327 lines
6.9 KiB
C
327 lines
6.9 KiB
C
/* $NetBSD: ipft_tx.c,v 1.1.1.1 2004/03/28 08:56:19 martti Exp $ */
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/*
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* Copyright (C) 1995-2001 by Darren Reed.
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*
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* See the IPFILTER.LICENCE file for details on licencing.
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*
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* Id: ipft_tx.c,v 1.15 2004/01/08 13:34:32 darrenr Exp
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*/
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#if !defined(lint)
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static const char sccsid[] = "@(#)ipft_tx.c 1.7 6/5/96 (C) 1993 Darren Reed";
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static const char rcsid[] = "@(#)Id: ipft_tx.c,v 1.15 2004/01/08 13:34:32 darrenr Exp";
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#endif
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#include <ctype.h>
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#include "ipf.h"
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#include "ipt.h"
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#ifndef linux
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#include <netinet/ip_var.h>
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#endif
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#include <netinet/tcpip.h>
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extern int opts;
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static char *tx_proto = "";
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static int text_open __P((char *)), text_close __P((void));
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static int text_readip __P((char *, int, char **, int *));
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static int parseline __P((char *, ip_t *, char **, int *));
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static char _tcp_flagset[] = "FSRPAUEC";
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static u_char _tcp_flags[] = { TH_FIN, TH_SYN, TH_RST, TH_PUSH,
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TH_ACK, TH_URG, TH_ECN, TH_CWR };
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struct ipread iptext = { text_open, text_close, text_readip, R_DO_CKSUM };
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static FILE *tfp = NULL;
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static int tfd = -1;
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static u_32_t tx_hostnum __P((char *, int *));
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static u_short tx_portnum __P((char *));
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/*
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* returns an ip address as a long var as a result of either a DNS lookup or
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* straight inet_addr() call
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*/
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static u_32_t tx_hostnum(host, resolved)
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char *host;
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int *resolved;
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{
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u_32_t ipa;
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*resolved = 0;
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if (!strcasecmp("any", host))
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return 0L;
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if (isdigit(*host))
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return inet_addr(host);
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if (gethost(host, &ipa) == -1) {
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*resolved = -1;
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fprintf(stderr, "can't resolve hostname: %s\n", host);
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return 0;
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}
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return ipa;
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}
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/*
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* find the port number given by the name, either from getservbyname() or
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* straight atoi()
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*/
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static u_short tx_portnum(name)
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char *name;
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{
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struct servent *sp, *sp2;
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u_short p1 = 0;
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if (isdigit(*name))
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return (u_short)atoi(name);
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if (!tx_proto)
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tx_proto = "tcp/udp";
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if (strcasecmp(tx_proto, "tcp/udp")) {
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sp = getservbyname(name, tx_proto);
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if (sp)
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return ntohs(sp->s_port);
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(void) fprintf(stderr, "unknown service \"%s\".\n", name);
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return 0;
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}
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sp = getservbyname(name, "tcp");
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if (sp)
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p1 = sp->s_port;
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sp2 = getservbyname(name, "udp");
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if (!sp || !sp2) {
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(void) fprintf(stderr, "unknown tcp/udp service \"%s\".\n",
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name);
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return 0;
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}
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if (p1 != sp2->s_port) {
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(void) fprintf(stderr, "%s %d/tcp is a different port to ",
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name, p1);
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(void) fprintf(stderr, "%s %d/udp\n", name, sp->s_port);
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return 0;
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}
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return ntohs(p1);
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}
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char *tx_icmptypes[] = {
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"echorep", (char *)NULL, (char *)NULL, "unreach", "squench",
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"redir", (char *)NULL, (char *)NULL, "echo", "routerad",
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"routersol", "timex", "paramprob", "timest", "timestrep",
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"inforeq", "inforep", "maskreq", "maskrep", "END"
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};
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static int text_open(fname)
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char *fname;
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{
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if (tfp && tfd != -1) {
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rewind(tfp);
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return tfd;
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}
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if (!strcmp(fname, "-")) {
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tfd = 0;
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tfp = stdin;
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} else {
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tfd = open(fname, O_RDONLY);
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if (tfd != -1)
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tfp = fdopen(tfd, "r");
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}
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return tfd;
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}
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static int text_close()
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{
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int cfd = tfd;
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tfd = -1;
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return close(cfd);
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}
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static int text_readip(buf, cnt, ifn, dir)
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char *buf, **ifn;
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int cnt, *dir;
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{
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register char *s;
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char line[513];
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*ifn = NULL;
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while (fgets(line, sizeof(line)-1, tfp)) {
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if ((s = strchr(line, '\n')))
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*s = '\0';
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if ((s = strchr(line, '\r')))
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*s = '\0';
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if ((s = strchr(line, '#')))
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*s = '\0';
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if (!*line)
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continue;
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if (!(opts & OPT_BRIEF))
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printf("input: %s\n", line);
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*ifn = NULL;
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*dir = 0;
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if (!parseline(line, (ip_t *)buf, ifn, dir))
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#if 0
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return sizeof(ip_t) + sizeof(tcphdr_t);
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#else
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return sizeof(ip_t);
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#endif
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}
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return -1;
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}
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static int parseline(line, ip, ifn, out)
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char *line;
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ip_t *ip;
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char **ifn;
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int *out;
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{
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tcphdr_t th, *tcp = &th;
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struct icmp icmp, *ic = &icmp;
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char *cps[20], **cpp, c, ipopts[68];
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int i, r;
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if (*ifn)
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free(*ifn);
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bzero((char *)ip, MAX(sizeof(*tcp), sizeof(*ic)) + sizeof(*ip));
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bzero((char *)tcp, sizeof(*tcp));
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bzero((char *)ic, sizeof(*ic));
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bzero(ipopts, sizeof(ipopts));
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IP_HL_A(ip, sizeof(*ip) >> 2);
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IP_V_A(ip, IPVERSION);
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for (i = 0, cps[0] = strtok(line, " \b\t\r\n"); cps[i] && i < 19; )
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cps[++i] = strtok(NULL, " \b\t\r\n");
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cpp = cps;
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if (!*cpp)
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return 1;
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c = **cpp;
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if (!isalpha(c) || (tolower(c) != 'o' && tolower(c) != 'i')) {
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fprintf(stderr, "bad direction \"%s\"\n", *cpp);
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return 1;
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}
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*out = (tolower(c) == 'o') ? 1 : 0;
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cpp++;
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if (!*cpp)
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return 1;
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if (!strcasecmp(*cpp, "on")) {
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cpp++;
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if (!*cpp)
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return 1;
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*ifn = strdup(*cpp++);
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if (!*cpp)
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return 1;
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}
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c = **cpp;
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ip->ip_len = sizeof(ip_t);
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if (!strcasecmp(*cpp, "tcp") || !strcasecmp(*cpp, "udp") ||
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!strcasecmp(*cpp, "icmp")) {
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if (c == 't') {
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ip->ip_p = IPPROTO_TCP;
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ip->ip_len += sizeof(struct tcphdr);
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tx_proto = "tcp";
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} else if (c == 'u') {
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ip->ip_p = IPPROTO_UDP;
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ip->ip_len += sizeof(struct udphdr);
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tx_proto = "udp";
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} else {
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ip->ip_p = IPPROTO_ICMP;
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ip->ip_len += ICMPERR_IPICMPHLEN;
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tx_proto = "icmp";
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}
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cpp++;
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} else if (isdigit(**cpp) && !index(*cpp, '.')) {
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ip->ip_p = atoi(*cpp);
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cpp++;
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} else
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ip->ip_p = IPPROTO_IP;
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if (!*cpp)
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return 1;
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if (ip->ip_p == IPPROTO_TCP || ip->ip_p == IPPROTO_UDP) {
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char *last;
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last = strchr(*cpp, ',');
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if (!last) {
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fprintf(stderr, "tcp/udp with no source port\n");
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return 1;
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}
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*last++ = '\0';
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tcp->th_sport = htons(tx_portnum(last));
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}
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ip->ip_src.s_addr = tx_hostnum(*cpp, &r);
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cpp++;
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if (!*cpp)
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return 1;
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if (ip->ip_p == IPPROTO_TCP || ip->ip_p == IPPROTO_UDP) {
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char *last;
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last = strchr(*cpp, ',');
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if (!last) {
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fprintf(stderr, "tcp/udp with no destination port\n");
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return 1;
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}
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*last++ = '\0';
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tcp->th_dport = htons(tx_portnum(last));
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}
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ip->ip_dst.s_addr = tx_hostnum(*cpp, &r);
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cpp++;
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if (*cpp && ip->ip_p == IPPROTO_TCP) {
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extern char _tcp_flagset[];
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extern u_char _tcp_flags[];
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char *s, *t;
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for (s = *cpp; *s; s++)
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if ((t = strchr(_tcp_flagset, *s)))
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tcp->th_flags |= _tcp_flags[t - _tcp_flagset];
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if (tcp->th_flags)
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cpp++;
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if (tcp->th_flags == 0)
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abort();
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tcp->th_win = htons(4096);
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TCP_OFF_A(tcp, sizeof(*tcp) >> 2);
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} else if (*cpp && ip->ip_p == IPPROTO_ICMP) {
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extern char *tx_icmptypes[];
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char **s, *t;
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int i;
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for (s = tx_icmptypes, i = 0; !*s || strcmp(*s, "END");
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s++, i++)
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if (*s && !strncasecmp(*cpp, *s, strlen(*s))) {
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ic->icmp_type = i;
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if ((t = strchr(*cpp, ',')))
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ic->icmp_code = atoi(t+1);
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cpp++;
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break;
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}
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}
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if (*cpp && !strcasecmp(*cpp, "opt")) {
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u_long olen;
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cpp++;
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olen = buildopts(*cpp, ipopts, (IP_HL(ip) - 5) << 2);
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if (olen) {
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bcopy(ipopts, (char *)(ip + 1), olen);
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IP_HL_A(ip, IP_HL(ip) + (olen >> 2));
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}
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}
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if (ip->ip_p == IPPROTO_TCP || ip->ip_p == IPPROTO_UDP)
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bcopy((char *)tcp, ((char *)ip) + (IP_HL(ip) << 2),
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sizeof(*tcp));
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else if (ip->ip_p == IPPROTO_ICMP)
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bcopy((char *)ic, ((char *)ip) + (IP_HL(ip) << 2),
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sizeof(*ic));
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ip->ip_len = htons(ip->ip_len);
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return 0;
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}
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