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mdev: plug a few memory and fd leaks; simplify code a bit

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This commit is contained in:
Denis Vlasenko 2008-03-27 22:45:44 +00:00
parent e1caabbb75
commit cf26ab70c1
3 changed files with 73 additions and 74 deletions
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6
libbb/remove_file.c
View File

@ -82,8 +82,10 @@ int remove_file(const char *path, int flags)
} }
/* !ISDIR */ /* !ISDIR */
if ((!(flags & FILEUTILS_FORCE) && access(path, W_OK) < 0 if ((!(flags & FILEUTILS_FORCE)
&& !S_ISLNK(path_stat.st_mode) && isatty(0)) && access(path, W_OK) < 0
&& !S_ISLNK(path_stat.st_mode)
&& isatty(0))
|| (flags & FILEUTILS_INTERACTIVE) || (flags & FILEUTILS_INTERACTIVE)
) { ) {
fprintf(stderr, "%s: remove '%s'? ", applet_name, path); fprintf(stderr, "%s: remove '%s'? ", applet_name, path);

1
testsuite/mdev.tests
View File

@ -25,7 +25,6 @@ testing "mdev add /block/sda" \
ls -ln mdev.testdir/dev | $FILTER_LS" \ ls -ln mdev.testdir/dev | $FILTER_LS" \
"\ "\
mdev: /etc/mdev.conf: No such file or directory mdev: /etc/mdev.conf: No such file or directory
mdev: chdir(/lib/firmware): No such file or directory
brw-rw---- 1 8,0 sda brw-rw---- 1 8,0 sda
" \ " \
"" "" "" ""

140
util-linux/mdev.c
View File

@ -21,7 +21,11 @@ struct globals {
#define MAX_SYSFS_DEPTH 3 /* prevent infinite loops in /sys symlinks */ #define MAX_SYSFS_DEPTH 3 /* prevent infinite loops in /sys symlinks */
/* We use additional 64+ bytes in make_device() */
#define SCRATCH_SIZE 80
/* mknod in /dev based on a path like "/sys/block/hda/hda1" */ /* mknod in /dev based on a path like "/sys/block/hda/hda1" */
/* NB: "mdev -s" may call us many times, do not leak memory/fds! */
static void make_device(char *path, int delete) static void make_device(char *path, int delete)
{ {
const char *device_name; const char *device_name;
@ -29,7 +33,7 @@ static void make_device(char *path, int delete)
int mode = 0660; int mode = 0660;
uid_t uid = 0; uid_t uid = 0;
gid_t gid = 0; gid_t gid = 0;
char *temp = path + strlen(path); char *dev_maj_min = path + strlen(path);
char *command = NULL; char *command = NULL;
char *alias = NULL; char *alias = NULL;
@ -42,21 +46,20 @@ static void make_device(char *path, int delete)
* also depend on path having writeable space after it. * also depend on path having writeable space after it.
*/ */
if (!delete) { if (!delete) {
strcat(path, "/dev"); strcpy(dev_maj_min, "/dev");
len = open_read_close(path, temp + 1, 64); len = open_read_close(path, dev_maj_min + 1, 64);
*temp++ = 0; *dev_maj_min++ = '\0';
if (len < 1) { if (len < 1) {
if (ENABLE_FEATURE_MDEV_EXEC) if (!ENABLE_FEATURE_MDEV_EXEC)
/* no "dev" file, so just try to run script */
*temp = 0;
else
return; return;
/* no "dev" file, so just try to run script */
*dev_maj_min = '\0';
} }
} }
/* Determine device name, type, major and minor */ /* Determine device name, type, major and minor */
device_name = bb_basename(path); device_name = bb_basename(path);
type = (path[5] == 'c' ? S_IFCHR : S_IFBLK); type = (path[5] == 'c' ? S_IFCHR : S_IFBLK); /* "/sys/[c]lass"? */
if (ENABLE_FEATURE_MDEV_CONF) { if (ENABLE_FEATURE_MDEV_CONF) {
FILE *fp; FILE *fp;
@ -70,15 +73,18 @@ static void make_device(char *path, int delete)
while ((vline = line = xmalloc_fgetline(fp)) != NULL) { while ((vline = line = xmalloc_fgetline(fp)) != NULL) {
int field; int field;
/* A pristine copy for command execution. */
char *orig_line; char *orig_line;
if (ENABLE_FEATURE_MDEV_EXEC) if (ENABLE_FEATURE_MDEV_EXEC)
orig_line = xstrdup(line); orig_line = xstrdup(line); /* pristine copy for command execution. */
++lineno; ++lineno;
/* Three fields: regex, uid:gid, mode */ // TODO: get rid of loop,
// just linear skip_whitespace() style code will do!
// (will also get rid of orig_line).
/* Fields: regex uid:gid mode [alias] [cmd] */
for (field = 0; field < (3 + ENABLE_FEATURE_MDEV_RENAME + ENABLE_FEATURE_MDEV_EXEC); ++field) { for (field = 0; field < (3 + ENABLE_FEATURE_MDEV_RENAME + ENABLE_FEATURE_MDEV_EXEC); ++field) {
/* Find a non-empty field */ /* Find a non-empty field */
@ -117,9 +123,9 @@ static void make_device(char *path, int delete)
struct group *grp; struct group *grp;
char *str_uid = val; char *str_uid = val;
char *str_gid = strchr(val, ':'); char *str_gid = strchrnul(val, ':');
if (str_gid) if (*str_gid)
*str_gid = '\0', ++str_gid; *str_gid++ = '\0';
/* Parse UID */ /* Parse UID */
pass = getpwnam(str_uid); pass = getpwnam(str_uid);
@ -128,7 +134,7 @@ static void make_device(char *path, int delete)
else else
uid = strtoul(str_uid, NULL, 10); uid = strtoul(str_uid, NULL, 10);
/* parse GID */ /* Parse GID */
grp = getgrnam(str_gid); grp = getgrnam(str_gid);
if (grp) if (grp)
gid = grp->gr_gid; gid = grp->gr_gid;
@ -144,8 +150,10 @@ static void make_device(char *path, int delete)
if (*val != '>') if (*val != '>')
++field; ++field;
else else {
free(alias); /* don't leak in case we matched it on prev line */
alias = xstrdup(val + 1); alias = xstrdup(val + 1);
}
} }
@ -162,12 +170,17 @@ static void make_device(char *path, int delete)
} }
/* Correlate the position in the "@$*" with the delete /* Correlate the position in the "@$*" with the delete
* step so that we get the proper behavior. * step so that we get the proper behavior:
* @cmd: run on create
* $cmd: run on delete
* *cmd: run on both
*/ */
if ((s2 - s + 1) & (1 << delete)) if ((s2 - s + 1) /*1/2/3*/ & /*1/2*/ (1 + delete)) {
free(command); /* don't leak in case we matched it on prev line */
command = xstrdup(orig_line + (val + 1 - line)); command = xstrdup(orig_line + (val + 1 - line));
}
} }
} } /* end of "for every field" */
/* Did everything parse happily? */ /* Did everything parse happily? */
if (field <= 2) if (field <= 2)
@ -177,21 +190,13 @@ static void make_device(char *path, int delete)
free(line); free(line);
if (ENABLE_FEATURE_MDEV_EXEC) if (ENABLE_FEATURE_MDEV_EXEC)
free(orig_line); free(orig_line);
} } /* end of "while line is read from /etc/mdev.conf" */
if (ENABLE_FEATURE_CLEAN_UP) fclose(fp);
fclose(fp);
end_parse: /* nothing */ ;
} }
end_parse:
if (!delete) { if (!delete && sscanf(dev_maj_min, "%u:%u", &major, &minor) == 2) {
if (sscanf(temp, "%d:%d", &major, &minor) != 2) {
if (ENABLE_FEATURE_MDEV_EXEC)
goto skip_creation;
else
return;
}
if (ENABLE_FEATURE_MDEV_RENAME) if (ENABLE_FEATURE_MDEV_RENAME)
unlink(device_name); unlink(device_name);
@ -208,39 +213,39 @@ static void make_device(char *path, int delete)
if (ENABLE_FEATURE_MDEV_RENAME && alias) { if (ENABLE_FEATURE_MDEV_RENAME && alias) {
char *dest; char *dest;
temp = strrchr(alias, '/'); dest = strrchr(alias, '/');
if (temp) { if (dest) {
if (temp[1] != '\0') if (dest[1] != '\0')
/* given a file name, so rename it */ /* given a file name, so rename it */
*temp = '\0'; *dest = '\0';
bb_make_directory(alias, 0755, FILEUTILS_RECUR); bb_make_directory(alias, 0755, FILEUTILS_RECUR);
dest = concat_path_file(alias, device_name); dest = concat_path_file(alias, device_name);
free(alias);
} else } else
dest = alias; dest = alias;
rename(device_name, dest); // TODO: xrename? rename(device_name, dest);
symlink(dest, device_name); symlink(dest, device_name);
if (alias != dest)
free(alias);
free(dest); free(dest);
} }
} }
skip_creation: /* nothing */ ;
} }
if (ENABLE_FEATURE_MDEV_EXEC && command) { if (ENABLE_FEATURE_MDEV_EXEC && command) {
/* setenv will leak memory, so use putenv */ /* setenv will leak memory, use putenv/unsetenv/free */
char *s = xasprintf("MDEV=%s", device_name); char *s = xasprintf("MDEV=%s", device_name);
putenv(s); putenv(s);
if (system(command) == -1) if (system(command) == -1)
bb_perror_msg_and_die("cannot run %s", command); bb_perror_msg_and_die("can't run '%s'", command);
s[4] = '\0'; s[4] = '\0';
unsetenv(s); unsetenv(s);
free(s); free(s);
free(command); free(command);
} }
if (delete) if (delete)
remove_file(device_name, FILEUTILS_FORCE); unlink(device_name);
} }
/* File callback for /sys/ traversal */ /* File callback for /sys/ traversal */
@ -249,14 +254,15 @@ static int fileAction(const char *fileName,
void *userData, void *userData,
int depth ATTRIBUTE_UNUSED) int depth ATTRIBUTE_UNUSED)
{ {
size_t len = strlen(fileName) - 4; size_t len = strlen(fileName) - 4; /* can't underflow */
char *scratch = userData; char *scratch = userData;
if (strcmp(fileName + len, "/dev")) /* len check is for paranoid reasons */
if (strcmp(fileName + len, "/dev") || len >= PATH_MAX)
return FALSE; return FALSE;
strcpy(scratch, fileName); strcpy(scratch, fileName);
scratch[len] = 0; scratch[len] = '\0';
make_device(scratch, 0); make_device(scratch, 0);
return TRUE; return TRUE;
@ -287,12 +293,6 @@ static void load_firmware(const char *const firmware, const char *const sysfs_pa
int cnt; int cnt;
int firmware_fd, loading_fd, data_fd; int firmware_fd, loading_fd, data_fd;
/* check for $FIRMWARE from kernel */
/* XXX: dont bother: open(NULL) works same as open("no-such-file")
* if (!firmware)
* return;
*/
/* check for /lib/firmware/$FIRMWARE */ /* check for /lib/firmware/$FIRMWARE */
xchdir("/lib/firmware"); xchdir("/lib/firmware");
firmware_fd = xopen(firmware, O_RDONLY); firmware_fd = xopen(firmware, O_RDONLY);
@ -304,16 +304,15 @@ static void load_firmware(const char *const firmware, const char *const sysfs_pa
xchdir(sysfs_path); xchdir(sysfs_path);
for (cnt = 0; cnt < 30; ++cnt) { for (cnt = 0; cnt < 30; ++cnt) {
loading_fd = open("loading", O_WRONLY); loading_fd = open("loading", O_WRONLY);
if (loading_fd == -1) if (loading_fd != -1)
sleep(1); goto loading;
else sleep(1);
break;
} }
if (loading_fd == -1) goto out;
goto out;
loading:
/* tell kernel we're loading by `echo 1 > /sys/$DEVPATH/loading` */ /* tell kernel we're loading by `echo 1 > /sys/$DEVPATH/loading` */
if (write(loading_fd, "1", 1) != 1) if (full_write(loading_fd, "1", 1) != 1)
goto out; goto out;
/* load firmware by `cat /lib/firmware/$FIRMWARE > /sys/$DEVPATH/data */ /* load firmware by `cat /lib/firmware/$FIRMWARE > /sys/$DEVPATH/data */
@ -324,9 +323,9 @@ static void load_firmware(const char *const firmware, const char *const sysfs_pa
/* tell kernel result by `echo [0|-1] > /sys/$DEVPATH/loading` */ /* tell kernel result by `echo [0|-1] > /sys/$DEVPATH/loading` */
if (cnt > 0) if (cnt > 0)
write(loading_fd, "0", 1); full_write(loading_fd, "0", 1);
else else
write(loading_fd, "-1", 2); full_write(loading_fd, "-1", 2);
out: out:
if (ENABLE_FEATURE_CLEAN_UP) { if (ENABLE_FEATURE_CLEAN_UP) {
@ -341,16 +340,14 @@ int mdev_main(int argc, char **argv)
{ {
char *action; char *action;
char *env_path; char *env_path;
RESERVE_CONFIG_BUFFER(temp,PATH_MAX); RESERVE_CONFIG_BUFFER(temp, PATH_MAX + SCRATCH_SIZE);
xchdir("/dev"); xchdir("/dev");
if (argc == 2 && !strcmp(argv[1],"-s")) { if (argc == 2 && !strcmp(argv[1], "-s")) {
/* Scan: /* Scan:
* mdev -s * mdev -s
*/ */
struct stat st; struct stat st;
xstat("/", &st); xstat("/", &st);
@ -366,26 +363,27 @@ int mdev_main(int argc, char **argv)
fileAction, dirAction, temp, 0); fileAction, dirAction, temp, 0);
} else { } else {
/* Hotplug: /* Hotplug:
* env ACTION=... DEVPATH=... mdev * env ACTION=... DEVPATH=... mdev
* ACTION can be "add" or "remove" * ACTION can be "add" or "remove"
* DEVPATH is like "/block/sda" or "/class/input/mice" * DEVPATH is like "/block/sda" or "/class/input/mice"
*/ */
action = getenv("ACTION"); action = getenv("ACTION");
env_path = getenv("DEVPATH"); env_path = getenv("DEVPATH");
if (!action || !env_path) if (!action || !env_path)
bb_show_usage(); bb_show_usage();
sprintf(temp, "/sys%s", env_path); snprintf(temp, PATH_MAX, "/sys%s", env_path);
if (!strcmp(action, "remove")) if (!strcmp(action, "remove"))
make_device(temp, 1); make_device(temp, 1);
else if (!strcmp(action, "add")) { else if (!strcmp(action, "add")) {
make_device(temp, 0); make_device(temp, 0);
if (ENABLE_FEATURE_MDEV_LOAD_FIRMWARE) if (ENABLE_FEATURE_MDEV_LOAD_FIRMWARE) {
load_firmware(getenv("FIRMWARE"), temp); char *fw = getenv("FIRMWARE");
if (fw)
load_firmware(fw, temp);
}
} }
} }