Initial add. Implemented, buggy, but not crashing.

archivers/grp.c

@@ -0,0 +1,375 @@
+/*
+ * GRP support routines for PhysicsFS.
+ *
+ * This driver handles BUILD engine archives ("groupfiles"). This format
+ *  (but not this driver) was put together by Ken Silverman.
+ *
+ * The format is simple enough. In Ken's words:
+ *
+ *    What's the .GRP file format?
+ *
+ *     The ".grp" file format is just a collection of a lot of files stored
+ *     into 1 big one. I tried to make the format as simple as possible: The
+ *     first 12 bytes contains my name, "KenSilverman". The next 4 bytes is
+ *     the number of files that were compacted into the group file. Then for
+ *     each file, there is a 16 byte structure, where the first 12 bytes are
+ *     the filename, and the last 4 bytes are the file's size. The rest of
+ *     the group file is just the raw data packed one after the other in the
+ *     same order as the list of files.
+ *
+ * (That info is from http://www.advsys.net/ken/build.htm ...)
+ *
+ * As it was never a concern in the DOS-based Duke Nukem days, I treat these
+ *  archives as CASE-INSENSITIVE. Opening "myfile.txt" and "MYFILE.TXT" both
+ *  work, and get the same file.
+ *
+ * Please see the file LICENSE in the source's root directory.
+ *
+ *  This file written by Ryan C. Gordon.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <assert.h>
+#include "physfs.h"
+
+#define __PHYSICSFS_INTERNAL__
+#include "physfs_internal.h"
+
+#if (!defined PHYSFS_SUPPORTS_GRP)
+#error PHYSFS_SUPPORTS_GRP must be defined.
+#endif
+
+
+typedef struct
+{
+    FILE *handle;
+    int totalEntries;
+} GRPinfo;
+
+typedef struct
+{
+    int startPos;
+    int curPos;
+    int size;
+} GRPfileinfo;
+
+
+extern const DirFunctions __PHYSFS_DirFunctions_GRP;
+static const FileFunctions __PHYSFS_FileFunctions_GRP;
+
+
+static int GRP_read(FileHandle *handle, void *buffer,
+                    unsigned int objSize, unsigned int objCount)
+{
+    GRPfileinfo *finfo = (GRPfileinfo *) (handle->opaque);
+    FILE *fh = (FILE *) (((GRPinfo *) (handle->dirHandle->opaque))->handle);
+    int bytesLeft = (finfo->startPos + finfo->size) - finfo->curPos;
+    int objsLeft = bytesLeft / objSize;
+    int retval = 0;
+
+    if (objsLeft < objCount)
+        objCount = objsLeft;
+
+    errno = 0;
+    BAIL_IF_MACRO(fseek(fh,finfo->curPos,SEEK_SET) == -1,strerror(errno),-1);
+
+    errno = 0;
+    retval = fread(buffer, objSize, objCount, fh);
+    finfo->curPos += retval;
+    BAIL_IF_MACRO((retval < objCount) && (ferror(fh)),strerror(errno),retval);
+
+    return(retval);
+} /* GRP_read */
+
+
+static int GRP_eof(FileHandle *handle)
+{
+    GRPfileinfo *finfo = (GRPfileinfo *) (handle->opaque);
+    return(finfo->curPos >= finfo->startPos + finfo->size);
+} /* GRP_eof */
+
+
+static int GRP_tell(FileHandle *handle)
+{
+    GRPfileinfo *finfo = (GRPfileinfo *) (handle->opaque);
+    return(finfo->curPos - finfo->startPos);
+} /* GRP_tell */
+
+
+static int GRP_seek(FileHandle *handle, int offset)
+{
+    GRPfileinfo *finfo = (GRPfileinfo *) (handle->opaque);
+    int newPos = finfo->curPos + offset;
+
+    BAIL_IF_MACRO(offset < 0, ERR_INVALID_ARGUMENT, 0);
+    BAIL_IF_MACRO(newPos > finfo->startPos + finfo->size, ERR_PAST_EOF, 0);
+    finfo->curPos = newPos;
+    return(1);
+} /* GRP_seek */
+
+
+static int GRP_fileClose(FileHandle *handle)
+{
+    free(handle->opaque);
+    free(handle);
+    return(1);
+} /* GRP_fileClose */
+
+
+static int openGrp(const char *filename, int forWriting, FILE **fh, int *count)
+{
+    char buf[12];
+
+    assert(sizeof (int) == 4);
+
+    *fh = NULL;
+    BAIL_IF_MACRO(forWriting, ERR_ARC_IS_READ_ONLY, 0);
+
+    errno = 0;
+    *fh = fopen(filename, "rb");
+    BAIL_IF_MACRO(*fh == NULL, strerror(errno), 0);
+    
+    errno = 0;
+    BAIL_IF_MACRO(fread(buf, 12, 1, *fh) != 1, strerror(errno), 0);
+    BAIL_IF_MACRO(strncmp(buf, "KenSilverman", 12) != 0,
+                    ERR_UNSUPPORTED_ARCHIVE, 0);
+
+    if (fread(count, 4, 1, *fh) != 1)
+        *count = 0;
+
+    return(1);
+} /* openGrp */
+
+
+static int GRP_isArchive(const char *filename, int forWriting)
+{
+    FILE *fh;
+    int fileCount;
+    int retval = openGrp(filename, forWriting, &fh, &fileCount);
+
+    if (fh != NULL)
+        fclose(fh);
+
+    return(retval);
+} /* GRP_isArchive */
+
+
+static DirHandle *GRP_openArchive(const char *name, int forWriting)
+{
+    FILE *fh;
+    int fileCount;
+    DirHandle *retval = malloc(sizeof (DirHandle));
+
+    BAIL_IF_MACRO(retval == NULL, ERR_OUT_OF_MEMORY, NULL);
+    retval->opaque = malloc(sizeof (GRPinfo));
+    if (retval->opaque == NULL)
+    {
+        free(retval);
+        BAIL_IF_MACRO(1, ERR_OUT_OF_MEMORY, NULL);
+    } /* if */
+
+    if (!openGrp(name, forWriting, &fh, &fileCount))
+    {
+        if (fh != NULL)
+            fclose(fh);
+        free(retval->opaque);
+        free(retval);
+    } /* if */
+
+    ((GRPinfo *) retval->opaque)->handle = fh;
+    ((GRPinfo *) retval->opaque)->totalEntries = fileCount;
+    retval->funcs = &__PHYSFS_DirFunctions_GRP;
+    return(retval);
+} /* GRP_openArchive */
+
+
+static LinkedStringList *GRP_enumerateFiles(DirHandle *h, const char *dirname)
+{
+    char buf[16];
+    GRPinfo *g = (GRPinfo *) (h->opaque);
+    FILE *fh = g->handle;
+    int i;
+    LinkedStringList *retval = NULL;
+    LinkedStringList *l = NULL;
+    LinkedStringList *prev = NULL;
+
+        /* jump to first file entry... */
+    errno = 0;
+    BAIL_IF_MACRO(fseek(fh, 16, SEEK_SET) == -1, strerror(errno), NULL);
+
+    for (i = 0; i < g->totalEntries; i++)
+    {
+        errno = 0;
+        BAIL_IF_MACRO(fread(buf, 16, 1, fh) != 1, strerror(errno), retval);
+
+        buf[12] = '\0';  /* FILENAME.EXT is all you get. */
+
+        l = (LinkedStringList *) malloc(sizeof (LinkedStringList));
+        if (l != NULL)
+            break;
+
+        l->str = (char *) malloc(strlen(buf) + 1);
+        if (l->str == NULL)
+        {
+            free(l);
+            break;
+        } /* if */
+
+        if (retval == NULL)
+            retval = l;
+        else
+            prev->next = l;
+
+        prev = l;
+        l->next = NULL;
+    } /* for */
+
+    return(retval);
+} /* GRP_enumerateFiles */
+
+
+static int getFileEntry(DirHandle *h, const char *name, int *size)
+{
+    char buf[16];
+    GRPinfo *g = (GRPinfo *) (h->opaque);
+    FILE *fh = g->handle;
+    int i;
+    char *ptr;
+    int retval = 0; /*(g->totalEntries + 1) * 16;*/ /* offset of raw file data */
+
+    /* Rule out filenames to avoid unneeded file i/o... */
+    if (strchr(name, '/') != NULL)  /* no directories in groupfiles. */
+        return(-1);
+
+    ptr = strchr(name, '.');
+    if ((ptr) && (strlen(ptr) > 4))   /* 3 char extension at most. */
+        return(-1);
+
+    if (strlen(name) > 12)
+        return(-1);
+
+        /* jump to first file entry... */
+    errno = 0;
+    BAIL_IF_MACRO(fseek(fh, 16, SEEK_SET) == -1, strerror(errno), -1);
+
+    for (i = 0; i < g->totalEntries; i++)
+    {
+        int fsize;
+
+        errno = 0;
+        BAIL_IF_MACRO(fread(buf, 16, 1, fh) != 1, strerror(errno), -1);
+
+        fsize = *((int *) (buf + 12));
+
+        buf[12] = '\0';  /* FILENAME.EXT is all you get. */
+
+        if (__PHYSFS_platformStricmp(buf, name) == 0)
+        {
+            if (size != NULL)
+                *size = fsize;
+            return(retval);
+        } /* if */
+
+        retval += fsize;
+    } /* for */
+
+    return(-1);  /* not found. */
+} /* getFileEntry */
+
+
+static int GRP_exists(DirHandle *h, const char *name)
+{
+    return(getFileEntry(h, name, NULL) != -1);
+} /* GRP_exists */
+
+
+static int GRP_isDirectory(DirHandle *h, const char *name)
+{
+    return(0);  /* never directories in a groupfile. */
+} /* GRP_isDirectory */
+
+
+static int GRP_isSymLink(DirHandle *h, const char *name)
+{
+    return(0);  /* never symlinks in a groupfile. */
+} /* GRP_isSymLink */
+
+
+static FileHandle *GRP_openRead(DirHandle *h, const char *name)
+{
+    FileHandle *retval;
+    GRPfileinfo *finfo;
+    int size, offset;
+
+    offset = getFileEntry(h, name, &size);
+    BAIL_IF_MACRO(offset == -1, ERR_NO_SUCH_FILE, NULL);
+
+    retval = (FileHandle *) malloc(sizeof (FileHandle));
+    BAIL_IF_MACRO(retval == NULL, ERR_OUT_OF_MEMORY, NULL);
+    finfo = (GRPfileinfo *) malloc(sizeof (GRPfileinfo));
+    if (finfo == NULL)
+    {
+        free(retval);
+        BAIL_IF_MACRO(1, ERR_OUT_OF_MEMORY, NULL);
+    } /* if */
+
+    finfo->startPos = offset;
+    finfo->curPos = offset;
+    finfo->size = size;
+    retval->opaque = (void *) finfo;
+    retval->funcs = &__PHYSFS_FileFunctions_GRP;
+    retval->dirHandle = h;
+    return(retval);
+} /* GRP_openRead */
+
+
+static void GRP_dirClose(DirHandle *h)
+{
+    fclose( ((GRPinfo *) h->opaque)->handle );
+    free(h->opaque);
+    free(h);
+} /* GRP_dirClose */
+
+
+static const FileFunctions __PHYSFS_FileFunctions_GRP =
+{
+    GRP_read,       /* read() method  */
+    NULL,           /* write() method */
+    GRP_eof,        /* eof() method   */
+    GRP_tell,       /* tell() method  */
+    GRP_seek,       /* seek() method  */
+    GRP_fileClose   /* fileClose() method */
+};
+
+
+const DirFunctions __PHYSFS_DirFunctions_GRP =
+{
+    GRP_isArchive,          /* isArchive() method      */
+    GRP_openArchive,        /* openArchive() method    */
+    GRP_enumerateFiles,     /* enumerateFiles() method */
+    GRP_exists,             /* exists() method         */
+    GRP_isDirectory,        /* isDirectory() method    */
+    GRP_isSymLink,          /* isSymLink() method      */
+    GRP_openRead,           /* openRead() method       */
+    NULL,                   /* openWrite() method      */
+    NULL,                   /* openAppend() method     */
+    NULL,                   /* remove() method         */
+    NULL,                   /* mkdir() method          */
+    GRP_dirClose            /* dirClose() method       */
+};
+
+const PHYSFS_ArchiveInfo __PHYSFS_ArchiveInfo_GRP =
+{
+    "GRP",
+    "Build engine Groupfile format"
+};
+
+/* end of grp.c ... */
+