lib/inet.c

   1 /*
   2  * lib/inet.c This file contains an implementation of the "INET"
   3  *              support functions for the net-tools.
   4  *              (NET-3 base distribution).
   5  *
   6  * Version:    $Id: inet.c,v 1.13 1999/12/11 13:35:56 freitag Exp $
   7  *
   8  * Author:      Fred N. van Kempen, <waltje@uwalt.nl.mugnet.org>
   9  *              Copyright 1993 MicroWalt Corporation
  10  *
  11  * Modified:
  12  *960113 {1.21} Bernd Eckenfels :       rresolve cache bug.
  13  *960128 {1.22} Bernd Eckenfels :       endian bug in print
  14  *960203 {1.23} Bernd Eckenfels :       net-features support
  15  *960217 {1.24} Bernd Eckenfels :       get_sname
  16  *960219 {1.25} Bernd Eckenfels :       extern int h_errno
  17  *960329 {1.26} Bernd Eckenfels :       resolve 255.255.255.255
  18  *980101 {1.27} Bernd Eckenfels :       resolve raw sockets in /etc/protocols
  19  *990302 {1.28} Phil Blundell   :       add netmask to INET_rresolve
  20  *991007        Kurt Garloff    :       rresolve, resolve: may be hosts
  21  *              <garloff@suse.de>       store type (host?) in cache
  22  *
  23  *              This program is free software; you can redistribute it
  24  *              and/or  modify it under  the terms of  the GNU General
  25  *              Public  License as  published  by  the  Free  Software
  26  *              Foundation;  either  version 2 of the License, or  (at
  27  *              your option) any later version.
  28  */
  29 #include "config.h"
  30
  31 /* FIXME.  Split this file into inet4.c for the IPv4 specific parts
  32    and inet.c for those shared between IPv4 and IPv6.  */
  33
  34 #if HAVE_AFINET || HAVE_AFINET6
  35 #include <netinet/in.h>
  36 #include <sys/types.h>
  37 #include <sys/socket.h>
  38 #include <arpa/inet.h>
  39 #include <arpa/nameser.h>
  40 #include <ctype.h>
  41 #include <errno.h>
  42 #include <netdb.h>
  43 #include <resolv.h>
  44 #include <stdlib.h>
  45 #include <string.h>
  46 #include <stdio.h>
  47 #include <unistd.h>
  48 #include "version.h"
  49 #include "net-support.h"
  50 #include "pathnames.h"
  51 #include "intl.h"
  52 #include "util.h"
  53
  54 extern int h_errno;             /* some netdb.h versions don't export this */
  55
  56 /* cache */
  57 struct addr {
  58     struct sockaddr_in addr;
  59     char *name;
  60     int host;
  61     struct addr *next;
  62 };
  63
  64 struct service {
  65     int number;
  66     char *name;
  67     struct service *next;
  68 };
  69
  70 static struct service *tcp_name = NULL, *udp_name = NULL, *raw_name = NULL;
  71
  72 #if HAVE_AFINET
  73
  74 static struct addr *INET_nn = NULL;     /* addr-to-name cache           */
  75
  76
  77 static int INET_resolve(char *name, struct sockaddr_in *sin, int hostfirst)
  78 {
  79     struct hostent *hp;
  80     struct netent *np;
  81
  82     /* Grmpf. -FvK */
  83     sin->sin_family = AF_INET;
  84     sin->sin_port = 0;
  85
  86     /* Default is special, meaning 0.0.0.0. */
  87     if (!strcmp(name, "default")) {
  88         sin->sin_addr.s_addr = INADDR_ANY;
  89         return (1);
  90     }
  91     /* Look to see if it's a dotted quad. */
  92     if (inet_aton(name, &sin->sin_addr)) {
  93         return 0;
  94     }
  95     /* If we expect this to be a hostname, try hostname database first */
  96 #ifdef DEBUG
  97     if (hostfirst) fprintf (stderr, "gethostbyname (%s)\n", name);
  98 #endif
  99     if (hostfirst &&
 100         (hp = gethostbyname(name)) != (struct hostent *) NULL) {
 101         memcpy((char *) &sin->sin_addr, (char *) hp->h_addr_list[0],
 102                 sizeof(struct in_addr));
 103         return 0;
 104     }
 105     /* Try the NETWORKS database to see if this is a known network. */
 106 #ifdef DEBUG
 107     fprintf (stderr, "getnetbyname (%s)\n", name);
 108 #endif
 109     if ((np = getnetbyname(name)) != (struct netent *) NULL) {
 110         sin->sin_addr.s_addr = htonl(np->n_net);
 111         return 1;
 112     }
 113     if (hostfirst) {
 114         /* Don't try again */
 115         errno = h_errno;
 116         return -1;
 117     }
 118 #ifdef DEBUG
 119     res_init();
 120     _res.options |= RES_DEBUG;
 121 #endif
 122
 123 #ifdef DEBUG
 124     fprintf (stderr, "gethostbyname (%s)\n", name);
 125 #endif
 126     if ((hp = gethostbyname(name)) == (struct hostent *) NULL) {
 127         errno = h_errno;
 128         return -1;
 129     }
 130     memcpy((char *) &sin->sin_addr, (char *) hp->h_addr_list[0],
 131            sizeof(struct in_addr));
 132
 133     return 0;
 134 }
 135
 136
 137 /* numeric: & 0x8000: default instead of *,
 138  *          & 0x4000: host instead of net,
 139  *          & 0x0fff: don't resolve
 140  */
 141 static int INET_rresolve(char *name, size_t len, struct sockaddr_in *sin,
 142                          int numeric, unsigned int netmask)
 143 {
 144     struct hostent *ent;
 145     struct netent *np;
 146     struct addr *pn;
 147     unsigned long ad, host_ad;
 148     int host = 0;
 149
 150     /* Grmpf. -FvK */
 151     if (sin->sin_family != AF_INET) {
 152 #ifdef DEBUG
 153         fprintf(stderr, _("rresolve: unsupport address family %d !\n"), sin->sin_family);
 154 #endif
 155         errno = EAFNOSUPPORT;
 156         return (-1);
 157     }
 158     ad = (unsigned long) sin->sin_addr.s_addr;
 159 #ifdef DEBUG
 160     fprintf (stderr, "rresolve: %08lx, mask %08x, num %08x \n", ad, netmask, numeric);
 161 #endif
 162     if (ad == INADDR_ANY) {
 163         if ((numeric & 0x0FFF) == 0) {
 164             if (numeric & 0x8000)
 165                 safe_strncpy(name, "default", len);
 166             else
 167                 safe_strncpy(name, "*", len);
 168             return (0);
 169         }
 170     }
 171     if (numeric & 0x0FFF) {
 172         safe_strncpy(name, inet_ntoa(sin->sin_addr), len);
 173         return (0);
 174     }
 175
 176     if ((ad & (~netmask)) != 0 || (numeric & 0x4000))
 177         host = 1;
 178 #if 0
 179     INET_nn = NULL;
 180 #endif
 181     pn = INET_nn;
 182     while (pn != NULL) {
 183         if (pn->addr.sin_addr.s_addr == ad && pn->host == host) {
 184             safe_strncpy(name, pn->name, len);
 185 #ifdef DEBUG
 186             fprintf (stderr, "rresolve: found %s %08lx in cache\n", (host? "host": "net"), ad);
 187 #endif
 188             return (0);
 189         }
 190         pn = pn->next;
 191     }
 192
 193     host_ad = ntohl(ad);
 194     np = NULL;
 195     ent = NULL;
 196     if (host) {
 197 #ifdef DEBUG
 198         fprintf (stderr, "gethostbyaddr (%08lx)\n", ad);
 199 #endif
 200         ent = gethostbyaddr((char *) &ad, 4, AF_INET);
 201         if (ent != NULL)
 202             safe_strncpy(name, ent->h_name, len);
 203     } else {
 204 #ifdef DEBUG
 205         fprintf (stderr, "getnetbyaddr (%08lx)\n", host_ad);
 206 #endif
 207         np = getnetbyaddr(host_ad, AF_INET);
 208         if (np != NULL)
 209             safe_strncpy(name, np->n_name, len);
 210     }
 211     if ((ent == NULL) && (np == NULL))
 212         safe_strncpy(name, inet_ntoa(sin->sin_addr), len);
 213     pn = (struct addr *) malloc(sizeof(struct addr));
 214     pn->addr = *sin;
 215     pn->next = INET_nn;
 216     pn->host = host;
 217     pn->name = (char *) malloc(strlen(name) + 1);
 218     strcpy(pn->name, name);
 219     INET_nn = pn;
 220
 221     return (0);
 222 }
 223
 224
 225 static void INET_reserror(char *text)
 226 {
 227     herror(text);
 228 }
 229
 230
 231 /* Display an Internet socket address. */
 232 static char *INET_print(unsigned char *ptr)
 233 {
 234     return (inet_ntoa((*(struct in_addr *) ptr)));
 235 }
 236
 237
 238 /* Display an Internet socket address. */
 239 static char *INET_sprint(struct sockaddr *sap, int numeric)
 240 {
 241     static char buff[128];
 242
 243     if (sap->sa_family == 0xFFFF || sap->sa_family == 0)
 244         return safe_strncpy(buff, _("[NONE SET]"), sizeof(buff));
 245
 246     if (INET_rresolve(buff, sizeof(buff), (struct sockaddr_in *) sap,
 247                       numeric, 0xffffff00) != 0)
 248         return (NULL);
 249
 250     return (buff);
 251 }
 252
 253 char *INET_sprintmask(struct sockaddr *sap, int numeric,
 254                       unsigned int netmask)
 255 {
 256     static char buff[128];
 257
 258     if (sap->sa_family == 0xFFFF || sap->sa_family == 0)
 259         return safe_strncpy(buff, _("[NONE SET]"), sizeof(buff));
 260     if (INET_rresolve(buff, sizeof(buff), (struct sockaddr_in *) sap,
 261                       numeric, netmask) != 0)
 262         return (NULL);
 263     return (buff);
 264 }
 265
 266
 267 static int INET_getsock(char *bufp, struct sockaddr *sap)
 268 {
 269     char *sp = bufp, *bp;
 270     unsigned int i;
 271     unsigned val;
 272     struct sockaddr_in *sin;
 273
 274     sin = (struct sockaddr_in *) sap;
 275     sin->sin_family = AF_INET;
 276     sin->sin_port = 0;
 277
 278     val = 0;
 279     bp = (char *) &val;
 280     for (i = 0; i < sizeof(sin->sin_addr.s_addr); i++) {
 281         *sp = toupper(*sp);
 282
 283         if ((*sp >= 'A') && (*sp <= 'F'))
 284             bp[i] |= (int) (*sp - 'A') + 10;
 285         else if ((*sp >= '0') && (*sp <= '9'))
 286             bp[i] |= (int) (*sp - '0');
 287         else
 288             return (-1);
 289
 290         bp[i] <<= 4;
 291         sp++;
 292         *sp = toupper(*sp);
 293
 294         if ((*sp >= 'A') && (*sp <= 'F'))
 295             bp[i] |= (int) (*sp - 'A') + 10;
 296         else if ((*sp >= '0') && (*sp <= '9'))
 297             bp[i] |= (int) (*sp - '0');
 298         else
 299             return (-1);
 300
 301         sp++;
 302     }
 303     sin->sin_addr.s_addr = htonl(val);
 304
 305     return (sp - bufp);
 306 }
 307
 308 static int INET_input(int type, char *bufp, struct sockaddr *sap)
 309 {
 310     switch (type) {
 311     case 1:
 312         return (INET_getsock(bufp, sap));
 313     case 256:
 314         return (INET_resolve(bufp, (struct sockaddr_in *) sap, 1));
 315     default:
 316         return (INET_resolve(bufp, (struct sockaddr_in *) sap, 0));
 317     }
 318 }
 319
 320 static int INET_getnetmask(char *adr, struct sockaddr *m, char *name)
 321 {
 322     struct sockaddr_in *mask = (struct sockaddr_in *) m;
 323     char *slash, *end;
 324     int prefix;
 325
 326     if ((slash = strchr(adr, '/')) == NULL)
 327         return 0;
 328
 329     *slash++ = '\0';
 330     prefix = strtoul(slash, &end, 0);
 331     if (*end != '\0')
 332         return -1;
 333
 334     if (name) {
 335         sprintf(name, "/%d", prefix);
 336     }
 337     mask->sin_family = AF_INET;
 338     mask->sin_addr.s_addr = htonl(~(0xffffffffU >> prefix));
 339     return 1;
 340 }
 341
 342
 343 struct aftype inet_aftype =
 344 {
 345     "inet", NULL, /*"DARPA Internet", */ AF_INET, sizeof(unsigned long),
 346     INET_print, INET_sprint, INET_input, INET_reserror,
 347     NULL /*INET_rprint */ , NULL /*INET_rinput */ ,
 348     INET_getnetmask,
 349     -1,
 350     NULL
 351 };
 352
 353 #endif                          /* HAVE_AFINET */
 354
 355 static void add2list(struct service **namebase, struct service *item)
 356 {
 357     if (*namebase == NULL) {
 358         *namebase = item;
 359         item->next = NULL;
 360     } else {
 361         item->next = *namebase;
 362         *namebase = item;
 363     }
 364 }
 365
 366
 367 static struct service *searchlist(struct service *servicebase, int number)
 368 {
 369     struct service *item;
 370
 371     for (item = servicebase; item != NULL; item = item->next) {
 372         if (item->number == number)
 373             return (item);
 374     }
 375     return (NULL);
 376 }
 377
 378
 379 static int read_services(void)
 380 {
 381     struct servent *se;
 382     struct protoent *pe;
 383     struct service *item;
 384
 385     setservent(1);
 386     while ((se = getservent())) {
 387         /* Allocate a service entry. */
 388         item = (struct service *) malloc(sizeof(struct service));
 389         if (item == NULL)
 390             perror("netstat");
 391         item->name = strdup(se->s_name);
 392         item->number = se->s_port;
 393
 394         /* Fill it in. */
 395         if (!strcmp(se->s_proto, "tcp")) {
 396             add2list(&tcp_name, item);
 397         } else if (!strcmp(se->s_proto, "udp")) {
 398             add2list(&udp_name, item);
 399         } else if (!strcmp(se->s_proto, "raw")) {
 400             add2list(&raw_name, item);
 401         }
 402     }
 403     endservent();
 404     setprotoent(1);
 405     while ((pe = getprotoent())) {
 406         /* Allocate a service entry. */
 407         item = (struct service *) malloc(sizeof(struct service));
 408         if (item == NULL)
 409             perror("netstat");
 410         item->name = strdup(pe->p_name);
 411         item->number = htons(pe->p_proto);
 412         add2list(&raw_name, item);
 413     }
 414     endprotoent();
 415     return (0);
 416 }
 417
 418
 419 char *get_sname(int socknumber, char *proto, int numeric)
 420 {
 421     static char buffer[64], init = 0;
 422     struct service *item;
 423
 424     if (socknumber == 0)
 425         return ("*");
 426     if (numeric) {
 427         sprintf(buffer, "%d", ntohs(socknumber));
 428         return (buffer);
 429     }
 430     if (!init) {
 431         (void) read_services();
 432         init = 1;
 433     }
 434     buffer[0] = '\0';
 435     if (!strcmp(proto, "tcp")) {
 436         if ((item = searchlist(tcp_name, socknumber)) != NULL)
 437             sprintf(buffer, "%s", item->name);
 438     } else if (!strcmp(proto, "udp")) {
 439         if ((item = searchlist(udp_name, socknumber)) != NULL)
 440             sprintf(buffer, "%s", item->name);
 441     } else if (!strcmp(proto, "raw")) {
 442         if ((item = searchlist(raw_name, socknumber)) != NULL)
 443             sprintf(buffer, "%s", item->name);
 444
 445     }
 446     if (!buffer[0])
 447         sprintf(buffer, "%d", ntohs(socknumber));
 448     return (buffer);
 449 }
 450
 451 #endif                          /* HAVE_AFINET || HAVE_AFINET6 */