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Network Working Group James E. White
Request for Comments: 122 UC Santa Barbara
NIC 5834 26 April 1971
NETWORK SPECIFICATIONS FOR UCSB's
SIMPLE-MINDED FILE SYSTEM
CONTENTS
Page
I. Preface........................................ 3
II. Implementation................................. 3
III. Login.......................................... 3
IV. Service Offered................................ 4
V. Primitive File Operations...................... 6
V.A. Allocate File (ALF)...................... 6
V.B. Update File (UDF)........................ 7
V.C. Replace File (RDF)....................... 8
V.D. Retrieve File (RTF)...................... 9
V.E. Space File (SPF)......................... 9
V.F. Delete File (DLF)........................ 10
V.G. Rename File (RNF)........................ 10
V.H. File No Operation (FNO).................. 10
V.I. No Operation (NOP)....................... 11
VI. Input Stream Format............................ 11
VII. Output Stream Format........................... 16
J. White [Page 1]
RFC 122 Simple-Minded file System April 1971
FIGURES
Page
Figure 1. Filename/Password Character Sets........... 5
Figure 2. Command Op Codes........................... 12
Figure 3. Defined Command Fields..................... 13
Figure 4. Definition of Command FLAGS Bits........... 14
Figure 5. Defined Command Response Fields............ 18
Figure 6. Completion Codes........................... 19
J. White [Page 2]
RFC 122 Simple-Minded file System April 1971
I. Preface
UCSB will provide file storage for Network users. UCSB's Simple
Minded File System (SMFS) is addressed as socket number X'401', site
3. No accounting parameters are required. This document is intended
to provide programmers with the information necessary to communicate
with SMFS which conducts all Network transactions trough its NCP
which operates under the Host-Host protocol of August 3, 1970.*
II. Implementation
The following information is not essential to use of SMFS but may be
of interest. SMFS will store user's files on IBM 2316 disk packs,
each with 29M 8-bit bytes of storage capacity. UCSB has two 2314
units, each with eight drives on-line. Initially, one drive will be
allocated for Network storage, and the appropriate pack will always
be mounted an that drive, and hence accessible to SMFS without
operator intervention. UCSB estimates that for the next year it will
have up to four drives that it can devote to Network use. The
second, third, and fourth drives will be allocated only as the need
arises. SMFS is written to accommodate any number of on-line drives
without modification.
If necessary, UCSB will investigate the possibility of making one of
the four drives a come-and-go drive on which one of a number of packs
can be mounted as required. Hence, the potential exists for
increased storage capacity with an accompanying increase in access
time.
Files stored with SMFS will be backed up to tape daily. The back-up
tape(s) will be off-line and available only in case the on-line
copies are destroyed.
In no sense does USB expect to become _the_ file storage node of the
Network; it hasn't the capacity. UCSB _is_ equipped, however, to
make a limited amount of secondary storage immediately available to
the Network community.
III. Login
SMFS can simultaneously service any number of Network users up to
some assembly-parameters maximum (currently ten). A potential user
must establish a pair of Network connections
- At the time of this writing, the NCP modifications of RFC #107 have not
as yet been implemented at UCSB.
J. White [Page 3]
RFC 122 Simple-Minded file System April 1971
(i.e., one full-duplex connection) to SMFS by executing a standard
ICP to socket X'401', site 3. SMFS always listens on that socket.
It will accept any call it receives -- say from the user's receive
socket 'm' -- and over the connection thus established transmit a
32-bit receive socket number (call it 'n'), and then close the
connection. SMFS will then issue two connection requests -- one
involving its receive socket 'n' and the user's send socket 'm+l', in
other involving its send socket 'n+l' and the user's receive socket
'm'. Once these two connections have been established, the user will
be considered logged in. A deviation from the Initial Connection
Protocol will occur only if SMFS or its NCP has insufficient
resources to support another connection.
SMFS will maintain its connections to the user indefinitely. It will
voluntarily terminate its connections to the user only if (1) a bad
op code is encountered in a user command (see Section VI), or (2)
closing one of the connections is required to signal end-of-data (see
Section V.D.). Barring such an occurrence, the user should close his
connections to SMFS when through, at which time SMFS will consider
the user logged out.
In the discussion to follow, the following terms are used. The
connections on which the user transmits data to and receives data
from SMFS are designated the input and output connections,
respectively (i.e., SMFS's rather than the user's point of view is
adopted). The string of bits which passes from the user to SMFS over
the input connection during the life of that connection is called the
_input stream_; the string of bits which passes from SMFS to the user
over the output connection during the life of that connection is
called the _output stream_.
IV. Service Offered
SMFS will provide storage for sequential, binary files of length
greater than or equal to an assembly-parameter minimum (currently one
bit) and less than or equal to an assembly-parameter maximum
(currently 25 million bits). There is no restriction on the contents
of the file.
Every file stored with SMFS has a _filename_, which may be any string
of from one to 36, 8-bit characters chosen from the set:
{ A,...,Z,0,...9,blank }
J. White [Page 4]
RFC 122 Simple-Minded file System April 1971
Graphic EBCDIC Code (Hex) ASCII Code (Hex)
UC LC UC LC UC LC
A a C1 81 41 61
B b C2 82 42 62
C c C3 83 43 63
D d C4 84 44 64
E e C5 85 45 65
F f C6 86 46 66
G g C7 87 47 67
H h C8 88 48 68
I i C9 89 49 69
J j D1 91 4A 6A
K k D2 92 4B 6B
L l D3 93 4C 6C
M m D4 94 4D 6D
N n D5 95 4E 6E
O o D6 96 4F 6F
P p D7 97 50 70
Q q D8 98 51 71
R r D9 99 52 72
S s E2 A2 53 73
T t E3 A3 54 74
U u E4 A4 55 75
V v E5 A5 56 76
W w E6 A6 57 77
X x E7 A7 58 78
Y y E8 A8 59 79
Z z E9 A9 5A 7A
0 - F0 - 30 -
1 - F1 - 31 -
2 - F2 - 32 -
3 - F3 - 33 -
4 - F4 - 34 -
5 - F5 - 35 -
6 - F6 - 36 -
7 - F7 - 37 -
8 - F8 - 38 -
9 - F9 - 39 -
blank - 40 - 20 -
Figure 1
Filename/Password Character Sets
J. White [Page 5]
RFC 122 Simple-Minded file System April 1971
Filenames may be specified by the user in either EBCDIC or ASCII (see
Figure 1), and the characters A,...,Z may be either upper- or lower-
case. However, the acceptance by SMFS of both upper- and lower-case,
and both EBCDIC and ASCII, is provided only as a convenience to the
user. In particular, such distinctions don't increase the number of
unique filenames that can be generated; the filenames 'FILE NUMBER 1'
and 'file number 1', in EBCDIC or ASCII, designate the same file.
Every file stored with SMFS may optionally be protected against
unauthorized retrieval and/or modification. When a file is created,
the user may associate with it a _modification password_ and/or an
_access password_. Thereafter, SMFS will demand that the appropriate
password be supplied before the file is modified or retrieved,
respectively. Since SMFS protects each file independently against
unauthorized modification and retrieval, a group of users can be
given access to a file while a single individual retains the
exclusive right to modify it. If no password is defined for a
particular type of reference to a file, then such references are
unrestricted. Passwords have the same attributes as filenames --
same length restrictions and same character sets.
Because of the manner in which SMFS writes files onto secondary
storage, it must insure that while one user is modifying a file, no
other user is simultaneously either modifying or retrieving the same
file. This requirement is effected by a mechanism internal to SMFS
and hence transparent to users, with the exception that when a user
attempts to retrieve or modify a file currently being modified by
another user, SMFS will delay action upon the request until the
current modification is complete. There is no restriction on the
number of users which may concurrently retrieve the same file.
V. Primitive File Operations
SMFS recognizes and will execute the following primitive file
operations:
V.A. Allocate File (ALF)
SMFS regards the reservation of filename, the assignment of
passwords, and the reservation of secondary storage as an operation
distinct from that of transmitting the file's contents. The
operation is called _file allocation_, abbreviated ALF. In
allocating a file, the user specifies the filename to be assigned to
it, the access password (if any), and the estimated size of the file
in bits. SMFS checks the proposed filename to insure that it doesn't
duplicate that of an existing file. SMFS also checks to insure that
it has sufficient secondary storage available to accommodate the new
J. White [Page 6]
RFC 122 Simple-Minded file System April 1971
file. If both requirements are met, SMFS allocates the file; the
filename is reserved, secondary storage is reserved, and the password
information is recorded.
In reserving secondary storage for a file, SMFS adds its estimate of
its overhead in storing the file to the user-declared size of the
file. In general, the user should slightly over-estimate the size of
his file at allocation. SMFS allocates a fixed amount of storage on
the basis of that estimate, an amount which cannot be increased
later. SMFS's actual overhead in storing a file is a function of the
manner in which the contents of the file are transmitted by the user.
The overhead is minimal when the file is transmitted in a single
series of operations (see Section VI) and increases as the number of
operations increases. It is the overhead associated with single-
series transmission that SMFS adds to the file size specified by the
user to determine the amount of storage to allocate. Hence, for
multiple-series transmission, the overhead will have been
underestimated.
V.B. Update File (UDF)
The operation of transmitting part or all of a previously allocated
file's contents for storage by SMFS is called _updating_ the _file_
(UDF). The user specifies the filename of the file to be updated,
the modification password if required, the amount of data in bits to
be added to the file, and finally the data itself. SMFS locates the
file on secondary storage, checks the password for validity, if
appropriate, and adds the data to the file. SMFS considers the
update complete when either the specified number of bits have been
extracted from the input stream and stored, or when the user
terminates transmission by closing the connection.
The data transmitted in a UDF operation is _concatenated_ to the
current contents of the file. Boundaries between updates are
transparent to the user when the file is retrieved. Hence, for
example, the contents of a file might be transmitted to SMFS in two
distinct UDF operations, and later retrieved in a single RTF
operation (see Section V.D.). The user should view a file stored
with SMFS as a potentially very long bit string which may be
transmitted to SMFS in any number of variable-length _segments_, and
is retrievable in any number of variable-length segments, with the
manner of segmentation chosen during retrieval independent of that
selected during the updating process.
The user may optionally request that SMFS 'remember' the manner in
which a file was updated, i.e., along with the data, store sufficient
information to reconstruct segment boundaries at retrieval time.
Such a file is said to be _formatted_. In retrieving a formatted
J. White [Page 7]
RFC 122 Simple-Minded file System April 1971
file, the user, rather than requesting that SMFS transmit the next
'n' bits of the file as he would do for an unformatted file (see
Section V.D.), requests that SMFS transmit the next segment of the
file; it is then SMFS's responsibility to supply the length of the
segment. Hence, the notion of a _logical record_ is introduced.
Of course, since the user may format the contents of a file in any
way he chooses, he can embed record-length information in the data
itself. Hence, the user can implement a record structure in a way
that's transparent to SMFS. This scheme, however, requires during
retrieval that, for each logical record retrieved, the user fetch
first the length field and then, using the length as an operand,
fetch the data itself. In this kind of arrangement, the retrieval
rate is apt to suffer. However, by allowing SMFS knowledge of
logical-record boundaries, the feedback loop is effectively shortened
(SMFS being closer to the file); hence, the potential exists for an
increased retrieval rate.
If the user intends that a file be formatted, he must so specify in
every update and every retrieve operation referencing that file.
SMFS in no way flags a file to indicate that it is formatted. Hence,
if the user invokes the option during retrieval without having done
so when the file was stored, results will be erroneous. Furthermore,
if an update of a formatted file is terminated before the bit count
for the operation is exhausted (i.e., because the user closed the
connection), retrieval results will again be erroneous.
V.C. Replace File (RPF)
The replace-file (RPF) operation is identical to UDF, except that the
new file segment, rather than being concatenated to the existing
file, _replaces_ the entire contents of the file. The previous
contents of the file are lost, and the new segment becomes the only
segment in the file.
RPF may be used to rewrite an existing file. If the rewritten file
is to contain just a single segment, that segment may be transmitted
to SMFS in an RPF operation. Otherwise, the first segment of the new
file must be transmitted in an RPF operation, and all succeeding
segments in UDF operations. Alternately, a dummy (bit count of zero)
RPF operation may be inserted before the first real segment is
transmitted; all segments of the file may then be transmitted in UDF
operations.
J. White [Page 8]
RFC 122 Simple-Minded file System April 1971
V.D. Retrieve File (RTF)
The operation which retrieves all or part of a file's contents is
called file retrieval (RTF). The user specifies the filename of the
file to be retrieved, the access password if required, and the amount
of data in bits to be fetched from the file. SMFS locates the file
on secondary storage, checks the password for validity (if
appropriate), and copies the bit count and the requested file segment
into the output stream. SMFS considers the retrieval complete when
either the requested number of bits have been placed in the output
stream, or when the contents of the file are exhausted. In this
latter case, SMFS closes the connection to signal end-of-data to the
user.
Successive RTF operations referencing the same file cause successive
segments of the file to be transmitted, provided that the operations
are juxtaposed in the input stream (however, NOP's may be
interspersed anywhere in the input stream). When a series of RTF
operations referencing a particular file is broken by an operation
referencing another file, or by a different type of operation
involving the same file, the next RTF operation designating the
original file will cause the _first_ segment of that file to be
transmitted. The manner in which the user segments a file for a
series of retrieve operations need bear no relationship to the
segmentation scheme employed when the file was updated, nor to that
employed in previous retrievals.
If the user elected to have his file formatted by SMFS, he should
re-invoke the option in the RTF operation, in which case SMFS will
supply the length of the segment, and place both it and the segment
itself into the output stream.
V.E. Space File (SPF)
Files stored with SMFS are sequential in organization. That is the
n+1th segment of the file cannot be retrieved without first
processing the nth segment. The user may, however, upon occasion,
wish to retrieve only selected segments of a file. This he could do,
effectively, by retrieving each segment of the file and flushing
those with which he was currently unconcerned. To avoid needless
Network traffic, SMFS provides a mechanism for flushing file segments
locally. The operation is called _spacing_ a file (SPF). It is
identical to RTF with the exception that transmission of data (but
not bit count) is suppressed. SPF operations may be freely inserted
anywhere within a series of RTF operations designating a particular
file, with the desired results.
J. White [Page 9]
RFC 122 Simple-Minded file System April 1971
V.F. Delete File (DLF)
A file may be deleted at any time after allocation. The user
specifies the filename of the file to be deleted and the modification
password if required. SMFS locates the file on secondary storage,
checks the password for validity (if appropriate), and, if the
password is correct, deletes the file. The filename is made
available for reassignment, and the secondary storage allocated to
the file is reclaimed by SMFS. The contents (if any) of the file are
lost.
V.G. Rename File (RNF)
A file stored with SMFS may be renamed at any time after allocation.
The user specifies the current filename of the file to be renamed,
the modification password if any, and the proposed new filename.
SMFS locates the file on secondary storage, checks the password for
validity (if appropriate), and assures that the proposed new filename
is not already assigned to another file. If these requirements are
met, the file is renamed, and all subsequent references to the file
must be by the newly-assigned filename.
RNF provides a means for protecting a file that must be rewritten in
its entirety against failures in the Net, or in the sending or
receiving host. The strategy is as follows. Allocate a new file,
assigning it some temporary name. Transmit the revised file contents
in one more UDF and/or RPF operations. Then delete the original file
and, using RNF, replace the newly-created file's temporary filename
with that of the original file.
V.H. File no Operation (FNO)
FNO is a dummy operation which is provided for use in terminating a
series of RTF operations. Should the user desire to retrieve the
contents of a file twice in succession, he may do so with a series of
RTF/SPF operations, followed by a FNO followed by a second series of
RTF/SPF operations. Each RTF/SPF operation in the first series will
retrieve/flush the next segment of the file. The first operation of
the second string, since it _is_ the first of a string, will, as
explained in Section V.D., retrieve/flush the _first_ segment of the
file. The remaining operations in the second string will, of course
retrieve/flush the 2nd, 3rd, etc., segments of the file. Hence, the
contents of the file are transmitted twice. FNO, when it terminates
such a string of operations, effectively repositions the user to the
first segment of the file.
FNO may appear anywhere within the input stream.
J. White [Page 10]
RFC 122 Simple-Minded file System April 1971
V.I. No Operation (NOP)
This operation is provided _solely_ to aid the user in formatting the
input stream, and is discarded without further processing whenever it
is encountered. In particular, a NOP embedded in a series of RTF
operations does not terminate the string as FNO does.
VI. Input Stream Format
The input stream shall consist of a contiguous string of commands to
SMFS. A command type is defined for each of the primitive file
operations of Section V. Each command has the following general
format:
8 16 32
______________//______//_________//__________//_________________//__
| | | | | | | | |
| OP | | | ACCESS |MODIFICATION| NEW | | |
|CODE|FLAGS|FILENAME|PASSWORD| PASSWORD | FILENAME|BIT COUNT| DATA |
|____|_____|___//___|__//____|____//______|___//____|_________|__//__|
where the lengths of fixed-length fields have been indicated in bits.
Each of the fields 'FILENAME','ACCESS PASSWORD', 'MODIFICATION
PASSWORD', and 'NEW FILENAME' is further divided into the following
subfields:
8 8*LENGTH
________________________//___
| | |
| LENGTH | FILENAME/PASSWORD |
|________|_______________//___|
where the 'LENGTH' subfield contains the length in 8-bit characters
of the 'FILENAME/PASSWORD' subfield.
This is the _general_ format for all SMFS commands. No one command
type requires all of the fields specified above. A particular subset
of these fields is defined for each type of command, and only those
fields should appear. The defined fields for each command type are
indicated in Figure 3.
Furthermore, not all of the fields which are defined for a particular
command type need always appear _explicitly_. The user should
envision that SMFS maintains filename, password, and bit-count
accumulators. Every time a filename (or new filename),
J. White [Page 11]
RFC 122 Simple-Minded file System April 1971
access/modification password, or bit count appears explicitly in the
input stream, it is saved in the appropriate accumulator (a null
password -- designated by setting Bits 0,3 or Bits 8,11 to zero
(Figure 4) -- should be thought of as appearing explicitly). The
user may cause a defined field to _default_ to the current contents
of the appropriate accumulator by turning on the appropriate bin in
the flags field (see Figure 4). When a field defaults in this
manner, that field is said to appear _implicitly_ in the command.
NOP 0 No operation.
FNO 1 File no operation.
ALF 2 Allocate file.
UDF 3 Update File.
RPF 4 Replace File.
RTF 5 Retrieve File.
SPF 6 Space File.
DLF 7 Delete File.
RNF 8 Rename File.
Figure 2
Command Op codes
The three accumulators are initially empty and hence an attempt to
default a field in the first command in the input stream illicits an
error indication. A field of the appropriate type must appear once
explicitly in the input stream before the corresponding accumulator
is considered defined. Furthermore, whenever SMFS detects an invalid
filename or password (i.e., improper length or deviation from the
character set) in the input stream, the appropriate accumulator is
left empty again.
SMFS allows operations on several files to be interleaved in the
input stream by including in its command formats provision for
explicitly specifying filename and password information in each
command. When many operations involving the same file appear
sequentially in the input stream, the user need only let the
appropriate fields default in all but the first command, avoiding
re-transmission of what would otherwise be redundant parameters.
J. White [Page 12]
RFC 122 Simple-Minded file System April 1971
M
O
D
I
F
I
A C
C A
C T
E I N
S O E
S N W
B
F P P F I
O I A A I T
P L S S L
F E S S E C
C L N W W N O D
O A A O O A U A
D G M R R M N T
E S E D D E T A
_____________________________________________________________
ALF X X X X X X
_____________________________________________________________
UDF X X X X X X
_____________________________________________________________
RPF X X X X X X
_____________________________________________________________
RTF X X X X X
_____________________________________________________________
SPF X X X X X
_____________________________________________________________
DLF X X X X
_____________________________________________________________
RNF X X X X X
_____________________________________________________________
FNO X
_____________________________________________________________
NOP X
_____________________________________________________________
Figure 3
Defined Command Fields
Note: Command fields marked with an 'X' are defined.
J. White [Page 13]
RFC 122 Simple-Minded file System April 1971
0 ACCESS PASSWORD The access password for this
DEFAULTS operation defaults to the access
or modification password which
appeared explicitly most
recently in the input stream;
hence, it does not appear
explicitly in the current
command.
1 BIT COUNT DEFAULTS The bit count for this operation
defaults to that which appeared
explicitly most recently in the
input stream; hence it does not
appear explicitly in the current
command.
2 FILENAME DEFAULTS The filename for this operation
defaults to the filename or new
filename which appeared explicitly
most recently in the input stream;
hence it does not appear
explicitly in the current command.
3 ACCESS PASSWORD The access password for this
APPEARS EXPLICITLY operation appears explicitly in
the current command. (Bits 0,
3 = 0 indicates that no access
password was/is-to-be defined
for the file.)
4 ECHO OP CODE SMFS shall echo the op code and
AND FILENAME filename (whether it appears
explicitly or not) by copying
them into the output stream
ahead of any other response to
the current command.
5-7 undefined Not examined; should be zeros.
8 MODIFICATION Same as Bit 0, but applied to
PASSWORD DEFAULTS the modification password, rather
than the access password.
Figure 4
Definition of Command FLAGS Bits
J. White [Page 14]
RFC 122 Simple-Minded file System April 1971
9 FILE FORMATTED FOR UDF/RTF: this segment is part
of a formatted file; hence SMFS
should record the bit count. For
RTF/SPF: the referenced file is
formatted; hence the bit count
does not appear explicitly in the
current command
10 NEW FILENAME same as Bit 2, but applied
DEFAULTS to the new filename, rather
than the filename.
11 MODIFICATION PASSWORD Same as Bit 3, but applied to
APPEARS EXPLICITLY the modification password,
rather than the access
password.
12-15 undefined Not examined; should be zeros.
Figure 4(continued)
Definition of Command FLAGS Bits
Note: The sixteen bits of FLAGS are numbered 0-15 from
left to right.
When a series of RTF/SPF operations referencing the same file are
juxtaposed in the input stream (as discussed in Section V.D.), they
cause successive segments of the file to be transmitted _only_ if
both filename and access password default (Bits 0,2 = 1) (a null
password is also acceptable) in those operations following the first
in the series. If the user specifies either parameter explicitly in
a command in the series -- even if the explicitly stated value is the
same as what would have been the default value -- SMFS considers the
series terminated, as if a FNO had been encountered, and hence the
command in question returns, or flushes, the first segment of the
file. Allowing both filename and password to default has the added
effect, in both RTF/SPF and UDF series, of decreasing the processing
time required by SMFS to execute the operations which comprise the
series. Under such circumstances, SMFS executes such initial
functions as file location and password verification only once at the
beginning of the series, rather than for each operation. Hence, a
potential for increased transmission rates exists. Furthermore, in
such a series of UDF/RPF operations, SMFS is able to conserve
secondary storage by concatenating file segments before they are
written out.
J. White [Page 15]
RFC 122 Simple-Minded file System April 1971
Whenever SMFS aborts the processing of a command in the input stream
(e.g., the filename is invalid, an incorrect password is supplied,
etc), SMFS flushes the entire command. Suppose, for example, that
the file specified in a UDF operation does not exist (i.e., has not
been allocated). If the data field for the operation is very long,
SMFS may well detect the non-existence of the file before the data
field has been transmitted by the user. In such cases, SMFS will
accept and flush whatever remains of the aborted command (in this
case, including the very long data field) until it reaches the point
in the input stream at which it expects to find the next command,
which it will process normally. SMFS will, however, notify the user
that the command was aborted by placing an appropriate indicator in
the output stream, and it will do this as soon as it detects the
error (and hence, in this case, before the erroneous command has been
flushed from the input stream). Hence, the user has the option of
aborting the process by closing the connection.
SMFS considers a command with an invalid op code as an especially
severe error, since it has no way of locating the start of the next
command. Accordingly, it places a special character (X'FF') in the
output stream, follows it with the invalid op code, and then closes
its connections to the user.
VII. Output Stream Format
SMFS will respond to each command it extracts from the input stream
-- every command except FNO and NOP -- by placing a command response
in the output stream. Command responses have the following general
format:
8 8 32
_________//___________________________//____
| OP | | CMPL | | |
|CODE | FILENAME | CODE |BIT COUNT| DATA |
|_____|___//_____|______|_________|____//____|
where the lengths of fixed-length fields have been indicated in bits.
The field 'FILENAME' is further divided into the following subfields:
8 8*LENGTH
_______________//______
| | |
| LENGTH | FILENAME |
|________|______//______|
where the 'LENGTH' subfield contains the length in 8-bit characters
of the 'FILENAME' subfield.
J. White [Page 16]
RFC 122 Simple-Minded file System April 1971
This is the general format for SMFS command responses. For responses
to particular commands, not all fields may be present. A particular
subset of these fields is defined for each type of command response;
no other fields will appear. The defined fields for each command
response type are indicated in Figure 5.
The fields 'OP CODE' and 'FILENAME' are the op code and filename
extracted by SMFS from the input stream and are echoed by SMFS in the
output stream. The filename is always echoed explicitly, even if it
appeared implicitly in the input stream. 'OP CODE' and 'FILENAME' are
suppressed and hence do not appear in the command response it Bit 4
of the 'FLAGS' field of the corresponding command is set to 0.
'CMPL CODE' contains an indication of the outcome of the operation.
If the operation was completed successfully, 'CMPL CODE' contains a
value equal to the op code of the command executed. Hence, if
echoing of 'OP CODE' and 'FILENAME' is not suppressed, the operation
was successful if and only if 'OP CODE' and 'CMPL CODE' are
identical. If the operation as unsuccessful, 'CMPL CODE' contains an
indication of the error encountered by SMFS in processing the
command. Completion codes are summarized in Figure 6.
J. White [Page 17]
RFC 122 Simple-Minded file System April 1971
C
O
M
P
L
E
F T B
I I I
O L O T
P E N
C
C N C O D
O A O U A
D M D N T
E E E T A
_____________________________________________________
NOP
_____________________________________________________
FNO
_____________________________________________________
ALF X X X
_____________________________________________________
UDF X X X
_____________________________________________________
RPF X X X
_____________________________________________________
RTF X X X X X
_____________________________________________________
SPF X X X X
_____________________________________________________
DLF X X X
_____________________________________________________
RNF X X X
_____________________________________________________
Figure 5
Defined Command Response Fields
Note: Command response fields marked with an 'X' are defined.
J. White [Page 18]
RFC 122 Simple-Minded file System April 1971
An invalid op code in the input stream constitutes a special type of
error. SMFS's response is as follows. A special command response is
constructed. It consists of the value X'FF' in an eight-bit field,
followed by the erroneous op code, also in an eight-bit field. The
command response is placed in the output stream and connections to
the user are closed.
2 ALLOCATION SUCCESSFUL The file was successfully allocated.
3 UPDATE SUCCESSFUL The file was successfully updated.
4 REPLACE SUCCESSFUL The file was successfully replaced.
5 RETRIEVE SUCCESSFUL The file segment was successfully
retrieved.
6 SPACE SUCCESSFUL The file segment was successfully
flushed.
7 DELETION SUCCESSFUL The file was successfully deleted.
8 RENAME SUCCESSFUL The file was successfully renamed.
20 NO DEFAULT FILENAME The user attempted to default the
filename (or new filename), and the
filename accumulator was empty.
21 ZERO-LENGTH FILENAME The length of the filename (or new
filename) was specified as zero.
22 FILENAME TOO LONG The length of the filename (or new
filename) exceeded 36 characters.
23 INVALID FILENAME The filename (or new filename)
contained character(s) that do not
appear in the character set.
24 NO DEFAULT PASSWORD The user attempted to default either
the access or modification password,
and the password accumulator was empty.
25 ZERO-LENGTH PASSWORD The length of either the access of
modification password was specified as
zero.
Figure 6
Completion Codes
J. White [Page 19]
RFC 122 Simple-Minded file System April 1971
26 PASSWORD TOO LONG The length of either the access or
modification password exceeded 36
characters.
27 NO DEFAULT BIT COUNT The user attempted to default the bit
count, and the bit-count accumulator
was empty.
28 INVALID PASSWORD Either the access or modification
password contained character(s) that do
not appear in the character set.
29 DUPLICATE FILENAME Either the filename (in an ALF
operation) or new filename (in a RNF
operation) is already assigned to
another file.
30 INSUFFICIENT SPACE (In an ALF operation) The requested
amount of secondary storage is
unavailable.
31 ALLOCATION I/O ERROR (In an ALF operation) An irrecoverable
I/O error was encountered by SMFS while
attempting to allocate the file.
32 FILE NOT FOUND The referenced file does not exist.
33 SEARCH I/O ERROR An irrecoverable I/O error was
encountered by SMFS while attempting to
locate the referenced file.
34 FILE FULL (In a UDF/RPF operation) The secondary
storage allocated to the file has been
exhausted.
35 INCORRECT PASSWORD The access or modification password
supplied by the user does not match
that declared when the file was
allocated.
36 FILE SIZE TOO SMALL (In an ALF operation) The bit count
specified is less than the minimum file
size accepted by SMFS.
Figure 6 (continued)
Completion Codes
J. White [Page 20]
RFC 122 Simple-Minded file System April 1971
37 FILE SIZE TOO BIG (In an ALF operation) The bit count
specified exceeded the maximum file
size accepted by SMFS.
38 WRITE I/O ERROR An irrecoverable I/O error as
encountered by SMFS. (In an ALF
operation) SMFS was attempting to
record password information, or (in a
UDF/RPF operation) SMFS as attempting
to add data to the file.
39 READ I/O ERROR An irrecoverable I/O error was
encountered by SMFS attempting to
retrieve either password information or
data.
40 RENAME I/O ERROR An irrecoverable I/O error was
encountered by SMFS while attempting to
rename the file.
41 DELETE I/O ERROR (In a DLF operation) An irrecoverable
I/O error was encountered by SMFS while
attempting to delete the file.
42 END-OF-DATA (In a RTF/SPR operation) The end of the
file was reached before the requested
segment had been transmitted/flushed.
Figure 6 (continued)
Completion Codes
[ This RFC was put into machine readable form for entry ]
[ into the online RFC archives by Gottfried Janik 2/98 ]
J. White [Page 21]