1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
|
/* $OpenBSD: ypldap_dns.c,v 1.8 2015/01/16 06:40:22 deraadt Exp $ */
/* $FreeBSD$ */
/*
* Copyright (c) 2003-2008 Henning Brauer <henning@openbsd.org>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
* IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
* OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/tree.h>
#include <sys/queue.h>
#include <netinet/in.h>
#include <arpa/nameser.h>
#include <netdb.h>
#include <pwd.h>
#include <errno.h>
#include <event.h>
#include <resolv.h>
#include <poll.h>
#include <signal.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <limits.h>
#include "ypldap.h"
volatile sig_atomic_t quit_dns = 0;
struct imsgev *iev_dns;
void dns_dispatch_imsg(int, short, void *);
void dns_sig_handler(int, short, void *);
void dns_shutdown(void);
int host_dns(const char *s, struct ypldap_addr **hn);
void
dns_sig_handler(int sig, short event, void *p)
{
switch (sig) {
case SIGINT:
case SIGTERM:
dns_shutdown();
break;
default:
fatalx("unexpected signal");
}
}
void
dns_shutdown(void)
{
log_info("dns engine exiting");
_exit(0);
}
pid_t
ypldap_dns(int pipe_ntp[2], struct passwd *pw)
{
pid_t pid;
struct event ev_sigint;
struct event ev_sigterm;
struct event ev_sighup;
struct env env;
switch (pid = fork()) {
case -1:
fatal("cannot fork");
break;
case 0:
break;
default:
return (pid);
}
setproctitle("dns engine");
close(pipe_ntp[0]);
if (setgroups(1, &pw->pw_gid) ||
setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) ||
setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid))
fatal("can't drop privileges");
endservent();
event_init();
signal_set(&ev_sigint, SIGINT, dns_sig_handler, NULL);
signal_set(&ev_sigterm, SIGTERM, dns_sig_handler, NULL);
signal_set(&ev_sighup, SIGHUP, dns_sig_handler, NULL);
signal_add(&ev_sigint, NULL);
signal_add(&ev_sigterm, NULL);
signal_add(&ev_sighup, NULL);
if ((env.sc_iev = calloc(1, sizeof(*env.sc_iev))) == NULL)
fatal(NULL);
env.sc_iev->events = EV_READ;
env.sc_iev->data = &env;
imsg_init(&env.sc_iev->ibuf, pipe_ntp[1]);
env.sc_iev->handler = dns_dispatch_imsg;
event_set(&env.sc_iev->ev, env.sc_iev->ibuf.fd, env.sc_iev->events,
env.sc_iev->handler, &env);
event_add(&env.sc_iev->ev, NULL);
event_dispatch();
dns_shutdown();
return (0);
}
void
dns_dispatch_imsg(int fd, short events, void *p)
{
struct imsg imsg;
int n, cnt;
char *name;
struct ypldap_addr *h, *hn;
struct ibuf *buf;
struct env *env = p;
struct imsgev *iev = env->sc_iev;
struct imsgbuf *ibuf = &iev->ibuf;
int shut = 0;
if ((events & (EV_READ | EV_WRITE)) == 0)
fatalx("unknown event");
if (events & EV_READ) {
if ((n = imsg_read(ibuf)) == -1)
fatal("imsg_read error");
if (n == 0)
shut = 1;
}
if (events & EV_WRITE) {
if ((n = msgbuf_write(&ibuf->w)) == -1 && errno != EAGAIN)
fatal("msgbuf_write");
if (n == 0)
shut = 1;
goto done;
}
for (;;) {
if ((n = imsg_get(ibuf, &imsg)) == -1)
fatal("client_dispatch_imsg: imsg_get error");
if (n == 0)
break;
switch (imsg.hdr.type) {
case IMSG_HOST_DNS:
name = imsg.data;
if (imsg.hdr.len < 1 + IMSG_HEADER_SIZE)
fatalx("invalid IMSG_HOST_DNS received");
imsg.hdr.len -= 1 + IMSG_HEADER_SIZE;
if (name[imsg.hdr.len] != '\0' ||
strlen(name) != imsg.hdr.len)
fatalx("invalid IMSG_HOST_DNS received");
if ((cnt = host_dns(name, &hn)) == -1)
break;
buf = imsg_create(ibuf, IMSG_HOST_DNS,
imsg.hdr.peerid, 0,
cnt * sizeof(struct sockaddr_storage));
if (buf == NULL)
break;
if (cnt > 0) {
h = hn;
while (h != NULL) {
imsg_add(buf, &h->ss, sizeof(h->ss));
hn = h->next;
free(h);
h = hn;
}
}
imsg_close(ibuf, buf);
break;
default:
break;
}
imsg_free(&imsg);
}
done:
if (!shut)
imsg_event_add(iev);
else {
/* this pipe is dead, so remove the event handler */
event_del(&iev->ev);
event_loopexit(NULL);
}
}
int
host_dns(const char *s, struct ypldap_addr **hn)
{
struct addrinfo hints, *res0, *res;
int error, cnt = 0;
struct sockaddr_in *sa_in;
struct sockaddr_in6 *sa_in6;
struct ypldap_addr *h, *hh = NULL;
bzero(&hints, sizeof(hints));
hints.ai_family = PF_UNSPEC;
hints.ai_socktype = SOCK_DGRAM; /* DUMMY */
error = getaddrinfo(s, NULL, &hints, &res0);
if (error == EAI_AGAIN || error == EAI_NONAME)
return (0);
if (error) {
log_warnx("could not parse \"%s\": %s", s,
gai_strerror(error));
return (-1);
}
for (res = res0; res && cnt < MAX_SERVERS_DNS; res = res->ai_next) {
if (res->ai_family != AF_INET &&
res->ai_family != AF_INET6)
continue;
if ((h = calloc(1, sizeof(struct ypldap_addr))) == NULL)
fatal(NULL);
h->ss.ss_family = res->ai_family;
if (res->ai_family == AF_INET) {
sa_in = (struct sockaddr_in *)&h->ss;
sa_in->sin_len = sizeof(struct sockaddr_in);
sa_in->sin_addr.s_addr = ((struct sockaddr_in *)
res->ai_addr)->sin_addr.s_addr;
} else {
sa_in6 = (struct sockaddr_in6 *)&h->ss;
sa_in6->sin6_len = sizeof(struct sockaddr_in6);
memcpy(&sa_in6->sin6_addr, &((struct sockaddr_in6 *)
res->ai_addr)->sin6_addr, sizeof(struct in6_addr));
}
h->next = hh;
hh = h;
cnt++;
}
freeaddrinfo(res0);
*hn = hh;
return (cnt);
}
|
