7bc7c104ee
effect the idle timer in different ways. Submitted by: Stefan Esser <se@freebsd.org> With adjustments by me to document the option in the man page and to give the same semantics for outgoing traffic as incoming. I made the style more consistent in ip.c - this should really have been done as a separate commit.
442 lines
11 KiB
C
442 lines
11 KiB
C
/*-
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* The code in this file was written by Eivind Eklund <perhaps@yes.no>,
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* who places it in the public domain without restriction.
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*
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* $FreeBSD$
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*/
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#include <sys/param.h>
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#include <netinet/in.h>
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#include <arpa/inet.h>
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#include <netdb.h>
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#include <netinet/in_systm.h>
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#include <netinet/in.h>
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#include <netinet/ip.h>
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#include <sys/un.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <termios.h>
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#ifdef LOCALNAT
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#include "alias.h"
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#else
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#include <alias.h>
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#endif
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#include "layer.h"
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#include "proto.h"
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#include "defs.h"
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#include "command.h"
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#include "log.h"
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#include "nat_cmd.h"
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#include "descriptor.h"
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#include "prompt.h"
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#include "timer.h"
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#include "fsm.h"
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#include "slcompress.h"
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#include "throughput.h"
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#include "iplist.h"
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#include "mbuf.h"
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#include "lqr.h"
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#include "hdlc.h"
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#include "ipcp.h"
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#include "lcp.h"
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#include "ccp.h"
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#include "link.h"
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#include "mp.h"
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#include "filter.h"
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#ifndef NORADIUS
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#include "radius.h"
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#endif
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#include "ip.h"
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#include "bundle.h"
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#define NAT_EXTRABUF (13)
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static int StrToAddr(const char *, struct in_addr *);
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static int StrToPortRange(const char *, u_short *, u_short *, const char *);
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static int StrToAddrAndPort(const char *, struct in_addr *, u_short *,
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u_short *, const char *);
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static void
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lowhigh(u_short *a, u_short *b)
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{
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if (a > b) {
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u_short c;
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c = *b;
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*b = *a;
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*a = c;
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}
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}
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int
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nat_RedirectPort(struct cmdargs const *arg)
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{
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if (!arg->bundle->NatEnabled) {
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prompt_Printf(arg->prompt, "Alias not enabled\n");
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return 1;
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} else if (arg->argc == arg->argn + 3 || arg->argc == arg->argn + 4) {
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char proto_constant;
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const char *proto;
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struct in_addr localaddr;
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u_short hlocalport, llocalport;
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struct in_addr aliasaddr;
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u_short haliasport, laliasport;
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struct in_addr remoteaddr;
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u_short hremoteport, lremoteport;
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struct alias_link *link;
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int error;
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proto = arg->argv[arg->argn];
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if (strcmp(proto, "tcp") == 0) {
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proto_constant = IPPROTO_TCP;
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} else if (strcmp(proto, "udp") == 0) {
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proto_constant = IPPROTO_UDP;
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} else {
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prompt_Printf(arg->prompt, "port redirect: protocol must be"
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" tcp or udp\n");
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return -1;
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}
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error = StrToAddrAndPort(arg->argv[arg->argn+1], &localaddr, &llocalport,
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&hlocalport, proto);
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if (error) {
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prompt_Printf(arg->prompt, "nat port: error reading localaddr:port\n");
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return -1;
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}
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error = StrToPortRange(arg->argv[arg->argn+2], &laliasport, &haliasport,
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proto);
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if (error) {
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prompt_Printf(arg->prompt, "nat port: error reading alias port\n");
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return -1;
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}
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aliasaddr.s_addr = INADDR_ANY;
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if (arg->argc == arg->argn + 4) {
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error = StrToAddrAndPort(arg->argv[arg->argn+3], &remoteaddr,
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&lremoteport, &hremoteport, proto);
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if (error) {
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prompt_Printf(arg->prompt, "nat port: error reading "
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"remoteaddr:port\n");
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return -1;
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}
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} else {
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remoteaddr.s_addr = INADDR_ANY;
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lremoteport = hremoteport = 0;
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}
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lowhigh(&llocalport, &hlocalport);
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lowhigh(&laliasport, &haliasport);
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lowhigh(&lremoteport, &hremoteport);
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if (haliasport - laliasport != hlocalport - llocalport) {
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prompt_Printf(arg->prompt, "nat port: local & alias port ranges "
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"are not equal\n");
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return -1;
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}
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if (hremoteport && hremoteport - lremoteport != hlocalport - llocalport) {
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prompt_Printf(arg->prompt, "nat port: local & remote port ranges "
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"are not equal\n");
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return -1;
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}
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while (laliasport <= haliasport) {
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link = PacketAliasRedirectPort(localaddr, htons(llocalport),
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remoteaddr, htons(lremoteport),
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aliasaddr, htons(laliasport),
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proto_constant);
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if (link == NULL) {
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prompt_Printf(arg->prompt, "nat port: %d: error %d\n", laliasport,
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error);
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return 1;
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}
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llocalport++;
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laliasport++;
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if (hremoteport)
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lremoteport++;
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}
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return 0;
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}
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return -1;
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}
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int
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nat_RedirectAddr(struct cmdargs const *arg)
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{
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if (!arg->bundle->NatEnabled) {
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prompt_Printf(arg->prompt, "nat not enabled\n");
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return 1;
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} else if (arg->argc == arg->argn+2) {
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int error;
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struct in_addr localaddr, aliasaddr;
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struct alias_link *link;
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error = StrToAddr(arg->argv[arg->argn], &localaddr);
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if (error) {
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prompt_Printf(arg->prompt, "address redirect: invalid local address\n");
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return 1;
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}
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error = StrToAddr(arg->argv[arg->argn+1], &aliasaddr);
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if (error) {
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prompt_Printf(arg->prompt, "address redirect: invalid alias address\n");
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prompt_Printf(arg->prompt, "Usage: nat %s %s\n", arg->cmd->name,
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arg->cmd->syntax);
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return 1;
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}
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link = PacketAliasRedirectAddr(localaddr, aliasaddr);
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if (link == NULL) {
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prompt_Printf(arg->prompt, "address redirect: packet aliasing"
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" engine error\n");
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prompt_Printf(arg->prompt, "Usage: nat %s %s\n", arg->cmd->name,
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arg->cmd->syntax);
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}
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} else
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return -1;
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return 0;
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}
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static int
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StrToAddr(const char *str, struct in_addr *addr)
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{
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struct hostent *hp;
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if (inet_aton(str, addr))
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return 0;
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hp = gethostbyname(str);
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if (!hp) {
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log_Printf(LogWARN, "StrToAddr: Unknown host %s.\n", str);
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return -1;
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}
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*addr = *((struct in_addr *) hp->h_addr);
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return 0;
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}
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static int
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StrToPort(const char *str, u_short *port, const char *proto)
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{
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struct servent *sp;
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char *end;
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*port = strtol(str, &end, 10);
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if (*end != '\0') {
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sp = getservbyname(str, proto);
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if (sp == NULL) {
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log_Printf(LogWARN, "StrToAddr: Unknown port or service %s/%s.\n",
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str, proto);
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return -1;
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}
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*port = ntohs(sp->s_port);
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}
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return 0;
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}
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static int
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StrToPortRange(const char *str, u_short *low, u_short *high, const char *proto)
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{
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char *minus;
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int res;
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minus = strchr(str, '-');
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if (minus)
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*minus = '\0'; /* Cheat the const-ness ! */
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res = StrToPort(str, low, proto);
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if (minus)
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*minus = '-'; /* Cheat the const-ness ! */
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if (res == 0) {
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if (minus)
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res = StrToPort(minus + 1, high, proto);
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else
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*high = *low;
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}
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return res;
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}
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static int
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StrToAddrAndPort(const char *str, struct in_addr *addr, u_short *low,
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u_short *high, const char *proto)
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{
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char *colon;
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int res;
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colon = strchr(str, ':');
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if (!colon) {
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log_Printf(LogWARN, "StrToAddrAndPort: %s is missing port number.\n", str);
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return -1;
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}
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*colon = '\0'; /* Cheat the const-ness ! */
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res = StrToAddr(str, addr);
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*colon = ':'; /* Cheat the const-ness ! */
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if (res != 0)
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return -1;
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return StrToPortRange(colon + 1, low, high, proto);
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}
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int
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nat_ProxyRule(struct cmdargs const *arg)
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{
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char cmd[LINE_LEN];
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int f, pos;
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size_t len;
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if (arg->argn >= arg->argc)
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return -1;
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for (f = arg->argn, pos = 0; f < arg->argc; f++) {
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len = strlen(arg->argv[f]);
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if (sizeof cmd - pos < len + (f ? 1 : 0))
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break;
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if (f)
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cmd[pos++] = ' ';
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strcpy(cmd + pos, arg->argv[f]);
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pos += len;
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}
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return PacketAliasProxyRule(cmd);
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}
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int
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nat_SetTarget(struct cmdargs const *arg)
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{
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struct in_addr addr;
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if (arg->argc == arg->argn) {
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addr.s_addr = INADDR_ANY;
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PacketAliasSetTarget(addr);
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return 0;
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}
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if (arg->argc != arg->argn + 1)
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return -1;
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if (!strcasecmp(arg->argv[arg->argn], "MYADDR")) {
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addr.s_addr = INADDR_ANY;
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PacketAliasSetTarget(addr);
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return 0;
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}
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addr = GetIpAddr(arg->argv[arg->argn]);
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if (addr.s_addr == INADDR_NONE) {
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log_Printf(LogWARN, "%s: invalid address\n", arg->argv[arg->argn]);
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return 1;
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}
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PacketAliasSetTarget(addr);
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return 0;
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}
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static struct mbuf *
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nat_LayerPush(struct bundle *bundle, struct link *l, struct mbuf *bp,
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int pri, u_short *proto)
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{
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if (!bundle->NatEnabled || *proto != PROTO_IP)
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return bp;
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log_Printf(LogDEBUG, "nat_LayerPush: PROTO_IP -> PROTO_IP\n");
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m_settype(bp, MB_NATOUT);
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/* Ensure there's a bit of extra buffer for the NAT code... */
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bp = m_pullup(m_append(bp, NULL, NAT_EXTRABUF));
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PacketAliasOut(MBUF_CTOP(bp), bp->m_len);
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bp->m_len = ntohs(((struct ip *)MBUF_CTOP(bp))->ip_len);
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return bp;
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}
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static struct mbuf *
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nat_LayerPull(struct bundle *bundle, struct link *l, struct mbuf *bp,
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u_short *proto)
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{
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static int gfrags;
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int ret, len, nfrags;
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struct mbuf **last;
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char *fptr;
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if (!bundle->NatEnabled || *proto != PROTO_IP)
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return bp;
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log_Printf(LogDEBUG, "nat_LayerPull: PROTO_IP -> PROTO_IP\n");
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m_settype(bp, MB_NATIN);
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/* Ensure there's a bit of extra buffer for the NAT code... */
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bp = m_pullup(m_append(bp, NULL, NAT_EXTRABUF));
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ret = PacketAliasIn(MBUF_CTOP(bp), bp->m_len);
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bp->m_len = ntohs(((struct ip *)MBUF_CTOP(bp))->ip_len);
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if (bp->m_len > MAX_MRU) {
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log_Printf(LogWARN, "nat_LayerPull: Problem with IP header length (%lu)\n",
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(unsigned long)bp->m_len);
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m_freem(bp);
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return NULL;
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}
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switch (ret) {
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case PKT_ALIAS_OK:
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break;
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case PKT_ALIAS_UNRESOLVED_FRAGMENT:
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/* Save the data for later */
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fptr = malloc(bp->m_len);
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bp = mbuf_Read(bp, fptr, bp->m_len);
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PacketAliasSaveFragment(fptr);
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log_Printf(LogDEBUG, "Store another frag (%lu) - now %d\n",
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(unsigned long)((struct ip *)fptr)->ip_id, ++gfrags);
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break;
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case PKT_ALIAS_FOUND_HEADER_FRAGMENT:
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/* Fetch all the saved fragments and chain them on the end of `bp' */
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last = &bp->m_nextpkt;
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nfrags = 0;
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while ((fptr = PacketAliasGetFragment(MBUF_CTOP(bp))) != NULL) {
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nfrags++;
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PacketAliasFragmentIn(MBUF_CTOP(bp), fptr);
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len = ntohs(((struct ip *)fptr)->ip_len);
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*last = m_get(len, MB_NATIN);
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memcpy(MBUF_CTOP(*last), fptr, len);
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free(fptr);
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last = &(*last)->m_nextpkt;
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}
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gfrags -= nfrags;
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log_Printf(LogDEBUG, "Found a frag header (%lu) - plus %d more frags (no"
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"w %d)\n", (unsigned long)((struct ip *)MBUF_CTOP(bp))->ip_id,
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nfrags, gfrags);
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break;
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case PKT_ALIAS_IGNORED:
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if (log_IsKept(LogTCPIP)) {
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log_Printf(LogTCPIP, "NAT engine ignored data:\n");
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PacketCheck(bundle, MBUF_CTOP(bp), bp->m_len, NULL, NULL, NULL);
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}
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break;
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default:
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log_Printf(LogWARN, "nat_LayerPull: Dropped a packet (%d)....\n", ret);
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m_freem(bp);
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bp = NULL;
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break;
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}
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return bp;
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}
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struct layer natlayer =
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{ LAYER_NAT, "nat", nat_LayerPush, nat_LayerPull };
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