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gtphub: make sure mapped TEIs aren't occupied (incomplete). 

This could be done way better, discussion is pending/ongoing. It is indeed
quite unlikely that any user will ever hit this situation, so there is no
strong drive to invest effort in a more comprehensive implementation.

Sponsored-by: On-Waves ehi
This commit is contained in:
Neels Hofmeyr 2015-11-27 01:22:13 +01:00
parent d121ea6124
commit 7174b169e0
1 changed files with 88 additions and 33 deletions
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121
openbsc/src/gprs/gtphub.c
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@ -1210,43 +1210,99 @@ static struct gtphub_tunnel *gtphub_tun_find(struct gtphub *hub,
return NULL;
}
static void gtphub_expire_reused_tei(struct gtphub *hub,
int side_idx,
int plane_idx,
struct gtphub_peer_port *from,
uint32_t tei_orig,
struct gtphub_tunnel *except)
static int gtphub_check_mapped_tei(struct gtphub_tunnel_endpoint *new_te,
struct gtphub_tunnel_endpoint *iterated_te,
uint32_t *tei_min,
uint32_t *tei_max)
{
struct gtphub_tunnel *exists, *e2;
if (new_te->tei_repl != iterated_te->tei_repl)
return 1;
llist_for_each_entry_safe(exists, e2, &hub->tunnels, entry) {
if (exists == except)
/* new_te->tei_repl is already taken. Try to find one out of the known
* range. */
if ((*tei_max) < 0xffffffff) {
(*tei_max)++;
new_te->tei_repl = *tei_max;
return 1;
} else if ((*tei_min) > 1) {
(*tei_min)--;
new_te->tei_repl = *tei_min;
return 1;
}
/* None seems to be available. */
return 0;
}
static int gtphub_check_reused_teis(struct gtphub *hub,
struct gtphub_tunnel *new_tun)
{
uint32_t tei_min = 0xffffffff;
uint32_t tei_max = 0;
int side_idx;
int plane_idx;
int side_idx2;
int plane_idx2;
struct gtphub_tunnel_endpoint *te;
struct gtphub_tunnel_endpoint *te2;
struct gtphub_tunnel *tun, *ntun;
llist_for_each_entry_safe(tun, ntun, &hub->tunnels, entry) {
if (tun == new_tun)
continue;
struct gtphub_tunnel_endpoint *te =
&exists->endpoint[side_idx][plane_idx];
if ((te->tei_orig == tei_orig)
&& gsn_addr_same(&te->peer->peer_addr->addr,
&from->peer_addr->addr)) {
/* Check whether the GSN sent a TEI that it is reusing from a
* previous tunnel. */
for_each_side_and_plane(side_idx, plane_idx) {
te = &tun->endpoint[side_idx][plane_idx];
te2 = &new_tun->endpoint[side_idx][plane_idx];
if ((te->tei_orig == te2->tei_orig)
&& gsn_addr_same(&te->peer->peer_addr->addr,
&te2->peer->peer_addr->addr)) {
/* The peer is reusing a TEI that I believe to
* be part of another tunnel. The other tunnel
* must be stale, then. */
LOG(LOGL_NOTICE,
"Expiring tunnel due to reused TEI:"
" peer %s sent %s TEI %x,"
" previously used by tunnel %s...\n",
gtphub_port_str(from),
gtphub_plane_idx_names[plane_idx],
tei_orig,
gtphub_tunnel_str(exists));
LOG(LOGL_NOTICE, "...while establishing tunnel %s\n",
gtphub_tunnel_str(except));
expiring_item_del(&exists->expiry_entry);
/* continue to find more matches. There shouldn't be
* any, but let's make sure. */
/* The peer is reusing a TEI that I believe to
* be part of another tunnel. The other tunnel
* must be stale, then. */
LOG(LOGL_NOTICE,
"Expiring tunnel due to reused TEI:"
" peer %s sent %s TEI %x,"
" previously used by tunnel %s...\n",
gtphub_port_str(te->peer),
gtphub_plane_idx_names[plane_idx],
te->tei_orig,
gtphub_tunnel_str(tun));
LOG(LOGL_NOTICE, "...while establishing tunnel %s\n",
gtphub_tunnel_str(new_tun));
expiring_item_del(&tun->expiry_entry);
/* continue to find more matches. There shouldn't be
* any, but let's make sure. */
}
}
/* Check whether the mapped TEIs assigned to the endpoints are
* used anywhere else. */
for_each_side_and_plane(side_idx, plane_idx) {
te = &tun->endpoint[side_idx][plane_idx];
tei_min = (tei_min < te->tei_repl)? tei_min : te->tei_repl;
tei_max = (tei_max > te->tei_repl)? tei_max : te->tei_repl;
for_each_side_and_plane(side_idx2, plane_idx2) {
te2 = &new_tun->endpoint[side_idx2][plane_idx2];
if (!gtphub_check_mapped_tei(te2, te, &tei_min, &tei_max)) {
LOG(LOGL_ERROR,
"No mapped TEI is readily available."
" Searching for holes between occupied"
" TEIs not implemented.");
return 0;
}
}
}
}
return 1;
}
static void gtphub_tunnel_refresh(struct gtphub *hub,
@ -1455,9 +1511,8 @@ static int gtphub_handle_pdp_ctx_ies(struct gtphub *hub,
tun->endpoint[side_idx][plane_idx].tei_repl = mapped_tei;
p->ie[ie_idx]->tv4.v = hton32(mapped_tei);
gtphub_expire_reused_tei(hub, side_idx, plane_idx,
peer_from_ie, tei_from_ie,
tun);
if (!gtphub_check_reused_teis(hub, tun))
return -1;
}
/* Replace the GSN address to reflect gtphub. */