blob: 142ea9e7a6d0d88989c2ca0b23548427def59d87 [file] [log] [blame]
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>
Ingo Molnar5b825c32017-02-02 17:54:15 +01006#include <linux/cred.h>
Catherine Zhangdc49c1f2006-08-02 14:12:06 -07007#include <linux/security.h>
Pavel Emelyanovb4888932007-10-18 23:40:14 -07008#include <linux/pid.h>
9#include <linux/nsproxy.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070010
11/* Well, we should have at least one descriptor open
12 * to accept passed FDs 8)
13 */
Eric Dumazetbba14de2010-11-23 14:09:15 +000014#define SCM_MAX_FD 253
Linus Torvalds1da177e2005-04-16 15:20:36 -070015
Eric W. Biedermandbe9a412012-09-06 18:20:01 +000016struct scm_creds {
17 u32 pid;
18 kuid_t uid;
19 kgid_t gid;
20};
21
Eric Dumazetfd2c3ef2009-11-03 03:26:03 +000022struct scm_fp_list {
Eric Dumazetbba14de2010-11-23 14:09:15 +000023 short count;
24 short max;
Hannes Frederic Sowa415e3d32016-02-03 02:11:03 +010025 struct user_struct *user;
David Millerf8d570a2008-11-06 00:37:40 -080026 struct file *fp[SCM_MAX_FD];
Linus Torvalds1da177e2005-04-16 15:20:36 -070027};
28
Eric Dumazetfd2c3ef2009-11-03 03:26:03 +000029struct scm_cookie {
Eric W. Biederman257b5352010-06-13 03:32:34 +000030 struct pid *pid; /* Skb credentials */
Linus Torvalds1da177e2005-04-16 15:20:36 -070031 struct scm_fp_list *fp; /* Passed files */
Eric W. Biedermandbe9a412012-09-06 18:20:01 +000032 struct scm_creds creds; /* Skb credentials */
Catherine Zhang877ce7c2006-06-29 12:27:47 -070033#ifdef CONFIG_SECURITY_NETWORK
Catherine Zhangdc49c1f2006-08-02 14:12:06 -070034 u32 secid; /* Passed security ID */
Catherine Zhang877ce7c2006-06-29 12:27:47 -070035#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -070036};
37
Joe Perches8153ff52013-09-22 10:32:24 -070038void 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);
Linus Torvalds1da177e2005-04-16 15:20:36 -070043
Catherine Zhangdc49c1f2006-08-02 14:12:06 -070044#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
Eric W. Biederman257b5352010-06-13 03:32:34 +000054static __inline__ void scm_set_cred(struct scm_cookie *scm,
Eric W. Biederman6b0ee8c02013-04-03 17:28:16 +000055 struct pid *pid, kuid_t uid, kgid_t gid)
Eric W. Biederman257b5352010-06-13 03:32:34 +000056{
57 scm->pid = get_pid(pid);
Eric W. Biedermandbe9a412012-09-06 18:20:01 +000058 scm->creds.pid = pid_vnr(pid);
Eric W. Biederman6b0ee8c02013-04-03 17:28:16 +000059 scm->creds.uid = uid;
60 scm->creds.gid = 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;
Eric W. Biederman257b5352010-06-13 03:32:34 +000067}
68
Linus Torvalds1da177e2005-04-16 15:20:36 -070069static __inline__ void scm_destroy(struct scm_cookie *scm)
70{
Eric W. Biederman257b5352010-06-13 03:32:34 +000071 scm_destroy_cred(scm);
David S. Miller2a6c8c72012-09-24 15:52:33 -040072 if (scm->fp)
Linus Torvalds1da177e2005-04-16 15:20:36 -070073 __scm_destroy(scm);
74}
75
76static __inline__ int scm_send(struct socket *sock, struct msghdr *msg,
Eric Dumazete0e3cea2012-08-21 06:21:17 +000077 struct scm_cookie *scm, bool forcecreds)
Linus Torvalds1da177e2005-04-16 15:20:36 -070078{
Eric Dumazet16e57262011-09-19 05:52:27 +000079 memset(scm, 0, sizeof(*scm));
Eric W. Biederman6b0ee8c02013-04-03 17:28:16 +000080 scm->creds.uid = INVALID_UID;
81 scm->creds.gid = INVALID_GID;
Eric Dumazete0e3cea2012-08-21 06:21:17 +000082 if (forcecreds)
David S. Miller6e0895c2013-04-22 20:32:51 -040083 scm_set_cred(scm, task_tgid(current), current_uid(), current_gid());
Catherine Zhangdc49c1f2006-08-02 14:12:06 -070084 unix_get_peersec_dgram(sock, scm);
Linus Torvalds1da177e2005-04-16 15:20:36 -070085 if (msg->msg_controllen <= 0)
86 return 0;
87 return __scm_send(sock, msg, scm);
88}
89
Catherine Zhang877ce7c2006-06-29 12:27:47 -070090#ifdef CONFIG_SECURITY_NETWORK
91static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm)
92{
Catherine Zhangdc49c1f2006-08-02 14:12:06 -070093 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 }
Catherine Zhang877ce7c2006-06-29 12:27:47 -0700105}
106#else
107static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm)
108{ }
109#endif /* CONFIG_SECURITY_NETWORK */
110
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111static __inline__ void scm_recv(struct socket *sock, struct msghdr *msg,
112 struct scm_cookie *scm, int flags)
113{
Eric Dumazetfd2c3ef2009-11-03 03:26:03 +0000114 if (!msg->msg_control) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700115 if (test_bit(SOCK_PASSCRED, &sock->flags) || scm->fp)
116 msg->msg_flags |= MSG_CTRUNC;
David S. Millerf78a5fd2011-09-16 19:34:00 -0400117 scm_destroy(scm);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118 return;
119 }
120
Eric W. Biedermandbe9a412012-09-06 18:20:01 +0000121 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 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130
David S. Millerf78a5fd2011-09-16 19:34:00 -0400131 scm_destroy_cred(scm);
132
Catherine Zhang877ce7c2006-06-29 12:27:47 -0700133 scm_passec(sock, msg, scm);
134
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135 if (!scm->fp)
136 return;
137
138 scm_detach_fds(msg, scm);
139}
140
141
142#endif /* __LINUX_NET_SCM_H */
143