/* User-kernel network link */
-/* We will eventually support a variety of methods for extracting
- packets from the kernel: userv-ipif, ipif on its own (when we run
- as root), the kernel TUN driver, SLIP to a pty, an external netlink
- daemon. There is a performance/security tradeoff. */
-
-/* When dealing with SLIP (to a pty, or ipif) we have separate rx, tx
- and client buffers. When receiving we may read() any amount, not
- just whole packets. When transmitting we need to bytestuff anyway,
- and may be part-way through receiving. */
-
-/* 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. */
+/* 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. */
/* 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. */
-/* XXX now implement TUN. Kernel needs recompiling. */
-
-#include <stdio.h>
-#include <string.h>
-#include <unistd.h>
-#include <fcntl.h>
-#include <sys/ioctl.h>
-
-#include "config.h"
#include "secnet.h"
#include "util.h"
-
-#ifdef HAVE_LINUX_IF_H
-#include <linux/if.h>
-#include <linux/if_tun.h>
-#endif
-
-/* XXX where do we find if_tun on other architectures? */
-
-#define DEFAULT_BUFSIZE 2048
-#define DEFAULT_MTU 1000
-#define ICMP_BUFSIZE 1024
-
-#define SLIP_END 192
-#define SLIP_ESC 219
-#define SLIP_ESCEND 220
-#define SLIP_ESCESC 221
-
-struct netlink_client {
- struct subnet_list *networks;
- netlink_deliver_fn *deliver;
- void *dst;
- string_t name;
- bool_t can_deliver;
- struct netlink_client *next;
-};
-
-/* Netlink provides one function to the device driver, to call to deliver
- a packet from the device. The device driver provides one function to
- netlink, for it to call to deliver a packet to the device. */
-
-struct netlink {
- closure_t cl;
- struct netlink_if ops;
- void *dst; /* Pointer to host interface state */
- string_t name;
- uint32_t max_start_pad;
- uint32_t max_end_pad;
- struct subnet_list networks;
- uint32_t local_address; /* host interface address */
- uint32_t secnet_address; /* our own address */
- uint32_t mtu;
- struct netlink_client *clients;
- netlink_deliver_fn *deliver_to_host; /* Provided by driver */
- struct buffer_if icmp; /* Buffer for assembly of outgoing ICMP */
-};
+#include "ipaddr.h"
+#include "netlink.h"
+#include "process.h"
/* Generic IP checksum routine */
static inline uint16_t ip_csum(uint8_t *iph,uint32_t count)
} d;
};
-static void netlink_packet_deliver(struct netlink *st, struct buffer_if *buf);
+static void netlink_packet_deliver(struct netlink *st,
+ struct netlink_client *client,
+ struct buffer_if *buf);
static struct icmphdr *netlink_icmp_tmpl(struct netlink *st,
uint32_t dest,uint16_t len)
static bool_t netlink_icmp_may_reply(struct buffer_if *buf)
{
struct iphdr *iph;
+ struct icmphdr *icmph;
uint32_t source;
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);
return (hlen>plen?plen:hlen);
}
+/* client indicates where the packet we're constructing a response to
+ comes from. NULL indicates the host. */
static void netlink_icmp_simple(struct netlink *st, struct buffer_if *buf,
+ struct netlink_client *client,
uint8_t type, uint8_t code)
{
struct iphdr *iph=(struct iphdr *)buf->start;
h->type=type; h->code=code;
memcpy(buf_append(&st->icmp,len),buf->start,len);
netlink_icmp_csum(h);
- netlink_packet_deliver(st,&st->icmp);
+ netlink_packet_deliver(st,NULL,&st->icmp);
BUF_ASSERT_FREE(&st->icmp);
}
}
struct iphdr *iph=(struct iphdr *)buf->start;
uint32_t len;
- if (iph->ihl < 5 || iph->version != 4) {
- printf("ihl/version check failed\n");
- return False;
- }
- if (buf->size < iph->ihl*4) {
- printf("buffer size check failed\n");
- return False;
- }
- if (ip_fast_csum((uint8_t *)iph, iph->ihl)!=0) {
- printf("checksum failed\n");
- return False;
- }
+ 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;
len=ntohs(iph->tot_len);
/* There should be no padding */
- if (buf->size!=len || len<(iph->ihl<<2)) {
- printf("length check failed buf->size=%d len=%d\n",buf->size,len);
- return False;
- }
-
+ if (buf->size!=len || len<(iph->ihl<<2)) return False;
/* XXX check that there's no source route specified */
return True;
}
-static void netlink_packet_deliver(struct netlink *st, struct buffer_if *buf)
+/* Deliver a packet. "client" points to the _origin_ of the packet, not
+ its destination. (May be used when sending ICMP response - avoid
+ asymmetric routing.) */
+static void netlink_packet_deliver(struct netlink *st,
+ struct netlink_client *client,
+ struct buffer_if *buf)
{
struct iphdr *iph=(struct iphdr *)buf->start;
uint32_t dest=ntohl(iph->daddr);
- struct netlink_client *c;
+ uint32_t source=ntohl(iph->saddr);
+ uint32_t best_quality;
+ int best_match;
+ int i;
BUF_ASSERT_USED(buf);
return;
}
- for (c=st->clients; c; c=c->next) {
- if (subnet_match(c->networks,dest)) {
- if (c->can_deliver) {
- c->deliver(c->dst,c,buf);
+ /* 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;
+ }
+ }
+ }
+ 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);
+ }
+ } else {
+ if (best_quality>0) {
+ st->routes[best_match].c->deliver(
+ st->routes[best_match].c->dst,
+ st->routes[best_match].c, buf);
BUF_ASSERT_FREE(buf);
} else {
/* Generate ICMP destination unreachable */
- netlink_icmp_simple(st,buf,3,0);
+ netlink_icmp_simple(st,buf,client,3,0); /* client==NULL */
BUF_FREE(buf);
}
- return;
+ }
+ } 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);
}
}
- if (subnet_match(&st->networks,dest)) {
- st->deliver_to_host(st->dst,NULL,buf);
- BUF_ASSERT_FREE(buf);
- return;
- }
- Message(M_ERROR,"%s: failed to deliver a packet (bad destination address)"
- "\nXXX make this message clearer\n");
- BUF_FREE(buf);
+ BUF_ASSERT_FREE(buf);
}
-static void netlink_packet_forward(struct netlink *st, struct buffer_if *buf)
+static void netlink_packet_forward(struct netlink *st,
+ struct netlink_client *client,
+ struct buffer_if *buf)
{
struct iphdr *iph=(struct iphdr *)buf->start;
/* Packet has already been checked */
if (iph->ttl<=1) {
/* Generate ICMP time exceeded */
- netlink_icmp_simple(st,buf,11,0);
+ netlink_icmp_simple(st,buf,client,11,0);
BUF_FREE(buf);
return;
}
iph->check=0;
iph->check=ip_fast_csum((uint8_t *)iph,iph->ihl);
- netlink_packet_deliver(st,buf);
+ netlink_packet_deliver(st,client,buf);
BUF_ASSERT_FREE(buf);
}
-/* Someone has been foolish enough to address a packet to us. I
- suppose we should reply to it, just to be polite. */
-static void netlink_packet_local(struct netlink *st, struct buffer_if *buf)
+/* Deal with packets addressed explicitly to us */
+static void netlink_packet_local(struct netlink *st,
+ struct netlink_client *client,
+ struct buffer_if *buf)
{
struct icmphdr *h;
h=(struct icmphdr *)buf->start;
if ((ntohs(h->iph.frag_off)&0xbfff)!=0) {
- Message(M_WARNING,"%s: fragmented packet addressed to us\n",st->name);
+ Message(M_WARNING,"%s: fragmented packet addressed to secnet; "
+ "ignoring it\n",st->name);
BUF_FREE(buf);
return;
}
h->iph.check=0;
h->iph.check=ip_fast_csum((uint8_t *)h,h->iph.ihl);
netlink_icmp_csum(h);
- netlink_packet_deliver(st,buf);
+ netlink_packet_deliver(st,NULL,buf);
return;
}
Message(M_WARNING,"%s: unknown incoming ICMP\n",st->name);
} else {
/* Send ICMP protocol unreachable */
- netlink_icmp_simple(st,buf,3,2);
+ netlink_icmp_simple(st,buf,client,3,2);
BUF_FREE(buf);
return;
}
BUF_FREE(buf);
}
-/* Called by site code when remote packet is available */
-/* buf is allocated on entry and free on return */
-static void netlink_from_tunnel(void *sst, void *cst, struct buffer_if *buf)
+/* 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)
{
struct netlink *st=sst;
- struct netlink_client *client=cst;
+ struct netlink_client *client=cid;
uint32_t source,dest;
struct iphdr *iph;
BUF_ASSERT_USED(buf);
if (!netlink_check(st,buf)) {
- Message(M_WARNING,"%s: bad IP packet from tunnel %s\n",
- st->name,client->name);
+ Message(M_WARNING,"%s: bad IP packet from %s\n",
+ st->name,client?client->name:"host");
BUF_FREE(buf);
return;
}
source=ntohl(iph->saddr);
dest=ntohl(iph->daddr);
- /* Check that the packet source is in 'nets' and its destination is
- in client->networks */
- if (!subnet_match(client->networks,source)) {
- string_t s,d;
- s=ipaddr_to_string(source);
- d=ipaddr_to_string(dest);
- Message(M_WARNING,"%s: packet from tunnel %s with bad source address "
- "(s=%s,d=%s)\n",st->name,client->name,s,d);
- free(s); free(d);
- BUF_FREE(buf);
+ /* Check source */
+ if (client) {
+ /* Check that the packet source is appropriate for the tunnel
+ it came down */
+ if (!subnet_matches_list(client->networks,source)) {
+ string_t s,d;
+ s=ipaddr_to_string(source);
+ d=ipaddr_to_string(dest);
+ Message(M_WARNING,"%s: packet from tunnel %s with bad "
+ "source address (s=%s,d=%s)\n",st->name,client->name,s,d);
+ free(s); free(d);
+ BUF_FREE(buf);
+ return;
+ }
+ } else {
+ /* 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)) {
+ string_t s,d;
+ s=ipaddr_to_string(source);
+ d=ipaddr_to_string(dest);
+ Message(M_WARNING,"%s: outgoing packet with bad source address "
+ "(s=%s,d=%s)\n",st->name,s,d);
+ free(s); free(d);
+ BUF_FREE(buf);
+ return;
+ }
+ }
+
+ /* 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 (st->ptp) {
+ if (client) {
+ st->deliver_to_host(st->dst,NULL,buf);
+ } else {
+ st->clients->deliver(st->clients->dst,NULL,buf);
+ }
+ BUF_ASSERT_FREE(buf);
return;
}
- /* (st->secnet_address needs checking before matching against
- st->networks because secnet's IP address may not be in the
- range the host is willing to deal with) */
+
+ /* (st->secnet_address needs checking before matching destination
+ addresses) */
if (dest==st->secnet_address) {
- netlink_packet_local(st,buf);
+ netlink_packet_local(st,client,buf);
BUF_ASSERT_FREE(buf);
return;
}
- if (!subnet_match(&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;
+ 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,buf);
-
+ netlink_packet_forward(st,client,buf);
BUF_ASSERT_FREE(buf);
}
-/* Called by driver code when packet is received from kernel */
-/* cid should be NULL */
-/* buf should be allocated on entry, and is free on return */
-static void netlink_from_host(void *sst, void *cid, struct buffer_if *buf)
+static void netlink_set_softlinks(struct netlink *st, struct netlink_client *c,
+ bool_t up, uint32_t quality)
{
- struct netlink *st=sst;
- uint32_t source,dest;
- struct iphdr *iph;
-
- BUF_ASSERT_USED(buf);
- if (!netlink_check(st,buf)) {
- Message(M_WARNING,"%s: bad IP packet from host\n",
- st->name);
- BUF_FREE(buf);
- return;
- }
- iph=(struct iphdr *)buf->start;
-
- source=ntohl(iph->saddr);
- dest=ntohl(iph->daddr);
-
- if (!subnet_match(&st->networks,source)) {
- string_t s,d;
- s=ipaddr_to_string(source);
- d=ipaddr_to_string(dest);
- Message(M_WARNING,"%s: outgoing packet with bad source address "
- "(s=%s,d=%s)\n",st->name,s,d);
- free(s); free(d);
- BUF_FREE(buf);
- return;
- }
- if (dest==st->secnet_address) {
- netlink_packet_local(st,buf);
- BUF_ASSERT_FREE(buf);
- return;
+ 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]);
+ }
+ }
}
- netlink_packet_forward(st,buf);
- BUF_ASSERT_FREE(buf);
}
-static void netlink_set_delivery(void *sst, void *cid, bool_t can_deliver)
+static void netlink_set_quality(void *sst, void *cid, uint32_t quality)
{
+ struct netlink *st=sst;
struct netlink_client *c=cid;
- c->can_deliver=can_deliver;
+ 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);
+ }
}
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,
- string_t client_name)
+ uint32_t options, string_t client_name)
{
struct netlink *st=sst;
struct netlink_client *c;
"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;
+ }
+
+ 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";
+ }
+
+ /* 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;
+ }
+
+ if (st->clients && st->ptp) {
+ fatal("%s: only one site may use a point-to-point netlink device\n",
+ st->name);
+ return NULL;
+ }
+
c=safe_malloc(sizeof(*c),"netlink_regnets");
c->networks=nets;
c->deliver=deliver;
c->dst=dst;
- c->name=client_name; /* XXX copy it? */
- c->can_deliver=False;
+ 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 netlink_deliver_fn *netlink_init(struct netlink *st,
- void *dst, struct cloc loc,
- dict_t *dict, string_t description,
- netlink_deliver_fn *to_host)
-{
- 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_from_tunnel;
- st->ops.set_delivery=netlink_set_delivery;
- st->max_start_pad=0;
- st->max_end_pad=0;
- st->clients=NULL;
- st->deliver_to_host=to_host;
-
- st->name=dict_read_string(dict,"name",False,"netlink",loc);
- if (!st->name) st->name=description;
- dict_read_subnet_list(dict, "networks", True, "netlink", loc,
- &st->networks);
- st->local_address=string_to_ipaddr(
- dict_find_item(dict,"local-address", True, "netlink", loc),"netlink");
- st->secnet_address=string_to_ipaddr(
- dict_find_item(dict,"secnet-address", True, "netlink", loc),"netlink");
- if (!subnet_match(&st->networks,st->local_address)) {
- cfgfatal(loc,"netlink","local-address must be in local networks\n");
- }
- st->mtu=dict_read_number(dict, "mtu", False, "netlink", loc, DEFAULT_MTU);
- buffer_new(&st->icmp,ICMP_BUFSIZE);
-
- return netlink_from_host;
-}
-
-/* Connection to the kernel through userv-ipif */
-
-struct userv {
- struct netlink nl;
- int txfd; /* We transmit to userv */
- int rxfd; /* We receive from userv */
- string_t userv_path;
- string_t service_user;
- string_t service_name;
- uint32_t txbuflen;
- struct buffer_if *buff; /* We unstuff received packets into here
- and send them to the site code. */
- bool_t pending_esc;
- netlink_deliver_fn *netlink_to_tunnel;
-};
-
-static int userv_beforepoll(void *sst, struct pollfd *fds, int *nfds_io,
- int *timeout_io, const struct timeval *tv_now,
- uint64_t *now)
-{
- struct userv *st=sst;
- *nfds_io=2;
- fds[0].fd=st->txfd;
- fds[0].events=POLLERR; /* Might want to pick up POLLOUT sometime */
- fds[1].fd=st->rxfd;
- fds[1].events=POLLIN|POLLERR|POLLHUP;
- return 0;
-}
-
-static void userv_afterpoll(void *sst, struct pollfd *fds, int nfds,
- const struct timeval *tv_now, uint64_t *now)
-{
- struct userv *st=sst;
- uint8_t rxbuf[DEFAULT_BUFSIZE];
- int l,i;
-
- if (fds[1].revents&POLLERR) {
- printf("userv_afterpoll: hup!\n");
- }
- if (fds[1].revents&POLLIN) {
- l=read(st->rxfd,rxbuf,DEFAULT_BUFSIZE);
- if (l<0) {
- fatal_perror("userv_afterpoll: read(rxfd)");
- }
- if (l==0) {
- fatal("userv_afterpoll: read(rxfd)=0; userv gone away?\n");
- }
- /* XXX really crude unstuff code */
- /* XXX check for buffer overflow */
- BUF_ASSERT_USED(st->buff);
- for (i=0; i<l; i++) {
- if (st->pending_esc) {
- st->pending_esc=False;
- switch(rxbuf[i]) {
- case SLIP_ESCEND:
- *(uint8_t *)buf_append(st->buff,1)=SLIP_END;
- break;
- case SLIP_ESCESC:
- *(uint8_t *)buf_append(st->buff,1)=SLIP_ESC;
- break;
- default:
- fatal("userv_afterpoll: bad SLIP escape character\n");
- }
- } else {
- switch (rxbuf[i]) {
- case SLIP_END:
- if (st->buff->size>0) {
- st->netlink_to_tunnel(&st->nl,NULL,
- st->buff);
- BUF_ALLOC(st->buff,"userv_afterpoll");
- }
- buffer_init(st->buff,st->nl.max_start_pad);
- break;
- case SLIP_ESC:
- st->pending_esc=True;
- break;
- default:
- *(uint8_t *)buf_append(st->buff,1)=rxbuf[i];
- break;
- }
- }
- }
- }
-}
-
-/* Send buf to the kernel. Free buf before returning. */
-static void userv_deliver_to_kernel(void *sst, void *cid,
- struct buffer_if *buf)
+static void netlink_dump_routes(struct netlink *st, bool_t requested)
{
- struct userv *st=sst;
- uint8_t txbuf[DEFAULT_BUFSIZE];
- uint8_t *i;
- uint32_t j;
-
- BUF_ASSERT_USED(buf);
-
- /* Spit the packet at userv-ipif: SLIP start marker, then
- bytestuff the packet, then SLIP end marker */
- /* XXX crunchy bytestuff code */
- j=0;
- txbuf[j++]=SLIP_END;
- for (i=buf->start; i<(buf->start+buf->size); i++) {
- switch (*i) {
- case SLIP_END:
- txbuf[j++]=SLIP_ESC;
- txbuf[j++]=SLIP_ESCEND;
- break;
- case SLIP_ESC:
- txbuf[j++]=SLIP_ESC;
- txbuf[j++]=SLIP_ESCESC;
- break;
- default:
- txbuf[j++]=*i;
- break;
- }
- }
- txbuf[j++]=SLIP_END;
- if (write(st->txfd,txbuf,j)<0) {
- fatal_perror("userv_deliver_to_kernel: write()");
- }
- BUF_FREE(buf);
-}
-
-static void userv_phase_hook(void *sst, uint32_t newphase)
-{
- struct userv *st=sst;
- pid_t child;
- int c_stdin[2];
- int c_stdout[2];
- string_t addrs;
- string_t nets;
- string_t s;
- struct netlink_client *c;
int i;
-
- /* This is where we actually invoke userv - all the networks we'll
- be using should already have been registered. */
-
- addrs=safe_malloc(512,"userv_phase_hook:addrs");
- snprintf(addrs,512,"%s,%s,%d,slip",ipaddr_to_string(st->nl.local_address),
- ipaddr_to_string(st->nl.secnet_address),st->nl.mtu);
-
- nets=safe_malloc(1024,"userv_phase_hook:nets");
- *nets=0;
- for (c=st->nl.clients; c; c=c->next) {
- for (i=0; i<c->networks->entries; i++) {
- s=subnet_to_string(&c->networks->list[i]);
- strcat(nets,s);
- strcat(nets,",");
- free(s);
- }
- }
- nets[strlen(nets)-1]=0;
-
- Message(M_INFO,"\nuserv_phase_hook: %s %s %s %s %s\n",st->userv_path,
- st->service_user,st->service_name,addrs,nets);
-
- /* Allocate buffer, plus space for padding. Make sure we end up
- with the start of the packet well-aligned. */
- /* ALIGN(st->max_start_pad,16); */
- /* ALIGN(st->max_end_pad,16); */
-
- st->pending_esc=False;
-
- /* Invoke userv */
- if (pipe(c_stdin)!=0) {
- fatal_perror("userv_phase_hook: pipe(c_stdin)");
- }
- if (pipe(c_stdout)!=0) {
- fatal_perror("userv_phase_hook: pipe(c_stdout)");
- }
- st->txfd=c_stdin[1];
- st->rxfd=c_stdout[0];
-
- child=fork();
- if (child==-1) {
- fatal_perror("userv_phase_hook: fork()");
+ string_t net;
+ 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);
+ 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);
+ free(net);
}
- if (child==0) {
- char **argv;
-
- /* We are the child. Modify our stdin and stdout, then exec userv */
- dup2(c_stdin[0],0);
- dup2(c_stdout[1],1);
- close(c_stdin[1]);
- close(c_stdout[0]);
-
- /* The arguments are:
- userv
- service-user
- service-name
- local-addr,secnet-addr,mtu,protocol
- route1,route2,... */
- argv=malloc(sizeof(*argv)*6);
- argv[0]=st->userv_path;
- argv[1]=st->service_user;
- argv[2]=st->service_name;
- argv[3]=addrs;
- argv[4]=nets;
- argv[5]=NULL;
- execvp(st->userv_path,argv);
- perror("netlink-userv-ipif: execvp");
-
- exit(1);
- }
- /* We are the parent... */
-
- /* Register for poll() */
- register_for_poll(st, userv_beforepoll, userv_afterpoll, 2, st->nl.name);
-}
-
-static list_t *userv_apply(closure_t *self, struct cloc loc, dict_t *context,
- list_t *args)
-{
- struct userv *st;
- item_t *item;
- dict_t *dict;
-
- st=safe_malloc(sizeof(*st),"userv_apply");
-
- /* First parameter must be a dict */
- item=list_elem(args,0);
- if (!item || item->type!=t_dict)
- cfgfatal(loc,"userv-ipif","parameter must be a dictionary\n");
-
- dict=item->data.dict;
-
- st->netlink_to_tunnel=
- netlink_init(&st->nl,st,loc,dict,
- "netlink-userv-ipif",userv_deliver_to_kernel);
-
- st->userv_path=dict_read_string(dict,"userv-path",False,"userv-netlink",
- loc);
- st->service_user=dict_read_string(dict,"service-user",False,
- "userv-netlink",loc);
- st->service_name=dict_read_string(dict,"service-name",False,
- "userv-netlink",loc);
- if (!st->userv_path) st->userv_path="userv";
- if (!st->service_user) st->service_user="root";
- if (!st->service_name) st->service_name="ipif";
- st->buff=find_cl_if(dict,"buffer",CL_BUFFER,True,"userv-netlink",loc);
- BUF_ALLOC(st->buff,"netlink:userv_apply");
-
- st->rxfd=-1; st->txfd=-1;
- add_hook(PHASE_DROPPRIV,userv_phase_hook,st);
-
- return new_closure(&st->nl.cl);
}
-/* Connection to the kernel through the universal TUN/TAP driver */
-
-struct tun {
- struct netlink nl;
- int fd;
- string_t device_path;
- string_t interface_name;
- string_t ifconfig_path;
- string_t route_path;
- struct buffer_if *buff; /* We receive packets into here
- and send them to the netlink code. */
- netlink_deliver_fn *netlink_to_tunnel;
-};
-
-static int tun_beforepoll(void *sst, struct pollfd *fds, int *nfds_io,
- int *timeout_io, const struct timeval *tv_now,
- uint64_t *now)
+static int netlink_compare_route_specificity(const void *ap, const void *bp)
{
- struct tun *st=sst;
- *nfds_io=1;
- fds[0].fd=st->fd;
- fds[0].events=POLLIN|POLLERR|POLLHUP;
- return 0;
-}
-
-static void tun_afterpoll(void *sst, struct pollfd *fds, int nfds,
- const struct timeval *tv_now, uint64_t *now)
-{
- struct tun *st=sst;
- int l;
+ const struct netlink_route *a=ap;
+ const struct netlink_route *b=bp;
- if (fds[0].revents&POLLERR) {
- printf("tun_afterpoll: hup!\n");
- }
- if (fds[0].revents&POLLIN) {
- BUF_ALLOC(st->buff,"tun_afterpoll");
- buffer_init(st->buff,st->nl.max_start_pad);
- l=read(st->fd,st->buff->start,st->buff->len-st->nl.max_start_pad);
- if (l<0) {
- fatal_perror("tun_afterpoll: read()");
- }
- if (l==0) {
- fatal("tun_afterpoll: read()=0; device gone away?\n");
- }
- if (l>0) {
- st->buff->size=l;
- st->netlink_to_tunnel(&st->nl,NULL,st->buff);
- BUF_ASSERT_FREE(st->buff);
- }
- }
+ if (a->net.len==b->net.len) return 0;
+ if (a->net.len<b->net.len) return 1;
+ return -1;
}
-static void tun_deliver_to_kernel(void *sst, void *cid,
- struct buffer_if *buf)
+static void netlink_phase_hook(void *sst, uint32_t new_phase)
{
- struct tun *st=sst;
-
- BUF_ASSERT_USED(buf);
-
- /* No error checking, because we'd just throw the packet away anyway */
- write(st->fd,buf->start,buf->size);
- BUF_FREE(buf);
-}
-
-static void tun_phase_hook(void *sst, uint32_t newphase)
-{
- struct tun *st=sst;
- string_t hostaddr,secnetaddr;
- uint8_t mtu[6];
- string_t network,mask;
+ struct netlink *st=sst;
struct netlink_client *c;
- int i;
-
- /* All the networks we'll be using have been registered. Invoke ifconfig
- to set the TUN device's address, and route to add routes to all
- our networks. */
-
- hostaddr=ipaddr_to_string(st->nl.local_address);
- secnetaddr=ipaddr_to_string(st->nl.secnet_address);
- snprintf(mtu,6,"%d",st->nl.mtu);
- mtu[5]=0;
-
- sys_cmd(st->ifconfig_path,"ifconfig",st->interface_name,
- hostaddr,"netmask","255.255.255.255","-broadcast",
- "pointopoint",secnetaddr,"mtu",mtu,"up",(char *)0);
-
- for (c=st->nl.clients; c; c=c->next) {
- for (i=0; i<c->networks->entries; i++) {
- network=ipaddr_to_string(c->networks->list[i].prefix);
- mask=ipaddr_to_string(c->networks->list[i].mask);
- sys_cmd(st->route_path,"route","add","-net",network,
- "netmask",mask,"gw",secnetaddr,(char *)0);
+ 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);
+ }
+
+ /* 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");
+ /* 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==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);
- /* Register for poll() */
- register_for_poll(st, tun_beforepoll, tun_afterpoll, 1, st->nl.name);
+ netlink_dump_routes(st,False);
}
-#ifdef HAVE_LINUX_IF_H
-static list_t *tun_apply(closure_t *self, struct cloc loc, dict_t *context,
- list_t *args)
+static void netlink_signal_handler(void *sst, int signum)
{
- struct tun *st;
- item_t *item;
- dict_t *dict;
- struct ifreq ifr;
-
- st=safe_malloc(sizeof(*st),"tun_apply");
-
- /* First parameter must be a dict */
- item=list_elem(args,0);
- if (!item || item->type!=t_dict)
- cfgfatal(loc,"tun","parameter must be a dictionary\n");
-
- dict=item->data.dict;
-
- st->netlink_to_tunnel=
- netlink_init(&st->nl,st,loc,dict,
- "netlink-tun",tun_deliver_to_kernel);
-
- st->device_path=dict_read_string(dict,"device",False,"tun-netlink",loc);
- st->interface_name=dict_read_string(dict,"interface",False,
- "tun-netlink",loc);
- st->ifconfig_path=dict_read_string(dict,"device",False,"tun-netlink",loc);
- st->route_path=dict_read_string(dict,"device",False,"tun-netlink",loc);
-
- if (!st->device_path) st->device_path="/dev/net/tun";
- if (!st->ifconfig_path) st->ifconfig_path="ifconfig";
- if (!st->route_path) st->route_path="route";
- st->buff=find_cl_if(dict,"buffer",CL_BUFFER,True,"tun-netlink",loc);
-
- /* New TUN interface: open the device, then do ioctl TUNSETIFF
- to set or find out the network interface name. */
- st->fd=open(st->device_path,O_RDWR);
- if (st->fd==-1) {
- fatal_perror("%s: can't open device file %s",st->nl.name,
- st->device_path);
- }
- memset(&ifr,0,sizeof(ifr));
- ifr.ifr_flags = IFF_TUN | IFF_NO_PI; /* Just send/receive IP packets,
- no extra headers */
- if (st->interface_name)
- strncpy(ifr.ifr_name,st->interface_name,IFNAMSIZ);
- if (ioctl(st->fd,TUNSETIFF,&ifr)<0) {
- fatal_perror("%s: ioctl(TUNSETIFF)",st->nl.name);
- }
- if (!st->interface_name) {
- st->interface_name=safe_malloc(strlen(ifr.ifr_name)+1,"tun_apply");
- strcpy(st->interface_name,ifr.ifr_name);
- Message(M_INFO,"%s: allocated network interface %s\n",st->nl.name,
- st->interface_name);
- }
-
- add_hook(PHASE_DROPPRIV,tun_phase_hook,st);
-
- return new_closure(&st->nl.cl);
+ struct netlink *st=sst;
+ Message(M_INFO,"%s: route dump requested by SIGUSR1\n",st->name);
+ netlink_dump_routes(st,True);
}
-#endif /* HAVE_LINUX_IF_H */
-static list_t *tun_old_apply(closure_t *self, struct cloc loc, dict_t *context,
- list_t *args)
+netlink_deliver_fn *netlink_init(struct netlink *st,
+ void *dst, struct cloc loc,
+ dict_t *dict, string_t description,
+ netlink_route_fn *set_route,
+ netlink_deliver_fn *to_host)
{
- struct tun *st;
- item_t *item;
- dict_t *dict;
- bool_t search_for_if;
+ item_t *sa, *ptpa;
- st=safe_malloc(sizeof(*st),"tun_old_apply");
-
- Message(M_WARNING,"the tun-old code has never been tested. Please report "
- "success or failure to steve@greenend.org.uk\n");
-
- /* First parameter must be a dict */
- item=list_elem(args,0);
- if (!item || item->type!=t_dict)
- cfgfatal(loc,"tun","parameter must be a dictionary\n");
-
- dict=item->data.dict;
+ 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->clients=NULL;
+ st->set_route=set_route;
+ st->deliver_to_host=to_host;
- st->netlink_to_tunnel=
- netlink_init(&st->nl,st,loc,dict,
- "netlink-tun",tun_deliver_to_kernel);
-
- st->device_path=dict_read_string(dict,"device",False,"tun-netlink",loc);
- st->interface_name=dict_read_string(dict,"interface",False,
- "tun-netlink",loc);
- search_for_if=dict_read_bool(dict,"interface-search",False,"tun-netlink",
- loc,st->device_path==NULL);
- st->ifconfig_path=dict_read_string(dict,"device",False,"tun-netlink",loc);
- st->route_path=dict_read_string(dict,"device",False,"tun-netlink",loc);
-
- if (!st->device_path) st->device_path="/dev/tun";
- if (!st->ifconfig_path) st->ifconfig_path="ifconfig";
- if (!st->route_path) st->route_path="route";
- st->buff=find_cl_if(dict,"buffer",CL_BUFFER,True,"tun-netlink",loc);
-
- /* Old TUN interface: the network interface name depends on which
- /dev/tunX file we open. If 'interface-search' is set to true, treat
- 'device' as the prefix and try numbers from 0--255. If it's set
- to false, treat 'device' as the whole name, and require than an
- appropriate interface name be specified. */
- if (search_for_if) {
- string_t dname;
- int i;
-
- if (st->interface_name) {
- cfgfatal(loc,"tun-old","you may not specify an interface name "
- "in interface-search mode\n");
- }
- dname=safe_malloc(strlen(st->device_path)+4,"tun_old_apply");
- st->interface_name=safe_malloc(8,"tun_old_apply");
-
- for (i=0; i<255; i++) {
- sprintf(dname,"%s%d",st->device_path,i);
- if ((st->fd=open(dname,O_RDWR))>0) {
- sprintf(st->interface_name,"tun%d",i);
- Message(M_INFO,"%s: allocated network interface %s "
- "through %s\n",st->nl.name,st->interface_name,dname);
- continue;
- }
- }
- if (st->fd==-1) {
- fatal("%s: unable to open any TUN device (%s...)\n",
- st->nl.name,st->device_path);
- }
+ st->name=dict_read_string(dict,"name",False,"netlink",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. */
+ sa=dict_find_item(dict,"secnet-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");
+ }
+ if (!(sa || ptpa)) {
+ cfgfatal(loc,st->name,"you must specify secnet-address or "
+ "ptp-address for this netlink device\n");
+ }
+ if (sa) {
+ st->secnet_address=string_to_ipaddr(sa,"netlink");
+ st->ptp=False;
} else {
- if (!st->interface_name) {
- cfgfatal(loc,"tun-old","you must specify an interface name "
- "when you explicitly specify a TUN device file\n");
- }
- st->fd=open(st->device_path,O_RDWR);
- if (st->fd==-1) {
- fatal_perror("%s: unable to open TUN device file %s",
- st->nl.name,st->device_path);
- }
+ st->secnet_address=string_to_ipaddr(ptpa,"netlink");
+ st->ptp=True;
}
+ 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;
- add_hook(PHASE_DROPPRIV,tun_phase_hook,st);
+ add_hook(PHASE_SETUP,netlink_phase_hook,st);
+ request_signal_notification(SIGUSR1, netlink_signal_handler, st);
- return new_closure(&st->nl.cl);
+ return netlink_incoming;
}
/* No connection to the kernel at all... */
struct netlink nl;
};
+static bool_t null_set_route(void *sst, struct netlink_route *route)
+{
+ 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;
+ return True;
+ }
+ return False;
+}
+
static void null_deliver(void *sst, void *cid, struct buffer_if *buf)
{
return;
dict=item->data.dict;
- netlink_init(&st->nl,st,loc,dict,"null-netlink",null_deliver);
+ netlink_init(&st->nl,st,loc,dict,"null-netlink",null_set_route,
+ null_deliver);
return new_closure(&st->nl.cl);
}
init_module netlink_module;
void netlink_module(dict_t *dict)
{
- add_closure(dict,"userv-ipif",userv_apply);
-#ifdef HAVE_LINUX_IF_H
- add_closure(dict,"tun",tun_apply);
-#endif
- add_closure(dict,"tun-old",tun_old_apply);
add_closure(dict,"null-netlink",null_apply);
-#if 0
- /* TODO */
- add_closure(dict,"pty-slip",ptyslip_apply);
- add_closure(dict,"slipd",slipd_apply);
-#endif /* 0 */
}
~ianmdlvl / secnet.git / blobdiff