wmbiff/wmbiff/socket.c

   1 /* $Id: socket.c,v 1.14 2004/10/01 21:05:36 bluehal Exp $ */
   2 /* Copyright (C) 1998 Trent Piepho  <xyzzy@u.washington.edu>
   3  *           (C) 1999 Trent Piepho  <xyzzy@speakeasy.org>
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License as published by the Free
   7  * Software Foundation; version 2 of the License.
   8  *
   9  * This program is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  12  * more details.
  13  *
  14  * You should have received a copy of the GNU General Public License along
  15  * with this program; if not, write to the Free Software Foundation, Inc.,
  16  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */
  17 #ifdef HAVE_CONFIG_H
  18 #include <config.h>
  19 #endif
  20 #include <stdio.h>
  21 #include <unistd.h>
  22 #include <sys/types.h>
  23 #include <fcntl.h>
  24 #include <time.h>
  25 #include <sys/stat.h>
  26 #include <sys/socket.h>
  27 #include <netinet/in.h>
  28 #include <arpa/inet.h>
  29 #include <errno.h>
  30 #include <string.h>
  31 #include <netdb.h>
  32 #include <stdio.h>
  33 #include "regulo.h"
  34
  35 #ifdef USE_DMALLOC
  36 #include <dmalloc.h>
  37 #endif
  38
  39 /* be paranoid about leaking passwords as hostnames, enough
  40    that we'll avoid attempting lookups on things that aren't
  41    host names */
  42 extern int Relax;
  43 static int sanity_check_hostname(const char *hostname)
  44 {
  45         struct in_addr dummy;
  46         return (Relax
  47                         || regulo_match("^[A-Za-z][-_A-Za-z0-9.]+$", hostname, NULL)
  48                         || inet_aton(hostname, &dummy));
  49 }
  50
  51 static int ipv4_sock_connect(struct in_addr *address, short port)
  52 {
  53         struct sockaddr_in addr;
  54         int fd, i;
  55         fd = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
  56         if (fd == -1) {
  57                 perror("Error opening socket");
  58                 printf("socket() failed.\n");
  59                 return (-1);
  60         };
  61        if (fcntl(fd, F_SETFD, FD_CLOEXEC) == -1)
  62                perror("fcntl(FD_CLOEXEC)");
  63
  64         addr.sin_family = AF_INET;
  65         addr.sin_addr.s_addr = *(u_long *) address;
  66         addr.sin_port = htons(port);
  67         i = connect(fd, (struct sockaddr *) &addr, sizeof(struct sockaddr));
  68         if (i == -1) {
  69                 int saved_errno = errno;
  70                 perror("Error connecting");
  71                 printf("connect(%s:%d) failed: %s\n", inet_ntoa(addr.sin_addr),
  72                            port, strerror(saved_errno));
  73                 close(fd);
  74                 return (-1);
  75         };
  76         return (fd);
  77 }
  78
  79 /* nspring/blueHal, 10 Apr 2002; added some extra error
  80    printing, in line with the debug-messages-to-stdout
  81    philosophy of the rest of the wmbiff code */
  82 /* 1 June 2002; incorporated IPv6 support by
  83    Jun-ichiro itojun Hagino <itojun@iijlab.net>, thanks! */
  84
  85 int sock_connect(const char *hostname, int port)
  86 {
  87 #ifdef HAVE_GETADDRINFO
  88         struct addrinfo hints, *res, *res0;
  89         struct sockaddr_in addr;
  90         int fd;
  91         char pbuf[NI_MAXSERV];
  92         int error;
  93
  94         if (!sanity_check_hostname(hostname)) {
  95                 printf
  96                         ("socket/connect to '%s' aborted: it does not appear to be a valid hostname\n",
  97                          hostname);
  98                 printf("if you really want this, use wmbiff's -relax option.\n");
  99                 return -1;
 100         }
 101
 102         /* we were given an IP address, no need to try getaddrinfo on it */
 103         if (inet_aton(hostname, &addr.sin_addr)) {
 104                 return ipv4_sock_connect(&addr.sin_addr, port);
 105         }
 106
 107         memset(&hints, 0, sizeof(hints));
 108         hints.ai_socktype = SOCK_STREAM;
 109         snprintf(pbuf, sizeof(pbuf), "%d", port);
 110         error = getaddrinfo(hostname, pbuf, &hints, &res0);
 111         if (error) {
 112                 static int last_error;
 113                 if (last_error != error) {
 114                         /* only report a problem if it's new.  this is an
 115                            approximation that minimizes kept state. */
 116                         printf("%s: %s\n", hostname, gai_strerror(error));
 117                         last_error = error;
 118                 }
 119                 return -1;
 120         }
 121
 122         fd = -1;
 123         for (res = res0; res; res = res->ai_next) {
 124                 fd = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
 125                 if (fd < 0)
 126                         continue;
 127                if (fcntl(fd, F_SETFD, FD_CLOEXEC) == -1)
 128                        perror("fcntl(FD_CLOEXEC)");
 129                 if (connect(fd, res->ai_addr, res->ai_addrlen) < 0) {
 130                         close(fd);
 131                         fd = -1;
 132                         continue;
 133                 }
 134                 break;
 135         }
 136         freeaddrinfo(res0);
 137         if (fd < 0) {
 138                 static int last_connecterr;
 139                 if (errno != last_connecterr) {
 140                         /* only report a problem if it's new.
 141                            EHOSTUNREACH is common when the net is down,
 142                            for example; again, this is an approximation
 143                            to minimize kept state. */
 144                         last_connecterr = errno;
 145                         fprintf(stderr, "Error connecting to %s:%d: %s\n",
 146                                         hostname, port, strerror(errno));
 147                         printf("socket/connect to %s failed: %s (%d)\n", hostname,
 148                                    strerror(errno), errno);
 149                 }
 150                 return -1;
 151         }
 152         return fd;
 153 #else
 154 #warning "This build will not support IPv6"
 155         struct hostent *host;
 156
 157         if (!sanity_check_hostname(hostname)) {
 158                 printf
 159                         ("socket/connect to '%s' aborted: it does not appear to be a valid hostname\n",
 160                          hostname);
 161                 printf("if you really want this, use wmbiff's -relax option.\n");
 162                 return -1;
 163         }
 164
 165         host = gethostbyname(hostname);
 166         if (host == NULL) {
 167                 herror("gethostbyname");
 168                 printf("gethostbyname(%s) failed.\n", hostname);
 169                 return (-1);
 170         };
 171
 172         return ipv4_sock_connect(host->h_addr_list[0], port);
 173
 174 #endif
 175 }
 176
 177 /* vim:set ts=4: */
 178 /*
 179  * Local Variables:
 180  * tab-width: 4
 181  * c-indent-level: 4
 182  * c-basic-offset: 4
 183  * End:
 184  */