| 0,0 → 1,456 |
|---|
| /* |
| * Copyright (c) 2017 rxi |
| * |
| * 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 <stdio.h> |
| #include <stdlib.h> |
| #include <stddef.h> |
| #include <string.h> |
| |
| #include <sys/ksys.h> |
| |
| #include "microtar.h" |
| |
| 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; |
| |
| static void * mtar_memset( void * s, int c, size_t n ){ |
| unsigned char * p = ( unsigned char * ) s; |
| while ( n-- ){ |
| *p++ = ( unsigned char ) c; |
| } |
| return s; |
| } |
| |
| #ifdef MTAR_OBJ |
| |
| size_t (*fread)(void *restrict, size_t size, size_t count, FILE *restrict)=NULL; |
| size_t (*fwrite)(const void *restrict, size_t size, size_t count, FILE *restrict)=NULL; |
| int (*fclose)(FILE *)=NULL; |
| FILE* (*fopen)(const char *restrict, const char *restrict)=NULL; |
| int (*fseek)(FILE *, long, int)=NULL; |
| long (*ftell)(FILE *)=NULL; |
| int (*sprintf)(char* buffer, const char* format, ...)=NULL; |
| int (*sscanf)(const char*, const char *restrict, ...)=NULL; |
| int (*strcmp)(const char * s1, const char* s2)=NULL; |
| char* (*strchr)(const char* s, int c)=NULL; |
| char* (*strcpy)(char* s1, const char* s2)=NULL; |
| |
| #endif |
| |
| static unsigned round_up(unsigned n, unsigned incr) { |
| return n + (incr - n % incr) % incr; |
| } |
| |
| |
| 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; |
| } |
| |
| |
| static int tread(mtar_t *tar, void *data, unsigned size) { |
| int err = tar->read(tar, data, size); |
| tar->pos += size; |
| return err; |
| } |
| |
| |
| static int twrite(mtar_t *tar, const void *data, unsigned size) { |
| |
| int err = tar->write(tar, data, size); |
| tar->pos += size; |
| return err; |
| } |
| |
| |
| 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; |
| } |
| |
| |
| static int raw_to_header(mtar_header_t *h, const mtar_raw_header_t *rh) { |
| unsigned chksum1, chksum2; |
| |
| /* If the checksum starts with a null byte we assume the record is NULL */ |
| if (*rh->checksum == '\0') { |
| return MTAR_ENULLRECORD; |
| } |
| |
| /* Build and compare checksum */ |
| chksum1 = checksum(rh); |
| sscanf(rh->checksum, "%o", &chksum2); |
| if (chksum1 != chksum2) { |
| return MTAR_EBADCHKSUM; |
| } |
| |
| /* Load raw header into header */ |
| sscanf(rh->mode, "%o", &h->mode); |
| sscanf(rh->owner, "%o", &h->owner); |
| sscanf(rh->size, "%o", &h->size); |
| sscanf(rh->mtime, "%o", &h->mtime); |
| h->type = rh->type; |
| strcpy(h->name, rh->name); |
| strcpy(h->linkname, rh->linkname); |
| |
| return MTAR_ESUCCESS; |
| } |
| |
| |
| static int header_to_raw(mtar_raw_header_t *rh, const mtar_header_t *h) { |
| unsigned chksum; |
| |
| /* Load header into raw header */ |
| mtar_memset(rh, 0, sizeof(*rh)); |
| sprintf(rh->mode, "%o", h->mode); |
| sprintf(rh->owner, "%o", h->owner); |
| sprintf(rh->size, "%o", h->size); |
| sprintf(rh->mtime, "%o", h->mtime); |
| rh->type = h->type ? h->type : MTAR_TREG; |
| strcpy(rh->name, h->name); |
| strcpy(rh->linkname, h->linkname); |
| |
| /* Calculate and write checksum */ |
| chksum = checksum(rh); |
| sprintf(rh->checksum, "%06o", chksum); |
| rh->checksum[7] = ' '; |
| |
| 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_EBADCHKSUM : return "bad checksum"; |
| case MTAR_ENULLRECORD : return "null record"; |
| case MTAR_ENOTFOUND : return "file not found"; |
| } |
| return "unknown error"; |
| } |
| |
| |
| 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; |
| } |
| |
| 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_seek(mtar_t *tar, unsigned offset) { |
| int res = fseek(tar->stream, offset, SEEK_SET); |
| return (res == 0) ? MTAR_ESUCCESS : MTAR_ESEEKFAIL; |
| } |
| |
| static int file_close(mtar_t *tar) { |
| fclose(tar->stream); |
| return MTAR_ESUCCESS; |
| } |
| |
| |
| int mtar_open(mtar_t *tar, const char *filename, const char *mode) { |
| int err; |
| mtar_header_t h; |
| |
| /* Init tar struct and functions */ |
| mtar_memset(tar, 0, sizeof(*tar)); |
| tar->write = file_write; |
| tar->read = file_read; |
| tar->seek = file_seek; |
| tar->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; |
| } |
| } |
| |
| /* Return ok */ |
| return MTAR_ESUCCESS; |
| } |
| |
| |
| int mtar_close(mtar_t *tar) { |
| return tar->close(tar); |
| } |
| |
| |
| int mtar_seek(mtar_t *tar, unsigned pos) { |
| int err = tar->seek(tar, pos); |
| tar->pos = pos; |
| return err; |
| } |
| |
| |
| int mtar_rewind(mtar_t *tar) { |
| tar->remaining_data = 0; |
| tar->last_header = 0; |
| return mtar_seek(tar, 0); |
| } |
| |
| |
| int mtar_next(mtar_t *tar) { |
| int err, n; |
| mtar_header_t h; |
| /* Load header */ |
| err = mtar_read_header(tar, &h); |
| if (err) { |
| return err; |
| } |
| /* Seek to next record */ |
| n = round_up(h.size, 512) + sizeof(mtar_raw_header_t); |
| return mtar_seek(tar, tar->pos + n); |
| } |
| |
| |
| int mtar_find(mtar_t *tar, const char *name, mtar_header_t *h) { |
| int err; |
| mtar_header_t header; |
| /* 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, &header)) == MTAR_ESUCCESS ) { |
| if ( !strcmp(header.name, name) ) { |
| if (h) { |
| *h = header; |
| } |
| return MTAR_ESUCCESS; |
| } |
| mtar_next(tar); |
| } |
| /* Return error */ |
| if (err == MTAR_ENULLRECORD) { |
| err = MTAR_ENOTFOUND; |
| } |
| return err; |
| } |
| |
| |
| int mtar_read_header(mtar_t *tar, mtar_header_t *h) { |
| int err; |
| mtar_raw_header_t rh; |
| /* Save header position */ |
| tar->last_header = tar->pos; |
| /* Read raw header */ |
| err = tread(tar, &rh, sizeof(rh)); |
| if (err) { |
| return err; |
| } |
| /* Seek back to start of header */ |
| err = mtar_seek(tar, tar->last_header); |
| if (err) { |
| return err; |
| } |
| /* Load raw header into header struct and return */ |
| return raw_to_header(h, &rh); |
| } |
| |
| |
| 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) { |
| mtar_header_t h; |
| /* Read header */ |
| err = mtar_read_header(tar, &h); |
| 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; |
| } |
| tar->remaining_data = h.size; |
| } |
| /* 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; |
| } |
| |
| |
| int mtar_write_header(mtar_t *tar, const mtar_header_t *h) { |
| mtar_raw_header_t rh; |
| /* Build raw header and write */ |
| header_to_raw(&rh, h); |
| tar->remaining_data = h->size; |
| return twrite(tar, &rh, sizeof(rh)); |
| } |
| |
| int mtar_write_file_header(mtar_t *tar, const char *name, unsigned size) { |
| mtar_header_t h; |
| /* Build header */ |
| mtar_memset(&h, 0, sizeof(h)); |
| strcpy(h.name, name); |
| h.size = size; |
| h.type = MTAR_TREG; |
| h.mode = 0664; |
| /* Write header */ |
| return mtar_write_header(tar, &h); |
| } |
| |
| |
| int mtar_write_dir_header(mtar_t *tar, const char *name) { |
| mtar_header_t h; |
| /* Build header */ |
| mtar_memset(&h, 0, sizeof(h)); |
| strcpy(h.name, name); |
| h.type = MTAR_TDIR; |
| h.mode = 0775; |
| /* Write header */ |
| return mtar_write_header(tar, &h); |
| } |
| |
| |
| int mtar_write_data(mtar_t *tar, const void *data, unsigned size) { |
| int err; |
| /* 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_finalize(mtar_t *tar) { |
| /* Write two NULL records */ |
| return write_null_bytes(tar, sizeof(mtar_raw_header_t) * 2); |
| } |
| |
| /* Load libc.obj */ |
| |
| #ifdef MTAR_OBJ |
| |
| #include <sys/ksys.h> |
| |
| void mtar_panic(char* func_name){ |
| _ksys_debug_puts("mtar.obj: "); |
| _ksys_debug_puts(func_name); |
| _ksys_debug_puts(" = NULL!\n"); |
| } |
| |
| int mtar_init(){ |
| ksys_coff_etable_t *libc = _ksys_load_coff("/sys/lib/libc.obj"); |
| if(!libc){ |
| _ksys_debug_puts("mtar.obj: libc.obj not loaded!"); |
| return 1; |
| } |
| |
| fread = _ksys_get_coff_func(libc, "fread", mtar_panic); |
| fwrite = _ksys_get_coff_func(libc, "fwrite", mtar_panic); |
| fclose = _ksys_get_coff_func(libc, "fclose", mtar_panic); |
| fopen = _ksys_get_coff_func(libc, "fopen", mtar_panic); |
| fseek = _ksys_get_coff_func(libc, "fseek", mtar_panic); |
| ftell = _ksys_get_coff_func(libc, "ftell", mtar_panic); |
| sprintf= _ksys_get_coff_func(libc, "sprintf", mtar_panic); |
| sscanf = _ksys_get_coff_func(libc, "sscanf", mtar_panic); |
| strcmp = _ksys_get_coff_func(libc, "strcmp", mtar_panic); |
| strchr = _ksys_get_coff_func(libc, "strchr", mtar_panic); |
| strcpy = _ksys_get_coff_func(libc, "strcpy", mtar_panic); |
| return 0; |
| } |
| |
| |
| ksys_coff_etable_t EXPORTS[] = { |
| {"mtar_init", mtar_init}, |
| {"mtar_open", mtar_open}, |
| {"mtar_close", mtar_close}, |
| {"mtar_seek", mtar_seek}, |
| {"mtar_rewind", mtar_rewind}, |
| {"mtar_next", mtar_next}, |
| {"mtar_find", mtar_find}, |
| {"mtar_read_header", mtar_read_header}, |
| {"mtar_read_data", mtar_read_data}, |
| {"mtar_write_header", mtar_write_header}, |
| {"mtar_write_file_header", mtar_write_file_header}, |
| {"mtar_write_dir_header", mtar_write_dir_header}, |
| {"mtar_write_data",mtar_write_data}, |
| {"mtar_finalize", mtar_finalize}, |
| {"mtar_strerror", mtar_strerror}, |
| NULL |
| }; |
| |
| #endif |