1/* vi: set sw=4 ts=4: */
2/*
3 * depmod - generate modules.dep
4 * Copyright (c) 2008 Bernhard Reutner-Fischer
5 * Copyrihgt (c) 2008 Timo Teras <timo.teras@iki.fi>
6 * Copyright (c) 2008 Vladimir Dronnikov
7 *
8 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
9 */
10
11#include "libbb.h"
12#include "modutils.h"
13#include <sys/utsname.h> /* uname() */
14
15/*
16 * Theory of operation:
17 * - iterate over all modules and record their full path
18 * - iterate over all modules looking for "depends=" entries
19 *   for each depends, look through our list of full paths and emit if found
20 */
21
22typedef struct module_info {
23	struct module_info *next;
24	char *name, *modname;
25	llist_t *dependencies;
26	llist_t *aliases;
27	llist_t *symbols;
28	struct module_info *dnext, *dprev;
29} module_info;
30
31static int FAST_FUNC parse_module(const char *fname, struct stat *sb UNUSED_PARAM,
32				  void *data, int depth UNUSED_PARAM)
33{
34	char modname[MODULE_NAME_LEN];
35	module_info **first = (module_info **) data;
36	char *image, *ptr;
37	module_info *info;
38	/* Arbitrary. Was sb->st_size, but that breaks .gz etc */
39	size_t len = (64*1024*1024 - 4096);
40
41	if (strrstr(fname, ".ko") == NULL)
42		return TRUE;
43
44	image = xmalloc_open_zipped_read_close(fname, &len);
45	info = xzalloc(sizeof(*info));
46
47	info->next = *first;
48	*first = info;
49
50	info->dnext = info->dprev = info;
51	info->name = xstrdup(fname + 2); /* skip "./" */
52	info->modname = xstrdup(filename2modname(fname, modname));
53	for (ptr = image; ptr < image + len - 10; ptr++) {
54		if (strncmp(ptr, "depends=", 8) == 0) {
55			char *u;
56
57			ptr += 8;
58			for (u = ptr; *u; u++)
59				if (*u == '-')
60					*u = '_';
61			ptr += string_to_llist(ptr, &info->dependencies, ",");
62		} else if (ENABLE_FEATURE_MODUTILS_ALIAS
63		 && strncmp(ptr, "alias=", 6) == 0
64		) {
65			llist_add_to(&info->aliases, xstrdup(ptr + 6));
66			ptr += strlen(ptr);
67		} else if (ENABLE_FEATURE_MODUTILS_SYMBOLS
68		 && strncmp(ptr, "__ksymtab_", 10) == 0
69		) {
70			ptr += 10;
71			if (strncmp(ptr, "gpl", 3) == 0
72			 || strcmp(ptr, "strings") == 0
73			) {
74				continue;
75			}
76			llist_add_to(&info->symbols, xstrdup(ptr));
77			ptr += strlen(ptr);
78		}
79	}
80	free(image);
81
82	return TRUE;
83}
84
85static module_info *find_module(module_info *modules, const char *modname)
86{
87	module_info *m;
88
89	for (m = modules; m != NULL; m = m->next)
90		if (strcmp(m->modname, modname) == 0)
91			return m;
92	return NULL;
93}
94
95static void order_dep_list(module_info *modules, module_info *start,
96			   llist_t *add)
97{
98	module_info *m;
99	llist_t *n;
100
101	for (n = add; n != NULL; n = n->link) {
102		m = find_module(modules, n->data);
103		if (m == NULL)
104			continue;
105
106		/* unlink current entry */
107		m->dnext->dprev = m->dprev;
108		m->dprev->dnext = m->dnext;
109
110		/* and add it to tail */
111		m->dnext = start;
112		m->dprev = start->dprev;
113		start->dprev->dnext = m;
114		start->dprev = m;
115
116		/* recurse */
117		order_dep_list(modules, start, m->dependencies);
118	}
119}
120
121static void xfreopen_write(const char *file, FILE *f)
122{
123	if (freopen(file, "w", f) == NULL)
124		bb_perror_msg_and_die("can't open '%s'", file);
125}
126
127/* Usage:
128 * [-aAenv] [-C FILE or DIR] [-b BASE] [-F System.map] [VERSION] [MODFILES]...
129 *	-a --all
130 *		Probe all modules. Default if no MODFILES.
131 *	-A --quick
132 *		Check modules.dep's mtime against module files' mtimes.
133 *	-b --basedir BASE
134 *		Use $BASE/lib/modules/VERSION
135 *	-C --config FILE or DIR
136 *		Path to /etc/depmod.conf or /etc/depmod.d/
137 *	-e --errsyms
138 *		When combined with the -F option, this reports any symbols which
139 *		which are not supplied by other modules or kernel.
140 *	-F --filesyms System.map
141 *	-n --dry-run
142 *		Print modules.dep etc to standard output
143 *	-v --verbose
144 *		Print to stdout all the symbols each module depends on
145 *		and the module's file name which provides that symbol.
146 *	-r	No-op
147 *
148 * So far we only support: [-rn] [-b BASE] [VERSION] [MODFILES]...
149 * -aAeF are accepted but ignored. -vC are not accepted.
150 */
151enum {
152	//OPT_a = (1 << 0), /* All modules, ignore mods in argv */
153	//OPT_A = (1 << 1), /* Only emit .ko that are newer than modules.dep file */
154	OPT_b = (1 << 2), /* base directory when modules are in staging area */
155	//OPT_e = (1 << 3), /* with -F, print unresolved symbols */
156	//OPT_F = (1 << 4), /* System.map that contains the symbols */
157	OPT_n = (1 << 5), /* dry-run, print to stdout only */
158	OPT_r = (1 << 6)  /* Compat dummy. Linux Makefile uses it */
159};
160
161int depmod_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
162int depmod_main(int argc UNUSED_PARAM, char **argv)
163{
164	module_info *modules, *m, *dep;
165	const char *moddir_base = "/";
166	char *moddir, *version;
167	struct utsname uts;
168	int tmp;
169
170	getopt32(argv, "aAb:eF:nr", &moddir_base, NULL);
171	argv += optind;
172
173	/* goto modules location */
174	xchdir(moddir_base);
175
176	/* If a version is provided, then that kernel version's module directory
177	 * is used, rather than the current kernel version (as returned by
178	 * "uname -r").  */
179	if (*argv && sscanf(*argv, "%u.%u.%u", &tmp, &tmp, &tmp) == 3) {
180		version = *argv++;
181	} else {
182		uname(&uts);
183		version = uts.release;
184	}
185	moddir = concat_path_file(&CONFIG_DEFAULT_MODULES_DIR[1], version);
186	xchdir(moddir);
187	if (ENABLE_FEATURE_CLEAN_UP)
188		free(moddir);
189
190	/* Scan modules */
191	modules = NULL;
192	if (*argv) {
193		do {
194			parse_module(*argv, /*sb (unused):*/ NULL, &modules, 0);
195		} while (*++argv);
196	} else {
197		recursive_action(".", ACTION_RECURSE,
198				 parse_module, NULL, &modules, 0);
199	}
200
201	/* Generate dependency and alias files */
202	if (!(option_mask32 & OPT_n))
203		xfreopen_write(CONFIG_DEFAULT_DEPMOD_FILE, stdout);
204	for (m = modules; m != NULL; m = m->next) {
205		printf("%s:", m->name);
206
207		order_dep_list(modules, m, m->dependencies);
208		while (m->dnext != m) {
209			dep = m->dnext;
210			printf(" %s", dep->name);
211
212			/* unlink current entry */
213			dep->dnext->dprev = dep->dprev;
214			dep->dprev->dnext = dep->dnext;
215			dep->dnext = dep->dprev = dep;
216		}
217		bb_putchar('\n');
218	}
219
220#if ENABLE_FEATURE_MODUTILS_ALIAS
221	if (!(option_mask32 & OPT_n))
222		xfreopen_write("modules.alias", stdout);
223	for (m = modules; m != NULL; m = m->next) {
224		const char *fname = bb_basename(m->name);
225		int fnlen = strchrnul(fname, '.') - fname;
226		while (m->aliases) {
227			/* Last word can well be m->modname instead,
228			 * but depmod from module-init-tools 3.4
229			 * uses module basename, i.e., no s/-/_/g.
230			 * (pathname and .ko.* are still stripped)
231			 * Mimicking that... */
232			printf("alias %s %.*s\n",
233				(char*)llist_pop(&m->aliases),
234				fnlen, fname);
235		}
236	}
237#endif
238#if ENABLE_FEATURE_MODUTILS_SYMBOLS
239	if (!(option_mask32 & OPT_n))
240		xfreopen_write("modules.symbols", stdout);
241	for (m = modules; m != NULL; m = m->next) {
242		const char *fname = bb_basename(m->name);
243		int fnlen = strchrnul(fname, '.') - fname;
244		while (m->symbols) {
245			printf("alias symbol:%s %.*s\n",
246				(char*)llist_pop(&m->symbols),
247				fnlen, fname);
248		}
249	}
250#endif
251
252	if (ENABLE_FEATURE_CLEAN_UP) {
253		while (modules) {
254			module_info *old = modules;
255			modules = modules->next;
256			free(old->name);
257			free(old->modname);
258			free(old);
259		}
260	}
261
262	return EXIT_SUCCESS;
263}
264