int r;
assert(s);
- assert(ret_uid);
r = safe_atolu(s, &ul);
if (r < 0)
if (uid == (uid_t) 0xFFFF)
return -ENXIO;
- *ret_uid = uid;
+ if (ret_uid)
+ *ret_uid = uid;
+
return 0;
}
* sometimes SI decimal suffixes. This function can parse
* both. Which one is the right way depends on the
* context. Wikipedia suggests that SI is customary for
- * hardrware metrics and network speeds, while IEC is
+ * hardware metrics and network speeds, while IEC is
* customary for most data sizes used by software and volatile
* (RAM) memory. Hence be careful which one you pick!
*
}
}
-char *replace_env(const char *format, char **env) {
- enum {
- WORD,
- CURLY,
- VARIABLE
- } state = WORD;
-
- const char *e, *word = format;
- char *r = NULL, *k;
-
- assert(format);
-
- for (e = format; *e; e ++) {
-
- switch (state) {
-
- case WORD:
- if (*e == '$')
- state = CURLY;
- break;
-
- case CURLY:
- if (*e == '{') {
- k = strnappend(r, word, e-word-1);
- if (!k)
- goto fail;
-
- free(r);
- r = k;
-
- word = e-1;
- state = VARIABLE;
-
- } else if (*e == '$') {
- k = strnappend(r, word, e-word);
- if (!k)
- goto fail;
-
- free(r);
- r = k;
-
- word = e+1;
- state = WORD;
- } else
- state = WORD;
- break;
-
- case VARIABLE:
- if (*e == '}') {
- const char *t;
-
- t = strempty(strv_env_get_n(env, word+2, e-word-2));
-
- k = strappend(r, t);
- if (!k)
- goto fail;
-
- free(r);
- r = k;
-
- word = e+1;
- state = WORD;
- }
- break;
- }
- }
-
- k = strnappend(r, word, e-word);
- if (!k)
- goto fail;
-
- free(r);
- return k;
-
-fail:
- free(r);
- return NULL;
-}
-
-char **replace_env_argv(char **argv, char **env) {
- char **ret, **i;
- unsigned k = 0, l = 0;
-
- l = strv_length(argv);
-
- ret = new(char*, l+1);
- if (!ret)
- return NULL;
-
- STRV_FOREACH(i, argv) {
-
- /* If $FOO appears as single word, replace it by the split up variable */
- if ((*i)[0] == '$' && (*i)[1] != '{') {
- char *e;
- char **w, **m = NULL;
- unsigned q;
-
- e = strv_env_get(env, *i+1);
- if (e) {
- int r;
-
- r = strv_split_quoted(&m, e, UNQUOTE_RELAX);
- if (r < 0) {
- ret[k] = NULL;
- strv_free(ret);
- return NULL;
- }
- } else
- m = NULL;
-
- q = strv_length(m);
- l = l + q - 1;
-
- w = realloc(ret, sizeof(char*) * (l+1));
- if (!w) {
- ret[k] = NULL;
- strv_free(ret);
- strv_free(m);
- return NULL;
- }
-
- ret = w;
- if (m) {
- memcpy(ret + k, m, q * sizeof(char*));
- free(m);
- }
-
- k += q;
- continue;
- }
-
- /* If ${FOO} appears as part of a word, replace it by the variable as-is */
- ret[k] = replace_env(*i, env);
- if (!ret[k]) {
- strv_free(ret);
- return NULL;
- }
- k++;
- }
-
- ret[k] = NULL;
- return ret;
-}
-
int files_same(const char *filea, const char *fileb) {
struct stat a, b;
return 0;
}
+int symlink_idempotent(const char *from, const char *to) {
+ _cleanup_free_ char *p = NULL;
+ int r;
+
+ assert(from);
+ assert(to);
+
+ if (symlink(from, to) < 0) {
+ if (errno != EEXIST)
+ return -errno;
+
+ r = readlink_malloc(to, &p);
+ if (r < 0)
+ return r;
+
+ if (!streq(p, from))
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
int mknod_atomic(const char *path, mode_t mode, dev_t dev) {
_cleanup_free_ char *t = NULL;
int r;
if (streq(p, "..") || startswith(p, "../") || endswith(p, "/..") || strstr(p, "/../"))
return false;
- if (strlen(p) > PATH_MAX)
+ if (strlen(p)+1 > PATH_MAX)
return false;
/* The following two checks are not really dangerous, but hey, they still are confusing */
#ifdef O_TMPFILE
/* Try O_TMPFILE first, if it is supported */
- fd = open(path, flags|O_TMPFILE, S_IRUSR|S_IWUSR);
+ fd = open(path, flags|O_TMPFILE|O_EXCL, S_IRUSR|S_IWUSR);
if (fd >= 0)
return fd;
#endif
/* Replaces a string pointer with an strdup()ed new string,
* possibly freeing the old one. */
+ if (streq_ptr(*p, s))
+ return 0;
+
if (s) {
t = strdup(s);
if (!t)
free(*p);
*p = t;
- return 0;
+ return 1;
}
int sethostname_idempotent(const char *s) {
int chattr_fd(int fd, unsigned value, unsigned mask) {
unsigned old_attr, new_attr;
+ struct stat st;
assert(fd >= 0);
+ if (fstat(fd, &st) < 0)
+ return -errno;
+
+ /* Explicitly check whether this is a regular file or
+ * directory. If it is anything else (such as a device node or
+ * fifo), then the ioctl will not hit the file systems but
+ * possibly drivers, where the ioctl might have different
+ * effects. Notably, DRM is using the same ioctl() number. */
+
+ if (!S_ISDIR(st.st_mode) && !S_ISREG(st.st_mode))
+ return -ENOTTY;
+
if (mask == 0)
return 0;
}
int read_attr_fd(int fd, unsigned *ret) {
+ struct stat st;
+
assert(fd >= 0);
+ if (fstat(fd, &st) < 0)
+ return -errno;
+
+ if (!S_ISDIR(st.st_mode) && !S_ISREG(st.st_mode))
+ return -ENOTTY;
+
if (ioctl(fd, FS_IOC_GETFLAGS, ret) < 0)
return -errno;
return read_attr_fd(fd, ret);
}
-int make_lock_file(const char *p, int operation, LockFile *ret) {
- _cleanup_close_ int fd = -1;
- _cleanup_free_ char *t = NULL;
- int r;
-
- /*
- * We use UNPOSIX locks if they are available. They have nice
- * semantics, and are mostly compatible with NFS. However,
- * they are only available on new kernels. When we detect we
- * are running on an older kernel, then we fall back to good
- * old BSD locks. They also have nice semantics, but are
- * slightly problematic on NFS, where they are upgraded to
- * POSIX locks, even though locally they are orthogonal to
- * POSIX locks.
- */
-
- t = strdup(p);
- if (!t)
- return -ENOMEM;
-
- for (;;) {
- struct flock fl = {
- .l_type = (operation & ~LOCK_NB) == LOCK_EX ? F_WRLCK : F_RDLCK,
- .l_whence = SEEK_SET,
- };
- struct stat st;
-
- fd = open(p, O_CREAT|O_RDWR|O_NOFOLLOW|O_CLOEXEC|O_NOCTTY, 0600);
- if (fd < 0)
- return -errno;
-
- r = fcntl(fd, (operation & LOCK_NB) ? F_OFD_SETLK : F_OFD_SETLKW, &fl);
- if (r < 0) {
-
- /* If the kernel is too old, use good old BSD locks */
- if (errno == EINVAL)
- r = flock(fd, operation);
-
- if (r < 0)
- return errno == EAGAIN ? -EBUSY : -errno;
- }
-
- /* If we acquired the lock, let's check if the file
- * still exists in the file system. If not, then the
- * previous exclusive owner removed it and then closed
- * it. In such a case our acquired lock is worthless,
- * hence try again. */
-
- r = fstat(fd, &st);
- if (r < 0)
- return -errno;
- if (st.st_nlink > 0)
- break;
-
- fd = safe_close(fd);
- }
-
- ret->path = t;
- ret->fd = fd;
- ret->operation = operation;
-
- fd = -1;
- t = NULL;
-
- return r;
-}
-
-int make_lock_file_for(const char *p, int operation, LockFile *ret) {
- const char *fn;
- char *t;
-
- assert(p);
- assert(ret);
-
- fn = basename(p);
- if (!filename_is_valid(fn))
- return -EINVAL;
-
- t = newa(char, strlen(p) + 2 + 4 + 1);
- stpcpy(stpcpy(stpcpy(mempcpy(t, p, fn - p), ".#"), fn), ".lck");
-
- return make_lock_file(t, operation, ret);
-}
-
-void release_lock_file(LockFile *f) {
- int r;
-
- if (!f)
- return;
-
- if (f->path) {
-
- /* If we are the exclusive owner we can safely delete
- * the lock file itself. If we are not the exclusive
- * owner, we can try becoming it. */
-
- if (f->fd >= 0 &&
- (f->operation & ~LOCK_NB) == LOCK_SH) {
- static const struct flock fl = {
- .l_type = F_WRLCK,
- .l_whence = SEEK_SET,
- };
-
- r = fcntl(f->fd, F_OFD_SETLK, &fl);
- if (r < 0 && errno == EINVAL)
- r = flock(f->fd, LOCK_EX|LOCK_NB);
-
- if (r >= 0)
- f->operation = LOCK_EX|LOCK_NB;
- }
-
- if ((f->operation & ~LOCK_NB) == LOCK_EX)
- unlink_noerrno(f->path);
-
- free(f->path);
- f->path = NULL;
- }
-
- f->fd = safe_close(f->fd);
- f->operation = 0;
-}
-
static size_t nul_length(const uint8_t *p, size_t sz) {
size_t n = 0;