busybox/modutils/modprobe.c
Denis Vlasenko 06af216528 suppress warnings about easch <applet>_main() having
no preceding prototype
2007-02-03 17:28:39 +00:00

904 lines
23 KiB
C

/* vi: set sw=4 ts=4: */
/*
* Modprobe written from scratch for BusyBox
*
* Copyright (c) 2002 by Robert Griebl, griebl@gmx.de
* Copyright (c) 2003 by Andrew Dennison, andrew.dennison@motec.com.au
* Copyright (c) 2005 by Jim Bauer, jfbauer@nfr.com
*
* Portions Copyright (c) 2005 by Yann E. MORIN, yann.morin.1998@anciens.enib.fr
*
* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
*/
#include "busybox.h"
#include <sys/utsname.h>
#include <fnmatch.h>
struct mod_opt_t { /* one-way list of options to pass to a module */
char * m_opt_val;
struct mod_opt_t * m_next;
};
struct dep_t { /* one-way list of dependency rules */
/* a dependency rule */
char * m_name; /* the module name*/
char * m_path; /* the module file path */
struct mod_opt_t * m_options; /* the module options */
int m_isalias : 1; /* the module is an alias */
int m_reserved : 15; /* stuffin' */
int m_depcnt : 16; /* the number of dependable module(s) */
char ** m_deparr; /* the list of dependable module(s) */
struct dep_t * m_next; /* the next dependency rule */
};
struct mod_list_t { /* two-way list of modules to process */
/* a module description */
const char * m_name;
char * m_path;
struct mod_opt_t * m_options;
struct mod_list_t * m_prev;
struct mod_list_t * m_next;
};
static struct dep_t *depend;
#define main_options "acdklnqrst:vVC:"
#define INSERT_ALL 1 /* a */
#define DUMP_CONF_EXIT 2 /* c */
#define D_OPT_IGNORED 4 /* d */
#define AUTOCLEAN_FLG 8 /* k */
#define LIST_ALL 16 /* l */
#define SHOW_ONLY 32 /* n */
#define QUIET 64 /* q */
#define REMOVE_OPT 128 /* r */
#define DO_SYSLOG 256 /* s */
#define RESTRICT_DIR 512 /* t */
#define VERBOSE 1024 /* v */
#define VERSION_ONLY 2048 /* V */
#define CONFIG_FILE 4096 /* C */
#define autoclean (main_opts & AUTOCLEAN_FLG)
#define show_only (main_opts & SHOW_ONLY)
#define quiet (main_opts & QUIET)
#define remove_opt (main_opts & REMOVE_OPT)
#define do_syslog (main_opts & DO_SYSLOG)
#define verbose (main_opts & VERBOSE)
static int main_opts;
static int parse_tag_value(char *buffer, char **ptag, char **pvalue)
{
char *tag, *value;
buffer = skip_whitespace(buffer);
tag = value = buffer;
while (!isspace(*value))
if (!*value) return 0;
else value++;
*value++ = 0;
value = skip_whitespace(value);
if (!*value) return 0;
*ptag = tag;
*pvalue = value;
return 1;
}
/*
* This function appends an option to a list
*/
static struct mod_opt_t *append_option(struct mod_opt_t *opt_list, char *opt)
{
struct mod_opt_t *ol = opt_list;
if (ol) {
while (ol->m_next) {
ol = ol->m_next;
}
ol->m_next = xmalloc(sizeof(struct mod_opt_t));
ol = ol->m_next;
} else {
ol = opt_list = xmalloc(sizeof(struct mod_opt_t));
}
ol->m_opt_val = xstrdup(opt);
ol->m_next = NULL;
return opt_list;
}
#if ENABLE_FEATURE_MODPROBE_MULTIPLE_OPTIONS
/* static char* parse_command_string(char* src, char **dst);
* src: pointer to string containing argument
* dst: pointer to where to store the parsed argument
* return value: the pointer to the first char after the parsed argument,
* NULL if there was no argument parsed (only trailing spaces).
* Note that memory is allocated with xstrdup when a new argument was
* parsed. Don't forget to free it!
*/
#define ARG_EMPTY 0x00
#define ARG_IN_DQUOTES 0x01
#define ARG_IN_SQUOTES 0x02
static char *parse_command_string(char *src, char **dst)
{
int opt_status = ARG_EMPTY;
char* tmp_str;
/* Dumb you, I have nothing to do... */
if (src == NULL) return src;
/* Skip leading spaces */
while (*src == ' ') {
src++;
}
/* Is the end of string reached? */
if (*src == '\0') {
return NULL;
}
/* Reached the start of an argument
* By the way, we duplicate a little too much
* here but what is too much is freed later. */
*dst = tmp_str = xstrdup(src);
/* Get to the end of that argument */
while (*tmp_str != '\0'
&& (*tmp_str != ' ' || (opt_status & (ARG_IN_DQUOTES | ARG_IN_SQUOTES)))
) {
switch (*tmp_str) {
case '\'':
if (opt_status & ARG_IN_DQUOTES) {
/* Already in double quotes, keep current char as is */
} else {
/* shift left 1 char, until end of string: get rid of the opening/closing quotes */
memmove(tmp_str, tmp_str + 1, strlen(tmp_str));
/* mark me: we enter or leave single quotes */
opt_status ^= ARG_IN_SQUOTES;
/* Back one char, as we need to re-scan the new char there. */
tmp_str--;
}
break;
case '"':
if (opt_status & ARG_IN_SQUOTES) {
/* Already in single quotes, keep current char as is */
} else {
/* shift left 1 char, until end of string: get rid of the opening/closing quotes */
memmove(tmp_str, tmp_str + 1, strlen(tmp_str));
/* mark me: we enter or leave double quotes */
opt_status ^= ARG_IN_DQUOTES;
/* Back one char, as we need to re-scan the new char there. */
tmp_str--;
}
break;
case '\\':
if (opt_status & ARG_IN_SQUOTES) {
/* Between single quotes: keep as is. */
} else {
switch (*(tmp_str+1)) {
case 'a':
case 'b':
case 't':
case 'n':
case 'v':
case 'f':
case 'r':
case '0':
/* We escaped a special character. For now, keep
* both the back-slash and the following char. */
tmp_str++; src++;
break;
default:
/* We escaped a space or a single or double quote,
* or a back-slash, or a non-escapable char. Remove
* the '\' and keep the new current char as is. */
memmove(tmp_str, tmp_str + 1, strlen(tmp_str));
break;
}
}
break;
/* Any other char that is special shall appear here.
* Example: $ starts a variable
case '$':
do_variable_expansion();
break;
* */
default:
/* any other char is kept as is. */
break;
}
tmp_str++; /* Go to next char */
src++; /* Go to next char to find the end of the argument. */
}
/* End of string, but still no ending quote */
if (opt_status & (ARG_IN_DQUOTES | ARG_IN_SQUOTES)) {
bb_error_msg_and_die("unterminated (single or double) quote in options list: %s", src);
}
*tmp_str++ = '\0';
*dst = xrealloc(*dst, (tmp_str - *dst));
return src;
}
#else
#define parse_command_string(src, dst) (0)
#endif /* ENABLE_FEATURE_MODPROBE_MULTIPLE_OPTIONS */
/*
* This function reads aliases and default module options from a configuration file
* (/etc/modprobe.conf syntax). It supports includes (only files, no directories).
*/
static void include_conf(struct dep_t **first, struct dep_t **current, char *buffer, int buflen, int fd)
{
int continuation_line = 0;
// alias parsing is not 100% correct (no correct handling of continuation lines within an alias) !
while (reads(fd, buffer, buflen)) {
int l;
char *p;
p = strchr(buffer, '#');
if (p)
*p = 0;
l = strlen(buffer);
while (l && isspace(buffer[l-1])) {
buffer[l-1] = 0;
l--;
}
if (l == 0) {
continuation_line = 0;
continue;
}
if (!continuation_line) {
if ((strncmp(buffer, "alias", 5) == 0) && isspace(buffer[5])) {
char *alias, *mod;
if (parse_tag_value(buffer + 6, &alias, &mod)) {
/* handle alias as a module dependent on the aliased module */
if (!*current) {
(*first) = (*current) = xzalloc(sizeof(struct dep_t));
}
else {
(*current)->m_next = xzalloc(sizeof(struct dep_t));
(*current) = (*current)->m_next;
}
(*current)->m_name = xstrdup(alias);
(*current)->m_isalias = 1;
if ((strcmp(mod, "off") == 0) || (strcmp(mod, "null") == 0)) {
(*current)->m_depcnt = 0;
(*current)->m_deparr = 0;
}
else {
(*current)->m_depcnt = 1;
(*current)->m_deparr = xmalloc(1 * sizeof(char *));
(*current)->m_deparr[0] = xstrdup(mod);
}
(*current)->m_next = 0;
}
}
else if ((strncmp(buffer, "options", 7) == 0) && isspace(buffer[7])) {
char *mod, *opt;
/* split the line in the module/alias name, and options */
if (parse_tag_value(buffer + 8, &mod, &opt)) {
struct dep_t *dt;
/* find the corresponding module */
for (dt = *first; dt; dt = dt->m_next) {
if (strcmp(dt->m_name, mod) == 0)
break;
}
if (dt) {
if (ENABLE_FEATURE_MODPROBE_MULTIPLE_OPTIONS) {
char* new_opt = NULL;
while ((opt = parse_command_string(opt, &new_opt))) {
dt->m_options = append_option(dt->m_options, new_opt);
}
} else {
dt->m_options = append_option(dt->m_options, opt);
}
}
}
}
else if ((strncmp(buffer, "include", 7) == 0) && isspace(buffer[7])) {
int fdi; char *filename;
filename = skip_whitespace(buffer + 8);
if ((fdi = open(filename, O_RDONLY)) >= 0) {
include_conf(first, current, buffer, buflen, fdi);
close(fdi);
}
}
}
}
}
/*
* This function builds a list of dependency rules from /lib/modules/`uname -r`\modules.dep.
* It then fills every modules and aliases with their default options, found by parsing
* modprobe.conf (or modules.conf, or conf.modules).
*/
static struct dep_t *build_dep(void)
{
int fd;
struct utsname un;
struct dep_t *first = 0;
struct dep_t *current = 0;
char buffer[2048];
char *filename;
int continuation_line = 0;
int k_version;
if (uname(&un))
bb_error_msg_and_die("can't determine kernel version");
k_version = 0;
if (un.release[0] == '2') {
k_version = un.release[2] - '0';
}
filename = xasprintf("/lib/modules/%s/modules.dep", un.release);
fd = open(filename, O_RDONLY);
if (ENABLE_FEATURE_CLEAN_UP)
free(filename);
if (fd < 0) {
/* Ok, that didn't work. Fall back to looking in /lib/modules */
fd = open("/lib/modules/modules.dep", O_RDONLY);
if (fd < 0) {
return 0;
}
}
while (reads(fd, buffer, sizeof(buffer))) {
int l = strlen(buffer);
char *p = 0;
while (l > 0 && isspace(buffer[l-1])) {
buffer[l-1] = 0;
l--;
}
if (l == 0) {
continuation_line = 0;
continue;
}
/* Is this a new module dep description? */
if (!continuation_line) {
/* find the dep beginning */
char *col = strchr(buffer, ':');
char *dot = col;
if (col) {
/* This line is a dep description */
char *mods;
char *modpath;
char *mod;
/* Find the beginning of the module file name */
*col = 0;
mods = strrchr(buffer, '/');
if (!mods)
mods = buffer; /* no path for this module */
else
mods++; /* there was a path for this module... */
/* find the path of the module */
modpath = strchr(buffer, '/'); /* ... and this is the path */
if (!modpath)
modpath = buffer; /* module with no path */
/* find the end of the module name in the file name */
if (ENABLE_FEATURE_2_6_MODULES &&
(k_version > 4) && (*(col-3) == '.') &&
(*(col-2) == 'k') && (*(col-1) == 'o'))
dot = col - 3;
else
if ((*(col-2) == '.') && (*(col-1) == 'o'))
dot = col - 2;
mod = xstrndup(mods, dot - mods);
/* enqueue new module */
if (!current) {
first = current = xmalloc(sizeof(struct dep_t));
}
else {
current->m_next = xmalloc(sizeof(struct dep_t));
current = current->m_next;
}
current->m_name = mod;
current->m_path = xstrdup(modpath);
current->m_options = NULL;
current->m_isalias = 0;
current->m_depcnt = 0;
current->m_deparr = 0;
current->m_next = 0;
p = col + 1;
}
else
/* this line is not a dep description */
p = 0;
}
else
/* It's a dep description continuation */
p = buffer;
while (p && *p && isblank(*p))
p++;
/* p points to the first dependable module; if NULL, no dependable module */
if (p && *p) {
char *end = &buffer[l-1];
char *deps;
char *dep;
char *next;
int ext = 0;
while (isblank(*end) || (*end == '\\'))
end--;
do {
/* search the end of the dependency */
next = strchr(p, ' ');
if (next) {
*next = 0;
next--;
}
else
next = end;
/* find the beginning of the module file name */
deps = strrchr(p, '/');
if (!deps || (deps < p)) {
deps = p;
while (isblank(*deps))
deps++;
} else
deps++;
/* find the end of the module name in the file name */
if (ENABLE_FEATURE_2_6_MODULES
&& (k_version > 4) && (*(next-2) == '.')
&& (*(next-1) == 'k') && (*next == 'o'))
ext = 3;
else
if ((*(next-1) == '.') && (*next == 'o'))
ext = 2;
/* Cope with blank lines */
if ((next-deps-ext+1) <= 0)
continue;
dep = xstrndup(deps, next - deps - ext + 1);
/* Add the new dependable module name */
current->m_depcnt++;
current->m_deparr = xrealloc(current->m_deparr,
sizeof(char *) * current->m_depcnt);
current->m_deparr[current->m_depcnt - 1] = dep;
p = next + 2;
} while (next < end);
}
/* is there other dependable module(s) ? */
if (buffer[l-1] == '\\')
continuation_line = 1;
else
continuation_line = 0;
}
close(fd);
/*
* First parse system-specific options and aliases
* as they take precedence over the kernel ones.
*/
if (!ENABLE_FEATURE_2_6_MODULES
|| (fd = open("/etc/modprobe.conf", O_RDONLY)) < 0)
if ((fd = open("/etc/modules.conf", O_RDONLY)) < 0)
fd = open("/etc/conf.modules", O_RDONLY);
if (fd >= 0) {
include_conf(&first, &current, buffer, sizeof(buffer), fd);
close(fd);
}
/* Only 2.6 has a modules.alias file */
if (ENABLE_FEATURE_2_6_MODULES) {
/* Parse kernel-declared aliases */
filename = xasprintf("/lib/modules/%s/modules.alias", un.release);
fd = open(filename, O_RDONLY);
if (fd < 0) {
/* Ok, that didn't work. Fall back to looking in /lib/modules */
fd = open("/lib/modules/modules.alias", O_RDONLY);
}
if (ENABLE_FEATURE_CLEAN_UP)
free(filename);
if (fd >= 0) {
include_conf(&first, &current, buffer, sizeof(buffer), fd);
close(fd);
}
}
return first;
}
/* return 1 = loaded, 0 = not loaded, -1 = can't tell */
static int already_loaded(const char *name)
{
int fd, ret = 0;
char buffer[4096];
fd = open("/proc/modules", O_RDONLY);
if (fd < 0)
return -1;
while (reads(fd, buffer, sizeof(buffer))) {
char *p;
p = strchr (buffer, ' ');
if (p) {
const char *n;
// Truncate buffer at first space and check for matches, with
// the idiosyncrasy that _ and - are interchangeable because the
// 2.6 kernel does weird things.
*p = 0;
for (p = buffer, n = name; ; p++, n++) {
if (*p != *n) {
if ((*p == '_' || *p == '-') && (*n == '_' || *n == '-'))
continue;
break;
}
// If we made it to the end, that's a match.
if (!*p) {
ret = 1;
goto done;
}
}
}
}
done:
close (fd);
return ret;
}
static int mod_process(const struct mod_list_t *list, int do_insert)
{
int rc = 0;
char **argv = NULL;
struct mod_opt_t *opts;
int argc_malloc; /* never used when CONFIG_FEATURE_CLEAN_UP not defined */
int argc;
while (list) {
argc = 0;
if (ENABLE_FEATURE_CLEAN_UP)
argc_malloc = 0;
/* If CONFIG_FEATURE_CLEAN_UP is not defined, then we leak memory
* each time we allocate memory for argv.
* But it is (quite) small amounts of memory that leak each
* time a module is loaded, and it is reclaimed when modprobe
* exits anyway (even when standalone shell?).
* This could become a problem when loading a module with LOTS of
* dependencies, with LOTS of options for each dependencies, with
* very little memory on the target... But in that case, the module
* would not load because there is no more memory, so there's no
* problem. */
/* enough for minimal insmod (5 args + NULL) or rmmod (3 args + NULL) */
argv = xmalloc(6 * sizeof(char*));
if (do_insert) {
if (already_loaded(list->m_name) != 1) {
argv[argc++] = (char*)"insmod";
if (ENABLE_FEATURE_2_4_MODULES) {
if (do_syslog)
argv[argc++] = (char*)"-s";
if (autoclean)
argv[argc++] = (char*)"-k";
if (quiet)
argv[argc++] = (char*)"-q";
else if (verbose) /* verbose and quiet are mutually exclusive */
argv[argc++] = (char*)"-v";
}
argv[argc++] = list->m_path;
if (ENABLE_FEATURE_CLEAN_UP)
argc_malloc = argc;
opts = list->m_options;
while (opts) {
/* Add one more option */
argc++;
argv = xrealloc(argv,(argc + 1)* sizeof(char*));
argv[argc-1] = opts->m_opt_val;
opts = opts->m_next;
}
}
} else {
/* modutils uses short name for removal */
if (already_loaded(list->m_name) != 0) {
argv[argc++] = (char*)"rmmod";
if (do_syslog)
argv[argc++] = (char*)"-s";
argv[argc++] = (char*)list->m_name;
if (ENABLE_FEATURE_CLEAN_UP)
argc_malloc = argc;
}
}
argv[argc] = NULL;
if (argc) {
if (verbose) {
printf("%s module %s\n", do_insert?"Loading":"Unloading", list->m_name);
}
if (!show_only) {
int rc2 = wait4pid(spawn(argv));
if (do_insert) {
rc = rc2; /* only last module matters */
}
else if (!rc2) {
rc = 0; /* success if remove any mod */
}
}
if (ENABLE_FEATURE_CLEAN_UP) {
/* the last value in the array has index == argc, but
* it is the terminating NULL, so we must not free it. */
while (argc_malloc < argc) {
free(argv[argc_malloc++]);
}
}
}
if (ENABLE_FEATURE_CLEAN_UP) {
free(argv);
argv = NULL;
}
list = do_insert ? list->m_prev : list->m_next;
}
return (show_only) ? 0 : rc;
}
/*
* Check the matching between a pattern and a module name.
* We need this as *_* is equivalent to *-*, even in pattern matching.
*/
static int check_pattern(const char* pat_src, const char* mod_src) {
int ret;
if (ENABLE_FEATURE_MODPROBE_FANCY_ALIAS) {
char* pat;
char* mod;
char* p;
pat = xstrdup (pat_src);
mod = xstrdup (mod_src);
for (p = pat; (p = strchr(p, '-')); *p++ = '_');
for (p = mod; (p = strchr(p, '-')); *p++ = '_');
ret = fnmatch(pat, mod, 0);
if (ENABLE_FEATURE_CLEAN_UP) {
free (pat);
free (mod);
}
return ret;
} else {
return fnmatch(pat_src, mod_src, 0);
}
}
/*
* Builds the dependency list (aka stack) of a module.
* head: the highest module in the stack (last to insmod, first to rmmod)
* tail: the lowest module in the stack (first to insmod, last to rmmod)
*/
static void check_dep(char *mod, struct mod_list_t **head, struct mod_list_t **tail)
{
struct mod_list_t *find;
struct dep_t *dt;
struct mod_opt_t *opt = 0;
char *path = 0;
/* Search for the given module name amongst all dependency rules.
* The module name in a dependency rule can be a shell pattern,
* so try to match the given module name against such a pattern.
* Of course if the name in the dependency rule is a plain string,
* then we consider it a pattern, and matching will still work. */
for (dt = depend; dt; dt = dt->m_next) {
if (check_pattern(dt->m_name, mod) == 0) {
break;
}
}
if (!dt) {
bb_error_msg("module %s not found", mod);
return;
}
// resolve alias names
while (dt->m_isalias) {
if (dt->m_depcnt == 1) {
struct dep_t *adt;
for (adt = depend; adt; adt = adt->m_next) {
if (check_pattern(adt->m_name, dt->m_deparr[0]) == 0)
break;
}
if (adt) {
/* This is the module we are aliased to */
struct mod_opt_t *opts = dt->m_options;
/* Option of the alias are appended to the options of the module */
while (opts) {
adt->m_options = append_option(adt->m_options, opts->m_opt_val);
opts = opts->m_next;
}
dt = adt;
}
else {
bb_error_msg("module %s not found", mod);
return;
}
}
else {
bb_error_msg("bad alias %s", dt->m_name);
return;
}
}
mod = dt->m_name;
path = dt->m_path;
opt = dt->m_options;
// search for duplicates
for (find = *head; find; find = find->m_next) {
if (!strcmp(mod, find->m_name)) {
// found ->dequeue it
if (find->m_prev)
find->m_prev->m_next = find->m_next;
else
*head = find->m_next;
if (find->m_next)
find->m_next->m_prev = find->m_prev;
else
*tail = find->m_prev;
break; // there can be only one duplicate
}
}
if (!find) { // did not find a duplicate
find = xmalloc(sizeof(struct mod_list_t));
find->m_name = mod;
find->m_path = path;
find->m_options = opt;
}
// enqueue at tail
if (*tail)
(*tail)->m_next = find;
find->m_prev = *tail;
find->m_next = 0;
if (!*head)
*head = find;
*tail = find;
if (dt) {
int i;
/* Add all dependable module for that new module */
for (i = 0; i < dt->m_depcnt; i++)
check_dep(dt->m_deparr[i], head, tail);
}
}
static int mod_insert(char *mod, int argc, char **argv)
{
struct mod_list_t *tail = NULL;
struct mod_list_t *head = NULL;
int rc;
// get dep list for module mod
check_dep(mod, &head, &tail);
rc = 1;
if (head && tail) {
if (argc) {
int i;
// append module args
for (i = 0; i < argc; i++)
head->m_options = append_option(head->m_options, argv[i]);
}
// process tail ---> head
rc = mod_process(tail, 1);
if (rc) {
/*
* In case of using udev, multiple instances of modprobe can be
* spawned to load the same module (think of two same usb devices,
* for example; or cold-plugging at boot time). Thus we shouldn't
* fail if the module was loaded, and not by us.
*/
if (already_loaded(mod))
rc = 0;
}
}
return rc;
}
static int mod_remove(char *mod)
{
int rc;
static const struct mod_list_t rm_a_dummy = { "-a", NULL, NULL, NULL, NULL };
struct mod_list_t *head = NULL;
struct mod_list_t *tail = NULL;
if (mod)
check_dep(mod, &head, &tail);
else // autoclean
head = tail = (struct mod_list_t*) &rm_a_dummy;
rc = 1;
if (head && tail)
rc = mod_process(head, 0); // process head ---> tail
return rc;
}
int modprobe_main(int argc, char** argv);
int modprobe_main(int argc, char** argv)
{
int rc = EXIT_SUCCESS;
char *unused;
opt_complementary = "?V-:q-v:v-q";
main_opts = getopt32(argc, argv, "acdklnqrst:vVC:",
&unused, &unused);
if (main_opts & (DUMP_CONF_EXIT | LIST_ALL))
return EXIT_SUCCESS;
if (main_opts & (RESTRICT_DIR | CONFIG_FILE))
bb_error_msg_and_die("-t and -C not supported");
depend = build_dep();
if (!depend)
bb_error_msg_and_die("cannot parse modules.dep");
if (remove_opt) {
do {
if (mod_remove(optind < argc ?
argv[optind] : NULL)) {
bb_error_msg("failed to remove module %s",
argv[optind]);
rc = EXIT_FAILURE;
}
} while (++optind < argc);
} else {
if (optind >= argc)
bb_error_msg_and_die("no module or pattern provided");
if (mod_insert(argv[optind], argc - optind - 1, argv + optind + 1))
bb_error_msg_and_die("failed to load module %s", argv[optind]);
}
/* Here would be a good place to free up memory allocated during the dependencies build. */
return rc;
}