Merge pull request #3191 from poettering/cgroups-agent-dgram

core: use an AF_UNIX/SOCK_DGRAM socket for cgroup agent notification

1 files changed, 11 insertions, 0 deletions

diff --git a/src/basic/socket-util.h b/src/basic/socket-util.h
index d17a2f35f8..daa4b24a37 100644
--- a/src/basic/socket-util.h
+++ b/src/basic/socket-util.h
@@ -137,3 +137,14 @@ ssize_t next_datagram_size_fd(int fd);
 
 #define CMSG_FOREACH(cmsg, mh)                                          \
         for ((cmsg) = CMSG_FIRSTHDR(mh); (cmsg); (cmsg) = CMSG_NXTHDR((mh), (cmsg)))
+
+/* Covers only file system and abstract AF_UNIX socket addresses, but not unnamed socket addresses. */
+#define SOCKADDR_UN_LEN(sa)                                             \
+        ({                                                              \
+                const struct sockaddr_un *_sa = &(sa);                  \
+                assert(_sa->sun_family == AF_UNIX);                     \
+                offsetof(struct sockaddr_un, sun_path) +                \
+                        (_sa->sun_path[0] == 0 ?                        \
+                         1 + strnlen(_sa->sun_path+1, sizeof(_sa->sun_path)-1) : \
+                         strnlen(_sa->sun_path, sizeof(_sa->sun_path))); \
+        })