Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
[linux-2.6-microblaze.git] / include / net / scm.h
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __LINUX_NET_SCM_H
3 #define __LINUX_NET_SCM_H
4
5 #include <linux/limits.h>
6 #include <linux/net.h>
7 #include <linux/cred.h>
8 #include <linux/security.h>
9 #include <linux/pid.h>
10 #include <linux/nsproxy.h>
11 #include <linux/sched/signal.h>
12
13 /* Well, we should have at least one descriptor open
14  * to accept passed FDs 8)
15  */
16 #define SCM_MAX_FD      253
17
18 struct scm_creds {
19         u32     pid;
20         kuid_t  uid;
21         kgid_t  gid;
22 };
23
24 struct scm_fp_list {
25         short                   count;
26         short                   max;
27         struct user_struct      *user;
28         struct file             *fp[SCM_MAX_FD];
29 };
30
31 struct scm_cookie {
32         struct pid              *pid;           /* Skb credentials */
33         struct scm_fp_list      *fp;            /* Passed files         */
34         struct scm_creds        creds;          /* Skb credentials      */
35 #ifdef CONFIG_SECURITY_NETWORK
36         u32                     secid;          /* Passed security ID   */
37 #endif
38 };
39
40 void scm_detach_fds(struct msghdr *msg, struct scm_cookie *scm);
41 void scm_detach_fds_compat(struct msghdr *msg, struct scm_cookie *scm);
42 int __scm_send(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm);
43 void __scm_destroy(struct scm_cookie *scm);
44 struct scm_fp_list *scm_fp_dup(struct scm_fp_list *fpl);
45
46 #ifdef CONFIG_SECURITY_NETWORK
47 static __inline__ void unix_get_peersec_dgram(struct socket *sock, struct scm_cookie *scm)
48 {
49         security_socket_getpeersec_dgram(sock, NULL, &scm->secid);
50 }
51 #else
52 static __inline__ void unix_get_peersec_dgram(struct socket *sock, struct scm_cookie *scm)
53 { }
54 #endif /* CONFIG_SECURITY_NETWORK */
55
56 static __inline__ void scm_set_cred(struct scm_cookie *scm,
57                                     struct pid *pid, kuid_t uid, kgid_t gid)
58 {
59         scm->pid  = get_pid(pid);
60         scm->creds.pid = pid_vnr(pid);
61         scm->creds.uid = uid;
62         scm->creds.gid = gid;
63 }
64
65 static __inline__ void scm_destroy_cred(struct scm_cookie *scm)
66 {
67         put_pid(scm->pid);
68         scm->pid  = NULL;
69 }
70
71 static __inline__ void scm_destroy(struct scm_cookie *scm)
72 {
73         scm_destroy_cred(scm);
74         if (scm->fp)
75                 __scm_destroy(scm);
76 }
77
78 static __inline__ int scm_send(struct socket *sock, struct msghdr *msg,
79                                struct scm_cookie *scm, bool forcecreds)
80 {
81         memset(scm, 0, sizeof(*scm));
82         scm->creds.uid = INVALID_UID;
83         scm->creds.gid = INVALID_GID;
84         if (forcecreds)
85                 scm_set_cred(scm, task_tgid(current), current_uid(), current_gid());
86         unix_get_peersec_dgram(sock, scm);
87         if (msg->msg_controllen <= 0)
88                 return 0;
89         return __scm_send(sock, msg, scm);
90 }
91
92 #ifdef CONFIG_SECURITY_NETWORK
93 static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm)
94 {
95         char *secdata;
96         u32 seclen;
97         int err;
98
99         if (test_bit(SOCK_PASSSEC, &sock->flags)) {
100                 err = security_secid_to_secctx(scm->secid, &secdata, &seclen);
101
102                 if (!err) {
103                         put_cmsg(msg, SOL_SOCKET, SCM_SECURITY, seclen, secdata);
104                         security_release_secctx(secdata, seclen);
105                 }
106         }
107 }
108 #else
109 static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm)
110 { }
111 #endif /* CONFIG_SECURITY_NETWORK */
112
113 static __inline__ void scm_recv(struct socket *sock, struct msghdr *msg,
114                                 struct scm_cookie *scm, int flags)
115 {
116         if (!msg->msg_control) {
117                 if (test_bit(SOCK_PASSCRED, &sock->flags) || scm->fp)
118                         msg->msg_flags |= MSG_CTRUNC;
119                 scm_destroy(scm);
120                 return;
121         }
122
123         if (test_bit(SOCK_PASSCRED, &sock->flags)) {
124                 struct user_namespace *current_ns = current_user_ns();
125                 struct ucred ucreds = {
126                         .pid = scm->creds.pid,
127                         .uid = from_kuid_munged(current_ns, scm->creds.uid),
128                         .gid = from_kgid_munged(current_ns, scm->creds.gid),
129                 };
130                 put_cmsg(msg, SOL_SOCKET, SCM_CREDENTIALS, sizeof(ucreds), &ucreds);
131         }
132
133         scm_destroy_cred(scm);
134
135         scm_passec(sock, msg, scm);
136
137         if (!scm->fp)
138                 return;
139         
140         scm_detach_fds(msg, scm);
141 }
142
143
144 #endif /* __LINUX_NET_SCM_H */
145