1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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  * $FreeBSD$
29  */
30 
31 #include <stdio.h>
32 #include <unistd.h>
33 #include <assert.h>
34 #include <err.h>
35 #include <time.h>
36 #include <string.h>
37 #include <stdlib.h>
38 #include <zlib.h>
39 #include <sys/endian.h>
40 
41 #include "fifolog.h"
42 #include "libfifolog.h"
43 #include "libfifolog_int.h"
44 #include "miniobj.h"
45 
46 /*--------------------------------------------------------------------*/
47 
48 struct fifolog_reader {
49 	unsigned		magic;
50 #define FIFOLOG_READER_MAGIC	0x1036d139
51 	struct fifolog_file	*ff;
52 	unsigned		olen;
53 	unsigned char		*obuf;
54 	time_t			now;
55 };
56 
57 struct fifolog_reader *
fifolog_reader_open(const char * fname)58 fifolog_reader_open(const char *fname)
59 {
60 	const char *retval;
61 	struct fifolog_reader *fr;
62 	int i;
63 
64 	fr = calloc(1, sizeof(*fr));
65 	if (fr == NULL)
66 		err(1, "Cannot malloc");
67 
68 	retval = fifolog_int_open(&fr->ff, fname, 0);
69 	if (retval != NULL)
70 		err(1, "%s", retval);
71 
72 	fr->obuf = calloc(16, fr->ff->recsize);
73 	if (fr->obuf == NULL)
74 		err(1, "Cannot malloc");
75 	fr->olen = fr->ff->recsize * 16;
76 
77 	i = inflateInit(fr->ff->zs);
78 	assert(i == Z_OK);
79 
80 	fr->magic = FIFOLOG_READER_MAGIC;
81 	return (fr);
82 }
83 
84 /*
85  * Find the next SYNC block
86  *
87  * Return:
88  *	0 - empty fifolog
89  *	1 - found sync block
90  *	2 - would have wrapped around
91  *	3 - End of written log.
92  */
93 
94 static int
fifolog_reader_findsync(const struct fifolog_file * ff,off_t * o)95 fifolog_reader_findsync(const struct fifolog_file *ff, off_t *o)
96 {
97 	int e;
98 	unsigned seq, seqs;
99 
100 	assert(*o < ff->logsize);
101 	e = fifolog_int_read(ff, *o);
102 	if (e)
103 		err(1, "Read error (%d) while looking for SYNC", e);
104 	seq = be32dec(ff->recbuf);
105 	if (*o == 0 && seq == 0)
106 		return (0);
107 
108 	if (ff->recbuf[4] & FIFOLOG_FLG_SYNC)
109 		return (1);		/* That was easy... */
110 	while(1) {
111 		assert(*o < ff->logsize);
112 		(*o)++;
113 		seq++;
114 		if (*o == ff->logsize)
115 			return (2);	/* wraparound */
116 		e = fifolog_int_read(ff, *o);
117 		if (e)
118 			err(1, "Read error (%d) while looking for SYNC", e);
119 		seqs = be32dec(ff->recbuf);
120 		if (seqs != seq)
121 			return (3);		/* End of log */
122 		if (ff->recbuf[4] & FIFOLOG_FLG_SYNC)
123 			return (1);		/* Bingo! */
124 	}
125 }
126 
127 /*
128  * Seek out a given timestamp
129  */
130 
131 off_t
fifolog_reader_seek(const struct fifolog_reader * fr,time_t t0)132 fifolog_reader_seek(const struct fifolog_reader *fr, time_t t0)
133 {
134 	off_t o, s, st;
135 	time_t t, tt;
136 	unsigned seq, seqs;
137 	const char *retval;
138 	int e;
139 
140 	CHECK_OBJ_NOTNULL(fr, FIFOLOG_READER_MAGIC);
141 
142 	/*
143 	 * First, find the first SYNC block
144 	 */
145 	o = 0;
146 	e = fifolog_reader_findsync(fr->ff, &o);
147 	if (e == 0)
148 		return (0);			/* empty fifolog */
149 	assert(e == 1);
150 
151 	assert(fr->ff->recbuf[4] & FIFOLOG_FLG_SYNC);
152 	seq = be32dec(fr->ff->recbuf);
153 	t = be32dec(fr->ff->recbuf + 5);
154 
155 	if (t > t0) {
156 		/* Check if there is a second older part we can use */
157 		retval = fifolog_int_findend(fr->ff, &s);
158 		if (retval != NULL)
159 			err(1, "%s", retval);
160 		s++;
161 		e = fifolog_reader_findsync(fr->ff, &s);
162 		if (e == 0)
163 			return (0);		/* empty fifolog */
164 		if (e == 1) {
165 			o = s;
166 			seq = be32dec(fr->ff->recbuf);
167 			t = be32dec(fr->ff->recbuf + 5);
168 		}
169 	}
170 
171 	/* Now do a binary search to find the sync block right before t0 */
172 	s = st = (fr->ff->logsize - o) / 2;
173 	while (s > 1) {
174 		/* We know we shouldn't wrap */
175 		if (o + st > fr->ff->logsize + 1) {
176 			s = st = s / 2;
177 			continue;
178 		}
179 		e = fifolog_int_read(fr->ff, o + st);
180 		if (e) {
181 			s = st = s / 2;
182 			continue;
183 		}
184 		/* If not in same part, sequence won't match */
185 		seqs = be32dec(fr->ff->recbuf);
186 		if (seqs != seq + st) {
187 			s = st = s / 2;
188 			continue;
189 		}
190 		/* If not sync block, try next */
191 		if (!(fr->ff->recbuf[4] & FIFOLOG_FLG_SYNC)) {
192 			st++;
193 			continue;
194 		}
195 		/* Check timestamp */
196 		tt = be32dec(fr->ff->recbuf + 5);
197 		if (tt >= t0) {
198 			s = st = s / 2;
199 			continue;
200 		}
201 		o += st;
202 		seq = seqs;
203 	}
204 	fprintf(stderr, "Read from %jx\n", o * fr->ff->recsize);
205 	return (o);
206 }
207 
208 static unsigned char *
fifolog_reader_chop(struct fifolog_reader * fr,fifolog_reader_render_t * func,void * priv)209 fifolog_reader_chop(struct fifolog_reader *fr, fifolog_reader_render_t *func, void *priv)
210 {
211 	u_char *p, *q;
212 	uint32_t v, w, u;
213 
214 	p = fr->obuf;
215 	q = fr->obuf + (fr->olen - fr->ff->zs->avail_out);
216 
217 	while (1) {
218 		/* Make sure we have a complete header */
219 		if (p + 5 >= q)
220 			return (p);
221 		w = 4;
222 		u = be32dec(p);
223 		if (u & FIFOLOG_TIMESTAMP) {
224 			fr->now = be32dec(p + 4);
225 			w += 4;
226 		}
227 		if (u & FIFOLOG_LENGTH) {
228 			v = p[w];
229 			w++;
230 			if (p + w + v >= q)
231 				return (p);
232 		} else {
233 			for (v = 0; p + v + w < q && p[v + w] != '\0'; v++)
234 				continue;
235 			if (p + v + w >= q)
236 				return (p);
237 			v++;
238 		}
239 		func(priv, fr->now, u, p + w, v);
240 		p += w + v;
241 	}
242 }
243 
244 /*
245  * Process fifolog until end of written log or provided timestamp
246  */
247 
248 void
fifolog_reader_process(struct fifolog_reader * fr,off_t from,fifolog_reader_render_t * func,void * priv,time_t end)249 fifolog_reader_process(struct fifolog_reader *fr, off_t from, fifolog_reader_render_t *func, void *priv, time_t end)
250 {
251 	uint32_t seq, lseq;
252 	off_t o = from;
253 	int i, e;
254 	time_t t;
255 	u_char *p, *q;
256 	z_stream *zs;
257 
258 	CHECK_OBJ_NOTNULL(fr, FIFOLOG_READER_MAGIC);
259 	zs = fr->ff->zs;
260 	lseq = 0;
261 	while (1) {
262 		e = fifolog_int_read(fr->ff, o);
263 		if (e)
264 			err(1, "Read error (%d)", e);
265 		if (++o >= fr->ff->logsize)
266 			o = 0;
267 		seq = be32dec(fr->ff->recbuf);
268 		if (lseq != 0 && seq != lseq + 1)
269 			break;
270 		lseq = seq;
271 		zs->avail_in = fr->ff->recsize - 5;
272 		zs->next_in = fr->ff->recbuf + 5;
273 		if (fr->ff->recbuf[4] & FIFOLOG_FLG_1BYTE)
274 			zs->avail_in -= fr->ff->recbuf[fr->ff->recsize - 1];
275 		if (fr->ff->recbuf[4] & FIFOLOG_FLG_4BYTE)
276 			zs->avail_in -=
277 			    be32dec(fr->ff->recbuf + fr->ff->recsize - 4);
278 		if (fr->ff->recbuf[4] & FIFOLOG_FLG_SYNC) {
279 			i = inflateReset(zs);
280 			assert(i == Z_OK);
281 			zs->next_out = fr->obuf;
282 			zs->avail_out = fr->olen;
283 			t = be32dec(fr->ff->recbuf + 5);
284 			if (t > end)
285 				break;
286 			zs->next_in += 4;
287 			zs->avail_in -= 4;
288 		}
289 
290 		while(zs->avail_in > 0) {
291 			i = inflate(zs, 0);
292 			if (i == Z_BUF_ERROR) {
293 #if 1
294 				fprintf(stderr,
295 				    "Z_BUF_ERROR [%d,%d] [%d,%d,%d]\n",
296 				    (int)(zs->next_in - fr->ff->recbuf),
297 				    zs->avail_in,
298 				    (int)(zs->next_out - fr->obuf),
299 				    zs->avail_out, fr->olen);
300 				exit (250);
301 #else
302 
303 				i = Z_OK;
304 #endif
305 			}
306 			if (i == Z_STREAM_END) {
307 				i = inflateReset(zs);
308 			}
309 			if (i != Z_OK) {
310 				fprintf(stderr, "inflate = %d\n", i);
311 				exit (250);
312 			}
313 			assert(i == Z_OK);
314 			if (zs->avail_out != fr->olen) {
315 				q = fr->obuf + (fr->olen - zs->avail_out);
316 				p = fifolog_reader_chop(fr, func, priv);
317 				if (p < q)
318 					(void)memmove(fr->obuf, p, q - p);
319 				zs->avail_out = fr->olen - (q - p);
320 				zs->next_out = fr->obuf + (q - p);
321 			}
322 		}
323 	}
324 }
325