+static void forward_syslog(Server *s, const void *buffer, size_t length, struct ucred *ucred, struct timeval *tv) {
+ struct msghdr msghdr;
+ struct iovec iovec;
+ struct cmsghdr *cmsg;
+ union {
+ struct cmsghdr cmsghdr;
+ uint8_t buf[CMSG_SPACE(sizeof(struct ucred)) +
+ CMSG_SPACE(sizeof(struct timeval))];
+ } control;
+ union sockaddr_union sa;
+
+ assert(s);
+
+ zero(msghdr);
+
+ zero(iovec);
+ iovec.iov_base = (void*) buffer;
+ iovec.iov_len = length;
+ msghdr.msg_iov = &iovec;
+ msghdr.msg_iovlen = 1;
+
+ zero(sa);
+ sa.un.sun_family = AF_UNIX;
+ strncpy(sa.un.sun_path, "/run/systemd/syslog", sizeof(sa.un.sun_path));
+ msghdr.msg_name = &sa;
+ msghdr.msg_namelen = offsetof(union sockaddr_union, un.sun_path) + strlen(sa.un.sun_path);
+
+ zero(control);
+ msghdr.msg_control = &control;
+ msghdr.msg_controllen = sizeof(control);
+
+ cmsg = CMSG_FIRSTHDR(&msghdr);
+ cmsg->cmsg_level = SOL_SOCKET;
+ cmsg->cmsg_type = SCM_CREDENTIALS;
+ cmsg->cmsg_len = CMSG_LEN(sizeof(struct ucred));
+ memcpy(CMSG_DATA(cmsg), ucred, sizeof(struct ucred));
+ msghdr.msg_controllen = cmsg->cmsg_len;
+
+ /* Forward the syslog message we received via /dev/log to
+ * /run/systemd/syslog. Unfortunately we currently can't set
+ * the SO_TIMESTAMP auxiliary data, and hence we don't. */
+
+ if (sendmsg(s->syslog_fd, &msghdr, MSG_NOSIGNAL) >= 0)
+ return;
+
+ if (errno == ESRCH) {
+ struct ucred u;
+
+ /* Hmm, presumably the sender process vanished
+ * by now, so let's fix it as good as we
+ * can, and retry */
+
+ u = *ucred;
+ u.pid = getpid();
+ memcpy(CMSG_DATA(cmsg), &u, sizeof(struct ucred));
+
+ if (sendmsg(s->syslog_fd, &msghdr, MSG_NOSIGNAL) >= 0)
+ return;
+ }
+
+ log_debug("Failed to forward syslog message: %m");
+}
+