From a65aa40f8a96504bdcabd6a66a24f5756413bbc2 Mon Sep 17 00:00:00 2001
From: Kay Sievers <kay.sievers@vrfy.org>
Date: Thu, 17 Jun 2010 21:50:58 +0200
Subject: [PATCH] udevd: in case we don't daemonize, send READY message to
 /sbin/init

---
 udev/udevd.c | 78 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 78 insertions(+)

diff --git a/udev/udevd.c b/udev/udevd.c
index 6dd59ae6..e38c6016 100644
--- a/udev/udevd.c
+++ b/udev/udevd.c
@@ -34,6 +34,7 @@
 #include <sys/time.h>
 #include <sys/prctl.h>
 #include <sys/socket.h>
+#include <sys/un.h>
 #include <sys/signalfd.h>
 #include <sys/select.h>
 #include <sys/poll.h>
@@ -950,6 +951,81 @@ static int mem_size_mb(void)
 	return memsize;
 }
 
+static int init_notify(const char *state)
+{
+	int fd = -1, r;
+	struct msghdr msghdr;
+	struct iovec iovec;
+	struct ucred *ucred;
+	union {
+		struct sockaddr sa;
+		struct sockaddr_un un;
+	} sockaddr;
+	union {
+		struct cmsghdr cmsghdr;
+		uint8_t buf[CMSG_SPACE(sizeof(struct ucred))];
+	} control;
+	const char *e;
+
+	if (!(e = getenv("NOTIFY_SOCKET"))) {
+		r = 0;
+		goto finish;
+	}
+
+	/* Must be an abstract socket, or an absolute path */
+	if ((e[0] != '@' && e[0] != '/') || e[1] == 0) {
+		r = -EINVAL;
+		goto finish;
+	}
+
+	if ((fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0)) < 0) {
+		r = -errno;
+		goto finish;
+	}
+
+	memset(&sockaddr, 0, sizeof(sockaddr));
+	sockaddr.sa.sa_family = AF_UNIX;
+	strncpy(sockaddr.un.sun_path, e, sizeof(sockaddr.un.sun_path));
+
+	if (sockaddr.un.sun_path[0] == '@')
+		sockaddr.un.sun_path[0] = 0;
+
+	memset(&iovec, 0, sizeof(iovec));
+	iovec.iov_base = (char*) state;
+	iovec.iov_len = strlen(state);
+
+	memset(&control, 0, sizeof(control));
+	control.cmsghdr.cmsg_level = SOL_SOCKET;
+	control.cmsghdr.cmsg_type = SCM_CREDENTIALS;
+	control.cmsghdr.cmsg_len = CMSG_LEN(sizeof(struct ucred));
+
+	ucred = (struct ucred*) CMSG_DATA(&control.cmsghdr);
+	ucred->pid = getpid();
+	ucred->uid = getuid();
+	ucred->gid = getgid();
+
+	memset(&msghdr, 0, sizeof(msghdr));
+	msghdr.msg_name = &sockaddr;
+	msghdr.msg_namelen = sizeof(struct sockaddr_un);
+	msghdr.msg_iov = &iovec;
+	msghdr.msg_iovlen = 1;
+	msghdr.msg_control = &control;
+	msghdr.msg_controllen = control.cmsghdr.cmsg_len;
+
+	if (sendmsg(fd, &msghdr, MSG_NOSIGNAL) < 0) {
+		r = -errno;
+		goto finish;
+	}
+
+	r = 0;
+
+finish:
+	if (fd >= 0)
+		close(fd);
+
+	return r;
+}
+
 int main(int argc, char *argv[])
 {
 	struct udev *udev;
@@ -1201,6 +1277,8 @@ int main(int argc, char *argv[])
 			rc = 0;
 			goto exit;
 		}
+	} else {
+		init_notify("READY=1");
 	}
 
 	/* set scheduling priority for the main daemon process */
-- 
2.39.5