mirror of
https://gitlab.nic.cz/labs/bird.git
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812 lines
20 KiB
C
812 lines
20 KiB
C
/*
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* BIRD -- BGP Packet Processing
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*
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* (c) 2000 Martin Mares <mj@ucw.cz>
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*
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* Can be freely distributed and used under the terms of the GNU GPL.
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*/
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#undef LOCAL_DEBUG
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#include "nest/bird.h"
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#include "nest/iface.h"
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#include "nest/protocol.h"
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#include "nest/route.h"
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#include "conf/conf.h"
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#include "lib/unaligned.h"
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#include "lib/socket.h"
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#include "bgp.h"
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static byte *
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bgp_create_notification(struct bgp_conn *conn, byte *buf)
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{
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struct bgp_proto *p = conn->bgp;
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BGP_TRACE(D_PACKETS, "Sending NOTIFICATION(code=%d.%d)", conn->notify_code, conn->notify_subcode);
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buf[0] = conn->notify_code;
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buf[1] = conn->notify_subcode;
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memcpy(buf+2, conn->notify_data, conn->notify_size);
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return buf + 2 + conn->notify_size;
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}
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static byte *
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bgp_create_open(struct bgp_conn *conn, byte *buf)
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{
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struct bgp_proto *p = conn->bgp;
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BGP_TRACE(D_PACKETS, "Sending OPEN(ver=%d,as=%d,hold=%d,id=%08x)",
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BGP_VERSION, p->local_as, p->cf->hold_time, p->local_id);
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buf[0] = BGP_VERSION;
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put_u16(buf+1, p->local_as);
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put_u16(buf+3, p->cf->hold_time);
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put_u32(buf+5, p->local_id);
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buf[9] = 0; /* No optional parameters */
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return buf+10;
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}
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static unsigned int
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bgp_encode_prefixes(struct bgp_proto *p, byte *w, struct bgp_bucket *buck, unsigned int remains)
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{
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byte *start = w;
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ip_addr a;
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int bytes;
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while (!EMPTY_LIST(buck->prefixes) && remains >= 5)
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{
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struct bgp_prefix *px = SKIP_BACK(struct bgp_prefix, bucket_node, HEAD(buck->prefixes));
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DBG("\tDequeued route %I/%d\n", px->n.prefix, px->n.pxlen);
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*w++ = px->n.pxlen;
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bytes = (px->n.pxlen + 7) / 8;
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a = px->n.prefix;
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ipa_hton(a);
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memcpy(w, &a, bytes);
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w += bytes;
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rem_node(&px->bucket_node);
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fib_delete(&p->prefix_fib, px);
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}
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return w - start;
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}
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#ifndef IPV6 /* IPv4 version */
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static byte *
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bgp_create_update(struct bgp_conn *conn, byte *buf)
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{
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struct bgp_proto *p = conn->bgp;
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struct bgp_bucket *buck;
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int remains = BGP_MAX_PACKET_LENGTH - BGP_HEADER_LENGTH - 4;
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byte *w;
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int wd_size = 0;
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int r_size = 0;
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int a_size = 0;
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BGP_TRACE(D_PACKETS, "Sending UPDATE");
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w = buf+2;
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if ((buck = p->withdraw_bucket) && !EMPTY_LIST(buck->prefixes))
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{
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DBG("Withdrawn routes:\n");
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wd_size = bgp_encode_prefixes(p, w, buck, remains);
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w += wd_size;
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remains -= wd_size;
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}
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put_u16(buf, wd_size);
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if (remains >= 2048)
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{
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while ((buck = (struct bgp_bucket *) HEAD(p->bucket_queue))->send_node.next)
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{
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if (EMPTY_LIST(buck->prefixes))
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{
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DBG("Deleting empty bucket %p\n", buck);
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rem_node(&buck->send_node);
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bgp_free_bucket(p, buck);
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continue;
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}
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DBG("Processing bucket %p\n", buck);
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a_size = bgp_encode_attrs(w+2, buck->eattrs, 1024);
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put_u16(w, a_size);
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w += a_size + 2;
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r_size = bgp_encode_prefixes(p, w, buck, remains - a_size);
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w += r_size;
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break;
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}
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}
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if (!a_size) /* Attributes not already encoded */
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{
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put_u16(w, 0);
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w += 2;
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}
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return (wd_size || r_size) ? w : NULL;
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}
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#else /* IPv6 version */
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static byte *
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bgp_create_update(struct bgp_conn *conn, byte *buf)
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{
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struct bgp_proto *p = conn->bgp;
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struct bgp_bucket *buck;
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int size, is_ll;
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int remains = BGP_MAX_PACKET_LENGTH - BGP_HEADER_LENGTH - 4;
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byte *w, *tmp, *tstart;
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ip_addr ip, ip_ll;
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ea_list *ea;
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eattr *nh;
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neighbor *n;
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BGP_TRACE(D_PACKETS, "Sending UPDATE");
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put_u16(buf, 0);
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w = buf+4;
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if ((buck = p->withdraw_bucket) && !EMPTY_LIST(buck->prefixes))
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{
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DBG("Withdrawn routes:\n");
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tmp = bgp_attach_attr(&ea, bgp_linpool, BA_MP_UNREACH_NLRI, remains-8);
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*tmp++ = 0;
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*tmp++ = BGP_AF_IPV6;
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*tmp++ = 1;
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ea->attrs[0].u.ptr->length = bgp_encode_prefixes(p, tmp, buck, remains-11);
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size = bgp_encode_attrs(w, ea, remains);
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w += size;
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remains -= size;
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}
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if (remains >= 2048)
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{
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while ((buck = (struct bgp_bucket *) HEAD(p->bucket_queue))->send_node.next)
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{
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if (EMPTY_LIST(buck->prefixes))
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{
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DBG("Deleting empty bucket %p\n", buck);
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rem_node(&buck->send_node);
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bgp_free_bucket(p, buck);
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continue;
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}
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DBG("Processing bucket %p\n", buck);
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size = bgp_encode_attrs(w, buck->eattrs, 1024);
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w += size;
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remains -= size;
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tstart = tmp = bgp_attach_attr(&ea, bgp_linpool, BA_MP_REACH_NLRI, remains-8);
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*tmp++ = 0;
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*tmp++ = BGP_AF_IPV6;
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*tmp++ = 1;
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nh = ea_find(buck->eattrs, EA_CODE(EAP_BGP, BA_NEXT_HOP));
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ASSERT(nh);
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ip = *(ip_addr *) nh->u.ptr->data;
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if (ipa_equal(ip, p->local_addr))
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is_ll = 1;
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else
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{
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n = neigh_find(&p->p, &ip, 0);
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if (n && n->iface == p->neigh->iface)
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is_ll = 1;
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else
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is_ll = 0;
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}
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if (is_ll)
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{
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*tmp++ = 32;
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ip_ll = ipa_or(ipa_build(0xfe80,0,0,0), ipa_and(ip, ipa_build(0,0,~0,~0)));
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ipa_hton(ip);
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memcpy(tmp, &ip, 16);
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ipa_hton(ip_ll);
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memcpy(tmp+16, &ip_ll, 16);
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tmp += 32;
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}
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else
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{
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*tmp++ = 16;
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ipa_hton(ip);
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memcpy(tmp, &ip, 16);
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tmp += 16;
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}
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*tmp++ = 0; /* No SNPA information */
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tmp += bgp_encode_prefixes(p, tmp, buck, remains - (8+3+32+1));
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ea->attrs[0].u.ptr->length = tmp - tstart;
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w += bgp_encode_attrs(w, ea, remains);
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break;
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}
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}
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size = w - (buf+4);
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put_u16(buf+2, size);
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lp_flush(bgp_linpool);
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return size ? w : NULL;
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}
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#endif
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static void
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bgp_create_header(byte *buf, unsigned int len, unsigned int type)
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{
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memset(buf, 0xff, 16); /* Marker */
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put_u16(buf+16, len);
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buf[18] = type;
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}
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static int
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bgp_fire_tx(struct bgp_conn *conn)
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{
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struct bgp_proto *p = conn->bgp;
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unsigned int s = conn->packets_to_send;
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sock *sk = conn->sk;
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byte *buf = sk->tbuf;
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byte *pkt = buf + BGP_HEADER_LENGTH;
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byte *end;
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int type;
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if (s & (1 << PKT_SCHEDULE_CLOSE))
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{
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bgp_close_conn(conn);
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return 0;
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}
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if (s & (1 << PKT_NOTIFICATION))
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{
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s = 1 << PKT_SCHEDULE_CLOSE;
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type = PKT_NOTIFICATION;
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end = bgp_create_notification(conn, pkt);
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}
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else if (s & (1 << PKT_KEEPALIVE))
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{
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s &= ~(1 << PKT_KEEPALIVE);
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type = PKT_KEEPALIVE;
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end = pkt; /* Keepalives carry no data */
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BGP_TRACE(D_PACKETS, "Sending KEEPALIVE");
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bgp_start_timer(conn->keepalive_timer, conn->keepalive_time);
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}
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else if (s & (1 << PKT_OPEN))
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{
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s &= ~(1 << PKT_OPEN);
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type = PKT_OPEN;
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end = bgp_create_open(conn, pkt);
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}
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else if (s & (1 << PKT_UPDATE))
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{
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end = bgp_create_update(conn, pkt);
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type = PKT_UPDATE;
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if (!end)
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{
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conn->packets_to_send = 0;
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return 0;
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}
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}
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else
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return 0;
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conn->packets_to_send = s;
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bgp_create_header(buf, end - buf, type);
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return sk_send(sk, end - buf);
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}
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void
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bgp_schedule_packet(struct bgp_conn *conn, int type)
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{
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DBG("BGP: Scheduling packet type %d\n", type);
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conn->packets_to_send |= 1 << type;
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if (conn->sk->tpos == conn->sk->tbuf)
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while (bgp_fire_tx(conn))
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;
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}
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void
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bgp_tx(sock *sk)
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{
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struct bgp_conn *conn = sk->data;
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DBG("BGP: TX hook\n");
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while (bgp_fire_tx(conn))
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;
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}
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static int
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bgp_parse_options(struct bgp_conn *conn, byte *opt, int len)
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{
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while (len > 0)
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{
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if (len < 2 || len < 2 + opt[1])
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{ bgp_error(conn, 2, 0, NULL, 0); return 0; }
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#ifdef LOCAL_DEBUG
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{
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int i;
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DBG("\tOption %02x:", opt[0]);
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for(i=0; i<opt[1]; i++)
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DBG(" %02x", opt[2+i]);
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DBG("\n");
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}
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#endif
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switch (opt[0])
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{
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case 2:
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/* Defined in draft-ietf-idr-bgp4-cap-neg-06 */
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/* We can safely ignore all capabilities */
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break;
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default:
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/*
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* BGP specs don't tell us to send which option
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* we didn't recognize, but it's common practice
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* to do so. Also, capability negotiation with
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* Cisco routers doesn't work without that.
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*/
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bgp_error(conn, 2, 4, opt, opt[1]);
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return 0;
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}
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len -= 2 + opt[1];
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opt += 2 + opt[1];
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}
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return 0;
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}
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static void
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bgp_rx_open(struct bgp_conn *conn, byte *pkt, int len)
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{
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struct bgp_conn *other;
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struct bgp_proto *p = conn->bgp;
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struct bgp_config *cf = p->cf;
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unsigned as, hold;
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u32 id;
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/* Check state */
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if (conn->state != BS_OPENSENT)
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{ bgp_error(conn, 5, 0, NULL, 0); }
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/* Check message contents */
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if (len < 29 || len != 29 + pkt[28])
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{ bgp_error(conn, 1, 2, pkt+16, 2); return; }
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if (pkt[19] != BGP_VERSION)
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{ bgp_error(conn, 2, 1, pkt+19, 1); return; } /* RFC 1771 says 16 bits, draft-09 tells to use 8 */
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as = get_u16(pkt+20);
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hold = get_u16(pkt+22);
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id = get_u32(pkt+24);
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BGP_TRACE(D_PACKETS, "Got OPEN(as=%d,hold=%d,id=%08x)", as, hold, id);
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if (cf->remote_as && as != p->remote_as)
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{ bgp_error(conn, 2, 2, pkt+20, -2); return; }
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if (hold > 0 && hold < 3)
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{ bgp_error(conn, 2, 6, pkt+22, 2); return; }
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p->remote_id = id;
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if (bgp_parse_options(conn, pkt+29, pkt[28]))
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return;
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if (!id || id == 0xffffffff || id == p->local_id)
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{ bgp_error(conn, 2, 3, pkt+24, -4); return; }
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/* Check the other connection */
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other = (conn == &p->outgoing_conn) ? &p->incoming_conn : &p->outgoing_conn;
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switch (other->state)
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{
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case BS_IDLE:
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break;
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case BS_CONNECT:
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case BS_ACTIVE:
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case BS_OPENSENT:
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BGP_TRACE(D_EVENTS, "Connection collision, giving up the other connection");
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bgp_close_conn(other);
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break;
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case BS_OPENCONFIRM:
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if ((p->local_id < id) == (conn == &p->incoming_conn))
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{
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/* Should close the other connection */
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BGP_TRACE(D_EVENTS, "Connection collision, giving up the other connection");
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bgp_error(other, 6, 0, NULL, 0);
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break;
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}
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/* Fall thru */
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case BS_ESTABLISHED:
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/* Should close this connection */
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BGP_TRACE(D_EVENTS, "Connection collision, giving up this connection");
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bgp_error(conn, 6, 0, NULL, 0);
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return;
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default:
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bug("bgp_rx_open: Unknown state");
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}
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/* Make this connection primary */
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conn->primary = 1;
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p->conn = conn;
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/* Update our local variables */
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if (hold < p->cf->hold_time)
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conn->hold_time = hold;
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else
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conn->hold_time = p->cf->hold_time;
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conn->keepalive_time = p->cf->keepalive_time ? : conn->hold_time / 3;
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p->remote_as = as;
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p->remote_id = id;
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DBG("BGP: Hold timer set to %d, keepalive to %d, AS to %d, ID to %x\n", conn->hold_time, conn->keepalive_time, p->remote_as, p->remote_id);
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bgp_schedule_packet(conn, PKT_KEEPALIVE);
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bgp_start_timer(conn->hold_timer, conn->hold_time);
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conn->state = BS_OPENCONFIRM;
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}
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#define DECODE_PREFIX(pp, ll) do { \
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int b = *pp++; \
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int q; \
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ll--; \
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if (b > BITS_PER_IP_ADDRESS) { err=10; goto bad; } \
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q = (b+7) / 8; \
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if (ll < q) { err=1; goto bad; } \
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memcpy(&prefix, pp, q); \
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pp += q; \
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ll -= q; \
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ipa_ntoh(prefix); \
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prefix = ipa_and(prefix, ipa_mkmask(b)); \
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pxlen = b; \
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} while (0)
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static inline int
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bgp_get_nexthop(struct bgp_proto *bgp, rta *a)
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{
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neighbor *neigh;
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ip_addr nexthop;
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struct eattr *nh = ea_find(a->eattrs, EA_CODE(EAP_BGP, BA_NEXT_HOP));
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ASSERT(nh);
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nexthop = *(ip_addr *) nh->u.ptr->data;
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if (ipa_equal(nexthop, bgp->local_addr))
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{
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DBG("BGP: Loop!\n");
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return 0;
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}
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neigh = neigh_find(&bgp->p, &nexthop, 0) ? : bgp->neigh;
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a->gw = neigh->addr;
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a->iface = neigh->iface;
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return 1;
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}
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#ifndef IPV6 /* IPv4 version */
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static void
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bgp_do_rx_update(struct bgp_conn *conn,
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byte *withdrawn, int withdrawn_len,
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byte *nlri, int nlri_len,
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byte *attrs, int attr_len)
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{
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struct bgp_proto *p = conn->bgp;
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rta *a0;
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rta *a = NULL;
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ip_addr prefix;
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net *n;
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rte e;
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int err = 0, pxlen;
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/* Withdraw routes */
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while (withdrawn_len)
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{
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DECODE_PREFIX(withdrawn, withdrawn_len);
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DBG("Withdraw %I/%d\n", prefix, pxlen);
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if (n = net_find(p->p.table, prefix, pxlen))
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rte_update(p->p.table, n, &p->p, NULL);
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}
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if (!attr_len && !nlri_len) /* shortcut */
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return;
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a0 = bgp_decode_attrs(conn, attrs, attr_len, bgp_linpool, nlri_len);
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if (a0 && nlri_len && bgp_get_nexthop(p, a0))
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{
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a = rta_lookup(a0);
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while (nlri_len)
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{
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rte *e;
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DECODE_PREFIX(nlri, nlri_len);
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DBG("Add %I/%d\n", prefix, pxlen);
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e = rte_get_temp(rta_clone(a));
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n = net_get(p->p.table, prefix, pxlen);
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e->net = n;
|
|
e->pflags = 0;
|
|
rte_update(p->p.table, n, &p->p, e);
|
|
}
|
|
}
|
|
bad:
|
|
if (a)
|
|
rta_free(a);
|
|
if (err)
|
|
bgp_error(conn, 3, err, NULL, 0);
|
|
return;
|
|
}
|
|
|
|
#else /* IPv6 version */
|
|
|
|
#define DO_NLRI(name) \
|
|
start = x = p->name##_start; \
|
|
len = len0 = p->name##_len; \
|
|
if (len) \
|
|
{ \
|
|
if (len < 3) goto bad; \
|
|
af = get_u16(x); \
|
|
sub = x[2]; \
|
|
x += 3; \
|
|
len -= 3; \
|
|
DBG("\tNLRI AF=%d sub=%d len=%d\n", af, sub, len);\
|
|
} \
|
|
else \
|
|
af = 0; \
|
|
if (af == BGP_AF_IPV6)
|
|
|
|
static void
|
|
bgp_do_rx_update(struct bgp_conn *conn,
|
|
byte *withdrawn, int withdrawn_len,
|
|
byte *nlri, int nlri_len,
|
|
byte *attrs, int attr_len)
|
|
{
|
|
struct bgp_proto *p = conn->bgp;
|
|
byte *start, *x;
|
|
int len, len0;
|
|
unsigned af, sub;
|
|
rta *a0;
|
|
rta *a = NULL;
|
|
ip_addr prefix;
|
|
net *n;
|
|
rte e;
|
|
int err = 0, pxlen;
|
|
|
|
p->mp_reach_len = 0;
|
|
p->mp_unreach_len = 0;
|
|
a0 = bgp_decode_attrs(conn, attrs, attr_len, bgp_linpool, 0);
|
|
if (!a0)
|
|
return;
|
|
|
|
DO_NLRI(mp_unreach)
|
|
{
|
|
while (len)
|
|
{
|
|
DECODE_PREFIX(x, len);
|
|
DBG("Withdraw %I/%d\n", prefix, pxlen);
|
|
if (n = net_find(p->p.table, prefix, pxlen))
|
|
rte_update(p->p.table, n, &p->p, NULL);
|
|
}
|
|
}
|
|
|
|
DO_NLRI(mp_reach)
|
|
{
|
|
int i;
|
|
|
|
/* Create fake NEXT_HOP attribute */
|
|
if (len < 1 || (*x != 16 && *x != 32) || len < *x + 2)
|
|
goto bad;
|
|
memcpy(bgp_attach_attr(&a0->eattrs, bgp_linpool, BA_NEXT_HOP, 16), x+1, 16);
|
|
len -= *x + 1;
|
|
x += *x + 1;
|
|
|
|
/* Ignore SNPA info */
|
|
i = *x++;
|
|
while (i--)
|
|
{
|
|
if (len < 1 || len < 1 + *x)
|
|
goto bad;
|
|
len -= *x + 1;
|
|
x += *x + 1;
|
|
}
|
|
|
|
if (bgp_get_nexthop(p, a0))
|
|
{
|
|
a = rta_lookup(a0);
|
|
while (len)
|
|
{
|
|
rte *e;
|
|
DECODE_PREFIX(x, len);
|
|
DBG("Add %I/%d\n", prefix, pxlen);
|
|
e = rte_get_temp(rta_clone(a));
|
|
n = net_get(p->p.table, prefix, pxlen);
|
|
e->net = n;
|
|
e->pflags = 0;
|
|
rte_update(p->p.table, n, &p->p, e);
|
|
}
|
|
rta_free(a);
|
|
}
|
|
}
|
|
|
|
return;
|
|
|
|
bad:
|
|
bgp_error(conn, 3, 9, start, len0);
|
|
if (a)
|
|
rta_free(a);
|
|
return;
|
|
}
|
|
|
|
#endif
|
|
|
|
static void
|
|
bgp_rx_update(struct bgp_conn *conn, byte *pkt, int len)
|
|
{
|
|
struct bgp_proto *p = conn->bgp;
|
|
byte *withdrawn, *attrs, *nlri;
|
|
int withdrawn_len, attr_len, nlri_len;
|
|
|
|
BGP_TRACE(D_PACKETS, "Got UPDATE");
|
|
if (conn->state != BS_ESTABLISHED)
|
|
{ bgp_error(conn, 5, 0, NULL, 0); return; }
|
|
bgp_start_timer(conn->hold_timer, conn->hold_time);
|
|
|
|
/* Find parts of the packet and check sizes */
|
|
if (len < 23)
|
|
{
|
|
bgp_error(conn, 1, 2, pkt+16, 2);
|
|
return;
|
|
}
|
|
withdrawn = pkt + 21;
|
|
withdrawn_len = get_u16(pkt + 19);
|
|
if (withdrawn_len + 23 > len)
|
|
goto malformed;
|
|
attrs = withdrawn + withdrawn_len + 2;
|
|
attr_len = get_u16(attrs - 2);
|
|
if (withdrawn_len + attr_len + 23 > len)
|
|
goto malformed;
|
|
nlri = attrs + attr_len;
|
|
nlri_len = len - withdrawn_len - attr_len - 23;
|
|
if (!attr_len && nlri_len)
|
|
goto malformed;
|
|
DBG("Sizes: withdrawn=%d, attrs=%d, NLRI=%d\n", withdrawn_len, attr_len, nlri_len);
|
|
|
|
lp_flush(bgp_linpool);
|
|
|
|
bgp_do_rx_update(conn, withdrawn, withdrawn_len, nlri, nlri_len, attrs, attr_len);
|
|
return;
|
|
|
|
malformed:
|
|
bgp_error(conn, 3, 1, NULL, 0);
|
|
}
|
|
|
|
static struct {
|
|
byte major, minor;
|
|
byte *msg;
|
|
} bgp_msg_table[] = {
|
|
{ 1, 0, "Invalid message header" },
|
|
{ 1, 1, "Connection not synchronized" },
|
|
{ 1, 2, "Bad message length" },
|
|
{ 1, 3, "Bad message type" },
|
|
{ 2, 0, "Invalid OPEN message" },
|
|
{ 2, 1, "Unsupported version number" },
|
|
{ 2, 2, "Bad peer AS" },
|
|
{ 2, 3, "Bad BGP identifier" },
|
|
{ 2, 4, "Unsupported optional parameter" },
|
|
{ 2, 5, "Authentication failure" },
|
|
{ 2, 6, "Unacceptable hold time" },
|
|
{ 2, 7, "Required capability missing" }, /* capability negotiation draft */
|
|
{ 3, 0, "Invalid UPDATE message" },
|
|
{ 3, 1, "Malformed attribute list" },
|
|
{ 3, 2, "Unrecognized well-known attribute" },
|
|
{ 3, 3, "Missing mandatory attribute" },
|
|
{ 3, 4, "Invalid attribute flags" },
|
|
{ 3, 5, "Invalid attribute length" },
|
|
{ 3, 6, "Invalid ORIGIN attribute" },
|
|
{ 3, 7, "AS routing loop" }, /* Deprecated */
|
|
{ 3, 8, "Invalid NEXT_HOP attribute" },
|
|
{ 3, 9, "Optional attribute error" },
|
|
{ 3, 10, "Invalid network field" },
|
|
{ 3, 11, "Malformed AS_PATH" },
|
|
{ 4, 0, "Hold timer expired" },
|
|
{ 5, 0, "Finite state machine error" },
|
|
{ 6, 0, "Cease" }
|
|
};
|
|
|
|
void
|
|
bgp_log_error(struct bgp_proto *p, char *msg, unsigned code, unsigned subcode, byte *data, unsigned len)
|
|
{
|
|
byte *name, namebuf[16];
|
|
byte *t, argbuf[36];
|
|
unsigned i;
|
|
|
|
if (code == 6 && !subcode) /* Don't report Cease messages */
|
|
return;
|
|
|
|
bsprintf(namebuf, "%d.%d", code, subcode);
|
|
name = namebuf;
|
|
for (i=0; i < ARRAY_SIZE(bgp_msg_table); i++)
|
|
if (bgp_msg_table[i].major == code && bgp_msg_table[i].minor == subcode)
|
|
{
|
|
name = bgp_msg_table[i].msg;
|
|
break;
|
|
}
|
|
t = argbuf;
|
|
if (len)
|
|
{
|
|
*t++ = ':';
|
|
*t++ = ' ';
|
|
if (len > 16)
|
|
len = 16;
|
|
for (i=0; i<len; i++)
|
|
t += bsprintf(t, "%02x", data[i]);
|
|
}
|
|
*t = 0;
|
|
log(L_REMOTE "%s: %s: %s%s", p->p.name, msg, name, argbuf);
|
|
}
|
|
|
|
static void
|
|
bgp_rx_notification(struct bgp_conn *conn, byte *pkt, int len)
|
|
{
|
|
if (len < 21)
|
|
{
|
|
bgp_error(conn, 1, 2, pkt+16, 2);
|
|
return;
|
|
}
|
|
bgp_log_error(conn->bgp, "Received error notification", pkt[19], pkt[20], pkt+21, len-21);
|
|
conn->error_flag = 1;
|
|
if (conn->primary)
|
|
proto_notify_state(&conn->bgp->p, PS_STOP);
|
|
bgp_schedule_packet(conn, PKT_SCHEDULE_CLOSE);
|
|
}
|
|
|
|
static void
|
|
bgp_rx_keepalive(struct bgp_conn *conn, byte *pkt, unsigned len)
|
|
{
|
|
struct bgp_proto *p = conn->bgp;
|
|
|
|
BGP_TRACE(D_PACKETS, "Got KEEPALIVE");
|
|
bgp_start_timer(conn->hold_timer, conn->hold_time);
|
|
switch (conn->state)
|
|
{
|
|
case BS_OPENCONFIRM:
|
|
DBG("BGP: UP!!!\n");
|
|
conn->state = BS_ESTABLISHED;
|
|
bgp_attr_init(conn->bgp);
|
|
proto_notify_state(&conn->bgp->p, PS_UP);
|
|
break;
|
|
case BS_ESTABLISHED:
|
|
break;
|
|
default:
|
|
bgp_error(conn, 5, 0, NULL, 0);
|
|
}
|
|
}
|
|
|
|
static void
|
|
bgp_rx_packet(struct bgp_conn *conn, byte *pkt, unsigned len)
|
|
{
|
|
DBG("BGP: Got packet %02x (%d bytes)\n", pkt[18], len);
|
|
switch (pkt[18])
|
|
{
|
|
case PKT_OPEN: return bgp_rx_open(conn, pkt, len);
|
|
case PKT_UPDATE: return bgp_rx_update(conn, pkt, len);
|
|
case PKT_NOTIFICATION: return bgp_rx_notification(conn, pkt, len);
|
|
case PKT_KEEPALIVE: return bgp_rx_keepalive(conn, pkt, len);
|
|
default: bgp_error(conn, 1, 3, pkt+18, 1);
|
|
}
|
|
}
|
|
|
|
int
|
|
bgp_rx(sock *sk, int size)
|
|
{
|
|
struct bgp_conn *conn = sk->data;
|
|
byte *pkt_start = sk->rbuf;
|
|
byte *end = pkt_start + size;
|
|
unsigned i, len;
|
|
|
|
DBG("BGP: RX hook: Got %d bytes\n", size);
|
|
while (end >= pkt_start + BGP_HEADER_LENGTH)
|
|
{
|
|
if (conn->error_flag)
|
|
{
|
|
/*
|
|
* We still need to remember the erroneous packet, so that
|
|
* we can generate error notifications properly. To avoid
|
|
* subsequent reads rewriting the buffer, we just reset the
|
|
* rx_hook.
|
|
*/
|
|
DBG("BGP: Error, dropping input\n");
|
|
sk->rx_hook = NULL;
|
|
return 0;
|
|
}
|
|
for(i=0; i<16; i++)
|
|
if (pkt_start[i] != 0xff)
|
|
{
|
|
bgp_error(conn, 1, 1, NULL, 0);
|
|
break;
|
|
}
|
|
len = get_u16(pkt_start+16);
|
|
if (len < BGP_HEADER_LENGTH || len > BGP_MAX_PACKET_LENGTH)
|
|
{
|
|
bgp_error(conn, 1, 2, pkt_start+16, 2);
|
|
break;
|
|
}
|
|
if (end < pkt_start + len)
|
|
break;
|
|
bgp_rx_packet(conn, pkt_start, len);
|
|
pkt_start += len;
|
|
}
|
|
if (pkt_start != sk->rbuf)
|
|
{
|
|
memmove(sk->rbuf, pkt_start, end - pkt_start);
|
|
sk->rpos = sk->rbuf + (end - pkt_start);
|
|
}
|
|
return 0;
|
|
}
|