JPH03280139A - File sharing system - Google Patents

Abstract

PURPOSE:To inhibit access to the third person while permitting the access to a member sharing a file by deciding the member belonging to a group instructed by both control files and giving access permission to the member. CONSTITUTION:As a first control file (File 1a) (1) to control a group name and the member, the control file is generated in a certain form composed of the File 1a, group identifier GID and member. Next, as a first control file (File 1b) (1) to control all the members, the control file is generated in a certain form composed of the File 1b, full member identifier UID and GID. Moreover, as a second control file (File 3) (2) with the members belonging to the plural groups as objects, the control file is generated in a certain form composed of the File 3x, group identifier GID and member. Then, the first control file (1) and the second control file (2) are checked and the access permission is given to the members belonging to groups (X, Y and Z) instructed by the both control files (1) and (2) while deciding those members as the same group.

Description

[Detailed Description of the Invention] [Table of Contents] Overview Industrial Application Fields Prior Art and Problems to be Solved by the Invention Examples of Means and Actions for Solving the Problems [Effects of the Invention [Summary] Multiple Groups (X , Y, Z) are shared by members belonging to each group (X, Y, Z). In case of multiple groups (X, Y,
Files (A, B, C, D) owned by Z)
For each of the above groups (X.

Read when members of Y, Z) are accessed.

In the method of setting permission for writing and execution, a first control file 2 manages the group identifier (GID) for each group, its member identifiers (xLx2+x3+~), and all member identifiers (LIID).

When the above member belongs to multiple groups (X, Y, Z), the member belongs to multiple groups (X, Y, Z)
A second control file indicating that the member belongs to ■
is set up, and each file (A, B, C, D) is checked for permission to read, write, and execute when a member of each group (X, Y, Z) accesses each file (A, B, C, D). , B, C, D) when checking for a match with the group identifier (GID) that owns
The first control file ■ and the second control file ■ are checked, and the file ( A, B, C, D) are determined to be the same group as the owning group, and access permission is granted.

[Industrial application field]

In the present invention, a group (X, Y, Z) that shares seven files (A, B, C, D) each owned by a plurality of groups (X, Y, Z).

The present invention relates to a file sharing method that allows all members belonging to 2) to access the file, while restricting access to third parties in each group.

With the recent improvement in the performance of computer systems, many users are now able to share the computer system through terminals, access multiple files, and develop one piece of software, for example. .

In this case, from the point of view of file protection, conventionally a certain group (X, Y, Z) (7) owned file Jl/(A, B
, C, and D), read, write, and execute permissions were set for the owner, members of the same group, and third parties. This is called permission.

For example, it is possible to allow reading, writing, and execution to members of the same group, but to prohibit third parties from doing so.

In this permission setting method, if a file owner belongs to a certain group (X, Y, Z), he or she can set permissions for members of the same group (X, Y, Z), but cannot set permissions for other members. When you want to share a file with a group, there is a problem that you cannot set appropriate permissions for other groups.

In the development of the software mentioned above, if members belonging to group a share some of the files owned by another group b and develop the software, group a's This means that a problem arises in that the members cannot access the file owned by group b at one time, or cannot set appropriate permissions for the shared file.

Therefore, when different groups share a file, it is possible to set permissions that allow access to the sharing members while prohibiting access to third parties. A method is needed.

[Prior art and problems to be solved by the invention] Figure 2 is a diagram explaining the conventional permission setting method.
al) and (a2) are each file group A, B, and C.

An example of setting permissions for D is shown, (b) shows a configuration example of a conventional file sharing method, and (c) shows a flowchart of conventional permission processing.

First, groups X, Y, Z and their members are (b)
In the group management processing section 1 shown in the figure,
Member X: xl+x2+x3+wl+ev2+w3Y:
yLy2+y3. x1, x2. x3Z: z1
, z2. z3+z4+z5, and its group management files la, lb■ (the file format will be described later) are generated.

At this time, in setting the permissions for each file group A, B, C, and D in Figure 2 (al) and (a2), (1) Set the owner of file C as yl of Y, and file Third party A
ooo ooo ---(Osu:x1.X)B ooo ooo
---(t-+:x1.X)Cooo o
oo---(oos:y1.Y)D
ooo ooo ---(Osu:z
1. Z) (Here, permission XXX is r from the left.
ead, 5vrite+execute, 0 indicates possible, - indicates not possible, oats: x1. (X indicates that xl is the owner as a member of group As is clear from the permission processing flow shown in Figure (C), A X: ooo Y: ---, Z: ---
B X: 0001 Y: ---+ Z: --
-CX: ---, Y: 0001 Z: ---D
X: ---, Y: ---, Z: oo.

becomes. Here, member xLx2. If you change the group to which x3 belongs to X-Y (that is, access it as belonging to group Y), the permissions are A X: ---, Y: ---, Z knee B X:
---, Y:---, Z:CXdanooo Y: oo
o, Z:----((danshi, member xl+ x2+
x3) D X: ---+ Y: ---, Z:
oo.

Then, Menno\(x2.
The only files that x3) can read/write are A, B, or C. (Permissions indicated by underline) (2) Owner of C: xl of Y, File Osu Gutop Third Party A
ooo ooo ---(Osu:x1.X)B ooo ooo
---(Oats: x1.X)Cooo
ooo ---(Osu:x1.Y)D
ooo ooo ---(Osu:
z1. Z), the permissions for members other than the owner of each group for files A, B, C, and D are A X: ooo, Y: ---, Z:
---B" Nijikuniji Y: ---, Z: -CX:
---, Y: ooo, Z: D χ: ---+ Y: ---, Z: o
o.

becomes. Here, members xi, x2. If you change the group to which x3 belongs to x-+y (that is, access it as belonging to group Y), the permissions are A X: ---, Y: ---, Z: B X
:---, Y:---, Z:CX: ooo Y:
OOO+ Z:---(member xiIx2+x3) D X:---, Y:---, Z: oo.

and owner x1 who belongs to both groups X and Y
Members of group X other than (x2, x3) read
The only files that can be /written are 8 and B or C. (Permissions shown underlined) Diagrams (al) and (a2) show the permissions in (1) and (2) above.

(3) Owner of C: xl of X, file osu gutob third party/l
ooo ooo ---(Osu:x1.X)B ooo oo
o---(Osu:x1.X)Cooo
ooo ---(Osu:x1.X)D
ooo ooo --- (Os: z1.Z), the permissions for each group for files A, B, C, and D for members other than one are A X: ooo, Y: ---,
Z: --B X: ooo, Y: ---
, Z: ---CX: ooo, Y: ---, Z:
-D X: ---, Y: ---+
Z: oo.

Therefore, members of group Y cannot access any files.

As described above, member x1. x2. Since x3 can only be a member of group X or Y at one time, in (1) and (2) above, member x2゜X3
cannot access files A, B, and C at the same time, and in (3), since file C is owned by group X, members of group Y cannot access it.

Therefore, members x2 .
There was a problem in that even if x3 tried to refer to files A, B, or C owned by group X or Y, respectively, at the same time, it was not possible.

In view of the above-mentioned conventional drawbacks, the present invention provides a plurality of groups (X,
7 ft. 71/ (A, B) owned by Y, Z) respectively
, C, D) among members belonging to each group (X, Y, Z), when members of different groups share the file, it is necessary to The purpose is to provide a file sharing method that can prohibit access to third parties.

[Means to solve the problem]

The above problems are solved by a file sharing method configured as follows.

A plurality of groups (χ, Y, Z) each own files (A, B, C, D), and each of the groups (X).

Read when members of Y, Z) are accessed.

In the method of setting write and execution permissions, the first control manages the group identifier (GID) for each group, its member identifiers (xl+x2.x3+~), and all member identifiers (UIII). File ■.

When the member belongs to a plurality of groups (X, Y, Z), a second control file (■) indicating that the member belongs to a plurality of groups (X, Y, Z) is provided, When the above files (A, B, C, D) are accessed by members of the above groups (χ, Y, Z), the files (A, B, C, When checking for a match with the group identifier that owns D), the first control file ■ and the second control file ■ are checked, and the group (X,
For members belonging to files (Y, Z), it is determined that they are the same group as the group that owns the file (A, B, C, D), and access permission is granted.

[Effect]

That is, according to the present invention, a plurality of groups (X, Y, Z)
In a method in which files (A, B, C, D) owned by each group are shared by members belonging to each group (X, Y, Z), (1) a first control for managing the group name and its members; File (File la) ■ Close, Fi
le la Nigeloop identifier: GID: Generates a control file in member format.

X: 10L: x1, x2. x3. w1, w2. w3Y:
102: y1, y2. y3. x1, x2. x3Z:10
3: z1, z2. z3. z4 z5 (2) First control file that manages all members File lb: All member identifiers: DID: G
Generate a control file in the ID format.

xl:201: 101, x2:202:
101, x3:203: 101yl:204
: 102, y2:205: 102,
y3:206: 10221:207: 103
, z2:208: 103, z3:20
9: 103 w1: 210: 101, w2
:211:101, w3:212:10
1 In the present invention, in addition to this, (3) a second control file (File 3) that targets members belonging to multiple groups;
x Nigeloop identifier: GIDx: Generates a member format control file.

For example, members belonging to group X xLx2+x3
If also belongs to group Y, then File
3y: Y:104:xi, x2. A control file x3 is first generated.

Then, in the verification check of each file, if a mismatch is found between the rGID J of the file and the group identifier Nigel-1 name (GID) to which the member belongs, in the present invention, the above-mentioned Fi
Check both le la■ and File 3y■.

When this check recognizes that the double-sided open files ■ and ■ belong to the specified group Y, the member is determined to be the same member as group Y that owns the file, and This allows access to

Therefore, even if the member is a member of a group , a control file () indicating that the member belongs to group Y is generated, and the member is recognized as a member sharing the file C, and is permitted to access the file C.

That is, in the file sharing method according to the present invention, while files are shared between different groups, a third party (i.e., a member for whom the second control file has not been generated)
This has the effect of restricting access to.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a diagram showing an embodiment of the present invention, (a)
shows a configuration example, (b) shows a permission operation flow, and (c) shows an example of setting permissions for files A, B, C, and D. When generating a management file (control file), the first control file (File la,
File lb) ■ together with a second control file (File lb) that indicates that a certain member also belongs to other groups.
e 3x)■ is generated, and when processing permissions, when checking whether the group identifier rGID J of the member who owns the file for which you want to set the permission matches the group to which the member to whom the permission is to be granted belongs. , If there is a mismatch, a match check is performed on both the first control file ■ and the second control file ■, and both files match (both files ■ and ■ are members of the group specified by them). is recognized), the present invention provides means for recognizing the member as belonging to the same group as the member who owns the file and allowing the member to access the file. It is a necessary means to implement it. Note that the same reference numerals indicate the same objects throughout the figures.

The file sharing method of the present invention will be explained below with reference to FIG.

First, in the group management processing section 1 shown in FIG. 1(a), a plurality of members x1, χ2. Generate a first control file ■ and a second control file ■ for X3. (See action column) (1) For example, if you try to register user (member) x 1 to group Y, group management processing unit 1
Checks if it does not belong to another group.

(2) In (1) above, if user x1 belongs to another group The second control file of the invention (File
3x) Register the member name xi in ■.

(3) Similarly, when attempting to register user X2 to group Y, group management processing section 1 checks whether user X2 does not belong to another group.

(4) In (3), if user x 2 belongs to another group
2 to group Y, and the above second control file (File 3x
) Register member name X2 in ■.

(5) Similarly, when attempting to register user x3 to group Y, the group management processing unit 1 checks whether user x3 does not belong to another group.

(6) In (5), if user x3 belongs to another group Y, the group management processing unit 1
3x to group Y, and also registers the second control file (File 3x) which is a duplicate member management file.
) Register member name X3 in ■.

(7) User X1 creates files A and B and sends the owner, group, and third party 11
1. Set 101,000.

(8) User y1 creates file C, and sends 111 requests to the owner, group, and third party as a permission.
, 101,000.

Next, the user xLx2 for whom the above group management registration was performed
The process when granting permission for +x3 is as follows:
(b) This will be explained below according to the operational flow shown in the figure.

(9) If member X2 of group X tries to access file C (file owned by member y1 of group Y), the permission check processing unit
(See Figure (a)) 2 is the first control file (Fil.
e la, lb) ■, it is determined that user x2 is a member of a different group. (Processing step 10
0.101) GO) Then, by the second control file (File 3x) of the present invention, the member x
2 is determined to belong to group Y, member x2 is recognized to have the same group identifier \'' as the user who owns file C, and member X2 is enabled to read and execute the file. (Processing steps 102.103.1
(See 04.107) Figure (c) shows the vermission at this time.

Here, files A and B are files owned by members of group X, and file C is a file owned by members of group Y.

As is clear from this figure, in the file sharing method according to the present invention, members X1+x2 belonging to two groups X and Y
+x3 is files A and B of both groups.

You will be able to access C.

(11) If member y1 of group Y has file A,
When attempting to access B, the permission/notion check processing unit 2 first accesses the first control file (File
la, lb) ■, it is determined that the member y1 is a member of a different group.

02) Next, the second control file of the present invention (File
3x) ■ It is determined that member y1 does not belong to group X, and member y1 is prohibited from all access to files A and B. (Processing step 102
．． 103.104.105.108) 03) Or,
When member z1 of group Z attempts to access files A and B, the permission check processing unit 2 first determines that member z1 is a member of a different group based on the first control file (File la, lb). be done.

Q4) Next, the permission check processing unit 2 refers to the second control file (File 3χ) of the present invention, but it is determined that the member z1 does not belong to either group X or Y, and the member z1 behaves so that all access is prohibited.

(Processing steps 102.103.104.105.10
8) As described above, in the present invention, when the group management processing unit generates management files (control files) for a plurality of members, the first control file (File la, File
le lb)■, along with a second control file (File
3x) Create ■, and when processing the permission check, use the group identifier rGID J of the member who owns the file for which you want to set the permission.
When checking the match with the group identifier rGID J belonging to the member to be granted permission, if there is a mismatch, a match is checked between the first control file ■ and the second control file ■, and both are checked. matches (if the member also belongs to the group specified by the second control file), the member is considered to be a member of the same group as the member that owns the file. The feature is that the file is recognized and the member is allowed to access the file.

〔Effect of the invention〕

As explained above in detail, the group sharing method of the present invention allows files (A, B, C, D) owned by a plurality of groups (X, Y, Z) to be shared by each group (X, Y, Z). )
When sharing with members belonging to the above groups (
Read when members of X, Y, Z) access,
In the method of setting write and execution permissions, a first control file that manages the group identifier (GID) for each group, its member identifiers (xLx2.x3, ~), and all member identifiers (UID). (2) When the above member belongs to multiple groups (X, Y, Z), the member belongs to multiple groups (X, Y, Z).

Each of the above files (A, B, C, D) is
In the read, write, and execution permission check when members of the above groups (X, Y, Z) access, the group identifier ( GID), the first control file ■ and the second control file ■ are checked, and the members belonging to the group (X, Y, Z) specified by both control files ■ and ■ are checked. is determined to be the same group as the group that owns the file (A, B, C, D) and is granted access permission, so the file cannot be shared between different groups. However, it has the effect of restricting access to third parties.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an embodiment of the present invention. FIG. 2 is a diagram explaining a conventional vermission setting method. It is. In the drawing, 1 is the group management processing unit. 2 is a permission check processing section. 100 to 108 are processing steps. ■ is the first control file (File la, lb) + ■
is the second control file (File 3x) + A, B, C are files. are shown respectively. (b) Figure (Part 2) (al) (a2) (b) Figure explaining the conventional permission setting method (Part 1) (c) Figure explaining the conventional permission setting method (Part 2) )

Claims (1)

[Claims] A file (A, B, C, D) owned by a plurality of groups (X, Y, Z) is accessed by members of each of the groups (X, Y, Z). In the method of setting read, write, and execution permissions for each group, the group identifier (GID) for each group, its member identifiers (x1, x2, x3, ~), and all member identifiers (UID) are managed. The first control file ((1)
), and when the above member belongs to multiple groups (X, Y, Z), a second control file (( 2
)) for each file in the read, write, and execution permission check when the above files (A, B, C, D) are accessed by members of the above groups (X, Y, Z). When checking for a match with the group identifier (GID) that owns (A, B, C, D), check the first control file ((1)) and the second control file ((2)) above. However, for members belonging to the group (X, Y, Z) specified by both of the above control files ((1), (2)), those who own the file (A, B, C, D) A file sharing method that is characterized by determining that the group is the same as the other group and granting access permission.