1 /*
2 * dhcpcd-online
3 * Copyright 2014-2015 Roy Marples <roy@marples.name>
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27 #include <errno.h>
28 #include <limits.h>
29 #include <poll.h>
30 #include <stdbool.h>
31 #include <stdio.h>
32 #include <stdlib.h>
33 #include <string.h>
34 #include <syslog.h>
35 #include <time.h>
36 #include <unistd.h>
37
38 #include "dhcpcd.h"
39
40 #if __GNUC__ > 2 || defined(__INTEL_COMPILER)
41 # ifndef __dead
42 # define __dead __attribute__((__noreturn__))
43 # endif
44 # ifndef __unused
45 # define __unused __attribute__((__unused__))
46 # endif
47 #else
48 # ifndef __dead
49 # define __dead
50 # endif
51 # ifndef __unused
52 # define __unused
53 # endif
54 #endif
55
56 #ifndef timespeccmp
57 #define timespeccmp(tsp, usp, cmp) \
58 (((tsp)->tv_sec == (usp)->tv_sec) ? \
59 ((tsp)->tv_nsec cmp (usp)->tv_nsec) : \
60 ((tsp)->tv_sec cmp (usp)->tv_sec))
61 #endif
62 #ifndef timespecsub
63 #define timespecsub(tsp, usp, vsp) \
64 do { \
65 (vsp)->tv_sec = (tsp)->tv_sec - (usp)->tv_sec; \
66 (vsp)->tv_nsec = (tsp)->tv_nsec - (usp)->tv_nsec; \
67 if ((vsp)->tv_nsec < 0) { \
68 (vsp)->tv_sec--; \
69 (vsp)->tv_nsec += 1000000000L; \
70 } \
71 } while (/* CONSTCOND */ 0)
72 #endif
73
74 /* Incase we need to pass anything else in context to status cb */
75 struct ctx {
76 struct pollfd pollfd;
77 };
78
79 static void __dead
do_exit(DHCPCD_CONNECTION * con,int code)80 do_exit(DHCPCD_CONNECTION *con, int code)
81 {
82
83 /* Unregister the status callback so that close doesn't spam. */
84 dhcpcd_set_status_callback(con, NULL, NULL);
85
86 dhcpcd_close(con);
87 dhcpcd_free(con);
88 exit(code);
89 }
90
91 static void
status_cb(DHCPCD_CONNECTION * con,unsigned int status,const char * status_msg,void * arg)92 status_cb(DHCPCD_CONNECTION *con,
93 unsigned int status, const char *status_msg, void *arg)
94 {
95 struct ctx *ctx;
96
97 syslog(LOG_INFO, "%s", status_msg);
98 switch (status) {
99 case DHC_CONNECTED:
100 do_exit(con, EXIT_SUCCESS);
101 /* NOT REACHED */
102 case DHC_DOWN:
103 ctx = arg;
104 ctx->pollfd.fd = -1;
105 break;
106 }
107 }
108
109 int
main(int argc,char ** argv)110 main(int argc, char **argv)
111 {
112 DHCPCD_CONNECTION *con;
113 bool xflag;
114 struct timespec now, end, t;
115 struct ctx ctx;
116 int timeout, n, lerrno;
117 long lnum;
118 char *lend;
119
120 /* Defaults */
121 timeout = 30;
122
123 xflag = false;
124 ctx.pollfd.fd = -1;
125 ctx.pollfd.events = POLLIN;
126 ctx.pollfd.revents = 0;
127
128 openlog("dhcpcd-online", LOG_PERROR, 0);
129 setlogmask(LOG_UPTO(LOG_INFO));
130
131 while ((n = getopt(argc, argv, "qt:x")) != -1) {
132 switch (n) {
133 case 'q':
134 closelog();
135 openlog("dhcpcd-online", 0, 0);
136 break;
137 case 't':
138 lnum = strtol(optarg, &lend, 0);
139 if (lend == NULL || *lend != '\0' ||
140 lnum < 0 || lnum > INT_MAX)
141 {
142 syslog(LOG_ERR, "-t %s: invalid timeout",
143 optarg);
144 exit(EXIT_FAILURE);
145 }
146 timeout = (int)lnum;
147 break;
148 case 'x':
149 xflag = true;
150 break;
151 case '?':
152 fprintf(stderr, "usage: dhcpcd-online "
153 "[-q] [-t timeout]\n");
154 exit(EXIT_FAILURE);
155 }
156 }
157
158 if ((con = dhcpcd_new()) == NULL) {
159 syslog(LOG_ERR, "dhcpcd_new: %m");
160 return EXIT_FAILURE;
161 }
162 dhcpcd_set_status_callback(con, status_cb, &ctx);
163
164 if ((ctx.pollfd.fd = dhcpcd_open(con, false)) == -1) {
165 lerrno = errno;
166 syslog(LOG_WARNING, "dhcpcd_open: %m");
167 if (xflag)
168 do_exit(con, EXIT_FAILURE);
169 } else
170 lerrno = 0;
171
172 /* Work out our timeout time */
173 if (clock_gettime(CLOCK_MONOTONIC, &end) == -1) {
174 syslog(LOG_ERR, "clock_gettime: %m");
175 do_exit(con, EXIT_FAILURE);
176 }
177 end.tv_sec += timeout;
178
179 for (;;) {
180 if (clock_gettime(CLOCK_MONOTONIC, &now) == -1) {
181 syslog(LOG_ERR, "clock_gettime: %m");
182 do_exit(con, EXIT_FAILURE);
183 }
184 if (timespeccmp(&now, &end, >)) {
185 syslog(LOG_ERR, "timed out");
186 do_exit(con, EXIT_FAILURE);
187 }
188 if (ctx.pollfd.fd == -1) {
189 n = poll(NULL, 0, DHCPCD_RETRYOPEN);
190 } else {
191 /* poll(2) should really take a timespec */
192 timespecsub(&end, &now, &t);
193 if (t.tv_sec > INT_MAX / 1000 ||
194 (t.tv_sec == INT_MAX / 1000 &&
195 (t.tv_nsec + 999999) / 1000000 > INT_MAX % 1000000))
196 timeout = INT_MAX;
197 else
198 timeout = (int)(t.tv_sec * 1000 +
199 (t.tv_nsec + 999999) / 1000000);
200 n = poll(&ctx.pollfd, 1, timeout);
201 }
202 if (n == -1) {
203 syslog(LOG_ERR, "poll: %m");
204 do_exit(con, EXIT_FAILURE);
205 }
206 if (ctx.pollfd.fd == -1) {
207 if ((ctx.pollfd.fd = dhcpcd_open(con, false)) == -1) {
208 if (lerrno != errno) {
209 lerrno = errno;
210 syslog(LOG_WARNING, "dhcpcd_open: %m");
211 }
212 }
213 } else {
214 if (n > 0 && ctx.pollfd.revents)
215 dhcpcd_dispatch(con);
216 }
217 }
218
219 /* Impossible to reach here */
220 do_exit(con, EXIT_FAILURE);
221 }
222