From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from firstgate.proxmox.com (firstgate.proxmox.com [212.224.123.68]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by lists.proxmox.com (Postfix) with ESMTPS id C4AAF60A16 for ; Tue, 15 Dec 2020 11:38:12 +0100 (CET) Received: from firstgate.proxmox.com (localhost [127.0.0.1]) by firstgate.proxmox.com (Proxmox) with ESMTP id B185F100FF for ; Tue, 15 Dec 2020 11:37:42 +0100 (CET) Received: from proxmox-new.maurer-it.com (proxmox-new.maurer-it.com [212.186.127.180]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by firstgate.proxmox.com (Proxmox) with ESMTPS id E047B100F7 for ; Tue, 15 Dec 2020 11:37:41 +0100 (CET) Received: from proxmox-new.maurer-it.com (localhost.localdomain [127.0.0.1]) by proxmox-new.maurer-it.com (Proxmox) with ESMTP id A047C45179 for ; Tue, 15 Dec 2020 11:37:41 +0100 (CET) From: Wolfgang Bumiller To: pbs-devel@lists.proxmox.com Date: Tue, 15 Dec 2020 11:37:37 +0100 Message-Id: <20201215103737.9957-1-w.bumiller@proxmox.com> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SPAM-LEVEL: Spam detection results: 0 AWL 0.018 Adjusted score from AWL reputation of From: address KAM_DMARC_STATUS 0.01 Test Rule for DKIM or SPF Failure with Strict Alignment RCVD_IN_DNSWL_MED -2.3 Sender listed at https://www.dnswl.org/, medium trust SPF_HELO_NONE 0.001 SPF: HELO does not publish an SPF Record SPF_PASS -0.001 SPF: sender matches SPF record URIBL_BLOCKED 0.001 ADMINISTRATOR NOTICE: The query to URIBL was blocked. See http://wiki.apache.org/spamassassin/DnsBlocklists#dnsbl-block for more information. [main.rs, mod.rs] Subject: [pbs-devel] [PATCH pxar] fix `decode_entry` on special files X-BeenThere: pbs-devel@lists.proxmox.com X-Mailman-Version: 2.1.29 Precedence: list List-Id: Proxmox Backup Server development discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 15 Dec 2020 10:38:12 -0000 When using the random accessor to access FIFOs or sockets, the ranged reader limits the data to only that entry, and the `decode_entry` will never see a `PAYLOAD` or `GOODBYE_TABLE` item to finish the entry. Instead, it'll reach EOF and we need to handle this. The accessor now tells the decoder to expect EOF as a valid condition for ending the entry. Signed-off-by: Wolfgang Bumiller --- The included testcase previously failed with "failed to decode entry for fifo0" src/accessor/mod.rs | 2 +- src/decoder/mod.rs | 52 +++++++++++++++++++++++++++++++++++--------- tests/simple/main.rs | 46 +++++++++++++++++++++++++++++++++++++++ 3 files changed, 89 insertions(+), 11 deletions(-) diff --git a/src/accessor/mod.rs b/src/accessor/mod.rs index 0ab03a6..d02dc13 100644 --- a/src/accessor/mod.rs +++ b/src/accessor/mod.rs @@ -229,7 +229,7 @@ async fn get_decoder( entry_range: Range, path: PathBuf, ) -> io::Result>> { - Ok(DecoderImpl::new_full(SeqReadAtAdapter::new(input, entry_range), path).await?) + Ok(DecoderImpl::new_full(SeqReadAtAdapter::new(input, entry_range), path, true).await?) } // NOTE: This performs the Decoder::read_next_item() behavior! Keep in mind when changing! diff --git a/src/decoder/mod.rs b/src/decoder/mod.rs index fcc2dd9..2a5e79a 100644 --- a/src/decoder/mod.rs +++ b/src/decoder/mod.rs @@ -155,6 +155,10 @@ pub(crate) struct DecoderImpl { path_lengths: Vec, state: State, with_goodbye_tables: bool, + + /// The random access code uses decoders for sub-ranges which may not end in a `PAYLOAD` for + /// entries like FIFOs or sockets, so there we explicitly allow an item to terminate with EOF. + eof_after_entry: bool, } enum State { @@ -191,14 +195,18 @@ pub(crate) enum ItemResult { impl DecoderImpl { pub async fn new(input: I) -> io::Result { - Self::new_full(input, "/".into()).await + Self::new_full(input, "/".into(), false).await } pub(crate) fn input(&self) -> &I { &self.input } - pub(crate) async fn new_full(input: I, path: PathBuf) -> io::Result { + pub(crate) async fn new_full( + input: I, + path: PathBuf, + eof_after_entry: bool, + ) -> io::Result { let this = DecoderImpl { input, current_header: unsafe { mem::zeroed() }, @@ -210,6 +218,7 @@ impl DecoderImpl { path_lengths: Vec::new(), state: State::Begin, with_goodbye_tables: false, + eof_after_entry, }; // this.read_next_entry().await?; @@ -383,7 +392,14 @@ impl DecoderImpl { self.current_header = unsafe { mem::zeroed() }; - while self.read_next_item().await? != ItemResult::Entry {} + loop { + match self.read_next_item_or_eof().await? { + Some(ItemResult::Entry) => break, + Some(ItemResult::Attribute) => continue, + None if self.eof_after_entry => break, + None => io_bail!("unexpected EOF in entry"), + } + } if self.entry.is_dir() { self.path_lengths @@ -402,24 +418,40 @@ impl DecoderImpl { .ok_or_else(|| io_format_err!("unexpected EOF")) } + async fn read_next_item(&mut self) -> io::Result { + match self.read_next_item_or_eof().await? { + Some(item) => Ok(item), + None => io_bail!("unexpected EOF"), + } + } + + // NOTE: The random accessor will decode FIFOs and Sockets in a decoder instance with a ranged + // reader so there is no PAYLOAD or GOODBYE TABLE to "end" an entry. + // // NOTE: This behavior method is also recreated in the accessor's `get_decoder_at_filename` // function! Keep in mind when changing! - async fn read_next_item(&mut self) -> io::Result { - self.read_next_header().await?; - self.read_current_item().await + async fn read_next_item_or_eof(&mut self) -> io::Result> { + match self.read_next_header_or_eof().await? { + Some(()) => self.read_current_item().await.map(Some), + None => Ok(None), + } } - async fn read_next_header(&mut self) -> io::Result<()> { + async fn read_next_header_or_eof(&mut self) -> io::Result> { let dest = unsafe { std::slice::from_raw_parts_mut( &mut self.current_header as *mut Header as *mut u8, size_of_val(&self.current_header), ) }; - seq_read_exact(&mut self.input, dest).await?; - self.current_header.check_header_size()?; - Ok(()) + match seq_read_exact_or_eof(&mut self.input, dest).await? { + Some(()) => { + self.current_header.check_header_size()?; + Ok(Some(())) + } + None => Ok(None), + } } /// Read the next item, the header is already loaded. diff --git a/tests/simple/main.rs b/tests/simple/main.rs index c73ca10..f15a0f5 100644 --- a/tests/simple/main.rs +++ b/tests/simple/main.rs @@ -42,6 +42,9 @@ fn test1() { assert!(!file.is_empty(), "encoder did not write any data"); + // may be useful for testing... + // std::fs::write("myarchive.pxar", &file).expect("failed to write out test archive"); + let mut input = &file[..]; let mut decoder = decoder::Decoder::from_std(&mut input).expect("failed to create decoder"); let decoded_fs = @@ -53,6 +56,7 @@ fn test1() { .expect("failed to create random access reader for encoded archive"); check_bunzip2(&accessor); + check_run_special_files(&accessor); } fn check_bunzip2(accessor: &accessor::Accessor<&[u8]>) { @@ -85,3 +89,45 @@ fn check_bunzip2(accessor: &accessor::Accessor<&[u8]>) { assert_eq!(content, "This is the bzip2 executable"); } + +fn check_run_special_files(accessor: &accessor::Accessor<&[u8]>) { + let rundir = accessor + .open_root() + .expect("failed to open root of encoded archive") + .lookup("run") + .expect("failed to open /run in encoded archive") + .expect("missing /run in encoded archive") + .enter_directory() + .expect("expected /run to be a directory in the test archive"); + + assert_eq!(rundir.entry_count(), 2, "expected 2 entries in /run"); + + let mut rd = rundir.read_dir(); + let fifo0 = rd + .next() + .expect("expected 'fifo0' entry in rundir") + .expect("failed to get first (fifo0) entry in test archive /run directory"); + assert_eq!( + fifo0.file_name(), + Path::new("fifo0"), + "expected first file in /run to be fifo0" + ); + + let _entry = fifo0 + .decode_entry() + .expect("failed to decode entry for fifo0"); + + let sock0 = rd + .next() + .expect("expected 'sock0' entry in rundir") + .expect("failed to get second (sock0) entry in test archive /run directory"); + assert_eq!( + sock0.file_name(), + Path::new("sock0"), + "expected second file in /run to be sock0" + ); + + let _entry = sock0 + .decode_entry() + .expect("failed to decode entry for sock0"); +} -- 2.20.1