fe92f6bb75
v17 of the blob format adds a field for the size of the structure block, but is backwards compatible with v16. This patch introduces definitions for the new field, and uses it to improve the bounds checking in the read-only code. It also cleans up the sequential write code using it: we no longer need to borrow the version field as a write pointer.
125 lines
3.0 KiB
C
125 lines
3.0 KiB
C
/*
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* libfdt - Flat Device Tree manipulation
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* Copyright (C) 2006 David Gibson, IBM Corporation.
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public License
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* as published by the Free Software Foundation; either version 2.1 of
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* the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include "libfdt_env.h"
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#include <fdt.h>
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#include <libfdt.h>
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#include "libfdt_internal.h"
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int _fdt_check_header(const struct fdt_header *fdt)
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{
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if (fdt_magic(fdt) == FDT_MAGIC) {
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/* Complete tree */
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if (fdt_version(fdt) < FDT_FIRST_SUPPORTED_VERSION)
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return FDT_ERR_BADVERSION;
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if (fdt_last_comp_version(fdt) > FDT_LAST_SUPPORTED_VERSION)
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return FDT_ERR_BADVERSION;
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} else if (fdt_magic(fdt) == SW_MAGIC) {
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/* Unfinished sequential-write blob */
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if (fdt_size_dt_struct(fdt) == 0)
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return FDT_ERR_BADSTATE;
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} else {
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return FDT_ERR_BADMAGIC;
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}
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return 0;
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}
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void *fdt_offset_ptr(const struct fdt_header *fdt, int offset, int len)
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{
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void *p;
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if (fdt_version(fdt) >= 0x11)
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if (((offset + len) < offset)
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|| ((offset + len) > fdt_size_dt_struct(fdt)))
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return NULL;
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p = (void *)fdt + fdt_off_dt_struct(fdt) + offset;
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if (p + len < p)
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return NULL;
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return p;
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}
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uint32_t _fdt_next_tag(const struct fdt_header *fdt, int offset, int *nextoffset)
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{
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const uint32_t *tagp, *lenp;
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uint32_t tag;
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const char *p;
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if (offset % FDT_TAGSIZE)
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return -1;
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tagp = fdt_offset_ptr(fdt, offset, FDT_TAGSIZE);
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if (! tagp)
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return FDT_END; /* premature end */
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tag = fdt32_to_cpu(*tagp);
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offset += FDT_TAGSIZE;
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switch (tag) {
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case FDT_BEGIN_NODE:
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/* skip name */
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do {
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p = fdt_offset_ptr(fdt, offset++, 1);
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} while (p && (*p != '\0'));
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if (! p)
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return FDT_END;
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break;
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case FDT_PROP:
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lenp = fdt_offset_ptr(fdt, offset + FDT_TAGSIZE, sizeof(*lenp));
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if (! lenp)
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return FDT_END;
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/* skip name offset, length and value */
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offset += 2*FDT_TAGSIZE + fdt32_to_cpu(*lenp);
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break;
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}
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if (nextoffset)
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*nextoffset = ALIGN(offset, FDT_TAGSIZE);
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return tag;
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}
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const char *_fdt_find_string(const char *strtab, int tabsize, const char *s)
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{
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int len = strlen(s) + 1;
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const char *last = strtab + tabsize - len;
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const char *p;
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for (p = strtab; p <= last; p++)
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if (memeq(p, s, len))
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return p;
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return NULL;
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}
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struct fdt_header *fdt_move(const struct fdt_header *fdt, void *buf, int bufsize)
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{
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int err = _fdt_check_header(fdt);
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if (err)
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return PTR_ERROR(err);
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if (fdt_totalsize(fdt) > bufsize)
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return PTR_ERROR(FDT_ERR_NOSPACE);
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memmove(buf, fdt, fdt_totalsize(fdt));
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return (struct fdt_header *)buf;
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}
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