xref: /freebsd/usr.sbin/fifolog/lib/fifolog_create.c (revision d0b2dbfa0ecf2bbc9709efc5e20baf8e4b44bbbf)
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 <errno.h>
31 #include <stdio.h>
32 #include <string.h>
33 #include <unistd.h>
34 #include <fcntl.h>
35 #include <stdlib.h>
36 #include <sys/endian.h>
37 #include <sys/stat.h>
38 #include <sys/disk.h>
39 
40 #include "fifolog.h"
41 #include "libfifolog.h"
42 
43 const char *
44 fifolog_create(const char *fn, off_t size, ssize_t recsize)
45 {
46 	int i, fd;
47 	ssize_t u;
48 	u_int uu;
49 	off_t ms;
50 	struct stat st;
51 	char *buf;
52 	int created;
53 
54 	fd = open(fn, O_WRONLY | O_TRUNC | O_EXCL | O_CREAT, 0644);
55 	if (fd < 0) {
56 		created = 0;
57 		fd = open(fn, O_WRONLY);
58 		if (fd < 0)
59 			return ("Could not open");
60 	} else
61 		created = 1;
62 
63 	/* Default sectorsize is 512 */
64 	if (recsize == 0)
65 		recsize = 512;
66 
67 	/* See what we got... */
68 	i = fstat(fd, &st);
69 	assert(i == 0);
70 	if (!S_ISBLK(st.st_mode) &&
71 	    !S_ISCHR(st.st_mode) &&
72 	    !S_ISREG(st.st_mode)) {
73 		assert(!close (fd));
74 		return ("Wrong file type");
75 	}
76 
77 	if(!created && S_ISREG(st.st_mode)) {
78 		assert(!close (fd));
79 		return ("Wrong file type");
80 	}
81 
82 	/* For raw disk with larger sectors: use 1 sector */
83 	i = ioctl(fd, DIOCGSECTORSIZE, &uu);
84 	u = uu;
85 	if (i == 0 && (u > recsize || (recsize % u) != 0))
86 		recsize = u;
87 
88 	/* If no configured size, or too large for disk, use device size */
89 	i = ioctl(fd, DIOCGMEDIASIZE, &ms);
90 	if (i == 0 && (size == 0 || size > ms))
91 		size = ms;
92 
93 	if (size == 0 && S_ISREG(st.st_mode))
94 		size = st.st_size;
95 
96 	if (size == 0)
97 		size = recsize * (off_t)(24*60*60);
98 
99 	if (S_ISREG(st.st_mode) && ftruncate(fd, size) < 0)
100 		return ("Could not ftrunc");
101 
102 	buf = calloc(1, recsize);
103 	if (buf == NULL)
104 		return ("Could not malloc");
105 
106 	strcpy(buf, FIFOLOG_FMT_MAGIC);		/*lint !e64 */
107 	be32enc(buf + FIFOLOG_OFF_BS, recsize);
108 	if (recsize != pwrite(fd, buf, recsize, 0)) {
109 		i = errno;
110 		free(buf);
111 		errno = i;
112 		return ("Could not write first sector");
113 	}
114 	memset(buf, 0, recsize);
115 	if ((int)recsize != pwrite(fd, buf, recsize, recsize)) {
116 		i = errno;
117 		free(buf);
118 		errno = i;
119 		return ("Could not write second sector");
120 	}
121 	free(buf);
122 	assert(0 == close(fd));
123 	return (NULL);
124 }
125