1 #ifndef __LINUX_NET_SCM_H 2 #define __LINUX_NET_SCM_H 3 4 #include <linux/limits.h> 5 #include <linux/net.h> 6 7 /* Well, we should have at least one descriptor open 8 * to accept passed FDs 8) 9 */ 10 #define SCM_MAX_FD (OPEN_MAX-1) 11 12 struct scm_fp_list 13 { 14 int count; 15 struct file *fp[SCM_MAX_FD]; 16 }; 17 18 struct scm_cookie 19 { 20 struct ucred creds; /* Skb credentials */ 21 struct scm_fp_list *fp; /* Passed files */ 22 unsigned long seq; /* Connection seqno */ 23 }; 24 25 extern void scm_detach_fds(struct msghdr *msg, struct scm_cookie *scm); 26 extern void scm_detach_fds_compat(struct msghdr *msg, struct scm_cookie *scm); 27 extern int __scm_send(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm); 28 extern void __scm_destroy(struct scm_cookie *scm); 29 extern struct scm_fp_list * scm_fp_dup(struct scm_fp_list *fpl); 30 31 static __inline__ void scm_destroy(struct scm_cookie *scm) 32 { 33 if (scm && scm->fp) 34 __scm_destroy(scm); 35 } 36 37 static __inline__ int scm_send(struct socket *sock, struct msghdr *msg, 38 struct scm_cookie *scm) 39 { 40 struct task_struct *p = current; 41 scm->creds.uid = p->uid; 42 scm->creds.gid = p->gid; 43 scm->creds.pid = p->tgid; 44 scm->fp = NULL; 45 scm->seq = 0; 46 if (msg->msg_controllen <= 0) 47 return 0; 48 return __scm_send(sock, msg, scm); 49 } 50 51 static __inline__ void scm_recv(struct socket *sock, struct msghdr *msg, 52 struct scm_cookie *scm, int flags) 53 { 54 if (!msg->msg_control) 55 { 56 if (test_bit(SOCK_PASSCRED, &sock->flags) || scm->fp) 57 msg->msg_flags |= MSG_CTRUNC; 58 scm_destroy(scm); 59 return; 60 } 61 62 if (test_bit(SOCK_PASSCRED, &sock->flags)) 63 put_cmsg(msg, SOL_SOCKET, SCM_CREDENTIALS, sizeof(scm->creds), &scm->creds); 64 65 if (!scm->fp) 66 return; 67 68 scm_detach_fds(msg, scm); 69 } 70 71 72 #endif /* __LINUX_NET_SCM_H */ 73 74