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TP-Link_Archer-XR500v/EN7526G_3.18Kernel_SDK/apps/public/dhcp-isc/relay/dhcrelay.c
2024-07-22 01:58:46 -03:00

423 lines
10 KiB
C
Executable File

/* dhcrelay.c
DHCP/BOOTP Relay Agent. */
/*
* Copyright (c) 1997, 1998, 1999 The Internet Software Consortium.
* All rights reserved.
*
* 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 Internet Software Consortium 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 INTERNET SOFTWARE CONSORTIUM 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 INTERNET SOFTWARE CONSORTIUM 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.
*
* This software has been written for the Internet Software Consortium
* by Ted Lemon <mellon@fugue.com> in cooperation with Vixie
* Enterprises. To learn more about the Internet Software Consortium,
* see ``http://www.vix.com/isc''. To learn more about Vixie
* Enterprises, see ``http://www.vix.com''.
*/
#ifndef EMBED
#ifndef lint
static char ocopyright [] =
"$Id: //BBN_Linux/Branch/Branch_for_Rel_TP_ASEAN_20161216/tclinux_phoenix/apps/public/dhcp-isc/relay/dhcrelay.c#1 $ Copyright (c) 1997, 1998, 1999 The Internet Software Consortium. All rights reserved.\n";
#endif /* not lint */
#endif
#include "dhcpd.h"
#include "version.h"
static void usage PROTO ((char *));
TIME cur_time;
TIME default_lease_time = 43200; /* 12 hours... */
TIME max_lease_time = 86400; /* 24 hours... */
struct tree_cache *global_options [256];
int log_perror = 1;
/* Needed to prevent linking against conflex.c. */
int lexline;
int lexchar;
char *token_line;
char *tlname;
char *path_dhcrelay_pid = _PATH_DHCRELAY_PID;
u_int16_t local_port;
u_int16_t remote_port;
int log_priority;
struct server_list {
struct server_list *next;
struct sockaddr_in to;
} *servers;
static char copyright [] =
"Copyright 1997, 1998, 1999 The Internet Software Consortium.";
static char arr [] = "All rights reserved.";
static char message [] = "Internet Software Consortium DHCP Relay Agent";
static char contrib [] = "Please contribute if you find this software useful.";
static char url [] = "For info, please visit http://www.isc.org/dhcp-contrib.html";
int main (argc, argv, envp)
int argc;
char **argv, **envp;
{
int i;
struct servent *ent;
struct server_list *sp = (struct server_list *)0;
int no_daemon = 0;
int quiet = 0;
char *s;
s = strrchr (argv [0], '/');
if (!s)
s = argv [0];
else
s++;
/* Initially, log errors to stderr as well as to syslogd. */
#ifdef SYSLOG_4_2
openlog (s, LOG_NDELAY);
log_priority = DHCPD_LOG_FACILITY;
#else
openlog (s, LOG_NDELAY, DHCPD_LOG_FACILITY);
#endif
#if !(defined (DEBUG) || defined (SYSLOG_4_2))
setlogmask (LOG_UPTO (LOG_INFO));
#endif
for (i = 1; i < argc; i++) {
if (!strcmp (argv [i], "-p")) {
if (++i == argc)
usage (s);
local_port = htons (atoi (argv [i]));
debug ("binding to user-specified port %d",
ntohs (local_port));
} else if (!strcmp (argv [i], "-pf")) {
if (++i == argc)
usage (s);
path_dhcrelay_pid = argv [i];
} else if (!strcmp (argv [i], "-d")) {
no_daemon = 1;
} else if (!strcmp (argv [i], "-i")) {
struct interface_info *tmp =
((struct interface_info *)
dmalloc (sizeof *tmp, "specified_interface"));
if (!tmp)
error ("Insufficient memory to %s %s",
"record interface", argv [i]);
if (++i == argc) {
usage (s);
}
memset (tmp, 0, sizeof *tmp);
strcpy (tmp -> name, argv [i]);
tmp -> next = interfaces;
tmp -> flags = INTERFACE_REQUESTED;
interfaces = tmp;
} else if (!strcmp (argv [i], "-q")) {
quiet = 1;
quiet_interface_discovery = 1;
} else if (argv [i][0] == '-') {
usage (s);
} else {
struct hostent *he;
struct in_addr ia, *iap = (struct in_addr *)0;
if (inet_aton (argv [i], &ia)) {
iap = &ia;
} else {
he = gethostbyname (argv [i]);
if (!he) {
warn ("%s: host unknown", argv [i]);
} else {
iap = ((struct in_addr *)
he -> h_addr_list [0]);
}
}
if (iap) {
sp = (struct server_list *)malloc (sizeof *sp);
if (!sp)
error ("no memory for server.\n");
sp -> next = servers;
servers = sp;
memcpy (&sp -> to.sin_addr,
iap, sizeof *iap);
}
}
}
if (!quiet) {
note ("%s %s", message, DHCP_VERSION);
note (copyright);
note (arr);
note ("");
note (contrib);
note (url);
note ("");
} else
log_perror = 0;
/* Default to the DHCP/BOOTP port. */
if (!local_port) {
ent = getservbyname ("dhcps", "udp");
if (!ent)
local_port = htons (67);
else
local_port = ent -> s_port;
endservent ();
}
remote_port = htons (ntohs (local_port) + 1);
printf("local_port=%d remote_port=%d\n", local_port, remote_port);
/* We need at least one server. */
if (!sp) {
usage (s);
}
/* Set up the server sockaddrs. */
for (sp = servers; sp; sp = sp -> next) {
sp -> to.sin_port = local_port;
sp -> to.sin_family = AF_INET;
#ifdef HAVE_SA_LEN
sp -> to.sin_len = sizeof sp -> to;
#endif
}
/* Get the current time... */
GET_TIME (&cur_time);
/* Discover all the network interfaces. */
discover_interfaces (DISCOVER_RELAY);
/* Set up the bootp packet handler... */
bootp_packet_handler = relay;
/* Become a daemon... */
if (!no_daemon) {
int pid;
FILE *pf;
int pfdesc;
log_perror = 0;
#ifndef TCSUPPORT_NEWTOOLCHAIN
pid = vfork();
#else
pid = fork();
#endif
if (pid < 0)
error ("can't fork daemon: %m");
else if (pid)
exit (0);
pfdesc = open (path_dhcrelay_pid,
O_CREAT | O_TRUNC | O_WRONLY, 0644);
if (pfdesc < 0) {
warn ("Can't create %s: %m", path_dhcrelay_pid);
} else {
pf = fdopen (pfdesc, "w");
if (!pf)
warn ("Can't fdopen %s: %m",
path_dhcrelay_pid);
else {
fprintf (pf, "%ld\n", (long)getpid ());
fclose (pf);
}
}
close (0);
close (1);
close (2);
pid = setsid ();
}
else
{
int pid;
FILE *pf;
int pfdesc;
pfdesc = open (path_dhcrelay_pid,
O_CREAT | O_TRUNC | O_WRONLY, 0644);
if (pfdesc < 0) {
warn ("Can't create %s: %m", path_dhcrelay_pid);
} else {
pf = fdopen (pfdesc, "w");
if (!pf)
warn ("Can't fdopen %s: %m",
path_dhcrelay_pid);
else {
fprintf (pf, "%ld\n", (long)getpid ());
fclose (pf);
}
}
}
/* Start dispatching packets and timeouts... */
dispatch ();
/*NOTREACHED*/
return 0;
}
void relay (ip, packet, length, from_port, from, hfrom)
struct interface_info *ip;
struct dhcp_packet *packet;
int length;
unsigned int from_port;
struct iaddr *from;
struct hardware *hfrom;
{
struct server_list *sp;
struct sockaddr_in to;
struct interface_info *out;
struct hardware hto;
if (packet -> hlen > sizeof packet -> chaddr) {
note ("Discarding packet with invalid hlen.");
return;
}
/* If it's a bootreply, forward it to the client. */
if (packet -> op == BOOTREPLY) {
if (!(packet -> flags & htons (BOOTP_BROADCAST)) &&
can_unicast_without_arp ()) {
to.sin_addr = packet -> yiaddr;
to.sin_port = remote_port;
} else {
to.sin_addr.s_addr = htonl (INADDR_BROADCAST);
to.sin_port = remote_port;
}
to.sin_family = AF_INET;
#ifdef HAVE_SA_LEN
to.sin_len = sizeof to;
#endif
/* Set up the hardware destination address. */
hto.hlen = packet -> hlen;
if (hto.hlen > sizeof hto.haddr)
hto.hlen = sizeof hto.haddr;
memcpy (hto.haddr, packet -> chaddr, hto.hlen);
hto.htype = packet -> htype;
/* Find the interface that corresponds to the giaddr
in the packet. */
for (out = interfaces; out; out = out -> next) {
if (!memcmp (&out -> primary_address,
&packet -> giaddr,
sizeof packet -> giaddr))
break;
}
if (!out) {
warn ("packet to bogus giaddr %s.\n",
inet_ntoa (packet -> giaddr));
return;
}
if (!send_packet (out,
(struct packet *)0,
packet, length, out -> primary_address,
&to, &hto) < 0)
debug ("forwarded BOOTREPLY for %s to %s",
print_hw_addr (packet -> htype, packet -> hlen,
packet -> chaddr),
inet_ntoa (to.sin_addr));
return;
}
/* If giaddr is set on a BOOTREQUEST, ignore it - it's already
been gatewayed. */
if (packet -> giaddr.s_addr) {
note ("ignoring BOOTREQUEST with giaddr of %s\n",
inet_ntoa (packet -> giaddr));
return;
}
/* Set the giaddr so the server can figure out what net it's
from and so that we can later forward the response to the
correct net. */
packet -> giaddr = ip -> primary_address;
/* Otherwise, it's a BOOTREQUEST, so forward it to all the
servers. */
for (sp = servers; sp; sp = sp -> next) {
if (!send_packet ((fallback_interface
? fallback_interface : interfaces),
(struct packet *)0,
packet, length, ip -> primary_address,
&sp -> to, (struct hardware *)0) < 0) {
debug ("forwarded BOOTREQUEST for %s to %s",
print_hw_addr (packet -> htype, packet -> hlen,
packet -> chaddr),
inet_ntoa (sp -> to.sin_addr));
}
}
}
static void usage (appname)
char *appname;
{
note (message);
note (copyright);
note (arr);
note ("");
note (contrib);
note (url);
note ("");
warn ("Usage: %s [-i] [-d] [-i if0] [...-i ifN] [-p <port>]", appname);
error (" [-pf pidfilename] [server1 [... serverN]]");
}
void cleanup ()
{
}
int write_lease (lease)
struct lease *lease;
{
return 1;
}
int commit_leases ()
{
return 1;
}
void bootp (packet)
struct packet *packet;
{
}
void dhcp (packet)
struct packet *packet;
{
}