/* User-kernel network link */
-/* Each netlink device is actually a router, with its own IP address.
- We do things like decreasing the TTL and recalculating the header
- checksum, generating ICMP, responding to pings, etc. */
+/* See RFCs 791, 792, 1123 and 1812 */
-/* This is where we have the anti-spoofing paranoia - before sending a
- packet to the kernel we check that the tunnel it came over could
- reasonably have produced it. */
+/* The netlink device is actually a router. Tunnels are unnumbered
+ point-to-point lines (RFC1812 section 2.2.7); the router has a
+ single address (the 'router-id'). */
+/* This is where we currently have the anti-spoofing paranoia - before
+ sending a packet to the kernel we check that the tunnel it came
+ over could reasonably have produced it. */
+
+
+/* Points to note from RFC1812 (which may require changes in this
+ file):
+
+3.3.4 Maximum Transmission Unit - MTU
+
+ The MTU of each logical interface MUST be configurable within the
+ range of legal MTUs for the interface.
+
+ Many Link Layer protocols define a maximum frame size that may be
+ sent. In such cases, a router MUST NOT allow an MTU to be set which
+ would allow sending of frames larger than those allowed by the Link
+ Layer protocol. However, a router SHOULD be willing to receive a
+ packet as large as the maximum frame size even if that is larger than
+ the MTU.
+
+4.2.1 A router SHOULD count datagrams discarded.
+
+4.2.2.1 Source route options - we probably should implement processing
+of source routes, even though mostly the security policy will prevent
+their use.
+
+5.3.13.4 Source Route Options
+
+ A router MUST implement support for source route options in forwarded
+ packets. A router MAY implement a configuration option that, when
+ enabled, causes all source-routed packets to be discarded. However,
+ such an option MUST NOT be enabled by default.
+
+5.3.13.5 Record Route Option
+
+ Routers MUST support the Record Route option in forwarded packets.
+
+ A router MAY provide a configuration option that, if enabled, will
+ cause the router to ignore (i.e., pass through unchanged) Record
+ Route options in forwarded packets. If provided, such an option MUST
+ default to enabling the record-route. This option should not affect
+ the processing of Record Route options in datagrams received by the
+ router itself (in particular, Record Route options in ICMP echo
+ requests will still be processed according to Section [4.3.3.6]).
+
+5.3.13.6 Timestamp Option
+
+ Routers MUST support the timestamp option in forwarded packets. A
+ timestamp value MUST follow the rules given [INTRO:2].
+
+ If the flags field = 3 (timestamp and prespecified address), the
+ router MUST add its timestamp if the next prespecified address
+ matches any of the router's IP addresses. It is not necessary that
+ the prespecified address be either the address of the interface on
+ which the packet arrived or the address of the interface over which
+ it will be sent.
+
+
+4.2.2.7 Fragmentation: RFC 791 Section 3.2
+
+ Fragmentation, as described in [INTERNET:1], MUST be supported by a
+ router.
+
+4.2.2.8 Reassembly: RFC 791 Section 3.2
+
+ As specified in the corresponding section of [INTRO:2], a router MUST
+ support reassembly of datagrams that it delivers to itself.
+
+4.2.2.9 Time to Live: RFC 791 Section 3.2
+
+ Note in particular that a router MUST NOT check the TTL of a packet
+ except when forwarding it.
+
+ A router MUST NOT discard a datagram just because it was received
+ with TTL equal to zero or one; if it is to the router and otherwise
+ valid, the router MUST attempt to receive it.
+
+ On messages the router originates, the IP layer MUST provide a means
+ for the transport layer to set the TTL field of every datagram that
+ is sent. When a fixed TTL value is used, it MUST be configurable.
+
+
+8.1 The Simple Network Management Protocol - SNMP
+8.1.1 SNMP Protocol Elements
+
+ Routers MUST be manageable by SNMP [MGT:3]. The SNMP MUST operate
+ using UDP/IP as its transport and network protocols.
+
+
+*/
+
+#include <string.h>
+#include <assert.h>
+#include <limits.h>
#include "secnet.h"
#include "util.h"
#include "ipaddr.h"
#include "netlink.h"
#include "process.h"
+#define ICMP_TYPE_ECHO_REPLY 0
+
+#define ICMP_TYPE_UNREACHABLE 3
+#define ICMP_CODE_NET_UNREACHABLE 0
+#define ICMP_CODE_PROTOCOL_UNREACHABLE 2
+#define ICMP_CODE_FRAGMENTATION_REQUIRED 4
+#define ICMP_CODE_NET_PROHIBITED 13
+
+#define ICMP_TYPE_ECHO_REQUEST 8
+
+#define ICMP_TYPE_TIME_EXCEEDED 11
+#define ICMP_CODE_TTL_EXCEEDED 0
+
/* Generic IP checksum routine */
-static inline uint16_t ip_csum(uint8_t *iph,uint32_t count)
+static inline uint16_t ip_csum(uint8_t *iph,int32_t count)
{
register uint32_t sum=0;
* By Jorge Cwik <jorge@laser.satlink.net>, adapted for linux by
* Arnt Gulbrandsen.
*/
-static inline uint16_t ip_fast_csum(uint8_t *iph, uint32_t ihl) {
+static inline uint16_t ip_fast_csum(uint8_t *iph, int32_t ihl) {
uint32_t sum;
- __asm__ __volatile__("
- movl (%1), %0
- subl $4, %2
- jbe 2f
- addl 4(%1), %0
- adcl 8(%1), %0
- adcl 12(%1), %0
-1: adcl 16(%1), %0
- lea 4(%1), %1
- decl %2
- jne 1b
- adcl $0, %0
- movl %0, %2
- shrl $16, %0
- addw %w2, %w0
- adcl $0, %0
- notl %0
-2:
- "
+ __asm__ __volatile__(
+ "movl (%1), %0 ;\n"
+ "subl $4, %2 ;\n"
+ "jbe 2f ;\n"
+ "addl 4(%1), %0 ;\n"
+ "adcl 8(%1), %0 ;\n"
+ "adcl 12(%1), %0 ;\n"
+"1: adcl 16(%1), %0 ;\n"
+ "lea 4(%1), %1 ;\n"
+ "decl %2 ;\n"
+ "jne 1b ;\n"
+ "adcl $0, %0 ;\n"
+ "movl %0, %2 ;\n"
+ "shrl $16, %0 ;\n"
+ "addw %w2, %w0 ;\n"
+ "adcl $0, %0 ;\n"
+ "notl %0 ;\n"
+"2: ;\n"
/* Since the input registers which are loaded with iph and ipl
are modified, we must also specify them as outputs, or gcc
will assume they contain their original values. */
: "=r" (sum), "=r" (iph), "=r" (ihl)
- : "1" (iph), "2" (ihl));
+ : "1" (iph), "2" (ihl)
+ : "memory");
return sum;
}
#else
-static inline uint16_t ip_fast_csum(uint8_t *iph, uint32_t ihl)
+static inline uint16_t ip_fast_csum(uint8_t *iph, int32_t ihl)
{
+ assert(ihl < INT_MAX/4);
return ip_csum(iph,ihl*4);
}
#endif
struct netlink_client *client,
struct buffer_if *buf);
+/* XXX RFC1812 4.3.2.5:
+ All other ICMP error messages (Destination Unreachable,
+ Redirect, Time Exceeded, and Parameter Problem) SHOULD have their
+ precedence value set to 6 (INTERNETWORK CONTROL) or 7 (NETWORK
+ CONTROL). The IP Precedence value for these error messages MAY be
+ settable.
+ */
static struct icmphdr *netlink_icmp_tmpl(struct netlink *st,
uint32_t dest,uint16_t len)
{
struct icmphdr *h;
BUF_ALLOC(&st->icmp,"netlink_icmp_tmpl");
- buffer_init(&st->icmp,st->max_start_pad);
+ buffer_init(&st->icmp,calculate_max_start_pad());
h=buf_append(&st->icmp,sizeof(*h));
h->iph.version=4;
h->iph.tot_len=htons(len+(h->iph.ihl*4)+8);
h->iph.id=0;
h->iph.frag_off=0;
- h->iph.ttl=255;
+ h->iph.ttl=255; /* XXX should be configurable */
h->iph.protocol=1;
h->iph.saddr=htonl(st->secnet_address);
h->iph.daddr=htonl(dest);
/* Fill in the ICMP checksum field correctly */
static void netlink_icmp_csum(struct icmphdr *h)
{
- uint32_t len;
+ int32_t len;
len=ntohs(h->iph.tot_len)-(4*h->iph.ihl);
h->check=0;
static bool_t netlink_icmp_may_reply(struct buffer_if *buf)
{
struct iphdr *iph;
+ struct icmphdr *icmph;
uint32_t source;
+ if (buf->size < (int)sizeof(struct icmphdr)) return False;
iph=(struct iphdr *)buf->start;
- if (iph->protocol==1) return False; /* Overly-broad; we may reply to
- eg. icmp echo-request */
+ icmph=(struct icmphdr *)buf->start;
+ if (iph->protocol==1) {
+ switch(icmph->type) {
+ case 3: /* Destination unreachable */
+ case 11: /* Time Exceeded */
+ case 12: /* Parameter Problem */
+ return False;
+ }
+ }
/* How do we spot broadcast destination addresses? */
if (ntohs(iph->frag_off)&0x1fff) return False; /* Non-initial fragment */
source=ntohl(iph->saddr);
/* How much of the original IP packet do we include in its ICMP
response? The header plus up to 64 bits. */
+
+/* XXX TODO RFC1812:
+4.3.2.3 Original Message Header
+
+ Historically, every ICMP error message has included the Internet
+ header and at least the first 8 data bytes of the datagram that
+ triggered the error. This is no longer adequate, due to the use of
+ IP-in-IP tunneling and other technologies. Therefore, the ICMP
+ datagram SHOULD contain as much of the original datagram as possible
+ without the length of the ICMP datagram exceeding 576 bytes. The
+ returned IP header (and user data) MUST be identical to that which
+ was received, except that the router is not required to undo any
+ modifications to the IP header that are normally performed in
+ forwarding that were performed before the error was detected (e.g.,
+ decrementing the TTL, or updating options). Note that the
+ requirements of Section [4.3.3.5] supersede this requirement in some
+ cases (i.e., for a Parameter Problem message, if the problem is in a
+ modified field, the router must undo the modification). See Section
+ [4.3.3.5]).
+ */
static uint16_t netlink_icmp_reply_len(struct buffer_if *buf)
{
+ if (buf->size < (int)sizeof(struct iphdr)) return 0;
struct iphdr *iph=(struct iphdr *)buf->start;
uint16_t hlen,plen;
struct netlink_client *client,
uint8_t type, uint8_t code)
{
- struct iphdr *iph=(struct iphdr *)buf->start;
struct icmphdr *h;
uint16_t len;
if (netlink_icmp_may_reply(buf)) {
+ struct iphdr *iph=(struct iphdr *)buf->start;
len=netlink_icmp_reply_len(buf);
h=netlink_icmp_tmpl(st,ntohl(iph->saddr),len);
h->type=type; h->code=code;
/*
* RFC1122: 3.1.2.2 MUST silently discard any IP frame that fails the
* checksum.
+ * RFC1812: 4.2.2.5 MUST discard messages containing invalid checksums.
*
* Is the datagram acceptable?
*
* 3. Checksums correctly.
* 4. Doesn't have a bogus length
*/
-static bool_t netlink_check(struct netlink *st, struct buffer_if *buf)
+static bool_t netlink_check(struct netlink *st, struct buffer_if *buf,
+ char *errmsgbuf, int errmsgbuflen)
{
+#define BAD(...) do{ \
+ snprintf(errmsgbuf,errmsgbuflen,__VA_ARGS__); \
+ return False; \
+ }while(0)
+
+ if (buf->size < (int)sizeof(struct iphdr)) BAD("len %"PRIu32"",buf->size);
struct iphdr *iph=(struct iphdr *)buf->start;
- uint32_t len;
+ int32_t len;
- if (iph->ihl < 5 || iph->version != 4) return False;
- if (buf->size < iph->ihl*4) return False;
- if (ip_fast_csum((uint8_t *)iph, iph->ihl)!=0) return False;
+ if (iph->ihl < 5) BAD("ihl %u",iph->ihl);
+ if (iph->version != 4) BAD("version %u",iph->version);
+ if (buf->size < iph->ihl*4) BAD("size %"PRId32"<%u*4",buf->size,iph->ihl);
+ if (ip_fast_csum((uint8_t *)iph, iph->ihl)!=0) BAD("csum");
len=ntohs(iph->tot_len);
/* There should be no padding */
- if (buf->size!=len || len<(iph->ihl<<2)) return False;
+ if (buf->size!=len) BAD("len %"PRId32"!=%"PRId32,buf->size,len);
+ if (len<(iph->ihl<<2)) BAD("len %"PRId32"<(%u<<2)",len,iph->ihl);
/* XXX check that there's no source route specified */
return True;
+
+#undef BAD
+}
+
+/* Deliver a packet _to_ client; used after we have decided
+ * what to do with it (and just to check that the client has
+ * actually registered a delivery function with us). */
+static void netlink_client_deliver(struct netlink *st,
+ struct netlink_client *client,
+ uint32_t source, uint32_t dest,
+ struct buffer_if *buf)
+{
+ if (!client->deliver) {
+ string_t s,d;
+ s=ipaddr_to_string(source);
+ d=ipaddr_to_string(dest);
+ Message(M_ERR,"%s: dropping %s->%s, client not registered\n",
+ st->name,s,d);
+ free(s); free(d);
+ BUF_FREE(buf);
+ return;
+ }
+ client->deliver(client->dst, buf);
+ client->outcount++;
}
-/* Deliver a packet. "client" points to the _origin_ of the packet, not
- its destination. (May be used when sending ICMP response - avoid
- asymmetric routing.) */
+/* Deliver a packet. "client" is the _origin_ of the packet, not its
+ destination, and is NULL for packets from the host and packets
+ generated internally in secnet. */
static void netlink_packet_deliver(struct netlink *st,
struct netlink_client *client,
struct buffer_if *buf)
{
+ if (buf->size < (int)sizeof(struct iphdr)) {
+ Message(M_ERR,"%s: trying to deliver a too-short packet"
+ " from %s!\n",st->name, client?client->name:"(local)");
+ BUF_FREE(buf);
+ return;
+ }
+
struct iphdr *iph=(struct iphdr *)buf->start;
uint32_t dest=ntohl(iph->daddr);
uint32_t source=ntohl(iph->saddr);
uint32_t best_quality;
+ bool_t allow_route=False;
+ bool_t found_allowed=False;
int best_match;
int i;
BUF_ASSERT_USED(buf);
if (dest==st->secnet_address) {
- Message(M_ERROR,"%s: trying to deliver a packet to myself!\n");
+ Message(M_ERR,"%s: trying to deliver a packet to myself!\n",st->name);
BUF_FREE(buf);
return;
}
- /* XXX we're going to need an extra value 'allow_route' for the
- source of the packet. It's always True for packets from the
- host. For packets from tunnels, we consult the client
- options. If !allow_route and the destination is a tunnel that
- also doesn't allow routing, we must reject the packet with an
- 'administratively prohibited' or something similar ICMP. */
- if (!client) {
- /* Origin of packet is host or secnet. Might be for a tunnel. */
- best_quality=0;
- best_match=-1;
- for (i=0; i<st->n_routes; i++) {
- if (st->routes[i].up && subnet_match(&st->routes[i].net,dest)) {
- if (st->routes[i].c->link_quality>best_quality
- || best_quality==0) {
- best_quality=st->routes[i].c->link_quality;
- best_match=i;
- /* If quality isn't perfect we may wish to
- consider kicking the tunnel with a 0-length
- packet to prompt it to perform a key setup.
- Then it'll eventually decide it's up or
- down. */
- /* If quality is perfect we don't need to search
- any more. */
- if (best_quality>=MAXIMUM_LINK_QUALITY) break;
- }
+ /* Packets from the host (client==NULL) may always be routed. Packets
+ from clients with the allow_route option will also be routed. */
+ if (!client || (client && (client->options & OPT_ALLOWROUTE)))
+ allow_route=True;
+
+ /* If !allow_route, we check the routing table anyway, and if
+ there's a suitable route with OPT_ALLOWROUTE set we use it. If
+ there's a suitable route, but none with OPT_ALLOWROUTE set then
+ we generate ICMP 'communication with destination network
+ administratively prohibited'. */
+
+ best_quality=0;
+ best_match=-1;
+ for (i=0; i<st->n_clients; i++) {
+ if (st->routes[i]->up &&
+ ipset_contains_addr(st->routes[i]->networks,dest)) {
+ /* It's an available route to the correct destination. But is
+ it better than the one we already have? */
+
+ /* If we have already found an allowed route then we don't
+ bother looking at routes we're not allowed to use. If
+ we don't yet have an allowed route we'll consider any. */
+ if (!allow_route && found_allowed) {
+ if (!(st->routes[i]->options&OPT_ALLOWROUTE)) continue;
}
- }
- if (best_match==-1) {
- /* Not going down a tunnel. Might be for the host.
- XXX think about this - only situation should be if we're
- sending ICMP. */
- if (source!=st->secnet_address) {
- Message(M_ERROR,"netlink_packet_deliver: outgoing packet "
- "from host that won't fit down any of our tunnels!\n");
- /* XXX I think this could also occur if a soft tunnel just
- went down, but still had packets queued in the kernel. */
- BUF_FREE(buf);
- } else {
- st->deliver_to_host(st->dst,NULL,buf);
- BUF_ASSERT_FREE(buf);
+
+ if (st->routes[i]->link_quality>best_quality
+ || best_quality==0) {
+ best_quality=st->routes[i]->link_quality;
+ best_match=i;
+ if (st->routes[i]->options&OPT_ALLOWROUTE)
+ found_allowed=True;
+ /* If quality isn't perfect we may wish to
+ consider kicking the tunnel with a 0-length
+ packet to prompt it to perform a key setup.
+ Then it'll eventually decide it's up or
+ down. */
+ /* If quality is perfect and we're allowed to use the
+ route we don't need to search any more. */
+ if (best_quality>=MAXIMUM_LINK_QUALITY &&
+ (allow_route || found_allowed)) break;
}
+ }
+ }
+ if (best_match==-1) {
+ /* The packet's not going down a tunnel. It might (ought to)
+ be for the host. */
+ if (ipset_contains_addr(st->networks,dest)) {
+ st->deliver_to_host(st->dst,buf);
+ st->outcount++;
+ BUF_ASSERT_FREE(buf);
+ } else {
+ string_t s,d;
+ s=ipaddr_to_string(source);
+ d=ipaddr_to_string(dest);
+ Message(M_DEBUG,"%s: don't know where to deliver packet "
+ "(s=%s, d=%s)\n", st->name, s, d);
+ free(s); free(d);
+ netlink_icmp_simple(st,buf,client,ICMP_TYPE_UNREACHABLE,
+ ICMP_CODE_NET_UNREACHABLE);
+ BUF_FREE(buf);
+ }
+ } else {
+ if (!allow_route &&
+ !(st->routes[best_match]->options&OPT_ALLOWROUTE)) {
+ string_t s,d;
+ s=ipaddr_to_string(source);
+ d=ipaddr_to_string(dest);
+ /* We have a usable route but aren't allowed to use it.
+ Generate ICMP destination unreachable: communication
+ with destination network administratively prohibited */
+ Message(M_NOTICE,"%s: denied forwarding for packet (s=%s, d=%s)\n",
+ st->name,s,d);
+ free(s); free(d);
+
+ netlink_icmp_simple(st,buf,client,ICMP_TYPE_UNREACHABLE,
+ ICMP_CODE_NET_PROHIBITED);
+ BUF_FREE(buf);
} else {
if (best_quality>0) {
- st->routes[best_match].c->deliver(
- st->routes[best_match].c->dst,
- st->routes[best_match].c, buf);
+ /* XXX Fragment if required */
+ netlink_client_deliver(st,st->routes[best_match],
+ source,dest,buf);
BUF_ASSERT_FREE(buf);
} else {
/* Generate ICMP destination unreachable */
- netlink_icmp_simple(st,buf,client,3,0); /* client==NULL */
+ netlink_icmp_simple(st,buf,client,ICMP_TYPE_UNREACHABLE,
+ ICMP_CODE_NET_UNREACHABLE); /* client==NULL */
BUF_FREE(buf);
}
}
- } else { /* client is set */
- /* We know the origin is a tunnel - packet must be for the host */
- /* XXX THIS IS NOT NECESSARILY TRUE, AND NEEDS FIXING */
- /* THIS FUNCTION MUST JUST DELIVER THE PACKET: IT MUST ASSUME
- THE PACKET HAS ALREADY BEEN CHECKED */
- if (subnet_matches_list(&st->networks,dest)) {
- st->deliver_to_host(st->dst,NULL,buf);
- BUF_ASSERT_FREE(buf);
- } else {
- Message(M_ERROR,"%s: packet from tunnel %s can't be delivered "
- "to the host\n",st->name,client->name);
- netlink_icmp_simple(st,buf,client,3,0);
- BUF_FREE(buf);
- }
}
BUF_ASSERT_FREE(buf);
}
struct netlink_client *client,
struct buffer_if *buf)
{
+ if (buf->size < (int)sizeof(struct iphdr)) return;
struct iphdr *iph=(struct iphdr *)buf->start;
BUF_ASSERT_USED(buf);
/* Packet has already been checked */
if (iph->ttl<=1) {
/* Generate ICMP time exceeded */
- netlink_icmp_simple(st,buf,client,11,0);
+ netlink_icmp_simple(st,buf,client,ICMP_TYPE_TIME_EXCEEDED,
+ ICMP_CODE_TTL_EXCEEDED);
BUF_FREE(buf);
return;
}
{
struct icmphdr *h;
+ st->localcount++;
+
+ if (buf->size < (int)sizeof(struct icmphdr)) {
+ Message(M_WARNING,"%s: short packet addressed to secnet; "
+ "ignoring it\n",st->name);
+ BUF_FREE(buf);
+ return;
+ }
h=(struct icmphdr *)buf->start;
if ((ntohs(h->iph.frag_off)&0xbfff)!=0) {
if (h->iph.protocol==1) {
/* It's ICMP */
- if (h->type==8 && h->code==0) {
+ if (h->type==ICMP_TYPE_ECHO_REQUEST && h->code==0) {
/* ICMP echo-request. Special case: we re-use the buffer
to construct the reply. */
- h->type=0;
+ h->type=ICMP_TYPE_ECHO_REPLY;
h->iph.daddr=h->iph.saddr;
h->iph.saddr=htonl(st->secnet_address);
- h->iph.ttl=255; /* Be nice and bump it up again... */
+ h->iph.ttl=255;
h->iph.check=0;
h->iph.check=ip_fast_csum((uint8_t *)h,h->iph.ihl);
netlink_icmp_csum(h);
Message(M_WARNING,"%s: unknown incoming ICMP\n",st->name);
} else {
/* Send ICMP protocol unreachable */
- netlink_icmp_simple(st,buf,client,3,2);
+ netlink_icmp_simple(st,buf,client,ICMP_TYPE_UNREACHABLE,
+ ICMP_CODE_PROTOCOL_UNREACHABLE);
BUF_FREE(buf);
return;
}
/* If cid==NULL packet is from host, otherwise cid specifies which tunnel
it came from. */
-static void netlink_incoming(void *sst, void *cid, struct buffer_if *buf)
+static void netlink_incoming(struct netlink *st, struct netlink_client *client,
+ struct buffer_if *buf)
{
- struct netlink *st=sst;
- struct netlink_client *client=cid;
uint32_t source,dest;
struct iphdr *iph;
+ char errmsgbuf[50];
+ const char *sourcedesc=client?client->name:"host";
BUF_ASSERT_USED(buf);
- if (!netlink_check(st,buf)) {
- Message(M_WARNING,"%s: bad IP packet from %s\n",
- st->name,client?client->name:"host");
+
+ if (!netlink_check(st,buf,errmsgbuf,sizeof(errmsgbuf))) {
+ Message(M_WARNING,"%s: bad IP packet from %s: %s\n",
+ st->name,sourcedesc,
+ errmsgbuf);
BUF_FREE(buf);
return;
}
+ assert(buf->size >= (int)sizeof(struct icmphdr));
iph=(struct iphdr *)buf->start;
source=ntohl(iph->saddr);
dest=ntohl(iph->daddr);
- /* Check source */
+ /* Check source. If we don't like the source, there's no point
+ generating ICMP because we won't know how to get it to the
+ source of the packet. */
if (client) {
/* Check that the packet source is appropriate for the tunnel
it came down */
- if (!subnet_matches_list(client->networks,source)) {
+ if (!ipset_contains_addr(client->networks,source)) {
string_t s,d;
s=ipaddr_to_string(source);
d=ipaddr_to_string(dest);
/* Check that the packet originates in our configured local
network, and hasn't been forwarded from elsewhere or
generated with the wrong source address */
- if (!subnet_matches_list(&st->networks,source)) {
+ if (!ipset_contains_addr(st->networks,source)) {
string_t s,d;
s=ipaddr_to_string(source);
d=ipaddr_to_string(dest);
}
}
- /* If this is a point-to-point device we don't examine the packet at
- all; we blindly send it down our one-and-only registered tunnel,
- or to the host, depending on where it came from. */
+ /* If this is a point-to-point device we don't examine the
+ destination address at all; we blindly send it down our
+ one-and-only registered tunnel, or to the host, depending on
+ where it came from. It's up to external software to check
+ address validity and generate ICMP, etc. */
if (st->ptp) {
if (client) {
- st->deliver_to_host(st->dst,NULL,buf);
+ st->deliver_to_host(st->dst,buf);
} else {
- st->clients->deliver(st->clients->dst,NULL,buf);
+ netlink_client_deliver(st,st->clients,source,dest,buf);
}
BUF_ASSERT_FREE(buf);
return;
}
- /* (st->secnet_address needs checking before matching destination
- addresses) */
+ /* st->secnet_address needs checking before matching destination
+ addresses */
if (dest==st->secnet_address) {
netlink_packet_local(st,client,buf);
BUF_ASSERT_FREE(buf);
return;
}
- if (client) {
- /* Check for free routing */
- if (!subnet_matches_list(&st->networks,dest)) {
- string_t s,d;
- s=ipaddr_to_string(source);
- d=ipaddr_to_string(dest);
- Message(M_WARNING,"%s: incoming packet from tunnel %s "
- "with bad destination address "
- "(s=%s,d=%s)\n",st->name,client->name,s,d);
- free(s); free(d);
- BUF_FREE(buf);
- return;
- }
- }
netlink_packet_forward(st,client,buf);
BUF_ASSERT_FREE(buf);
}
-static void netlink_set_softlinks(struct netlink *st, struct netlink_client *c,
- bool_t up, uint32_t quality)
+static void netlink_inst_incoming(void *sst, struct buffer_if *buf)
{
- uint32_t i;
-
- if (!st->routes) return; /* Table has not yet been created */
- for (i=0; i<st->n_routes; i++) {
- if (st->routes[i].c==c) {
- st->routes[i].quality=quality;
- if (!st->routes[i].hard) {
- st->routes[i].up=up;
- st->set_route(st->dst,&st->routes[i]);
- }
- }
- }
+ struct netlink_client *c=sst;
+ struct netlink *st=c->nst;
+
+ netlink_incoming(st,c,buf);
}
-static void netlink_set_quality(void *sst, void *cid, uint32_t quality)
+static void netlink_dev_incoming(void *sst, struct buffer_if *buf)
{
struct netlink *st=sst;
- struct netlink_client *c=cid;
- c->link_quality=quality;
- if (c->link_quality==LINK_QUALITY_DOWN) {
- netlink_set_softlinks(st,c,False,c->link_quality);
- } else {
- netlink_set_softlinks(st,c,True,c->link_quality);
- }
+ netlink_incoming(st,NULL,buf);
}
-static void *netlink_regnets(void *sst, struct subnet_list *nets,
- netlink_deliver_fn *deliver, void *dst,
- uint32_t max_start_pad, uint32_t max_end_pad,
- uint32_t options, string_t client_name)
+static void netlink_set_quality(void *sst, uint32_t quality)
{
- struct netlink *st=sst;
- struct netlink_client *c;
-
- Message(M_DEBUG_CONFIG,"netlink_regnets: request for %d networks, "
- "max_start_pad=%d, max_end_pad=%d\n",
- nets->entries,max_start_pad,max_end_pad);
-
- if ((options&NETLINK_OPTION_SOFTROUTE) && !st->set_route) {
- Message(M_ERROR,"%s: this netlink device does not support "
- "soft routes.\n");
- return NULL;
- }
+ struct netlink_client *c=sst;
+ struct netlink *st=c->nst;
- if (options&NETLINK_OPTION_SOFTROUTE) {
- /* XXX for now we assume that soft routes require root privilege;
- this may not always be true. The device driver can tell us. */
- require_root_privileges=True;
- require_root_privileges_explanation="netlink: soft routes";
+ c->link_quality=quality;
+ c->up=(c->link_quality==LINK_QUALITY_DOWN)?False:True;
+ if (c->options&OPT_SOFTROUTE) {
+ st->set_routes(st->dst,c);
}
+}
- /* Check that nets do not intersect st->exclude_remote_networks;
- refuse to register if they do. */
- if (subnet_lists_intersect(&st->exclude_remote_networks,nets)) {
- Message(M_ERROR,"%s: site %s specifies networks that "
- "intersect with the explicitly excluded remote networks\n",
- st->name,client_name);
- return NULL;
- }
+static void netlink_output_subnets(struct netlink *st, uint32_t loglevel,
+ struct subnet_list *snets)
+{
+ int32_t i;
+ string_t net;
- if (st->clients && st->ptp) {
- fatal("%s: only one site may use a point-to-point netlink device\n",
- st->name);
- return NULL;
+ for (i=0; i<snets->entries; i++) {
+ net=subnet_to_string(snets->list[i]);
+ Message(loglevel,"%s ",net);
+ free(net);
}
-
- c=safe_malloc(sizeof(*c),"netlink_regnets");
- c->networks=nets;
- c->deliver=deliver;
- c->dst=dst;
- c->name=client_name;
- c->options=options;
- c->link_quality=LINK_QUALITY_DOWN;
- c->next=st->clients;
- st->clients=c;
- if (max_start_pad > st->max_start_pad) st->max_start_pad=max_start_pad;
- if (max_end_pad > st->max_end_pad) st->max_end_pad=max_end_pad;
- st->n_routes+=nets->entries;
-
- return c;
}
static void netlink_dump_routes(struct netlink *st, bool_t requested)
uint32_t c=M_INFO;
if (requested) c=M_WARNING;
- Message(c,"%s: routing table:\n",st->name);
- for (i=0; i<st->n_routes; i++) {
- net=subnet_to_string(&st->routes[i].net);
- Message(c,"%s -> tunnel %s (%s,%s route,%s,quality %d)\n",net,
- st->routes[i].c->name,
- st->routes[i].hard?"hard":"soft",
- st->routes[i].allow_route?"free":"restricted",
- st->routes[i].up?"up":"down",
- st->routes[i].quality);
+ if (st->ptp) {
+ net=ipaddr_to_string(st->secnet_address);
+ Message(c,"%s: point-to-point (remote end is %s); routes: ",
+ st->name, net);
free(net);
- }
- Message(c,"%s/32 -> netlink \"%s\"\n",
- ipaddr_to_string(st->secnet_address),st->name);
- for (i=0; i<st->networks.entries; i++) {
- net=subnet_to_string(&st->networks.list[i]);
- Message(c,"%s -> host\n",net);
+ netlink_output_subnets(st,c,st->clients->subnets);
+ Message(c,"\n");
+ } else {
+ Message(c,"%s: routing table:\n",st->name);
+ for (i=0; i<st->n_clients; i++) {
+ netlink_output_subnets(st,c,st->routes[i]->subnets);
+ Message(c,"-> tunnel %s (%s,mtu %d,%s routes,%s,"
+ "quality %d,use %d,pri %lu)\n",
+ st->routes[i]->name,
+ st->routes[i]->up?"up":"down",
+ st->routes[i]->mtu,
+ st->routes[i]->options&OPT_SOFTROUTE?"soft":"hard",
+ st->routes[i]->options&OPT_ALLOWROUTE?"free":"restricted",
+ st->routes[i]->link_quality,
+ st->routes[i]->outcount,
+ (unsigned long)st->routes[i]->priority);
+ }
+ net=ipaddr_to_string(st->secnet_address);
+ Message(c,"%s/32 -> netlink \"%s\" (use %d)\n",
+ net,st->name,st->localcount);
free(net);
+ for (i=0; i<st->subnets->entries; i++) {
+ net=subnet_to_string(st->subnets->list[i]);
+ Message(c,"%s ",net);
+ free(net);
+ }
+ if (i>0)
+ Message(c,"-> host (use %d)\n",st->outcount);
}
}
-static int netlink_compare_route_specificity(const void *ap, const void *bp)
+/* ap is a pointer to a member of the routes array */
+static int netlink_compare_client_priority(const void *ap, const void *bp)
{
- const struct netlink_route *a=ap;
- const struct netlink_route *b=bp;
+ const struct netlink_client *const*a=ap;
+ const struct netlink_client *const*b=bp;
- if (a->net.len==b->net.len) return 0;
- if (a->net.len<b->net.len) return 1;
+ if ((*a)->priority==(*b)->priority) return 0;
+ if ((*a)->priority<(*b)->priority) return 1;
return -1;
}
{
struct netlink *st=sst;
struct netlink_client *c;
- uint32_t i,j;
-
- if (!st->clients && st->ptp) {
- /* Point-to-point netlink devices must have precisely one
- client. If none has registered by now, complain. */
- fatal("%s: point-to-point netlink devices must have precisely "
- "one client. This one doesn't have any.\n",st->name);
- }
+ int32_t i;
/* All the networks serviced by the various tunnels should now
* have been registered. We build a routing table by sorting the
- * routes into most-specific-first order. */
- st->routes=safe_malloc(st->n_routes*sizeof(*st->routes),
- "netlink_phase_hook");
+ * clients by priority. */
+ st->routes=safe_malloc_ary(sizeof(*st->routes),st->n_clients,
+ "netlink_phase_hook");
/* Fill the table */
i=0;
for (c=st->clients; c; c=c->next) {
- for (j=0; j<c->networks->entries; j++) {
- st->routes[i].net=c->networks->list[j];
- st->routes[i].c=c;
- /* Hard routes are always up;
- soft routes default to down */
- st->routes[i].up=c->options&NETLINK_OPTION_SOFTROUTE?False:True;
- st->routes[i].kup=False;
- st->routes[i].hard=c->options&NETLINK_OPTION_SOFTROUTE?False:True;
- st->routes[i].allow_route=c->options&NETLINK_OPTION_ALLOW_ROUTE?
- True:False;
- st->routes[i].quality=c->link_quality;
- i++;
- }
+ assert(i<INT_MAX);
+ st->routes[i++]=c;
}
- /* ASSERT i==st->n_routes */
- if (i!=st->n_routes) {
- fatal("netlink: route count error: expected %d got %d\n",
- st->n_routes,i);
- }
- /* Sort the table in descending order of specificity */
- qsort(st->routes,st->n_routes,sizeof(*st->routes),
- netlink_compare_route_specificity);
+ /* Sort the table in descending order of priority */
+ qsort(st->routes,st->n_clients,sizeof(*st->routes),
+ netlink_compare_client_priority);
netlink_dump_routes(st,False);
}
netlink_dump_routes(st,True);
}
+static void netlink_inst_set_mtu(void *sst, int32_t new_mtu)
+{
+ struct netlink_client *c=sst;
+
+ c->mtu=new_mtu;
+}
+
+static void netlink_inst_reg(void *sst, netlink_deliver_fn *deliver,
+ void *dst)
+{
+ struct netlink_client *c=sst;
+
+ c->deliver=deliver;
+ c->dst=dst;
+}
+
+static struct flagstr netlink_option_table[]={
+ { "soft", OPT_SOFTROUTE },
+ { "allow-route", OPT_ALLOWROUTE },
+ { NULL, 0}
+};
+/* This is the routine that gets called when the closure that's
+ returned by an invocation of a netlink device closure (eg. tun,
+ userv-ipif) is invoked. It's used to create routes and pass in
+ information about them; the closure it returns is used by site
+ code. */
+static closure_t *netlink_inst_create(struct netlink *st,
+ struct cloc loc, dict_t *dict)
+{
+ struct netlink_client *c;
+ string_t name;
+ struct ipset *networks;
+ uint32_t options,priority;
+ int32_t mtu;
+ list_t *l;
+
+ name=dict_read_string(dict, "name", True, st->name, loc);
+
+ l=dict_lookup(dict,"routes");
+ if (!l)
+ cfgfatal(loc,st->name,"required parameter \"routes\" not found\n");
+ networks=string_list_to_ipset(l,loc,st->name,"routes");
+ options=string_list_to_word(dict_lookup(dict,"options"),
+ netlink_option_table,st->name);
+
+ priority=dict_read_number(dict,"priority",False,st->name,loc,0);
+ mtu=dict_read_number(dict,"mtu",False,st->name,loc,0);
+
+ if ((options&OPT_SOFTROUTE) && !st->set_routes) {
+ cfgfatal(loc,st->name,"this netlink device does not support "
+ "soft routes.\n");
+ return NULL;
+ }
+
+ if (options&OPT_SOFTROUTE) {
+ /* XXX for now we assume that soft routes require root privilege;
+ this may not always be true. The device driver can tell us. */
+ require_root_privileges=True;
+ require_root_privileges_explanation="netlink: soft routes";
+ if (st->ptp) {
+ cfgfatal(loc,st->name,"point-to-point netlinks do not support "
+ "soft routes.\n");
+ return NULL;
+ }
+ }
+
+ /* Check that nets are a subset of st->remote_networks;
+ refuse to register if they are not. */
+ if (!ipset_is_subset(st->remote_networks,networks)) {
+ cfgfatal(loc,st->name,"routes are not allowed\n");
+ return NULL;
+ }
+
+ c=safe_malloc(sizeof(*c),"netlink_inst_create");
+ c->cl.description=name;
+ c->cl.type=CL_NETLINK;
+ c->cl.apply=NULL;
+ c->cl.interface=&c->ops;
+ c->ops.st=c;
+ c->ops.reg=netlink_inst_reg;
+ c->ops.deliver=netlink_inst_incoming;
+ c->ops.set_quality=netlink_set_quality;
+ c->ops.set_mtu=netlink_inst_set_mtu;
+ c->nst=st;
+
+ c->networks=networks;
+ c->subnets=ipset_to_subnet_list(networks);
+ c->priority=priority;
+ c->deliver=NULL;
+ c->dst=NULL;
+ c->name=name;
+ c->link_quality=LINK_QUALITY_UNUSED;
+ c->mtu=mtu?mtu:st->mtu;
+ c->options=options;
+ c->outcount=0;
+ c->up=False;
+ c->kup=False;
+ c->next=st->clients;
+ st->clients=c;
+ assert(st->n_clients < INT_MAX);
+ st->n_clients++;
+
+ return &c->cl;
+}
+
+static list_t *netlink_inst_apply(closure_t *self, struct cloc loc,
+ dict_t *context, list_t *args)
+{
+ struct netlink *st=self->interface;
+
+ dict_t *dict;
+ item_t *item;
+ closure_t *cl;
+
+ item=list_elem(args,0);
+ if (!item || item->type!=t_dict) {
+ cfgfatal(loc,st->name,"must have a dictionary argument\n");
+ }
+ dict=item->data.dict;
+
+ cl=netlink_inst_create(st,loc,dict);
+
+ return new_closure(cl);
+}
+
netlink_deliver_fn *netlink_init(struct netlink *st,
void *dst, struct cloc loc,
- dict_t *dict, string_t description,
- netlink_route_fn *set_route,
+ dict_t *dict, cstring_t description,
+ netlink_route_fn *set_routes,
netlink_deliver_fn *to_host)
{
item_t *sa, *ptpa;
+ list_t *l;
st->dst=dst;
st->cl.description=description;
- st->cl.type=CL_NETLINK;
- st->cl.apply=NULL;
- st->cl.interface=&st->ops;
- st->ops.st=st;
- st->ops.regnets=netlink_regnets;
- st->ops.deliver=netlink_incoming;
- st->ops.set_quality=netlink_set_quality;
- st->max_start_pad=0;
- st->max_end_pad=0;
+ st->cl.type=CL_PURE;
+ st->cl.apply=netlink_inst_apply;
+ st->cl.interface=st;
st->clients=NULL;
- st->set_route=set_route;
+ st->routes=NULL;
+ st->n_clients=0;
+ st->set_routes=set_routes;
st->deliver_to_host=to_host;
- st->name=dict_read_string(dict,"name",False,"netlink",loc);
+ st->name=dict_read_string(dict,"name",False,description,loc);
if (!st->name) st->name=description;
- dict_read_subnet_list(dict, "networks", True, "netlink", loc,
- &st->networks);
- dict_read_subnet_list(dict, "exclude-remote-networks", False, "netlink",
- loc, &st->exclude_remote_networks);
- /* secnet-address does not have to be in local-networks;
- however, it should be advertised in the 'sites' file for the
- local site. */
+ l=dict_lookup(dict,"networks");
+ if (l)
+ st->networks=string_list_to_ipset(l,loc,st->name,"networks");
+ else {
+ struct ipset *empty;
+ empty=ipset_new();
+ st->networks=ipset_complement(empty);
+ ipset_free(empty);
+ }
+ l=dict_lookup(dict,"remote-networks");
+ if (l) {
+ st->remote_networks=string_list_to_ipset(l,loc,st->name,
+ "remote-networks");
+ } else {
+ struct ipset *empty;
+ empty=ipset_new();
+ st->remote_networks=ipset_complement(empty);
+ ipset_free(empty);
+ }
+
sa=dict_find_item(dict,"secnet-address",False,"netlink",loc);
- ptpa=dict_find_item(dict,"ptp-address", False, "netlink", loc);
+ ptpa=dict_find_item(dict,"ptp-address",False,"netlink",loc);
if (sa && ptpa) {
cfgfatal(loc,st->name,"you may not specify secnet-address and "
"ptp-address in the same netlink device\n");
"ptp-address for this netlink device\n");
}
if (sa) {
- st->secnet_address=string_to_ipaddr(sa,"netlink");
+ st->secnet_address=string_item_to_ipaddr(sa,"netlink");
st->ptp=False;
} else {
- st->secnet_address=string_to_ipaddr(ptpa,"netlink");
+ st->secnet_address=string_item_to_ipaddr(ptpa,"netlink");
st->ptp=True;
}
+ /* To be strictly correct we could subtract secnet_address from
+ networks here. It shouldn't make any practical difference,
+ though, and will make the route dump look complicated... */
+ st->subnets=ipset_to_subnet_list(st->networks);
st->mtu=dict_read_number(dict, "mtu", False, "netlink", loc, DEFAULT_MTU);
buffer_new(&st->icmp,ICMP_BUFSIZE);
- st->n_routes=0;
- st->routes=NULL;
+ st->outcount=0;
+ st->localcount=0;
add_hook(PHASE_SETUP,netlink_phase_hook,st);
request_signal_notification(SIGUSR1, netlink_signal_handler, st);
- return netlink_incoming;
+ /* If we're point-to-point then we return a CL_NETLINK directly,
+ rather than a CL_NETLINK_OLD or pure closure (depending on
+ compatibility). This CL_NETLINK is for our one and only
+ client. Our cl.apply function is NULL. */
+ if (st->ptp) {
+ closure_t *cl;
+ cl=netlink_inst_create(st,loc,dict);
+ st->cl=*cl;
+ }
+ return netlink_dev_incoming;
}
/* No connection to the kernel at all... */
struct netlink nl;
};
-static bool_t null_set_route(void *sst, struct netlink_route *route)
+static bool_t null_set_route(void *sst, struct netlink_client *routes)
{
struct null *st=sst;
- string_t t;
-
- if (route->up!=route->kup) {
- t=subnet_to_string(&route->net);
- Message(M_INFO,"%s: setting route %s to state %s\n",st->nl.name,
- t, route->up?"up":"down");
- free(t);
- route->kup=route->up;
+
+ if (routes->up!=routes->kup) {
+ Message(M_INFO,"%s: setting routes for tunnel %s to state %s\n",
+ st->nl.name,routes->name,
+ routes->up?"up":"down");
+ routes->kup=routes->up;
return True;
}
return False;
}
-static void null_deliver(void *sst, void *cid, struct buffer_if *buf)
+static void null_deliver(void *sst, struct buffer_if *buf)
{
return;
}
return new_closure(&st->nl.cl);
}
-init_module netlink_module;
void netlink_module(dict_t *dict)
{
add_closure(dict,"null-netlink",null_apply);
~ian / secnet.git / blobdiff