Allow use of interface name in rules file. This way if you have a dynamic

IP address you don't have to edit the rules file every time you connect.

Example of usage:

coyote% cat /etc/nat.rules
map ppp0 10.0.0.0/8 -> ppp0/32 portmap tcp/udp 10000:20000

ppp0 is automagically transformed into the IP address of the ppp0 interface.

diff --git a/sbin/ipnat/ipnat.c b/sbin/ipnat/ipnat.c
index afc2230..f1911c5 100644 (file)
--- a/sbin/ipnat/ipnat.c
+++ b/sbin/ipnat/ipnat.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: ipnat.c,v 1.10 1997/02/11 22:24:20 kstailey Exp $     */
+/*     $OpenBSD: ipnat.c,v 1.11 1997/02/13 01:19:05 kstailey Exp $     */
 /*
  * (C)opyright 1993,1994,1995 by Darren Reed.
  *
@@ -373,6 +373,67 @@ char       *msk;
        return mask;
 }
 
+/* 
+ * get_if_addr(): given a string containing an interface name (e.g. "ppp0")
+ *               return the IP address it represents as an unsigned long
+ */
+u_long if_addr(name)
+char   *name;
+{
+       struct ifconf ifc;
+       struct ifreq ifreq, *ifr;
+       char *inbuf = NULL;
+       int s, i, len = 8192;
+
+       if ((s = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
+               warn("socket");
+               return INADDR_NONE;
+       }
+       
+       while (1) {
+               ifc.ifc_len = len;
+               ifc.ifc_buf = inbuf = realloc(inbuf, len);
+               if (inbuf == NULL)
+                       err(1, "malloc");
+               if (ioctl(s, SIOCGIFCONF, &ifc) < 0) {
+                       warn("SIOCGIFCONF");
+                       goto if_addr_lose;
+               }
+               if (ifc.ifc_len + sizeof(ifreq) < len)
+                       break;
+               len *= 2;
+       }
+       ifr = ifc.ifc_req;
+       ifreq.ifr_name[0] = '\0';
+       for (i = 0; i < ifc.ifc_len; ) {
+               ifr = (struct ifreq *)((caddr_t)ifc.ifc_req + i);
+               i += sizeof(ifr->ifr_name) +
+                       (ifr->ifr_addr.sa_len > sizeof(struct sockaddr)
+                               ? ifr->ifr_addr.sa_len
+                               : sizeof(struct sockaddr));
+               if (!strncmp(ifreq.ifr_name, ifr->ifr_name,
+                            sizeof(ifr->ifr_name)))
+                       continue;
+               ifreq = *ifr;
+               if (ioctl(s, SIOCGIFADDR, (caddr_t)ifr) < 0) {
+                       warn("SIOCGIFADDR");
+                       goto if_addr_lose;
+               }
+               if (ifr->ifr_addr.sa_family != AF_INET)
+                       continue;
+               if (!strcmp(name, ifr->ifr_name)) {
+                       struct sockaddr_in *sin;
+                       close(s);
+                       free(inbuf);
+                       sin = (struct sockaddr_in *)&ifr->ifr_addr;
+                       return (sin->sin_addr.s_addr);
+               }
+       }
+if_addr_lose:
+       close(s);
+       free(inbuf);
+       return INADDR_NONE;
+}
 
 /*
  * returns an ip address as a long var as a result of either a DNS lookup or
@@ -386,13 +447,16 @@ int       *resolved;
        struct  netent  *np;
 
        *resolved = 0;
-       if (!strcasecmp("any",host))
+       if (!strcasecmp("any", host))
                return 0L;
        if (isdigit(*host))
                return inet_addr(host);
 
        if (!(hp = gethostbyname(host))) {
                if (!(np = getnetbyname(host))) {
+                       u_long addr;
+                       if ((addr = if_addr(host)) != INADDR_NONE)
+                               return addr;
                        *resolved = -1;
                        fprintf(stderr, "can't resolve hostname: %s\n", host);
                        return 0;