1 // Copyright 2023, The Android Open Source Project 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); 4 // you may not use this file except in compliance with the License. 5 // You may obtain a copy of the License at 6 // 7 // http://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 // See the License for the specific language governing permissions and 13 // limitations under the License. 14 15 //! Struct and functions relating to well-known partition names. 16 17 use crate::error::AvbIOError; 18 use crate::utils::is_not_null; 19 use core::ffi::{c_char, CStr}; 20 21 #[derive(Clone, Copy, Debug, Default, PartialEq, Eq)] 22 pub(crate) enum PartitionName { 23 /// The default `PartitionName` is needed to build the default `HashDescriptor`. 24 #[default] 25 Kernel, 26 InitrdNormal, 27 InitrdDebug, 28 } 29 30 impl PartitionName { 31 pub(crate) const NUM_OF_KNOWN_PARTITIONS: usize = 3; 32 33 const KERNEL_PARTITION_NAME: &[u8] = b"boot\0"; 34 const INITRD_NORMAL_PARTITION_NAME: &[u8] = b"initrd_normal\0"; 35 const INITRD_DEBUG_PARTITION_NAME: &[u8] = b"initrd_debug\0"; 36 as_cstr(&self) -> &CStr37 pub(crate) fn as_cstr(&self) -> &CStr { 38 CStr::from_bytes_with_nul(self.as_bytes()).unwrap() 39 } 40 as_non_null_terminated_bytes(&self) -> &[u8]41 fn as_non_null_terminated_bytes(&self) -> &[u8] { 42 let partition_name = self.as_bytes(); 43 &partition_name[..partition_name.len() - 1] 44 } 45 as_bytes(&self) -> &[u8]46 fn as_bytes(&self) -> &[u8] { 47 match self { 48 Self::Kernel => Self::KERNEL_PARTITION_NAME, 49 Self::InitrdNormal => Self::INITRD_NORMAL_PARTITION_NAME, 50 Self::InitrdDebug => Self::INITRD_DEBUG_PARTITION_NAME, 51 } 52 } 53 } 54 55 impl TryFrom<*const c_char> for PartitionName { 56 type Error = AvbIOError; 57 try_from(partition_name: *const c_char) -> Result<Self, Self::Error>58 fn try_from(partition_name: *const c_char) -> Result<Self, Self::Error> { 59 is_not_null(partition_name)?; 60 // SAFETY: It is safe as the raw pointer `partition_name` is a nonnull pointer. 61 let partition_name = unsafe { CStr::from_ptr(partition_name) }; 62 partition_name.try_into() 63 } 64 } 65 66 impl TryFrom<&CStr> for PartitionName { 67 type Error = AvbIOError; 68 try_from(partition_name: &CStr) -> Result<Self, Self::Error>69 fn try_from(partition_name: &CStr) -> Result<Self, Self::Error> { 70 match partition_name.to_bytes_with_nul() { 71 Self::KERNEL_PARTITION_NAME => Ok(Self::Kernel), 72 Self::INITRD_NORMAL_PARTITION_NAME => Ok(Self::InitrdNormal), 73 Self::INITRD_DEBUG_PARTITION_NAME => Ok(Self::InitrdDebug), 74 _ => Err(AvbIOError::NoSuchPartition), 75 } 76 } 77 } 78 79 impl TryFrom<&[u8]> for PartitionName { 80 type Error = AvbIOError; 81 try_from(non_null_terminated_name: &[u8]) -> Result<Self, Self::Error>82 fn try_from(non_null_terminated_name: &[u8]) -> Result<Self, Self::Error> { 83 match non_null_terminated_name { 84 x if x == Self::Kernel.as_non_null_terminated_bytes() => Ok(Self::Kernel), 85 x if x == Self::InitrdNormal.as_non_null_terminated_bytes() => Ok(Self::InitrdNormal), 86 x if x == Self::InitrdDebug.as_non_null_terminated_bytes() => Ok(Self::InitrdDebug), 87 _ => Err(AvbIOError::NoSuchPartition), 88 } 89 } 90 } 91