1 | /* |
2 | * QEMU System Emulator |
3 | * |
4 | * Copyright (c) 2003-2008 Fabrice Bellard |
5 | * |
6 | * Permission is hereby granted, free of charge, to any person obtaining a copy |
7 | * of this software and associated documentation files (the "Software"), to deal |
8 | * in the Software without restriction, including without limitation the rights |
9 | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
10 | * copies of the Software, and to permit persons to whom the Software is |
11 | * furnished to do so, subject to the following conditions: |
12 | * |
13 | * The above copyright notice and this permission notice shall be included in |
14 | * all copies or substantial portions of the Software. |
15 | * |
16 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
17 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
18 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
19 | * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
20 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
21 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
22 | * THE SOFTWARE. |
23 | */ |
24 | |
25 | #include "qemu/osdep.h" |
26 | #include "chardev/char.h" |
27 | #include "qapi/error.h" |
28 | #include "qapi/qapi-commands-char.h" |
29 | #include "qemu/base64.h" |
30 | #include "qemu/module.h" |
31 | #include "qemu/option.h" |
32 | |
33 | /* Ring buffer chardev */ |
34 | |
35 | typedef struct { |
36 | Chardev parent; |
37 | size_t size; |
38 | size_t prod; |
39 | size_t cons; |
40 | uint8_t *cbuf; |
41 | } RingBufChardev; |
42 | |
43 | #define RINGBUF_CHARDEV(obj) \ |
44 | OBJECT_CHECK(RingBufChardev, (obj), TYPE_CHARDEV_RINGBUF) |
45 | |
46 | static size_t ringbuf_count(const Chardev *chr) |
47 | { |
48 | const RingBufChardev *d = RINGBUF_CHARDEV(chr); |
49 | |
50 | return d->prod - d->cons; |
51 | } |
52 | |
53 | static int ringbuf_chr_write(Chardev *chr, const uint8_t *buf, int len) |
54 | { |
55 | RingBufChardev *d = RINGBUF_CHARDEV(chr); |
56 | int i; |
57 | |
58 | if (!buf || (len < 0)) { |
59 | return -1; |
60 | } |
61 | |
62 | for (i = 0; i < len; i++) { |
63 | d->cbuf[d->prod++ & (d->size - 1)] = buf[i]; |
64 | if (d->prod - d->cons > d->size) { |
65 | d->cons = d->prod - d->size; |
66 | } |
67 | } |
68 | |
69 | return len; |
70 | } |
71 | |
72 | static int ringbuf_chr_read(Chardev *chr, uint8_t *buf, int len) |
73 | { |
74 | RingBufChardev *d = RINGBUF_CHARDEV(chr); |
75 | int i; |
76 | |
77 | qemu_mutex_lock(&chr->chr_write_lock); |
78 | for (i = 0; i < len && d->cons != d->prod; i++) { |
79 | buf[i] = d->cbuf[d->cons++ & (d->size - 1)]; |
80 | } |
81 | qemu_mutex_unlock(&chr->chr_write_lock); |
82 | |
83 | return i; |
84 | } |
85 | |
86 | static void char_ringbuf_finalize(Object *obj) |
87 | { |
88 | RingBufChardev *d = RINGBUF_CHARDEV(obj); |
89 | |
90 | g_free(d->cbuf); |
91 | } |
92 | |
93 | static void qemu_chr_open_ringbuf(Chardev *chr, |
94 | ChardevBackend *backend, |
95 | bool *be_opened, |
96 | Error **errp) |
97 | { |
98 | ChardevRingbuf *opts = backend->u.ringbuf.data; |
99 | RingBufChardev *d = RINGBUF_CHARDEV(chr); |
100 | |
101 | d->size = opts->has_size ? opts->size : 65536; |
102 | |
103 | /* The size must be power of 2 */ |
104 | if (d->size & (d->size - 1)) { |
105 | error_setg(errp, "size of ringbuf chardev must be power of two" ); |
106 | return; |
107 | } |
108 | |
109 | d->prod = 0; |
110 | d->cons = 0; |
111 | d->cbuf = g_malloc0(d->size); |
112 | } |
113 | |
114 | void qmp_ringbuf_write(const char *device, const char *data, |
115 | bool has_format, enum DataFormat format, |
116 | Error **errp) |
117 | { |
118 | Chardev *chr; |
119 | const uint8_t *write_data; |
120 | int ret; |
121 | gsize write_count; |
122 | |
123 | chr = qemu_chr_find(device); |
124 | if (!chr) { |
125 | error_setg(errp, "Device '%s' not found" , device); |
126 | return; |
127 | } |
128 | |
129 | if (!CHARDEV_IS_RINGBUF(chr)) { |
130 | error_setg(errp, "%s is not a ringbuf device" , device); |
131 | return; |
132 | } |
133 | |
134 | if (has_format && (format == DATA_FORMAT_BASE64)) { |
135 | write_data = qbase64_decode(data, -1, |
136 | &write_count, |
137 | errp); |
138 | if (!write_data) { |
139 | return; |
140 | } |
141 | } else { |
142 | write_data = (uint8_t *)data; |
143 | write_count = strlen(data); |
144 | } |
145 | |
146 | ret = ringbuf_chr_write(chr, write_data, write_count); |
147 | |
148 | if (write_data != (uint8_t *)data) { |
149 | g_free((void *)write_data); |
150 | } |
151 | |
152 | if (ret < 0) { |
153 | error_setg(errp, "Failed to write to device %s" , device); |
154 | return; |
155 | } |
156 | } |
157 | |
158 | char *qmp_ringbuf_read(const char *device, int64_t size, |
159 | bool has_format, enum DataFormat format, |
160 | Error **errp) |
161 | { |
162 | Chardev *chr; |
163 | uint8_t *read_data; |
164 | size_t count; |
165 | char *data; |
166 | |
167 | chr = qemu_chr_find(device); |
168 | if (!chr) { |
169 | error_setg(errp, "Device '%s' not found" , device); |
170 | return NULL; |
171 | } |
172 | |
173 | if (!CHARDEV_IS_RINGBUF(chr)) { |
174 | error_setg(errp, "%s is not a ringbuf device" , device); |
175 | return NULL; |
176 | } |
177 | |
178 | if (size <= 0) { |
179 | error_setg(errp, "size must be greater than zero" ); |
180 | return NULL; |
181 | } |
182 | |
183 | count = ringbuf_count(chr); |
184 | size = size > count ? count : size; |
185 | read_data = g_malloc(size + 1); |
186 | |
187 | ringbuf_chr_read(chr, read_data, size); |
188 | |
189 | if (has_format && (format == DATA_FORMAT_BASE64)) { |
190 | data = g_base64_encode(read_data, size); |
191 | g_free(read_data); |
192 | } else { |
193 | /* |
194 | * FIXME should read only complete, valid UTF-8 characters up |
195 | * to @size bytes. Invalid sequences should be replaced by a |
196 | * suitable replacement character. Except when (and only |
197 | * when) ring buffer lost characters since last read, initial |
198 | * continuation characters should be dropped. |
199 | */ |
200 | read_data[size] = 0; |
201 | data = (char *)read_data; |
202 | } |
203 | |
204 | return data; |
205 | } |
206 | |
207 | static void qemu_chr_parse_ringbuf(QemuOpts *opts, ChardevBackend *backend, |
208 | Error **errp) |
209 | { |
210 | int val; |
211 | ChardevRingbuf *ringbuf; |
212 | |
213 | backend->type = CHARDEV_BACKEND_KIND_RINGBUF; |
214 | ringbuf = backend->u.ringbuf.data = g_new0(ChardevRingbuf, 1); |
215 | qemu_chr_parse_common(opts, qapi_ChardevRingbuf_base(ringbuf)); |
216 | |
217 | val = qemu_opt_get_size(opts, "size" , 0); |
218 | if (val != 0) { |
219 | ringbuf->has_size = true; |
220 | ringbuf->size = val; |
221 | } |
222 | } |
223 | |
224 | static void char_ringbuf_class_init(ObjectClass *oc, void *data) |
225 | { |
226 | ChardevClass *cc = CHARDEV_CLASS(oc); |
227 | |
228 | cc->parse = qemu_chr_parse_ringbuf; |
229 | cc->open = qemu_chr_open_ringbuf; |
230 | cc->chr_write = ringbuf_chr_write; |
231 | } |
232 | |
233 | static const TypeInfo char_ringbuf_type_info = { |
234 | .name = TYPE_CHARDEV_RINGBUF, |
235 | .parent = TYPE_CHARDEV, |
236 | .class_init = char_ringbuf_class_init, |
237 | .instance_size = sizeof(RingBufChardev), |
238 | .instance_finalize = char_ringbuf_finalize, |
239 | }; |
240 | |
241 | /* Bug-compatibility: */ |
242 | static const TypeInfo char_memory_type_info = { |
243 | .name = TYPE_CHARDEV_MEMORY, |
244 | .parent = TYPE_CHARDEV_RINGBUF, |
245 | }; |
246 | |
247 | static void register_types(void) |
248 | { |
249 | type_register_static(&char_ringbuf_type_info); |
250 | type_register_static(&char_memory_type_info); |
251 | } |
252 | |
253 | type_init(register_types); |
254 | |