52 lines
1.6 KiB
Rust
52 lines
1.6 KiB
Rust
// Copyright 2015-2017 Parity Technologies (UK) Ltd.
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// This file is part of Parity.
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// Parity is free software: you can redistribute it and/or modify
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// it under the terms of the GNU General Public License as published by
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// the Free Software Foundation, either version 3 of the License, or
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// (at your option) any later version.
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// Parity is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU General Public License for more details.
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// You should have received a copy of the GNU General Public License
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// along with Parity. If not, see <http://www.gnu.org/licenses/>.
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//! Wasm bound-checked ptr
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use parity_wasm::interpreter;
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/// Bound-checked wrapper for webassembly memory
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pub struct WasmPtr(u32);
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/// Error in bound check
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#[derive(Debug)]
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pub enum Error {
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AccessViolation,
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}
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impl From<u32> for WasmPtr {
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fn from(raw: u32) -> Self {
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WasmPtr(raw)
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}
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}
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impl WasmPtr {
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// todo: use memory view when they are on
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/// Check memory range and return data with given length starting from the current pointer value
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pub fn slice(&self, len: u32, mem: &interpreter::MemoryInstance) -> Result<Vec<u8>, Error> {
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mem.get(self.0, len as usize).map_err(|_| Error::AccessViolation)
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}
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// todo: maybe 2gb limit can be enhanced
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/// Convert i32 from wasm stack to the wrapped pointer
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pub fn from_i32(raw_ptr: i32) -> Result<Self, Error> {
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if raw_ptr < 0 { return Err(Error::AccessViolation); }
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Ok(WasmPtr(raw_ptr as u32))
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}
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/// Return pointer raw value
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pub fn as_raw(&self) -> u32 { self.0 }
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} |