IXUSR | S_IXGRP | S_IXOTH)) || S_ISDIR (oldmode))
if ((newmode & (S_IXUSR | S_IXGRP | S_IXOTH)) | dir)
value |= S_IXUSR | S_IXGRP | S_IXOTH;
break;
}
/* If WHO was specified, limit the change to the affected bits.
Otherwise, apply the umask. */
value &= (affected ? affected : ~umask_value);
Otherwise, apply the umask. Either way, omit changes as
requested. */
value &= (affected ? affected : ~umask_value) & ~ omit_change;
switch (changes->op)
{
@ -337,17 +361,26 @@ mode_adjust (mode_t oldmode, struct mode_change const *changes,
/* If WHO was specified, preserve the previous values of
bits that are not affected by this change operation.
Otherwise, clear all the bits. */
newmode = (affected ? newmode & ~affected : 0);
/* Fall through. */
{
mode_t preserved = (affected ? ~affected : 0) | omit_change;
mode_bits |= CHMOD_MODE_BITS & ~preserved;
newmode = (newmode & preserved) | value;
break;
}
case '+':
mode_bits |= value;
newmode |= value;
break;
case '-':
mode_bits |= value;
newmode &= ~value;
break;
}
}
if (pmode_bits)
*pmode_bits = mode_bits;
return newmode;
}