minix3/commands/dhcpd/devices.c

348 lines
8.6 KiB
C

/* devices.c - Handle network devices.
* Author: Kees J. Bot
* 11 Jun 1999
*/
#include <sys/types.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <string.h>
#include <limits.h>
#include <signal.h>
#include <time.h>
#include <sys/ioctl.h>
#include <sys/asynchio.h>
#include <net/hton.h>
#include <net/gen/in.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <net/gen/ether.h>
#include <net/gen/eth_hdr.h>
#include <net/gen/eth_io.h>
#include <net/gen/ip_hdr.h>
#include <net/gen/ip_io.h>
#include <net/gen/udp.h>
#include <net/gen/udp_hdr.h>
#include <net/gen/udp_io.h>
#include <net/gen/dhcp.h>
#include "dhcpd.h"
void get_buf(buf_t **bp)
{
/* Allocate and return a buffer pointer iff *bp == nil. */
if (*bp != nil) {
/* Already has one. */
} else {
/* Get one from the heap. */
buf_t *new= allocate(sizeof(*new));
new->dhcp= (dhcp_t *) (new->buf + sizeof(eth_hdr_t)
+ sizeof(ip_hdr_t) + sizeof(udp_hdr_t));
new->udpio= ((udp_io_hdr_t *) new->dhcp) - 1;
new->udp= ((udp_hdr_t *) new->dhcp) - 1;
new->ip= ((ip_hdr_t *) new->udp) - 1;
new->eth= ((eth_hdr_t *) new->ip) - 1;
*bp= new;
}
}
void put_buf(buf_t **bp)
{
/* Return a buffer to the heap. */
if (*bp != nil) {
free(*bp);
*bp= nil;
}
}
void give_buf(buf_t **dbp, buf_t **sbp)
{
/* Hand over a buffer to another variable. */
put_buf(dbp);
*dbp= *sbp;
*sbp= nil;
}
#define N_FDS 16 /* Minix can go async on many fds. */
static fd_t fds[N_FDS]; /* List of open descriptors. */
static struct network *fdwaitq; /* Queue of nets waiting for fds. */
network_t *newnetwork(void)
{
/* Create and initialize a network structure. */
network_t *new;
new= allocate(sizeof(*new));
memset(new, 0, sizeof(*new));
new->hostname= nil;
new->solicit= NEVER;
new->sol_ct= -1;
return new;
}
void closefd(fd_t *fdp)
{
/* Close a descriptor. */
if (fdp->fdtype != FT_CLOSED) {
asyn_close(&asyn, fdp->fd);
close(fdp->fd);
fdp->fdtype= FT_CLOSED;
fdp->since= 0;
put_buf(&fdp->bp);
if (debug >= 3) printf("%s: Closed\n", fdp->device);
}
}
static void timeout(int signum)
{
/* nothing to do, ioctl will be aborted automatically */
if (alarm(1) < 0) fatal("alarm(1)");
}
int opendev(network_t *np, fdtype_t fdtype, int compete)
{
/* Make sure that a network has the proper device open and configured.
* Return true if this is made so, or false if the device doesn't exist.
* If compete is true then the caller competes for old descriptors.
* The errno value is EAGAIN if we're out of descriptors.
*/
fd_t *fdp, *fdold;
time_t oldest;
nwio_ethstat_t ethstat;
nwio_ethopt_t ethopt;
nwio_ipopt_t ipopt;
nwio_udpopt_t udpopt;
network_t **pqp;
static char devbytype[][4] = { "", "eth", "ip", "udp", "udp" };
/* Don't attempt to open higher level devices if not bound. */
if (!(np->flags & NF_BOUND) && fdtype > FT_ETHERNET) {
errno= EAGAIN;
return 0;
}
/* Check if already open / Find the oldest descriptor. */
fdold= nil;
oldest= NEVER;
for (fdp= fds; fdp < arraylimit(fds); fdp++) {
if (fdp->n == np->n && fdp->fdtype == fdtype) {
/* Already open. */
np->fdp= fdp;
return 1;
}
if (fdp->since <= oldest) { fdold= fdp; oldest= fdp->since; }
}
/* None free? Then wait for one to get old if so desired. */
if (fdold->fdtype != FT_CLOSED && !compete) {
errno= EAGAIN;
return 0;
}
if (!(np->flags & NF_WAIT)) {
for (pqp= &fdwaitq; *pqp != nil; pqp= &(*pqp)->wait) {}
*pqp= np;
np->wait= nil;
np->flags |= NF_WAIT;
}
/* We allow a net to keep a descriptor for half of the fast period. */
oldest += DELTA_FAST/2;
if (fdwaitq != np || (fdold->fdtype != FT_CLOSED && oldest > now)) {
/* This net is not the first in the queue, or the oldest isn't
* old enough. Forget it for now.
*/
if (oldest < event) event= oldest;
errno= EAGAIN;
return 0;
}
/* The oldest is mine. */
np->flags &= ~NF_WAIT;
fdwaitq= np->wait;
closefd(fdold);
/* Open the proper device in the proper mode. */
fdp= fdold;
fdp->n= np->n;
if (lwip && (fdtype == FT_ETHERNET || fdtype == FT_ICMP))
sprintf(fdp->device, "/dev/ip");
else
sprintf(fdp->device, "/dev/%s%d", devbytype[fdtype], np->n);
np->fdp= fdp;
if ((fdp->fd= open(fdp->device, O_RDWR)) < 0) {
if (errno == ENOENT || errno == ENODEV || errno == ENXIO) return 0;
fatal(fdp->device);
}
switch (fdtype) {
case FT_ETHERNET:
if (lwip) {
nwio_ipopt_t ipopt;
int result;
char ethdev[64];
int efd;
sprintf(ethdev, "/dev/eth%d", np->n);
if ((efd = open(fdp->device, O_RDWR)) < 0) {
if (errno == ENOENT || errno == ENODEV ||
errno == ENXIO)
return 0;
fatal(ethdev);
}
if (ioctl(efd, NWIOGETHSTAT, &ethstat) < 0) {
/* Not an Ethernet. */
close(efd);
return 0;
}
close(efd);
np->eth= ethstat.nwes_addr;
ipopt.nwio_flags= NWIO_COPY | NWIO_PROTOSPEC;
ipopt.nwio_proto= 17; /* UDP */
result= ioctl (fdp->fd, NWIOSIPOPT, &ipopt);
if (result<0)
perror("ioctl (NWIOSIPOPT)"), exit(1);
break;
}
/* Cannot use NWIOGETHSTAT in non-blocking mode due to a race between
* the reply from the ethernet driver and the cancel message from VFS
* for reaching inet. Hence, a signal is used to interrupt NWIOGETHSTAT
* in case the driver isn't ready yet.
*/
if (signal(SIGALRM, timeout) == SIG_ERR) fatal("signal(SIGALRM)");
if (alarm(1) < 0) fatal("alarm(1)");
if (ioctl(np->fdp->fd, NWIOGETHSTAT, &ethstat) < 0) {
/* Not an Ethernet. */
close(fdp->fd);
return 0;
}
if (alarm(0) < 0) fatal("alarm(0)");
np->eth= ethstat.nwes_addr;
ethopt.nweo_flags= NWEO_COPY | NWEO_EN_LOC | NWEO_EN_BROAD
| NWEO_REMANY | NWEO_TYPEANY | NWEO_RWDATALL;
if (ioctl(fdp->fd, NWIOSETHOPT, &ethopt) < 0) {
fprintf(stderr, "%s: %s: Unable to set eth options: %s\n",
program, fdp->device, strerror(errno));
exit(1);
}
break;
case FT_ICMP:
ipopt.nwio_flags= NWIO_COPY | NWIO_EN_LOC | NWIO_EN_BROAD
| NWIO_REMANY | NWIO_PROTOSPEC
| NWIO_HDR_O_SPEC | NWIO_RWDATALL;
ipopt.nwio_tos= 0;
ipopt.nwio_ttl= 1;
ipopt.nwio_df= 0;
ipopt.nwio_hdropt.iho_opt_siz= 0;
ipopt.nwio_proto= IPPROTO_ICMP;
if (ioctl(fdp->fd, NWIOSIPOPT, &ipopt) < 0) {
fprintf(stderr, "%s: %s: Unable to set IP options: %s\n",
program, fdp->device, strerror(errno));
exit(1);
}
break;
case FT_BOOTPC:
if (lwip) {
struct sockaddr_in si_me;
close(fdp->fd);
fdp->fd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
if (fdp->fd < 0)
return 0;
memset((char *) &si_me, 0, sizeof(si_me));
si_me.sin_family = AF_INET;
si_me.sin_addr.s_addr = htonl(INADDR_ANY);
si_me.sin_port = htons(port_client);
if (bind(fdp->fd, (struct sockaddr *) &si_me,
sizeof(si_me)) == -1) {
close(fdp->fd);
printf("DHCP : cannot bind client socket to port %d\n",
port_client);
return 0;
}
break;
}
udpopt.nwuo_flags= NWUO_COPY | NWUO_EN_LOC | NWUO_EN_BROAD
| NWUO_RP_ANY | NWUO_RA_ANY | NWUO_RWDATALL
| NWUO_DI_IPOPT | NWUO_LP_SET;
udpopt.nwuo_locport= port_client;
goto udp;
case FT_BOOTPS:
udpopt.nwuo_flags= NWUO_EXCL | NWUO_EN_LOC | NWUO_EN_BROAD
| NWUO_RP_ANY | NWUO_RA_ANY | NWUO_RWDATALL
| NWUO_DI_IPOPT | NWUO_LP_SET;
udpopt.nwuo_locport= port_server;
udp:
if (ioctl(fdp->fd, NWIOSUDPOPT, &udpopt) == -1) {
fprintf(stderr, "%s: %s: Unable to set UDP options: %s\n",
program, fdp->device, strerror(errno));
exit(1);
}
break;
default:;
}
fdp->fdtype= fdtype;
fdp->since= now;
if (debug >= 3) printf("%s: Opened\n", fdp->device);
return 1;
}
void closedev(network_t *np, fdtype_t fdtype)
{
/* We no longer need a given type of device to be open. */
fd_t *fdp;
for (fdp= fds; fdp < arraylimit(fds); fdp++) {
if (fdp->n == np->n && (fdp->fdtype == fdtype || fdtype == FT_ALL)) {
closefd(fdp);
}
}
}
char *ipdev(int n)
{
/* IP device for network #n. */
static char device[sizeof("/dev/ipNNN")];
sprintf(device, "/dev/ip%d", n);
return device;
}
void set_ipconf(char *device, ipaddr_t ip, ipaddr_t mask, unsigned mtu)
{
/* Set IP address and netmask of an IP device. */
int fd;
nwio_ipconf_t ipconf;
if (test > 0) return;
if ((fd= open(device, O_RDWR)) < 0) fatal(device);
ipconf.nwic_flags= NWIC_IPADDR_SET | NWIC_NETMASK_SET;
ipconf.nwic_ipaddr= ip;
ipconf.nwic_netmask= mask;
#ifdef NWIC_MTU_SET
if (mtu != 0) {
ipconf.nwic_flags |= NWIC_MTU_SET;
ipconf.nwic_mtu= mtu;
}
#endif
if (ioctl(fd, NWIOSIPCONF, &ipconf) < 0) fatal(device);
close(fd);
}