1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2005-2008 Poul-Henning Kamp
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <assert.h>
30 #include <stdio.h>
31 #include <string.h>
32 #include <stdlib.h>
33 #include <unistd.h>
34 #include <stdint.h>
35 #include <time.h>
36 #include <sys/endian.h>
37 
38 #include <zlib.h>
39 
40 #include "fifolog.h"
41 #include "libfifolog_int.h"
42 #include "fifolog_write.h"
43 #include "miniobj.h"
44 
45 static int fifolog_write_gzip(struct fifolog_writer *f, time_t now);
46 
47 #define ALLOC(ptr, size) do {                   \
48 	(*(ptr)) = calloc(1, size);             \
49 	assert(*(ptr) != NULL);                 \
50 } while (0)
51 
52 
53 const char *fifolog_write_statnames[] = {
54 	[FIFOLOG_PT_BYTES_PRE] =	"Bytes before compression",
55 	[FIFOLOG_PT_BYTES_POST] =	"Bytes after compression",
56 	[FIFOLOG_PT_WRITES] =		"Writes",
57 	[FIFOLOG_PT_FLUSH] =		"Flushes",
58 	[FIFOLOG_PT_SYNC] =		"Syncs",
59 	[FIFOLOG_PT_RUNTIME] =		"Runtime"
60 };
61 
62 /**********************************************************************
63  * Check that everything is all right
64  */
65 static void
66 fifolog_write_assert(const struct fifolog_writer *f)
67 {
68 
69 	CHECK_OBJ_NOTNULL(f, FIFOLOG_WRITER_MAGIC);
70 	assert(f->ff->zs->next_out + f->ff->zs->avail_out == \
71 	    f->obuf + f->obufsize);
72 }
73 
74 /**********************************************************************
75  * Allocate/Destroy a new fifolog writer instance
76  */
77 
78 struct fifolog_writer *
79 fifolog_write_new(void)
80 {
81 	struct fifolog_writer *f;
82 
83 	ALLOC_OBJ(f, FIFOLOG_WRITER_MAGIC);
84 	assert(f != NULL);
85 	return (f);
86 }
87 
88 void
89 fifolog_write_destroy(struct fifolog_writer *f)
90 {
91 
92 	free(f->obuf);
93 	free(f->ibuf);
94 	FREE_OBJ(f);
95 }
96 
97 /**********************************************************************
98  * Open/Close the fifolog
99  */
100 
101 void
102 fifolog_write_close(struct fifolog_writer *f)
103 {
104 	time_t now;
105 
106 	CHECK_OBJ_NOTNULL(f, FIFOLOG_WRITER_MAGIC);
107 	fifolog_write_assert(f);
108 
109 	f->cleanup = 1;
110 	time(&now);
111 	fifolog_write_gzip(f, now);
112 	fifolog_write_assert(f);
113 	fifolog_int_close(&f->ff);
114 	free(f->ff);
115 }
116 
117 const char *
118 fifolog_write_open(struct fifolog_writer *f, const char *fn,
119     unsigned writerate, unsigned syncrate, unsigned compression)
120 {
121 	const char *es;
122 	int i;
123 	time_t now;
124 	off_t o;
125 
126 	CHECK_OBJ_NOTNULL(f, FIFOLOG_WRITER_MAGIC);
127 
128 	/* Check for legal compression value */
129 	if (compression > Z_BEST_COMPRESSION)
130 		return ("Illegal compression value");
131 
132 	f->writerate = writerate;
133 	f->syncrate = syncrate;
134 	f->compression = compression;
135 
136 	/* Reset statistics */
137 	memset(f->cnt, 0, sizeof f->cnt);
138 
139 	es = fifolog_int_open(&f->ff, fn, 1);
140 	if (es != NULL)
141 		return (es);
142 	es = fifolog_int_findend(f->ff, &o);
143 	if (es != NULL)
144 		return (es);
145 	i = fifolog_int_read(f->ff, o);
146 	if (i)
147 		return ("Read error, looking for seq");
148 	f->seq = be32dec(f->ff->recbuf);
149 	if (f->seq == 0) {
150 		/* Empty fifolog */
151 		f->seq = random();
152 	} else {
153 		f->recno = o + 1;
154 		f->seq++;
155 	}
156 
157 	f->obufsize = f->ff->recsize;
158 	ALLOC(&f->obuf, f->obufsize);
159 
160 	f->ibufsize = f->obufsize * 10;
161 	ALLOC(&f->ibuf, f->ibufsize);
162 	f->ibufptr = 0;
163 
164 	i = deflateInit(f->ff->zs, (int)f->compression);
165 	assert(i == Z_OK);
166 
167 	f->flag |= FIFOLOG_FLG_RESTART;
168 	f->flag |= FIFOLOG_FLG_SYNC;
169 	f->ff->zs->next_out = f->obuf + 9;
170 	f->ff->zs->avail_out = f->obufsize - 9;
171 
172 	time(&now);
173 	f->starttime = now;
174 	f->lastsync = now;
175 	f->lastwrite = now;
176 
177 	fifolog_write_assert(f);
178 	return (NULL);
179 }
180 
181 /**********************************************************************
182  * Write an output record
183  * Returns -1 if there are trouble writing data
184  */
185 
186 static int
187 fifolog_write_output(struct fifolog_writer *f, int fl, time_t now)
188 {
189 	long h, l = f->ff->zs->next_out - f->obuf;
190 	ssize_t i, w;
191 	int retval = 0;
192 
193 	h = 4;					/* seq */
194 	be32enc(f->obuf, f->seq);
195 	f->obuf[h] = f->flag;
196 	h += 1;					/* flag */
197 	if (f->flag & FIFOLOG_FLG_SYNC) {
198 		be32enc(f->obuf + h, now);
199 		h += 4;				/* timestamp */
200 	}
201 
202 	assert(l <= (long)f->ff->recsize);	/* NB: l includes h */
203 	assert(l >= h);
204 
205 	/* We will never write an entirely empty buffer */
206 	if (l == h)
207 		return (0);
208 
209 	if (l < (long)f->ff->recsize && fl == Z_NO_FLUSH)
210 		return (0);
211 
212 	w = f->ff->recsize - l;
213 	if (w >  255) {
214 		be32enc(f->obuf + f->ff->recsize - 4, w);
215 		f->obuf[4] |= FIFOLOG_FLG_4BYTE;
216 	} else if (w > 0) {
217 		f->obuf[f->ff->recsize - 1] = (uint8_t)w;
218 		f->obuf[4] |= FIFOLOG_FLG_1BYTE;
219 	}
220 
221 	f->cnt[FIFOLOG_PT_BYTES_POST] += l - h;
222 
223 	i = pwrite(f->ff->fd, f->obuf, f->ff->recsize,
224 	    (f->recno + 1) * f->ff->recsize);
225 	if (i != f->ff->recsize)
226 		retval = -1;
227 	else
228 		retval = 1;
229 
230 	f->cnt[FIFOLOG_PT_WRITES]++;
231 	f->cnt[FIFOLOG_PT_RUNTIME] = now - f->starttime;
232 
233 	f->lastwrite = now;
234 	/*
235 	 * We increment these even on error, so as to properly skip bad,
236 	 * sectors or other light trouble.
237 	 */
238 	f->seq++;
239 	f->recno++;
240 
241 	/*
242 	 * Ensure we wrap recno once we hit the file size (in records.)
243 	 */
244 	if (f->recno >= f->ff->logsize)
245 		/* recno 0 is header; skip */
246 		f->recno = 1;
247 
248 	f->flag = 0;
249 
250 	memset(f->obuf, 0, f->obufsize);
251 	f->ff->zs->next_out = f->obuf + 5;
252 	f->ff->zs->avail_out = f->obufsize - 5;
253 	return (retval);
254 }
255 
256 /**********************************************************************
257  * Run the compression engine
258  * Returns -1 if there are trouble writing data
259  */
260 
261 static int
262 fifolog_write_gzip(struct fifolog_writer *f, time_t now)
263 {
264 	int i, fl, retval = 0;
265 
266 	assert(now != 0);
267 	if (f->cleanup || now >= (int)(f->lastsync + f->syncrate)) {
268 		f->cleanup = 0;
269 		fl = Z_FINISH;
270 		f->cnt[FIFOLOG_PT_SYNC]++;
271 	} else if (now >= (int)(f->lastwrite + f->writerate)) {
272 		fl = Z_SYNC_FLUSH;
273 		f->cnt[FIFOLOG_PT_FLUSH]++;
274 	} else if (f->ibufptr == 0)
275 		return (0);
276 	else
277 		fl = Z_NO_FLUSH;
278 
279 	f->ff->zs->avail_in = f->ibufptr;
280 	f->ff->zs->next_in = f->ibuf;
281 
282 	while (1) {
283 		i = deflate(f->ff->zs, fl);
284 		assert(i == Z_OK || i == Z_BUF_ERROR || i == Z_STREAM_END);
285 
286 		i = fifolog_write_output(f, fl, now);
287 		if (i == 0)
288 			break;
289 		if (i < 0)
290 			retval = -1;
291 	}
292 	assert(f->ff->zs->avail_in == 0);
293 	f->ibufptr = 0;
294 	if (fl == Z_FINISH) {
295 		f->flag |= FIFOLOG_FLG_SYNC;
296 		f->ff->zs->next_out = f->obuf + 9;
297 		f->ff->zs->avail_out = f->obufsize - 9;
298 		f->lastsync = now;
299 		assert(Z_OK == deflateReset(f->ff->zs));
300 	}
301 	return (retval);
302 }
303 
304 /**********************************************************************
305  * Poll to see if we need to flush out a record
306  * Returns -1 if there are trouble writing data
307  */
308 
309 int
310 fifolog_write_poll(struct fifolog_writer *f, time_t now)
311 {
312 
313 	if (now == 0)
314 		time(&now);
315 	return (fifolog_write_gzip(f, now));
316 }
317 
318 /**********************************************************************
319  * Attempt to write an entry into the ibuf.
320  * Return zero if there is no space, one otherwise
321  */
322 
323 int
324 fifolog_write_record(struct fifolog_writer *f, uint32_t id, time_t now,
325     const void *ptr, ssize_t len)
326 {
327 	const unsigned char *p;
328 	uint8_t buf[9];
329 	ssize_t bufl;
330 
331 	fifolog_write_assert(f);
332 	assert(!(id & (FIFOLOG_TIMESTAMP|FIFOLOG_LENGTH)));
333 	assert(ptr != NULL);
334 
335 	p = ptr;
336 	if (len == 0) {
337 		len = strlen(ptr);
338 		len++;
339 	} else {
340 		assert(len <= 255);
341 		id |= FIFOLOG_LENGTH;
342 	}
343 	assert (len > 0);
344 
345 	/* Do a timestamp, if needed */
346 	if (now == 0)
347 		time(&now);
348 
349 	if (now != f->last)
350 		id |= FIFOLOG_TIMESTAMP;
351 
352 	/* Emit instance+flag */
353 	be32enc(buf, id);
354 	bufl = 4;
355 
356 	if (id & FIFOLOG_TIMESTAMP) {
357 		be32enc(buf + bufl, (uint32_t)now);
358 		bufl += 4;
359 	}
360 	if (id & FIFOLOG_LENGTH)
361 		buf[bufl++] = (u_char)len;
362 
363 	if (bufl + len + f->ibufptr > f->ibufsize)
364 		return (0);
365 
366 	memcpy(f->ibuf + f->ibufptr, buf, bufl);
367 	f->ibufptr += bufl;
368 	memcpy(f->ibuf + f->ibufptr, p, len);
369 	f->ibufptr += len;
370 	f->cnt[FIFOLOG_PT_BYTES_PRE] += bufl + len;
371 
372 	if (id & FIFOLOG_TIMESTAMP)
373 		f->last = now;
374 	return (1);
375 }
376 
377 /**********************************************************************
378  * Write an entry, polling the gzip/writer until success.
379  * Long binary entries are broken into 255 byte chunks.
380  * Returns -1 if there are problems writing data
381  */
382 
383 int
384 fifolog_write_record_poll(struct fifolog_writer *f, uint32_t id, time_t now,
385     const void *ptr, ssize_t len)
386 {
387 	u_int l;
388 	const unsigned char *p;
389 	int retval = 0;
390 
391 	if (now == 0)
392 		time(&now);
393 	fifolog_write_assert(f);
394 
395 	assert(!(id & (FIFOLOG_TIMESTAMP|FIFOLOG_LENGTH)));
396 	assert(ptr != NULL);
397 
398 	if (len == 0) {
399 		if (!fifolog_write_record(f, id, now, ptr, len)) {
400 			if (fifolog_write_gzip(f, now) < 0)
401 				retval = -1;
402 			/* The string could be too long for the ibuf, so... */
403 			if (!fifolog_write_record(f, id, now, ptr, len))
404 				retval = -1;
405 		}
406 	} else {
407 		for (p = ptr; len > 0; len -= l, p += l) {
408 			l = len;
409 			if (l > 255)
410 				l = 255;
411 			while (!fifolog_write_record(f, id, now, p, l))
412 				if (fifolog_write_gzip(f, now) < 0)
413 					retval = -1;
414 		}
415 	}
416 	if (fifolog_write_gzip(f, now) < 0)
417 		retval = -1;
418 	fifolog_write_assert(f);
419 	return (retval);
420 }
421