fake-getnameinfo.c

   1 /*
   2  * fake library for ssh
   3  *
   4  * This file includes getnameinfo().
   5  * These funtions are defined in rfc2133.
   6  *
   7  * But these functions are not implemented correctly. The minimum subset
   8  * is implemented for ssh use only. For exapmle, this routine assumes
   9  * that ai_family is AF_INET. Don't use it for another purpose.
  10  */
  11
  12 #include "includes.h"
  13 #include "ssh.h"
  14
  15 #ifndef HAVE_GETNAMEINFO
  16 int getnameinfo(const struct sockaddr *sa, size_t salen, char *host,
  17                 size_t hostlen, char *serv, size_t servlen, int flags)
  18 {
  19         struct sockaddr_in *sin = (struct sockaddr_in *)sa;
  20         struct hostent *hp;
  21         char tmpserv[16];
  22
  23         if (serv) {
  24                 snprintf(tmpserv, sizeof(tmpserv), "%d", ntohs(sin->sin_port));
  25                 if (strlen(tmpserv) >= servlen)
  26                         return EAI_MEMORY;
  27                 else
  28                         strcpy(serv, tmpserv);
  29         }
  30
  31         if (host) {
  32                 if (flags & NI_NUMERICHOST) {
  33                         if (strlen(inet_ntoa(sin->sin_addr)) >= hostlen)
  34                                 return EAI_MEMORY;
  35
  36                         strcpy(host, inet_ntoa(sin->sin_addr));
  37                         return 0;
  38                 } else {
  39                         hp = gethostbyaddr((char *)&sin->sin_addr,
  40                                 sizeof(struct in_addr), AF_INET);
  41                         if (hp == NULL)
  42                                 return EAI_NODATA;
  43
  44                         if (strlen(hp->h_name) >= hostlen)
  45                                 return EAI_MEMORY;
  46
  47                         strcpy(host, hp->h_name);
  48                         return 0;
  49                 }
  50         }
  51         return 0;
  52 }
  53 #endif /* !HAVE_GETNAMEINFO */