lib/masq_info.c

   1 /*
   2  * lib/masq_info.c    This file contains a the functio masq_info
   3  *                      to print a table of current masquerade connections.
   4  *
   5  * NET-LIB      A collection of functions used from the base set of the
   6  *              NET-3 Networking Distribution for the LINUX operating
   7  *              system. (net-tools, net-drivers)
   8  *
   9  * Version:     $Id: masq_info.c,v 1.7 2000/10/08 01:00:44 ecki Exp $
  10  *
  11  * Author:      Bernd 'eckes' Eckenfels <net-tools@lina.inka.de>
  12  *              Copyright 1999 Bernd Eckenfels, Germany
  13  *
  14  * Modifications:
  15  *
  16  *960217 {0.01} Bernd Eckenfels:        creatin from the code of
  17  *                                      Jos Vos' ipfwadm 2.0beta1
  18  *950218 {0.02} Bernd Eckenfels:        <linux/if.h> added
  19  *
  20  *980405 {0.03} Arnaldo Carvalho:       i18n CATGETS -> gettext
  21  *
  22  *              This program is free software; you can redistribute it
  23  *              and/or  modify it under  the terms of  the GNU General
  24  *              Public  License as  published  by  the  Free  Software
  25  *              Foundation;  either  version 2 of the License, or  (at
  26  *              your option) any later version.
  27  */
  28 #include <sys/types.h>
  29 #include <sys/socket.h>
  30 #include <netinet/in.h>
  31 #include <arpa/inet.h>
  32 #include <errno.h>
  33 #include <stdio.h>
  34 #include <malloc.h>
  35 #include <string.h>
  36 #include <unistd.h>
  37 #include "net-support.h"
  38 #include "pathnames.h"
  39 #include "version.h"
  40 #include "config.h"
  41 #include "intl.h"
  42 #include "net-features.h"
  43
  44 #if HAVE_FW_MASQUERADE
  45
  46 struct masq {
  47     unsigned long expires;      /* Expiration timer */
  48     char *proto;                /* Which protocol are we talking? */
  49     struct sockaddr_in src, dst;        /* Source and destination IP addresses */
  50     unsigned short sport, dport;        /* Source and destination ports */
  51     unsigned short mport;       /* Masqueraded port */
  52     unsigned long initseq;      /* Add delta from this seq. on */
  53     short delta;                /* Delta in sequence numbers */
  54     short pdelta;               /* Delta in sequence numbers before last */
  55 };
  56
  57 static struct aftype *ap;       /* current address family       */
  58 static int has_pdelta;
  59
  60 static void print_masq(struct masq *ms, int numeric_host, int numeric_port,
  61                        int ext)
  62 {
  63     unsigned long minutes, seconds, sec100s;
  64
  65     printf("%-4s", ms->proto);
  66
  67     sec100s = ms->expires % 100L;
  68     seconds = (ms->expires / 100L) % 60;
  69     minutes = ms->expires / 6000L;
  70
  71     printf("%3ld:%02ld.%02ld ", minutes, seconds, sec100s);
  72
  73     if (ext > 1) {
  74         if (has_pdelta)
  75             printf("%10lu %5hd %5hd ", ms->initseq,
  76                    ms->delta, ms->pdelta);
  77         else
  78             printf("%10lu %5hd     - ", ms->initseq,
  79                    ms->delta);
  80     }
  81     printf("%-20s ", ap->sprint((struct sockaddr *) &(ms->src), numeric_host));
  82     printf("%-20s ", ap->sprint((struct sockaddr *) &(ms->dst), numeric_host));
  83
  84     printf("%s -> ", get_sname(ms->sport, ms->proto, numeric_port));
  85     printf("%s", get_sname(ms->dport, ms->proto, numeric_port));
  86     printf(" (%s)\n", get_sname(ms->mport, ms->proto, numeric_port));
  87 }
  88
  89
  90 static int read_masqinfo(FILE * f, struct masq *mslist, int nmslist)
  91 {
  92     int n, nread = 0;
  93     struct masq *ms;
  94     char buf[256];
  95
  96     for (nread = 0; nread < nmslist; nread++) {
  97         ms = &mslist[nread];
  98         if (has_pdelta) {
  99             if ((n = fscanf(f, " %s %lX:%hX %lX:%hX %hX %lX %hd %hd %lu",
 100                             buf,
 101                   (unsigned long *) &ms->src.sin_addr.s_addr, &ms->sport,
 102                   (unsigned long *) &ms->dst.sin_addr.s_addr, &ms->dport,
 103                             &ms->mport, &ms->initseq, &ms->delta,
 104                             &ms->pdelta, &ms->expires)) == -1)
 105                 return nread;
 106         } else {
 107             if ((n = fscanf(f, " %s %lX:%hX %lX:%hX %hX %lX %hd %lu",
 108                             buf,
 109                   (unsigned long *) &ms->src.sin_addr.s_addr, &ms->sport,
 110                   (unsigned long *) &ms->dst.sin_addr.s_addr, &ms->dport,
 111                             &ms->mport, &ms->initseq, &ms->delta,
 112                             &ms->expires)) == -1)
 113                 return nread;
 114         }
 115         if ((has_pdelta && (n != 10)) || (!has_pdelta && (n != 9))) {
 116             EINTERN("masq_info.c", "ip_masquerade format error");
 117             return (-1);
 118         }
 119         ms->src.sin_family = AF_INET;
 120         ms->dst.sin_family = AF_INET;
 121
 122         if (strcmp("TCP", buf) == 0)
 123             ms->proto = "tcp";
 124         else if (strcmp("UDP", buf) == 0)
 125             ms->proto = "udp";
 126         else if (strcmp("ICMP", buf) == 0)
 127             ms->proto = "icmp";
 128         else if (strcmp("GRE", buf) == 0)
 129             ms->proto = "gre";
 130         else if (strcmp("ESP", buf) == 0)
 131             ms->proto = "esp";
 132         else {
 133             EINTERN("masq_info.c", "ip_masquerade unknown type");
 134             return (-1);
 135         }
 136
 137         /* we always keep these addresses in network byte order */
 138         ms->src.sin_addr.s_addr = htonl(ms->src.sin_addr.s_addr);
 139         ms->dst.sin_addr.s_addr = htonl(ms->dst.sin_addr.s_addr);
 140         ms->sport = htons(ms->sport);
 141         ms->dport = htons(ms->dport);
 142         ms->mport = htons(ms->mport);
 143     }
 144     return nread;
 145 }
 146
 147
 148 int ip_masq_info(int numeric_host, int numeric_port, int ext)
 149 {
 150     FILE *f;
 151     int i;
 152     char buf[256];
 153     struct masq *mslist;
 154     int ntotal = 0, nread;
 155
 156     if (!(f = fopen(_PATH_PROCNET_IP_MASQ, "r"))) {
 157         if (errno != ENOENT) {
 158             perror(_PATH_PROCNET_IP_MASQ);
 159             return (-1);
 160         }
 161         ESYSNOT("netstat", "ip_masquerade");
 162         return (1);
 163     }
 164     if ((ap = get_aftype("inet")) == NULL) {
 165         ENOSUPP("masq_info", "AF INET");
 166         fclose(f);
 167         return (-1);
 168     }
 169     fgets(buf, sizeof(buf), f);
 170     has_pdelta = strstr(buf, "PDelta") ? 1 : 0;
 171
 172     mslist = (struct masq *) malloc(16 * sizeof(struct masq));
 173     if (!mslist) {
 174         EINTERN("masq_info", "malloc() failed");
 175         fclose(f);
 176         return (-1);
 177     }
 178     while ((nread = read_masqinfo(f, &(mslist[ntotal]), 16)) == 16) {
 179         ntotal += nread;
 180         mslist = (struct masq *) realloc(mslist,
 181                                     (ntotal + 16) * sizeof(struct masq));
 182         if (!mslist) {
 183             EINTERN("masq_info", "realloc() failed");
 184             fclose(f);
 185             return (-1);
 186         }
 187     }
 188     fclose(f);
 189
 190     if (nread < 0) {
 191         if (mslist)
 192             free(mslist);
 193         return (-1);
 194     }
 195     ntotal += nread;
 196
 197     if (ntotal > 0) {
 198         printf(_("IP masquerading entries\n"));
 199         switch (ext) {
 200         case 1:
 201             printf(_("prot   expire source               destination          ports\n"));
 202             break;
 203         default:
 204             printf(_("prot   expire    initseq delta prevd source               destination          ports\n"));
 205             break;
 206         }
 207         for (i = 0; i < ntotal; i++)
 208             print_masq(&(mslist[i]), numeric_host, numeric_port, ext);
 209         if (mslist)
 210             free(mslist);
 211
 212     }
 213     return 0;
 214 }
 215 #endif