-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(sa_family_t) + strlen(e);
- if (msghdr.msg_namelen > sizeof(struct sockaddr_un))
- 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;
-}
-