1 /* 2 * systemd socket activation support 3 * 4 * Copyright 2017 Red Hat, Inc. and/or its affiliates 5 * 6 * Authors: 7 * Richard W.M. Jones <rjones@redhat.com> 8 * 9 * This work is licensed under the terms of the GNU GPL, version 2 or later. 10 * See the COPYING file in the top-level directory. 11 */ 12 13 #include "qemu/osdep.h" 14 #include "qemu/systemd.h" 15 #include "qemu/cutils.h" 16 #include "qemu/error-report.h" 17 18 #ifndef _WIN32 19 unsigned int check_socket_activation(void) 20 { 21 const char *s; 22 unsigned long pid; 23 unsigned long nr_fds; 24 unsigned int i; 25 int fd; 26 int err; 27 28 s = getenv("LISTEN_PID"); 29 if (s == NULL) { 30 return 0; 31 } 32 err = qemu_strtoul(s, NULL, 10, &pid); 33 if (err) { 34 return 0; 35 } 36 if (pid != getpid()) { 37 return 0; 38 } 39 40 s = getenv("LISTEN_FDS"); 41 if (s == NULL) { 42 return 0; 43 } 44 err = qemu_strtoul(s, NULL, 10, &nr_fds); 45 if (err) { 46 return 0; 47 } 48 assert(nr_fds <= UINT_MAX); 49 50 /* So these are not passed to any child processes we might start. */ 51 unsetenv("LISTEN_FDS"); 52 unsetenv("LISTEN_PID"); 53 54 /* So the file descriptors don't leak into child processes. */ 55 for (i = 0; i < nr_fds; ++i) { 56 fd = FIRST_SOCKET_ACTIVATION_FD + i; 57 if (fcntl(fd, F_SETFD, FD_CLOEXEC) == -1) { 58 /* If we cannot set FD_CLOEXEC then it probably means the file 59 * descriptor is invalid, so socket activation has gone wrong 60 * and we should exit. 61 */ 62 error_report("Socket activation failed: " 63 "invalid file descriptor fd = %d: %s", 64 fd, g_strerror(errno)); 65 exit(EXIT_FAILURE); 66 } 67 } 68 69 return (unsigned int) nr_fds; 70 } 71 72 #else /* !_WIN32 */ 73 unsigned int check_socket_activation(void) 74 { 75 return 0; 76 } 77 #endif 78