diff options
author | Patrick McHardy <kaber@trash.net> | 2011-01-14 08:12:37 -0500 |
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committer | Patrick McHardy <kaber@trash.net> | 2011-01-14 08:12:37 -0500 |
commit | 0134e89c7bcc9fde1da962c82a120691e185619f (patch) | |
tree | 3e03335cf001019a2687d161e956de4f73379984 /net/tipc/log.c | |
parent | c7066f70d9610df0b9406cc635fc09e86136e714 (diff) | |
parent | 6faee60a4e82075853a437831768cc9e2e563e4e (diff) |
Merge branch 'master' of git://1984.lsi.us.es/net-next-2.6
Conflicts:
net/ipv4/route.c
Signed-off-by: Patrick McHardy <kaber@trash.net>
Diffstat (limited to 'net/tipc/log.c')
-rw-r--r-- | net/tipc/log.c | 351 |
1 files changed, 351 insertions, 0 deletions
diff --git a/net/tipc/log.c b/net/tipc/log.c new file mode 100644 index 000000000000..952c39f643e6 --- /dev/null +++ b/net/tipc/log.c | |||
@@ -0,0 +1,351 @@ | |||
1 | /* | ||
2 | * net/tipc/log.c: TIPC print buffer routines for debugging | ||
3 | * | ||
4 | * Copyright (c) 1996-2006, Ericsson AB | ||
5 | * Copyright (c) 2005-2007, Wind River Systems | ||
6 | * All rights reserved. | ||
7 | * | ||
8 | * Redistribution and use in source and binary forms, with or without | ||
9 | * modification, are permitted provided that the following conditions are met: | ||
10 | * | ||
11 | * 1. Redistributions of source code must retain the above copyright | ||
12 | * notice, this list of conditions and the following disclaimer. | ||
13 | * 2. Redistributions in binary form must reproduce the above copyright | ||
14 | * notice, this list of conditions and the following disclaimer in the | ||
15 | * documentation and/or other materials provided with the distribution. | ||
16 | * 3. Neither the names of the copyright holders nor the names of its | ||
17 | * contributors may be used to endorse or promote products derived from | ||
18 | * this software without specific prior written permission. | ||
19 | * | ||
20 | * Alternatively, this software may be distributed under the terms of the | ||
21 | * GNU General Public License ("GPL") version 2 as published by the Free | ||
22 | * Software Foundation. | ||
23 | * | ||
24 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" | ||
25 | * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | ||
26 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | ||
27 | * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE | ||
28 | * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR | ||
29 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF | ||
30 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS | ||
31 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN | ||
32 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) | ||
33 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE | ||
34 | * POSSIBILITY OF SUCH DAMAGE. | ||
35 | */ | ||
36 | |||
37 | #include "core.h" | ||
38 | #include "config.h" | ||
39 | #include "log.h" | ||
40 | |||
41 | /* | ||
42 | * TIPC pre-defines the following print buffers: | ||
43 | * | ||
44 | * TIPC_NULL : null buffer (i.e. print nowhere) | ||
45 | * TIPC_CONS : system console | ||
46 | * TIPC_LOG : TIPC log buffer | ||
47 | * | ||
48 | * Additional user-defined print buffers are also permitted. | ||
49 | */ | ||
50 | |||
51 | static struct print_buf null_buf = { NULL, 0, NULL, 0 }; | ||
52 | struct print_buf *const TIPC_NULL = &null_buf; | ||
53 | |||
54 | static struct print_buf cons_buf = { NULL, 0, NULL, 1 }; | ||
55 | struct print_buf *const TIPC_CONS = &cons_buf; | ||
56 | |||
57 | static struct print_buf log_buf = { NULL, 0, NULL, 1 }; | ||
58 | struct print_buf *const TIPC_LOG = &log_buf; | ||
59 | |||
60 | /* | ||
61 | * Locking policy when using print buffers. | ||
62 | * | ||
63 | * 1) tipc_printf() uses 'print_lock' to protect against concurrent access to | ||
64 | * 'print_string' when writing to a print buffer. This also protects against | ||
65 | * concurrent writes to the print buffer being written to. | ||
66 | * | ||
67 | * 2) tipc_log_XXX() leverages the aforementioned use of 'print_lock' to | ||
68 | * protect against all types of concurrent operations on their associated | ||
69 | * print buffer (not just write operations). | ||
70 | * | ||
71 | * Note: All routines of the form tipc_printbuf_XXX() are lock-free, and rely | ||
72 | * on the caller to prevent simultaneous use of the print buffer(s) being | ||
73 | * manipulated. | ||
74 | */ | ||
75 | |||
76 | static char print_string[TIPC_PB_MAX_STR]; | ||
77 | static DEFINE_SPINLOCK(print_lock); | ||
78 | |||
79 | static void tipc_printbuf_move(struct print_buf *pb_to, | ||
80 | struct print_buf *pb_from); | ||
81 | |||
82 | #define FORMAT(PTR, LEN, FMT) \ | ||
83 | {\ | ||
84 | va_list args;\ | ||
85 | va_start(args, FMT);\ | ||
86 | LEN = vsprintf(PTR, FMT, args);\ | ||
87 | va_end(args);\ | ||
88 | *(PTR + LEN) = '\0';\ | ||
89 | } | ||
90 | |||
91 | /** | ||
92 | * tipc_printbuf_init - initialize print buffer to empty | ||
93 | * @pb: pointer to print buffer structure | ||
94 | * @raw: pointer to character array used by print buffer | ||
95 | * @size: size of character array | ||
96 | * | ||
97 | * Note: If the character array is too small (or absent), the print buffer | ||
98 | * becomes a null device that discards anything written to it. | ||
99 | */ | ||
100 | |||
101 | void tipc_printbuf_init(struct print_buf *pb, char *raw, u32 size) | ||
102 | { | ||
103 | pb->buf = raw; | ||
104 | pb->crs = raw; | ||
105 | pb->size = size; | ||
106 | pb->echo = 0; | ||
107 | |||
108 | if (size < TIPC_PB_MIN_SIZE) { | ||
109 | pb->buf = NULL; | ||
110 | } else if (raw) { | ||
111 | pb->buf[0] = 0; | ||
112 | pb->buf[size - 1] = ~0; | ||
113 | } | ||
114 | } | ||
115 | |||
116 | /** | ||
117 | * tipc_printbuf_reset - reinitialize print buffer to empty state | ||
118 | * @pb: pointer to print buffer structure | ||
119 | */ | ||
120 | |||
121 | static void tipc_printbuf_reset(struct print_buf *pb) | ||
122 | { | ||
123 | if (pb->buf) { | ||
124 | pb->crs = pb->buf; | ||
125 | pb->buf[0] = 0; | ||
126 | pb->buf[pb->size - 1] = ~0; | ||
127 | } | ||
128 | } | ||
129 | |||
130 | /** | ||
131 | * tipc_printbuf_empty - test if print buffer is in empty state | ||
132 | * @pb: pointer to print buffer structure | ||
133 | * | ||
134 | * Returns non-zero if print buffer is empty. | ||
135 | */ | ||
136 | |||
137 | static int tipc_printbuf_empty(struct print_buf *pb) | ||
138 | { | ||
139 | return !pb->buf || (pb->crs == pb->buf); | ||
140 | } | ||
141 | |||
142 | /** | ||
143 | * tipc_printbuf_validate - check for print buffer overflow | ||
144 | * @pb: pointer to print buffer structure | ||
145 | * | ||
146 | * Verifies that a print buffer has captured all data written to it. | ||
147 | * If data has been lost, linearize buffer and prepend an error message | ||
148 | * | ||
149 | * Returns length of print buffer data string (including trailing NUL) | ||
150 | */ | ||
151 | |||
152 | int tipc_printbuf_validate(struct print_buf *pb) | ||
153 | { | ||
154 | char *err = "\n\n*** PRINT BUFFER OVERFLOW ***\n\n"; | ||
155 | char *cp_buf; | ||
156 | struct print_buf cb; | ||
157 | |||
158 | if (!pb->buf) | ||
159 | return 0; | ||
160 | |||
161 | if (pb->buf[pb->size - 1] == 0) { | ||
162 | cp_buf = kmalloc(pb->size, GFP_ATOMIC); | ||
163 | if (cp_buf) { | ||
164 | tipc_printbuf_init(&cb, cp_buf, pb->size); | ||
165 | tipc_printbuf_move(&cb, pb); | ||
166 | tipc_printbuf_move(pb, &cb); | ||
167 | kfree(cp_buf); | ||
168 | memcpy(pb->buf, err, strlen(err)); | ||
169 | } else { | ||
170 | tipc_printbuf_reset(pb); | ||
171 | tipc_printf(pb, err); | ||
172 | } | ||
173 | } | ||
174 | return pb->crs - pb->buf + 1; | ||
175 | } | ||
176 | |||
177 | /** | ||
178 | * tipc_printbuf_move - move print buffer contents to another print buffer | ||
179 | * @pb_to: pointer to destination print buffer structure | ||
180 | * @pb_from: pointer to source print buffer structure | ||
181 | * | ||
182 | * Current contents of destination print buffer (if any) are discarded. | ||
183 | * Source print buffer becomes empty if a successful move occurs. | ||
184 | */ | ||
185 | |||
186 | static void tipc_printbuf_move(struct print_buf *pb_to, | ||
187 | struct print_buf *pb_from) | ||
188 | { | ||
189 | int len; | ||
190 | |||
191 | /* Handle the cases where contents can't be moved */ | ||
192 | |||
193 | if (!pb_to->buf) | ||
194 | return; | ||
195 | |||
196 | if (!pb_from->buf) { | ||
197 | tipc_printbuf_reset(pb_to); | ||
198 | return; | ||
199 | } | ||
200 | |||
201 | if (pb_to->size < pb_from->size) { | ||
202 | strcpy(pb_to->buf, "*** PRINT BUFFER MOVE ERROR ***"); | ||
203 | pb_to->buf[pb_to->size - 1] = ~0; | ||
204 | pb_to->crs = strchr(pb_to->buf, 0); | ||
205 | return; | ||
206 | } | ||
207 | |||
208 | /* Copy data from char after cursor to end (if used) */ | ||
209 | |||
210 | len = pb_from->buf + pb_from->size - pb_from->crs - 2; | ||
211 | if ((pb_from->buf[pb_from->size - 1] == 0) && (len > 0)) { | ||
212 | strcpy(pb_to->buf, pb_from->crs + 1); | ||
213 | pb_to->crs = pb_to->buf + len; | ||
214 | } else | ||
215 | pb_to->crs = pb_to->buf; | ||
216 | |||
217 | /* Copy data from start to cursor (always) */ | ||
218 | |||
219 | len = pb_from->crs - pb_from->buf; | ||
220 | strcpy(pb_to->crs, pb_from->buf); | ||
221 | pb_to->crs += len; | ||
222 | |||
223 | tipc_printbuf_reset(pb_from); | ||
224 | } | ||
225 | |||
226 | /** | ||
227 | * tipc_printf - append formatted output to print buffer | ||
228 | * @pb: pointer to print buffer | ||
229 | * @fmt: formatted info to be printed | ||
230 | */ | ||
231 | |||
232 | void tipc_printf(struct print_buf *pb, const char *fmt, ...) | ||
233 | { | ||
234 | int chars_to_add; | ||
235 | int chars_left; | ||
236 | char save_char; | ||
237 | |||
238 | spin_lock_bh(&print_lock); | ||
239 | |||
240 | FORMAT(print_string, chars_to_add, fmt); | ||
241 | if (chars_to_add >= TIPC_PB_MAX_STR) | ||
242 | strcpy(print_string, "*** PRINT BUFFER STRING TOO LONG ***"); | ||
243 | |||
244 | if (pb->buf) { | ||
245 | chars_left = pb->buf + pb->size - pb->crs - 1; | ||
246 | if (chars_to_add <= chars_left) { | ||
247 | strcpy(pb->crs, print_string); | ||
248 | pb->crs += chars_to_add; | ||
249 | } else if (chars_to_add >= (pb->size - 1)) { | ||
250 | strcpy(pb->buf, print_string + chars_to_add + 1 | ||
251 | - pb->size); | ||
252 | pb->crs = pb->buf + pb->size - 1; | ||
253 | } else { | ||
254 | strcpy(pb->buf, print_string + chars_left); | ||
255 | save_char = print_string[chars_left]; | ||
256 | print_string[chars_left] = 0; | ||
257 | strcpy(pb->crs, print_string); | ||
258 | print_string[chars_left] = save_char; | ||
259 | pb->crs = pb->buf + chars_to_add - chars_left; | ||
260 | } | ||
261 | } | ||
262 | |||
263 | if (pb->echo) | ||
264 | printk("%s", print_string); | ||
265 | |||
266 | spin_unlock_bh(&print_lock); | ||
267 | } | ||
268 | |||
269 | /** | ||
270 | * tipc_log_resize - change the size of the TIPC log buffer | ||
271 | * @log_size: print buffer size to use | ||
272 | */ | ||
273 | |||
274 | int tipc_log_resize(int log_size) | ||
275 | { | ||
276 | int res = 0; | ||
277 | |||
278 | spin_lock_bh(&print_lock); | ||
279 | kfree(TIPC_LOG->buf); | ||
280 | TIPC_LOG->buf = NULL; | ||
281 | if (log_size) { | ||
282 | if (log_size < TIPC_PB_MIN_SIZE) | ||
283 | log_size = TIPC_PB_MIN_SIZE; | ||
284 | res = TIPC_LOG->echo; | ||
285 | tipc_printbuf_init(TIPC_LOG, kmalloc(log_size, GFP_ATOMIC), | ||
286 | log_size); | ||
287 | TIPC_LOG->echo = res; | ||
288 | res = !TIPC_LOG->buf; | ||
289 | } | ||
290 | spin_unlock_bh(&print_lock); | ||
291 | |||
292 | return res; | ||
293 | } | ||
294 | |||
295 | /** | ||
296 | * tipc_log_resize_cmd - reconfigure size of TIPC log buffer | ||
297 | */ | ||
298 | |||
299 | struct sk_buff *tipc_log_resize_cmd(const void *req_tlv_area, int req_tlv_space) | ||
300 | { | ||
301 | u32 value; | ||
302 | |||
303 | if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_UNSIGNED)) | ||
304 | return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR); | ||
305 | |||
306 | value = ntohl(*(__be32 *)TLV_DATA(req_tlv_area)); | ||
307 | if (value != delimit(value, 0, 32768)) | ||
308 | return tipc_cfg_reply_error_string(TIPC_CFG_INVALID_VALUE | ||
309 | " (log size must be 0-32768)"); | ||
310 | if (tipc_log_resize(value)) | ||
311 | return tipc_cfg_reply_error_string( | ||
312 | "unable to create specified log (log size is now 0)"); | ||
313 | return tipc_cfg_reply_none(); | ||
314 | } | ||
315 | |||
316 | /** | ||
317 | * tipc_log_dump - capture TIPC log buffer contents in configuration message | ||
318 | */ | ||
319 | |||
320 | struct sk_buff *tipc_log_dump(void) | ||
321 | { | ||
322 | struct sk_buff *reply; | ||
323 | |||
324 | spin_lock_bh(&print_lock); | ||
325 | if (!TIPC_LOG->buf) { | ||
326 | spin_unlock_bh(&print_lock); | ||
327 | reply = tipc_cfg_reply_ultra_string("log not activated\n"); | ||
328 | } else if (tipc_printbuf_empty(TIPC_LOG)) { | ||
329 | spin_unlock_bh(&print_lock); | ||
330 | reply = tipc_cfg_reply_ultra_string("log is empty\n"); | ||
331 | } else { | ||
332 | struct tlv_desc *rep_tlv; | ||
333 | struct print_buf pb; | ||
334 | int str_len; | ||
335 | |||
336 | str_len = min(TIPC_LOG->size, 32768u); | ||
337 | spin_unlock_bh(&print_lock); | ||
338 | reply = tipc_cfg_reply_alloc(TLV_SPACE(str_len)); | ||
339 | if (reply) { | ||
340 | rep_tlv = (struct tlv_desc *)reply->data; | ||
341 | tipc_printbuf_init(&pb, TLV_DATA(rep_tlv), str_len); | ||
342 | spin_lock_bh(&print_lock); | ||
343 | tipc_printbuf_move(&pb, TIPC_LOG); | ||
344 | spin_unlock_bh(&print_lock); | ||
345 | str_len = strlen(TLV_DATA(rep_tlv)) + 1; | ||
346 | skb_put(reply, TLV_SPACE(str_len)); | ||
347 | TLV_SET(rep_tlv, TIPC_TLV_ULTRA_STRING, NULL, str_len); | ||
348 | } | ||
349 | } | ||
350 | return reply; | ||
351 | } | ||