Merge branch 'for-linus' of git://git.kernel.dk/linux-block
[linux-2.6.git] / 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 #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      253
14
15 struct scm_fp_list {
16         struct list_head        list;
17         short                   count;
18         short                   max;
19         struct file             *fp[SCM_MAX_FD];
20 };
21
22 struct scm_cookie {
23         struct pid              *pid;           /* Skb credentials */
24         const struct cred       *cred;
25         struct scm_fp_list      *fp;            /* Passed files         */
26         struct ucred            creds;          /* Skb credentials      */
27 #ifdef CONFIG_SECURITY_NETWORK
28         u32                     secid;          /* Passed security ID   */
29 #endif
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_set_cred(struct scm_cookie *scm,
49                                     struct pid *pid, const struct cred *cred)
50 {
51         scm->pid  = get_pid(pid);
52         scm->cred = get_cred(cred);
53         cred_to_ucred(pid, cred, &scm->creds);
54 }
55
56 static __inline__ void scm_destroy_cred(struct scm_cookie *scm)
57 {
58         put_pid(scm->pid);
59         scm->pid  = NULL;
60
61         if (scm->cred)
62                 put_cred(scm->cred);
63         scm->cred = NULL;
64 }
65
66 static __inline__ void scm_destroy(struct scm_cookie *scm)
67 {
68         scm_destroy_cred(scm);
69         if (scm && scm->fp)
70                 __scm_destroy(scm);
71 }
72
73 static __inline__ int scm_send(struct socket *sock, struct msghdr *msg,
74                                struct scm_cookie *scm)
75 {
76         scm_set_cred(scm, task_tgid(current), current_cred());
77         scm->fp = NULL;
78         unix_get_peersec_dgram(sock, scm);
79         if (msg->msg_controllen <= 0)
80                 return 0;
81         return __scm_send(sock, msg, scm);
82 }
83
84 #ifdef CONFIG_SECURITY_NETWORK
85 static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm)
86 {
87         char *secdata;
88         u32 seclen;
89         int err;
90
91         if (test_bit(SOCK_PASSSEC, &sock->flags)) {
92                 err = security_secid_to_secctx(scm->secid, &secdata, &seclen);
93
94                 if (!err) {
95                         put_cmsg(msg, SOL_SOCKET, SCM_SECURITY, seclen, secdata);
96                         security_release_secctx(secdata, seclen);
97                 }
98         }
99 }
100 #else
101 static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm)
102 { }
103 #endif /* CONFIG_SECURITY_NETWORK */
104
105 static __inline__ void scm_recv(struct socket *sock, struct msghdr *msg,
106                                 struct scm_cookie *scm, int flags)
107 {
108         if (!msg->msg_control) {
109                 if (test_bit(SOCK_PASSCRED, &sock->flags) || scm->fp)
110                         msg->msg_flags |= MSG_CTRUNC;
111                 scm_destroy(scm);
112                 return;
113         }
114
115         if (test_bit(SOCK_PASSCRED, &sock->flags))
116                 put_cmsg(msg, SOL_SOCKET, SCM_CREDENTIALS, sizeof(scm->creds), &scm->creds);
117
118         scm_destroy_cred(scm);
119
120         scm_passec(sock, msg, scm);
121
122         if (!scm->fp)
123                 return;
124         
125         scm_detach_fds(msg, scm);
126 }
127
128
129 #endif /* __LINUX_NET_SCM_H */
130