/* 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. */
-
-/* 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>
+/*
+ * This file is part of secnet.
+ * See README for full list of copyright holders.
+ *
+ * secnet is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * secnet is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * version 3 along with secnet; if not, see
+ * https://www.gnu.org/licenses/gpl.html.
+ */
+
+/* See RFCs 791, 792, 1123 and 1812 */
+
+/* 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"
+
+#ifdef NETLINK_DEBUG
+#define MDEBUG(...) Message(M_DEBUG, __VA_ARGS__)
+#else /* !NETLINK_DEBUG */
+#define MDEBUG(...) ((void)0)
+#endif /* !NETLINK_DEBUG */
+
+#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 DEFAULT_BUFSIZE 2048
+#define ICMP_TYPE_ECHO_REQUEST 8
-#define SLIP_END 192
-#define SLIP_ESC 219
-#define SLIP_ESCEND 220
-#define SLIP_ESCESC 221
+#define ICMP_TYPE_TIME_EXCEEDED 11
+#define ICMP_CODE_TTL_EXCEEDED 0
-struct netlink_client {
- struct subnet_list *networks;
- netlink_deliver_fn *deliver;
- void *dst;
- struct netlink_client *next;
+/* Generic IP checksum routine */
+static inline uint16_t ip_csum(const uint8_t *iph,int32_t count)
+{
+ register uint32_t sum=0;
+
+ 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);
+}
+
+#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(const uint8_t *iph, int32_t ihl) {
+ uint32_t sum;
+
+ __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)
+ : "memory");
+ return sum;
+}
+#else
+static inline uint16_t ip_fast_csum(const uint8_t *iph, int32_t ihl)
+{
+ assert(ihl < INT_MAX/4);
+ 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;
+#define IPHDR_FRAG_OFF ((uint16_t)0x1fff)
+#define IPHDR_FRAG_MORE ((uint16_t)0x2000)
+#define IPHDR_FRAG_DONT ((uint16_t)0x4000)
+/* reserved 0x8000 */
+ 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 icmpinfofield {
+ 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;
+ struct {
+ uint16_t unused;
+ uint16_t mtu;
+ } fragneeded;
+ } d;
};
-static int userv_beforepoll(void *sst, struct pollfd *fds, int *nfds_io,
- int *timeout_io, const struct timeval *tv_now,
- uint64_t *now)
+static const union icmpinfofield icmp_noinfo;
+
+static void netlink_client_deliver(struct netlink *st,
+ struct netlink_client *client,
+ uint32_t source, uint32_t dest,
+ struct buffer_if *buf);
+static void netlink_host_deliver(struct netlink *st,
+ struct netlink_client *sender,
+ uint32_t source, uint32_t dest,
+ struct buffer_if *buf);
+
+static const char *sender_name(struct netlink_client *sender /* or NULL */)
{
- 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;
+ return sender?sender->name:"(local)";
}
-static void process_local_packet(struct userv *st)
+static void netlink_packet_deliver(struct netlink *st,
+ 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 source, uint32_t dest,
+ uint16_t len)
{
- uint32_t source,dest;
- struct netlink_client *c;
+ struct icmphdr *h;
- source=ntohl(*(uint32_t *)(st->buff->start+12));
- dest=ntohl(*(uint32_t *)(st->buff->start+16));
+ BUF_ALLOC(&st->icmp,"netlink_icmp_tmpl");
+ buffer_init(&st->icmp,calculate_max_start_pad());
+ h=buf_append(&st->icmp,sizeof(*h));
-/* 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;
+ 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=0;
+ h->iph.ttl=255; /* XXX should be configurable */
+ h->iph.protocol=1;
+ h->iph.saddr=htonl(source);
+ 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;
+}
+
+/* Fill in the ICMP checksum field correctly */
+static void netlink_icmp_csum(struct icmphdr *h)
+{
+ int32_t len;
+
+ 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;
+ struct icmphdr *icmph;
+ uint32_t source;
+
+ if (buf->size < (int)sizeof(struct icmphdr)) return False;
+ iph=(struct iphdr *)buf->start;
+ icmph=(struct icmphdr *)buf->start;
+ if (iph->protocol==1) {
+ switch(icmph->type) {
+ /* Based on http://www.iana.org/assignments/icmp-parameters/icmp-parameters.xhtml#icmp-parameters-types
+ * as retrieved Thu, 20 Mar 2014 00:16:44 +0000.
+ * Deprecated, reserved, unassigned and experimental
+ * options are treated as not safe to reply to.
+ */
+ case 0: /* Echo Reply */
+ case 8: /* Echo */
+ case 13: /* Timestamp */
+ case 14: /* Timestamp Reply */
+ return True;
+ default:
+ return False;
+ }
}
- 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;
+ /* How do we spot broadcast destination addresses? */
+ if (ntohs(iph->frag)&IPHDR_FRAG_OFF) return False;
+ 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. */
+
+/* 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;
+
+ 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 MIN(hlen,plen);
+}
+
+/* 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 netlink_client *origsender,
+ struct buffer_if *buf,
+ uint8_t type, uint8_t code,
+ union icmpinfofield info)
+{
+ struct icmphdr *h;
+ uint16_t len;
+
+ if (netlink_icmp_may_reply(buf)) {
+ struct iphdr *iph=(struct iphdr *)buf->start;
+
+ uint32_t icmpdest = ntohl(iph->saddr);
+ uint32_t icmpsource;
+ const char *icmpsourcedebugprefix;
+ if (!st->ptp) {
+ icmpsource=st->secnet_address;
+ icmpsourcedebugprefix="";
+ } else if (origsender) {
+ /* was from peer, send reply as if from host */
+ icmpsource=st->local_address;
+ icmpsourcedebugprefix="L!";
+ } else {
+ /* was from host, send reply as if from peer */
+ icmpsource=st->secnet_address; /* actually, peer address */
+ icmpsourcedebugprefix="P!";
}
+ MDEBUG("%s: generating ICMP re %s[%s]->[%s]:"
+ " from %s%s type=%u code=%u\n",
+ st->name, sender_name(origsender),
+ ipaddr_to_string(ntohl(iph->saddr)),
+ ipaddr_to_string(ntohl(iph->daddr)),
+ icmpsourcedebugprefix,
+ ipaddr_to_string(icmpsource),
+ type, code);
+
+ len=netlink_icmp_reply_len(buf);
+ h=netlink_icmp_tmpl(st,icmpsource,icmpdest,len);
+ h->type=type; h->code=code; h->d=info;
+ BUF_ADD_BYTES(append,&st->icmp,buf->start,len);
+ netlink_icmp_csum(h);
+
+ if (!st->ptp) {
+ netlink_packet_deliver(st,NULL,&st->icmp);
+ } else if (origsender) {
+ netlink_client_deliver(st,origsender,icmpsource,icmpdest,&st->icmp);
+ } else {
+ netlink_host_deliver(st,NULL,icmpsource,icmpdest,&st->icmp);
+ }
+ BUF_ASSERT_FREE(&st->icmp);
}
- 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));
+}
+
+/*
+ * 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?
+ *
+ * 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,
+ 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;
+ int32_t len;
+
+ if (iph->version != 4) BAD("version %u",iph->version);
+ if (iph->ihl < 5) BAD("ihl %u",iph->ihl);
+ 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) 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
+}
+
+static const char *fragment_filter_header(uint8_t *base, long *hlp)
+{
+ const int fixedhl = sizeof(struct iphdr);
+ long hl = *hlp;
+ const uint8_t *ipend = base + hl;
+ uint8_t *op = base + fixedhl;
+ const uint8_t *ip = op;
+
+ while (ip < ipend) {
+ uint8_t opt = ip[0];
+ int remain = ipend - ip;
+ if (opt == 0x00) /* End of Options List */ break;
+ if (opt == 0x01) /* No Operation */ continue;
+ if (remain < 2) return "IPv4 options truncated at length";
+ int optlen = ip[1];
+ if (remain < optlen) return "IPv4 options truncated in option";
+ if (opt & 0x80) /* copy */ {
+ memmove(op, ip, optlen);
+ op += optlen;
+ }
+ ip += optlen;
+ }
+ while ((hl = (op - base)) & 0x3)
+ *op++ = 0x00 /* End of Option List */;
+ ((struct iphdr*)base)->ihl = hl >> 2;
+ *hlp = hl;
+
+ return 0;
+}
+
+/* Fragment or send ICMP Fragmentation Needed */
+static void netlink_maybe_fragment(struct netlink *st,
+ struct netlink_client *sender,
+ netlink_deliver_fn *deliver,
+ void *deliver_dst,
+ const char *delivery_name,
+ int32_t mtu,
+ uint32_t source, uint32_t dest,
+ struct buffer_if *buf)
+{
+ struct iphdr *iph=(struct iphdr*)buf->start;
+ long hl = iph->ihl*4;
+ const char *ssource = ipaddr_to_string(source);
+
+ if (buf->size <= mtu) {
+ deliver(deliver_dst, buf);
+ return;
+ }
+
+ MDEBUG("%s: fragmenting %s->%s org.size=%"PRId32"\n",
+ st->name, ssource, delivery_name, buf->size);
+
+#define BADFRAG(m, ...) \
+ Message(M_WARNING, \
+ "%s: fragmenting packet from source %s" \
+ " for transmission via %s: " m "\n", \
+ st->name, ssource, delivery_name, \
+ ## __VA_ARGS__);
+
+ unsigned orig_frag = ntohs(iph->frag);
+
+ if (orig_frag&IPHDR_FRAG_DONT) {
+ union icmpinfofield info =
+ { .fragneeded = { .unused = 0, .mtu = htons(mtu) } };
+ netlink_icmp_simple(st,sender,buf,
+ ICMP_TYPE_UNREACHABLE,
+ ICMP_CODE_FRAGMENTATION_REQUIRED,
+ info);
+ BUF_FREE(buf);
+ return;
+ }
+ if (mtu < hl + 8) {
+ BADFRAG("mtu %"PRId32" too small", mtu);
+ BUF_FREE(buf);
return;
}
- {
+
+ /* we (ab)use the icmp buffer to stash the original packet */
+ struct buffer_if *orig = &st->icmp;
+ BUF_ALLOC(orig,"netlink_client_deliver fragment orig");
+ buffer_copy(orig,buf);
+ BUF_FREE(buf);
+
+ const uint8_t *startindata = orig->start + hl;
+ const uint8_t *indata = startindata;
+ const uint8_t *endindata = orig->start + orig->size;
+ _Bool filtered = 0;
+
+ for (;;) {
+ /* compute our fragment offset */
+ long dataoffset = indata - startindata
+ + (orig_frag & IPHDR_FRAG_OFF)*8;
+ assert(!(dataoffset & 7));
+ if (dataoffset > IPHDR_FRAG_OFF*8) {
+ BADFRAG("ultimate fragment offset out of range");
+ break;
+ }
+
+ BUF_ALLOC(buf,"netlink_client_deliver fragment frag");
+ buffer_init(buf,calculate_max_start_pad());
+
+ /* copy header (possibly filtered); will adjust in a bit */
+ struct iphdr *fragh = buf_append(buf, hl);
+ memcpy(fragh, orig->start, hl);
+
+ /* decide how much payload to copy and copy it */
+ long avail = mtu - hl;
+ long remain = endindata - indata;
+ long use = avail < remain ? (avail & ~(long)7) : remain;
+ BUF_ADD_BYTES(append, buf, indata, use);
+ indata += use;
+
+ _Bool last_frag = indata >= endindata;
+
+ /* adjust the header */
+ fragh->tot_len = htons(buf->size);
+ fragh->frag =
+ htons((orig_frag & ~IPHDR_FRAG_OFF) |
+ (last_frag ? 0 : IPHDR_FRAG_MORE) |
+ (dataoffset >> 3));
+ fragh->check = 0;
+ fragh->check = ip_fast_csum((const void*)fragh, fragh->ihl);
+
+ /* actually send it */
+ deliver(deliver_dst, buf);
+ if (last_frag)
+ break;
+
+ /* after copying the header for the first frag,
+ * we filter the header for the remaining frags */
+ if (!filtered++) {
+ const char *bad = fragment_filter_header(orig->start, &hl);
+ if (bad) { BADFRAG("%s", bad); break; }
+ }
+ }
+
+ BUF_FREE(orig);
+
+#undef BADFRAG
+}
+
+/* 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_WARNING,"%s: outgoing packet with bad destination address "
- "(s=%s,d=%s)\n",st->name,s,d);
- free(s); free(d);
+ Message(M_ERR,"%s: dropping %s->%s, client not registered\n",
+ st->name,s,d);
+ BUF_FREE(buf);
return;
}
+ netlink_maybe_fragment(st,NULL, client->deliver,client->dst,client->name,
+ client->mtu, source,dest,buf);
+ client->outcount++;
}
-static void userv_afterpoll(void *sst, struct pollfd *fds, int nfds,
- const struct timeval *tv_now, uint64_t *now)
+/* Deliver a packet to the host; used after we have decided that that
+ * is what to do with it. */
+static void netlink_host_deliver(struct netlink *st,
+ struct netlink_client *sender,
+ uint32_t source, uint32_t dest,
+ struct buffer_if *buf)
{
- struct userv *st=sst;
- uint8_t rxbuf[DEFAULT_BUFSIZE];
- int l,i;
+ netlink_maybe_fragment(st,sender, st->deliver_to_host,st->dst,"(host)",
+ st->mtu, source,dest,buf);
+ st->outcount++;
+}
+
+/* Deliver a packet. "sender"==NULL for packets from the host and packets
+ generated internally in secnet. */
+static void netlink_packet_deliver(struct netlink *st,
+ struct netlink_client *sender,
+ 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, sender_name(sender));
+ 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;
- if (fds[1].revents&POLLERR) {
- printf("userv_afterpoll: hup!\n");
+ BUF_ASSERT_USED(buf);
+
+ if (dest==st->secnet_address) {
+ Message(M_ERR,"%s: trying to deliver a packet to myself!\n",st->name);
+ 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)");
+
+ /* Packets from the host (sender==NULL) may always be routed. Packets
+ from clients with the allow_route option will also be routed. */
+ if (!sender || (sender && (sender->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 (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 (l==0) {
- fatal("userv_afterpoll: read(rxfd)=0; userv gone away?\n");
+ }
+ 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)) {
+ netlink_host_deliver(st,sender,source,dest,buf);
+ 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);
+ netlink_icmp_simple(st,sender,buf,ICMP_TYPE_UNREACHABLE,
+ ICMP_CODE_NET_UNREACHABLE, icmp_noinfo);
+ BUF_FREE(buf);
}
- /* 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");
- }
+ } 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);
+
+ netlink_icmp_simple(st,sender,buf,ICMP_TYPE_UNREACHABLE,
+ ICMP_CODE_NET_PROHIBITED, icmp_noinfo);
+ BUF_FREE(buf);
+ } else {
+ if (best_quality>0) {
+ netlink_client_deliver(st,st->routes[best_match],
+ source,dest,buf);
+ BUF_ASSERT_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;
- }
+ /* Generate ICMP destination unreachable */
+ netlink_icmp_simple(st,sender,buf,
+ ICMP_TYPE_UNREACHABLE,
+ ICMP_CODE_NET_UNREACHABLE,
+ icmp_noinfo);
+ 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 *sender,
+ 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;
+ if (buf->size < (int)sizeof(struct iphdr)) return;
+ 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,sender,buf,ICMP_TYPE_TIME_EXCEEDED,
+ ICMP_CODE_TTL_EXCEEDED,icmp_noinfo);
+ 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,sender,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 *sender,
+ struct buffer_if *buf)
+{
+ 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;
+
+ unsigned fraginfo = ntohs(h->iph.frag);
+ if ((fraginfo&(IPHDR_FRAG_OFF|IPHDR_FRAG_MORE))!=0) {
+ if (!(fraginfo & IPHDR_FRAG_OFF))
+ /* report only for first fragment */
+ Message(M_WARNING,"%s: fragmented packet addressed to secnet; "
+ "ignoring it\n",st->name);
+ BUF_FREE(buf);
+ return;
+ }
+
+ if (h->iph.protocol==1) {
+ /* It's ICMP */
+ 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=ICMP_TYPE_ECHO_REPLY;
+ h->iph.daddr=h->iph.saddr;
+ h->iph.saddr=htonl(st->secnet_address);
+ h->iph.ttl=255;
+ 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,sender,buf,ICMP_TYPE_UNREACHABLE,
+ ICMP_CODE_PROTOCOL_UNREACHABLE,icmp_noinfo);
+ 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);
+ BUF_FREE(buf);
+}
- /* 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); */
+/* If cid==NULL packet is from host, otherwise cid specifies which tunnel
+ it came from. */
+static void netlink_incoming(struct netlink *st, struct netlink_client *sender,
+ struct buffer_if *buf)
+{
+ uint32_t source,dest;
+ struct iphdr *iph;
+ char errmsgbuf[50];
+ const char *sourcedesc=sender?sender->name:"host";
- st->pending_esc=False;
+ BUF_ASSERT_USED(buf);
- /* Invoke userv */
- if (pipe(c_stdin)!=0) {
- fatal_perror("userv_phase_hook: pipe(c_stdin)");
+ 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;
}
- if (pipe(c_stdout)!=0) {
- fatal_perror("userv_phase_hook: pipe(c_stdout)");
+ assert(buf->size >= (int)sizeof(struct iphdr));
+ iph=(struct iphdr *)buf->start;
+
+ source=ntohl(iph->saddr);
+ dest=ntohl(iph->daddr);
+
+ /* 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 (sender) {
+ /* Check that the packet source is appropriate for the tunnel
+ it came down */
+ if (!ipset_contains_addr(sender->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,sender->name,s,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 (!ipset_contains_addr(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);
+ BUF_FREE(buf);
+ return;
+ }
}
- st->txfd=c_stdin[1];
- st->rxfd=c_stdout[0];
- child=fork();
- if (child==-1) {
- fatal_perror("userv_phase_hook: fork()");
+ /* 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 (sender) {
+ netlink_host_deliver(st,sender,source,dest,buf);
+ } else {
+ netlink_client_deliver(st,st->clients,source,dest,buf);
+ }
+ BUF_ASSERT_FREE(buf);
+ return;
}
- 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]);
+ /* st->secnet_address needs checking before matching destination
+ addresses */
+ if (dest==st->secnet_address) {
+ netlink_packet_local(st,sender,buf);
+ BUF_ASSERT_FREE(buf);
+ return;
+ }
+ netlink_packet_forward(st,sender,buf);
+ BUF_ASSERT_FREE(buf);
+}
- /* 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");
+static void netlink_inst_incoming(void *sst, struct buffer_if *buf)
+{
+ struct netlink_client *c=sst;
+ struct netlink *st=c->nst;
- exit(1);
- }
- /* We are the parent... */
-
- /* Register for poll() */
- register_for_poll(st, userv_beforepoll, userv_afterpoll, 2, "netlink");
+ netlink_incoming(st,c,buf);
}
-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_dev_incoming(void *sst, struct buffer_if *buf)
{
- struct userv *st=sst;
- struct netlink_client *c;
+ struct netlink *st=sst;
- Message(M_DEBUG_CONFIG,"userv_regnets: request for %d networks, "
- "max_start_pad=%d, max_end_pad=%d\n",
- nets->entries,max_start_pad,max_end_pad);
+ netlink_incoming(st,NULL,buf);
+}
- c=safe_malloc(sizeof(*c),"userv_regnets");
- c->networks=nets;
- c->deliver=deliver;
- c->dst=dst;
- 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;
+static void netlink_set_quality(void *sst, uint32_t quality)
+{
+ struct netlink_client *c=sst;
+ struct netlink *st=c->nst;
- return c;
+ 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);
+ }
}
-static void userv_deliver(void *sst, void *cid, struct buffer_if *buf)
+static void netlink_output_subnets(struct netlink *st, uint32_t loglevel,
+ struct subnet_list *snets)
{
- struct userv *st=sst;
- struct netlink_client *client=cid;
- uint8_t txbuf[DEFAULT_BUFSIZE];
+ int32_t i;
+ string_t net;
- uint32_t source,dest;
- uint8_t *i;
- uint32_t j;
+ for (i=0; i<snets->entries; i++) {
+ net=subnet_to_string(snets->list[i]);
+ Message(loglevel,"%s ",net);
+ }
+}
- source=ntohl(*(uint32_t *)(buf->start+12));
- dest=ntohl(*(uint32_t *)(buf->start+16));
+static void netlink_dump_routes(struct netlink *st, bool_t requested)
+{
+ int i;
+ string_t net;
+ uint32_t c=M_INFO;
- /* 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;
+ if (requested) c=M_WARNING;
+ if (st->ptp) {
+ net=ipaddr_to_string(st->secnet_address);
+ Message(c,"%s: point-to-point (remote end is %s); routes: ",
+ st->name, 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);
+ for (i=0; i<st->subnets->entries; i++) {
+ net=subnet_to_string(st->subnets->list[i]);
+ Message(c,"%s ",net);
+ }
+ if (i>0)
+ Message(c,"-> host (use %d)\n",st->outcount);
}
- 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;
+}
+
+/* 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_client *const*a=ap;
+ const struct netlink_client *const*b=bp;
+
+ if ((*a)->priority==(*b)->priority) return 0;
+ if ((*a)->priority<(*b)->priority) return 1;
+ return -1;
+}
+
+static void netlink_phase_hook(void *sst, uint32_t new_phase)
+{
+ struct netlink *st=sst;
+ struct netlink_client *c;
+ int32_t i;
+
+ /* All the networks serviced by the various tunnels should now
+ * have been registered. We build a routing table by sorting the
+ * clients by priority. */
+ NEW_ARY(st->routes,st->n_clients);
+ /* Fill the table */
+ i=0;
+ for (c=st->clients; c; c=c->next) {
+ assert(i<INT_MAX);
+ st->routes[i++]=c;
}
+ /* Sort the table in descending order of priority */
+ qsort(st->routes,st->n_clients,sizeof(*st->routes),
+ netlink_compare_client_priority);
- /* 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! */
+ netlink_dump_routes(st,False);
+}
- /* (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 void netlink_signal_handler(void *sst, int signum)
+{
+ struct netlink *st=sst;
+ Message(M_INFO,"%s: route dump requested by SIGUSR1\n",st->name);
+ netlink_dump_routes(st,True);
+}
- if (dest==st->secnet_address) {
- printf("%s: incoming tunneled packet for secnet!\n",st->name);
- return;
+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, uint32_t *localmtu_r)
+{
+ struct netlink_client *c=sst;
+ struct netlink *st=c->nst;
+
+ c->deliver=deliver;
+ c->dst=dst;
+
+ if (localmtu_r)
+ *localmtu_r=st->mtu;
+}
+
+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;
}
- /* 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;
+ 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;
}
}
- txbuf[j++]=SLIP_END;
- if (write(st->txfd,txbuf,j)<0) {
- fatal_perror("userv_deliver: write()");
+
+ /* 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;
}
- return;
+ NEW(c);
+ 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 *userv_apply(closure_t *self, struct cloc loc, dict_t *context,
- list_t *args)
+static list_t *netlink_inst_apply(closure_t *self, struct cloc loc,
+ dict_t *context, list_t *args)
{
- struct userv *st;
- item_t *item;
- dict_t *dict;
+ struct netlink *st=self->interface;
- st=safe_malloc(sizeof(*st),"userv_apply (netlink)");
- st->cl.description="userv-netlink";
- 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->max_start_pad=0;
- st->max_end_pad=0;
- st->rxfd=-1; st->txfd=-1;
- st->clients=NULL;
+ dict_t *dict;
+ item_t *item;
+ closure_t *cl;
- /* 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");
-
+ if (!item || item->type!=t_dict) {
+ cfgfatal(loc,st->name,"must have a dictionary argument\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->networks);
- st->local_address=string_to_ipaddr(
- dict_find_item(dict,"local-address", True, "userv-netlink", loc),
- "userv-netlink");
- 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");
-
- add_hook(PHASE_DROPPRIV,userv_phase_hook,st);
-
- return new_closure(&st->cl);
+
+ 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, 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_PURE;
+ st->cl.apply=netlink_inst_apply;
+ st->cl.interface=st;
+ st->clients=NULL;
+ 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,description,loc);
+ if (!st->name) st->name=description;
+ 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);
+ }
+ st->local_address=string_item_to_ipaddr(
+ dict_find_item(dict,"local-address", True, "netlink", loc),"netlink");
+
+ 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_item_to_ipaddr(sa,"netlink");
+ st->ptp=False;
+ } else {
+ 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,MAX(ICMP_BUFSIZE,st->mtu));
+ st->outcount=0;
+ st->localcount=0;
+
+ add_hook(PHASE_SETUP,netlink_phase_hook,st);
+ request_signal_notification(SIGUSR1, netlink_signal_handler, st);
+
+ /* 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 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_client *routes)
{
- 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;
-static void null_deliver(void *sst, void *cid, struct buffer_if *buf)
+ 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, struct buffer_if *buf)
{
return;
}
list_t *args)
{
struct null *st;
+ item_t *item;
+ dict_t *dict;
+
+ NEW(st);
+
+ 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;
- 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;
+ 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);
}