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mdev: don't reparse rules on -s

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function                                             old     new   delta
make_device                                         1648    1843    +195
clean_up_cur_rule                                      -      61     +61
make_default_cur_rule                                  -      41     +41
mdev_main                                            690     712     +22
------------------------------------------------------------------------------
(add/remove: 2/0 grow/shrink: 2/0 up/down: 319/0)             Total: 319 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2011-09-22 03:46:30 +02:00
parent 16714245f9
commit 3eccd7ecbe
1 changed files with 342 additions and 218 deletions
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392
util-linux/mdev.c
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@ -168,9 +168,29 @@
* This happens regardless of /sys/class/.../dev existence. * This happens regardless of /sys/class/.../dev existence.
*/ */
struct rule {
bool keep_matching;
bool regex_compiled;
bool regex_has_slash;
mode_t mode;
int maj, min0, min1;
struct bb_uidgid_t ugid;
char *envvar;
char *ren_mov;
IF_FEATURE_MDEV_EXEC(char *r_cmd;)
regex_t match;
};
struct globals { struct globals {
int root_major, root_minor; int root_major, root_minor;
char *subsystem; char *subsystem;
#if ENABLE_FEATURE_MDEV_CONF
const char *filename;
parser_t *parser;
struct rule **rule_vec;
unsigned rule_idx;
#endif
struct rule cur_rule;
} FIX_ALIASING; } FIX_ALIASING;
#define G (*(struct globals*)&bb_common_bufsiz1) #define G (*(struct globals*)&bb_common_bufsiz1)
#define INIT_G() do { } while (0) #define INIT_G() do { } while (0)
@ -182,6 +202,164 @@ struct globals {
/* We use additional 64+ bytes in make_device() */ /* We use additional 64+ bytes in make_device() */
#define SCRATCH_SIZE 80 #define SCRATCH_SIZE 80
#if 0
# define dbg(...) bb_error_msg(__VA_ARGS__)
#else
# define dbg(...) ((void)0)
#endif
#if ENABLE_FEATURE_MDEV_CONF
static void make_default_cur_rule(void)
{
memset(&G.cur_rule, 0, sizeof(G.cur_rule));
G.cur_rule.maj = -1; /* "not a @major,minor rule" */
G.cur_rule.mode = 0660;
}
static void clean_up_cur_rule(void)
{
free(G.cur_rule.envvar);
if (G.cur_rule.regex_compiled)
regfree(&G.cur_rule.match);
free(G.cur_rule.ren_mov);
IF_FEATURE_MDEV_EXEC(free(G.cur_rule.r_cmd);)
make_default_cur_rule();
}
static void parse_next_rule(void)
{
/* Note: on entry, G.cur_rule is set to default */
while (1) {
char *tokens[4];
char *val;
if (!config_read(G.parser, tokens, 4, 3, "# \t", PARSE_NORMAL))
break;
/* Fields: [-]regex uid:gid mode [alias] [cmd] */
dbg("token1:'%s'", tokens[1]);
/* 1st field */
val = tokens[0];
G.cur_rule.keep_matching = ('-' == val[0]);
val += G.cur_rule.keep_matching; /* swallow leading dash */
if (val[0] == '@') {
/* @major,minor[-minor2] */
/* (useful when name is ambiguous:
* "/sys/class/usb/lp0" and
* "/sys/class/printer/lp0")
*/
int sc = sscanf(val, "@%u,%u-%u", &G.cur_rule.maj, &G.cur_rule.min0, &G.cur_rule.min1);
if (sc < 2 || G.cur_rule.maj < 0) {
bb_error_msg("bad @maj,min on line %d", G.parser->lineno);
goto next_rule;
}
if (sc == 2)
G.cur_rule.min1 = G.cur_rule.min0;
} else {
if (val[0] == '$') {
char *eq = strchr(++val, '=');
if (!eq) {
bb_error_msg("bad $envvar=regex on line %d", G.parser->lineno);
goto next_rule;
}
G.cur_rule.envvar = xstrndup(val, eq - val);
val = eq + 1;
}
xregcomp(&G.cur_rule.match, val, REG_EXTENDED);
G.cur_rule.regex_compiled = 1;
G.cur_rule.regex_has_slash = (strchr(val, '/') != NULL);
}
/* 2nd field: uid:gid - device ownership */
if (get_uidgid(&G.cur_rule.ugid, tokens[1], /*allow_numeric:*/ 1) == 0) {
bb_error_msg("unknown user/group '%s' on line %d", tokens[1], G.parser->lineno);
goto next_rule;
}
/* 3rd field: mode - device permissions */
bb_parse_mode(tokens[2], &G.cur_rule.mode);
/* 4th field (opt): ">|=alias" or "!" to not create the node */
val = tokens[3];
if (ENABLE_FEATURE_MDEV_RENAME && val && strchr(">=!", val[0])) {
char *s = skip_non_whitespace(val);
G.cur_rule.ren_mov = xstrndup(val, s - val);
val = skip_whitespace(s);
}
if (ENABLE_FEATURE_MDEV_EXEC && val && val[0]) {
const char *s = "$@*";
const char *s2 = strchr(s, val[0]);
if (!s2) {
bb_error_msg("bad line %u", G.parser->lineno);
goto next_rule;
}
IF_FEATURE_MDEV_EXEC(G.cur_rule.r_cmd = xstrdup(val);)
}
return;
next_rule:
clean_up_cur_rule();
} /* while (config_read) */
dbg("config_close(G.parser)");
config_close(G.parser);
G.parser = NULL;
return;
}
/* If mdev -s, we remember rules in G.rule_vec[].
* Otherwise, there is no point in doing it, and we just
* save only one parsed rule in G.cur_rule.
*/
static const struct rule *next_rule(void)
{
struct rule *rule;
/* Open conf file if we didn't do it yet */
if (!G.parser && G.filename) {
dbg("config_open('%s')", G.filename);
G.parser = config_open2(G.filename, fopen_for_read);
G.filename = NULL;
}
if (G.rule_vec) {
/* mdev -s */
/* Do we have rule parsed already? */
if (G.rule_vec[G.rule_idx]) {
dbg("< G.rule_vec[G.rule_idx:%d]=%p", G.rule_idx, G.rule_vec[G.rule_idx]);
return G.rule_vec[G.rule_idx++];
}
make_default_cur_rule();
} else {
/* not mdev -s */
clean_up_cur_rule();
}
/* Parse one more rule if file isn't fully read */
rule = &G.cur_rule;
if (G.parser) {
parse_next_rule();
if (G.rule_vec) { /* mdev -s */
rule = memcpy(xmalloc(sizeof(G.cur_rule)), &G.cur_rule, sizeof(G.cur_rule));
G.rule_vec = xrealloc_vector(G.rule_vec, 4, G.rule_idx);
G.rule_vec[G.rule_idx++] = rule;
dbg("> G.rule_vec[G.rule_idx:%d]=%p", G.rule_idx, G.rule_vec[G.rule_idx]);
}
}
return rule;
}
#else
# define next_rule() (&G.cur_rule)
#endif
/* Builds an alias path. /* Builds an alias path.
* This function potentionally reallocates the alias parameter. * This function potentionally reallocates the alias parameter.
@ -218,8 +396,8 @@ static void make_device(char *path, int delete)
{ {
char *device_name, *subsystem_slash_devname; char *device_name, *subsystem_slash_devname;
int major, minor, type, len; int major, minor, type, len;
mode_t mode;
parser_t *parser; dbg("%s('%s', delete:%d)", __func__, path, delete);
/* Try to read major/minor string. Note that the kernel puts \n after /* Try to read major/minor string. Note that the kernel puts \n after
* the data, so we don't need to worry about null terminating the string * the data, so we don't need to worry about null terminating the string
@ -272,79 +450,44 @@ static void make_device(char *path, int delete)
path = subsystem_slash_devname; path = subsystem_slash_devname;
} }
/* If we have config file, look up user settings */ #if ENABLE_FEATURE_MDEV_CONF
if (ENABLE_FEATURE_MDEV_CONF) G.rule_idx = 0; /* restart from the beginning (think mdev -s) */
parser = config_open2("/etc/mdev.conf", fopen_for_read); #endif
for (;;) {
do { const char *str_to_match;
int keep_matching;
struct bb_uidgid_t ugid;
char *tokens[4];
char *command = NULL;
char *alias = NULL;
char aliaslink = aliaslink; /* for compiler */
/* Defaults in case we won't match any line */
ugid.uid = ugid.gid = 0;
keep_matching = 0;
mode = 0660;
if (ENABLE_FEATURE_MDEV_CONF
&& config_read(parser, tokens, 4, 3, "# \t", PARSE_NORMAL)
) {
char *val;
char *str_to_match;
regmatch_t off[1 + 9 * ENABLE_FEATURE_MDEV_RENAME_REGEXP]; regmatch_t off[1 + 9 * ENABLE_FEATURE_MDEV_RENAME_REGEXP];
char *command;
char *alias;
char aliaslink = aliaslink; /* for compiler */
const char *node_name;
const struct rule *rule;
val = tokens[0]; str_to_match = "";
keep_matching = ('-' == val[0]);
val += keep_matching; /* swallow leading dash */
/* Match against either "subsystem/device_name" rule = next_rule();
* or "device_name" alone */
str_to_match = strchr(val, '/') ? path : device_name;
/* Fields: regex uid:gid mode [alias] [cmd] */ #if ENABLE_FEATURE_MDEV_CONF
if (rule->maj >= 0) { /* @maj,min rule */
if (val[0] == '@') { if (major != rule->maj)
/* @major,minor[-minor2] */
/* (useful when name is ambiguous:
* "/sys/class/usb/lp0" and
* "/sys/class/printer/lp0") */
int cmaj, cmin0, cmin1, sc;
if (major < 0)
continue; /* no dev, no match */
sc = sscanf(val, "@%u,%u-%u", &cmaj, &cmin0, &cmin1);
if (sc < 1
|| major != cmaj
|| (sc == 2 && minor != cmin0)
|| (sc == 3 && (minor < cmin0 || minor > cmin1))
) {
continue; /* this line doesn't match */
}
goto line_matches;
}
if (val[0] == '$') {
/* regex to match an environment variable */
char *eq = strchr(++val, '=');
if (!eq)
continue; continue;
*eq = '\0'; if (minor < rule->min0 || minor > rule->min1)
str_to_match = getenv(val); continue;
memset(off, 0, sizeof(off));
goto rule_matches;
}
if (rule->envvar) { /* $envvar=regex rule */
str_to_match = getenv(rule->envvar);
dbg("getenv('%s'):'%s'", rule->envvar, str_to_match);
if (!str_to_match) if (!str_to_match)
continue; continue;
str_to_match -= strlen(val) + 1; } else {
*eq = '='; /* regex to match [subsystem/]device_name */
str_to_match = (rule->regex_has_slash ? path : device_name);
} }
/* else: regex to match [subsystem/]device_name */
{ if (rule->regex_compiled) {
regex_t match; int regex_match = regexec(&rule->match, str_to_match, ARRAY_SIZE(off), off, 0);
int result; dbg("regex_match for '%s':%d", str_to_match, regex_match);
xregcomp(&match, val, REG_EXTENDED);
result = regexec(&match, str_to_match, ARRAY_SIZE(off), off, 0);
regfree(&match);
//bb_error_msg("matches:"); //bb_error_msg("matches:");
//for (int i = 0; i < ARRAY_SIZE(off); i++) { //for (int i = 0; i < ARRAY_SIZE(off); i++) {
// if (off[i].rm_so < 0) continue; // if (off[i].rm_so < 0) continue;
@ -353,65 +496,47 @@ static void make_device(char *path, int delete)
// device_name + off[i].rm_so); // device_name + off[i].rm_so);
//} //}
/* If no match, skip rest of line */ if (regex_match != 0
/* (regexec returns whole pattern as "range" 0) */ /* regexec returns whole pattern as "range" 0 */
if (result || off[0].rm_so != 0
|| off[0].rm_so || (int)off[0].rm_eo != (int)strlen(str_to_match)
|| ((int)off[0].rm_eo != (int)strlen(str_to_match))
) { ) {
continue; /* this line doesn't match */ continue; /* this rule doesn't match */
} }
} }
line_matches: /* else: it's final implicit "match-all" rule */
/* This line matches. Stop parsing after parsing #endif
* the rest the line unless keep_matching == 1 */
/* 2nd field: uid:gid - device ownership */ rule_matches:
if (get_uidgid(&ugid, tokens[1], /*allow_numeric:*/ 1) == 0) dbg("rule matched");
bb_error_msg("unknown user/group %s on line %d", tokens[1], parser->lineno);
/* 3rd field: mode - device permissions */ /* Build alias name */
bb_parse_mode(tokens[2], &mode); alias = NULL;
if (ENABLE_FEATURE_MDEV_RENAME && rule->ren_mov) {
val = tokens[3]; aliaslink = rule->ren_mov[0];
/* 4th field (opt): ">|=alias" or "!" to not create the node */ if (aliaslink == '!') {
if (ENABLE_FEATURE_MDEV_RENAME && val) {
char *a, *s, *st;
a = val;
s = strchrnul(val, ' ');
st = strchrnul(val, '\t');
if (st < s)
s = st;
st = (s[0] && s[1]) ? s+1 : NULL;
aliaslink = a[0];
if (aliaslink == '!' && s == a+1) {
val = st;
/* "!": suppress node creation/deletion */ /* "!": suppress node creation/deletion */
major = -2; major = -2;
} }
else if (aliaslink == '>' || aliaslink == '=') { else if (aliaslink == '>' || aliaslink == '=') {
val = st;
s[0] = '\0';
if (ENABLE_FEATURE_MDEV_RENAME_REGEXP) { if (ENABLE_FEATURE_MDEV_RENAME_REGEXP) {
char *s;
char *p; char *p;
unsigned i, n; unsigned n;
/* substitute %1..9 with off[1..9], if any */ /* substitute %1..9 with off[1..9], if any */
n = 0; n = 0;
s = a; s = rule->ren_mov;
while (*s) while (*s)
if (*s++ == '%') if (*s++ == '%')
n++; n++;
p = alias = xzalloc(strlen(a) + n * strlen(str_to_match)); p = alias = xzalloc(strlen(rule->ren_mov) + n * strlen(str_to_match));
s = a + 1; s = rule->ren_mov + 1;
while (*s) { while (*s) {
*p = *s; *p = *s;
if ('%' == *s) { if ('%' == *s) {
i = (s[1] - '0'); unsigned i = (s[1] - '0');
if (i <= 9 && off[i].rm_so >= 0) { if (i <= 9 && off[i].rm_so >= 0) {
n = off[i].rm_eo - off[i].rm_so; n = off[i].rm_eo - off[i].rm_so;
strncpy(p, str_to_match + off[i].rm_so, n); strncpy(p, str_to_match + off[i].rm_so, n);
@ -423,21 +548,17 @@ static void make_device(char *path, int delete)
s++; s++;
} }
} else { } else {
alias = xstrdup(a + 1); alias = xstrdup(rule->ren_mov + 1);
} }
} }
} }
dbg("alias:'%s'", alias);
if (ENABLE_FEATURE_MDEV_EXEC && val) { command = NULL;
IF_FEATURE_MDEV_EXEC(command = rule->r_cmd;)
if (command) {
const char *s = "$@*"; const char *s = "$@*";
const char *s2 = strchr(s, val[0]); const char *s2 = strchr(s, command[0]);
if (!s2) {
bb_error_msg("bad line %u", parser->lineno);
if (ENABLE_FEATURE_MDEV_RENAME)
free(alias);
continue;
}
/* Are we running this command now? /* Are we running this command now?
* Run $cmd on delete, @cmd on create, *cmd on both * Run $cmd on delete, @cmd on create, *cmd on both
@ -447,29 +568,29 @@ static void make_device(char *path, int delete)
* or: '@' and delete = 0, * or: '@' and delete = 0,
* or: '$' and delete = 1 * or: '$' and delete = 1
*/ */
command = xstrdup(val + 1); command++;
} else {
command = NULL;
} }
} }
} dbg("command:'%s'", command);
/* End of field parsing */
/* "Execute" the line we found */ /* "Execute" the line we found */
{
const char *node_name;
node_name = device_name; node_name = device_name;
if (ENABLE_FEATURE_MDEV_RENAME && alias) if (ENABLE_FEATURE_MDEV_RENAME && alias) {
node_name = alias = build_alias(alias, device_name); node_name = alias = build_alias(alias, device_name);
dbg("alias2:'%s'", alias);
}
if (!delete && major >= 0) { if (!delete && major >= 0) {
if (mknod(node_name, mode | type, makedev(major, minor)) && errno != EEXIST) dbg("mknod('%s',%o,(%d,%d))", node_name, rule->mode | type, major, minor);
if (mknod(node_name, rule->mode | type, makedev(major, minor)) && errno != EEXIST)
bb_perror_msg("can't create '%s'", node_name); bb_perror_msg("can't create '%s'", node_name);
if (major == G.root_major && minor == G.root_minor) if (major == G.root_major && minor == G.root_minor)
symlink(node_name, "root"); symlink(node_name, "root");
if (ENABLE_FEATURE_MDEV_CONF) { if (ENABLE_FEATURE_MDEV_CONF) {
chmod(node_name, mode); chmod(node_name, rule->mode);
chown(node_name, ugid.uid, ugid.gid); chown(node_name, rule->ugid.uid, rule->ugid.gid);
} }
if (ENABLE_FEATURE_MDEV_RENAME && alias) { if (ENABLE_FEATURE_MDEV_RENAME && alias) {
if (aliaslink == '>') if (aliaslink == '>')
@ -487,7 +608,6 @@ static void make_device(char *path, int delete)
bb_perror_msg("can't run '%s'", command); bb_perror_msg("can't run '%s'", command);
bb_unsetenv_and_free(s1); bb_unsetenv_and_free(s1);
bb_unsetenv_and_free(s); bb_unsetenv_and_free(s);
free(command);
} }
if (delete && major >= -1) { if (delete && major >= -1) {
@ -500,18 +620,14 @@ static void make_device(char *path, int delete)
if (ENABLE_FEATURE_MDEV_RENAME) if (ENABLE_FEATURE_MDEV_RENAME)
free(alias); free(alias);
}
/* We found matching line. /* We found matching line.
* Stop unless it was prefixed with '-' */ * Stop unless it was prefixed with '-'
if (ENABLE_FEATURE_MDEV_CONF && !keep_matching) */
if (!ENABLE_FEATURE_MDEV_CONF || !rule->keep_matching)
break; break;
} /* for (;;) */
/* end of "while line is read from /etc/mdev.conf" */
} while (ENABLE_FEATURE_MDEV_CONF);
if (ENABLE_FEATURE_MDEV_CONF)
config_close(parser);
free(subsystem_slash_devname); free(subsystem_slash_devname);
} }
@ -618,6 +734,10 @@ int mdev_main(int argc UNUSED_PARAM, char **argv)
INIT_G(); INIT_G();
#if ENABLE_FEATURE_MDEV_CONF
G.filename = "/etc/mdev.conf";
#endif
/* We can be called as hotplug helper */ /* We can be called as hotplug helper */
/* Kernel cannot provide suitable stdio fds for us, do it ourself */ /* Kernel cannot provide suitable stdio fds for us, do it ourself */
bb_sanitize_stdio(); bb_sanitize_stdio();
@ -633,6 +753,10 @@ int mdev_main(int argc UNUSED_PARAM, char **argv)
*/ */
struct stat st; struct stat st;
#if ENABLE_FEATURE_MDEV_CONF
/* Same as xrealloc_vector(NULL, 4, 0): */
G.rule_vec = xzalloc((1 << 4) * sizeof(*G.rule_vec));
#endif
xstat("/", &st); xstat("/", &st);
G.root_major = major(st.st_dev); G.root_major = major(st.st_dev);
G.root_minor = minor(st.st_dev); G.root_minor = minor(st.st_dev);