/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 1983, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include "defs.h"
#include "pathnames.h"
#include <sys/stat.h>

static struct parm *parms;
struct intnet *intnets;
struct r1net *r1nets;
struct tgate *tgates;


/* use configured parameters
 */
void
get_parms(struct interface *ifp)
{
        static int warned_auth_in, warned_auth_out;
        struct parm *parmp;
        int i, num_passwds = 0;

        /* get all relevant parameters
         */
        for (parmp = parms; parmp != NULL; parmp = parmp->parm_next) {
                if (parmp->parm_name[0] == '\0'
                    || !strcmp(ifp->int_name, parmp->parm_name)
                    || (parmp->parm_name[0] == '\n'
                        && on_net(ifp->int_addr,
                                  parmp->parm_net, parmp->parm_mask))) {

                        /* This group of parameters is relevant,
                         * so get its settings
                         */
                        ifp->int_state |= parmp->parm_int_state;
                        for (i = 0; i < MAX_AUTH_KEYS; i++) {
                                if (parmp->parm_auth[0].type == RIP_AUTH_NONE
                                    || num_passwds >= MAX_AUTH_KEYS)
                                        break;
                                memcpy(&ifp->int_auth[num_passwds++],
                                       &parmp->parm_auth[i],
                                       sizeof(ifp->int_auth[0]));
                        }
                        if (parmp->parm_rdisc_pref != 0)
                                ifp->int_rdisc_pref = parmp->parm_rdisc_pref;
                        if (parmp->parm_rdisc_int != 0)
                                ifp->int_rdisc_int = parmp->parm_rdisc_int;
                        if (parmp->parm_adj_inmetric != 0)
                            ifp->int_adj_inmetric = parmp->parm_adj_inmetric;
                        if (parmp->parm_adj_outmetric != 0)
                            ifp->int_adj_outmetric = parmp->parm_adj_outmetric;
                }
        }

        /* Set general defaults.
         *
         * Default poor-man's router discovery to a metric that will
         * be heard by old versions of `routed`.  They ignored received
         * routes with metric 15.
         */
        if ((ifp->int_state & IS_PM_RDISC)
            && ifp->int_d_metric == 0)
                ifp->int_d_metric = FAKE_METRIC;

        if (ifp->int_rdisc_int == 0)
                ifp->int_rdisc_int = DefMaxAdvertiseInterval;

        if (!(ifp->int_if_flags & IFF_MULTICAST)
            && !(ifp->int_state & IS_REMOTE))
                ifp->int_state |= IS_BCAST_RDISC;

        if (ifp->int_if_flags & IFF_POINTOPOINT) {
                ifp->int_state |= IS_BCAST_RDISC;
                /* By default, point-to-point links should be passive
                 * about router-discovery for the sake of demand-dialing.
                 */
                if (0 == (ifp->int_state & GROUP_IS_SOL_OUT))
                        ifp->int_state |= IS_NO_SOL_OUT;
                if (0 == (ifp->int_state & GROUP_IS_ADV_OUT))
                        ifp->int_state |= IS_NO_ADV_OUT;
        }

        if (0 != (ifp->int_state & (IS_PASSIVE | IS_REMOTE)))
                ifp->int_state |= IS_NO_RDISC;
        if (ifp->int_state & IS_PASSIVE)
                ifp->int_state |= IS_NO_RIP;

        if (!IS_RIP_IN_OFF(ifp->int_state)
            && ifp->int_auth[0].type != RIP_AUTH_NONE
            && !(ifp->int_state & IS_NO_RIPV1_IN)
            && !warned_auth_in) {
                msglog("Warning: RIPv1 input via %s"
                       " will be accepted without authentication",
                       ifp->int_name);
                warned_auth_in = 1;
        }
        if (!IS_RIP_OUT_OFF(ifp->int_state)
            && ifp->int_auth[0].type != RIP_AUTH_NONE
            && !(ifp->int_state & IS_NO_RIPV1_OUT)) {
                if (!warned_auth_out) {
                        msglog("Warning: RIPv1 output via %s"
                               " will be sent without authentication",
                               ifp->int_name);
                        warned_auth_out = 1;
                }
        }
}


/* Read a list of gateways from /etc/gateways and add them to our tables.
 *
 * This file contains a list of "remote" gateways.  That is usually
 * a gateway which we cannot immediately determine if it is present or
 * not as we can do for those provided by directly connected hardware.
 *
 * If a gateway is marked "passive" in the file, then we assume it
 * does not understand RIP and assume it is always present.  Those
 * not marked passive are treated as if they were directly connected
 * and assumed to be broken if they do not send us advertisements.
 * All remote interfaces are added to our list, and those not marked
 * passive are sent routing updates.
 *
 * A passive interface can also be local, hardware interface exempt
 * from RIP.
 */
void
gwkludge(void)
{
        FILE *fp;
        char *p, *lptr;
        const char *cp;
        char lbuf[200], net_host[5], dname[64+1+64+1];
        char gname[GNAME_LEN+1], qual[9];
        struct interface *ifp;
        naddr dst, netmask, gate;
        int metric, n, lnum;
        struct stat sb;
        u_int state;
        const char *type;


        fp = fopen(_PATH_GATEWAYS, "r");
        if (fp == NULL)
                return;

        if (0 > fstat(fileno(fp), &sb)) {
                msglog("could not stat() "_PATH_GATEWAYS);
                (void)fclose(fp);
                return;
        }

        for (lnum = 1; ; lnum++) {
                if (fgets(lbuf, sizeof(lbuf), fp) == NULL)
                        break;
                lptr = lbuf;
                while (*lptr == ' ')
                        lptr++;
                p = lptr+strlen(lptr)-1;
                while (*p == '\n'
                       || (*p == ' ' && (p == lptr+1 || *(p-1) != '\\')))
                        *p-- = '\0';
                if (*lptr == '\0'       /* ignore null and comment lines */
                    || *lptr == '#')
                        continue;

                /* notice newfangled parameter lines
                 */
                if (strncasecmp("net", lptr, 3)
                    && strncasecmp("host", lptr, 4)) {
                        cp = parse_parms(lptr,
                                         (sb.st_uid == 0
                                          && !(sb.st_mode&(S_IRWXG|S_IRWXO))));
                        if (cp != NULL)
                                msglog("%s in line %d of "_PATH_GATEWAYS,
                                       cp, lnum);
                        continue;
                }

/*  {net | host} XX[/M] XX gateway XX metric DD [passive | external]\n */
                qual[0] = '\0';
                /* the '64' here must be GNAME_LEN */
                n = sscanf(lptr, "%4s %129[^ \t] gateway"
                           " %64[^ / \t] metric %u %8s\n",
                           net_host, dname, gname, &metric, qual);
                if (n != 4 && n != 5) {
                        msglog("bad "_PATH_GATEWAYS" entry \"%s\"; %d values",
                               lptr, n);
                        continue;
                }
                if (metric >= HOPCNT_INFINITY) {
                        msglog("bad metric in "_PATH_GATEWAYS" entry \"%s\"",
                               lptr);
                        continue;
                }
                if (!strcasecmp(net_host, "host")) {
                        if (!gethost(dname, &dst)) {
                                msglog("bad host \"%s\" in "_PATH_GATEWAYS
                                       " entry \"%s\"", dname, lptr);
                                continue;
                        }
                        netmask = HOST_MASK;
                } else if (!strcasecmp(net_host, "net")) {
                        if (!getnet(dname, &dst, &netmask)) {
                                msglog("bad net \"%s\" in "_PATH_GATEWAYS
                                       " entry \"%s\"", dname, lptr);
                                continue;
                        }
                        if (dst == RIP_DEFAULT) {
                                msglog("bad net \"%s\" in "_PATH_GATEWAYS
                                       " entry \"%s\"--cannot be default",
                                       dname, lptr);
                                continue;
                        }
                        /* Turn network # into IP address. */
                        dst = htonl(dst);
                } else {
                        msglog("bad \"%s\" in "_PATH_GATEWAYS
                               " entry \"%s\"", net_host, lptr);
                        continue;
                }

                if (!gethost(gname, &gate)) {
                        msglog("bad gateway \"%s\" in "_PATH_GATEWAYS
                               " entry \"%s\"", gname, lptr);
                        continue;
                }

                if (!strcasecmp(qual, type = "passive")) {
                        /* Passive entries are not placed in our tables,
                         * only the kernel's, so we don't copy all of the
                         * external routing information within a net.
                         * Internal machines should use the default
                         * route to a suitable gateway (like us).
                         */
                        state = IS_REMOTE | IS_PASSIVE;
                        if (metric == 0)
                                metric = 1;

                } else if (!strcasecmp(qual, type = "external")) {
                        /* External entries are handled by other means
                         * such as EGP, and are placed only in the daemon
                         * tables to prevent overriding them with something
                         * else.
                         */
                        strcpy(qual,"external");
                        state = IS_REMOTE | IS_PASSIVE | IS_EXTERNAL;
                        if (metric == 0)
                                metric = 1;

                } else if (!strcasecmp(qual, "active")
                           || qual[0] == '\0') {
                        if (metric != 0) {
                                /* Entries that are neither "passive" nor
                                 * "external" are "remote" and must behave
                                 * like physical interfaces.  If they are not
                                 * heard from regularly, they are deleted.
                                 */
                                state = IS_REMOTE;
                                type = "remote";
                        } else {
                                /* "remote" entries with a metric of 0
                                 * are aliases for our own interfaces
                                 */
                                state = IS_REMOTE | IS_PASSIVE | IS_ALIAS;
                                type = "alias";
                        }

                } else {
                        msglog("bad "_PATH_GATEWAYS" entry \"%s\";"
                               " unknown type %s", lptr, qual);
                        continue;
                }

                if (0 != (state & (IS_PASSIVE | IS_REMOTE)))
                        state |= IS_NO_RDISC;
                if (state & IS_PASSIVE)
                        state |= IS_NO_RIP;

                ifp = check_dup(gate,dst,netmask,state);
                if (ifp != NULL) {
                        msglog("duplicate "_PATH_GATEWAYS" entry \"%s\"",lptr);
                        continue;
                }

                ifp = (struct interface *)rtmalloc(sizeof(*ifp), "gwkludge()");
                memset(ifp, 0, sizeof(*ifp));

                ifp->int_state = state;
                if (netmask == HOST_MASK)
                        ifp->int_if_flags = IFF_POINTOPOINT | IFF_UP;
                else
                        ifp->int_if_flags = IFF_UP;
                ifp->int_act_time = NEVER;
                ifp->int_addr = gate;
                ifp->int_dstaddr = dst;
                ifp->int_mask = netmask;
                ifp->int_ripv1_mask = netmask;
                ifp->int_std_mask = std_mask(gate);
                ifp->int_net = ntohl(dst);
                ifp->int_std_net = ifp->int_net & ifp->int_std_mask;
                ifp->int_std_addr = htonl(ifp->int_std_net);
                ifp->int_metric = metric;
                if (!(state & IS_EXTERNAL)
                    && ifp->int_mask != ifp->int_std_mask)
                        ifp->int_state |= IS_SUBNET;
                (void)sprintf(ifp->int_name, "%s(%s)", type, gname);
                ifp->int_index = -1;

                if_link(ifp);
        }

        /* After all of the parameter lines have been read,
         * apply them to any remote interfaces.
         */
        LIST_FOREACH(ifp, &ifnet, int_list) {
                get_parms(ifp);

                tot_interfaces++;
                if (!IS_RIP_OFF(ifp->int_state))
                        rip_interfaces++;

                trace_if("Add", ifp);
        }

        (void)fclose(fp);
}


/* like strtok(), but honoring backslash and not changing the source string
 */
static int                              /* 0=ok, -1=bad */
parse_quote(char **linep,               /* look here */
            const char *delims,         /* for these delimiters */
            char *delimp,               /* 0 or put found delimiter here */
            char *buf,                  /* copy token to here */
            int lim)                    /* at most this many bytes */
{
        char c = '\0', *pc;
        const char *p;


        pc = *linep;
        if (*pc == '\0')
                return -1;

        while (lim != 0) {
                c = *pc++;
                if (c == '\0')
                        break;

                if (c == '\\' && *pc != '\0') {
                        if ((c = *pc++) == 'n') {
                                c = '\n';
                        } else if (c == 'r') {
                                c = '\r';
                        } else if (c == 't') {
                                c = '\t';
                        } else if (c == 'b') {
                                c = '\b';
                        } else if (c >= '0' && c <= '7') {
                                c -= '0';
                                if (*pc >= '0' && *pc <= '7') {
                                        c = (c<<3)+(*pc++ - '0');
                                        if (*pc >= '0' && *pc <= '7')
                                            c = (c<<3)+(*pc++ - '0');
                                }
                        }

                } else {
                        for (p = delims; *p != '\0'; ++p) {
                                if (*p == c)
                                        goto exit;
                        }
                }

                *buf++ = c;
                --lim;
        }
exit:
        if (lim == 0)
                return -1;

        *buf = '\0';                    /* terminate copy of token */
        if (delimp != NULL)
                *delimp = c;            /* return delimiter */
        *linep = pc-1;                  /* say where we ended */
        return 0;
}


/* Parse password timestamp
 */
static char *
parse_ts(time_t *tp,
         char **valp,
         char *val0,
         char *delimp,
         char *buf,
         u_int bufsize)
{
        struct tm tm;
        char *ptr;

        if (0 > parse_quote(valp, "| ,\n\r", delimp,
                            buf,bufsize)
            || buf[bufsize-1] != '\0'
            || buf[bufsize-2] != '\0') {
                sprintf(buf,"bad timestamp %.25s", val0);
                return buf;
        }
        strcat(buf,"\n");
        memset(&tm, 0, sizeof(tm));
        ptr = strptime(buf, "%y/%m/%d@%H:%M\n", &tm);
        if (ptr == NULL || *ptr != '\0') {
                sprintf(buf,"bad timestamp %.25s", val0);
                return buf;
        }

        if ((*tp = mktime(&tm)) == -1) {
                sprintf(buf,"bad timestamp %.25s", val0);
                return buf;
        }

        return 0;
}


/* Get a password, key ID, and expiration date in the format
 *      passwd|keyID|year/mon/day@hour:min|year/mon/day@hour:min
 */
static const char *                     /* 0 or error message */
get_passwd(char *tgt,
           char *val,
           struct parm *parmp,
           u_int16_t type,
           int safe)                    /* 1=from secure file */
{
        static char buf[80];
        char *val0, *p, delim;
        struct auth k, *ap, *ap2;
        int i;
        u_long l;

        assert(val != NULL);
        if (!safe)
                return "ignore unsafe password";

        for (ap = parmp->parm_auth, i = 0;
             ap->type != RIP_AUTH_NONE; i++, ap++) {
                if (i >= MAX_AUTH_KEYS)
                        return "too many passwords";
        }

        memset(&k, 0, sizeof(k));
        k.type = type;
        k.end = -1-DAY;

        val0 = val;
        if (0 > parse_quote(&val, "| ,\n\r", &delim,
                            (char *)k.key, sizeof(k.key)))
                return tgt;

        if (delim != '|') {
                if (type == RIP_AUTH_MD5)
                        return "missing Keyid";
        } else {
                val0 = ++val;
                buf[sizeof(buf)-1] = '\0';
                if (0 > parse_quote(&val, "| ,\n\r", &delim, buf,sizeof(buf))
                    || buf[sizeof(buf)-1] != '\0'
                    || (l = strtoul(buf,&p,0)) > 255
                    || *p != '\0') {
                        sprintf(buf,"bad KeyID \"%.20s\"", val0);
                        return buf;
                }
                for (ap2 = parmp->parm_auth; ap2 < ap; ap2++) {
                        if (ap2->keyid == l) {
                                sprintf(buf,"duplicate KeyID \"%.20s\"", val0);
                                return buf;
                        }
                }
                k.keyid = (int)l;

                if (delim == '|') {
                        val0 = ++val;
                        if (NULL != (p = parse_ts(&k.start,&val,val0,&delim,
                                                  buf,sizeof(buf))))
                                return p;
                        if (delim != '|')
                                return "missing second timestamp";
                        val0 = ++val;
                        if (NULL != (p = parse_ts(&k.end,&val,val0,&delim,
                                                  buf,sizeof(buf))))
                                return p;
                        if ((u_long)k.start > (u_long)k.end) {
                                sprintf(buf,"out of order timestamp %.30s",
                                        val0);
                                return buf;
                        }
                }
        }
        if (delim != '\0')
                return tgt;

        memmove(ap, &k, sizeof(*ap));
        return 0;
}


static const char *
bad_str(const char *estr)
{
        static char buf[100+8];

        sprintf(buf, "bad \"%.100s\"", estr);
        return buf;
}


/* Parse a set of parameters for an interface.
 */
const char *                                    /* 0 or error message */
parse_parms(char *line,
            int safe)                   /* 1=from secure file */
{
#define PARS(str) (!strcasecmp(tgt, str))
#define PARSEQ(str) (!strncasecmp(tgt, str"=", sizeof(str)))
#define CKF(g,b) {if (0 != (parm.parm_int_state & ((g) & ~(b)))) break; \
        parm.parm_int_state |= (b);}
        struct parm parm;
        struct intnet *intnetp;
        struct r1net *r1netp;
        struct tgate *tg;
        naddr addr, mask;
        char delim, *val0 = NULL, *tgt, *val, *p;
        const char *msg;
        char buf[BUFSIZ], buf2[BUFSIZ];
        int i;


        /* "subnet=x.y.z.u/mask[,metric]" must be alone on the line */
        if (!strncasecmp(line, "subnet=", sizeof("subnet=")-1)
            && *(val = &line[sizeof("subnet=")-1]) != '\0') {
                if (0 > parse_quote(&val, ",", &delim, buf, sizeof(buf)))
                        return bad_str(line);
                intnetp = (struct intnet*)rtmalloc(sizeof(*intnetp),
                                                   "parse_parms subnet");
                intnetp->intnet_metric = 1;
                if (delim == ',') {
                        intnetp->intnet_metric = (int)strtol(val+1,&p,0);
                        if (*p != '\0'
                            || intnetp->intnet_metric <= 0
                            || intnetp->intnet_metric >= HOPCNT_INFINITY) {
                                free(intnetp);
                                return bad_str(line);
                        }
                }
                if (!getnet(buf, &intnetp->intnet_addr, &intnetp->intnet_mask)
                    || intnetp->intnet_mask == HOST_MASK
                    || intnetp->intnet_addr == RIP_DEFAULT) {
                        free(intnetp);
                        return bad_str(line);
                }
                intnetp->intnet_addr = htonl(intnetp->intnet_addr);
                intnetp->intnet_next = intnets;
                intnets = intnetp;
                return 0;
        }

        /* "ripv1_mask=x.y.z.u/mask1,mask2" must be alone on the line.
         * This requires that x.y.z.u/mask1 be considered a subnet of
         * x.y.z.u/mask2, as if x.y.z.u/mask2 were a class-full network.
         */
        if (!strncasecmp(line, "ripv1_mask=", sizeof("ripv1_mask=")-1)
            && *(val = &line[sizeof("ripv1_mask=")-1]) != '\0') {
                if (0 > parse_quote(&val, ",", &delim, buf, sizeof(buf))
                    || delim == '\0')
                        return bad_str(line);
                if ((i = (int)strtol(val+1, &p, 0)) <= 0
                    || i > 32 || *p != '\0')
                        return bad_str(line);
                r1netp = (struct r1net *)rtmalloc(sizeof(*r1netp),
                                                  "parse_parms ripv1_mask");
                r1netp->r1net_mask = HOST_MASK << (32-i);
                if (!getnet(buf, &r1netp->r1net_net, &r1netp->r1net_match)
                    || r1netp->r1net_net == RIP_DEFAULT
                    || r1netp->r1net_mask > r1netp->r1net_match) {
                        free(r1netp);
                        return bad_str(line);
                }
                r1netp->r1net_next = r1nets;
                r1nets = r1netp;
                return 0;
        }

        memset(&parm, 0, sizeof(parm));

        for (;;) {
                tgt = line + strspn(line, " ,\n\r");
                if (*tgt == '\0' || *tgt == '#')
                        break;
                line = tgt+strcspn(tgt, "= #,\n\r");
                delim = *line;
                if (delim == '=') {
                        val0 = ++line;
                        if (0 > parse_quote(&line, " #,\n\r",&delim,
                                            buf,sizeof(buf)))
                                return bad_str(tgt);
                } else {
                        val0 = NULL;
                }
                if (delim != '\0') {
                        for (;;) {
                                *line = '\0';
                                if (delim == '#')
                                        break;
                                ++line;
                                if (delim != ' '
                                    || (delim = *line) != ' ')
                                        break;
                        }
                }

                if (PARSEQ("if")) {
                        if (parm.parm_name[0] != '\0'
                            || strlen(buf) > IF_NAME_LEN)
                                return bad_str(tgt);
                        strcpy(parm.parm_name, buf);

                } else if (PARSEQ("addr")) {
                        /* This is a bad idea, because the address based
                         * sets of parameters cannot be checked for
                         * consistency with the interface name parameters.
                         * The parm_net stuff is needed to allow several
                         * -F settings.
                         */
                        if (val0 == NULL || !getnet(val0, &addr, &mask)
                            || parm.parm_name[0] != '\0')
                                return bad_str(tgt);
                        parm.parm_net = addr;
                        parm.parm_mask = mask;
                        parm.parm_name[0] = '\n';

                } else if (PARSEQ("passwd")) {
                        /* since cleartext passwords are so weak allow
                         * them anywhere
                         */
                        if (val0 == NULL)
                                return bad_str("no passwd");
                        msg = get_passwd(tgt,val0,&parm,RIP_AUTH_PW,1);
                        if (msg) {
                                *val0 = '\0';
                                return bad_str(msg);
                        }

                } else if (PARSEQ("md5_passwd")) {
                        msg = get_passwd(tgt,val0,&parm,RIP_AUTH_MD5,safe);
                        if (msg) {
                                *val0 = '\0';
                                return bad_str(msg);
                        }

                } else if (PARS("no_ag")) {
                        parm.parm_int_state |= (IS_NO_AG | IS_NO_SUPER_AG);

                } else if (PARS("no_super_ag")) {
                        parm.parm_int_state |= IS_NO_SUPER_AG;

                } else if (PARS("no_rip_out")) {
                        parm.parm_int_state |= IS_NO_RIP_OUT;

                } else if (PARS("no_ripv1_in")) {
                        parm.parm_int_state |= IS_NO_RIPV1_IN;

                } else if (PARS("no_ripv2_in")) {
                        parm.parm_int_state |= IS_NO_RIPV2_IN;

                } else if (PARS("ripv2_out")) {
                        if (parm.parm_int_state & IS_NO_RIPV2_OUT)
                                return bad_str(tgt);
                        parm.parm_int_state |= IS_NO_RIPV1_OUT;

                } else if (PARS("ripv2")) {
                        if ((parm.parm_int_state & IS_NO_RIPV2_OUT)
                            || (parm.parm_int_state & IS_NO_RIPV2_IN))
                                return bad_str(tgt);
                        parm.parm_int_state |= (IS_NO_RIPV1_IN
                                                | IS_NO_RIPV1_OUT);

                } else if (PARS("no_rip")) {
                        CKF(IS_PM_RDISC, IS_NO_RIP);

                } else if (PARS("no_rip_mcast")) {
                        parm.parm_int_state |= IS_NO_RIP_MCAST;

                } else if (PARS("no_rdisc")) {
                        CKF((GROUP_IS_SOL_OUT|GROUP_IS_ADV_OUT), IS_NO_RDISC);

                } else if (PARS("no_solicit")) {
                        CKF(GROUP_IS_SOL_OUT, IS_NO_SOL_OUT);

                } else if (PARS("send_solicit")) {
                        CKF(GROUP_IS_SOL_OUT, IS_SOL_OUT);

                } else if (PARS("no_rdisc_adv")) {
                        CKF(GROUP_IS_ADV_OUT, IS_NO_ADV_OUT);

                } else if (PARS("rdisc_adv")) {
                        CKF(GROUP_IS_ADV_OUT, IS_ADV_OUT);

                } else if (PARS("bcast_rdisc")) {
                        parm.parm_int_state |= IS_BCAST_RDISC;

                } else if (PARS("passive")) {
                        CKF((GROUP_IS_SOL_OUT|GROUP_IS_ADV_OUT), IS_NO_RDISC);
                        parm.parm_int_state |= IS_NO_RIP | IS_PASSIVE;

                } else if (PARSEQ("rdisc_pref")) {
                        if (parm.parm_rdisc_pref != 0
                            || (parm.parm_rdisc_pref = (int)strtol(buf,&p,0),
                                *p != '\0'))
                                return bad_str(tgt);

                } else if (PARS("pm_rdisc")) {
                        if (IS_RIP_OUT_OFF(parm.parm_int_state))
                                return bad_str(tgt);
                        parm.parm_int_state |= IS_PM_RDISC;

                } else if (PARSEQ("rdisc_interval")) {
                        if (parm.parm_rdisc_int != 0
                            || (parm.parm_rdisc_int = (int)strtoul(buf,&p,0),
                                *p != '\0')
                            || parm.parm_rdisc_int < MinMaxAdvertiseInterval
                            || parm.parm_rdisc_int > MaxMaxAdvertiseInterval)
                                return bad_str(tgt);

                } else if (PARSEQ("fake_default")) {
                        if (parm.parm_d_metric != 0
                            || IS_RIP_OUT_OFF(parm.parm_int_state)
                            || (i = strtoul(buf,&p,0), *p != '\0')
                            || i > HOPCNT_INFINITY-1)
                                return bad_str(tgt);
                        parm.parm_d_metric = i;

                } else if (PARSEQ("adj_inmetric")) {
                        if (parm.parm_adj_inmetric != 0
                            || (i = strtoul(buf,&p,0), *p != '\0')
                            || i > HOPCNT_INFINITY-1)
                                return bad_str(tgt);
                        parm.parm_adj_inmetric = i;

                } else if (PARSEQ("adj_outmetric")) {
                        if (parm.parm_adj_outmetric != 0
                            || (i = strtoul(buf,&p,0), *p != '\0')
                            || i > HOPCNT_INFINITY-1)
                                return bad_str(tgt);
                        parm.parm_adj_outmetric = i;

                } else if (PARSEQ("trust_gateway")) {
                        /* look for trust_gateway=x.y.z|net/mask|...) */
                        p = buf;
                        if (0 > parse_quote(&p, "|", &delim,
                                            buf2, sizeof(buf2))
                            || !gethost(buf2,&addr))
                                return bad_str(tgt);
                        tg = (struct tgate *)rtmalloc(sizeof(*tg),
                                                      "parse_parms"
                                                      "trust_gateway");
                        memset(tg, 0, sizeof(*tg));
                        tg->tgate_addr = addr;
                        i = 0;
                        /* The default is to trust all routes. */
                        while (delim == '|') {
                                p++;
                                if (i >= MAX_TGATE_NETS
                                    || 0 > parse_quote(&p, "|", &delim,
                                                       buf2, sizeof(buf2))
                                    || !getnet(buf2, &tg->tgate_nets[i].net,
                                               &tg->tgate_nets[i].mask)
                                    || tg->tgate_nets[i].net == RIP_DEFAULT
                                    || tg->tgate_nets[i].mask == 0) {
                                        free(tg);
                                        return bad_str(tgt);
                                }
                                i++;
                        }
                        tg->tgate_next = tgates;
                        tgates = tg;
                        parm.parm_int_state |= IS_DISTRUST;

                } else if (PARS("redirect_ok")) {
                        parm.parm_int_state |= IS_REDIRECT_OK;

                } else {
                        return bad_str(tgt);    /* error */
                }
        }

        return check_parms(&parm);
#undef PARS
#undef PARSEQ
}


/* check for duplicate parameter specifications */
const char *                            /* 0 or error message */
check_parms(struct parm *new)
{
        struct parm *parmp, **parmpp;
        int i, num_passwds;

        /* set implicit values
         */
        if (new->parm_int_state & IS_NO_ADV_IN)
                new->parm_int_state |= IS_NO_SOL_OUT;
        if (new->parm_int_state & IS_NO_SOL_OUT)
                new->parm_int_state |= IS_NO_ADV_IN;

        for (i = num_passwds = 0; i < MAX_AUTH_KEYS; i++) {
                if (new->parm_auth[i].type != RIP_AUTH_NONE)
                        num_passwds++;
        }

        /* compare with existing sets of parameters
         */
        for (parmpp = &parms;
             (parmp = *parmpp) != NULL;
             parmpp = &parmp->parm_next) {
                if (strcmp(new->parm_name, parmp->parm_name))
                        continue;
                if (!on_net(htonl(parmp->parm_net),
                            new->parm_net, new->parm_mask)
                    && !on_net(htonl(new->parm_net),
                               parmp->parm_net, parmp->parm_mask))
                        continue;

                for (i = 0; i < MAX_AUTH_KEYS; i++) {
                        if (parmp->parm_auth[i].type != RIP_AUTH_NONE)
                                num_passwds++;
                }
                if (num_passwds > MAX_AUTH_KEYS)
                        return "too many conflicting passwords";

                if ((0 != (new->parm_int_state & GROUP_IS_SOL_OUT)
                     && 0 != (parmp->parm_int_state & GROUP_IS_SOL_OUT)
                     && 0 != ((new->parm_int_state ^ parmp->parm_int_state)
                              & GROUP_IS_SOL_OUT))
                    || (0 != (new->parm_int_state & GROUP_IS_ADV_OUT)
                        && 0 != (parmp->parm_int_state & GROUP_IS_ADV_OUT)
                        && 0 != ((new->parm_int_state ^ parmp->parm_int_state)
                                 & GROUP_IS_ADV_OUT))
                    || (new->parm_rdisc_pref != 0
                        && parmp->parm_rdisc_pref != 0
                        && new->parm_rdisc_pref != parmp->parm_rdisc_pref)
                    || (new->parm_rdisc_int != 0
                        && parmp->parm_rdisc_int != 0
                        && new->parm_rdisc_int != parmp->parm_rdisc_int)) {
                        return ("conflicting, duplicate router discovery"
                                " parameters");

                }

                if (new->parm_d_metric != 0
                     && parmp->parm_d_metric != 0
                     && new->parm_d_metric != parmp->parm_d_metric) {
                        return ("conflicting, duplicate poor man's router"
                                " discovery or fake default metric");
                }

                if (new->parm_adj_inmetric != 0
                    && parmp->parm_adj_inmetric != 0
                    && new->parm_adj_inmetric != parmp->parm_adj_inmetric) {
                        return ("conflicting interface input "
                                "metric adjustments");
                }

                if (new->parm_adj_outmetric != 0
                    && parmp->parm_adj_outmetric != 0
                    && new->parm_adj_outmetric != parmp->parm_adj_outmetric) {
                        return ("conflicting interface output "
                                "metric adjustments");
                }
        }

        /* link new entry on the list so that when the entries are scanned,
         * they affect the result in the order the operator specified.
         */
        parmp = (struct parm*)rtmalloc(sizeof(*parmp), "check_parms");
        memcpy(parmp, new, sizeof(*parmp));
        *parmpp = parmp;

        return 0;
}


/* get a network number as a name or a number, with an optional "/xx"
 * netmask.
 */
int                                     /* 0=bad */
getnet(char *name,
       naddr *netp,                     /* network in host byte order */
       naddr *maskp)                    /* masks are always in host order */
{
        int i;
        struct netent *np;
        naddr mask;                     /* in host byte order */
        struct in_addr in;              /* a network and so host byte order */
        char hname[MAXHOSTNAMELEN+1];
        char *mname, *p;


        /* Detect and separate "1.2.3.4/24"
         */
        if (NULL != (mname = strrchr(name,'/'))) {
                i = (int)(mname - name);
                if (i > (int)sizeof(hname)-1)   /* name too long */
                        return 0;
                memmove(hname, name, i);
                hname[i] = '\0';
                mname++;
                name = hname;
        }

        np = getnetbyname(name);
        if (np != NULL) {
                in.s_addr = (naddr)np->n_net;
                if (0 == (in.s_addr & 0xff000000))
                        in.s_addr <<= 8;
                if (0 == (in.s_addr & 0xff000000))
                        in.s_addr <<= 8;
                if (0 == (in.s_addr & 0xff000000))
                        in.s_addr <<= 8;
        } else if (inet_aton(name, &in) == 1) {
                in.s_addr = ntohl(in.s_addr);
        } else if (!mname && !strcasecmp(name,"default")) {
                in.s_addr = RIP_DEFAULT;
        } else {
                return 0;
        }

        if (!mname) {
                /* we cannot use the interfaces here because we have not
                 * looked at them yet.
                 */
                mask = std_mask(htonl(in.s_addr));
                if ((~mask & in.s_addr) != 0)
                        mask = HOST_MASK;
        } else {
                mask = (naddr)strtoul(mname, &p, 0);
                if (*p != '\0' || mask > 32)
                        return 0;
                if (mask != 0)
                        mask = HOST_MASK << (32-mask);
        }

        /* must have mask of 0 with default */
        if (mask != 0 && in.s_addr == RIP_DEFAULT)
                return 0;
        /* no host bits allowed in a network number */
        if ((~mask & in.s_addr) != 0)
                return 0;
        /* require non-zero network number */
        if ((mask & in.s_addr) == 0 && in.s_addr != RIP_DEFAULT)
                return 0;
        if (in.s_addr>>24 == 0 && in.s_addr != RIP_DEFAULT)
                return 0;
        if (in.s_addr>>24 == 0xff)
                return 0;

        *netp = in.s_addr;
        *maskp = mask;
        return 1;
}


int                                     /* 0=bad */
gethost(char *name,
        naddr *addrp)
{
        struct hostent *hp;
        struct in_addr in;


        /* Try for a number first, even in IRIX where gethostbyname()
         * is smart.  This avoids hitting the name server which
         * might be sick because routing is.
         */
        if (inet_aton(name, &in) == 1) {
                /* get a good number, but check that it makes some
                 * sense.
                 */
                if (ntohl(in.s_addr)>>24 == 0
                    || ntohl(in.s_addr)>>24 == 0xff)
                        return 0;
                *addrp = in.s_addr;
                return 1;
        }

        hp = gethostbyname(name);
        if (hp) {
                memcpy(addrp, hp->h_addr, sizeof(*addrp));
                return 1;
        }

        return 0;
}