--- /dev/null
+/*
+ * Copyright (C) 2013
+ * Dale Weiler
+ *
+ * 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 <sys/stat.h>
+#include <dirent.h>
+#include "gmqcc.h"
+
+typedef struct {
+ uint32_t magic; /* "PACK" */
+
+ /*
+ * Offset to first directory entry in PAK file. It's often
+ * best to store the directories at the end of the file opposed
+ * to the front, since it allows easy insertion without having
+ * to load the entire file into memory again.
+ */
+ uint32_t diroff;
+ uint32_t dirlen;
+} pak_header_t;
+
+/*
+ * A directory, is sort of a "file entry". The concept of
+ * a directory in Quake world is a "file entry/record". This
+ * describes a file (with directories/nested ones too in it's
+ * file name). Hence it can be a file, file with directory, or
+ * file with directories.
+ */
+typedef struct {
+ char name[56];
+ uint32_t pos;
+ uint32_t len;
+} pak_directory_t;
+
+/*
+ * Used to get the next token from a string, where the
+ * strings themselfs are seperated by chracters from
+ * `sep`. This is essentially strsep.
+ */
+static char *pak_tree_sep(char **str, const char *sep) {
+ char *beg = *str;
+ char *end;
+
+ if (!beg)
+ return NULL;
+
+ if (*(end = beg + strcspn(beg, sep)))
+ * end++ = '\0'; /* null terminate */
+ else
+ end = 0;
+
+ *str = end;
+ return beg;
+}
+
+/*
+ * Used to spawn a directory when creating the pak directory structure/
+ * tree. Think of this as mkdir(path, 0700). We just cargo cult our
+ * own because _mkdir on windows is "illegal" for Windows8 Certification
+ * do to the requirement of SECURITY_ATTRIBUTES on everything.
+ */
+static bool pak_tree_spawn(const char *path) {
+#ifdef _MSC_VER
+ return CreateDirectoryA(path, NULL); /* non-zero on success */
+#else
+ return !!(mkdir(path, 0700)); /* zero on success */
+#endif
+}
+
+/*
+ * When given a string like "a/b/c/d/e/file"
+ * this function will handle the creation of
+ * the directory structure, included nested
+ * directories.
+ */
+static void pak_tree_build(const char *entry) {
+ char *directory;
+ char *elements[28];
+ char *pathsplit;
+
+ size_t itr;
+ size_t jtr;
+
+ pathsplit = mem_a(56);
+ directory = mem_a(56);
+
+ strncpy(directory, entry, 56);
+ for (itr = 0; (elements[itr] = pak_tree_sep(&directory, "/")); itr++);
+ for (jtr = 0; jtr < itr - 1; jtr++) {
+ strcat(pathsplit, elements[jtr]);
+ strcat(pathsplit, "/");
+
+ pak_tree_spawn(pathsplit);
+ }
+
+ mem_d(pathsplit);
+ mem_d(directory);
+}
+
+typedef struct {
+ pak_directory_t *directories;
+ pak_header_t header;
+ FILE *handle;
+ bool insert;
+} pak_file_t;
+
+pak_file_t *pak_open_read(const char *file) {
+ pak_file_t *pak;
+ size_t itr;
+
+ if (!(pak = mem_a(sizeof(pak_file_t))))
+ return NULL;
+
+ if (!(pak->handle = file_open(file, "rb"))) {
+ mem_d(pak);
+ return NULL;
+ }
+
+ pak->directories = NULL;
+ pak->insert = false; /* read doesn't allow insert */
+
+ memset (&(pak->header), 0, sizeof(pak_header_t));
+ file_read (&(pak->header), 1, sizeof(pak_header_t), pak->handle);
+ util_endianswap(&(pak->header), 1, sizeof(pak_header_t));
+
+ /*
+ * Every PAK file has "PACK" stored as little endian data in the
+ * header. If this data cannot compare (as checked here), it's
+ * probably not a PAK file.
+ */
+ if (!(memcmp(&(pak->header.magic), (const void*)"PACK", sizeof(uint32_t)))) {
+ file_close(pak->handle);
+ mem_d (pak);
+ return NULL;
+ }
+
+ /*
+ * Time to read in the directory handles and prepare the directories
+ * vector. We're going to be reading some the file inwards soon.
+ */
+ file_seek(pak->handle, pak->header.diroff, SEEK_SET);
+
+ /*
+ * Read in all directories from the PAK file. These are considered
+ * to be the "file entries".
+ */
+ for (itr = 0; itr < pak->header.dirlen / 64; itr++) {
+ pak_directory_t dir;
+ file_read (&dir, 1, sizeof(pak_directory_t), pak->handle);
+ util_endianswap(&dir, 1, sizeof(pak_directory_t));
+
+ vec_push(pak->directories, dir);
+ }
+ return pak;
+}
+
+pak_file_t *pak_open_write(const char *file) {
+ pak_file_t *pak;
+
+ if (!(pak = mem_a(sizeof(pak_file_t))))
+ return NULL;
+
+ /*
+ * Generate the required directory structure / tree for
+ * writing this PAK file too.
+ */
+ pak_tree_build(file);
+
+ if (!(pak->handle = file_open(file, "wb"))) {
+ /*
+ * The directory tree that was created, needs to be
+ * removed entierly if we failed to open a file.
+ */
+ /* TODO backup directory clean */
+
+ return NULL;
+ }
+
+ memset(&(pak->header), 0, sizeof(pak_header_t));
+
+ /*
+ * We're in "insert" mode, we need to do things like header
+ * "patching" and writing the directories at the end of the
+ * file.
+ */
+ pak->insert = true;
+
+ /*
+ * A valid PAK file contains the magic "PACK" in it's header
+ * stored in little endian format.
+ */
+ memcpy(&(pak->header.magic), (const void*)"PACK", sizeof(uint32_t));
+
+ /*
+ * We need to write out the header since files will be wrote out to
+ * this even with directory entries, and that not wrote. The header
+ * will need to be patched in later with a file_seek, and overwrite,
+ * we could use offsets and other trickery. This is just easier.
+ */
+ file_write(&(pak->header), sizeof(pak_header_t), 1, pak->handle);
+
+ return pak;
+}
+
+bool pak_exists(pak_file_t *pak, const char *file, pak_directory_t **dir) {
+ size_t itr;
+
+ if (!pak || !file)
+ return false;
+
+ /*
+ * We could technically use a hashtable here. But I don't think
+ * the lookup complexity is a performance concern. This may be
+ * O(n) lookup. But meh?
+ */
+ for (itr = 0; itr < vec_size(pak->directories); itr++) {
+ if (!strcmp(pak->directories[itr].name, file)) {
+ /*
+ * Store back a pointer to the directory that matches
+ * the request if requested (NULL is not allowed).
+ */
+ if (dir) {
+ *dir = &(pak->directories[itr]);
+ }
+ return true;
+ }
+ }
+
+ return false;
+}
+
+/*
+ * Extraction abilities. These work as you expect them to.
+ */
+bool pak_extract_one(pak_file_t *pak, const char *file) {
+ pak_directory_t *dir = NULL;
+ unsigned char *dat = NULL;
+ FILE *out;
+
+ if (!pak_exists(pak, file, &dir)) {
+ return false;
+ }
+
+ if (!(dat = (unsigned char *)mem_a(dir->len))) {
+ return false;
+ }
+
+ /*
+ * Generate the directory structure / tree that will be required
+ * to store the extracted file.
+ */
+ pak_tree_build(file);
+
+ /*
+ * Now create the file, if this operation fails. Then abort
+ * It shouldn't fail though.
+ */
+ if (!(out = file_open(file, "wb"))) {
+ mem_d(dat);
+ return false;
+ }
+
+
+ /* read */
+ file_seek (pak->handle, dir->pos, SEEK_SET);
+ file_read (dat, 1, dir->len, pak->handle);
+
+ /* write */
+ file_write(dat, 1, dir->len, out);
+
+ /* close */
+ file_close(out);
+
+ /* free */
+ mem_d(dat);
+
+ return true;
+}
+
+bool pak_extract_all(pak_file_t *pak) {
+ size_t itr;
+ for (itr = 0; itr < vec_size(pak->directories); itr++) {
+ if (!pak_extract_one(pak, pak->directories[itr].name))
+ return false;
+ }
+
+ return true;
+}
+
+/*
+ * Insertion functions (the opposite of extraction). Yes for generating
+ * PAKs.
+ */
+bool pak_insert_one(pak_file_t *pak, const char *file) {
+ pak_directory_t dir;
+ unsigned char *dat;
+ FILE *fp;
+
+ /*
+ * We don't allow insertion on files that already exist within the
+ * pak file. Weird shit can happen if we allow that ;). We also
+ * don't allow insertion if the pak isn't opened in write mode.
+ */
+ if (!pak || !file || !pak->insert || pak_exists(pak, file, NULL))
+ return false;
+
+ if (!(fp = fopen(file, "rb")))
+ return false;
+
+ /*
+ * Calculate the total file length, since it will be wrote to
+ * the directory entry, and the actual contents of the file
+ * to the PAK file itself.
+ */
+ file_seek(fp, 0, SEEK_END);
+ dir.len = ftell(fp);
+ file_seek(fp, 0, SEEK_SET);
+
+ dir.pos = ftell(pak->handle);
+
+ /*
+ * Allocate some memory for loading in the data that will be
+ * redirected into the PAK file.
+ */
+ if (!(dat = (unsigned char *)mem_a(dir.len))) {
+ file_close(fp);
+ return false;
+ }
+
+ file_read (dat, dir.len, 1, fp);
+ file_close(fp);
+ file_write(dat, dir.len, 1, pak->handle);
+
+ return true;
+}
+
+/*
+ * Like pak_insert_one, except this collects files in all directories
+ * from a root directory, and inserts them all.
+ */
+bool pak_insert_all(pak_file_t *pak, const char *dir) {
+ DIR *dp;
+ struct dirent *dirp;
+
+ if (!(pak->insert))
+ return false;
+
+ if (!(dp = opendir(dir)))
+ return false;
+
+ while ((dirp = readdir(dp))) {
+ if (!(pak_insert_one(pak, dirp->d_name))) {
+ closedir(dp);
+ return false;
+ }
+ }
+
+ closedir(dp);
+ return true;
+}
+
+bool pak_close(pak_file_t *pak) {
+ size_t itr;
+
+ if (!pak)
+ return false;
+
+ /*
+ * In insert mode we need to patch the header, and write
+ * our directory entries at the end of the file.
+ */
+ if (pak->insert) {
+ pak->header.dirlen = vec_size(pak->directories) * 64;
+ pak->header.diroff = ftell(pak->handle);
+
+ /* patch header */
+ file_seek (pak->handle, 0, SEEK_SET);
+ file_write(&(pak->header), sizeof(pak_header_t), 1, pak->handle);
+
+ /* write directories */
+ file_seek (pak->handle, pak->header.diroff, SEEK_SET);
+
+ for (itr = 0; itr < vec_size(pak->directories); itr++) {
+ file_write(&(pak->directories[itr]), sizeof(pak_directory_t), 1, pak->handle);
+ }
+ }
+
+ vec_free (pak->directories);
+ file_close(pak->handle);
+ mem_d (pak);
+
+ return true;
+}