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8#include <linux/module.h>
9#include <linux/signal.h>
10#include <linux/capability.h>
11#include <linux/errno.h>
12#include <linux/sched.h>
13#include <linux/sched/user.h>
14#include <linux/mm.h>
15#include <linux/kernel.h>
16#include <linux/stat.h>
17#include <linux/socket.h>
18#include <linux/file.h>
19#include <linux/fcntl.h>
20#include <linux/net.h>
21#include <linux/interrupt.h>
22#include <linux/netdevice.h>
23#include <linux/security.h>
24#include <linux/pid_namespace.h>
25#include <linux/pid.h>
26#include <linux/nsproxy.h>
27#include <linux/slab.h>
28#include <linux/errqueue.h>
29
30#include <linux/uaccess.h>
31
32#include <net/protocol.h>
33#include <linux/skbuff.h>
34#include <net/sock.h>
35#include <net/compat.h>
36#include <net/scm.h>
37#include <net/cls_cgroup.h>
38
39
40
41
42
43
44
45static __inline__ int scm_check_creds(struct ucred *creds)
46{
47 const struct cred *cred = current_cred();
48 kuid_t uid = make_kuid(cred->user_ns, creds->uid);
49 kgid_t gid = make_kgid(cred->user_ns, creds->gid);
50
51 if (!uid_valid(uid) || !gid_valid(gid))
52 return -EINVAL;
53
54 if ((creds->pid == task_tgid_vnr(current) ||
55 ns_capable(task_active_pid_ns(current)->user_ns, CAP_SYS_ADMIN)) &&
56 ((uid_eq(uid, cred->uid) || uid_eq(uid, cred->euid) ||
57 uid_eq(uid, cred->suid)) || ns_capable(cred->user_ns, CAP_SETUID)) &&
58 ((gid_eq(gid, cred->gid) || gid_eq(gid, cred->egid) ||
59 gid_eq(gid, cred->sgid)) || ns_capable(cred->user_ns, CAP_SETGID))) {
60 return 0;
61 }
62 return -EPERM;
63}
64
65static int scm_fp_copy(struct cmsghdr *cmsg, struct scm_fp_list **fplp)
66{
67 int *fdp = (int*)CMSG_DATA(cmsg);
68 struct scm_fp_list *fpl = *fplp;
69 struct file **fpp;
70 int i, num;
71
72 num = (cmsg->cmsg_len - sizeof(struct cmsghdr))/sizeof(int);
73
74 if (num <= 0)
75 return 0;
76
77 if (num > SCM_MAX_FD)
78 return -EINVAL;
79
80 if (!fpl)
81 {
82 fpl = kmalloc(sizeof(struct scm_fp_list), GFP_KERNEL);
83 if (!fpl)
84 return -ENOMEM;
85 *fplp = fpl;
86 fpl->count = 0;
87 fpl->max = SCM_MAX_FD;
88 fpl->user = NULL;
89 }
90 fpp = &fpl->fp[fpl->count];
91
92 if (fpl->count + num > fpl->max)
93 return -EINVAL;
94
95
96
97
98
99 for (i=0; i< num; i++)
100 {
101 int fd = fdp[i];
102 struct file *file;
103
104 if (fd < 0 || !(file = fget_raw(fd)))
105 return -EBADF;
106 *fpp++ = file;
107 fpl->count++;
108 }
109
110 if (!fpl->user)
111 fpl->user = get_uid(current_user());
112
113 return num;
114}
115
116void __scm_destroy(struct scm_cookie *scm)
117{
118 struct scm_fp_list *fpl = scm->fp;
119 int i;
120
121 if (fpl) {
122 scm->fp = NULL;
123 for (i=fpl->count-1; i>=0; i--)
124 fput(fpl->fp[i]);
125 free_uid(fpl->user);
126 kfree(fpl);
127 }
128}
129EXPORT_SYMBOL(__scm_destroy);
130
131int __scm_send(struct socket *sock, struct msghdr *msg, struct scm_cookie *p)
132{
133 struct cmsghdr *cmsg;
134 int err;
135
136 for_each_cmsghdr(cmsg, msg) {
137 err = -EINVAL;
138
139
140
141
142
143
144
145
146
147 if (!CMSG_OK(msg, cmsg))
148 goto error;
149
150 if (cmsg->cmsg_level != SOL_SOCKET)
151 continue;
152
153 switch (cmsg->cmsg_type)
154 {
155 case SCM_RIGHTS:
156 if (!sock->ops || sock->ops->family != PF_UNIX)
157 goto error;
158 err=scm_fp_copy(cmsg, &p->fp);
159 if (err<0)
160 goto error;
161 break;
162 case SCM_CREDENTIALS:
163 {
164 struct ucred creds;
165 kuid_t uid;
166 kgid_t gid;
167 if (cmsg->cmsg_len != CMSG_LEN(sizeof(struct ucred)))
168 goto error;
169 memcpy(&creds, CMSG_DATA(cmsg), sizeof(struct ucred));
170 err = scm_check_creds(&creds);
171 if (err)
172 goto error;
173
174 p->creds.pid = creds.pid;
175 if (!p->pid || pid_vnr(p->pid) != creds.pid) {
176 struct pid *pid;
177 err = -ESRCH;
178 pid = find_get_pid(creds.pid);
179 if (!pid)
180 goto error;
181 put_pid(p->pid);
182 p->pid = pid;
183 }
184
185 err = -EINVAL;
186 uid = make_kuid(current_user_ns(), creds.uid);
187 gid = make_kgid(current_user_ns(), creds.gid);
188 if (!uid_valid(uid) || !gid_valid(gid))
189 goto error;
190
191 p->creds.uid = uid;
192 p->creds.gid = gid;
193 break;
194 }
195 default:
196 goto error;
197 }
198 }
199
200 if (p->fp && !p->fp->count)
201 {
202 kfree(p->fp);
203 p->fp = NULL;
204 }
205 return 0;
206
207error:
208 scm_destroy(p);
209 return err;
210}
211EXPORT_SYMBOL(__scm_send);
212
213int put_cmsg(struct msghdr * msg, int level, int type, int len, void *data)
214{
215 struct cmsghdr __user *cm
216 = (__force struct cmsghdr __user *)msg->msg_control;
217 struct cmsghdr cmhdr;
218 int cmlen = CMSG_LEN(len);
219 int err;
220
221 if (MSG_CMSG_COMPAT & msg->msg_flags)
222 return put_cmsg_compat(msg, level, type, len, data);
223
224 if (cm==NULL || msg->msg_controllen < sizeof(*cm)) {
225 msg->msg_flags |= MSG_CTRUNC;
226 return 0;
227 }
228 if (msg->msg_controllen < cmlen) {
229 msg->msg_flags |= MSG_CTRUNC;
230 cmlen = msg->msg_controllen;
231 }
232 cmhdr.cmsg_level = level;
233 cmhdr.cmsg_type = type;
234 cmhdr.cmsg_len = cmlen;
235
236 err = -EFAULT;
237 if (copy_to_user(cm, &cmhdr, sizeof cmhdr))
238 goto out;
239 if (copy_to_user(CMSG_DATA(cm), data, cmlen - sizeof(struct cmsghdr)))
240 goto out;
241 cmlen = CMSG_SPACE(len);
242 if (msg->msg_controllen < cmlen)
243 cmlen = msg->msg_controllen;
244 msg->msg_control += cmlen;
245 msg->msg_controllen -= cmlen;
246 err = 0;
247out:
248 return err;
249}
250EXPORT_SYMBOL(put_cmsg);
251
252void put_cmsg_scm_timestamping64(struct msghdr *msg, struct scm_timestamping_internal *tss_internal)
253{
254 struct scm_timestamping64 tss;
255 int i;
256
257 for (i = 0; i < ARRAY_SIZE(tss.ts); i++) {
258 tss.ts[i].tv_sec = tss_internal->ts[i].tv_sec;
259 tss.ts[i].tv_nsec = tss_internal->ts[i].tv_nsec;
260 }
261
262 put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMPING_NEW, sizeof(tss), &tss);
263}
264EXPORT_SYMBOL(put_cmsg_scm_timestamping64);
265
266void put_cmsg_scm_timestamping(struct msghdr *msg, struct scm_timestamping_internal *tss_internal)
267{
268 struct scm_timestamping tss;
269 int i;
270
271 for (i = 0; i < ARRAY_SIZE(tss.ts); i++)
272 tss.ts[i] = timespec64_to_timespec(tss_internal->ts[i]);
273
274 put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMPING_OLD, sizeof(tss), &tss);
275}
276EXPORT_SYMBOL(put_cmsg_scm_timestamping);
277
278void scm_detach_fds(struct msghdr *msg, struct scm_cookie *scm)
279{
280 struct cmsghdr __user *cm
281 = (__force struct cmsghdr __user*)msg->msg_control;
282
283 int fdmax = 0;
284 int fdnum = scm->fp->count;
285 struct file **fp = scm->fp->fp;
286 int __user *cmfptr;
287 int err = 0, i;
288
289 if (MSG_CMSG_COMPAT & msg->msg_flags) {
290 scm_detach_fds_compat(msg, scm);
291 return;
292 }
293
294 if (msg->msg_controllen > sizeof(struct cmsghdr))
295 fdmax = ((msg->msg_controllen - sizeof(struct cmsghdr))
296 / sizeof(int));
297
298 if (fdnum < fdmax)
299 fdmax = fdnum;
300
301 for (i=0, cmfptr=(__force int __user *)CMSG_DATA(cm); i<fdmax;
302 i++, cmfptr++)
303 {
304 struct socket *sock;
305 int new_fd;
306 err = security_file_receive(fp[i]);
307 if (err)
308 break;
309 err = get_unused_fd_flags(MSG_CMSG_CLOEXEC & msg->msg_flags
310 ? O_CLOEXEC : 0);
311 if (err < 0)
312 break;
313 new_fd = err;
314 err = put_user(new_fd, cmfptr);
315 if (err) {
316 put_unused_fd(new_fd);
317 break;
318 }
319
320 sock = sock_from_file(fp[i], &err);
321 if (sock) {
322 sock_update_netprioidx(&sock->sk->sk_cgrp_data);
323 sock_update_classid(&sock->sk->sk_cgrp_data);
324 }
325 fd_install(new_fd, get_file(fp[i]));
326 }
327
328 if (i > 0)
329 {
330 int cmlen = CMSG_LEN(i*sizeof(int));
331 err = put_user(SOL_SOCKET, &cm->cmsg_level);
332 if (!err)
333 err = put_user(SCM_RIGHTS, &cm->cmsg_type);
334 if (!err)
335 err = put_user(cmlen, &cm->cmsg_len);
336 if (!err) {
337 cmlen = CMSG_SPACE(i*sizeof(int));
338 if (msg->msg_controllen < cmlen)
339 cmlen = msg->msg_controllen;
340 msg->msg_control += cmlen;
341 msg->msg_controllen -= cmlen;
342 }
343 }
344 if (i < fdnum || (fdnum && fdmax <= 0))
345 msg->msg_flags |= MSG_CTRUNC;
346
347
348
349
350
351 __scm_destroy(scm);
352}
353EXPORT_SYMBOL(scm_detach_fds);
354
355struct scm_fp_list *scm_fp_dup(struct scm_fp_list *fpl)
356{
357 struct scm_fp_list *new_fpl;
358 int i;
359
360 if (!fpl)
361 return NULL;
362
363 new_fpl = kmemdup(fpl, offsetof(struct scm_fp_list, fp[fpl->count]),
364 GFP_KERNEL);
365 if (new_fpl) {
366 for (i = 0; i < fpl->count; i++)
367 get_file(fpl->fp[i]);
368 new_fpl->max = new_fpl->count;
369 new_fpl->user = get_uid(fpl->user);
370 }
371 return new_fpl;
372}
373EXPORT_SYMBOL(scm_fp_dup);
374
