tree-wide: introduce new SOCKADDR_UN_LEN() macro, and use it everywhere

The macro determines the right length of a AF_UNIX "struct sockaddr_un" to pass to
connect() or bind(). It automatically figures out if the socket refers to an
abstract namespace socket, or a socket in the file system, and properly handles
the full length of the path field.

This macro is not only safer, but also simpler to use, than the usual
offsetof() + strlen() logic.

1 files changed, 7 insertions, 7 deletions

diff --git a/src/journal/journal-send.c b/src/journal/journal-send.c
index f0959b6237..5e8a3e3200 100644
--- a/src/journal/journal-send.c
+++ b/src/journal/journal-send.c
@@ -208,13 +208,13 @@ _public_ int sd_journal_sendv(const struct iovec *iov, int n) {
         struct iovec *w;
         uint64_t *l;
         int i, j = 0;
-        struct sockaddr_un sa = {
-                .sun_family = AF_UNIX,
-                .sun_path = "/run/systemd/journal/socket",
+        static const union sockaddr_union sa = {
+                .un.sun_family = AF_UNIX,
+                .un.sun_path = "/run/systemd/journal/socket",
         };
         struct msghdr mh = {
-                .msg_name = &sa,
-                .msg_namelen = offsetof(struct sockaddr_un, sun_path) + strlen(sa.sun_path),
+                .msg_name = (struct sockaddr*) &sa.sa,
+                .msg_namelen = SOCKADDR_UN_LEN(sa.un),
         };
         ssize_t k;
         bool have_syslog_identifier = false;
@@ -392,7 +392,7 @@ _public_ int sd_journal_perror(const char *message) {
 }
 
 _public_ int sd_journal_stream_fd(const char *identifier, int priority, int level_prefix) {
-        union sockaddr_union sa = {
+        static const union sockaddr_union sa = {
                 .un.sun_family = AF_UNIX,
                 .un.sun_path = "/run/systemd/journal/stdout",
         };
@@ -408,7 +408,7 @@ _public_ int sd_journal_stream_fd(const char *identifier, int priority, int leve
         if (fd < 0)
                 return -errno;
 
-        r = connect(fd, &sa.sa, offsetof(union sockaddr_union, un.sun_path) + strlen(sa.un.sun_path));
+        r = connect(fd, &sa.sa, SOCKADDR_UN_LEN(sa.un));
         if (r < 0)
                 return -errno;