socat/xio-ip4.c

/* source: xio-ip4.c */
/* Copyright Gerhard Rieger 2001-2008 */
/* Published under the GNU General Public License V.2, see file COPYING */

/* this file contains the source for IP4 related functions */

#include "xiosysincludes.h"

#if WITH_IP4

#include "xioopen.h"
#include "xio-socket.h"
#include "xio-ip.h"
#include "xio-ip4.h"


int xioparsenetwork_ip4(const char *rangename, struct xiorange *range) {
   struct hostent *maskaddr;
   struct in_addr *netaddr_in = &range->netaddr.ip4.sin_addr;
   struct in_addr *netmask_in = &range->netmask.ip4.sin_addr;
   char *rangename1;	/* a copy of rangename with writing allowed */
   char *delimpos;	/* absolute address of delimiter */
   int bits;

   if ((rangename1 = strdup(rangename)) == NULL) {
      Error1("strdup(\"%s\"): out of memory", rangename);
      return STAT_RETRYLATER;
   }

   if (delimpos = strchr(rangename1, '/')) {
      bits = strtoul(delimpos+1, NULL, 10);
      netmask_in->s_addr = htonl((0xffffffff << (32-bits)));
   } else if (delimpos = strchr(rangename1, ':')) {
      if ((maskaddr = Gethostbyname(delimpos+1)) == NULL) {
	 Error2("gethostbyname(\"%s\"): %s", delimpos+1,
		h_errno == NETDB_INTERNAL ? strerror(errno) :
		hstrerror(h_errno));
	 return STAT_NORETRY;
      }
      netmask_in->s_addr = *(uint32_t *)maskaddr->h_addr_list[0];
   } else {
      Error1("xioparsenetwork_ip4(\"%s\",,): missing netmask delimiter", rangename);
      free(rangename1);
      return STAT_NORETRY;
   }
   {
      struct hostent *nameaddr;
      *delimpos = 0;
      if ((nameaddr = Gethostbyname(rangename1)) == NULL) {
	 Error2("gethostbyname(\"%s\"): %s", rangename1,
		h_errno == NETDB_INTERNAL ? strerror(errno) :
		hstrerror(h_errno));
	    free(rangename1);
	 return STAT_NORETRY;
      }
      netaddr_in->s_addr = *(unsigned long *)nameaddr->h_addr_list[0];
   }
   free(rangename1);
   return STAT_OK;
}

/* check if peer address is within permitted range.
   return >= 0 if so. */
int xiocheckrange_ip4(struct sockaddr_in *pa, struct xiorange *range) {
   struct in_addr *netaddr_in = &range->netaddr.ip4.sin_addr;
   struct in_addr *netmask_in = &range->netmask.ip4.sin_addr;
   char addrbuf[256], maskbuf[256];
   char peername[256];

   /* is provided client address valid? */
   if (pa->sin_addr.s_addr == 0) {
      Warn("invalid client address 0.0.0.0");
      return -1;
   }
   /* client address restriction */
   Debug2("permitted client subnet: %s:%s",
	  inet4addr_info(ntohl(netaddr_in->s_addr), addrbuf, sizeof(addrbuf)),
	  inet4addr_info(ntohl(netmask_in->s_addr), maskbuf, sizeof(maskbuf)));
   Debug1("client address is 0x%08x",
	  ntohl(pa->sin_addr.s_addr));
   Debug1("masked address is 0x%08x",
	  ntohl(pa->sin_addr.s_addr & netmask_in->s_addr));
   if ((pa->sin_addr.s_addr & netmask_in->s_addr)
       != netaddr_in->s_addr) {
      Debug1("client address %s is not permitted",
	     sockaddr_inet4_info(pa, peername, sizeof(peername)));
      return -1;
   }
   return 0;
}

#endif /* WITH_IP4 */