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osmo-msc/openbsc/src/gprs/gtphub.c

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/* GTP Hub Implementation */
/* (C) 2015 by sysmocom s.f.m.c. GmbH <info@sysmocom.de>
* All Rights Reserved
*
* Author: Neels Hofmeyr
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <string.h>
#include <errno.h>
#include <inttypes.h>
#include <time.h>
#include <limits.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <gtp.h>
#include <gtpie.h>
#include <openbsc/gtphub.h>
#include <openbsc/debug.h>
#include <osmocom/core/utils.h>
#include <osmocom/core/logging.h>
#include <osmocom/core/socket.h>
#define GTPHUB_DEBUG 1
static const int GTPH_GC_TICK_SECONDS = 1;
void *osmo_gtphub_ctx;
#define LOGERR(fmt, args...) \
LOGP(DGTPHUB, LOGL_ERROR, fmt, ##args)
#define LOG(fmt, args...) \
LOGP(DGTPHUB, LOGL_NOTICE, fmt, ##args)
#define ZERO_STRUCT(struct_pointer) memset(struct_pointer, '\0', sizeof(*(struct_pointer)))
/* TODO move this to osmocom/core/select.h ? */
typedef int (*osmo_fd_cb_t)(struct osmo_fd *fd, unsigned int what);
/* TODO move this to osmocom/core/linuxlist.h ? */
#define __llist_first(head) (((head)->next == (head)) ? NULL : (head)->next)
#define llist_first(head, type, entry) llist_entry(__llist_first(head), type, entry)
/* TODO move GTP header stuff to openggsn/gtp/ ? See gtp_decaps*() */
enum gtp_rc {
GTP_RC_UNKNOWN = 0,
GTP_RC_TINY = 1, /* no IEs (like ping/pong) */
GTP_RC_PDU = 2, /* a real packet with IEs */
GTP_RC_TOOSHORT = -1,
GTP_RC_UNSUPPORTED_VERSION = -2,
GTP_RC_INVALID_IE = -3,
};
struct gtp_packet_desc {
union gtp_packet *data;
int data_len;
int header_len;
int version;
uint8_t type;
uint16_t seq;
uint32_t header_tei;
int rc; /* enum gtp_rc */
unsigned int plane_idx;
union gtpie_member *ie[GTPIE_SIZE];
};
void gsn_addr_copy(struct gsn_addr *gsna, const struct gsn_addr *src)
{
memcpy(gsna, src, sizeof(struct gsn_addr));
}
/* Decode sa to gsna. Return 0 on success. If port is non-NULL, the port number
* from sa is also returned. */
int gsn_addr_from_sockaddr(struct gsn_addr *gsna, uint16_t *port,
const struct osmo_sockaddr *sa)
{
char addr_str[256];
char port_str[6];
if (osmo_sockaddr_to_strs(addr_str, sizeof(addr_str),
port_str, sizeof(port_str),
sa, (NI_NUMERICHOST | NI_NUMERICSERV))
!= 0) {
return -1;
}
if (port)
*port = atoi(port_str);
return gsn_addr_from_str(gsna, addr_str);
}
int gsn_addr_from_str(struct gsn_addr *gsna, const char *numeric_addr_str)
{
int af = AF_INET;
gsna->len = 4;
const char *pos = numeric_addr_str;
for (; *pos; pos++) {
if (*pos == ':') {
af = AF_INET6;
gsna->len = 16;
break;
}
}
int rc = inet_pton(af, numeric_addr_str, gsna->buf);
if (rc != 1) {
LOGERR("Cannot resolve numeric address: '%s'\n", numeric_addr_str);
return -1;
}
return 0;
}
const char *gsn_addr_to_str(const struct gsn_addr *gsna)
{
static char buf[INET6_ADDRSTRLEN + 1];
return gsn_addr_to_strb(gsna, buf, sizeof(buf));
}
const char *gsn_addr_to_strb(const struct gsn_addr *gsna,
char *strbuf,
int strbuf_len)
{
int af;
switch (gsna->len) {
case 4:
af = AF_INET;
break;
case 16:
af = AF_INET6;
break;
default:
return NULL;
}
const char *r = inet_ntop(af, gsna->buf, strbuf, strbuf_len);
if (!r) {
LOGERR("Cannot convert gsn_addr to string: %s: len=%d, buf=%s\n",
strerror(errno),
(int)gsna->len,
osmo_hexdump(gsna->buf, sizeof(gsna->buf)));
}
return r;
}
int gsn_addr_same(const struct gsn_addr *a, const struct gsn_addr *b)
{
if (a == b)
return 1;
if ((!a) || (!b))
return 0;
if (a->len != b->len)
return 0;
return (memcmp(a->buf, b->buf, a->len) == 0)? 1 : 0;
}
static int gsn_addr_get(struct gsn_addr *gsna, const struct gtp_packet_desc *p, int idx)
{
if (p->rc != GTP_RC_PDU)
return -1;
unsigned int len;
/* gtpie.h fails to declare gtpie_gettlv()'s first arg as const. */
if (gtpie_gettlv((union gtpie_member**)p->ie, GTPIE_GSN_ADDR, idx,
&len, gsna->buf, sizeof(gsna->buf))
!= 0)
return -1;
gsna->len = len;
return 0;
}
static int gsn_addr_put(const struct gsn_addr *gsna, struct gtp_packet_desc *p, int idx)
{
if (p->rc != GTP_RC_PDU)
return -1;
int ie_idx;
ie_idx = gtpie_getie(p->ie, GTPIE_GSN_ADDR, idx);
if (ie_idx < 0)
return -1;
struct gtpie_tlv *ie = &p->ie[ie_idx]->tlv;
int ie_l = ntoh16(ie->l);
if (ie_l != gsna->len) {
LOG("Not implemented: replace an IE address of different size:"
" replace %d with %d\n", (int)ie_l, (int)gsna->len);
return -1;
}
memcpy(ie->v, gsna->buf, (int)ie_l);
return 0;
}
/* Validate GTP version 0 data; analogous to validate_gtp1_header(), see there.
*/
void validate_gtp0_header(struct gtp_packet_desc *p)
{
const struct gtp0_header *pheader = &(p->data->gtp0.h);
p->rc = GTP_RC_UNKNOWN;
p->header_len = 0;
OSMO_ASSERT(p->data_len >= 1);
OSMO_ASSERT(p->version == 0);
if (p->data_len < GTP0_HEADER_SIZE) {
LOGERR("GTP0 packet too short: %d\n", p->data_len);
p->rc = GTP_RC_TOOSHORT;
return;
}
p->type = ntoh8(pheader->type);
p->seq = ntoh16(pheader->seq);
p->header_tei = 0; /* TODO */
if (p->data_len == GTP0_HEADER_SIZE) {
p->rc = GTP_RC_TINY;
p->header_len = GTP0_HEADER_SIZE;
return;
}
/* Check packet length field versus length of packet */
if (p->data_len != (ntoh16(pheader->length) + GTP0_HEADER_SIZE)) {
LOGERR("GTP packet length field (%d + %d) does not match"
" actual length (%d)\n",
GTP0_HEADER_SIZE, (int)ntoh16(pheader->length),
p->data_len);
p->rc = GTP_RC_TOOSHORT;
return;
}
LOG("GTP v0 TID = %" PRIu64 "\n", pheader->tid);
p->header_len = GTP0_HEADER_SIZE;
p->rc = GTP_RC_PDU;
}
/* Validate GTP version 1 data, and update p->rc with the result, as well as
* p->header_len in case of a valid header. */
void validate_gtp1_header(struct gtp_packet_desc *p)
{
const struct gtp1_header_long *pheader = &(p->data->gtp1l.h);
p->rc = GTP_RC_UNKNOWN;
p->header_len = 0;
OSMO_ASSERT(p->data_len >= 1);
OSMO_ASSERT(p->version == 1);
if ((p->data_len < GTP1_HEADER_SIZE_LONG)
&& (p->data_len != GTP1_HEADER_SIZE_SHORT)){
LOGERR("GTP packet too short: %d\n", p->data_len);
p->rc = GTP_RC_TOOSHORT;
return;
}
p->type = ntoh8(pheader->type);
p->header_tei = ntoh32(pheader->tei);
p->seq = ntoh16(pheader->seq);
LOG("|GTPv1\n");
LOG("| type = %" PRIu8 " 0x%02" PRIx8 "\n",
p->type, p->type);
LOG("| length = %" PRIu16 " 0x%04" PRIx16 "\n",
ntoh16(pheader->length), ntoh16(pheader->length));
LOG("| TEI = %" PRIu32 " 0x%08" PRIx32 "\n",
p->header_tei, p->header_tei);
LOG("| seq = %" PRIu16 " 0x%04" PRIx16 "\n",
p->seq, p->seq);
LOG("| npdu = %" PRIu8 " 0x%02" PRIx8 "\n",
pheader->npdu, pheader->npdu);
LOG("| next = %" PRIu8 " 0x%02" PRIx8 "\n",
pheader->next, pheader->next);
if (p->data_len <= GTP1_HEADER_SIZE_LONG) {
p->rc = GTP_RC_TINY;
p->header_len = GTP1_HEADER_SIZE_SHORT;
return;
}
/* Check packet length field versus length of packet */
if (p->data_len != (ntoh16(pheader->length) + GTP1_HEADER_SIZE_SHORT)) {
LOGERR("GTP packet length field (%d + %d) does not match"
" actual length (%d)\n",
GTP1_HEADER_SIZE_SHORT, (int)ntoh16(pheader->length),
p->data_len);
p->rc = GTP_RC_TOOSHORT;
return;
}
p->rc = GTP_RC_PDU;
p->header_len = GTP1_HEADER_SIZE_LONG;
}
/* Examine whether p->data of size p->data_len has a valid GTP header. Set
* p->version, p->rc and p->header_len. On error, p->rc <= 0 (see enum
* gtp_rc). p->data must point at a buffer with p->data_len set. */
void validate_gtp_header(struct gtp_packet_desc *p)
{
p->rc = GTP_RC_UNKNOWN;
/* Need at least 1 byte in order to check version */
if (p->data_len < 1) {
LOGERR("Discarding packet - too small: %d\n", p->data_len);
p->rc = GTP_RC_TOOSHORT;
return;
}
p->version = p->data->flags >> 5;
switch (p->version) {
case 0:
validate_gtp0_header(p);
break;
case 1:
validate_gtp1_header(p);
break;
default:
LOGERR("Unsupported GTP version: %d\n", p->version);
p->rc = GTP_RC_UNSUPPORTED_VERSION;
break;
}
}
/* Return the value of the i'th IMSI IEI by copying to *imsi.
* The first IEI is reached by passing i = 0.
* imsi must point at allocated space of (at least) 8 bytes.
* Return 1 on success, or 0 if not found. */
static int get_ie_imsi(union gtpie_member *ie[], uint8_t *imsi, int i)
{
return gtpie_gettv0(ie, GTPIE_IMSI, i, imsi, 8) == 0;
}
/* Analogous to get_ie_imsi(). nsapi must point at a single uint8_t. */
static int get_ie_nsapi(union gtpie_member *ie[], uint8_t *nsapi, int i)
{
return gtpie_gettv1(ie, GTPIE_NSAPI, i, nsapi) == 0;
}
static char imsi_digit_to_char(uint8_t nibble)
{
nibble &= 0x0f;
if (nibble > 9)
return (nibble == 0x0f) ? '\0' : '?';
return '0' + nibble;
}
/* Return a human readable IMSI string, in a static buffer.
* imsi must point at 8 octets of IMSI IE encoded IMSI data. */
static const char *imsi_to_str(uint8_t *imsi)
{
static char str[17];
int i;
for (i = 0; i < 8; i++) {
str[2*i] = imsi_digit_to_char(imsi[i]);
str[2*i + 1] = imsi_digit_to_char(imsi[i] >> 4);
}
str[16] = '\0';
return str;
}
/* Validate header, and index information elements. Write decoded packet
* information to *res. res->data will point at the given data buffer. On
* error, p->rc is set <= 0 (see enum gtp_rc). */
static void gtp_decode(const uint8_t *data, int data_len,
unsigned int from_plane_idx,
struct gtp_packet_desc *res)
{
ZERO_STRUCT(res);
res->data = (union gtp_packet*)data;
res->data_len = data_len;
res->plane_idx = from_plane_idx;
validate_gtp_header(res);
if (res->rc <= 0) {
LOGERR("INVALID: dropping GTP packet.\n");
return;
}
LOG("Valid GTP header (v%d)\n", res->version);
if (res->rc != GTP_RC_PDU) {
LOG("no IEs in this GTP packet\n");
return;
}
if (gtpie_decaps(res->ie, res->version,
(void*)(data + res->header_len),
res->data_len - res->header_len) != 0) {
res->rc = GTP_RC_INVALID_IE;
return;
}
#if GTPHUB_DEBUG
int i;
for (i = 0; i < 10; i++) {
uint8_t imsi[8];
if (!get_ie_imsi(res->ie, imsi, i))
break;
LOG("| IMSI %s\n", imsi_to_str(imsi));
}
for (i = 0; i < 10; i++) {
uint8_t nsapi;
if (!get_ie_nsapi(res->ie, &nsapi, i))
break;
LOG("| NSAPI %d\n", (int)nsapi);
}
for (i = 0; i < 2; i++) {
struct gsn_addr addr;
if (gsn_addr_get(&addr, res, i) == 0)
LOG("| addr %s\n", gsn_addr_to_str(&addr));
}
for (i = 0; i < 10; i++) {
uint32_t tei;
if (gtpie_gettv4(res->ie, GTPIE_TEI_DI, i, &tei) != 0)
break;
LOG("| TEI DI (USER) %" PRIu32 " 0x%08" PRIx32 "\n",
tei, tei);
}
for (i = 0; i < 10; i++) {
uint32_t tei;
if (gtpie_gettv4(res->ie, GTPIE_TEI_C, i, &tei) != 0)
break;
LOG("| TEI (CTRL) %" PRIu32 " 0x%08" PRIx32 "\n",
tei, tei);
}
#endif
}
/* expiry */
void expiry_init(struct expiry *exq, int expiry_in_seconds)
{
ZERO_STRUCT(exq);
exq->expiry_in_seconds = expiry_in_seconds;
INIT_LLIST_HEAD(&exq->items);
}
void expiry_add(struct expiry *exq, struct expiring_item *item, time_t now)
{
item->expiry = now + exq->expiry_in_seconds;
/* Add/move to the tail to always sort by expiry, ascending. */
llist_del(&item->entry);
llist_add_tail(&item->entry, &exq->items);
}
int expiry_tick(struct expiry *exq, time_t now)
{
int expired = 0;
struct expiring_item *m, *n;
llist_for_each_entry_safe(m, n, &exq->items, entry) {
if (m->expiry <= now) {
expiring_item_del(m);
expired ++;
} else {
LOG("Not expired: %d > %d\n", (int)m->expiry, (int)now);
/* The items are added sorted by expiry. So when we hit
* an unexpired entry, only more unexpired ones will
* follow. */
break;
}
}
return expired;
}
void expiring_item_init(struct expiring_item *item)
{
ZERO_STRUCT(item);
INIT_LLIST_HEAD(&item->entry);
}
void expiring_item_del(struct expiring_item *item)
{
OSMO_ASSERT(item);
llist_del(&item->entry);
INIT_LLIST_HEAD(&item->entry);
if (item->del_cb) {
/* avoid loops */
del_cb_t del_cb = item->del_cb;
item->del_cb = 0;
(del_cb)(item);
}
}
/* nr_map, nr_pool */
void nr_pool_init(struct nr_pool *pool)
{
*pool = (struct nr_pool){};
}
nr_t nr_pool_next(struct nr_pool *pool)
{
pool->last_nr ++;
OSMO_ASSERT(pool->last_nr > 0);
/* TODO: gracefully handle running out of TEIs. */
/* TODO: random TEIs. */
return pool->last_nr;
}
void nr_map_init(struct nr_map *map, struct nr_pool *pool,
struct expiry *exq)
{
ZERO_STRUCT(map);
map->pool = pool;
map->add_items_to_expiry = exq;
INIT_LLIST_HEAD(&map->mappings);
}
void nr_mapping_init(struct nr_mapping *m)
{
ZERO_STRUCT(m);
INIT_LLIST_HEAD(&m->entry);
expiring_item_init(&m->expiry_entry);
}
void nr_map_add(struct nr_map *map, struct nr_mapping *mapping, time_t now)
{
/* Generate a mapped number */
mapping->repl = nr_pool_next(map->pool);
/* Add to the tail to always yield a list sorted by expiry, in
* ascending order. */
llist_add_tail(&mapping->entry, &map->mappings);
if (map->add_items_to_expiry)
expiry_add(map->add_items_to_expiry,
&mapping->expiry_entry,
now);
}
void nr_map_clear(struct nr_map *map)
{
struct nr_mapping *m;
struct nr_mapping *n;
llist_for_each_entry_safe(m, n, &map->mappings, entry) {
nr_mapping_del(m);
}
}
int nr_map_empty(const struct nr_map *map)
{
return llist_empty(&map->mappings);
}
struct nr_mapping *nr_map_get(const struct nr_map *map,
void *origin, nr_t nr_orig)
{
struct nr_mapping *mapping;
llist_for_each_entry(mapping, &map->mappings, entry) {
if ((mapping->origin == origin)
&& (mapping->orig == nr_orig))
return mapping;
}
/* Not found. */
return NULL;
}
struct nr_mapping *nr_map_get_inv(const struct nr_map *map, nr_t nr_repl)
{
struct nr_mapping *mapping;
llist_for_each_entry(mapping, &map->mappings, entry) {
if (mapping->repl == nr_repl) {
return mapping;
}
}
/* Not found. */
return NULL;
}
void nr_mapping_del(struct nr_mapping *mapping)
{
OSMO_ASSERT(mapping);
llist_del(&mapping->entry);
INIT_LLIST_HEAD(&mapping->entry);
expiring_item_del(&mapping->expiry_entry);
}
/* gtphub */
const char* const gtphub_plane_idx_names[GTPH_PLANE_N] = {
"CTRL",
"USER",
};
const uint16_t gtphub_plane_idx_default_port[GTPH_PLANE_N] = {
2123,
2152,
};
time_t gtphub_now(void)
{
struct timespec now_tp;
OSMO_ASSERT(clock_gettime(CLOCK_MONOTONIC, &now_tp) >= 0);
return now_tp.tv_sec;
}
/* Remove a gtphub_peer from its list and free it. */
static void gtphub_peer_del(struct gtphub_peer *peer)
{
nr_map_clear(&peer->seq_map);
llist_del(&peer->entry);
talloc_free(peer);
}
static void gtphub_peer_addr_del(struct gtphub_peer_addr *pa)
{
OSMO_ASSERT(llist_empty(&pa->ports));
llist_del(&pa->entry);
talloc_free(pa);
}
static void gtphub_peer_port_del(struct gtphub_peer_port *pp)
{
OSMO_ASSERT(pp->ref_count == 0);
llist_del(&pp->entry);
talloc_free(pp);
}
/* From the information in the gtp_packet_desc, return the address of a GGSN.
* Return -1 on error. */
static struct gtphub_peer_port *gtphub_resolve_ggsn(struct gtphub *hub,
struct gtp_packet_desc *p);
/* See gtphub_ext.c (wrapped by unit test) */
int gtphub_resolve_ggsn_addr(struct gtphub *hub,
struct osmo_sockaddr *result,
struct gtp_packet_desc *p);
static struct gtphub_peer_port *gtphub_port_find(const struct gtphub_bind *bind,
const struct gsn_addr *addr,
uint16_t port);
static struct gtphub_peer_port *gtphub_port_have(struct gtphub *hub,
struct gtphub_bind *bind,
const struct gsn_addr *addr,
uint16_t port);
static void gtphub_zero(struct gtphub *hub)
{
ZERO_STRUCT(hub);
}
static int gtphub_sock_init(struct osmo_fd *ofd,
const struct gtphub_cfg_addr *addr,
osmo_fd_cb_t cb,
void *data,
int ofd_id)
{
if (!addr->addr_str) {
LOGERR("Cannot bind: empty address.\n");
return -1;
}
if (!addr->port) {
LOGERR("Cannot bind: zero port not permitted.\n");
return -1;
}
ofd->when = BSC_FD_READ;
ofd->cb = cb;
ofd->data = data;
ofd->priv_nr = ofd_id;
int rc;
rc = osmo_sock_init_ofd(ofd,
AF_UNSPEC, SOCK_DGRAM, IPPROTO_UDP,
addr->addr_str, addr->port,
OSMO_SOCK_F_BIND);
if (rc < 1) {
LOGERR("Cannot bind to %s port %d (rc %d)\n",
addr->addr_str, (int)addr->port, rc);
return -1;
}
return 0;
}
static void gtphub_bind_init(struct gtphub_bind *b)
{
ZERO_STRUCT(b);
INIT_LLIST_HEAD(&b->peers);
}
static int gtphub_bind_start(struct gtphub_bind *b,
const struct gtphub_cfg_bind *cfg,
osmo_fd_cb_t cb, void *cb_data,
unsigned int ofd_id)
{
if (gsn_addr_from_str(&b->local_addr, cfg->bind.addr_str) != 0)
return -1;
if (gtphub_sock_init(&b->ofd, &cfg->bind, cb, cb_data, ofd_id) != 0)
return -1;
return 0;
}
/* Recv datagram from from->fd, optionally write sender's address to *from_addr.
* Return the number of bytes read, zero on error. */
static int gtphub_read(const struct osmo_fd *from,
struct osmo_sockaddr *from_addr,
uint8_t *buf, size_t buf_len)
{
/* recvfrom requires the available length to be set in *from_addr_len. */
if (from_addr)
from_addr->l = sizeof(from_addr->a);
errno = 0;
ssize_t received = recvfrom(from->fd, buf, buf_len, 0,
(struct sockaddr*)&from_addr->a, &from_addr->l);
/* TODO use recvmsg and get a MSG_TRUNC flag to make sure the message
* is not truncated. Then maybe reduce buf's size. */
if (received <= 0) {
if (errno != EAGAIN)
LOGERR("error: %s\n", strerror(errno));
return 0;
}
if (from_addr) {
LOG("from %s\n", osmo_sockaddr_to_str(from_addr));
}
if (received <= 0) {
LOGERR("error: %s\n", strerror(errno));
return 0;
}
LOG("Received %d\n%s\n", (int)received, osmo_hexdump(buf, received));
return received;
}
inline void gtphub_port_ref_count_inc(struct gtphub_peer_port *pp)
{
OSMO_ASSERT(pp->ref_count < UINT_MAX);
pp->ref_count++;
}
inline void gtphub_port_ref_count_dec(struct gtphub_peer_port *pp)
{
OSMO_ASSERT(pp->ref_count > 0);
pp->ref_count--;
}
inline void set_seq(struct gtp_packet_desc *p, uint16_t seq)
{
OSMO_ASSERT(p->version == 1);
p->data->gtp1l.h.seq = hton16(seq);
p->seq = seq;
}
inline void set_tei(struct gtp_packet_desc *p, uint32_t tei)
{
OSMO_ASSERT(p->version == 1);
p->data->gtp1l.h.tei = hton32(tei);
p->header_tei = tei;
}
static void gtphub_mapping_del_cb(struct expiring_item *expi);
static struct nr_mapping *gtphub_mapping_new()
{
struct nr_mapping *nrm;
nrm = talloc_zero(osmo_gtphub_ctx, struct nr_mapping);
OSMO_ASSERT(nrm);
nr_mapping_init(nrm);
nrm->expiry_entry.del_cb = gtphub_mapping_del_cb;
return nrm;
}
static const char *gtphub_peer_strb(struct gtphub_peer *peer, char *buf, int buflen)
{
if (llist_empty(&peer->addresses))
return "(addressless)";
struct gtphub_peer_addr *a = llist_first(&peer->addresses,
struct gtphub_peer_addr,
entry);
return gsn_addr_to_strb(&a->addr, buf, buflen);
}
static const char *gtphub_port_strb(struct gtphub_peer_port *port, char *buf, int buflen)
{
if (!port)
return "(null port)";
snprintf(buf, buflen, "%s port %d",
gsn_addr_to_str(&port->peer_addr->addr),
(int)port->port);
return buf;
}
const char *gtphub_peer_str(struct gtphub_peer *peer)
{
static char buf[256];
return gtphub_peer_strb(peer, buf, sizeof(buf));
}
const char *gtphub_peer_str2(struct gtphub_peer *peer)
{
static char buf[256];
return gtphub_peer_strb(peer, buf, sizeof(buf));
}
static const char *gtphub_port_str(struct gtphub_peer_port *port)
{
static char buf[256];
return gtphub_port_strb(port, buf, sizeof(buf));
}
static const char *gtphub_port_str2(struct gtphub_peer_port *port)
{
static char buf[256];
return gtphub_port_strb(port, buf, sizeof(buf));
}
static void gtphub_mapping_del_cb(struct expiring_item *expi)
{
expi->del_cb = 0; /* avoid recursion loops */
struct nr_mapping *nrm = container_of(expi,
struct nr_mapping,
expiry_entry);
llist_del(&nrm->entry);
INIT_LLIST_HEAD(&nrm->entry); /* mark unused */
/* Just for log */
struct gtphub_peer_port *from = nrm->origin;
OSMO_ASSERT(from);
LOG("expired: %d: nr mapping from %s: %d->%d\n",
(int)nrm->expiry_entry.expiry,
gtphub_port_str(from),
(int)nrm->orig, (int)nrm->repl);
gtphub_port_ref_count_dec(from);
talloc_free(nrm);
}
static struct nr_mapping *gtphub_mapping_have(struct nr_map *map,
struct gtphub_peer_port *from,
nr_t orig_nr,
time_t now)
{
struct nr_mapping *nrm;
nrm = nr_map_get(map, from, orig_nr);
if (!nrm) {
nrm = gtphub_mapping_new();
nrm->orig = orig_nr;
nrm->origin = from;
nr_map_add(map, nrm, now);
gtphub_port_ref_count_inc(from);
LOG("peer %s: MAP %d --> %d\n",
gtphub_port_str(from),
(int)(nrm->orig), (int)(nrm->repl));
} else {
/* restart expiry timeout */
expiry_add(map->add_items_to_expiry, &nrm->expiry_entry,
now);
}
OSMO_ASSERT(nrm);
return nrm;
}
static uint32_t gtphub_tei_mapping_have(struct gtphub *hub,
int plane_idx,
struct gtphub_peer_port *from,
uint32_t orig_tei,
time_t now)
{
struct nr_mapping *nrm = gtphub_mapping_have(&hub->tei_map[plane_idx],
from, orig_tei, now);
LOG("New %s TEI: (from %s, TEI %d) <-- TEI %d\n",
gtphub_plane_idx_names[plane_idx],
gtphub_port_str(from),
(int)orig_tei, (int)nrm->repl);
return (uint32_t)nrm->repl;
}
static int gtphub_map_seq(struct gtp_packet_desc *p,
struct gtphub_peer_port *from_port,
struct gtphub_peer_port *to_port,
time_t now)
{
/* Store a mapping in to_peer's map, so when we later receive a GTP
* packet back from to_peer, the seq nr can be unmapped back to its
* origin (from_peer here). */
struct nr_mapping *nrm;
nrm = gtphub_mapping_have(&to_port->peer_addr->peer->seq_map,
from_port, p->seq, now);
/* Change the GTP packet to yield the new, mapped seq nr */
set_seq(p, nrm->repl);
return 0;
}
static struct gtphub_peer_port *gtphub_unmap_seq(struct gtp_packet_desc *p,
struct gtphub_peer_port *responding_port)
{
OSMO_ASSERT(p->version == 1);
struct nr_mapping *nrm = nr_map_get_inv(&responding_port->peer_addr->peer->seq_map,
p->seq);
if (!nrm)
return NULL;
LOG("peer %p: UNMAP %d <-- %d\n", nrm->origin, (int)(nrm->orig), (int)(nrm->repl));
set_seq(p, nrm->orig);
return nrm->origin;
}
static void gtphub_check_restart_counter(struct gtphub *hub,
struct gtp_packet_desc *p,
struct gtphub_peer_port *from)
{
/* TODO */
/* If the peer is sending a Recovery IE (7.7.11) with a restart counter
* that doesn't match the peer's previously sent restart counter, clear
* that peer and cancel PDP contexts. */
}
static void gtphub_map_restart_counter(struct gtphub *hub,
struct gtp_packet_desc *p,
struct gtphub_peer_port *from,
struct gtphub_peer_port *to)
{
/* TODO */
}
/* gtphub_map_ie_teis() and gtphub_unmap_header_tei():
*
* TEI mapping must happen symmetrically. An SGSN contacts gtphub instead of N
* GGSNs, and a GGSN replies to gtphub for N SGSNs. From either end, TEIs may
* collide: two GGSNs picking the same TEIs, or two SGSNs picking the same
* TEIs. Since the opposite side sees the sender address being gtphub's
* address, TEIs among the SGSNs, and among the GGSNs, must not overlap. If a
* peer sends a TEI already sent before from a peer of the same side, gtphub
* replaces it with a TEI not yet seen from that side and remembers the
* mapping.
*
* Consider two SGSNs A and B contacting two GGSNs C and D thru gtphub.
*
* A: Create PDP Ctx, I have TEI 1.
* ---> gtphub: A has TEI 1, sending 1 for C.
* ---> C: gtphub has TEI 1.
* <--- C: Response to TEI 1: I have TEI 11.
* <--- gtphub: ok, telling A: 11.
* A: gtphub's first TEI is 11. (1)
*
* B: Create PDP Ctx, I have TEIs 1.
* ---> gtphub: 1 already taken for C, sending 2 for B. (map)
* ---> C: gtphub also has 2.
* <--- C: Response to TEI 2: I have TEI 12.
* <--- gtphub: ok, TEI 2 is actually B with TEI 1. (unmap)
* B: gtphub's first TEI is 12, as far as I can tell.
*
* Now the second GGSN comes into play:
*
* A: Create PDP Ctx, I have TEI 2.
* ---> gtphub: A also has TEI 2, but for D, sending 1. (2)
* ---> D: gtphub has 1.
* <--- D: Response to TEI 1: I have TEI 11.
* <--- gtphub: from D, 1 is A. 11 already taken by C, sending 13. (3)
* A: gtphub also has TEI 13. (4)
*
* And some messages routed through:
*
* A: message to TEI 11, see (1).
* ---> gtphub: ok, telling C with TEI 11.
* ---> C: I see, 11 means reply with 1.
* <--- C: Response to TEI 1
* <--- gtphub: 1 from C is actually for A with TEI 1.
* A: ah, my TEI 1, thanks!
*
* A: message to TEI 13, see (4).
* ---> gtphub: ok, but not 13, D wanted TEI 11 instead, see (3).
* ---> D: I see, 11 means reply with 1.
* <--- D: Response to TEI 1
* <--- gtphub: 1 from D is actually for A with TEI 2, see (2).
* A: ah, my TEI 2, thanks!
*
* What if a GGSN initiates a request:
*
* <--- D: Request to gtphub TEI 1
* <--- gtphub: 1 from D is for A with 2, see (2).
* A: my TEI 2 means reply with 13.
* ---> gtphub: 13 was D with 11, see (3).
* ---> D: 11 from gtphub: a reply to my request for TEI 1.
*
* Note that usually, it's the sequence numbers that route a response back to
* the requesting peer. Nevertheless, the TEI mappings must be carried out to
* replace the TEIs in the GTP packet that is relayed.
*
* Also note: the TEI in the GTP header is "reversed" from the TEI in the IEs:
* the TEI in the header is used to send something *to* a peer, while the TEI
* in e.g. a Create PDP Context Request's IE is for routing messages *back*
* later. */
static int gtphub_unmap_header_tei(struct gtphub_peer_port **to_port_p,
struct gtphub *hub,
struct gtp_packet_desc *p,
struct gtphub_peer_port *from_port)
{
OSMO_ASSERT(p->version == 1);
*to_port_p = NULL;
/* If the header's TEI is zero, no PDP context has been established
* yet. If nonzero, a mapping should actually already exist for this
* TEI, since it must have been announced in a PDP context creation. */
uint32_t tei = p->header_tei;
if (!tei)
return 0;
/* to_peer has previously announced a TEI, which was stored and
* mapped in from_peer's tei_map. */
struct nr_mapping *nrm;
nrm = nr_map_get_inv(&hub->tei_map[p->plane_idx], tei);
if (!nrm) {
LOGERR("Received unknown TEI %" PRIu32 " from %s\n",
tei, gtphub_port_str(from_port));
return -1;
}
struct gtphub_peer_port *to_port = nrm->origin;
uint32_t unmapped_tei = nrm->orig;
set_tei(p, unmapped_tei);
LOG("Unmapped TEI coming from %s: %d -> %d (to %s)\n",
gtphub_port_str(from_port), tei, unmapped_tei,
gtphub_port_str2(to_port));
*to_port_p = to_port;
return 0;
}
/* Read GSN address IEs from p, and make sure these peer addresses exist in
* bind[plane_idx] with default ports, in their respective planes (both Ctrl
* and User). Map TEIs announced in IEs, and write mapped TEIs in-place into
* the packet p. */
static int gtphub_handle_pdp_ctx_ies(struct gtphub *hub,
struct gtphub_bind from_bind[],
struct gtphub_bind to_bind[],
struct gtp_packet_desc *p,
time_t now)
{
OSMO_ASSERT(p->plane_idx == GTPH_PLANE_CTRL);
int rc;
int plane_idx;
switch (p->type) {
case GTP_CREATE_PDP_REQ:
case GTP_CREATE_PDP_RSP:
/* Go for it below */
break;
default:
/* Nothing to do for this message type. */
return 0;
}
/* TODO enforce a Request only from SGSN, a Response only from GGSN? */
osmo_static_assert((GTPH_PLANE_CTRL == 0) && (GTPH_PLANE_USER == 1),
plane_nrs_match_GSN_addr_IE_indices);
uint8_t ie_type[] = { GTPIE_TEI_C, GTPIE_TEI_DI };
int ie_mandatory = (p->type == GTP_CREATE_PDP_REQ);
for (plane_idx = 0; plane_idx < 2; plane_idx++) {
struct gsn_addr addr_from_ie;
uint32_t tei_from_ie;
int ie_idx;
/* Fetch GSN Address and TEI from IEs */
rc = gsn_addr_get(&addr_from_ie, p, plane_idx);
if (rc) {
LOGERR("Cannot read %s GSN Address IE\n",
gtphub_plane_idx_names[plane_idx]);
return -1;
}
LOG("Read %s GSN addr %s (%d)\n",
gtphub_plane_idx_names[plane_idx],
gsn_addr_to_str(&addr_from_ie),
addr_from_ie.len);
ie_idx = gtpie_getie(p->ie, ie_type[plane_idx], 0);
if (ie_idx < 0) {
if (ie_mandatory) {
LOGERR("Create PDP Context message invalid:"
" missing IE %d\n", (int)ie_type[plane_idx]);
return -1;
}
tei_from_ie = 0;
}
else
tei_from_ie = ntoh32(p->ie[ie_idx]->tv4.v);
/* Make sure an entry for this peer address with default port
* exists */
struct gtphub_peer_port *peer_from_ie =
gtphub_port_have(hub, &from_bind[plane_idx],
&addr_from_ie,
gtphub_plane_idx_default_port[plane_idx]);
if (tei_from_ie) {
/* Create TEI mapping and replace in GTP packet IE */
uint32_t mapped_tei =
gtphub_tei_mapping_have(hub, plane_idx,
peer_from_ie,
tei_from_ie,
now);
p->ie[ie_idx]->tv4.v = hton32(mapped_tei);
}
/* Replace the GSN address to reflect gtphub. */
rc = gsn_addr_put(&to_bind[plane_idx].local_addr, p, plane_idx);
if (rc) {
LOGERR("Cannot write %s GSN Address IE\n",
gtphub_plane_idx_names[plane_idx]);
return -1;
}
}
return 0;
}
static int gtphub_write(const struct osmo_fd *to,
const struct osmo_sockaddr *to_addr,
const uint8_t *buf, size_t buf_len)
{
errno = 0;
ssize_t sent = sendto(to->fd, buf, buf_len, 0,
(struct sockaddr*)&to_addr->a, to_addr->l);
if (to_addr) {
LOG("to %s\n", osmo_sockaddr_to_str(to_addr));
}
if (sent == -1) {
LOGERR("error: %s\n", strerror(errno));
return -EINVAL;
}
if (sent != buf_len)
LOGERR("sent(%d) != data_len(%d)\n", (int)sent, (int)buf_len);
else
LOG("Sent %d\n%s\n", (int)sent, osmo_hexdump(buf, sent));
return 0;
}
static int from_ggsns_read_cb(struct osmo_fd *from_ggsns_ofd, unsigned int what)
{
unsigned int plane_idx = from_ggsns_ofd->priv_nr;
OSMO_ASSERT(plane_idx < GTPH_PLANE_N);
LOG("\n\n=== reading from GGSN (%s)\n", gtphub_plane_idx_names[plane_idx]);
if (!(what & BSC_FD_READ))
return 0;
struct gtphub *hub = from_ggsns_ofd->data;
static uint8_t buf[4096];
struct osmo_sockaddr from_addr;
struct osmo_sockaddr to_addr;
struct osmo_fd *to_ofd;
size_t len;
len = gtphub_read(from_ggsns_ofd, &from_addr, buf, sizeof(buf));
if (len < 1)
return 0;
len = gtphub_from_ggsns_handle_buf(hub, plane_idx, &from_addr, buf, len,
gtphub_now(),
&to_ofd, &to_addr);
if (len < 1)
return 0;
return gtphub_write(to_ofd, &to_addr, buf, len);
}
static int gtphub_unmap(struct gtphub *hub,
struct gtp_packet_desc *p,
struct gtphub_peer_port *from,
struct gtphub_peer_port *to_proxy,
struct gtphub_peer_port **final_unmapped,
struct gtphub_peer_port **unmapped_from_seq,
struct gtphub_peer_port **unmapped_from_tei)
{
/* Always (try to) unmap sequence and TEI numbers, which need to be
* replaced in the packet. Either way, give precedence to the proxy, if
* configured. */
struct gtphub_peer_port *from_seq = NULL;
struct gtphub_peer_port *from_tei = NULL;
struct gtphub_peer_port *unmapped = NULL;
if (unmapped_from_seq)
*unmapped_from_seq = from_seq;
if (unmapped_from_tei)
*unmapped_from_tei = from_tei;
if (final_unmapped)
*final_unmapped = unmapped;
from_seq = gtphub_unmap_seq(p, from);
if (gtphub_unmap_header_tei(&from_tei, hub, p, from) < 0)
return -1;
struct gtphub_peer *from_peer = from->peer_addr->peer;
if (from_seq && from_tei && (from_seq != from_tei)) {
LOGERR("Seq unmap and TEI unmap yield two different peers. Using seq unmap."
"(from %s %s: seq %d yields %s, tei %u yields %s)\n",
gtphub_plane_idx_names[p->plane_idx],
gtphub_peer_str(from_peer),
(int)p->seq,
gtphub_port_str(from_seq),
(int)p->header_tei,
gtphub_port_str2(from_tei)
);
}
unmapped = (from_seq? from_seq : from_tei);
if (unmapped && to_proxy && (unmapped != to_proxy)) {
LOGERR("Unmap yields a different peer than the configured proxy. Using proxy."
" unmapped: %s proxy: %s\n",
gtphub_port_str(unmapped),
gtphub_port_str2(to_proxy)
);
}
unmapped = (to_proxy? to_proxy : unmapped);
if (!unmapped) {
/* Return no error, but returned pointers are all NULL. */
return 0;
}
LOG("from seq %p; from tei %p; unmapped => %p\n",
from_seq, from_tei, unmapped);
if (unmapped_from_seq)
*unmapped_from_seq = from_seq;
if (unmapped_from_tei)
*unmapped_from_tei = from_tei;
if (final_unmapped)
*final_unmapped = unmapped;
return 0;
}
static int gsn_addr_to_sockaddr(struct gsn_addr *src,
uint16_t port,
struct osmo_sockaddr *dst)
{
return osmo_sockaddr_init_udp(dst, gsn_addr_to_str(src), port);
}
static int gtphub_handle_echo(const struct gtp_packet_desc *p)
{
/* TODO */
return 0;
}
/* Parse buffer as GTP packet, replace elements in-place and return the ofd and
* address to forward to. Return a pointer to the osmo_fd, but copy the
* sockaddr to *to_addr. The reason for this is that the sockaddr may expire at
* any moment, while the osmo_fd is guaranteed to persist. Return the number of
* bytes to forward, 0 or less on failure. */
int gtphub_from_ggsns_handle_buf(struct gtphub *hub,
unsigned int plane_idx,
const struct osmo_sockaddr *from_addr,
uint8_t *buf,
size_t received,
time_t now,
struct osmo_fd **to_ofd,
struct osmo_sockaddr *to_addr)
{
LOG("<- rx from GGSN %s\n", osmo_sockaddr_to_str(from_addr));
*to_ofd = &hub->to_sgsns[plane_idx].ofd;
static struct gtp_packet_desc p;
gtp_decode(buf, received, plane_idx, &p);
if (p.rc <= 0)
return -1;
int rc;
rc = gtphub_handle_echo(&p);
if (rc == 1) {
/* It was en echo. Nothing left to do. */
/* (*to_ofd already set above.) */
osmo_sockaddr_copy(to_addr, from_addr);
return 0;
}
if (rc < 0)
return -1; /* Invalid packet. */
/* If a GGSN proxy is configured, check that it's indeed that proxy
* talking to us. A proxy is a forced 1:1 connection, e.g. to another
* gtphub, so no-one else is allowed to talk to us from that side. */
struct gtphub_peer_port *ggsn = hub->ggsn_proxy[plane_idx];
if (ggsn) {
if (osmo_sockaddr_cmp(&ggsn->sa, from_addr) != 0) {
LOGERR("Rejecting: GGSN proxy configured, but GTP packet"
" received on GGSN bind is from another sender:"
" proxy: %s sender: %s\n",
gtphub_port_str(ggsn),
osmo_sockaddr_to_str(from_addr));
return -1;
}
}
if (!ggsn) {
ggsn = gtphub_port_find_sa(&hub->to_ggsns[plane_idx], from_addr);
}
/* If any PDP context has been created, we already have an entry for
* this GGSN. If we don't have an entry, the GGSN has nothing to tell
* us about. */
if (!ggsn) {
LOGERR("Invalid GGSN peer. Dropping packet.\n");
return -1;
}
LOG("GGSN peer: %s\n", gtphub_port_str(ggsn));
struct gtphub_peer_port *sgsn_from_seq;
struct gtphub_peer_port *sgsn;
if (gtphub_unmap(hub, &p, ggsn,
hub->sgsn_proxy[plane_idx],
&sgsn, &sgsn_from_seq,
NULL /* not interested, got it in &sgsn already */
)
!= 0) {
return -1;
}
if (!sgsn) {
/* A GGSN initiated request would go to a known TEI. So this is
* bogus. */
LOGERR("No SGSN to send to. Dropping packet.\n");
return -1;
}
if (plane_idx == GTPH_PLANE_CTRL) {
/* This may be a Create PDP Context response. If it is, there are other
* addresses in the GTP message to set up apart from the sender. */
if (gtphub_handle_pdp_ctx_ies(hub, hub->to_ggsns,
hub->to_sgsns, &p, now)
!= 0)
return -1;
}
gtphub_check_restart_counter(hub, &p, ggsn);
gtphub_map_restart_counter(hub, &p, ggsn, sgsn);
/* If the GGSN is replying to an SGSN request, the sequence nr has
* already been unmapped above (sgsn_from_seq != NULL), and we need not
* create a new mapping. */
if (!sgsn_from_seq)
gtphub_map_seq(&p, ggsn, sgsn, now);
osmo_sockaddr_copy(to_addr, &sgsn->sa);
return received;
}
static int from_sgsns_read_cb(struct osmo_fd *from_sgsns_ofd, unsigned int what)
{
unsigned int plane_idx = from_sgsns_ofd->priv_nr;
OSMO_ASSERT(plane_idx < GTPH_PLANE_N);
LOG("\n\n=== reading from SGSN (%s)\n", gtphub_plane_idx_names[plane_idx]);
if (!(what & BSC_FD_READ))
return 0;
struct gtphub *hub = from_sgsns_ofd->data;
static uint8_t buf[4096];
struct osmo_sockaddr from_addr;
struct osmo_sockaddr to_addr;
struct osmo_fd *to_ofd;
size_t len;
len = gtphub_read(from_sgsns_ofd, &from_addr, buf, sizeof(buf));
if (len < 1)
return 0;
len = gtphub_from_sgsns_handle_buf(hub, plane_idx, &from_addr, buf, len,
gtphub_now(),
&to_ofd, &to_addr);
if (len < 1)
return 0;
return gtphub_write(to_ofd, &to_addr, buf, len);
}
/* Analogous to gtphub_from_ggsns_handle_buf(), see the comment there. */
int gtphub_from_sgsns_handle_buf(struct gtphub *hub,
unsigned int plane_idx,
const struct osmo_sockaddr *from_addr,
uint8_t *buf,
size_t received,
time_t now,
struct osmo_fd **to_ofd,
struct osmo_sockaddr *to_addr)
{
LOG("-> rx from SGSN %s\n", osmo_sockaddr_to_str(from_addr));
*to_ofd = &hub->to_ggsns[plane_idx].ofd;
static struct gtp_packet_desc p;
gtp_decode(buf, received, plane_idx, &p);
if (p.rc <= 0)
return -1;
int rc;
rc = gtphub_handle_echo(&p);
if (rc == 1) {
/* It was en echo. Nothing left to do. */
/* (*to_ofd already set above.) */
osmo_sockaddr_copy(to_addr, from_addr);
return 0;
}
if (rc < 0)
return -1; /* Invalid packet. */
/* If an SGSN proxy is configured, check that it's indeed that proxy
* talking to us. A proxy is a forced 1:1 connection, e.g. to another
* gtphub, so no-one else is allowed to talk to us from that side. */
struct gtphub_peer_port *sgsn = hub->sgsn_proxy[plane_idx];
if (sgsn) {
if (osmo_sockaddr_cmp(&sgsn->sa, from_addr) != 0) {
LOGERR("Rejecting: GGSN proxy configured, but GTP packet"
" received on GGSN bind is from another sender:"
" proxy: %s sender: %s\n",
gtphub_port_str(sgsn),
osmo_sockaddr_to_str(from_addr));
return -1;
}
}
if (!sgsn) {
/* If any contact has been made before, we already have an
* entry for this SGSN. */
sgsn = gtphub_port_find_sa(&hub->to_sgsns[plane_idx], from_addr);
}
if (!sgsn) {
/* A new peer. If this is on the Ctrl plane, an SGSN may make
* first contact without being known yet, so create the peer
* struct for the current sender. */
if (plane_idx != GTPH_PLANE_CTRL) {
LOGERR("User plane peer was not announced by PDP Context, discarding: %s\n",
osmo_sockaddr_to_str(from_addr));
return -1;
}
struct gsn_addr from_gsna;
uint16_t from_port;
if (gsn_addr_from_sockaddr(&from_gsna, &from_port, from_addr) != 0)
return -1;
sgsn = gtphub_port_have(hub, &hub->to_sgsns[plane_idx],
&from_gsna, from_port);
}
if (!sgsn) {
/* This could theoretically happen for invalid address data or somesuch. */
LOGERR("Invalid SGSN peer. Dropping packet.\n");
return -1;
}
LOG("SGSN peer: %s\n", gtphub_port_str(sgsn));
struct gtphub_peer_port *ggsn_from_seq;
struct gtphub_peer_port *ggsn;
if (gtphub_unmap(hub, &p, sgsn,
hub->ggsn_proxy[plane_idx],
&ggsn, &ggsn_from_seq,
NULL /* not interested, got it in &ggsn already */
)
!= 0) {
return -1;
}
/* See what our GGSN guess would be from the packet data per se. */
/* TODO maybe not do this always? */
struct gtphub_peer_port *ggsn_from_packet;
ggsn_from_packet = gtphub_resolve_ggsn(hub, &p);
if (ggsn_from_packet && ggsn
&& (ggsn_from_packet != ggsn)) {
LOGERR("GGSN implied from packet does not match unmapped"
" GGSN, using unmapped GGSN:"
" from packet: %s unmapped: %s\n",
gtphub_port_str(ggsn_from_packet),
gtphub_port_str2(ggsn));
/* TODO return -1; ? */
}
if (!ggsn)
ggsn = ggsn_from_packet;
if (!ggsn) {
LOGERR("No GGSN to send to. Dropping packet.\n");
return -1;
}
if (plane_idx == GTPH_PLANE_CTRL) {
/* This may be a Create PDP Context requst. If it is, there are other
* addresses in the GTP message to set up apart from the sender. */
if (gtphub_handle_pdp_ctx_ies(hub, hub->to_sgsns,
hub->to_ggsns, &p, now)
!= 0)
return -1;
}
gtphub_check_restart_counter(hub, &p, sgsn);
gtphub_map_restart_counter(hub, &p, sgsn, ggsn);
/* If the SGSN is replying to a GGSN request, the sequence nr has
* already been unmapped above (unmap_ggsn != NULL), and we need not
* create a new outgoing sequence map. */
if (!ggsn_from_seq)
gtphub_map_seq(&p, sgsn, ggsn, now);
osmo_sockaddr_copy(to_addr, &ggsn->sa);
return received;
}
static int gtphub_gc_peer_port(struct gtphub_peer_port *pp)
{
return pp->ref_count == 0;
}
static int gtphub_gc_peer_addr(struct gtphub_peer_addr *pa)
{
struct gtphub_peer_port *pp, *npp;
llist_for_each_entry_safe(pp, npp, &pa->ports, entry) {
if (gtphub_gc_peer_port(pp)) {
LOG("expired: peer %s\n",
gtphub_port_str(pp));
gtphub_peer_port_del(pp);
}
}
return llist_empty(&pa->ports);
}
static int gtphub_gc_peer(struct gtphub_peer *p)
{
struct gtphub_peer_addr *pa, *npa;
llist_for_each_entry_safe(pa, npa, &p->addresses, entry) {
if (gtphub_gc_peer_addr(pa)) {
gtphub_peer_addr_del(pa);
}
}
/* Note that there's a ref_count in each gtphub_peer_port instance
* listed within p->addresses, referenced by TEI mappings from
* hub->tei_map. As long as those don't expire, this peer will stay. */
LOG("gc peer %p llist_empty %d seq_map_empty %d\n", p,
(int)llist_empty(&p->addresses), (int) nr_map_empty(&p->seq_map));
if (! nr_map_empty(&p->seq_map)) {
printf("not empty\n");
struct nr_mapping *nrm;
llist_for_each_entry(nrm, &p->seq_map.mappings, entry) {
printf("%p %s %d -> %d\n",
nrm->origin, gtphub_port_str(nrm->origin),nrm->orig, nrm->repl);
}
}
return llist_empty(&p->addresses)
&& nr_map_empty(&p->seq_map);
}
static void gtphub_gc_bind(struct gtphub_bind *b)
{
struct gtphub_peer *p, *n;
llist_for_each_entry_safe(p, n, &b->peers, entry) {
if (gtphub_gc_peer(p)) {
gtphub_peer_del(p);
}
}
}
void gtphub_gc(struct gtphub *hub, time_t now)
{
int expired;
expired = expiry_tick(&hub->expire_seq_maps, now);
expired += expiry_tick(&hub->expire_tei_maps, now);
/* ... */
if (expired) {
int i;
for (i = 0; i < GTPH_PLANE_N; i++) {
gtphub_gc_bind(&hub->to_sgsns[i]);
gtphub_gc_bind(&hub->to_ggsns[i]);
}
}
}
static void gtphub_gc_cb(void *data)
{
struct gtphub *hub = data;
gtphub_gc(hub, gtphub_now());
osmo_timer_schedule(&hub->gc_timer, GTPH_GC_TICK_SECONDS, 0);
}
static void gtphub_gc_start(struct gtphub *hub)
{
hub->gc_timer.cb = gtphub_gc_cb;
hub->gc_timer.data = hub;
osmo_timer_schedule(&hub->gc_timer, GTPH_GC_TICK_SECONDS, 0);
}
/* called by unit tests */
void gtphub_init(struct gtphub *hub)
{
gtphub_zero(hub);
expiry_init(&hub->expire_seq_maps, GTPH_SEQ_MAPPING_EXPIRY_SECS);
expiry_init(&hub->expire_tei_maps, GTPH_TEI_MAPPING_EXPIRY_MINUTES * 60);
int plane_idx;
for (plane_idx = 0; plane_idx < GTPH_PLANE_N; plane_idx++) {
nr_pool_init(&hub->tei_pool[plane_idx]);
nr_map_init(&hub->tei_map[plane_idx],
&hub->tei_pool[plane_idx],
&hub->expire_tei_maps);
gtphub_bind_init(&hub->to_ggsns[plane_idx]);
gtphub_bind_init(&hub->to_sgsns[plane_idx]);
}
}
static int gtphub_make_proxy(struct gtphub *hub,
struct gtphub_peer_port **pp,
struct gtphub_bind *bind,
const struct gtphub_cfg_addr *addr)
{
if (!addr->addr_str)
return 0;
struct gsn_addr gsna;
if (gsn_addr_from_str(&gsna, addr->addr_str) != 0)
return -1;
*pp = gtphub_port_have(hub, bind, &gsna, addr->port);
/* This is *the* proxy. Make sure it is never expired. */
gtphub_port_ref_count_inc(*pp);
return 0;
}
int gtphub_start(struct gtphub *hub, struct gtphub_cfg *cfg)
{
int rc;
gtphub_init(hub);
int plane_idx;
for (plane_idx = 0; plane_idx < GTPH_PLANE_N; plane_idx++) {
rc = gtphub_bind_start(&hub->to_ggsns[plane_idx],
&cfg->to_ggsns[plane_idx],
from_ggsns_read_cb, hub, plane_idx);
if (rc) {
LOGERR("Failed to bind for GGSNs (%s)\n",
gtphub_plane_idx_names[plane_idx]);
return rc;
}
rc = gtphub_bind_start(&hub->to_sgsns[plane_idx],
&cfg->to_sgsns[plane_idx],
from_sgsns_read_cb, hub, plane_idx);
if (rc) {
LOGERR("Failed to bind for SGSNs (%s)\n",
gtphub_plane_idx_names[plane_idx]);
return rc;
}
}
for (plane_idx = 0; plane_idx < GTPH_PLANE_N; plane_idx++) {
if (gtphub_make_proxy(hub,
&hub->sgsn_proxy[plane_idx],
&hub->to_sgsns[plane_idx],
&cfg->sgsn_proxy[plane_idx])
!= 0) {
LOGERR("Cannot configure SGSN proxy %s port %d.\n",
cfg->sgsn_proxy[plane_idx].addr_str,
(int)cfg->sgsn_proxy[plane_idx].port);
return -1;
}
if (gtphub_make_proxy(hub,
&hub->ggsn_proxy[plane_idx],
&hub->to_ggsns[plane_idx],
&cfg->ggsn_proxy[plane_idx])
!= 0) {
LOGERR("Cannot configure GGSN proxy.\n");
return -1;
}
}
for (plane_idx = 0; plane_idx < GTPH_PLANE_N; plane_idx++) {
if (hub->sgsn_proxy[plane_idx])
LOG("Using SGSN %s proxy %s\n",
gtphub_plane_idx_names[plane_idx],
gtphub_port_str(hub->sgsn_proxy[plane_idx]));
}
for (plane_idx = 0; plane_idx < GTPH_PLANE_N; plane_idx++) {
if (hub->sgsn_proxy[plane_idx])
LOG("Using GGSN %s proxy %s\n",
gtphub_plane_idx_names[plane_idx],
gtphub_port_str(hub->ggsn_proxy[plane_idx]));
}
gtphub_gc_start(hub);
return 0;
}
static struct gtphub_peer_addr *gtphub_peer_find_addr(const struct gtphub_peer *peer,
const struct gsn_addr *addr)
{
struct gtphub_peer_addr *a;
llist_for_each_entry(a, &peer->addresses, entry) {
if (gsn_addr_same(&a->addr, addr))
return a;
}
return NULL;
}
static struct gtphub_peer_port *gtphub_addr_find_port(const struct gtphub_peer_addr *a,
uint16_t port)
{
OSMO_ASSERT(port);
struct gtphub_peer_port *pp;
llist_for_each_entry(pp, &a->ports, entry) {
if (pp->port == port)
return pp;
}
return NULL;
}
static struct gtphub_peer_addr *gtphub_addr_find(const struct gtphub_bind *bind,
const struct gsn_addr *addr)
{
struct gtphub_peer *peer;
llist_for_each_entry(peer, &bind->peers, entry) {
struct gtphub_peer_addr *a = gtphub_peer_find_addr(peer, addr);
if (a)
return a;
}
return NULL;
}
static struct gtphub_peer_port *gtphub_port_find(const struct gtphub_bind *bind,
const struct gsn_addr *addr,
uint16_t port)
{
struct gtphub_peer_addr *a = gtphub_addr_find(bind, addr);
if (!a)
return NULL;
return gtphub_addr_find_port(a, port);
}
struct gtphub_peer_port *gtphub_port_find_sa(const struct gtphub_bind *bind,
const struct osmo_sockaddr *addr)
{
struct gsn_addr gsna;
uint16_t port;
gsn_addr_from_sockaddr(&gsna, &port, addr);
return gtphub_port_find(bind, &gsna, port);
}
static struct gtphub_peer *gtphub_peer_new(struct gtphub *hub,
struct gtphub_bind *bind)
{
struct gtphub_peer *peer = talloc_zero(osmo_gtphub_ctx, struct gtphub_peer);
OSMO_ASSERT(peer);
INIT_LLIST_HEAD(&peer->addresses);
nr_pool_init(&peer->seq_pool);
nr_map_init(&peer->seq_map, &peer->seq_pool, &hub->expire_seq_maps);
/* TODO use something random to pick the initial sequence nr.
0x6d31 produces the ASCII character sequence 'm1', currently used in
gtphub_nc_test.sh. */
peer->seq_pool.last_nr = 0x6d31 - 1;
llist_add(&peer->entry, &bind->peers);
return peer;
}
static struct gtphub_peer_addr *gtphub_peer_add_addr(struct gtphub_peer *peer,
const struct gsn_addr *addr)
{
struct gtphub_peer_addr *a;
a = talloc_zero(osmo_gtphub_ctx, struct gtphub_peer_addr);
OSMO_ASSERT(a);
a->peer = peer;
gsn_addr_copy(&a->addr, addr);
INIT_LLIST_HEAD(&a->ports);
llist_add(&a->entry, &peer->addresses);
return a;
}
static struct gtphub_peer_addr *gtphub_addr_have(struct gtphub *hub,
struct gtphub_bind *bind,
const struct gsn_addr *addr)
{
struct gtphub_peer_addr *a = gtphub_addr_find(bind, addr);
if (a)
return a;
/* If we haven't found an address, that means we need to create an
* entirely new peer for the new address. More addresses may be added
* to this peer later, but not via this function. */
struct gtphub_peer *peer = gtphub_peer_new(hub, bind);
return gtphub_peer_add_addr(peer, addr);
}
static struct gtphub_peer_port *gtphub_addr_add_port(struct gtphub_peer_addr *a,
uint16_t port)
{
struct gtphub_peer_port *pp;
pp = talloc_zero(osmo_gtphub_ctx, struct gtphub_peer_port);
OSMO_ASSERT(pp);
pp->peer_addr = a;
pp->port = port;
if (gsn_addr_to_sockaddr(&a->addr, port, &pp->sa) != 0) {
talloc_free(pp);
return NULL;
}
llist_add(&pp->entry, &a->ports);
LOG("New peer: %s port %d\n",
gsn_addr_to_str(&a->addr),
(int)port);
return pp;
}
static struct gtphub_peer_port *gtphub_port_have(struct gtphub *hub,
struct gtphub_bind *bind,
const struct gsn_addr *addr,
uint16_t port)
{
struct gtphub_peer_addr *a = gtphub_addr_have(hub, bind, addr);
struct gtphub_peer_port *pp = gtphub_addr_find_port(a, port);
if (pp)
return pp;
return gtphub_addr_add_port(a, port);
}
/* port_override: <=0: use port from addr; >0: use this number as port. Return
* NULL if the address cannot be parsed. */
static struct gtphub_peer_port *gtphub_port_have_sockaddr(struct gtphub *hub,
struct gtphub_bind *bind,
const struct osmo_sockaddr *addr,
int port_override)
{
struct gsn_addr gsna;
uint16_t port;
if (gsn_addr_from_sockaddr(&gsna, &port, addr) != 0)
return NULL;
if (port_override > 0)
port = port_override;
return gtphub_port_have(hub, bind, &gsna, port);
}
static struct gtphub_peer_port *gtphub_have_ggsn(struct gtphub *hub,
struct osmo_sockaddr *addr,
unsigned int plane_idx,
int port_override)
{
if (port_override == 0)
port_override = gtphub_plane_idx_default_port[plane_idx];
return gtphub_port_have_sockaddr(hub, &hub->to_ggsns[plane_idx], addr,
port_override);
}
static struct gtphub_peer_port *gtphub_resolve_ggsn(struct gtphub *hub,
struct gtp_packet_desc *p)
{
int rc;
struct osmo_sockaddr addr;
rc = gtphub_resolve_ggsn_addr(hub, &addr, p);
if (rc < 0)
return NULL;
return gtphub_have_ggsn(hub, &addr, p->plane_idx, -1);
}
/* TODO move to osmocom/core/socket.c ? */
/* The caller is required to call freeaddrinfo(*result), iff zero is returned. */
/* use this in osmo_sock_init() to remove dup. */
static int _osmo_getaddrinfo(struct addrinfo **result,
uint16_t family, uint16_t type, uint8_t proto,
const char *host, uint16_t port)
{
struct addrinfo hints;
char portbuf[16];
sprintf(portbuf, "%u", port);
memset(&hints, '\0', sizeof(struct addrinfo));
hints.ai_family = family;
if (type == SOCK_RAW) {
/* Workaround for glibc, that returns EAI_SERVICE (-8) if
* SOCK_RAW and IPPROTO_GRE is used.
*/
hints.ai_socktype = SOCK_DGRAM;
hints.ai_protocol = IPPROTO_UDP;
} else {
hints.ai_socktype = type;
hints.ai_protocol = proto;
}
return getaddrinfo(host, portbuf, &hints, result);
}
/* TODO move to osmocom/core/socket.c ? */
int osmo_sockaddr_init(struct osmo_sockaddr *addr,
uint16_t family, uint16_t type, uint8_t proto,
const char *host, uint16_t port)
{
struct addrinfo *res;
int rc;
rc = _osmo_getaddrinfo(&res, family, type, proto, host, port);
if (rc != 0) {
LOGERR("getaddrinfo returned error %d\n", (int)rc);
return -EINVAL;
}
OSMO_ASSERT(res->ai_addrlen <= sizeof(addr->a));
memcpy(&addr->a, res->ai_addr, res->ai_addrlen);
addr->l = res->ai_addrlen;
freeaddrinfo(res);
return 0;
}
int osmo_sockaddr_to_strs(char *addr_str, size_t addr_str_len,
char *port_str, size_t port_str_len,
const struct osmo_sockaddr *addr,
int flags)
{
int rc;
if ((addr->l < 1) || (addr->l > sizeof(addr->a))) {
LOGP(DGTPHUB, LOGL_ERROR, "Invalid address size: %d\n", addr->l);
return -1;
}
if (addr->l > sizeof(addr->a)) {
LOGP(DGTPHUB, LOGL_ERROR, "Invalid address: too long: %d\n", addr->l);
return -1;
}
rc = getnameinfo((struct sockaddr*)&addr->a, addr->l,
addr_str, addr_str_len,
port_str, port_str_len,
flags);
if (rc)
LOGP(DGTPHUB, LOGL_ERROR, "Invalid address: %s: %s\n", gai_strerror(rc),
osmo_hexdump((uint8_t*)&addr->a, addr->l));
return rc;
}
const char *osmo_sockaddr_to_strb(const struct osmo_sockaddr *addr,
char *buf, size_t buf_len)
{
const int portbuf_len = 6;
OSMO_ASSERT(buf_len > portbuf_len);
char *portbuf = buf + buf_len - portbuf_len;
buf_len -= portbuf_len;
if (osmo_sockaddr_to_strs(buf, buf_len,
portbuf, portbuf_len,
addr,
NI_NUMERICHOST | NI_NUMERICSERV))
return NULL;
char *pos = buf + strnlen(buf, buf_len-1);
size_t len = buf_len - (pos - buf);
snprintf(pos, len, " port %s", portbuf);
buf[buf_len-1] = '\0';
return buf;
}
const char *osmo_sockaddr_to_str(const struct osmo_sockaddr *addr)
{
static char buf[256];
const char *result = osmo_sockaddr_to_strb(addr, buf, sizeof(buf));
if (! result)
return "(invalid)";
return result;
}
int osmo_sockaddr_cmp(const struct osmo_sockaddr *a, const struct osmo_sockaddr *b)
{
if (a == b)
return 0;
if (!a)
return -1;
if (!b)
return 1;
if (a->l != b->l) {
/* Lengths are not the same, but determine the order. Will
* anyone ever sort a list by osmo_sockaddr though...? */
int cmp = memcmp(&a->a, &b->a, (a->l < b->l)? a->l : b->l);
if (cmp == 0) {
if (a->l < b->l)
return -1;
else
return 1;
}
return cmp;
}
return memcmp(&a->a, &b->a, a->l);
}
void osmo_sockaddr_copy(struct osmo_sockaddr *dst, const struct osmo_sockaddr *src)
{
OSMO_ASSERT(src->l <= sizeof(dst->a));
memcpy(&dst->a, &src->a, src->l);
dst->l = src->l;
}
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