modutils/depmod.c - busybox - Git at Google

 /* vi: set sw=4 ts=4: */
 /*
  * depmod - generate modules.dep
  * Copyright (c) 2008 Bernhard Fischer
  *
  * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
  */

 #undef _GNU_SOURCE
 #define _GNU_SOURCE
 #include <libbb.h>
 #include <sys/utsname.h> /* uname() */
 /*
  * Theory of operation:
  * - iterate over all modules and record their full path
  * - iterate over all modules looking for "depends=" entries
  *   for each depends, look through our list of full paths and emit if found
  */

 typedef struct dep_lst_t {
 	char *name;
 	llist_t *dependencies;
 	llist_t *aliases;
 	struct dep_lst_t *next;
 } dep_lst_t;

 struct globals {
 	dep_lst_t *lst; /* modules without their corresponding extension */
 };
 #define G (*(struct globals*)&bb_common_bufsiz1)
 /* We have to zero it out because of NOEXEC */
 #define INIT_G() memset(&G, 0, sizeof(G))

 static char* find_keyword(void *the_module, size_t len, const char * const word)
 {
 	char *ptr = the_module;
 	do {
 		/* search for the first char in word */
 		ptr = memchr(ptr, *word, len - (ptr - (char*)the_module));
 		if (ptr == NULL) /* no occurance left, done */
 			return NULL;
 		if (!strncmp(ptr, word, strlen(word))) {
 			ptr += strlen(word);
 			break;
 		}
 		++ptr;
 	} while (1);
 	return ptr;
 }
 static int fileAction(const char *fname, struct stat *sb,
 					void ATTRIBUTE_UNUSED *data, int ATTRIBUTE_UNUSED depth)
 {
 	size_t len = sb->st_size;
 	void *the_module;
 	char *ptr;
 	int fd;
 	char *depends, *deps;
 	dep_lst_t *this;

 	if (strrstr(fname, ".ko") == NULL) /* not a module */
 		goto skip;

 /*XXX: FIXME: does not handle compressed modules!
  * There should be a function that looks at the extension and sets up
  * open_transformer for us.
  */
 	fd = xopen(fname, O_RDONLY);
 	the_module = mmap(NULL, len, PROT_READ, MAP_SHARED
 #if defined MAP_POPULATE
 						|MAP_POPULATE
 #endif
 						, fd, 0);
 	close(fd);
 	if (the_module == MAP_FAILED)
 		bb_perror_msg_and_die("mmap");

 	this = xzalloc(sizeof(dep_lst_t));
 	this->name = xstrdup(fname);
 	this->next = G.lst;
 	G.lst = this;
 //bb_info_msg("fname='%s'", fname);
 	ptr = find_keyword(the_module, len, "depends=");
 	if (!*ptr)
 		goto d_none;
 	deps = depends = xstrdup(ptr);
 //bb_info_msg(" depends='%s'", depends);
 	while (deps) {
 		ptr = strsep(&deps, ",");
 //bb_info_msg("[%s] -> '%s'", fname, (char*)ptr);
 		llist_add_to_end(&this->dependencies, xstrdup(ptr));
 	}
 	free(depends);
  d_none:
 	if (ENABLE_FEATURE_DEPMOD_ALIAS)
 	{
 		size_t pos = 0;
 		do {
 			ptr = find_keyword(the_module + pos, len - pos, "alias=");
 			if (ptr) {
 //bb_info_msg("[%s] alias '%s'", fname, (char*)ptr);
 					llist_add_to_end(&this->aliases, xstrdup(ptr));
 			} else
 				break;
 			pos = (ptr - (char*)the_module);
 		} while (1);
 	}
 	munmap(the_module, sb->st_size);
  skip:
 	return TRUE;
 }

 int depmod_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int depmod_main(int ATTRIBUTE_UNUSED argc, char **argv)
 {
 	int ret;
 	size_t moddir_base_len = 0; /* length of the "-b basedir" */
 	char *moddir_base = NULL, *moddir, *system_map, *chp;
 	FILE *filedes = stdout;
 	enum {
 		ARG_a = (1<<0), /* All modules, ignore mods in argv */
 		ARG_A = (1<<1), /* Only emit .ko that are newer than modules.dep file */
 		ARG_b = (1<<2), /* not /lib/modules/$(uname -r)/ but this base-dir */
 		ARG_e = (1<<3), /* with -F, print unresolved symbols */
 		ARG_F = (1<<4), /* System.map that contains the symbols */
 		ARG_n = (1<<5)  /* dry-run, print to stdout only */
 	};
 	INIT_G();

 	getopt32(argv, "aAb:eF:n", &moddir_base, &system_map);
 	argv += optind;

 	/* If a version is provided, then that kernel version’s module directory
 	 * is used, rather than the current kernel version (as returned by
 	 * "uname -r").  */
 	if (*argv && (sscanf(*argv, "%d.%d.%d", &ret, &ret, &ret) == 3)) {
 		moddir = concat_path_file(CONFIG_DEFAULT_MODULES_DIR, *argv++);
 	} else {
 		struct utsname uts;
 		if (uname(&uts) < 0)
 			bb_simple_perror_msg_and_die("uname");
 		moddir = concat_path_file(CONFIG_DEFAULT_MODULES_DIR, uts.release);
 	}
 	/* If no modules are given on the command-line, -a is on per default.  */
 	option_mask32 |= *argv == NULL;

 	if (option_mask32 & ARG_b) {
 		moddir_base_len = strlen(moddir_base) + 1;
 		xchdir(moddir_base);
 	}

 	if (!(option_mask32 & ARG_n)) { /* --dry-run */
 		chp = concat_path_file(moddir, CONFIG_DEFAULT_DEPMOD_FILE);
 		filedes = xfopen(chp, "w");
 		if (ENABLE_FEATURE_CLEAN_UP)
 			free(chp);
 	}
 	ret = EXIT_SUCCESS;
 	do {
 		chp = option_mask32 & ARG_a ? moddir : (*argv + moddir_base_len);

 		if (!recursive_action(chp,
 				ACTION_RECURSE, /* flags */
 				fileAction, /* file action */
 				NULL, /* dir action */
 				NULL, /* user data */
 				0)) { /* depth */
 			ret = EXIT_FAILURE;
 		}
 	} while (!(option_mask32 & ARG_a) && *++argv);

 	{
 	dep_lst_t *mods = G.lst;

 	/* Fixup the module names in the depends list */
 	while (mods) {
 		llist_t *deps = NULL, *old_deps = mods->dependencies;

 		while (old_deps) {
 			dep_lst_t *all = G.lst;
 			char *longname = NULL;
 			char *shortname = llist_pop(&old_deps);

 			while (all) {
 				char *nam =
 					xstrdup(bb_get_last_path_component_nostrip(all->name));
 				char *tmp = strrstr(nam, ".ko");

 				*tmp = '\0';
 				if (!strcmp(nam, shortname)) {
 					if (ENABLE_FEATURE_CLEAN_UP)
 						free(nam);
 					longname = all->name;
 					break;
 				}
 				free(nam);
 				all = all->next;
 			}
 			llist_add_to_end(&deps, longname);
 		}
 		mods->dependencies = deps;
 		mods = mods->next;
 	}

 #if ENABLE_FEATURE_DEPMOD_PRUNE_FANCY
 	/* modprobe allegedly wants dependencies without duplicates, i.e.
 	 * mod1: mod2 mod3
 	 * mod2: mod3
 	 * mod3:
 	 * implies that mod1 directly depends on mod2 and _not_ mod3 as mod3 is
 	 * already implicitely pulled in via mod2. This leaves us with:
 	 * mod1: mod2
 	 * mod2: mod3
 	 * mod3:
 	 */
 	mods = G.lst;
 	while (mods) {
 		llist_t *deps = mods->dependencies;
 		while (deps) {
 			dep_lst_t *all = G.lst;
 			while (all) {
 				if (!strcmp(all->name, deps->data)) {
 					llist_t *implied = all->dependencies;
 					while (implied) {
 						/* XXX:FIXME: erm, it would be nicer to just
 						 * llist_unlink(&mods->dependencies, implied)  */
 						llist_t *prune = mods->dependencies;
 						while (prune) {
 							if (!strcmp(implied->data, prune->data))
 								break;
 							prune = prune->link;
 						}
 //if (prune) bb_info_msg("[%s] '%s' implies '%s', removing", mods->name, all->name, implied->data);
 						llist_unlink(&mods->dependencies, prune);
 						implied = implied->link;
 					}
 				}
 				all = all->next;
 			}
 			deps = deps->link;
 		}
 		mods = mods->next;
 	}
 #endif

 	mods = G.lst;
 	/* Finally print them.  */
 	while (mods) {
 		fprintf(filedes, "%s:", mods->name);
 		/* If we did not resolve all modules, then it's likely that we just did
 		 * not see the names of all prerequisites (which will be NULL in this
 		 * case).  */
 		while (mods->dependencies) {
 			char *the_dep = llist_pop(&mods->dependencies);
 			if (the_dep)
 				fprintf(filedes, " %s", the_dep);
 		}
 		fprintf(filedes, "\n");
 		if (ENABLE_FEATURE_DEPMOD_ALIAS)
 		{
 			char *shortname =
 				xstrdup(bb_get_last_path_component_nostrip(mods->name));
 			char *tmp = strrstr(shortname, ".ko");

 			*tmp = '\0';

 			while (mods->aliases) {
 				fprintf(filedes, "alias %s %s\n",
 					(char*)llist_pop(&mods->aliases),
 					shortname);
 			}
 			free(shortname);
 		}
 		mods = mods->next;
 	}
 	}

 	if (ENABLE_FEATURE_CLEAN_UP) {
 		fclose_if_not_stdin(filedes);
 		free(moddir);
 		while (G.lst) {
 			dep_lst_t *old = G.lst;
 			G.lst = G.lst->next;
 			free(old->name);
 			free(old);
 		}
 	}
 	return ret;
 }
	/* vi: set sw=4 ts=4: */
	/*
	* depmod - generate modules.dep
	* Copyright (c) 2008 Bernhard Fischer
	*
	* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
	*/

	#undef _GNU_SOURCE
	#define _GNU_SOURCE
	#include <libbb.h>
	#include <sys/utsname.h> /* uname() */
	/*
	* Theory of operation:
	* - iterate over all modules and record their full path
	* - iterate over all modules looking for "depends=" entries
	* for each depends, look through our list of full paths and emit if found
	*/

	typedef struct dep_lst_t {
	char *name;
	llist_t *dependencies;
	llist_t *aliases;
	struct dep_lst_t *next;
	} dep_lst_t;

	struct globals {
	dep_lst_t lst; / modules without their corresponding extension */
	};
	#define G ((struct globals)&bb_common_bufsiz1)
	/* We have to zero it out because of NOEXEC */
	#define INIT_G() memset(&G, 0, sizeof(G))

	static char* find_keyword(void the_module, size_t len, const char const word)
	{
	char *ptr = the_module;
	do {
	/* search for the first char in word */
	ptr = memchr(ptr, word, len - (ptr - (char)the_module));
	if (ptr == NULL) /* no occurance left, done */
	return NULL;
	if (!strncmp(ptr, word, strlen(word))) {
	ptr += strlen(word);
	break;
	}
	++ptr;
	} while (1);
	return ptr;
	}
	static int fileAction(const char fname, struct stat sb,
	void ATTRIBUTE_UNUSED *data, int ATTRIBUTE_UNUSED depth)
	{
	size_t len = sb->st_size;
	void *the_module;
	char *ptr;
	int fd;
	char depends, deps;
	dep_lst_t *this;

	if (strrstr(fname, ".ko") == NULL) /* not a module */
	goto skip;

	/*XXX: FIXME: does not handle compressed modules!
	* There should be a function that looks at the extension and sets up
	* open_transformer for us.
	*/
	fd = xopen(fname, O_RDONLY);
	the_module = mmap(NULL, len, PROT_READ, MAP_SHARED
	#if defined MAP_POPULATE
	\|MAP_POPULATE
	#endif
	, fd, 0);
	close(fd);
	if (the_module == MAP_FAILED)
	bb_perror_msg_and_die("mmap");

	this = xzalloc(sizeof(dep_lst_t));
	this->name = xstrdup(fname);
	this->next = G.lst;
	G.lst = this;
	//bb_info_msg("fname='%s'", fname);
	ptr = find_keyword(the_module, len, "depends=");
	if (!*ptr)
	goto d_none;
	deps = depends = xstrdup(ptr);
	//bb_info_msg(" depends='%s'", depends);
	while (deps) {
	ptr = strsep(&deps, ",");
	//bb_info_msg("[%s] -> '%s'", fname, (char*)ptr);
	llist_add_to_end(&this->dependencies, xstrdup(ptr));
	}
	free(depends);
	d_none:
	if (ENABLE_FEATURE_DEPMOD_ALIAS)
	{
	size_t pos = 0;
	do {
	ptr = find_keyword(the_module + pos, len - pos, "alias=");
	if (ptr) {
	//bb_info_msg("[%s] alias '%s'", fname, (char*)ptr);
	llist_add_to_end(&this->aliases, xstrdup(ptr));
	} else
	break;
	pos = (ptr - (char*)the_module);
	} while (1);
	}
	munmap(the_module, sb->st_size);
	skip:
	return TRUE;
	}

	int depmod_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
	int depmod_main(int ATTRIBUTE_UNUSED argc, char **argv)
	{
	int ret;
	size_t moddir_base_len = 0; /* length of the "-b basedir" */
	char moddir_base = NULL, moddir, system_map, chp;
	FILE *filedes = stdout;
	enum {
	ARG_a = (1<<0), /* All modules, ignore mods in argv */
	ARG_A = (1<<1), /* Only emit .ko that are newer than modules.dep file */
	ARG_b = (1<<2), /* not /lib/modules/$(uname -r)/ but this base-dir */
	ARG_e = (1<<3), /* with -F, print unresolved symbols */
	ARG_F = (1<<4), /* System.map that contains the symbols */
	ARG_n = (1<<5) /* dry-run, print to stdout only */
	};
	INIT_G();

	getopt32(argv, "aAb:eF:n", &moddir_base, &system_map);
	argv += optind;

	/* If a version is provided, then that kernel version’s module directory
	* is used, rather than the current kernel version (as returned by
	* "uname -r"). */
	if (argv && (sscanf(argv, "%d.%d.%d", &ret, &ret, &ret) == 3)) {
	moddir = concat_path_file(CONFIG_DEFAULT_MODULES_DIR, *argv++);
	} else {
	struct utsname uts;
	if (uname(&uts) < 0)
	bb_simple_perror_msg_and_die("uname");
	moddir = concat_path_file(CONFIG_DEFAULT_MODULES_DIR, uts.release);
	}
	/* If no modules are given on the command-line, -a is on per default. */
	option_mask32 \|= *argv == NULL;

	if (option_mask32 & ARG_b) {
	moddir_base_len = strlen(moddir_base) + 1;
	xchdir(moddir_base);
	}

	if (!(option_mask32 & ARG_n)) { /* --dry-run */
	chp = concat_path_file(moddir, CONFIG_DEFAULT_DEPMOD_FILE);
	filedes = xfopen(chp, "w");
	if (ENABLE_FEATURE_CLEAN_UP)
	free(chp);
	}
	ret = EXIT_SUCCESS;
	do {
	chp = option_mask32 & ARG_a ? moddir : (*argv + moddir_base_len);

	if (!recursive_action(chp,
	ACTION_RECURSE, /* flags */
	fileAction, /* file action */
	NULL, /* dir action */
	NULL, /* user data */
	0)) { /* depth */
	ret = EXIT_FAILURE;
	}
	} while (!(option_mask32 & ARG_a) && *++argv);

	{
	dep_lst_t *mods = G.lst;

	/* Fixup the module names in the depends list */
	while (mods) {
	llist_t deps = NULL, old_deps = mods->dependencies;

	while (old_deps) {
	dep_lst_t *all = G.lst;
	char *longname = NULL;
	char *shortname = llist_pop(&old_deps);

	while (all) {
	char *nam =
	xstrdup(bb_get_last_path_component_nostrip(all->name));
	char *tmp = strrstr(nam, ".ko");

	*tmp = '\0';
	if (!strcmp(nam, shortname)) {
	if (ENABLE_FEATURE_CLEAN_UP)
	free(nam);
	longname = all->name;
	break;
	}
	free(nam);
	all = all->next;
	}
	llist_add_to_end(&deps, longname);
	}
	mods->dependencies = deps;
	mods = mods->next;
	}

	#if ENABLE_FEATURE_DEPMOD_PRUNE_FANCY
	/* modprobe allegedly wants dependencies without duplicates, i.e.
	* mod1: mod2 mod3
	* mod2: mod3
	* mod3:
	* implies that mod1 directly depends on mod2 and _not_ mod3 as mod3 is
	* already implicitely pulled in via mod2. This leaves us with:
	* mod1: mod2
	* mod2: mod3
	* mod3:
	*/
	mods = G.lst;
	while (mods) {
	llist_t *deps = mods->dependencies;
	while (deps) {
	dep_lst_t *all = G.lst;
	while (all) {
	if (!strcmp(all->name, deps->data)) {
	llist_t *implied = all->dependencies;
	while (implied) {
	/* XXX:FIXME: erm, it would be nicer to just
	* llist_unlink(&mods->dependencies, implied) */
	llist_t *prune = mods->dependencies;
	while (prune) {
	if (!strcmp(implied->data, prune->data))
	break;
	prune = prune->link;
	}
	//if (prune) bb_info_msg("[%s] '%s' implies '%s', removing", mods->name, all->name, implied->data);
	llist_unlink(&mods->dependencies, prune);
	implied = implied->link;
	}
	}
	all = all->next;
	}
	deps = deps->link;
	}
	mods = mods->next;
	}
	#endif

	mods = G.lst;
	/* Finally print them. */
	while (mods) {
	fprintf(filedes, "%s:", mods->name);
	/* If we did not resolve all modules, then it's likely that we just did
	* not see the names of all prerequisites (which will be NULL in this
	* case). */
	while (mods->dependencies) {
	char *the_dep = llist_pop(&mods->dependencies);
	if (the_dep)
	fprintf(filedes, " %s", the_dep);
	}
	fprintf(filedes, "\n");
	if (ENABLE_FEATURE_DEPMOD_ALIAS)
	{
	char *shortname =
	xstrdup(bb_get_last_path_component_nostrip(mods->name));
	char *tmp = strrstr(shortname, ".ko");

	*tmp = '\0';

	while (mods->aliases) {
	fprintf(filedes, "alias %s %s\n",
	(char*)llist_pop(&mods->aliases),
	shortname);
	}
	free(shortname);
	}
	mods = mods->next;
	}
	}

	if (ENABLE_FEATURE_CLEAN_UP) {
	fclose_if_not_stdin(filedes);
	free(moddir);
	while (G.lst) {
	dep_lst_t *old = G.lst;
	G.lst = G.lst->next;
	free(old->name);
	free(old);
	}
	}
	return ret;
	}