From c838758db236844e59db9cdb75efed2639eac90a Mon Sep 17 00:00:00 2001 From: Pedro Alvarez Date: Thu, 7 Dec 2017 17:09:31 +0000 Subject: [PATCH] Added downlink IP tunnel. Downlink user plane packets reach the UE. --- lib/include/srslte/upper/gtpu.h | 95 ++++++++++++++++++++++++++++++++ lib/src/upper/gtpu.cc | 96 +++++++++++++++++++++++++++++++++ srsepc/src/mme/s1ap.cc | 2 +- srsepc/src/spgw/spgw.cc | 33 ++++++++++-- 4 files changed, 220 insertions(+), 6 deletions(-) create mode 100644 lib/include/srslte/upper/gtpu.h create mode 100644 lib/src/upper/gtpu.cc diff --git a/lib/include/srslte/upper/gtpu.h b/lib/include/srslte/upper/gtpu.h new file mode 100644 index 000000000..3cd8a1202 --- /dev/null +++ b/lib/include/srslte/upper/gtpu.h @@ -0,0 +1,95 @@ +/** + * + * \section COPYRIGHT + * + * Copyright 2013-2017 Software Radio Systems Limited + * + * \section LICENSE + * + * This file is part of the srsLTE library. + * + * srsUE 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. + * + * srsUE 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. + * + * A copy of the GNU Affero General Public License can be found in + * the LICENSE file in the top-level directory of this distribution + * and at http://www.gnu.org/licenses/. + * + */ + +#ifndef SRSLTE_GTPU_H +#define SRSLTE_GTPU_H + +#include +#include "srslte/common/common.h" + +namespace srslte { + +/**************************************************************************** + * GTPU Header + * Ref: 3GPP TS 29.281 v10.1.0 Section 5 + * + * | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | + * + * 1 | Version |PT | * | E | S |PN | + * 2 | Message Type | + * 3 | Length (1st Octet) | + * 4 | Length (2nd Octet) | + * 5 | TEID (1st Octet) | + * 6 | TEID (2nd Octet) | + * 7 | TEID (3rd Octet) | + * 8 | TEID (4th Octet) | + ***************************************************************************/ + +#define GTPU_HEADER_LEN 8 + +typedef struct{ + uint8_t flags; // Only support 0x30 - v1, PT1 (GTP), no other flags + uint8_t message_type; // Only support 0xFF - T-PDU type + uint16_t length; + uint32_t teid; +}gtpu_header_t; + + +bool gtpu_read_header(srslte::byte_buffer_t *pdu, gtpu_header_t *header); +bool gtpu_write_header(gtpu_header_t *header, srslte::byte_buffer_t *pdu); + +inline void uint8_to_uint32(uint8_t *buf, uint32_t *i) +{ + *i = (uint32_t)buf[0] << 24 | + (uint32_t)buf[1] << 16 | + (uint32_t)buf[2] << 8 | + (uint32_t)buf[3]; +} + +inline void uint32_to_uint8(uint32_t i, uint8_t *buf) +{ + buf[0] = (i >> 24) & 0xFF; + buf[1] = (i >> 16) & 0xFF; + buf[2] = (i >> 8) & 0xFF; + buf[3] = i & 0xFF; +} + +inline void uint8_to_uint16(uint8_t *buf, uint16_t *i) +{ + *i = (uint32_t)buf[0] << 8 | + (uint32_t)buf[1]; +} + +inline void uint16_to_uint8(uint16_t i, uint8_t *buf) +{ + buf[0] = (i >> 8) & 0xFF; + buf[1] = i & 0xFF; +} + + +}//namespace + +#endif diff --git a/lib/src/upper/gtpu.cc b/lib/src/upper/gtpu.cc new file mode 100644 index 000000000..668af8915 --- /dev/null +++ b/lib/src/upper/gtpu.cc @@ -0,0 +1,96 @@ +/** + * + * \section COPYRIGHT + * + * Copyright 2013-2017 Software Radio Systems Limited + * + * \section LICENSE + * + * This file is part of the srsLTE library. + * + * srsUE 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. + * + * srsUE 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. + * + * A copy of the GNU Affero General Public License can be found in + * the LICENSE file in the top-level directory of this distribution + * and at http://www.gnu.org/licenses/. + * + */ + + +#include "srslte/upper/gtpu.h" + + +namespace srslte { + +/**************************************************************************** + * Header pack/unpack helper functions + * Ref: 3GPP TS 29.281 v10.1.0 Section 5 + ***************************************************************************/ + +bool gtpu_write_header(gtpu_header_t *header, srslte::byte_buffer_t *pdu) +{ + if(header->flags != 0x30) { + //gtpu_log->error("gtpu_write_header - Unhandled header flags: 0x%x\n", header->flags); + return false; + } + if(header->message_type != 0xFF) { + //gtpu_log->error("gtpu_write_header - Unhandled message type: 0x%x\n", header->message_type); + return false; + } + if(pdu->get_headroom() < GTPU_HEADER_LEN) { + //gtpu_log->error("gtpu_write_header - No room in PDU for header\n"); + return false; + } + + pdu->msg -= GTPU_HEADER_LEN; + pdu->N_bytes += GTPU_HEADER_LEN; + + uint8_t *ptr = pdu->msg; + + *ptr = header->flags; + ptr++; + *ptr = header->message_type; + ptr++; + uint16_to_uint8(header->length, ptr); + ptr += 2; + uint32_to_uint8(header->teid, ptr); + + return true; +} + +bool gtpu_read_header(srslte::byte_buffer_t *pdu, gtpu_header_t *header) +{ + uint8_t *ptr = pdu->msg; + + pdu->msg += GTPU_HEADER_LEN; + pdu->N_bytes -= GTPU_HEADER_LEN; + + header->flags = *ptr; + ptr++; + header->message_type = *ptr; + ptr++; + uint8_to_uint16(ptr, &header->length); + ptr += 2; + uint8_to_uint32(ptr, &header->teid); + + if(header->flags != 0x30) { + //gtpu_log->error("gtpu_read_header - Unhandled header flags: 0x%x\n", header->flags); + return false; + } + if(header->message_type != 0xFF) { + //gtpu_log->error("gtpu_read_header - Unhandled message type: 0x%x\n", header->message_type); + return false; + } + + return true; +} + +} // namespace srslte diff --git a/srsepc/src/mme/s1ap.cc b/srsepc/src/mme/s1ap.cc index 370ed87c2..4cef13cab 100644 --- a/srsepc/src/mme/s1ap.cc +++ b/srsepc/src/mme/s1ap.cc @@ -698,7 +698,7 @@ s1ap::handle_initial_context_setup_response(LIBLTE_S1AP_MESSAGE_INITIALCONTEXTSE m_s1ap_log->error("Could not find UE's context in active UE's map\n"); return false; } - for(uint32_t i; iE_RABSetupListCtxtSURes.len;i++) + for(uint32_t i=0; iE_RABSetupListCtxtSURes.len;i++) { uint8_t erab_id = in_ctxt_resp->E_RABSetupListCtxtSURes.buffer[i].e_RAB_ID.E_RAB_ID; erab_ctx_t *erab_ctx = &ue_ctx_it->second->erabs_ctx[erab_id]; diff --git a/srsepc/src/spgw/spgw.cc b/srsepc/src/spgw/spgw.cc index fcde590da..d31cf6832 100644 --- a/srsepc/src/spgw/spgw.cc +++ b/srsepc/src/spgw/spgw.cc @@ -35,7 +35,7 @@ #include #include "spgw/spgw.h" #include "mme/mme_gtpc.h" - +#include "srslte/upper/gtpu.h" namespace srsepc{ @@ -263,7 +263,7 @@ spgw::run_thread() //m_spgw_log->info("Waiting for S1-U or SGi packets.\n"); int n = select(max_fd+1, &set, NULL, NULL, NULL); if (n == -1) - { + { m_spgw_log->error("Error from select\n"); } else if (n) @@ -328,11 +328,34 @@ spgw::handle_sgi_pdu(srslte::byte_buffer_t *msg) m_spgw_log->console("IP Packet is not for any UE\n"); return; } - struct in_addr enb_addr; - enb_addr.s_addr = enb_fteid.ipv4; - m_spgw_log->console("UE F-TEID found, TEID 0x%x, eNB IP %s\n", enb_fteid.teid, inet_ntoa(enb_addr)); + struct sockaddr_in enb_addr; + enb_addr.sin_family = AF_INET; + enb_addr.sin_port = htons(GTPU_RX_PORT); + enb_addr.sin_addr.s_addr = enb_fteid.ipv4; + m_spgw_log->console("UE F-TEID found, TEID 0x%x, eNB IP %s\n", enb_fteid.teid, inet_ntoa(enb_addr.sin_addr)); + + //Setup GTP-U header + srslte::gtpu_header_t header; + header.flags = 0x30; + header.message_type = 0xFF; + header.length = msg->N_bytes; + header.teid = enb_fteid.teid; + + //Write header into packet + if(!srslte::gtpu_write_header(&header, msg)) + { + m_spgw_log->console("Error writing GTP-U header on PDU\n"); + } + //Send packet to destination + int n = sendto(m_s1u,msg->msg,msg->N_bytes,0,(struct sockaddr*) &enb_addr,sizeof(enb_addr)); + if(n<0) + { + m_spgw_log->console("Error sending packet to eNB\n"); + return; + } + m_spgw_log->console("Sent packet to %s:%d. Bytes=%d\n",inet_ntoa(enb_addr.sin_addr), GTPU_RX_PORT,n); return; }