static int unix_listen_saddr(UnixSocketAddress *saddr, bool update_addr, Error **errp) { struct sockaddr_un un; int sock, fd; sock = qemu_socket(PF_UNIX, SOCK_STREAM, 0); if (sock < 0) { error_setg_errno(errp, errno, "Failed to create Unix socket"); return -1; } memset(&un, 0, sizeof(un)); un.sun_family = AF_UNIX; if (saddr->path && strlen(saddr->path)) { snprintf(un.sun_path, sizeof(un.sun_path), "%s", saddr->path); } else { const char *tmpdir = getenv("TMPDIR"); tmpdir = tmpdir ? tmpdir : "/tmp"; if (snprintf(un.sun_path, sizeof(un.sun_path), "%s/qemu-socket-XXXXXX", tmpdir) >= sizeof(un.sun_path)) { error_setg_errno(errp, errno, "TMPDIR environment variable (%s) too large", tmpdir); goto err; } /* * This dummy fd usage silences the mktemp() unsecure warning. * Using mkstemp() doesn't make things more secure here * though. bind() complains about existing files, so we have * to unlink first and thus re-open the race window. The * worst case possible is bind() failing, i.e. a DoS attack. */ fd = mkstemp(un.sun_path); if (fd < 0) { error_setg_errno(errp, errno, "Failed to make a temporary socket name in %s", tmpdir); goto err; } close(fd); if (update_addr) { g_free(saddr->path); saddr->path = g_strdup(un.sun_path); } } if (unlink(un.sun_path) < 0 && errno != ENOENT) { error_setg_errno(errp, errno, "Failed to unlink socket %s", un.sun_path); goto err; } if (bind(sock, (struct sockaddr*) &un, sizeof(un)) < 0) { error_setg_errno(errp, errno, "Failed to bind socket to %s", un.sun_path); goto err; } if (listen(sock, 1) < 0) { error_setg_errno(errp, errno, "Failed to listen on socket"); goto err; } return sock; err: closesocket(sock); return -1; }