xref: /freebsd/usr.sbin/fifolog/lib/fifolog_create.c (revision b9f654b163bce26de79705e77b872427c9f2afa1)
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 <assert.h>
32 #include <errno.h>
33 #include <stdio.h>
34 #include <string.h>
35 #include <unistd.h>
36 #include <fcntl.h>
37 #include <stdlib.h>
38 #include <sys/endian.h>
39 #include <sys/stat.h>
40 #include <sys/disk.h>
41 
42 #include "fifolog.h"
43 #include "libfifolog.h"
44 
45 const char *
46 fifolog_create(const char *fn, off_t size, ssize_t recsize)
47 {
48 	int i, fd;
49 	ssize_t u;
50 	u_int uu;
51 	off_t ms;
52 	struct stat st;
53 	char *buf;
54 	int created;
55 
56 	fd = open(fn, O_WRONLY | O_TRUNC | O_EXCL | O_CREAT, 0644);
57 	if (fd < 0) {
58 		created = 0;
59 		fd = open(fn, O_WRONLY);
60 		if (fd < 0)
61 			return ("Could not open");
62 	} else
63 		created = 1;
64 
65 	/* Default sectorsize is 512 */
66 	if (recsize == 0)
67 		recsize = 512;
68 
69 	/* See what we got... */
70 	i = fstat(fd, &st);
71 	assert(i == 0);
72 	if (!S_ISBLK(st.st_mode) &&
73 	    !S_ISCHR(st.st_mode) &&
74 	    !S_ISREG(st.st_mode)) {
75 		assert(!close (fd));
76 		return ("Wrong file type");
77 	}
78 
79 	if(!created && S_ISREG(st.st_mode)) {
80 		assert(!close (fd));
81 		return ("Wrong file type");
82 	}
83 
84 	/* For raw disk with larger sectors: use 1 sector */
85 	i = ioctl(fd, DIOCGSECTORSIZE, &uu);
86 	u = uu;
87 	if (i == 0 && (u > recsize || (recsize % u) != 0))
88 		recsize = u;
89 
90 	/* If no configured size, or too large for disk, use device size */
91 	i = ioctl(fd, DIOCGMEDIASIZE, &ms);
92 	if (i == 0 && (size == 0 || size > ms))
93 		size = ms;
94 
95 	if (size == 0 && S_ISREG(st.st_mode))
96 		size = st.st_size;
97 
98 	if (size == 0)
99 		size = recsize * (off_t)(24*60*60);
100 
101 	if (S_ISREG(st.st_mode) && ftruncate(fd, size) < 0)
102 		return ("Could not ftrunc");
103 
104 	buf = calloc(1, recsize);
105 	if (buf == NULL)
106 		return ("Could not malloc");
107 
108 	strcpy(buf, FIFOLOG_FMT_MAGIC);		/*lint !e64 */
109 	be32enc(buf + FIFOLOG_OFF_BS, recsize);
110 	if (recsize != pwrite(fd, buf, recsize, 0)) {
111 		i = errno;
112 		free(buf);
113 		errno = i;
114 		return ("Could not write first sector");
115 	}
116 	memset(buf, 0, recsize);
117 	if ((int)recsize != pwrite(fd, buf, recsize, recsize)) {
118 		i = errno;
119 		free(buf);
120 		errno = i;
121 		return ("Could not write second sector");
122 	}
123 	free(buf);
124 	assert(0 == close(fd));
125 	return (NULL);
126 }
127