root/sbin/ipf/iplang/iplang_y.y

%{
/*
 * Copyright (C) 2012 by Darren Reed.
 *
 * See the IPFILTER.LICENCE file for details on licencing.
 *
 * Id: iplang_y.y,v 2.9.2.4 2006/03/17 12:11:29 darrenr Exp $
 */

#include <stdio.h>
#include <string.h>
#include <fcntl.h>
#if !defined(__SVR4) && !defined(__svr4__)
# include <strings.h>
#else
# include <sys/byteorder.h>
#endif
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/param.h>
#include <sys/time.h>
#include <stdlib.h>
#include <unistd.h>
#include <stddef.h>
#include <sys/socket.h>
#include <net/if.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
# include <netinet/ip_var.h>
# include <net/route.h>
# include <netinet/if_ether.h>
#include <netdb.h>
#include <arpa/nameser.h>
#include <arpa/inet.h>
#include <resolv.h>
#include <ctype.h>
#include "ipsend.h"
#include "ip_compat.h"
#include "ipf.h"
#include "iplang.h"

extern  int     opts;
extern  struct ipopt_names ionames[];
extern  int     state, state, lineNum, token;
extern  int     yylineno;
extern  char    yytext[];
extern  FILE    *yyin;
int     yylex   __P((void));
#define YYDEBUG 1
int     yydebug = 1;

iface_t *iflist = NULL, **iftail = &iflist;
iface_t *cifp = NULL;
arp_t *arplist = NULL, **arptail = &arplist, *carp = NULL;
struct in_addr defrouter;
send_t  sending;
char    *sclass = NULL;
u_short c_chksum(u_short *, u_int, u_long);
u_long  p_chksum(u_short *, u_int);

u_long  ipbuffer[67584/sizeof(u_long)];         /* 66K */
aniphdr_t       *aniphead = NULL, *canip = NULL, **aniptail = &aniphead;
ip_t            *ip = NULL;
udphdr_t        *udp = NULL;
tcphdr_t        *tcp = NULL;
icmphdr_t       *icmp = NULL;

struct statetoopt {
        int     sto_st;
        int     sto_op;
};

struct  in_addr getipv4addr(char *arg);
u_short getportnum(char *, char *);
struct  ether_addr *geteaddr(char *, struct ether_addr *);
void    *new_header(int);
void    free_aniplist(void);
void    inc_anipheaders(int);
void    new_data(void);
void    set_datalen(char **);
void    set_datafile(char **);
void    set_data(char **);
void    new_packet(void);
void    set_ipv4proto(char **);
void    set_ipv4src(char **);
void    set_ipv4dst(char **);
void    set_ipv4off(char **);
void    set_ipv4v(char **);
void    set_ipv4hl(char **);
void    set_ipv4ttl(char **);
void    set_ipv4tos(char **);
void    set_ipv4id(char **);
void    set_ipv4sum(char **);
void    set_ipv4len(char **);
void    new_tcpheader(void);
void    set_tcpsport(char **);
void    set_tcpdport(char **);
void    set_tcpseq(char **);
void    set_tcpack(char **);
void    set_tcpoff(char **);
void    set_tcpurp(char **);
void    set_tcpwin(char **);
void    set_tcpsum(char **);
void    set_tcpflags(char **);
void    set_tcpopt(int, char **);
void    end_tcpopt(void);
void    new_udpheader(void);
void    set_udplen(char **);
void    set_udpsum(char **);
void    prep_packet(void);
void    packet_done(void);
void    new_interface(void);
void    check_interface(void);
void    set_ifname(char **);
void    set_ifmtu(int);
void    set_ifv4addr(char **);
void    set_ifeaddr(char **);
void    new_arp(void);
void    set_arpeaddr(char **);
void    set_arpv4addr(char **);
void    reset_send(void);
void    set_sendif(char **);
void    set_sendvia(char **);
void    set_defaultrouter(char **);
void    new_icmpheader(void);
void    set_icmpcode(int);
void    set_icmptype(int);
void    set_icmpcodetok(char **);
void    set_icmptypetok(char **);
void    set_icmpid(int);
void    set_icmpseq(int);
void    set_icmpotime(int);
void    set_icmprtime(int);
void    set_icmpttime(int);
void    set_icmpmtu(int);
void    set_redir(int, char **);
void    new_ipv4opt(void);
void    set_icmppprob(int);
void    add_ipopt(int, void *);
void    end_ipopt(void);
void    set_secclass(char **);
void    free_anipheader(void);
void    end_ipv4(void);
void    end_icmp(void);
void    end_udp(void);
void    end_tcp(void);
void    end_data(void);
void    yyerror(char *);
void    iplang(FILE *);
int     arp_getipv4(char *, char *);
int     yyparse(void);
%}
%union {
        char    *str;
        int     num;
}
%token  <num> IL_NUMBER
%type   <num> number digits optnumber
%token  <str> IL_TOKEN
%type   <str> token optoken
%token  IL_HEXDIGIT IL_COLON IL_DOT IL_EOF IL_COMMENT
%token  IL_INTERFACE IL_IFNAME IL_MTU IL_EADDR
%token  IL_IPV4 IL_V4PROTO IL_V4SRC IL_V4DST IL_V4OFF IL_V4V IL_V4HL IL_V4TTL
%token  IL_V4TOS IL_V4SUM IL_V4LEN IL_V4OPT IL_V4ID
%token  IL_TCP IL_SPORT IL_DPORT IL_TCPFL IL_TCPSEQ IL_TCPACK IL_TCPOFF
%token  IL_TCPWIN IL_TCPSUM IL_TCPURP IL_TCPOPT IL_TCPO_NOP IL_TCPO_EOL
%token  IL_TCPO_MSS IL_TCPO_WSCALE IL_TCPO_TS
%token  IL_UDP IL_UDPLEN IL_UDPSUM
%token  IL_ICMP IL_ICMPTYPE IL_ICMPCODE
%token  IL_SEND IL_VIA
%token  IL_ARP
%token  IL_DEFROUTER
%token  IL_SUM IL_OFF IL_LEN IL_V4ADDR IL_OPT
%token  IL_DATA IL_DLEN IL_DVALUE IL_DFILE
%token  IL_IPO_NOP IL_IPO_RR IL_IPO_ZSU IL_IPO_MTUP IL_IPO_MTUR IL_IPO_EOL
%token  IL_IPO_TS IL_IPO_TR IL_IPO_SEC IL_IPO_LSRR IL_IPO_ESEC
%token  IL_IPO_SATID IL_IPO_SSRR IL_IPO_ADDEXT IL_IPO_VISA IL_IPO_IMITD
%token  IL_IPO_EIP IL_IPO_FINN IL_IPO_SECCLASS IL_IPO_CIPSO IL_IPO_ENCODE
%token  <str> IL_IPS_RESERV4 IL_IPS_TOPSECRET IL_IPS_SECRET IL_IPS_RESERV3
%token  <str> IL_IPS_CONFID IL_IPS_UNCLASS IL_IPS_RESERV2 IL_IPS_RESERV1
%token  IL_ICMP_ECHOREPLY IL_ICMP_UNREACH IL_ICMP_UNREACH_NET
%token  IL_ICMP_UNREACH_HOST IL_ICMP_UNREACH_PROTOCOL IL_ICMP_UNREACH_PORT
%token  IL_ICMP_UNREACH_NEEDFRAG IL_ICMP_UNREACH_SRCFAIL
%token  IL_ICMP_UNREACH_NET_UNKNOWN IL_ICMP_UNREACH_HOST_UNKNOWN
%token  IL_ICMP_UNREACH_ISOLATED IL_ICMP_UNREACH_NET_PROHIB
%token  IL_ICMP_UNREACH_HOST_PROHIB IL_ICMP_UNREACH_TOSNET
%token  IL_ICMP_UNREACH_TOSHOST IL_ICMP_UNREACH_FILTER_PROHIB
%token  IL_ICMP_UNREACH_HOST_PRECEDENCE IL_ICMP_UNREACH_PRECEDENCE_CUTOFF
%token  IL_ICMP_SOURCEQUENCH IL_ICMP_REDIRECT IL_ICMP_REDIRECT_NET
%token  IL_ICMP_REDIRECT_HOST IL_ICMP_REDIRECT_TOSNET
%token  IL_ICMP_REDIRECT_TOSHOST IL_ICMP_ECHO IL_ICMP_ROUTERADVERT
%token  IL_ICMP_ROUTERSOLICIT IL_ICMP_TIMXCEED IL_ICMP_TIMXCEED_INTRANS
%token  IL_ICMP_TIMXCEED_REASS IL_ICMP_PARAMPROB IL_ICMP_PARAMPROB_OPTABSENT
%token  IL_ICMP_TSTAMP IL_ICMP_TSTAMPREPLY IL_ICMP_IREQ IL_ICMP_IREQREPLY
%token  IL_ICMP_MASKREQ IL_ICMP_MASKREPLY IL_ICMP_SEQ IL_ICMP_ID
%token  IL_ICMP_OTIME IL_ICMP_RTIME IL_ICMP_TTIME

%%
file:   line
        | line file
        | IL_COMMENT
        | IL_COMMENT file
        ;

line:   iface
        | arp
        | send
        | defrouter
        | ipline
        ;

iface:  ifhdr '{' ifaceopts '}' ';'     { check_interface(); }
        ;

ifhdr:  IL_INTERFACE                    { new_interface(); }
        ;

ifaceopts:
        ifaceopt
        | ifaceopt ifaceopts
        ;

ifaceopt:
        IL_IFNAME token                 { set_ifname(&$2); }
        | IL_MTU number                 { set_ifmtu($2); }
        | IL_V4ADDR token               { set_ifv4addr(&$2); }
        | IL_EADDR token                { set_ifeaddr(&$2); }
        ;

send:   sendhdr '{' sendbody '}' ';'    { packet_done(); }
        | sendhdr ';'                   { packet_done(); }
        ;

sendhdr:
        IL_SEND                         { reset_send(); }
        ;

sendbody:
        sendopt
        | sendbody sendopt
        ;

sendopt:
        IL_IFNAME token                 { set_sendif(&$2); }
        | IL_VIA token                  { set_sendvia(&$2); }
        ;

arp:    arphdr '{' arpbody '}' ';'
        ;

arphdr: IL_ARP                          { new_arp(); }
        ;

arpbody:
        arpopt
        | arpbody arpopt
        ;

arpopt: IL_V4ADDR token                 { set_arpv4addr(&$2); }
        | IL_EADDR token                { set_arpeaddr(&$2); }
        ;

defrouter:
        IL_DEFROUTER token              { set_defaultrouter(&$2); }
        ;

bodyline:
        ipline
        | tcp tcpline
        | udp udpline
        | icmp icmpline
        | data dataline
        ;

ipline: ipv4 '{' ipv4body '}' ';'       { end_ipv4(); }
        ;

ipv4:   IL_IPV4                         { new_packet(); }

ipv4body:
        ipv4type
        | ipv4type ipv4body
        | bodyline
        ;

ipv4type:
        IL_V4PROTO token                { set_ipv4proto(&$2); }
        | IL_V4SRC token                { set_ipv4src(&$2); }
        | IL_V4DST token                { set_ipv4dst(&$2); }
        | IL_V4OFF token                { set_ipv4off(&$2); }
        | IL_V4V token                  { set_ipv4v(&$2); }
        | IL_V4HL token                 { set_ipv4hl(&$2); }
        | IL_V4ID token                 { set_ipv4id(&$2); }
        | IL_V4TTL token                { set_ipv4ttl(&$2); }
        | IL_V4TOS token                { set_ipv4tos(&$2); }
        | IL_V4SUM token                { set_ipv4sum(&$2); }
        | IL_V4LEN token                { set_ipv4len(&$2); }
        | ipv4opt '{' ipv4optlist '}' ';'       { end_ipopt(); }
        ;

tcp:    IL_TCP                          { new_tcpheader(); }
        ;

tcpline:
        '{' tcpheader '}' ';'           { end_tcp(); }
        ;

tcpheader:
        tcpbody
        | tcpbody tcpheader
        | bodyline
        ;

tcpbody:
        IL_SPORT token                  { set_tcpsport(&$2); }
        | IL_DPORT token                { set_tcpdport(&$2); }
        | IL_TCPSEQ token               { set_tcpseq(&$2); }
        | IL_TCPACK token               { set_tcpack(&$2); }
        | IL_TCPOFF token               { set_tcpoff(&$2); }
        | IL_TCPURP token               { set_tcpurp(&$2); }
        | IL_TCPWIN token               { set_tcpwin(&$2); }
        | IL_TCPSUM token               { set_tcpsum(&$2); }
        | IL_TCPFL token                { set_tcpflags(&$2); }
        | IL_TCPOPT '{' tcpopts '}' ';' { end_tcpopt(); }
        ;

tcpopts:
        | tcpopt tcpopts
        ;

tcpopt: IL_TCPO_NOP ';'                 { set_tcpopt(IL_TCPO_NOP, NULL); }
        | IL_TCPO_EOL ';'               { set_tcpopt(IL_TCPO_EOL, NULL); }
        | IL_TCPO_MSS optoken           { set_tcpopt(IL_TCPO_MSS,&$2);}
        | IL_TCPO_WSCALE optoken        { set_tcpopt(IL_TCPO_WSCALE,&$2);}
        | IL_TCPO_TS optoken            { set_tcpopt(IL_TCPO_TS, &$2);}
        ;

udp:    IL_UDP                          { new_udpheader(); }
        ;

udpline:
        '{' udpheader '}' ';'           { end_udp(); }
        ;


udpheader:
        udpbody
        | udpbody udpheader
        | bodyline
        ;

udpbody:
        IL_SPORT token                  { set_tcpsport(&$2); }
        | IL_DPORT token                { set_tcpdport(&$2); }
        | IL_UDPLEN token               { set_udplen(&$2); }
        | IL_UDPSUM token               { set_udpsum(&$2); }
        ;

icmp:   IL_ICMP                         { new_icmpheader(); }
        ;

icmpline:
        '{' icmpbody '}' ';'            { end_icmp(); }
        ;

icmpbody:
        icmpheader
        | icmpheader bodyline
        ;

icmpheader:
        IL_ICMPTYPE icmptype
        | IL_ICMPTYPE icmptype icmpcode
        ;

icmpcode:
        IL_ICMPCODE token               { set_icmpcodetok(&$2); }
        ;

icmptype:
        IL_ICMP_ECHOREPLY ';'           { set_icmptype(ICMP_ECHOREPLY); }
        | IL_ICMP_ECHOREPLY '{' icmpechoopts '}' ';'
        | unreach
        | IL_ICMP_SOURCEQUENCH ';'      { set_icmptype(ICMP_SOURCEQUENCH); }
        | redirect
        | IL_ICMP_ROUTERADVERT ';'      { set_icmptype(ICMP_ROUTERADVERT); }
        | IL_ICMP_ROUTERSOLICIT ';'     { set_icmptype(ICMP_ROUTERSOLICIT); }
        | IL_ICMP_ECHO ';'              { set_icmptype(ICMP_ECHO); }
        | IL_ICMP_ECHO '{' icmpechoopts '}' ';'
        | IL_ICMP_TIMXCEED ';'          { set_icmptype(ICMP_TIMXCEED); }
        | IL_ICMP_TIMXCEED '{' exceed '}' ';'
        | IL_ICMP_TSTAMP ';'            { set_icmptype(ICMP_TSTAMP); }
        | IL_ICMP_TSTAMPREPLY ';'       { set_icmptype(ICMP_TSTAMPREPLY); }
        | IL_ICMP_TSTAMPREPLY '{' icmptsopts '}' ';'
        | IL_ICMP_IREQ ';'              { set_icmptype(ICMP_IREQ); }
        | IL_ICMP_IREQREPLY ';'         { set_icmptype(ICMP_IREQREPLY); }
        | IL_ICMP_IREQREPLY '{' data dataline '}' ';'
        | IL_ICMP_MASKREQ ';'           { set_icmptype(ICMP_MASKREQ); }
        | IL_ICMP_MASKREPLY ';'         { set_icmptype(ICMP_MASKREPLY); }
        | IL_ICMP_MASKREPLY '{' token '}' ';'
        | IL_ICMP_PARAMPROB ';'         { set_icmptype(ICMP_PARAMPROB); }
        | IL_ICMP_PARAMPROB '{' paramprob '}' ';'
        | IL_TOKEN ';'                  { set_icmptypetok(&$1); }
        ;

icmpechoopts:
        | icmpechoopts icmpecho
        ;

icmpecho:
        IL_ICMP_SEQ number              { set_icmpseq($2); }
        | IL_ICMP_ID number             { set_icmpid($2); }
        ;

icmptsopts:
        | icmptsopts icmpts ';'
        ;

icmpts: IL_ICMP_OTIME number            { set_icmpotime($2); }
        | IL_ICMP_RTIME number          { set_icmprtime($2); }
        | IL_ICMP_TTIME number          { set_icmpttime($2); }
        ;

unreach:
        IL_ICMP_UNREACH
        | IL_ICMP_UNREACH '{' unreachopts '}' ';'
        ;

unreachopts:
        IL_ICMP_UNREACH_NET line
        | IL_ICMP_UNREACH_HOST line
        | IL_ICMP_UNREACH_PROTOCOL line
        | IL_ICMP_UNREACH_PORT line
        | IL_ICMP_UNREACH_NEEDFRAG number ';'   { set_icmpmtu($2); }
        | IL_ICMP_UNREACH_SRCFAIL line
        | IL_ICMP_UNREACH_NET_UNKNOWN line
        | IL_ICMP_UNREACH_HOST_UNKNOWN line
        | IL_ICMP_UNREACH_ISOLATED line
        | IL_ICMP_UNREACH_NET_PROHIB line
        | IL_ICMP_UNREACH_HOST_PROHIB line
        | IL_ICMP_UNREACH_TOSNET line
        | IL_ICMP_UNREACH_TOSHOST line
        | IL_ICMP_UNREACH_FILTER_PROHIB line
        | IL_ICMP_UNREACH_HOST_PRECEDENCE line
        | IL_ICMP_UNREACH_PRECEDENCE_CUTOFF line
        ;

redirect:
        IL_ICMP_REDIRECT
        | IL_ICMP_REDIRECT '{' redirectopts '}' ';'
        ;

redirectopts:
        | IL_ICMP_REDIRECT_NET token            { set_redir(0, &$2); }
        | IL_ICMP_REDIRECT_HOST token           { set_redir(1, &$2); }
        | IL_ICMP_REDIRECT_TOSNET token         { set_redir(2, &$2); }
        | IL_ICMP_REDIRECT_TOSHOST token        { set_redir(3, &$2); }
        ;

exceed:
        IL_ICMP_TIMXCEED_INTRANS line
        | IL_ICMP_TIMXCEED_REASS line
        ;

paramprob:
        IL_ICMP_PARAMPROB_OPTABSENT
        | IL_ICMP_PARAMPROB_OPTABSENT paraprobarg

paraprobarg:
        '{' number '}' ';'              { set_icmppprob($2); }
        ;

ipv4opt:        IL_V4OPT                { new_ipv4opt(); }
        ;

ipv4optlist:
        | ipv4opts ipv4optlist
        ;

ipv4opts:
        IL_IPO_NOP ';'                  { add_ipopt(IL_IPO_NOP, NULL); }
        | IL_IPO_RR optnumber           { add_ipopt(IL_IPO_RR, &$2); }
        | IL_IPO_ZSU ';'                { add_ipopt(IL_IPO_ZSU, NULL); }
        | IL_IPO_MTUP ';'               { add_ipopt(IL_IPO_MTUP, NULL); }
        | IL_IPO_MTUR ';'               { add_ipopt(IL_IPO_MTUR, NULL); }
        | IL_IPO_ENCODE ';'             { add_ipopt(IL_IPO_ENCODE, NULL); }
        | IL_IPO_TS ';'                 { add_ipopt(IL_IPO_TS, NULL); }
        | IL_IPO_TR ';'                 { add_ipopt(IL_IPO_TR, NULL); }
        | IL_IPO_SEC ';'                { add_ipopt(IL_IPO_SEC, NULL); }
        | IL_IPO_SECCLASS secclass      { add_ipopt(IL_IPO_SECCLASS, sclass); }
        | IL_IPO_LSRR token             { add_ipopt(IL_IPO_LSRR,&$2); }
        | IL_IPO_ESEC ';'               { add_ipopt(IL_IPO_ESEC, NULL); }
        | IL_IPO_CIPSO ';'              { add_ipopt(IL_IPO_CIPSO, NULL); }
        | IL_IPO_SATID optnumber        { add_ipopt(IL_IPO_SATID,&$2);}
        | IL_IPO_SSRR token             { add_ipopt(IL_IPO_SSRR,&$2); }
        | IL_IPO_ADDEXT ';'             { add_ipopt(IL_IPO_ADDEXT, NULL); }
        | IL_IPO_VISA ';'               { add_ipopt(IL_IPO_VISA, NULL); }
        | IL_IPO_IMITD ';'              { add_ipopt(IL_IPO_IMITD, NULL); }
        | IL_IPO_EIP ';'                { add_ipopt(IL_IPO_EIP, NULL); }
        | IL_IPO_FINN ';'               { add_ipopt(IL_IPO_FINN, NULL); }
        ;

secclass:
        IL_IPS_RESERV4 ';'              { set_secclass(&$1); }
        | IL_IPS_TOPSECRET ';'          { set_secclass(&$1); }
        | IL_IPS_SECRET ';'             { set_secclass(&$1); }
        | IL_IPS_RESERV3 ';'            { set_secclass(&$1); }
        | IL_IPS_CONFID ';'             { set_secclass(&$1); }
        | IL_IPS_UNCLASS ';'            { set_secclass(&$1); }
        | IL_IPS_RESERV2 ';'            { set_secclass(&$1); }
        | IL_IPS_RESERV1 ';'            { set_secclass(&$1); }
        ;

data:   IL_DATA                         { new_data(); }
        ;

dataline:
        '{' databody '}' ';'            { end_data(); }
        ;

databody: dataopts
        | dataopts databody
        ;

dataopts:
        IL_DLEN token                   { set_datalen(&$2); }
        | IL_DVALUE token               { set_data(&$2); }
        | IL_DFILE token                { set_datafile(&$2); }
        ;

token: IL_TOKEN ';'
        ;

optoken: ';'                            { $$ = ""; }
        | token
        ;

number: digits ';'
        ;

optnumber: ';'                          { $$ = 0; }
        | number
        ;

digits: IL_NUMBER
        | digits IL_NUMBER
        ;
%%

struct  statetoopt      toipopts[] = {
        { IL_IPO_NOP,           IPOPT_NOP },
        { IL_IPO_RR,            IPOPT_RR },
        { IL_IPO_ZSU,           IPOPT_ZSU },
        { IL_IPO_MTUP,          IPOPT_MTUP },
        { IL_IPO_MTUR,          IPOPT_MTUR },
        { IL_IPO_ENCODE,        IPOPT_ENCODE },
        { IL_IPO_TS,            IPOPT_TS },
        { IL_IPO_TR,            IPOPT_TR },
        { IL_IPO_SEC,           IPOPT_SECURITY },
        { IL_IPO_SECCLASS,      IPOPT_SECURITY },
        { IL_IPO_LSRR,          IPOPT_LSRR },
        { IL_IPO_ESEC,          IPOPT_E_SEC },
        { IL_IPO_CIPSO,         IPOPT_CIPSO },
        { IL_IPO_SATID,         IPOPT_SATID },
        { IL_IPO_SSRR,          IPOPT_SSRR },
        { IL_IPO_ADDEXT,        IPOPT_ADDEXT },
        { IL_IPO_VISA,          IPOPT_VISA },
        { IL_IPO_IMITD,         IPOPT_IMITD },
        { IL_IPO_EIP,           IPOPT_EIP },
        { IL_IPO_FINN,          IPOPT_FINN },
        { 0, 0 }
};

struct  statetoopt      tosecopts[] = {
        { IL_IPS_RESERV4,       IPSO_CLASS_RES4 },
        { IL_IPS_TOPSECRET,     IPSO_CLASS_TOPS },
        { IL_IPS_SECRET,        IPSO_CLASS_SECR },
        { IL_IPS_RESERV3,       IPSO_CLASS_RES3 },
        { IL_IPS_CONFID,        IPSO_CLASS_CONF },
        { IL_IPS_UNCLASS,       IPSO_CLASS_UNCL },
        { IL_IPS_RESERV2,       IPSO_CLASS_RES2 },
        { IL_IPS_RESERV1,       IPSO_CLASS_RES1 },
        { 0, 0 }
};


struct in_addr getipv4addr(arg)
char *arg;
{
        struct hostent *hp;
        struct in_addr in;

        in.s_addr = 0xffffffff;

        if ((hp = gethostbyname(arg)))
                bcopy(hp->h_addr, &in.s_addr, sizeof(struct in_addr));
        else
                in.s_addr = inet_addr(arg);
        return(in);
}


u_short getportnum(pr, name)
char *pr, *name;
{
        struct servent *sp;

        if (!(sp = getservbyname(name, pr)))
                return(htons(atoi(name)));
        return(sp->s_port);
}


struct ether_addr *geteaddr(char *arg, struct ether_addr *buf)
{
        struct ether_addr *e;

        e = ether_aton(arg);
        if (!e)
                fprintf(stderr, "Invalid ethernet address: %s\n", arg);
        else
# ifdef __FreeBSD__
                bcopy(e->octet, buf->octet, sizeof(e->octet));
# else
                bcopy(e->ether_addr_octet, buf->ether_addr_octet,
                      sizeof(e->ether_addr_octet));
# endif
        return(e);
}


void *new_header(int type)
{
        aniphdr_t *aip, *oip = canip;
        int     sz = 0;

        aip = (aniphdr_t *)calloc(1, sizeof(*aip));
        *aniptail = aip;
        aniptail = &aip->ah_next;
        aip->ah_p = type;
        aip->ah_prev = oip;
        canip = aip;

        if (type == IPPROTO_UDP)
                sz = sizeof(udphdr_t);
        else if (type == IPPROTO_TCP)
                sz = sizeof(tcphdr_t);
        else if (type == IPPROTO_ICMP)
                sz = sizeof(icmphdr_t);
        else if (type == IPPROTO_IP)
                sz = sizeof(ip_t);

        if (oip)
                canip->ah_data = oip->ah_data + oip->ah_len;
        else
                canip->ah_data = (char *)ipbuffer;

        /*
         * Increase the size fields in all wrapping headers.
         */
        for (aip = aniphead; aip; aip = aip->ah_next) {
                aip->ah_len += sz;
                if (aip->ah_p == IPPROTO_IP)
                        aip->ah_ip->ip_len += sz;
                else if (aip->ah_p == IPPROTO_UDP)
                        aip->ah_udp->uh_ulen += sz;
        }
        return(void *)canip->ah_data;
}


void free_aniplist(void)
{
        aniphdr_t *aip, **aipp = &aniphead;

        while ((aip = *aipp)) {
                *aipp = aip->ah_next;
                free(aip);
        }
        aniptail = &aniphead;
}


void inc_anipheaders(int inc)
{
        aniphdr_t *aip;

        for (aip = aniphead; aip; aip = aip->ah_next) {
                aip->ah_len += inc;
                if (aip->ah_p == IPPROTO_IP)
                        aip->ah_ip->ip_len += inc;
                else if (aip->ah_p == IPPROTO_UDP)
                        aip->ah_udp->uh_ulen += inc;
        }
}


void new_data(void)
{
        (void) new_header(-1);
        canip->ah_len = 0;
}


void set_datalen(char **arg)
{
        int     len;

        len = strtol(*arg, NULL, 0);
        inc_anipheaders(len);
        free(*arg);
        *arg = NULL;
}


void set_data(char **arg)
{
        u_char *s = (u_char *)*arg, *t = (u_char *)canip->ah_data, c;
        int len = 0, todo = 0, quote = 0, val = 0;

        while ((c = *s++)) {
                if (todo) {
                        if (ISDIGIT(c)) {
                                todo--;
                                if (c > '7') {
                                        fprintf(stderr, "octal with %c!\n", c);
                                        break;
                                }
                                val <<= 3;
                                val |= (c - '0');
                        }
                        if (!ISDIGIT(c) || !todo) {
                                *t++ = (u_char)(val & 0xff);
                                todo = 0;
                        }
                        if (todo)
                                continue;
                }
                if (quote) {
                        if (ISDIGIT(c)) {
                                todo = 2;
                                if (c > '7') {
                                        fprintf(stderr, "octal with %c!\n", c);
                                        break;
                                }
                                val = (c - '0');
                        } else {
                                switch (c)
                                {
                                case '\"' :
                                        *t++ = '\"';
                                        break;
                                case '\\' :
                                        *t++ = '\\';
                                        break;
                                case 'n' :
                                        *t++ = '\n';
                                        break;
                                case 'r' :
                                        *t++ = '\r';
                                        break;
                                case 't' :
                                        *t++ = '\t';
                                        break;
                                }
                        }
                        quote = 0;
                        continue;
                }

                if (c == '\\')
                        quote = 1;
                else
                        *t++ = c;
        }
        if (todo)
                *t++ = (u_char)(val & 0xff);
        if (quote)
                *t++ = '\\';
        len = t - (u_char *)canip->ah_data;
        inc_anipheaders(len - canip->ah_len);
        canip->ah_len = len;
}


void set_datafile(char **arg)
{
        struct stat sb;
        char *file = *arg;
        int fd, len;

        if ((fd = open(file, O_RDONLY)) == -1) {
                perror("open");
                exit(-1);
        }

        if (fstat(fd, &sb) == -1) {
                perror("fstat");
                exit(-1);
        }

        if ((sb.st_size + aniphead->ah_len ) > 65535) {
                fprintf(stderr, "data file %s too big to include.\n", file);
                close(fd);
                return;
        }
        if ((len = read(fd, canip->ah_data, sb.st_size)) == -1) {
                perror("read");
                close(fd);
                return;
        }
        inc_anipheaders(len);
        canip->ah_len += len;
        close(fd);
}


void new_packet(void)
{
        static  u_short id = 0;

        if (!aniphead)
                bzero((char *)ipbuffer, sizeof(ipbuffer));

        ip = (ip_t *)new_header(IPPROTO_IP);
        ip->ip_v = IPVERSION;
        ip->ip_hl = sizeof(ip_t) >> 2;
        ip->ip_len = sizeof(ip_t);
        ip->ip_ttl = 63;
        ip->ip_id = htons(id++);
}


void set_ipv4proto(arg)
char **arg;
{
        struct protoent *pr;

        if ((pr = getprotobyname(*arg)))
                ip->ip_p = pr->p_proto;
        else
                if (!(ip->ip_p = atoi(*arg)))
                        fprintf(stderr, "unknown protocol %s\n", *arg);
        free(*arg);
        *arg = NULL;
}


void set_ipv4src(char **arg)
{
        ip->ip_src = getipv4addr(*arg);
        free(*arg);
        *arg = NULL;
}


void set_ipv4dst(char **arg)
{
        ip->ip_dst = getipv4addr(*arg);
        free(*arg);
        *arg = NULL;
}


void set_ipv4off(char **arg)
{
        ip->ip_off = htons(strtol(*arg, NULL, 0));
        free(*arg);
        *arg = NULL;
}


void set_ipv4v(char **arg)
{
        ip->ip_v = strtol(*arg, NULL, 0);
        free(*arg);
        *arg = NULL;
}


void set_ipv4hl(char **arg)
{
        int newhl, inc;

        newhl = strtol(*arg, NULL, 0);
        inc = (newhl - ip->ip_hl) << 2;
        ip->ip_len += inc;
        ip->ip_hl = newhl;
        canip->ah_len += inc;
        free(*arg);
        *arg = NULL;
}


void set_ipv4ttl(char **arg)
{
        ip->ip_ttl = strtol(*arg, NULL, 0);
        free(*arg);
        *arg = NULL;
}


void set_ipv4tos(char **arg)
{
        ip->ip_tos = strtol(*arg, NULL, 0);
        free(*arg);
        *arg = NULL;
}


void set_ipv4id(char **arg)
{
        ip->ip_id = htons(strtol(*arg, NULL, 0));
        free(*arg);
        *arg = NULL;
}


void set_ipv4sum(char **arg)
{
        ip->ip_sum = strtol(*arg, NULL, 0);
        free(*arg);
        *arg = NULL;
}


void set_ipv4len(char **arg)
{
        int len;

        len = strtol(*arg, NULL, 0);
        inc_anipheaders(len - ip->ip_len);
        ip->ip_len = len;
        free(*arg);
        *arg = NULL;
}


void new_tcpheader(void)
{

        if ((ip->ip_p) && (ip->ip_p != IPPROTO_TCP)) {
                fprintf(stderr, "protocol %d specified with TCP!\n", ip->ip_p);
                return;
        }
        ip->ip_p = IPPROTO_TCP;

        tcp = (tcphdr_t *)new_header(IPPROTO_TCP);
        tcp->th_win = htons(4096);
        tcp->th_off = sizeof(*tcp) >> 2;
}


void set_tcpsport(char **arg)
{
        u_short *port;
        char *pr;

        if (ip->ip_p == IPPROTO_UDP) {
                port = &udp->uh_sport;
                pr = "udp";
        } else {
                port = &tcp->th_sport;
                pr = "udp";
        }

        *port = getportnum(pr, *arg);
        free(*arg);
        *arg = NULL;
}


void set_tcpdport(char **arg)
{
        u_short *port;
        char *pr;

        if (ip->ip_p == IPPROTO_UDP) {
                port = &udp->uh_dport;
                pr = "udp";
        } else {
                port = &tcp->th_dport;
                pr = "udp";
        }

        *port = getportnum(pr, *arg);
        free(*arg);
        *arg = NULL;
}


void set_tcpseq(char **arg)
{
        tcp->th_seq = htonl(strtol(*arg, NULL, 0));
        free(*arg);
        *arg = NULL;
}


void set_tcpack(char **arg)
{
        tcp->th_ack = htonl(strtol(*arg, NULL, 0));
        free(*arg);
        *arg = NULL;
}


void set_tcpoff(char **arg)
{
        int     off;

        off = strtol(*arg, NULL, 0);
        inc_anipheaders((off - tcp->th_off) << 2);
        tcp->th_off = off;
        free(*arg);
        *arg = NULL;
}


void set_tcpurp(char **arg)
{
        tcp->th_urp = htons(strtol(*arg, NULL, 0));
        free(*arg);
        *arg = NULL;
}


void set_tcpwin(char **arg)
{
        tcp->th_win = htons(strtol(*arg, NULL, 0));
        free(*arg);
        *arg = NULL;
}


void set_tcpsum(char **arg)
{
        tcp->th_sum = strtol(*arg, NULL, 0);
        free(*arg);
        *arg = NULL;
}


void set_tcpflags(char **arg)
{
        static  char    flags[] = "ASURPFEWe";
        static  int     flagv[] = { TH_ACK, TH_SYN, TH_URG, TH_RST, TH_PUSH,
                                    TH_FIN, TH_ECE, TH_CWR, TH_AE } ;
        char *s, *t;

        for (s = *arg; *s; s++)
                if (!(t = strchr(flags, *s))) {
                        if (s - *arg) {
                                fprintf(stderr, "unknown TCP flag %c\n", *s);
                                break;
                        }
                        __tcp_set_flags(tcp, strtol(*arg, NULL, 0));
                        break;
                } else
                        __tcp_set_flags(tcp, __tcp_get_flags(tcp) |
                                        flagv[t - flags]);
        free(*arg);
        *arg = NULL;
}


void set_tcpopt(int state, char **arg)
{
        u_char *s;
        int val, len, val2, pad, optval;

        if (arg && *arg)
                val = atoi(*arg);
        else
                val = 0;

        s = (u_char *)tcp + sizeof(*tcp) + canip->ah_optlen;
        switch (state)
        {
        case IL_TCPO_EOL :
                optval = 0;
                len = 1;
                break;
        case IL_TCPO_NOP :
                optval = 1;
                len = 1;
                break;
        case IL_TCPO_MSS :
                optval = 2;
                len = 4;
                break;
        case IL_TCPO_WSCALE :
                optval = 3;
                len = 3;
                break;
        case IL_TCPO_TS :
                optval = 8;
                len = 10;
                break;
        default :
                optval = 0;
                len = 0;
                break;
        }

        if (len > 1) {
                /*
                 * prepend padding - if required.
                 */
                if (len & 3)
                        for (pad = 4 - (len & 3); pad; pad--) {
                                *s++ = 1;
                                canip->ah_optlen++;
                        }
                /*
                 * build tcp option
                 */
                *s++ = (u_char)optval;
                *s++ = (u_char)len;
                if (len > 2) {
                        if (len == 3) {         /* 1 byte - char */
                                *s++ = (u_char)val;
                        } else if (len == 4) {  /* 2 bytes - short */
                                *s++ = (u_char)((val >> 8) & 0xff);
                                *s++ = (u_char)(val & 0xff);
                        } else if (len >= 6) {  /* 4 bytes - long */
                                val2 = htonl(val);
                                bcopy((char *)&val2, s, 4);
                        }
                        s += (len - 2);
                }
        } else
                *s++ = (u_char)optval;

        canip->ah_lastopt = optval;
        canip->ah_optlen += len;

        if (arg && *arg) {
                free(*arg);
                *arg = NULL;
        }
}


void end_tcpopt(void)
{
        int pad;
        char *s = (char *)tcp;

        s += sizeof(*tcp) + canip->ah_optlen;
        /*
         * pad out so that we have a multiple of 4 bytes in size fo the
         * options.  make sure last byte is EOL.
         */
        if (canip->ah_optlen & 3) {
                if (canip->ah_lastopt != 1) {
                        for (pad = 3 - (canip->ah_optlen & 3); pad; pad--) {
                                *s++ = 1;
                                canip->ah_optlen++;
                        }
                        canip->ah_optlen++;
                } else {
                        s -= 1;

                        for (pad = 3 - (canip->ah_optlen & 3); pad; pad--) {
                                *s++ = 1;
                                canip->ah_optlen++;
                        }
                }
                *s++ = 0;
        }
        tcp->th_off = (sizeof(*tcp) + canip->ah_optlen) >> 2;
        inc_anipheaders(canip->ah_optlen);
}


void new_udpheader(void)
{
        if ((ip->ip_p) && (ip->ip_p != IPPROTO_UDP)) {
                fprintf(stderr, "protocol %d specified with UDP!\n", ip->ip_p);
                return;
        }
        ip->ip_p = IPPROTO_UDP;

        udp = (udphdr_t *)new_header(IPPROTO_UDP);
        udp->uh_ulen = sizeof(*udp);
}


void set_udplen(arg)
char **arg;
{
        int len;

        len = strtol(*arg, NULL, 0);
        inc_anipheaders(len - udp->uh_ulen);
        udp->uh_ulen = len;
        free(*arg);
        *arg = NULL;
}


void set_udpsum(char **arg)
{
        udp->uh_sum = strtol(*arg, NULL, 0);
        free(*arg);
        *arg = NULL;
}


void prep_packet(void)
{
        iface_t *ifp;
        struct in_addr gwip;

        ifp = sending.snd_if;
        if (!ifp) {
                fprintf(stderr, "no interface defined for sending!\n");
                return;
        }
        if (ifp->if_fd == -1)
                ifp->if_fd = initdevice(ifp->if_name, 5);
        gwip = sending.snd_gw;
        if (!gwip.s_addr) {
                if (aniphead == NULL) {
                        fprintf(stderr,
                                "no destination address defined for sending\n");
                        return;
                }
                gwip = aniphead->ah_ip->ip_dst;
        }
        (void) send_ip(ifp->if_fd, ifp->if_MTU, (ip_t *)ipbuffer, gwip, 2);
}


void packet_done(void)
{
        char    outline[80];
        int     i, j, k;
        u_char  *s = (u_char *)ipbuffer, *t = (u_char *)outline;

        if (opts & OPT_VERBOSE) {
                ip->ip_len = htons(ip->ip_len);
                for (i = ntohs(ip->ip_len), j = 0; i; i--, j++, s++) {
                        if (j && !(j & 0xf)) {
                                *t++ = '\n';
                                *t = '\0';
                                fputs(outline, stdout);
                                fflush(stdout);
                                t = (u_char *)outline;
                                *t = '\0';
                        }
                        sprintf((char *)t, "%02x", *s & 0xff);
                        t += 2;
                        if (!((j + 1) & 0xf)) {
                                s -= 15;
                                sprintf((char *)t, "    ");
                                t += 8;
                                for (k = 16; k; k--, s++)
                                        *t++ = (isprint(*s) ? *s : '.');
                                s--;
                        }

                        if ((j + 1) & 0xf)
                                *t++ = ' ';;
                }

                if (j & 0xf) {
                        for (k = 16 - (j & 0xf); k; k--) {
                                *t++ = ' ';
                                *t++ = ' ';
                                *t++ = ' ';
                        }
                        sprintf((char *)t, "       ");
                        t += 7;
                        s -= j & 0xf;
                        for (k = j & 0xf; k; k--, s++)
                                *t++ = (isprint(*s) ? *s : '.');
                        *t++ = '\n';
                        *t = '\0';
                }
                fputs(outline, stdout);
                fflush(stdout);
                ip->ip_len = ntohs(ip->ip_len);
        }

        prep_packet();
        free_aniplist();
}


void new_interface(void)
{
        cifp = (iface_t *)calloc(1, sizeof(iface_t));
        *iftail = cifp;
        iftail = &cifp->if_next;
        cifp->if_fd = -1;
}


void check_interface(void)
{
        if (!cifp->if_name || !*cifp->if_name)
                fprintf(stderr, "No interface name given!\n");
        if (!cifp->if_MTU || !*cifp->if_name)
                fprintf(stderr, "Interface %s has an MTU of 0!\n",
                        cifp->if_name);
}


void set_ifname(char **arg)
{
        cifp->if_name = *arg;
        *arg = NULL;
}


void set_ifmtu(int arg)
{
        cifp->if_MTU = arg;
}


void set_ifv4addr(char **arg)
{
        cifp->if_addr = getipv4addr(*arg);
        free(*arg);
        *arg = NULL;
}


void set_ifeaddr(char **arg)
{
        (void) geteaddr(*arg, &cifp->if_eaddr);
        free(*arg);
        *arg = NULL;
}


void new_arp(void)
{
        carp = (arp_t *)calloc(1, sizeof(arp_t));
        *arptail = carp;
        arptail = &carp->arp_next;
}


void set_arpeaddr(char **arg)
{
        (void) geteaddr(*arg, &carp->arp_eaddr);
        free(*arg);
        *arg = NULL;
}


void set_arpv4addr(char **arg)
{
        carp->arp_addr = getipv4addr(*arg);
        free(*arg);
        *arg = NULL;
}


int arp_getipv4(char *ip, char *addr)
{
        arp_t *a;

        for (a = arplist; a; a = a->arp_next)
                if (!bcmp(ip, (char *)&a->arp_addr, 4)) {
                        bcopy((char *)&a->arp_eaddr, addr, 6);
                        return(0);
                }
        return(-1);
}


void reset_send(void)
{
        sending.snd_if = iflist;
        sending.snd_gw = defrouter;
}


void set_sendif(char **arg)
{
        iface_t *ifp;

        for (ifp = iflist; ifp; ifp = ifp->if_next)
                if (ifp->if_name && !strcmp(ifp->if_name, *arg))
                        break;
        sending.snd_if = ifp;
        if (!ifp)
                fprintf(stderr, "couldn't find interface %s\n", *arg);
        free(*arg);
        *arg = NULL;
}


void set_sendvia(char **arg)
{
        sending.snd_gw = getipv4addr(*arg);
        free(*arg);
        *arg = NULL;
}


void set_defaultrouter(char **arg)
{
        defrouter = getipv4addr(*arg);
        free(*arg);
        *arg = NULL;
}


void new_icmpheader(void)
{
        if ((ip->ip_p) && (ip->ip_p != IPPROTO_ICMP)) {
                fprintf(stderr, "protocol %d specified with ICMP!\n",
                        ip->ip_p);
                return;
        }
        ip->ip_p = IPPROTO_ICMP;
        icmp = (icmphdr_t *)new_header(IPPROTO_ICMP);
}


void set_icmpcode(int code)
{
        icmp->icmp_code = code;
}


void set_icmptype(int type)
{
        icmp->icmp_type = type;
}


void set_icmpcodetok(char **code)
{
        char    *s;
        int     i;

        for (i = 0; (s = icmpcodes[i]); i++)
                if (!strcmp(s, *code)) {
                        icmp->icmp_code = i;
                        break;
                }
        if (!s)
                fprintf(stderr, "unknown ICMP code %s\n", *code);
        free(*code);
        *code = NULL;
}


void set_icmptypetok(char **type)
{
        char    *s;
        int     i, done = 0;

        for (i = 0; !(s = icmptypes[i]) || strcmp(s, "END"); i++)
                if (s && !strcmp(s, *type)) {
                        icmp->icmp_type = i;
                        done = 1;
                        break;
                }
        if (!done)
                fprintf(stderr, "unknown ICMP type %s\n", *type);
        free(*type);
        *type = NULL;
}


void set_icmpid(int arg)
{
        icmp->icmp_id = htons(arg);
}


void set_icmpseq(int arg)
{
        icmp->icmp_seq = htons(arg);
}


void set_icmpotime(int arg)
{
        icmp->icmp_otime = htonl(arg);
}


void set_icmprtime(int arg)
{
        icmp->icmp_rtime = htonl(arg);
}


void set_icmpttime(int arg)
{
        icmp->icmp_ttime = htonl(arg);
}


void set_icmpmtu(int arg)
{
        icmp->icmp_nextmtu = htons(arg);
}


void set_redir(int redir, char **arg)
{
        icmp->icmp_code = redir;
        icmp->icmp_gwaddr = getipv4addr(*arg);
        free(*arg);
        *arg = NULL;
}


void set_icmppprob(int num)
{
        icmp->icmp_pptr = num;
}


void new_ipv4opt(void)
{
        new_header(-2);
}


void add_ipopt(int state, void *ptr)
{
        struct ipopt_names *io;
        struct statetoopt *sto;
        char numbuf[16], *arg, **param = ptr;
        int inc, hlen;

        if (state == IL_IPO_RR || state == IL_IPO_SATID) {
                if (param)
                        snprintf(numbuf, sizeof(numbuf), "%d", *(int *)param);
                else
                        strcpy(numbuf, "0");
                arg = numbuf;
        } else
                arg = param ? *param : NULL;

        if (canip->ah_next) {
                fprintf(stderr, "cannot specify options after data body\n");
                return;
        }
        for (sto = toipopts; sto->sto_st; sto++)
                if (sto->sto_st == state)
                        break;
        if (!sto->sto_st) {
                fprintf(stderr, "No mapping for state %d to IP option\n",
                        state);
                return;
        }

        hlen = sizeof(ip_t) + canip->ah_optlen;
        for (io = ionames; io->on_name; io++)
                if (io->on_value == sto->sto_op)
                        break;
        canip->ah_lastopt = io->on_value;

        if (io->on_name) {
                inc = addipopt((char *)ip + hlen, io, hlen - sizeof(ip_t),arg);
                if (inc > 0) {
                        while (inc & 3) {
                                ((char *)ip)[sizeof(*ip) + inc] = IPOPT_NOP;
                                canip->ah_lastopt = IPOPT_NOP;
                                inc++;
                        }
                        hlen += inc;
                }
        }

        canip->ah_optlen = hlen - sizeof(ip_t);

        if (state != IL_IPO_RR && state != IL_IPO_SATID)
                if (param && *param) {
                        free(*param);
                        *param = NULL;
                }
        sclass = NULL;
}


void end_ipopt(void)
{
        int pad;
        char *s, *buf = (char *)ip;

        /*
         * pad out so that we have a multiple of 4 bytes in size fo the
         * options.  make sure last byte is EOL.
         */
        if (canip->ah_lastopt == IPOPT_NOP) {
                buf[sizeof(*ip) + canip->ah_optlen - 1] = IPOPT_EOL;
        } else if (canip->ah_lastopt != IPOPT_EOL) {
                s = buf + sizeof(*ip) + canip->ah_optlen;

                for (pad = 3 - (canip->ah_optlen & 3); pad; pad--) {
                        *s++ = IPOPT_NOP;
                        *s = IPOPT_EOL;
                        canip->ah_optlen++;
                }
                canip->ah_optlen++;
        } else {
                s = buf + sizeof(*ip) + canip->ah_optlen - 1;

                for (pad = 3 - (canip->ah_optlen & 3); pad; pad--) {
                        *s++ = IPOPT_NOP;
                        *s = IPOPT_EOL;
                        canip->ah_optlen++;
                }
        }
        ip->ip_hl = (sizeof(*ip) + canip->ah_optlen) >> 2;
        inc_anipheaders(canip->ah_optlen);
        free_anipheader();
}


void set_secclass(char **arg)
{
        sclass = *arg;
        *arg = NULL;
}


void free_anipheader(void)
{
        aniphdr_t *aip;

        aip = canip;
        if ((canip = aip->ah_prev)) {
                canip->ah_next = NULL;
                aniptail = &canip->ah_next;
        }

        if (canip)
                free(aip);
}


void end_ipv4(void)
{
        aniphdr_t *aip;

        ip->ip_sum = 0;
        ip->ip_len = htons(ip->ip_len);
        ip->ip_sum = chksum((u_short *)ip, ip->ip_hl << 2);
        ip->ip_len = ntohs(ip->ip_len);
        free_anipheader();
        for (aip = aniphead, ip = NULL; aip; aip = aip->ah_next)
                if (aip->ah_p == IPPROTO_IP)
                        ip = aip->ah_ip;
}


void end_icmp(void)
{
        aniphdr_t *aip;

        icmp->icmp_cksum = 0;
        icmp->icmp_cksum = chksum((u_short *)icmp, canip->ah_len);
        free_anipheader();
        for (aip = aniphead, icmp = NULL; aip; aip = aip->ah_next)
                if (aip->ah_p == IPPROTO_ICMP)
                        icmp = aip->ah_icmp;
}


void end_udp(void)
{
        u_long  sum;
        aniphdr_t *aip;
        ip_t    iptmp;

        bzero((char *)&iptmp, sizeof(iptmp));
        iptmp.ip_p = ip->ip_p;
        iptmp.ip_src = ip->ip_src;
        iptmp.ip_dst = ip->ip_dst;
        iptmp.ip_len = htons(ip->ip_len - (ip->ip_hl << 2));
        sum = p_chksum((u_short *)&iptmp, (u_int)sizeof(iptmp));
        udp->uh_ulen = htons(udp->uh_ulen);
        udp->uh_sum = c_chksum((u_short *)udp, (u_int)ntohs(iptmp.ip_len), sum);
        free_anipheader();
        for (aip = aniphead, udp = NULL; aip; aip = aip->ah_next)
                if (aip->ah_p == IPPROTO_UDP)
                        udp = aip->ah_udp;
}


void end_tcp(void)
{
        u_long  sum;
        aniphdr_t *aip;
        ip_t    iptmp;

        bzero((char *)&iptmp, sizeof(iptmp));
        iptmp.ip_p = ip->ip_p;
        iptmp.ip_src = ip->ip_src;
        iptmp.ip_dst = ip->ip_dst;
        iptmp.ip_len = htons(ip->ip_len - (ip->ip_hl << 2));
        sum = p_chksum((u_short *)&iptmp, (u_int)sizeof(iptmp));
        tcp->th_sum = 0;
        tcp->th_sum = c_chksum((u_short *)tcp, (u_int)ntohs(iptmp.ip_len), sum);
        free_anipheader();
        for (aip = aniphead, tcp = NULL; aip; aip = aip->ah_next)
                if (aip->ah_p == IPPROTO_TCP)
                        tcp = aip->ah_tcp;
}


void end_data(void)
{
        free_anipheader();
}


void iplang(FILE *fp)
{
        yyin = fp;

        yydebug = (opts & OPT_DEBUG) ? 1 : 0;

        while (!feof(fp))
                yyparse();
}


u_short c_chksum(u_short *buf, u_int len, u_long init)
{
        u_long  sum = init;
        int     nwords = len >> 1;

        for(; nwords > 0; nwords--)
                sum += *buf++;
        sum = (sum>>16) + (sum & 0xffff);
        sum += (sum >>16);
        return(~sum);
}


u_long  p_chksum(u_short *buf, u_int len)
{
        u_long  sum = 0;
        int     nwords = len >> 1;

        for(; nwords > 0; nwords--)
                sum += *buf++;
        return(sum);
}