[header-override-650] implement header overriding in GetObject (fix #650)header-override-650

3 files changed, 87 insertions, 6 deletions

diff --git a/src/api/s3/api_server.rs b/src/api/s3/api_server.rs
index 0065ca59..7fac6261 100644
--- a/src/api/s3/api_server.rs
+++ b/src/api/s3/api_server.rs
@@ -178,8 +178,26 @@ impl ApiHandler for S3ApiServer {
 				key, part_number, ..
 			} => handle_head(garage, &req, bucket_id, &key, part_number).await,
 			Endpoint::GetObject {
-				key, part_number, ..
-			} => handle_get(garage, &req, bucket_id, &key, part_number).await,
+				key,
+				part_number,
+				response_cache_control,
+				response_content_disposition,
+				response_content_encoding,
+				response_content_language,
+				response_content_type,
+				response_expires,
+				..
+			} => {
+				let overrides = GetObjectOverrides {
+					response_cache_control,
+					response_content_disposition,
+					response_content_encoding,
+					response_content_language,
+					response_content_type,
+					response_expires,
+				};
+				handle_get(garage, &req, bucket_id, &key, part_number, overrides).await
+			}
 			Endpoint::UploadPart {
 				key,
 				part_number,
diff --git a/src/api/s3/get.rs b/src/api/s3/get.rs
index f70dad7d..53f0a345 100644
--- a/src/api/s3/get.rs
+++ b/src/api/s3/get.rs
@@ -1,12 +1,14 @@
 //! Function related to GET and HEAD requests
+use std::convert::TryInto;
 use std::sync::Arc;
 use std::time::{Duration, UNIX_EPOCH};
 
 use futures::future;
 use futures::stream::{self, StreamExt};
 use http::header::{
-	ACCEPT_RANGES, CONTENT_LENGTH, CONTENT_RANGE, CONTENT_TYPE, ETAG, IF_MODIFIED_SINCE,
-	IF_NONE_MATCH, LAST_MODIFIED, RANGE,
+	ACCEPT_RANGES, CACHE_CONTROL, CONTENT_DISPOSITION, CONTENT_ENCODING, CONTENT_LANGUAGE,
+	CONTENT_LENGTH, CONTENT_RANGE, CONTENT_TYPE, ETAG, EXPIRES, IF_MODIFIED_SINCE, IF_NONE_MATCH,
+	LAST_MODIFIED, RANGE,
 };
 use hyper::{body::Body, Request, Response, StatusCode};
 use tokio::sync::mpsc;
@@ -27,6 +29,16 @@ use crate::s3::error::*;
 
 const X_AMZ_MP_PARTS_COUNT: &str = "x-amz-mp-parts-count";
 
+#[derive(Default)]
+pub struct GetObjectOverrides {
+	pub(crate) response_cache_control: Option<String>,
+	pub(crate) response_content_disposition: Option<String>,
+	pub(crate) response_content_encoding: Option<String>,
+	pub(crate) response_content_language: Option<String>,
+	pub(crate) response_content_type: Option<String>,
+	pub(crate) response_expires: Option<String>,
+}
+
 fn object_headers(
 	version: &ObjectVersion,
 	version_meta: &ObjectVersionMeta,
@@ -52,6 +64,32 @@ fn object_headers(
 	resp
 }
 
+/// Override headers according to specific query parameters, see
+/// section "Overriding response header values through the request" in
+/// https://docs.aws.amazon.com/AmazonS3/latest/API/API_GetObject.html
+fn getobject_override_headers(
+	overrides: GetObjectOverrides,
+	resp: &mut http::response::Builder,
+) -> Result<(), Error> {
+	// TODO: this only applies for signed requests, so when we support
+	// anonymous access in the future we will have to do a permission check here
+	let overrides = [
+		(CACHE_CONTROL, overrides.response_cache_control),
+		(CONTENT_DISPOSITION, overrides.response_content_disposition),
+		(CONTENT_ENCODING, overrides.response_content_encoding),
+		(CONTENT_LANGUAGE, overrides.response_content_language),
+		(CONTENT_TYPE, overrides.response_content_type),
+		(EXPIRES, overrides.response_expires),
+	];
+	for (hdr, val_opt) in overrides {
+		if let Some(val) = val_opt {
+			let val = val.try_into().ok_or_bad_request("invalid header value")?;
+			resp.headers_mut().unwrap().insert(hdr, val);
+		}
+	}
+	Ok(())
+}
+
 fn try_answer_cached(
 	version: &ObjectVersion,
 	version_meta: &ObjectVersionMeta,
@@ -185,6 +223,7 @@ pub async fn handle_get(
 	bucket_id: Uuid,
 	key: &str,
 	part_number: Option<u64>,
+	overrides: GetObjectOverrides,
 ) -> Result<Response<ResBody>, Error> {
 	let object = garage
 		.object_table
@@ -236,9 +275,10 @@ pub async fn handle_get(
 		(None, None) => (),
 	}
 
-	let resp_builder = object_headers(last_v, last_v_meta)
+	let mut resp_builder = object_headers(last_v, last_v_meta)
 		.header(CONTENT_LENGTH, format!("{}", last_v_meta.size))
 		.status(StatusCode::OK);
+	getobject_override_headers(overrides, &mut resp_builder)?;
 
 	match &last_v_data {
 		ObjectVersionData::DeleteMarker => unreachable!(),
@@ -303,6 +343,9 @@ async fn handle_get_range(
 	begin: u64,
 	end: u64,
 ) -> Result<Response<ResBody>, Error> {
+	// Here we do not use getobject_override_headers because we don't
+	// want to add any overridden headers (those should not be added
+	// when returning PARTIAL_CONTENT)
 	let resp_builder = object_headers(version, version_meta)
 		.header(CONTENT_LENGTH, format!("{}", end - begin))
 		.header(
@@ -343,6 +386,7 @@ async fn handle_get_part(
 	version_meta: &ObjectVersionMeta,
 	part_number: u64,
 ) -> Result<Response<ResBody>, Error> {
+	// Same as for get_range, no getobject_override_headers
 	let resp_builder =
 		object_headers(object_version, version_meta).status(StatusCode::PARTIAL_CONTENT);
 
diff --git a/src/api/s3/router.rs b/src/api/s3/router.rs
index 05882885..e7ac1d77 100644
--- a/src/api/s3/router.rs
+++ b/src/api/s3/router.rs
@@ -125,6 +125,12 @@ pub enum Endpoint {
 		key: String,
 		part_number: Option<u64>,
 		version_id: Option<String>,
+		response_cache_control: Option<String>,
+		response_content_disposition: Option<String>,
+		response_content_encoding: Option<String>,
+		response_content_language: Option<String>,
+		response_content_type: Option<String>,
+		response_expires: Option<String>,
 	},
 	GetObjectAcl {
 		key: String,
@@ -358,7 +364,14 @@ impl Endpoint {
 			(query.keyword.take().unwrap_or_default(), key, query, None),
 			key: [
 				EMPTY if upload_id => ListParts (query::upload_id, opt_parse::max_parts, opt_parse::part_number_marker),
-				EMPTY => GetObject (query_opt::version_id, opt_parse::part_number),
+				EMPTY => GetObject (query_opt::version_id,
+									opt_parse::part_number,
+									query_opt::response_cache_control,
+									query_opt::response_content_disposition,
+									query_opt::response_content_encoding,
+									query_opt::response_content_language,
+									query_opt::response_content_type,
+									query_opt::response_expires),
 				ACL => GetObjectAcl (query_opt::version_id),
 				LEGAL_HOLD => GetObjectLegalHold (query_opt::version_id),
 				RETENTION => GetObjectRetention (query_opt::version_id),
@@ -671,6 +684,12 @@ generateQueryParameters! {
 		"partNumber" => part_number,
 		"part-number-marker" => part_number_marker,
 		"prefix" => prefix,
+		"response-cache-control" => response_cache_control,
+		"response-content-disposition" => response_content_disposition,
+		"response-content-encoding" => response_content_encoding,
+		"response-content-language" => response_content_language,
+		"response-content-type" => response_content_type,
+		"response-expires" => response_expires,
 		"select-type" => select_type,
 		"start-after" => start_after,
 		"uploadId" => upload_id,