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| 1 | +use r_efi::protocols::loaded_image; |
| 2 | + |
| 3 | +use crate::env::current_exe; |
| 4 | +use crate::ffi::OsString; |
| 5 | +use crate::fmt; |
| 6 | +use crate::iter::Iterator; |
| 7 | +use crate::mem::size_of; |
| 8 | +use crate::sys::uefi::helpers; |
| 9 | +use crate::vec; |
| 10 | + |
| 11 | +pub struct Args { |
| 12 | + parsed_args_list: vec::IntoIter<OsString>, |
| 13 | +} |
| 14 | + |
| 15 | +pub fn args() -> Args { |
| 16 | + let lazy_current_exe = || Vec::from([current_exe().map(Into::into).unwrap_or_default()]); |
| 17 | + |
| 18 | + // Each loaded image has an image handle that supports `EFI_LOADED_IMAGE_PROTOCOL`. Thus, this |
| 19 | + // will never fail. |
| 20 | + let protocol = |
| 21 | + helpers::image_handle_protocol::<loaded_image::Protocol>(loaded_image::PROTOCOL_GUID) |
| 22 | + .unwrap(); |
| 23 | + |
| 24 | + let lp_size = unsafe { (*protocol.as_ptr()).load_options_size } as usize; |
| 25 | + // Break if we are sure that it cannot be UTF-16 |
| 26 | + if lp_size < size_of::<u16>() || lp_size % size_of::<u16>() != 0 { |
| 27 | + return Args { parsed_args_list: lazy_current_exe().into_iter() }; |
| 28 | + } |
| 29 | + let lp_size = lp_size / size_of::<u16>(); |
| 30 | + |
| 31 | + let lp_cmd_line = unsafe { (*protocol.as_ptr()).load_options as *const u16 }; |
| 32 | + if !lp_cmd_line.is_aligned() { |
| 33 | + return Args { parsed_args_list: lazy_current_exe().into_iter() }; |
| 34 | + } |
| 35 | + let lp_cmd_line = unsafe { crate::slice::from_raw_parts(lp_cmd_line, lp_size) }; |
| 36 | + |
| 37 | + Args { |
| 38 | + parsed_args_list: parse_lp_cmd_line(lp_cmd_line) |
| 39 | + .unwrap_or_else(lazy_current_exe) |
| 40 | + .into_iter(), |
| 41 | + } |
| 42 | +} |
| 43 | + |
| 44 | +impl fmt::Debug for Args { |
| 45 | + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { |
| 46 | + self.parsed_args_list.as_slice().fmt(f) |
| 47 | + } |
| 48 | +} |
| 49 | + |
| 50 | +impl Iterator for Args { |
| 51 | + type Item = OsString; |
| 52 | + |
| 53 | + fn next(&mut self) -> Option<OsString> { |
| 54 | + self.parsed_args_list.next() |
| 55 | + } |
| 56 | + |
| 57 | + fn size_hint(&self) -> (usize, Option<usize>) { |
| 58 | + self.parsed_args_list.size_hint() |
| 59 | + } |
| 60 | +} |
| 61 | + |
| 62 | +impl ExactSizeIterator for Args { |
| 63 | + fn len(&self) -> usize { |
| 64 | + self.parsed_args_list.len() |
| 65 | + } |
| 66 | +} |
| 67 | + |
| 68 | +impl DoubleEndedIterator for Args { |
| 69 | + fn next_back(&mut self) -> Option<OsString> { |
| 70 | + self.parsed_args_list.next_back() |
| 71 | + } |
| 72 | +} |
| 73 | + |
| 74 | +/// Implements the UEFI command-line argument parsing algorithm. |
| 75 | +/// |
| 76 | +/// This implementation is based on what is defined in Section 3.4 of |
| 77 | +/// [UEFI Shell Specification](https://uefi.org/sites/default/files/resources/UEFI_Shell_Spec_2_0.pdf) |
| 78 | +/// |
| 79 | +/// Return None in the following cases: |
| 80 | +/// - Invalid UTF-16 (unpaired surrogate) |
| 81 | +/// - Empty/improper arguments |
| 82 | +fn parse_lp_cmd_line(code_units: &[u16]) -> Option<Vec<OsString>> { |
| 83 | + const QUOTE: char = '"'; |
| 84 | + const SPACE: char = ' '; |
| 85 | + const CARET: char = '^'; |
| 86 | + const NULL: char = '\0'; |
| 87 | + |
| 88 | + let mut ret_val = Vec::new(); |
| 89 | + let mut code_units_iter = char::decode_utf16(code_units.iter().cloned()).peekable(); |
| 90 | + |
| 91 | + // The executable name at the beginning is special. |
| 92 | + let mut in_quotes = false; |
| 93 | + let mut cur = String::new(); |
| 94 | + while let Some(w) = code_units_iter.next() { |
| 95 | + let w = w.ok()?; |
| 96 | + match w { |
| 97 | + // break on NULL |
| 98 | + NULL => break, |
| 99 | + // A quote mark always toggles `in_quotes` no matter what because |
| 100 | + // there are no escape characters when parsing the executable name. |
| 101 | + QUOTE => in_quotes = !in_quotes, |
| 102 | + // If not `in_quotes` then whitespace ends argv[0]. |
| 103 | + SPACE if !in_quotes => break, |
| 104 | + // In all other cases the code unit is taken literally. |
| 105 | + _ => cur.push(w), |
| 106 | + } |
| 107 | + } |
| 108 | + |
| 109 | + // If exe name is missing, the cli args are invalid |
| 110 | + if cur.is_empty() { |
| 111 | + return None; |
| 112 | + } |
| 113 | + |
| 114 | + ret_val.push(OsString::from(cur)); |
| 115 | + // Skip whitespace. |
| 116 | + while code_units_iter.next_if_eq(&Ok(SPACE)).is_some() {} |
| 117 | + |
| 118 | + // Parse the arguments according to these rules: |
| 119 | + // * All code units are taken literally except space, quote and caret. |
| 120 | + // * When not `in_quotes`, space separate arguments. Consecutive spaces are |
| 121 | + // treated as a single separator. |
| 122 | + // * A space `in_quotes` is taken literally. |
| 123 | + // * A quote toggles `in_quotes` mode unless it's escaped. An escaped quote is taken literally. |
| 124 | + // * A quote can be escaped if preceded by caret. |
| 125 | + // * A caret can be escaped if preceded by caret. |
| 126 | + let mut cur = String::new(); |
| 127 | + let mut in_quotes = false; |
| 128 | + while let Some(w) = code_units_iter.next() { |
| 129 | + let w = w.ok()?; |
| 130 | + match w { |
| 131 | + // break on NULL |
| 132 | + NULL => break, |
| 133 | + // If not `in_quotes`, a space or tab ends the argument. |
| 134 | + SPACE if !in_quotes => { |
| 135 | + ret_val.push(OsString::from(&cur[..])); |
| 136 | + cur.truncate(0); |
| 137 | + |
| 138 | + // Skip whitespace. |
| 139 | + while code_units_iter.next_if_eq(&Ok(SPACE)).is_some() {} |
| 140 | + } |
| 141 | + // Caret can escape quotes or carets |
| 142 | + CARET if in_quotes => { |
| 143 | + if let Some(x) = code_units_iter.next() { |
| 144 | + cur.push(x.ok()?); |
| 145 | + } |
| 146 | + } |
| 147 | + // If quote then flip `in_quotes` |
| 148 | + QUOTE => in_quotes = !in_quotes, |
| 149 | + // Everything else is always taken literally. |
| 150 | + _ => cur.push(w), |
| 151 | + } |
| 152 | + } |
| 153 | + // Push the final argument, if any. |
| 154 | + if !cur.is_empty() || in_quotes { |
| 155 | + ret_val.push(OsString::from(cur)); |
| 156 | + } |
| 157 | + Some(ret_val) |
| 158 | +} |
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