/****************************************************************************/

/*

 *  QEMU bFLT binary loader.  Based on linux/fs/binfmt_flat.c

 *

 *  This program is free software; you can redistribute it and/or modify

 *  it under the terms of the GNU General Public License as published by

 *  the Free Software Foundation; either version 2 of the License, or

 *  (at your option) any later version.

 *

 *  This program is distributed in the hope that it will be useful,

 *  but WITHOUT ANY WARRANTY; without even the implied warranty of

 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 *  GNU General Public License for more details.

 *

 *  You should have received a copy of the GNU General Public License

 *  along with this program; if not, write to the Free Software

 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

 *

 *      Copyright (C) 2006 CodeSourcery.

 *	Copyright (C) 2000-2003 David McCullough <davidm@snapgear.com>

 *	Copyright (C) 2002 Greg Ungerer <gerg@snapgear.com>

 *	Copyright (C) 2002 SnapGear, by Paul Dale <pauli@snapgear.com>

 *	Copyright (C) 2000, 2001 Lineo, by David McCullough <davidm@lineo.com>

 *  based heavily on:

 *

 *  linux/fs/binfmt_aout.c:

 *      Copyright (C) 1991, 1992, 1996  Linus Torvalds

 *  linux/fs/binfmt_flat.c for 2.0 kernel

 *	    Copyright (C) 1998  Kenneth Albanowski <kjahds@kjahds.com>

 *	JAN/99 -- coded full program relocation (gerg@snapgear.com)

 */

/* ??? ZFLAT and shared library support is currently disabled.  */

/****************************************************************************/

#include <stdio.h>

#include <stdlib.h>

#include <errno.h>

#include <sys/mman.h>

#include <unistd.h>

#include "qemu.h"

#include "flat.h"

//#define DEBUG

#ifdef DEBUG

#define	DBG_FLT(a...)	printf(a)

#else

#define	DBG_FLT(a...)

#endif

#define flat_reloc_valid(reloc, size)             ((reloc) <= (size))

#define flat_old_ram_flag(flag)                   (flag)

#ifdef TARGET_WORDS_BIGENDIAN

#define flat_get_relocate_addr(relval)            (relval)

#else

#define flat_get_relocate_addr(relval)            bswap32(relval)

#endif

#define RELOC_FAILED 0xff00ff01		/* Relocation incorrect somewhere */

#define UNLOADED_LIB 0x7ff000ff		/* Placeholder for unused library */

struct lib_info {

    abi_ulong start_code;       /* Start of text segment */

    abi_ulong start_data;       /* Start of data segment */

    abi_ulong end_data;         /* Start of bss section */

    abi_ulong start_brk;        /* End of data segment */

    abi_ulong text_len;	        /* Length of text segment */

    abi_ulong entry;	        /* Start address for this module */

    abi_ulong build_date;       /* When this one was compiled */

    short loaded;		/* Has this library been loaded? */

};

#ifdef CONFIG_BINFMT_SHARED_FLAT

static int load_flat_shared_library(int id, struct lib_info *p);

#endif

struct linux_binprm;

#define ntohl(x) be32_to_cpu(x)

/****************************************************************************/

/*

 * create_flat_tables() parses the env- and arg-strings in new user

 * memory and creates the pointer tables from them, and puts their

 * addresses on the "stack", returning the new stack pointer value.

 */

/* Push a block of strings onto the guest stack.  */

static abi_ulong copy_strings(abi_ulong p, int n, char **s)

{

    int len;

    while (n-- > 0) {

        len = strlen(s[n]) + 1;

        p -= len;

        memcpy_to_target(p, s[n], len);

    }

    return p;

}

static int target_pread(int fd, abi_ulong ptr, abi_ulong len,

                        abi_ulong offset)

{

    void *buf;

    int ret;

    buf = lock_user(VERIFY_WRITE, ptr, len, 0);

    ret = pread(fd, buf, len, offset);

    unlock_user(buf, ptr, len);

    return ret;

}

/****************************************************************************/

#ifdef CONFIG_BINFMT_ZFLAT

#include <linux/zlib.h>

#define LBUFSIZE	4000

/* gzip flag byte */

#define ASCII_FLAG   0x01 /* bit 0 set: file probably ASCII text */

#define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */

#define EXTRA_FIELD  0x04 /* bit 2 set: extra field present */

#define ORIG_NAME    0x08 /* bit 3 set: original file name present */

#define COMMENT      0x10 /* bit 4 set: file comment present */

#define ENCRYPTED    0x20 /* bit 5 set: file is encrypted */

#define RESERVED     0xC0 /* bit 6,7:   reserved */

static int decompress_exec(

	struct linux_binprm *bprm,

	unsigned long offset,

	char *dst,

	long len,

	int fd)

{

	unsigned char *buf;

	z_stream strm;

	loff_t fpos;

	int ret, retval;

	DBG_FLT("decompress_exec(offset=%x,buf=%x,len=%x)\n",(int)offset, (int)dst, (int)len);

	memset(&strm, 0, sizeof(strm));

	strm.workspace = kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL);

	if (strm.workspace == NULL) {

		DBG_FLT("binfmt_flat: no memory for decompress workspace\n");

		return -ENOMEM;

	}

	buf = kmalloc(LBUFSIZE, GFP_KERNEL);

	if (buf == NULL) {

		DBG_FLT("binfmt_flat: no memory for read buffer\n");

		retval = -ENOMEM;

		goto out_free;

	}

	/* Read in first chunk of data and parse gzip header. */

	fpos = offset;

	ret = bprm->file->f_op->read(bprm->file, buf, LBUFSIZE, &fpos);

	strm.next_in = buf;

	strm.avail_in = ret;

	strm.total_in = 0;

	retval = -ENOEXEC;

	/* Check minimum size -- gzip header */

	if (ret < 10) {

		DBG_FLT("binfmt_flat: file too small?\n");

		goto out_free_buf;

	}

	/* Check gzip magic number */

	if ((buf[0] != 037) || ((buf[1] != 0213) && (buf[1] != 0236))) {

		DBG_FLT("binfmt_flat: unknown compression magic?\n");

		goto out_free_buf;

	}

	/* Check gzip method */

	if (buf[2] != 8) {

		DBG_FLT("binfmt_flat: unknown compression method?\n");

		goto out_free_buf;

	}

	/* Check gzip flags */

	if ((buf[3] & ENCRYPTED) || (buf[3] & CONTINUATION) ||

	    (buf[3] & RESERVED)) {

		DBG_FLT("binfmt_flat: unknown flags?\n");

		goto out_free_buf;

	}

	ret = 10;

	if (buf[3] & EXTRA_FIELD) {

		ret += 2 + buf[10] + (buf[11] << 8);

		if (unlikely(LBUFSIZE == ret)) {

			DBG_FLT("binfmt_flat: buffer overflow (EXTRA)?\n");

			goto out_free_buf;

		}

	}

	if (buf[3] & ORIG_NAME) {

		for (; ret < LBUFSIZE && (buf[ret] != 0); ret++)

			;

		if (unlikely(LBUFSIZE == ret)) {

			DBG_FLT("binfmt_flat: buffer overflow (ORIG_NAME)?\n");

			goto out_free_buf;

		}

	}

	if (buf[3] & COMMENT) {

		for (;  ret < LBUFSIZE && (buf[ret] != 0); ret++)

			;

		if (unlikely(LBUFSIZE == ret)) {

			DBG_FLT("binfmt_flat: buffer overflow (COMMENT)?\n");

			goto out_free_buf;

		}

	}

	strm.next_in += ret;

	strm.avail_in -= ret;

	strm.next_out = dst;

	strm.avail_out = len;

	strm.total_out = 0;

	if (zlib_inflateInit2(&strm, -MAX_WBITS) != Z_OK) {

		DBG_FLT("binfmt_flat: zlib init failed?\n");

		goto out_free_buf;

	}

	while ((ret = zlib_inflate(&strm, Z_NO_FLUSH)) == Z_OK) {

		ret = bprm->file->f_op->read(bprm->file, buf, LBUFSIZE, &fpos);

		if (ret <= 0)

			break;

		if (ret >= (unsigned long) -4096)

			break;

		len -= ret;

		strm.next_in = buf;

		strm.avail_in = ret;

		strm.total_in = 0;

	}

	if (ret < 0) {

		DBG_FLT("binfmt_flat: decompression failed (%d), %s\n",

			ret, strm.msg);

		goto out_zlib;

	}

	retval = 0;

out_zlib:

	zlib_inflateEnd(&strm);

out_free_buf:

	kfree(buf);

out_free:

	kfree(strm.workspace);

out:

	return retval;

}

#endif /* CONFIG_BINFMT_ZFLAT */

/****************************************************************************/

static abi_ulong

calc_reloc(abi_ulong r, struct lib_info *p, int curid, int internalp)

{

    abi_ulong addr;

    int id;

    abi_ulong start_brk;

    abi_ulong start_data;

    abi_ulong text_len;

    abi_ulong start_code;

#ifdef CONFIG_BINFMT_SHARED_FLAT

#error needs checking

    if (r == 0)

        id = curid;	/* Relocs of 0 are always self referring */

    else {

        id = (r >> 24) & 0xff;	/* Find ID for this reloc */

        r &= 0x00ffffff;	/* Trim ID off here */

    }

    if (id >= MAX_SHARED_LIBS) {

        fprintf(stderr, "BINFMT_FLAT: reference 0x%x to shared library %d\n",

                (unsigned) r, id);

        goto failed;

    }

    if (curid != id) {

        if (internalp) {

            fprintf(stderr, "BINFMT_FLAT: reloc address 0x%x not "

                    "in same module (%d != %d)\n",

                    (unsigned) r, curid, id);

            goto failed;

        } else if ( ! p[id].loaded &&

                    load_flat_shared_library(id, p) > (unsigned long) -4096) {

            fprintf(stderr, "BINFMT_FLAT: failed to load library %d\n", id);

            goto failed;

        }

        /* Check versioning information (i.e. time stamps) */

        if (p[id].build_date && p[curid].build_date

            && p[curid].build_date < p[id].build_date) {

            fprintf(stderr, "BINFMT_FLAT: library %d is younger than %d\n",

                    id, curid);

            goto failed;

        }

    }

#else

    id = 0;

#endif

    start_brk = p[id].start_brk;

    start_data = p[id].start_data;

    start_code = p[id].start_code;

    text_len = p[id].text_len;

    if (!flat_reloc_valid(r, start_brk - start_data + text_len)) {

        fprintf(stderr, "BINFMT_FLAT: reloc outside program 0x%x "

                "(0 - 0x%x/0x%x)\n",

               (int) r,(int)(start_brk-start_code),(int)text_len);

        goto failed;

    }

    if (r < text_len)			/* In text segment */

        addr = r + start_code;

    else					/* In data segment */

        addr = r - text_len + start_data;

    /* Range checked already above so doing the range tests is redundant...*/

    return(addr);

failed:

    abort();

    return RELOC_FAILED;

}

/****************************************************************************/

/* ??? This does not handle endianness correctly.  */

static void old_reloc(struct lib_info *libinfo, uint32_t rl)

{

#ifdef DEBUG

	char *segment[] = { "TEXT", "DATA", "BSS", "*UNKNOWN*" };

#endif

	uint32_t *ptr;

        uint32_t offset;

        int reloc_type;

        offset = rl & 0x3fffffff;

        reloc_type = rl >> 30;

        /* ??? How to handle this?  */

#if defined(CONFIG_COLDFIRE)

	ptr = (uint32_t *) ((unsigned long) libinfo->start_code + offset);

#else

	ptr = (uint32_t *) ((unsigned long) libinfo->start_data + offset);

#endif

#ifdef DEBUG

	fprintf(stderr, "Relocation of variable at DATASEG+%x "

		"(address %p, currently %x) into segment %s\n",

		offset, ptr, (int)*ptr, segment[reloc_type]);

#endif

	switch (reloc_type) {

	case OLD_FLAT_RELOC_TYPE_TEXT:

		*ptr += libinfo->start_code;

		break;

	case OLD_FLAT_RELOC_TYPE_DATA:

		*ptr += libinfo->start_data;

		break;

	case OLD_FLAT_RELOC_TYPE_BSS:

		*ptr += libinfo->end_data;

		break;

	default:

		fprintf(stderr, "BINFMT_FLAT: Unknown relocation type=%x\n",

                        reloc_type);

		break;

	}

	DBG_FLT("Relocation became %x\n", (int)*ptr);

}

/****************************************************************************/

static int load_flat_file(struct linux_binprm * bprm,

		struct lib_info *libinfo, int id, abi_ulong *extra_stack)

{

    struct flat_hdr * hdr;

    abi_ulong textpos = 0, datapos = 0, result;

    abi_ulong realdatastart = 0;

    abi_ulong text_len, data_len, bss_len, stack_len, flags;

    abi_ulong memp = 0; /* for finding the brk area */

    abi_ulong extra;

    abi_ulong reloc = 0, rp;

    int i, rev, relocs = 0;

    abi_ulong fpos;

    abi_ulong start_code, end_code;

    abi_ulong indx_len;

    hdr = ((struct flat_hdr *) bprm->buf);		/* exec-header */

    text_len  = ntohl(hdr->data_start);

    data_len  = ntohl(hdr->data_end) - ntohl(hdr->data_start);

    bss_len   = ntohl(hdr->bss_end) - ntohl(hdr->data_end);

    stack_len = ntohl(hdr->stack_size);

    if (extra_stack) {

        stack_len += *extra_stack;

        *extra_stack = stack_len;

    }

    relocs    = ntohl(hdr->reloc_count);

    flags     = ntohl(hdr->flags);

    rev       = ntohl(hdr->rev);

    DBG_FLT("BINFMT_FLAT: Loading file: %s\n", bprm->filename);

    if (rev != FLAT_VERSION && rev != OLD_FLAT_VERSION) {

        fprintf(stderr, "BINFMT_FLAT: bad magic/rev (0x%x, need 0x%x)\n",

                rev, (int) FLAT_VERSION);

        return -ENOEXEC;

    }

    /* Don't allow old format executables to use shared libraries */

    if (rev == OLD_FLAT_VERSION && id != 0) {

        fprintf(stderr, "BINFMT_FLAT: shared libraries are not available\n");

        return -ENOEXEC;

    }

    /*

     * fix up the flags for the older format,  there were all kinds

     * of endian hacks,  this only works for the simple cases

     */

    if (rev == OLD_FLAT_VERSION && flat_old_ram_flag(flags))

        flags = FLAT_FLAG_RAM;

#ifndef CONFIG_BINFMT_ZFLAT

    if (flags & (FLAT_FLAG_GZIP|FLAT_FLAG_GZDATA)) {

        fprintf(stderr, "Support for ZFLAT executables is not enabled\n");

        return -ENOEXEC;

    }

#endif

    /*

     * calculate the extra space we need to map in

     */

    extra = relocs * sizeof(abi_ulong);

    if (extra < bss_len + stack_len)

        extra = bss_len + stack_len;

    /* Add space for library base pointers.  Make sure this does not

       misalign the  doesn't misalign the data segment.  */

    indx_len = MAX_SHARED_LIBS * sizeof(abi_ulong);

    indx_len = (indx_len + 15) & ~(abi_ulong)15;

    /*

     * there are a couple of cases here,  the separate code/data

     * case,  and then the fully copied to RAM case which lumps

     * it all together.

     */

    if ((flags & (FLAT_FLAG_RAM|FLAT_FLAG_GZIP)) == 0) {

        /*

         * this should give us a ROM ptr,  but if it doesn't we don't

         * really care

         */

        DBG_FLT("BINFMT_FLAT: ROM mapping of file (we hope)\n");

        textpos = target_mmap(0, text_len, PROT_READ|PROT_EXEC,

                              MAP_PRIVATE, bprm->fd, 0);

        if (textpos == -1) {

            fprintf(stderr, "Unable to mmap process text\n");

            return -1;

        }

        realdatastart = target_mmap(0, data_len + extra + indx_len,

                                    PROT_READ|PROT_WRITE|PROT_EXEC,

                                    MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);

        if (realdatastart == -1) {

            fprintf(stderr, "Unable to allocate RAM for process data\n");

            return realdatastart;

        }

        datapos = realdatastart + indx_len;

        DBG_FLT("BINFMT_FLAT: Allocated data+bss+stack (%d bytes): %x\n",

                        (int)(data_len + bss_len + stack_len), (int)datapos);

        fpos = ntohl(hdr->data_start);

#ifdef CONFIG_BINFMT_ZFLAT

        if (flags & FLAT_FLAG_GZDATA) {

            result = decompress_exec(bprm, fpos, (char *) datapos,

                                     data_len + (relocs * sizeof(abi_ulong)))

        } else

#endif

        {

            result = target_pread(bprm->fd, datapos,

                                  data_len + (relocs * sizeof(abi_ulong)),

                                  fpos);

        }

        if (result < 0) {

            fprintf(stderr, "Unable to read data+bss\n");

            return result;

        }

        reloc = datapos + (ntohl(hdr->reloc_start) - text_len);

        memp = realdatastart;

    } else {

        textpos = target_mmap(0, text_len + data_len + extra + indx_len,

                              PROT_READ | PROT_EXEC | PROT_WRITE,

                              MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);

        if (textpos == -1 ) {

            fprintf(stderr, "Unable to allocate RAM for process text/data\n");

            return -1;

        }

        realdatastart = textpos + ntohl(hdr->data_start);

        datapos = realdatastart + indx_len;

        reloc = (textpos + ntohl(hdr->reloc_start) + indx_len);

        memp = textpos;

#ifdef CONFIG_BINFMT_ZFLAT

#error code needs checking

        /*

         * load it all in and treat it like a RAM load from now on

         */

        if (flags & FLAT_FLAG_GZIP) {

                result = decompress_exec(bprm, sizeof (struct flat_hdr),

                                 (((char *) textpos) + sizeof (struct flat_hdr)),

                                 (text_len + data_len + (relocs * sizeof(unsigned long))

                                          - sizeof (struct flat_hdr)),