busybox/miscutils/makedevs.c
Denys Vlasenko 9536ef7c98 makedevs: make it NOEXEC
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-08-06 21:47:07 +02:00

313 lines
9.1 KiB
C

/* vi: set sw=4 ts=4: */
/*
* public domain -- Dave 'Kill a Cop' Cinege <dcinege@psychosis.com>
*
* makedevs
* Make ranges of device files quickly.
* known bugs: can't deal with alpha ranges
*/
//config:config MAKEDEVS
//config: bool "makedevs (9.3 kb)"
//config: default y
//config: help
//config: 'makedevs' is a utility used to create a batch of devices with
//config: one command.
//config:
//config: There are two choices for command line behaviour, the interface
//config: as used by LEAF/Linux Router Project, or a device table file.
//config:
//config: 'leaf' is traditionally what busybox follows, it allows multiple
//config: devices of a particluar type to be created per command.
//config: e.g. /dev/hda[0-9]
//config: Device properties are passed as command line arguments.
//config:
//config: 'table' reads device properties from a file or stdin, allowing
//config: a batch of unrelated devices to be made with one command.
//config: User/group names are allowed as an alternative to uid/gid.
//config:
//config:choice
//config: prompt "Choose makedevs behaviour"
//config: depends on MAKEDEVS
//config: default FEATURE_MAKEDEVS_TABLE
//config:
//config:config FEATURE_MAKEDEVS_LEAF
//config: bool "leaf"
//config:
//config:config FEATURE_MAKEDEVS_TABLE
//config: bool "table"
//config:
//config:endchoice
//applet:IF_MAKEDEVS(APPLET_NOEXEC(makedevs, makedevs, BB_DIR_SBIN, BB_SUID_DROP, makedevs))
//kbuild:lib-$(CONFIG_MAKEDEVS) += makedevs.o
//usage:#if ENABLE_FEATURE_MAKEDEVS_LEAF
//usage:#define makedevs_trivial_usage
//usage: "NAME TYPE MAJOR MINOR FIRST LAST [s]"
//usage:#define makedevs_full_usage "\n\n"
//usage: "Create a range of block or character special files"
//usage: "\n"
//usage: "\nTYPE is:"
//usage: "\n b Block device"
//usage: "\n c Character device"
//usage: "\n f FIFO, MAJOR and MINOR are ignored"
//usage: "\n"
//usage: "\nFIRST..LAST specify numbers appended to NAME."
//usage: "\nIf 's' is the last argument, the base device is created as well."
//usage: "\n"
//usage: "\nExamples:"
//usage: "\n makedevs /dev/ttyS c 4 66 2 63 -> ttyS2-ttyS63"
//usage: "\n makedevs /dev/hda b 3 0 0 8 s -> hda,hda1-hda8"
//usage:
//usage:#define makedevs_example_usage
//usage: "# makedevs /dev/ttyS c 4 66 2 63\n"
//usage: "[creates ttyS2-ttyS63]\n"
//usage: "# makedevs /dev/hda b 3 0 0 8 s\n"
//usage: "[creates hda,hda1-hda8]\n"
//usage:#endif
//usage:
//usage:#if ENABLE_FEATURE_MAKEDEVS_TABLE
//usage:#define makedevs_trivial_usage
//usage: "[-d device_table] rootdir"
//usage:#define makedevs_full_usage "\n\n"
//usage: "Create a range of special files as specified in a device table.\n"
//usage: "Device table entries take the form of:\n"
//usage: "<name> <type> <mode> <uid> <gid> <major> <minor> <start> <inc> <count>\n"
//usage: "Where name is the file name, type can be one of:\n"
//usage: " f Regular file\n"
//usage: " d Directory\n"
//usage: " c Character device\n"
//usage: " b Block device\n"
//usage: " p Fifo (named pipe)\n"
//usage: "uid is the user id for the target file, gid is the group id for the\n"
//usage: "target file. The rest of the entries (major, minor, etc) apply to\n"
//usage: "to device special files. A '-' may be used for blank entries."
//usage:
//usage:#define makedevs_example_usage
//usage: "For example:\n"
//usage: "<name> <type> <mode><uid><gid><major><minor><start><inc><count>\n"
//usage: "/dev d 755 0 0 - - - - -\n"
//usage: "/dev/console c 666 0 0 5 1 - - -\n"
//usage: "/dev/null c 666 0 0 1 3 0 0 -\n"
//usage: "/dev/zero c 666 0 0 1 5 0 0 -\n"
//usage: "/dev/hda b 640 0 0 3 0 0 0 -\n"
//usage: "/dev/hda b 640 0 0 3 1 1 1 15\n\n"
//usage: "Will Produce:\n"
//usage: "/dev\n"
//usage: "/dev/console\n"
//usage: "/dev/null\n"
//usage: "/dev/zero\n"
//usage: "/dev/hda\n"
//usage: "/dev/hda[0-15]\n"
//usage:#endif
#include "libbb.h"
#if ENABLE_FEATURE_MAKEDEVS_LEAF
/*
makedevs NAME TYPE MAJOR MINOR FIRST LAST [s]
TYPEs:
b Block device
c Character device
f FIFO
FIRST..LAST specify numbers appended to NAME.
If 's' is the last argument, the base device is created as well.
Examples:
makedevs /dev/ttyS c 4 66 2 63 -> ttyS2-ttyS63
makedevs /dev/hda b 3 0 0 8 s -> hda,hda1-hda8
*/
int makedevs_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int makedevs_main(int argc, char **argv)
{
mode_t mode;
char *basedev, *type, *nodname, *buf;
int Smajor, Sminor, S, E;
if (argc < 7 || argv[1][0] == '-')
bb_show_usage();
basedev = argv[1];
buf = xasprintf("%s%u", argv[1], (unsigned)-1);
type = argv[2];
Smajor = xatoi_positive(argv[3]);
Sminor = xatoi_positive(argv[4]);
S = xatoi_positive(argv[5]);
E = xatoi_positive(argv[6]);
nodname = argv[7] ? basedev : buf;
mode = 0660;
switch (type[0]) {
case 'c':
mode |= S_IFCHR;
break;
case 'b':
mode |= S_IFBLK;
break;
case 'f':
mode |= S_IFIFO;
break;
default:
bb_show_usage();
}
while (S <= E) {
sprintf(buf, "%s%u", basedev, S);
/* if mode != S_IFCHR and != S_IFBLK,
* third param in mknod() ignored */
if (mknod(nodname, mode, makedev(Smajor, Sminor)) != 0
&& errno != EEXIST
) {
bb_perror_msg("can't create '%s'", nodname);
}
/*if (nodname == basedev)*/ /* ex. /dev/hda - to /dev/hda1 ... */
nodname = buf;
S++;
Sminor++;
}
return 0;
}
#elif ENABLE_FEATURE_MAKEDEVS_TABLE
/* Licensed under GPLv2 or later, see file LICENSE in this source tree. */
int makedevs_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int makedevs_main(int argc UNUSED_PARAM, char **argv)
{
parser_t *parser;
char *line = (char *)"-";
int ret = EXIT_SUCCESS;
opt_complementary = "=1"; /* exactly one param */
getopt32(argv, "d:", &line);
argv += optind;
xchdir(*argv); /* ensure root dir exists */
umask(0);
printf("rootdir=%s\ntable=", *argv);
if (NOT_LONE_DASH(line)) {
printf("'%s'\n", line);
} else {
puts("<stdin>");
}
parser = config_open(line);
while (config_read(parser, &line, 1, 1, "# \t", PARSE_NORMAL)) {
int linenum;
char type;
unsigned mode = 0755;
unsigned major = 0;
unsigned minor = 0;
unsigned count = 0;
unsigned increment = 0;
unsigned start = 0;
char user[41];
char group[41];
char *full_name;
int name_len;
uid_t uid;
gid_t gid;
linenum = parser->lineno;
if ((1 > sscanf(line, "%*s%n %c %o %40s %40s %u %u %u %u %u",
&name_len, &type, &mode, user, group,
&major, &minor, &start, &increment, &count))
|| ((unsigned)(major | minor | start | count | increment) > 255)
) {
bb_error_msg("invalid line %d: '%s'", linenum, line);
ret = EXIT_FAILURE;
continue;
}
gid = (*group) ? get_ug_id(group, xgroup2gid) : getgid();
uid = (*user) ? get_ug_id(user, xuname2uid) : getuid();
line[name_len] = '\0';
full_name = line;
/* We are already in the right root dir,
* so make absolute paths relative */
if ('/' == full_name[0])
full_name++;
if (type == 'd') {
bb_make_directory(full_name, mode | S_IFDIR, FILEUTILS_RECUR);
if (chown(full_name, uid, gid) == -1) {
chown_fail:
bb_perror_msg("line %d: can't chown %s", linenum, full_name);
ret = EXIT_FAILURE;
continue;
}
if (chmod(full_name, mode) < 0) {
chmod_fail:
bb_perror_msg("line %d: can't chmod %s", linenum, full_name);
ret = EXIT_FAILURE;
continue;
}
} else if (type == 'f') {
struct stat st;
if ((stat(full_name, &st) < 0 || !S_ISREG(st.st_mode))) {
bb_perror_msg("line %d: regular file '%s' does not exist", linenum, full_name);
ret = EXIT_FAILURE;
continue;
}
if (chown(full_name, uid, gid) < 0)
goto chown_fail;
if (chmod(full_name, mode) < 0)
goto chmod_fail;
} else {
unsigned i;
if (type == 'p') {
mode |= S_IFIFO;
} else if (type == 'c') {
mode |= S_IFCHR;
} else if (type == 'b') {
mode |= S_IFBLK;
} else {
bb_error_msg("line %d: unsupported file type %c", linenum, type);
ret = EXIT_FAILURE;
continue;
}
if (count != 0)
count--;
for (i = 0; i <= count; i++) {
dev_t rdev;
char *nameN = full_name;
if (count != 0)
nameN = xasprintf("%s%u", full_name, start + i);
rdev = makedev(major, minor + i * increment);
if (mknod(nameN, mode, rdev) != 0
&& errno != EEXIST
) {
bb_perror_msg("line %d: can't create node %s", linenum, nameN);
ret = EXIT_FAILURE;
} else if (chown(nameN, uid, gid) < 0) {
bb_perror_msg("line %d: can't chown %s", linenum, nameN);
ret = EXIT_FAILURE;
} else if (chmod(nameN, mode) < 0) {
bb_perror_msg("line %d: can't chmod %s", linenum, nameN);
ret = EXIT_FAILURE;
}
if (count != 0)
free(nameN);
}
}
}
if (ENABLE_FEATURE_CLEAN_UP)
config_close(parser);
return ret;
}
#else
# error makedevs configuration error, either leaf or table must be selected
#endif