1 /*
2 * Copyright (c) 2021 Huawei Device Co., Ltd.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at
6 *
7 * http://www.apache.org/licenses/LICENSE-2.0
8 *
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
14 */
15
16 #include "secureprintoutput.h"
17
18 static inline int SecVsnprintfPImpl(char *string, size_t count, int priv, const char *format, va_list arglist);
19
20 /*******************************************************************************
21 * <FUNCTION DESCRIPTION>
22 * The vsnprintf_s function is equivalent to the vsnprintf function
23 * except for the parameter destMax/count and the explicit runtime-constraints violation
24 * The vsnprintf_s function takes a pointer to an argument list, then formats
25 * and writes up to count characters of the given data to the memory pointed
26 * to by strDest and appends a terminating null.
27 *
28 * <INPUT PARAMETERS>
29 * strDest Storage location for the output.
30 * destMax The size of the strDest for output.
31 * count Maximum number of character to write(not including
32 * the terminating NULL)
33 * priv_on whether print <private> for not-public args
34 * format Format-control string.
35 * arglist pointer to list of arguments.
36 *
37 * <OUTPUT PARAMETERS>
38 * strDest is updated
39 *
40 * <RETURN VALUE>
41 * return the number of characters written, not including the terminating null
42 * return -1 if an error occurs.
43 * return -1 if count < destMax and the output string has been truncated
44 *
45 * If there is a runtime-constraint violation, strDest[0] will be set to the '\0' when strDest and destMax valid
46 *******************************************************************************
47 */
vsnprintfp_s(char * strDest,size_t destMax,size_t count,int priv,const char * format,va_list arglist)48 int vsnprintfp_s(char *strDest, size_t destMax, size_t count, int priv, const char *format, va_list arglist)
49 {
50 int retVal;
51
52 if (format == NULL || strDest == NULL || destMax == 0 || destMax > SECUREC_STRING_MAX_LEN ||
53 (count > (SECUREC_STRING_MAX_LEN - 1) && count != (size_t)-1)) {
54 if (strDest != NULL && destMax > 0) {
55 strDest[0] = '\0';
56 }
57 SECUREC_ERROR_INVALID_PARAMTER("vsnprintfp_s");
58 return -1;
59 }
60
61 if (destMax > count) {
62 retVal = SecVsnprintfPImpl(strDest, count + 1, priv, format, arglist);
63 if (retVal == SECUREC_PRINTF_TRUNCATE) { /* lsd add to keep dest buffer not destroyed 2014.2.18 */
64 /* the string has been truncated, return -1 */
65 return -1; /* to skip error handler, return strlen(strDest) or -1 */
66 }
67 } else { /* destMax <= count */
68 retVal = SecVsnprintfPImpl(strDest, destMax, priv, format, arglist);
69 #ifdef SECUREC_COMPATIBLE_WIN_FORMAT
70 if (retVal == SECUREC_PRINTF_TRUNCATE && count == (size_t)-1) {
71 return -1;
72 }
73 #endif
74 }
75
76 if (retVal < 0) {
77 strDest[0] = '\0'; /* empty the dest strDest */
78
79 if (retVal == SECUREC_PRINTF_TRUNCATE) {
80 /* Buffer too small */
81 SECUREC_ERROR_INVALID_RANGE("vsnprintfp_s");
82 }
83
84 SECUREC_ERROR_INVALID_PARAMTER("vsnprintfp_s");
85 return -1;
86 }
87
88 return retVal;
89 }
90
91 #ifdef SECUREC_FOR_WCHAR
92 #undef SECUREC_FOR_WCHAR
93 #endif
94
95 typedef char SecChar;
96 #define SECUREC_CHAR(x) x
97
98 #define SECUREC_WRITE_MULTI_CHAR SecWriteMultiChar
99 #define SECUREC_WRITE_STRING SecWriteString
100 #include "output_p.inl"
101
102 /* put a char to output */
103 #define SECUREC_PUTC(_c,_stream) ((--(_stream)->count >= 0) ? ((*(_stream)->cur++ = (char)(_c)) & 0xff) : EOF)
104 /* to clear e835 */
105 #define SECUREC_PUTC_ZERO(_stream) ((--(_stream)->count >= 0) ? ((*(_stream)->cur++ = (char)('\0'))) : EOF)
106
SecVsnprintfPImpl(char * string,size_t count,int priv,const char * format,va_list arglist)107 static inline int SecVsnprintfPImpl(char *string, size_t count, int priv, const char *format, va_list arglist)
108 {
109 SecPrintfStream str;
110 int retVal;
111
112 str.count = (int)count; /* this count include \0 character */
113 str.cur = string;
114
115 retVal = SecOutputPS(&str, priv, format, arglist);
116 if ((retVal >= 0) && (SECUREC_PUTC_ZERO(&str) != EOF)) {
117 return (retVal);
118 } else if (str.count < 0) {
119 /* the buffer was too small; we return truncation */
120 string[count - 1] = 0;
121 return SECUREC_PRINTF_TRUNCATE;
122 }
123
124 return -1;
125 }
126