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Moving of mulipath merging code from OSPF to nest

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This commit is contained in:
Ondrej Zajicek 2015-05-31 23:25:33 +02:00
parent ca34698ca6
commit d217ba5111
5 changed files with 110 additions and 94 deletions
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1
nest/route.h
View file

@ -482,6 +482,7 @@ void ea_format_bitfield(struct eattr *a, byte *buf, int bufsize, const char **na
int mpnh__same(struct mpnh *x, struct mpnh *y); /* Compare multipath nexthops */
static inline int mpnh_same(struct mpnh *x, struct mpnh *y)
{ return (x == y) || mpnh__same(x, y); }
struct mpnh *mpnh_merge(struct mpnh *x, struct mpnh *y, int rx, int ry, int max, linpool *lp);
void rta_init(void);
rta *rta_lookup(rta *); /* Get rta equivalent to this one, uc++ */

94
nest/rt-attr.c
View file

@ -167,7 +167,7 @@ rt_get_source(struct proto *p, u32 id)
src->private_id = id;
src->global_id = rte_src_alloc_id();
src->uc = 0;
HASH_INSERT2(src_hash, RSH, rta_pool, src);
return src;
@ -215,6 +215,94 @@ mpnh__same(struct mpnh *x, struct mpnh *y)
return x == y;
}
static int
mpnh_compare_node(struct mpnh *x, struct mpnh *y)
{
int r;
if (!x)
return 1;
if (!y)
return -1;
r = ((int) y->weight) - ((int) x->weight);
if (r)
return r;
r = ipa_compare(x->gw, y->gw);
if (r)
return r;
return ((int) x->iface->index) - ((int) y->iface->index);
}
static inline struct mpnh *
mpnh_copy_node(const struct mpnh *src, linpool *lp)
{
struct mpnh *n = lp_alloc(lp, sizeof(struct mpnh));
n->gw = src->gw;
n->iface = src->iface;
n->next = NULL;
n->weight = src->weight;
return n;
}
/**
* mpnh_merge - merge nexthop lists
* @x: list 1
* @y: list 2
* @rx: reusability of list @x
* @ry: reusability of list @y
* @max: max number of nexthops
* @lp: linpool for allocating nexthops
*
* The mpnh_merge() function takes two nexthop lists @x and @y and merges them,
* eliminating possible duplicates. The input lists must be sorted and the
* result is sorted too. The number of nexthops in result is limited by @max.
* New nodes are allocated from linpool @lp.
*
* The arguments @rx and @ry specify whether corresponding input lists may be
* consumed by the function (i.e. their nodes reused in the resulting list), in
* that case the caller should not access these lists after that. To eliminate
* issues with deallocation of these lists, the caller should use some form of
* bulk deallocation (e.g. stack or linpool) to free these nodes when the
* resulting list is no longer needed. When reusability is not set, the
* corresponding lists are not modified nor linked from the resulting list.
*/
struct mpnh *
mpnh_merge(struct mpnh *x, struct mpnh *y, int rx, int ry, int max, linpool *lp)
{
struct mpnh *root = NULL;
struct mpnh **n = &root;
while ((x || y) && max--)
{
int cmp = mpnh_compare_node(x, y);
if (cmp < 0)
{
*n = rx ? x : mpnh_copy_node(x, lp);
x = x->next;
}
else if (cmp > 0)
{
*n = ry ? y : mpnh_copy_node(y, lp);
y = y->next;
}
else
{
*n = rx ? x : (ry ? y : mpnh_copy_node(x, lp));
x = x->next;
y = y->next;
}
n = &((*n)->next);
}
*n = NULL;
return root;
}
static struct mpnh *
mpnh_copy(struct mpnh *o)
{
@ -635,7 +723,7 @@ get_generic_attr(eattr *a, byte **buf, int buflen UNUSED)
*buf += bsprintf(*buf, "igp_metric");
return GA_NAME;
}
return GA_UNKNOWN;
}
@ -741,7 +829,7 @@ ea_show(struct cli *c, eattr *e)
}
else if (EA_PROTO(e->id))
pos += bsprintf(pos, "%02x.", EA_PROTO(e->id));
else
else
status = get_generic_attr(e, &pos, end - pos);
if (status < GA_NAME)

104
proto/ospf/rt.c
View file

@ -53,88 +53,6 @@ new_nexthop(struct ospf_proto *p, ip_addr gw, struct iface *iface, byte weight)
return nh;
}
static inline struct mpnh *
copy_nexthop(struct ospf_proto *p, const struct mpnh *src)
{
struct mpnh *nh = lp_alloc(p->nhpool, sizeof(struct mpnh));
nh->gw = src->gw;
nh->iface = src->iface;
nh->next = NULL;
nh->weight = src->weight;
return nh;
}
/* Compare nexthops during merge.
We need to maintain nhs sorted to eliminate duplicities */
static int
cmp_nhs(struct mpnh *s1, struct mpnh *s2)
{
int r;
if (!s1)
return 1;
if (!s2)
return -1;
r = ((int) s2->weight) - ((int) s1->weight);
if (r)
return r;
r = ipa_compare(s1->gw, s2->gw);
if (r)
return r;
return ((int) s1->iface->index) - ((int) s2->iface->index);
}
static struct mpnh *
merge_nexthops(struct ospf_proto *p, struct mpnh *s1, struct mpnh *s2, int r1, int r2)
{
struct mpnh *root = NULL;
struct mpnh **n = &root;
int count = p->ecmp;
ASSERT(p->ecmp);
/*
* r1, r2 signalize whether we can reuse nexthops from s1, s2.
* New nexthops (s2, new) can be reused if they are not inherited
* from the parent (i.e. it is allocated in calc_next_hop()).
* Current nexthops (s1, en->nhs) can be reused if they weren't
* inherited in previous steps (that is stored in nhs_reuse,
* i.e. created by merging or allocalted in calc_next_hop()).
*
* Generally, a node first inherits shared nexthops from its
* parent and later possibly gets reusable copy during merging.
*/
while ((s1 || s2) && count--)
{
int cmp = cmp_nhs(s1, s2);
if (cmp < 0)
{
*n = r1 ? s1 : copy_nexthop(p, s1);
s1 = s1->next;
}
else if (cmp > 0)
{
*n = r2 ? s2 : copy_nexthop(p, s2);
s2 = s2->next;
}
else
{
*n = r1 ? s1 : (r2 ? s2 : copy_nexthop(p, s1));
s1 = s1->next;
s2 = s2->next;
}
n = &((*n)->next);
}
*n = NULL;
return root;
}
/* Returns true if there are device nexthops in n */
static inline int
has_device_nexthops(const struct mpnh *n)
@ -178,7 +96,7 @@ fix_device_nexthops(struct ospf_proto *p, const struct mpnh *n, ip_addr gw)
}
}
return merge_nexthops(p, root1, root2, 1, 1);
return mpnh_merge(root1, root2, 1, 1, p->ecmp, p->nhpool);
}
@ -374,7 +292,8 @@ ort_merge(struct ospf_proto *p, ort *o, const orta *new)
if (old->nhs != new->nhs)
{
old->nhs = merge_nexthops(p, old->nhs, new->nhs, old->nhs_reuse, new->nhs_reuse);
old->nhs = mpnh_merge(old->nhs, new->nhs, old->nhs_reuse, new->nhs_reuse,
p->ecmp, p->nhpool);
old->nhs_reuse = 1;
}
@ -389,7 +308,8 @@ ort_merge_ext(struct ospf_proto *p, ort *o, const orta *new)
if (old->nhs != new->nhs)
{
old->nhs = merge_nexthops(p, old->nhs, new->nhs, old->nhs_reuse, new->nhs_reuse);
old->nhs = mpnh_merge(old->nhs, new->nhs, old->nhs_reuse, new->nhs_reuse,
p->ecmp, p->nhpool);
old->nhs_reuse = 1;
}
@ -1885,8 +1805,7 @@ add_cand(list * l, struct top_hash_entry *en, struct top_hash_entry *par,
return;
}
/* We know that en->color == CANDIDATE and en->nhs is defined. */
/* If en->dist > 0, we know that en->color == CANDIDATE and en->nhs is defined. */
if ((dist == en->dist) && !nh_is_vlink(en->nhs))
{
/*
@ -1900,7 +1819,14 @@ add_cand(list * l, struct top_hash_entry *en, struct top_hash_entry *par,
* allocated in calc_next_hop()).
*
* Generally, a node first inherits shared nexthops from its parent and
* later possibly gets reusable copy during merging.
* later possibly gets reusable (private) copy during merging. This is more
* or less same for both top_hash_entry nodes and orta nodes.
*
* Note that when a child inherits a private nexthop from its parent, it
* should make the nexthop shared for both parent and child, while we only
* update nhs_reuse for the child node. This makes nhs_reuse field for the
* parent technically incorrect, but it is not a problem as parent's nhs
* will not be modified (and nhs_reuse examined) afterwards.
*/
/* Keep old ones */
@ -1909,7 +1835,7 @@ add_cand(list * l, struct top_hash_entry *en, struct top_hash_entry *par,
/* Merge old and new */
int new_reuse = (par->nhs != nhs);
en->nhs = merge_nexthops(p, en->nhs, nhs, en->nhs_reuse, new_reuse);
en->nhs = mpnh_merge(en->nhs, nhs, en->nhs_reuse, new_reuse, p->ecmp, p->nhpool);
en->nhs_reuse = 1;
return;
}

3
proto/ospf/rt.h
View file

@ -18,7 +18,8 @@
typedef struct orta
{
u8 type; /* RTS_OSPF_* */
u8 nhs_reuse; /* Whether nhs nodes can be reused during merging */
u8 nhs_reuse; /* Whether nhs nodes can be reused during merging.
See a note in rt.c:add_cand() */
u32 options;
/*
* For ORT_ROUTER routes, options field are router-LSA style

2
proto/ospf/topology.h
View file

@ -39,7 +39,7 @@ struct top_hash_entry
#define INSPF 2
u8 mode; /* LSA generated during RT calculation (LSA_RTCALC or LSA_STALE)*/
u8 nhs_reuse; /* Whether nhs nodes can be reused during merging.
See a note in rt.c:merge_nexthops() */
See a note in rt.c:add_cand() */
};