text: /* vi: set sw=4 ts=4: */
  /*
   * depmod - generate modules.dep
   * Copyright (c) 2008 Bernhard Reutner-Fischer
   * Copyrihgt (c) 2008 Timo Teras <timo.teras@iki.fi>
   * Copyright (c) 2008 Vladimir Dronnikov
   *
   * Licensed under GPLv2 or later, see file LICENSE in this source tree.
   */
  //config:config DEPMOD
  //config:	bool "depmod"
  //config:	default y
  //config:	select PLATFORM_LINUX
  //config:	help
  //config:	  depmod generates modules.dep (and potentially modules.alias
  //config:	  and modules.symbols) that contain dependency information
  //config:	  for modprobe.
  
  //applet:IF_DEPMOD(IF_NOT_MODPROBE_SMALL(APPLET(depmod, BB_DIR_SBIN, BB_SUID_DROP)))
  
  //kbuild:ifneq ($(CONFIG_MODPROBE_SMALL),y)
  //kbuild:lib-$(CONFIG_DEPMOD) += depmod.o modutils.o
  //kbuild:endif
  
  #include "libbb.h"
  #include "modutils.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
   */
  
  static int FAST_FUNC parse_module(const char *fname, struct stat *sb UNUSED_PARAM,
  				void *data, int depth UNUSED_PARAM)
  {
  	module_db *modules = data;
  	char *image, *ptr;
  	module_entry *e;
  
  	/* Arbitrary. Was sb->st_size, but that breaks .gz etc */
  	size_t len = (64*1024*1024 - 4096);
  
  	if (strrstr(fname, ".ko") == NULL)
  		return TRUE;
  
  	image = xmalloc_open_zipped_read_close(fname, &len);
  
  	e = moddb_get_or_create(modules, bb_get_last_path_component_nostrip(fname));
  	e->name = xstrdup(fname + 2); /* skip "./" */
  
  	for (ptr = image; ptr < image + len - 10; ptr++) {
  		if (is_prefixed_with(ptr, "depends=")) {
  			char *u;
  
  			ptr += 8;
  			for (u = ptr; *u; u++)
  				if (*u == '-')
  					*u = '_';
  			ptr += string_to_llist(ptr, &e->deps, ",");
  		} else if (ENABLE_FEATURE_MODUTILS_ALIAS
  		 && is_prefixed_with(ptr, "alias=")
  		) {
  			llist_add_to(&e->aliases, xstrdup(ptr + 6));
  			ptr += strlen(ptr);
  		} else if (ENABLE_FEATURE_MODUTILS_SYMBOLS
  		 && is_prefixed_with(ptr, "__ksymtab_")
  		) {
  			ptr += 10;
  			if (is_prefixed_with(ptr, "gpl")
  			 || strcmp(ptr, "strings") == 0
  			) {
  				continue;
  			}
  			llist_add_to(&e->symbols, xstrdup(ptr));
  			ptr += strlen(ptr);
  		}
  	}
  	free(image);
  
  	return TRUE;
  }
  
  static void order_dep_list(module_db *modules, module_entry *start, llist_t *add)
  {
  	module_entry *m;
  	llist_t *n;
  
  	for (n = add; n != NULL; n = n->link) {
  		m = moddb_get(modules, n->data);
  		if (m == NULL)
  			continue;
  
  		/* unlink current entry */
  		m->dnext->dprev = m->dprev;
  		m->dprev->dnext = m->dnext;
  
  		/* and add it to tail */
  		m->dnext = start;
  		m->dprev = start->dprev;
  		start->dprev->dnext = m;
  		start->dprev = m;
  
  		/* recurse */
  		order_dep_list(modules, start, m->deps);
  	}
  }
  
  static void xfreopen_write(const char *file, FILE *f)
  {
  	if (freopen(file, "w", f) == NULL)
  		bb_perror_msg_and_die("can't open '%s'", file);
  }
  
  //usage:#if !ENABLE_MODPROBE_SMALL
  //usage:#define depmod_trivial_usage "[-n] [-b BASE] [VERSION] [MODFILES]..."
  //usage:#define depmod_full_usage "\n\n"
  //usage:       "Generate modules.dep, alias, and symbols files"
  //usage:     "\n"
  //usage:     "\n	-b BASE	Use BASE/lib/modules/VERSION"
  //usage:     "\n	-n	Dry run: print files to stdout"
  //usage:#endif
  
  /* Upstream usage:
   * [-aAenv] [-C FILE or DIR] [-b BASE] [-F System.map] [VERSION] [MODFILES]...
   *	-a --all
   *		Probe all modules. Default if no MODFILES.
   *	-A --quick
   *		Check modules.dep's mtime against module files' mtimes.
   *	-b --basedir BASE
   *		Use $BASE/lib/modules/VERSION
   *	-C --config FILE or DIR
   *		Path to /etc/depmod.conf or /etc/depmod.d/
   *	-e --errsyms
   *		When combined with the -F option, this reports any symbols
   *		which are not supplied by other modules or kernel.
   *	-F --filesyms System.map
   *	-n --dry-run
   *		Print modules.dep etc to standard output
   *	-v --verbose
   *		Print to stdout all the symbols each module depends on
   *		and the module's file name which provides that symbol.
   *	-r	No-op
   *	-u	No-op
   *	-q	No-op
   *
   * So far we only support: [-n] [-b BASE] [VERSION] [MODFILES]...
   * Accepted but ignored:
   * -aAe
   * -F System.map
   * -C FILE/DIR
   *
   * Not accepted: -v
   */
  enum {
  	//OPT_a = (1 << 0), /* All modules, ignore mods in argv */
  	//OPT_A = (1 << 1), /* Only emit .ko that are newer than modules.dep file */
  	OPT_b = (1 << 2), /* base directory when modules are in staging area */
  	//OPT_e = (1 << 3), /* with -F, print unresolved symbols */
  	//OPT_F = (1 << 4), /* System.map that contains the symbols */
  	OPT_n = (1 << 5), /* dry-run, print to stdout only */
  	OPT_r = (1 << 6), /* Compat dummy. Linux Makefile uses it */
  	OPT_u = (1 << 7), /* -u,--unresolved-error: ignored */
  	OPT_q = (1 << 8), /* -q,--quiet: ignored */
  	OPT_C = (1 << 9), /* -C,--config etc_modules_conf: ignored */
  };
  
  int depmod_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  int depmod_main(int argc UNUSED_PARAM, char **argv)
  {
  	module_db modules;
  	module_entry *m, *dep;
  	const char *moddir_base = "/";
  	char *moddir, *version;
  	struct utsname uts;
  	unsigned i;
  	int tmp;
  
  	getopt32(argv, "aAb:eF:nruqC:", &moddir_base, NULL, NULL);
  	argv += optind;
  
  	/* goto modules location */
  	xchdir(moddir_base);
  
  	/* 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, "%u.%u.%u", &tmp, &tmp, &tmp) == 3) {
  		version = *argv++;
  	} else {
  		uname(&uts);
  		version = uts.release;
  	}
  	moddir = concat_path_file(&CONFIG_DEFAULT_MODULES_DIR[1], version);
  	xchdir(moddir);
  	if (ENABLE_FEATURE_CLEAN_UP)
  		free(moddir);
  
  	/* Scan modules */
  	memset(&modules, 0, sizeof(modules));
  	if (*argv) {
  		do {
  			parse_module(*argv, /*sb (unused):*/ NULL, &modules, 0);
  		} while (*++argv);
  	} else {
  		recursive_action(".", ACTION_RECURSE,
  				parse_module, NULL, &modules, 0);
  	}
  
  	/* Generate dependency and alias files */
  	if (!(option_mask32 & OPT_n))
  		xfreopen_write(CONFIG_DEFAULT_DEPMOD_FILE, stdout);
  
  	moddb_foreach_module(&modules, m, i) {
  		printf("%s:", m->name);
  
  		order_dep_list(&modules, m, m->deps);
  		while (m->dnext != m) {
  			dep = m->dnext;
  			printf(" %s", dep->name);
  
  			/* unlink current entry */
  			dep->dnext->dprev = dep->dprev;
  			dep->dprev->dnext = dep->dnext;
  			dep->dnext = dep->dprev = dep;
  		}
  		bb_putchar('\n');
  	}
  
  #if ENABLE_FEATURE_MODUTILS_ALIAS
  	if (!(option_mask32 & OPT_n))
  		xfreopen_write("modules.alias", stdout);
  	moddb_foreach_module(&modules, m, i) {
  		while (m->aliases) {
  			/*
  			 * Last word used to be a basename
  			 * (filename with path and .ko.* stripped)
  			 * at the time of module-init-tools 3.4.
  			 * kmod v.12 uses module name, i.e., s/-/_/g.
  			 */
  			printf("alias %s %s\n",
  				(char*)llist_pop(&m->aliases),
  				m->modname);
  		}
  	}
  #endif
  #if ENABLE_FEATURE_MODUTILS_SYMBOLS
  	if (!(option_mask32 & OPT_n))
  		xfreopen_write("modules.symbols", stdout);
  	moddb_foreach_module(&modules, m, i) {
  		while (m->symbols) {
  			printf("alias symbol:%s %s\n",
  				(char*)llist_pop(&m->symbols),
  				m->modname);
  		}
  	}
  #endif
  
  	if (ENABLE_FEATURE_CLEAN_UP)
  		moddb_free(&modules);
  
  	return EXIT_SUCCESS;
  }
  