git.zerfleddert.de Git - amt/blob - tcp.c

   1 /*
   2  *  TCP helper functions.
   3  *
   4  *  Copyright (C) 2007 Gerd Hoffmann <kraxel@redhat.com
   5  *
   6  *  This program is free software; you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License as published by
   8  *  the Free Software Foundation; either version 2 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  This program is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License along
  17  *  with this program; if not, write to the Free Software Foundation, Inc.,
  18  *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  19  */
  20
  21 #include <stdio.h>
  22 #include <stdlib.h>
  23 #include <errno.h>
  24 #include <string.h>
  25 #include <unistd.h>
  26 #include <fcntl.h>
  27
  28 #include "tcp.h"
  29
  30 int tcp_verbose;
  31
  32 /* ------------------------------------------------------------------ */
  33
  34 static char *strfamily(int family)
  35 {
  36     switch (family) {
  37     case PF_INET6: return "ipv6";
  38     case PF_INET:  return "ipv4";
  39     case PF_UNIX:  return "unix";
  40     }
  41     return "????";
  42 }
  43
  44 int tcp_connect(struct addrinfo *ai,
  45                 char *addr, char *port,
  46                 char *host, char *serv)
  47 {
  48     struct addrinfo *res,*e;
  49     struct addrinfo *lres, ask;
  50     char uaddr[INET6_ADDRSTRLEN+1];
  51     char uport[33];
  52     char uhost[INET6_ADDRSTRLEN+1];
  53     char userv[33];
  54     int sock,rc,opt=1;
  55
  56     /* lookup peer */
  57     ai->ai_flags = AI_CANONNAME;
  58     if (0 != (rc = getaddrinfo(host, serv, ai, &res))) {
  59         if (tcp_verbose)
  60             fprintf(stderr,"getaddrinfo (peer): %s\n", gai_strerror(rc));
  61         return -1;
  62     }
  63     for (e = res; e != NULL; e = e->ai_next) {
  64         if (0 != getnameinfo((struct sockaddr*)e->ai_addr,e->ai_addrlen,
  65                              uhost,INET6_ADDRSTRLEN,userv,32,
  66                              NI_NUMERICHOST | NI_NUMERICSERV)) {
  67             if (tcp_verbose)
  68                 fprintf(stderr,"getnameinfo (peer): oops\n");
  69             continue;
  70         }
  71         if (-1 == (sock = socket(e->ai_family, e->ai_socktype,
  72                                  e->ai_protocol))) {
  73             if (tcp_verbose)
  74                 fprintf(stderr,"socket (%s): %s\n",
  75                         strfamily(e->ai_family),strerror(errno));
  76             continue;
  77         }
  78         setsockopt(sock,SOL_SOCKET,SO_REUSEADDR,&opt,sizeof(opt));
  79         if (NULL != addr || NULL != port) {
  80             /* bind local port */
  81             memset(&ask,0,sizeof(ask));
  82             ask.ai_flags    = AI_PASSIVE;
  83             ask.ai_family   = e->ai_family;
  84             ask.ai_socktype = e->ai_socktype;
  85             if (0 != (rc = getaddrinfo(addr, port, &ask, &lres))) {
  86                 if (tcp_verbose)
  87                     fprintf(stderr,"getaddrinfo (local): %s\n",
  88                             gai_strerror(rc));
  89                 continue;
  90             }
  91             if (0 != getnameinfo((struct sockaddr*)lres->ai_addr,
  92                                  lres->ai_addrlen,
  93                                  uaddr,INET6_ADDRSTRLEN,uport,32,
  94                                  NI_NUMERICHOST | NI_NUMERICSERV)) {
  95                 if (tcp_verbose)
  96                     fprintf(stderr,"getnameinfo (local): oops\n");
  97                 continue;
  98             }
  99             if (-1 == bind(sock, lres->ai_addr, lres->ai_addrlen)) {
 100                 if (tcp_verbose)
 101                     fprintf(stderr,"%s [%s] %s bind: %s\n",
 102                             strfamily(lres->ai_family),uaddr,uport,
 103                             strerror(errno));
 104                 continue;
 105             }
 106         }
 107         /* connect to peer */
 108         if (-1 == connect(sock,e->ai_addr,e->ai_addrlen)) {
 109             if (tcp_verbose)
 110                 fprintf(stderr,"%s %s [%s] %s connect: %s\n",
 111                         strfamily(e->ai_family),e->ai_canonname,uhost,userv,
 112                         strerror(errno));
 113             close(sock);
 114             continue;
 115         }
 116         if (tcp_verbose)
 117             fprintf(stderr,"%s %s [%s] %s open\n",
 118                     strfamily(e->ai_family),e->ai_canonname,uhost,userv);
 119         fcntl(sock,F_SETFL,O_NONBLOCK);
 120         return sock;
 121     }
 122     return -1;
 123 }
 124
 125 int tcp_listen(struct addrinfo *ai, char *addr, char *port)
 126 {
 127     struct addrinfo *res,*e;
 128     char uaddr[INET6_ADDRSTRLEN+1];
 129     char uport[33];
 130     int slisten,rc,opt=1;
 131
 132     /* lookup */
 133     ai->ai_flags = AI_PASSIVE;
 134     if (0 != (rc = getaddrinfo(addr, port, ai, &res))) {
 135         if (tcp_verbose)
 136             fprintf(stderr,"getaddrinfo: %s\n",gai_strerror(rc));
 137         exit(1);
 138     }
 139
 140     /* create socket + bind */
 141     for (e = res; e != NULL; e = e->ai_next) {
 142         getnameinfo((struct sockaddr*)e->ai_addr,e->ai_addrlen,
 143                     uaddr,INET6_ADDRSTRLEN,uport,32,
 144                     NI_NUMERICHOST | NI_NUMERICSERV);
 145         if (-1 == (slisten = socket(e->ai_family, e->ai_socktype,
 146                                     e->ai_protocol))) {
 147             if (tcp_verbose)
 148                 fprintf(stderr,"socket (%s): %s\n",
 149                         strfamily(e->ai_family),strerror(errno));
 150             continue;
 151         }
 152         opt = 1;
 153         setsockopt(slisten,SOL_SOCKET,SO_REUSEADDR,&opt,sizeof(opt));
 154         if (-1 == bind(slisten, e->ai_addr, e->ai_addrlen)) {
 155             if (tcp_verbose)
 156                 fprintf(stderr,"%s [%s] %s bind: %s\n",
 157                         strfamily(e->ai_family),uaddr,uport,
 158                         strerror(errno));
 159             continue;
 160         }
 161         listen(slisten,1);
 162         break;
 163     }
 164     if (NULL == e)
 165         return -1;
 166
 167     /* wait for a incoming connection */
 168     if (tcp_verbose)
 169         fprintf(stderr,"listen on %s [%s] %s ...\n",
 170                 strfamily(e->ai_family),uaddr,uport);
 171     fcntl(slisten,F_SETFL,O_NONBLOCK);
 172     return slisten;
 173 }