1 /*
2 * Copyright (C) 2007 Michael Brown <mbrown@fensystems.co.uk>.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License as
6 * published by the Free Software Foundation; either version 2 of the
7 * License, or any later version.
8 *
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
17 * 02110-1301, USA.
18 *
19 * You can also choose to distribute this program under the terms of
20 * the Unmodified Binary Distribution Licence (as given in the file
21 * COPYING.UBDL), provided that you have satisfied its requirements.
22 */
23
24 FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
25
26 /** @file
27 *
28 * CPIO archives
29 *
30 */
31
32 #include <stdio.h>
33 #include <stdlib.h>
34 #include <string.h>
35 #include <ipxe/cpio.h>
36
37 /**
38 * Set field within a CPIO header
39 *
40 * @v field Field within CPIO header
41 * @v value Value to set
42 */
cpio_set_field(char * field,unsigned long value)43 void cpio_set_field ( char *field, unsigned long value ) {
44 char buf[9];
45
46 snprintf ( buf, sizeof ( buf ), "%08lx", value );
47 memcpy ( field, buf, 8 );
48 }
49
50 /**
51 * Get CPIO image filename
52 *
53 * @v image Image
54 * @ret len CPIO filename length (0 for no filename)
55 */
cpio_name_len(struct image * image)56 size_t cpio_name_len ( struct image *image ) {
57 const char *name = cpio_name ( image );
58 char *sep;
59 size_t len;
60
61 /* Check for existence of CPIO filename */
62 if ( ! name )
63 return 0;
64
65 /* Locate separator (if any) */
66 sep = strchr ( name, ' ' );
67 len = ( sep ? ( ( size_t ) ( sep - name ) ) : strlen ( name ) );
68
69 return len;
70 }
71
72 /**
73 * Parse CPIO image parameters
74 *
75 * @v image Image
76 * @v cpio CPIO header to fill in
77 */
cpio_parse_cmdline(struct image * image,struct cpio_header * cpio)78 static void cpio_parse_cmdline ( struct image *image,
79 struct cpio_header *cpio ) {
80 const char *cmdline;
81 char *arg;
82 char *end;
83 unsigned int mode;
84
85 /* Skip image filename */
86 cmdline = ( cpio_name ( image ) + cpio_name_len ( image ) );
87
88 /* Look for "mode=" */
89 if ( ( arg = strstr ( cmdline, "mode=" ) ) ) {
90 arg += 5;
91 mode = strtoul ( arg, &end, 8 /* Octal for file mode */ );
92 if ( *end && ( *end != ' ' ) ) {
93 DBGC ( image, "CPIO %p strange \"mode=\" "
94 "terminator '%c'\n", image, *end );
95 }
96 cpio_set_field ( cpio->c_mode, ( 0100000 | mode ) );
97 }
98 }
99
100 /**
101 * Construct CPIO header for image, if applicable
102 *
103 * @v image Image
104 * @v cpio CPIO header to fill in
105 * @ret len Length of magic CPIO header (including filename)
106 */
cpio_header(struct image * image,struct cpio_header * cpio)107 size_t cpio_header ( struct image *image, struct cpio_header *cpio ) {
108 size_t name_len;
109 size_t len;
110
111 /* Get filename length */
112 name_len = cpio_name_len ( image );
113
114 /* Images with no filename are assumed to already be CPIO archives */
115 if ( ! name_len )
116 return 0;
117
118 /* Construct CPIO header */
119 memset ( cpio, '0', sizeof ( *cpio ) );
120 memcpy ( cpio->c_magic, CPIO_MAGIC, sizeof ( cpio->c_magic ) );
121 cpio_set_field ( cpio->c_mode, 0100644 );
122 cpio_set_field ( cpio->c_nlink, 1 );
123 cpio_set_field ( cpio->c_filesize, image->len );
124 cpio_set_field ( cpio->c_namesize, ( name_len + 1 /* NUL */ ) );
125 cpio_parse_cmdline ( image, cpio );
126
127 /* Calculate total length */
128 len = ( ( sizeof ( *cpio ) + name_len + 1 /* NUL */ + CPIO_ALIGN - 1 )
129 & ~( CPIO_ALIGN - 1 ) );
130
131 return len;
132 }
133