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