include/net/scm.h

   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 #ifdef CONFIG_SECURITY_NETWORK
  23         char                    *secdata;       /* Security context     */
  24         u32                     seclen;         /* Security length      */
  25 #endif
  26         unsigned long           seq;            /* Connection seqno     */
  27 };
  28
  29 extern void scm_detach_fds(struct msghdr *msg, struct scm_cookie *scm);
  30 extern void scm_detach_fds_compat(struct msghdr *msg, struct scm_cookie *scm);
  31 extern int __scm_send(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm);
  32 extern void __scm_destroy(struct scm_cookie *scm);
  33 extern struct scm_fp_list * scm_fp_dup(struct scm_fp_list *fpl);
  34
  35 static __inline__ void scm_destroy(struct scm_cookie *scm)
  36 {
  37         if (scm && scm->fp)
  38                 __scm_destroy(scm);
  39 }
  40
  41 static __inline__ int scm_send(struct socket *sock, struct msghdr *msg,
  42                                struct scm_cookie *scm)
  43 {
  44         struct task_struct *p = current;
  45         scm->creds.uid = p->uid;
  46         scm->creds.gid = p->gid;
  47         scm->creds.pid = p->tgid;
  48         scm->fp = NULL;
  49         scm->seq = 0;
  50         if (msg->msg_controllen <= 0)
  51                 return 0;
  52         return __scm_send(sock, msg, scm);
  53 }
  54
  55 #ifdef CONFIG_SECURITY_NETWORK
  56 static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm)
  57 {
  58         if (test_bit(SOCK_PASSSEC, &sock->flags) && scm->secdata != NULL)
  59                 put_cmsg(msg, SOL_SOCKET, SCM_SECURITY, scm->seclen, scm->secdata);
  60 }
  61 #else
  62 static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm)
  63 { }
  64 #endif /* CONFIG_SECURITY_NETWORK */
  65
  66 static __inline__ void scm_recv(struct socket *sock, struct msghdr *msg,
  67                                 struct scm_cookie *scm, int flags)
  68 {
  69         if (!msg->msg_control)
  70         {
  71                 if (test_bit(SOCK_PASSCRED, &sock->flags) || scm->fp)
  72                         msg->msg_flags |= MSG_CTRUNC;
  73                 scm_destroy(scm);
  74                 return;
  75         }
  76
  77         if (test_bit(SOCK_PASSCRED, &sock->flags))
  78                 put_cmsg(msg, SOL_SOCKET, SCM_CREDENTIALS, sizeof(scm->creds), &scm->creds);
  79
  80         scm_passec(sock, msg, scm);
  81
  82         if (!scm->fp)
  83                 return;
  84
  85         scm_detach_fds(msg, scm);
  86 }
  87
  88
  89 #endif /* __LINUX_NET_SCM_H */
  90