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

   1 /* client.c -- connect to a server
   2  *
   3  * This code is Copyright (c) 2002, by the authors of nmh.  See the
   4  * COPYRIGHT file in the root directory of the nmh distribution for
   5  * complete copyright information.
   6  */
   7
   8 #include "h/mh.h"
   9 #include "client.h"
  10 #include "h/mts.h"
  11 #include "h/utils.h"
  12 #include <sys/socket.h>
  13 #include <netinet/in.h>
  14 #include <netdb.h>
  15 #include <arpa/inet.h>
  16 #include <errno.h>
  17
  18
  19 int
  20 client (char *server, char *service, char *response, int len_response,
  21         int debug)
  22 {
  23     int sd, rc;
  24     struct addrinfo hints, *res, *ai;
  25
  26     if (!server || *server == '\0') {
  27         snprintf(response, len_response, "Internal error: NULL server name "
  28                  "passed to client()");
  29         return NOTOK;
  30     }
  31
  32     ZERO(&hints);
  33 #ifdef AI_ADDRCONFIG
  34     hints.ai_flags = AI_ADDRCONFIG;
  35 #endif
  36     hints.ai_family = PF_UNSPEC;
  37     hints.ai_socktype = SOCK_STREAM;
  38
  39     if (debug) {
  40         fprintf(stderr, "Trying to connect to \"%s\" ...\n", server);
  41     }
  42
  43     rc = getaddrinfo(server, service, &hints, &res);
  44
  45     if (rc) {
  46         snprintf(response, len_response, "Lookup of \"%s\" failed: %s",
  47                  server, gai_strerror(rc));
  48         return NOTOK;
  49     }
  50
  51     for (ai = res; ai != NULL; ai = ai->ai_next) {
  52         if (debug) {
  53             char address[NI_MAXHOST];
  54             char port[NI_MAXSERV];
  55
  56             rc = getnameinfo(ai->ai_addr, ai->ai_addrlen, address,
  57                              sizeof(address), port, sizeof port,
  58                              NI_NUMERICHOST | NI_NUMERICSERV);
  59
  60             fprintf(stderr, "Connecting to %s:%s...\n",
  61                     rc ? "unknown" : address, rc ? "--" : port);
  62         }
  63
  64         sd = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
  65
  66         if (sd < 0) {
  67             if (debug)
  68                 fprintf(stderr, "socket() failed: %s\n", strerror(errno));
  69             rc = errno;
  70             continue;
  71         }
  72
  73         if (connect(sd, ai->ai_addr, ai->ai_addrlen) == 0) {
  74             freeaddrinfo(res);
  75             return sd;
  76         }
  77
  78         rc = errno;
  79
  80         if (debug) {
  81             fprintf(stderr, "Connection failed: %s\n", strerror(errno));
  82         }
  83
  84         close(sd);
  85     }
  86
  87     /*
  88      * Improve error handling a bit. If we were given multiple IP addresses
  89      * then return the old "no servers available" error, but point the user
  90      * to -snoop (hopefully that's universal).  Otherwise report a specific
  91      * error.
  92      */
  93
  94     if (res->ai_next)
  95         snprintf(response, len_response, "no servers available (use -snoop "
  96                  "for details");
  97     else
  98         snprintf(response, len_response, "Connection to \"%s\" failed: %s",
  99                  server, strerror(errno));
 100
 101     freeaddrinfo(res);
 102
 103     return NOTOK;
 104 }