1 #ifndef __LINUX_NET_SCM_H 2 #define __LINUX_NET_SCM_H 3 4 #include <linux/limits.h> 5 #include <linux/net.h> 6 #include <linux/security.h> 7 #include <linux/pid.h> 8 #include <linux/nsproxy.h> 9 10 /* Well, we should have at least one descriptor open 11 * to accept passed FDs 8) 12 */ 13 #define SCM_MAX_FD 255 14 15 struct scm_fp_list 16 { 17 struct list_head list; 18 int count; 19 struct file *fp[SCM_MAX_FD]; 20 }; 21 22 struct scm_cookie 23 { 24 struct ucred creds; /* Skb credentials */ 25 struct scm_fp_list *fp; /* Passed files */ 26 #ifdef CONFIG_SECURITY_NETWORK 27 u32 secid; /* Passed security ID */ 28 #endif 29 }; 30 31 extern void scm_detach_fds(struct msghdr *msg, struct scm_cookie *scm); 32 extern void scm_detach_fds_compat(struct msghdr *msg, struct scm_cookie *scm); 33 extern int __scm_send(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm); 34 extern void __scm_destroy(struct scm_cookie *scm); 35 extern struct scm_fp_list * scm_fp_dup(struct scm_fp_list *fpl); 36 37 #ifdef CONFIG_SECURITY_NETWORK 38 static __inline__ void unix_get_peersec_dgram(struct socket *sock, struct scm_cookie *scm) 39 { 40 security_socket_getpeersec_dgram(sock, NULL, &scm->secid); 41 } 42 #else 43 static __inline__ void unix_get_peersec_dgram(struct socket *sock, struct scm_cookie *scm) 44 { } 45 #endif /* CONFIG_SECURITY_NETWORK */ 46 47 static __inline__ void scm_destroy(struct scm_cookie *scm) 48 { 49 if (scm && scm->fp) 50 __scm_destroy(scm); 51 } 52 53 static __inline__ int scm_send(struct socket *sock, struct msghdr *msg, 54 struct scm_cookie *scm) 55 { 56 struct task_struct *p = current; 57 scm->creds.uid = current_uid(); 58 scm->creds.gid = current_gid(); 59 scm->creds.pid = task_tgid_vnr(p); 60 scm->fp = NULL; 61 unix_get_peersec_dgram(sock, scm); 62 if (msg->msg_controllen <= 0) 63 return 0; 64 return __scm_send(sock, msg, scm); 65 } 66 67 #ifdef CONFIG_SECURITY_NETWORK 68 static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm) 69 { 70 char *secdata; 71 u32 seclen; 72 int err; 73 74 if (test_bit(SOCK_PASSSEC, &sock->flags)) { 75 err = security_secid_to_secctx(scm->secid, &secdata, &seclen); 76 77 if (!err) { 78 put_cmsg(msg, SOL_SOCKET, SCM_SECURITY, seclen, secdata); 79 security_release_secctx(secdata, seclen); 80 } 81 } 82 } 83 #else 84 static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm) 85 { } 86 #endif /* CONFIG_SECURITY_NETWORK */ 87 88 static __inline__ void scm_recv(struct socket *sock, struct msghdr *msg, 89 struct scm_cookie *scm, int flags) 90 { 91 if (!msg->msg_control) 92 { 93 if (test_bit(SOCK_PASSCRED, &sock->flags) || scm->fp) 94 msg->msg_flags |= MSG_CTRUNC; 95 scm_destroy(scm); 96 return; 97 } 98 99 if (test_bit(SOCK_PASSCRED, &sock->flags)) 100 put_cmsg(msg, SOL_SOCKET, SCM_CREDENTIALS, sizeof(scm->creds), &scm->creds); 101 102 scm_passec(sock, msg, scm); 103 104 if (!scm->fp) 105 return; 106 107 scm_detach_fds(msg, scm); 108 } 109 110 111 #endif /* __LINUX_NET_SCM_H */ 112 113