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/file.h>
9 #include <linux/security.h>
10 #include <linux/pid.h>
11 #include <linux/nsproxy.h>
12 #include <linux/sched/signal.h>
13 #include <net/compat.h>
14
15 /* Well, we should have at least one descriptor open
16 * to accept passed FDs 8)
17 */
18 #define SCM_MAX_FD 253
19
20 struct scm_creds {
21 u32 pid;
22 kuid_t uid;
23 kgid_t gid;
24 };
25
26 #ifdef CONFIG_UNIX
27 struct unix_edge;
28 #endif
29
30 struct scm_fp_list {
31 short count;
32 short count_unix;
33 short max;
34 #ifdef CONFIG_UNIX
35 bool inflight;
36 bool dead;
37 struct list_head vertices;
38 struct unix_edge *edges;
39 #endif
40 struct user_struct *user;
41 struct file *fp[SCM_MAX_FD];
42 };
43
44 struct scm_cookie {
45 struct pid *pid; /* Skb credentials */
46 struct scm_fp_list *fp; /* Passed files */
47 struct scm_creds creds; /* Skb credentials */
48 #ifdef CONFIG_SECURITY_NETWORK
49 u32 secid; /* Passed security ID */
50 #endif
51 };
52
53 void scm_detach_fds(struct msghdr *msg, struct scm_cookie *scm);
54 void scm_detach_fds_compat(struct msghdr *msg, struct scm_cookie *scm);
55 int __scm_send(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm);
56 void __scm_destroy(struct scm_cookie *scm);
57 struct scm_fp_list *scm_fp_dup(struct scm_fp_list *fpl);
58
59 #ifdef CONFIG_SECURITY_NETWORK
unix_get_peersec_dgram(struct socket * sock,struct scm_cookie * scm)60 static __inline__ void unix_get_peersec_dgram(struct socket *sock, struct scm_cookie *scm)
61 {
62 security_socket_getpeersec_dgram(sock, NULL, &scm->secid);
63 }
64 #else
unix_get_peersec_dgram(struct socket * sock,struct scm_cookie * scm)65 static __inline__ void unix_get_peersec_dgram(struct socket *sock, struct scm_cookie *scm)
66 { }
67 #endif /* CONFIG_SECURITY_NETWORK */
68
scm_set_cred(struct scm_cookie * scm,struct pid * pid,kuid_t uid,kgid_t gid)69 static __inline__ void scm_set_cred(struct scm_cookie *scm,
70 struct pid *pid, kuid_t uid, kgid_t gid)
71 {
72 scm->pid = get_pid(pid);
73 scm->creds.pid = pid_vnr(pid);
74 scm->creds.uid = uid;
75 scm->creds.gid = gid;
76 }
77
scm_destroy_cred(struct scm_cookie * scm)78 static __inline__ void scm_destroy_cred(struct scm_cookie *scm)
79 {
80 put_pid(scm->pid);
81 scm->pid = NULL;
82 }
83
scm_destroy(struct scm_cookie * scm)84 static __inline__ void scm_destroy(struct scm_cookie *scm)
85 {
86 scm_destroy_cred(scm);
87 if (scm->fp)
88 __scm_destroy(scm);
89 }
90
scm_send(struct socket * sock,struct msghdr * msg,struct scm_cookie * scm,bool forcecreds)91 static __inline__ int scm_send(struct socket *sock, struct msghdr *msg,
92 struct scm_cookie *scm, bool forcecreds)
93 {
94 memset(scm, 0, sizeof(*scm));
95 scm->creds.uid = INVALID_UID;
96 scm->creds.gid = INVALID_GID;
97 if (forcecreds)
98 scm_set_cred(scm, task_tgid(current), current_uid(), current_gid());
99 unix_get_peersec_dgram(sock, scm);
100 if (msg->msg_controllen <= 0)
101 return 0;
102 return __scm_send(sock, msg, scm);
103 }
104
105 void scm_recv(struct socket *sock, struct msghdr *msg,
106 struct scm_cookie *scm, int flags);
107 void scm_recv_unix(struct socket *sock, struct msghdr *msg,
108 struct scm_cookie *scm, int flags);
109
scm_recv_one_fd(struct file * f,int __user * ufd,unsigned int flags)110 static inline int scm_recv_one_fd(struct file *f, int __user *ufd,
111 unsigned int flags)
112 {
113 if (!ufd)
114 return -EFAULT;
115 return receive_fd(f, ufd, flags);
116 }
117
118 #endif /* __LINUX_NET_SCM_H */
119
120