summaryrefslogtreecommitdiff
path: root/initd/main.c
blob: 3a824e422ea737582c48409948322c0acd8715ad (plain)
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
/* SPDX-License-Identifier: ISC */
#include "init.h"

static int sigfd = -1;
static int sockfd = -1;

static void handle_signal(void)
{
	struct signalfd_siginfo info;
	int status;
	pid_t pid;

	if (read(sigfd, &info, sizeof(info)) != sizeof(info)) {
		perror("read on signal fd");
		return;
	}

	switch (info.ssi_signo) {
	case SIGCHLD:
		while ((pid = waitpid(-1, &status, WNOHANG)) > 0) {
			status = WIFEXITED(status) ? WEXITSTATUS(status) :
						     EXIT_FAILURE;

			supervisor_handle_exited(pid, status);
		}
		break;
	case SIGTERM:
		supervisor_set_target(TGT_SHUTDOWN);
		break;
	case SIGINT:
		supervisor_set_target(TGT_REBOOT);
		break;
	case SIGUSR1:
		if (sockfd >= 0) {
			close(sockfd);
			unlink(INIT_SOCK_PATH);
			sockfd = -1;
		}
		sockfd = init_socket_create();
		break;
	}
}

static void handle_request(void)
{
	struct sockaddr_un addr;
	init_request_t rq;
	socklen_t addrlen;
	ssize_t ret;
retry:
	memset(&rq, 0, sizeof(rq));
	addrlen = sizeof(addr);
	ret = recvfrom(sockfd, &rq, sizeof(rq), MSG_DONTWAIT | MSG_TRUNC,
		       (struct sockaddr *)&addr, &addrlen);

	if (ret < 0 && errno == EINTR)
		goto retry;

	if ((size_t)ret < sizeof(rq))
		return;

	switch (rq.rq) {
	case EIR_STATUS:
		supervisor_answer_status_request(sockfd, &addr, addrlen);
		break;
	}
}

void target_completed(int target)
{
	switch (target) {
	case TGT_BOOT:
		if (sockfd < 0)
			sockfd = init_socket_create();
		break;
	case TGT_SHUTDOWN:
		for (;;)
			reboot(RB_POWER_OFF);
		break;
	case TGT_REBOOT:
		for (;;)
			reboot(RB_AUTOBOOT);
		break;
	}
}

int main(void)
{
	int i, ret, count;
	struct pollfd pfd[2];

	if (getpid() != 1) {
		fputs("init does not have pid 1, terminating!\n", stderr);
		return EXIT_FAILURE;
	}

	supervisor_init();

	sigfd = sigsetup();
	if (sigfd < 0)
		return -1;

	for (;;) {
		while (supervisor_process_queues())
			;

		memset(pfd, 0, sizeof(pfd));
		count = 0;

		pfd[count].fd = sigfd;
		pfd[count].events = POLLIN;
		++count;

		if (sockfd >= 0) {
			pfd[count].fd = sockfd;
			pfd[count].events = POLLIN;
			++count;
		}

		ret = poll(pfd, count, -1);
		if (ret <= 0)
			continue;

		for (i = 0; i < count; ++i) {
			if (pfd[i].revents & POLLIN) {
				if (pfd[i].fd == sigfd)
					handle_signal();
				if (pfd[i].fd == sockfd)
					handle_request();
			}
		}
	}

	return EXIT_SUCCESS;
}