include/net/scm.h

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