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 "src/core/lib/surface/validate_metadata.h"
20
21 #include <grpc/grpc.h>
22 #include <grpc/support/port_platform.h>
23
24 #include "absl/status/status.h"
25 #include "absl/strings/string_view.h"
26 #include "src/core/lib/iomgr/error.h"
27 #include "src/core/lib/slice/slice_internal.h"
28 #include "src/core/util/bitset.h"
29
30 namespace grpc_core {
31
32 namespace {
33 class LegalHeaderKeyBits : public BitSet<256> {
34 public:
LegalHeaderKeyBits()35 constexpr LegalHeaderKeyBits() {
36 for (int i = 'a'; i <= 'z'; i++) set(i);
37 for (int i = '0'; i <= '9'; i++) set(i);
38 set('-');
39 set('_');
40 set('.');
41 }
42 };
43 constexpr LegalHeaderKeyBits g_legal_header_key_bits;
44
ConformsTo(absl::string_view x,const BitSet<256> & legal_bits,ValidateMetadataResult error)45 ValidateMetadataResult ConformsTo(absl::string_view x,
46 const BitSet<256>& legal_bits,
47 ValidateMetadataResult error) {
48 for (uint8_t c : x) {
49 if (!legal_bits.is_set(c)) {
50 return error;
51 }
52 }
53 return ValidateMetadataResult::kOk;
54 }
55
UpgradeToStatus(ValidateMetadataResult result)56 absl::Status UpgradeToStatus(ValidateMetadataResult result) {
57 if (result == ValidateMetadataResult::kOk) return absl::OkStatus();
58 return absl::InternalError(ValidateMetadataResultToString(result));
59 }
60
61 } // namespace
62
ValidateHeaderKeyIsLegal(absl::string_view key)63 ValidateMetadataResult ValidateHeaderKeyIsLegal(absl::string_view key) {
64 if (key.empty()) {
65 return ValidateMetadataResult::kCannotBeZeroLength;
66 }
67 if (key.size() > UINT32_MAX) {
68 return ValidateMetadataResult::kTooLong;
69 }
70 return ConformsTo(key, g_legal_header_key_bits,
71 ValidateMetadataResult::kIllegalHeaderKey);
72 }
73
ValidateMetadataResultToString(ValidateMetadataResult result)74 const char* ValidateMetadataResultToString(ValidateMetadataResult result) {
75 switch (result) {
76 case ValidateMetadataResult::kOk:
77 return "Ok";
78 case ValidateMetadataResult::kCannotBeZeroLength:
79 return "Metadata keys cannot be zero length";
80 case ValidateMetadataResult::kTooLong:
81 return "Metadata keys cannot be larger than UINT32_MAX";
82 case ValidateMetadataResult::kIllegalHeaderKey:
83 return "Illegal header key";
84 case ValidateMetadataResult::kIllegalHeaderValue:
85 return "Illegal header value";
86 }
87 GPR_UNREACHABLE_CODE(return "Unknown");
88 }
89
90 } // namespace grpc_core
91
error2int(grpc_error_handle error)92 static int error2int(grpc_error_handle error) {
93 int r = (error.ok());
94 return r;
95 }
96
grpc_validate_header_key_is_legal(const grpc_slice & slice)97 grpc_error_handle grpc_validate_header_key_is_legal(const grpc_slice& slice) {
98 return grpc_core::UpgradeToStatus(grpc_core::ValidateHeaderKeyIsLegal(
99 grpc_core::StringViewFromSlice(slice)));
100 }
101
grpc_header_key_is_legal(grpc_slice slice)102 int grpc_header_key_is_legal(grpc_slice slice) {
103 return error2int(grpc_validate_header_key_is_legal(slice));
104 }
105
106 namespace {
107 class LegalHeaderNonBinValueBits : public grpc_core::BitSet<256> {
108 public:
LegalHeaderNonBinValueBits()109 constexpr LegalHeaderNonBinValueBits() {
110 for (int i = 32; i <= 126; i++) {
111 set(i);
112 }
113 }
114 };
115 constexpr LegalHeaderNonBinValueBits g_legal_header_non_bin_value_bits;
116 } // namespace
117
grpc_validate_header_nonbin_value_is_legal(const grpc_slice & slice)118 grpc_error_handle grpc_validate_header_nonbin_value_is_legal(
119 const grpc_slice& slice) {
120 return grpc_core::UpgradeToStatus(grpc_core::ConformsTo(
121 grpc_core::StringViewFromSlice(slice), g_legal_header_non_bin_value_bits,
122 grpc_core::ValidateMetadataResult::kIllegalHeaderValue));
123 }
124
grpc_header_nonbin_value_is_legal(grpc_slice slice)125 int grpc_header_nonbin_value_is_legal(grpc_slice slice) {
126 return error2int(grpc_validate_header_nonbin_value_is_legal(slice));
127 }
128
grpc_is_binary_header_internal(const grpc_slice & slice)129 int grpc_is_binary_header_internal(const grpc_slice& slice) {
130 return grpc_key_is_binary_header(GRPC_SLICE_START_PTR(slice),
131 GRPC_SLICE_LENGTH(slice));
132 }
133
grpc_is_binary_header(grpc_slice slice)134 int grpc_is_binary_header(grpc_slice slice) {
135 return grpc_is_binary_header_internal(slice);
136 }
137