1#include <unistd.h>
2#include <sys/types.h>
3#include <fcntl.h>
4#include <stdlib.h>
5#include <stdio.h>
6#include <errno.h>
7#include <string.h>
8#include <limits.h>
9#include <ctype.h>
10#include "selinux_internal.h"
11#include "policy.h"
12#include "mapping.h"
13
14static int object_name_encode(const char *objname, char *buffer, size_t buflen)
15{
16	int	code;
17	size_t	offset = 0;
18
19	if (buflen - offset < 1)
20		return -1;
21	buffer[offset++] = ' ';
22
23	do {
24		code = *objname++;
25
26		if (isalnum(code) || code == '\0' || code == '-' ||
27		    code == '.' || code == '_' || code == '~') {
28			if (buflen - offset < 1)
29				return -1;
30			buffer[offset++] = code;
31		} else if (code == ' ') {
32			if (buflen - offset < 1)
33				return -1;
34			buffer[offset++] = '+';
35		} else {
36			static const char *table = "0123456789ABCDEF";
37			int	l = (code & 0x0f);
38			int	h = (code & 0xf0) >> 4;
39
40			if (buflen - offset < 3)
41				return -1;
42			buffer[offset++] = '%';
43			buffer[offset++] = table[h];
44			buffer[offset++] = table[l];
45		}
46	} while (code != '\0');
47
48	return 0;
49}
50
51int security_compute_create_name_raw(const char * scon,
52				     const char * tcon,
53				     security_class_t tclass,
54				     const char *objname,
55				     char ** newcon)
56{
57	char path[PATH_MAX];
58	char *buf;
59	size_t size;
60	int fd, ret, len;
61
62	if (!selinux_mnt) {
63		errno = ENOENT;
64		return -1;
65	}
66
67	snprintf(path, sizeof path, "%s/create", selinux_mnt);
68	fd = open(path, O_RDWR);
69	if (fd < 0)
70		return -1;
71
72	size = selinux_page_size;
73	buf = malloc(size);
74	if (!buf) {
75		ret = -1;
76		goto out;
77	}
78	len = snprintf(buf, size, "%s %s %hu",
79		       scon, tcon, unmap_class(tclass));
80	if (objname &&
81	    object_name_encode(objname, buf + len, size - len) < 0) {
82		errno = ENAMETOOLONG;
83		ret = -1;
84		goto out2;
85	}
86
87	ret = write(fd, buf, strlen(buf));
88	if (ret < 0)
89		goto out2;
90
91	memset(buf, 0, size);
92	ret = read(fd, buf, size - 1);
93	if (ret < 0)
94		goto out2;
95
96	*newcon = strdup(buf);
97	if (!(*newcon)) {
98		ret = -1;
99		goto out2;
100	}
101	ret = 0;
102      out2:
103	free(buf);
104      out:
105	close(fd);
106	return ret;
107}
108hidden_def(security_compute_create_name_raw)
109
110int security_compute_create_raw(const char * scon,
111				const char * tcon,
112				security_class_t tclass,
113				char ** newcon)
114{
115	return security_compute_create_name_raw(scon, tcon, tclass,
116						NULL, newcon);
117}
118hidden_def(security_compute_create_raw)
119
120int security_compute_create_name(const char * scon,
121				 const char * tcon,
122				 security_class_t tclass,
123				 const char *objname,
124				 char ** newcon)
125{
126	int ret;
127	char * rscon;
128	char * rtcon;
129	char * rnewcon;
130
131	if (selinux_trans_to_raw_context(scon, &rscon))
132		return -1;
133	if (selinux_trans_to_raw_context(tcon, &rtcon)) {
134		freecon(rscon);
135		return -1;
136	}
137
138	ret = security_compute_create_name_raw(rscon, rtcon, tclass,
139					       objname, &rnewcon);
140	freecon(rscon);
141	freecon(rtcon);
142	if (!ret) {
143		ret = selinux_raw_to_trans_context(rnewcon, newcon);
144		freecon(rnewcon);
145	}
146
147	return ret;
148}
149hidden_def(security_compute_create_name)
150
151int security_compute_create(const char * scon,
152				const char * tcon,
153			    security_class_t tclass,
154				char ** newcon)
155{
156	return security_compute_create_name(scon, tcon, tclass, NULL, newcon);
157}
158hidden_def(security_compute_create)
159