/*
 * Copyright (c) 1992 Regents of the University of California.
 * All rights reserved.
 *
 * This software was developed by the Computer Systems Engineering group
 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
 * contributed to Berkeley.
 *
 * 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 <sys/cdefs.h>

#include <stddef.h>
#include <sys/types.h>
#include <sys/limits.h>
#include <sys/endian.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>

#include <string.h>

#define BOOTP_DEBUGxx
#define SUPPORT_DHCP

#define DHCP_ENV_NOVENDOR       1       /* do not parse vendor options */
#define DHCP_ENV_PXE            10      /* assume pxe vendor options */
#define DHCP_ENV_FREEBSD        11      /* assume freebsd vendor options */
/* set DHCP_ENV to one of the values above to export dhcp options to kenv */
#define DHCP_ENV                DHCP_ENV_NO_VENDOR

#include "stand.h"
#include "net.h"
#include "netif.h"
#include "bootp.h"


struct in_addr servip;

static time_t   bot;

static  char vm_rfc1048[4] = VM_RFC1048;
#ifdef BOOTP_VEND_CMU
static  char vm_cmu[4] = VM_CMU;
#endif

/* Local forwards */
static  ssize_t bootpsend(struct iodesc *, void *, size_t);
static  ssize_t bootprecv(struct iodesc *, void **, void **, time_t, void *);
static  int vend_rfc1048(uchar_t *, uint_t);
#ifdef BOOTP_VEND_CMU
static  void vend_cmu(uchar_t *);
#endif

#ifdef DHCP_ENV         /* export the dhcp response to kenv */
struct dhcp_opt;
static void setenv_(uchar_t *cp,  uchar_t *ep, struct dhcp_opt *opts);
#else
#define setenv_(a, b, c)
#endif

#ifdef SUPPORT_DHCP
static char expected_dhcpmsgtype = -1, dhcp_ok;
struct in_addr dhcp_serverip;
#endif
struct bootp *bootp_response;
size_t bootp_response_size;

static void
bootp_fill_request(unsigned char *bp_vend)
{
        /*
         * We are booting from PXE, we want to send the string
         * 'PXEClient' to the DHCP server so you have the option of
         * only responding to PXE aware dhcp requests.
         */
        bp_vend[0] = TAG_CLASSID;
        bp_vend[1] = 9;
        bcopy("PXEClient", &bp_vend[2], 9);
        bp_vend[11] = TAG_USER_CLASS;
        /* len of each user class + number of user class */
        bp_vend[12] = 8;
        /* len of the first user class */
        bp_vend[13] = 7;
        bcopy("illumos", &bp_vend[14], 7);
        bp_vend[21] = TAG_PARAM_REQ;
        bp_vend[22] = 7;
        bp_vend[23] = TAG_SUBNET_MASK;
        bp_vend[24] = TAG_GATEWAY;
        bp_vend[25] = TAG_HOSTNAME;
        bp_vend[26] = TAG_SWAPSERVER;
        bp_vend[27] = TAG_ROOTPATH;
        bp_vend[28] = TAG_INTF_MTU;
        bp_vend[29] = TAG_SERVERID;
        bp_vend[30] = TAG_END;
}

/* Fetch required bootp infomation */
void
bootp(int sock)
{
        void *pkt;
        struct iodesc *d;
        struct bootp *bp;
        struct {
                uchar_t header[HEADER_SIZE];
                struct bootp wbootp;
        } wbuf;
        struct bootp *rbootp;

#ifdef BOOTP_DEBUG
        if (debug)
                printf("bootp: socket=%d\n", sock);
#endif
        if (!bot)
                bot = getsecs();

        if (!(d = socktodesc(sock))) {
                printf("bootp: bad socket. %d\n", sock);
                return;
        }
#ifdef BOOTP_DEBUG
        if (debug)
                printf("bootp: d=%lx\n", (long)d);
#endif

        bp = &wbuf.wbootp;
        bzero(bp, sizeof (*bp));

        bp->bp_op = BOOTREQUEST;
        bp->bp_htype = 1;               /* 10Mb Ethernet (48 bits) */
        bp->bp_hlen = 6;
        bp->bp_xid = htonl(d->xid);
        MACPY(d->myea, bp->bp_chaddr);
        strncpy(bp->bp_file, bootfile, sizeof (bp->bp_file));
        bcopy(vm_rfc1048, bp->bp_vend, sizeof (vm_rfc1048));
#ifdef SUPPORT_DHCP
        bp->bp_vend[4] = TAG_DHCP_MSGTYPE;
        bp->bp_vend[5] = 1;
        bp->bp_vend[6] = DHCPDISCOVER;
        bootp_fill_request(&bp->bp_vend[7]);
#else
        bp->bp_vend[4] = TAG_END;
#endif

        d->myip.s_addr = INADDR_ANY;
        d->myport = htons(IPPORT_BOOTPC);
        d->destip.s_addr = INADDR_BROADCAST;
        d->destport = htons(IPPORT_BOOTPS);

#ifdef SUPPORT_DHCP
        expected_dhcpmsgtype = DHCPOFFER;
        dhcp_ok = 0;
#endif

        if (sendrecv(d, bootpsend, bp, sizeof (*bp),
            bootprecv, &pkt, (void **)&rbootp, NULL) == -1) {
                printf("bootp: no reply\n");
                return;
        }

#ifdef SUPPORT_DHCP
        if (dhcp_ok) {
                uint32_t leasetime;
                bp->bp_vend[6] = DHCPREQUEST;
                bp->bp_vend[7] = TAG_REQ_ADDR;
                bp->bp_vend[8] = 4;
                bcopy(&rbootp->bp_yiaddr, &bp->bp_vend[9], 4);
                bp->bp_vend[13] = TAG_SERVERID;
                bp->bp_vend[14] = 4;
                bcopy(&dhcp_serverip.s_addr, &bp->bp_vend[15], 4);
                bp->bp_vend[19] = TAG_LEASETIME;
                bp->bp_vend[20] = 4;
                leasetime = htonl(300);
                bcopy(&leasetime, &bp->bp_vend[21], 4);
                bootp_fill_request(&bp->bp_vend[25]);

                expected_dhcpmsgtype = DHCPACK;

                free(pkt);
                if (sendrecv(d, bootpsend, bp, sizeof (*bp),
                    bootprecv, &pkt, (void **)&rbootp, NULL) == -1) {
                        printf("DHCPREQUEST failed\n");
                        return;
                }
        }
#endif

        myip = d->myip = rbootp->bp_yiaddr;
        servip = rbootp->bp_siaddr;
        if (rootip.s_addr == INADDR_ANY)
                rootip = servip;
        bcopy(rbootp->bp_file, bootfile, sizeof (bootfile));
        bootfile[sizeof (bootfile) - 1] = '\0';

        if (!netmask) {
                if (IN_CLASSA(ntohl(myip.s_addr)))
                        netmask = htonl(IN_CLASSA_NET);
                else if (IN_CLASSB(ntohl(myip.s_addr)))
                        netmask = htonl(IN_CLASSB_NET);
                else
                        netmask = htonl(IN_CLASSC_NET);
#ifdef BOOTP_DEBUG
                if (debug)
                        printf("'native netmask' is %s\n", intoa(netmask));
#endif
        }

#ifdef BOOTP_DEBUG
        if (debug)
                printf("mask: %s\n", intoa(netmask));
#endif

        /* We need a gateway if root is on a different net */
        if (!SAMENET(myip, rootip, netmask)) {
#ifdef BOOTP_DEBUG
                if (debug)
                        printf("need gateway for root ip\n");
#endif
        }

        /* Toss gateway if on a different net */
        if (!SAMENET(myip, gateip, netmask)) {
#ifdef BOOTP_DEBUG
                if (debug)
                        printf("gateway ip (%s) bad\n", inet_ntoa(gateip));
#endif
                gateip.s_addr = 0;
        }

        /* Bump xid so next request will be unique. */
        ++d->xid;
        free(pkt);
}

/* Transmit a bootp request */
static ssize_t
bootpsend(struct iodesc *d, void *pkt, size_t len)
{
        struct bootp *bp;

#ifdef BOOTP_DEBUG
        if (debug)
                printf("bootpsend: d=%lx called.\n", (long)d);
#endif

        bp = pkt;
        bp->bp_secs = htons((ushort_t)(getsecs() - bot));

#ifdef BOOTP_DEBUG
        if (debug)
                printf("bootpsend: calling sendudp\n");
#endif

        return (sendudp(d, pkt, len));
}

static ssize_t
bootprecv(struct iodesc *d, void **pkt, void **payload, time_t tleft,
    void *extra __unused)
{
        ssize_t n;
        struct bootp *bp;
        void *ptr;

#ifdef BOOTP_DEBUG
        if (debug)
                printf("bootp_recvoffer: called\n");
#endif

        ptr = NULL;
        n = readudp(d, &ptr, (void **)&bp, tleft);
        if (n == -1 || n < sizeof (struct bootp) - BOOTP_VENDSIZE)
                goto bad;

#ifdef BOOTP_DEBUG
        if (debug)
                printf("bootprecv: checked.  bp = %p, n = %zd\n", bp, n);
#endif
        if (bp->bp_xid != htonl(d->xid)) {
#ifdef BOOTP_DEBUG
                if (debug) {
                        printf("bootprecv: expected xid 0x%lx, got 0x%x\n",
                            d->xid, ntohl(bp->bp_xid));
                }
#endif
                goto bad;
        }

#ifdef BOOTP_DEBUG
        if (debug)
                printf("bootprecv: got one!\n");
#endif

        /* Suck out vendor info */
        if (bcmp(vm_rfc1048, bp->bp_vend, sizeof (vm_rfc1048)) == 0) {
                int vsize = n - offsetof(struct bootp, bp_vend);
                if (vend_rfc1048(bp->bp_vend, vsize) != 0)
                        goto bad;

                /* Save copy of bootp reply or DHCP ACK message */
                if (bp->bp_op == BOOTREPLY &&
                    ((dhcp_ok == 1 && expected_dhcpmsgtype == DHCPACK) ||
                    dhcp_ok == 0)) {
                        free(bootp_response);
                        bootp_response = malloc(n);
                        if (bootp_response != NULL) {
                                bootp_response_size = n;
                                bcopy(bp, bootp_response, bootp_response_size);
                        }
                }
        }
#ifdef BOOTP_VEND_CMU
        else if (bcmp(vm_cmu, bp->bp_vend, sizeof (vm_cmu)) == 0)
                vend_cmu(bp->bp_vend);
#endif
        else
                printf("bootprecv: unknown vendor 0x%lx\n", (long)bp->bp_vend);

        *pkt = ptr;
        *payload = bp;
        return (n);
bad:
        free(ptr);
        errno = 0;
        return (-1);
}

static int
vend_rfc1048(uchar_t *cp, uint_t len)
{
        uchar_t *ep;
        int size;
        uchar_t tag;
        const char *val;

#ifdef BOOTP_DEBUG
        if (debug)
                printf("vend_rfc1048 bootp info. len=%d\n", len);
#endif
        ep = cp + len;

        /* Step over magic cookie */
        cp += sizeof (int);

        setenv_(cp, ep, NULL);

        while (cp < ep) {
                tag = *cp++;
                size = *cp++;
                if (tag == TAG_END)
                        break;

                if (tag == TAG_SUBNET_MASK) {
                        bcopy(cp, &netmask, sizeof (netmask));
                }
                if (tag == TAG_GATEWAY) {
                        bcopy(cp, &gateip.s_addr, sizeof (gateip.s_addr));
                }
                if (tag == TAG_SWAPSERVER) {
                        /* let it override bp_siaddr */
                        bcopy(cp, &rootip.s_addr, sizeof (rootip.s_addr));
                }
                if (tag == TAG_ROOTPATH) {
                        if ((val = getenv("dhcp.root-path")) == NULL)
                                val = (const char *)cp;
                        strlcpy(rootpath, val, sizeof (rootpath));
                }
                if (tag == TAG_HOSTNAME) {
                        if ((val = getenv("dhcp.host-name")) == NULL)
                                val = (const char *)cp;
                        strlcpy(hostname, val, sizeof (hostname));
                }
                if (tag == TAG_INTF_MTU) {
                        intf_mtu = 0;
                        if ((val = getenv("dhcp.interface-mtu")) != NULL) {
                                unsigned long tmp;
                                char *end;

                                errno = 0;
                                /*
                                 * Do not allow MTU to exceed max IPv4 packet
                                 * size, max value of 16-bit word.
                                 */
                                tmp = strtoul(val, &end, 0);
                                if (errno != 0 ||
                                    *val == '\0' || *end != '\0' ||
                                    tmp > USHRT_MAX) {
                                        printf("%s: bad value: \"%s\", "
                                            "ignoring\n",
                                            "dhcp.interface-mtu", val);
                                } else {
                                        intf_mtu = (uint_t)tmp;
                                }
                        }
                        if (intf_mtu == 0)
                                intf_mtu = be16dec(cp);
                }
#ifdef SUPPORT_DHCP
                if (tag == TAG_DHCP_MSGTYPE) {
                        if (*cp != expected_dhcpmsgtype)
                                return (-1);
                        dhcp_ok = 1;
                }
                if (tag == TAG_SERVERID) {
                        bcopy(cp, &dhcp_serverip.s_addr,
                            sizeof (dhcp_serverip.s_addr));
                }
#endif
                cp += size;
        }
        return (0);
}

#ifdef BOOTP_VEND_CMU
static void
vend_cmu(uchar_t *cp)
{
        struct cmu_vend *vp;

#ifdef BOOTP_DEBUG
        if (debug)
                printf("vend_cmu bootp info.\n");
#endif
        vp = (struct cmu_vend *)cp;

        if (vp->v_smask.s_addr != 0) {
                netmask = vp->v_smask.s_addr;
        }
        if (vp->v_dgate.s_addr != 0) {
                gateip = vp->v_dgate;
        }
}
#endif

#ifdef DHCP_ENV
/*
 * Parse DHCP options and store them into kenv variables.
 * Original code from Danny Braniss, modifications by Luigi Rizzo.
 *
 * The parser is driven by tables which specify the type and name of
 * each dhcp option and how it appears in kenv.
 * The first entry in the list contains the prefix used to set the kenv
 * name (including the . if needed), the last entry must have a 0 tag.
 * Entries do not need to be sorted though it helps for readability.
 *
 * Certain vendor-specific tables can be enabled according to DHCP_ENV.
 * Set it to 0 if you don't want any.
 */
enum opt_fmt { __NONE = 0,
        __8 = 1, __16 = 2, __32 = 4,    /* Unsigned fields, value=size  */
        __IP,                           /* IPv4 address                 */
        __TXT,                          /* C string                     */
        __BYTES,                        /* byte sequence, printed %02x  */
        __INDIR,                        /* name=value                   */
        __ILIST,                        /* name=value;name=value ... */
        __VE,                           /* vendor specific, recurse     */
};

struct dhcp_opt {
        uint8_t tag;
        uint8_t fmt;
        const char      *desc;
};

static struct dhcp_opt vndr_opt[] = { /* Vendor Specific Options */
#if DHCP_ENV == DHCP_ENV_FREEBSD /* FreeBSD table in the original code */
        {0,     0,      "FreeBSD"},             /* prefix */
        {1,     __TXT,  "kernel"},
        {2,     __TXT,  "kernelname"},
        {3,     __TXT,  "kernel_options"},
        {4,     __IP,   "usr-ip"},
        {5,     __TXT,  "conf-path"},
        {6,     __TXT,  "rc.conf0"},
        {7,     __TXT,  "rc.conf1"},
        {8,     __TXT,  "rc.conf2"},
        {9,     __TXT,  "rc.conf3"},
        {10,    __TXT,  "rc.conf4"},
        {11,    __TXT,  "rc.conf5"},
        {12,    __TXT,  "rc.conf6"},
        {13,    __TXT,  "rc.conf7"},
        {14,    __TXT,  "rc.conf8"},
        {15,    __TXT,  "rc.conf9"},

        {20,    __TXT,  "boot.nfsroot.options"},

        {245,   __INDIR, ""},
        {246,   __INDIR, ""},
        {247,   __INDIR, ""},
        {248,   __INDIR, ""},
        {249,   __INDIR, ""},
        {250,   __INDIR, ""},
        {251,   __INDIR, ""},
        {252,   __INDIR, ""},
        {253,   __INDIR, ""},
        {254,   __INDIR, ""},

#elif DHCP_ENV == DHCP_ENV_PXE          /* some pxe options, RFC4578 */
        {0,     0,      "pxe"},         /* prefix */
        {93,    __16,   "system-architecture"},
        {94,    __BYTES,        "network-interface"},
        {97,    __BYTES,        "machine-identifier"},
#else                                   /* default (empty) table */
        {0,     0,      "dhcp.vendor."},                /* prefix */
#endif
        {0,     __TXT,  "%soption-%d"}
};

static struct dhcp_opt dhcp_opt[] = {
        /* DHCP Option names, formats and codes, from RFC2132. */
        {0,     0,      "dhcp."},       // prefix
        {1,     __IP,   "subnet-mask"},
        {2,     __32,   "time-offset"}, /* this is signed */
        {3,     __IP,   "routers"},
        {4,     __IP,   "time-servers"},
        {5,     __IP,   "ien116-name-servers"},
        {6,     __IP,   "domain-name-servers"},
        {7,     __IP,   "log-servers"},
        {8,     __IP,   "cookie-servers"},
        {9,     __IP,   "lpr-servers"},
        {10,    __IP,   "impress-servers"},
        {11,    __IP,   "resource-location-servers"},
        {12,    __TXT,  "host-name"},
        {13,    __16,   "boot-size"},
        {14,    __TXT,  "merit-dump"},
        {15,    __TXT,  "domain-name"},
        {16,    __IP,   "swap-server"},
        {17,    __TXT,  "root-path"},
        {18,    __TXT,  "extensions-path"},
        {19,    __8,    "ip-forwarding"},
        {20,    __8,    "non-local-source-routing"},
        {21,    __IP,   "policy-filter"},
        {22,    __16,   "max-dgram-reassembly"},
        {23,    __8,    "default-ip-ttl"},
        {24,    __32,   "path-mtu-aging-timeout"},
        {25,    __16,   "path-mtu-plateau-table"},
        {26,    __16,   "interface-mtu"},
        {27,    __8,    "all-subnets-local"},
        {28,    __IP,   "broadcast-address"},
        {29,    __8,    "perform-mask-discovery"},
        {30,    __8,    "mask-supplier"},
        {31,    __8,    "perform-router-discovery"},
        {32,    __IP,   "router-solicitation-address"},
        {33,    __IP,   "static-routes"},
        {34,    __8,    "trailer-encapsulation"},
        {35,    __32,   "arp-cache-timeout"},
        {36,    __8,    "ieee802-3-encapsulation"},
        {37,    __8,    "default-tcp-ttl"},
        {38,    __32,   "tcp-keepalive-interval"},
        {39,    __8,    "tcp-keepalive-garbage"},
        {40,    __TXT,  "nis-domain"},
        {41,    __IP,   "nis-servers"},
        {42,    __IP,   "ntp-servers"},
        {43,    __VE,   "vendor-encapsulated-options"},
        {44,    __IP,   "netbios-name-servers"},
        {45,    __IP,   "netbios-dd-server"},
        {46,    __8,    "netbios-node-type"},
        {47,    __TXT,  "netbios-scope"},
        {48,    __IP,   "x-font-servers"},
        {49,    __IP,   "x-display-managers"},
        {50,    __IP,   "dhcp-requested-address"},
        {51,    __32,   "dhcp-lease-time"},
        {52,    __8,    "dhcp-option-overload"},
        {53,    __8,    "dhcp-message-type"},
        {54,    __IP,   "dhcp-server-identifier"},
        {55,    __8,    "dhcp-parameter-request-list"},
        {56,    __TXT,  "dhcp-message"},
        {57,    __16,   "dhcp-max-message-size"},
        {58,    __32,   "dhcp-renewal-time"},
        {59,    __32,   "dhcp-rebinding-time"},
        {60,    __TXT,  "vendor-class-identifier"},
        {61,    __TXT,  "dhcp-client-identifier"},
        {64,    __TXT,  "nisplus-domain"},
        {65,    __IP,   "nisplus-servers"},
        {66,    __TXT,  "tftp-server-name"},
        {67,    __TXT,  "bootfile-name"},
        {68,    __IP,   "mobile-ip-home-agent"},
        {69,    __IP,   "smtp-server"},
        {70,    __IP,   "pop-server"},
        {71,    __IP,   "nntp-server"},
        {72,    __IP,   "www-server"},
        {73,    __IP,   "finger-server"},
        {74,    __IP,   "irc-server"},
        {75,    __IP,   "streettalk-server"},
        {76,    __IP,   "streettalk-directory-assistance-server"},
        {77,    __TXT,  "user-class"},
        {85,    __IP,   "nds-servers"},
        {86,    __TXT,  "nds-tree-name"},
        {87,    __TXT,  "nds-context"},
        {210,   __TXT,  "authenticate"},

        /* use the following entries for arbitrary variables */
        {246,   __ILIST, ""},
        {247,   __ILIST, ""},
        {248,   __ILIST, ""},
        {249,   __ILIST, ""},
        {250,   __INDIR, ""},
        {251,   __INDIR, ""},
        {252,   __INDIR, ""},
        {253,   __INDIR, ""},
        {254,   __INDIR, ""},
        {0,     __TXT,  "%soption-%d"}
};

/*
 * parse a dhcp response, set environment variables translating options
 * names and values according to the tables above. Also set dhcp.tags
 * to the list of selected tags.
 */
static void
setenv_(uchar_t *cp,  uchar_t *ep, struct dhcp_opt *opts)
{
        uchar_t *ncp;
        uchar_t tag;
        char    tags[512], *tp; /* the list of tags */

#define FLD_SEP ','     /* separator in list of elements */
        ncp = cp;
        tp = tags;
        if (opts == NULL)
                opts = dhcp_opt;

        while (ncp < ep) {
                unsigned int    size;           /* option size */
                char *vp, *endv, buf[256];      /* the value buffer */
                struct dhcp_opt *op;

                tag = *ncp++;                   /* extract tag and size */
                size = *ncp++;
                cp = ncp;                       /* current payload */
                ncp += size;                    /* point to the next option */

                if (tag == TAG_END)
                        break;
                if (tag == 0)
                        continue;

                for (op = opts+1; op->tag && op->tag != tag; op++)
                        ;
                /* if not found we end up on the default entry */

                /*
                 * Copy data into the buffer. libstand does not have snprintf
                 * so we need to be careful with sprintf(). With strings, the
                 * source is always <256 char so shorter than the buffer so we
                 * are safe; with other arguments, the longest string is
                 * inet_ntoa which is 16 bytes so we make sure to have always
                 * enough room in the string before trying an sprint.
                 */
                vp = buf;
                *vp = '\0';
                /* last valid write position */
                endv = buf + sizeof (buf) - 1 - 16;

                switch (op->fmt) {
                case __NONE:
                        break;  /* should not happen */

                case __VE: /* recurse, vendor specific */
                        setenv_(cp, cp+size, vndr_opt);
                        break;

                case __IP:      /* ip address */
                        for (; size > 0 && vp < endv; size -= 4, cp += 4) {
                                struct  in_addr in_ip;  /* ip addresses */
                                if (vp != buf)
                                        *vp++ = FLD_SEP;
                                bcopy(cp, &in_ip.s_addr, sizeof (in_ip.s_addr));
                                sprintf(vp, "%s", inet_ntoa(in_ip));
                                vp += strlen(vp);
                        }
                        break;

                case __BYTES:   /* opaque byte string */
                        for (; size > 0 && vp < endv; size -= 1, cp += 1) {
                                sprintf(vp, "%02x", *cp);
                                vp += strlen(vp);
                        }
                        break;

                case __TXT:
                        bcopy(cp, buf, size);   /* cannot overflow */
                        buf[size] = 0;
                        break;

                case __32:
                case __16:
                case __8:       /* op->fmt is also the length of each field */
                        for (; size > 0 && vp < endv;
                            size -= op->fmt, cp += op->fmt) {
                                uint32_t v;
                                if (op->fmt == __32)
                                        v = (cp[0]<<24) + (cp[1]<<16) +
                                            (cp[2]<<8) + cp[3];
                                else if (op->fmt == __16)
                                        v = (cp[0]<<8) + cp[1];
                                else
                                        v = cp[0];
                                if (vp != buf)
                                        *vp++ = FLD_SEP;
                                sprintf(vp, "%u", v);
                                vp += strlen(vp);
                        }
                        break;

                case __INDIR:   /* name=value */
                case __ILIST:   /* name=value;name=value... */
                        bcopy(cp, buf, size);   /* cannot overflow */
                        buf[size] = '\0';
                        for (endv = buf; endv; endv = vp) {
                                char *s = NULL; /* semicolon ? */

                                /* skip leading whitespace */
                                while (*endv && strchr(" \t\n\r", *endv))
                                        endv++;
                                /* find name=value separator */
                                vp = strchr(endv, '=');
                                if (!vp)
                                        break;
                                *vp++ = 0;
                                if (op->fmt == __ILIST && (s = strchr(vp, ';')))
                                        *s++ = '\0';
                                setenv(endv, vp, 1);
                                vp = s; /* prepare for next round */
                        }
                        buf[0] = '\0';  /* option already done */
                }

                if (tp - tags < sizeof (tags) - 5) {
                        /* add tag to the list */
                        if (tp != tags)
                                *tp++ = FLD_SEP;
                        sprintf(tp, "%d", tag);
                        tp += strlen(tp);
                }
                if (buf[0]) {
                        char    env[128];       /* the string name */

                        if (op->tag == 0)
                                sprintf(env, op->desc, opts[0].desc, tag);
                        else
                                sprintf(env, "%s%s", opts[0].desc, op->desc);
                        /*
                         * Do not replace existing values in the environment,
                         * so that locally-obtained values can override
                         * server-provided values.
                         */
                        setenv(env, buf, 0);
                }
        }
        if (tp != tags) {
                char    env[128];       /* the string name */
                sprintf(env, "%stags", opts[0].desc);
                setenv(env, tags, 1);
        }
}
#endif /* additional dhcp */