xref: /minix/minix/lib/libhgfs/file.c (revision 7f5f010b)
1 /* Part of libhgfs - (c) 2009, D.C. van Moolenbroek */
2 
3 #include "inc.h"
4 
5 #include <fcntl.h>
6 #include <sys/stat.h>
7 
8 /*===========================================================================*
9  *				hgfs_open				     *
10  *===========================================================================*/
11 int hgfs_open(
12 	char *path,        	/* path name to open */
13 	int flags,         	/* open flags to use */
14 	int mode,          	/* mode to create (user bits only) */
15 	sffs_file_t *handle	/* place to store resulting handle */
16 )
17 {
18 /* Open a file. Store a file handle upon success.
19  */
20   int r, type;
21 
22   /* We could implement this, but that means we would have to start tracking
23    * open files in order to associate data with them. Rather not.
24    */
25   if (flags & O_APPEND) return EINVAL;
26 
27   if (flags & O_CREAT) {
28     if (flags & O_EXCL) type = HGFS_OPEN_TYPE_C;
29     else if (flags & O_TRUNC) type = HGFS_OPEN_TYPE_COT;
30     else type = HGFS_OPEN_TYPE_CO;
31   } else {
32     if (flags & O_TRUNC) type = HGFS_OPEN_TYPE_OT;
33     else type = HGFS_OPEN_TYPE_O;
34   }
35 
36   RPC_REQUEST(HGFS_REQ_OPEN);
37   RPC_NEXT32 = (flags & O_ACCMODE);
38   RPC_NEXT32 = type;
39   RPC_NEXT8 = HGFS_MODE_TO_PERM(mode);
40 
41   path_put(path);
42 
43   if ((r = rpc_query()) != OK)
44 	return r;
45 
46   *handle = (sffs_file_t)RPC_NEXT32;
47 
48   return OK;
49 }
50 
51 /*===========================================================================*
52  *				hgfs_read				     *
53  *===========================================================================*/
54 ssize_t hgfs_read(
55 	sffs_file_t handle,	/* handle to open file */
56 	char *buf,         	/* data buffer or NULL */
57 	size_t size,       	/* maximum number of bytes to read */
58 	u64_t off          	/* file offset */
59 )
60 {
61 /* Read from an open file. Upon success, return the number of bytes read.
62  */
63   int r, len, max;
64 
65   RPC_REQUEST(HGFS_REQ_READ);
66   RPC_NEXT32 = (u32_t)handle;
67   RPC_NEXT32 = ex64lo(off);
68   RPC_NEXT32 = ex64hi(off);
69 
70   max = RPC_BUF_SIZE - RPC_LEN - sizeof(u32_t);
71   RPC_NEXT32 = (size < max) ? size : max;
72 
73   if ((r = rpc_query()) != OK)
74 	return r;
75 
76   len = RPC_NEXT32;
77   if (len > max) len = max; /* sanity check */
78 
79   /* Only copy out data if we're not operating directly on the RPC buffer. */
80   if (buf != RPC_PTR)
81 	memcpy(buf, RPC_PTR, len);
82 
83   return len;
84 }
85 
86 /*===========================================================================*
87  *				hgfs_write				     *
88  *===========================================================================*/
89 ssize_t hgfs_write(
90 	sffs_file_t handle,	/* handle to open file */
91 	char *buf,         	/* data buffer or NULL */
92 	size_t len,        	/* number of bytes to write */
93 	u64_t off          	/* file offset */
94 )
95 {
96 /* Write to an open file. Upon success, return the number of bytes written.
97  */
98   int r;
99 
100   RPC_REQUEST(HGFS_REQ_WRITE);
101   RPC_NEXT32 = (u32_t)handle;
102   RPC_NEXT8 = 0;		/* append flag */
103   RPC_NEXT32 = ex64lo(off);
104   RPC_NEXT32 = ex64hi(off);
105   RPC_NEXT32 = len;
106 
107   /* Only copy in data if we're not operating directly on the RPC buffer. */
108   if (RPC_PTR != buf)
109 	memcpy(RPC_PTR, buf, len);
110   RPC_ADVANCE(len);
111 
112   if ((r = rpc_query()) != OK)
113 	return r;
114 
115   return RPC_NEXT32;
116 }
117 
118 /*===========================================================================*
119  *				hgfs_close				     *
120  *===========================================================================*/
121 int hgfs_close(
122 	sffs_file_t handle		/* handle to open file */
123 )
124 {
125 /* Close an open file.
126  */
127 
128   RPC_REQUEST(HGFS_REQ_CLOSE);
129   RPC_NEXT32 = (u32_t)handle;
130 
131   return rpc_query();
132 }
133 
134 /*===========================================================================*
135  *				hgfs_readbuf				     *
136  *===========================================================================*/
137 size_t hgfs_readbuf(char **ptr)
138 {
139 /* Return information about the read buffer, for zero-copy purposes. Store a
140  * pointer to the first byte of the read buffer, and return the maximum data
141  * size. The results are static, but must only be used directly prior to a
142  * hgfs_read() call (with a NULL data buffer address).
143  */
144   u32_t off;
145 
146   off = RPC_HDR_SIZE + sizeof(u32_t);
147 
148   RPC_RESET;
149   RPC_ADVANCE(off);
150   *ptr = RPC_PTR;
151 
152   return RPC_BUF_SIZE - off;
153 }
154 
155 /*===========================================================================*
156  *				hgfs_writebuf				     *
157  *===========================================================================*/
158 size_t hgfs_writebuf(char **ptr)
159 {
160 /* Return information about the write buffer, for zero-copy purposes. Store a
161  * pointer to the first byte of the write buffer, and return the maximum data
162  * size. The results are static, but must only be used immediately after a
163  * hgfs_write() call (with a NULL data buffer address).
164  */
165   u32_t off;
166 
167   off = RPC_HDR_SIZE + sizeof(u32_t) + sizeof(u8_t) + sizeof(u32_t) * 3;
168 
169   RPC_RESET;
170   RPC_ADVANCE(off);
171   *ptr = RPC_PTR;
172 
173   return RPC_BUF_SIZE - off;
174 }
175