sanchayanmaity/minix
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity
minix/commands/dhcpd/dhcpd.c
David van Moolenbroek afb8067c4f dhcpd: fix newly introduced ACK warnings
2011-04-16 11:13:31 +00:00

1420 lines
37 KiB
C
Raw Blame History

/* 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 <net/gen/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:
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;
}
Reference in a new issue View git blame Copy permalink