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