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Linus Torvalds1da177e2005-04-16 15:20:36 -07001#ifndef __LINUX_NET_SCM_H
2#define __LINUX_NET_SCM_H
3
4#include <linux/limits.h>
5#include <linux/net.h>
Catherine Zhangdc49c1f2006-08-02 14:12:06 -07006#include <linux/security.h>
Pavel Emelyanovb4888932007-10-18 23:40:14 -07007#include <linux/pid.h>
8#include <linux/nsproxy.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -07009
10/* Well, we should have at least one descriptor open
11 * to accept passed FDs 8)
12 */
Eric Dumazetbba14de2010-11-23 14:09:15 +000013#define SCM_MAX_FD 253
Linus Torvalds1da177e2005-04-16 15:20:36 -070014
Eric W. Biedermandbe9a412012-09-06 18:20:01 +000015struct scm_creds {
16 u32 pid;
17 kuid_t uid;
18 kgid_t gid;
19};
20
Eric Dumazetfd2c3ef2009-11-03 03:26:03 +000021struct scm_fp_list {
Eric Dumazetbba14de2010-11-23 14:09:15 +000022 short count;
23 short max;
David Millerf8d570a2008-11-06 00:37:40 -080024 struct file *fp[SCM_MAX_FD];
Linus Torvalds1da177e2005-04-16 15:20:36 -070025};
26
Eric Dumazetfd2c3ef2009-11-03 03:26:03 +000027struct scm_cookie {
Eric W. Biederman257b5352010-06-13 03:32:34 +000028 struct pid *pid; /* Skb credentials */
29 const struct cred *cred;
Linus Torvalds1da177e2005-04-16 15:20:36 -070030 struct scm_fp_list *fp; /* Passed files */
Eric W. Biedermandbe9a412012-09-06 18:20:01 +000031 struct scm_creds creds; /* Skb credentials */
Catherine Zhang877ce7c2006-06-29 12:27:47 -070032#ifdef CONFIG_SECURITY_NETWORK
Catherine Zhangdc49c1f2006-08-02 14:12:06 -070033 u32 secid; /* Passed security ID */
Catherine Zhang877ce7c2006-06-29 12:27:47 -070034#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -070035};
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
Catherine Zhangdc49c1f2006-08-02 14:12:06 -070043#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
Eric W. Biederman257b5352010-06-13 03:32:34 +000053static __inline__ void scm_set_cred(struct scm_cookie *scm,
54 struct pid *pid, const struct cred *cred)
55{
56 scm->pid = get_pid(pid);
Eric Dumazet16e57262011-09-19 05:52:27 +000057 scm->cred = cred ? get_cred(cred) : NULL;
Eric W. Biedermandbe9a412012-09-06 18:20:01 +000058 scm->creds.pid = pid_vnr(pid);
59 scm->creds.uid = cred ? cred->euid : INVALID_UID;
60 scm->creds.gid = cred ? cred->egid : INVALID_GID;
Eric W. Biederman257b5352010-06-13 03:32:34 +000061}
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
Linus Torvalds1da177e2005-04-16 15:20:36 -070073static __inline__ void scm_destroy(struct scm_cookie *scm)
74{
Eric W. Biederman257b5352010-06-13 03:32:34 +000075 scm_destroy_cred(scm);
David S. Miller2a6c8c72012-09-24 15:52:33 -040076 if (scm->fp)
Linus Torvalds1da177e2005-04-16 15:20:36 -070077 __scm_destroy(scm);
78}
79
80static __inline__ int scm_send(struct socket *sock, struct msghdr *msg,
Eric Dumazete0e3cea2012-08-21 06:21:17 +000081 struct scm_cookie *scm, bool forcecreds)
Linus Torvalds1da177e2005-04-16 15:20:36 -070082{
Eric Dumazet16e57262011-09-19 05:52:27 +000083 memset(scm, 0, sizeof(*scm));
Eric Dumazete0e3cea2012-08-21 06:21:17 +000084 if (forcecreds)
85 scm_set_cred(scm, task_tgid(current), current_cred());
Catherine Zhangdc49c1f2006-08-02 14:12:06 -070086 unix_get_peersec_dgram(sock, scm);
Linus Torvalds1da177e2005-04-16 15:20:36 -070087 if (msg->msg_controllen <= 0)
88 return 0;
89 return __scm_send(sock, msg, scm);
90}
91
Catherine Zhang877ce7c2006-06-29 12:27:47 -070092#ifdef CONFIG_SECURITY_NETWORK
93static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm)
94{
Catherine Zhangdc49c1f2006-08-02 14:12:06 -070095 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 }
Catherine Zhang877ce7c2006-06-29 12:27:47 -0700107}
108#else
109static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm)
110{ }
111#endif /* CONFIG_SECURITY_NETWORK */
112
Linus Torvalds1da177e2005-04-16 15:20:36 -0700113static __inline__ void scm_recv(struct socket *sock, struct msghdr *msg,
114 struct scm_cookie *scm, int flags)
115{
Eric Dumazetfd2c3ef2009-11-03 03:26:03 +0000116 if (!msg->msg_control) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700117 if (test_bit(SOCK_PASSCRED, &sock->flags) || scm->fp)
118 msg->msg_flags |= MSG_CTRUNC;
David S. Millerf78a5fd2011-09-16 19:34:00 -0400119 scm_destroy(scm);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120 return;
121 }
122
Eric W. Biedermandbe9a412012-09-06 18:20:01 +0000123 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 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132
David S. Millerf78a5fd2011-09-16 19:34:00 -0400133 scm_destroy_cred(scm);
134
Catherine Zhang877ce7c2006-06-29 12:27:47 -0700135 scm_passec(sock, msg, scm);
136
Linus Torvalds1da177e2005-04-16 15:20:36 -0700137 if (!scm->fp)
138 return;
139
140 scm_detach_fds(msg, scm);
141}
142
143
144#endif /* __LINUX_NET_SCM_H */
145