From c1709e3194855b93ffd6f68eaa750c6704b3e52f Mon Sep 17 00:00:00 2001 From: Aidan MacDonald Date: Fri, 26 Nov 2021 14:37:36 +0000 Subject: microtar: Update to latest upstream commit This is a major overhaul of the library with some API changes and ease of use improvements, particularly for creating new archives. The updated functionality is intended to support a new X1000 installer framework. Change-Id: Icf192bb546831231d49303fbf529ef1c1ce8905c --- lib/microtar/.gitignore | 3 + lib/microtar/LICENSE | 1 + lib/microtar/Makefile | 25 + lib/microtar/README.md | 312 +++++++++---- lib/microtar/README.rockbox | 14 + lib/microtar/mtar.c | 243 ++++++++++ lib/microtar/src/microtar-rockbox.c | 115 +++-- lib/microtar/src/microtar-rockbox.h | 29 ++ lib/microtar/src/microtar-stdio.c | 113 +++-- lib/microtar/src/microtar-stdio.h | 39 ++ lib/microtar/src/microtar.c | 886 ++++++++++++++++++++++++------------ lib/microtar/src/microtar.h | 193 ++++---- 12 files changed, 1415 insertions(+), 558 deletions(-) create mode 100644 lib/microtar/.gitignore create mode 100644 lib/microtar/Makefile create mode 100644 lib/microtar/README.rockbox create mode 100644 lib/microtar/mtar.c create mode 100644 lib/microtar/src/microtar-rockbox.h create mode 100644 lib/microtar/src/microtar-stdio.h diff --git a/lib/microtar/.gitignore b/lib/microtar/.gitignore new file mode 100644 index 0000000000..cccd994a85 --- /dev/null +++ b/lib/microtar/.gitignore @@ -0,0 +1,3 @@ +*.o +*.a +/mtar diff --git a/lib/microtar/LICENSE b/lib/microtar/LICENSE index 7e3bf17ccb..72cf80d63b 100644 --- a/lib/microtar/LICENSE +++ b/lib/microtar/LICENSE @@ -1,4 +1,5 @@ Copyright (c) 2017 rxi +Copyright (c) 2021 Aidan MacDonald Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in diff --git a/lib/microtar/Makefile b/lib/microtar/Makefile new file mode 100644 index 0000000000..ae2c4f6d6e --- /dev/null +++ b/lib/microtar/Makefile @@ -0,0 +1,25 @@ +CPPFLAGS = -Isrc +CFLAGS = -std=c99 -Wall -Wextra -O2 + +MTAR_OBJ = mtar.o +MTAR_BIN = mtar + +MICROTAR_OBJ = src/microtar.o src/microtar-stdio.o +MICROTAR_LIB = libmicrotar.a + +$(MTAR_BIN): $(MTAR_OBJ) $(MICROTAR_LIB) + $(CC) $(CFLAGS) $(CPPFLAGS) -o $@ $^ + +$(MICROTAR_LIB): $(MICROTAR_OBJ) + $(AR) cr $@ $^ + +%.o: %.c + $(CC) $(CFLAGS) $(CPPFLAGS) -c $< -o $@ + +src/microtar.o: src/microtar.h +src/microtar-stdio.o: src/microtar.h src/microtar-stdio.h +mtar.o: src/microtar.h src/microtar-stdio.h + +clean: + rm -f $(MICROTAR_LIB) $(MICROTAR_OBJ) + rm -f $(MTAR_BIN) $(MTAR_OBJ) diff --git a/lib/microtar/README.md b/lib/microtar/README.md index 18153caa21..109626cdd4 100644 --- a/lib/microtar/README.md +++ b/lib/microtar/README.md @@ -1,128 +1,268 @@ # microtar -A lightweight tar library written in ANSI C +A lightweight tar library written in ANSI C. -## Modifications from upstream +This version is a fork of [rxi's microtar](https://github.com/rxi/microtar) +with bugfixes and API changes aimed at improving usability, but still keeping +with the minimal design of the original library. -[Upstream](https://github.com/rxi/microtar) has numerous bugs and gotchas, -which I fixed in order to improve the overall robustness of the library. +## License + +This library is free software; you can redistribute it and/or modify it under +the terms of the MIT license. See [LICENSE](LICENSE) for details. -A summary of my changes, in no particular order: -- Fix possible sscanf beyond the bounds of the input buffer -- Fix possible buffer overruns due to strcpy on untrusted input -- Fix incorrect octal formatting by sprintf and possible output overrruns -- Catch read/writes which are too big and handle them gracefully -- Handle over-long names in `mtar_write_file_header` / `mtar_write_dir_header` -- Ensure strings in `mtar_header_t` are always null-terminated -- Save and load group information so we don't lose information -- Move `mtar_open()` to `microtar-stdio.c` so `microtar.c` can be used in - a freestanding environment -- Allow control of stack usage by moving temporary variables into `mtar_t`, - so the caller can decide whether to use the stack or heap +## Supported format variants -An up-to-date copy of this modified version can be found -[here](https://github.com/amachronic/microtar). +No effort has been put into handling every tar format variant. Basically +what is accepted is the "old-style" format, which appears to work well +enough to access basic archives created by GNU `tar`. -## Modifications for Rockbox +## Basic usage -Added file `microtar-rockbox.c` implementing `mtar_open()` with native -Rockbox filesystem API. +The library consists of two files, `microtar.c` and `microtar.h`, which only +depend on a tiny part of the standard C library & can be easily incorporated +into a host project's build system. +The core library does not include any I/O hooks as these are supposed to be +provided by the host application. If the C library's `fopen` and friends is +good enough, you can use `microtar-stdio.c`. -## Basic Usage -The library consists of `microtar.c` and `microtar.h`. These two files can be -dropped into an existing project and compiled along with it. +### Initialization + +Initialization is very simple. Everything the library needs is contained in +the `mtar_t` struct; there is no memory allocation and no global state. It is +enough to zero-initialize an `mtar_t` object to put it into a "closed" state. +You can use `mtar_is_open()` to query whether the archive is open or not. + +An archive can be opened for reading _or_ writing, but not both. You have to +specify which access mode you're using when you create the archive. -#### Reading ```c mtar_t tar; -mtar_header_t h; -char *p; +mtar_init(&tar, MTAR_READ, my_io_ops, my_stream); +``` -/* Open archive for reading */ -mtar_open(&tar, "test.tar", "r"); +Or if using `microtar-stdio.c`: -/* Print all file names and sizes */ -while ( (mtar_read_header(&tar, &h)) != MTAR_ENULLRECORD ) { - printf("%s (%d bytes)\n", h.name, h.size); - mtar_next(&tar); +```c +int error = mtar_open(&tar, "file.tar", "rb"); +if(error) { + /* do something about it */ } +``` -/* Load and print contents of file "test.txt" */ -mtar_find(&tar, "test.txt", &h); -p = calloc(1, h.size + 1); -mtar_read_data(&tar, p, h.size); -printf("%s", p); -free(p); +Note that `mtar_init()` is called for you in this case and the access mode is +deduced from the mode flags. -/* Close archive */ -mtar_close(&tar); -``` -#### Writing +### Iterating and locating files + +If you opened an archive for reading, you'll likely want to iterate over +all the files. Here's the long way of doing it: + ```c mtar_t tar; -const char *str1 = "Hello world"; -const char *str2 = "Goodbye world"; +int err; + +/* Go to the start of the archive... Not necessary if you've + * just opened the archive and are already at the beginning. + * (And of course you normally want to check the return value.) */ +mtar_rewind(&tar); -/* Open archive for writing */ -mtar_open(&tar, "test.tar", "w"); +/* Iterate over the archive members */ +while((err = mtar_next(&tar)) == MTAR_ESUCCESS) { + /* Get a pointer to the current file header. It will + * remain valid until you move to another record with + * mtar_next() or call mtar_rewind() */ + const mtar_header_t* header = mtar_get_header(&tar); -/* Write strings to files `test1.txt` and `test2.txt` */ -mtar_write_file_header(&tar, "test1.txt", strlen(str1)); -mtar_write_data(&tar, str1, strlen(str1)); -mtar_write_file_header(&tar, "test2.txt", strlen(str2)); -mtar_write_data(&tar, str2, strlen(str2)); + printf("%s (%d bytes)\n", header->name, header->size); +} + +if(err != MTAR_ENULLRECORD) { + /* ENULLRECORD means we hit end of file; any + * other return value is an actual error. */ +} +``` -/* Finalize -- this needs to be the last thing done before closing */ -mtar_finalize(&tar); +There's a useful shortcut for this type of iteration which removes the +loop boilerplate, replacing it with another kind of boilerplate that may +be more palatable in some cases. + +```c +/* Will be called for each archive member visited by mtar_foreach(). + * The member's header is passed in as an argument so you don't need + * to fetch it manually with mtar_get_header(). You can freely read + * data (if present) and seek around. There is no special cleanup + * required and it is not necessary to read to the end of the stream. + * + * The callback should return zero (= MTAR_SUCCESS) to continue the + * iteration or return nonzero to abort. On abort, the value returned + * by the callback will be returned from mtar_foreach(). Since it may + * also return normal microtar error codes, it is suggested to use a + * positive value or pass the result via 'arg'. + */ +int foreach_cb(mtar_t* tar, const mtar_header_t* header, void* arg) +{ + // ... + return 0; +} -/* Close archive */ -mtar_close(&tar); +void main() +{ + mtar_t tar; + + // ... + + int ret = mtar_foreach(&tar, foreach_cb, NULL); + if(ret < 0) { + /* Microtar error codes are negative and may be returned if + * there is a problem with the iteration. */ + } else if(ret == MTAR_ESUCCESS) { + /* If the iteration reaches the end of the archive without + * errors, the return code is MTAR_ESUCCESS. */ + } else if(ret > 0) { + /* Positive values might be returned by the callback to + * signal some condition was met; they'll never be returned + * by microtar */ + } +} +``` + +The other thing you're likely to do is look for a specific file: + +```c +/* Seek to a specific member in the archive */ +int err = mtar_find(&tar, "foo.txt"); +if(err == MTAR_ESUCCESS) { + /* File was found -- read the header with mtar_get_header() */ +} else if(err == MTAR_ENOTFOUND) { + /* File wasn't in the archive */ +} else { + /* Some error occurred */ +} ``` +Note this isn't terribly efficient since it scans the entire archive +looking for the file. + + +### Reading file data + +Once pointed at a file via `mtar_next()` or `mtar_find()` you can read the +data with a simple POSIX-like API. + +- `mtar_read_data(tar, buf, count)` reads up to `count` bytes into `buf`, + returning the actual number of bytes read, or a negative error value. + If at EOF, this returns zero. + +- `mtar_seek_data(tar, offset, whence)` works exactly like `fseek()` with + `whence` being one of `SEEK_SET`, `SEEK_CUR`, or `SEEK_END` and `offset` + indicating a point relative to the beginning, current position, or end + of the file. Returns zero on success, or a negative error code. + +- `mtar_eof_data(tar)` returns nonzero if the end of the file has been + reached. It is possible to seek backward to clear this condition. + + +### Writing archives + +Microtar has limited support for creating archives. When an archive is opened +for writing, you can add new members using `mtar_write_header()`. + +- `mtar_write_header(tar, header)` writes out the header for a new member. + The amount of data that follows is dictated by `header->size`, though if + the underlying stream supports seeking and re-writing data, this size can + be updated later with `mtar_update_header()` or `mtar_update_file_size()`. + +- `mtar_update_header(tar, header)` will re-write the previously written + header. This may be used to change any header field. The underlying stream + must support seeking. On a successful return the stream will be returned + to the position it was at before the call. + +File data can be written with `mtar_write_data()`, and if the underlying stream +supports seeking, you can seek with `mtar_seek_data()` and read back previously +written data with `mtar_read_data()`. Note that it is not possible to truncate +the file stream by any means. + +- `mtar_write_data(tar, buf, count)` will write up to `count` bytes from + `buf` to the current member's data. Returns the number of bytes actually + written or a negative error code. + +- `mtar_update_file_size(tar)` will update the header size to reflect the + actual amount of written data. This is intended to be called right before + `mtar_end_data()` if you are not declaring file sizes in advance. + +- `mtar_end_data(tar)` will end the current member. It will complain if you + did not write the correct amount data provided in the header. This must be + called before writing the next header. + +- `mtar_finalize(tar)` is called after you have written all members to the + archive. It writes out some null records which mark the end of the archive, + so you cannot write any more archive members after this. + +Note that `mtar_close()` can fail if there was a problem flushing buffered +data to disk, so its return value should always be checked. + ## Error handling -All functions which return an `int` will return `MTAR_ESUCCESS` if the operation -is successful. If an error occurs an error value less-than-zero will be -returned; this value can be passed to the function `mtar_strerror()` to get its -corresponding error string. +Most functions that return `int` return an error code from `enum mtar_error`. +Zero is success and all other error codes are negative. `mtar_strerror()` can +return a string describing the error code. -## Wrapping a stream -If you want to read or write from something other than a file, the `mtar_t` -struct can be manually initialized with your own callback functions and a -`stream` pointer. +A couple of functions use a different return value convention: -All callback functions are passed a pointer to the `mtar_t` struct as their -first argument. They should return `MTAR_ESUCCESS` if the operation succeeds -without an error, or an integer below zero if an error occurs. +- `mtar_foreach()` may error codes or an arbitrary nonzero value provided + by the callback. +- `mtar_read_data()` and `mtar_write_data()` returns the number of bytes read + or written, or a negative error code. In particular zero means that no bytes + were read or written. +- `mtar_get_header()` may return `NULL` if there is no valid header. + It is only possible to see a null pointer if misusing the API or after + a previous error so checking for this is usually not necessary. -After the `stream` field has been set, all required callbacks have been set and -all unused fields have been zeroset the `mtar_t` struct can be safely used with -the microtar functions. `mtar_open` *should not* be called if the `mtar_t` -struct was initialized manually. +There is essentially no support for error recovery. After an error you can +only do two things reliably: close the archive with `mtar_close()` or try +rewinding to the beginning with `mtar_rewind()`. -#### Reading -The following callbacks should be set for reading an archive from a stream: -Name | Arguments | Description ---------|------------------------------------------|--------------------------- -`read` | `mtar_t *tar, void *data, unsigned size` | Read data from the stream -`seek` | `mtar_t *tar, unsigned pos` | Set the position indicator -`close` | `mtar_t *tar` | Close the stream +## I/O hooks -#### Writing -The following callbacks should be set for writing an archive to a stream: +You can provide your own I/O hooks in a `mtar_ops_t` struct. The same ops +struct can be shared among multiple `mtar_t` objects but each object gets +its own `void* stream` pointer. -Name | Arguments | Description ---------|------------------------------------------------|--------------------- -`write` | `mtar_t *tar, const void *data, unsigned size` | Write data to the stream +Name | Arguments | Required +--------|-------------------------------------------|------------ +`read` | `void* stream, void* data, unsigned size` | If reading +`write` | `void* stream, void* data, unsigned size` | If writing +`seek` | `void* stream, unsigned pos` | If reading +`close` | `void* stream` | Always +`read` and `write` should transfer the number of bytes indicated +and return the number of bytes actually read or written, or a negative +`enum mtar_error` code on error. -## License -This library is free software; you can redistribute it and/or modify it under -the terms of the MIT license. See [LICENSE](LICENSE) for details. +`seek` must have semantics like `lseek(..., pos, SEEK_SET)`; that is, +the position is an absolute byte offset in the stream. Seeking is not +optional for read support, but the library only performs backward +seeks under two circumstances: + +- `mtar_rewind()` seeks to position 0. +- `mtar_seek_data()` may seek backward if the user requests it. + +Therefore, you will be able to get away with a limited forward-only +seek function if you're able to read everything in a single pass use +the API carefully. Note `mtar_find()` and `mtar_foreach()` will call +`mtar_rewind()`. + +`close` is called by `mtar_close()` to clean up the stream. Note the +library assumes that the stream handle is cleaned up by `close` even +if an error occurs. + +`seek` and `close` should return an `enum mtar_error` code, either +`MTAR_SUCCESS`, or a negative value on error. diff --git a/lib/microtar/README.rockbox b/lib/microtar/README.rockbox new file mode 100644 index 0000000000..944f792996 --- /dev/null +++ b/lib/microtar/README.rockbox @@ -0,0 +1,14 @@ +Upstream commit/repo + 1e921369b2c92bb219fcef84a37d4d2347794c0f + https://github.com/amachronic/microtar + +Summary of Rockbox-specific changes: + +- microtar.make, SOURCES + Target build system integration. + +- microtar-rockbox.c, microtar-rockbox.h + Implements mtar ops with Rockbox filesystem API. + +- microtar.c + Define strncpy since Rockbox's libc doesn't define it. diff --git a/lib/microtar/mtar.c b/lib/microtar/mtar.c new file mode 100644 index 0000000000..4a9a27b782 --- /dev/null +++ b/lib/microtar/mtar.c @@ -0,0 +1,243 @@ +/* + * Copyright (c) 2021 Aidan MacDonald + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to + * deal in the Software without restriction, including without limitation the + * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or + * sell copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS + * IN THE SOFTWARE. + */ + +#include "microtar-stdio.h" +#include +#include +#include +#include +#include +#include +#include +#include + +/* exit codes */ +#define E_TAR 1 +#define E_FS 2 +#define E_OTHER 4 +#define E_ARGS 8 + +enum { + OP_LIST, + OP_CREATE, + OP_EXTRACT, +}; + +void die(int err, const char* msg, ...) +{ + fprintf(stderr, "mtar: "); + + va_list ap; + va_start(ap, msg); + vfprintf(stderr, msg, ap); + va_end(ap); + + fprintf(stderr, "\n"); + exit(err); +} + +int list_foreach_cb(mtar_t* tar, const mtar_header_t* h, void* arg) +{ + (void)tar; + (void)arg; + printf("%s\n", h->name); + return 0; +} + +void list_files(mtar_t* tar) +{ + int err = mtar_foreach(tar, list_foreach_cb, NULL); + if(err) + die(E_TAR, "listing failed: %s", mtar_strerror(err)); +} + +struct extract_args { + char** names; + int count; +}; + +int extract_foreach_cb(mtar_t* tar, const mtar_header_t* h, void* arg) +{ + struct extract_args* args = arg; + (void)args; /* TODO */ + + if(h->type == MTAR_TDIR) { + if(mkdir(h->name, h->mode) != 0) + die(E_FS, "cannot create directory \"%s\"", h->name); + return 0; + } + + if(h->type != MTAR_TREG) { + fprintf(stderr, "warning: not extracting unsupported type \"%s\"", h->name); + return 0; + } + + int fd = open(h->name, O_CREAT|O_WRONLY|O_TRUNC, h->mode); + if(fd < 0) + die(E_FS, "extracting \"%s\" failed: %s", h->name, strerror(errno)); + + char iobuf[1024]; + while(!mtar_eof_data(tar)) { + int rcount = mtar_read_data(tar, iobuf, sizeof(iobuf)); + if(rcount < 0) + die(E_TAR, "extracting \"%s\" failed: %s", h->name, mtar_strerror(rcount)); + + int wcount = write(fd, iobuf, rcount); + if(wcount != rcount) + die(E_FS, "extracting \"%s\" failed: %s", h->name, strerror(errno)); + } + + close(fd); + return 0; +} + +void extract_files(mtar_t* tar, char** files, int num_files) +{ + struct extract_args args; + args.names = files; + args.count = num_files; + + int err = mtar_foreach(tar, extract_foreach_cb, &args); + if(err) + die(E_TAR, "extraction failed: %s", mtar_strerror(err)); +} + +void add_files(mtar_t* tar, char** files, int num_files) +{ + for(int i = 0; i < num_files; ++i) { + int fd = open(files[i], O_RDONLY); + if(fd < 0) + die(E_FS, "adding \"%s\" failed: %s", files[i], strerror(errno)); + + off_t off = lseek(fd, 0, SEEK_END); + if(off < 0) + die(E_FS, "adding \"%s\" failed: %s", files[i], strerror(errno)); + + unsigned filesize = off; + lseek(fd, 0, SEEK_SET); + + int err = mtar_write_file_header(tar, files[i], filesize); + if(err) + die(E_TAR, "adding \"%s\" failed: %s", files[i], mtar_strerror(err)); + + char iobuf[1024]; + while(1) { + int rcount = read(fd, iobuf, sizeof(iobuf)); + if(rcount < 0) + die(E_FS, "adding \"%s\" failed: %s", files[i], strerror(errno)); + if(rcount == 0) + break; + + int wcount = mtar_write_data(tar, iobuf, rcount); + if(wcount < 0) + die(E_TAR, "adding \"%s\" failed: %s", files[i], mtar_strerror(wcount)); + if(wcount != rcount) + die(E_TAR, "adding \"%s\" failed: write too short %d/%d", files[i], wcount, rcount); + } + + close(fd); + + err = mtar_end_data(tar); + if(err) + die(E_TAR, "adding \"%s\" failed: %s", files[i], mtar_strerror(err)); + } +} + +int main(int argc, char* argv[]) +{ + ++argv, --argc; + if(argc == 0) + die(E_ARGS, "no input files"); + + if(!strcmp(*argv, "--help")) { + printf( +"usage:\n" +" mtar list tar-file\n" +" List the members of the given tar archive, one filename per line.\n" +"\n" +" mtar create tar-file members...\n" +" mtar add tar-file members...\n" +" Create a new tar archive from the files listed on the command line.\n" +" WARNING: Any existing file at tar-file will be overwritten!\n" +"\n" +" mtar extract tar-file [members...]\n" +" Extract the contents of the tar archive to the current directory.\n" +" If filenames are given, only the named members will be extracted.\n" +"\n"); + exit(E_ARGS); + } + + int op; + if(!strcmp(*argv, "list")) + op = OP_LIST; + else if(!strcmp(*argv, "create")) + op = OP_CREATE; + else if(!strcmp(*argv, "extract")) + op = OP_EXTRACT; + else + die(E_ARGS, "invalid operation \"%s\"", *argv); + ++argv, --argc; + + if(argc == 0) + die(E_ARGS, "missing archive name"); + const char* archive_name = *argv; + ++argv, --argc; + + if(op == OP_LIST && argc != 0) + die(E_ARGS, "excess arguments on command line"); + + const char* mode = "rb"; + if(op == OP_CREATE) + mode = "wb"; + + mtar_t tar; + int err = mtar_open(&tar, archive_name, mode); + if(err) + die(E_TAR, "can't open archive: %s", mtar_strerror(err)); + + switch(op) { + case OP_LIST: + list_files(&tar); + break; + + case OP_EXTRACT: + extract_files(&tar, argv, argc); + break; + + case OP_CREATE: + add_files(&tar, argv, argc); + err = mtar_finalize(&tar); + if(err) + die(E_TAR, "failed to finalize archive: %s", mtar_strerror(err)); + break; + + default: + die(E_OTHER, "not implemented"); + break; + } + + err = mtar_close(&tar); + if(err) + die(E_TAR, "failed to close archive: %s", mtar_strerror(err)); + + return 0; +} diff --git a/lib/microtar/src/microtar-rockbox.c b/lib/microtar/src/microtar-rockbox.c index 04ba93cc42..d0f579fefb 100644 --- a/lib/microtar/src/microtar-rockbox.c +++ b/lib/microtar/src/microtar-rockbox.c @@ -20,81 +20,72 @@ ****************************************************************************/ #include "file.h" -#include "microtar.h" +#include "microtar-rockbox.h" #include -static int fd_write(mtar_t *tar, const void *data, unsigned size) { - intptr_t fd = (intptr_t)tar->stream; - ssize_t res = write(fd, data, size); - if(res < 0 || ((unsigned)res != size)) - return MTAR_EWRITEFAIL; - else - return MTAR_ESUCCESS; -} +static int fd_read(void* stream, void* data, unsigned size) +{ + ssize_t res = read((intptr_t)stream, data, size); + if(res < 0) + return MTAR_EREADFAIL; -static int fd_read(mtar_t *tar, void *data, unsigned size) { - intptr_t fd = (intptr_t)tar->stream; - ssize_t res = read(fd, data, size); - if(res < 0 || ((unsigned)res != size)) - return MTAR_EREADFAIL; - else - return MTAR_ESUCCESS; + return res; } -static int fd_seek(mtar_t *tar, unsigned offset) { - intptr_t fd = (intptr_t)tar->stream; - off_t res = lseek(fd, offset, SEEK_SET); - if(res < 0 || ((unsigned)res != offset)) - return MTAR_ESEEKFAIL; - else - return MTAR_ESUCCESS; -} +static int fd_write(void* stream, const void* data, unsigned size) +{ + ssize_t res = write((intptr_t)stream, data, size); + if(res < 0) + return MTAR_EWRITEFAIL; -static int fd_close(mtar_t *tar) { - intptr_t fd = (intptr_t)tar->stream; - close(fd); - return MTAR_ESUCCESS; + return res; } +static int fd_seek(void* stream, unsigned offset) +{ + off_t res = lseek((intptr_t)stream, offset, SEEK_SET); + if(res < 0 || ((unsigned)res != offset)) + return MTAR_ESEEKFAIL; + else + return MTAR_ESUCCESS; +} -int mtar_open(mtar_t *tar, const char *filename, const char *mode) { - int err; - int openmode; - int fd; - - /* Init tar struct and functions */ - memset(tar, 0, sizeof(*tar)); - tar->write = fd_write; - tar->read = fd_read; - tar->seek = fd_seek; - tar->close = fd_close; +static int fd_close(void* stream) +{ + close((intptr_t)stream); + return MTAR_ESUCCESS; +} - /* Get correct mode flags */ - if ( strchr(mode, 'r') ) - openmode = O_RDONLY; - else if ( strchr(mode, 'w') ) - openmode = O_CREAT|O_TRUNC|O_WRONLY; - else if ( strchr(mode, 'a') ) - openmode = O_WRONLY|O_APPEND; - else - return MTAR_EFAILURE; +static const mtar_ops_t fd_ops = { + .read = fd_read, + .write = fd_write, + .seek = fd_seek, + .close = fd_close, +}; - /* Open file */ - fd = open(filename, openmode); - if(fd < 0) - return MTAR_EOPENFAIL; +int mtar_open(mtar_t* tar, const char* filename, int flags) +{ + /* Determine access mode */ + int access; + switch(flags & O_ACCMODE) { + case O_RDONLY: + access = MTAR_READ; + break; - tar->stream = (void*)(intptr_t)fd; + case O_WRONLY: + access = MTAR_WRITE; + break; - /* Read first header to check it is valid if mode is `r` */ - if ( openmode & O_RDONLY ) { - err = mtar_read_header(tar, &tar->header); - if (err != MTAR_ESUCCESS) { - mtar_close(tar); - return err; + default: + /* Note - O_RDWR isn't very useful so we don't allow it */ + return MTAR_EAPI; } - } - /* Return ok */ - return MTAR_ESUCCESS; + int fd = open(filename, flags); + if(fd < 0) + return MTAR_EOPENFAIL; + + /* Init tar struct and functions */ + mtar_init(tar, access, &fd_ops, (void*)(intptr_t)fd); + return MTAR_ESUCCESS; } diff --git a/lib/microtar/src/microtar-rockbox.h b/lib/microtar/src/microtar-rockbox.h new file mode 100644 index 0000000000..36acbb2bfe --- /dev/null +++ b/lib/microtar/src/microtar-rockbox.h @@ -0,0 +1,29 @@ +/*************************************************************************** + * __________ __ ___. + * Open \______ \ ____ ____ | | _\_ |__ _______ ___ + * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ / + * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < < + * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \ + * \/ \/ \/ \/ \/ + * $Id$ + * + * Copyright (C) 2021 Aidan MacDonald + * + * 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 the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY + * KIND, either express or implied. + * + ****************************************************************************/ + +#ifndef MICROTAR_ROCKBOX_H +#define MICROTAR_ROCKBOX_H + +#include "microtar.h" + +int mtar_open(mtar_t* tar, const char* filename, int flags); + +#endif diff --git a/lib/microtar/src/microtar-stdio.c b/lib/microtar/src/microtar-stdio.c index 215000aa98..2697d005cd 100644 --- a/lib/microtar/src/microtar-stdio.c +++ b/lib/microtar/src/microtar-stdio.c @@ -1,65 +1,88 @@ -/** +/* * Copyright (c) 2017 rxi + * Copyright (c) 2021 Aidan MacDonald * - * This library is free software; you can redistribute it and/or modify it - * under the terms of the MIT license. See `microtar.c` for details. + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to + * deal in the Software without restriction, including without limitation the + * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or + * sell copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS + * IN THE SOFTWARE. */ +#include "microtar-stdio.h" #include #include -#include "microtar.h" +static int file_read(void* stream, void* data, unsigned size) +{ + unsigned res = fread(data, 1, size, (FILE*)stream); + if(res != size && ferror((FILE*)stream)) + return MTAR_EREADFAIL; -static int file_write(mtar_t *tar, const void *data, unsigned size) { - unsigned res = fwrite(data, 1, size, tar->stream); - return (res == size) ? MTAR_ESUCCESS : MTAR_EWRITEFAIL; + return res; } -static int file_read(mtar_t *tar, void *data, unsigned size) { - unsigned res = fread(data, 1, size, tar->stream); - return (res == size) ? MTAR_ESUCCESS : MTAR_EREADFAIL; -} +static int file_write(void* stream, const void* data, unsigned size) +{ + unsigned res = fwrite(data, 1, size, (FILE*)stream); + if(res != size && ferror((FILE*)stream)) + return MTAR_EWRITEFAIL; -static int file_seek(mtar_t *tar, unsigned offset) { - int res = fseek(tar->stream, offset, SEEK_SET); - return (res == 0) ? MTAR_ESUCCESS : MTAR_ESEEKFAIL; + return res; } -static int file_close(mtar_t *tar) { - fclose(tar->stream); - return MTAR_ESUCCESS; +static int file_seek(void* stream, unsigned offset) +{ + int res = fseek((FILE*)stream, offset, SEEK_SET); + return (res == 0) ? MTAR_ESUCCESS : MTAR_ESEEKFAIL; } +static int file_close(void* stream) +{ + int err = fclose((FILE*)stream); + return (err == 0 ? MTAR_ESUCCESS : MTAR_EFAILURE); +} -int mtar_open(mtar_t *tar, const char *filename, const char *mode) { - int err; - mtar_header_t h; - - /* Init tar struct and functions */ - memset(tar, 0, sizeof(*tar)); - tar->write = file_write; - tar->read = file_read; - tar->seek = file_seek; - tar->close = file_close; +static const mtar_ops_t file_ops = { + .read = file_read, + .write = file_write, + .seek = file_seek, + .close = file_close, +}; - /* Assure mode is always binary */ - if ( strchr(mode, 'r') ) mode = "rb"; - if ( strchr(mode, 'w') ) mode = "wb"; - if ( strchr(mode, 'a') ) mode = "ab"; - /* Open file */ - tar->stream = fopen(filename, mode); - if (!tar->stream) { - return MTAR_EOPENFAIL; - } - /* Read first header to check it is valid if mode is `r` */ - if (*mode == 'r') { - err = mtar_read_header(tar, &h); - if (err != MTAR_ESUCCESS) { - mtar_close(tar); - return err; +int mtar_open(mtar_t* tar, const char* filename, const char* mode) +{ + /* Determine access mode */ + int access; + char* read = strchr(mode, 'r'); + char* write = strchr(mode, 'w'); + if(read) { + if(write) + return MTAR_EAPI; + access = MTAR_READ; + } else if(write) { + access = MTAR_WRITE; + } else { + return MTAR_EAPI; } - } - /* Return ok */ - return MTAR_ESUCCESS; + /* Open file */ + FILE* file = fopen(filename, mode); + if(!file) + return MTAR_EOPENFAIL; + + mtar_init(tar, access, &file_ops, file); + return MTAR_ESUCCESS; } diff --git a/lib/microtar/src/microtar-stdio.h b/lib/microtar/src/microtar-stdio.h new file mode 100644 index 0000000000..ad46af0390 --- /dev/null +++ b/lib/microtar/src/microtar-stdio.h @@ -0,0 +1,39 @@ +/* + * Copyright (c) 2017 rxi + * Copyright (c) 2021 Aidan MacDonald + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to + * deal in the Software without restriction, including without limitation the + * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or + * sell copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS + * IN THE SOFTWARE. + */ + +#ifndef MICROTAR_STDIO_H +#define MICROTAR_STDIO_H + +#include "microtar.h" + +#ifdef __cplusplus +extern "C" { +#endif + +int mtar_open(mtar_t* tar, const char* filename, const char* mode); + +#ifdef __cplusplus +} +#endif + +#endif diff --git a/lib/microtar/src/microtar.c b/lib/microtar/src/microtar.c index 04cd4ea132..8ab9a8c5f4 100644 --- a/lib/microtar/src/microtar.c +++ b/lib/microtar/src/microtar.c @@ -1,5 +1,6 @@ /* * Copyright (c) 2017 rxi + * Copyright (c) 2021 Aidan MacDonald * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to @@ -20,16 +21,14 @@ * IN THE SOFTWARE. */ -#include -#include +#include "microtar.h" #include #include -#include "microtar.h" - #ifdef ROCKBOX /* Rockbox lacks strncpy in its libc */ -static char* strncpy(char* dest, const char* src, size_t n) { +#define strncpy my_strncpy +static char* my_strncpy(char* dest, const char* src, size_t n) { size_t i; for(i = 0; i < n && *src; ++i) @@ -42,362 +41,685 @@ static char* strncpy(char* dest, const char* src, size_t n) { } #endif +enum { + S_HEADER_VALID = 1 << 0, + S_WROTE_HEADER = 1 << 1, + S_WROTE_DATA = 1 << 2, + S_WROTE_DATA_EOF = 1 << 3, + S_WROTE_FINALIZE = 1 << 4, +}; + +enum { + NAME_OFF = 0, NAME_LEN = 100, + MODE_OFF = NAME_OFF+NAME_LEN, MODE_LEN = 8, + OWNER_OFF = MODE_OFF+MODE_LEN, OWNER_LEN = 8, + GROUP_OFF = OWNER_OFF+OWNER_LEN, GROUP_LEN = 8, + SIZE_OFF = GROUP_OFF+GROUP_LEN, SIZE_LEN = 12, + MTIME_OFF = SIZE_OFF+SIZE_LEN, MTIME_LEN = 12, + CHKSUM_OFF = MTIME_OFF+MTIME_LEN, CHKSUM_LEN = 8, + TYPE_OFF = CHKSUM_OFF+CHKSUM_LEN, + LINKNAME_OFF = TYPE_OFF+1, LINKNAME_LEN = 100, + + HEADER_LEN = 512, +}; + +static int parse_octal(const char* str, size_t len, unsigned* ret) +{ + unsigned n = 0; + + while(len-- > 0 && *str != 0) { + if(*str < '0' || *str > '9') + return MTAR_EOVERFLOW; + + if(n > UINT_MAX/8) + return MTAR_EOVERFLOW; + else + n *= 8; + + char r = *str++ - '0'; + + if(n > UINT_MAX - r) + return MTAR_EOVERFLOW; + else + n += r; + } -static int parse_octal(const char* str, size_t len, unsigned* ret) { - unsigned n = 0; - while(len-- > 0 && *str != 0) { - if(*str < '0' || *str > '9') - return MTAR_EOVERFLOW; - - if(n > UINT_MAX/8) - return MTAR_EOVERFLOW; - else - n *= 8; - - char r = *str++ - '0'; - if(n > UINT_MAX - r) - return MTAR_EOVERFLOW; - else - n += r; - } - - *ret = n; - return MTAR_ESUCCESS; + *ret = n; + return MTAR_ESUCCESS; } +static int print_octal(char* str, size_t len, unsigned value) +{ + /* move backwards over the output string */ + char* ptr = str + len - 1; + *ptr = 0; -static int print_octal(char* str, size_t len, unsigned value) { - /* move backwards over the output string */ - char* ptr = str + len - 1; - *ptr = 0; + /* output the significant digits */ + while(value > 0) { + if(ptr == str) + return MTAR_EOVERFLOW; - /* output the significant digits */ - while(value > 0) { - if(ptr == str) - return MTAR_EOVERFLOW; + --ptr; + *ptr = '0' + (value % 8); + value /= 8; + } - --ptr; - *ptr = '0' + (value % 8); - value /= 8; - } + /* pad the remainder of the field with zeros */ + while(ptr != str) { + --ptr; + *ptr = '0'; + } - /* pad the remainder of the field with zeros */ - while(ptr != str) { - --ptr; - *ptr = '0'; - } + return MTAR_ESUCCESS; +} - return MTAR_ESUCCESS; +static unsigned round_up_512(unsigned n) +{ + return (n + 511u) & ~511u; } +static int tread(mtar_t* tar, void* data, unsigned size) +{ + int ret = tar->ops->read(tar->stream, data, size); + if(ret >= 0) + tar->pos += ret; -static unsigned round_up(unsigned n, unsigned incr) { - return n + (incr - n % incr) % incr; + return ret; } +static int twrite(mtar_t* tar, const void* data, unsigned size) +{ + int ret = tar->ops->write(tar->stream, data, size); + if(ret >= 0) + tar->pos += ret; -static unsigned checksum(const mtar_raw_header_t* rh) { - unsigned i; - unsigned char *p = (unsigned char*) rh; - unsigned res = 256; - for (i = 0; i < offsetof(mtar_raw_header_t, checksum); i++) { - res += p[i]; - } - for (i = offsetof(mtar_raw_header_t, type); i < sizeof(*rh); i++) { - res += p[i]; - } - return res; + return ret; } - -static int tread(mtar_t *tar, void *data, unsigned size) { - int err = tar->read(tar, data, size); - tar->pos += size; - return err; +static int tseek(mtar_t* tar, unsigned pos) +{ + int err = tar->ops->seek(tar->stream, pos); + tar->pos = pos; + return err; } +static int write_null_bytes(mtar_t* tar, size_t count) +{ + int ret; + size_t n; + + memset(tar->buffer, 0, sizeof(tar->buffer)); + while(count > 0) { + n = count < sizeof(tar->buffer) ? count : sizeof(tar->buffer); + ret = twrite(tar, tar->buffer, n); + if(ret < 0) + return ret; + if(ret != (int)n) + return MTAR_EWRITEFAIL; + + count -= n; + } -static int twrite(mtar_t *tar, const void *data, unsigned size) { - int err = tar->write(tar, data, size); - tar->pos += size; - return err; + return MTAR_ESUCCESS; } +static unsigned checksum(const char* raw) +{ + unsigned i; + unsigned char* p = (unsigned char*)raw; + unsigned res = 256; -static int write_null_bytes(mtar_t *tar, int n) { - int i, err; - char nul = '\0'; - for (i = 0; i < n; i++) { - err = twrite(tar, &nul, 1); - if (err) { - return err; - } - } - return MTAR_ESUCCESS; + for(i = 0; i < CHKSUM_OFF; i++) + res += p[i]; + for(i = TYPE_OFF; i < HEADER_LEN; i++) + res += p[i]; + + return res; } +static int raw_to_header(mtar_header_t* h, const char* raw) +{ + unsigned chksum; + int rc; + + /* If the checksum starts with a null byte we assume the record is NULL */ + if(raw[CHKSUM_OFF] == '\0') + return MTAR_ENULLRECORD; + + /* Compare the checksum */ + if((rc = parse_octal(&raw[CHKSUM_OFF], CHKSUM_LEN, &chksum))) + return rc; + if(chksum != checksum(raw)) + return MTAR_EBADCHKSUM; + + /* Load raw header into header */ + if((rc = parse_octal(&raw[MODE_OFF], MODE_LEN, &h->mode))) + return rc; + if((rc = parse_octal(&raw[OWNER_OFF], OWNER_LEN, &h->owner))) + return rc; + if((rc = parse_octal(&raw[GROUP_OFF], GROUP_LEN, &h->group))) + return rc; + if((rc = parse_octal(&raw[SIZE_OFF], SIZE_LEN, &h->size))) + return rc; + if((rc = parse_octal(&raw[MTIME_OFF], MTIME_LEN, &h->mtime))) + return rc; + + h->type = raw[TYPE_OFF]; + if(!h->type) + h->type = MTAR_TREG; + + memcpy(h->name, &raw[NAME_OFF], NAME_LEN); + h->name[sizeof(h->name) - 1] = 0; + + memcpy(h->linkname, &raw[LINKNAME_OFF], LINKNAME_LEN); + h->linkname[sizeof(h->linkname) - 1] = 0; + + return MTAR_ESUCCESS; +} -static int raw_to_header(mtar_header_t *h, const mtar_raw_header_t *rh) { - unsigned chksum1, chksum2; - int rc; +static int header_to_raw(char* raw, const mtar_header_t* h) +{ + unsigned chksum; + int rc; + + memset(raw, 0, HEADER_LEN); + + /* Load header into raw header */ + if((rc = print_octal(&raw[MODE_OFF], MODE_LEN, h->mode))) + return rc; + if((rc = print_octal(&raw[OWNER_OFF], OWNER_LEN, h->owner))) + return rc; + if((rc = print_octal(&raw[GROUP_OFF], GROUP_LEN, h->group))) + return rc; + if((rc = print_octal(&raw[SIZE_OFF], SIZE_LEN, h->size))) + return rc; + if((rc = print_octal(&raw[MTIME_OFF], MTIME_LEN, h->mtime))) + return rc; + + raw[TYPE_OFF] = h->type ? h->type : MTAR_TREG; + +#if defined(__GNUC__) && (__GNUC__ >= 8) +/* Sigh. GCC wrongly assumes the output of strncpy() is supposed to be + * a null-terminated string -- which it is not, and we are relying on + * that fact here -- and tries to warn about 'string truncation' because + * the null terminator might not be copied. Just suppress the warning. */ +# pragma GCC diagnostic push +# pragma GCC diagnostic ignored "-Wstringop-truncation" +#endif - /* If the checksum starts with a null byte we assume the record is NULL */ - if (*rh->checksum == '\0') { - return MTAR_ENULLRECORD; - } + strncpy(&raw[NAME_OFF], h->name, NAME_LEN); + strncpy(&raw[LINKNAME_OFF], h->linkname, LINKNAME_LEN); - /* Build and compare checksum */ - chksum1 = checksum(rh); - if((rc = parse_octal(rh->checksum, sizeof(rh->checksum), &chksum2))) - return rc; - if (chksum1 != chksum2) { - return MTAR_EBADCHKSUM; - } +#if defined(__GNUC__) && (__GNUC__ >= 8) +# pragma GCC diagnostic pop +#endif - /* Load raw header into header */ - if((rc = parse_octal(rh->mode, sizeof(rh->mode), &h->mode))) - return rc; - if((rc = parse_octal(rh->owner, sizeof(rh->owner), &h->owner))) - return rc; - if((rc = parse_octal(rh->group, sizeof(rh->group), &h->group))) - return rc; - if((rc = parse_octal(rh->size, sizeof(rh->size), &h->size))) - return rc; - if((rc = parse_octal(rh->mtime, sizeof(rh->mtime), &h->mtime))) - return rc; + /* Calculate and write checksum */ + chksum = checksum(raw); + if((rc = print_octal(&raw[CHKSUM_OFF], CHKSUM_LEN-1, chksum))) + return rc; - h->type = rh->type; + raw[CHKSUM_OFF + CHKSUM_LEN - 1] = ' '; - memcpy(h->name, rh->name, sizeof(rh->name)); - h->name[sizeof(h->name) - 1] = 0; + return MTAR_ESUCCESS; +} - memcpy(h->linkname, rh->linkname, sizeof(rh->linkname)); - h->linkname[sizeof(h->linkname) - 1] = 0; +static unsigned data_beg_pos(const mtar_t* tar) +{ + return tar->header_pos + HEADER_LEN; +} - return MTAR_ESUCCESS; +static unsigned data_end_pos(const mtar_t* tar) +{ + return tar->end_pos; } +static int ensure_header(mtar_t* tar) +{ + int ret, err; -static int header_to_raw(mtar_raw_header_t *rh, const mtar_header_t *h) { - unsigned chksum; - int rc; + if(tar->state & S_HEADER_VALID) + return MTAR_ESUCCESS; - /* Load header into raw header */ - memset(rh, 0, sizeof(*rh)); - if((rc = print_octal(rh->mode, sizeof(rh->mode), h->mode))) - return rc; - if((rc = print_octal(rh->owner, sizeof(rh->owner), h->owner))) - return rc; - if((rc = print_octal(rh->group, sizeof(rh->group), h->group))) - return rc; - if((rc = print_octal(rh->size, sizeof(rh->size), h->size))) - return rc; - if((rc = print_octal(rh->mtime, sizeof(rh->mtime), h->mtime))) - return rc; - rh->type = h->type ? h->type : MTAR_TREG; - strncpy(rh->name, h->name, sizeof(rh->name)); - strncpy(rh->linkname, h->linkname, sizeof(rh->linkname)); + if(tar->pos > UINT_MAX - HEADER_LEN) + return MTAR_EOVERFLOW; - /* Calculate and write checksum */ - chksum = checksum(rh); - if((rc = print_octal(rh->checksum, 7, chksum))) - return rc; - rh->checksum[7] = ' '; + tar->header_pos = tar->pos; + tar->end_pos = data_beg_pos(tar); - return MTAR_ESUCCESS; -} + ret = tread(tar, tar->buffer, HEADER_LEN); + if(ret < 0) + return ret; + if(ret != HEADER_LEN) + return MTAR_EREADFAIL; + err = raw_to_header(&tar->header, tar->buffer); + if(err) + return err; -const char* mtar_strerror(int err) { - switch (err) { - case MTAR_ESUCCESS : return "success"; - case MTAR_EFAILURE : return "failure"; - case MTAR_EOPENFAIL : return "could not open"; - case MTAR_EREADFAIL : return "could not read"; - case MTAR_EWRITEFAIL : return "could not write"; - case MTAR_ESEEKFAIL : return "could not seek"; - case MTAR_EBADCHKSUM : return "bad checksum"; - case MTAR_ENULLRECORD : return "null record"; - case MTAR_ENOTFOUND : return "file not found"; - case MTAR_EOVERFLOW : return "overflow"; - } - return "unknown error"; + if(tar->end_pos > UINT_MAX - tar->header.size) + return MTAR_EOVERFLOW; + tar->end_pos += tar->header.size; + + tar->state |= S_HEADER_VALID; + return MTAR_ESUCCESS; } +const char* mtar_strerror(int err) +{ + switch(err) { + case MTAR_ESUCCESS: return "success"; + case MTAR_EFAILURE: return "failure"; + case MTAR_EOPENFAIL: return "could not open"; + case MTAR_EREADFAIL: return "could not read"; + case MTAR_EWRITEFAIL: return "could not write"; + case MTAR_ESEEKFAIL: return "could not seek"; + case MTAR_ESEEKRANGE: return "seek out of bounds"; + case MTAR_EBADCHKSUM: return "bad checksum"; + case MTAR_ENULLRECORD: return "null record"; + case MTAR_ENOTFOUND: return "file not found"; + case MTAR_EOVERFLOW: return "overflow"; + case MTAR_EAPI: return "API usage error"; + case MTAR_ENAMETOOLONG: return "name too long"; + case MTAR_EWRONGSIZE: return "wrong amount of data written"; + case MTAR_EACCESS: return "wrong access mode"; + default: return "unknown error"; + } +} -int mtar_close(mtar_t *tar) { - return tar->close(tar); +void mtar_init(mtar_t* tar, int access, const mtar_ops_t* ops, void* stream) +{ + memset(tar, 0, sizeof(mtar_t)); + tar->access = access; + tar->ops = ops; + tar->stream = stream; } +int mtar_close(mtar_t* tar) +{ + int err = tar->ops->close(tar->stream); + tar->ops = NULL; + tar->stream = NULL; + return err; +} -int mtar_seek(mtar_t *tar, unsigned pos) { - int err = tar->seek(tar, pos); - tar->pos = pos; - return err; +int mtar_is_open(mtar_t* tar) +{ + return (tar->ops != NULL) ? 1 : 0; } +mtar_header_t* mtar_get_header(mtar_t* tar) +{ + if(tar->state & S_HEADER_VALID) + return &tar->header; + else + return NULL; +} -int mtar_rewind(mtar_t *tar) { - tar->remaining_data = 0; - tar->last_header = 0; - return mtar_seek(tar, 0); +int mtar_access_mode(const mtar_t* tar) +{ + return tar->access; } +int mtar_rewind(mtar_t* tar) +{ +#ifndef MICROTAR_DISABLE_API_CHECKS + if(tar->access != MTAR_READ) + return MTAR_EAPI; +#endif -int mtar_next(mtar_t *tar) { - int err, n; - /* Load header */ - err = mtar_read_header(tar, &tar->header); - if (err) { + int err = tseek(tar, 0); + tar->state = 0; return err; - } - /* Seek to next record */ - n = round_up(tar->header.size, 512) + sizeof(mtar_raw_header_t); - return mtar_seek(tar, tar->pos + n); } +int mtar_next(mtar_t* tar) +{ +#ifndef MICROTAR_DISABLE_API_CHECKS + if(tar->access != MTAR_READ) + return MTAR_EACCESS; +#endif -int mtar_find(mtar_t *tar, const char *name, mtar_header_t *h) { - int err; - /* Start at beginning */ - err = mtar_rewind(tar); - if (err) { - return err; - } - /* Iterate all files until we hit an error or find the file */ - while ( (err = mtar_read_header(tar, &tar->header)) == MTAR_ESUCCESS ) { - if ( !strcmp(tar->header.name, name) ) { - if (h) { - *h = tar->header; - } - return MTAR_ESUCCESS; - } - err = mtar_next(tar); - if (err) { - return err; + if(tar->state & S_HEADER_VALID) { + tar->state &= ~S_HEADER_VALID; + + /* seek to the next header */ + int err = tseek(tar, round_up_512(data_end_pos(tar))); + if(err) + return err; } - } - /* Return error */ - if (err == MTAR_ENULLRECORD) { - err = MTAR_ENOTFOUND; - } - return err; -} - - -int mtar_read_header(mtar_t *tar, mtar_header_t *h) { - int err; - /* Save header position */ - tar->last_header = tar->pos; - /* Read raw header */ - err = tread(tar, &tar->raw_header, sizeof(tar->raw_header)); - if (err) { + + return ensure_header(tar); +} + +int mtar_foreach(mtar_t* tar, mtar_foreach_cb cb, void* arg) +{ +#ifndef MICROTAR_DISABLE_API_CHECKS + if(tar->access != MTAR_READ) + return MTAR_EACCESS; +#endif + + int err = mtar_rewind(tar); + if(err) + return err; + + while((err = mtar_next(tar)) == MTAR_ESUCCESS) + if((err = cb(tar, &tar->header, arg)) != 0) + return err; + + if(err == MTAR_ENULLRECORD) + err = MTAR_ESUCCESS; + return err; - } - /* Seek back to start of header */ - err = mtar_seek(tar, tar->last_header); - if (err) { +} + +static int find_foreach_cb(mtar_t* tar, const mtar_header_t* h, void* arg) +{ + (void)tar; + const char* name = (const char*)arg; + return strcmp(name, h->name) ? 0 : 1; +} + +int mtar_find(mtar_t* tar, const char* name) +{ + int err = mtar_foreach(tar, find_foreach_cb, (void*)name); + if(err == 1) + err = MTAR_ESUCCESS; + else if(err == MTAR_ESUCCESS) + err = MTAR_ENOTFOUND; + return err; - } - /* Load raw header into header struct and return */ - return raw_to_header(h, &tar->raw_header); } +int mtar_read_data(mtar_t* tar, void* ptr, unsigned size) +{ +#ifndef MICROTAR_DISABLE_API_CHECKS + if(!(tar->state & S_HEADER_VALID)) + return MTAR_EAPI; +#endif -int mtar_read_data(mtar_t *tar, void *ptr, unsigned size) { - int err; - /* If we have no remaining data then this is the first read, we get the size, - * set the remaining data and seek to the beginning of the data */ - if (tar->remaining_data == 0) { - /* Read header */ - err = mtar_read_header(tar, &tar->header); - if (err) { - return err; - } - /* Seek past header and init remaining data */ - err = mtar_seek(tar, tar->pos + sizeof(mtar_raw_header_t)); - if (err) { - return err; + /* have we reached end of file? */ + unsigned data_end = data_end_pos(tar); + if(tar->pos >= data_end) + return 0; + + /* truncate the read if it would go beyond EOF */ + unsigned data_left = data_end - tar->pos; + if(data_left < size) + size = data_left; + + return tread(tar, ptr, size); +} + +int mtar_seek_data(mtar_t* tar, int offset, int whence) +{ +#ifndef MICROTAR_DISABLE_API_CHECKS + if(!(tar->state & S_HEADER_VALID)) + return MTAR_EAPI; +#endif + + unsigned data_beg = data_beg_pos(tar); + unsigned data_end = data_end_pos(tar); + unsigned newpos; + + switch(whence) { + case SEEK_SET: + if(offset < 0) + return MTAR_ESEEKRANGE; + + newpos = data_beg + offset; + break; + + case SEEK_CUR: + if((offset > 0 && (unsigned) offset > data_end - tar->pos) || + (offset < 0 && (unsigned)-offset > tar->pos - data_beg)) + return MTAR_ESEEKRANGE; + + newpos = tar->pos + offset; + break; + + case SEEK_END: + if(offset > 0) + return MTAR_ESEEKRANGE; + + newpos = data_end + offset; + break; + + default: + return MTAR_EAPI; } - tar->remaining_data = tar->header.size; - } - /* Ensure caller does not read too much */ - if(size > tar->remaining_data) - return MTAR_EOVERFLOW; - /* Read data */ - err = tread(tar, ptr, size); - if (err) { - return err; - } - tar->remaining_data -= size; - /* If there is no remaining data we've finished reading and seek back to the - * header */ - if (tar->remaining_data == 0) { - return mtar_seek(tar, tar->last_header); - } - return MTAR_ESUCCESS; + + return tseek(tar, newpos); +} + +unsigned mtar_tell_data(mtar_t* tar) +{ +#ifndef MICROTAR_DISABLE_API_CHECKS + if(!(tar->state & S_HEADER_VALID)) + return MTAR_EAPI; +#endif + + return tar->pos - data_beg_pos(tar); } +int mtar_eof_data(mtar_t* tar) +{ + /* API usage error, but just claim EOF. */ + if(!(tar->state & S_HEADER_VALID)) + return 1; -int mtar_write_header(mtar_t *tar, const mtar_header_t *h) { - /* Build raw header and write */ - header_to_raw(&tar->raw_header, h); - tar->remaining_data = h->size; - return twrite(tar, &tar->raw_header, sizeof(tar->raw_header)); + return tar->pos >= data_end_pos(tar) ? 1 : 0; } +int mtar_write_header(mtar_t* tar, const mtar_header_t* h) +{ +#ifndef MICROTAR_DISABLE_API_CHECKS + if(tar->access != MTAR_WRITE) + return MTAR_EACCESS; + if(((tar->state & S_WROTE_DATA) && !(tar->state & S_WROTE_DATA_EOF)) || + (tar->state & S_WROTE_FINALIZE)) + return MTAR_EAPI; +#endif + + tar->state &= ~(S_HEADER_VALID | S_WROTE_HEADER | + S_WROTE_DATA | S_WROTE_DATA_EOF); + + /* ensure we have enough space to write the declared amount of data */ + if(tar->pos > UINT_MAX - HEADER_LEN - round_up_512(h->size)) + return MTAR_EOVERFLOW; + + tar->header_pos = tar->pos; + tar->end_pos = data_beg_pos(tar); + + if(h != &tar->header) + tar->header = *h; + + int err = header_to_raw(tar->buffer, &tar->header); + if(err) + return err; + + int ret = twrite(tar, tar->buffer, HEADER_LEN); + if(ret < 0) + return ret; + if(ret != HEADER_LEN) + return MTAR_EWRITEFAIL; -int mtar_write_file_header(mtar_t *tar, const char *name, unsigned size) { - /* Build header */ - memset(&tar->header, 0, sizeof(tar->header)); - /* Ensure name fits within header */ - if(strlen(name) > sizeof(tar->header.name)) - return MTAR_EOVERFLOW; - strncpy(tar->header.name, name, sizeof(tar->header.name)); - tar->header.size = size; - tar->header.type = MTAR_TREG; - tar->header.mode = 0664; - /* Write header */ - return mtar_write_header(tar, &tar->header); + tar->state |= (S_HEADER_VALID | S_WROTE_HEADER); + return MTAR_ESUCCESS; } +int mtar_update_header(mtar_t* tar, const mtar_header_t* h) +{ +#ifndef MICROTAR_DISABLE_API_CHECKS + if(tar->access != MTAR_WRITE) + return MTAR_EACCESS; + if(!(tar->state & S_WROTE_HEADER) || + (tar->state & S_WROTE_DATA_EOF) || + (tar->state & S_WROTE_FINALIZE)) + return MTAR_EAPI; +#endif + + unsigned beg_pos = data_beg_pos(tar); + if(beg_pos > UINT_MAX - h->size) + return MTAR_EOVERFLOW; + + unsigned old_pos = tar->pos; + int err = tseek(tar, tar->header_pos); + if(err) + return err; + + if(h != &tar->header) + tar->header = *h; -int mtar_write_dir_header(mtar_t *tar, const char *name) { - /* Build header */ - memset(&tar->header, 0, sizeof(tar->header)); - /* Ensure name fits within header */ - if(strlen(name) > sizeof(tar->header.name)) - return MTAR_EOVERFLOW; - strncpy(tar->header.name, name, sizeof(tar->header.name)); - tar->header.type = MTAR_TDIR; - tar->header.mode = 0775; - /* Write header */ - return mtar_write_header(tar, &tar->header); + err = header_to_raw(tar->buffer, &tar->header); + if(err) + return err; + + int len = twrite(tar, tar->buffer, HEADER_LEN); + if(len < 0) + return len; + if(len != HEADER_LEN) + return MTAR_EWRITEFAIL; + + return tseek(tar, old_pos); } +int mtar_write_file_header(mtar_t* tar, const char* name, unsigned size) +{ +#ifndef MICROTAR_DISABLE_API_CHECKS + if(tar->access != MTAR_WRITE) + return MTAR_EACCESS; + if(((tar->state & S_WROTE_DATA) && !(tar->state & S_WROTE_DATA_EOF)) || + (tar->state & S_WROTE_FINALIZE)) + return MTAR_EAPI; +#endif -int mtar_write_data(mtar_t *tar, const void *data, unsigned size) { - int err; + size_t namelen = strlen(name); + if(namelen > NAME_LEN) + return MTAR_ENAMETOOLONG; - /* Ensure we are writing the correct amount of data */ - if(size > tar->remaining_data) - return MTAR_EOVERFLOW; + tar->header.mode = 0644; + tar->header.owner = 0; + tar->header.group = 0; + tar->header.size = size; + tar->header.mtime = 0; + tar->header.type = MTAR_TREG; + memcpy(tar->header.name, name, namelen + 1); + tar->header.linkname[0] = '\0'; + + return mtar_write_header(tar, &tar->header); +} + +int mtar_write_dir_header(mtar_t* tar, const char* name) +{ +#ifndef MICROTAR_DISABLE_API_CHECKS + if(tar->access != MTAR_WRITE) + return MTAR_EACCESS; + if(((tar->state & S_WROTE_DATA) && !(tar->state & S_WROTE_DATA_EOF)) || + (tar->state & S_WROTE_FINALIZE)) + return MTAR_EAPI; +#endif + + size_t namelen = strlen(name); + if(namelen > NAME_LEN) + return MTAR_ENAMETOOLONG; + + tar->header.mode = 0755; + tar->header.owner = 0; + tar->header.group = 0; + tar->header.size = 0; + tar->header.mtime = 0; + tar->header.type = MTAR_TDIR; + memcpy(tar->header.name, name, namelen + 1); + tar->header.linkname[0] = '\0'; + + return mtar_write_header(tar, &tar->header); +} + +int mtar_write_data(mtar_t* tar, const void* ptr, unsigned size) +{ +#ifndef MICROTAR_DISABLE_API_CHECKS + if(tar->access != MTAR_WRITE) + return MTAR_EACCESS; + if(!(tar->state & S_WROTE_HEADER) || + (tar->state & S_WROTE_DATA_EOF) || + (tar->state & S_WROTE_FINALIZE)) + return MTAR_EAPI; +#endif + + tar->state |= S_WROTE_DATA; + + int err = twrite(tar, ptr, size); + if(tar->pos > tar->end_pos) + tar->end_pos = tar->pos; - /* Write data */ - err = twrite(tar, data, size); - if (err) { return err; - } - tar->remaining_data -= size; - /* Write padding if we've written all the data for this file */ - if (tar->remaining_data == 0) { - return write_null_bytes(tar, round_up(tar->pos, 512) - tar->pos); - } - return MTAR_ESUCCESS; } +int mtar_update_file_size(mtar_t* tar) +{ +#ifndef MICROTAR_DISABLE_API_CHECKS + if(tar->access != MTAR_WRITE) + return MTAR_EACCESS; + if(!(tar->state & S_WROTE_HEADER) || + (tar->state & S_WROTE_DATA_EOF) || + (tar->state & S_WROTE_FINALIZE)) + return MTAR_EAPI; +#endif + + unsigned new_size = data_end_pos(tar) - data_beg_pos(tar); + if(new_size == tar->header.size) + return MTAR_ESUCCESS; + else { + tar->header.size = new_size; + return mtar_update_header(tar, &tar->header); + } +} + +int mtar_end_data(mtar_t* tar) +{ +#ifndef MICROTAR_DISABLE_API_CHECKS + if(tar->access != MTAR_WRITE) + return MTAR_EACCESS; + if(!(tar->state & S_WROTE_HEADER) || + (tar->state & S_WROTE_DATA_EOF) || + (tar->state & S_WROTE_FINALIZE)) + return MTAR_EAPI; +#endif + + int err; + + /* ensure the caller wrote the correct amount of data */ + unsigned expected_end = data_beg_pos(tar) + tar->header.size; + if(tar->end_pos != expected_end) + return MTAR_EWRONGSIZE; + + /* ensure we're positioned at the end of the stream */ + if(tar->pos != tar->end_pos) { + err = tseek(tar, tar->end_pos); + if(err) + return err; + } + + /* write remainder of the 512-byte record */ + err = write_null_bytes(tar, round_up_512(tar->pos) - tar->pos); + if(err) + return err; + + tar->state |= S_WROTE_DATA_EOF; + return MTAR_ESUCCESS; +} + +int mtar_finalize(mtar_t* tar) +{ +#ifndef MICROTAR_DISABLE_API_CHECKS + if(tar->access != MTAR_WRITE) + return MTAR_EACCESS; + if(((tar->state & S_WROTE_DATA) && !(tar->state & S_WROTE_DATA_EOF)) || + (tar->state & S_WROTE_FINALIZE)) + return MTAR_EAPI; +#endif -int mtar_finalize(mtar_t *tar) { - /* Write two NULL records */ - return write_null_bytes(tar, sizeof(mtar_raw_header_t) * 2); + tar->state |= S_WROTE_FINALIZE; + return write_null_bytes(tar, 1024); } diff --git a/lib/microtar/src/microtar.h b/lib/microtar/src/microtar.h index d30c829521..7a9be2ac92 100644 --- a/lib/microtar/src/microtar.h +++ b/lib/microtar/src/microtar.h @@ -1,105 +1,132 @@ -/** +/* * Copyright (c) 2017 rxi + * Copyright (c) 2021 Aidan MacDonald * - * This library is free software; you can redistribute it and/or modify it - * under the terms of the MIT license. See `microtar.c` for details. + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to + * deal in the Software without restriction, including without limitation the + * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or + * sell copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS + * IN THE SOFTWARE. */ #ifndef MICROTAR_H #define MICROTAR_H #ifdef __cplusplus -extern "C" -{ +extern "C" { #endif -#include -#include - -#define MTAR_VERSION "0.1.0" - -enum { - MTAR_ESUCCESS = 0, - MTAR_EFAILURE = -1, - MTAR_EOPENFAIL = -2, - MTAR_EREADFAIL = -3, - MTAR_EWRITEFAIL = -4, - MTAR_ESEEKFAIL = -5, - MTAR_EBADCHKSUM = -6, - MTAR_ENULLRECORD = -7, - MTAR_ENOTFOUND = -8, - MTAR_EOVERFLOW = -9, +#include /* SEEK_SET et al. */ + +enum mtar_error { + MTAR_ESUCCESS = 0, + MTAR_EFAILURE = -1, + MTAR_EOPENFAIL = -2, + MTAR_EREADFAIL = -3, + MTAR_EWRITEFAIL = -4, + MTAR_ESEEKFAIL = -5, + MTAR_ESEEKRANGE = -6, + MTAR_EBADCHKSUM = -7, + MTAR_ENULLRECORD = -8, + MTAR_ENOTFOUND = -9, + MTAR_EOVERFLOW = -10, + MTAR_EAPI = -11, + MTAR_ENAMETOOLONG = -12, + MTAR_EWRONGSIZE = -13, + MTAR_EACCESS = -14, +}; + +enum mtar_type { + MTAR_TREG = '0', + MTAR_TLNK = '1', + MTAR_TSYM = '2', + MTAR_TCHR = '3', + MTAR_TBLK = '4', + MTAR_TDIR = '5', + MTAR_TFIFO = '6', }; -enum { - MTAR_TREG = '0', - MTAR_TLNK = '1', - MTAR_TSYM = '2', - MTAR_TCHR = '3', - MTAR_TBLK = '4', - MTAR_TDIR = '5', - MTAR_TFIFO = '6' +enum mtar_access { + MTAR_READ, + MTAR_WRITE, }; -typedef struct { - unsigned mode; - unsigned owner; - unsigned group; - unsigned size; - unsigned mtime; - unsigned type; - char name[101]; /* +1 byte in order to ensure null termination */ - char linkname[101]; -} mtar_header_t; - - -typedef struct { - char name[100]; - char mode[8]; - char owner[8]; - char group[8]; - char size[12]; - char mtime[12]; - char checksum[8]; - char type; - char linkname[100]; - char _padding[255]; -} mtar_raw_header_t; - - -typedef struct mtar_t mtar_t; - -struct mtar_t { - int (*read)(mtar_t *tar, void *data, unsigned size); - int (*write)(mtar_t *tar, const void *data, unsigned size); - int (*seek)(mtar_t *tar, unsigned pos); - int (*close)(mtar_t *tar); - void *stream; - unsigned pos; - unsigned remaining_data; - unsigned last_header; - mtar_header_t header; - mtar_raw_header_t raw_header; +typedef struct mtar_header mtar_header_t; +typedef struct mtar mtar_t; +typedef struct mtar_ops mtar_ops_t; + +typedef int(*mtar_foreach_cb)(mtar_t*, const mtar_header_t*, void*); + +struct mtar_header { + unsigned mode; + unsigned owner; + unsigned group; + unsigned size; + unsigned mtime; + unsigned type; + char name[101]; /* +1 byte in order to ensure null termination */ + char linkname[101]; }; +struct mtar_ops { + int(*read)(void* stream, void* data, unsigned size); + int(*write)(void* stream, const void* data, unsigned size); + int(*seek)(void* stream, unsigned pos); + int(*close)(void* stream); +}; + +struct mtar { + char buffer[512]; /* IO buffer, put first to allow library users to + * control its alignment */ + int state; /* Used to simplify the API and verify API usage */ + int access; /* Access mode */ + unsigned pos; /* Current position in file */ + unsigned end_pos; /* End position of the current file */ + unsigned header_pos; /* Position of the current header */ + mtar_header_t header; /* Most recently parsed header */ + const mtar_ops_t* ops; /* Stream operations */ + void* stream; /* Stream handle */ +}; const char* mtar_strerror(int err); -int mtar_open(mtar_t *tar, const char *filename, const char *mode); -int mtar_close(mtar_t *tar); - -int mtar_seek(mtar_t *tar, unsigned pos); -int mtar_rewind(mtar_t *tar); -int mtar_next(mtar_t *tar); -int mtar_find(mtar_t *tar, const char *name, mtar_header_t *h); -int mtar_read_header(mtar_t *tar, mtar_header_t *h); -int mtar_read_data(mtar_t *tar, void *ptr, unsigned size); - -int mtar_write_header(mtar_t *tar, const mtar_header_t *h); -int mtar_write_file_header(mtar_t *tar, const char *name, unsigned size); -int mtar_write_dir_header(mtar_t *tar, const char *name); -int mtar_write_data(mtar_t *tar, const void *data, unsigned size); -int mtar_finalize(mtar_t *tar); +void mtar_init(mtar_t* tar, int access, const mtar_ops_t* ops, void* stream); +int mtar_close(mtar_t* tar); +int mtar_is_open(mtar_t* tar); + +mtar_header_t* mtar_get_header(mtar_t* tar); +int mtar_access_mode(const mtar_t* tar); + +int mtar_rewind(mtar_t* tar); +int mtar_next(mtar_t* tar); +int mtar_foreach(mtar_t* tar, mtar_foreach_cb cb, void* arg); +int mtar_find(mtar_t* tar, const char* name); + +int mtar_read_data(mtar_t* tar, void* ptr, unsigned size); +int mtar_seek_data(mtar_t* tar, int offset, int whence); +unsigned mtar_tell_data(mtar_t* tar); +int mtar_eof_data(mtar_t* tar); + +int mtar_write_header(mtar_t* tar, const mtar_header_t* h); +int mtar_update_header(mtar_t* tar, const mtar_header_t* h); +int mtar_write_file_header(mtar_t* tar, const char* name, unsigned size); +int mtar_write_dir_header(mtar_t* tar, const char* name); +int mtar_write_data(mtar_t* tar, const void* ptr, unsigned size); +int mtar_update_file_size(mtar_t* tar); +int mtar_end_data(mtar_t* tar); +int mtar_finalize(mtar_t* tar); #ifdef __cplusplus } -- cgit v1.2.3