Create tun_if module for TUN interface handling

Move openair3/RRC/NAS/nas_config.c to common/utils/tun_if.c, and remove the former from all targets.
2024-08-02 15:31:04 +02:00
parent 39e7839f19
commit 89d89a7564
12 changed files with 32 additions and 40 deletions
@@ -13,6 +13,6 @@ add_subdirectory(T)
 add_subdirectory(nr)
 add_subdirectory(LOG)
 add_subdirectory(threadPool)
-add_library(utils utils.c system.c time_meas.c time_stat.c)
+add_library(utils utils.c system.c time_meas.c time_stat.c tun_if.c)
 target_include_directories(utils PUBLIC .)
 target_link_libraries(utils PRIVATE ${T_LIB})
@@ -0,0 +1,188 @@
+/*
+ * Licensed to the OpenAirInterface (OAI) Software Alliance under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The OpenAirInterface Software Alliance licenses this file to You under
+ * the OAI Public License, Version 1.1  (the "License"); you may not use this file
+ * except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.openairinterface.org/?page_id=698
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *-------------------------------------------------------------------------------
+ * For more information about the OpenAirInterface (OAI) Software Alliance:
+ *      contact@openairinterface.org
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <sys/ioctl.h>
+#include <net/if.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <linux/ipv6.h>
+
+#include "tun_if.h"
+#include "common/utils/LOG/log.h"
+#include "common/utils/system.h"
+
+/*
+ * \brief set a genneric interface parameter
+ * \param ifn the name of the interface to modify
+ * \param if_addr the address that needs to be modified
+ * \param operation one of SIOCSIFADDR (set interface address), SIOCSIFNETMASK
+ *   (set network mask), SIOCSIFBRDADDR (set broadcast address), SIOCSIFFLAGS
+ *   (set flags)
+ * \return true on success, false otherwise
+ */
+static bool setInterfaceParameter(int sock_fd, const char *ifn, int af, const char *if_addr, int operation)
+{
+  DevAssert(af == AF_INET || af == AF_INET6);
+  struct ifreq ifr = {0};
+  strncpy(ifr.ifr_name, ifn, sizeof(ifr.ifr_name));
+  struct in6_ifreq ifr6 = {0};
+
+  void *ioctl_opt = NULL;
+  if (af == AF_INET) {
+    struct sockaddr_in addr = {.sin_family = AF_INET};
+    int ret = inet_pton(af, if_addr, &addr.sin_addr);
+    if (ret != 1) {
+      LOG_E(OIP, "inet_pton(): cannot convert %s to IPv4 network address\n", if_addr);
+      return false;
+    }
+    memcpy(&ifr.ifr_ifru.ifru_addr,&addr,sizeof(struct sockaddr_in));
+    ioctl_opt = &ifr;
+  } else {
+    struct sockaddr_in6 addr6 = {.sin6_family = AF_INET6};
+    int ret = inet_pton(af, if_addr, &addr6.sin6_addr);
+    if (ret != 1) {
+      LOG_E(OIP, "inet_pton(): cannot convert %s to IPv6 network address\n", if_addr);
+      return false;
+    }
+    memcpy(&ifr6.ifr6_addr, &addr6.sin6_addr, sizeof(struct in6_addr));
+    // we need to get the if index to put it into ifr6
+    if (ioctl(sock_fd, SIOGIFINDEX, &ifr) < 0) {
+      LOG_E(OIP, "ioctl() failed: errno %d, %s\n", errno, strerror(errno));
+      return false;
+    }
+    ifr6.ifr6_ifindex = ifr.ifr_ifindex;
+    ifr6.ifr6_prefixlen = 64;
+    ioctl_opt = &ifr6;
+  }
+
+  bool success = ioctl(sock_fd, operation, ioctl_opt) == 0;
+  if (!success)
+    LOG_E(OIP, "Setting operation %d for %s: ioctl call failed: %d, %s\n", operation, ifn, errno, strerror(errno));
+  return success;
+}
+
+/*
+ * \brief bring interface up (up != 0) or down (up == 0)
+ */
+typedef enum { INTERFACE_DOWN, INTERFACE_UP } if_action_t;
+static bool change_interface_state(int sock_fd, const char *ifn, if_action_t if_action)
+{
+  const char* action = if_action == INTERFACE_DOWN ? "DOWN" : "UP";
+
+  struct ifreq ifr = {0};
+  strncpy(ifr.ifr_name, ifn, sizeof(ifr.ifr_name));
+  /* get flags of this interface: see netdevice(7) */
+  bool success = ioctl(sock_fd, SIOCGIFFLAGS, (caddr_t)&ifr) == 0;
+  if (!success)
+    goto fail_interface_state;
+
+  if (if_action == INTERFACE_UP) {
+    ifr.ifr_flags |= IFF_UP | IFF_NOARP | IFF_POINTOPOINT;
+    ifr.ifr_flags &= ~IFF_MULTICAST;
+  } else {
+    ifr.ifr_flags &= ~IFF_UP;
+  }
+
+  success = ioctl(sock_fd, SIOCSIFFLAGS, (caddr_t)&ifr) == 0;
+  if (!success)
+    goto fail_interface_state;
+  return true;
+
+fail_interface_state:
+  LOG_E(OIP, "Bringing interface %s for %s: ioctl call failed: %d, %s\n", action, ifn, errno, strerror(errno));
+  return false;
+}
+
+// non blocking full configuration of the interface (address, and the two lest octets of the address)
+bool tun_config(int interface_id, const char *ipv4, const char *ipv6, const char *ifpref)
+{
+  char interfaceName[IFNAMSIZ];
+  snprintf(interfaceName, sizeof(interfaceName), "%s%d", ifpref, interface_id);
+
+  AssertFatal(ipv4 != NULL || ipv6 != NULL, "need to have IP address, but none given\n");
+
+  int sock_fd = socket(AF_INET, SOCK_DGRAM, 0);
+  if (sock_fd < 0) {
+    LOG_E(UTIL, "Failed creating socket for interface management: %d, %s\n", errno, strerror(errno));
+    return false;
+  }
+
+  change_interface_state(sock_fd, interfaceName, INTERFACE_DOWN);
+  bool success = true;
+  if (ipv4 != NULL)
+    success = setInterfaceParameter(sock_fd, interfaceName, AF_INET, ipv4, SIOCSIFADDR);
+  // set the machine network mask for IPv4
+  if (success && ipv4 != NULL)
+    success = setInterfaceParameter(sock_fd, interfaceName, AF_INET, "255.255.255.0", SIOCSIFNETMASK);
+
+  if (ipv6 != NULL) {
+    // for setting the IPv6 address, we need an IPv6 socket. For setting IPv4,
+    // we need an IPv4 socket. So do all operations using IPv4 socket, except
+    // for setting the IPv6
+    int sock_fd = socket(AF_INET6, SOCK_DGRAM, 0);
+    if (sock_fd < 0) {
+      LOG_E(UTIL, "Failed creating socket for interface management: %d, %s\n", errno, strerror(errno));
+      success = false;
+    }
+    success = success && setInterfaceParameter(sock_fd, interfaceName, AF_INET6, ipv6, SIOCSIFADDR);
+    close(sock_fd);
+  }
+
+  if (success)
+    success = change_interface_state(sock_fd, interfaceName, INTERFACE_UP);
+
+  if (success)
+    LOG_I(OIP, "Interface %s successfully configured, IPv4 %s, IPv6 %s\n", interfaceName, ipv4, ipv6);
+  else
+    LOG_E(OIP, "Interface %s couldn't be configured (IPv4 %s, IPv6 %s)\n", interfaceName, ipv4, ipv6);
+
+  close(sock_fd);
+  return success;
+}
+
+void setup_ue_ipv4_route(int interface_id, const char *ipv4, const char *ifpref)
+{
+  int table_id = interface_id - 1 + 10000;
+  char interfaceName[IFNAMSIZ];
+  snprintf(interfaceName, sizeof(interfaceName), "%s%d", ifpref, interface_id);
+
+  char command_line[500];
+  int res = sprintf(command_line,
+                    "ip rule add from %s/32 table %d && "
+                    "ip rule add to %s/32 table %d && "
+                    "ip route add default dev %s table %d",
+                    ipv4,
+                    table_id,
+                    ipv4,
+                    table_id,
+                    interfaceName,
+                    table_id);
+
+  if (res < 0) {
+    LOG_E(UTIL, "Could not create ip rule/route commands string\n");
+    return;
+  }
+  background_system(command_line);
+}
+
@@ -0,0 +1,57 @@
+/*
+ * Licensed to the OpenAirInterface (OAI) Software Alliance under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The OpenAirInterface Software Alliance licenses this file to You under
+ * the OAI Public License, Version 1.1  (the "License"); you may not use this file
+ * except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.openairinterface.org/?page_id=698
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *-------------------------------------------------------------------------------
+ * For more information about the OpenAirInterface (OAI) Software Alliance:
+ *      contact@openairinterface.org
+ */
+
+#ifndef TUN_IF_H_
+#define TUN_IF_H_
+
+#include <stdbool.h>
+
+/*! \fn int  tun_config(char*, int, int)
+ * \brief This function initializes the nasmesh interface using the basic values,
+ * basic address, network mask and broadcast address, as the default configured
+ * ones
+ * \param[in] interface_id number of this interface, prepended after interface
+ * name
+ * \param[in] ipv4 IPv4 address of this interface as a string
+ * \param[in] ipv6 IPv6 address of this interface as a string
+ * \param[in] ifprefix interface name prefix to which an interface number will
+ * be appended
+ * \return true on success, otherwise false
+ * \note
+ * @ingroup  _nas
+ */
+bool tun_config(int interface_id, const char *ipv4, const char *ipv6, const char *ifprefix);
+
+/*!
+ * \brief Setup a IPv4 rule in table (interface_id - 1 + 10000) and route to
+ * force packets coming into interface back through it, and workaround
+ * net.ipv4.conf.all.rp_filter=2 (strict source filtering would filter out
+ * responses of packets going out through interface to another IP address not
+ * in same subnet).
+ * \param[in] interface_id number of this interface, prepended after interface
+ * name
+ * \param[in] ipv4 IPv4 address of the UE
+ * \param[in] ifprefix interface name prefix to which an interface number will
+ * be appended
+ */
+void setup_ue_ipv4_route(int interface_id, const char *ipv4, const char *ifpref);
+
+#endif /*TUN_IF_H_*/