busybox/runit/runsv.c

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2006-11-18 00:28:49 +05:30
/* Busyboxed by Denis Vlasenko <vda.linux@googlemail.com> */
/* TODO: depends on runit_lib.c - review and reduce/eliminate */
#include <sys/poll.h>
#include <sys/file.h>
#include "busybox.h"
#include "runit_lib.h"
static int selfpipe[2];
/* state */
#define S_DOWN 0
#define S_RUN 1
#define S_FINISH 2
/* ctrl */
#define C_NOOP 0
#define C_TERM 1
#define C_PAUSE 2
/* want */
#define W_UP 0
#define W_DOWN 1
#define W_EXIT 2
struct svdir {
int pid;
int state;
int ctrl;
int want;
struct taia start;
int fdlock;
int fdcontrol;
int fdcontrolwrite;
int islog;
};
static struct svdir svd[2];
static int sigterm = 0;
static int haslog = 0;
static int pidchanged = 1;
static int logpipe[2];
static char *dir;
#define usage() bb_show_usage()
static void fatal2_cannot(const char *m1, const char *m2)
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{
bb_perror_msg_and_die("%s: fatal: cannot %s%s", dir, m1, m2);
/* was exiting 111 */
}
static void fatal_cannot(const char *m)
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{
fatal2_cannot(m, "");
/* was exiting 111 */
}
static void fatal2x_cannot(const char *m1, const char *m2)
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{
bb_error_msg_and_die("%s: fatal: cannot %s%s", dir, m1, m2);
/* was exiting 111 */
}
static void warn_cannot(const char *m)
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{
bb_perror_msg("%s: warning: cannot %s", dir, m);
}
static void warnx_cannot(const char *m)
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{
bb_error_msg("%s: warning: cannot %s", dir, m);
}
static void stopservice(struct svdir *);
static void s_child(int sig_no)
{
write(selfpipe[1], "", 1);
}
static void s_term(int sig_no)
{
sigterm = 1;
write(selfpipe[1], "", 1); /* XXX */
}
static char *add_str(char *p, const char *to_add)
{
while ((*p = *to_add) != '\0') {
p++;
to_add++;
}
return p;
}
static int open_trunc_or_warn(const char *name)
{
int fd = open_trunc(name);
if (fd < 0)
bb_perror_msg("%s: warning: cannot open %s",
dir, name);
return fd;
}
static int rename_or_warn(const char *old, const char *new)
{
if (rename(old, new) == -1) {
bb_perror_msg("%s: warning: cannot rename %s to %s",
dir, old, new);
return -1;
}
return 0;
}
static void update_status(struct svdir *s)
{
unsigned long l;
int fd;
char status[20];
/* pid */
if (pidchanged) {
fd = open_trunc_or_warn("supervise/pid.new");
if (fd < 0)
return;
if (s->pid) {
char spid[sizeof(s->pid)*3 + 2];
int size = sprintf(spid, "%d\n", s->pid);
write(fd, spid, size);
}
close(fd);
if (s->islog) {
if (rename_or_warn("supervise/pid.new", "log/supervise/pid"))
return;
} else if (rename_or_warn("supervise/pid.new", "supervise/pid")) {
return;
}
pidchanged = 0;
}
/* stat */
fd = open_trunc_or_warn("supervise/stat.new");
if (fd < -1)
return;
{
char stat_buf[sizeof("finish, paused, got TERM, want down\n")];
char *p = stat_buf;
switch (s->state) {
case S_DOWN:
p = add_str(p, "down");
break;
case S_RUN:
p = add_str(p, "run");
break;
case S_FINISH:
p = add_str(p, "finish");
break;
}
if (s->ctrl & C_PAUSE) p = add_str(p, ", paused");
if (s->ctrl & C_TERM) p = add_str(p, ", got TERM");
if (s->state != S_DOWN)
switch (s->want) {
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case W_DOWN:
p = add_str(p, ", want down");
break;
case W_EXIT:
p = add_str(p, ", want exit");
break;
}
*p++ = '\n';
write(fd, stat_buf, p - stat_buf);
close(fd);
}
if (s->islog) {
rename_or_warn("supervise/stat.new", "log/supervise/stat");
} else {
rename_or_warn("supervise/stat.new", "log/supervise/stat"+4);
}
/* supervise compatibility */
taia_pack(status, &s->start);
l = (unsigned long)s->pid;
status[12] = l; l >>=8;
status[13] = l; l >>=8;
status[14] = l; l >>=8;
status[15] = l;
if (s->ctrl & C_PAUSE)
status[16] = 1;
else
status[16] = 0;
if (s->want == W_UP)
status[17] = 'u';
else
status[17] = 'd';
if (s->ctrl & C_TERM)
status[18] = 1;
else
status[18] = 0;
status[19] = s->state;
fd = open_trunc_or_warn("supervise/status.new");
if (fd < 0)
return;
l = write(fd, status, sizeof status);
if (l < 0) {
warn_cannot("write supervise/status.new");
close(fd);
unlink("supervise/status.new");
return;
}
close(fd);
if (l < sizeof status) {
warnx_cannot("write supervise/status.new: partial write");
return;
}
if (s->islog) {
rename_or_warn("supervise/status.new", "log/supervise/status");
} else {
rename_or_warn("supervise/status.new", "log/supervise/status"+4);
}
}
static unsigned custom(struct svdir *s, char c)
{
int pid;
int w;
char a[10];
struct stat st;
char *prog[2];
if (s->islog) return 0;
memcpy(a, "control/?", 10);
a[8] = c;
if (stat(a, &st) == 0) {
if (st.st_mode & S_IXUSR) {
pid = fork();
if (pid == -1) {
warn_cannot("fork for control/?");
return 0;
}
if (!pid) {
if (haslog && fd_copy(1, logpipe[1]) == -1)
warn_cannot("setup stdout for control/?");
prog[0] = a;
prog[1] = 0;
execve(a, prog, environ);
fatal_cannot("run control/?");
}
while (wait_pid(&w, pid) == -1) {
if (errno == EINTR) continue;
warn_cannot("wait for child control/?");
return 0;
}
return !wait_exitcode(w);
}
}
else {
if (errno == ENOENT) return 0;
warn_cannot("stat control/?");
}
return 0;
}
static void stopservice(struct svdir *s)
{
if (s->pid && ! custom(s, 't')) {
kill(s->pid, SIGTERM);
s->ctrl |=C_TERM;
update_status(s);
}
if (s->want == W_DOWN) {
kill(s->pid, SIGCONT);
custom(s, 'd'); return;
}
if (s->want == W_EXIT) {
kill(s->pid, SIGCONT);
custom(s, 'x');
}
}
static void startservice(struct svdir *s)
{
int p;
char *run[2];
if (s->state == S_FINISH)
run[0] = (char*)"./finish";
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else {
run[0] = (char*)"./run";
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custom(s, 'u');
}
run[1] = NULL;
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if (s->pid != 0) stopservice(s); /* should never happen */
while ((p = fork()) == -1) {
warn_cannot("fork, sleeping");
sleep(5);
}
if (p == 0) {
/* child */
if (haslog) {
if (s->islog) {
if (fd_copy(0, logpipe[0]) == -1)
fatal_cannot("setup filedescriptor for ./log/run");
close(logpipe[1]);
if (chdir("./log") == -1)
fatal_cannot("change directory to ./log");
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} else {
if (fd_copy(1, logpipe[1]) == -1)
fatal_cannot("setup filedescriptor for ./run");
close(logpipe[0]);
}
}
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sig_uncatch(SIGCHLD);
sig_unblock(SIGCHLD);
sig_uncatch(SIGTERM);
sig_unblock(SIGTERM);
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execve(*run, run, environ);
if (s->islog)
fatal2_cannot("start log/", *run);
else
fatal2_cannot("start ", *run);
}
if (s->state != S_FINISH) {
taia_now(&s->start);
s->state = S_RUN;
}
s->pid = p;
pidchanged = 1;
s->ctrl = C_NOOP;
update_status(s);
}
static int ctrl(struct svdir *s, char c)
{
switch (c) {
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case 'd': /* down */
s->want = W_DOWN;
update_status(s);
if (s->pid && s->state != S_FINISH) stopservice(s);
break;
case 'u': /* up */
s->want = W_UP;
update_status(s);
if (s->pid == 0) startservice(s);
break;
case 'x': /* exit */
if (s->islog) break;
s->want = W_EXIT;
update_status(s);
if (s->pid && s->state != S_FINISH) stopservice(s);
break;
case 't': /* sig term */
if (s->pid && s->state != S_FINISH) stopservice(s);
break;
case 'k': /* sig kill */
if (s->pid && ! custom(s, c)) kill(s->pid, SIGKILL);
s->state = S_DOWN;
break;
case 'p': /* sig pause */
if (s->pid && ! custom(s, c)) kill(s->pid, SIGSTOP);
s->ctrl |=C_PAUSE;
update_status(s);
break;
case 'c': /* sig cont */
if (s->pid && ! custom(s, c)) kill(s->pid, SIGCONT);
if (s->ctrl & C_PAUSE) s->ctrl &=~C_PAUSE;
update_status(s);
break;
case 'o': /* once */
s->want = W_DOWN;
update_status(s);
if (!s->pid) startservice(s);
break;
case 'a': /* sig alarm */
if (s->pid && ! custom(s, c)) kill(s->pid, SIGALRM);
break;
case 'h': /* sig hup */
if (s->pid && ! custom(s, c)) kill(s->pid, SIGHUP);
break;
case 'i': /* sig int */
if (s->pid && ! custom(s, c)) kill(s->pid, SIGINT);
break;
case 'q': /* sig quit */
if (s->pid && ! custom(s, c)) kill(s->pid, SIGQUIT);
break;
case '1': /* sig usr1 */
if (s->pid && ! custom(s, c)) kill(s->pid, SIGUSR1);
break;
case '2': /* sig usr2 */
if (s->pid && ! custom(s, c)) kill(s->pid, SIGUSR2);
break;
}
return 1;
}
int runsv_main(int argc, char **argv);
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int runsv_main(int argc, char **argv)
{
struct stat s;
int fd;
int r;
char buf[256];
if (!argv[1] || argv[2]) usage();
dir = argv[1];
if (pipe(selfpipe) == -1) fatal_cannot("create selfpipe");
coe(selfpipe[0]);
coe(selfpipe[1]);
ndelay_on(selfpipe[0]);
ndelay_on(selfpipe[1]);
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sig_block(SIGCHLD);
sig_catch(SIGCHLD, s_child);
sig_block(SIGTERM);
sig_catch(SIGTERM, s_term);
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xchdir(dir);
svd[0].pid = 0;
svd[0].state = S_DOWN;
svd[0].ctrl = C_NOOP;
svd[0].want = W_UP;
svd[0].islog = 0;
svd[1].pid = 0;
taia_now(&svd[0].start);
if (stat("down", &s) != -1) svd[0].want = W_DOWN;
if (stat("log", &s) == -1) {
if (errno != ENOENT)
warn_cannot("stat ./log");
} else {
if (!S_ISDIR(s.st_mode))
warnx_cannot("stat log/down: log is not a directory");
else {
haslog = 1;
svd[1].state = S_DOWN;
svd[1].ctrl = C_NOOP;
svd[1].want = W_UP;
svd[1].islog = 1;
taia_now(&svd[1].start);
if (stat("log/down", &s) != -1)
svd[1].want = W_DOWN;
if (pipe(logpipe) == -1)
fatal_cannot("create log pipe");
coe(logpipe[0]);
coe(logpipe[1]);
}
}
if (mkdir("supervise", 0700) == -1) {
r = readlink("supervise", buf, 256);
if (r != -1) {
if (r == 256)
fatal2x_cannot("readlink ./supervise: ", "name too long");
buf[r] = 0;
mkdir(buf, 0700);
} else {
if ((errno != ENOENT) && (errno != EINVAL))
fatal_cannot("readlink ./supervise");
}
}
svd[0].fdlock = xopen3("log/supervise/lock"+4,
O_WRONLY|O_NDELAY|O_APPEND|O_CREAT, 0600);
if (lock_exnb(svd[0].fdlock) == -1)
fatal_cannot("lock supervise/lock");
coe(svd[0].fdlock);
if (haslog) {
if (mkdir("log/supervise", 0700) == -1) {
r = readlink("log/supervise", buf, 256);
if (r != -1) {
if (r == 256)
fatal2x_cannot("readlink ./log/supervise: ", "name too long");
buf[r] = 0;
fd = xopen(".", O_RDONLY|O_NDELAY);
xchdir("./log");
mkdir(buf, 0700);
if (fchdir(fd) == -1)
fatal_cannot("change back to service directory");
close(fd);
}
else {
if ((errno != ENOENT) && (errno != EINVAL))
fatal_cannot("readlink ./log/supervise");
}
}
svd[1].fdlock = xopen3("log/supervise/lock",
O_WRONLY|O_NDELAY|O_APPEND|O_CREAT, 0600);
if (lock_ex(svd[1].fdlock) == -1)
fatal_cannot("lock log/supervise/lock");
coe(svd[1].fdlock);
}
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mkfifo("log/supervise/control"+4, 0600);
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svd[0].fdcontrol = xopen("log/supervise/control"+4, O_RDONLY|O_NDELAY);
coe(svd[0].fdcontrol);
svd[0].fdcontrolwrite = xopen("log/supervise/control"+4, O_WRONLY|O_NDELAY);
coe(svd[0].fdcontrolwrite);
update_status(&svd[0]);
if (haslog) {
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mkfifo("log/supervise/control", 0600);
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svd[1].fdcontrol = xopen("log/supervise/control", O_RDONLY|O_NDELAY);
coe(svd[1].fdcontrol);
svd[1].fdcontrolwrite = xopen("log/supervise/control", O_WRONLY|O_NDELAY);
coe(svd[1].fdcontrolwrite);
update_status(&svd[1]);
}
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mkfifo("log/supervise/ok"+4, 0600);
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fd = xopen("log/supervise/ok"+4, O_RDONLY|O_NDELAY);
coe(fd);
if (haslog) {
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mkfifo("log/supervise/ok", 0600);
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fd = xopen("log/supervise/ok", O_RDONLY|O_NDELAY);
coe(fd);
}
for (;;) {
iopause_fd x[3];
struct taia deadline;
struct taia now;
char ch;
if (haslog)
if (!svd[1].pid && svd[1].want == W_UP)
startservice(&svd[1]);
if (!svd[0].pid)
if (svd[0].want == W_UP || svd[0].state == S_FINISH)
startservice(&svd[0]);
x[0].fd = selfpipe[0];
x[0].events = IOPAUSE_READ;
x[1].fd = svd[0].fdcontrol;
x[1].events = IOPAUSE_READ;
if (haslog) {
x[2].fd = svd[1].fdcontrol;
x[2].events = IOPAUSE_READ;
}
taia_now(&now);
taia_uint(&deadline, 3600);
taia_add(&deadline, &now, &deadline);
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sig_unblock(SIGTERM);
sig_unblock(SIGCHLD);
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iopause(x, 2+haslog, &deadline, &now);
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sig_block(SIGTERM);
sig_block(SIGCHLD);
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while (read(selfpipe[0], &ch, 1) == 1)
;
for (;;) {
int child;
int wstat;
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child = wait_nohang(&wstat);
if (!child) break;
if ((child == -1) && (errno != EINTR)) break;
if (child == svd[0].pid) {
svd[0].pid = 0;
pidchanged = 1;
svd[0].ctrl &=~C_TERM;
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if (svd[0].state != S_FINISH) {
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fd = open_read("finish");
if (fd != -1) {
close(fd);
svd[0].state = S_FINISH;
update_status(&svd[0]);
continue;
}
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}
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svd[0].state = S_DOWN;
taia_uint(&deadline, 1);
taia_add(&deadline, &svd[0].start, &deadline);
taia_now(&svd[0].start);
update_status(&svd[0]);
if (taia_less(&svd[0].start, &deadline)) sleep(1);
}
if (haslog) {
if (child == svd[1].pid) {
svd[1].pid = 0;
pidchanged = 1;
svd[1].state = S_DOWN;
svd[1].ctrl &=~C_TERM;
taia_uint(&deadline, 1);
taia_add(&deadline, &svd[1].start, &deadline);
taia_now(&svd[1].start);
update_status(&svd[1]);
if (taia_less(&svd[1].start, &deadline)) sleep(1);
}
}
}
if (read(svd[0].fdcontrol, &ch, 1) == 1)
ctrl(&svd[0], ch);
if (haslog)
if (read(svd[1].fdcontrol, &ch, 1) == 1)
ctrl(&svd[1], ch);
if (sigterm) {
ctrl(&svd[0], 'x');
sigterm = 0;
}
if (svd[0].want == W_EXIT && svd[0].state == S_DOWN) {
if (svd[1].pid == 0)
_exit(0);
if (svd[1].want != W_EXIT) {
svd[1].want = W_EXIT;
/* stopservice(&svd[1]); */
update_status(&svd[1]);
close(logpipe[1]);
close(logpipe[0]);
//if (close(logpipe[1]) == -1)
// warn_cannot("close logpipe[1]");
//if (close(logpipe[0]) == -1)
// warn_cannot("close logpipe[0]");
}
}
}
/* not reached */
return 0;
}