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/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
15struct scm_creds {
16 u32 pid;
17 kuid_t uid;
18 kgid_t gid;
19};
20
21struct scm_fp_list {
22 short count;
23 short max;
24 struct file *fp[SCM_MAX_FD];
25};
26
27struct scm_cookie {
28 struct pid *pid; /* Skb credentials */
29 const struct cred *cred;
30 struct scm_fp_list *fp; /* Passed files */
31 struct scm_creds creds; /* Skb credentials */
32#ifdef CONFIG_SECURITY_NETWORK
33 u32 secid; /* Passed security ID */
34#endif
35};
36
37extern void scm_detach_fds(struct msghdr *msg, struct scm_cookie *scm);
38extern void scm_detach_fds_compat(struct msghdr *msg, struct scm_cookie *scm);
39extern int __scm_send(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm);
40extern void __scm_destroy(struct scm_cookie *scm);
41extern struct scm_fp_list * scm_fp_dup(struct scm_fp_list *fpl);
42
43#ifdef CONFIG_SECURITY_NETWORK
44static __inline__ void unix_get_peersec_dgram(struct socket *sock, struct scm_cookie *scm)
45{
46 security_socket_getpeersec_dgram(sock, NULL, &scm->secid);
47}
48#else
49static __inline__ void unix_get_peersec_dgram(struct socket *sock, struct scm_cookie *scm)
50{ }
51#endif /* CONFIG_SECURITY_NETWORK */
52
53static __inline__ void scm_set_cred(struct scm_cookie *scm,
54 struct pid *pid, const struct cred *cred)
55{
56 scm->pid = get_pid(pid);
57 scm->cred = cred ? get_cred(cred) : NULL;
58 scm->creds.pid = pid_vnr(pid);
59 scm->creds.uid = cred ? cred->euid : INVALID_UID;
60 scm->creds.gid = cred ? cred->egid : INVALID_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 if (scm->cred)
69 put_cred(scm->cred);
70 scm->cred = NULL;
71}
72
73static __inline__ void scm_destroy(struct scm_cookie *scm)
74{
75 scm_destroy_cred(scm);
76 if (scm->fp)
77 __scm_destroy(scm);
78}
79
80static __inline__ int scm_send(struct socket *sock, struct msghdr *msg,
81 struct scm_cookie *scm, bool forcecreds)
82{
83 memset(scm, 0, sizeof(*scm));
84 if (forcecreds)
85 scm_set_cred(scm, task_tgid(current), current_cred());
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
93static 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
109static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm)
110{ }
111#endif /* CONFIG_SECURITY_NETWORK */
112
113static __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