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1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef __LINUX_NET_SCM_H
3#define __LINUX_NET_SCM_H
4
5#include <linux/limits.h>
6#include <linux/net.h>
7#include <linux/cred.h>
8#include <linux/security.h>
9#include <linux/pid.h>
10#include <linux/nsproxy.h>
11#include <linux/sched/signal.h>
12
13/* Well, we should have at least one descriptor open
14 * to accept passed FDs 8)
15 */
16#define SCM_MAX_FD 253
17
18struct scm_creds {
19 u32 pid;
20 kuid_t uid;
21 kgid_t gid;
22};
23
24struct scm_fp_list {
25 short count;
26 short max;
27 struct user_struct *user;
28 struct file *fp[SCM_MAX_FD];
29};
30
31struct scm_cookie {
32 struct pid *pid; /* Skb credentials */
33 struct scm_fp_list *fp; /* Passed files */
34 struct scm_creds creds; /* Skb credentials */
35#ifdef CONFIG_SECURITY_NETWORK
36 u32 secid; /* Passed security ID */
37#endif
38};
39
40void scm_detach_fds(struct msghdr *msg, struct scm_cookie *scm);
41void scm_detach_fds_compat(struct msghdr *msg, struct scm_cookie *scm);
42int __scm_send(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm);
43void __scm_destroy(struct scm_cookie *scm);
44struct scm_fp_list *scm_fp_dup(struct scm_fp_list *fpl);
45
46#ifdef CONFIG_SECURITY_NETWORK
47static __inline__ void unix_get_peersec_dgram(struct socket *sock, struct scm_cookie *scm)
48{
49 security_socket_getpeersec_dgram(sock, NULL, &scm->secid);
50}
51#else
52static __inline__ void unix_get_peersec_dgram(struct socket *sock, struct scm_cookie *scm)
53{ }
54#endif /* CONFIG_SECURITY_NETWORK */
55
56static __inline__ void scm_set_cred(struct scm_cookie *scm,
57 struct pid *pid, kuid_t uid, kgid_t gid)
58{
59 scm->pid = get_pid(pid);
60 scm->creds.pid = pid_vnr(pid);
61 scm->creds.uid = uid;
62 scm->creds.gid = gid;
63}
64
65static __inline__ void scm_destroy_cred(struct scm_cookie *scm)
66{
67 put_pid(scm->pid);
68 scm->pid = NULL;
69}
70
71static __inline__ void scm_destroy(struct scm_cookie *scm)
72{
73 scm_destroy_cred(scm);
74 if (scm->fp)
75 __scm_destroy(scm);
76}
77
78static __inline__ int scm_send(struct socket *sock, struct msghdr *msg,
79 struct scm_cookie *scm, bool forcecreds)
80{
81 memset(scm, 0, sizeof(*scm));
82 scm->creds.uid = INVALID_UID;
83 scm->creds.gid = INVALID_GID;
84 if (forcecreds)
85 scm_set_cred(scm, task_tgid(current), current_uid(), current_gid());
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
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 struct scm_fp_list *fp; /* Passed files */
30 struct scm_creds creds; /* Skb credentials */
31#ifdef CONFIG_SECURITY_NETWORK
32 u32 secid; /* Passed security ID */
33#endif
34};
35
36void scm_detach_fds(struct msghdr *msg, struct scm_cookie *scm);
37void scm_detach_fds_compat(struct msghdr *msg, struct scm_cookie *scm);
38int __scm_send(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm);
39void __scm_destroy(struct scm_cookie *scm);
40struct scm_fp_list *scm_fp_dup(struct scm_fp_list *fpl);
41
42#ifdef CONFIG_SECURITY_NETWORK
43static __inline__ void unix_get_peersec_dgram(struct socket *sock, struct scm_cookie *scm)
44{
45 security_socket_getpeersec_dgram(sock, NULL, &scm->secid);
46}
47#else
48static __inline__ void unix_get_peersec_dgram(struct socket *sock, struct scm_cookie *scm)
49{ }
50#endif /* CONFIG_SECURITY_NETWORK */
51
52static __inline__ void scm_set_cred(struct scm_cookie *scm,
53 struct pid *pid, kuid_t uid, kgid_t gid)
54{
55 scm->pid = get_pid(pid);
56 scm->creds.pid = pid_vnr(pid);
57 scm->creds.uid = uid;
58 scm->creds.gid = gid;
59}
60
61static __inline__ void scm_destroy_cred(struct scm_cookie *scm)
62{
63 put_pid(scm->pid);
64 scm->pid = NULL;
65}
66
67static __inline__ void scm_destroy(struct scm_cookie *scm)
68{
69 scm_destroy_cred(scm);
70 if (scm->fp)
71 __scm_destroy(scm);
72}
73
74static __inline__ int scm_send(struct socket *sock, struct msghdr *msg,
75 struct scm_cookie *scm, bool forcecreds)
76{
77 memset(scm, 0, sizeof(*scm));
78 scm->creds.uid = INVALID_UID;
79 scm->creds.gid = INVALID_GID;
80 if (forcecreds)
81 scm_set_cred(scm, task_tgid(current), current_uid(), current_gid());
82 unix_get_peersec_dgram(sock, scm);
83 if (msg->msg_controllen <= 0)
84 return 0;
85 return __scm_send(sock, msg, scm);
86}
87
88#ifdef CONFIG_SECURITY_NETWORK
89static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm)
90{
91 char *secdata;
92 u32 seclen;
93 int err;
94
95 if (test_bit(SOCK_PASSSEC, &sock->flags)) {
96 err = security_secid_to_secctx(scm->secid, &secdata, &seclen);
97
98 if (!err) {
99 put_cmsg(msg, SOL_SOCKET, SCM_SECURITY, seclen, secdata);
100 security_release_secctx(secdata, seclen);
101 }
102 }
103}
104#else
105static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm)
106{ }
107#endif /* CONFIG_SECURITY_NETWORK */
108
109static __inline__ void scm_recv(struct socket *sock, struct msghdr *msg,
110 struct scm_cookie *scm, int flags)
111{
112 if (!msg->msg_control) {
113 if (test_bit(SOCK_PASSCRED, &sock->flags) || scm->fp)
114 msg->msg_flags |= MSG_CTRUNC;
115 scm_destroy(scm);
116 return;
117 }
118
119 if (test_bit(SOCK_PASSCRED, &sock->flags)) {
120 struct user_namespace *current_ns = current_user_ns();
121 struct ucred ucreds = {
122 .pid = scm->creds.pid,
123 .uid = from_kuid_munged(current_ns, scm->creds.uid),
124 .gid = from_kgid_munged(current_ns, scm->creds.gid),
125 };
126 put_cmsg(msg, SOL_SOCKET, SCM_CREDENTIALS, sizeof(ucreds), &ucreds);
127 }
128
129 scm_destroy_cred(scm);
130
131 scm_passec(sock, msg, scm);
132
133 if (!scm->fp)
134 return;
135
136 scm_detach_fds(msg, scm);
137}
138
139
140#endif /* __LINUX_NET_SCM_H */
141