summaryrefslogtreecommitdiffstats
path: root/proto/bgp
diff options
context:
space:
mode:
Diffstat (limited to 'proto/bgp')
-rw-r--r--proto/bgp/attrs.c291
-rw-r--r--proto/bgp/bgp.h4
-rw-r--r--proto/bgp/packets.c69
3 files changed, 274 insertions, 90 deletions
diff --git a/proto/bgp/attrs.c b/proto/bgp/attrs.c
index 6d4fd9c..bc3de3b 100644
--- a/proto/bgp/attrs.c
+++ b/proto/bgp/attrs.c
@@ -31,13 +31,172 @@ struct attr_desc {
void (*format)(eattr *ea, byte *buf);
};
-extern struct attr_desc bgp_attr_table[];
+static int
+bgp_check_origin(struct bgp_proto *p, byte *a, int len)
+{
+ if (len > 2)
+ return 6;
+ return 0;
+}
+
+static void
+bgp_format_origin(eattr *a, byte *buf)
+{
+ static char *bgp_origin_names[] = { "IGP", "EGP", "Incomplete" };
+
+ bsprintf(buf, bgp_origin_names[a->u.data]);
+}
+
+static int
+bgp_check_path(struct bgp_proto *p, byte *a, int len)
+{
+ while (len)
+ {
+ DBG("Path segment %02x %02x\n", a[0], a[1]);
+ if (len < 2 ||
+ a[0] != BGP_PATH_AS_SET && a[0] != BGP_PATH_AS_SEQUENCE ||
+ 2*a[1] + 2 > len)
+ return 11;
+ len -= 2*a[1] + 2;
+ a += 2*a[1] + 2;
+ }
+ return 0;
+}
+
+static int
+bgp_check_next_hop(struct bgp_proto *p, byte *a, int len)
+{
+ ip_addr addr;
+
+ memcpy(&addr, a, len);
+ ipa_ntoh(addr);
+ if (ipa_classify(addr) & IADDR_HOST)
+ return 0;
+ else
+ return 8;
+}
+
+static int
+bgp_check_local_pref(struct bgp_proto *p, byte *a, int len)
+{
+ if (!p->is_internal) /* Ignore local preference from EBGP connections */
+ return -1;
+ return 0;
+}
+
+static struct attr_desc bgp_attr_table[] = {
+ { NULL, -1, 0, 0, /* Undefined */
+ NULL, NULL },
+ { "origin", 1, BAF_TRANSITIVE, EAF_TYPE_INT, /* BA_ORIGIN */
+ bgp_check_origin, bgp_format_origin },
+ { "as_path", -1, BAF_TRANSITIVE, EAF_TYPE_AS_PATH, /* BA_AS_PATH */
+ bgp_check_path, NULL },
+ { "next_hop", 4, BAF_TRANSITIVE, EAF_TYPE_IP_ADDRESS, /* BA_NEXT_HOP */
+ bgp_check_next_hop, NULL },
+ { "MED", 4, BAF_OPTIONAL, EAF_TYPE_INT, /* BA_MULTI_EXIT_DISC */
+ NULL, NULL },
+ { "local_pref", 4, BAF_OPTIONAL, EAF_TYPE_INT, /* BA_LOCAL_PREF */
+ bgp_check_local_pref, NULL },
+ { "atomic_aggr", 0, BAF_OPTIONAL, EAF_TYPE_OPAQUE, /* BA_ATOMIC_AGGR */
+ NULL, NULL },
+ { "aggregator", 6, BAF_OPTIONAL, EAF_TYPE_OPAQUE, /* BA_AGGREGATOR */
+ NULL, NULL },
+#if 0
+ /* FIXME: Handle community lists and remember to convert their endianity and normalize them */
+ { 0, 0 }, /* BA_COMMUNITY */
+ { 0, 0 }, /* BA_ORIGINATOR_ID */
+ { 0, 0 }, /* BA_CLUSTER_LIST */
+#endif
+};
+
+byte *
+bgp_encode_attrs(byte *w, struct bgp_bucket *buck)
+{
+ int remains = 1024;
+ unsigned int i, code, flags;
+ byte *start = w;
+ int len;
+
+ w += 2;
+ for(i=0; i<buck->eattrs->count; i++)
+ {
+ eattr *a = &buck->eattrs->attrs[i];
+ ASSERT(EA_PROTO(a->id) == EAP_BGP);
+ code = EA_ID(a->id);
+ if (code && code < ARRAY_SIZE(bgp_attr_table))
+ {
+ struct attr_desc *desc = &bgp_attr_table[code];
+ len = desc->expected_length;
+ if (len < 0)
+ {
+ ASSERT(!(a->type & EAF_EMBEDDED));
+ len = a->u.ptr->length;
+ }
+ }
+ else
+ {
+ ASSERT((a->type & EAF_TYPE_MASK) == EAF_TYPE_OPAQUE);
+ len = a->u.ptr->length;
+ }
+ DBG("\tAttribute %02x (type %02x, %d bytes)\n", code, a->type, len);
+ /* FIXME: Partial bit for locally added transitive attributes */
+ if (remains < len + 4)
+ {
+ log(L_ERR "BGP: attribute list too long, ignoring the remaining attributes");
+ break;
+ }
+ flags = a->flags & (BAF_OPTIONAL | BAF_TRANSITIVE | BAF_PARTIAL);
+ if (len < 256)
+ {
+ *w++ = flags;
+ *w++ = code;
+ *w++ = len;
+ remains -= 3;
+ }
+ else
+ {
+ *w++ = flags | BAF_EXT_LEN;
+ *w++ = code;
+ put_u16(w, len);
+ w += 2;
+ remains -= 4;
+ }
+ switch (a->type & EAF_TYPE_MASK)
+ {
+ case EAF_TYPE_INT:
+ case EAF_TYPE_ROUTER_ID:
+ if (len == 4)
+ put_u32(w, a->u.data);
+ else
+ *w = a->u.data;
+ break;
+ case EAF_TYPE_IP_ADDRESS:
+ {
+ ip_addr ip = *(ip_addr *)a->u.ptr->data;
+ ipa_hton(ip);
+ memcpy(w, &ip, len);
+ break;
+ }
+ case EAF_TYPE_OPAQUE:
+ case EAF_TYPE_AS_PATH:
+ case EAF_TYPE_INT_SET:
+ memcpy(w, a->u.ptr->data, len);
+ break;
+ default:
+ bug("bgp_encode_attrs: unknown attribute type %02x", a->type);
+ }
+ remains -= len;
+ w += len;
+ }
+ put_u16(start, w-start-2);
+ return w;
+}
static void
bgp_init_prefix(struct fib_node *N)
{
struct bgp_prefix *p = (struct bgp_prefix *) N;
- /* FIXME */
+ p->bucket_node.next = NULL;
}
static void
@@ -104,6 +263,8 @@ bgp_new_bucket(struct bgp_proto *p, ea_list *new, unsigned hash)
p->bucket_hash[index] = b;
b->hash_prev = NULL;
b->hash = hash;
+ add_tail(&p->bucket_queue, &b->send_node);
+ init_list(&b->prefixes);
memcpy(b->eattrs, new, ea_size);
dest = ((byte *)b->eattrs) + ea_size_aligned;
@@ -169,7 +330,7 @@ bgp_get_bucket(struct bgp_proto *p, ea_list *old, ea_list *tmp)
*d = *a;
switch (d->type & EAF_TYPE_MASK)
{
- case EAF_TYPE_INT_SET:
+ case EAF_TYPE_INT_SET: /* FIXME: Normalize the other attributes? */
{
struct adata *z = alloca(sizeof(struct adata) + d->u.ptr->length);
z->length = d->u.ptr->length;
@@ -200,27 +361,60 @@ bgp_get_bucket(struct bgp_proto *p, ea_list *old, ea_list *tmp)
return NULL;
}
+ /* Check if next hop is valid */
+ a = ea_find(new, EA_CODE(EAP_BGP, BA_NEXT_HOP));
+ ASSERT(a);
+ if (ipa_equal(p->next_hop, *(ip_addr *)a->u.ptr))
+ return NULL;
+
/* Create new bucket */
DBG("Creating bucket.\n");
return bgp_new_bucket(p, new, hash);
}
void
+bgp_free_bucket(struct bgp_proto *p, struct bgp_bucket *buck)
+{
+ if (buck->hash_next)
+ buck->hash_next->hash_prev = buck->hash_prev;
+ if (buck->hash_prev)
+ buck->hash_prev->hash_next = buck->hash_next;
+ else
+ p->bucket_hash[buck->hash & (p->hash_size-1)] = buck->hash_next;
+ mb_free(buck);
+}
+
+void
bgp_rt_notify(struct proto *P, net *n, rte *new, rte *old, ea_list *tmpa)
{
struct bgp_proto *p = (struct bgp_proto *) P;
+ struct bgp_bucket *buck;
+ struct bgp_prefix *px;
- DBG("BGP: Got route %I/%d\n", n->n.prefix, n->n.pxlen);
+ DBG("BGP: Got route %I/%d %s\n", n->n.prefix, n->n.pxlen, new ? "up" : "down");
if (new)
{
- struct bgp_bucket *buck = bgp_get_bucket(p, new->attrs->eattrs, tmpa);
+ buck = bgp_get_bucket(p, new->attrs->eattrs, tmpa);
if (!buck) /* Inconsistent attribute list */
return;
}
-
- /* FIXME: Normalize attributes */
- /* FIXME: Check next hop */
+ else
+ {
+ if (!(buck = p->withdraw_bucket))
+ {
+ buck = p->withdraw_bucket = mb_alloc(P->pool, sizeof(struct bgp_bucket));
+ init_list(&buck->prefixes);
+ }
+ }
+ px = fib_get(&p->prefix_fib, &n->n.prefix, n->n.pxlen);
+ if (px->bucket_node.next)
+ {
+ DBG("\tRemoving old entry.\n");
+ rem_node(&px->bucket_node);
+ }
+ add_tail(&buck->prefixes, &px->bucket_node);
+ bgp_schedule_packet(p->conn, PKT_UPDATE);
}
static int
@@ -404,83 +598,6 @@ bgp_path_loopy(struct bgp_proto *p, eattr *a)
return 0;
}
-static int
-bgp_check_origin(struct bgp_proto *p, byte *a, int len)
-{
- if (len > 2)
- return 6;
- return 0;
-}
-
-static void
-bgp_format_origin(eattr *a, byte *buf)
-{
- static char *bgp_origin_names[] = { "IGP", "EGP", "Incomplete" };
-
- bsprintf(buf, bgp_origin_names[a->u.data]);
-}
-
-static int
-bgp_check_path(struct bgp_proto *p, byte *a, int len)
-{
- while (len)
- {
- DBG("Path segment %02x %02x\n", a[0], a[1]);
- if (len < 2 ||
- a[0] != BGP_PATH_AS_SET && a[0] != BGP_PATH_AS_SEQUENCE ||
- 2*a[1] + 2 > len)
- return 11;
- len -= 2*a[1] + 2;
- a += 2*a[1] + 2;
- }
- return 0;
-}
-
-static int
-bgp_check_next_hop(struct bgp_proto *p, byte *a, int len)
-{
- ip_addr addr;
-
- memcpy(&addr, a, len);
- if (ipa_classify(ipa_ntoh(addr)) & IADDR_HOST)
- return 0;
- else
- return 8;
-}
-
-static int
-bgp_check_local_pref(struct bgp_proto *p, byte *a, int len)
-{
- if (!p->is_internal) /* Ignore local preference from EBGP connections */
- return -1;
- return 0;
-}
-
-static struct attr_desc bgp_attr_table[] = {
- { NULL, -1, 0, 0, /* Undefined */
- NULL, NULL },
- { "origin", 1, BAF_TRANSITIVE, EAF_TYPE_INT, /* BA_ORIGIN */
- bgp_check_origin, bgp_format_origin },
- { "as_path", -1, BAF_TRANSITIVE, EAF_TYPE_AS_PATH, /* BA_AS_PATH */
- bgp_check_path, NULL },
- { "next_hop", 4, BAF_TRANSITIVE, EAF_TYPE_IP_ADDRESS, /* BA_NEXT_HOP */
- bgp_check_next_hop, NULL },
- { "MED", 4, BAF_OPTIONAL, EAF_TYPE_INT, /* BA_MULTI_EXIT_DISC */
- NULL, NULL },
- { "local_pref", 4, BAF_OPTIONAL, EAF_TYPE_INT, /* BA_LOCAL_PREF */
- bgp_check_local_pref, NULL },
- { "atomic_aggr", 0, BAF_OPTIONAL, EAF_TYPE_OPAQUE, /* BA_ATOMIC_AGGR */
- NULL, NULL },
- { "aggregator", 6, BAF_OPTIONAL, EAF_TYPE_OPAQUE, /* BA_AGGREGATOR */
- NULL, NULL },
-#if 0
- /* FIXME: Handle community lists and remember to convert their endianity and normalize them */
- { 0, 0 }, /* BA_COMMUNITY */
- { 0, 0 }, /* BA_ORIGINATOR_ID */
- { 0, 0 }, /* BA_CLUSTER_LIST */
-#endif
-};
-
struct rta *
bgp_decode_attrs(struct bgp_conn *conn, byte *attr, unsigned int len, struct linpool *pool)
{
@@ -540,7 +657,7 @@ bgp_decode_attrs(struct bgp_conn *conn, byte *attr, unsigned int len, struct lin
DBG("Attr %02x %02x %d\n", code, flags, l);
if (seen[code/8] & (1 << (code%8)))
goto malformed;
- if (code && code < sizeof(bgp_attr_table)/sizeof(bgp_attr_table[0]))
+ if (code && code < ARRAY_SIZE(bgp_attr_table))
{
struct attr_desc *desc = &bgp_attr_table[code];
if (desc->expected_length >= 0 && desc->expected_length != (int) l)
@@ -591,7 +708,7 @@ bgp_decode_attrs(struct bgp_conn *conn, byte *attr, unsigned int len, struct lin
ea->attrs[0].u.data = get_u32(z);
break;
case EAF_TYPE_IP_ADDRESS:
- *(ip_addr *)ad->data = ipa_ntoh(*(ip_addr *)ad->data);
+ ipa_ntoh(*(ip_addr *)ad->data);
break;
}
}
diff --git a/proto/bgp/bgp.h b/proto/bgp/bgp.h
index 9ee5b41..0f84c3b 100644
--- a/proto/bgp/bgp.h
+++ b/proto/bgp/bgp.h
@@ -68,8 +68,8 @@ struct bgp_prefix {
};
struct bgp_bucket {
- struct bgp_bucket *hash_next, *hash_prev; /* Node in bucket hash table */
node send_node; /* Node in send queue */
+ struct bgp_bucket *hash_next, *hash_prev; /* Node in bucket hash table */
unsigned hash; /* Hash over extended attributes */
list prefixes; /* Prefixes in this buckets */
ea_list eattrs[0]; /* Per-bucket extended attributes */
@@ -97,6 +97,8 @@ int bgp_rte_better(struct rte *, struct rte *);
void bgp_rt_notify(struct proto *, struct network *, struct rte *, struct rte *, struct ea_list *);
int bgp_import_control(struct proto *, struct rte **, struct ea_list **, struct linpool *);
void bgp_attr_init(struct bgp_proto *);
+byte *bgp_encode_attrs(byte *w, struct bgp_bucket *buck);
+void bgp_free_bucket(struct bgp_proto *p, struct bgp_bucket *buck);
/* packets.c */
diff --git a/proto/bgp/packets.c b/proto/bgp/packets.c
index e85d5c0..2f3f8ad 100644
--- a/proto/bgp/packets.c
+++ b/proto/bgp/packets.c
@@ -46,12 +46,76 @@ bgp_create_open(struct bgp_conn *conn, byte *buf)
return buf+10;
}
+static unsigned int
+bgp_encode_prefixes(struct bgp_proto *p, byte *w, struct bgp_bucket *buck, unsigned int remains)
+{
+ byte *start = w;
+ ip_addr a;
+ int bytes;
+
+ while (!EMPTY_LIST(buck->prefixes) && remains >= 5)
+ {
+ struct bgp_prefix *px = SKIP_BACK(struct bgp_prefix, bucket_node, HEAD(buck->prefixes));
+ DBG("\tDequeued route %I/%d\n", px->n.prefix, px->n.pxlen);
+ *w++ = px->n.pxlen;
+ bytes = (px->n.pxlen + 7) / 8;
+ a = px->n.prefix;
+ ipa_hton(a);
+ memcpy(w, &a, bytes);
+ w += bytes;
+ rem_node(&px->bucket_node);
+ fib_delete(&p->prefix_fib, px);
+ }
+ return w - start;
+}
+
static byte *
bgp_create_update(struct bgp_conn *conn, byte *buf)
{
+ struct bgp_proto *bgp = conn->bgp;
+ struct bgp_bucket *buck;
+ int remains = BGP_MAX_PACKET_LENGTH - BGP_HEADER_LENGTH - 4;
+ byte *w, *wold;
+ ip_addr ip;
+ int wd_size = 0;
+ int r_size = 0;
+
DBG("BGP: Sending update\n");
+ w = buf+2;
+ if ((buck = bgp->withdraw_bucket) && !EMPTY_LIST(buck->prefixes))
+ {
+ DBG("Withdrawn routes:\n");
+ wd_size = bgp_encode_prefixes(bgp, w, buck, remains);
+ w += wd_size;
+ remains -= wd_size;
+ }
+ put_u16(buf, wd_size);
- bug("Don't know how to create updates");
+ if (remains >= 2048)
+ {
+ while ((buck = (struct bgp_bucket *) HEAD(bgp->bucket_queue))->send_node.next)
+ {
+ if (EMPTY_LIST(buck->prefixes))
+ {
+ DBG("Deleting empty bucket %p\n", buck);
+ rem_node(&buck->send_node);
+ bgp_free_bucket(bgp, buck);
+ continue;
+ }
+ DBG("Processing bucket %p\n", buck);
+ w = bgp_encode_attrs(w, buck);
+ remains = BGP_MAX_PACKET_LENGTH - BGP_HEADER_LENGTH - (w-buf);
+ r_size = bgp_encode_prefixes(bgp, w, buck, remains);
+ w += r_size;
+ break;
+ }
+ }
+ else
+ {
+ put_u16(w, 0);
+ w += 2;
+ }
+ return (wd_size || r_size) ? w : NULL;
}
static void
@@ -225,7 +289,8 @@ bgp_rx_open(struct bgp_conn *conn, byte *pkt, int len)
memcpy(&prefix, pp, q); \
pp += q; \
ll -= q; \
- prefix = ipa_and(ipa_ntoh(prefix), ipa_mkmask(b)); \
+ ipa_ntoh(prefix); \
+ prefix = ipa_and(prefix, ipa_mkmask(b)); \
pxlen = b; \
} while (0)
/* FIXME: Check validity of prefixes */
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-24 00:46:08 +0100