/*      $OpenBSD: rquotad.c,v 1.26 2024/05/21 05:00:47 jsg Exp $        */

/*
 * by Manuel Bouyer (bouyer@ensta.fr). Public domain.
 */

#include <sys/param.h>  /* DEV_BSIZE */
#include <sys/types.h>
#include <sys/mount.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <signal.h>

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

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

void rquota_service(struct svc_req *request, SVCXPRT *transp);
void sendquota(struct svc_req *request, SVCXPRT *transp);
void initfs(void);
int getfsquota(long id, char *path, struct dqblk *dqblk);
int hasquota(struct fstab *fs, char **qfnamep);

/*
 * structure containing information 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 */
};
struct fs_stat *fs_begin = NULL;

int from_inetd = 1;

static void
cleanup(int signo)
{
        (void) pmap_unset(RQUOTAPROG, RQUOTAVERS);      /* XXX signal races */
        _exit(0);
}

int
main(int argc, char *argv[])
{
        SVCXPRT *transp;
        int sock = 0;
        int proto = 0;
        struct sockaddr_storage from;
        socklen_t fromlen;

        fromlen = sizeof(from);
        if (getsockname(0, (struct sockaddr *)&from, &fromlen) == -1) {
                from_inetd = 0;
                sock = RPC_ANYSOCK;
                proto = IPPROTO_UDP;
        }

        if (!from_inetd) {
                daemon(0, 0);

                (void) pmap_unset(RQUOTAPROG, RQUOTAVERS);

                (void) signal(SIGINT, cleanup);
                (void) signal(SIGTERM, cleanup);
                (void) signal(SIGHUP, cleanup);
        }

        openlog("rpc.rquotad", LOG_CONS|LOG_PID, LOG_DAEMON);

        /* create and register the service */
        transp = svcudp_create(sock);
        if (transp == NULL) {
                syslog(LOG_ERR, "couldn't create udp service.");
                exit(1);
        }
        if (!svc_register(transp, RQUOTAPROG, RQUOTAVERS, rquota_service, proto)) {
                syslog(LOG_ERR, "unable to register (RQUOTAPROG, RQUOTAVERS, %s).",
                    proto ? "udp" : "(inetd)");
                exit(1);
        }

        initfs();               /* init the fs_stat list */
        svc_run();
        syslog(LOG_ERR, "svc_run returned");
        exit(1);
}

void
rquota_service(struct svc_req *request, SVCXPRT *transp)
{
        switch (request->rq_proc) {
        case NULLPROC:
                (void)svc_sendreply(transp, xdr_void, (char *)NULL);
                break;

        case RQUOTAPROC_GETQUOTA:
        case RQUOTAPROC_GETACTIVEQUOTA:
                sendquota(request, transp);
                break;

        default:
                svcerr_noproc(transp);
                break;
        }
        if (from_inetd)
                exit(0);
}

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

        bzero((char *)&getq_args, sizeof(getq_args));
        if (!svc_getargs(transp, xdr_getquota_args, (caddr_t)&getq_args)) {
                svcerr_decode(transp);
                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)) {
                /* failed, return noquota */
                getq_rslt.status = Q_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(transp, xdr_getquota_rslt, (char *)&getq_rslt)) {
                svcerr_systemerr(transp);
        }
        if (!svc_freeargs(transp, xdr_getquota_args, (caddr_t)&getq_args)) {
                syslog(LOG_ERR, "unable to free arguments");
                exit(1);
        }
}

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

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

                fs_current = malloc(sizeof(struct fs_stat));
                if (fs_current == NULL) {
                        syslog(LOG_ERR, "can't malloc: %m");
                        exit(1);
                }
                fs_current->fs_next = fs_next;  /* next element */

                fs_current->fs_file = strdup(fs->fs_file);
                if (fs_current->fs_file == NULL) {
                        syslog(LOG_ERR, "can't strdup: %m");
                        exit(1);
                }

                fs_current->qfpathname = strdup(qfpathname);
                if (fs_current->qfpathname == NULL) {
                        syslog(LOG_ERR, "can't strdup: %m");
                        exit(1);
                }

                stat(fs_current->fs_file, &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(long id, char *path, struct dqblk *dqblk)
{
        struct stat st_path;
        struct fs_stat *fs;
        int     qcmd, fd, ret = 0;

        if (stat(path, &st_path) == -1)
                return (0);

        qcmd = QCMD(Q_GETQUOTA, USRQUOTA);

        for (fs = fs_begin; fs != NULL; fs = fs->fs_next) {
                /* where the device 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, (char *)dqblk) == 0)
                        return (1);

                if ((fd = open(fs->qfpathname, O_RDONLY)) == -1) {
                        syslog(LOG_ERR, "open error: %s: %m", fs->qfpathname);
                        return (0);
                }
                if (lseek(fd, (off_t)(id * sizeof(struct dqblk)), SEEK_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(struct fstab *fs, char **qfnamep)
{
        static char initname, usrname[100];
        static char buf[BUFSIZ];
        char    *opt, *cp;
        char    *qfextension[] = INITQFNAMES;

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