Rename modify to ziptool and install it.
diff --git a/src/source_hole.c b/src/source_hole.c
new file mode 100644
index 0000000..d2f1a16
--- /dev/null
+++ b/src/source_hole.c
@@ -0,0 +1,589 @@
+/*
+ source_hole.c -- source for handling huge files that are mostly NULs
+ Copyright (C) 2014-2016 Dieter Baron and Thomas Klausner
+
+ This file is part of libzip, a library to manipulate ZIP archives.
+ The authors can be contacted at <libzip@nih.at>
+
+ Redistribution and use in source and binary forms, with or without
+ modification, are permitted provided that the following conditions
+ are met:
+ 1. Redistributions of source code must retain the above copyright
+ notice, this list of conditions and the following disclaimer.
+ 2. Redistributions in binary form must reproduce the above copyright
+ notice, this list of conditions and the following disclaimer in
+ the documentation and/or other materials provided with the
+ distribution.
+ 3. The names of the authors may not be used to endorse or promote
+ products derived from this software without specific prior
+ written permission.
+
+ THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS
+ OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY
+ DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
+ GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
+ IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+ OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
+ IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <errno.h>
+#include <limits.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+#include "zip.h"
+
+/* public API */
+
+zip_source_t *source_hole_create(const char *, int flags, zip_error_t *);
+
+
+#ifndef EFTYPE
+#define EFTYPE EINVAL
+#endif
+
+
+#define MY_MIN(a, b) ((a) < (b) ? (a) : (b))
+
+#define FRAGMENT_SIZE (8*1024)
+
+#define MARK_BEGIN "NiH0"
+#define MARK_DATA "NiH1"
+#define MARK_NUL "NiH2"
+
+
+typedef struct buffer {
+ zip_uint64_t fragment_size;
+ zip_uint8_t **fragment;
+ zip_uint64_t nfragments;
+ zip_uint64_t size;
+ zip_uint64_t offset;
+} buffer_t;
+
+static void buffer_free(buffer_t *buffer);
+static buffer_t *buffer_from_file(const char *fname, int flags, zip_error_t *error);
+static buffer_t *buffer_new(void);
+static zip_int64_t buffer_read(buffer_t *buffer, zip_uint8_t *data, zip_uint64_t length, zip_error_t *error);
+static int buffer_read_file(buffer_t *buffer, FILE *f, zip_error_t *error);
+static zip_int64_t buffer_seek(buffer_t *buffer, void *data, zip_uint64_t length, zip_error_t *error);
+static int buffer_to_file(buffer_t *buffer, const char *fname, zip_error_t *error);
+static zip_int64_t buffer_write(buffer_t *buffer, const zip_uint8_t *data, zip_uint64_t length, zip_error_t *error);
+static zip_uint64_t get_u64(const zip_uint8_t *b);
+static int only_nul(const zip_uint8_t *data, zip_uint64_t length);
+static int write_nuls(zip_uint64_t n, FILE *f);
+static int write_u64(zip_uint64_t u64, FILE *f);
+
+
+typedef struct hole {
+ zip_error_t error;
+ char *fname;
+ buffer_t *in;
+ buffer_t *out;
+} hole_t;
+
+static hole_t *hole_new(const char *fname, int flags, zip_error_t *error);
+static zip_int64_t source_hole_cb(void *ud, void *data, zip_uint64_t length, zip_source_cmd_t command);
+
+
+zip_source_t *source_hole_create(const char *fname, int flags, zip_error_t *error)
+{
+ hole_t *ud = hole_new(fname, flags, error);
+
+ if (ud == NULL) {
+ return NULL;
+ }
+ return zip_source_function_create(source_hole_cb, ud, error);
+}
+
+
+static void
+buffer_free(buffer_t *buffer)
+{
+ zip_uint64_t i;
+
+ if (buffer == NULL) {
+ return;
+ }
+
+ if (buffer->fragment) {
+ for (i=0; i<buffer->nfragments; i++) {
+ free(buffer->fragment[i]);
+ }
+ free(buffer->fragment);
+ }
+ free(buffer);
+}
+
+
+static buffer_t *
+buffer_from_file(const char *fname, int flags, zip_error_t *error)
+{
+ buffer_t *buffer;
+ FILE *f;
+
+ if ((buffer = buffer_new()) == NULL) {
+ zip_error_set(error, ZIP_ER_MEMORY, 0);
+ return NULL;
+
+ }
+
+ if ((flags & ZIP_TRUNCATE) == 0) {
+ if ((f = fopen(fname, "rb")) == NULL) {
+ if (!(errno == ENOENT && (flags & ZIP_CREATE))) {
+ buffer_free(buffer);
+ return NULL;
+ }
+ }
+ else {
+ if (buffer_read_file(buffer, f, error) < 0) {
+ buffer_free(buffer);
+ fclose(f);
+ return NULL;
+ }
+ fclose(f);
+ }
+ }
+
+ return buffer;
+}
+
+
+static buffer_t *
+buffer_new(void)
+{
+ buffer_t *buffer;
+
+ if ((buffer = (buffer_t *)malloc(sizeof(*buffer))) == NULL) {
+ return NULL;
+ }
+
+ buffer->fragment = NULL;
+ buffer->nfragments = 0;
+ buffer->fragment_size = FRAGMENT_SIZE;
+ buffer->size = 0;
+ buffer->offset = 0;
+
+ return buffer;
+}
+
+
+static zip_int64_t
+buffer_read(buffer_t *buffer, zip_uint8_t *data, zip_uint64_t length, zip_error_t *error)
+{
+ zip_uint64_t n, i, fragment_offset;
+
+ length = MY_MIN(length, buffer->size - buffer->offset);
+
+ if (length == 0) {
+ return 0;
+ }
+ if (length > ZIP_INT64_MAX) {
+ return -1;
+ }
+
+ i = buffer->offset / buffer->fragment_size;
+ fragment_offset = buffer->offset % buffer->fragment_size;
+ n = 0;
+ while (n < length) {
+ zip_uint64_t left = MY_MIN(length - n, buffer->fragment_size - fragment_offset);
+
+ if (buffer->fragment[i]) {
+ memcpy(data + n, buffer->fragment[i] + fragment_offset, left);
+ }
+ else {
+ memset(data + n, 0, left);
+ }
+
+ n += left;
+ i++;
+ fragment_offset = 0;
+ }
+
+ buffer->offset += n;
+ return (zip_int64_t)n;
+}
+
+
+static int
+buffer_read_file(buffer_t *buffer, FILE *f, zip_error_t *error)
+{
+ zip_uint8_t b[20];
+ zip_uint64_t i;
+
+ if (fread(b, 20, 1, f) != 1) {
+ zip_error_set(error, ZIP_ER_READ, errno);
+ return -1;
+ }
+
+ if (memcmp(b, MARK_BEGIN, 4) != 0) {
+ zip_error_set(error, ZIP_ER_READ, EFTYPE);
+ return -1;
+ }
+
+ buffer->fragment_size = get_u64(b+4);
+ buffer->size = get_u64(b+12);
+
+ if (buffer->size + buffer->fragment_size < buffer->size) {
+ zip_error_set(error, ZIP_ER_MEMORY, 0);
+ return -1;
+ }
+ buffer->nfragments = (buffer->size + buffer->fragment_size - 1) / buffer->fragment_size;
+ if ((buffer->nfragments > SIZE_MAX/sizeof(buffer->fragment[0]))
+ || ((buffer->fragment = (zip_uint8_t **)malloc(sizeof(buffer->fragment[0]) * buffer->nfragments)) == NULL)) {
+ zip_error_set(error, ZIP_ER_MEMORY, 0);
+ return -1;
+ }
+
+ for (i = 0; i < buffer->nfragments; i++) {
+ buffer->fragment[i] = NULL;
+ }
+
+ i = 0;
+ while (i < buffer->nfragments) {
+ if (fread(b, 4, 1, f) != 1) {
+ zip_error_set(error, ZIP_ER_READ, errno);
+ return -1;
+ }
+
+ if (memcmp(b, MARK_DATA, 4) == 0) {
+ if (buffer->fragment_size > SIZE_MAX) {
+ zip_error_set(error, ZIP_ER_MEMORY, 0);
+ return -1;
+ }
+ if ((buffer->fragment[i] = (zip_uint8_t *)malloc(buffer->fragment_size)) == NULL) {
+ zip_error_set(error, ZIP_ER_MEMORY, 0);
+ return -1;
+ }
+ if (fread(buffer->fragment[i], buffer->fragment_size, 1, f) != 1) {
+ zip_error_set(error, ZIP_ER_READ, errno);
+ return -1;
+ }
+ i++;
+ }
+ else if (memcmp(b, MARK_NUL, 4) == 0) {
+ if (fread(b, 8, 1, f) != 1) {
+ zip_error_set(error, ZIP_ER_READ, errno);
+ return -1;
+ }
+ i += get_u64(b);
+ }
+ else {
+ zip_error_set(error, ZIP_ER_READ, EFTYPE);
+ return -1;
+ }
+ }
+
+ return 0;
+}
+
+static zip_int64_t
+buffer_seek(buffer_t *buffer, void *data, zip_uint64_t length, zip_error_t *error)
+{
+ zip_int64_t new_offset = zip_source_seek_compute_offset(buffer->offset, buffer->size, data, length, error);
+
+ if (new_offset < 0) {
+ return -1;
+ }
+
+ buffer->offset = (zip_uint64_t)new_offset;
+ return 0;
+}
+
+
+static int
+buffer_to_file(buffer_t *buffer, const char *fname, zip_error_t *error)
+{
+ FILE *f = fopen(fname, "wb");
+ zip_uint64_t i;
+ zip_uint64_t nul_run;
+
+ if (f == NULL) {
+ zip_error_set(error, ZIP_ER_OPEN, errno);
+ return -1;
+ }
+
+ fwrite(MARK_BEGIN, 4, 1, f);
+ write_u64(buffer->fragment_size, f);
+ write_u64(buffer->size, f);
+
+ nul_run = 0;
+ for (i=0; i * buffer->fragment_size <buffer->size; i++) {
+ if (buffer->fragment[i] == NULL || only_nul(buffer->fragment[i], buffer->fragment_size)) {
+ nul_run++;
+ }
+ else {
+ if (nul_run > 0) {
+ write_nuls(nul_run, f);
+ nul_run = 0;
+ }
+ fwrite(MARK_DATA, 4, 1, f);
+
+ fwrite(buffer->fragment[i], 1, buffer->fragment_size, f);
+ }
+ }
+
+ if (nul_run > 0) {
+ write_nuls(nul_run, f);
+ }
+
+ if (fclose(f) != 0) {
+ zip_error_set(error, ZIP_ER_WRITE, errno);
+ return -1;
+ }
+
+ return 0;
+}
+
+
+static zip_int64_t
+buffer_write(buffer_t *buffer, const zip_uint8_t *data, zip_uint64_t length, zip_error_t *error)
+{
+ zip_uint8_t **fragment;
+ if (buffer->offset + length > buffer->nfragments * buffer->fragment_size) {
+ zip_uint64_t needed_fragments = (buffer->offset + length + buffer->fragment_size - 1) / buffer->fragment_size;
+ zip_uint64_t new_capacity = buffer->nfragments;
+ zip_uint64_t i;
+
+ if (new_capacity == 0) {
+ new_capacity = 4;
+ }
+ while (new_capacity < needed_fragments) {
+ new_capacity *= 2;
+ }
+
+ fragment = realloc(buffer->fragment, new_capacity * sizeof(*fragment));
+
+ if (fragment == NULL) {
+ zip_error_set(error, ZIP_ER_MEMORY, 0);
+ return -1;
+ }
+
+ for (i = buffer->nfragments; i < new_capacity; i++) {
+ fragment[i] = NULL;
+ }
+
+ buffer->fragment = fragment;
+ buffer->nfragments = new_capacity;
+ }
+
+ if (!only_nul(data, length)) {
+ zip_uint64_t idx, n, fragment_offset;
+
+ idx = buffer->offset / buffer->fragment_size;
+ fragment_offset = buffer->offset % buffer->fragment_size;
+ n = 0;
+
+ while (n < length) {
+ zip_uint64_t left = MY_MIN(length - n, buffer->fragment_size - fragment_offset);
+
+ if (buffer->fragment[idx] == NULL) {
+ if ((buffer->fragment[idx] = (zip_uint8_t *)malloc(buffer->fragment_size)) == NULL) {
+ zip_error_set(error, ZIP_ER_MEMORY, 0);
+ return -1;
+ }
+ memset(buffer->fragment[idx], 0, buffer->fragment_size);
+ }
+ memcpy(buffer->fragment[idx] + fragment_offset, data + n, left);
+
+ n += left;
+ idx++;
+ fragment_offset = 0;
+ }
+ }
+
+ buffer->offset += length;
+ if (buffer->offset > buffer->size) {
+ buffer->size = buffer->offset;
+ }
+
+ return (zip_int64_t)length;
+}
+
+
+static zip_uint64_t
+get_u64(const zip_uint8_t *b)
+{
+ zip_uint64_t i;
+
+ i = (zip_uint64_t)b[0] << 56 | (zip_uint64_t)b[1] << 48 | (zip_uint64_t)b[2] << 40 | (zip_uint64_t)b[3] << 32 | (zip_uint64_t)b[4] << 24 | (zip_uint64_t)b[5] << 16 | (zip_uint64_t)b[6] << 8 | (zip_uint64_t)b[7];
+
+ return i;
+}
+
+
+static int
+only_nul(const zip_uint8_t *data, zip_uint64_t length)
+{
+ zip_uint64_t i;
+
+ for (i=0; i< length; i++) {
+ if (data[i] != '\0') {
+ return 0;
+ }
+ }
+
+ return 1;
+}
+
+
+static int
+write_nuls(zip_uint64_t n, FILE *f)
+{
+ if (fwrite(MARK_NUL, 4, 1, f) != 1) {
+ return -1;
+ }
+ return write_u64(n, f);
+}
+
+
+static int
+write_u64(zip_uint64_t u64, FILE *f)
+{
+ zip_uint8_t b[8];
+
+ b[0] = (zip_uint8_t)((u64 >> 56) & 0xff);
+ b[1] = (zip_uint8_t)((u64 >> 48) & 0xff);
+ b[2] = (zip_uint8_t)((u64 >> 40) & 0xff);
+ b[3] = (zip_uint8_t)((u64 >> 32) & 0xff);
+ b[4] = (zip_uint8_t)((u64 >> 24) & 0xff);
+ b[5] = (zip_uint8_t)((u64 >> 16) & 0xff);
+ b[6] = (zip_uint8_t)((u64 >> 8) & 0xff);
+ b[7] = (zip_uint8_t)(u64 & 0xff);
+
+ return fwrite(b, 8, 1, f) == 1 ? 0 : -1;
+}
+
+
+static void
+hole_free(hole_t *hole) {
+ if (hole == NULL) {
+ return;
+ }
+ zip_error_fini(&hole->error);
+ buffer_free(hole->in);
+ buffer_free(hole->out);
+ free(hole->fname);
+ free(hole);
+}
+
+
+static hole_t *
+hole_new(const char *fname, int flags, zip_error_t *error)
+{
+ hole_t *ctx = (hole_t *)malloc(sizeof(*ctx));
+
+ if (ctx == NULL) {
+ zip_error_set(error, ZIP_ER_MEMORY, 0);
+ return NULL;
+ }
+
+ if ((ctx->fname = strdup(fname)) == NULL) {
+ free(ctx);
+ zip_error_set(error, ZIP_ER_MEMORY, 0);
+ return NULL;
+ }
+
+ if ((ctx->in = buffer_from_file(fname, flags, error)) == NULL) {
+ free(ctx);
+ return NULL;
+ }
+
+ zip_error_init(&ctx->error);
+ ctx->out = NULL;
+
+ return ctx;
+}
+
+
+static zip_int64_t
+source_hole_cb(void *ud, void *data, zip_uint64_t length, zip_source_cmd_t command)
+{
+ hole_t *ctx = (hole_t *)ud;
+
+ switch (command) {
+ case ZIP_SOURCE_BEGIN_WRITE:
+ ctx->out = buffer_new();
+ return 0;
+
+ case ZIP_SOURCE_CLOSE:
+ return 0;
+
+ case ZIP_SOURCE_COMMIT_WRITE:
+ if (buffer_to_file(ctx->out, ctx->fname, &ctx->error) < 0) {
+ return -1;
+ }
+ buffer_free(ctx->in);
+ ctx->in = ctx->out;
+ ctx->out = NULL;
+ return 0;
+
+ case ZIP_SOURCE_ERROR:
+ return zip_error_to_data(&ctx->error, data, length);
+
+ case ZIP_SOURCE_FREE:
+ hole_free(ctx);
+ return 0;
+
+ case ZIP_SOURCE_OPEN:
+ ctx->in->offset = 0;
+ return 0;
+
+ case ZIP_SOURCE_READ:
+ return buffer_read(ctx->in, data, length, &ctx->error);
+
+ case ZIP_SOURCE_REMOVE:
+ buffer_free(ctx->in);
+ ctx->in = buffer_new();
+ buffer_free(ctx->out);
+ ctx->out = NULL;
+ (void)remove(ctx->fname);
+ return 0;
+
+ case ZIP_SOURCE_ROLLBACK_WRITE:
+ buffer_free(ctx->out);
+ ctx->out = NULL;
+ return 0;
+
+ case ZIP_SOURCE_SEEK:
+ return buffer_seek(ctx->in, data, length, &ctx->error);
+
+ case ZIP_SOURCE_SEEK_WRITE:
+ return buffer_seek(ctx->out, data, length, &ctx->error);
+
+ case ZIP_SOURCE_STAT: {
+ zip_stat_t *st = ZIP_SOURCE_GET_ARGS(zip_stat_t, data, length, &ctx->error);
+
+ if (st == NULL) {
+ return -1;
+ }
+
+ /* TODO: return ENOENT if fname doesn't exist */
+
+ st->valid |= ZIP_STAT_SIZE;
+ st->size = ctx->in->size;
+ return 0;
+ }
+
+ case ZIP_SOURCE_TELL:
+ return (zip_int64_t)ctx->in->offset;
+
+ case ZIP_SOURCE_TELL_WRITE:
+ return (zip_int64_t)ctx->out->offset;
+
+ case ZIP_SOURCE_WRITE:
+ return buffer_write(ctx->out, data, length, &ctx->error);
+
+ case ZIP_SOURCE_SUPPORTS:
+ return zip_source_make_command_bitmap(ZIP_SOURCE_BEGIN_WRITE, ZIP_SOURCE_COMMIT_WRITE, ZIP_SOURCE_CLOSE, ZIP_SOURCE_ERROR, ZIP_SOURCE_FREE, ZIP_SOURCE_OPEN, ZIP_SOURCE_READ, ZIP_SOURCE_REMOVE, ZIP_SOURCE_ROLLBACK_WRITE, ZIP_SOURCE_SEEK, ZIP_SOURCE_SEEK_WRITE, ZIP_SOURCE_STAT, ZIP_SOURCE_TELL, ZIP_SOURCE_TELL_WRITE, ZIP_SOURCE_WRITE, -1);
+
+ default:
+ zip_error_set(&ctx->error, ZIP_ER_OPNOTSUPP, 0);
+ return -1;
+ }
+}
