1 /***
2 This file is part of avahi.
3
4 avahi is free software; you can redistribute it and/or modify it
5 under the terms of the GNU Lesser General Public License as
6 published by the Free Software Foundation; either version 2.1 of the
7 License, or (at your option) any later version.
8
9 avahi is distributed in the hope that it will be useful, but WITHOUT
10 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
11 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General
12 Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with avahi; if not, write to the Free Software
16 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
17 USA.
18 ***/
19
20 #ifdef HAVE_CONFIG_H
21 #include <config.h>
22 #endif
23
24 #include <unistd.h>
25 #include <assert.h>
26 #include <string.h>
27 #include <errno.h>
28 #include <signal.h>
29 #include <fcntl.h>
30 #include <stdio.h>
31
32 #include <avahi-common/gccmacro.h>
33 #include "sigint.h"
34
35 static AvahiSimplePoll *simple_poll = NULL;
36 static struct sigaction old_sigint_sa, old_sigterm_sa;
37 static int pipe_fds[2] = { -1, -1 };
38 static AvahiWatch *watch = NULL;
39
set_nonblock(int fd)40 static int set_nonblock(int fd) {
41 int n;
42
43 assert(fd >= 0);
44
45 if ((n = fcntl(fd, F_GETFL)) < 0)
46 return -1;
47
48 if (n & O_NONBLOCK)
49 return 0;
50
51 return fcntl(fd, F_SETFL, n|O_NONBLOCK);
52 }
53
handler(int s)54 static void handler(int s) {
55 write(pipe_fds[1], &s, sizeof(s));
56 }
57
close_pipe_fds(void)58 static void close_pipe_fds(void) {
59 if (pipe_fds[0] >= 0)
60 close(pipe_fds[0]);
61 if (pipe_fds[1] >= 0)
62 close(pipe_fds[1]);
63
64 pipe_fds[0] = pipe_fds[1] = -1;
65 }
66
watch_callback(AvahiWatch * w,int fd,AvahiWatchEvent event,AVAHI_GCC_UNUSED void * userdata)67 static void watch_callback(AvahiWatch *w, int fd, AvahiWatchEvent event, AVAHI_GCC_UNUSED void *userdata) {
68 int s;
69 ssize_t l;
70
71 assert(w);
72 assert(fd == pipe_fds[0]);
73 assert(event == AVAHI_WATCH_IN);
74
75 l = read(fd, &s, sizeof(s));
76 assert(l == sizeof(s));
77
78 fprintf(stderr, "Got %s, quitting.\n", s == SIGINT ? "SIGINT" : "SIGTERM");
79 avahi_simple_poll_quit(simple_poll);
80 }
81
sigint_install(AvahiSimplePoll * spoll)82 int sigint_install(AvahiSimplePoll *spoll) {
83 struct sigaction sa;
84 const AvahiPoll *p;
85
86 assert(spoll);
87 assert(!simple_poll);
88 assert(pipe_fds[0] == -1 && pipe_fds[1] == -1);
89
90 if (pipe(pipe_fds) < 0) {
91 fprintf(stderr, "pipe() failed: %s\n", strerror(errno));
92 return -1;
93 }
94
95 set_nonblock(pipe_fds[0]);
96 set_nonblock(pipe_fds[1]);
97
98 memset(&sa, 0, sizeof(sa));
99 sa.sa_handler = handler;
100 sa.sa_flags = SA_RESTART;
101
102 if (sigaction(SIGINT, &sa, &old_sigint_sa) < 0) {
103 fprintf(stderr, "sigaction() failed: %s\n", strerror(errno));
104 close_pipe_fds();
105 return -1;
106 }
107
108 if (sigaction(SIGTERM, &sa, &old_sigterm_sa) < 0) {
109 sigaction(SIGINT, &old_sigint_sa, NULL);
110 fprintf(stderr, "sigaction() failed: %s\n", strerror(errno));
111 close_pipe_fds();
112 return -1;
113 }
114
115 p = avahi_simple_poll_get(spoll);
116 watch = p->watch_new(p, pipe_fds[0], AVAHI_WATCH_IN, watch_callback, NULL);
117 assert(watch);
118
119 simple_poll = spoll;
120 return 0;
121 }
122
sigint_uninstall(void)123 void sigint_uninstall(void) {
124
125 if (!simple_poll)
126 return;
127
128 sigaction(SIGTERM, &old_sigterm_sa, NULL);
129 sigaction(SIGINT, &old_sigint_sa, NULL);
130
131 close_pipe_fds();
132
133 if (watch) {
134 const AvahiPoll *p;
135
136 assert(simple_poll);
137 p = avahi_simple_poll_get(simple_poll);
138
139 p->watch_free(watch);
140 watch = NULL;
141 }
142
143 simple_poll = NULL;
144 }
145