1 // SPDX-License-Identifier: MIT
2 /*
3 * Copyright (C) 2015-2020 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
4 */
5
6 #include <arpa/inet.h>
7 #include <errno.h>
8 #include <limits.h>
9 #include <net/if.h>
10 #include <netdb.h>
11 #include <netinet/in.h>
12 #include <stddef.h>
13 #include <stdio.h>
14 #include <stdlib.h>
15 #include <string.h>
16 #include <sys/socket.h>
17 #include "containers.h"
18 #include "curve25519.h"
19 #include "encoding.h"
20 #include "ctype.h"
21
22 #ifdef _WIN32
23 #include "ipc-uapi-windows.h"
24 #else
25 #include "ipc-uapi-unix.h"
26 #endif
27
userspace_set_device(struct wgdevice * dev)28 static int userspace_set_device(struct wgdevice *dev)
29 {
30 char hex[WG_KEY_LEN_HEX], ip[INET6_ADDRSTRLEN], host[4096 + 1], service[512 + 1];
31 struct wgpeer *peer;
32 struct wgallowedip *allowedip;
33 FILE *f;
34 int ret, set_errno = -EPROTO;
35 socklen_t addr_len;
36 size_t line_buffer_len = 0, line_len;
37 char *key = NULL, *value;
38
39 f = userspace_interface_file(dev->name);
40 if (!f)
41 return -errno;
42 fprintf(f, "set=1\n");
43
44 if (dev->flags & WGDEVICE_HAS_PRIVATE_KEY) {
45 key_to_hex(hex, dev->private_key);
46 fprintf(f, "private_key=%s\n", hex);
47 }
48 if (dev->flags & WGDEVICE_HAS_LISTEN_PORT)
49 fprintf(f, "listen_port=%u\n", dev->listen_port);
50 if (dev->flags & WGDEVICE_HAS_FWMARK)
51 fprintf(f, "fwmark=%u\n", dev->fwmark);
52 if (dev->flags & WGDEVICE_REPLACE_PEERS)
53 fprintf(f, "replace_peers=true\n");
54
55 for_each_wgpeer(dev, peer) {
56 key_to_hex(hex, peer->public_key);
57 fprintf(f, "public_key=%s\n", hex);
58 if (peer->flags & WGPEER_REMOVE_ME) {
59 fprintf(f, "remove=true\n");
60 continue;
61 }
62 if (peer->flags & WGPEER_HAS_PRESHARED_KEY) {
63 key_to_hex(hex, peer->preshared_key);
64 fprintf(f, "preshared_key=%s\n", hex);
65 }
66 if (peer->endpoint.addr.sa_family == AF_INET || peer->endpoint.addr.sa_family == AF_INET6) {
67 addr_len = 0;
68 if (peer->endpoint.addr.sa_family == AF_INET)
69 addr_len = sizeof(struct sockaddr_in);
70 else if (peer->endpoint.addr.sa_family == AF_INET6)
71 addr_len = sizeof(struct sockaddr_in6);
72 if (!getnameinfo(&peer->endpoint.addr, addr_len, host, sizeof(host), service, sizeof(service), NI_DGRAM | NI_NUMERICSERV | NI_NUMERICHOST)) {
73 if (peer->endpoint.addr.sa_family == AF_INET6 && strchr(host, ':'))
74 fprintf(f, "endpoint=[%s]:%s\n", host, service);
75 else
76 fprintf(f, "endpoint=%s:%s\n", host, service);
77 }
78 }
79 if (peer->flags & WGPEER_HAS_PERSISTENT_KEEPALIVE_INTERVAL)
80 fprintf(f, "persistent_keepalive_interval=%u\n", peer->persistent_keepalive_interval);
81 if (peer->flags & WGPEER_REPLACE_ALLOWEDIPS)
82 fprintf(f, "replace_allowed_ips=true\n");
83 for_each_wgallowedip(peer, allowedip) {
84 if (allowedip->family == AF_INET) {
85 if (!inet_ntop(AF_INET, &allowedip->ip4, ip, INET6_ADDRSTRLEN))
86 continue;
87 } else if (allowedip->family == AF_INET6) {
88 if (!inet_ntop(AF_INET6, &allowedip->ip6, ip, INET6_ADDRSTRLEN))
89 continue;
90 } else
91 continue;
92 fprintf(f, "allowed_ip=%s/%d\n", ip, allowedip->cidr);
93 }
94 }
95 fprintf(f, "\n");
96 fflush(f);
97
98 while (getline(&key, &line_buffer_len, f) > 0) {
99 line_len = strlen(key);
100 ret = set_errno;
101 if (line_len == 1 && key[0] == '\n')
102 goto out;
103 value = strchr(key, '=');
104 if (!value || line_len == 0 || key[line_len - 1] != '\n')
105 break;
106 *value++ = key[--line_len] = '\0';
107
108 if (!strcmp(key, "errno")) {
109 long long num;
110 char *end;
111 if (value[0] != '-' && !char_is_digit(value[0]))
112 break;
113 num = strtoll(value, &end, 10);
114 if (*end || num > INT_MAX || num < INT_MIN)
115 break;
116 set_errno = num;
117 }
118 }
119 ret = errno ? -errno : -EPROTO;
120 out:
121 free(key);
122 fclose(f);
123 errno = -ret;
124 return ret;
125 }
126
127 #define NUM(max) ({ \
128 unsigned long long num; \
129 char *end; \
130 if (!char_is_digit(value[0])) \
131 break; \
132 num = strtoull(value, &end, 10); \
133 if (*end || num > max) \
134 break; \
135 num; \
136 })
137
userspace_get_device(struct wgdevice ** out,const char * iface)138 static int userspace_get_device(struct wgdevice **out, const char *iface)
139 {
140 struct wgdevice *dev;
141 struct wgpeer *peer = NULL;
142 struct wgallowedip *allowedip = NULL;
143 size_t line_buffer_len = 0, line_len;
144 char *key = NULL, *value;
145 FILE *f;
146 int ret = -EPROTO;
147
148 *out = dev = calloc(1, sizeof(*dev));
149 if (!dev)
150 return -errno;
151
152 f = userspace_interface_file(iface);
153 if (!f) {
154 ret = -errno;
155 free(dev);
156 *out = NULL;
157 return ret;
158 }
159
160 fprintf(f, "get=1\n\n");
161 fflush(f);
162
163 strncpy(dev->name, iface, IFNAMSIZ - 1);
164 dev->name[IFNAMSIZ - 1] = '\0';
165
166 while (getline(&key, &line_buffer_len, f) > 0) {
167 line_len = strlen(key);
168 if (line_len == 1 && key[0] == '\n')
169 goto err;
170 value = strchr(key, '=');
171 if (!value || line_len == 0 || key[line_len - 1] != '\n')
172 break;
173 *value++ = key[--line_len] = '\0';
174
175 if (!peer && !strcmp(key, "private_key")) {
176 if (!key_from_hex(dev->private_key, value))
177 break;
178 curve25519_generate_public(dev->public_key, dev->private_key);
179 dev->flags |= WGDEVICE_HAS_PRIVATE_KEY | WGDEVICE_HAS_PUBLIC_KEY;
180 } else if (!peer && !strcmp(key, "listen_port")) {
181 dev->listen_port = NUM(0xffffU);
182 dev->flags |= WGDEVICE_HAS_LISTEN_PORT;
183 } else if (!peer && !strcmp(key, "fwmark")) {
184 dev->fwmark = NUM(0xffffffffU);
185 dev->flags |= WGDEVICE_HAS_FWMARK;
186 } else if (!strcmp(key, "public_key")) {
187 struct wgpeer *new_peer = calloc(1, sizeof(*new_peer));
188
189 if (!new_peer) {
190 ret = -ENOMEM;
191 goto err;
192 }
193 allowedip = NULL;
194 if (peer)
195 peer->next_peer = new_peer;
196 else
197 dev->first_peer = new_peer;
198 peer = new_peer;
199 if (!key_from_hex(peer->public_key, value))
200 break;
201 peer->flags |= WGPEER_HAS_PUBLIC_KEY;
202 } else if (peer && !strcmp(key, "preshared_key")) {
203 if (!key_from_hex(peer->preshared_key, value))
204 break;
205 if (!key_is_zero(peer->preshared_key))
206 peer->flags |= WGPEER_HAS_PRESHARED_KEY;
207 } else if (peer && !strcmp(key, "endpoint")) {
208 char *begin, *end;
209 struct addrinfo *resolved;
210 struct addrinfo hints = {
211 .ai_family = AF_UNSPEC,
212 .ai_socktype = SOCK_DGRAM,
213 .ai_protocol = IPPROTO_UDP
214 };
215 if (!strlen(value))
216 break;
217 if (value[0] == '[') {
218 begin = &value[1];
219 end = strchr(value, ']');
220 if (!end)
221 break;
222 *end++ = '\0';
223 if (*end++ != ':' || !*end)
224 break;
225 } else {
226 begin = value;
227 end = strrchr(value, ':');
228 if (!end || !*(end + 1))
229 break;
230 *end++ = '\0';
231 }
232 if (getaddrinfo(begin, end, &hints, &resolved) != 0) {
233 ret = ENETUNREACH;
234 goto err;
235 }
236 if ((resolved->ai_family == AF_INET && resolved->ai_addrlen == sizeof(struct sockaddr_in)) ||
237 (resolved->ai_family == AF_INET6 && resolved->ai_addrlen == sizeof(struct sockaddr_in6)))
238 memcpy(&peer->endpoint.addr, resolved->ai_addr, resolved->ai_addrlen);
239 else {
240 freeaddrinfo(resolved);
241 break;
242 }
243 freeaddrinfo(resolved);
244 } else if (peer && !strcmp(key, "persistent_keepalive_interval")) {
245 peer->persistent_keepalive_interval = NUM(0xffffU);
246 peer->flags |= WGPEER_HAS_PERSISTENT_KEEPALIVE_INTERVAL;
247 } else if (peer && !strcmp(key, "allowed_ip")) {
248 struct wgallowedip *new_allowedip;
249 char *end, *mask = value, *ip = strsep(&mask, "/");
250
251 if (!mask || !char_is_digit(mask[0]))
252 break;
253 new_allowedip = calloc(1, sizeof(*new_allowedip));
254 if (!new_allowedip) {
255 ret = -ENOMEM;
256 goto err;
257 }
258 if (allowedip)
259 allowedip->next_allowedip = new_allowedip;
260 else
261 peer->first_allowedip = new_allowedip;
262 allowedip = new_allowedip;
263 allowedip->family = AF_UNSPEC;
264 if (strchr(ip, ':')) {
265 if (inet_pton(AF_INET6, ip, &allowedip->ip6) == 1)
266 allowedip->family = AF_INET6;
267 } else {
268 if (inet_pton(AF_INET, ip, &allowedip->ip4) == 1)
269 allowedip->family = AF_INET;
270 }
271 allowedip->cidr = strtoul(mask, &end, 10);
272 if (*end || allowedip->family == AF_UNSPEC || (allowedip->family == AF_INET6 && allowedip->cidr > 128) || (allowedip->family == AF_INET && allowedip->cidr > 32))
273 break;
274 } else if (peer && !strcmp(key, "last_handshake_time_sec"))
275 peer->last_handshake_time.tv_sec = NUM(0x7fffffffffffffffULL);
276 else if (peer && !strcmp(key, "last_handshake_time_nsec"))
277 peer->last_handshake_time.tv_nsec = NUM(0x7fffffffffffffffULL);
278 else if (peer && !strcmp(key, "rx_bytes"))
279 peer->rx_bytes = NUM(0xffffffffffffffffULL);
280 else if (peer && !strcmp(key, "tx_bytes"))
281 peer->tx_bytes = NUM(0xffffffffffffffffULL);
282 else if (!strcmp(key, "errno"))
283 ret = -NUM(0x7fffffffU);
284 }
285 ret = -EPROTO;
286 err:
287 free(key);
288 if (ret) {
289 free_wgdevice(dev);
290 *out = NULL;
291 }
292 fclose(f);
293 errno = -ret;
294 return ret;
295
296 }
297 #undef NUM
298