fix arithmetic side-effects

Signed-off-by: Jason Volk <jason@zemos.net>

src/service/rooms/auth_chain/mod.rs

@@ -5,7 +5,7 @@ use std::{
 	sync::Arc,
 };
 
-use conduit::{debug, error, trace, warn, Error, Result};
+use conduit::{debug, error, trace, validated, warn, Error, Result};
 use data::Data;
 use ruma::{api::client::error::ErrorKind, EventId, RoomId};
 
@@ -43,20 +43,20 @@ impl Service {
 
 	#[tracing::instrument(skip_all, name = "auth_chain")]
 	pub async fn get_auth_chain(&self, room_id: &RoomId, starting_events: &[&EventId]) -> Result<Vec<u64>> {
-		const NUM_BUCKETS: usize = 50; //TODO: change possible w/o disrupting db?
+		const NUM_BUCKETS: u64 = 50; //TODO: change possible w/o disrupting db?
 		const BUCKET: BTreeSet<(u64, &EventId)> = BTreeSet::new();
 
 		let started = std::time::Instant::now();
-		let mut buckets = [BUCKET; NUM_BUCKETS];
-		for (i, short) in services()
+		let mut buckets = [BUCKET; NUM_BUCKETS as usize];
+		for (i, &short) in services()
 			.rooms
 			.short
 			.multi_get_or_create_shorteventid(starting_events)?
 			.iter()
 			.enumerate()
 		{
-			let bucket = short % NUM_BUCKETS as u64;
-			buckets[bucket as usize].insert((*short, starting_events[i]));
+			let bucket = validated!(short % NUM_BUCKETS)?;
+			buckets[bucket as usize].insert((short, starting_events[i]));
 		}
 
 		debug!(

src/service/rooms/event_handler/mod.rs

@@ -191,7 +191,7 @@ impl Service {
 							e.insert((Instant::now(), 1));
 						},
 						hash_map::Entry::Occupied(mut e) => {
-							*e.get_mut() = (Instant::now(), e.get().1 + 1);
+							*e.get_mut() = (Instant::now(), e.get().1.saturating_add(1));
 						},
 					};
 				},
@@ -1072,7 +1072,7 @@ impl Service {
 				let mut todo_auth_events = vec![Arc::clone(id)];
 				let mut events_in_reverse_order = Vec::with_capacity(todo_auth_events.len());
 				let mut events_all = HashSet::with_capacity(todo_auth_events.len());
-				let mut i = 0;
+				let mut i: u64 = 0;
 				while let Some(next_id) = todo_auth_events.pop() {
 					if let Some((time, tries)) = services()
 						.globals
@@ -1094,7 +1094,7 @@ impl Service {
 						continue;
 					}
 
-					i += 1;
+					i = i.saturating_add(1);
 					if i % 100 == 0 {
 						tokio::task::yield_now().await;
 					}

src/service/rooms/pdu_metadata/mod.rs

@@ -205,7 +205,7 @@ impl Service {
 					if let Ok(relations) = self.db.relations_until(user_id, room_id, target, until) {
 						for relation in relations.flatten() {
 							if stack_pdu.1 < max_depth {
-								stack.push((relation.clone(), stack_pdu.1 + 1));
+								stack.push((relation.clone(), stack_pdu.1.saturating_add(1)));
 							}
 
 							pdus.push(relation);

src/service/rooms/read_receipt/data.rs

@@ -76,10 +76,12 @@ impl Data {
 				.iter_from(&first_possible_edu, false)
 				.take_while(move |(k, _)| k.starts_with(&prefix2))
 				.map(move |(k, v)| {
-					let count = utils::u64_from_bytes(&k[prefix.len()..prefix.len() + size_of::<u64>()])
+					let count_offset = prefix.len().saturating_add(size_of::<u64>());
+					let count = utils::u64_from_bytes(&k[prefix.len()..count_offset])
 						.map_err(|_| Error::bad_database("Invalid readreceiptid count in db."))?;
+					let user_id_offset = count_offset.saturating_add(1);
 					let user_id = UserId::parse(
-						utils::string_from_bytes(&k[prefix.len() + size_of::<u64>() + 1..])
+						utils::string_from_bytes(&k[user_id_offset..])
 							.map_err(|_| Error::bad_database("Invalid readreceiptid userid bytes in db."))?,
 					)
 					.map_err(|_| Error::bad_database("Invalid readreceiptid userid in db."))?;

src/service/rooms/spaces/mod.rs

@@ -7,7 +7,7 @@ use std::{
 	sync::Arc,
 };
 
-use conduit::debug_info;
+use conduit::{checked, debug_info};
 use lru_cache::LruCache;
 use ruma::{
 	api::{
@@ -508,7 +508,8 @@ impl Service {
 							}
 
 							// We have reached the room after where we last left off
-							if parents.len() + 1 == short_room_ids.len() {
+							let parents_len = parents.len();
+							if checked!(parents_len + 1)? == short_room_ids.len() {
 								populate_results = true;
 							}
 						}

src/service/rooms/state_compressor/data.rs

@@ -1,6 +1,6 @@
 use std::{collections::HashSet, mem::size_of, sync::Arc};
 
-use conduit::{utils, Error, Result};
+use conduit::{checked, utils, Error, Result};
 use database::{Database, Map};
 
 use super::CompressedStateEvent;
@@ -38,11 +38,12 @@ impl Data {
 		let mut added = HashSet::new();
 		let mut removed = HashSet::new();
 
-		let mut i = size_of::<u64>();
-		while let Some(v) = value.get(i..i + 2 * size_of::<u64>()) {
+		let stride = size_of::<u64>();
+		let mut i = stride;
+		while let Some(v) = value.get(i..checked!(i + 2 * stride)?) {
 			if add_mode && v.starts_with(&0_u64.to_be_bytes()) {
 				add_mode = false;
-				i += size_of::<u64>();
+				i = checked!(i + stride)?;
 				continue;
 			}
 			if add_mode {
@@ -50,7 +51,7 @@ impl Data {
 			} else {
 				removed.insert(v.try_into().expect("we checked the size above"));
 			}
-			i += 2 * size_of::<u64>();
+			i = checked!(i + 2 * stride)?;
 		}
 
 		Ok(StateDiff {

src/service/rooms/state_compressor/mod.rs

@@ -7,7 +7,7 @@ use std::{
 	sync::{Arc, Mutex as StdMutex, Mutex},
 };
 
-use conduit::{utils, Result};
+use conduit::{checked, utils, Result};
 use data::Data;
 use lru_cache::LruCache;
 use ruma::{EventId, RoomId};
@@ -169,12 +169,14 @@ impl Service {
 		statediffremoved: Arc<HashSet<CompressedStateEvent>>, diff_to_sibling: usize,
 		mut parent_states: ParentStatesVec,
 	) -> Result<()> {
-		let diffsum = statediffnew.len() + statediffremoved.len();
+		let statediffnew_len = statediffnew.len();
+		let statediffremoved_len = statediffremoved.len();
+		let diffsum = checked!(statediffnew_len + statediffremoved_len)?;
 
 		if parent_states.len() > 3 {
 			// Number of layers
 			// To many layers, we have to go deeper
-			let parent = parent_states.pop().unwrap();
+			let parent = parent_states.pop().expect("parent must have a state");
 
 			let mut parent_new = (*parent.2).clone();
 			let mut parent_removed = (*parent.3).clone();
@@ -226,10 +228,12 @@ impl Service {
 		// 1. We add the current diff on top of the parent layer.
 		// 2. We replace a layer above
 
-		let parent = parent_states.pop().unwrap();
-		let parent_diff = parent.2.len() + parent.3.len();
+		let parent = parent_states.pop().expect("parent must have a state");
+		let parent_2_len = parent.2.len();
+		let parent_3_len = parent.3.len();
+		let parent_diff = checked!(parent_2_len + parent_3_len)?;
 
-		if diffsum * diffsum >= 2 * diff_to_sibling * parent_diff {
+		if checked!(diffsum * diffsum)? >= checked!(2 * diff_to_sibling * parent_diff)? {
 			// Diff too big, we replace above layer(s)
 			let mut parent_new = (*parent.2).clone();
 			let mut parent_removed = (*parent.3).clone();

src/service/rooms/threads/data.rs

@@ -1,6 +1,6 @@
 use std::{mem::size_of, sync::Arc};
 
-use conduit::{utils, Error, Result};
+use conduit::{checked, utils, Error, Result};
 use database::{Database, Map};
 use ruma::{api::client::threads::get_threads::v1::IncludeThreads, OwnedUserId, RoomId, UserId};
 
@@ -31,7 +31,7 @@ impl Data {
 			.to_vec();
 
 		let mut current = prefix.clone();
-		current.extend_from_slice(&(until - 1).to_be_bytes());
+		current.extend_from_slice(&(checked!(until - 1)?).to_be_bytes());
 
 		Ok(Box::new(
 			self.threadid_userids

src/service/rooms/threads/mod.rs

@@ -64,7 +64,7 @@ impl Service {
 				.and_then(|relations| serde_json::from_value::<BundledThread>(relations.clone().into()).ok())
 			{
 				// Thread already existed
-				relations.count += uint!(1);
+				relations.count = relations.count.saturating_add(uint!(1));
 				relations.latest_event = pdu.to_message_like_event();
 
 				let content = serde_json::to_value(relations).expect("to_value always works");

src/service/rooms/timeline/data.rs

@@ -4,7 +4,7 @@ use std::{
 	sync::{Arc, Mutex},
 };
 
-use conduit::{error, utils, Error, Result};
+use conduit::{checked, error, utils, Error, Result};
 use database::{Database, Map};
 use ruma::{api::client::error::ErrorKind, CanonicalJsonObject, EventId, OwnedRoomId, OwnedUserId, RoomId, UserId};
 
@@ -281,10 +281,12 @@ impl Data {
 
 /// Returns the `count` of this pdu's id.
 pub(super) fn pdu_count(pdu_id: &[u8]) -> Result<PduCount> {
-	let last_u64 = utils::u64_from_bytes(&pdu_id[pdu_id.len() - size_of::<u64>()..])
+	let stride = size_of::<u64>();
+	let pdu_id_len = pdu_id.len();
+	let last_u64 = utils::u64_from_bytes(&pdu_id[checked!(pdu_id_len - stride)?..])
 		.map_err(|_| Error::bad_database("PDU has invalid count bytes."))?;
 	let second_last_u64 =
-		utils::u64_from_bytes(&pdu_id[pdu_id.len() - 2 * size_of::<u64>()..pdu_id.len() - size_of::<u64>()]);
+		utils::u64_from_bytes(&pdu_id[checked!(pdu_id_len - 2 * stride)?..checked!(pdu_id_len - stride)?]);
 
 	if matches!(second_last_u64, Ok(0)) {
 		Ok(PduCount::Backfilled(u64::MAX.saturating_sub(last_u64)))

src/service/rooms/timeline/mod.rs

@@ -6,7 +6,7 @@ use std::{
 	sync::Arc,
 };
 
-use conduit::{debug, error, info, utils, utils::mutex_map, warn, Error, Result};
+use conduit::{debug, error, info, utils, utils::mutex_map, validated, warn, Error, Result};
 use data::Data;
 use itertools::Itertools;
 use rand::prelude::SliceRandom;
@@ -670,7 +670,7 @@ impl Service {
 			.filter_map(|event_id| Some(self.get_pdu(event_id).ok()??.depth))
 			.max()
 			.unwrap_or_else(|| uint!(0))
-			+ uint!(1);
+			.saturating_add(uint!(1));
 
 		let mut unsigned = unsigned.unwrap_or_default();
 
@@ -1240,10 +1240,11 @@ impl Service {
 
 		let insert_lock = services().globals.roomid_mutex_insert.lock(&room_id).await;
 
+		let max = u64::MAX;
 		let count = services().globals.next_count()?;
 		let mut pdu_id = shortroomid.to_be_bytes().to_vec();
 		pdu_id.extend_from_slice(&0_u64.to_be_bytes());
-		pdu_id.extend_from_slice(&(u64::MAX - count).to_be_bytes());
+		pdu_id.extend_from_slice(&(validated!(max - count)?).to_be_bytes());
 
 		// Insert pdu
 		self.db.prepend_backfill_pdu(&pdu_id, &event_id, &value)?;