/* 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 <unistd.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <osmocom/gtp/gtp.h>
#include <osmocom/gtp/gtpie.h>
#include <osmocom/gtphub/gtphub.h>
#include <osmocom/sgsn/debug.h>
#include <osmocom/sgsn/gprs_utils.h>
#include <osmocom/core/utils.h>
#include <osmocom/core/logging.h>
#include <osmocom/core/socket.h>
#include <osmocom/core/rate_ctr.h>
#include <osmocom/core/stats.h>
#include <osmocom/gsm/apn.h>
static const int GTPH_GC_TICK_SECONDS = 1;
void *osmo_gtphub_ctx;
/* Convenience makro, note: only within this C file. */
#define LOG(level, fmt, args...) \
LOGP(DGTPHUB, level, 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 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_C = 2, /* a real packet with IEs */
GTP_RC_PDU_U = 3, /* a real packet with User data */
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_rx;
uint32_t header_tei;
int rc; /* enum gtp_rc */
unsigned int plane_idx;
unsigned int side_idx;
struct gtphub_tunnel *tun;
time_t timestamp;
union gtpie_member *ie[GTPIE_SIZE];
};
struct pending_delete {
struct llist_head entry;
struct expiring_item expiry_entry;
struct gtphub_tunnel *tun;
uint8_t teardown_ind;
uint8_t nsapi;
};
/* counters */
enum gtphub_counters_io {
GTPH_CTR_PKTS_IN = 0,
GTPH_CTR_PKTS_OUT,
GTPH_CTR_BYTES_IN,
GTPH_CTR_BYTES_OUT
};
static const struct rate_ctr_desc gtphub_counters_io_desc[] = {
{ "packets.in", "Packets ( In)" },
{ "packets.out", "Packets (Out)" },
{ "bytes.in", "Bytes ( In)" },
{ "bytes.out", "Bytes (Out)" },
};
static const struct rate_ctr_group_desc gtphub_ctrg_io_desc = {
.group_name_prefix = "gtphub:bind",
.group_description = "I/O Statistics",
.num_ctr = ARRAY_SIZE(gtphub_counters_io_desc),
.ctr_desc = gtphub_counters_io_desc,
.class_id = OSMO_STATS_CLASS_GLOBAL,
};
/* support */
static const char *gtp_type_str(uint8_t type)
{
switch (type) {
case 1:
return " (Echo Request)";
case 2:
return " (Echo Response)";
case 16:
return " (Create PDP Ctx Request)";
case 17:
return " (Create PDP Ctx Response)";
case 18:
return " (Update PDP Ctx Request)";
case 19:
return " (Update PDP Ctx Response)";
case 20:
return " (Delete PDP Ctx Request)";
case 21:
return " (Delete PDP Ctx Response)";
case 255:
return " (User Data)";
default:
return "";
}
}
void gsn_addr_copy(struct gsn_addr *gsna, const struct gsn_addr *src)
{
*gsna = *src;
}
int gsn_addr_from_sockaddr(struct gsn_addr *gsna, uint16_t *port,
const struct sgsn_sockaddr *sa)
{
char addr_str[256];
char port_str[6];
if (sgsn_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)
{
if ((!gsna) || (!numeric_addr_str))
return -1;
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) {
LOG(LOGL_ERROR, "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) {
LOG(LOGL_ERROR, "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_C)
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_C)
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(LOGL_ERROR, "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) {
LOG(LOGL_ERROR, "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_rx = 0; /* TODO */
p->header_tei = p->header_tei_rx;
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)) {
LOG(LOGL_ERROR, "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(LOGL_DEBUG, "GTP v0 TID = %" PRIu64 "\n", pheader->tid);
p->header_len = GTP0_HEADER_SIZE;
p->rc = GTP_RC_PDU_C;
}
/* 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)){
LOG(LOGL_ERROR, "GTP packet too short: %d\n", p->data_len);
p->rc = GTP_RC_TOOSHORT;
return;
}
p->type = ntoh8(pheader->type);
p->header_tei_rx = ntoh32(pheader->tei);
p->header_tei = p->header_tei_rx;
p->seq = ntoh16(pheader->seq);
LOG(LOGL_DEBUG, "| GTPv1\n");
LOG(LOGL_DEBUG, "| type = %" PRIu8 " 0x%02" PRIx8 "\n", p->type, p->type);
LOG(LOGL_DEBUG, "| length = %" PRIu16 " 0x%04" PRIx16 "\n", ntoh16(pheader->length), ntoh16(pheader->length));
LOG(LOGL_DEBUG, "| TEI = %" PRIu32 " 0x%08" PRIx32 "\n", p->header_tei_rx, p->header_tei_rx);
LOG(LOGL_DEBUG, "| seq = %" PRIu16 " 0x%04" PRIx16 "\n", p->seq, p->seq);
LOG(LOGL_DEBUG, "| npdu = %" PRIu8 " 0x%02" PRIx8 "\n", pheader->npdu, pheader->npdu);
LOG(LOGL_DEBUG, "| 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 */
int announced_len = ntoh16(pheader->length) + GTP1_HEADER_SIZE_SHORT;
if (p->data_len != announced_len) {
LOG(LOGL_ERROR, "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_C;
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) {
LOG(LOGL_ERROR, "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:
LOG(LOGL_ERROR, "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[], int i, uint8_t *imsi)
{
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[], int i, uint8_t *nsapi)
{
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 int imsi_to_str(uint8_t *imsi, const char **imsi_str)
{
static char str[17];
int i;
for (i = 0; i < 8; i++) {
char c;
c = imsi_digit_to_char(imsi[i]);
if (c == '?')
return -1;
str[2*i] = c;
c = imsi_digit_to_char(imsi[i] >> 4);
if (c == '?')
return -1;
str[2*i + 1] = c;
}
str[16] = '\0';
*imsi_str = str;
return 1;
}
/* Return 0 if not present, 1 if present and decoded successfully, -1 if
* present but cannot be decoded. */
static int get_ie_imsi_str(union gtpie_member *ie[], int i,
const char **imsi_str)
{
uint8_t imsi_buf[8];
if (!get_ie_imsi(ie, i, imsi_buf))
return 0;
return imsi_to_str(imsi_buf, imsi_str);
}
/* Return 0 if not present, 1 if present and decoded successfully, -1 if
* present but cannot be decoded. */
static int get_ie_apn_str(union gtpie_member *ie[], const char **apn_str)
{
static char apn_buf[APN_MAXLEN+1];
unsigned int len;
if (gtpie_gettlv(ie, GTPIE_APN, 0,
&len, apn_buf, sizeof(apn_buf)) != 0)
return 0;
if (len < 2) {
LOG(LOGL_ERROR, "APN IE: invalid length: %d\n",
(int)len);
return -1;
}
if (len > (sizeof(apn_buf) - 1))
len = sizeof(apn_buf) - 1;
apn_buf[len] = '\0';
*apn_str = osmo_apn_to_str(apn_buf, (uint8_t*)apn_buf, len);
if (!(*apn_str)) {
LOG(LOGL_ERROR, "APN IE: present but cannot be decoded: %s\n",
osmo_hexdump((uint8_t*)apn_buf, len));
return -1;
}
return 1;
}
/* 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_side_idx,
unsigned int from_plane_idx,
struct gtp_packet_desc *res,
time_t now)
{
ZERO_STRUCT(res);
res->data = (union gtp_packet*)data;
res->data_len = data_len;
res->side_idx = from_side_idx;
res->plane_idx = from_plane_idx;
res->timestamp = now;
validate_gtp_header(res);
if (res->rc <= 0)
return;
LOG(LOGL_DEBUG, "Valid GTP header (v%d)\n", res->version);
if (from_plane_idx == GTPH_PLANE_USER) {
res->rc = GTP_RC_PDU_U;
return;
}
if (res->rc != GTP_RC_PDU_C) {
LOG(LOGL_DEBUG, "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;
LOG(LOGL_ERROR, "INVALID: cannot decode IEs."
" Dropping GTP packet%s.\n",
gtp_type_str(res->type)
);
return;
}
#if 1
/* TODO if (<loglevel is debug>)
(waiting for a commit from jerlbeck) */
int i;
for (i = 0; i < 10; i++) {
const char *imsi;
if (get_ie_imsi_str(res->ie, i, &imsi) < 1)
break;
LOG(LOGL_DEBUG, "| IMSI %s\n", imsi);
}
for (i = 0; i < 10; i++) {
uint8_t nsapi;
if (!get_ie_nsapi(res->ie, i, &nsapi))
break;
LOG(LOGL_DEBUG, "| NSAPI %d\n", (int)nsapi);
}
for (i = 0; i < 2; i++) {
struct gsn_addr addr;
if (gsn_addr_get(&addr, res, i) == 0)
LOG(LOGL_DEBUG, "| 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(LOGL_DEBUG, "| 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(LOGL_DEBUG, "| 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;
OSMO_ASSERT(llist_empty(&exq->items)
|| (item->expiry
>= llist_last_entry(&exq->items, struct expiring_item, entry)->expiry));
/* 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 {
/* The items are added sorted by expiry. So when we hit
* an unexpired entry, only more unexpired ones will
* follow. */
break;
}
}
return expired;
}
void expiry_clear(struct expiry *exq)
{
struct expiring_item *m, *n;
llist_for_each_entry_safe(m, n, &exq->items, entry) {
expiring_item_del(m);
}
}
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, nr_t nr_min, nr_t nr_max)
{
*pool = (struct nr_pool){
.nr_min = nr_min,
.nr_max = nr_max,
.last_nr = nr_max
};
}
nr_t nr_pool_next(struct nr_pool *pool)
{
if (pool->last_nr >= pool->nr_max)
pool->last_nr = pool->nr_min;
else
pool->last_nr ++;
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);
nr_map_refresh(map, mapping, now);
}
void nr_map_refresh(struct nr_map *map, struct nr_mapping *mapping, time_t now)
{
if (!map->add_items_to_expiry)
return;
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,
};
const char* const gtphub_side_idx_names[GTPH_SIDE_N] = {
"SGSN",
"GGSN",
};
time_t gtphub_now(void)
{
struct timespec now_tp;
OSMO_ASSERT(osmo_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)
{
OSMO_ASSERT(llist_empty(&peer->addresses));
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);
rate_ctr_group_free(pp->counters_io);
talloc_free(pp);
}
/* From the information in the gtp_packet_desc, return the address of a GGSN.
* Return -1 on error. */
static int gtphub_resolve_ggsn(struct gtphub *hub,
struct gtp_packet_desc *p,
struct gtphub_peer_port **pp);
/* See gtphub_ext.c (wrapped by unit test) */
struct gtphub_peer_port *gtphub_resolve_ggsn_addr(struct gtphub *hub,
const char *imsi_str,
const char *apn_ni_str);
int gtphub_ares_init(struct gtphub *hub);
static void gtphub_zero(struct gtphub *hub)
{
ZERO_STRUCT(hub);
INIT_LLIST_HEAD(&hub->ggsn_lookups);
INIT_LLIST_HEAD(&hub->resolved_ggsns);
}
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) {
LOG(LOGL_FATAL, "Cannot bind: empty address.\n");
return -1;
}
if (!addr->port) {
LOG(LOGL_FATAL, "Cannot bind: zero port not permitted.\n");
return -1;
}
osmo_fd_setup(ofd, -1, OSMO_FD_READ, cb, data, 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) {
LOG(LOGL_FATAL, "Cannot bind to %s port %d (rc %d)\n",
addr->addr_str, (int)addr->port, rc);
return -1;
}
return 0;
}
static void gtphub_sock_close(struct osmo_fd *ofd)
{
close(ofd->fd);
osmo_fd_unregister(ofd);
ofd->cb = NULL;
}
static void gtphub_bind_init(struct gtphub_bind *b, uint32_t idx)
{
ZERO_STRUCT(b);
INIT_LLIST_HEAD(&b->peers);
b->counters_io = rate_ctr_group_alloc(osmo_gtphub_ctx,
>phub_ctrg_io_desc, idx);
OSMO_ASSERT(b->counters_io);
}
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)
{
LOG(LOGL_DEBUG, "Starting bind %s\n", b->label);
if (gsn_addr_from_str(&b->local_addr, cfg->bind.addr_str) != 0) {
LOG(LOGL_FATAL, "Invalid bind address for %s: %s\n",
b->label, cfg->bind.addr_str);
return -1;
}
if (gtphub_sock_init(&b->ofd, &cfg->bind, cb, cb_data, ofd_id) != 0) {
LOG(LOGL_FATAL, "Cannot bind for %s: %s\n",
b->label, cfg->bind.addr_str);
return -1;
}
b->local_port = cfg->bind.port;
return 0;
}
static void gtphub_bind_free(struct gtphub_bind *b)
{
OSMO_ASSERT(llist_empty(&b->peers));
if (b->counters_io)
rate_ctr_group_free(b->counters_io);
}
static void gtphub_bind_stop(struct gtphub_bind *b) {
gtphub_sock_close(&b->ofd);
gtphub_bind_free(b);
}
/* Recv datagram from from->fd, 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 sgsn_sockaddr *from_addr,
uint8_t *buf, size_t buf_len)
{
OSMO_ASSERT(from_addr);
/* recvfrom requires the available length set in *from_addr_len. */
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) {
LOG((errno == EAGAIN? LOGL_DEBUG : LOGL_ERROR),
"error: %s\n", strerror(errno));
return 0;
}
LOG(LOGL_DEBUG, "Received %d bytes from %s: %s%s\n",
(int)received, sgsn_sockaddr_to_str(from_addr),
osmo_hexdump(buf, received > 1000? 1000 : received),
received > 1000 ? "..." : "");
return received;
}
static inline void gtphub_port_ref_count_inc(struct gtphub_peer_port *pp)
{
OSMO_ASSERT(pp);
OSMO_ASSERT(pp->ref_count < UINT_MAX);
pp->ref_count++;
}
static inline void gtphub_port_ref_count_dec(struct gtphub_peer_port *pp)
{
OSMO_ASSERT(pp);
OSMO_ASSERT(pp->ref_count > 0);
pp->ref_count--;
}
static 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;
}
static 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(void)
{
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;
}
#define APPEND(args...) \
l = snprintf(pos, left, args); \
pos += l; \
left -= l
static const char *gtphub_tunnel_side_str(struct gtphub_tunnel *tun,
int side_idx)
{
static char buf[256];
char *pos = buf;
int left = sizeof(buf);
int l;
struct gtphub_tunnel_endpoint *c, *u;
c = &tun->endpoint[side_idx][GTPH_PLANE_CTRL];
u = &tun->endpoint[side_idx][GTPH_PLANE_USER];
/* print both only if they differ. */
if (!c->peer) {
APPEND("(uninitialized)");
} else {
APPEND("%s", gsn_addr_to_str(&c->peer->peer_addr->addr));
}
if (!u->peer) {
if (c->peer) {
APPEND("/(uninitialized)");
}
} else if ((!c->peer)
|| (!gsn_addr_same(&u->peer->peer_addr->addr,
&c->peer->peer_addr->addr))) {
APPEND("/%s", gsn_addr_to_str(&u->peer->peer_addr->addr));
}
APPEND(" (TEI C=%x U=%x)",
c->tei_orig,
u->tei_orig);
return buf;
}
const char *gtphub_tunnel_str(struct gtphub_tunnel *tun)
{
static char buf[512];
char *pos = buf;
int left = sizeof(buf);
int l;
if (!tun)
return "null-tunnel";
APPEND("TEI=%x: ", tun->tei_repl);
APPEND("%s", gtphub_tunnel_side_str(tun, GTPH_SIDE_SGSN));
APPEND(" <-> %s", gtphub_tunnel_side_str(tun, GTPH_SIDE_GGSN));
return buf;
}
#undef APPEND
void gtphub_tunnel_endpoint_set_peer(struct gtphub_tunnel_endpoint *te,
struct gtphub_peer_port *pp)
{
if (te->peer)
gtphub_port_ref_count_dec(te->peer);
te->peer = pp;
if (te->peer)
gtphub_port_ref_count_inc(te->peer);
}
int gtphub_tunnel_complete(struct gtphub_tunnel *tun)
{
if (!tun)
return 0;
if (!tun->tei_repl)
return 0;
int side_idx;
int plane_idx;
for_each_side_and_plane(side_idx, plane_idx) {
struct gtphub_tunnel_endpoint *te =
&tun->endpoint[side_idx][plane_idx];
if (!(te->peer && te->tei_orig))
return 0;
}
return 1;
}
static void gtphub_tunnel_del_cb(struct expiring_item *expi)
{
struct gtphub_tunnel *tun = container_of(expi,
struct gtphub_tunnel,
expiry_entry);
LOG(LOGL_DEBUG, "expired: %s\n", gtphub_tunnel_str(tun));
llist_del(&tun->entry);
INIT_LLIST_HEAD(&tun->entry); /* mark unused */
expi->del_cb = 0; /* avoid recursion loops */
expiring_item_del(&tun->expiry_entry); /* usually already done, but make sure. */
int side_idx;
int plane_idx;
for_each_side_and_plane(side_idx, plane_idx) {
struct gtphub_tunnel_endpoint *te = &tun->endpoint[side_idx][plane_idx];
/* clear ref count */
gtphub_tunnel_endpoint_set_peer(te, NULL);
rate_ctr_group_free(te->counters_io);
}
talloc_free(tun);
}
#define CTR_IDX(s, p, a, b) (a + s + (p + b) * 2)
/* rate counter index for tunnels: [3; 6] */
#define CTR_IDX_TUN(s, p) CTR_IDX(s, p, 1, 1)
/* rate counter index for hubs: [7; 10] */
#define CTR_IDX_HUB(s, p) CTR_IDX(s, p, 3, 2)
static struct gtphub_tunnel *gtphub_tunnel_new(void)
{
struct gtphub_tunnel *tun;
tun = talloc_zero(osmo_gtphub_ctx, struct gtphub_tunnel);
OSMO_ASSERT(tun);
INIT_LLIST_HEAD(&tun->entry);
expiring_item_init(&tun->expiry_entry);
int side_idx, plane_idx;
for_each_side_and_plane(side_idx, plane_idx) {
struct gtphub_tunnel_endpoint *te = &tun->endpoint[side_idx][plane_idx];
te->counters_io = rate_ctr_group_alloc(osmo_gtphub_ctx,
>phub_ctrg_io_desc,
CTR_IDX_TUN(side_idx, plane_idx));
if (!te->counters_io)
return NULL;
}
tun->expiry_entry.del_cb = gtphub_tunnel_del_cb;
return tun;
}
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_entry_or_null(&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_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 */
expiring_item_del(expi); /* usually already done, but make sure. */
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(LOGL_DEBUG, "expired: %d: nr mapping from %s: %u->%u\n",
(int)nrm->expiry_entry.expiry,
gtphub_port_str(from),
(unsigned int)nrm->orig, (unsigned 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(LOGL_DEBUG, "peer %s: sequence map %d --> %d\n",
gtphub_port_str(from),
(int)(nrm->orig), (int)(nrm->repl));
} else {
nr_map_refresh(map, nrm, now);
}
OSMO_ASSERT(nrm);
return nrm;
}
static void gtphub_map_seq(struct gtp_packet_desc *p,
struct gtphub_peer_port *from_port,
struct gtphub_peer_port *to_port)
{
/* 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, p->timestamp);
/* Change the GTP packet to yield the new, mapped seq nr */
set_seq(p, nrm->repl);
}
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(LOGL_DEBUG, "peer %p: sequence unmap %d <-- %d\n",
nrm->origin, (int)(nrm->orig), (int)(nrm->repl));
set_seq(p, nrm->orig);
return nrm->origin;
}
static int gtphub_check_mapped_tei(struct gtphub_tunnel *new_tun,
struct gtphub_tunnel *iterated_tun,
uint32_t *tei_min,
uint32_t *tei_max)
{
if (!new_tun->tei_repl || !iterated_tun->tei_repl)
return 1;
*tei_min = (*tei_min < iterated_tun->tei_repl)? *tei_min : iterated_tun->tei_repl;
*tei_max = (*tei_max > iterated_tun->tei_repl)? *tei_max : iterated_tun->tei_repl;
if (new_tun->tei_repl != iterated_tun->tei_repl)
return 1;
/* new_tun->tei_repl is already taken. Try to find one out of the known
* range. */
LOG(LOGL_DEBUG, "TEI replacement %d already taken.\n", new_tun->tei_repl);
if ((*tei_max) < 0xffffffff) {
(*tei_max)++;
new_tun->tei_repl = *tei_max;
LOG(LOGL_DEBUG, "Using TEI %d instead.\n", new_tun->tei_repl);
return 1;
} else if ((*tei_min) > 1) {
(*tei_min)--;
new_tun->tei_repl = *tei_min;
LOG(LOGL_DEBUG, "Using TEI %d instead.\n", new_tun->tei_repl);
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;
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;
/* Check whether the GSN sent a TEI that it is reusing from a
* previous tunnel. */
int tun_continue = 0;
for_each_side(side_idx) {
for_each_plane(plane_idx) {
te = &tun->endpoint[side_idx][plane_idx];
te2 = &new_tun->endpoint[side_idx][plane_idx];
if ((te->tei_orig == 0)
|| (te->tei_orig != te2->tei_orig)
|| (!te->peer)
|| (!te2->peer)
|| !gsn_addr_same(&te->peer->peer_addr->addr,
&te2->peer->peer_addr->addr))
continue;
/* 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:"
" %s peer %s sent %s TEI %x,"
" previously used by tunnel %s...\n",
gtphub_side_idx_names[side_idx],
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. However, tun is deleted,
* so we need to skip to the next tunnel. */
tun_continue = 1;
break;
}
if (tun_continue)
break;
}
if (tun_continue)
continue;
/* Check whether the mapped TEI is already used by another
* tunnel. */
if (!gtphub_check_mapped_tei(new_tun, tun, &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,
struct gtphub_tunnel *tun,
time_t now)
{
expiry_add(&hub->expire_slowly,
&tun->expiry_entry,
now);
}
static struct gtphub_tunnel_endpoint *gtphub_unmap_tei(struct gtphub *hub,
struct gtp_packet_desc *p,
struct gtphub_peer_port *from,
struct gtphub_tunnel **unmapped_from_tun)
{
OSMO_ASSERT(from);
int other_side = other_side_idx(p->side_idx);
struct gtphub_tunnel *tun;
llist_for_each_entry(tun, &hub->tunnels, entry) {
struct gtphub_tunnel_endpoint *te_from =
&tun->endpoint[p->side_idx][p->plane_idx];
struct gtphub_tunnel_endpoint *te_to =
&tun->endpoint[other_side][p->plane_idx];
if ((tun->tei_repl == p->header_tei_rx)
&& te_from->peer
&& gsn_addr_same(&te_from->peer->peer_addr->addr,
&from->peer_addr->addr)) {
gtphub_tunnel_refresh(hub, tun, p->timestamp);
if (unmapped_from_tun)
*unmapped_from_tun = tun;
return te_to;
}
}
if (unmapped_from_tun)
*unmapped_from_tun = NULL;
return NULL;
}
static void gtphub_map_restart_counter(struct gtphub *hub,
struct gtp_packet_desc *p)
{
if (p->rc != GTP_RC_PDU_C)
return;
int ie_idx;
ie_idx = gtpie_getie(p->ie, GTPIE_RECOVERY, 0);
if (ie_idx < 0)
return;
/* Always send gtphub's own restart counter */
p->ie[ie_idx]->tv1.v = hton8(hub->restart_counter);
}
static int gtphub_unmap_header_tei(struct gtphub_peer_port **to_port_p,
struct gtphub_tunnel **unmapped_from_tun,
struct gtphub *hub,
struct gtp_packet_desc *p,
struct gtphub_peer_port *from_port)
{
OSMO_ASSERT(p->version == 1);
*to_port_p = NULL;
if (unmapped_from_tun)
*unmapped_from_tun = 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. */
if (!p->header_tei_rx)
return 0;
/* to_peer has previously announced a TEI, which was stored and
* mapped in a tunnel struct. */
struct gtphub_tunnel_endpoint *to;
to = gtphub_unmap_tei(hub, p, from_port, unmapped_from_tun);
if (!to) {
LOG(LOGL_ERROR, "Received unknown TEI %" PRIx32 " from %s\n",
p->header_tei_rx, gtphub_port_str(from_port));
return -1;
}
if (unmapped_from_tun) {
OSMO_ASSERT(*unmapped_from_tun);
LOG(LOGL_DEBUG, "Unmapped TEI coming from: %s\n",
gtphub_tunnel_str(*unmapped_from_tun));
}
uint32_t unmapped_tei = to->tei_orig;
set_tei(p, unmapped_tei);
/* May be NULL for an invalidated tunnel. */
*to_port_p = to->peer;
return 0;
}
static int gtphub_handle_create_pdp_ctx(struct gtphub *hub,
struct gtp_packet_desc *p,
struct gtphub_peer_port *from_ctrl,
struct gtphub_peer_port *to_ctrl)
{
int plane_idx;
osmo_static_assert((GTPH_PLANE_CTRL == 0) && (GTPH_PLANE_USER == 1),
plane_nrs_match_GSN_addr_IE_indices);
struct gtphub_tunnel *tun = p->tun;
if (p->type == GTP_CREATE_PDP_REQ) {
if (p->side_idx != GTPH_SIDE_SGSN) {
LOG(LOGL_ERROR, "Wrong side: Create PDP Context"
" Request from the GGSN side: %s",
gtphub_port_str(from_ctrl));
return -1;
}
if (tun) {
LOG(LOGL_ERROR, "Not implemented: Received"
" Create PDP Context Request for an already"
" established tunnel:"
" from %s, tunnel %s\n",
gtphub_port_str(from_ctrl),
gtphub_tunnel_str(p->tun));
return -1;
}
/* A new tunnel. */
tun = gtphub_tunnel_new();
if (!tun) {
LOG(LOGL_ERROR, "Failed to allocate new tunnel %s <-> %s\n",
gtphub_port_str(from_ctrl), gtphub_port_str(to_ctrl));
return -1;
}
p->tun = tun;
/* Create TEI mapping */
tun->tei_repl = nr_pool_next(&hub->tei_pool);
llist_add(&tun->entry, &hub->tunnels);
gtphub_tunnel_refresh(hub, tun, p->timestamp);
/* The endpoint peers on this side (SGSN) will be set from IEs
* below. Also set the GGSN Ctrl endpoint, for logging. */
gtphub_tunnel_endpoint_set_peer(&tun->endpoint[GTPH_SIDE_GGSN][GTPH_PLANE_CTRL],
to_ctrl);
} else if (p->type == GTP_CREATE_PDP_RSP) {
if (p->side_idx != GTPH_SIDE_GGSN) {
LOG(LOGL_ERROR, "Wrong side: Create PDP Context"
" Response from the SGSN side: %s",
gtphub_port_str(from_ctrl));
return -1;
}
/* The tunnel should already have been resolved from the header
* TEI and be available in tun (== p->tun). Just fill in the
* GSN Addresses below.*/
OSMO_ASSERT(tun);
OSMO_ASSERT(tun->tei_repl == p->header_tei_rx);
OSMO_ASSERT(to_ctrl);
}
uint8_t ie_type[] = { GTPIE_TEI_C, GTPIE_TEI_DI };
int ie_mandatory = (p->type == GTP_CREATE_PDP_REQ);
unsigned int side_idx = p->side_idx;
for_each_plane(plane_idx) {
int rc;
struct gsn_addr use_addr;
uint16_t use_port;
uint32_t tei_from_ie;
int ie_idx;
/* Fetch GSN Address and TEI from IEs. As ensured by above
* static asserts, plane_idx corresponds to the GSN Address IE
* index (the first one = 0 = ctrl, second one = 1 = user). */
rc = gsn_addr_get(&use_addr, p, plane_idx);
if (rc) {
LOG(LOGL_ERROR, "Cannot read %s GSN Address IE\n",
gtphub_plane_idx_names[plane_idx]);
return -1;
}
LOG(LOGL_DEBUG, "Read %s GSN addr %s (%d)\n",
gtphub_plane_idx_names[plane_idx],
gsn_addr_to_str(&use_addr),
use_addr.len);
ie_idx = gtpie_getie(p->ie, ie_type[plane_idx], 0);
if (ie_idx < 0) {
if (ie_mandatory) {
LOG(LOGL_ERROR,
"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.
*
* Exception: if sgsn_use_sender is set, instead use the
* sender's address and port for Ctrl -- the User port is not
* known until the first User packet arrives.
*
* Note: doing this here is just an optimization, because
* gtphub_handle_buf() has code to replace the tunnel
* endpoints' addresses with the sender (needed for User
* plane). We could just ignore sgsn_use_sender here. But if we
* set up a default port here and replace it in
* gtphub_handle_buf(), we'd be creating a peer port just to
* expire it right away. */
if (hub->sgsn_use_sender && (side_idx == GTPH_SIDE_SGSN)) {
int rc = gsn_addr_from_sockaddr(&use_addr, &use_port, &from_ctrl->sa);
if (rc < 0)
LOG(LOGL_ERROR, "%s(): failed to obtain GSN address\n", __func__);
} else {
use_port = gtphub_plane_idx_default_port[plane_idx];
}
struct gtphub_peer_port *peer_from_ie;
peer_from_ie = gtphub_port_have(hub,
&hub->to_gsns[side_idx][plane_idx],
&use_addr, use_port);
gtphub_tunnel_endpoint_set_peer(&tun->endpoint[side_idx][plane_idx],
peer_from_ie);
if (!tei_from_ie &&
!tun->endpoint[side_idx][plane_idx].tei_orig) {
LOG(LOGL_ERROR,
"Create PDP Context message omits %s TEI, but"
" no TEI has been announced for this tunnel: %s\n",
gtphub_plane_idx_names[plane_idx],
gtphub_tunnel_str(tun));
return -1;
}
if (tei_from_ie) {
/* Replace TEI in GTP packet IE */
tun->endpoint[side_idx][plane_idx].tei_orig = tei_from_ie;
p->ie[ie_idx]->tv4.v = hton32(tun->tei_repl);
if (!gtphub_check_reused_teis(hub, tun)) {
/* It's highly unlikely that all TEIs are
* taken. But the code looking for an unused
* TEI is, at the time of writing this comment,
* not able to find gaps in the TEI space. To
* explicitly alert the user of this problem,
* rather abort than carry on. */
LOG(LOGL_FATAL, "TEI range exhausted. Cannot create TEI mapping, aborting.\n");
abort();
}
}
/* Replace the GSN address to reflect gtphub. */
rc = gsn_addr_put(&hub->to_gsns[other_side_idx(side_idx)][plane_idx].local_addr,
p, plane_idx);
if (rc) {
LOG(LOGL_ERROR, "Cannot write %s GSN Address IE\n",
gtphub_plane_idx_names[plane_idx]);
return -1;
}
}
if (p->type == GTP_CREATE_PDP_REQ) {
LOG(LOGL_DEBUG, "New tunnel, first half: %s\n",
gtphub_tunnel_str(tun));
} else if (p->type == GTP_CREATE_PDP_RSP) {
LOG(LOGL_DEBUG, "New tunnel: %s\n",
gtphub_tunnel_str(tun));
}
return 0;
}
static void pending_delete_del_cb(struct expiring_item *expi)
{
struct pending_delete *pd;
pd = container_of(expi, struct pending_delete, expiry_entry);
llist_del(&pd->entry);
INIT_LLIST_HEAD(&pd->entry);
pd->expiry_entry.del_cb = 0;
expiring_item_del(&pd->expiry_entry);
talloc_free(pd);
}
static struct pending_delete *pending_delete_new(void)
{
struct pending_delete *pd = talloc_zero(osmo_gtphub_ctx, struct pending_delete);
INIT_LLIST_HEAD(&pd->entry);
expiring_item_init(&pd->expiry_entry);
pd->expiry_entry.del_cb = pending_delete_del_cb;
return pd;
}
static int gtphub_handle_delete_pdp_ctx(struct gtphub *hub,
struct gtp_packet_desc *p,
struct gtphub_peer_port *from_ctrl,
struct gtphub_peer_port *to_ctrl)
{
struct gtphub_tunnel *known_tun = p->tun;
if (p->type == GTP_DELETE_PDP_REQ) {
if (!known_tun) {
LOG(LOGL_ERROR, "Cannot find tunnel for Delete PDP Context Request.\n");
return -1;
}
/* Store the Delete Request until a successful Response is seen. */
uint8_t teardown_ind;
uint8_t nsapi;
if (gtpie_gettv1(p->ie, GTPIE_TEARDOWN, 0, &teardown_ind) != 0) {
LOG(LOGL_ERROR, "Missing Teardown Ind IE in Delete PDP Context Request.\n");
return -1;
}
if (gtpie_gettv1(p->ie, GTPIE_NSAPI, 0, &nsapi) != 0) {
LOG(LOGL_ERROR, "Missing NSAPI IE in Delete PDP Context Request.\n");
return -1;
}
struct pending_delete *pd = NULL;
struct pending_delete *pdi = NULL;
llist_for_each_entry(pdi, &hub->pending_deletes, entry) {
if ((pdi->tun == known_tun)
&& (pdi->teardown_ind == teardown_ind)
&& (pdi->nsapi == nsapi)) {
pd = pdi;
break;
}
}
if (!pd) {
pd = pending_delete_new();
pd->tun = known_tun;
pd->teardown_ind = teardown_ind;
pd->nsapi = nsapi;
LOG(LOGL_DEBUG, "Tunnel delete pending: %s\n",
gtphub_tunnel_str(known_tun));
llist_add(&pd->entry, &hub->pending_deletes);
}
/* Add or refresh timeout. */
expiry_add(&hub->expire_quickly, &pd->expiry_entry, p->timestamp);
/* If a pending_delete should expire before the response to
* indicate success comes in, the responding peer will have the
* tunnel deactivated, while the requesting peer gets no reply
* and keeps the tunnel. The hope is that the requesting peer
* will try again and get a useful response. */
} else if (p->type == GTP_DELETE_PDP_RSP) {
/* Find the Delete Request for this Response. */
struct pending_delete *pd = NULL;
struct pending_delete *pdi;
llist_for_each_entry(pdi, &hub->pending_deletes, entry) {
if (known_tun == pdi->tun) {
pd = pdi;
break;
}
}
if (!pd) {
LOG(LOGL_ERROR, "Delete PDP Context Response:"
" Cannot find matching request.");
/* If we delete the tunnel now, anyone can send a
* Delete response to kill tunnels at will. */
return -1;
}
/* TODO handle teardown_ind and nsapi */
expiring_item_del(&pd->expiry_entry);
uint8_t cause;
if (gtpie_gettv1(p->ie, GTPIE_CAUSE, 0, &cause) != 0) {
LOG(LOGL_ERROR, "Delete PDP Context Response:"
" Missing Cause IE.");
/* If we delete the tunnel now, at least one of the
* peers may still think it is active. */
return -1;
}
if (cause != GTPCAUSE_ACC_REQ) {
LOG(LOGL_NOTICE,
"Delete PDP Context Response indicates failure;"
"for %s\n",
gtphub_tunnel_str(known_tun));
return -1;
}
LOG(LOGL_DEBUG, "Delete PDP Context: removing tunnel %s\n",
gtphub_tunnel_str(known_tun));
p->tun = NULL;
expiring_item_del(&known_tun->expiry_entry);
}
return 0;
}
static int gtphub_handle_update_pdp_ctx(struct gtphub *hub,
struct gtp_packet_desc *p,
struct gtphub_peer_port *from_ctrl,
struct gtphub_peer_port *to_ctrl)
{
/* TODO */
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(struct gtphub *hub,
struct gtp_packet_desc *p,
struct gtphub_peer_port *from_ctrl,
struct gtphub_peer_port *to_ctrl)
{
OSMO_ASSERT(p->plane_idx == GTPH_PLANE_CTRL);
switch (p->type) {
case GTP_CREATE_PDP_REQ:
case GTP_CREATE_PDP_RSP:
return gtphub_handle_create_pdp_ctx(hub, p,
from_ctrl, to_ctrl);
case GTP_DELETE_PDP_REQ:
case GTP_DELETE_PDP_RSP:
return gtphub_handle_delete_pdp_ctx(hub, p,
from_ctrl, to_ctrl);
case GTP_UPDATE_PDP_REQ:
case GTP_UPDATE_PDP_RSP:
return gtphub_handle_update_pdp_ctx(hub, p,
from_ctrl, to_ctrl);
default:
/* Nothing to do for this message type. */
return 0;
}
}
static int gtphub_send_del_pdp_ctx(struct gtphub *hub,
struct gtphub_tunnel *tun,
int to_side)
{
static uint8_t del_ctx_msg[16] = {
0x32, /* GTP v1 flags */
GTP_DELETE_PDP_REQ,
0x00, 0x08, /* Length in network byte order */
0x00, 0x00, 0x00, 0x00, /* TEI to be replaced */
0, 0, /* Seq, to be replaced */
0, 0, /* no extensions */
0x13, 0xff, /* 19: Teardown ind = 1 */
0x14, 0 /* 20: NSAPI = 0 */
};
uint32_t *tei = (uint32_t*)&del_ctx_msg[4];
uint16_t *seq = (uint16_t*)&del_ctx_msg[8];
struct gtphub_tunnel_endpoint *te =
&tun->endpoint[to_side][GTPH_PLANE_CTRL];
if (! te->peer)
return 0;
*tei = hton32(te->tei_orig);
*seq = hton16(nr_pool_next(&te->peer->peer_addr->peer->seq_pool));
struct gtphub_bind *to_bind = &hub->to_gsns[to_side][GTPH_PLANE_CTRL];
int rc = gtphub_write(&to_bind->ofd, &te->peer->sa,
del_ctx_msg, sizeof(del_ctx_msg));
if (rc != 0) {
LOG(LOGL_ERROR,
"Failed to send out-of-band Delete PDP Context Request to %s\n",
gtphub_port_str(te->peer));
}
return rc;
}
/* Tell all peers on the other end of tunnels that PDP contexts are void. */
static void gtphub_restarted(struct gtphub *hub,
struct gtp_packet_desc *p,
struct gtphub_peer_port *pp)
{
LOG(LOGL_NOTICE, "Peer has restarted: %s\n",
gtphub_port_str(pp));
int deleted_count = 0;
struct gtphub_tunnel *tun;
llist_for_each_entry(tun, &hub->tunnels, entry) {
int side_idx;
for_each_side(side_idx) {
struct gtphub_tunnel_endpoint *te = &tun->endpoint[side_idx][GTPH_PLANE_CTRL];
struct gtphub_tunnel_endpoint *te2 = &tun->endpoint[other_side_idx(side_idx)][GTPH_PLANE_CTRL];
if ((!te->peer)
|| (!te2->tei_orig)
|| (pp->peer_addr->peer != te->peer->peer_addr->peer))
continue;
LOG(LOGL_DEBUG, "Deleting tunnel due to peer restart: %s\n",
gtphub_tunnel_str(tun));
deleted_count ++;
/* Send a Delete PDP Context Request to the
* peer on the other side, remember the pending
* delete and wait for the response to delete
* the tunnel. Clear this side of the tunnel to
* make sure it isn't used.
*
* Should the delete message send fail, or if no
* response is received, this tunnel will expire. If
* its TEIs come up in a new PDP Context Request, it
* will be removed. If messages for this tunnel should
* come in (from the not restarted side), they will be
* dropped because the tunnel is rendered unusable. */
gtphub_send_del_pdp_ctx(hub, tun, other_side_idx(side_idx));
gtphub_tunnel_endpoint_set_peer(&tun->endpoint[side_idx][GTPH_PLANE_CTRL],
NULL);
gtphub_tunnel_endpoint_set_peer(&tun->endpoint[side_idx][GTPH_PLANE_USER],
NULL);
}
}
if (deleted_count)
LOG(LOGL_NOTICE, "Deleting %d tunnels due to restart of: %s\n",
deleted_count,
gtphub_port_str(pp));
}
static int get_restart_count(struct gtp_packet_desc *p)
{
int ie_idx;
ie_idx = gtpie_getie(p->ie, GTPIE_RECOVERY, 0);
if (ie_idx < 0)
return -1;
return ntoh8(p->ie[ie_idx]->tv1.v);
}
static void gtphub_check_restart_counter(struct gtphub *hub,
struct gtp_packet_desc *p,
struct gtphub_peer_port *from)
{
/* 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. */
int restart = get_restart_count(p);
if ((restart < 0) || (restart > 255))
return;
if ((from->last_restart_count >= 0) && (from->last_restart_count <= 255)) {
if (from->last_restart_count != restart) {
gtphub_restarted(hub, p, from);
}
}
from->last_restart_count = restart;
}
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(LOGL_DEBUG, "=== reading from SGSN (%s)\n",
gtphub_plane_idx_names[plane_idx]);
if (!(what & OSMO_FD_READ))
return 0;
struct gtphub *hub = from_sgsns_ofd->data;
static uint8_t buf[4096];
struct sgsn_sockaddr from_addr;
struct sgsn_sockaddr to_addr;
struct osmo_fd *to_ofd;
int len;
uint8_t *reply_buf;
len = gtphub_read(from_sgsns_ofd, &from_addr, buf, sizeof(buf));
if (len < 1)
return 0;
len = gtphub_handle_buf(hub, GTPH_SIDE_SGSN, plane_idx, &from_addr,
buf, len, gtphub_now(),
&reply_buf, &to_ofd, &to_addr);
if (len < 1)
return 0;
return gtphub_write(to_ofd, &to_addr, reply_buf, len);
}
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(LOGL_DEBUG, "=== reading from GGSN (%s)\n",
gtphub_plane_idx_names[plane_idx]);
if (!(what & OSMO_FD_READ))
return 0;
struct gtphub *hub = from_ggsns_ofd->data;
static uint8_t buf[4096];
struct sgsn_sockaddr from_addr;
struct sgsn_sockaddr to_addr;
struct osmo_fd *to_ofd;
int len;
uint8_t *reply_buf;
len = gtphub_read(from_ggsns_ofd, &from_addr, buf, sizeof(buf));
if (len < 1)
return 0;
len = gtphub_handle_buf(hub, GTPH_SIDE_GGSN, plane_idx, &from_addr,
buf, len, gtphub_now(),
&reply_buf, &to_ofd, &to_addr);
if (len < 1)
return 0;
return gtphub_write(to_ofd, &to_addr, reply_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)
{
/* 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. */
if (unmapped_from_seq)
*unmapped_from_seq = NULL;
if (final_unmapped)
*final_unmapped = NULL;
p->tun = NULL;
struct gtphub_peer_port *from_seq = NULL;
struct gtphub_peer_port *from_tei = NULL;
struct gtphub_peer_port *unmapped = NULL;
from_seq = gtphub_unmap_seq(p, from);
if (gtphub_unmap_header_tei(&from_tei, &p->tun, hub, p, from) < 0)
return -1;
struct gtphub_peer *from_peer = from->peer_addr->peer;
if (from_seq && from_tei && (from_seq != from_tei)) {
LOG(LOGL_DEBUG,
"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),
(unsigned int)p->header_tei_rx,
gtphub_port_str2(from_tei)
);
}
unmapped = (from_seq? from_seq : from_tei);
if (unmapped && to_proxy && (unmapped != to_proxy)) {
LOG(LOGL_NOTICE,
"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;
}
if (unmapped_from_seq)
*unmapped_from_seq = from_seq;
if (final_unmapped)
*final_unmapped = unmapped;
return 0;
}
static int gsn_addr_to_sockaddr(struct gsn_addr *src,
uint16_t port,
struct sgsn_sockaddr *dst)
{
return sgsn_sockaddr_init_udp(dst, gsn_addr_to_str(src), port);
}
/* If p is an Echo request, replace p's data with the matching response and
* return 1. If p is no Echo request, return 0, or -1 if an invalid packet is
* detected. */
static int gtphub_handle_echo_req(struct gtphub *hub, struct gtp_packet_desc *p,
uint8_t **reply_buf)
{
if (p->type != GTP_ECHO_REQ)
return 0;
static uint8_t echo_response_data[14] = {
0x32, /* GTP v1 flags */
GTP_ECHO_RSP,
0x00, 14 - 8, /* Length in network byte order */
0x00, 0x00, 0x00, 0x00, /* Zero TEI */
0, 0, /* Seq, to be replaced */
0, 0, /* no extensions */
0x0e, /* Recovery IE */
0 /* Restart counter, to be replaced */
};
uint16_t *seq = (uint16_t*)&echo_response_data[8];
uint8_t *recovery = &echo_response_data[13];
*seq = hton16(p->seq);
*recovery = hub->restart_counter;
*reply_buf = echo_response_data;
return sizeof(echo_response_data);
}
struct gtphub_peer_port *gtphub_known_addr_have_port(const struct gtphub_bind *bind,
const struct sgsn_sockaddr *addr);
/* 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_handle_buf(struct gtphub *hub,
unsigned int side_idx,
unsigned int plane_idx,
const struct sgsn_sockaddr *from_addr,
uint8_t *buf,
size_t received,
time_t now,
uint8_t **reply_buf,
struct osmo_fd **to_ofd,
struct sgsn_sockaddr *to_addr)
{
struct gtphub_bind *from_bind = &hub->to_gsns[side_idx][plane_idx];
struct gtphub_bind *to_bind = &hub->to_gsns[other_side_idx(side_idx)][plane_idx];
rate_ctr_add(rate_ctr_group_get_ctr(from_bind->counters_io, GTPH_CTR_BYTES_IN),
received);
struct gtp_packet_desc p;
gtp_decode(buf, received, side_idx, plane_idx, &p, now);
LOG(LOGL_DEBUG, "%s rx %s from %s %s%s\n",
(side_idx == GTPH_SIDE_GGSN)? "<-" : "->",
gtphub_plane_idx_names[plane_idx],
gtphub_side_idx_names[side_idx],
sgsn_sockaddr_to_str(from_addr),
gtp_type_str(p.type));
if (p.rc <= 0) {
LOG(LOGL_ERROR, "INVALID: dropping GTP packet%s from %s %s %s\n",
gtp_type_str(p.type),
gtphub_side_idx_names[side_idx],
gtphub_plane_idx_names[plane_idx],
sgsn_sockaddr_to_str(from_addr));
return -1;
}
rate_ctr_inc(rate_ctr_group_get_ctr(from_bind->counters_io, GTPH_CTR_PKTS_IN));
int reply_len;
reply_len = gtphub_handle_echo_req(hub, &p, reply_buf);
if (reply_len > 0) {
/* It was an echo. Nothing left to do. */
sgsn_sockaddr_copy(to_addr, from_addr);
*to_ofd = &from_bind->ofd;
rate_ctr_inc(rate_ctr_group_get_ctr(from_bind->counters_io, GTPH_CTR_PKTS_OUT));
rate_ctr_add(rate_ctr_group_get_ctr(from_bind->counters_io, GTPH_CTR_BYTES_OUT),
reply_len);
LOG(LOGL_DEBUG, "%s Echo response to %s: %d bytes to %s\n",
(side_idx == GTPH_SIDE_GGSN)? "-->" : "<--",
gtphub_side_idx_names[side_idx],
(int)reply_len, sgsn_sockaddr_to_str(to_addr));
return reply_len;
}
if (reply_len < 0)
return -1;
*to_ofd = &to_bind->ofd;
/* If a 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 *from_peer = hub->proxy[side_idx][plane_idx];
if (from_peer) {
if (sgsn_sockaddr_cmp(&from_peer->sa, from_addr) != 0) {
LOG(LOGL_ERROR,
"Rejecting: %s proxy configured, but GTP packet"
" received on %s bind is from another sender:"
" proxy: %s sender: %s\n",
gtphub_side_idx_names[side_idx],
gtphub_side_idx_names[side_idx],
gtphub_port_str(from_peer),
sgsn_sockaddr_to_str(from_addr));
return -1;
}
}
if (!from_peer) {
/* Find or create a peer with a matching address. The sender's
* port may in fact differ. */
from_peer = gtphub_known_addr_have_port(from_bind, from_addr);
}
/* If any PDP context has been created, we already have an entry for
* this GSN. If we don't have an entry, a GGSN has nothing to tell us
* about, while an SGSN may initiate a PDP context. */
if (!from_peer) {
if (side_idx == GTPH_SIDE_GGSN) {
LOG(LOGL_ERROR, "Dropping packet%s: unknown GGSN peer: %s\n",
gtp_type_str(p.type),
sgsn_sockaddr_to_str(from_addr));
return -1;
} else {
/* 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) {
LOG(LOGL_ERROR,
"Dropping packet%s: User plane peer was not"
"announced by PDP Context: %s\n",
gtp_type_str(p.type),
sgsn_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;
from_peer = gtphub_port_have(hub, from_bind, &from_gsna, from_port);
}
}
if (!from_peer) {
/* This could theoretically happen for invalid address data or
* somesuch. */
LOG(LOGL_ERROR, "Dropping packet%s: invalid %s peer: %s\n",
gtp_type_str(p.type),
gtphub_side_idx_names[side_idx],
sgsn_sockaddr_to_str(from_addr));
return -1;
}
rate_ctr_add(rate_ctr_group_get_ctr(from_peer->counters_io, GTPH_CTR_BYTES_IN),
received);
rate_ctr_inc(rate_ctr_group_get_ctr(from_peer->counters_io, GTPH_CTR_PKTS_IN));
LOG(LOGL_DEBUG, "from %s peer: %s\n", gtphub_side_idx_names[side_idx],
gtphub_port_str(from_peer));
gtphub_check_restart_counter(hub, &p, from_peer);
gtphub_map_restart_counter(hub, &p);
struct gtphub_peer_port *to_peer_from_seq;
struct gtphub_peer_port *to_peer;
if (gtphub_unmap(hub, &p, from_peer,
hub->proxy[other_side_idx(side_idx)][plane_idx],
&to_peer, &to_peer_from_seq)
!= 0) {
return -1;
}
if (p.tun) {
struct gtphub_tunnel_endpoint *te = &p.tun->endpoint[p.side_idx][p.plane_idx];
rate_ctr_add(rate_ctr_group_get_ctr(te->counters_io, GTPH_CTR_BYTES_IN),
received);
rate_ctr_inc(rate_ctr_group_get_ctr(te->counters_io, GTPH_CTR_PKTS_IN));
}
if ((!to_peer) && (side_idx == GTPH_SIDE_SGSN)) {
if (gtphub_resolve_ggsn(hub, &p, &to_peer) < 0)
return -1;
}
if (!to_peer && p.tun && p.type == GTP_DELETE_PDP_RSP) {
/* It's a delete confirmation for a tunnel that is partly
* invalid, probably marked unsuable due to a restarted peer.
* Remove the tunnel and be happy without forwarding. */
expiring_item_del(&p.tun->expiry_entry);
p.tun = NULL;
return 0;
}
if (!to_peer) {
LOG(LOGL_ERROR, "No %s to send to. Dropping packet%s"
" (type=%" PRIu8 ", header-TEI=%" PRIx32 ", seq=%" PRIx16 ").\n",
gtphub_side_idx_names[other_side_idx(side_idx)],
gtp_type_str(p.type),
p.type, p.header_tei_rx, p.seq
);
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(hub, &p, from_peer, to_peer)
!= 0)
return -1;
}
/* Either to_peer was resolved from an existing tunnel,
* or a PDP Ctx and thus a tunnel has just been created,
* or the tunnel has been deleted due to this message. */
OSMO_ASSERT(p.tun || (p.type == GTP_DELETE_PDP_RSP));
/* If the GGSN is replying to an SGSN request, the sequence nr has
* already been unmapped above (to_peer_from_seq != NULL), and we need not
* create a new mapping. */
if (!to_peer_from_seq)
gtphub_map_seq(&p, from_peer, to_peer);
sgsn_sockaddr_copy(to_addr, &to_peer->sa);
*reply_buf = (uint8_t*)p.data;
if (received) {
rate_ctr_inc(rate_ctr_group_get_ctr(to_bind->counters_io, GTPH_CTR_PKTS_OUT));
rate_ctr_add(rate_ctr_group_get_ctr(to_bind->counters_io, GTPH_CTR_BYTES_OUT),
received);
rate_ctr_inc(rate_ctr_group_get_ctr(to_peer->counters_io, GTPH_CTR_PKTS_OUT));
rate_ctr_add(rate_ctr_group_get_ctr(to_peer->counters_io, GTPH_CTR_BYTES_OUT),
received);
}
if (p.tun) {
struct gtphub_tunnel_endpoint *te = &p.tun->endpoint[other_side_idx(p.side_idx)][p.plane_idx];
rate_ctr_inc(rate_ctr_group_get_ctr(te->counters_io, GTPH_CTR_PKTS_OUT));
rate_ctr_add(rate_ctr_group_get_ctr(te->counters_io, GTPH_CTR_BYTES_OUT),
received);
}
LOG(LOGL_DEBUG, "%s Forward to %s:"
" header-TEI %" PRIx32", seq %" PRIx16", %d bytes to %s\n",
(side_idx == GTPH_SIDE_SGSN)? "-->" : "<--",
gtphub_side_idx_names[other_side_idx(side_idx)],
p.header_tei, p.seq,
(int)received, sgsn_sockaddr_to_str(to_addr));
return received;
}
static void resolved_gssn_del_cb(struct expiring_item *expi)
{
struct gtphub_resolved_ggsn *ggsn;
ggsn = container_of(expi, struct gtphub_resolved_ggsn, expiry_entry);
gtphub_port_ref_count_dec(ggsn->peer);
llist_del(&ggsn->entry);
ggsn->expiry_entry.del_cb = 0;
expiring_item_del(&ggsn->expiry_entry);
talloc_free(ggsn);
}
void gtphub_resolved_ggsn(struct gtphub *hub, const char *apn_oi_str,
struct gsn_addr *resolved_addr,
time_t now)
{
struct gtphub_peer_port *pp;
struct gtphub_resolved_ggsn *ggsn;
LOG(LOGL_DEBUG, "Resolved GGSN callback: %s %s\n",
apn_oi_str, osmo_hexdump((unsigned char*)resolved_addr,
sizeof(*resolved_addr)));
pp = gtphub_port_have(hub, &hub->to_gsns[GTPH_SIDE_GGSN][GTPH_PLANE_CTRL],
resolved_addr, 2123);
if (!pp) {
LOG(LOGL_ERROR, "Internal: Cannot create/find peer '%s'\n",
gsn_addr_to_str(resolved_addr));
return;
}
ggsn = talloc_zero(osmo_gtphub_ctx, struct gtphub_resolved_ggsn);
OSMO_ASSERT(ggsn);
INIT_LLIST_HEAD(&ggsn->entry);
expiring_item_init(&ggsn->expiry_entry);
ggsn->peer = pp;
gtphub_port_ref_count_inc(pp);
osmo_strlcpy(ggsn->apn_oi_str, apn_oi_str, sizeof(ggsn->apn_oi_str));
ggsn->expiry_entry.del_cb = resolved_gssn_del_cb;
expiry_add(&hub->expire_slowly, &ggsn->expiry_entry, now);
llist_add(&ggsn->entry, &hub->resolved_ggsns);
}
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(LOGL_DEBUG, "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. */
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_quickly, now);
expired += expiry_tick(&hub->expire_slowly, now);
/* ... */
if (expired) {
int s, p;
for_each_side_and_plane(s, p) {
gtphub_gc_bind(&hub->to_gsns[s][p]);
}
}
}
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)
{
osmo_timer_setup(&hub->gc_timer, gtphub_gc_cb, 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);
INIT_LLIST_HEAD(&hub->tunnels);
INIT_LLIST_HEAD(&hub->pending_deletes);
expiry_init(&hub->expire_quickly, GTPH_EXPIRE_QUICKLY_SECS);
expiry_init(&hub->expire_slowly, GTPH_EXPIRE_SLOWLY_MINUTES * 60);
nr_pool_init(&hub->tei_pool, 1, 0xffffffff);
int side_idx;
int plane_idx;
for_each_side_and_plane(side_idx, plane_idx) {
gtphub_bind_init(&hub->to_gsns[side_idx][plane_idx], CTR_IDX_HUB(side_idx, plane_idx));
}
hub->to_gsns[GTPH_SIDE_SGSN][GTPH_PLANE_CTRL].label = "SGSN Ctrl";
hub->to_gsns[GTPH_SIDE_GGSN][GTPH_PLANE_CTRL].label = "GGSN Ctrl";
hub->to_gsns[GTPH_SIDE_SGSN][GTPH_PLANE_USER].label = "SGSN User";
hub->to_gsns[GTPH_SIDE_GGSN][GTPH_PLANE_USER].label = "GGSN User";
}
/* For the test suite, this is kept separate from gtphub_stop(), which also
* closes sockets. The test suite avoids using sockets and would cause
* segfaults when trying to close uninitialized ofds. */
void gtphub_free(struct gtphub *hub)
{
/* By expiring all mappings, a garbage collection should free
* everything else. A gtphub_bind_free() will assert that everything is
* indeed empty. */
expiry_clear(&hub->expire_quickly);
expiry_clear(&hub->expire_slowly);
int side_idx;
int plane_idx;
for_each_side_and_plane(side_idx, plane_idx) {
gtphub_gc_bind(&hub->to_gsns[side_idx][plane_idx]);
gtphub_bind_free(&hub->to_gsns[side_idx][plane_idx]);
}
}
void gtphub_stop(struct gtphub *hub)
{
int side_idx;
int plane_idx;
for_each_side_and_plane(side_idx, plane_idx) {
gtphub_bind_stop(&hub->to_gsns[side_idx][plane_idx]);
}
gtphub_free(hub);
}
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,
uint8_t restart_counter)
{
gtphub_init(hub);
hub->restart_counter = restart_counter;
hub->sgsn_use_sender = cfg->sgsn_use_sender? 1 : 0;
/* If a Ctrl plane proxy is configured, ares will never be used. */
if (!cfg->proxy[GTPH_SIDE_GGSN][GTPH_PLANE_CTRL].addr_str) {
if (gtphub_ares_init(hub) != 0) {
LOG(LOGL_FATAL, "Failed to initialize ares\n");
return -1;
}
}
int side_idx;
int plane_idx;
for_each_side_and_plane(side_idx, plane_idx) {
int rc;
rc = gtphub_bind_start(&hub->to_gsns[side_idx][plane_idx],
&cfg->to_gsns[side_idx][plane_idx],
(side_idx == GTPH_SIDE_SGSN)
? from_sgsns_read_cb
: from_ggsns_read_cb,
hub, plane_idx);
if (rc) {
LOG(LOGL_FATAL, "Failed to bind for %ss (%s)\n",
gtphub_side_idx_names[side_idx],
gtphub_plane_idx_names[plane_idx]);
return rc;
}
}
for_each_side_and_plane(side_idx, plane_idx) {
if (gtphub_make_proxy(hub,
&hub->proxy[side_idx][plane_idx],
&hub->to_gsns[side_idx][plane_idx],
&cfg->proxy[side_idx][plane_idx])
!= 0) {
LOG(LOGL_FATAL, "Cannot configure %s proxy"
" %s port %d.\n",
gtphub_side_idx_names[side_idx],
cfg->proxy[side_idx][plane_idx].addr_str,
(int)cfg->proxy[side_idx][plane_idx].port);
return -1;
}
}
for_each_side_and_plane(side_idx, plane_idx) {
if (hub->proxy[side_idx][plane_idx])
LOG(LOGL_NOTICE, "Using %s %s proxy %s\n",
gtphub_side_idx_names[side_idx],
gtphub_plane_idx_names[plane_idx],
gtphub_port_str(hub->proxy[side_idx][plane_idx]));
}
if (hub->sgsn_use_sender)
LOG(LOGL_NOTICE, "Using sender address and port for SGSN instead of GSN Addr IE and default ports.\n");
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 sgsn_sockaddr *addr)
{
struct gsn_addr gsna;
uint16_t port;
if (gsn_addr_from_sockaddr(&gsna, &port, addr) != 0)
return NULL;
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, 0, 0xffff);
nr_map_init(&peer->seq_map, &peer->seq_pool, &hub->expire_quickly);
/* 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);
a = gtphub_peer_add_addr(peer, addr);
LOG(LOGL_DEBUG, "New peer address: %s %s\n",
bind->label,
gsn_addr_to_str(&a->addr));
return a;
}
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;
pp->last_restart_count = -1;
if (gsn_addr_to_sockaddr(&a->addr, port, &pp->sa) != 0) {
talloc_free(pp);
return NULL;
}
pp->counters_io = rate_ctr_group_alloc(osmo_gtphub_ctx,
>phub_ctrg_io_desc, port);
if (!pp->counters_io) {
LOG(LOGL_ERROR, "Failed to allocate rate counters for %s:%u\n", gsn_addr_to_str(&a->addr), port);
talloc_free(pp);
return NULL;
}
llist_add(&pp->entry, &a->ports);
LOG(LOGL_DEBUG, "New peer port: %s port %d\n",
gsn_addr_to_str(&a->addr),
(int)port);
return pp;
}
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);
}
/* Find a GGSN peer with a matching address. If the address is known but the
* port not, create a new port for that peer address. */
struct gtphub_peer_port *gtphub_known_addr_have_port(const struct gtphub_bind *bind,
const struct sgsn_sockaddr *addr)
{
struct gtphub_peer_addr *pa;
struct gtphub_peer_port *pp;
struct gsn_addr gsna;
uint16_t port;
int rc = gsn_addr_from_sockaddr(&gsna, &port, addr);
if (rc < 0)
LOG(LOGL_ERROR, "%s(): failed to obtain GSN address\n", __func__);
pa = gtphub_addr_find(bind, &gsna);
if (!pa)
return NULL;
pp = gtphub_addr_find_port(pa, port);
if (!pp)
pp = gtphub_addr_add_port(pa, port);
return pp;
}
/* Return 0 if the message in p is not applicable for GGSN resolution, -1 if
* resolution should be possible but failed, and 1 if resolution was
* successful. *pp will be set to NULL if <1 is returned. */
static int gtphub_resolve_ggsn(struct gtphub *hub,
struct gtp_packet_desc *p,
struct gtphub_peer_port **pp)
{
*pp = NULL;
/* TODO determine from message type whether IEs should be present? */
int rc;
const char *imsi_str;
rc = get_ie_imsi_str(p->ie, 0, &imsi_str);
if (rc < 1)
return rc;
OSMO_ASSERT(imsi_str);
const char *apn_str;
rc = get_ie_apn_str(p->ie, &apn_str);
if (rc < 1)
return rc;
OSMO_ASSERT(apn_str);
*pp = gtphub_resolve_ggsn_addr(hub, imsi_str, apn_str);
return (*pp)? 1 : -1;
}
/* TODO move to osmocom/core/socket.c ? */
/* use this in osmo_sock_init() to remove dup. */
/* Internal: call getaddrinfo for sgsn_sockaddr_init(). The caller is required
to call freeaddrinfo(*result), iff zero is returned. */
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 sgsn_sockaddr_init(struct sgsn_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) {
LOG(LOGL_ERROR, "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 sgsn_sockaddr_to_strs(char *addr_str, size_t addr_str_len,
char *port_str, size_t port_str_len,
const struct sgsn_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 *sgsn_sockaddr_to_strb(const struct sgsn_sockaddr *addr,
char *buf, size_t buf_len)
{
char portbuf[6];
const int portbuf_len = 6;
OSMO_ASSERT(buf_len > portbuf_len);
buf_len -= portbuf_len;
if (sgsn_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 *sgsn_sockaddr_to_str(const struct sgsn_sockaddr *addr)
{
static char buf[256];
const char *result = sgsn_sockaddr_to_strb(addr, buf, sizeof(buf));
if (! result)
return "(invalid)";
return result;
}
int sgsn_sockaddr_cmp(const struct sgsn_sockaddr *a,
const struct sgsn_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 sgsn_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 sgsn_sockaddr_copy(struct sgsn_sockaddr *dst,
const struct sgsn_sockaddr *src)
{
OSMO_ASSERT(src->l <= sizeof(dst->a));
memcpy(&dst->a, &src->a, src->l);
dst->l = src->l;
}