FreeBSD/Linux Kernel Cross Reference
sys/boot/common/load.c
1 /*-
2 * Copyright (c) 1998 Michael Smith <msmith@freebsd.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD: src/sys/boot/common/load.c,v 1.5 2004/08/22 08:57:05 maxim Exp $");
29
30 #include <stand.h>
31
32 #define LOAD_TINYBUF 2048
33
34 /*
35 * Attempt to load the file at (path) into an allocated
36 * area on the heap, return a pointer to it or NULL
37 * on failure.
38 *
39 * Because in many cases it is impossible to determine the
40 * true size of a file without reading it, we do just that.
41 */
42 char *
43 filedup(const char *path, int flags)
44 {
45 char *buf;
46 int fd;
47 size_t size, result;
48
49 if ((fd = open(path, F_READ | flags)) == -1)
50 return(NULL);
51
52 printf("%s open, flags 0x%x\n", path, files[fd].f_flags);
53 buf = alloc(LOAD_TINYBUF);
54
55 /* Read the first buffer-full */
56 size = read(fd, buf, LOAD_TINYBUF);
57 if (size < 1) {
58 free(buf, LOAD_TINYBUF);
59 close(fd);
60 return(NULL);
61 }
62 /* If it all fitted, then just return the buffer straight out */
63 if (size < LOAD_TINYBUF) {
64 close(fd);
65 buf[size] = 0;
66 return(buf);
67 }
68
69 printf("tinybuf loaded, size %d\n", size);
70 getchar();
71
72 /* Read everything until we know how big it is */
73 for (;;) {
74 result = read(fd, buf, LOAD_TINYBUF);
75 if (result == -1) {
76 free(buf, LOAD_TINYBUF);
77 close(fd);
78 return(NULL);
79 }
80 if (result == 0)
81 break;
82 size += result;
83 }
84
85 /* discard the old buffer, close the file */
86 free(buf, LOAD_TINYBUF);
87 close(fd);
88
89 /* reopen the file, realloc the buffer */
90 if ((fd = open(path, F_READ | flags)) == -1)
91 return(NULL);
92 buf = alloc(size);
93 result = read(fd, buf, size);
94 close(fd);
95 if (result != size) {
96 free(buf, size);
97 return(NULL);
98 }
99 return(buf);
100 }
101
102 Cache object: b5b636c5986276170a7312cbfafaa583
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