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
|
/**
* Copyright © 2015 Mattias Andrée <maandree@member.fsf.org>
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
*/
#include <unistd.h>
#include <errno.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <sys/file.h>
#include "daemonise.h"
#include "common.h"
/**
* The size of the backlog on the socket.
*/
#ifndef SATD_BACKLOG
# define SATD_BACKLOG 5
#endif
COMMAND("satd")
USAGE("[-f]")
/**
* Create the socket.
*
* @param address Output parameter for the socket address.
* @return The file descriptor for the socket, -1 on error.
*/
static int
create_socket(struct sockaddr_un *address)
{
int fd = -1, bound = 0;
ssize_t len;
char *dir;
int saved_errno;
/* Get socket address. */
dir = getenv("XDG_RUNTIME_DIR"), dir = (dir ? dir : "/run");
t (snprintf(NULL, 0, "%s/satd.socket%zn", dir, &len) == -1);
if ((len < 0) || ((size_t)len >= sizeof(address->sun_path)))
t ((errno = ENAMETOOLONG));
sprintf(address->sun_path, "%s/satd.socket", dir);
address->sun_family = AF_UNIX;
/* Check that no living process owns the socket. */
fd = open(address->sun_path, O_RDONLY);
if (fd == -1) {
t (errno != ENOENT);
goto does_not_exist;
} else {
if (flock(fd, LOCK_EX | LOCK_NB) == -1) {
t (errno != EWOULDBLOCK);
fprintf(stderr, "%s: the daemon's socket file is already in use.\n", argv0);
errno = 0;
goto fail;
}
flock(fd, LOCK_UN);
close(fd), fd = -1;
}
/* Create socket. */
unlink(address->sun_path);
does_not_exist:
t ((fd = socket(PF_UNIX, SOCK_STREAM, 0)) == -1);
t (fchmod(fd, S_IRWXU) == -1);
t (fchown(fd, getuid(), getgid()) == -1);
t (bind(fd, (struct sockaddr *)address, sizeof(*address)) == -1);
/* EADDRINUSE just means that the file already exists, not that it is actually used. */
bound = 1;
/* Mark the socket as owned by a living process. */
t (flock(fd, LOCK_SH));
return fd;
fail:
saved_errno = errno;
if (fd >= 0)
close(fd);
if (bound)
unlink(address->sun_path);
errno = saved_errno;
return -1;
}
/**
* The sat daemon.
*
* @param argc Any value in [0, 2] is accepted.
* @param argv The name of the process, and -f if the process
* shall not be daemonised.
* @return 0 The process was successful.
* @return 1 The process failed queuing the job.
* @return 2 User error, you do not know what you are doing.
*/
int
main(int argc, char *argv[])
{
struct sockaddr_un address;
int sock = -1, foreground = 0;
/* Parse command line. */
if (argc > 0) argv0 = argv[0];
if (argc > 2) usage();
if (argc == 2)
if (!(foreground = !strcmp(argv[1], "-f")))
usage();
/* Daemonise. */
t (foreground ? 0 : daemonise("satd", 0));
/* Create socket. */
t (sock = create_socket(&address), sock == -1);
if (sock != 3) {
t (dup2(sock, 3) == -1);
close(sock), sock = 3;
}
/* Get hook-script pathname. */
/* TODO */
/* Listen for incoming conections. */
#if SOMAXCONN < SATD_BACKLOG
t (listen(sock, SOMAXCONN));
#else
t (listen(sock, SATD_BACKLOG));
#endif
close(sock);
unlink(address.sun_path);
undaemonise();
return 0;
fail:
if (errno)
perror(argv0);
if (sock >= 0) {
close(sock);
unlink(address.sun_path);
}
undaemonise();
return 1;
}
|
