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/file.h> 9 #include <linux/security.h> 10 #include <linux/pid.h> 11 #include <linux/nsproxy.h> 12 #include <linux/sched/signal.h> 13 #include <net/compat.h> 14 15 /* Well, we should have at least one descriptor open 16 * to accept passed FDs 8) 17 */ 18 #define SCM_MAX_FD 253 19 20 struct scm_creds { 21 u32 pid; 22 kuid_t uid; 23 kgid_t gid; 24 }; 25 26 #ifdef CONFIG_UNIX 27 struct unix_edge; 28 #endif 29 30 struct scm_fp_list { 31 short count; 32 short count_unix; 33 short max; 34 #ifdef CONFIG_UNIX 35 bool inflight; 36 bool dead; 37 struct list_head vertices; 38 struct unix_edge *edges; 39 #endif 40 struct user_struct *user; 41 struct file *fp[SCM_MAX_FD]; 42 }; 43 44 struct scm_cookie { 45 struct pid *pid; /* Skb credentials */ 46 struct scm_fp_list *fp; /* Passed files */ 47 struct scm_creds creds; /* Skb credentials */ 48 #ifdef CONFIG_SECURITY_NETWORK 49 u32 secid; /* Passed security ID */ 50 #endif 51 }; 52 53 void scm_detach_fds(struct msghdr *msg, struct scm_cookie *scm); 54 void scm_detach_fds_compat(struct msghdr *msg, struct scm_cookie *scm); 55 int __scm_send(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm); 56 void __scm_destroy(struct scm_cookie *scm); 57 struct scm_fp_list *scm_fp_dup(struct scm_fp_list *fpl); 58 59 #ifdef CONFIG_SECURITY_NETWORK 60 static __inline__ void unix_get_peersec_dgram(struct socket *sock, struct scm_cookie *scm) 61 { 62 security_socket_getpeersec_dgram(sock, NULL, &scm->secid); 63 } 64 #else 65 static __inline__ void unix_get_peersec_dgram(struct socket *sock, struct scm_cookie *scm) 66 { } 67 #endif /* CONFIG_SECURITY_NETWORK */ 68 69 static __inline__ void scm_set_cred(struct scm_cookie *scm, 70 struct pid *pid, kuid_t uid, kgid_t gid) 71 { 72 scm->pid = get_pid(pid); 73 scm->creds.pid = pid_vnr(pid); 74 scm->creds.uid = uid; 75 scm->creds.gid = gid; 76 } 77 78 static __inline__ void scm_destroy_cred(struct scm_cookie *scm) 79 { 80 put_pid(scm->pid); 81 scm->pid = NULL; 82 } 83 84 static __inline__ void scm_destroy(struct scm_cookie *scm) 85 { 86 scm_destroy_cred(scm); 87 if (scm->fp) 88 __scm_destroy(scm); 89 } 90 91 static __inline__ int scm_send(struct socket *sock, struct msghdr *msg, 92 struct scm_cookie *scm, bool forcecreds) 93 { 94 memset(scm, 0, sizeof(*scm)); 95 scm->creds.uid = INVALID_UID; 96 scm->creds.gid = INVALID_GID; 97 if (forcecreds) 98 scm_set_cred(scm, task_tgid(current), current_uid(), current_gid()); 99 unix_get_peersec_dgram(sock, scm); 100 if (msg->msg_controllen <= 0) 101 return 0; 102 return __scm_send(sock, msg, scm); 103 } 104 105 void scm_recv(struct socket *sock, struct msghdr *msg, 106 struct scm_cookie *scm, int flags); 107 void scm_recv_unix(struct socket *sock, struct msghdr *msg, 108 struct scm_cookie *scm, int flags); 109 110 static inline int scm_recv_one_fd(struct file *f, int __user *ufd, 111 unsigned int flags) 112 { 113 if (!ufd) 114 return -EFAULT; 115 return receive_fd(f, ufd, flags); 116 } 117 118 #endif /* __LINUX_NET_SCM_H */ 119 120