/*
* Copyright (c) 2018 Stefan Sperling <stsp@openbsd.org>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <sys/queue.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <zlib.h>
#include <sha1.h>
#include <time.h>
#include <zlib.h>
#include "got_error.h"
#include "got_repository.h"
#include "got_object.h"
#include "got_lib_delta.h"
#include "got_lib_path.h"
#include "got_lib_inflate.h"
#include "got_lib_object.h"
#ifndef MIN
#define MIN(_a,_b) ((_a) < (_b) ? (_a) : (_b))
#endif
struct got_delta *
got_delta_open(off_t offset, size_t tslen, int type, size_t size,
off_t data_offset, uint8_t *delta_buf, size_t delta_len)
{
struct got_delta *delta;
delta = malloc(sizeof(*delta));
if (delta == NULL)
return NULL;
delta->type = type;
delta->offset = offset;
delta->tslen = tslen;
delta->size = size;
delta->data_offset = data_offset;
delta->delta_buf = delta_buf;
delta->delta_len = delta_len;
return delta;
}
void
got_delta_close(struct got_delta *delta)
{
free(delta->delta_buf);
free(delta);
}
const struct got_error *
got_delta_chain_get_base_type(int *type, struct got_delta_chain *deltas)
{
struct got_delta *delta;
/* The first delta in the chain should represent the base object. */
delta = SIMPLEQ_FIRST(&deltas->entries);
if (delta->type == GOT_OBJ_TYPE_COMMIT ||
delta->type == GOT_OBJ_TYPE_TREE ||
delta->type == GOT_OBJ_TYPE_BLOB ||
delta->type == GOT_OBJ_TYPE_TAG) {
*type = delta->type;
return NULL;
}
return got_error(GOT_ERR_BAD_DELTA_CHAIN);
}
/* Fetch another (required) byte from the delta stream. */
static const struct got_error *
next_delta_byte(const uint8_t **p, size_t *remain)
{
if (--(*remain) == 0)
return got_error(GOT_ERR_BAD_DELTA);
(*p)++;
return NULL;
}
static const struct got_error *
parse_size(uint64_t *size, const uint8_t **p, size_t *remain)
{
const struct got_error *err = NULL;
int i = 0;
*size = 0;
do {
/* We do not support size values which don't fit in 64 bit. */
if (i > 9)
return got_error(GOT_ERR_NO_SPACE);
if (i == 0)
*size = ((**p) & GOT_DELTA_SIZE_VAL_MASK);
else {
size_t shift = GOT_DELTA_SIZE_SHIFT * i;
*size |= (((**p) & GOT_DELTA_SIZE_VAL_MASK) << shift);
}
if (((**p) & GOT_DELTA_SIZE_MORE) == 0)
break;
i++;
err = next_delta_byte(p, remain);
} while (err == NULL);
return err;
}
static const struct got_error *
parse_opcode(off_t *offset, size_t *len, const uint8_t **p, size_t *remain)
{
const struct got_error *err = NULL;
off_t o = 0;
size_t l = 0;
uint8_t opcode = **p;
if (opcode & GOT_DELTA_COPY_OFF1) {
err = next_delta_byte(p, remain);
if (err)
return err;
o = (off_t)(**p);
}
if (opcode & GOT_DELTA_COPY_OFF2) {
err = next_delta_byte(p, remain);
if (err)
return err;
o |= ((off_t)(**p)) << 8;
}
if (opcode & GOT_DELTA_COPY_OFF3) {
err = next_delta_byte(p, remain);
if (err)
return err;
o |= ((off_t)(**p)) << 16;
}
if (opcode & GOT_DELTA_COPY_OFF4) {
err = next_delta_byte(p, remain);
if (err)
return err;
o |= ((off_t)(**p)) << 24;
}
if (opcode & GOT_DELTA_COPY_LEN1) {
err = next_delta_byte(p, remain);
if (err)
return err;
l = (off_t)(**p);
}
if (opcode & GOT_DELTA_COPY_LEN2) {
err = next_delta_byte(p, remain);
if (err)
return err;
l |= ((off_t)(**p)) << 8;
}
if (opcode & GOT_DELTA_COPY_LEN3) {
err = next_delta_byte(p, remain);
if (err)
return err;
l |= ((off_t)(**p)) << 16;
}
if (o == 0)
o = GOT_DELTA_COPY_DEFAULT_OFF;
if (l == 0)
l = GOT_DELTA_COPY_DEFAULT_LEN;
*offset = o;
*len = l;
return NULL;
}
static const struct got_error *
copy_from_base(FILE *base_file, off_t offset, size_t size, FILE *outfile)
{
if (fseeko(base_file, offset, SEEK_SET) != 0)
return got_error_from_errno();
while (size > 0) {
uint8_t data[2048];
size_t len = MIN(size, sizeof(data));
size_t n;
n = fread(data, len, 1, base_file);
if (n != 1)
return got_ferror(base_file, GOT_ERR_IO);
n = fwrite(data, len, 1, outfile);
if (n != 1)
return got_ferror(outfile, GOT_ERR_IO);
size -= len;
}
return NULL;
}
static const struct got_error *
copy_from_delta(const uint8_t **p, size_t *remain, size_t len, FILE *outfile)
{
size_t n;
if (*remain < len)
return got_error(GOT_ERR_BAD_DELTA);
n = fwrite(*p, len, 1, outfile);
if (n != 1)
return got_ferror(outfile, GOT_ERR_IO);
*p += len;
*remain -= len;
return NULL;
}
static const struct got_error *
parse_delta_sizes(uint64_t *base_size, uint64_t *result_size,
const uint8_t **p, size_t *remain)
{
const struct got_error *err;
/* Read the two size fields at the beginning of the stream. */
err = parse_size(base_size, p, remain);
if (err)
return err;
err = next_delta_byte(p, remain);
if (err)
return err;
err = parse_size(result_size, p, remain);
if (err)
return err;
return NULL;
}
const struct got_error *
got_delta_get_sizes(uint64_t *base_size, uint64_t *result_size,
const uint8_t *delta_buf, size_t delta_len)
{
size_t remain;
const uint8_t *p;
if (delta_len < GOT_DELTA_STREAM_LENGTH_MIN)
return got_error(GOT_ERR_BAD_DELTA);
p = delta_buf;
remain = delta_len;
return parse_delta_sizes(base_size, result_size, &p, &remain);
}
const struct got_error *
got_delta_apply_in_mem(uint8_t *base_buf, size_t base_bufsz,
const uint8_t *delta_buf, size_t delta_len, uint8_t *outbuf,
size_t *outsize, size_t maxoutsize)
{
const struct got_error *err = NULL;
uint64_t base_size, result_size;
size_t remain;
const uint8_t *p;
*outsize= 0;
if (delta_len < GOT_DELTA_STREAM_LENGTH_MIN)
return got_error(GOT_ERR_BAD_DELTA);
p = delta_buf;
remain = delta_len;
err = parse_delta_sizes(&base_size, &result_size, &p, &remain);
if (err)
return err;
/* Decode and execute copy instructions from the delta stream. */
err = next_delta_byte(&p, &remain);
while (err == NULL && remain > 0) {
if (*p & GOT_DELTA_BASE_COPY) {
off_t offset = 0;
size_t len = 0;
err = parse_opcode(&offset, &len, &p, &remain);
if (err)
break;
if (SIZE_MAX - offset < len || offset + len < 0 ||
base_bufsz < offset + len ||
*outsize + len > maxoutsize)
return got_error(GOT_ERR_BAD_DELTA);
memcpy(outbuf + *outsize, base_buf + offset, len);
if (err == NULL) {
*outsize += len;
if (remain > 0) {
p++;
remain--;
}
}
} else {
size_t len = (size_t)*p;
if (len == 0) {
err = got_error(GOT_ERR_BAD_DELTA);
break;
}
err = next_delta_byte(&p, &remain);
if (err)
break;
if (remain < len || SIZE_MAX - *outsize < len ||
*outsize + len > maxoutsize)
return got_error(GOT_ERR_BAD_DELTA);
memcpy(outbuf + *outsize, p, len);
p += len;
remain -= len;
*outsize += len;
}
}
if (*outsize != result_size)
err = got_error(GOT_ERR_BAD_DELTA);
return err;
}
const struct got_error *
got_delta_apply(FILE *base_file, const uint8_t *delta_buf,
size_t delta_len, FILE *outfile, size_t *outsize)
{
const struct got_error *err = NULL;
uint64_t base_size, result_size;
size_t remain = 0;
const uint8_t *p;
FILE *memstream = NULL;
char *memstream_buf = NULL;
size_t memstream_size = 0;
*outsize = 0;
if (delta_len < GOT_DELTA_STREAM_LENGTH_MIN)
return got_error(GOT_ERR_BAD_DELTA);
p = delta_buf;
remain = delta_len;
err = parse_delta_sizes(&base_size, &result_size, &p, &remain);
if (err)
return err;
if (result_size < GOT_DELTA_RESULT_SIZE_CACHED_MAX)
memstream = open_memstream(&memstream_buf, &memstream_size);
/* Decode and execute copy instructions from the delta stream. */
err = next_delta_byte(&p, &remain);
while (err == NULL && remain > 0) {
if (*p & GOT_DELTA_BASE_COPY) {
off_t offset = 0;
size_t len = 0;
err = parse_opcode(&offset, &len, &p, &remain);
if (err)
break;
err = copy_from_base(base_file, offset, len,
memstream ? memstream : outfile);
if (err == NULL) {
*outsize += len;
if (remain > 0) {
p++;
remain--;
}
}
} else {
size_t len = (size_t)*p;
if (len == 0) {
err = got_error(GOT_ERR_BAD_DELTA);
break;
}
err = next_delta_byte(&p, &remain);
if (err)
break;
err = copy_from_delta(&p, &remain, len,
memstream ? memstream : outfile);
if (err == NULL)
*outsize += len;
}
}
if (*outsize != result_size)
err = got_error(GOT_ERR_BAD_DELTA);
if (memstream != NULL) {
if (fclose(memstream) != 0)
err = got_error_from_errno();
if (err == NULL) {
size_t n;
n = fwrite(memstream_buf, 1, memstream_size, outfile);
if (n != memstream_size)
err = got_ferror(outfile, GOT_ERR_IO);
}
free(memstream_buf);
}
if (err == NULL)
rewind(outfile);
return err;
}
