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ddeb4241 LP |
1 | /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ |
2 | ||
3 | /*** | |
4 | This file is part of systemd. | |
5 | ||
6 | Copyright 2013 Lennart Poettering | |
7 | ||
8 | systemd is free software; you can redistribute it and/or modify it | |
9 | under the terms of the GNU Lesser General Public License as published by | |
10 | the Free Software Foundation; either version 2.1 of the License, or | |
11 | (at your option) any later version. | |
12 | ||
13 | systemd is distributed in the hope that it will be useful, but | |
14 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
16 | Lesser General Public License for more details. | |
17 | ||
18 | You should have received a copy of the GNU Lesser General Public License | |
19 | along with systemd; If not, see <http://www.gnu.org/licenses/>. | |
20 | ***/ | |
21 | ||
22 | #include <stdio.h> | |
23 | #include <fcntl.h> | |
24 | #include <sys/ioctl.h> | |
25 | #include <sys/mman.h> | |
26 | ||
27 | #include "util.h" | |
28 | #include "kdbus.h" | |
29 | ||
30 | #include "sd-memfd.h" | |
31 | ||
32 | struct sd_memfd { | |
33 | int fd; | |
34 | FILE *f; | |
35 | }; | |
36 | ||
d9f644e2 | 37 | _public_ int sd_memfd_new(sd_memfd **m) { |
135a4eb4 KS |
38 | struct kdbus_cmd_memfd_make cmd = { |
39 | .size = sizeof(struct kdbus_cmd_memfd_make), | |
40 | }; | |
ddeb4241 LP |
41 | _cleanup_close_ int kdbus = -1; |
42 | sd_memfd *n; | |
ddeb4241 | 43 | |
53ab52ac | 44 | assert_return(m, -EINVAL); |
ddeb4241 LP |
45 | |
46 | kdbus = open("/dev/kdbus/control", O_RDWR|O_NOCTTY|O_CLOEXEC); | |
0d1b9a96 | 47 | if (kdbus < 0) |
ddeb4241 LP |
48 | return -errno; |
49 | ||
135a4eb4 | 50 | if (ioctl(kdbus, KDBUS_CMD_MEMFD_NEW, &cmd) < 0) |
ddeb4241 LP |
51 | return -errno; |
52 | ||
53 | n = new0(struct sd_memfd, 1); | |
135a4eb4 KS |
54 | if (!n) { |
55 | close_nointr_nofail(cmd.fd); | |
ddeb4241 | 56 | return -ENOMEM; |
135a4eb4 | 57 | } |
ddeb4241 | 58 | |
135a4eb4 | 59 | n->fd = cmd.fd; |
ddeb4241 LP |
60 | *m = n; |
61 | return 0; | |
62 | } | |
63 | ||
d9f644e2 | 64 | _public_ int sd_memfd_make(int fd, sd_memfd **m) { |
ddeb4241 LP |
65 | sd_memfd *n; |
66 | uint64_t sz; | |
67 | ||
53ab52ac TA |
68 | assert_return(m, -EINVAL); |
69 | assert_return(fd >= 0, -EINVAL); | |
ddeb4241 LP |
70 | |
71 | /* Check if this is a valid memfd */ | |
72 | if (ioctl(fd, KDBUS_CMD_MEMFD_SIZE_GET, &sz) < 0) | |
73 | return -ENOTTY; | |
74 | ||
75 | n = new0(struct sd_memfd, 1); | |
76 | if (!n) | |
77 | return -ENOMEM; | |
78 | ||
79 | n->fd = fd; | |
80 | *m = n; | |
81 | ||
82 | return 0; | |
83 | } | |
84 | ||
d9f644e2 | 85 | _public_ void sd_memfd_free(sd_memfd *m) { |
ddeb4241 LP |
86 | if (!m) |
87 | return; | |
88 | ||
89 | if (m->f) | |
90 | fclose(m->f); | |
91 | else | |
92 | close_nointr_nofail(m->fd); | |
93 | ||
94 | free(m); | |
95 | } | |
96 | ||
d9f644e2 | 97 | _public_ int sd_memfd_get_fd(sd_memfd *m) { |
53ab52ac | 98 | assert_return(m, -EINVAL); |
ddeb4241 LP |
99 | |
100 | return m->fd; | |
101 | } | |
102 | ||
d9f644e2 | 103 | _public_ int sd_memfd_get_file(sd_memfd *m, FILE **f) { |
53ab52ac TA |
104 | assert_return(m, -EINVAL); |
105 | assert_return(f, -EINVAL); | |
ddeb4241 | 106 | |
a7c54c8c | 107 | if (!m->f) { |
ddeb4241 LP |
108 | m->f = fdopen(m->fd, "r+"); |
109 | if (!m->f) | |
110 | return -errno; | |
111 | } | |
112 | ||
113 | *f = m->f; | |
114 | return 0; | |
115 | } | |
116 | ||
d9f644e2 | 117 | _public_ int sd_memfd_dup_fd(sd_memfd *m) { |
ddeb4241 LP |
118 | int fd; |
119 | ||
53ab52ac | 120 | assert_return(m, -EINVAL); |
ddeb4241 LP |
121 | |
122 | fd = fcntl(m->fd, F_DUPFD_CLOEXEC, 3); | |
123 | if (fd < 0) | |
124 | return -errno; | |
125 | ||
126 | return fd; | |
127 | } | |
128 | ||
d9f644e2 | 129 | _public_ int sd_memfd_map(sd_memfd *m, uint64_t offset, size_t size, void **p) { |
ddeb4241 LP |
130 | void *q; |
131 | int sealed; | |
132 | ||
53ab52ac TA |
133 | assert_return(m, -EINVAL); |
134 | assert_return(size > 0, -EINVAL); | |
135 | assert_return(p, -EINVAL); | |
ddeb4241 LP |
136 | |
137 | sealed = sd_memfd_get_sealed(m); | |
138 | if (sealed < 0) | |
139 | return sealed; | |
140 | ||
141 | q = mmap(NULL, size, sealed ? PROT_READ : PROT_READ|PROT_WRITE, MAP_SHARED, m->fd, offset); | |
142 | if (q == MAP_FAILED) | |
143 | return -errno; | |
144 | ||
145 | *p = q; | |
146 | return 0; | |
147 | } | |
148 | ||
d9f644e2 | 149 | _public_ int sd_memfd_set_sealed(sd_memfd *m, int b) { |
ddeb4241 LP |
150 | int r; |
151 | ||
53ab52ac | 152 | assert_return(m, -EINVAL); |
ddeb4241 LP |
153 | |
154 | r = ioctl(m->fd, KDBUS_CMD_MEMFD_SEAL_SET, b); | |
155 | if (r < 0) | |
156 | return -errno; | |
157 | ||
158 | return 0; | |
159 | } | |
160 | ||
d9f644e2 | 161 | _public_ int sd_memfd_get_sealed(sd_memfd *m) { |
ddeb4241 LP |
162 | int r, b; |
163 | ||
53ab52ac | 164 | assert_return(m, -EINVAL); |
ddeb4241 LP |
165 | |
166 | r = ioctl(m->fd, KDBUS_CMD_MEMFD_SEAL_GET, &b); | |
167 | if (r < 0) | |
168 | return -errno; | |
169 | ||
170 | return !!b; | |
171 | } | |
172 | ||
d9f644e2 | 173 | _public_ int sd_memfd_get_size(sd_memfd *m, uint64_t *sz) { |
ddeb4241 LP |
174 | int r; |
175 | ||
53ab52ac TA |
176 | assert_return(m, -EINVAL); |
177 | assert_return(sz, -EINVAL); | |
ddeb4241 LP |
178 | |
179 | r = ioctl(m->fd, KDBUS_CMD_MEMFD_SIZE_GET, sz); | |
180 | if (r < 0) | |
181 | return -errno; | |
182 | ||
183 | return r; | |
184 | } | |
185 | ||
d9f644e2 | 186 | _public_ int sd_memfd_set_size(sd_memfd *m, uint64_t sz) { |
ddeb4241 LP |
187 | int r; |
188 | ||
53ab52ac | 189 | assert_return(m, -EINVAL); |
ddeb4241 LP |
190 | |
191 | r = ioctl(m->fd, KDBUS_CMD_MEMFD_SIZE_SET, &sz); | |
192 | if (r < 0) | |
193 | return -errno; | |
194 | ||
195 | return r; | |
196 | } | |
453a0c29 | 197 | |
d9f644e2 | 198 | _public_ int sd_memfd_new_and_map(sd_memfd **m, size_t sz, void **p) { |
453a0c29 LP |
199 | sd_memfd *n; |
200 | int r; | |
201 | ||
202 | r = sd_memfd_new(&n); | |
203 | if (r < 0) | |
204 | return r; | |
205 | ||
206 | r = sd_memfd_set_size(n, sz); | |
207 | if (r < 0) { | |
208 | sd_memfd_free(n); | |
209 | return r; | |
210 | } | |
211 | ||
212 | r = sd_memfd_map(n, 0, sz, p); | |
213 | if (r < 0) { | |
214 | sd_memfd_free(n); | |
215 | return r; | |
216 | } | |
217 | ||
218 | *m = n; | |
219 | return 0; | |
220 | } |