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freebsd/stand/libsa/bootp.c
Warner Losh a23c26b2fe stand: use snprintf here 
This code was written prior to snprintf being in the then libstand (now
libsa). Since we have it, use it for extra safety. The code already
tries to be safe, but since we have snprintf as well, the added layer of
protection will suffice. The current code reserves 16 bytes (plus a NUL)
at the end for worst case of inet_ntoa, which is still a little
pessimal, but safe from overflow.

Sponsored by:		Netflix
Reviewed by:		tsoome
Differential Revision:	https://reviews.freebsd.org/D35102
2022-08-03 11:24:38 -06:00

785 lines
20 KiB
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Raw Blame History

/* $NetBSD: bootp.c,v 1.14 1998/02/16 11:10:54 drochner Exp $ */
/*
* 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.
*
* @(#) Header: bootp.c,v 1.4 93/09/11 03:13:51 leres Exp (LBL)
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#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(u_char *, u_int);
#ifdef BOOTP_VEND_CMU
static void vend_cmu(u_char *);
#endif
#ifdef DHCP_ENV /* export the dhcp response to kenv */
struct dhcp_opt;
static void setenv_(u_char *cp, u_char *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("FreeBSD", &bp_vend[14], 7);
bp_vend[21] = TAG_PARAM_REQ;
bp_vend[22] = 7;
bp_vend[23] = TAG_ROOTPATH;
bp_vend[24] = TAG_HOSTNAME;
bp_vend[25] = TAG_SWAPSERVER;
bp_vend[26] = TAG_GATEWAY;
bp_vend[27] = TAG_SUBNET_MASK;
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 {
u_char 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((u_short)(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)
{
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(u_char *cp, u_int len)
{
u_char *ep;
int size;
u_char 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 = (u_int)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(u_char *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_(u_char *cp, u_char *ep, struct dhcp_opt *opts)
{
u_char *ncp;
u_char 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. While the code uses snprintf, it's also
* careful never to insert strings that would be truncated. inet_ntoa is
* tricky to know the size, so it assumes we can always insert it
* because we reserve 16 bytes at the end of the string for its worst
* case. Other cases are covered because they will write fewer than
* these reserved bytes at the end. Source strings can't overflow (as
* noted below) because buf is 256 bytes and all strings are limited by
* the protocol to be 256 bytes or smaller.
*/
vp = buf;
*vp = '\0';
endv = buf + sizeof(buf) - 1 - 16; /* last valid write position */
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));
snprintf(vp, endv - vp, "%s", inet_ntoa(in_ip));
vp += strlen(vp);
}
break;
case __BYTES: /* opaque byte string */
for (; size > 0 && vp < endv; size -= 1, cp += 1) {
snprintf(vp, endv - 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;
snprintf(vp, endv - 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++;
vp = strchr(endv, '='); /* find name=value separator */
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 */
break;
}
if (tp - tags < sizeof(tags) - 5) { /* add tag to the list */
if (tp != tags)
*tp++ = FLD_SEP;
snprintf(tp, sizeof(tags) - (tp - tags), "%d", tag);
tp += strlen(tp);
}
if (buf[0]) {
char env[128]; /* the string name */
if (op->tag == 0)
snprintf(env, sizeof(env), op->desc, opts[0].desc, tag);
else
snprintf(env, sizeof(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 */
snprintf(env, sizeof(env), "%stags", opts[0].desc);
setenv(env, tags, 1);
}
}
#endif /* additional dhcp */
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