/*
 * by Manuel Bouyer (bouyer@ensta.fr)
 * 
 * There is no copyright, you can use it as you want.
 */

#include <sys/param.h>
#include <sys/types.h>
#include <sys/mount.h>
#include <sys/file.h>
#include <sys/stat.h>
#include <sys/signal.h>

#include <stdio.h>
#include <fstab.h>
#include <ctype.h>
#include <stdlib.h>
#include <string.h>
#include <pwd.h>
#include <grp.h>
#include <errno.h>

#include <syslog.h>
#include <varargs.h>

#include <ufs/ufs/quota.h>
#include <rpc/rpc.h>
#include <rpcsvc/rquota.h>

void rquota_svc __P((struct svc_req *request, SVCXPRT *transport));
void exit_svc __P((int signo));
void sendquota __P((struct svc_req *request, SVCXPRT *transport));
void printerr_reply __P((SVCXPRT *transport));
void initfs __P((void));
int getfsquota __P((long id, char *path, struct dqblk *dqblk));
int hasquota __P((struct fstab *fs, char **qfnamep));

/*
 * structure containing informations about ufs filesystems
 * initialised by initfs()
 */
struct fs_stat {
	struct fs_stat *fs_next;	/* next element */
	char   *fs_file;		/* mount point of the filesystem */
	char   *qfpathname;		/* pathname of the quota file */
	dev_t   st_dev;			/* device of the filesystem */
} fs_stat;
struct fs_stat *fs_begin = NULL;

int
main(argc, argv)
	int     argc;
	char   *argv[];
{
	SVCXPRT *transport;
	int     sock = 0;
	int     proto = 0;
	int     from_inetd = 1;
	struct sockaddr_in from;
	int     fromlen;

	openlog("rquotad", LOG_PID, LOG_DAEMON);
	if (getsockname(0, (struct sockaddr *) & from, &fromlen) < 0) {
		from_inetd = 0;
		sock = RPC_ANYSOCK;
		proto = IPPROTO_UDP;
	}
	if (!from_inetd) {
		daemon(0, 0);
		pmap_unset(RQUOTAPROG, RQUOTAVERS);
		signal(SIGINT, exit_svc);	/* trap some signals */
		signal(SIGQUIT, exit_svc);	/* to unregister the service */
		signal(SIGTERM, exit_svc);	/* before exiting */
	}

	/* create and register the service */
	if ((transport = svcudp_create(sock)) == NULL) {
		syslog(LOG_ERR, "couldn't create UDP transport");
		exit(1);
	}
	if (svc_register(transport, RQUOTAPROG, RQUOTAVERS,
	    rquota_svc, proto) == 0) {
		syslog(LOG_ERR, "couldn't register service");
		exit(1);
	}
	initfs();		/* init the fs_stat list */
	svc_run();
	syslog(LOG_ERR, "svc_run has returned !");
	exit(1);		/* svc_run don't return */
}

/* rquota service */
void 
rquota_svc(request, transport)
	struct svc_req *request;
	SVCXPRT *transport;
{
	switch (request->rq_proc) {
	case NULLPROC:
		errno = 0;
		if (svc_sendreply(transport, xdr_void, 0) == 0)
			printerr_reply(transport);
		break;
	case RQUOTAPROC_GETQUOTA:
	case RQUOTAPROC_GETACTIVEQUOTA:
		sendquota(request, transport);
		break;
	default:
		svcerr_noproc(transport);
		break;
	}
	return;
}

/* read quota for the specified id, and send it */
void 
sendquota(request, transport)
	struct svc_req *request;
	SVCXPRT *transport;
{
	struct getquota_args getq_args;
	struct getquota_rslt getq_rslt;
	struct dqblk dqblk;
	struct timeval timev;

	getq_args.gqa_pathp = NULL;	/* allocated by svc_getargs */
	if (svc_getargs(transport, xdr_getquota_args, &getq_args) == 0) {
		svcerr_decode(transport);
		return;
	}
	if (request->rq_cred.oa_flavor != AUTH_UNIX) {
		/* bad auth */
		getq_rslt.status = Q_EPERM;
	} else if (getfsquota(getq_args.gqa_uid, getq_args.gqa_pathp,
	    &dqblk) == 0) {
		getq_rslt.status = Q_NOQUOTA;	/* failed, return noquota */
	} else {
		gettimeofday(&timev, NULL);
		getq_rslt.status = Q_OK;
		getq_rslt.getquota_rslt_u.gqr_rquota.rq_active = TRUE;
		getq_rslt.getquota_rslt_u.gqr_rquota.rq_bsize = DEV_BSIZE;
		getq_rslt.getquota_rslt_u.gqr_rquota.rq_bhardlimit =
		    dqblk.dqb_bhardlimit;
		getq_rslt.getquota_rslt_u.gqr_rquota.rq_bsoftlimit =
		    dqblk.dqb_bsoftlimit;
		getq_rslt.getquota_rslt_u.gqr_rquota.rq_curblocks =
		    dqblk.dqb_curblocks;
		getq_rslt.getquota_rslt_u.gqr_rquota.rq_fhardlimit =
		    dqblk.dqb_ihardlimit;
		getq_rslt.getquota_rslt_u.gqr_rquota.rq_fsoftlimit =
		    dqblk.dqb_isoftlimit;
		getq_rslt.getquota_rslt_u.gqr_rquota.rq_curfiles =
		    dqblk.dqb_curinodes;
		getq_rslt.getquota_rslt_u.gqr_rquota.rq_btimeleft =
		    dqblk.dqb_btime - timev.tv_sec;
		getq_rslt.getquota_rslt_u.gqr_rquota.rq_ftimeleft =
		    dqblk.dqb_itime - timev.tv_sec;
	}
	if (svc_sendreply(transport, xdr_getquota_rslt, (char *)&getq_rslt) == 0)
		printerr_reply(transport);
	return;
}

void 
exit_svc(signo)			/* signal trapped */
	int     signo;
{
	syslog(LOG_ERR, "exiting on signal %d", signo);
	pmap_unset(RQUOTAPROG, RQUOTAVERS);
	exit(0);
}

void 
printerr_reply(transport)	/* when a reply to a request failed */
	SVCXPRT *transport;
{
	char   *name;
	struct sockaddr_in *caller;
	int     save_errno;

	save_errno = errno;

	caller = svc_getcaller(transport);
	name = (char *)inet_ntoa(caller->sin_addr);
	errno = save_errno;
	if (errno == 0)
		syslog(LOG_ERR, "couldn't send reply to %s", name);
	else
		syslog(LOG_ERR, "couldn't send reply to %s: %m", name);
	return;
}

/* initialise the fs_tab list from entries in /etc/fstab */
void 
initfs()
{
	struct fs_stat *fs_current = NULL;
	struct fs_stat *fs_next = NULL;
	char *qfpathname;
	struct fstab *fs;
	struct stat st;
	char *qfextension[] = INITQFNAMES;

	setfsent();
	while (fs = getfsent()) {
		if (strcmp(fs->fs_vfstype, "ufs"))
			continue;
		if (!hasquota(fs, &qfpathname))
			continue;

		fs_current = (struct fs_stat *) malloc(sizeof(struct fs_stat));
		fs_current->fs_next = fs_next;	/* next element */

		fs_current->fs_file = malloc(sizeof(char) * (strlen(fs->fs_file) + 1));
		strcpy(fs_current->fs_file, fs->fs_file);

		fs_current->qfpathname = malloc(sizeof(char) * (strlen(qfpathname) + 1));
		strcpy(fs_current->qfpathname, qfpathname);

		stat(qfpathname, &st);
		fs_current->st_dev = st.st_dev;

		fs_next = fs_current;
	}
	endfsent();
	fs_begin = fs_current;
}

/*
 * gets the quotas for id, filesystem path.
 * Return 0 if fail, 1 otherwise
 */
int
getfsquota(id, path, dqblk)
	long id;
	char   *path;
	struct dqblk *dqblk;
{
	struct stat st_path;
	struct fs_stat *fs;
	int	qcmd, fd, ret = 0;
	char	*qfextension[] = INITQFNAMES;

	if (stat(path, &st_path) < 0)
		return (0);

	qcmd = QCMD(Q_GETQUOTA, USRQUOTA);

	for (fs = fs_begin; fs != NULL; fs = fs->fs_next) {
		/* where the devise is the same as path */
		if (fs->st_dev != st_path.st_dev)
			continue;

		/* find the specified filesystem. get and return quota */
		if (quotactl(fs->fs_file, qcmd, id, dqblk) == 0)
			return (1);

		if ((fd = open(fs->qfpathname, O_RDONLY)) < 0) {
			syslog(LOG_ERR, "couldn't read %s:%m", fs->qfpathname);
			return (0);
		}
		if (lseek(fd, (off_t)(id * sizeof(struct dqblk)), L_SET) == (off_t)-1) {
			close(fd);
			return (1);
		}
		switch (read(fd, dqblk, sizeof(struct dqblk))) {
		case 0:
			/*
                         * Convert implicit 0 quota (EOF)
                         * into an explicit one (zero'ed dqblk)
                         */
			bzero((caddr_t) dqblk, sizeof(struct dqblk));
			ret = 1;
			break;
		case sizeof(struct dqblk):	/* OK */
			ret = 1;
			break;
		default:	/* ERROR */
			syslog(LOG_ERR, "read error: %s: %m", fs->qfpathname);
			close(fd);
			return (0);
		}
		close(fd);
	}
	return (ret);
}

/*
 * Check to see if a particular quota is to be enabled.
 * Comes from quota.c, NetBSD 0.9
 */
int
hasquota(fs, qfnamep)
	struct fstab *fs;
	char  **qfnamep;
{
	static char initname, usrname[100];
	static char buf[BUFSIZ];
	char	*opt, *cp;
	char	*qfextension[] = INITQFNAMES;

	if (!initname) {
		sprintf(usrname, "%s%s", qfextension[USRQUOTA], QUOTAFILENAME);
		initname = 1;
	}
	strcpy(buf, fs->fs_mntops);
	for (opt = strtok(buf, ","); opt; opt = strtok(NULL, ",")) {
		if (cp = index(opt, '='))
			*cp++ = '\0';
		if (strcmp(opt, usrname) == 0)
			break;
	}
	if (!opt)
		return (0);
	if (cp) {
		*qfnamep = cp;
		return (1);
	}
	sprintf(buf, "%s/%s.%s", fs->fs_file, QUOTAFILENAME, qfextension[USRQUOTA]);
	*qfnamep = buf;
	return (1);
}