1 /* Copyright (c) 2021-2022 Huawei Device Co., Ltd.
2 * Licensed under the Apache License, Version 2.0 (the "License");
3 * you may not use this file except in compliance with the License.
4 * You may obtain a copy of the License at
5 *
6 * http://www.apache.org/licenses/LICENSE-2.0
7 *
8 * Unless required by applicable law or agreed to in writing, software
9 * distributed under the License is distributed on an "AS IS" BASIS,
10 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
11 * See the License for the specific language governing permissions and
12 * limitations under the License.
13 */
14
15 #include "stdio_impl.h"
16 #include <stdlib.h>
17 #include <sys/ioctl.h>
18 #include <sys/stat.h>
19 #include <fcntl.h>
20 #include <errno.h>
21 #include <string.h>
22 #include "libc.h"
23
__get_bufsize(int fd)24 static size_t __get_bufsize(int fd)
25 {
26 struct stat st;
27 size_t buf_size = 0;
28
29 if (fstat(fd, &st) < 0) {
30 buf_size = BUFSIZ;
31 } else if (st.st_blksize == 0) {
32 buf_size = BUFSIZ;
33 } else {
34 buf_size = st.st_blksize;
35 }
36
37 return buf_size;
38 }
39
__falloc_buf(FILE * f)40 int __falloc_buf(FILE *f)
41 {
42 /* return if already allocated, or F_NOBUF set */
43 if (f->buf != NULL || f->buf_size != 0 || f->flags & F_NOBUF) {
44 return 0;
45 }
46
47 /* Default, base and buf are NULL,and buf_size = 0 */
48 size_t buf_size = 0;
49
50 /* get buffer size via file stat */
51 buf_size = __get_bufsize(f->fd);
52
53 /* alloc R/W buffer */
54 f->base = (unsigned char *)malloc(UNGET + buf_size * sizeof(unsigned char));
55 if (!f->base) {
56 errno = -ENOMEM;
57 return errno;
58 }
59
60 /* reserve UNGET buffer */
61 f->buf = f->base + UNGET;
62 f->buf_size = buf_size;
63
64 return 0;
65 }
66
__fdopen(int fd,const char * mode)67 FILE *__fdopen(int fd, const char *mode)
68 {
69 FILE *f = NULL;
70 int file_flags = 0;
71 int mode_flags = 0;
72
73 int flags = syscall(SYS_fcntl, fd, F_GETFL, 0);
74 if (flags == -1) {
75 return NULL;
76 }
77
78 /* Compute the flags to pass to open() */
79 mode_flags = __fmodeflags(mode, &file_flags);
80 if (mode_flags < 0) {
81 return NULL;
82 }
83
84 if (mode_flags & O_CLOEXEC) {
85 __syscall(SYS_fcntl, fd, F_SETFD, FD_CLOEXEC);
86 }
87
88 if (mode_flags & O_APPEND) {
89 flags = __syscall(SYS_fcntl, fd, F_GETFL);
90 if (!(flags & O_APPEND))
91 __syscall(SYS_fcntl, fd, F_SETFL, flags | O_APPEND);
92 }
93
94 f = __fdopenx(fd, file_flags);
95 if (f) {
96 return f;
97 }
98
99 return NULL;
100 }
101 weak_alias(__fdopen, fdopen);
102
__fdopenx(int fd,int flags)103 FILE *__fdopenx(int fd, int flags)
104 {
105 FILE *f = 0;
106 struct winsize wsz;
107
108 /* Allocate FILE or fail */
109 if (!(f = __ofl_alloc())) {
110 return NULL;
111 }
112
113 /* Zero-fill only the struct, not the buffer */
114 memset(f, 0, sizeof *f);
115
116 f->flags = flags;
117 f->fd = fd;
118
119 /* Activate line buffered mode for terminals */
120 f->lbf = EOF;
121 if (!(f->flags & F_NOWR) && !__syscall(SYS_ioctl, fd, TIOCGWINSZ, &wsz)) {
122 f->lbf = '\n';
123 }
124
125 /* set file tag in fdtable, FILE type */
126 fdsan_exchange_owner_tag(fd, 0, __get_file_tag(f));
127
128 /* Initialize op ptrs. No problem if some are unneeded. */
129 f->read = __stdio_read;
130 f->write = __stdio_write;
131 f->seek = __stdio_seek;
132 f->close = __stdio_close;
133 f->readx = __stdio_readx;
134
135 if (!libc.threaded) {
136 f->lock = -1;
137 }
138
139 /* Add new FILE to open file list */
140 return __ofl_add(f);
141 }
142
143