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minix/minix/commands/dhcpd/dhcpd.c
David van Moolenbroek aa4ee93d43 dhcpd: don't crash so easily 
The jump-to-start hack is not resetting global variables, resulting in
a crash after several such restarts cause an overflow in the network
table.  This patch fixes that particular issue, but more similar
issues (in particular memory leaks) are bound to come up.  As such this
is a stopgap measure until we can get rid of the old dhcpd altogether.

This resolves the additional issue reported in #2.

Change-Id: Ic4cd80eae520cf2b97e893bac63b3ab1ecfea6d8
2014-11-17 20:17:43 +00:00

1422 lines
37 KiB
C
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/* dhcpd 1.15 - Dynamic Host Configuration Protocol daemon.
* Author: Kees J. Bot
* 11 Jun 1999
*/
#include <sys/types.h>
#include <stdio.h>
#include <stddef.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <signal.h>
#include <string.h>
#include <time.h>
#include <limits.h>
#include <configfile.h>
#include <sys/ioctl.h>
#include <sys/asynchio.h>
#include <net/hton.h>
#include <net/gen/socket.h>
#include <netdb.h>
#include <net/gen/in.h>
#include <net/gen/inet.h>
#include <net/gen/ether.h>
#include <net/gen/if_ether.h>
#include <net/gen/eth_hdr.h>
#include <net/gen/ip_hdr.h>
#include <net/gen/udp.h>
#include <net/gen/udp_hdr.h>
#include <net/gen/udp_io.h>
#include <net/gen/dhcp.h>
#include "arp.h"
#define EXTERN
#include "dhcpd.h"
char *configfile= PATH_DHCPCONF;
char *poolfile= PATH_DHCPPOOL;
static char *cachefile= PATH_DHCPCACHE;
static int qflag; /* True if printing cached DHCP data. */
static int aflag, rflag; /* True if adding or deleting pool addresses. */
#define BCAST_IP htonl(0xFFFFFFFFUL)
/* We try to play with up to this many networks. */
#define N_NETS 32
static unsigned n_nets; /* Actual number of networks. */
int lwip;
void report(const char *label)
{
static FILE *logfp;
if(!logfp)
logfp = fopen("/usr/log/dhcp.log", "w");
if(logfp)
fprintf(logfp, "%s: %s: %s\n", program, label, strerror(errno));
}
void fatal(const char *label)
{
report(label);
exit(1);
}
void *allocate(size_t size)
{
void *mem;
if ((mem= malloc(size)) == nil) fatal("Can't allocate memory");
return mem;
}
/* Choose a DHCP xid based on the start time and network number. Not really
* random, but we don't have anything more random than the clock anyway.
*/
#define XID(np) htonl(((u32_t) (np)->start << 8) | (np)->n)
static network_t *network[N_NETS];
int ifname2if(const char *name)
{
/* Translate an interface name to a number, -1 if bad. */
char *end;
unsigned long n;
if (*name++ != 'i' || *name++ != 'p') return -1;
n= strtoul(name, &end, 10);
if (end == name || *end != 0) return -1;
if (n >= N_NETS) return -1;
return n;
}
network_t *if2net(int n)
{
/* Translate an interface number to a network struct. */
int i;
for (i= 0; i < n_nets; i++) {
if (network[i]->n == n) return network[i];
}
return nil;
}
static ipaddr_t defaultmask(ipaddr_t ip)
{
/* Compute netmask by the oldfashioned Class rules. */
if (B(&ip)[0] < 0x80) return htonl(0xFF000000UL); /* Class A. */
if (B(&ip)[0] < 0xC0) return htonl(0xFFFF0000UL); /* Class B. */
if (B(&ip)[0] < 0xE0) return htonl(0xFFFFFF00UL); /* Class C. */
return htonl(0xFFFFFFFFUL); /* Multicast? Shouldn't happen... */
}
#define POOL_MAGIC htonl(0x81F85D00UL)
typedef struct pool { /* Dynamic pool entry. */
u32_t magic; /* Pool file magic number. */
ipaddr_t ip; /* IP address. */
u32_t expire; /* When does/did the lease expire? */
u8_t len; /* Client ID length. */
u8_t unused[19]; /* Space for extensions. */
u8_t clid[CLID_MAX]; /* Client ID of current/last user. */
} pool_t;
static int openpool(int mode)
{
/* Open the dynamic pool and lock it, return fd on success or -1. */
int fd;
struct flock lck;
if ((fd= open(poolfile, mode, 0644)) < 0) {
if (errno != ENOENT) fatal(poolfile);
return -1;
}
if (mode != O_RDONLY) {
lck.l_type= F_WRLCK;
lck.l_whence= SEEK_SET;
lck.l_start= 0;
lck.l_len= 0;
if (fcntl(fd, F_SETLKW, &lck) < 0) fatal(poolfile);
}
return fd;
}
static int readpool(int fd, pool_t *entry)
{
/* Read one pool table entry, return true unless EOF. */
ssize_t r;
if ((r= read(fd, entry, sizeof(*entry))) < 0) fatal(poolfile);
if (r == 0) return 0;
if (r != sizeof(*entry) || entry->magic != POOL_MAGIC) {
fprintf(stderr, "%s: %s: Pool table is corrupt\n",
program, poolfile);
close(fd);
return 0;
}
return 1;
}
static void writepool(int fd, pool_t *entry)
{
/* (Over)write a pool table entry. */
if (write(fd, entry, sizeof(*entry)) < 0
|| (entry->expire > now && fsync(fd) < 0)
) {
fatal(poolfile);
}
}
static ipaddr_t findpool(u8_t *client, size_t len, ipaddr_t ifip)
{
/* Look for a client ID in the dynamic address pool within the same network
* as 'ifip'. Select an unused one for a new client if necessary. Return
* 0 if nothing is available, otherwise the IP address we can offer.
*/
int fd, found;
pool_t entry, oldest;
dhcp_t dhcp;
u8_t *pmask;
ipaddr_t mask;
/* Any information available on the network the client is at? */
if (!makedhcp(&dhcp, nil, 0, nil, 0, ifip, ifip, nil)) return 0;
if ((fd= openpool(O_RDWR)) < 0) return 0;
(void) gettag(&dhcp, DHCP_TAG_NETMASK, &pmask, nil);
memcpy(&mask, pmask, sizeof(mask));
oldest.expire= NEVER;
while ((found= readpool(fd, &entry))) {
/* Deleted entry? */
if (entry.ip == 0) continue;
/* Correct network? */
if (((entry.ip ^ ifip) & mask) != 0) continue;
/* Client present? */
if (entry.len == len && memcmp(entry.clid, client, len) == 0) break;
/* Oldest candidate for a new lease? */
entry.expire= ntohl(entry.expire);
if (entry.expire < oldest.expire) oldest= entry;
}
close(fd);
if (found) return entry.ip;
if (oldest.expire <= now) return oldest.ip;
return 0;
}
static int commitpool(ipaddr_t ip, u8_t *client, size_t len, time_t expire)
{
/* Commit a new binding to stable storage, return true on success. */
int fd;
pool_t entry;
if ((fd= openpool(O_RDWR)) < 0) return 0;
do {
if (!readpool(fd, &entry)) {
close(fd);
return 0;
}
} while (entry.ip != ip);
entry.expire= htonl(expire);
entry.len= len;
memcpy(entry.clid, client, len);
if (lseek(fd, -(off_t)sizeof(entry), SEEK_CUR) == -1) fatal(poolfile);
writepool(fd, &entry);
close(fd);
return 1;
}
static void updatepool(int add, const char *name)
{
/* Add a new IP address to the dynamic pool. */
ipaddr_t ip;
int fd, i;
pool_t entry;
struct hostent *he;
off_t off, off0;
if ((he= gethostbyname(name)) == nil || he->h_addrtype != AF_INET) {
fprintf(stderr, "%s: %s: Unknown host\n", program, name);
exit(1);
}
for (i= 0; he->h_addr_list[i] != nil; i++) {}
if (i != 1) {
fprintf(stderr, "%s: %s has %d addresses\n", program, name, i);
exit(1);
}
memcpy(&ip, he->h_addr_list[0], sizeof(ip));
if ((fd= openpool(O_RDWR|O_CREAT)) < 0) fatal(poolfile);
off= 0;
off0= -1;
while (readpool(fd, &entry)) {
if (add) {
if (entry.ip == ip) {
fprintf(stderr, "%s: %s: %s is already present\n",
program, poolfile, name);
exit(1);
}
if (entry.ip == 0 && off0 == -1) off0= off;
} else {
if (entry.ip == ip) {
memset(&entry, 0, sizeof(entry));
entry.magic= POOL_MAGIC;
entry.ip= 0;
if (lseek(fd, off, SEEK_SET) == -1) fatal(poolfile);
writepool(fd, &entry);
}
}
off+= sizeof(entry);
}
if (add) {
if (off0 != -1 && lseek(fd, off0, SEEK_SET) == -1) fatal(poolfile);
memset(&entry, 0, sizeof(entry));
entry.magic= POOL_MAGIC;
entry.ip= ip;
writepool(fd, &entry);
}
close(fd);
}
static void cachedhcp(int n, dhcp_t *dp)
{
/* Store a DHCP packet in a cache where those who care can find it. */
static int inited;
FILE *fp;
int fd;
int mode;
if (test > 0) return;
if (!inited) {
/* First time, clear store and also save my pid. */
if ((fp= fopen(PATH_DHCPPID, "w")) != nil) {
if (fprintf(fp, "%d\n", getpid()) == EOF || fclose(fp) == EOF) {
fatal(PATH_DHCPPID);
}
}
inited= 1;
mode= O_WRONLY | O_CREAT | O_TRUNC;
} else {
mode= O_WRONLY;
}
dp->xid= htonl(now); /* To tell how old this data is. */
if ((fd= open(cachefile, mode, 0666)) < 0
|| lseek(fd, (off_t) n * sizeof(*dp), SEEK_SET) == -1
|| write(fd, dp, sizeof(*dp)) < 0
|| close(fd) < 0
) {
if (errno != ENOENT) fatal(cachefile);
}
}
static void printdata(void)
{
/* Show the contents of the cache and the dynamic pool. */
int fd;
dhcp_t d;
ssize_t r;
int i;
pool_t entry;
unsigned long expire;
char delta[3*sizeof(u32_t)];
initdhcpconf();
if ((fd= open(cachefile, O_RDONLY)) < 0) fatal(cachefile);
i= 0;
while ((r= read(fd, &d, sizeof(d))) == sizeof(d)) {
if (d.yiaddr != 0) {
printf("DHCP data for network %d:\n", i);
printdhcp(&d);
}
i++;
}
if (r < 0) fatal(cachefile);
close(fd);
if ((fd= openpool(O_RDONLY)) >= 0) {
printf("Dynamic address pool since %ld:\n", (long) now);
while (readpool(fd, &entry)) {
if (entry.ip == 0) continue;
expire= ntohl(entry.expire);
if (expire == 0) {
strcpy(delta, "unused");
} else
if (expire == 0xFFFFFFFFUL) {
strcpy(delta, "infinite");
} else
if (expire < now) {
sprintf(delta, "-%lu", now - expire);
} else {
sprintf(delta, "+%lu", expire - now);
}
printf("\t%-15s %8s ", inet_ntoa(entry.ip), delta);
for (i= 0; i < entry.len; i++) {
printf("%02X", entry.clid[i]);
}
fputc('\n', stdout);
}
close(fd);
}
}
static udpport_t portbyname(const char *name)
{
struct servent *se;
if ((se= getservbyname(name, "udp")) == nil) {
fprintf(stderr, "%s: Unknown port \"%s\"\n", program, name);
exit(1);
}
return se->s_port;
}
static int sendpacket(network_t *np, void *data, size_t len)
{
/* Send out a packet using a filedescriptor that is probably in async mode,
* so first dup() a sync version, then write. Return true on success.
*/
int fd;
ssize_t r;
if ((fd= dup(np->fdp->fd)) < 0) fatal("Can't dup()");
if ((r= write(fd, data, len)) < 0) {
report(np->fdp->device);
sleep(10);
}
close(fd);
return r >= 0;
}
static size_t servdhcp(network_t *np, buf_t *bp, size_t dlen)
{
buf_t *abp= nil;
ipaddr_t cip, ifip;
u8_t defclid[1+sizeof(bp->dhcp->chaddr)];
u8_t *pdata, *client, *class, *server, *reqip, *lease;
u32_t expire;
size_t len, cilen, calen;
int type, dyn;
u8_t atype;
static char NAKMESS[] = "IP address requested isn't yours";
if (test > 0) return 0;
/* The IP address of the interface close to the client. */
ifip= bp->dhcp->giaddr != 0 ? bp->dhcp->giaddr : np->ip;
/* All kinds of DHCP tags. */
if (gettag(bp->dhcp, DHCP_TAG_TYPE, &pdata, nil)) {
type= *pdata;
} else {
type= -1; /* BOOTP? */
}
if (!gettag(bp->dhcp, DHCP_TAG_CLIENTID, &client, &cilen)) {
defclid[0]= bp->dhcp->htype;
memcpy(defclid+1, bp->dhcp->chaddr, bp->dhcp->hlen);
client= defclid;
cilen= 1+bp->dhcp->hlen;
}
if (!gettag(bp->dhcp, DHCP_TAG_CLASSID, &class, &calen)) {
calen= 0;
}
if (!gettag(bp->dhcp, DHCP_TAG_SERVERID, &server, nil)) {
server= B(&np->ip);
}
if (!gettag(bp->dhcp, DHCP_TAG_REQIP, &reqip, nil)) {
reqip= nil;
}
/* I'm a server? Then see if I know this client. */
if ((np->flags & NF_SERVING)
&& bp->dhcp->op == DHCP_BOOTREQUEST
&& between(1, bp->dhcp->hlen, sizeof(bp->dhcp->chaddr))
&& (server == nil || memcmp(server, &np->ip, sizeof(np->ip)) == 0)
) {
get_buf(&abp);
/* Is the client in my tables? */
(void) makedhcp(abp->dhcp, class, calen, client, cilen, 0, ifip, nil);
cip= abp->dhcp->yiaddr;
dyn= 0;
/* If not, do we have a dynamic address? */
if (cip == 0 && (cip= findpool(client, cilen, ifip)) != 0) dyn= 1;
if (type == DHCP_INFORM) {
/* The client already has an address, it just wants information.
* We only answer if we could answer a normal request (cip != 0),
* unless configured to answer anyone.
*/
if (cip != 0 || (np->flags & NF_INFORM)) cip= bp->dhcp->ciaddr;
}
if (cip == 0 || !makedhcp(abp->dhcp, class, calen,
client, cilen, cip, ifip, nil)) {
put_buf(&abp);
}
if (abp != nil) {
if (gettag(abp->dhcp, DHCP_TAG_LEASE, &lease, nil)) {
memcpy(&expire, lease, sizeof(expire));
expire= now + ntohl(expire);
if (expire < now) expire= 0xFFFFFFFFUL;
} else {
if (dyn) {
/* A dynamic address must have a lease. */
fprintf(stderr, "%s: No lease set for address %s\n",
program, inet_ntoa(cip));
exit(1);
}
lease= nil;
expire= 0xFFFFFFFFUL;
}
/* What does our client want, and what do we say? */
switch (type) {
case DHCP_DISCOVER:
atype= DHCP_OFFER;
/* Assign this address for a short moment. */
if (dyn && !commitpool(cip, client, cilen, now + DELTA_FAST)) {
put_buf(&abp);
}
break;
case -1:/* BOOTP */
case DHCP_REQUEST:
case DHCP_INFORM:
atype= DHCP_ACK;
/* The address wanted must be the address we offer. */
if ((reqip != nil && memcmp(reqip, &cip, sizeof(cip)) != 0)
|| (bp->dhcp->ciaddr != 0 && bp->dhcp->ciaddr != cip)
) {
atype= DHCP_NAK;
} else
if (dyn && type == DHCP_REQUEST) {
/* Assign this address for the duration of the lease. */
if (!commitpool(cip, client, cilen, expire)) put_buf(&abp);
}
break;
case DHCP_DECLINE:
/* Our client doesn't want the offered address! */
if (dyn
&& reqip != nil
&& memcmp(reqip, &cip, sizeof(cip)) == 0
) {
int i;
fprintf(stderr, "%s: ", program);
for (i= 0; i < cilen; i++) {
fprintf(stderr, "%02X", client[i]);
}
fprintf(stderr, " declines %s", inet_ntoa(cip));
if (gettag(bp->dhcp, DHCP_TAG_MESSAGE, &pdata, &len)) {
fprintf(stderr, " saying: \"%.*s\"", (int)len, pdata);
}
fputc('\n', stderr);
/* Disable address for the duration of the lease. */
(void) commitpool(cip, nil, 0, expire);
}
put_buf(&abp);
break;
case DHCP_RELEASE:
/* Our client is nice enough to return its address. */
if (dyn) (void) commitpool(cip, client, cilen, now);
put_buf(&abp);
break;
default: /* Anything else is ignored. */
put_buf(&abp);
}
}
if (abp != nil) {
/* Finish the return packet. */
abp->dhcp->htype= bp->dhcp->htype;
abp->dhcp->hlen= bp->dhcp->hlen;
abp->dhcp->hops= 0;
abp->dhcp->xid= bp->dhcp->xid;
abp->dhcp->secs= 0;
abp->dhcp->flags= bp->dhcp->flags;
abp->dhcp->ciaddr= 0;
abp->dhcp->yiaddr= atype == DHCP_NAK ? 0 : cip;
if (atype == DHCP_NAK) abp->dhcp->siaddr= 0;
abp->dhcp->giaddr= bp->dhcp->giaddr;
memcpy(abp->dhcp->chaddr,bp->dhcp->chaddr,sizeof(bp->dhcp->chaddr));
settag(abp->dhcp, DHCP_TAG_SERVERID, &np->ip, sizeof(np->ip));
if (lease == nil) {
/* No lease specified? Then give an infinite lease. */
settag(abp->dhcp, DHCP_TAG_LEASE, &expire, sizeof(expire));
}
if (type == DHCP_INFORM) {
/* Oops, this one has a fixed address, so no lease business. */
abp->dhcp->yiaddr= 0;
settag(abp->dhcp, DHCP_TAG_LEASE, nil, 0);
settag(abp->dhcp, DHCP_TAG_RENEWAL, nil, 0);
settag(abp->dhcp, DHCP_TAG_REBINDING, nil, 0);
}
if (atype == DHCP_NAK) {
/* A NAK doesn't need much. */
memset(abp->dhcp->sname, 0, sizeof(abp->dhcp->sname));
memset(abp->dhcp->file, 0, sizeof(abp->dhcp->file));
memset(abp->dhcp->options, 255, sizeof(abp->dhcp->options));
settag(abp->dhcp, DHCP_TAG_MESSAGE, NAKMESS, sizeof(NAKMESS));
}
settag(abp->dhcp, DHCP_TAG_TYPE, &atype, sizeof(atype));
/* Figure out where to send this to. */
abp->udpio->uih_src_addr= np->ip;
abp->udpio->uih_src_port= port_server;
if (bp->dhcp->giaddr != 0) {
abp->udpio->uih_dst_addr= bp->dhcp->giaddr;
abp->udpio->uih_dst_port= port_server;
} else
if (bp->dhcp->flags & DHCP_FLAGS_BCAST) {
abp->udpio->uih_dst_addr= BCAST_IP;
abp->udpio->uih_dst_port= port_client;
} else
if (bp->udpio->uih_src_addr != 0
&& bp->udpio->uih_dst_addr == np->ip
) {
abp->udpio->uih_dst_addr= bp->udpio->uih_src_addr;
abp->udpio->uih_dst_port= port_client;
} else {
abp->udpio->uih_dst_addr= BCAST_IP;
abp->udpio->uih_dst_port= port_client;
}
abp->udpio->uih_ip_opt_len= 0;
abp->udpio->uih_data_len= sizeof(dhcp_t);
/* Copy the packet to the input buffer, and return the new size. */
memcpy(bp->buf, abp->buf, sizeof(bp->buf));
put_buf(&abp);
return sizeof(udp_io_hdr_t) + sizeof(dhcp_t);
}
}
/* I'm a relay? If it is a not already a relayed request then relay. */
if ((np->flags & NF_RELAYING)
&& bp->dhcp->op == DHCP_BOOTREQUEST
&& bp->dhcp->giaddr == 0
) {
bp->dhcp->giaddr= np->ip;
bp->udpio->uih_src_addr= np->ip;
bp->udpio->uih_src_port= port_server;
bp->udpio->uih_dst_addr= np->server;
bp->udpio->uih_dst_port= port_server;
return dlen;
}
/* I'm a relay? If the server sends a reply to me then relay back. */
if ((np->flags & NF_RELAYING)
&& bp->dhcp->op == DHCP_BOOTREPLY
&& bp->dhcp->giaddr == np->ip
) {
bp->dhcp->giaddr= 0;
bp->udpio->uih_src_addr= np->ip;
bp->udpio->uih_src_port= port_server;
bp->udpio->uih_dst_addr= BCAST_IP;
bp->udpio->uih_dst_port= port_client;
return dlen;
}
/* Don't know what to do otherwise, so doing nothing seems wise. */
return 0;
}
static void onsig(int sig)
{
switch (sig) {
case SIGUSR1: debug++; break;
case SIGUSR2: debug= 0; break;
}
}
static void usage(void)
{
fprintf(stderr,
"Usage: %s [-qar] [-t[L]] [-d[L]] [-f config] [-c cache] [-p pool] [host ...]\n",
program);
exit(1);
}
int main(int argc, char **argv)
{
int i;
network_t *np;
struct sigaction sa;
ssize_t r;
buf_t *bp;
static struct timeval eventtv;
main:
n_nets = 0;
r = -1;
bp = nil;
program= argv[0];
start= now= time(nil);
debug= 0;
i= 1;
while (i < argc && argv[i][0] == '-') {
char *opt= argv[i++]+1;
if (opt[0] == '-' && opt[1] == 0) break; /* -- */
if (strcmp(opt, "-lwip") == 0) {
lwip = 1;
continue;
}
while (*opt != 0) switch (*opt++) {
case 'f':
if (*opt == 0) {
if (i == argc) usage();
opt= argv[i++];
}
configfile= opt;
opt= "";
break;
case 'c':
if (*opt == 0) {
if (i == argc) usage();
opt= argv[i++];
}
cachefile= opt;
opt= "";
break;
case 'p':
if (*opt == 0) {
if (i == argc) usage();
opt= argv[i++];
}
poolfile= opt;
opt= "";
break;
case 't':
test= 1;
if (between('0', *opt, '9')) test= strtoul(opt, &opt, 10);
break;
case 'd':
debug= 1;
if (between('0', *opt, '9')) debug= strtoul(opt, &opt, 10);
break;
case 'q':
qflag= 1;
break;
case 'a':
aflag= 1;
break;
case 'r':
rflag= 1;
break;
default:
usage();
}
}
if (aflag + rflag + qflag > 1) usage();
if (aflag || rflag) {
/* Add or remove addresses from the dynamic pool. */
while (i < argc) updatepool(aflag, argv[i++]);
exit(0);
}
if (i != argc) usage();
if (qflag) {
/* Only show the contents of the cache and dynamic pool to the user. */
printdata();
exit(0);
}
/* BOOTP ports. */
port_server= portbyname("bootps");
port_client= portbyname("bootpc");
sa.sa_handler= onsig;
sigemptyset(&sa.sa_mask);
sa.sa_flags= 0;
sigaction(SIGUSR1, &sa, nil);
sigaction(SIGUSR2, &sa, nil);
/* Initial configuration. */
for (i= 0; i < N_NETS; i++) {
int fd;
ipaddr_t ip, mask;
/* Is there something there? */
if ((fd= open(ipdev(i), O_RDWR|O_NONBLOCK)) < 0) {
if (errno != ENOENT && errno != ENODEV && errno != ENXIO) {
fatal(ipdev(i));
}
continue;
}
close(fd);
network[n_nets++]= np= newnetwork();
np->n= i;
/* Ethernet? */
if (lwip) {
np->type = NT_ETHERNET;
} else if (opendev(np, FT_ETHERNET, 1)) {
np->type= B(&np->eth)[0] != 'Z' ? NT_ETHERNET : NT_SINK;
if (debug >= 1) {
printf("%s: Ethernet address is %s%s\n",
np->fdp->device, ether_ntoa(&np->eth),
np->type == NT_SINK ? " (sink)" : "");
}
closedev(np, FT_ETHERNET);
}
/* Only true Ethernets worry about DHCP. */
if (np->type != NT_ETHERNET) np->renew= np->rebind= np->lease= NEVER;
}
/* Try to find my interfaces in the DHCP table. */
for (i= 0; i < n_nets; i++) {
ipaddr_t cip;
u8_t clid[1+DHCP_HLEN_ETH];
size_t cilen;
np= network[i];
if (np->flags & NF_BOUND) continue;
if (np->type == NT_IP) {
cilen= 0;
} else {
ether2clid(clid, &np->eth);
cilen= 1+DHCP_HLEN_ETH;
}
/* Try to find an Ethernet address, or the IP address of an already
* configured network. If we have data we get an IP address back.
*/
get_buf(&bp);
(void) makedhcp(bp->dhcp, (u8_t *) "Minix", 5,
clid, cilen, np->ip, 0, np);
cip= bp->dhcp->yiaddr;
/* Gather information on the interface. */
if (cip != 0
&& makedhcp(bp->dhcp, (u8_t *) "Minix", 5,
clid, cilen, cip, cip, np)
&& test < 2
) {
u8_t *pdata;
u16_t mtu;
cachedhcp(np->n, bp->dhcp);
np->ip= cip;
(void) gettag(bp->dhcp, DHCP_TAG_NETMASK, &pdata, nil);
memcpy(&np->mask, pdata, sizeof(np->mask));
if (gettag(bp->dhcp, DHCP_TAG_GATEWAY, &pdata, nil)) {
memcpy(&np->gateway, pdata, sizeof(np->gateway));
} else {
np->gateway= 0;
}
if (gettag(bp->dhcp, DHCP_TAG_IPMTU, &pdata, nil)) {
memcpy(&mtu, pdata, sizeof(mtu));
mtu= ntohs(mtu);
} else {
mtu= 0;
}
set_ipconf(ipdev(np->n), np->ip, np->mask, mtu);
if (debug >= 1) {
printf("%s: IP address is %s\n",
ipdev(np->n), cidr_ntoa(np->ip, np->mask));
}
np->flags |= NF_BOUND;
np->renew= np->rebind= np->lease= NEVER;
np->sol_ct= N_SOLICITS;
np->solicit= 0;
/* Other (previous) interfaces may have been defined. */
i= 0;
}
put_buf(&bp);
}
for (;;) {
now= time(nil);
event= NEVER;
/* Is it time to request/renew a lease? */
for (i= 0; i < n_nets; i++) {
np= network[i];
if (np->renew <= now) {
u8_t type;
static u8_t taglist[] = {
DHCP_TAG_NETMASK, DHCP_TAG_GATEWAY, DHCP_TAG_DNS,
DHCP_TAG_HOSTNAME
};
u8_t ethclid[1+DHCP_HLEN_ETH];
/* We may have lost our binding or even our lease. */
if (np->rebind <= now) np->server= BCAST_IP;
if (np->lease <= now) {
if (np->flags & NF_BOUND) closedev(np, FT_ALL);
if ((np->flags & (NF_BOUND | NF_POSSESSIVE)) == NF_BOUND) {
set_ipconf(ipdev(np->n), np->ip= 0, np->mask= 0, 0);
if (debug >= 1) {
printf("%s: Interface disabled (lease expired)\n",
ipdev(np->n));
}
}
np->flags &= ~NF_BOUND;
}
/* See if we can open the network we need to send on. */
if (!(np->flags & NF_BOUND)) {
if (!opendev(np, FT_ETHERNET, 1)) continue;
} else {
if (!opendev(np, FT_BOOTPC, 1)) continue;
}
if (!(np->flags & NF_NEGOTIATING)) {
/* We need to start querying a DHCP server. */
np->start= now;
np->delta= DELTA_FIRST;
np->flags |= NF_NEGOTIATING;
}
/* Fill in a DHCP query packet. */
get_buf(&bp);
dhcp_init(bp->dhcp);
bp->dhcp->op= DHCP_BOOTREQUEST;
bp->dhcp->htype= DHCP_HTYPE_ETH;
bp->dhcp->hlen= DHCP_HLEN_ETH;
bp->dhcp->xid= XID(np);
bp->dhcp->secs= htons(now - np->start > 0xFFFF
? 0xFFFF : now - np->start);
memcpy(bp->dhcp->chaddr, &np->eth, sizeof(np->eth));
if (np->lease <= now) {
/* First time, or my old server is unresponsive. */
type= DHCP_DISCOVER;
} else {
/* Request an offered address or renew an address. */
type= DHCP_REQUEST;
if (np->flags & NF_BOUND) {
/* A renewal, I claim my current address. */
bp->dhcp->ciaddr= np->ip;
} else {
/* Nicely ask for the address just offered. */
settag(bp->dhcp, DHCP_TAG_REQIP, &np->ip,
sizeof(np->ip));
settag(bp->dhcp, DHCP_TAG_SERVERID, &np->server,
sizeof(np->server));
}
}
settag(bp->dhcp, DHCP_TAG_TYPE, &type, 1);
/* My client ID. Simply use the default. */
ether2clid(ethclid, &np->eth);
settag(bp->dhcp, DHCP_TAG_CLIENTID, ethclid, sizeof(ethclid));
/* The Class ID may serve to recognize Minix hosts. */
settag(bp->dhcp, DHCP_TAG_CLASSID, "Minix", 5);
/* The few tags that Minix can make good use of. */
settag(bp->dhcp, DHCP_TAG_REQPAR, taglist, sizeof(taglist));
/* Some weird sites use a hostname, not a client ID. */
if (np->hostname != nil) {
settag(bp->dhcp, DHCP_TAG_HOSTNAME,
np->hostname, strlen(np->hostname));
}
bp->udpio->uih_src_addr= np->ip;
bp->udpio->uih_dst_addr= np->server;
bp->udpio->uih_src_port= port_client;
bp->udpio->uih_dst_port= port_server;
bp->udpio->uih_ip_opt_len= 0;
bp->udpio->uih_data_len= sizeof(dhcp_t);
if (!(np->flags & NF_BOUND)) {
/* Rebind over Ethernet. */
udp2ether(bp, np);
if (sendpacket(np, (lwip ? bp->ip : (void *) bp->eth),
(lwip ? 0 : sizeof(eth_hdr_t)) + sizeof(ip_hdr_t)
+ sizeof(udp_hdr_t) + sizeof(dhcp_t))) {
if (debug >= 1) {
printf("%s: Broadcast DHCP %s\n",
np->fdp->device, dhcptypename(type));
if (debug >= 2) printdhcp(bp->dhcp);
}
}
} else {
/* Renew over UDP. */
if (sendpacket(np, bp->udpio, sizeof(udp_io_hdr_t)
+ sizeof(dhcp_t))) {
if (debug >= 1) {
printf("%s: Sent DHCP %s to %s\n",
np->fdp->device,
dhcptypename(type),
inet_ntoa(np->server));
if (debug >= 2) printdhcp(bp->dhcp);
}
}
}
put_buf(&bp);
/* When to continue querying a DHCP server? */
if (np->flags & NF_BOUND) {
/* Still bound, keep halving time till next event. */
time_t e, d;
e= now < np->rebind ? np->rebind : np->lease;
d= (e - now) / 2;
if (d < DELTA_SLOW) d= DELTA_SLOW;
np->renew= now + d;
if (np->renew > e) np->renew= e;
} else {
/* Not bound, be desparate. */
np->renew= now + np->delta;
if ((np->delta *= 2) > DELTA_FAST) np->delta= DELTA_FAST;
}
}
if (np->renew < event) event= np->renew;
}
/* Read DHCP responses. */
for (i= 0; i < n_nets; i++) {
np= network[i];
if (!(np->flags & NF_NEGOTIATING)) continue;
if (!(np->flags & NF_BOUND)) {
if (!opendev(np, FT_ETHERNET, 0)) continue;
get_buf(&np->fdp->bp);
r= asyn_read(&asyn, np->fdp->fd,
lwip ? np->fdp->bp->ip : (void *) np->fdp->bp->eth,
lwip ? BUF_IP_SIZE : BUF_ETH_SIZE);
} else {
if (!opendev(np, FT_BOOTPC, 0)) continue;
get_buf(&np->fdp->bp);
r= asyn_read(&asyn, np->fdp->fd, np->fdp->bp->udpio,
BUF_UDP_SIZE);
}
if (r != -1) break;
if (errno != ASYN_INPROGRESS && errno != EPACKSIZE) {
report(np->fdp->device);
sleep(10);
}
}
/* Is there a response? */
if (i < n_nets) {
give_buf(&bp, &np->fdp->bp);
if (((!(np->flags & NF_BOUND)
&& r >= (lwip ? 0 : (sizeof(eth_hdr_t)) + sizeof(ip_hdr_t)
+ sizeof(udp_hdr_t) + offsetof(dhcp_t, options))
&& ether2udp(bp)
&& bp->udpio->uih_dst_port == port_client)
||
((np->flags & NF_BOUND)
&& r >= sizeof(udp_io_hdr_t) + offsetof(dhcp_t, options)))
&& bp->dhcp->op == DHCP_BOOTREPLY
&& bp->dhcp->htype == DHCP_HTYPE_ETH
&& bp->dhcp->hlen == DHCP_HLEN_ETH
&& bp->dhcp->xid == XID(np)
&& memcmp(bp->dhcp->chaddr, &np->eth, sizeof(np->eth)) == 0
) {
/* Pfew! We got a DHCP reply! */
u8_t *pdata;
size_t len;
int type;
ipaddr_t mask, gateway, relay, server;
u16_t mtu;
u32_t lease, renew, rebind, t;
relay= bp->udpio->uih_src_addr;
if (gettag(bp->dhcp, DHCP_TAG_SERVERID, &pdata, nil)) {
memcpy(&server, pdata, sizeof(server));
} else {
server= relay;
}
if (gettag(bp->dhcp, DHCP_TAG_TYPE, &pdata, nil)) {
type= pdata[0];
} else {
type= DHCP_ACK; /* BOOTP? */
}
if (debug >= 1) {
printf("%s: Got a DHCP %s from %s",
np->fdp->device, dhcptypename(type), inet_ntoa(server));
printf(relay != server ? " through %s\n" : "\n",
inet_ntoa(relay));
if (debug >= 2) printdhcp(bp->dhcp);
}
if (gettag(bp->dhcp, DHCP_TAG_NETMASK, &pdata, nil)) {
memcpy(&mask, pdata, sizeof(mask));
} else {
mask= defaultmask(bp->dhcp->ciaddr);
}
if (gettag(bp->dhcp, DHCP_TAG_IPMTU, &pdata, nil)) {
memcpy(&mtu, pdata, sizeof(mtu));
mtu= ntohs(mtu);
} else {
mtu= 0;
}
if (gettag(bp->dhcp, DHCP_TAG_GATEWAY, &pdata, nil)) {
memcpy(&gateway, pdata, sizeof(gateway));
} else {
gateway= 0;
}
lease= NEVER;
if (gettag(bp->dhcp, DHCP_TAG_LEASE, &pdata, nil)) {
memcpy(&lease, pdata, sizeof(lease));
lease= ntohl(lease);
}
rebind= lease - lease / 8;
if (gettag(bp->dhcp, DHCP_TAG_REBINDING, &pdata, nil)) {
memcpy(&t, pdata, sizeof(t));
t= ntohl(t);
if (t < rebind) rebind= t;
}
renew= lease / 2;
if (gettag(bp->dhcp, DHCP_TAG_RENEWAL, &pdata, nil)) {
memcpy(&t, pdata, sizeof(t));
t= ntohl(t);
if (t < renew) renew= t;
}
if (type == DHCP_OFFER && np->rebind <= np->renew) {
/* It's an offer for an address and we haven't taken one
* yet. It's all the same to us, so take this one.
*/
np->ip= bp->dhcp->yiaddr;
np->mask= mask;
np->server= server;
np->gateway= gateway;
np->delta= DELTA_FIRST;
np->renew= now;
np->rebind= np->lease= now + DELTA_FAST;
/* Send out an ARP request to see if the offered address
* is in use already.
*/
make_arp(bp, np);
if (sendpacket(np, bp->eth, sizeof(arp46_t))) {
if (debug >= 2) {
printf("Sent ARP for %s\n", inet_ntoa(np->ip));
}
}
np->flags &= ~NF_CONFLICT;
}
if (type == DHCP_ACK && !(np->flags & NF_CONFLICT)) {
/* An acknowledgment. The address is all mine. */
cachedhcp(np->n, bp->dhcp);
np->ip= bp->dhcp->yiaddr;
np->mask= mask;
np->server= server;
set_ipconf(ipdev(np->n), np->ip, np->mask, mtu);
if (debug >= 1) {
printf("%s: Address set to %s\n",
ipdev(np->n), cidr_ntoa(np->ip, np->mask));
}
if (lease >= NEVER - now) {
/* The lease is infinite! */
np->renew= np->rebind= np->lease= NEVER;
} else {
np->lease= now + lease;
np->renew= now + renew;
np->rebind= now + rebind;
}
if (test >= 3) {
np->renew= now + 60;
np->rebind= test >= 4 ? np->renew : np->renew + 60;
np->lease= test >= 5 ? np->rebind : np->rebind + 60;
}
if (!(np->flags & NF_IRDP)) {
np->sol_ct= (np->flags & NF_BOUND) ? 1 : N_SOLICITS;
np->solicit= 0;
}
np->flags &= ~NF_NEGOTIATING;
np->flags |= NF_BOUND;
closedev(np, FT_ETHERNET);
closedev(np, FT_BOOTPC);
}
if (type == DHCP_ACK && (np->flags & NF_CONFLICT)) {
/* Alas there is a conflict. Decline to use the address. */
u8_t ethclid[1+DHCP_HLEN_ETH];
static char USED[]= "Address in use by 00:00:00:00:00:00";
type= DHCP_DECLINE;
dhcp_init(bp->dhcp);
bp->dhcp->op= DHCP_BOOTREQUEST;
bp->dhcp->htype= DHCP_HTYPE_ETH;
bp->dhcp->hlen= DHCP_HLEN_ETH;
bp->dhcp->xid= XID(np);
bp->dhcp->secs= 0;
memcpy(bp->dhcp->chaddr, &np->eth, sizeof(np->eth));
settag(bp->dhcp, DHCP_TAG_REQIP, &np->ip, sizeof(np->ip));
settag(bp->dhcp, DHCP_TAG_TYPE, &type, 1);
ether2clid(ethclid, &np->eth);
settag(bp->dhcp, DHCP_TAG_CLIENTID,ethclid,sizeof(ethclid));
strcpy(USED+18, ether_ntoa(&np->conflict));
settag(bp->dhcp, DHCP_TAG_MESSAGE, USED, strlen(USED));
bp->udpio->uih_src_port= port_client;
bp->udpio->uih_dst_port= port_server;
bp->udpio->uih_ip_opt_len= 0;
bp->udpio->uih_data_len= sizeof(dhcp_t);
udp2ether(bp, np);
if (sendpacket(np, bp->eth,
sizeof(eth_hdr_t) + sizeof(ip_hdr_t)
+ sizeof(udp_hdr_t) + sizeof(dhcp_t))) {
if (debug >= 1) {
printf("%s: Broadcast DHCP %s\n",
np->fdp->device, dhcptypename(type));
if (debug >= 2) printdhcp(bp->dhcp);
}
}
np->renew= np->rebind= np->lease= now + DELTA_FAST;
np->delta= DELTA_FIRST;
}
if (type == DHCP_NAK) {
/* Oops, a DHCP server doesn't like me, start over! */
np->renew= np->rebind= np->lease= now + DELTA_FAST;
np->delta= DELTA_FIRST;
fprintf(stderr, "%s: Got a NAK from %s",
program, inet_ntoa(server));
if (relay != server) {
fprintf(stderr, " through %s", inet_ntoa(relay));
}
if (gettag(bp->dhcp, DHCP_TAG_MESSAGE, &pdata, &len)) {
fprintf(stderr, " saying: \"%.*s\"", (int)len, pdata);
}
fputc('\n', stderr);
}
} else
if (!(np->flags & NF_BOUND)
&& np->rebind > now
&& r >= sizeof(arp46_t)
&& is_arp_me(bp, np)
) {
/* Oh no, someone else is using the address offered to me! */
np->flags |= NF_CONFLICT;
fprintf(stderr, "%s: %s: %s offered by ",
program,
np->fdp->device,
inet_ntoa(np->ip));
fprintf(stderr, "%s is already in use by %s\n",
inet_ntoa(np->server),
ether_ntoa(&np->conflict));
}
put_buf(&bp);
if (np->renew < event) event= np->renew;
}
/* Perform router solicitations. */
for (i= 0; i < n_nets; i++) {
np= network[i];
if (!(np->flags & NF_BOUND)) continue;
if (np->solicit <= now) {
if (!opendev(np, FT_ICMP, 1)) continue;
np->solicit= NEVER;
get_buf(&bp);
if (np->gateway != 0) {
/* No IRDP response seen yet, advertise the router given
* by DHCP to my own interface.
*/
icmp_advert(bp, np);
if (sendpacket(np, bp->ip, sizeof(ip_hdr_t) + 16)) {
if (debug >= 2) {
printf("%s: Sent advert for %s to self\n",
np->fdp->device, inet_ntoa(np->gateway));
}
}
np->solicit= now + DELTA_ADV/2;
}
if (np->sol_ct >= 0 && --np->sol_ct >= 0) {
/* Send a router solicitation. */
icmp_solicit(bp);
if (sendpacket(np, bp->ip, sizeof(*bp->ip) + 8)) {
if (debug >= 2) {
printf("%s: Broadcast router solicitation\n",
np->fdp->device);
}
}
np->solicit= now + DELTA_SOL;
} else {
/* No response, or not soliciting right now. */
closedev(np, FT_ICMP);
}
put_buf(&bp);
}
if (np->solicit < event) event= np->solicit;
}
/* Read router adverts. */
for (i= 0; i < n_nets; i++) {
np= network[i];
if (!(np->flags & NF_BOUND)) continue;
if (np->sol_ct < 0) continue;
if (!opendev(np, FT_ICMP, 0)) continue;
get_buf(&np->fdp->bp);
r= asyn_read(&asyn, np->fdp->fd, np->fdp->bp->ip, BUF_IP_SIZE);
if (r != -1) break;
if (errno != ASYN_INPROGRESS && errno != EPACKSIZE) {
report(np->fdp->device);
sleep(10);
}
}
/* Is there an advert? */
if (i < n_nets && r >= sizeof(ip_hdr_t) + 8) {
ipaddr_t router;
give_buf(&bp, &np->fdp->bp);
if ((router= icmp_is_advert(bp)) != 0) {
if (debug >= 2) {
printf("%s: Router advert received from %s\n",
np->fdp->device, inet_ntoa(router));
}
np->solicit= NEVER;
np->sol_ct= -1;
np->flags |= NF_IRDP;
closedev(np, FT_ICMP);
}
put_buf(&bp);
}
/* We start serving if all the interfaces so marked are configured. */
for (i= 0; i < n_nets; i++) {
np= network[i];
if ((np->flags & NF_RELAYING) && (np->flags & NF_BOUND)) {
if (((np->ip ^ np->server) & np->mask) == 0) {
/* Don't relay to a server that is on this same net. */
np->flags &= ~NF_RELAYING;
}
}
if (!(np->flags & (NF_SERVING|NF_RELAYING))) continue;
if (!(np->flags & NF_BOUND)) { serving= 0; break; }
serving= 1;
}
/* Read DHCP requests. */
for (i= 0; i < n_nets; i++) {
np= network[i];
if (!(np->flags & NF_BOUND)) continue;
if (!(np->flags & (NF_SERVING|NF_RELAYING)) || !serving) continue;
if (!opendev(np, FT_BOOTPS, 0)) continue;
get_buf(&np->fdp->bp);
r= asyn_read(&asyn, np->fdp->fd, np->fdp->bp->udpio, BUF_UDP_SIZE);
if (r != -1) break;
if (errno != ASYN_INPROGRESS && errno != EPACKSIZE) {
report(np->fdp->device);
sleep(10);
}
}
/* Is there a request? */
if (i < n_nets
&& r >= sizeof(udp_io_hdr_t) + offsetof(dhcp_t, options)
) {
give_buf(&bp, &np->fdp->bp);
if (debug >= 1) {
printf("%s: Got DHCP packet from %s to ",
np->fdp->device, inet_ntoa(bp->udpio->uih_src_addr));
printf("%s\n", inet_ntoa(bp->udpio->uih_dst_addr));
if (debug >= 2) printdhcp(bp->dhcp);
}
/* Can we do something with this DHCP packet? */
if ((r= servdhcp(np, bp, r)) > 0) {
/* Yes, we have something to send somewhere. */
if (sendpacket(np, bp->udpio, r)) {
if (debug >= 1) {
printf("%s: Sent DHCP packet to %s\n",
np->fdp->device,
inet_ntoa(bp->udpio->uih_dst_addr));
if (debug >= 2) printdhcp(bp->dhcp);
}
}
}
put_buf(&bp);
}
if (debug >= 1) {
static char *lastbrk;
extern char _end;
if (sbrk(0) != lastbrk) {
lastbrk= sbrk(0);
printf("Memory use = %lu\n",
(unsigned long) (lastbrk - &_end));
}
fflush(stdout);
}
/* Bail out if not a server, and there is nothing else to do ever. */
if (!serving && event == NEVER) break;
/* Wait for something to do. */
eventtv.tv_sec= event;
if (asyn_wait(&asyn, 0, event == NEVER ? nil : &eventtv) < 0) {
if (errno != EINTR) {
report("asyn_wait()");
sleep(10);
}
}
}
if (debug >= 1) printf("Nothing more to do! Starting over...\n");
sleep(2);
goto main;
return 0;
}
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