diff options
| -rw-r--r-- | NEWS | 1 | ||||
| -rw-r--r-- | src/archive/plugins/Iso9660ArchivePlugin.cxx | 105 |
2 files changed, 86 insertions, 20 deletions
@@ -5,6 +5,7 @@ ver 0.21.26 (not yet released) * archive - bzip2: fix crash on corrupt bzip2 file - bzip2: flush output at end of input file + - iso9660: fix unaligned reads - zzip: fix crash on corrupt ZIP file * decoder - sndfile: fix lost samples at end of file diff --git a/src/archive/plugins/Iso9660ArchivePlugin.cxx b/src/archive/plugins/Iso9660ArchivePlugin.cxx index 6314fb025..f81f6fd98 100644 --- a/src/archive/plugins/Iso9660ArchivePlugin.cxx +++ b/src/archive/plugins/Iso9660ArchivePlugin.cxx @@ -29,9 +29,12 @@ #include "fs/Path.hxx" #include "util/RuntimeError.hxx" #include "util/StringCompare.hxx" +#include "util/WritableBuffer.hxx" #include <cdio/iso9660.h> +#include <array> + #include <stdlib.h> #include <string.h> @@ -144,6 +147,47 @@ class Iso9660InputStream final : public InputStream { const lsn_t lsn; + /** + * libiso9660 can only read whole sectors at a time, and this + * buffer is used to store one whole sector and allow Read() + * to handle partial sector reads. + */ + class BlockBuffer { + size_t position = 0, fill = 0; + + std::array<uint8_t, ISO_BLOCKSIZE> data; + + public: + ConstBuffer<uint8_t> Read() const noexcept { + assert(fill <= data.size()); + assert(position <= fill); + + return {&data[position], &data[fill]}; + } + + void Consume(size_t nbytes) noexcept { + assert(nbytes <= Read().size); + + position += nbytes; + } + + WritableBuffer<uint8_t> Write() noexcept { + assert(Read().empty()); + + return {data.data(), data.size()}; + } + + void Append(size_t nbytes) noexcept { + assert(Read().empty()); + assert(nbytes <= data.size()); + + fill = nbytes; + position = 0; + } + }; + + BlockBuffer buffer; + public: Iso9660InputStream(const std::shared_ptr<Iso9660> &_iso, const char *_uri, @@ -182,35 +226,56 @@ Iso9660ArchiveFile::OpenStream(const char *pathname, size_t Iso9660InputStream::Read(void *ptr, size_t read_size) { - const ScopeUnlock unlock(mutex); + const offset_type remaining = size - offset; + if (remaining == 0) + return 0; - int readed = 0; - int no_blocks, cur_block; - size_t left_bytes = size - offset; + if (offset_type(read_size) > remaining) + read_size = remaining; - if (left_bytes < read_size) { - no_blocks = CEILING(left_bytes, ISO_BLOCKSIZE); - } else { - no_blocks = read_size / ISO_BLOCKSIZE; - } + auto r = buffer.Read(); - if (no_blocks == 0) - return 0; + if (r.empty()) { + /* the buffer is empty - read more data from the ISO file */ + + assert(offset % ISO_BLOCKSIZE == 0); - cur_block = offset / ISO_BLOCKSIZE; + const ScopeUnlock unlock(mutex); - readed = iso->SeekRead(ptr, lsn + cur_block, no_blocks); + const lsn_t read_lsn = lsn + offset / ISO_BLOCKSIZE; - if (readed != no_blocks * ISO_BLOCKSIZE) - throw FormatRuntimeError("error reading ISO file at lsn %lu", - (unsigned long)cur_block); + if (read_size >= ISO_BLOCKSIZE) { + /* big read - read right into the caller's buffer */ - if (left_bytes < read_size) { - readed = left_bytes; + auto nbytes = iso->SeekRead(ptr, read_lsn, + read_size / ISO_BLOCKSIZE); + if (nbytes <= 0) + throw std::runtime_error("Failed to read ISO9660 file"); + + offset += nbytes; + return nbytes; + } + + /* fill the buffer */ + + auto w = buffer.Write(); + auto nbytes = iso->SeekRead(w.data, read_lsn, + w.size / ISO_BLOCKSIZE); + if (nbytes <= 0) + throw std::runtime_error("Failed to read ISO9660 file"); + + buffer.Append(nbytes); + + r = buffer.Read(); } - offset += readed; - return readed; + assert(!r.empty()); + + size_t nbytes = std::min(read_size, r.size); + memcpy(ptr, r.data, nbytes); + buffer.Consume(nbytes); + offset += nbytes; + return nbytes; } bool |