1 /*
2 * Copyright (c) 2009-2021, Google LLC
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are met:
7 * * Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * * Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 * * Neither the name of Google LLC nor the
13 * names of its contributors may be used to endorse or promote products
14 * derived from this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
17 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL Google LLC BE LIABLE FOR ANY DIRECT,
20 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
21 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
22 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
23 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
25 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
27
28 // upb_decode: parsing into a upb_Message using a upb_MiniTable.
29
30 #ifndef UPB_WIRE_DECODE_H_
31 #define UPB_WIRE_DECODE_H_
32
33 #include "upb/mem/arena.h"
34 #include "upb/message/message.h"
35 #include "upb/mini_table/extension_registry.h"
36
37 // Must be last.
38 #include "upb/port/def.inc"
39
40 #ifdef __cplusplus
41 extern "C" {
42 #endif
43
44 enum {
45 /* If set, strings will alias the input buffer instead of copying into the
46 * arena. */
47 kUpb_DecodeOption_AliasString = 1,
48
49 /* If set, the parse will return failure if any message is missing any
50 * required fields when the message data ends. The parse will still continue,
51 * and the failure will only be reported at the end.
52 *
53 * IMPORTANT CAVEATS:
54 *
55 * 1. This can throw a false positive failure if an incomplete message is seen
56 * on the wire but is later completed when the sub-message occurs again.
57 * For this reason, a second pass is required to verify a failure, to be
58 * truly robust.
59 *
60 * 2. This can return a false success if you are decoding into a message that
61 * already has some sub-message fields present. If the sub-message does
62 * not occur in the binary payload, we will never visit it and discover the
63 * incomplete sub-message. For this reason, this check is only useful for
64 * implemting ParseFromString() semantics. For MergeFromString(), a
65 * post-parse validation step will always be necessary. */
66 kUpb_DecodeOption_CheckRequired = 2,
67 };
68
upb_DecodeOptions_MaxDepth(uint16_t depth)69 UPB_INLINE uint32_t upb_DecodeOptions_MaxDepth(uint16_t depth) {
70 return (uint32_t)depth << 16;
71 }
72
upb_DecodeOptions_GetMaxDepth(uint32_t options)73 UPB_INLINE uint16_t upb_DecodeOptions_GetMaxDepth(uint32_t options) {
74 return options >> 16;
75 }
76
77 // Enforce an upper bound on recursion depth.
upb_Decode_LimitDepth(uint32_t decode_options,uint32_t limit)78 UPB_INLINE int upb_Decode_LimitDepth(uint32_t decode_options, uint32_t limit) {
79 uint32_t max_depth = upb_DecodeOptions_GetMaxDepth(decode_options);
80 if (max_depth > limit) max_depth = limit;
81 return upb_DecodeOptions_MaxDepth(max_depth) | (decode_options & 0xffff);
82 }
83
84 typedef enum {
85 kUpb_DecodeStatus_Ok = 0,
86 kUpb_DecodeStatus_Malformed = 1, // Wire format was corrupt
87 kUpb_DecodeStatus_OutOfMemory = 2, // Arena alloc failed
88 kUpb_DecodeStatus_BadUtf8 = 3, // String field had bad UTF-8
89 kUpb_DecodeStatus_MaxDepthExceeded =
90 4, // Exceeded upb_DecodeOptions_MaxDepth
91
92 // kUpb_DecodeOption_CheckRequired failed (see above), but the parse otherwise
93 // succeeded.
94 kUpb_DecodeStatus_MissingRequired = 5,
95 } upb_DecodeStatus;
96
97 UPB_API upb_DecodeStatus upb_Decode(const char* buf, size_t size,
98 upb_Message* msg, const upb_MiniTable* l,
99 const upb_ExtensionRegistry* extreg,
100 int options, upb_Arena* arena);
101
102 #ifdef __cplusplus
103 } /* extern "C" */
104 #endif
105
106 #include "upb/port/undef.inc"
107
108 #endif /* UPB_WIRE_DECODE_H_ */
109