• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 /*
2  *
3  * Copyright 2016 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 #include <grpc/support/port_platform.h>
20 
21 #include "src/core/lib/transport/error_utils.h"
22 
23 #include <grpc/support/string_util.h>
24 #include "src/core/lib/iomgr/error_internal.h"
25 #include "src/core/lib/slice/slice_internal.h"
26 #include "src/core/lib/transport/status_conversion.h"
27 
recursively_find_error_with_field(grpc_error * error,grpc_error_ints which)28 static grpc_error* recursively_find_error_with_field(grpc_error* error,
29                                                      grpc_error_ints which) {
30   intptr_t unused;
31   // If the error itself has a status code, return it.
32   if (grpc_error_get_int(error, which, &unused)) {
33     return error;
34   }
35   if (grpc_error_is_special(error)) return nullptr;
36   // Otherwise, search through its children.
37   uint8_t slot = error->first_err;
38   while (slot != UINT8_MAX) {
39     grpc_linked_error* lerr =
40         reinterpret_cast<grpc_linked_error*>(error->arena + slot);
41     grpc_error* result = recursively_find_error_with_field(lerr->err, which);
42     if (result) return result;
43     slot = lerr->next;
44   }
45   return nullptr;
46 }
47 
grpc_error_get_status(grpc_error * error,grpc_millis deadline,grpc_status_code * code,grpc_slice * slice,grpc_http2_error_code * http_error,const char ** error_string)48 void grpc_error_get_status(grpc_error* error, grpc_millis deadline,
49                            grpc_status_code* code, grpc_slice* slice,
50                            grpc_http2_error_code* http_error,
51                            const char** error_string) {
52   // Fast path: We expect no error.
53   if (GPR_LIKELY(error == GRPC_ERROR_NONE)) {
54     if (code != nullptr) *code = GRPC_STATUS_OK;
55     if (slice != nullptr) {
56       // Normally, we call grpc_error_get_str(
57       //   error, GRPC_ERROR_STR_GRPC_MESSAGE, slice).
58       // We can fastpath since we know that:
59       // 1) Error is null
60       // 2) which == GRPC_ERROR_STR_GRPC_MESSAGE
61       // 3) The resulting slice is statically known.
62       // 4) Said resulting slice is of length 0 ("").
63       // This means 3 movs, instead of 10s of instructions and a strlen.
64       *slice = grpc_core::ExternallyManagedSlice("");
65     }
66     if (http_error != nullptr) {
67       *http_error = GRPC_HTTP2_NO_ERROR;
68     }
69     return;
70   }
71 
72   // Start with the parent error and recurse through the tree of children
73   // until we find the first one that has a status code.
74   grpc_error* found_error =
75       recursively_find_error_with_field(error, GRPC_ERROR_INT_GRPC_STATUS);
76   if (found_error == nullptr) {
77     /// If no grpc-status exists, retry through the tree to find a http2 error
78     /// code
79     found_error =
80         recursively_find_error_with_field(error, GRPC_ERROR_INT_HTTP2_ERROR);
81   }
82 
83   // If we found an error with a status code above, use that; otherwise,
84   // fall back to using the parent error.
85   if (found_error == nullptr) found_error = error;
86 
87   grpc_status_code status = GRPC_STATUS_UNKNOWN;
88   intptr_t integer;
89   if (grpc_error_get_int(found_error, GRPC_ERROR_INT_GRPC_STATUS, &integer)) {
90     status = static_cast<grpc_status_code>(integer);
91   } else if (grpc_error_get_int(found_error, GRPC_ERROR_INT_HTTP2_ERROR,
92                                 &integer)) {
93     status = grpc_http2_error_to_grpc_status(
94         static_cast<grpc_http2_error_code>(integer), deadline);
95   }
96   if (code != nullptr) *code = status;
97 
98   if (error_string != nullptr && status != GRPC_STATUS_OK) {
99     *error_string = gpr_strdup(grpc_error_string(error));
100   }
101 
102   if (http_error != nullptr) {
103     if (grpc_error_get_int(found_error, GRPC_ERROR_INT_HTTP2_ERROR, &integer)) {
104       *http_error = static_cast<grpc_http2_error_code>(integer);
105     } else if (grpc_error_get_int(found_error, GRPC_ERROR_INT_GRPC_STATUS,
106                                   &integer)) {
107       *http_error =
108           grpc_status_to_http2_error(static_cast<grpc_status_code>(integer));
109     } else {
110       *http_error = found_error == GRPC_ERROR_NONE ? GRPC_HTTP2_NO_ERROR
111                                                    : GRPC_HTTP2_INTERNAL_ERROR;
112     }
113   }
114 
115   // If the error has a status message, use it.  Otherwise, fall back to
116   // the error description.
117   if (slice != nullptr) {
118     if (!grpc_error_get_str(found_error, GRPC_ERROR_STR_GRPC_MESSAGE, slice)) {
119       if (!grpc_error_get_str(found_error, GRPC_ERROR_STR_DESCRIPTION, slice)) {
120         *slice = grpc_slice_from_static_string("unknown error");
121       }
122     }
123   }
124 }
125 
grpc_error_to_absl_status(grpc_error * error)126 absl::Status grpc_error_to_absl_status(grpc_error* error) {
127   grpc_status_code status;
128   // TODO(yashykt): This should be updated once we decide on how to use the
129   // absl::Status payload to capture all the contents of grpc_error.
130   grpc_slice message;
131   grpc_error_get_status(error, GRPC_MILLIS_INF_FUTURE, &status, &message,
132                         nullptr /* http_error */, nullptr /* error_string */);
133   return absl::Status(static_cast<absl::StatusCode>(status),
134                       absl::string_view(reinterpret_cast<const char*>(
135                                             GRPC_SLICE_START_PTR(message)),
136                                         GRPC_SLICE_LENGTH(message)));
137 }
138 
grpc_error_has_clear_grpc_status(grpc_error * error)139 bool grpc_error_has_clear_grpc_status(grpc_error* error) {
140   intptr_t unused;
141   if (grpc_error_get_int(error, GRPC_ERROR_INT_GRPC_STATUS, &unused)) {
142     return true;
143   }
144   uint8_t slot = error->first_err;
145   while (slot != UINT8_MAX) {
146     grpc_linked_error* lerr =
147         reinterpret_cast<grpc_linked_error*>(error->arena + slot);
148     if (grpc_error_has_clear_grpc_status(lerr->err)) {
149       return true;
150     }
151     slot = lerr->next;
152   }
153   return false;
154 }
155