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dhcprelay: new applet

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This commit is contained in:
Denis Vlasenko 2006-11-20 19:40:36 +00:00
parent c9cdeaa3fe
commit 736230e209
7 changed files with 386 additions and 13 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
include/applets.h
View File

@ -94,6 +94,7 @@ USE_DELGROUP(APPLET_ODDNAME(delgroup, deluser, _BB_DIR_BIN, _BB_SUID_NEVER, delg
USE_DELUSER(APPLET(deluser, _BB_DIR_BIN, _BB_SUID_NEVER))
USE_DEVFSD(APPLET(devfsd, _BB_DIR_SBIN, _BB_SUID_NEVER))
USE_DF(APPLET(df, _BB_DIR_BIN, _BB_SUID_NEVER))
USE_APP_DHCPRELAY(APPLET(dhcprelay, _BB_DIR_USR_SBIN, _BB_SUID_NEVER))
USE_DIFF(APPLET(diff, _BB_DIR_USR_BIN, _BB_SUID_NEVER))
USE_DIRNAME(APPLET(dirname, _BB_DIR_USR_BIN, _BB_SUID_NEVER))
USE_DMESG(APPLET(dmesg, _BB_DIR_BIN, _BB_SUID_NEVER))

10
include/usage.h
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@ -539,6 +539,16 @@ USE_FEATURE_DATE_ISOFMT( \
"Filesystem 1k-blocks Used Available Use% Mounted on\n" \
"/dev/sda3 8690864 8553540 137324 98% /\n"
#define dhcprelay_trivial_usage \
"[client_device_list] [server_device]"
#define dhcprelay_full_usage \
"Relays dhcp requests from client devices to server device"
#define dhcprelay_trivial_usage \
"[client_device_list] [server_device]"
#define dhcprelay_full_usage \
"Relays dhcp requests from client devices to server device"
#define diff_trivial_usage \
"[-abdiNqrTstw] [-L LABEL] [-S FILE] [-U LINES] FILE1 FILE2"
#define diff_full_usage \

9
networking/ifupdown.c
View File

@ -598,6 +598,9 @@ static const struct address_family_t *get_address_family(const struct address_fa
{
int i;
if (!name)
return NULL;
for (i = 0; af[i]; i++) {
if (strcmp(af[i]->name, name) == 0) {
return af[i];
@ -610,6 +613,9 @@ static const struct method_t *get_method(const struct address_family_t *af, char
{
int i;
if (!name)
return NULL;
for (i = 0; i < af->n_methods; i++) {
if (strcmp(af->method[i].name, name) == 0) {
return &af->method[i];
@ -620,6 +626,9 @@ static const struct method_t *get_method(const struct address_family_t *af, char
static const llist_t *find_list_string(const llist_t *list, const char *string)
{
if (string == NULL)
return NULL;
while (list) {
if (strcmp(list->data, string) == 0) {
return list;

9
networking/udhcp/Config.in
View File

@ -12,6 +12,15 @@ config APP_UDHCPD
See http://udhcp.busybox.net for further details.
config APP_DHCPRELAY
bool "dhcprelay"
default n
depends on APP_UDHCPD
help
dhcprelay listens for dhcp requests on one or more interfaces
and forwards these requests to a different interface or dhcp
server.
config APP_DUMPLEASES
bool "Lease display utility (dumpleases)"
default n

1
networking/udhcp/Kbuild
View File

@ -15,3 +15,4 @@ lib-$(CONFIG_APP_UDHCPC) += dhcpc.o clientpacket.o clientsocket.o \
lib-$(CONFIG_APP_UDHCPD) += dhcpd.o arpping.o files.o leases.o \
serverpacket.o static_leases.o
lib-$(CONFIG_APP_DUMPLEASES) += dumpleases.o
lib-$(CONFIG_APP_DHCPRELAY) += dhcprelay.o

339
networking/udhcp/dhcprelay.c Normal file
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@ -0,0 +1,339 @@
/* vi: set sw=4 ts=4: */
/* Port to Busybox Copyright (C) 2006 Jesse Dutton <jessedutton@gmail.com>
*
* Licensed under GPL v2, see file LICENSE in this tarball for details.
*
* DHCP Relay for 'DHCPv4 Configuration of IPSec Tunnel Mode' support
* Copyright (C) 2002 Mario Strasser <mast@gmx.net>,
* Zuercher Hochschule Winterthur,
* Netbeat AG
* Upstream has GPL v2 or later
*/
#include "common.h"
#include "dhcpd.h"
#include "options.h"
/* constants */
#define SELECT_TIMEOUT 5 /* select timeout in sec. */
#define MAX_LIFETIME 2*60 /* lifetime of an xid entry in sec. */
#define MAX_INTERFACES 9
/* This list holds information about clients. The xid_* functions manipulate this list. */
struct xid_item {
u_int32_t xid;
struct sockaddr_in ip;
int client;
time_t timestamp;
struct xid_item *next;
} dhcprelay_xid_list = {0, {0}, 0, 0, NULL};
static struct xid_item * xid_add(u_int32_t xid, struct sockaddr_in *ip, int client)
{
struct xid_item *item;
/* create new xid entry */
item = xmalloc(sizeof(struct xid_item));
/* add xid entry */
item->ip = *ip;
item->xid = xid;
item->client = client;
item->timestamp = time(NULL);
item->next = dhcprelay_xid_list.next;
dhcprelay_xid_list.next = item;
return item;
}
static void xid_expire(void)
{
struct xid_item *item = dhcprelay_xid_list.next;
struct xid_item *last = &dhcprelay_xid_list;
time_t current_time = time(NULL);
while (item != NULL) {
if ((current_time-item->timestamp) > MAX_LIFETIME) {
last->next = item->next;
free(item);
item = last->next;
} else {
last = item;
item = item->next;
}
}
}
static struct xid_item * xid_find(u_int32_t xid)
{
struct xid_item *item = dhcprelay_xid_list.next;
while (item != NULL) {
if (item->xid == xid) {
return item;
}
item = item->next;
}
return NULL;
}
static void xid_del(u_int32_t xid)
{
struct xid_item *item = dhcprelay_xid_list.next;
struct xid_item *last = &dhcprelay_xid_list;
while (item != NULL) {
if (item->xid == xid) {
last->next = item->next;
free(item);
item = last->next;
} else {
last = item;
item = item->next;
}
}
}
/**
* get_dhcp_packet_type - gets the message type of a dhcp packet
* p - pointer to the dhcp packet
* returns the message type on success, -1 otherwise
*/
static int get_dhcp_packet_type(struct dhcpMessage *p)
{
u_char *op;
/* it must be either a BOOTREQUEST or a BOOTREPLY */
if (p->op != BOOTREQUEST && p->op != BOOTREPLY)
return -1;
/* get message type option */
op = get_option(p, DHCP_MESSAGE_TYPE);
if (op != NULL)
return op[0];
return -1;
}
/**
* signal_handler - handles signals ;-)
* sig - sent signal
*/
static int dhcprelay_stopflag;
static void dhcprelay_signal_handler(int sig)
{
dhcprelay_stopflag = 1;
}
/**
* get_client_devices - parses the devices list
* dev_list - comma separated list of devices
* returns array
*/
static char ** get_client_devices(char *dev_list, int *client_number)
{
char *s, *list, **client_dev;
int i, cn=1;
/* copy list */
list = xstrdup(dev_list);
if (list == NULL) return NULL;
/* get number of items */
for (s = dev_list; *s; s++) if (*s == ',')
cn++;
client_dev = xzalloc(cn * sizeof(*client_dev));
/* parse list */
s = strtok(list, ",");
i = 0;
while (s != NULL) {
client_dev[i++] = xstrdup(s);
s = strtok(NULL, ",");
}
/* free copy and exit */
free(list);
*client_number = cn;
return client_dev;
}
/* Creates listen sockets (in fds) and returns the number allocated. */
static int init_sockets(char **client, int num_clients,
char *server, int *fds, int *max_socket)
{
int i;
// talk to real server on bootps
fds[0] = listen_socket(htonl(INADDR_ANY), 67, server);
if (fds[0] < 0) return -1;
*max_socket = fds[0];
// array starts at 1 since server is 0
num_clients++;
for (i=1; i < num_clients; i++) {
// listen for clients on bootps
fds[i] = listen_socket(htonl(INADDR_ANY), 67, client[i-1]);
if (fds[i] < 0) return -1;
if (fds[i] > *max_socket) *max_socket = fds[i];
}
return i;
}
/**
* pass_on() - forwards dhcp packets from client to server
* p - packet to send
* client - number of the client
*/
static void pass_on(struct dhcpMessage *p, int packet_len, int client, int *fds,
struct sockaddr_in *client_addr, struct sockaddr_in *server_addr)
{
int res, type;
struct xid_item *item;
/* check packet_type */
type = get_dhcp_packet_type(p);
if (type != DHCPDISCOVER && type != DHCPREQUEST
&& type != DHCPDECLINE && type != DHCPRELEASE
&& type != DHCPINFORM
) {
return;
}
/* create new xid entry */
item = xid_add(p->xid, client_addr, client);
/* forward request to LAN (server) */
res = sendto(fds[0], p, packet_len, 0, (struct sockaddr*)server_addr,
sizeof(struct sockaddr_in));
if (res != packet_len) {
bb_perror_msg("pass_on");
return;
}
}
/**
* pass_back() - forwards dhcp packets from server to client
* p - packet to send
*/
static void pass_back(struct dhcpMessage *p, int packet_len, int *fds)
{
int res, type;
struct xid_item *item;
/* check xid */
item = xid_find(p->xid);
if (!item) {
return;
}
/* check packet type */
type = get_dhcp_packet_type(p);
if (type != DHCPOFFER && type != DHCPACK && type != DHCPNAK) {
return;
}
if (item->ip.sin_addr.s_addr == htonl(INADDR_ANY))
item->ip.sin_addr.s_addr = htonl(INADDR_BROADCAST);
if (item->client > MAX_INTERFACES)
return;
res = sendto(fds[item->client], p, packet_len, 0, (struct sockaddr*)(&item->ip),
sizeof(item->ip));
if (res != packet_len) {
bb_perror_msg("pass_back");
return;
}
/* remove xid entry */
xid_del(p->xid);
}
static void dhcprelay_loop(int *fds, int num_sockets, int max_socket, char **clients,
struct sockaddr_in *server_addr, uint32_t gw_ip)
{
struct dhcpMessage dhcp_msg;
fd_set rfds;
size_t packlen, addr_size;
struct sockaddr_in client_addr;
struct timeval tv;
int i;
while (!dhcprelay_stopflag) {
FD_ZERO(&rfds);
for (i = 0; i < num_sockets; i++)
FD_SET(fds[i], &rfds);
tv.tv_sec = SELECT_TIMEOUT;
tv.tv_usec = 0;
if (select(max_socket + 1, &rfds, NULL, NULL, &tv) > 0) {
/* server */
if (FD_ISSET(fds[0], &rfds)) {
packlen = udhcp_get_packet(&dhcp_msg, fds[0]);
if (packlen > 0) {
pass_back(&dhcp_msg, packlen, fds);
}
}
for (i = 1; i < num_sockets; i++) {
/* clients */
if (!FD_ISSET(fds[i], &rfds))
continue;
addr_size = sizeof(struct sockaddr_in);
packlen = recvfrom(fds[i], &dhcp_msg, sizeof(dhcp_msg), 0,
(struct sockaddr *)(&client_addr), &addr_size);
if (packlen <= 0)
continue;
if (read_interface(clients[i-1], NULL, &dhcp_msg.giaddr, NULL) < 0)
dhcp_msg.giaddr = gw_ip;
pass_on(&dhcp_msg, packlen, i, fds, &client_addr, server_addr);
}
}
xid_expire();
}
}
int dhcprelay_main(int argc, char **argv)
{
int i, num_sockets, max_socket, fds[MAX_INTERFACES];
uint32_t gw_ip;
char **clients;
struct sockaddr_in server_addr;
server_addr.sin_family = AF_INET;
server_addr.sin_port = htons(67);
if (argc == 4) {
if (!inet_aton(argv[3], &server_addr.sin_addr))
bb_perror_msg_and_die("didn't grok server");
} else if (argc == 3) {
server_addr.sin_addr.s_addr = htonl(INADDR_BROADCAST);
} else {
bb_show_usage();
}
clients = get_client_devices(argv[1], &num_sockets);
if (!clients) return 0;
signal(SIGTERM, dhcprelay_signal_handler);
signal(SIGQUIT, dhcprelay_signal_handler);
signal(SIGINT, dhcprelay_signal_handler);
num_sockets = init_sockets(clients, num_sockets, argv[2], fds, &max_socket);
if (num_sockets == -1)
bb_perror_msg_and_die("init_sockets() failed");
if (read_interface(argv[2], NULL, &gw_ip, NULL) == -1)
return 1;
dhcprelay_loop(fds, num_sockets, max_socket, clients, &server_addr, gw_ip);
if (ENABLE_FEATURE_CLEAN_UP) {
for (i = 0; i < num_sockets; i++) {
close(fds[i]);
free(clients[i]);
}
}
return 0;
}

30
networking/udhcp/socket.c
View File

@ -63,23 +63,27 @@ int read_interface(char *interface, int *ifindex, uint32_t *addr, uint8_t *arp)
DEBUG("%s (our ip) = %s", ifr.ifr_name, inet_ntoa(our_ip->sin_addr));
}
if (ioctl(fd, SIOCGIFINDEX, &ifr) == 0) {
bb_perror_msg("SIOCGIFINDEX failed");
close(fd);
return -1;
if (ifindex) {
if (ioctl(fd, SIOCGIFINDEX, &ifr) == 0) {
bb_perror_msg("SIOCGIFINDEX failed");
close(fd);
return -1;
}
DEBUG("adapter index %d", ifr.ifr_ifindex);
*ifindex = ifr.ifr_ifindex;
}
DEBUG("adapter index %d", ifr.ifr_ifindex);
*ifindex = ifr.ifr_ifindex;
if (ioctl(fd, SIOCGIFHWADDR, &ifr) != 0) {
bb_perror_msg("SIOCGIFHWADDR failed");
close(fd);
return -1;
if (arp) {
if (ioctl(fd, SIOCGIFHWADDR, &ifr) != 0) {
bb_perror_msg("SIOCGIFHWADDR failed");
close(fd);
return -1;
}
memcpy(arp, ifr.ifr_hwaddr.sa_data, 6);
DEBUG("adapter hardware address %02x:%02x:%02x:%02x:%02x:%02x",
arp[0], arp[1], arp[2], arp[3], arp[4], arp[5]);
}
memcpy(arp, ifr.ifr_hwaddr.sa_data, 6);
DEBUG("adapter hardware address %02x:%02x:%02x:%02x:%02x:%02x",
arp[0], arp[1], arp[2], arp[3], arp[4], arp[5]);
return 0;
}