1/*
2 * Common modutils related functions for busybox
3 *
4 * Copyright (C) 2008 by Timo Teras <timo.teras@iki.fi>
5 *
6 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
7 */
8#include "modutils.h"
9
10#ifdef __UCLIBC__
11extern int init_module(void *module, unsigned long len, const char *options);
12extern int delete_module(const char *module, unsigned int flags);
13#else
14# include <sys/syscall.h>
15# define init_module(mod, len, opts) syscall(__NR_init_module, mod, len, opts)
16# define delete_module(mod, flags) syscall(__NR_delete_module, mod, flags)
17#endif
18
19void FAST_FUNC replace(char *s, char what, char with)
20{
21	while (*s) {
22		if (what == *s)
23			*s = with;
24		++s;
25	}
26}
27
28char* FAST_FUNC replace_underscores(char *s)
29{
30	replace(s, '-', '_');
31	return s;
32}
33
34int FAST_FUNC string_to_llist(char *string, llist_t **llist, const char *delim)
35{
36	char *tok;
37	int len = 0;
38
39	while ((tok = strsep(&string, delim)) != NULL) {
40		if (tok[0] == '\0')
41			continue;
42		llist_add_to_end(llist, xstrdup(tok));
43		len += strlen(tok);
44	}
45	return len;
46}
47
48char* FAST_FUNC filename2modname(const char *filename, char *modname)
49{
50	int i;
51	char *from;
52
53	if (filename == NULL)
54		return NULL;
55	if (modname == NULL)
56		modname = xmalloc(MODULE_NAME_LEN);
57	from = bb_get_last_path_component_nostrip(filename);
58	for (i = 0; i < (MODULE_NAME_LEN-1) && from[i] != '\0' && from[i] != '.'; i++)
59		modname[i] = (from[i] == '-') ? '_' : from[i];
60	modname[i] = '\0';
61
62	return modname;
63}
64
65char* FAST_FUNC parse_cmdline_module_options(char **argv)
66{
67	char *options;
68	int optlen;
69
70	options = xzalloc(1);
71	optlen = 0;
72	while (*++argv) {
73		options = xrealloc(options, optlen + 2 + strlen(*argv) + 2);
74		/* Older versions were enclosing space-containing *argv in "",
75		 * but both modprobe and insmod from module-init-tools 3.11.1
76		 * don't do this anymore. (As to extra trailing space,
77		 * insmod adds it but modprobe does not. We do in both cases)
78		 */
79		optlen += sprintf(options + optlen, "%s ", *argv);
80	}
81	return options;
82}
83
84#if ENABLE_FEATURE_INSMOD_TRY_MMAP
85void* FAST_FUNC try_to_mmap_module(const char *filename, size_t *image_size_p)
86{
87	/* We have user reports of failure to load 3MB module
88	 * on a 16MB RAM machine. Apparently even a transient
89	 * memory spike to 6MB during module load
90	 * is too big for that system. */
91	void *image;
92	struct stat st;
93	int fd;
94
95	fd = xopen(filename, O_RDONLY);
96	fstat(fd, &st);
97	image = NULL;
98	/* st.st_size is off_t, we can't just pass it to mmap */
99	if (st.st_size <= *image_size_p) {
100		size_t image_size = st.st_size;
101		image = mmap(NULL, image_size, PROT_READ, MAP_PRIVATE, fd, 0);
102		if (image == MAP_FAILED) {
103			image = NULL;
104		} else if (*(uint32_t*)image != SWAP_BE32(0x7f454C46)) {
105			/* No ELF signature. Compressed module? */
106			munmap(image, image_size);
107			image = NULL;
108		} else {
109			/* Success. Report the size */
110			*image_size_p = image_size;
111		}
112	}
113	close(fd);
114	return image;
115}
116#endif
117
118/* Return:
119 * 0 on success,
120 * -errno on open/read error,
121 * errno on init_module() error
122 */
123int FAST_FUNC bb_init_module(const char *filename, const char *options)
124{
125	size_t image_size;
126	char *image;
127	int rc;
128	bool mmaped;
129
130	if (!options)
131		options = "";
132
133//TODO: audit bb_init_module_24 to match error code convention
134#if ENABLE_FEATURE_2_4_MODULES
135	if (get_linux_version_code() < KERNEL_VERSION(2,6,0))
136		return bb_init_module_24(filename, options);
137#endif
138
139	image_size = INT_MAX - 4095;
140	mmaped = 0;
141	image = try_to_mmap_module(filename, &image_size);
142	if (image) {
143		mmaped = 1;
144	} else {
145		errno = ENOMEM; /* may be changed by e.g. open errors below */
146		image = xmalloc_open_zipped_read_close(filename, &image_size);
147		if (!image)
148			return -errno;
149	}
150
151	errno = 0;
152	init_module(image, image_size, options);
153	rc = errno;
154	if (mmaped)
155		munmap(image, image_size);
156	else
157		free(image);
158	return rc;
159}
160
161int FAST_FUNC bb_delete_module(const char *module, unsigned int flags)
162{
163	errno = 0;
164	delete_module(module, flags);
165	return errno;
166}
167
168const char* FAST_FUNC moderror(int err)
169{
170	switch (err) {
171	case -1: /* btw: it's -EPERM */
172		return "no such module";
173	case ENOEXEC:
174		return "invalid module format";
175	case ENOENT:
176		return "unknown symbol in module, or unknown parameter";
177	case ESRCH:
178		return "module has wrong symbol version";
179	case ENOSYS:
180		return "kernel does not support requested operation";
181	}
182	if (err < 0) /* should always be */
183		err = -err;
184	return strerror(err);
185}
186