1 /*
2 * Copyright (c) 2013-2019 Huawei Technologies Co., Ltd. All rights reserved.
3 * Copyright (c) 2020-2021 Huawei Device Co., Ltd. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without modification,
6 * are permitted provided that the following conditions are met:
7 *
8 * 1. Redistributions of source code must retain the above copyright notice, this list of
9 * conditions and the following disclaimer.
10 *
11 * 2. Redistributions in binary form must reproduce the above copyright notice, this list
12 * of conditions and the following disclaimer in the documentation and/or other materials
13 * provided with the distribution.
14 *
15 * 3. Neither the name of the copyright holder nor the names of its contributors may be used
16 * to endorse or promote products derived from this software without specific prior written
17 * permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
20 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
21 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
23 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
24 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
25 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
26 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
27 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
28 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
29 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 */
31
32 #include "sys/types.h"
33 #include "sys/uio.h"
34 #include "unistd.h"
35 #include "string.h"
36 #include "stdlib.h"
37 #include "fs/file.h"
38 #include "user_copy.h"
39 #include "limits.h"
40
iov_trans_to_buf(char * buf,ssize_t totallen,const struct iovec * iov,int iovcnt)41 static int iov_trans_to_buf(char *buf, ssize_t totallen, const struct iovec *iov, int iovcnt)
42 {
43 int i;
44 size_t ret, writepart;
45 size_t bytestowrite;
46 char *writebuf = NULL;
47 char *curbuf = buf;
48
49 for (i = 0; i < iovcnt; ++i) {
50 writebuf = (char *)iov[i].iov_base;
51 bytestowrite = iov[i].iov_len;
52 if (bytestowrite == 0) {
53 continue;
54 }
55
56 if (totallen == 0) {
57 break;
58 }
59
60 bytestowrite = (totallen < bytestowrite) ? totallen : bytestowrite;
61 ret = LOS_CopyToKernel(curbuf, bytestowrite, writebuf, bytestowrite);
62 if (ret != 0) {
63 if (ret == bytestowrite) {
64 set_errno(EFAULT);
65 return VFS_ERROR;
66 } else {
67 writepart = bytestowrite - ret;
68 curbuf += writepart;
69 totallen -= writepart;
70 break;
71 }
72 }
73 curbuf += bytestowrite;
74 totallen -= bytestowrite;
75 }
76
77 return (int)((intptr_t)curbuf - (intptr_t)buf);
78 }
79
vfs_writev(int fd,const struct iovec * iov,int iovcnt,off_t * offset)80 ssize_t vfs_writev(int fd, const struct iovec *iov, int iovcnt, off_t *offset)
81 {
82 int i, ret;
83 char *buf = NULL;
84 size_t buflen = 0;
85 size_t bytestowrite;
86 ssize_t totalbyteswritten;
87 size_t totallen;
88
89 if ((iov == NULL) || (iovcnt > IOV_MAX)) {
90 return VFS_ERROR;
91 }
92
93 for (i = 0; i < iovcnt; ++i) {
94 if (SSIZE_MAX - buflen < iov[i].iov_len) {
95 set_errno(EINVAL);
96 return VFS_ERROR;
97 }
98 buflen += iov[i].iov_len;
99 }
100
101 if (buflen == 0) {
102 return 0;
103 }
104
105 totallen = buflen * sizeof(char);
106 #ifdef LOSCFG_KERNEL_VM
107 buf = (char *)LOS_VMalloc(totallen);
108 #else
109 buf = (char *)malloc(totallen);
110 #endif
111 if (buf == NULL) {
112 return VFS_ERROR;
113 }
114
115 ret = iov_trans_to_buf(buf, totallen, iov, iovcnt);
116 if (ret <= 0) {
117 #ifdef LOSCFG_KERNEL_VM
118 LOS_VFree(buf);
119 #else
120 free(buf);
121 #endif
122 return VFS_ERROR;
123 }
124
125 bytestowrite = (ssize_t)ret;
126 totalbyteswritten = (offset == NULL) ? write(fd, buf, bytestowrite)
127 : pwrite(fd, buf, bytestowrite, *offset);
128 #ifdef LOSCFG_KERNEL_VM
129 LOS_VFree(buf);
130 #else
131 free(buf);
132 #endif
133 return totalbyteswritten;
134 }
135
writev(int fd,const struct iovec * iov,int iovcnt)136 ssize_t writev(int fd, const struct iovec *iov, int iovcnt)
137 {
138 return vfs_writev(fd, iov, iovcnt, NULL);
139 }
140