Loading...
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 user_struct *user;
25 struct file *fp[SCM_MAX_FD];
26};
27
28struct scm_cookie {
29 struct pid *pid; /* Skb credentials */
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
37void scm_detach_fds(struct msghdr *msg, struct scm_cookie *scm);
38void scm_detach_fds_compat(struct msghdr *msg, struct scm_cookie *scm);
39int __scm_send(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm);
40void __scm_destroy(struct scm_cookie *scm);
41struct 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, kuid_t uid, kgid_t gid)
55{
56 scm->pid = get_pid(pid);
57 scm->creds.pid = pid_vnr(pid);
58 scm->creds.uid = uid;
59 scm->creds.gid = gid;
60}
61
62static __inline__ void scm_destroy_cred(struct scm_cookie *scm)
63{
64 put_pid(scm->pid);
65 scm->pid = NULL;
66}
67
68static __inline__ void scm_destroy(struct scm_cookie *scm)
69{
70 scm_destroy_cred(scm);
71 if (scm->fp)
72 __scm_destroy(scm);
73}
74
75static __inline__ int scm_send(struct socket *sock, struct msghdr *msg,
76 struct scm_cookie *scm, bool forcecreds)
77{
78 memset(scm, 0, sizeof(*scm));
79 scm->creds.uid = INVALID_UID;
80 scm->creds.gid = INVALID_GID;
81 if (forcecreds)
82 scm_set_cred(scm, task_tgid(current), current_uid(), current_gid());
83 unix_get_peersec_dgram(sock, scm);
84 if (msg->msg_controllen <= 0)
85 return 0;
86 return __scm_send(sock, msg, scm);
87}
88
89#ifdef CONFIG_SECURITY_NETWORK
90static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm)
91{
92 char *secdata;
93 u32 seclen;
94 int err;
95
96 if (test_bit(SOCK_PASSSEC, &sock->flags)) {
97 err = security_secid_to_secctx(scm->secid, &secdata, &seclen);
98
99 if (!err) {
100 put_cmsg(msg, SOL_SOCKET, SCM_SECURITY, seclen, secdata);
101 security_release_secctx(secdata, seclen);
102 }
103 }
104}
105#else
106static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm)
107{ }
108#endif /* CONFIG_SECURITY_NETWORK */
109
110static __inline__ void scm_recv(struct socket *sock, struct msghdr *msg,
111 struct scm_cookie *scm, int flags)
112{
113 if (!msg->msg_control) {
114 if (test_bit(SOCK_PASSCRED, &sock->flags) || scm->fp)
115 msg->msg_flags |= MSG_CTRUNC;
116 scm_destroy(scm);
117 return;
118 }
119
120 if (test_bit(SOCK_PASSCRED, &sock->flags)) {
121 struct user_namespace *current_ns = current_user_ns();
122 struct ucred ucreds = {
123 .pid = scm->creds.pid,
124 .uid = from_kuid_munged(current_ns, scm->creds.uid),
125 .gid = from_kgid_munged(current_ns, scm->creds.gid),
126 };
127 put_cmsg(msg, SOL_SOCKET, SCM_CREDENTIALS, sizeof(ucreds), &ucreds);
128 }
129
130 scm_destroy_cred(scm);
131
132 scm_passec(sock, msg, scm);
133
134 if (!scm->fp)
135 return;
136
137 scm_detach_fds(msg, scm);
138}
139
140
141#endif /* __LINUX_NET_SCM_H */
142