contrib/tcp_wrappers/scaffold.c

   1  /*
   2   * Routines for testing only. Not really industrial strength.
   3   *
   4   * Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
   5   *
   6   * $FreeBSD: src/contrib/tcp_wrappers/scaffold.c,v 1.2.2.1 2000/07/18 08:34:55 ume Exp $
   7   */
   8
   9 /* System libraries. */
  10
  11 #include <sys/types.h>
  12 #include <sys/stat.h>
  13 #include <sys/socket.h>
  14 #include <netinet/in.h>
  15 #include <arpa/inet.h>
  16 #include <netdb.h>
  17 #include <stdio.h>
  18 #include <syslog.h>
  19 #include <setjmp.h>
  20 #include <string.h>
  21 #include <stdlib.h>
  22
  23 #ifndef INADDR_NONE
  24 #define INADDR_NONE     (-1)            /* XXX should be 0xffffffff */
  25 #endif
  26
  27 #ifndef INET6
  28 #include <stdlib.h>
  29 #endif
  30
  31 /* Application-specific. */
  32
  33 #include "tcpd.h"
  34 #include "scaffold.h"
  35
  36  /*
  37   * These are referenced by the options module and by rfc931.c.
  38   */
  39 int     allow_severity = SEVERITY;
  40 int     deny_severity = LOG_WARNING;
  41 int     rfc931_timeout = RFC931_TIMEOUT;
  42
  43 #ifndef INET6
  44 /* dup_hostent - create hostent in one memory block */
  45
  46 static struct hostent *dup_hostent(hp)
  47 struct hostent *hp;
  48 {
  49     struct hostent_block {
  50         struct hostent host;
  51         char   *addr_list[1];
  52     };
  53     struct hostent_block *hb;
  54     int     count;
  55     char   *data;
  56     char   *addr;
  57
  58     for (count = 0; hp->h_addr_list[count] != 0; count++)
  59          /* void */ ;
  60
  61     if ((hb = (struct hostent_block *) malloc(sizeof(struct hostent_block)
  62                          + (hp->h_length + sizeof(char *)) * count)) == 0) {
  63         fprintf(stderr, "Sorry, out of memory\n");
  64         exit(1);
  65     }
  66     memset((char *) &hb->host, 0, sizeof(hb->host));
  67     hb->host.h_length = hp->h_length;
  68     hb->host.h_addr_list = hb->addr_list;
  69     hb->host.h_addr_list[count] = 0;
  70     data = (char *) (hb->host.h_addr_list + count + 1);
  71
  72     for (count = 0; (addr = hp->h_addr_list[count]) != 0; count++) {
  73         hb->host.h_addr_list[count] = data + hp->h_length * count;
  74         memcpy(hb->host.h_addr_list[count], addr, hp->h_length);
  75     }
  76     return (&hb->host);
  77 }
  78 #endif
  79
  80 /* find_inet_addr - find all addresses for this host, result to free() */
  81
  82 #ifdef INET6
  83 struct addrinfo *find_inet_addr(host)
  84 char   *host;
  85 {
  86     struct addrinfo hints, *res;
  87
  88     memset(&hints, 0, sizeof(hints));
  89     hints.ai_family = PF_UNSPEC;
  90     hints.ai_socktype = SOCK_STREAM;
  91     hints.ai_flags = AI_PASSIVE | AI_NUMERICHOST;
  92     if (getaddrinfo(host, NULL, &hints, &res) == 0)
  93         return (res);
  94
  95     memset(&hints, 0, sizeof(hints));
  96     hints.ai_family = PF_UNSPEC;
  97     hints.ai_socktype = SOCK_STREAM;
  98     hints.ai_flags = AI_PASSIVE | AI_CANONNAME;
  99     if (getaddrinfo(host, NULL, &hints, &res) != 0) {
 100         tcpd_warn("%s: host not found", host);
 101         return (0);
 102     }
 103     if (res->ai_family != AF_INET6 && res->ai_family != AF_INET) {
 104         tcpd_warn("%d: not an internet host", res->ai_family);
 105         freeaddrinfo(res);
 106         return (0);
 107     }
 108     if (!res->ai_canonname) {
 109         tcpd_warn("%s: hostname alias", host);
 110         tcpd_warn("(cannot obtain official name)");
 111     } else if (STR_NE(host, res->ai_canonname)) {
 112         tcpd_warn("%s: hostname alias", host);
 113         tcpd_warn("(official name: %.*s)", STRING_LENGTH, res->ai_canonname);
 114     }
 115     return (res);
 116 }
 117 #else
 118 struct hostent *find_inet_addr(host)
 119 char   *host;
 120 {
 121     struct in_addr addr;
 122     struct hostent *hp;
 123     static struct hostent h;
 124     static char *addr_list[2];
 125
 126     /*
 127      * Host address: translate it to internal form.
 128      */
 129     if ((addr.s_addr = dot_quad_addr(host)) != INADDR_NONE) {
 130         h.h_addr_list = addr_list;
 131         h.h_addr_list[0] = (char *) &addr;
 132         h.h_length = sizeof(addr);
 133         return (dup_hostent(&h));
 134     }
 135
 136     /*
 137      * Map host name to a series of addresses. Watch out for non-internet
 138      * forms or aliases. The NOT_INADDR() is here in case gethostbyname() has
 139      * been "enhanced" to accept numeric addresses. Make a copy of the
 140      * address list so that later gethostbyXXX() calls will not clobber it.
 141      */
 142     if (NOT_INADDR(host) == 0) {
 143         tcpd_warn("%s: not an internet address", host);
 144         return (0);
 145     }
 146     if ((hp = gethostbyname(host)) == 0) {
 147         tcpd_warn("%s: host not found", host);
 148         return (0);
 149     }
 150     if (hp->h_addrtype != AF_INET) {
 151         tcpd_warn("%d: not an internet host", hp->h_addrtype);
 152         return (0);
 153     }
 154     if (STR_NE(host, hp->h_name)) {
 155         tcpd_warn("%s: hostname alias", host);
 156         tcpd_warn("(official name: %.*s)", STRING_LENGTH, hp->h_name);
 157     }
 158     return (dup_hostent(hp));
 159 }
 160 #endif
 161
 162 /* check_dns - give each address thorough workout, return address count */
 163
 164 int     check_dns(host)
 165 char   *host;
 166 {
 167     struct request_info request;
 168 #ifdef INET6
 169     struct sockaddr_storage sin;
 170     struct addrinfo *hp, *res;
 171 #else
 172     struct sockaddr_in sin;
 173     struct hostent *hp;
 174     char   *addr;
 175 #endif
 176     int     count;
 177
 178     if ((hp = find_inet_addr(host)) == 0)
 179         return (0);
 180     request_init(&request, RQ_CLIENT_SIN, &sin, 0);
 181     sock_methods(&request);
 182 #ifndef INET6
 183     memset((char *) &sin, 0, sizeof(sin));
 184     sin.sin_family = AF_INET;
 185 #endif
 186
 187 #ifdef INET6
 188     for (res = hp, count = 0; res; res = res->ai_next, count++) {
 189         memcpy(&sin, res->ai_addr, res->ai_addrlen);
 190 #else
 191     for (count = 0; (addr = hp->h_addr_list[count]) != 0; count++) {
 192         memcpy((char *) &sin.sin_addr, addr, sizeof(sin.sin_addr));
 193 #endif
 194
 195         /*
 196          * Force host name and address conversions. Use the request structure
 197          * as a cache. Detect hostname lookup problems. Any name/name or
 198          * name/address conflicts will be reported while eval_hostname() does
 199          * its job.
 200          */
 201         request_set(&request, RQ_CLIENT_ADDR, "", RQ_CLIENT_NAME, "", 0);
 202         if (STR_EQ(eval_hostname(request.client), unknown))
 203             tcpd_warn("host address %s->name lookup failed",
 204                       eval_hostaddr(request.client));
 205     }
 206 #ifdef INET6
 207     freeaddrinfo(hp);
 208 #else
 209     free((char *) hp);
 210 #endif
 211     return (count);
 212 }
 213
 214 /* dummy function to intercept the real shell_cmd() */
 215
 216 /* ARGSUSED */
 217
 218 void    shell_cmd(command)
 219 char   *command;
 220 {
 221     if (hosts_access_verbose)
 222         printf("command: %s", command);
 223 }
 224
 225 /* dummy function  to intercept the real clean_exit() */
 226
 227 /* ARGSUSED */
 228
 229 void    clean_exit(request)
 230 struct request_info *request;
 231 {
 232     exit(0);
 233 }
 234
 235 /* check_path - examine accessibility */
 236
 237 int     check_path(path, st)
 238 char   *path;
 239 struct stat *st;
 240 {
 241     struct stat stbuf;
 242     char    buf[BUFSIZ];
 243
 244     if (stat(path, st) < 0)
 245         return (-1);
 246 #ifdef notdef
 247     if (st->st_uid != 0)
 248         tcpd_warn("%s: not owned by root", path);
 249     if (st->st_mode & 020)
 250         tcpd_warn("%s: group writable", path);
 251 #endif
 252     if (st->st_mode & 002)
 253         tcpd_warn("%s: world writable", path);
 254     if (path[0] == '/' && path[1] != 0) {
 255         strrchr(strcpy(buf, path), '/')[0] = 0;
 256         (void) check_path(buf[0] ? buf : "/", &stbuf);
 257     }
 258     return (0);
 259 }