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Merge pull request #11673 from cscarpitta/srv6-per-vrf-sid
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bgpd: add support for SRv6 L3VPN for IPv4 and IPv6 address families using a single SID
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@ton31337
ton31337 authored Oct 24, 2022
2 parents 6eb8da3 + 537b8b1 commit 695f387
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Showing 91 changed files with 6,179 additions and 36 deletions.
286 changes: 283 additions & 3 deletions bgpd/bgp_mplsvpn.c
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Original file line number Diff line number Diff line change
Expand Up @@ -360,7 +360,7 @@ void vpn_leak_zebra_vrf_label_withdraw(struct bgp *bgp, afi_t afi)
* leaked to VPN. Zebra should install this srv6-function in the kernel with
* an action of "End.DT4/6's IP FIB to route the PDU."
*/
void vpn_leak_zebra_vrf_sid_update(struct bgp *bgp, afi_t afi)
void vpn_leak_zebra_vrf_sid_update_per_af(struct bgp *bgp, afi_t afi)
{
int debug = BGP_DEBUG(vpn, VPN_LEAK_LABEL);
enum seg6local_action_t act;
Expand Down Expand Up @@ -406,11 +406,78 @@ void vpn_leak_zebra_vrf_sid_update(struct bgp *bgp, afi_t afi)
bgp->vpn_policy[afi].tovpn_zebra_vrf_sid_last_sent = tovpn_sid_ls;
}

/*
* This function informs zebra of the srv6-function this vrf sets on routes
* leaked to VPN. Zebra should install this srv6-function in the kernel with
* an action of "End.DT46's IP FIB to route the PDU."
*/
void vpn_leak_zebra_vrf_sid_update_per_vrf(struct bgp *bgp)
{
int debug = BGP_DEBUG(vpn, VPN_LEAK_LABEL);
enum seg6local_action_t act;
struct seg6local_context ctx = {};
struct in6_addr *tovpn_sid = NULL;
struct in6_addr *tovpn_sid_ls = NULL;
struct vrf *vrf;

if (bgp->vrf_id == VRF_UNKNOWN) {
if (debug)
zlog_debug(
"%s: vrf %s: vrf_id not set, can't set zebra vrf label",
__func__, bgp->name_pretty);
return;
}

tovpn_sid = bgp->tovpn_sid;
if (!tovpn_sid) {
if (debug)
zlog_debug("%s: vrf %s: sid not set", __func__,
bgp->name_pretty);
return;
}

if (debug)
zlog_debug("%s: vrf %s: setting sid %pI6 for vrf id %d",
__func__, bgp->name_pretty, tovpn_sid, bgp->vrf_id);

vrf = vrf_lookup_by_id(bgp->vrf_id);
if (!vrf)
return;

ctx.table = vrf->data.l.table_id;
act = ZEBRA_SEG6_LOCAL_ACTION_END_DT46;
zclient_send_localsid(zclient, tovpn_sid, bgp->vrf_id, act, &ctx);

tovpn_sid_ls = XCALLOC(MTYPE_BGP_SRV6_SID, sizeof(struct in6_addr));
*tovpn_sid_ls = *tovpn_sid;
bgp->tovpn_zebra_vrf_sid_last_sent = tovpn_sid_ls;
}

/*
* This function informs zebra of the srv6-function this vrf sets on routes
* leaked to VPN. Zebra should install this srv6-function in the kernel with
* an action of "End.DT4/6/46's IP FIB to route the PDU."
*/
void vpn_leak_zebra_vrf_sid_update(struct bgp *bgp, afi_t afi)
{
int debug = BGP_DEBUG(vpn, VPN_LEAK_LABEL);

if (bgp->vpn_policy[afi].tovpn_sid)
return vpn_leak_zebra_vrf_sid_update_per_af(bgp, afi);

if (bgp->tovpn_sid)
return vpn_leak_zebra_vrf_sid_update_per_vrf(bgp);

if (debug)
zlog_debug("%s: vrf %s: afi %s: sid not set", __func__,
bgp->name_pretty, afi2str(afi));
}

/*
* If zebra tells us vrf has become unconfigured, tell zebra not to
* use this srv6-function to forward to the vrf anymore
*/
void vpn_leak_zebra_vrf_sid_withdraw(struct bgp *bgp, afi_t afi)
void vpn_leak_zebra_vrf_sid_withdraw_per_af(struct bgp *bgp, afi_t afi)
{
int debug = BGP_DEBUG(vpn, VPN_LEAK_LABEL);

Expand All @@ -432,6 +499,45 @@ void vpn_leak_zebra_vrf_sid_withdraw(struct bgp *bgp, afi_t afi)
bgp->vpn_policy[afi].tovpn_zebra_vrf_sid_last_sent);
}

/*
* If zebra tells us vrf has become unconfigured, tell zebra not to
* use this srv6-function to forward to the vrf anymore
*/
void vpn_leak_zebra_vrf_sid_withdraw_per_vrf(struct bgp *bgp)
{
int debug = BGP_DEBUG(vpn, VPN_LEAK_LABEL);

if (bgp->vrf_id == VRF_UNKNOWN) {
if (debug)
zlog_debug(
"%s: vrf %s: vrf_id not set, can't set zebra vrf label",
__func__, bgp->name_pretty);
return;
}

if (debug)
zlog_debug("%s: deleting sid for vrf %s (id=%d)", __func__,
bgp->name_pretty, bgp->vrf_id);

zclient_send_localsid(zclient, bgp->tovpn_zebra_vrf_sid_last_sent,
bgp->vrf_id, ZEBRA_SEG6_LOCAL_ACTION_UNSPEC,
NULL);
XFREE(MTYPE_BGP_SRV6_SID, bgp->tovpn_zebra_vrf_sid_last_sent);
}

/*
* If zebra tells us vrf has become unconfigured, tell zebra not to
* use this srv6-function to forward to the vrf anymore
*/
void vpn_leak_zebra_vrf_sid_withdraw(struct bgp *bgp, afi_t afi)
{
if (bgp->vpn_policy[afi].tovpn_zebra_vrf_sid_last_sent)
vpn_leak_zebra_vrf_sid_withdraw_per_af(bgp, afi);

if (bgp->tovpn_zebra_vrf_sid_last_sent)
vpn_leak_zebra_vrf_sid_withdraw_per_vrf(bgp);
}

int vpn_leak_label_callback(
mpls_label_t label,
void *labelid,
Expand Down Expand Up @@ -505,6 +611,18 @@ static void sid_register(struct bgp *bgp, const struct in6_addr *sid,
listnode_add(bgp->srv6_functions, func);
}

static void sid_unregister(struct bgp *bgp, const struct in6_addr *sid)
{
struct listnode *node, *nnode;
struct bgp_srv6_function *func;

for (ALL_LIST_ELEMENTS(bgp->srv6_functions, node, nnode, func))
if (sid_same(&func->sid, sid)) {
listnode_delete(bgp->srv6_functions, func);
XFREE(MTYPE_BGP_SRV6_FUNCTION, func);
}
}

static bool sid_exist(struct bgp *bgp, const struct in6_addr *sid)
{
struct listnode *node;
Expand Down Expand Up @@ -610,7 +728,8 @@ static uint32_t alloc_new_sid(struct bgp *bgp, uint32_t index,
return label;
}

void ensure_vrf_tovpn_sid(struct bgp *bgp_vpn, struct bgp *bgp_vrf, afi_t afi)
void ensure_vrf_tovpn_sid_per_af(struct bgp *bgp_vpn, struct bgp *bgp_vrf,
afi_t afi)
{
int debug = BGP_DEBUG(vpn, VPN_LEAK_FROM_VRF);
char buf[256];
Expand Down Expand Up @@ -678,6 +797,144 @@ void ensure_vrf_tovpn_sid(struct bgp *bgp_vpn, struct bgp *bgp_vrf, afi_t afi)
tovpn_sid_transpose_label;
}

void ensure_vrf_tovpn_sid_per_vrf(struct bgp *bgp_vpn, struct bgp *bgp_vrf)
{
int debug = BGP_DEBUG(vpn, VPN_LEAK_FROM_VRF);
struct srv6_locator_chunk *tovpn_sid_locator;
struct in6_addr *tovpn_sid;
uint32_t tovpn_sid_index = 0, tovpn_sid_transpose_label;
bool tovpn_sid_auto = false;

if (debug)
zlog_debug("%s: try to allocate new SID for vrf %s", __func__,
bgp_vrf->name_pretty);

/* skip when tovpn sid is already allocated on vrf instance */
if (bgp_vrf->tovpn_sid)
return;

/*
* skip when bgp vpn instance ins't allocated
* or srv6 locator chunk isn't allocated
*/
if (!bgp_vpn || !bgp_vpn->srv6_locator_chunks)
return;

tovpn_sid_index = bgp_vrf->tovpn_sid_index;
tovpn_sid_auto = CHECK_FLAG(bgp_vrf->vrf_flags, BGP_VRF_TOVPN_SID_AUTO);

/* skip when VPN isn't configured on vrf-instance */
if (tovpn_sid_index == 0 && !tovpn_sid_auto)
return;

/* check invalid case both configured index and auto */
if (tovpn_sid_index != 0 && tovpn_sid_auto) {
zlog_err("%s: index-mode and auto-mode both selected. ignored.",
__func__);
return;
}

tovpn_sid_locator = srv6_locator_chunk_alloc();
tovpn_sid = XCALLOC(MTYPE_BGP_SRV6_SID, sizeof(struct in6_addr));

tovpn_sid_transpose_label = alloc_new_sid(bgp_vpn, tovpn_sid_index,
tovpn_sid_locator, tovpn_sid);

if (tovpn_sid_transpose_label == 0) {
if (debug)
zlog_debug("%s: not allocated new sid for vrf %s",
__func__, bgp_vrf->name_pretty);
srv6_locator_chunk_free(tovpn_sid_locator);
XFREE(MTYPE_BGP_SRV6_SID, tovpn_sid);
return;
}

if (debug)
zlog_debug("%s: new sid %pI6 allocated for vrf %s", __func__,
tovpn_sid, bgp_vrf->name_pretty);

bgp_vrf->tovpn_sid = tovpn_sid;
bgp_vrf->tovpn_sid_locator = tovpn_sid_locator;
bgp_vrf->tovpn_sid_transpose_label = tovpn_sid_transpose_label;
}

void ensure_vrf_tovpn_sid(struct bgp *bgp_vpn, struct bgp *bgp_vrf, afi_t afi)
{
/* per-af sid */
if (bgp_vrf->vpn_policy[afi].tovpn_sid_index != 0 ||
CHECK_FLAG(bgp_vrf->vpn_policy[afi].flags,
BGP_VPN_POLICY_TOVPN_SID_AUTO))
return ensure_vrf_tovpn_sid_per_af(bgp_vpn, bgp_vrf, afi);

/* per-vrf sid */
if (bgp_vrf->tovpn_sid_index != 0 ||
CHECK_FLAG(bgp_vrf->vrf_flags, BGP_VRF_TOVPN_SID_AUTO))
return ensure_vrf_tovpn_sid_per_vrf(bgp_vpn, bgp_vrf);
}

void delete_vrf_tovpn_sid_per_af(struct bgp *bgp_vpn, struct bgp *bgp_vrf,
afi_t afi)
{
int debug = BGP_DEBUG(vpn, VPN_LEAK_FROM_VRF);
uint32_t tovpn_sid_index = 0;
bool tovpn_sid_auto = false;

if (debug)
zlog_debug("%s: try to remove SID for vrf %s: afi %s", __func__,
bgp_vrf->name_pretty, afi2str(afi));

tovpn_sid_index = bgp_vrf->vpn_policy[afi].tovpn_sid_index;
tovpn_sid_auto = CHECK_FLAG(bgp_vrf->vpn_policy[afi].flags,
BGP_VPN_POLICY_TOVPN_SID_AUTO);

/* skip when VPN is configured on vrf-instance */
if (tovpn_sid_index != 0 || tovpn_sid_auto)
return;

srv6_locator_chunk_free(bgp_vrf->vpn_policy[afi].tovpn_sid_locator);
bgp_vrf->vpn_policy[afi].tovpn_sid_locator = NULL;

if (bgp_vrf->vpn_policy[afi].tovpn_sid) {
sid_unregister(bgp_vrf, bgp_vrf->vpn_policy[afi].tovpn_sid);
XFREE(MTYPE_BGP_SRV6_SID, bgp_vrf->vpn_policy[afi].tovpn_sid);
}
bgp_vrf->vpn_policy[afi].tovpn_sid_transpose_label = 0;
}

void delete_vrf_tovpn_sid_per_vrf(struct bgp *bgp_vpn, struct bgp *bgp_vrf)
{
int debug = BGP_DEBUG(vpn, VPN_LEAK_FROM_VRF);
uint32_t tovpn_sid_index = 0;
bool tovpn_sid_auto = false;

if (debug)
zlog_debug("%s: try to remove SID for vrf %s", __func__,
bgp_vrf->name_pretty);

tovpn_sid_index = bgp_vrf->tovpn_sid_index;
tovpn_sid_auto =
CHECK_FLAG(bgp_vrf->vrf_flags, BGP_VPN_POLICY_TOVPN_SID_AUTO);

/* skip when VPN is configured on vrf-instance */
if (tovpn_sid_index != 0 || tovpn_sid_auto)
return;

srv6_locator_chunk_free(bgp_vrf->tovpn_sid_locator);
bgp_vrf->tovpn_sid_locator = NULL;

if (bgp_vrf->tovpn_sid) {
sid_unregister(bgp_vrf, bgp_vrf->tovpn_sid);
XFREE(MTYPE_BGP_SRV6_SID, bgp_vrf->tovpn_sid);
}
bgp_vrf->tovpn_sid_transpose_label = 0;
}

void delete_vrf_tovpn_sid(struct bgp *bgp_vpn, struct bgp *bgp_vrf, afi_t afi)
{
delete_vrf_tovpn_sid_per_af(bgp_vpn, bgp_vrf, afi);
delete_vrf_tovpn_sid_per_vrf(bgp_vpn, bgp_vrf);
}

/*
* This function embeds upper `len` bits of `label` in `sid`,
* starting at offset `offset` as seen from the MSB of `sid`.
Expand Down Expand Up @@ -1337,6 +1594,29 @@ void vpn_leak_from_vrf_update(struct bgp *to_bgp, /* to */
&from_bgp->vpn_policy[afi]
.tovpn_sid_locator->prefix.prefix,
sizeof(struct in6_addr));
} else if (from_bgp->tovpn_sid_locator) {
encode_label(from_bgp->tovpn_sid_transpose_label, &label);
static_attr.srv6_l3vpn =
XCALLOC(MTYPE_BGP_SRV6_L3VPN,
sizeof(struct bgp_attr_srv6_l3vpn));
static_attr.srv6_l3vpn->sid_flags = 0x00;
static_attr.srv6_l3vpn->endpoint_behavior = 0xffff;
static_attr.srv6_l3vpn->loc_block_len =
from_bgp->tovpn_sid_locator->block_bits_length;
static_attr.srv6_l3vpn->loc_node_len =
from_bgp->tovpn_sid_locator->node_bits_length;
static_attr.srv6_l3vpn->func_len =
from_bgp->tovpn_sid_locator->function_bits_length;
static_attr.srv6_l3vpn->arg_len =
from_bgp->tovpn_sid_locator->argument_bits_length;
static_attr.srv6_l3vpn->transposition_len =
from_bgp->tovpn_sid_locator->function_bits_length;
static_attr.srv6_l3vpn->transposition_offset =
from_bgp->tovpn_sid_locator->block_bits_length +
from_bgp->tovpn_sid_locator->node_bits_length;
memcpy(&static_attr.srv6_l3vpn->sid,
&from_bgp->tovpn_sid_locator->prefix.prefix,
sizeof(struct in6_addr));
}


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