busybox/selinux/setfiles.c
Denis Vlasenko 6ca409e0e4 trylink: produce even more info about final link stage
trylink: explain how to modify link and drastically decrease amount
  of padding (unfortunately, needs hand editing ATM).
*: add ALIGN1 / ALIGN2 to global strings and arrays of bytes and shorts

size saving: 0.5k
2007-08-12 20:58:27 +00:00

643 lines
15 KiB
C

/*
setfiles: based on policycoreutils 2.0.19
policycoreutils was released under GPL 2.
Port to BusyBox (c) 2007 by Yuichi Nakamura <ynakam@hitachisoft.jp>
*/
#include "libbb.h"
#if ENABLE_FEATURE_SETFILES_CHECK_OPTION
#include <sepol/sepol.h>
#endif
#define MAX_EXCLUDES 50
struct edir {
char *directory;
size_t size;
};
struct globals {
FILE *outfile;
char *policyfile;
char *rootpath;
int rootpathlen;
unsigned count;
int excludeCtr;
int errors;
int verbose; /* getopt32 uses it, has to be int */
smallint recurse; /* Recursive descent */
smallint follow_mounts;
/* Behavior flags determined based on setfiles vs. restorecon */
smallint expand_realpath; /* Expand paths via realpath */
smallint abort_on_error; /* Abort the file tree walk upon an error */
int add_assoc; /* Track inode associations for conflict detection */
int matchpathcon_flags; /* Flags to matchpathcon */
dev_t dev_id; /* Device id where target file exists */
int nerr;
struct edir excludeArray[MAX_EXCLUDES];
};
#define G (*(struct globals*)&bb_common_bufsiz1)
void BUG_setfiles_globals_too_big(void);
#define INIT_G() do { \
if (sizeof(G) > COMMON_BUFSIZE) \
BUG_setfiles_globals_too_big(); \
/* memset(&G, 0, sizeof(G)); - already is */ \
} while (0)
#define outfile (G.outfile )
#define policyfile (G.policyfile )
#define rootpath (G.rootpath )
#define rootpathlen (G.rootpathlen )
#define count (G.count )
#define excludeCtr (G.excludeCtr )
#define errors (G.errors )
#define verbose (G.verbose )
#define recurse (G.recurse )
#define follow_mounts (G.follow_mounts )
#define expand_realpath (G.expand_realpath )
#define abort_on_error (G.abort_on_error )
#define add_assoc (G.add_assoc )
#define matchpathcon_flags (G.matchpathcon_flags)
#define dev_id (G.dev_id )
#define nerr (G.nerr )
#define excludeArray (G.excludeArray )
/* Must match getopt32 string! */
enum {
OPT_d = (1 << 0),
OPT_e = (1 << 1),
OPT_f = (1 << 2),
OPT_i = (1 << 3),
OPT_l = (1 << 4),
OPT_n = (1 << 5),
OPT_p = (1 << 6),
OPT_q = (1 << 7),
OPT_r = (1 << 8),
OPT_s = (1 << 9),
OPT_v = (1 << 10),
OPT_o = (1 << 11),
OPT_F = (1 << 12),
OPT_W = (1 << 13),
OPT_c = (1 << 14), /* c only for setfiles */
OPT_R = (1 << 14), /* R only for restorecon */
};
#define FLAG_d_debug (option_mask32 & OPT_d)
#define FLAG_e (option_mask32 & OPT_e)
#define FLAG_f (option_mask32 & OPT_f)
#define FLAG_i_ignore_enoent (option_mask32 & OPT_i)
#define FLAG_l_take_log (option_mask32 & OPT_l)
#define FLAG_n_dry_run (option_mask32 & OPT_n)
#define FLAG_p_progress (option_mask32 & OPT_p)
#define FLAG_q_quiet (option_mask32 & OPT_q)
#define FLAG_r (option_mask32 & OPT_r)
#define FLAG_s (option_mask32 & OPT_s)
#define FLAG_v (option_mask32 & OPT_v)
#define FLAG_o (option_mask32 & OPT_o)
#define FLAG_F_force (option_mask32 & OPT_F)
#define FLAG_W_warn_no_match (option_mask32 & OPT_W)
#define FLAG_c (option_mask32 & OPT_c)
#define FLAG_R (option_mask32 & OPT_R)
static void qprintf(const char *fmt, ...)
{
/* quiet, do nothing */
}
static void inc_err(void)
{
nerr++;
if (nerr > 9 && !FLAG_d_debug) {
bb_error_msg_and_die("exiting after 10 errors");
}
}
static void add_exclude(const char *const directory)
{
struct stat sb;
size_t len;
if (directory == NULL || directory[0] != '/') {
bb_error_msg_and_die("full path required for exclude: %s", directory);
}
if (lstat(directory, &sb)) {
bb_error_msg("directory \"%s\" not found, ignoring", directory);
return;
}
if ((sb.st_mode & S_IFDIR) == 0) {
bb_error_msg("\"%s\" is not a directory: mode %o, ignoring",
directory, sb.st_mode);
return;
}
if (excludeCtr == MAX_EXCLUDES) {
bb_error_msg_and_die("maximum excludes %d exceeded", MAX_EXCLUDES);
}
len = strlen(directory);
while (len > 1 && directory[len - 1] == '/') {
len--;
}
excludeArray[excludeCtr].directory = xstrndup(directory, len);
excludeArray[excludeCtr++].size = len;
}
static bool exclude(const char *file)
{
int i = 0;
for (i = 0; i < excludeCtr; i++) {
if (strncmp(file, excludeArray[i].directory,
excludeArray[i].size) == 0) {
if (file[excludeArray[i].size] == '\0'
|| file[excludeArray[i].size] == '/') {
return 1;
}
}
}
return 0;
}
static int match(const char *name, struct stat *sb, char **con)
{
int ret;
char path[PATH_MAX + 1];
char *tmp_path = xstrdup(name);
if (excludeCtr > 0 && exclude(name)) {
goto err;
}
ret = lstat(name, sb);
if (ret) {
if (FLAG_i_ignore_enoent && errno == ENOENT) {
free(tmp_path);
return 0;
}
bb_error_msg("stat(%s)", name);
goto err;
}
if (expand_realpath) {
if (S_ISLNK(sb->st_mode)) {
char *p = NULL;
char *file_sep;
size_t len = 0;
if (verbose > 1)
bb_error_msg("warning! %s refers to a symbolic link, not following last component", name);
file_sep = strrchr(tmp_path, '/');
if (file_sep == tmp_path) {
file_sep++;
p[0] = '\0';
p = path;
} else if (file_sep) {
*file_sep++ = '\0';
p = realpath(tmp_path, path);
} else {
file_sep = tmp_path;
p = realpath("./", path);
}
if (p)
len = strlen(p);
if (!p || len + strlen(file_sep) + 2 > PATH_MAX) {
bb_perror_msg("realpath(%s) failed", name);
goto err;
}
p += len;
/* ensure trailing slash of directory name */
if (len == 0 || p[-1] != '/') {
*p++ = '/';
}
strcpy(p, file_sep);
name = path;
if (excludeCtr > 0 && exclude(name))
goto err;
} else {
char *p;
p = realpath(name, path);
if (!p) {
bb_perror_msg("realpath(%s)", name);
goto err;
}
name = p;
if (excludeCtr > 0 && exclude(name))
goto err;
}
}
/* name will be what is matched in the policy */
if (NULL != rootpath) {
if (0 != strncmp(rootpath, name, rootpathlen)) {
bb_error_msg("%s is not located in %s",
name, rootpath);
goto err;
}
name += rootpathlen;
}
free(tmp_path);
if (rootpath != NULL && name[0] == '\0')
/* this is actually the root dir of the alt root */
return matchpathcon_index("/", sb->st_mode, con);
return matchpathcon_index(name, sb->st_mode, con);
err:
free(tmp_path);
return -1;
}
/* Compare two contexts to see if their differences are "significant",
* or whether the only difference is in the user. */
static bool only_changed_user(const char *a, const char *b)
{
if (FLAG_F_force)
return 0;
if (!a || !b)
return 0;
a = strchr(a, ':'); /* Rest of the context after the user */
b = strchr(b, ':');
if (!a || !b)
return 0;
return (strcmp(a, b) == 0);
}
static int restore(const char *file)
{
char *my_file;
struct stat my_sb;
int i, j, ret;
char *context = NULL;
char *newcon = NULL;
bool user_only_changed = 0;
int retval = 0;
my_file = bb_simplify_path(file);
i = match(my_file, &my_sb, &newcon);
if (i < 0) /* No matching specification. */
goto out;
if (FLAG_p_progress) {
count++;
if (count % 0x400 == 0) { /* every 1024 times */
count = (count % (80*0x400));
if (count == 0)
fputc('\n', stdout);
fputc('*', stdout);
fflush(stdout);
}
}
/*
* Try to add an association between this inode and
* this specification. If there is already an association
* for this inode and it conflicts with this specification,
* then use the last matching specification.
*/
if (add_assoc) {
j = matchpathcon_filespec_add(my_sb.st_ino, i, my_file);
if (j < 0)
goto err;
if (j != i) {
/* There was already an association and it took precedence. */
goto out;
}
}
if (FLAG_d_debug)
printf("%s: %s matched by %s\n", applet_name, my_file, newcon);
/* Get the current context of the file. */
ret = lgetfilecon_raw(my_file, &context);
if (ret < 0) {
if (errno == ENODATA) {
context = NULL; /* paranoia */
} else {
bb_perror_msg("lgetfilecon_raw on %s", my_file);
goto err;
}
user_only_changed = 0;
} else
user_only_changed = only_changed_user(context, newcon);
/*
* Do not relabel the file if the matching specification is
* <<none>> or the file is already labeled according to the
* specification.
*/
if ((strcmp(newcon, "<<none>>") == 0)
|| (context && (strcmp(context, newcon) == 0) && !FLAG_F_force)) {
goto out;
}
if (!FLAG_F_force && context && (is_context_customizable(context) > 0)) {
if (verbose > 1) {
bb_error_msg("skipping %s. %s is customizable_types",
my_file, context);
}
goto out;
}
if (verbose) {
/* If we're just doing "-v", trim out any relabels where
* the user has changed but the role and type are the
* same. For "-vv", emit everything. */
if (verbose > 1 || !user_only_changed) {
bb_info_msg("%s: reset %s context %s->%s",
applet_name, my_file, context ?: "", newcon);
}
}
if (FLAG_l_take_log && !user_only_changed) {
if (context)
bb_info_msg("relabeling %s from %s to %s", my_file, context, newcon);
else
bb_info_msg("labeling %s to %s", my_file, newcon);
}
if (outfile && !user_only_changed)
fprintf(outfile, "%s\n", my_file);
/*
* Do not relabel the file if -n was used.
*/
if (FLAG_n_dry_run || user_only_changed)
goto out;
/*
* Relabel the file to the specified context.
*/
ret = lsetfilecon(my_file, newcon);
if (ret) {
bb_perror_msg("lsetfileconon(%s,%s)", my_file, newcon);
goto err;
}
out:
freecon(context);
freecon(newcon);
free(my_file);
return retval;
err:
retval--; /* -1 */
goto out;
}
/*
* Apply the last matching specification to a file.
* This function is called by recursive_action on each file during
* the directory traversal.
*/
static int apply_spec(const char *file,
struct stat *sb, void *userData, int depth)
{
if (!follow_mounts) {
/* setfiles does not process across different mount points */
if (sb->st_dev != dev_id) {
return SKIP;
}
}
errors |= restore(file);
if (abort_on_error && errors)
return FALSE;
return TRUE;
}
static int canoncon(const char *path, unsigned lineno, char **contextp)
{
static const char err_msg[] ALIGN1 = "%s: line %u has invalid context %s";
char *tmpcon;
char *context = *contextp;
int invalid = 0;
#if ENABLE_FEATURE_SETFILES_CHECK_OPTION
if (policyfile) {
if (sepol_check_context(context) >= 0)
return 0;
/* Exit immediately if we're in checking mode. */
bb_error_msg_and_die(err_msg, path, lineno, context);
}
#endif
if (security_canonicalize_context_raw(context, &tmpcon) < 0) {
if (errno != ENOENT) {
invalid = 1;
inc_err();
}
} else {
free(context);
*contextp = tmpcon;
}
if (invalid) {
bb_error_msg(err_msg, path, lineno, context);
}
return invalid;
}
static int process_one(char *name)
{
struct stat sb;
int rc;
rc = lstat(name, &sb);
if (rc < 0) {
if (FLAG_i_ignore_enoent && errno == ENOENT)
return 0;
bb_perror_msg("stat(%s)", name);
goto err;
}
dev_id = sb.st_dev;
if (S_ISDIR(sb.st_mode) && recurse) {
if (recursive_action(name,
ACTION_RECURSE,
apply_spec,
apply_spec,
NULL, 0) != TRUE) {
bb_error_msg("error while labeling %s", name);
goto err;
}
} else {
rc = restore(name);
if (rc)
goto err;
}
out:
if (add_assoc) {
if (FLAG_q_quiet)
set_matchpathcon_printf(&qprintf);
matchpathcon_filespec_eval();
set_matchpathcon_printf(NULL);
matchpathcon_filespec_destroy();
}
return rc;
err:
rc = -1;
goto out;
}
int setfiles_main(int argc, char **argv);
int setfiles_main(int argc, char **argv)
{
struct stat sb;
int rc, i = 0;
const char *input_filename = NULL;
char *buf = NULL;
size_t buf_len;
int flags;
llist_t *exclude_dir = NULL;
char *out_filename = NULL;
INIT_G();
if (applet_name[0] == 's') { /* "setfiles" */
/*
* setfiles:
* Recursive descent,
* Does not expand paths via realpath,
* Aborts on errors during the file tree walk,
* Try to track inode associations for conflict detection,
* Does not follow mounts,
* Validates all file contexts at init time.
*/
recurse = 1;
abort_on_error = 1;
add_assoc = 1;
/* follow_mounts = 0; - already is */
matchpathcon_flags = MATCHPATHCON_VALIDATE | MATCHPATHCON_NOTRANS;
} else {
/*
* restorecon:
* No recursive descent unless -r/-R,
* Expands paths via realpath,
* Do not abort on errors during the file tree walk,
* Do not try to track inode associations for conflict detection,
* Follows mounts,
* Does lazy validation of contexts upon use.
*/
expand_realpath = 1;
follow_mounts = 1;
matchpathcon_flags = MATCHPATHCON_NOTRANS;
/* restorecon only */
selinux_or_die();
}
set_matchpathcon_flags(matchpathcon_flags);
opt_complementary = "e::vv:v--p:p--v:v--q:q--v";
/* Option order must match OPT_x definitions! */
if (applet_name[0] == 'r') { /* restorecon */
flags = getopt32(argc, argv, "de:f:ilnpqrsvo:FWR",
&exclude_dir, &input_filename, &out_filename, &verbose);
} else { /* setfiles */
flags = getopt32(argc, argv, "de:f:ilnpqr:svo:FW"
USE_FEATURE_SETFILES_CHECK_OPTION("c:"),
&exclude_dir, &input_filename, &rootpath, &out_filename,
USE_FEATURE_SETFILES_CHECK_OPTION(&policyfile,)
&verbose);
}
#if ENABLE_FEATURE_SETFILES_CHECK_OPTION
if ((applet_name[0] == 's') && (flags & OPT_c)) {
FILE *policystream;
policystream = xfopen(policyfile, "r");
if (sepol_set_policydb_from_file(policystream) < 0) {
bb_error_msg_and_die("sepol_set_policydb_from_file on %s", policyfile);
}
fclose(policystream);
/* Only process the specified file_contexts file, not
any .homedirs or .local files, and do not perform
context translations. */
set_matchpathcon_flags(MATCHPATHCON_BASEONLY |
MATCHPATHCON_NOTRANS |
MATCHPATHCON_VALIDATE);
}
#endif
while (exclude_dir)
add_exclude(llist_pop(&exclude_dir));
if (flags & OPT_o) {
outfile = stdout;
if (NOT_LONE_CHAR(out_filename, '-')) {
outfile = xfopen(out_filename, "w");
}
}
if (applet_name[0] == 'r') { /* restorecon */
if (flags & (OPT_r | OPT_R))
recurse = 1;
} else { /* setfiles */
if (flags & OPT_r)
rootpathlen = strlen(rootpath);
}
if (flags & OPT_s) {
input_filename = "-";
add_assoc = 0;
}
if (applet_name[0] == 's') { /* setfiles */
/* Use our own invalid context checking function so that
we can support either checking against the active policy or
checking against a binary policy file. */
set_matchpathcon_canoncon(&canoncon);
if (argc == 1)
bb_show_usage();
if (stat(argv[optind], &sb) < 0) {
bb_perror_msg_and_die("%s", argv[optind]);
}
if (!S_ISREG(sb.st_mode)) {
bb_error_msg_and_die("spec file %s is not a regular file", argv[optind]);
}
/* Load the file contexts configuration and check it. */
rc = matchpathcon_init(argv[optind]);
if (rc < 0) {
bb_perror_msg_and_die("%s", argv[optind]);
}
optind++;
if (nerr)
exit(1);
}
if (input_filename) {
ssize_t len;
FILE *f = stdin;
if (NOT_LONE_CHAR(input_filename, '-'))
f = xfopen(input_filename, "r");
while ((len = getline(&buf, &buf_len, f)) > 0) {
buf[len - 1] = '\0';
errors |= process_one(buf);
}
if (ENABLE_FEATURE_CLEAN_UP)
fclose_if_not_stdin(f);
} else {
if (optind >= argc)
bb_show_usage();
for (i = optind; i < argc; i++) {
errors |= process_one(argv[i]);
}
}
if (FLAG_W_warn_no_match)
matchpathcon_checkmatches(argv[0]);
if (ENABLE_FEATURE_CLEAN_UP && outfile)
fclose(outfile);
return errors;
}