/*      $OpenBSD: yp.c,v 1.14 2015/02/11 01:26:00 pelikan Exp $ */
/*
 * Copyright (c) 2008 Pierre-Yves Ritschard <pyr@openbsd.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/types.h>
#include <sys/param.h>
#include <sys/queue.h>
#include <sys/socket.h>
#include <sys/select.h>
#include <sys/tree.h>

#include <netinet/in.h>
#include <arpa/inet.h>

#include <errno.h>
#include <event.h>
#include <fcntl.h>
#include <unistd.h>
#include <pwd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <limits.h>

#include <rpc/rpc.h>
#include <rpc/xdr.h>
#include <rpc/pmap_clnt.h>
#include <rpc/pmap_prot.h>
#include <rpc/pmap_rmt.h>
#include <rpcsvc/yp.h>
#include <rpcsvc/ypclnt.h>

#include "ypldap.h"

void    yp_dispatch(struct svc_req *, SVCXPRT *);
void    yp_disable_events(void);
void    yp_fd_event(int, short, void *);
int     yp_check(struct svc_req *);
int     yp_valid_domain(char *, struct ypresp_val *);
void    yp_make_val(struct ypresp_val *, char *, int);
void    yp_make_keyval(struct ypresp_key_val *, char *, char *);

static struct env       *env;

struct yp_event {
        TAILQ_ENTRY(yp_event)    ye_entry;
        struct event             ye_event;
};

struct yp_data {
        SVCXPRT                 *yp_trans_udp;
        SVCXPRT                 *yp_trans_tcp;
        TAILQ_HEAD(, yp_event)   yd_events;
};

void
yp_disable_events(void)
{
        struct yp_event *ye;

        while ((ye = TAILQ_FIRST(&env->sc_yp->yd_events)) != NULL) {
                TAILQ_REMOVE(&env->sc_yp->yd_events, ye, ye_entry);
                event_del(&ye->ye_event);
                free(ye);
        }
}

void
yp_enable_events(void)
{
        int i;
        struct yp_event *ye;

        for (i = 0; i < getdtablesize(); i++) {
                if ((ye = calloc(1, sizeof(*ye))) == NULL)
                        fatal(NULL);
                event_set(&ye->ye_event, i, EV_READ, yp_fd_event, NULL);
                event_add(&ye->ye_event, NULL);
                TAILQ_INSERT_TAIL(&env->sc_yp->yd_events, ye, ye_entry);
        }
}

void
yp_fd_event(int fd, short event, void *p)
{
        svc_getreq_common(fd);
        yp_disable_events();
        yp_enable_events();
}

void
yp_init(struct env *x_env)
{
        struct yp_data  *yp;

        if ((yp = calloc(1, sizeof(*yp))) == NULL)
                fatal(NULL);
        TAILQ_INIT(&yp->yd_events);

        env = x_env;
        env->sc_yp = yp;
        
        (void)pmap_unset(YPPROG, YPVERS);

        if ((yp->yp_trans_udp = svcudp_create(RPC_ANYSOCK)) == NULL)
                fatal("cannot create udp service");
        if ((yp->yp_trans_tcp = svctcp_create(RPC_ANYSOCK, 0, 0)) == NULL)
                fatal("cannot create tcp service");

        if (!svc_register(yp->yp_trans_udp, YPPROG, YPVERS,
            yp_dispatch, IPPROTO_UDP)) {
                fatal("unable to register (YPPROG, YPVERS, udp)");
        }
        if (!svc_register(yp->yp_trans_tcp, YPPROG, YPVERS,
            yp_dispatch, IPPROTO_TCP)) {
                fatal("unable to register (YPPROG, YPVERS, tcp)");
        }
}

/*
 * lots of inspiration from ypserv by Mats O Jansson
 */
void
yp_dispatch(struct svc_req *req, SVCXPRT *trans)
{
        xdrproc_t                xdr_argument;
        xdrproc_t                xdr_result;
        char                    *result;
        char                    *(*cb)(char *, struct svc_req *);
        union {
                domainname       ypproc_domain_2_arg;
                domainname       ypproc_domain_nonack_2_arg;
                ypreq_key        ypproc_match_2_arg;
                ypreq_nokey      ypproc_first_2_arg;
                ypreq_key        ypproc_next_2_arg;
                ypreq_xfr        ypproc_xfr_2_arg;
                ypreq_nokey      ypproc_all_2_arg;
                ypreq_nokey      ypproc_master_2_arg;
                ypreq_nokey      ypproc_order_2_arg;
                domainname       ypproc_maplist_2_arg;
        } argument;

        xdr_argument = (xdrproc_t) xdr_void;
        xdr_result = (xdrproc_t) xdr_void;
        cb = NULL;
        switch (req->rq_proc) {
        case YPPROC_NULL:
                xdr_argument = (xdrproc_t) xdr_void;
                xdr_result = (xdrproc_t) xdr_void;
                if (yp_check(req) == -1)
                        return;
                result = NULL;
                if (!svc_sendreply(trans, (xdrproc_t) xdr_void,
                    (void *)&result))
                        svcerr_systemerr(trans);
                return;
        case YPPROC_DOMAIN:
                xdr_argument = (xdrproc_t) xdr_domainname;
                xdr_result = (xdrproc_t) xdr_bool;
                if (yp_check(req) == -1)
                        return;
                cb = (void *)ypproc_domain_2_svc;
                break;
        case YPPROC_DOMAIN_NONACK:
                xdr_argument = (xdrproc_t) xdr_domainname;
                xdr_result = (xdrproc_t) xdr_bool;
                if (yp_check(req) == -1)
                        return;
                cb = (void *)ypproc_domain_nonack_2_svc;
                break;
        case YPPROC_MATCH:
                xdr_argument = (xdrproc_t) xdr_ypreq_key;
                xdr_result = (xdrproc_t) xdr_ypresp_val;
                if (yp_check(req) == -1)
                        return;
                cb = (void *)ypproc_match_2_svc;
                break;
        case YPPROC_FIRST:
                xdr_argument = (xdrproc_t) xdr_ypreq_nokey;
                xdr_result = (xdrproc_t) xdr_ypresp_key_val;
                if (yp_check(req) == -1)
                        return;
                cb = (void *)ypproc_first_2_svc;
                break;
        case YPPROC_NEXT:
                xdr_argument = (xdrproc_t) xdr_ypreq_key;
                xdr_result = (xdrproc_t) xdr_ypresp_key_val;
                if (yp_check(req) == -1)
                        return;
                cb = (void *)ypproc_next_2_svc;
                break;
        case YPPROC_XFR:
                if (yp_check(req) == -1)
                        return;
                svcerr_noproc(trans);
                return;
        case YPPROC_CLEAR:
                log_debug("ypproc_clear");
                if (yp_check(req) == -1)
                        return;
                svcerr_noproc(trans);
                return;
        case YPPROC_ALL:
                log_debug("ypproc_all");
                xdr_argument = (xdrproc_t) xdr_ypreq_nokey;
                xdr_result = (xdrproc_t) xdr_ypresp_all;
                if (yp_check(req) == -1)
                        return;
                cb = (void *)ypproc_all_2_svc;
                break;
        case YPPROC_MASTER:
                log_debug("ypproc_master");
                xdr_argument = (xdrproc_t) xdr_ypreq_nokey;
                xdr_result = (xdrproc_t) xdr_ypresp_master;
                if (yp_check(req) == -1)
                        return;
                cb = (void *)ypproc_master_2_svc;
                break;
        case YPPROC_ORDER:
                log_debug("ypproc_order");
                if (yp_check(req) == -1)
                        return;
                svcerr_noproc(trans);
                return;
        case YPPROC_MAPLIST:
                log_debug("ypproc_maplist");
                xdr_argument = (xdrproc_t) xdr_domainname;
                xdr_result = (xdrproc_t) xdr_ypresp_maplist;
                if (yp_check(req) == -1)
                        return;
                cb = (void *)ypproc_maplist_2_svc;
                break;
        default:
                svcerr_noproc(trans);
                return;
        }
        (void)memset(&argument, 0, sizeof(argument));

        if (!svc_getargs(trans, xdr_argument, (caddr_t)&argument)) {
                svcerr_decode(trans);
                return;
        }
        result = (*cb)((char *)&argument, req);
        if (result != NULL && !svc_sendreply(trans, xdr_result, result))
                svcerr_systemerr(trans);
        if (!svc_freeargs(trans, xdr_argument, (caddr_t)&argument)) {
                /*
                 * ypserv does it too.
                 */
                fatal("unable to free arguments");
        }
}

int
yp_check(struct svc_req *req)
{
        /*
         * We might want to know who we allow here.
         */
        return (0);
}

int
yp_valid_domain(char *domain, struct ypresp_val *res)
{
        if (domain == NULL) {
                log_debug("NULL domain !");
                return (-1);
        }
        if (strcmp(domain, env->sc_domainname) != 0) {
                res->stat = YP_NODOM;
                return (-1);
        }
        return (0);
}

bool_t *
ypproc_domain_2_svc(domainname *arg, struct svc_req *req)
{
        static bool_t   res;
        
        res = (bool_t)1;
        if (strcmp(*arg, env->sc_domainname) != 0)
                res = (bool_t)0;
        return (&res);
}

bool_t *
ypproc_domain_nonack_2_svc(domainname *arg, struct svc_req *req)
{
        static bool_t   res;
        
        if (strcmp(*arg, env->sc_domainname) != 0)
                return NULL;
        res = (bool_t)1;
        return (&res);
}

ypresp_val *
ypproc_match_2_svc(ypreq_key *arg, struct svc_req *req)
{
        struct userent           ukey;
        struct userent          *ue;
        struct groupent          gkey;
        struct groupent         *ge;
        static struct ypresp_val res;
        const char              *estr;
        char                    *bp, *cp;
        char                     *key;

        log_debug("matching '%.*s' in map %s", arg->key.keydat_len,
           arg->key.keydat_val, arg->map);

        if (yp_valid_domain(arg->domain, (struct ypresp_val *)&res) == -1)
                return (&res);

        if (env->sc_user_names == NULL) {
                /*
                 * tree not ready.
                 */
                return (NULL);
        }

        if (arg->key.keydat_len > YPMAXRECORD) {
                log_debug("argument too long");
                return (NULL);
        }
        key = calloc(arg->key.keydat_len + 1, 1);
        if (key == NULL)
                return (NULL);
        (void)strncpy(key, arg->key.keydat_val, arg->key.keydat_len);

        if (strcmp(arg->map, "passwd.byname") == 0 ||
            strcmp(arg->map, "master.passwd.byname") == 0) {
                ukey.ue_line = key;
                if ((ue = RB_FIND(user_name_tree, env->sc_user_names,
                    &ukey)) == NULL) {
                        res.stat = YP_NOKEY;
                        goto out;
                }

                yp_make_val(&res, ue->ue_line, 1);
                goto out;
        } else if (strcmp(arg->map, "passwd.byuid") == 0 ||
                   strcmp(arg->map, "master.passwd.byuid") == 0) {
                ukey.ue_uid = strtonum(key, 0, UID_MAX, &estr); 
                if (estr) {
                        res.stat = YP_BADARGS;
                        goto out;
                }

                if ((ue = RB_FIND(user_uid_tree, &env->sc_user_uids,
                    &ukey)) == NULL) {
                        res.stat = YP_NOKEY;
                        goto out;
                }

                yp_make_val(&res, ue->ue_line, 1);
                return (&res);
        } else if (strcmp(arg->map, "group.bygid") == 0) {
                gkey.ge_gid = strtonum(key, 0, GID_MAX, &estr); 
                if (estr) {
                        res.stat = YP_BADARGS;
                        goto out;
                }
                if ((ge = RB_FIND(group_gid_tree, &env->sc_group_gids,
                    &gkey)) == NULL) {
                        res.stat = YP_NOKEY;
                        goto out;
                }

                yp_make_val(&res, ge->ge_line, 1);
                return (&res);
        } else if (strcmp(arg->map, "group.byname") == 0) {
                gkey.ge_line = key;
                if ((ge = RB_FIND(group_name_tree, env->sc_group_names,
                    &gkey)) == NULL) {
                        res.stat = YP_NOKEY;
                        goto out;
                }

                yp_make_val(&res, ge->ge_line, 1);
                return (&res);
        } else if (strcmp(arg->map, "netid.byname") == 0) {
                bp = cp = key;

                if (strncmp(bp, "unix.", strlen("unix.")) != 0) {
                        res.stat = YP_BADARGS;
                        goto out;
                }

                bp += strlen("unix.");

                if (*bp == '\0') {
                        res.stat = YP_BADARGS;
                        goto out;
                }

                if (!(cp = strsep(&bp, "@"))) {
                        res.stat = YP_BADARGS;
                        goto out;
                }

                if (strcmp(bp, arg->domain) != 0) {
                        res.stat = YP_BADARGS;
                        goto out;
                }

                ukey.ue_uid = strtonum(cp, 0, UID_MAX, &estr); 
                if (estr) {
                        res.stat = YP_BADARGS;
                        goto out;
                }

                if ((ue = RB_FIND(user_uid_tree, &env->sc_user_uids,
                    &ukey)) == NULL) {
                        res.stat = YP_NOKEY;
                        goto out;
                }

                yp_make_val(&res, ue->ue_netid_line, 0);
                goto out;
        
        } else {
                log_debug("unknown map %s", arg->map);
                res.stat = YP_NOMAP;
                goto out;
        }
out:
        free(key);
        return (&res);
}

ypresp_key_val *
ypproc_first_2_svc(ypreq_nokey *arg, struct svc_req *req)
{
        static struct ypresp_key_val    res;

        if (yp_valid_domain(arg->domain, (struct ypresp_val *)&res) == -1)
                return (&res);

        if (strcmp(arg->map, "passwd.byname") == 0 ||
            strcmp(arg->map, "master.passwd.byname") == 0) {
                if (env->sc_user_lines == NULL)
                        return (NULL);

                yp_make_keyval(&res, env->sc_user_lines, env->sc_user_lines);
        } else if (strcmp(arg->map, "group.byname") == 0) {
                if (env->sc_group_lines == NULL)
                        return (NULL);

                yp_make_keyval(&res, env->sc_group_lines, env->sc_group_lines);
        } else {
                log_debug("unknown map %s", arg->map);
                res.stat = YP_NOMAP;
        }

        return (&res);
}

ypresp_key_val *
ypproc_next_2_svc(ypreq_key *arg, struct svc_req *req)
{
        struct userent                   ukey;
        struct userent                  *ue;
        struct groupent                  gkey;
        struct groupent                 *ge;
        char                            *line;
        static struct ypresp_key_val     res;
        char                             *key;

        if (yp_valid_domain(arg->domain, (struct ypresp_val *)&res) == -1)
                return (&res);

        key = NULL;
        if (strcmp(arg->map, "passwd.byname") == 0 ||
            strcmp(arg->map, "master.passwd.byname") == 0) {
                key = calloc(arg->key.keydat_len + 1, 1);
                if (key == NULL) {
                        res.stat = YP_YPERR;
                        return (&res);
                }
                (void)strncpy(key, arg->key.keydat_val,
                    arg->key.keydat_len);
                ukey.ue_line = key;
                if ((ue = RB_FIND(user_name_tree, env->sc_user_names,
                    &ukey)) == NULL) {
                        /*
                         * canacar's trick:
                         * the user might have been deleted in between calls
                         * to next since the tree may be modified by a reload.
                         * next should still return the next user in
                         * lexicographical order, hence insert the search key
                         * and look up the next field, then remove it again.
                         */
                        RB_INSERT(user_name_tree, env->sc_user_names, &ukey);
                        if ((ue = RB_NEXT(user_name_tree, &env->sc_user_names,
                            &ukey)) == NULL) {
                                RB_REMOVE(user_name_tree, env->sc_user_names,
                                    &ukey);
                                res.stat = YP_NOKEY;
                                free(key);
                                return (&res);
                        }
                        RB_REMOVE(user_name_tree, env->sc_user_names, &ukey);
                }
                line = ue->ue_line + (strlen(ue->ue_line) + 1);
                line = line + (strlen(line) + 1);
                yp_make_keyval(&res, line, line);
                free(key);
                return (&res);


        } else if (strcmp(arg->map, "group.byname") == 0) {
                key = calloc(arg->key.keydat_len + 1, 1);
                if (key == NULL) {
                        res.stat = YP_YPERR;
                        return (&res);
                }
                (void)strncpy(key, arg->key.keydat_val,
                    arg->key.keydat_len);
                
                gkey.ge_line = key;
                if ((ge = RB_FIND(group_name_tree, env->sc_group_names,
                    &gkey)) == NULL) {
                        /*
                         * canacar's trick reloaded.
                         */
                        RB_INSERT(group_name_tree, env->sc_group_names, &gkey);
                        if ((ge = RB_NEXT(group_name_tree, &env->sc_group_names,
                            &gkey)) == NULL) {
                                RB_REMOVE(group_name_tree, env->sc_group_names,
                                    &gkey);
                                res.stat = YP_NOKEY;
                                free(key);
                                return (&res);
                        }
                        RB_REMOVE(group_name_tree, env->sc_group_names, &gkey);
                }

                line = ge->ge_line + (strlen(ge->ge_line) + 1);
                line = line + (strlen(line) + 1);
                yp_make_keyval(&res, line, line);
                free(key);
                return (&res);
        } else {
                log_debug("unknown map %s", arg->map);
                res.stat = YP_NOMAP;
                return (&res);
        }
}

ypresp_all *
ypproc_all_2_svc(ypreq_nokey *arg, struct svc_req *req)
{
        static struct ypresp_all        res;

        if (yp_valid_domain(arg->domain, (struct ypresp_val *)&res) == -1)
                return (&res);

        svcerr_auth(req->rq_xprt, AUTH_FAILED);
        return (NULL);
}

ypresp_master *
ypproc_master_2_svc(ypreq_nokey *arg, struct svc_req *req)
{
        static struct ypresp_master      res;
        static char master[YPMAXPEER + 1];

        memset(&res, 0, sizeof(res));
        if (yp_valid_domain(arg->domain, (struct ypresp_val *)&res) == -1)
                return (&res);
        
        if (gethostname(master, sizeof(master)) == 0) {
                res.peer = (peername)master;
                res.stat = YP_TRUE;
        } else
                res.stat = YP_NOKEY;

        return (&res);
}

ypresp_maplist *
ypproc_maplist_2_svc(domainname *arg, struct svc_req *req)
{
        size_t                   i;
        static struct {
                char            *name;
                int              cond;
        }                        mapnames[] = {
                { "passwd.byname",              YPMAP_PASSWD_BYNAME },
                { "passwd.byuid",               YPMAP_PASSWD_BYUID },
                { "master.passwd.byname",       YPMAP_MASTER_PASSWD_BYNAME },
                { "master.passwd.byuid",        YPMAP_MASTER_PASSWD_BYUID },
                { "group.byname",               YPMAP_GROUP_BYNAME },
                { "group.bygid",                YPMAP_GROUP_BYGID },
                { "netid.byname",               YPMAP_NETID_BYNAME },
        };
        static ypresp_maplist    res;
        static struct ypmaplist  maps[nitems(mapnames)];
        
        if (yp_valid_domain(*arg, (struct ypresp_val *)&res) == -1)
                return (&res);

        res.stat = YP_TRUE;
        res.maps = NULL;
        for (i = 0; i < nitems(mapnames); i++) {
                if (!(env->sc_flags & mapnames[i].cond))
                        continue;
                maps[i].map = mapnames[i].name;
                maps[i].next = res.maps;
                res.maps = &maps[i];
        }

        return (&res);
}

void
yp_make_val(struct ypresp_val *res, char *line, int replacecolon)
{
        static char              buf[LINE_WIDTH];

        memset(buf, 0, sizeof(buf));

        if (replacecolon)
                line[strlen(line)] = ':';
        (void)strlcpy(buf, line, sizeof(buf));
        if (replacecolon)
                line[strcspn(line, ":")] = '\0';
        log_debug("sending out %s", buf);

        res->stat = YP_TRUE;
        res->val.valdat_len = strlen(buf);
        res->val.valdat_val = buf;
}

void
yp_make_keyval(struct ypresp_key_val *res, char *key, char *line)
{
        static char     keybuf[YPMAXRECORD+1];
        static char     buf[LINE_WIDTH];

        memset(keybuf, 0, sizeof(keybuf));
        memset(buf, 0, sizeof(buf));
        
        (void)strlcpy(keybuf, key, sizeof(keybuf));
        res->key.keydat_len = strlen(keybuf);
        res->key.keydat_val = keybuf;

        if (*line == '\0') {
                res->stat = YP_NOMORE;
                return;
        }
        res->stat = YP_TRUE;
        line[strlen(line)] = ':';
        (void)strlcpy(buf, line, sizeof(buf));
        line[strcspn(line, ":")] = '\0';
        log_debug("sending out %s => %s", keybuf, buf);

        res->val.valdat_len = strlen(buf);
        res->val.valdat_val = buf;
}