r3443: the next stage in the include files re-organisation.

I have created the include/system/ directory, which will contain the
wrappers for the system includes for logical subsystems. So far I have
created include/system/kerberos.h and include/system/network.h, which
contain all the system includes for kerberos code and networking code.
These are the included in subsystems that need kerberos or networking
respectively.

Note that this method avoids the mess of #ifdef HAVE_XXX_H in every C
file, instead each C module includes the include/system/XXX.h file for
the logical system support it needs, and the details are kept isolated
in include/system/

This patch also creates a "struct ipv4_addr" which replaces "struct
in_addr" in our code. That avoids every C file needing to import all
the system networking headers.
(This used to be commit 2e25c71853f8996f73755277e448e7d670810349)

1 files changed, 355 insertions, 0 deletions

diff --git a/source4/lib/netif/interface.c b/source4/lib/netif/interface.c
new file mode 100644
index 0000000000..75fdf8c976
--- /dev/null
+++ b/source4/lib/netif/interface.c
@@ -0,0 +1,355 @@
+/* 
+   Unix SMB/CIFS implementation.
+   multiple interface handling
+   Copyright (C) Andrew Tridgell 1992-1998
+   
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+   
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+   
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+#include "includes.h"
+#include "system/network.h"
+#include "lib/netif/netif.h"
+
+static struct iface_struct *probed_ifaces;
+static int total_probed;
+
+static struct ipv4_addr allones_ip;
+struct ipv4_addr loopback_ip;
+
+/* used for network interfaces */
+struct interface {
+	struct interface *next, *prev;
+	struct ipv4_addr ip;
+	struct ipv4_addr bcast;
+	struct ipv4_addr nmask;
+};
+
+static struct interface *local_interfaces;
+
+#define ALLONES  ((uint32_t)0xFFFFFFFF)
+#define MKBCADDR(_IP, _NM) ((_IP & _NM) | (_NM ^ ALLONES))
+#define MKNETADDR(_IP, _NM) (_IP & _NM)
+
+static struct ipv4_addr tov4(struct in_addr in)
+{
+	struct ipv4_addr in2;
+	in2.s_addr = in.s_addr;
+	return in2;
+}
+
+/****************************************************************************
+Try and find an interface that matches an ip. If we cannot, return NULL
+  **************************************************************************/
+static struct interface *iface_find(struct in_addr ip, BOOL CheckMask)
+{
+	struct interface *i;
+	if (is_zero_ip(tov4(ip))) return local_interfaces;
+
+	for (i=local_interfaces;i;i=i->next)
+		if (CheckMask) {
+			if (same_net(i->ip,tov4(ip),i->nmask)) return i;
+		} else if ((i->ip).s_addr == ip.s_addr) return i;
+
+	return NULL;
+}
+
+
+/****************************************************************************
+add an interface to the linked list of interfaces
+****************************************************************************/
+static void add_interface(struct in_addr ip, struct in_addr nmask)
+{
+	struct interface *iface;
+	if (iface_find(ip, False)) {
+		DEBUG(3,("not adding duplicate interface %s\n",inet_ntoa(ip)));
+		return;
+	}
+
+	if (ip_equal(nmask, allones_ip)) {
+		DEBUG(3,("not adding non-broadcast interface %s\n",inet_ntoa(ip)));
+		return;
+	}
+
+	iface = (struct interface *)malloc(sizeof(*iface));
+	if (!iface) return;
+	
+	ZERO_STRUCTPN(iface);
+
+	iface->ip = tov4(ip);
+	iface->nmask = tov4(nmask);
+	iface->bcast.s_addr = MKBCADDR(iface->ip.s_addr, iface->nmask.s_addr);
+
+	DLIST_ADD(local_interfaces, iface);
+
+	DEBUG(2,("added interface ip=%s ",sys_inet_ntoa(iface->ip)));
+	DEBUG(2,("bcast=%s ",sys_inet_ntoa(iface->bcast)));
+	DEBUG(2,("nmask=%s\n",sys_inet_ntoa(iface->nmask)));	     
+}
+
+
+
+/****************************************************************************
+interpret a single element from a interfaces= config line 
+
+This handles the following different forms:
+
+1) wildcard interface name
+2) DNS name
+3) IP/masklen
+4) ip/mask
+5) bcast/mask
+****************************************************************************/
+static void interpret_interface(TALLOC_CTX *mem_ctx, const char *token)
+{
+	struct in_addr ip, nmask;
+	char *p;
+	int i, added=0;
+
+	ip.s_addr = 0;
+	nmask.s_addr = 0;
+	
+	/* first check if it is an interface name */
+	for (i=0;i<total_probed;i++) {
+		if (gen_fnmatch(token, probed_ifaces[i].name) == 0) {
+			add_interface(probed_ifaces[i].ip,
+				      probed_ifaces[i].netmask);
+			added = 1;
+		}
+	}
+	if (added) return;
+
+	/* maybe it is a DNS name */
+	p = strchr_m(token,'/');
+	if (!p) {
+		ip.s_addr = interpret_addr2(token).s_addr;
+		for (i=0;i<total_probed;i++) {
+			if (ip.s_addr == probed_ifaces[i].ip.s_addr &&
+			    !ip_equal(allones_ip, probed_ifaces[i].netmask)) {
+				add_interface(probed_ifaces[i].ip,
+					      probed_ifaces[i].netmask);
+				return;
+			}
+		}
+		DEBUG(2,("can't determine netmask for %s\n", token));
+		return;
+	}
+
+	/* parse it into an IP address/netmasklength pair */
+	*p++ = 0;
+
+	ip.s_addr = interpret_addr2(token).s_addr;
+
+	if (strlen(p) > 2) {
+		nmask.s_addr = interpret_addr2(p).s_addr;
+	} else {
+		nmask.s_addr = htonl(((ALLONES >> atoi(p)) ^ ALLONES));
+	}
+
+	/* maybe the first component was a broadcast address */
+	if (ip.s_addr == MKBCADDR(ip.s_addr, nmask.s_addr) ||
+	    ip.s_addr == MKNETADDR(ip.s_addr, nmask.s_addr)) {
+		for (i=0;i<total_probed;i++) {
+			if (same_net(tov4(ip), tov4(probed_ifaces[i].ip), tov4(nmask))) {
+				add_interface(probed_ifaces[i].ip, nmask);
+				return;
+			}
+		}
+		DEBUG(2,("Can't determine ip for broadcast address %s\n", token));
+		return;
+	}
+
+	add_interface(ip, nmask);
+}
+
+
+/****************************************************************************
+load the list of network interfaces
+****************************************************************************/
+void load_interfaces(void)
+{
+	const char **ptr;
+	int i;
+	struct iface_struct ifaces[MAX_INTERFACES];
+	TALLOC_CTX *mem_ctx;
+
+	ptr = lp_interfaces();
+	mem_ctx = talloc_init("load_interfaces");
+    if (!mem_ctx) {
+    	DEBUG(2,("no memory to load interfaces \n"));
+		return;
+    }
+
+	allones_ip = interpret_addr2("255.255.255.255");
+	loopback_ip = interpret_addr2("127.0.0.1");
+
+	SAFE_FREE(probed_ifaces);
+
+	/* dump the current interfaces if any */
+	while (local_interfaces) {
+		struct interface *iface = local_interfaces;
+		DLIST_REMOVE(local_interfaces, local_interfaces);
+		ZERO_STRUCTPN(iface);
+		SAFE_FREE(iface);
+	}
+
+	/* probe the kernel for interfaces */
+	total_probed = get_interfaces(ifaces, MAX_INTERFACES);
+
+	if (total_probed > 0) {
+		probed_ifaces = memdup(ifaces, sizeof(ifaces[0])*total_probed);
+	}
+
+	/* if we don't have a interfaces line then use all broadcast capable 
+	   interfaces except loopback */
+	if (!ptr || !*ptr || !**ptr) {
+		if (total_probed <= 0) {
+			DEBUG(0,("ERROR: Could not determine network interfaces, you must use a interfaces config line\n"));
+			exit(1);
+		}
+		for (i=0;i<total_probed;i++) {
+			if (probed_ifaces[i].netmask.s_addr != allones_ip.s_addr &&
+			    probed_ifaces[i].ip.s_addr != loopback_ip.s_addr) {
+				add_interface(probed_ifaces[i].ip, 
+					      probed_ifaces[i].netmask);
+			}
+		}
+		goto exit;
+	}
+
+	if (ptr) {
+		while (*ptr) {
+			interpret_interface(mem_ctx, *ptr);
+			ptr++;
+		}
+	}
+
+	if (!local_interfaces) {
+		DEBUG(0,("WARNING: no network interfaces found\n"));
+	}
+	
+exit:
+	talloc_destroy(mem_ctx);
+}
+
+
+/****************************************************************************
+return True if the list of probed interfaces has changed
+****************************************************************************/
+BOOL interfaces_changed(void)
+{
+	int n;
+	struct iface_struct ifaces[MAX_INTERFACES];
+
+	n = get_interfaces(ifaces, MAX_INTERFACES);
+
+	if ((n > 0 )&& (n != total_probed ||
+	    memcmp(ifaces, probed_ifaces, sizeof(ifaces[0])*n))) {
+		return True;
+	}
+	
+	return False;
+}
+
+
+/****************************************************************************
+  check if an IP is one of mine
+  **************************************************************************/
+BOOL ismyip(struct ipv4_addr ip)
+{
+	struct interface *i;
+	for (i=local_interfaces;i;i=i->next)
+		if (ip_equal(i->ip,ip)) return True;
+	return False;
+}
+
+/****************************************************************************
+  check if a packet is from a local (known) net
+  **************************************************************************/
+BOOL is_local_net(struct ipv4_addr from)
+{
+	struct interface *i;
+	for (i=local_interfaces;i;i=i->next) {
+		if((from.s_addr & i->nmask.s_addr) == 
+		   (i->ip.s_addr & i->nmask.s_addr))
+			return True;
+	}
+	return False;
+}
+
+/****************************************************************************
+  how many interfaces do we have
+  **************************************************************************/
+int iface_count(void)
+{
+	int ret = 0;
+	struct interface *i;
+
+	for (i=local_interfaces;i;i=i->next)
+		ret++;
+	return ret;
+}
+
+/****************************************************************************
+  return IP of the Nth interface
+  **************************************************************************/
+struct ipv4_addr *iface_n_ip(int n)
+{
+	struct interface *i;
+  
+	for (i=local_interfaces;i && n;i=i->next)
+		n--;
+
+	if (i) return &i->ip;
+	return NULL;
+}
+
+/****************************************************************************
+  return bcast of the Nth interface
+  **************************************************************************/
+struct ipv4_addr *iface_n_bcast(int n)
+{
+	struct interface *i;
+  
+	for (i=local_interfaces;i && n;i=i->next)
+		n--;
+
+	if (i) return &i->bcast;
+	return NULL;
+}
+
+
+/* these 3 functions return the ip/bcast/nmask for the interface
+   most appropriate for the given ip address. If they can't find
+   an appropriate interface they return the requested field of the
+   first known interface. */
+
+struct ipv4_addr *iface_ip(struct ipv4_addr ip)
+{
+	struct in_addr in;
+	struct interface *i;
+	in.s_addr = ip.s_addr;
+	i = iface_find(in, True);
+	return(i ? &i->ip : &local_interfaces->ip);
+}
+
+/*
+  return True if a IP is directly reachable on one of our interfaces
+*/
+BOOL iface_local(struct ipv4_addr ip)
+{
+	struct in_addr in;
+	in.s_addr = ip.s_addr;
+	return iface_find(in, True) ? True : False;
+}