Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
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_fp_list {
16 short count;
17 short max;
18 struct file *fp[SCM_MAX_FD];
19};
20
21struct scm_cookie {
22 struct pid *pid; /* Skb credentials */
23 const struct cred *cred;
24 struct scm_fp_list *fp; /* Passed files */
25 struct ucred creds; /* Skb credentials */
26#ifdef CONFIG_SECURITY_NETWORK
27 u32 secid; /* Passed security ID */
28#endif
29};
30
31extern void scm_detach_fds(struct msghdr *msg, struct scm_cookie *scm);
32extern void scm_detach_fds_compat(struct msghdr *msg, struct scm_cookie *scm);
33extern int __scm_send(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm);
34extern void __scm_destroy(struct scm_cookie *scm);
35extern struct scm_fp_list * scm_fp_dup(struct scm_fp_list *fpl);
36
37#ifdef CONFIG_SECURITY_NETWORK
38static __inline__ void unix_get_peersec_dgram(struct socket *sock, struct scm_cookie *scm)
39{
40 security_socket_getpeersec_dgram(sock, NULL, &scm->secid);
41}
42#else
43static __inline__ void unix_get_peersec_dgram(struct socket *sock, struct scm_cookie *scm)
44{ }
45#endif /* CONFIG_SECURITY_NETWORK */
46
47static __inline__ void scm_set_cred(struct scm_cookie *scm,
48 struct pid *pid, const struct cred *cred)
49{
50 scm->pid = get_pid(pid);
51 scm->cred = cred ? get_cred(cred) : NULL;
52 cred_to_ucred(pid, cred, &scm->creds);
53}
54
55static __inline__ void scm_destroy_cred(struct scm_cookie *scm)
56{
57 put_pid(scm->pid);
58 scm->pid = NULL;
59
60 if (scm->cred)
61 put_cred(scm->cred);
62 scm->cred = NULL;
63}
64
65static __inline__ void scm_destroy(struct scm_cookie *scm)
66{
67 scm_destroy_cred(scm);
68 if (scm && scm->fp)
69 __scm_destroy(scm);
70}
71
72static __inline__ int scm_send(struct socket *sock, struct msghdr *msg,
73 struct scm_cookie *scm, bool forcecreds)
74{
75 memset(scm, 0, sizeof(*scm));
76 if (forcecreds)
77 scm_set_cred(scm, task_tgid(current), current_cred());
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
85static 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
101static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm)
102{ }
103#endif /* CONFIG_SECURITY_NETWORK */
104
105static __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