systemd: merge branch systemd into master

Reimport systemd because it uses STRLEN() macro.
We need to when building with -Wvla warning enabled.

Related: https://github.com/systemd/systemd/pull/7625

src/systemd/src/basic/fd-util.c

@@ -372,7 +372,7 @@ bool fdname_is_valid(const char *s) {
 }
 
 int fd_get_path(int fd, char **ret) {
-        char procfs_path[strlen("/proc/self/fd/") + DECIMAL_STR_MAX(int)];
+        char procfs_path[STRLEN("/proc/self/fd/") + DECIMAL_STR_MAX(int)];
         int r;
 
         xsprintf(procfs_path, "/proc/self/fd/%i", fd);

src/systemd/src/basic/fileio.c

@@ -170,6 +170,9 @@ int write_string_file_ts(
                 }
         }
 
+        if (flags & WRITE_STRING_FILE_DISABLE_BUFFER)
+                setvbuf(f, NULL, _IONBF, 0);
+
         r = write_string_stream_ts(f, line, flags, ts);
         if (r < 0)
                 goto fail;

src/systemd/src/basic/fileio.h

@@ -35,6 +35,7 @@ typedef enum {
         WRITE_STRING_FILE_AVOID_NEWLINE     = 1<<2,
         WRITE_STRING_FILE_VERIFY_ON_FAILURE = 1<<3,
         WRITE_STRING_FILE_SYNC              = 1<<4,
+        WRITE_STRING_FILE_DISABLE_BUFFER    = 1<<5,
 
         /* And before you wonder, why write_string_file_atomic_label_ts() is a separate function instead of just one
            more flag here: it's about linking: we don't want to pull -lselinux into all users of write_string_file()

src/systemd/src/basic/hostname-util.c

@@ -226,6 +226,38 @@ int sethostname_idempotent(const char *s) {
         return 1;
 }
 
+int shorten_overlong(const char *s, char **ret) {
+        char *h, *p;
+
+        /* Shorten an overlong name to HOST_NAME_MAX or to the first dot,
+         * whatever comes earlier. */
+
+        assert(s);
+
+        h = strdup(s);
+        if (!h)
+                return -ENOMEM;
+
+        if (hostname_is_valid(h, false)) {
+                *ret = h;
+                return 0;
+        }
+
+        p = strchr(h, '.');
+        if (p)
+                *p = 0;
+
+        strshorten(h, HOST_NAME_MAX);
+
+        if (!hostname_is_valid(h, false)) {
+                free(h);
+                return -EDOM;
+        }
+
+        *ret = h;
+        return 1;
+}
+
 int read_etc_hostname_stream(FILE *f, char **ret) {
         int r;
 

src/systemd/src/basic/hostname-util.h

@@ -39,5 +39,7 @@ bool is_gateway_hostname(const char *hostname);
 
 int sethostname_idempotent(const char *s);
 
+int shorten_overlong(const char *s, char **ret);
+
 int read_etc_hostname_stream(FILE *f, char **ret);
 int read_etc_hostname(const char *path, char **ret);

src/systemd/src/basic/macro.h

@@ -153,6 +153,14 @@ static inline unsigned long ALIGN_POWER2(unsigned long u) {
                 !__builtin_types_compatible_p(typeof(x), typeof(&*(x))), \
                 sizeof(x)/sizeof((x)[0]),                                \
                 (void)0))
+
+/*
+ * STRLEN - return the length of a string literal, minus the trailing NUL byte.
+ *          Contrary to strlen(), this is a constant expression.
+ * @x: a string literal.
+ */
+#define STRLEN(x) (sizeof(""x"") - 1)
+
 /*
  * container_of - cast a member of a structure out to the containing structure
  * @ptr: the pointer to the member.

src/systemd/src/libsystemd-network/sd-dhcp-lease.c

@@ -989,7 +989,7 @@ int dhcp_lease_save(sd_dhcp_lease *lease, const char *lease_file) {
         }
 
         LIST_FOREACH(options, option, lease->private_options) {
-                char key[strlen("OPTION_000")+1];
+                char key[STRLEN("OPTION_000")+1];
 
                 xsprintf(key, "OPTION_%" PRIu8, option->tag);
                 r = serialize_dhcp_option(f, key, option->data, option->length);

src/systemd/src/shared/dns-domain.c

@@ -702,23 +702,26 @@ int dns_name_change_suffix(const char *name, const char *old_suffix, const char
 }
 
 int dns_name_between(const char *a, const char *b, const char *c) {
-        int n;
-
         /* Determine if b is strictly greater than a and strictly smaller than c.
            We consider the order of names to be circular, so that if a is
            strictly greater than c, we consider b to be between them if it is
            either greater than a or smaller than c. This is how the canonical
            DNS name order used in NSEC records work. */
 
-        n = dns_name_compare_func(a, c);
-        if (n == 0)
-                return -EINVAL;
-        else if (n < 0)
-                /*       a<---b--->c       */
+        if (dns_name_compare_func(a, c) < 0)
+                /*
+                   a and c are properly ordered:
+                   a<---b--->c
+                */
                 return dns_name_compare_func(a, b) < 0 &&
                        dns_name_compare_func(b, c) < 0;
         else
-                /* <--b--c         a--b--> */
+                /*
+                   a and c are equal or 'reversed':
+                   <--b--c         a----->
+                   or:
+                   <-----c         a--b-->
+                */
                 return dns_name_compare_func(b, c) < 0 ||
                        dns_name_compare_func(a, b) < 0;
 }