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 unsigned long seq; /* Connection seqno */ 30 }; 31 32 extern void scm_detach_fds(struct msghdr *msg, struct scm_cookie *scm); 33 extern void scm_detach_fds_compat(struct msghdr *msg, struct scm_cookie *scm); 34 extern int __scm_send(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm); 35 extern void __scm_destroy(struct scm_cookie *scm); 36 extern struct scm_fp_list * scm_fp_dup(struct scm_fp_list *fpl); 37 38 #ifdef CONFIG_SECURITY_NETWORK 39 static __inline__ void unix_get_peersec_dgram(struct socket *sock, struct scm_cookie *scm) 40 { 41 security_socket_getpeersec_dgram(sock, NULL, &scm->secid); 42 } 43 #else 44 static __inline__ void unix_get_peersec_dgram(struct socket *sock, struct scm_cookie *scm) 45 { } 46 #endif /* CONFIG_SECURITY_NETWORK */ 47 48 static __inline__ void scm_destroy(struct scm_cookie *scm) 49 { 50 if (scm && scm->fp) 51 __scm_destroy(scm); 52 } 53 54 static __inline__ int scm_send(struct socket *sock, struct msghdr *msg, 55 struct scm_cookie *scm) 56 { 57 struct task_struct *p = current; 58 scm->creds.uid = current_uid(); 59 scm->creds.gid = current_gid(); 60 scm->creds.pid = task_tgid_vnr(p); 61 scm->fp = NULL; 62 scm->seq = 0; 63 unix_get_peersec_dgram(sock, scm); 64 if (msg->msg_controllen <= 0) 65 return 0; 66 return __scm_send(sock, msg, scm); 67 } 68 69 #ifdef CONFIG_SECURITY_NETWORK 70 static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm) 71 { 72 char *secdata; 73 u32 seclen; 74 int err; 75 76 if (test_bit(SOCK_PASSSEC, &sock->flags)) { 77 err = security_secid_to_secctx(scm->secid, &secdata, &seclen); 78 79 if (!err) { 80 put_cmsg(msg, SOL_SOCKET, SCM_SECURITY, seclen, secdata); 81 security_release_secctx(secdata, seclen); 82 } 83 } 84 } 85 #else 86 static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm) 87 { } 88 #endif /* CONFIG_SECURITY_NETWORK */ 89 90 static __inline__ void scm_recv(struct socket *sock, struct msghdr *msg, 91 struct scm_cookie *scm, int flags) 92 { 93 if (!msg->msg_control) 94 { 95 if (test_bit(SOCK_PASSCRED, &sock->flags) || scm->fp) 96 msg->msg_flags |= MSG_CTRUNC; 97 scm_destroy(scm); 98 return; 99 } 100 101 if (test_bit(SOCK_PASSCRED, &sock->flags)) 102 put_cmsg(msg, SOL_SOCKET, SCM_CREDENTIALS, sizeof(scm->creds), &scm->creds); 103 104 scm_passec(sock, msg, scm); 105 106 if (!scm->fp) 107 return; 108 109 scm_detach_fds(msg, scm); 110 } 111 112 113 #endif /* __LINUX_NET_SCM_H */ 114 115