strans/tests/daemon_collision_test.c

#define _GNU_SOURCE
#include <dbus/dbus.h>
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <poll.h>
#include <signal.h>
#include <stdarg.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/inotify.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/un.h>
#include <sys/wait.h>
#include <time.h>
#include <unistd.h>

#include "ipc.h"

enum
{
	Calltimeout = 4000,
	Starttimeout = 8000,
	Stoptimeout = 3000,
};

typedef struct Test Test;

struct Test
{
	pid_t first;
	pid_t second;
	int firsterrfd;
	int seconderrfd;
	int notifyfd;
	int buswd;
	int ipcfirst;
	int ipcnew;
	DBusConnection *busfirst;
	DBusConnection *busnew;
	char root[256];
	char runtime[320];
	char config[320];
	char ibus[384];
	char bus[448];
	char home[320];
	char socket[384];
	char addrfile[512];
	char address[512];
	char addrcontents[2048];
	size_t naddrcontents;
	struct stat socketst;
	struct stat addrst;
	char firsterr[8192];
	size_t nfirsterr;
	char seconderr[8192];
	size_t nseconderr;
};

static int
fail(char *fmt, ...)
{
	va_list ap;

	fprintf(stderr, "daemon_collision_test: ");
	va_start(ap, fmt);
	vfprintf(stderr, fmt, ap);
	va_end(ap);
	fputc('\n', stderr);
	return 0;
}

static int64_t
nowms(void)
{
	struct timespec ts;

	if(clock_gettime(CLOCK_MONOTONIC, &ts) < 0)
		return 0;
	return (int64_t)ts.tv_sec * 1000 + ts.tv_nsec / 1000000;
}

static int
leftms(int64_t deadline)
{
	int64_t n;

	n = deadline - nowms();
	if(n <= 0)
		return 0;
	if(n > 0x7fffffff)
		return 0x7fffffff;
	return n;
}

static int
makedir(char *path)
{
	if(mkdir(path, 0700) == 0)
		return 1;
	return fail("mkdir %s: %s", path, strerror(errno));
}

static void
readpipe(int fd, char *buf, size_t cap, size_t *used)
{
	ssize_t n;

	if(fd < 0 || cap == 0)
		return;
	while(*used + 1 < cap){
		n = read(fd, buf + *used, cap - *used - 1);
		if(n > 0){
			*used += n;
			continue;
		}
		if(n < 0 && errno == EINTR)
			continue;
		break;
	}
	buf[*used] = '\0';
}

static void
showerrors(Test *t)
{
	readpipe(t->firsterrfd, t->firsterr, sizeof t->firsterr,
		&t->nfirsterr);
	readpipe(t->seconderrfd, t->seconderr, sizeof t->seconderr,
		&t->nseconderr);
	if(t->nfirsterr != 0)
		fprintf(stderr, "daemon_collision_test: first daemon stderr:\n%s",
			t->firsterr);
	if(t->nseconderr != 0)
		fprintf(stderr, "daemon_collision_test: second daemon stderr:\n%s",
			t->seconderr);
}

static int
setup(Test *t)
{
	memset(t, 0, sizeof *t);
	t->first = -1;
	t->second = -1;
	t->firsterrfd = -1;
	t->seconderrfd = -1;
	t->notifyfd = -1;
	t->buswd = -1;
	t->ipcfirst = -1;
	t->ipcnew = -1;
	snprintf(t->root, sizeof t->root, "/tmp/strans-collision.XXXXXX");
	if(mkdtemp(t->root) == NULL){
		t->root[0] = '\0';
		return fail("mkdtemp: %s", strerror(errno));
	}
	if(snprintf(t->runtime, sizeof t->runtime, "%s/runtime", t->root)
	   >= (int)sizeof t->runtime ||
	   snprintf(t->config, sizeof t->config, "%s/config", t->root)
	   >= (int)sizeof t->config ||
	   snprintf(t->ibus, sizeof t->ibus, "%s/ibus", t->config)
	   >= (int)sizeof t->ibus ||
	   snprintf(t->bus, sizeof t->bus, "%s/bus", t->ibus)
	   >= (int)sizeof t->bus ||
	   snprintf(t->home, sizeof t->home, "%s/home", t->root)
	   >= (int)sizeof t->home ||
	   snprintf(t->socket, sizeof t->socket, "%s/strans.sock", t->runtime)
	   >= (int)sizeof t->socket)
		return fail("temporary path is too long");
	if(!makedir(t->runtime) || !makedir(t->config) || !makedir(t->ibus) ||
	   !makedir(t->bus) || !makedir(t->home))
		return 0;
	t->notifyfd = inotify_init1(IN_CLOEXEC|IN_NONBLOCK);
	if(t->notifyfd < 0)
		return fail("inotify_init1: %s", strerror(errno));
	t->buswd = inotify_add_watch(t->notifyfd, t->bus,
		IN_CREATE|IN_MOVED_TO|IN_ATTRIB|IN_DELETE);
	if(t->buswd < 0)
		return fail("watch IBus directory: %s", strerror(errno));
	return 1;
}

static int
startchild(Test *t, char *program, char *mapdir, pid_t *child, int *errfd)
{
	int errpipe[2], fd;
	long maxfd;
	pid_t pid;

	if(pipe2(errpipe, O_CLOEXEC|O_NONBLOCK) < 0)
		return fail("pipe2: %s", strerror(errno));
	pid = fork();
	if(pid < 0){
		close(errpipe[0]);
		close(errpipe[1]);
		return fail("fork: %s", strerror(errno));
	}
	if(pid == 0){
		close(errpipe[0]);
		if(dup2(errpipe[1], STDOUT_FILENO) < 0 ||
		   dup2(errpipe[1], STDERR_FILENO) < 0)
			_exit(126);
		close(errpipe[1]);
		if(close_range(3, UINT_MAX, 0) < 0){
			maxfd = sysconf(_SC_OPEN_MAX);
			if(maxfd < 0)
				maxfd = 1024;
			for(fd = 3; fd < maxfd; fd++)
				close(fd);
		}
		if(setenv("XDG_RUNTIME_DIR", t->runtime, 1) < 0 ||
		   setenv("XDG_CONFIG_HOME", t->config, 1) < 0 ||
		   setenv("HOME", t->home, 1) < 0 || unsetenv("DISPLAY") < 0 ||
		   unsetenv("DBUS_SESSION_BUS_ADDRESS") < 0 ||
		   unsetenv("IBUS_ADDRESS") < 0){
			dprintf(STDERR_FILENO, "set daemon environment: %s\n",
				strerror(errno));
			_exit(126);
		}
		execl(program, program, mapdir, (char*)0);
		dprintf(STDERR_FILENO, "exec %s: %s\n", program, strerror(errno));
		_exit(127);
	}
	close(errpipe[1]);
	*child = pid;
	*errfd = errpipe[0];
	return 1;
}

static int
drainnotify(Test *t, int trackbus, int *changed)
{
	char buf[4096];
	struct inotify_event *ev;
	ssize_t n;
	size_t off;

	for(;;){
		n = read(t->notifyfd, buf, sizeof buf);
		if(n < 0 && errno == EINTR)
			continue;
		if(n < 0 && errno == EAGAIN)
			return 1;
		if(n < 0)
			return fail("read endpoint watches: %s", strerror(errno));
		if(n == 0)
			return 1;
		for(off = 0; off + sizeof *ev <= (size_t)n;
		   off += sizeof *ev + ev->len){
			ev = (struct inotify_event*)(buf + off);
			if(off + sizeof *ev + ev->len > (size_t)n)
				return fail("truncated inotify event");
			if(ev->mask & IN_Q_OVERFLOW)
				return fail("endpoint watch queue overflowed");
			if(trackbus && changed != NULL && ev->wd == t->buswd &&
			   ev->len != 0 &&
			   (ev->mask & (IN_CREATE|IN_MOVED_TO|IN_DELETE|IN_ATTRIB))){
				*changed = 1;
			}
		}
	}
}

static int
findaddress(Test *t)
{
	DIR *dir;
	struct dirent *de;
	int count, ok;

	dir = opendir(t->bus);
	if(dir == NULL){
		fail("open IBus directory %s: %s", t->bus, strerror(errno));
		return -1;
	}
	count = 0;
	ok = 1;
	errno = 0;
	while((de = readdir(dir)) != NULL){
		if(strcmp(de->d_name, ".") == 0 || strcmp(de->d_name, "..") == 0 ||
		   strstr(de->d_name, ".tmp.") != NULL)
			continue;
		count++;
		if(snprintf(t->addrfile, sizeof t->addrfile, "%s/%s", t->bus,
		   de->d_name) >= (int)sizeof t->addrfile){
			fail("IBus address path is too long");
			ok = 0;
			break;
		}
	}
	if(errno != 0){
		fail("read IBus directory %s: %s", t->bus, strerror(errno));
		ok = 0;
	}
	if(closedir(dir) < 0){
		fail("close IBus directory %s: %s", t->bus, strerror(errno));
		ok = 0;
	}
	if(!ok)
		return -1;
	if(count > 1){
		fail("found %d IBus address files", count);
		return -1;
	}
	return count;
}

static int
readfile(char *path, char *buf, size_t cap, size_t *nread)
{
	struct stat st;
	ssize_t n;
	size_t off;
	char extra;
	int fd, ok;

	fd = open(path, O_RDONLY|O_CLOEXEC);
	if(fd < 0)
		return fail("open %s: %s", path, strerror(errno));
	ok = 0;
	if(fstat(fd, &st) < 0){
		fail("stat open address file %s: %s", path, strerror(errno));
		goto out;
	}
	if(st.st_size < 0 || (uintmax_t)st.st_size >= cap){
		fail("address file %s is too large", path);
		goto out;
	}
	off = 0;
	while(off < (size_t)st.st_size){
		n = read(fd, buf + off, (size_t)st.st_size - off);
		if(n < 0 && errno == EINTR)
			continue;
		if(n <= 0){
			fail("read %s: %s", path,
				n == 0 ? "unexpected EOF" : strerror(errno));
			goto out;
		}
		off += n;
	}
	do
		n = read(fd, &extra, 1);
	while(n < 0 && errno == EINTR);
	if(n != 0){
		fail("address file %s changed while being read", path);
		goto out;
	}
	buf[off] = '\0';
	*nread = off;
	ok = 1;
out:
	if(close(fd) < 0){
		fail("close %s: %s", path, strerror(errno));
		ok = 0;
	}
	return ok;
}

static int
parseaddress(char *contents, size_t ncontents, char *address, size_t naddress,
	pid_t expected)
{
	char found[512];
	long pid;
	int consumed;

	consumed = -1;
	if(strlen(contents) != ncontents ||
	   sscanf(contents, "IBUS_ADDRESS=%511[^\n]\nIBUS_DAEMON_PID=%ld\n%n",
	   found, &pid, &consumed) != 2 || consumed != (int)ncontents)
		return fail("invalid IBus address file contents");
	if(pid != expected)
		return fail("IBus address PID %ld, expected %ld", pid,
			(long)expected);
	if(snprintf(address, naddress, "%s", found) >= (int)naddress)
		return fail("private IBus address is too long");
	return 1;
}

static int
childalive(pid_t *pid, char *which)
{
	int n, status;

	do
		n = waitpid(*pid, &status, WNOHANG);
	while(n < 0 && errno == EINTR);
	if(n == 0)
		return 1;
	if(n == *pid){
		fail("%s daemon exited unexpectedly with wait status %#x", which,
			status);
		*pid = -1;
		return 0;
	}
	if(n < 0){
		fail("check %s daemon %ld: %s", which, (long)*pid,
			strerror(errno));
		if(errno == ECHILD)
			*pid = -1;
		return 0;
	}
	return fail("waitpid returned the wrong %s child", which);
}

static int
waitready(Test *t)
{
	struct pollfd pfd[2];
	struct stat st;
	char contents[2048], address[512];
	size_t ncontents;
	int n, count, socketready, timeout;
	int64_t deadline;

	deadline = nowms() + Starttimeout;
	for(;;){
		socketready = lstat(t->socket, &st) == 0 && S_ISSOCK(st.st_mode) &&
			(st.st_mode & 0777) == 0600;
		count = findaddress(t);
		if(count < 0)
			return 0;
		if(socketready && count == 1 &&
		   readfile(t->addrfile, contents, sizeof contents, &ncontents) &&
		   parseaddress(contents, ncontents, address, sizeof address,
		   t->first))
			return 1;
		if(!childalive(&t->first, "first"))
			return 0;
		timeout = leftms(deadline);
		if(timeout == 0)
			return fail("timed out waiting for both daemon endpoints");
		pfd[0].fd = t->notifyfd;
		pfd[0].events = POLLIN;
		pfd[0].revents = 0;
		pfd[1].fd = t->firsterrfd;
		pfd[1].events = POLLIN|POLLHUP;
		pfd[1].revents = 0;
		n = poll(pfd, 2, timeout);
		if(n < 0 && errno == EINTR)
			continue;
		if(n < 0)
			return fail("poll daemon readiness: %s", strerror(errno));
		if(pfd[1].revents != 0)
			readpipe(t->firsterrfd, t->firsterr, sizeof t->firsterr,
				&t->nfirsterr);
		if((pfd[0].revents & POLLIN) && !drainnotify(t, 0, NULL))
			return 0;
	}
}

static int
snapshot(Test *t)
{
	if(lstat(t->socket, &t->socketst) < 0)
		return fail("stat first IPC socket: %s", strerror(errno));
	if(!S_ISSOCK(t->socketst.st_mode) || (t->socketst.st_mode & 0777) != 0600)
		return fail("first IPC endpoint is not a protected socket");
	if(lstat(t->addrfile, &t->addrst) < 0)
		return fail("stat first IBus address file: %s", strerror(errno));
	if(!S_ISREG(t->addrst.st_mode) || (t->addrst.st_mode & 0777) != 0600)
		return fail("first IBus address is not a protected regular file");
	if(!readfile(t->addrfile, t->addrcontents, sizeof t->addrcontents,
	   &t->naddrcontents))
		return 0;
	return parseaddress(t->addrcontents, t->naddrcontents, t->address,
		sizeof t->address, t->first);
}

static int
connectsocket(char *path, int64_t deadline)
{
	struct sockaddr_un addr;
	struct pollfd pfd;
	socklen_t nerr;
	int err, fd, flags, n;

	memset(&addr, 0, sizeof addr);
	addr.sun_family = AF_UNIX;
	if(snprintf(addr.sun_path, sizeof addr.sun_path, "%s", path)
	   >= (int)sizeof addr.sun_path){
		errno = ENAMETOOLONG;
		return -1;
	}
	fd = socket(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
	if(fd < 0)
		return -1;
	if(connect(fd, (struct sockaddr*)&addr, sizeof addr) < 0 &&
	   errno != EINPROGRESS){
		err = errno;
		close(fd);
		errno = err;
		return -1;
	}
	for(;;){
		n = leftms(deadline);
		if(n == 0){
			close(fd);
			errno = ETIMEDOUT;
			return -1;
		}
		pfd.fd = fd;
		pfd.events = POLLOUT;
		pfd.revents = 0;
		n = poll(&pfd, 1, n);
		if(n < 0 && errno == EINTR)
			continue;
		if(n <= 0){
			err = n == 0 ? ETIMEDOUT : errno;
			close(fd);
			errno = err;
			return -1;
		}
		break;
	}
	err = 0;
	nerr = sizeof err;
	if(getsockopt(fd, SOL_SOCKET, SO_ERROR, &err, &nerr) < 0 || err != 0){
		if(err == 0)
			err = errno;
		close(fd);
		errno = err;
		return -1;
	}
	flags = fcntl(fd, F_GETFL);
	if(flags < 0 || fcntl(fd, F_SETFL, flags & ~O_NONBLOCK) < 0){
		err = errno;
		close(fd);
		errno = err;
		return -1;
	}
	return fd;
}

static int
readuntil(int fd, void *buf, size_t n, int64_t deadline)
{
	struct pollfd pfd;
	unsigned char *p;
	ssize_t r;
	int timeout;

	p = buf;
	while(n > 0){
		timeout = leftms(deadline);
		if(timeout == 0){
			errno = ETIMEDOUT;
			return -1;
		}
		pfd.fd = fd;
		pfd.events = POLLIN;
		pfd.revents = 0;
		r = poll(&pfd, 1, timeout);
		if(r < 0 && errno == EINTR)
			continue;
		if(r <= 0){
			if(r == 0)
				errno = ETIMEDOUT;
			return -1;
		}
		r = recv(fd, p, n, 0);
		if(r < 0 && errno == EINTR)
			continue;
		if(r <= 0){
			if(r == 0)
				errno = ECONNRESET;
			return -1;
		}
		p += r;
		n -= r;
	}
	return 0;
}

static int
ipcprobe(int fd, char *where)
{
	unsigned char req[Ipcreqsz], reply[Ipcresphdrsz+Ipclensz];

	ipcpackreq(req, 1, 0, Kmodfirst);
	if(ipcsend(fd, req, sizeof req) < 0)
		return fail("send %s IPC request: %s", where, strerror(errno));
	if(readuntil(fd, reply, sizeof reply, nowms() + Calltimeout) < 0)
		return fail("read %s IPC response: %s", where, strerror(errno));
	if(reply[0] != 0 || reply[1] != 0 || reply[2] != 0 ||
	   reply[3] != 0 || reply[4] != 0)
		return fail("%s IPC response was not an empty modifier reply", where);
	return 1;
}

static void
closebus(DBusConnection **conn)
{
	if(*conn == NULL)
		return;
	dbus_connection_close(*conn);
	dbus_connection_unref(*conn);
	*conn = NULL;
}

static DBusMessage*
sendcall(DBusConnection *conn, DBusMessage *m, char *where)
{
	DBusMessage *reply;
	DBusPendingCall *pending;
	int timeout;
	int64_t deadline;

	if(m == NULL){
		fail("allocate %s call", where);
		return NULL;
	}
	pending = NULL;
	if(!dbus_connection_send_with_reply(conn, m, &pending, Calltimeout) ||
	   pending == NULL){
		dbus_message_unref(m);
		fail("queue %s call", where);
		return NULL;
	}
	dbus_message_unref(m);
	deadline = nowms() + Calltimeout;
	while(!dbus_pending_call_get_completed(pending)){
		timeout = leftms(deadline);
		if(timeout == 0){
			fail("timed out waiting for %s", where);
			goto fail;
		}
		if(!dbus_connection_read_write_dispatch(conn, timeout)){
			fail("connection closed waiting for %s", where);
			goto fail;
		}
	}
	reply = dbus_pending_call_steal_reply(pending);
	dbus_pending_call_unref(pending);
	if(reply == NULL)
		fail("%s completed without a reply", where);
	return reply;
fail:
	dbus_pending_call_cancel(pending);
	dbus_pending_call_unref(pending);
	return NULL;
}

static DBusConnection*
openbus(char *address)
{
	DBusConnection *conn;
	DBusError err;

	dbus_error_init(&err);
	conn = dbus_connection_open_private(address, &err);
	if(conn == NULL){
		fail("open private IBus connection: %s",
			err.message != NULL ? err.message : "D-Bus error");
		dbus_error_free(&err);
		return NULL;
	}
	dbus_error_free(&err);
	dbus_connection_set_exit_on_disconnect(conn, FALSE);
	return conn;
}

static int
hello(DBusConnection *conn, char *name, size_t nname, char *where)
{
	DBusMessage *m, *reply;
	DBusError err;
	const char *s;

	m = dbus_message_new_method_call("org.freedesktop.DBus",
		"/org/freedesktop/DBus", "org.freedesktop.DBus", "Hello");
	reply = sendcall(conn, m, where);
	if(reply == NULL)
		return 0;
	dbus_error_init(&err);
	if(!dbus_message_has_signature(reply, "s") ||
	   !dbus_message_get_args(reply, &err, DBUS_TYPE_STRING, &s,
	   DBUS_TYPE_INVALID)){
		dbus_message_unref(reply);
		dbus_error_free(&err);
		return fail("%s returned an invalid Hello reply", where);
	}
	if(snprintf(name, nname, "%s", s) >= (int)nname){
		dbus_error_free(&err);
		dbus_message_unref(reply);
		return fail("%s Hello name is too long", where);
	}
	dbus_error_free(&err);
	dbus_message_unref(reply);
	return name[0] == ':' || fail("%s returned invalid Hello name %s",
		where, name);
}

static int
createcontext(DBusConnection *conn, char *path, size_t npath, char *where)
{
	DBusMessage *m, *reply;
	DBusError err;
	const char *client, *p;

	client = "daemon-collision-test";
	m = dbus_message_new_method_call("org.freedesktop.IBus",
		"/org/freedesktop/IBus", "org.freedesktop.IBus",
		"CreateInputContext");
	if(m == NULL || !dbus_message_append_args(m, DBUS_TYPE_STRING, &client,
	   DBUS_TYPE_INVALID)){
		if(m != NULL)
			dbus_message_unref(m);
		return fail("build %s CreateInputContext call", where);
	}
	reply = sendcall(conn, m, where);
	if(reply == NULL)
		return 0;
	dbus_error_init(&err);
	if(!dbus_message_has_signature(reply, "o") ||
	   !dbus_message_get_args(reply, &err, DBUS_TYPE_OBJECT_PATH, &p,
	   DBUS_TYPE_INVALID)){
		dbus_message_unref(reply);
		dbus_error_free(&err);
		return fail("%s returned an invalid context reply", where);
	}
	if(snprintf(path, npath, "%s", p) >= (int)npath){
		dbus_error_free(&err);
		dbus_message_unref(reply);
		return fail("%s context path is too long", where);
	}
	dbus_error_free(&err);
	dbus_message_unref(reply);
	return path[0] == '/' || fail("%s returned invalid context path %s",
		where, path);
}

static int
killowned(pid_t *pid, int *status)
{
	int n, ok;

	ok = 1;
	if(kill(*pid, SIGKILL) < 0 && errno != ESRCH){
		fail("kill -9 %ld: %s", (long)*pid, strerror(errno));
		ok = 0;
	}
	do
		n = waitpid(*pid, status, 0);
	while(n < 0 && errno == EINTR);
	if(n != *pid){
		fail("reap %ld after SIGKILL: %s", (long)*pid,
			n < 0 ? strerror(errno) : "wrong child");
		ok = 0;
	}else
		*pid = -1;
	return ok;
}

static int
waitsecond(Test *t, int *changed)
{
	struct pollfd pfd[2];
	int n, status, timeout;
	int64_t deadline;

	deadline = nowms() + Starttimeout;
	for(;;){
		do
			n = waitpid(t->second, &status, WNOHANG);
		while(n < 0 && errno == EINTR);
		if(n == t->second){
			t->second = -1;
			readpipe(t->seconderrfd, t->seconderr, sizeof t->seconderr,
				&t->nseconderr);
			if(!drainnotify(t, 1, changed))
				return 0;
			if(!WIFEXITED(status) || WEXITSTATUS(status) == 0)
				return fail("second daemon did not exit unsuccessfully: %#x",
					status);
			if(strstr(t->seconderr, "IPC endpoint is already in use") == NULL)
				return fail("second daemon did not report the IPC collision");
			return 1;
		}
		if(n < 0){
			fail("waitpid second daemon %ld: %s", (long)t->second,
				strerror(errno));
			if(errno == ECHILD)
				t->second = -1;
			return 0;
		}
		if(!childalive(&t->first, "first"))
			return 0;
		timeout = leftms(deadline);
		if(timeout == 0){
			fail("second daemon did not exit after the endpoint collision");
			if(!killowned(&t->second, &status))
				return 0;
			return 0;
		}
		pfd[0].fd = t->notifyfd;
		pfd[0].events = POLLIN;
		pfd[0].revents = 0;
		pfd[1].fd = t->seconderrfd;
		pfd[1].events = POLLIN|POLLHUP;
		pfd[1].revents = 0;
		n = poll(pfd, 2, timeout);
		if(n < 0 && errno == EINTR)
			continue;
		if(n < 0)
			return fail("poll second daemon: %s", strerror(errno));
		if(pfd[1].revents != 0)
			readpipe(t->seconderrfd, t->seconderr, sizeof t->seconderr,
				&t->nseconderr);
		if((pfd[0].revents & POLLIN) &&
		   !drainnotify(t, 1, changed))
			return 0;
	}
}

static int
checksocket(Test *t)
{
	struct stat st;

	if(lstat(t->socket, &st) < 0)
		return fail("first IPC socket disappeared: %s", strerror(errno));
	if(!S_ISSOCK(st.st_mode) || st.st_mode != t->socketst.st_mode ||
	   st.st_dev != t->socketst.st_dev || st.st_ino != t->socketst.st_ino)
		return fail("first IPC socket identity or protection changed");
	return 1;
}

static int
checkaddress(Test *t)
{
	struct stat st;
	char contents[2048], address[512];
	size_t ncontents;

	if(lstat(t->addrfile, &st) < 0)
		return fail("first IBus address file disappeared: %s",
			strerror(errno));
	if(st.st_mode != t->addrst.st_mode || st.st_dev != t->addrst.st_dev ||
	   st.st_ino != t->addrst.st_ino)
		return fail("first IBus address file identity or protection changed");
	if(!readfile(t->addrfile, contents, sizeof contents, &ncontents))
		return 0;
	if(ncontents != t->naddrcontents ||
	   memcmp(contents, t->addrcontents, ncontents) != 0)
		return fail("first IBus address file contents changed");
	if(!parseaddress(contents, ncontents, address, sizeof address, t->first))
		return 0;
	return strcmp(address, t->address) == 0 ||
		fail("first private IBus address changed");
}

static int
onlyaddress(Test *t)
{
	DIR *dir;
	struct dirent *de;
	char expected[512];
	char *base;
	int count, ok;

	base = strrchr(t->addrfile, '/');
	if(base == NULL)
		return fail("invalid recorded IBus address path");
	if(snprintf(expected, sizeof expected, "%s", base + 1)
	   >= (int)sizeof expected)
		return fail("recorded IBus address name is too long");
	dir = opendir(t->bus);
	if(dir == NULL)
		return fail("open IBus directory after collision: %s",
			strerror(errno));
	count = 0;
	ok = 1;
	errno = 0;
	while((de = readdir(dir)) != NULL){
		if(strcmp(de->d_name, ".") == 0 || strcmp(de->d_name, "..") == 0)
			continue;
		count++;
		if(strcmp(de->d_name, expected) != 0){
			fail("unexpected IBus directory entry %s", de->d_name);
			ok = 0;
		}
	}
	if(errno != 0){
		fail("read IBus directory after collision: %s", strerror(errno));
		ok = 0;
	}
	if(closedir(dir) < 0){
		fail("close IBus directory after collision: %s", strerror(errno));
		ok = 0;
	}
	if(count != 1){
		fail("IBus directory contains %d entries after collision", count);
		ok = 0;
	}
	return ok;
}

static int
runcollision(Test *t, char *program, char *mapdir)
{
	char firsthello[32], newhello[32];
	char firstpath[96], persistentpath[96], newpath[96];
	int changed;

	if(!startchild(t, program, mapdir, &t->first, &t->firsterrfd) ||
	   !waitready(t) || !snapshot(t))
		return 0;
	t->ipcfirst = connectsocket(t->socket, nowms() + Calltimeout);
	if(t->ipcfirst < 0)
		return fail("connect persistent IPC client: %s", strerror(errno));
	if(!ipcprobe(t->ipcfirst, "persistent pre-collision"))
		return 0;
	t->busfirst = openbus(t->address);
	if(t->busfirst == NULL ||
	   !hello(t->busfirst, firsthello, sizeof firsthello,
	   "persistent pre-collision Hello") ||
	   !createcontext(t->busfirst, firstpath, sizeof firstpath,
	   "persistent pre-collision context"))
		return 0;
	if(!drainnotify(t, 0, NULL))
		return 0;
	changed = 0;
	if(!startchild(t, program, mapdir, &t->second, &t->seconderrfd) ||
	   !waitsecond(t, &changed))
		return 0;
	if(changed)
		return fail("second daemon touched the first IBus address directory");
	if(!childalive(&t->first, "first") || !checksocket(t) ||
	   !checkaddress(t) || !onlyaddress(t))
		return 0;
	if(!ipcprobe(t->ipcfirst, "persistent post-collision"))
		return 0;
	if(!createcontext(t->busfirst, persistentpath, sizeof persistentpath,
	   "persistent post-collision context"))
		return 0;
	t->ipcnew = connectsocket(t->socket, nowms() + Calltimeout);
	if(t->ipcnew < 0)
		return fail("connect new IPC client after collision: %s",
			strerror(errno));
	if(!ipcprobe(t->ipcnew, "new post-collision"))
		return 0;
	t->busnew = openbus(t->address);
	if(t->busnew == NULL ||
	   !hello(t->busnew, newhello, sizeof newhello,
	   "new post-collision Hello") ||
	   !createcontext(t->busnew, newpath, sizeof newpath,
	   "new post-collision context"))
		return 0;
	return childalive(&t->first, "first");
}

static int
stopfirst(Test *t)
{
	struct pollfd pfd;
	int n, ok, reaped, status;
	int64_t deadline;

	if(t->first <= 0)
		return 1;
	ok = 1;
	if(!childalive(&t->first, "first"))
		return 0;
	if(kill(t->first, SIGTERM) < 0){
		fail("kill first daemon %ld: %s", (long)t->first, strerror(errno));
		ok = 0;
	}
	reaped = 0;
	deadline = nowms() + Stoptimeout;
	while(t->first > 0){
		n = waitpid(t->first, &status, WNOHANG);
		if(n == t->first){
			reaped = 1;
			t->first = -1;
			break;
		}
		if(n < 0 && errno == EINTR)
			continue;
		if(n < 0){
			fail("waitpid first daemon %ld: %s", (long)t->first,
				strerror(errno));
			if(errno == ECHILD)
				t->first = -1;
			ok = 0;
			break;
		}
		n = leftms(deadline);
		if(n == 0){
			fail("first daemon %ld did not stop after SIGTERM",
				(long)t->first);
			ok = 0;
			if(!killowned(&t->first, &status))
				ok = 0;
			break;
		}
		pfd.fd = t->firsterrfd;
		pfd.events = POLLIN|POLLHUP;
		pfd.revents = 0;
		if(poll(&pfd, 1, n) < 0 && errno != EINTR){
			fail("poll first daemon termination: %s", strerror(errno));
			ok = 0;
			if(!killowned(&t->first, &status))
				ok = 0;
			break;
		}
		readpipe(t->firsterrfd, t->firsterr, sizeof t->firsterr,
			&t->nfirsterr);
	}
	if(reaped &&
	   !((WIFSIGNALED(status) && WTERMSIG(status) == SIGTERM) ||
	   (WIFEXITED(status) && WEXITSTATUS(status) == 1))){
		fail("first daemon exited with unexpected wait status %#x", status);
		ok = 0;
	}
	return ok;
}

static int
clearbus(Test *t)
{
	DIR *dir;
	struct dirent *de;
	char path[576];
	int ok;

	dir = opendir(t->bus);
	if(dir == NULL)
		return errno == ENOENT || fail("open cleanup directory %s: %s",
			t->bus, strerror(errno));
	ok = 1;
	errno = 0;
	while((de = readdir(dir)) != NULL){
		if(strcmp(de->d_name, ".") == 0 || strcmp(de->d_name, "..") == 0)
			continue;
		if(snprintf(path, sizeof path, "%s/%s", t->bus, de->d_name)
		   >= (int)sizeof path){
			fail("cleanup path is too long: %s", de->d_name);
			ok = 0;
			continue;
		}
		if(unlink(path) < 0 && errno != ENOENT){
			fail("remove IBus cleanup file %s: %s", de->d_name,
				strerror(errno));
			ok = 0;
		}
		errno = 0;
	}
	if(errno != 0){
		fail("read cleanup directory %s: %s", t->bus, strerror(errno));
		ok = 0;
	}
	if(closedir(dir) < 0){
		fail("close cleanup directory %s: %s", t->bus, strerror(errno));
		ok = 0;
	}
	return ok;
}

static int
rmdirknown(char *path)
{
	if(path[0] == '\0' || rmdir(path) == 0 || errno == ENOENT)
		return 1;
	return fail("rmdir %s: %s", path, strerror(errno));
}

static int
cleanup(Test *t)
{
	int n, ok, status;

	ok = 1;
	closebus(&t->busnew);
	closebus(&t->busfirst);
	if(t->ipcnew >= 0){
		if(close(t->ipcnew) < 0){
			fail("close new IPC client: %s", strerror(errno));
			ok = 0;
		}
		t->ipcnew = -1;
	}
	if(t->ipcfirst >= 0){
		if(close(t->ipcfirst) < 0){
			fail("close persistent IPC client: %s", strerror(errno));
			ok = 0;
		}
		t->ipcfirst = -1;
	}
	if(t->second > 0){
		do
			n = waitpid(t->second, &status, WNOHANG);
		while(n < 0 && errno == EINTR);
		if(n == t->second)
			t->second = -1;
		else if(n == 0){
			fail("second daemon still running during cleanup");
			ok = 0;
			if(!killowned(&t->second, &status))
				ok = 0;
		}else{
			fail("check second daemon during cleanup: %s", strerror(errno));
			ok = 0;
			if(errno == ECHILD)
				t->second = -1;
			else if(!killowned(&t->second, &status))
				ok = 0;
		}
	}
	if(!stopfirst(t))
		ok = 0;
	readpipe(t->firsterrfd, t->firsterr, sizeof t->firsterr,
		&t->nfirsterr);
	readpipe(t->seconderrfd, t->seconderr, sizeof t->seconderr,
		&t->nseconderr);
	if(t->firsterrfd >= 0){
		if(close(t->firsterrfd) < 0){
			fail("close first daemon stderr: %s", strerror(errno));
			ok = 0;
		}
		t->firsterrfd = -1;
	}
	if(t->seconderrfd >= 0){
		if(close(t->seconderrfd) < 0){
			fail("close second daemon stderr: %s", strerror(errno));
			ok = 0;
		}
		t->seconderrfd = -1;
	}
	if(t->notifyfd >= 0){
		if(t->buswd >= 0 &&
		   inotify_rm_watch(t->notifyfd, t->buswd) < 0 && errno != EINVAL){
			fail("remove IBus watch: %s", strerror(errno));
			ok = 0;
		}
		if(close(t->notifyfd) < 0){
			fail("close endpoint watches: %s", strerror(errno));
			ok = 0;
		}
		t->notifyfd = -1;
	}
	if(t->socket[0] != '\0' && unlink(t->socket) < 0 && errno != ENOENT){
		fail("remove IPC socket %s: %s", t->socket, strerror(errno));
		ok = 0;
	}
	if(t->bus[0] != '\0' && !clearbus(t)) ok = 0;
	if(!rmdirknown(t->bus)) ok = 0;
	if(!rmdirknown(t->ibus)) ok = 0;
	if(!rmdirknown(t->config)) ok = 0;
	if(!rmdirknown(t->runtime)) ok = 0;
	if(!rmdirknown(t->home)) ok = 0;
	if(!rmdirknown(t->root)) ok = 0;
	return ok;
}

int
main(int argc, char **argv)
{
	Test test;
	int ok;

	if(argc != 3){
		fprintf(stderr, "usage: daemon_collision_test strans mapdir\n");
		return 2;
	}
	ok = setup(&test);
	if(ok)
		ok = runcollision(&test, argv[1], argv[2]);
	if(!cleanup(&test))
		ok = 0;
	if(!ok){
		showerrors(&test);
		return 1;
	}
	printf("daemon endpoint collision ownership: ok\n");
	return 0;
}