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Diffstat (limited to 'drivers/gpu/drm/drm_panic_qr.rs')
| -rw-r--r-- | drivers/gpu/drm/drm_panic_qr.rs | 1003 |
1 files changed, 1003 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_panic_qr.rs b/drivers/gpu/drm/drm_panic_qr.rs new file mode 100644 index 000000000000..1ef56cb07dfb --- /dev/null +++ b/drivers/gpu/drm/drm_panic_qr.rs @@ -0,0 +1,1003 @@ +// SPDX-License-Identifier: MIT + +//! This is a simple QR encoder for DRM panic. +//! +//! It is called from a panic handler, so it should't allocate memory and +//! does all the work on the stack or on the provided buffers. For +//! simplification, it only supports low error correction, and applies the +//! first mask (checkerboard). It will draw the smallest QRcode that can +//! contain the string passed as parameter. To get the most compact +//! QR code, the start of the URL is encoded as binary, and the +//! compressed kmsg is encoded as numeric. +//! +//! The binary data must be a valid URL parameter, so the easiest way is +//! to use base64 encoding. But this wastes 25% of data space, so the +//! whole stack trace won't fit in the QR code. So instead it encodes +//! every 13bits of input into 4 decimal digits, and then uses the +//! efficient numeric encoding, that encode 3 decimal digits into +//! 10bits. This makes 39bits of compressed data into 12 decimal digits, +//! into 40bits in the QR code, so wasting only 2.5%. And the numbers are +//! valid URL parameter, so the website can do the reverse, to get the +//! binary data. +//! +//! Inspired by these 3 projects, all under MIT license: +//! +//! * <https://github.com/kennytm/qrcode-rust> +//! * <https://github.com/erwanvivien/fast_qr> +//! * <https://github.com/bjguillot/qr> + +use core::cmp; +use kernel::str::CStr; + +#[derive(Debug, Clone, Copy, PartialEq, Eq, Ord, PartialOrd)] +struct Version(usize); + +// Generator polynomials for ECC, only those that are needed for low quality. +const P7: [u8; 7] = [87, 229, 146, 149, 238, 102, 21]; +const P10: [u8; 10] = [251, 67, 46, 61, 118, 70, 64, 94, 32, 45]; +const P15: [u8; 15] = [ + 8, 183, 61, 91, 202, 37, 51, 58, 58, 237, 140, 124, 5, 99, 105, +]; +const P18: [u8; 18] = [ + 215, 234, 158, 94, 184, 97, 118, 170, 79, 187, 152, 148, 252, 179, 5, 98, 96, 153, +]; +const P20: [u8; 20] = [ + 17, 60, 79, 50, 61, 163, 26, 187, 202, 180, 221, 225, 83, 239, 156, 164, 212, 212, 188, 190, +]; +const P22: [u8; 22] = [ + 210, 171, 247, 242, 93, 230, 14, 109, 221, 53, 200, 74, 8, 172, 98, 80, 219, 134, 160, 105, + 165, 231, +]; +const P24: [u8; 24] = [ + 229, 121, 135, 48, 211, 117, 251, 126, 159, 180, 169, 152, 192, 226, 228, 218, 111, 0, 117, + 232, 87, 96, 227, 21, +]; +const P26: [u8; 26] = [ + 173, 125, 158, 2, 103, 182, 118, 17, 145, 201, 111, 28, 165, 53, 161, 21, 245, 142, 13, 102, + 48, 227, 153, 145, 218, 70, +]; +const P28: [u8; 28] = [ + 168, 223, 200, 104, 224, 234, 108, 180, 110, 190, 195, 147, 205, 27, 232, 201, 21, 43, 245, 87, + 42, 195, 212, 119, 242, 37, 9, 123, +]; +const P30: [u8; 30] = [ + 41, 173, 145, 152, 216, 31, 179, 182, 50, 48, 110, 86, 239, 96, 222, 125, 42, 173, 226, 193, + 224, 130, 156, 37, 251, 216, 238, 40, 192, 180, +]; + +/// QR Code parameters for Low quality ECC: +/// - Error Correction polynomial. +/// - Number of blocks in group 1. +/// - Number of blocks in group 2. +/// - Block size in group 1. +/// +/// (Block size in group 2 is one more than group 1). +struct VersionParameter(&'static [u8], u8, u8, u8); +const VPARAM: [VersionParameter; 40] = [ + VersionParameter(&P7, 1, 0, 19), // V1 + VersionParameter(&P10, 1, 0, 34), // V2 + VersionParameter(&P15, 1, 0, 55), // V3 + VersionParameter(&P20, 1, 0, 80), // V4 + VersionParameter(&P26, 1, 0, 108), // V5 + VersionParameter(&P18, 2, 0, 68), // V6 + VersionParameter(&P20, 2, 0, 78), // V7 + VersionParameter(&P24, 2, 0, 97), // V8 + VersionParameter(&P30, 2, 0, 116), // V9 + VersionParameter(&P18, 2, 2, 68), // V10 + VersionParameter(&P20, 4, 0, 81), // V11 + VersionParameter(&P24, 2, 2, 92), // V12 + VersionParameter(&P26, 4, 0, 107), // V13 + VersionParameter(&P30, 3, 1, 115), // V14 + VersionParameter(&P22, 5, 1, 87), // V15 + VersionParameter(&P24, 5, 1, 98), // V16 + VersionParameter(&P28, 1, 5, 107), // V17 + VersionParameter(&P30, 5, 1, 120), // V18 + VersionParameter(&P28, 3, 4, 113), // V19 + VersionParameter(&P28, 3, 5, 107), // V20 + VersionParameter(&P28, 4, 4, 116), // V21 + VersionParameter(&P28, 2, 7, 111), // V22 + VersionParameter(&P30, 4, 5, 121), // V23 + VersionParameter(&P30, 6, 4, 117), // V24 + VersionParameter(&P26, 8, 4, 106), // V25 + VersionParameter(&P28, 10, 2, 114), // V26 + VersionParameter(&P30, 8, 4, 122), // V27 + VersionParameter(&P30, 3, 10, 117), // V28 + VersionParameter(&P30, 7, 7, 116), // V29 + VersionParameter(&P30, 5, 10, 115), // V30 + VersionParameter(&P30, 13, 3, 115), // V31 + VersionParameter(&P30, 17, 0, 115), // V32 + VersionParameter(&P30, 17, 1, 115), // V33 + VersionParameter(&P30, 13, 6, 115), // V34 + VersionParameter(&P30, 12, 7, 121), // V35 + VersionParameter(&P30, 6, 14, 121), // V36 + VersionParameter(&P30, 17, 4, 122), // V37 + VersionParameter(&P30, 4, 18, 122), // V38 + VersionParameter(&P30, 20, 4, 117), // V39 + VersionParameter(&P30, 19, 6, 118), // V40 +]; + +const MAX_EC_SIZE: usize = 30; +const MAX_BLK_SIZE: usize = 123; + +/// Position of the alignment pattern grid. +const ALIGNMENT_PATTERNS: [&[u8]; 40] = [ + &[], + &[6, 18], + &[6, 22], + &[6, 26], + &[6, 30], + &[6, 34], + &[6, 22, 38], + &[6, 24, 42], + &[6, 26, 46], + &[6, 28, 50], + &[6, 30, 54], + &[6, 32, 58], + &[6, 34, 62], + &[6, 26, 46, 66], + &[6, 26, 48, 70], + &[6, 26, 50, 74], + &[6, 30, 54, 78], + &[6, 30, 56, 82], + &[6, 30, 58, 86], + &[6, 34, 62, 90], + &[6, 28, 50, 72, 94], + &[6, 26, 50, 74, 98], + &[6, 30, 54, 78, 102], + &[6, 28, 54, 80, 106], + &[6, 32, 58, 84, 110], + &[6, 30, 58, 86, 114], + &[6, 34, 62, 90, 118], + &[6, 26, 50, 74, 98, 122], + &[6, 30, 54, 78, 102, 126], + &[6, 26, 52, 78, 104, 130], + &[6, 30, 56, 82, 108, 134], + &[6, 34, 60, 86, 112, 138], + &[6, 30, 58, 86, 114, 142], + &[6, 34, 62, 90, 118, 146], + &[6, 30, 54, 78, 102, 126, 150], + &[6, 24, 50, 76, 102, 128, 154], + &[6, 28, 54, 80, 106, 132, 158], + &[6, 32, 58, 84, 110, 136, 162], + &[6, 26, 54, 82, 110, 138, 166], + &[6, 30, 58, 86, 114, 142, 170], +]; + +/// Version information for format V7-V40. +const VERSION_INFORMATION: [u32; 34] = [ + 0b00_0111_1100_1001_0100, + 0b00_1000_0101_1011_1100, + 0b00_1001_1010_1001_1001, + 0b00_1010_0100_1101_0011, + 0b00_1011_1011_1111_0110, + 0b00_1100_0111_0110_0010, + 0b00_1101_1000_0100_0111, + 0b00_1110_0110_0000_1101, + 0b00_1111_1001_0010_1000, + 0b01_0000_1011_0111_1000, + 0b01_0001_0100_0101_1101, + 0b01_0010_1010_0001_0111, + 0b01_0011_0101_0011_0010, + 0b01_0100_1001_1010_0110, + 0b01_0101_0110_1000_0011, + 0b01_0110_1000_1100_1001, + 0b01_0111_0111_1110_1100, + 0b01_1000_1110_1100_0100, + 0b01_1001_0001_1110_0001, + 0b01_1010_1111_1010_1011, + 0b01_1011_0000_1000_1110, + 0b01_1100_1100_0001_1010, + 0b01_1101_0011_0011_1111, + 0b01_1110_1101_0111_0101, + 0b01_1111_0010_0101_0000, + 0b10_0000_1001_1101_0101, + 0b10_0001_0110_1111_0000, + 0b10_0010_1000_1011_1010, + 0b10_0011_0111_1001_1111, + 0b10_0100_1011_0000_1011, + 0b10_0101_0100_0010_1110, + 0b10_0110_1010_0110_0100, + 0b10_0111_0101_0100_0001, + 0b10_1000_1100_0110_1001, +]; + +/// Format info for low quality ECC. +const FORMAT_INFOS_QR_L: [u16; 8] = [ + 0x77c4, 0x72f3, 0x7daa, 0x789d, 0x662f, 0x6318, 0x6c41, 0x6976, +]; + +impl Version { + /// Returns the smallest QR version than can hold these segments. + fn from_segments(segments: &[&Segment<'_>]) -> Option<Version> { + for v in (1..=40).map(|k| Version(k)) { + if v.max_data() * 8 >= segments.iter().map(|s| s.total_size_bits(v)).sum() { + return Some(v); + } + } + None + } + + fn width(&self) -> u8 { + (self.0 as u8) * 4 + 17 + } + + fn max_data(&self) -> usize { + self.g1_blk_size() * self.g1_blocks() + (self.g1_blk_size() + 1) * self.g2_blocks() + } + + fn ec_size(&self) -> usize { + VPARAM[self.0 - 1].0.len() + } + + fn g1_blocks(&self) -> usize { + VPARAM[self.0 - 1].1 as usize + } + + fn g2_blocks(&self) -> usize { + VPARAM[self.0 - 1].2 as usize + } + + fn g1_blk_size(&self) -> usize { + VPARAM[self.0 - 1].3 as usize + } + + fn alignment_pattern(&self) -> &'static [u8] { + &ALIGNMENT_PATTERNS[self.0 - 1] + } + + fn poly(&self) -> &'static [u8] { + VPARAM[self.0 - 1].0 + } + + fn version_info(&self) -> u32 { + if *self >= Version(7) { + VERSION_INFORMATION[self.0 - 7] + } else { + 0 + } + } +} + +/// Exponential table for Galois Field GF(256). +const EXP_TABLE: [u8; 256] = [ + 1, 2, 4, 8, 16, 32, 64, 128, 29, 58, 116, 232, 205, 135, 19, 38, 76, 152, 45, 90, 180, 117, + 234, 201, 143, 3, 6, 12, 24, 48, 96, 192, 157, 39, 78, 156, 37, 74, 148, 53, 106, 212, 181, + 119, 238, 193, 159, 35, 70, 140, 5, 10, 20, 40, 80, 160, 93, 186, 105, 210, 185, 111, 222, 161, + 95, 190, 97, 194, 153, 47, 94, 188, 101, 202, 137, 15, 30, 60, 120, 240, 253, 231, 211, 187, + 107, 214, 177, 127, 254, 225, 223, 163, 91, 182, 113, 226, 217, 175, 67, 134, 17, 34, 68, 136, + 13, 26, 52, 104, 208, 189, 103, 206, 129, 31, 62, 124, 248, 237, 199, 147, 59, 118, 236, 197, + 151, 51, 102, 204, 133, 23, 46, 92, 184, 109, 218, 169, 79, 158, 33, 66, 132, 21, 42, 84, 168, + 77, 154, 41, 82, 164, 85, 170, 73, 146, 57, 114, 228, 213, 183, 115, 230, 209, 191, 99, 198, + 145, 63, 126, 252, 229, 215, 179, 123, 246, 241, 255, 227, 219, 171, 75, 150, 49, 98, 196, 149, + 55, 110, 220, 165, 87, 174, 65, 130, 25, 50, 100, 200, 141, 7, 14, 28, 56, 112, 224, 221, 167, + 83, 166, 81, 162, 89, 178, 121, 242, 249, 239, 195, 155, 43, 86, 172, 69, 138, 9, 18, 36, 72, + 144, 61, 122, 244, 245, 247, 243, 251, 235, 203, 139, 11, 22, 44, 88, 176, 125, 250, 233, 207, + 131, 27, 54, 108, 216, 173, 71, 142, 1, +]; + +/// Reverse exponential table for Galois Field GF(256). +const LOG_TABLE: [u8; 256] = [ + 175, 0, 1, 25, 2, 50, 26, 198, 3, 223, 51, 238, 27, 104, 199, 75, 4, 100, 224, 14, 52, 141, + 239, 129, 28, 193, 105, 248, 200, 8, 76, 113, 5, 138, 101, 47, 225, 36, 15, 33, 53, 147, 142, + 218, 240, 18, 130, 69, 29, 181, 194, 125, 106, 39, 249, 185, 201, 154, 9, 120, 77, 228, 114, + 166, 6, 191, 139, 98, 102, 221, 48, 253, 226, 152, 37, 179, 16, 145, 34, 136, 54, 208, 148, + 206, 143, 150, 219, 189, 241, 210, 19, 92, 131, 56, 70, 64, 30, 66, 182, 163, 195, 72, 126, + 110, 107, 58, 40, 84, 250, 133, 186, 61, 202, 94, 155, 159, 10, 21, 121, 43, 78, 212, 229, 172, + 115, 243, 167, 87, 7, 112, 192, 247, 140, 128, 99, 13, 103, 74, 222, 237, 49, 197, 254, 24, + 227, 165, 153, 119, 38, 184, 180, 124, 17, 68, 146, 217, 35, 32, 137, 46, 55, 63, 209, 91, 149, + 188, 207, 205, 144, 135, 151, 178, 220, 252, 190, 97, 242, 86, 211, 171, 20, 42, 93, 158, 132, + 60, 57, 83, 71, 109, 65, 162, 31, 45, 67, 216, 183, 123, 164, 118, 196, 23, 73, 236, 127, 12, + 111, 246, 108, 161, 59, 82, 41, 157, 85, 170, 251, 96, 134, 177, 187, 204, 62, 90, 203, 89, 95, + 176, 156, 169, 160, 81, 11, 245, 22, 235, 122, 117, 44, 215, 79, 174, 213, 233, 230, 231, 173, + 232, 116, 214, 244, 234, 168, 80, 88, 175, +]; + +// 4 bits segment header. +const MODE_STOP: u16 = 0; +const MODE_NUMERIC: u16 = 1; +const MODE_BINARY: u16 = 4; +/// Padding bytes. +const PADDING: [u8; 2] = [236, 17]; + +/// Get the next 13 bits of data, starting at specified offset (in bits). +fn get_next_13b(data: &[u8], offset: usize) -> Option<(u16, usize)> { + if offset < data.len() * 8 { + let size = cmp::min(13, data.len() * 8 - offset); + let byte_off = offset / 8; + let bit_off = offset % 8; + // `b` is 20 at max (`bit_off` <= 7 and `size` <= 13). + let b = (bit_off + size) as u16; + + let first_byte = (data[byte_off] << bit_off >> bit_off) as u16; + + let number = match b { + 0..=8 => first_byte >> (8 - b), + 9..=16 => (first_byte << (b - 8)) + (data[byte_off + 1] >> (16 - b)) as u16, + _ => { + (first_byte << (b - 8)) + + ((data[byte_off + 1] as u16) << (b - 16)) + + (data[byte_off + 2] >> (24 - b)) as u16 + } + }; + Some((number, size)) + } else { + None + } +} + +/// Number of bits to encode characters in numeric mode. +const NUM_CHARS_BITS: [usize; 4] = [0, 4, 7, 10]; +const POW10: [u16; 4] = [1, 10, 100, 1000]; + +enum Segment<'a> { + Numeric(&'a [u8]), + Binary(&'a [u8]), +} + +impl Segment<'_> { + fn get_header(&self) -> (u16, usize) { + match self { + Segment::Binary(_) => (MODE_BINARY, 4), + Segment::Numeric(_) => (MODE_NUMERIC, 4), + } + } + + // Returns the size of the length field in bits, depending on QR Version. + fn length_bits_count(&self, version: Version) -> usize { + let Version(v) = version; + match self { + Segment::Binary(_) => match v { + 1..=9 => 8, + _ => 16, + }, + Segment::Numeric(_) => match v { + 1..=9 => 10, + 10..=26 => 12, + _ => 14, + }, + } + } + + // Number of characters in the segment. + fn character_count(&self) -> usize { + match self { + Segment::Binary(data) => data.len(), + Segment::Numeric(data) => { + let data_bits = data.len() * 8; + let last_chars = match data_bits % 13 { + 1 => 1, + k => (k + 1) / 3, + }; + // 4 decimal numbers per 13bits + remainder. + 4 * (data_bits / 13) + last_chars + } + } + } + + fn get_length_field(&self, version: Version) -> (u16, usize) { + ( + self.character_count() as u16, + self.length_bits_count(version), + ) + } + + fn total_size_bits(&self, version: Version) -> usize { + let data_size = match self { + Segment::Binary(data) => data.len() * 8, + Segment::Numeric(_) => { + let digits = self.character_count(); + 10 * (digits / 3) + NUM_CHARS_BITS[digits % 3] + } + }; + // header + length + data. + 4 + self.length_bits_count(version) + data_size + } + + fn iter(&self) -> SegmentIterator<'_> { + SegmentIterator { + segment: self, + offset: 0, + carry: 0, + carry_len: 0, + } + } +} + +struct SegmentIterator<'a> { + segment: &'a Segment<'a>, + offset: usize, + carry: u16, + carry_len: usize, +} + +impl Iterator for SegmentIterator<'_> { + type Item = (u16, usize); + + fn next(&mut self) -> Option<Self::Item> { + match self.segment { + Segment::Binary(data) => { + if self.offset < data.len() { + let byte = data[self.offset] as u16; + self.offset += 1; + Some((byte, 8)) + } else { + None + } + } + Segment::Numeric(data) => { + if self.carry_len == 3 { + let out = (self.carry, NUM_CHARS_BITS[self.carry_len]); + self.carry_len = 0; + self.carry = 0; + Some(out) + } else if let Some((bits, size)) = get_next_13b(data, self.offset) { + self.offset += size; + let new_chars = match size { + 1 => 1, + k => (k + 1) / 3, + }; + if self.carry_len + new_chars > 3 { + self.carry_len = new_chars + self.carry_len - 3; + let out = ( + self.carry * POW10[new_chars - self.carry_len] + + bits / POW10[self.carry_len], + NUM_CHARS_BITS[3], + ); + self.carry = bits % POW10[self.carry_len]; + Some(out) + } else { + let out = ( + self.carry * POW10[new_chars] + bits, + NUM_CHARS_BITS[self.carry_len + new_chars], + ); + self.carry_len = 0; + Some(out) + } + } else if self.carry_len > 0 { + let out = (self.carry, NUM_CHARS_BITS[self.carry_len]); + self.carry_len = 0; + Some(out) + } else { + None + } + } + } + } +} + +struct EncodedMsg<'a> { + data: &'a mut [u8], + ec_size: usize, + g1_blocks: usize, + g2_blocks: usize, + g1_blk_size: usize, + g2_blk_size: usize, + poly: &'static [u8], + version: Version, +} + +/// Data to be put in the QR code, with correct segment encoding, padding, and +/// Error Code Correction. +impl EncodedMsg<'_> { + fn new<'a, 'b>(segments: &[&Segment<'b>], data: &'a mut [u8]) -> Option<EncodedMsg<'a>> { + let version = Version::from_segments(segments)?; + let ec_size = version.ec_size(); + let g1_blocks = version.g1_blocks(); + let g2_blocks = version.g2_blocks(); + let g1_blk_size = version.g1_blk_size(); + let g2_blk_size = g1_blk_size + 1; + let poly = version.poly(); + + // clear the output. + data.fill(0); + + let mut em = EncodedMsg { + data: data, + ec_size, + g1_blocks, + g2_blocks, + g1_blk_size, + g2_blk_size, + poly, + version, + }; + em.encode(segments); + Some(em) + } + + /// Push bits of data at an offset (in bits). + fn push(&mut self, offset: &mut usize, bits: (u16, usize)) { + let (number, len_bits) = bits; + let byte_off = *offset / 8; + let bit_off = *offset % 8; + let b = bit_off + len_bits; + + match (bit_off, b) { + (0, 0..=8) => { + self.data[byte_off] = (number << (8 - b)) as u8; + } + (0, _) => { + self.data[byte_off] = (number >> (b - 8)) as u8; + self.data[byte_off + 1] = (number << (16 - b)) as u8; + } + (_, 0..=8) => { + self.data[byte_off] |= (number << (8 - b)) as u8; + } + (_, 9..=16) => { + self.data[byte_off] |= (number >> (b - 8)) as u8; + self.data[byte_off + 1] = (number << (16 - b)) as u8; + } + _ => { + self.data[byte_off] |= (number >> (b - 8)) as u8; + self.data[byte_off + 1] = (number >> (b - 16)) as u8; + self.data[byte_off + 2] = (number << (24 - b)) as u8; + } + } + *offset += len_bits; + } + + fn add_segments(&mut self, segments: &[&Segment<'_>]) { + let mut offset: usize = 0; + + for s in segments.iter() { + self.push(&mut offset, s.get_header()); + self.push(&mut offset, s.get_length_field(self.version)); + for bits in s.iter() { + self.push(&mut offset, bits); + } + } + self.push(&mut offset, (MODE_STOP, 4)); + + let pad_offset = (offset + 7) / 8; + for i in pad_offset..self.version.max_data() { + self.data[i] = PADDING[(i & 1) ^ (pad_offset & 1)]; + } + } + + fn error_code_for_blocks(&mut self, offset: usize, size: usize, ec_offset: usize) { + let mut tmp: [u8; MAX_BLK_SIZE + MAX_EC_SIZE] = [0; MAX_BLK_SIZE + MAX_EC_SIZE]; + + tmp[0..size].copy_from_slice(&self.data[offset..offset + size]); + for i in 0..size { + let lead_coeff = tmp[i] as usize; + if lead_coeff == 0 { + continue; + } + let log_lead_coeff = usize::from(LOG_TABLE[lead_coeff]); + for (u, &v) in tmp[i + 1..].iter_mut().zip(self.poly.iter()) { + *u ^= EXP_TABLE[(usize::from(v) + log_lead_coeff) % 255]; + } + } + self.data[ec_offset..ec_offset + self.ec_size] + .copy_from_slice(&tmp[size..size + self.ec_size]); + } + + fn compute_error_code(&mut self) { + let mut offset = 0; + let mut ec_offset = self.g1_blocks * self.g1_blk_size + self.g2_blocks * self.g2_blk_size; + + for _ in 0..self.g1_blocks { + self.error_code_for_blocks(offset, self.g1_blk_size, ec_offset); + offset += self.g1_blk_size; + ec_offset += self.ec_size; + } + for _ in 0..self.g2_blocks { + self.error_code_for_blocks(offset, self.g2_blk_size, ec_offset); + offset += self.g2_blk_size; + ec_offset += self.ec_size; + } + } + + fn encode(&mut self, segments: &[&Segment<'_>]) { + self.add_segments(segments); + self.compute_error_code(); + } + + fn iter(&self) -> EncodedMsgIterator<'_> { + EncodedMsgIterator { + em: self, + offset: 0, + } + } +} + +/// Iterator, to retrieve the data in the interleaved order needed by QR code. +struct EncodedMsgIterator<'a> { + em: &'a EncodedMsg<'a>, + offset: usize, +} + +impl Iterator for EncodedMsgIterator<'_> { + type Item = u8; + + // Send the bytes in interleaved mode, first byte of first block of group1, + // then first byte of second block of group1, ... + fn next(&mut self) -> Option<Self::Item> { + let em = self.em; + let blocks = em.g1_blocks + em.g2_blocks; + let g1_end = em.g1_blocks * em.g1_blk_size; + let g2_end = g1_end + em.g2_blocks * em.g2_blk_size; + let ec_end = g2_end + em.ec_size * blocks; + + if self.offset >= ec_end { + return None; + } + + let offset = if self.offset < em.g1_blk_size * blocks { + // group1 and group2 interleaved + let blk = self.offset % blocks; + let blk_off = self.offset / blocks; + if blk < em.g1_blocks { + blk * em.g1_blk_size + blk_off + } else { + g1_end + em.g2_blk_size * (blk - em.g1_blocks) + blk_off + } + } else if self.offset < g2_end { + // last byte of group2 blocks + let blk2 = self.offset - blocks * em.g1_blk_size; + em.g1_blk_size * em.g1_blocks + blk2 * em.g2_blk_size + em.g2_blk_size - 1 + } else { + // EC blocks + let ec_offset = self.offset - g2_end; + let blk = ec_offset % blocks; + let blk_off = ec_offset / blocks; + + g2_end + blk * em.ec_size + blk_off + }; + self.offset += 1; + Some(em.data[offset]) + } +} + +/// A QR code image, encoded as a linear binary framebuffer. +/// 1 bit per module (pixel), each new line start at next byte boundary. +/// Max width is 177 for V40 QR code, so `u8` is enough for coordinate. +struct QrImage<'a> { + data: &'a mut [u8], + width: u8, + stride: u8, + version: Version, +} + +impl QrImage<'_> { + fn new<'a, 'b>(em: &'b EncodedMsg<'b>, qrdata: &'a mut [u8]) -> QrImage<'a> { + let width = em.version.width(); + let stride = (width + 7) / 8; + let data = qrdata; + + let mut qr_image = QrImage { + data, + width, + stride, + version: em.version, + }; + qr_image.draw_all(em.iter()); + qr_image + } + + fn clear(&mut self) { + self.data.fill(0); + } + + // Set pixel to light color. + fn set(&mut self, x: u8, y: u8) { + let off = y as usize * self.stride as usize + x as usize / 8; + let mut v = self.data[off]; + v |= 0x80 >> (x % 8); + self.data[off] = v; + } + + // Invert a module color. + fn xor(&mut self, x: u8, y: u8) { + let off = y as usize * self.stride as usize + x as usize / 8; + self.data[off] ^= 0x80 >> (x % 8); + } + + // Draw a light square at (x, y) top left corner. + fn draw_square(&mut self, x: u8, y: u8, size: u8) { + for k in 0..size { + self.set(x + k, y); + self.set(x, y + k + 1); + self.set(x + size, y + k); + self.set(x + k + 1, y + size); + } + } + + // Finder pattern: 3 8x8 square at the corners. + fn draw_finders(&mut self) { + self.draw_square(1, 1, 4); + self.draw_square(self.width - 6, 1, 4); + self.draw_square(1, self.width - 6, 4); + for k in 0..8 { + self.set(k, 7); + self.set(self.width - k - 1, 7); + self.set(k, self.width - 8); + } + for k in 0..7 { + self.set(7, k); + self.set(self.width - 8, k); + self.set(7, self.width - 1 - k); + } + } + + fn is_finder(&self, x: u8, y: u8) -> bool { + let end = self.width - 8; + (x < 8 && y < 8) || (x < 8 && y >= end) || (x >= end && y < 8) + } + + // Alignment pattern: 5x5 squares in a grid. + fn draw_alignments(&mut self) { + let positions = self.version.alignment_pattern(); + for &x in positions.iter() { + for &y in positions.iter() { + if !self.is_finder(x, y) { + self.draw_square(x - 1, y - 1, 2); + } + } + } + } + + fn is_alignment(&self, x: u8, y: u8) -> bool { + let positions = self.version.alignment_pattern(); + for &ax in positions.iter() { + for &ay in positions.iter() { + if self.is_finder(ax, ay) { + continue; + } + if x >= ax - 2 && x <= ax + 2 && y >= ay - 2 && y <= ay + 2 { + return true; + } + } + } + false + } + + // Timing pattern: 2 dotted line between the finder patterns. + fn draw_timing_patterns(&mut self) { + let end = self.width - 8; + + for x in (9..end).step_by(2) { + self.set(x, 6); + self.set(6, x); + } + } + + fn is_timing(&self, x: u8, y: u8) -> bool { + x == 6 || y == 6 + } + + // Mask info: 15 bits around the finders, written twice for redundancy. + fn draw_maskinfo(&mut self) { + let info: u16 = FORMAT_INFOS_QR_L[0]; + let mut skip = 0; + + for k in 0..7 { + if k == 6 { + skip = 1; + } + if info & (1 << (14 - k)) == 0 { + self.set(k + skip, 8); + self.set(8, self.width - 1 - k); + } + } + skip = 0; + for k in 0..8 { + if k == 2 { + skip = 1; + } + if info & (1 << (7 - k)) == 0 { + self.set(8, 8 - skip - k); + self.set(self.width - 8 + k, 8); + } + } + } + + fn is_maskinfo(&self, x: u8, y: u8) -> bool { + let end = self.width - 8; + // Count the dark module as mask info. + (x <= 8 && y == 8) || (y <= 8 && x == 8) || (x == 8 && y >= end) || (x >= end && y == 8) + } + + // Version info: 18bits written twice, close to the finders. + fn draw_version_info(&mut self) { + let vinfo = self.version.version_info(); + let pos = self.width - 11; + + if vinfo != 0 { + for x in 0..3 { + for y in 0..6 { + if vinfo & (1 << (x + y * 3)) == 0 { + self.set(x + pos, y); + self.set(y, x + pos); + } + } + } + } + } + + fn is_version_info(&self, x: u8, y: u8) -> bool { + let vinfo = self.version.version_info(); + let pos = self.width - 11; + + vinfo != 0 && ((x >= pos && x < pos + 3 && y < 6) || (y >= pos && y < pos + 3 && x < 6)) + } + + // Returns true if the module is reserved (Not usable for data and EC). + fn is_reserved(&self, x: u8, y: u8) -> bool { + self.is_alignment(x, y) + || self.is_finder(x, y) + || self.is_timing(x, y) + || self.is_maskinfo(x, y) + || self.is_version_info(x, y) + } + + // Last module to draw, at bottom left corner. + fn is_last(&self, x: u8, y: u8) -> bool { + x == 0 && y == self.width - 1 + } + + // Move to the next module according to QR code order. + // From bottom right corner, to bottom left corner. + fn next(&self, x: u8, y: u8) -> (u8, u8) { + let x_adj = if x <= 6 { x + 1 } else { x }; + let column_type = (self.width - x_adj) % 4; + + match column_type { + 2 if y > 0 => (x + 1, y - 1), + 0 if y < self.width - 1 => (x + 1, y + 1), + 0 | 2 if x == 7 => (x - 2, y), + _ => (x - 1, y), + } + } + + // Find next module that can hold data. + fn next_available(&self, x: u8, y: u8) -> (u8, u8) { + let (mut x, mut y) = self.next(x, y); + while self.is_reserved(x, y) && !self.is_last(x, y) { + (x, y) = self.next(x, y); + } + (x, y) + } + + fn draw_data(&mut self, data: impl Iterator<Item = u8>) { + let (mut x, mut y) = (self.width - 1, self.width - 1); + for byte in data { + for s in 0..8 { + if byte & (0x80 >> s) == 0 { + self.set(x, y); + } + (x, y) = self.next_available(x, y); + } + } + // Set the remaining modules (0, 3 or 7 depending on version). + // because 0 correspond to a light module. + while !self.is_last(x, y) { + if !self.is_reserved(x, y) { + self.set(x, y); + } + (x, y) = self.next(x, y); + } + } + + // Apply checkerboard mask to all non-reserved modules. + fn apply_mask(&mut self) { + for x in 0..self.width { + for y in 0..self.width { + if (x ^ y) % 2 == 0 && !self.is_reserved(x, y) { + self.xor(x, y); + } + } + } + } + + // Draw the QR code with the provided data iterator. + fn draw_all(&mut self, data: impl Iterator<Item = u8>) { + // First clear the table, as it may have already some data. + self.clear(); + self.draw_finders(); + self.draw_alignments(); + self.draw_timing_patterns(); + self.draw_version_info(); + self.draw_data(data); + self.draw_maskinfo(); + self.apply_mask(); + } +} + +/// C entry point for the rust QR Code generator. +/// +/// Write the QR code image in the data buffer, and return the QR code width, +/// or 0, if the data doesn't fit in a QR code. +/// +/// * `url`: The base URL of the QR code. It will be encoded as Binary segment. +/// * `data`: A pointer to the binary data, to be encoded. if URL is NULL, it +/// will be encoded as binary segment, otherwise it will be encoded +/// efficiently as a numeric segment, and appended to the URL. +/// * `data_len`: Length of the data, that needs to be encoded, must be less +/// than data_size. +/// * `data_size`: Size of data buffer, it should be at least 4071 bytes to hold +/// a V40 QR code. It will then be overwritten with the QR code image. +/// * `tmp`: A temporary buffer that the QR code encoder will use, to write the +/// segments and ECC. +/// * `tmp_size`: Size of the temporary buffer, it must be at least 3706 bytes +/// long for V40. +/// +/// # Safety +/// +/// * `url` must be null or point at a nul-terminated string. +/// * `data` must be valid for reading and writing for `data_size` bytes. +/// * `tmp` must be valid for reading and writing for `tmp_size` bytes. +/// +/// They must remain valid for the duration of the function call. + +#[no_mangle] +pub unsafe extern "C" fn drm_panic_qr_generate( + url: *const i8, + data: *mut u8, + data_len: usize, + data_size: usize, + tmp: *mut u8, + tmp_size: usize, +) -> u8 { + if data_size < 4071 || tmp_size < 3706 || data_len > data_size { + return 0; + } + // SAFETY: The caller ensures that `data` is a valid pointer for reading and + // writing `data_size` bytes. + let data_slice: &mut [u8] = unsafe { core::slice::from_raw_parts_mut(data, data_size) }; + // SAFETY: The caller ensures that `tmp` is a valid pointer for reading and + // writing `tmp_size` bytes. + let tmp_slice: &mut [u8] = unsafe { core::slice::from_raw_parts_mut(tmp, tmp_size) }; + if url.is_null() { + match EncodedMsg::new(&[&Segment::Binary(&data_slice[0..data_len])], tmp_slice) { + None => 0, + Some(em) => { + let qr_image = QrImage::new(&em, data_slice); + qr_image.width + } + } + } else { + // SAFETY: The caller ensures that `url` is a valid pointer to a + // nul-terminated string. + let url_cstr: &CStr = unsafe { CStr::from_char_ptr(url) }; + let segments = &[ + &Segment::Binary(url_cstr.as_bytes()), + &Segment::Numeric(&data_slice[0..data_len]), + ]; + match EncodedMsg::new(segments, tmp_slice) { + None => 0, + Some(em) => { + let qr_image = QrImage::new(&em, data_slice); + qr_image.width + } + } + } +} + +/// Returns the maximum data size that can fit in a QR code of this version. +/// * `version`: QR code version, between 1-40. +/// * `url_len`: Length of the URL. +/// +/// * If `url_len` > 0, remove the 2 segments header/length and also count the +/// conversion to numeric segments. +/// * If `url_len` = 0, only removes 3 bytes for 1 binary segment. +#[no_mangle] +pub extern "C" fn drm_panic_qr_max_data_size(version: u8, url_len: usize) -> usize { + if version < 1 || version > 40 { + return 0; + } + let max_data = Version(version as usize).max_data(); + + if url_len > 0 { + // Binary segment (URL) 4 + 16 bits, numeric segment (kmsg) 4 + 12 bits => 5 bytes. + if url_len + 5 >= max_data { + 0 + } else { + let max = max_data - url_len - 5; + (max * 39) / 40 + } + } else { + // Remove 3 bytes for the binary segment (header 4 bits, length 16 bits, stop 4bits). + max_data - 3 + } +} |