root/usr/src/cmd/ipf/lib/ipft_tx.c
/*
 * Copyright (C) 1995-2001 by Darren Reed.
 *
 * See the IPFILTER.LICENCE file for details on licencing.
 *
 * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#if !defined(lint)
static const char sccsid[] = "@(#)ipft_tx.c     1.7 6/5/96 (C) 1993 Darren Reed";
static const char rcsid[] = "@(#)$Id: ipft_tx.c,v 1.15.2.3 2005/06/18 02:41:34 darrenr Exp $";
#endif

#include <ctype.h>

#include "ipf.h"
#include "ipt.h"

#ifndef linux
#include <netinet/ip_var.h>
#endif
#include <netinet/tcpip.h>


extern  int     opts;

static  char    *tx_proto = "";

static  int     text_open __P((char *)), text_close __P((void));
static  int     text_readip __P((char *, int, char **, int *));
static  int     parseline __P((char *, ip_t *, char **, int *));

static  char    myflagset[] = "FSRPAUEC";
static  u_char  myflags[] = { TH_FIN, TH_SYN, TH_RST, TH_PUSH,
                                TH_ACK, TH_URG, TH_ECN, TH_CWR };

struct  ipread  iptext = { text_open, text_close, text_readip, R_DO_CKSUM };
static  FILE    *tfp = NULL;
static  int     tfd = -1;

static  u_32_t  tx_hostnum __P((char *, int *));
static  u_short tx_portnum __P((char *));


/*
 * returns an ip address as a long var as a result of either a DNS lookup or
 * straight inet_addr() call
 */
static  u_32_t  tx_hostnum(host, resolved)
char    *host;
int     *resolved;
{
        i6addr_t ipa;

        *resolved = 0;
        if (!strcasecmp("any", host))
                return 0L;
        if (ISDIGIT(*host))
                return inet_addr(host);

        if (gethost(host, &ipa, 0) == -1) {
                *resolved = -1;
                fprintf(stderr, "can't resolve hostname: %s\n", host);
                return 0;
        }
        return ipa.in4_addr;
}


/*
 * find the port number given by the name, either from getservbyname() or
 * straight atoi()
 */
static  u_short tx_portnum(name)
char    *name;
{
        struct  servent *sp, *sp2;
        u_short p1 = 0;

        if (ISDIGIT(*name))
                return (u_short)atoi(name);
        if (!tx_proto)
                tx_proto = "tcp/udp";
        if (strcasecmp(tx_proto, "tcp/udp")) {
                sp = getservbyname(name, tx_proto);
                if (sp)
                        return ntohs(sp->s_port);
                (void) fprintf(stderr, "unknown service \"%s\".\n", name);
                return 0;
        }
        sp = getservbyname(name, "tcp");
        if (sp)
                p1 = sp->s_port;
        sp2 = getservbyname(name, "udp");
        if (!sp || !sp2) {
                (void) fprintf(stderr, "unknown tcp/udp service \"%s\".\n",
                        name);
                return 0;
        }
        if (p1 != sp2->s_port) {
                (void) fprintf(stderr, "%s %d/tcp is a different port to ",
                        name, p1);
                (void) fprintf(stderr, "%s %d/udp\n", name, sp->s_port);
                return 0;
        }
        return ntohs(p1);
}


char    *tx_icmptypes[] = {
        "echorep", (char *)NULL, (char *)NULL, "unreach", "squench",
        "redir", (char *)NULL, (char *)NULL, "echo", "routerad",
        "routersol", "timex", "paramprob", "timest", "timestrep",
        "inforeq", "inforep", "maskreq", "maskrep", "END"
};

static  int     text_open(fname)
char    *fname;
{
        if (tfp && tfd != -1) {
                rewind(tfp);
                return tfd;
        }

        if (!strcmp(fname, "-")) {
                tfd = 0;
                tfp = stdin;
        } else {
                tfd = open(fname, O_RDONLY);
                if (tfd != -1)
                        tfp = fdopen(tfd, "r");
        }
        return tfd;
}


static  int     text_close()
{
        int     cfd = tfd;

        tfd = -1;
        return close(cfd);
}


static  int     text_readip(buf, cnt, ifn, dir)
char    *buf, **ifn;
int     cnt, *dir;
{
        register char *s;
        char    line[513];

        *ifn = NULL;
        while (fgets(line, sizeof(line)-1, tfp)) {
                if ((s = strchr(line, '\n')))
                        *s = '\0';
                if ((s = strchr(line, '\r')))
                        *s = '\0';
                if ((s = strchr(line, '#')))
                        *s = '\0';
                if (!*line)
                        continue;
                if (!(opts & OPT_BRIEF))
                        printf("input: %s\n", line);
                *ifn = NULL;
                *dir = 0;
                if (!parseline(line, (ip_t *)buf, ifn, dir))
#if 0
                        return sizeof(ip_t) + sizeof(tcphdr_t);
#else
                        return sizeof(ip_t);
#endif
        }
        return -1;
}

static  int     parseline(line, ip, ifn, out)
char    *line;
ip_t    *ip;
char    **ifn;
int     *out;
{
        tcphdr_t        th, *tcp = &th;
        struct  icmp    icmp, *ic = &icmp;
        char    *cps[20], **cpp, c, ipopts[68];
        int     i, r;

        if (*ifn)
                free(*ifn);
        bzero((char *)ip, MAX(sizeof(*tcp), sizeof(*ic)) + sizeof(*ip));
        bzero((char *)tcp, sizeof(*tcp));
        bzero((char *)ic, sizeof(*ic));
        bzero(ipopts, sizeof(ipopts));
        IP_HL_A(ip, sizeof(*ip) >> 2);
        IP_V_A(ip, IPVERSION);
        for (i = 0, cps[0] = strtok(line, " \b\t\r\n"); cps[i] && i < 19; )
                cps[++i] = strtok(NULL, " \b\t\r\n");

        cpp = cps;
        if (!*cpp)
                return 1;

        c = **cpp;
        if (!ISALPHA(c) || (TOLOWER(c) != 'o' && TOLOWER(c) != 'i')) {
                fprintf(stderr, "bad direction \"%s\"\n", *cpp);
                return 1;
        }
        *out = (TOLOWER(c) == 'o') ? 1 : 0;
        cpp++;
        if (!*cpp)
                return 1;

        if (!strcasecmp(*cpp, "on")) {
                cpp++;
                if (!*cpp)
                        return 1;
                *ifn = strdup(*cpp++);
                if (!*cpp)
                        return 1;
        }

        c = **cpp;
        ip->ip_len = sizeof(ip_t);
        if (!strcasecmp(*cpp, "tcp") || !strcasecmp(*cpp, "udp") ||
            !strcasecmp(*cpp, "icmp")) {
                if (c == 't') {
                        ip->ip_p = IPPROTO_TCP;
                        ip->ip_len += sizeof(struct tcphdr);
                        tx_proto = "tcp";
                } else if (c == 'u') {
                        ip->ip_p = IPPROTO_UDP;
                        ip->ip_len += sizeof(struct udphdr);
                        tx_proto = "udp";
                } else {
                        ip->ip_p = IPPROTO_ICMP;
                        ip->ip_len += ICMPERR_IPICMPHLEN;
                        tx_proto = "icmp";
                }
                cpp++;
        } else if (ISDIGIT(**cpp) && !index(*cpp, '.')) {
                ip->ip_p = atoi(*cpp);
                cpp++;
        } else
                ip->ip_p = IPPROTO_IP;

        if (!*cpp)
                return 1;
        if (ip->ip_p == IPPROTO_TCP || ip->ip_p == IPPROTO_UDP) {
                char    *last;

                last = strchr(*cpp, ',');
                if (!last) {
                        fprintf(stderr, "tcp/udp with no source port\n");
                        return 1;
                }
                *last++ = '\0';
                tcp->th_sport = htons(tx_portnum(last));
                if (ip->ip_p == IPPROTO_TCP) {
                        tcp->th_win = htons(4096);
                        TCP_OFF_A(tcp, sizeof(*tcp) >> 2);
                }
        }
        ip->ip_src.s_addr = tx_hostnum(*cpp, &r);
        cpp++;
        if (!*cpp)
                return 1;

        if (ip->ip_p == IPPROTO_TCP || ip->ip_p == IPPROTO_UDP) {
                char    *last;

                last = strchr(*cpp, ',');
                if (!last) {
                        fprintf(stderr, "tcp/udp with no destination port\n");
                        return 1;
                }
                *last++ = '\0';
                tcp->th_dport = htons(tx_portnum(last));
        }
        ip->ip_dst.s_addr = tx_hostnum(*cpp, &r);
        cpp++;
        if (*cpp && ip->ip_p == IPPROTO_TCP) {
                char    *s, *t;

                tcp->th_flags = 0;
                for (s = *cpp; *s; s++)
                        if ((t  = strchr(myflagset, *s)))
                                tcp->th_flags |= myflags[t - myflagset];
                if (tcp->th_flags)
                        cpp++;
                if (tcp->th_flags == 0)
                        abort();
                if (tcp->th_flags & TH_URG)
                        tcp->th_urp = htons(1);
        } else if (*cpp && ip->ip_p == IPPROTO_ICMP) {
                extern  char    *tx_icmptypes[];
                char    **s, *t;
                int     i;

                for (s = tx_icmptypes, i = 0; !*s || strcmp(*s, "END");
                     s++, i++)
                        if (*s && !strncasecmp(*cpp, *s, strlen(*s))) {
                                ic->icmp_type = i;
                                if ((t = strchr(*cpp, ',')))
                                        ic->icmp_code = atoi(t+1);
                                cpp++;
                                break;
                        }
        }

        if (*cpp && !strcasecmp(*cpp, "opt")) {
                u_long  olen;

                cpp++;
                olen = buildopts(*cpp, ipopts, (IP_HL(ip) - 5) << 2);
                if (olen) {
                        bcopy(ipopts, (char *)(ip + 1), olen);
                        IP_HL_A(ip, IP_HL(ip) + (olen >> 2));
                }
        }
        if (ip->ip_p == IPPROTO_TCP || ip->ip_p == IPPROTO_UDP)
                bcopy((char *)tcp, ((char *)ip) + (IP_HL(ip) << 2),
                        sizeof(*tcp));
        else if (ip->ip_p == IPPROTO_ICMP)
                bcopy((char *)ic, ((char *)ip) + (IP_HL(ip) << 2),
                        sizeof(*ic));
        ip->ip_len = htons(ip->ip_len);
        return 0;
}