/* User-kernel network link */
-/* We support a variety of methods: userv-ipif, ipif on its own (when
- we run as root), 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 should eventually do things like decreasing the TTL and
- recalculating the header checksum, generating ICMP, responding to
- pings, etc. but for now we can get away without them. We should
- implement this stuff no matter how we get the packets to/from the
- kernel. */
+/* 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. */
-#include <stdio.h>
-#include <string.h>
-#include <unistd.h>
-#include <fcntl.h>
-
#include "secnet.h"
#include "util.h"
+#include "netlink.h"
-#define DEFAULT_BUFSIZE 2048
+/* Generic IP checksum routine */
+static inline uint16_t ip_csum(uint8_t *iph,uint32_t count)
+{
+ register uint32_t sum=0;
-#define SLIP_END 192
-#define SLIP_ESC 219
-#define SLIP_ESCEND 220
-#define SLIP_ESCESC 221
+ while (count>1) {
+ sum+=ntohs(*(uint16_t *)iph);
+ iph+=2;
+ count-=2;
+ }
+ if(count>0)
+ sum+=*(uint8_t *)iph;
+ while (sum>>16)
+ sum=(sum&0xffff)+(sum>>16);
+ return htons(~sum);
+}
-struct netlink_client {
- struct subnet_list *networks;
- netlink_deliver_fn *deliver;
- void *dst;
- struct netlink_client *next;
+#ifdef i386
+/*
+ * This is a version of ip_compute_csum() optimized for IP headers,
+ * which always checksum on 4 octet boundaries.
+ *
+ * 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) {
+ 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:
+ "
+ /* 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));
+ return sum;
+}
+#else
+static inline uint16_t ip_fast_csum(uint8_t *iph, uint32_t ihl)
+{
+ return ip_csum(iph,ihl*4);
+}
+#endif
+
+struct iphdr {
+#if defined (WORDS_BIGENDIAN)
+ uint8_t version:4,
+ ihl:4;
+#else
+ uint8_t ihl:4,
+ version:4;
+#endif
+ uint8_t tos;
+ uint16_t tot_len;
+ uint16_t id;
+ uint16_t frag_off;
+ uint8_t ttl;
+ uint8_t protocol;
+ uint16_t check;
+ uint32_t saddr;
+ uint32_t daddr;
+ /* The options start here. */
};
-struct userv {
- closure_t cl;
- struct netlink_if ops;
- uint32_t max_start_pad;
- uint32_t max_end_pad;
- int txfd; /* We transmit to userv */
- int rxfd; /* We receive from userv */
- struct netlink_client *clients;
- string_t name;
- string_t userv_path;
- string_t service_user;
- string_t service_name;
- struct subnet_list networks;
- uint32_t local_address;
- uint32_t secnet_address;
- uint32_t mtu;
- uint32_t txbuflen;
- struct buffer_if *buff; /* We unstuff received packets into here
- and send them to the site code. */
- bool_t pending_esc;
+struct icmphdr {
+ struct iphdr iph;
+ uint8_t type;
+ uint8_t code;
+ uint16_t check;
+ union {
+ uint32_t unused;
+ struct {
+ uint8_t pointer;
+ uint8_t unused1;
+ uint16_t unused2;
+ } pprob;
+ uint32_t gwaddr;
+ struct {
+ uint16_t id;
+ uint16_t seq;
+ } echo;
+ } d;
};
+
+static void netlink_packet_deliver(struct netlink *st,
+ struct netlink_client *client,
+ struct buffer_if *buf);
-static int userv_beforepoll(void *sst, struct pollfd *fds, int *nfds_io,
- int *timeout_io, const struct timeval *tv_now,
- uint64_t *now)
+static struct icmphdr *netlink_icmp_tmpl(struct netlink *st,
+ uint32_t dest,uint16_t len)
{
- 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;
+ struct icmphdr *h;
+
+ BUF_ALLOC(&st->icmp,"netlink_icmp_tmpl");
+ buffer_init(&st->icmp,st->max_start_pad);
+ h=buf_append(&st->icmp,sizeof(*h));
+
+ h->iph.version=4;
+ h->iph.ihl=5;
+ h->iph.tos=0;
+ 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.protocol=1;
+ h->iph.saddr=htonl(st->secnet_address);
+ h->iph.daddr=htonl(dest);
+ h->iph.check=0;
+ h->iph.check=ip_fast_csum((uint8_t *)&h->iph,h->iph.ihl);
+ h->check=0;
+ h->d.unused=0;
+
+ return h;
}
-static void process_local_packet(struct userv *st)
+/* Fill in the ICMP checksum field correctly */
+static void netlink_icmp_csum(struct icmphdr *h)
{
- uint32_t source,dest;
- struct netlink_client *c;
+ uint32_t len;
- source=ntohl(*(uint32_t *)(st->buff->start+12));
- dest=ntohl(*(uint32_t *)(st->buff->start+16));
-
-/* printf("process_local_packet source=%s dest=%s len=%d\n",
- ipaddr_to_string(source),ipaddr_to_string(dest),
- st->buff->size); */
- 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);
- return;
- }
- for (c=st->clients; c; c=c->next) {
- if (subnet_match(c->networks,dest)) {
- c->deliver(c->dst,c,st->buff);
- BUF_ALLOC(st->buff,"netlink:process_local_packet");
- return;
- }
- }
- if (dest==st->secnet_address) {
- printf("%s: secnet received packet of len %d from %s\n",st->name,
- st->buff->size,ipaddr_to_string(source));
- return;
- }
- {
- string_t s,d;
- s=ipaddr_to_string(source);
- d=ipaddr_to_string(dest);
- Message(M_WARNING,"%s: outgoing packet with bad destination address "
- "(s=%s,d=%s)\n",st->name,s,d);
- free(s); free(d);
- return;
+ len=ntohs(h->iph.tot_len)-(4*h->iph.ihl);
+ h->check=0;
+ h->check=ip_csum(&h->type,len);
+}
+
+/* RFC1122:
+ * An ICMP error message MUST NOT be sent as the result of
+ * receiving:
+ *
+ * * an ICMP error message, or
+ *
+ * * a datagram destined to an IP broadcast or IP multicast
+ * address, or
+ *
+ * * a datagram sent as a link-layer broadcast, or
+ *
+ * * a non-initial fragment, or
+ *
+ * * a datagram whose source address does not define a single
+ * host -- e.g., a zero address, a loopback address, a
+ * broadcast address, a multicast address, or a Class E
+ * address.
+ */
+static bool_t netlink_icmp_may_reply(struct buffer_if *buf)
+{
+ struct iphdr *iph;
+ uint32_t source;
+
+ iph=(struct iphdr *)buf->start;
+ if (iph->protocol==1) return False; /* Overly-broad; we may reply to
+ eg. icmp echo-request */
+ /* How do we spot broadcast destination addresses? */
+ if (ntohs(iph->frag_off)&0x1fff) return False; /* Non-initial fragment */
+ source=ntohl(iph->saddr);
+ if (source==0) return False;
+ if ((source&0xff000000)==0x7f000000) return False;
+ /* How do we spot broadcast source addresses? */
+ if ((source&0xf0000000)==0xe0000000) return False; /* Multicast */
+ if ((source&0xf0000000)==0xf0000000) return False; /* Class E */
+ return True;
+}
+
+/* How much of the original IP packet do we include in its ICMP
+ response? The header plus up to 64 bits. */
+static uint16_t netlink_icmp_reply_len(struct buffer_if *buf)
+{
+ struct iphdr *iph=(struct iphdr *)buf->start;
+ uint16_t hlen,plen;
+
+ hlen=iph->ihl*4;
+ /* We include the first 8 bytes of the packet data, provided they exist */
+ hlen+=8;
+ plen=ntohs(iph->tot_len);
+ 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;
+ struct icmphdr *h;
+ uint16_t len;
+
+ if (netlink_icmp_may_reply(buf)) {
+ len=netlink_icmp_reply_len(buf);
+ h=netlink_icmp_tmpl(st,ntohl(iph->saddr),len);
+ h->type=type; h->code=code;
+ memcpy(buf_append(&st->icmp,len),buf->start,len);
+ netlink_icmp_csum(h);
+ netlink_packet_deliver(st,NULL,&st->icmp);
+ BUF_ASSERT_FREE(&st->icmp);
}
}
-static void userv_afterpoll(void *sst, struct pollfd *fds, int nfds,
- const struct timeval *tv_now, uint64_t *now)
+/*
+ * RFC1122: 3.1.2.2 MUST silently discard any IP frame that fails the
+ * checksum.
+ *
+ * Is the datagram acceptable?
+ *
+ * 1. Length at least the size of an ip header
+ * 2. Version of 4
+ * 3. Checksums correctly.
+ * 4. Doesn't have a bogus length
+ */
+static bool_t netlink_check(struct netlink *st, struct buffer_if *buf)
{
- struct userv *st=sst;
- uint8_t rxbuf[DEFAULT_BUFSIZE];
- int l,i;
+ struct iphdr *iph=(struct iphdr *)buf->start;
+ uint32_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;
+ len=ntohs(iph->tot_len);
+ /* There should be no padding */
+ if (buf->size!=len || len<(iph->ihl<<2)) return False;
+ /* XXX check that there's no source route specified */
+ return True;
+}
+
+/* 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);
+ uint32_t source=ntohl(iph->saddr);
+ uint32_t best_quality;
+ int best_match;
+ int i;
- if (fds[1].revents&POLLERR) {
- printf("userv_afterpoll: hup!\n");
+ BUF_ASSERT_USED(buf);
+
+ if (dest==st->secnet_address) {
+ Message(M_ERROR,"%s: trying to deliver a packet to myself!\n");
+ BUF_FREE(buf);
+ return;
}
- 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 */
- 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");
+
+ /* 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 {
- switch (rxbuf[i]) {
- case SLIP_END:
- if (st->buff->size>0) process_local_packet(st);
- BUF_ASSERT_USED(st->buff);
- buffer_init(st->buff,st->max_start_pad);
- break;
- case SLIP_ESC:
- st->pending_esc=True;
- break;
- default:
- *(uint8_t *)buf_append(st->buff,1)=rxbuf[i];
- break;
- }
+ 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,client,3,0); /* 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);
+ }
}
- return;
+ BUF_ASSERT_FREE(buf);
}
-static void userv_phase_hook(void *sst, uint32_t newphase)
+static void netlink_packet_forward(struct netlink *st,
+ struct netlink_client *client,
+ struct buffer_if *buf)
{
- 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;
+ struct iphdr *iph=(struct iphdr *)buf->start;
+
+ BUF_ASSERT_USED(buf);
- /* This is where we actually invoke userv - all the networks we'll
- be using should already have been registered. */
+ /* Packet has already been checked */
+ if (iph->ttl<=1) {
+ /* Generate ICMP time exceeded */
+ netlink_icmp_simple(st,buf,client,11,0);
+ BUF_FREE(buf);
+ return;
+ }
+ iph->ttl--;
+ iph->check=0;
+ iph->check=ip_fast_csum((uint8_t *)iph,iph->ihl);
- addrs=safe_malloc(512,"userv_phase_hook:addrs");
- snprintf(addrs,512,"%s,%s,%d,slip",ipaddr_to_string(st->local_address),
- ipaddr_to_string(st->secnet_address),st->mtu);
+ netlink_packet_deliver(st,client,buf);
+ BUF_ASSERT_FREE(buf);
+}
- nets=safe_malloc(1024,"userv_phase_hook:nets");
- *nets=0;
- for (c=st->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);
- }
+/* 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 secnet; "
+ "ignoring it\n",st->name);
+ BUF_FREE(buf);
+ return;
}
- 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);
+ if (h->iph.protocol==1) {
+ /* It's ICMP */
+ if (h->type==8 && h->code==0) {
+ /* ICMP echo-request. Special case: we re-use the buffer
+ to construct the reply. */
+ h->type=0;
+ 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.check=0;
+ h->iph.check=ip_fast_csum((uint8_t *)h,h->iph.ihl);
+ netlink_icmp_csum(h);
+ 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,client,3,2);
+ BUF_FREE(buf);
+ return;
+ }
- /* 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); */
+ BUF_FREE(buf);
+}
- st->pending_esc=False;
+/* 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=cid;
+ uint32_t source,dest;
+ struct iphdr *iph;
- /* Invoke userv */
- if (pipe(c_stdin)!=0) {
- fatal_perror("userv_phase_hook: pipe(c_stdin)");
+ 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");
+ BUF_FREE(buf);
+ return;
}
- if (pipe(c_stdout)!=0) {
- fatal_perror("userv_phase_hook: pipe(c_stdout)");
+ iph=(struct iphdr *)buf->start;
+
+ source=ntohl(iph->saddr);
+ dest=ntohl(iph->daddr);
+
+ /* Check source */
+ if (client) {
+ /* Check that the packet source is in 'nets' and its destination is
+ in st->networks */
+ 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 {
+ 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;
+ }
}
- st->txfd=c_stdin[1];
- st->rxfd=c_stdout[0];
+ /* (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 i;
- child=fork();
- if (child==-1) {
- fatal_perror("userv_phase_hook: fork()");
+ if (!st->routes) return; /* Table has not yet been created */
+ for (i=0; i<st->n_routes; i++) {
+ if (!st->routes[i].hard && st->routes[i].c==c) {
+ st->routes[i].up=up;
+ st->set_route(st->dst,&st->routes[i]);
+ }
}
- 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);
+}
+
+static void netlink_set_quality(void *sst, void *cid, uint32_t quality)
+{
+ 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);
+ } else {
+ netlink_set_softlinks(st,c,True);
}
- /* We are the parent... */
-
- /* Register for poll() */
- register_for_poll(st, userv_beforepoll, userv_afterpoll, 2, "netlink");
}
-static void *userv_regnets(void *sst, struct subnet_list *nets,
- netlink_deliver_fn *deliver, void *dst,
- uint32_t max_start_pad, uint32_t max_end_pad)
+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)
{
- struct userv *st=sst;
+ struct netlink *st=sst;
struct netlink_client *c;
- Message(M_DEBUG_CONFIG,"userv_regnets: request for %d networks, "
+ 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);
- c=safe_malloc(sizeof(*c),"userv_regnets");
+ 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 False;
+ }
+
+ c=safe_malloc(sizeof(*c),"netlink_regnets");
c->networks=nets;
c->deliver=deliver;
c->dst=dst;
+ c->name=client_name; /* XXX copy it? */
+ 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 userv_deliver(void *sst, void *cid, struct buffer_if *buf)
+static void netlink_dump_routes(struct netlink *st)
{
- struct userv *st=sst;
- struct netlink_client *client=cid;
- uint8_t txbuf[DEFAULT_BUFSIZE];
-
- uint32_t source,dest;
- uint8_t *i;
- uint32_t j;
-
- source=ntohl(*(uint32_t *)(buf->start+12));
- dest=ntohl(*(uint32_t *)(buf->start+16));
-
- /* 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: incoming packet with bad source address "
- "(s=%s,d=%s)\n",st->name,s,d);
- free(s); free(d);
- return;
+ int i;
+ string_t net;
+
+ Message(M_INFO,"%s: routing table:\n",st->name);
+ for (i=0; i<st->n_routes; i++) {
+ net=subnet_to_string(&st->routes[i].net);
+ Message(M_INFO,"%s -> tunnel %s (%s,%s route,%s)\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");
+ free(net);
}
- 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 with bad destination address "
- "(s=%s,d=%s)\n",st->name,s,d);
- free(s); free(d);
- return;
+ Message(M_INFO,"%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(M_INFO,"%s -> host\n",net);
+ free(net);
}
+}
- /* Really we should decrease TTL, check it's above zero, and
- recalculate header checksum here. If it gets down to zero,
- generate an ICMP time-exceeded and send the new packet back to
- the originating tunnel. XXX check buffer usage! */
-
- /* (Basically do full IP packet forwarding stuff. Except that we
- know any packet passed in here is destined for the local
- machine; only exception is if it's destined for us.) */
+static int netlink_compare_route_specificity(const void *ap, const void *bp)
+{
+ const struct netlink_route *a=ap;
+ const struct netlink_route *b=bp;
- if (dest==st->secnet_address) {
- printf("%s: incoming tunneled packet for secnet!\n",st->name);
- return;
- }
+ if (a->net.len==b->net.len) return 0;
+ if (a->net.len<b->net.len) return 1;
+ return -1;
+}
- /* Now 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;
+static void netlink_phase_hook(void *sst, uint32_t new_phase)
+{
+ struct netlink *st=sst;
+ struct netlink_client *c;
+ uint32_t i,j;
+
+ /* 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;
+ i++;
}
}
- txbuf[j++]=SLIP_END;
- if (write(st->txfd,txbuf,j)<0) {
- fatal_perror("userv_deliver: write()");
+ /* 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);
- return;
+ netlink_dump_routes(st);
}
-static list_t *userv_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 userv *st;
- item_t *item;
- dict_t *dict;
-
- st=safe_malloc(sizeof(*st),"userv_apply (netlink)");
- st->cl.description="userv-netlink";
+ 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=userv_regnets;
- st->ops.deliver=userv_deliver;
+ 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->rxfd=-1; st->txfd=-1;
st->clients=NULL;
+ st->set_route=set_route;
+ st->deliver_to_host=to_host;
- /* 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->name=dict_read_string(dict,"name",False,"userv-netlink",loc);
- 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->name) st->name="netlink-userv-ipif";
- if (!st->userv_path) st->userv_path="userv";
- if (!st->service_user) st->service_user="root";
- if (!st->service_name) st->service_name="ipif";
- dict_read_subnet_list(dict, "networks", True, "userv-netlink", loc,
+ 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, "userv-netlink", loc),
- "userv-netlink");
+ 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. */
st->secnet_address=string_to_ipaddr(
- dict_find_item(dict,"secnet-address", True, "userv-netlink", loc),
- "userv-netlink");
- if (!subnet_match(&st->networks,st->local_address)) {
- cfgfatal(loc,"netlink-userv-ipif","local-address must be in "
- "local networks\n");
- }
- st->mtu=dict_read_number(dict, "mtu", False, "userv-netlink", loc, 1000);
- st->buff=find_cl_if(dict,"buffer",CL_BUFFER,True,"userv-netlink",loc);
- BUF_ALLOC(st->buff,"netlink:userv_apply");
+ dict_find_item(dict,"secnet-address", True, "netlink", loc),"netlink");
+ 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,userv_phase_hook,st);
+ add_hook(PHASE_SETUP,netlink_phase_hook,st);
- return new_closure(&st->cl);
+ return netlink_incoming;
}
+/* No connection to the kernel at all... */
+
struct null {
- closure_t cl;
- struct netlink_if ops;
+ struct netlink nl;
};
-static void *null_regnets(void *sst, struct subnet_list *nets,
- netlink_deliver_fn *deliver, void *dst,
- uint32_t max_start_pad, uint32_t max_end_pad)
+static bool_t null_set_route(void *sst, struct netlink_route *route)
{
- Message(M_DEBUG_CONFIG,"null_regnets: request for %d networks, "
- "max_start_pad=%d, max_end_pad=%d\n",
- nets->entries,max_start_pad,max_end_pad);
- return NULL;
+ 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;
list_t *args)
{
struct null *st;
+ item_t *item;
+ dict_t *dict;
- st=safe_malloc(sizeof(*st),"null_apply (netlink)");
- st->cl.description="null-netlink";
- st->cl.type=CL_NETLINK;
- st->cl.apply=NULL;
- st->cl.interface=&st->ops;
- st->ops.st=st;
- st->ops.regnets=null_regnets;
- st->ops.deliver=null_deliver;
+ st=safe_malloc(sizeof(*st),"null_apply");
+
+ item=list_elem(args,0);
+ if (!item || item->type!=t_dict)
+ cfgfatal(loc,"null-netlink","parameter must be a dictionary\n");
+
+ dict=item->data.dict;
+
+ netlink_init(&st->nl,st,loc,dict,"null-netlink",null_set_route,
+ null_deliver);
- return new_closure(&st->cl);
+ return new_closure(&st->nl.cl);
}
init_module netlink_module;
void netlink_module(dict_t *dict)
{
- add_closure(dict,"userv-ipif",userv_apply);
-#if 0
- add_closure(dict,"pty-slip",ptyslip_apply);
- add_closure(dict,"slipd",slipd_apply);
-#endif /* 0 */
add_closure(dict,"null-netlink",null_apply);
}
~ianmdlvl / secnet.git / blobdiff