diplodocus.org Git - nmh/blob - sbr/client.c

   1
   2 /*
   3  * client.c -- connect to a server
   4  *
   5  * $Id$
   6  *
   7  * This code is Copyright (c) 2002, by the authors of nmh.  See the
   8  * COPYRIGHT file in the root directory of the nmh distribution for
   9  * complete copyright information.
  10  */
  11
  12 #include <h/mh.h>
  13 #include <h/mts.h>
  14 #include <h/utils.h>
  15 #include <errno.h>
  16 #include <sys/socket.h>
  17 #include <netinet/in.h>
  18 #include <netdb.h>
  19
  20 #ifdef HAVE_ARPA_INET_H
  21 # include <arpa/inet.h>
  22 #endif
  23
  24 #ifdef HESIOD
  25 # include <hesiod.h>
  26 #endif
  27
  28 #ifdef KPOP
  29 # include <krb.h>
  30 # include <ctype.h>
  31 #endif  /* KPOP */
  32
  33 #define TRUE         1
  34 #define FALSE        0
  35
  36 #define OOPS1      (-2)
  37 #define OOPS2      (-3)
  38
  39 #define MAXARGS   1000
  40 #define MAXNETS      5
  41 #define MAXHOSTS    25
  42
  43 struct addrent {
  44     int a_addrtype;             /* assumes AF_INET for inet_netof () */
  45     union {
  46         int un_net;
  47         char un_addr[14];
  48     } un;
  49 };
  50
  51 #define a_net  un.un_net
  52 #define a_addr un.un_addr
  53
  54 static struct addrent *n1, *n2;
  55 static struct addrent nets[MAXNETS];
  56 static struct addrent *h1, *h2;
  57 static struct addrent hosts[MAXHOSTS];
  58
  59 #ifdef KPOP
  60 static CREDENTIALS cred;
  61 static MSG_DAT msg_data;
  62 static KTEXT ticket = (KTEXT) NULL;
  63 static Key_schedule schedule;
  64 static char *kservice;                  /* "pop" if using kpop */
  65 char krb_realm[REALM_SZ];
  66 char *PrincipalHostname();
  67 #endif /* KPOP */
  68
  69 #if !defined(h_addr)
  70 # define h_addr h_addr_list[0]
  71 #endif
  72
  73 #define inaddr_copy(hp,sin) \
  74     memcpy(&((sin)->sin_addr), (hp)->h_addr, (hp)->h_length)
  75
  76 /*
  77  * static prototypes
  78  */
  79 static int rcaux (struct servent *, struct hostent *, int, char *, int);
  80 static int getport (int, int, char *, int);
  81 static int inet (struct hostent *, int);
  82 struct hostent *gethostbystring (char *s);
  83
  84 /* client's own static version of several nmh subroutines */
  85 static char **client_brkstring (char *, char *, char *);
  86 static int client_brkany (char, char *);
  87 static char **client_copyip (char **, char **, int);
  88 static char *client_getcpy (char *);
  89
  90
  91 int
  92 client (char *args, char *protocol, char *service, int rproto,
  93                 char *response, int len_response)
  94 {
  95     int sd;
  96     register char **ap;
  97     char *arguments[MAXARGS];
  98     register struct hostent *hp;
  99     register struct servent *sp;
 100 #ifndef HAVE_GETHOSTBYNAME
 101     register struct netent *np;
 102 #endif
 103
 104 #ifdef KPOP
 105     char *cp;
 106
 107     kservice = service;
 108     if (cp = strchr (service, '/')) {   /* "pop/kpop" */
 109         *cp++ = '\0';           /* kservice = "pop" */
 110         service = cp;           /* service  = "kpop" */
 111     } else {
 112         kservice = NULL;        /* not using KERBEROS */
 113     }
 114 #endif  /* KPOP */
 115
 116
 117     if ((sp = getservbyname (service, protocol)) == NULL) {
 118 #ifdef HESIOD
 119         if ((sp = hes_getservbyname (service, protocol)) == NULL) {
 120             snprintf (response, len_response, "%s/%s: unknown service", protocol, service);
 121             return NOTOK;
 122         }
 123 #else
 124         snprintf (response, len_response, "%s/%s: unknown service", protocol, service);
 125         return NOTOK;
 126 #endif
 127     }
 128
 129     ap = arguments;
 130     if (args != NULL && *args != 0) {
 131         ap = client_copyip (client_brkstring (client_getcpy (args), " ", "\n"),
 132                 ap, MAXARGS);
 133     } else {
 134         if (servers != NULL && *servers != 0)
 135             ap = client_copyip (client_brkstring (client_getcpy (servers), " ", "\n"),
 136                 ap, MAXARGS);
 137     }
 138     if (ap == arguments) {
 139         *ap++ = client_getcpy ("localhost");
 140         *ap = NULL;
 141     }
 142
 143     n1 = nets;
 144     n2 = nets + sizeof(nets) / sizeof(nets[0]);
 145
 146     h1 = hosts;
 147     h2 = hosts + sizeof(hosts) / sizeof(hosts[0]);
 148
 149     for (ap = arguments; *ap; ap++) {
 150         if (**ap == '\01') {
 151 /*
 152  * the assumption here is that if the system doesn't have a
 153  * gethostbyname() function, it must not use DNS. So we need to look
 154  * into the /etc/hosts using gethostent(). There probablly aren't any
 155  * systems still like this, but you never know. On every system I have
 156  * access to, this section is ignored.
 157  */
 158 #ifndef HAVE_GETHOSTBYNAME
 159             if ((np = getnetbyname (*ap + 1))) {
 160 #ifdef HAVE_SETHOSTENT
 161                 sethostent (1);
 162 #endif /* HAVE_SETHOSTENT */
 163                 while ((hp = gethostent()))
 164                     if (np->n_addrtype == hp->h_addrtype
 165                             && inet (hp, np->n_net)) {
 166                         switch (sd = rcaux (sp, hp, rproto, response, len_response)) {
 167                             case NOTOK:
 168                                 continue;
 169                             case OOPS1:
 170                                 break;
 171                             case OOPS2:
 172                                 return NOTOK;
 173
 174                             default:
 175                                 return sd;
 176                         }
 177                         break;
 178                     }
 179             }
 180 #endif /* don't HAVE_GETHOSTBYNAME */
 181             continue;
 182         }
 183
 184         if ((hp = gethostbystring (*ap))) {
 185             switch (sd = rcaux (sp, hp, rproto, response, len_response)) {
 186                 case NOTOK:
 187                 case OOPS1:
 188                     break;
 189                 case OOPS2:
 190                     return NOTOK;
 191
 192                 default:
 193                     return sd;
 194             }
 195             continue;
 196         }
 197     }
 198
 199     strncpy (response, "no servers available", len_response);
 200     return NOTOK;
 201 }
 202
 203
 204 static int
 205 rcaux (struct servent *sp, struct hostent *hp, int rproto,
 206                 char *response, int len_response)
 207 {
 208     int sd;
 209     struct in_addr in;
 210     register struct addrent *ap;
 211     struct sockaddr_in in_socket;
 212     register struct sockaddr_in *isock = &in_socket;
 213
 214 #ifdef KPOP
 215     int rem;
 216     struct hostent *hp2;
 217 #endif  /* KPOP */
 218
 219     for (ap = nets; ap < n1; ap++)
 220         if (ap->a_addrtype == hp->h_addrtype && inet (hp, ap->a_net))
 221             return NOTOK;
 222
 223     for (ap = hosts; ap < h1; ap++)
 224         if (ap->a_addrtype == hp->h_addrtype
 225                 && memcmp(ap->a_addr, hp->h_addr, hp->h_length) == 0)
 226             return NOTOK;
 227
 228     if ((sd = getport (rproto, hp->h_addrtype, response, len_response)) == NOTOK)
 229         return OOPS2;
 230
 231     memset (isock, 0, sizeof(*isock));
 232     isock->sin_family = hp->h_addrtype;
 233     inaddr_copy (hp, isock);
 234     isock->sin_port = sp->s_port;
 235
 236     if (connect (sd, (struct sockaddr *) isock, sizeof(*isock)) == NOTOK)
 237         switch (errno) {
 238             case ENETDOWN:
 239             case ENETUNREACH:
 240                 close (sd);
 241                 if (n1 < n2) {
 242                     n1->a_addrtype = hp->h_addrtype;
 243                     memcpy(&in, hp->h_addr, sizeof(in));
 244                     n1->a_net = inet_netof (in);
 245                     n1++;
 246                 }
 247                 return OOPS1;
 248
 249             case ETIMEDOUT:
 250             case ECONNREFUSED:
 251             default:
 252                 close (sd);
 253                 if (h1 < h2) {
 254                     h1->a_addrtype = hp->h_addrtype;
 255                     memcpy(h1->a_addr, hp->h_addr, hp->h_length);
 256                     h1++;
 257                 }
 258                 return NOTOK;
 259         }
 260
 261 #ifdef KPOP
 262     if (kservice) {     /* "pop" */
 263         char *instance;
 264
 265         if (( hp2 = gethostbyaddr( hp->h_addr, hp->h_length, hp->h_addrtype ))
 266                 == NULL ) {
 267             return NOTOK;
 268         }
 269         if ((instance = strdup (hp2->h_name)) == NULL) {
 270             close (sd);
 271             strncpy (response, "Out of memory.", len_response);
 272             return OOPS2;
 273         }
 274         ticket = (KTEXT) mh_xmalloc (sizeof(KTEXT_ST));
 275         rem = krb_sendauth (0L, sd, ticket, kservice, instance,
 276                            (char *) krb_realmofhost (instance),
 277                            (unsigned long) 0, &msg_data, &cred, schedule,
 278                            (struct sockaddr_in *) NULL,
 279                            (struct sockaddr_in *) NULL,
 280                            "KPOPV0.1");
 281         free (instance);
 282         if (rem != KSUCCESS) {
 283             close (sd);
 284             strncpy (response, "Post office refused connection: ", len_response);
 285             strncat (response, krb_err_txt[rem], len_response - strlen(response));
 286             return OOPS2;
 287         }
 288     }
 289 #endif /* KPOP */
 290
 291     return sd;
 292 }
 293
 294
 295 static int
 296 getport (int rproto, int addrtype, char *response, int len_response)
 297 {
 298     int sd, port;
 299     struct sockaddr_in in_socket, *isock;
 300
 301     isock = &in_socket;
 302     if (rproto && addrtype != AF_INET) {
 303         snprintf (response, len_response, "reserved ports not supported for af=%d", addrtype);
 304         errno = ENOPROTOOPT;
 305         return NOTOK;
 306     }
 307
 308     if ((sd = socket (AF_INET, SOCK_STREAM, 0)) == NOTOK) {
 309         char *s;
 310
 311         if ((s = strerror (errno)))
 312             snprintf (response, len_response, "unable to create socket: %s", s);
 313         else
 314             snprintf (response, len_response, "unable to create socket: unknown error");
 315         return NOTOK;
 316     }
 317 #ifdef KPOP
 318     if (kservice)       /* "pop" */
 319         return(sd);
 320 #endif  /* KPOP */
 321     if (!rproto)
 322         return sd;
 323
 324     memset(isock, 0, sizeof(*isock));
 325     isock->sin_family = addrtype;
 326     for (port = IPPORT_RESERVED - 1;;) {
 327         isock->sin_port = htons ((unsigned short) port);
 328         if (bind (sd, (struct sockaddr *) isock, sizeof(*isock)) != NOTOK)
 329             return sd;
 330
 331         switch (errno) {
 332             char *s;
 333
 334             case EADDRINUSE:
 335             case EADDRNOTAVAIL:
 336                 if (--port <= IPPORT_RESERVED / 2) {
 337                     strncpy (response, "ports available", len_response);
 338                     return NOTOK;
 339                 }
 340                 break;
 341
 342             default:
 343                 if ((s = strerror (errno)))
 344                     snprintf (response, len_response, "unable to bind socket: %s", s);
 345                 else
 346                     snprintf (response, len_response, "unable to bind socket: unknown error");
 347                 return NOTOK;
 348         }
 349     }
 350 }
 351
 352
 353 static int
 354 inet (struct hostent *hp, int net)
 355 {
 356     struct in_addr in;
 357
 358     memcpy(&in, hp->h_addr, sizeof(in));
 359     return (inet_netof (in) == net);
 360 }
 361
 362
 363 /*
 364  * taken from ISODE's compat/internet.c
 365  */
 366
 367 static char *empty = NULL;
 368
 369 #ifdef h_addr
 370 static char *addrs[2] = { NULL };
 371 #endif
 372
 373 struct hostent *
 374 gethostbystring (char *s)
 375 {
 376     register struct hostent *h;
 377     static struct hostent hs;
 378 #ifdef DG
 379     static struct in_addr iaddr;
 380 #else
 381     static unsigned long iaddr;
 382 #endif
 383
 384     iaddr = inet_addr (s);
 385 #ifdef DG
 386     if (iaddr.s_addr == NOTOK && strcmp (s, "255.255.255.255"))
 387 #else
 388     if (((int) iaddr == NOTOK) && strcmp (s, "255.255.255.255"))
 389 #endif
 390         return gethostbyname (s);
 391
 392     h = &hs;
 393     h->h_name = s;
 394     h->h_aliases = &empty;
 395     h->h_addrtype = AF_INET;
 396     h->h_length = sizeof(iaddr);
 397 #ifdef h_addr
 398     h->h_addr_list = addrs;
 399     memset(addrs, 0, sizeof(addrs));
 400 #endif
 401     h->h_addr = (char *) &iaddr;
 402
 403     return h;
 404 }
 405
 406
 407 /*
 408  * static copies of three nmh subroutines
 409  */
 410
 411 static char *broken[MAXARGS + 1];
 412
 413 static char **
 414 client_brkstring (char *strg, char *brksep, char *brkterm)
 415 {
 416     register int bi;
 417     register char c, *sp;
 418
 419     sp = strg;
 420
 421     for (bi = 0; bi < MAXARGS; bi++) {
 422         while (client_brkany (c = *sp, brksep))
 423             *sp++ = 0;
 424         if (!c || client_brkany (c, brkterm)) {
 425             *sp = 0;
 426             broken[bi] = 0;
 427             return broken;
 428         }
 429
 430         broken[bi] = sp;
 431         while ((c = *++sp) && !client_brkany (c, brksep) && !client_brkany (c, brkterm))
 432             continue;
 433     }
 434     broken[MAXARGS] = 0;
 435
 436     return broken;
 437 }
 438
 439
 440 /*
 441  * returns 1 if chr in strg, 0 otherwise
 442  */
 443 static int
 444 client_brkany (char chr, char *strg)
 445 {
 446     register char *sp;
 447
 448     if (strg)
 449         for (sp = strg; *sp; sp++)
 450             if (chr == *sp)
 451                 return 1;
 452     return 0;
 453 }
 454
 455
 456 /*
 457  * copy a string array and return pointer to end
 458  */
 459 static char **
 460 client_copyip (char **p, char **q, int len_q)
 461 {
 462     while (*p && --len_q > 0)
 463         *q++ = *p++;
 464
 465     *q = NULL;
 466
 467     return q;
 468 }
 469
 470
 471 static char *
 472 client_getcpy (char *str)
 473 {
 474     char *cp;
 475     size_t len;
 476
 477     len = strlen(str) + 1;
 478     cp = mh_xmalloc(len);
 479
 480     memcpy (cp, str, len);
 481     return cp;
 482 }
 483