1 //
2 //
3 // Copyright 2015 gRPC authors.
4 //
5 // Licensed under the Apache License, Version 2.0 (the "License");
6 // you may not use this file except in compliance with the License.
7 // You may obtain a copy of the License at
8 //
9 //     http://www.apache.org/licenses/LICENSE-2.0
10 //
11 // Unless required by applicable law or agreed to in writing, software
12 // distributed under the License is distributed on an "AS IS" BASIS,
13 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 // See the License for the specific language governing permissions and
15 // limitations under the License.
16 //
17 //
18 
19 #ifndef GRPC_SRC_CORE_LIB_HTTP_HTTPCLI_H
20 #define GRPC_SRC_CORE_LIB_HTTP_HTTPCLI_H
21 
22 #include <grpc/support/port_platform.h>
23 
24 #include <stddef.h>
25 
26 #include <functional>
27 #include <memory>
28 #include <vector>
29 
30 #include "absl/base/thread_annotations.h"
31 #include "absl/status/status.h"
32 #include "absl/status/statusor.h"
33 #include "absl/types/optional.h"
34 
35 #include <grpc/grpc.h>
36 #include <grpc/slice.h>
37 
38 #include "src/core/lib/gprpp/debug_location.h"
39 #include "src/core/lib/gprpp/orphanable.h"
40 #include "src/core/lib/gprpp/ref_counted_ptr.h"
41 #include "src/core/lib/gprpp/sync.h"
42 #include "src/core/lib/gprpp/time.h"
43 #include "src/core/lib/http/parser.h"
44 #include "src/core/lib/iomgr/closure.h"
45 #include "src/core/lib/iomgr/endpoint.h"
46 #include "src/core/lib/iomgr/error.h"
47 #include "src/core/lib/iomgr/exec_ctx.h"
48 #include "src/core/lib/iomgr/iomgr_fwd.h"
49 #include "src/core/lib/iomgr/iomgr_internal.h"
50 #include "src/core/lib/iomgr/polling_entity.h"
51 #include "src/core/lib/iomgr/resolve_address.h"
52 #include "src/core/lib/iomgr/resolved_address.h"
53 #include "src/core/lib/resource_quota/resource_quota.h"
54 #include "src/core/lib/transport/handshaker.h"
55 #include "src/core/lib/uri/uri_parser.h"
56 
57 // User agent this library reports
58 #define GRPC_HTTPCLI_USER_AGENT "grpc-httpcli/0.0"
59 
60 // override functions return 1 if they handled the request, 0 otherwise
61 typedef int (*grpc_httpcli_get_override)(const grpc_http_request* request,
62                                          const char* host, const char* path,
63                                          grpc_core::Timestamp deadline,
64                                          grpc_closure* on_complete,
65                                          grpc_http_response* response);
66 typedef int (*grpc_httpcli_post_override)(
67     const grpc_http_request* request, const char* host, const char* path,
68     const char* body_bytes, size_t body_size, grpc_core::Timestamp deadline,
69     grpc_closure* on_complete, grpc_http_response* response);
70 typedef int (*grpc_httpcli_put_override)(
71     const grpc_http_request* request, const char* host, const char* path,
72     const char* body_bytes, size_t body_size, grpc_core::Timestamp deadline,
73     grpc_closure* on_complete, grpc_http_response* response);
74 
75 namespace grpc_core {
76 
77 // Tracks an in-progress GET or POST request. Calling \a Start()
78 // begins async work and calling \a Orphan() arranges for async work
79 // to be completed as sooon as possible (possibly aborting the request
80 // if it's in flight).
81 // TODO(ctiller): allow caching and capturing multiple requests for the
82 //                same content and combining them
83 class HttpRequest : public InternallyRefCounted<HttpRequest> {
84  public:
85   // Asynchronously perform a HTTP GET.
86   // 'uri' is the target to make the request to. The scheme field is used to
87   //  determine the port number. The authority field is the target host. The
88   //  path field determines the path of the request. No other fields are used.
89   // 'args' are optional channel args for the request.
90   // 'pollent' indicates a grpc_polling_entity that is interested in the result
91   //   of the get - work on this entity may be used to progress the get
92   //   operation
93   // 'request' contains request parameters - these are caller owned and
94   //   can be destroyed once the call returns
95   // 'deadline' contains a deadline for the request (or gpr_inf_future)
96   // 'on_done' is a callback to report results to
97   // 'channel_creds' are used to configurably secure the connection.
98   //   For insecure requests, use grpc_insecure_credentials_create.
99   //   For secure requests, use CreateHttpRequestSSLCredentials().
100   //   nullptr is treated as insecure credentials.
101   //   TODO(yihuaz): disallow nullptr as a value after unsecure builds
102   //   are removed.
103   static OrphanablePtr<HttpRequest> Get(
104       URI uri, const grpc_channel_args* args, grpc_polling_entity* pollent,
105       const grpc_http_request* request, Timestamp deadline,
106       grpc_closure* on_done, grpc_http_response* response,
107       RefCountedPtr<grpc_channel_credentials> channel_creds)
108       GRPC_MUST_USE_RESULT;
109 
110   // Asynchronously perform a HTTP POST.
111   // 'uri' is the target to make the request to. The scheme field is used to
112   //  determine the port number. The authority field is the target host. The
113   //  path field determines the path of the request. No other fields are used.
114   // 'args' are optional channel args for the request.
115   // 'pollent' indicates a grpc_polling_entity that is interested in the result
116   //   of the post - work on this entity may be used to progress the post
117   //   operation
118   // 'request' contains request parameters - these are caller owned and can be
119   //   destroyed once the call returns
120   // 'deadline' contains a deadline for the request (or gpr_inf_future)
121   // 'on_done' is a callback to report results to
122   // 'channel_creds' are used to configurably secure the connection.
123   //   For insecure requests, use grpc_insecure_credentials_create.
124   //   For secure requests, use CreateHttpRequestSSLCredentials().
125   //   nullptr is treated as insecure credentials.
126   //   TODO(apolcyn): disallow nullptr as a value after unsecure builds
127   //   are removed.
128   // Does not support ?var1=val1&var2=val2 in the path.
129   static OrphanablePtr<HttpRequest> Post(
130       URI uri, const grpc_channel_args* args, grpc_polling_entity* pollent,
131       const grpc_http_request* request, Timestamp deadline,
132       grpc_closure* on_done, grpc_http_response* response,
133       RefCountedPtr<grpc_channel_credentials> channel_creds)
134       GRPC_MUST_USE_RESULT;
135 
136   // Asynchronously perform a HTTP PUT.
137   // 'uri' is the target to make the request to. The scheme field is used to
138   //  determine the port number. The authority field is the target host. The
139   //  path field determines the path of the request. No other fields are used.
140   // 'args' are optional channel args for the request.
141   // 'pollent' indicates a grpc_polling_entity that is interested in the result
142   //   of the post - work on this entity may be used to progress the post
143   //   operation
144   // 'request' contains request parameters - these are caller owned and can be
145   //   destroyed once the call returns
146   // 'deadline' contains a deadline for the request (or gpr_inf_future)
147   // 'on_done' is a callback to report results to
148   // 'channel_creds' are used to configurably secure the connection.
149   //   For insecure requests, use grpc_insecure_credentials_create.
150   //   For secure requests, use CreateHttpRequestSSLCredentials().
151   //   nullptr is treated as insecure credentials.
152   //   TODO(apolcyn): disallow nullptr as a value after unsecure builds
153   //   are removed.
154   // Does not support ?var1=val1&var2=val2 in the path.
155   static OrphanablePtr<HttpRequest> Put(
156       URI uri, const grpc_channel_args* args, grpc_polling_entity* pollent,
157       const grpc_http_request* request, Timestamp deadline,
158       grpc_closure* on_done, grpc_http_response* response,
159       RefCountedPtr<grpc_channel_credentials> channel_creds)
160       GRPC_MUST_USE_RESULT;
161 
162   HttpRequest(URI uri, const grpc_slice& request_text,
163               grpc_http_response* response, Timestamp deadline,
164               const grpc_channel_args* channel_args, grpc_closure* on_done,
165               grpc_polling_entity* pollent, const char* name,
166               absl::optional<std::function<void()>> test_only_generate_response,
167               RefCountedPtr<grpc_channel_credentials> channel_creds);
168 
169   ~HttpRequest() override;
170 
171   void Start();
172 
173   void Orphan() override;
174 
175   static void SetOverride(grpc_httpcli_get_override get,
176                           grpc_httpcli_post_override post,
177                           grpc_httpcli_put_override put);
178 
179   static void TestOnlySetOnHandshakeDoneIntercept(
180       void (*intercept)(HttpRequest* req));
181 
182  private:
Finish(grpc_error_handle error)183   void Finish(grpc_error_handle error) ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu_) {
184     grpc_polling_entity_del_from_pollset_set(pollent_, pollset_set_);
185     ExecCtx::Run(DEBUG_LOCATION, on_done_, error);
186   }
187 
188   void AppendError(grpc_error_handle error) ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu_);
189 
DoRead()190   void DoRead() ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu_) {
191     Ref().release();  // ref held by pending read
192     grpc_endpoint_read(ep_, &incoming_, &on_read_, /*urgent=*/true,
193                        /*min_progress_size=*/1);
194   }
195 
OnRead(void * user_data,grpc_error_handle error)196   static void OnRead(void* user_data, grpc_error_handle error) {
197     HttpRequest* req = static_cast<HttpRequest*>(user_data);
198     ExecCtx::Run(DEBUG_LOCATION,
199                  &req->continue_on_read_after_schedule_on_exec_ctx_, error);
200   }
201 
202   // Needed since OnRead may be called inline from grpc_endpoint_read
ContinueOnReadAfterScheduleOnExecCtx(void * user_data,grpc_error_handle error)203   static void ContinueOnReadAfterScheduleOnExecCtx(void* user_data,
204                                                    grpc_error_handle error) {
205     RefCountedPtr<HttpRequest> req(static_cast<HttpRequest*>(user_data));
206     MutexLock lock(&req->mu_);
207     req->OnReadInternal(error);
208   }
209 
210   void OnReadInternal(grpc_error_handle error)
211       ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu_);
212 
OnWritten()213   void OnWritten() ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu_) { DoRead(); }
214 
DoneWrite(void * arg,grpc_error_handle error)215   static void DoneWrite(void* arg, grpc_error_handle error) {
216     HttpRequest* req = static_cast<HttpRequest*>(arg);
217     ExecCtx::Run(DEBUG_LOCATION,
218                  &req->continue_done_write_after_schedule_on_exec_ctx_, error);
219   }
220 
221   // Needed since DoneWrite may be called inline from grpc_endpoint_write
222   static void ContinueDoneWriteAfterScheduleOnExecCtx(void* arg,
223                                                       grpc_error_handle error);
224 
225   void StartWrite() ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu_);
226 
227   static void OnHandshakeDone(void* arg, grpc_error_handle error);
228 
229   void DoHandshake(const grpc_resolved_address* addr)
230       ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu_);
231 
232   void NextAddress(grpc_error_handle error) ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu_);
233 
234   void OnResolved(
235       absl::StatusOr<std::vector<grpc_resolved_address>> addresses_or);
236 
237   const URI uri_;
238   const grpc_slice request_text_;
239   const Timestamp deadline_;
240   const grpc_channel_args* channel_args_;
241   RefCountedPtr<grpc_channel_credentials> channel_creds_;
242   grpc_closure on_read_;
243   grpc_closure continue_on_read_after_schedule_on_exec_ctx_;
244   grpc_closure done_write_;
245   grpc_closure continue_done_write_after_schedule_on_exec_ctx_;
246   grpc_endpoint* ep_ = nullptr;
247   grpc_closure* on_done_;
248   ResourceQuotaRefPtr resource_quota_;
249   grpc_polling_entity* pollent_;
250   grpc_pollset_set* pollset_set_;
251   const absl::optional<std::function<void()>> test_only_generate_response_;
252   Mutex mu_;
253   RefCountedPtr<HandshakeManager> handshake_mgr_ ABSL_GUARDED_BY(mu_);
254   bool own_endpoint_ ABSL_GUARDED_BY(mu_) = true;
255   bool cancelled_ ABSL_GUARDED_BY(mu_) = false;
256   grpc_http_parser parser_ ABSL_GUARDED_BY(mu_);
257   std::vector<grpc_resolved_address> addresses_ ABSL_GUARDED_BY(mu_);
258   size_t next_address_ ABSL_GUARDED_BY(mu_) = 0;
259   int have_read_byte_ ABSL_GUARDED_BY(mu_) = 0;
260   grpc_iomgr_object iomgr_obj_ ABSL_GUARDED_BY(mu_);
261   grpc_slice_buffer incoming_ ABSL_GUARDED_BY(mu_);
262   grpc_slice_buffer outgoing_ ABSL_GUARDED_BY(mu_);
263   grpc_error_handle overall_error_ ABSL_GUARDED_BY(mu_) = absl::OkStatus();
264   std::shared_ptr<DNSResolver> resolver_;
265   absl::optional<DNSResolver::TaskHandle> dns_request_handle_
266       ABSL_GUARDED_BY(mu_) = DNSResolver::kNullHandle;
267 };
268 
269 }  // namespace grpc_core
270 
271 #endif  // GRPC_SRC_CORE_LIB_HTTP_HTTPCLI_H
272