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