Refactor tun_if.h

Use a common function for generating interface name. Use full interface
name in tun_if.h functions.

common/utils/tun_if.c

@@ -38,7 +38,7 @@
 int nas_sock_fd[MAX_MOBILES_PER_ENB * 2]; // Allocated for both LTE UE and NR UE.
 int nas_sock_mbms_fd;
 
-static int tun_alloc(char *dev)
+static int tun_alloc(const char *dev)
 {
   struct ifreq ifr;
   int fd, err;
@@ -55,25 +55,27 @@ static int tun_alloc(char *dev)
    *        IFF_NO_PI - Do not provide packet information
    */
   ifr.ifr_flags = IFF_TUN | IFF_NO_PI;
-
+  strncpy(ifr.ifr_name, dev, sizeof(ifr.ifr_name) - 1);
-  if (*dev)
-    strncpy(ifr.ifr_name, dev, sizeof(ifr.ifr_name) - 1);
-
   if ((err = ioctl(fd, TUNSETIFF, (void *)&ifr)) < 0) {
     close(fd);
     return err;
   }
+  // According to https://www.kernel.org/doc/Documentation/networking/tuntap.txt, TUNSETIFF performs string
+  // formatting on ifr_name. To ensure that the generated name is what we expect, check it here.
+  AssertFatal(strcmp(ifr.ifr_name, dev) == 0, "Failed to create tun interface, expected ifname %s, got %s\n", dev, ifr.ifr_name);
+
+  err = fcntl(fd, F_SETFL, O_NONBLOCK);
+  if (err == -1) {
+    close(fd);
+    LOG_E(UTIL, "Error fcntl (%d:%s)\n", errno, strerror(errno));
+    return err;
+  }
 
-  strcpy(dev, ifr.ifr_name);
   return fd;
 }
 
-int tun_init_mbms(char *ifprefix, int id)
+int tun_init_mbms(char *ifname)
 {
-  int ret;
-  char ifname[64];
-
-  sprintf(ifname, "%s%d", ifprefix, id);
   nas_sock_mbms_fd = tun_alloc(ifname);
 
   if (nas_sock_mbms_fd == -1) {
@@ -82,48 +84,26 @@ int tun_init_mbms(char *ifprefix, int id)
   }
 
   LOG_D(UTIL, "Opened socket %s with fd %d\n", ifname, nas_sock_mbms_fd);
-  ret = fcntl(nas_sock_mbms_fd, F_SETFL, O_NONBLOCK);
-
-  if (ret == -1) {
-    LOG_E(UTIL, "Error fcntl (%d:%s)\n", errno, strerror(errno));
-    return 0;
-  }
 
   struct sockaddr_nl nas_src_addr = {0};
   nas_src_addr.nl_family = AF_NETLINK;
   nas_src_addr.nl_pid = 1;
   nas_src_addr.nl_groups = 0; /* not in mcast groups */
-  ret = bind(nas_sock_mbms_fd, (struct sockaddr *)&nas_src_addr, sizeof(nas_src_addr));
+  bind(nas_sock_mbms_fd, (struct sockaddr *)&nas_src_addr, sizeof(nas_src_addr));
 
   return 1;
 }
 
-int tun_init(const char *ifprefix, int num_if, int id)
+int tun_init(const char *ifname, int instance_id)
 {
-  int ret;
+  nas_sock_fd[instance_id] = tun_alloc(ifname);
-  char ifname[64];
 
-  int begx = (id == 0) ? 0 : id - 1;
+  if (nas_sock_fd[instance_id] == -1) {
-  int endx = (id == 0) ? num_if : id;
+    LOG_E(UTIL, "Error opening socket %s (%d:%s)\n", ifname, errno, strerror(errno));
-  for (int i = begx; i < endx; i++) {
+    return 0;
-    sprintf(ifname, "%s%d", ifprefix, i + 1);
-    nas_sock_fd[i] = tun_alloc(ifname);
-
-    if (nas_sock_fd[i] == -1) {
-      LOG_E(UTIL, "Error opening socket %s (%d:%s)\n", ifname, errno, strerror(errno));
-      return 0;
-    }
-
-    LOG_I(UTIL, "Opened socket %s with fd nas_sock_fd[%d]=%d\n", ifname, i, nas_sock_fd[i]);
-    ret = fcntl(nas_sock_fd[i], F_SETFL, O_NONBLOCK);
-
-    if (ret == -1) {
-      LOG_E(UTIL, "Error fcntl (%d:%s)\n", errno, strerror(errno));
-
-      return 0;
-    }
   }
 
+  LOG_I(UTIL, "Opened socket %s with fd nas_sock_fd[%d]=%d\n", ifname, instance_id, nas_sock_fd[instance_id]);
   return 1;
 }
 
@@ -209,12 +189,8 @@ fail_interface_state:
   return false;
 }
 
-// non blocking full configuration of the interface (address, and the two lest octets of the address)
+bool tun_config(const char* ifname, const char *ipv4, const char *ipv6)
-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);
@@ -223,13 +199,16 @@ bool tun_config(int interface_id, const char *ipv4, const char *ipv6, const char
     return false;
   }
 
-  change_interface_state(sock_fd, interfaceName, INTERFACE_DOWN);
+  if (!change_interface_state(sock_fd, ifname, INTERFACE_DOWN)) {
+    close(sock_fd);
+    return false;
+  }
   bool success = true;
   if (ipv4 != NULL)
-    success = setInterfaceParameter(sock_fd, interfaceName, AF_INET, ipv4, SIOCSIFADDR);
+    success = setInterfaceParameter(sock_fd, ifname, 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);
+    success = setInterfaceParameter(sock_fd, ifname, AF_INET, "255.255.255.0", SIOCSIFNETMASK);
 
   if (ipv6 != NULL) {
     // for setting the IPv6 address, we need an IPv6 socket. For setting IPv4,
@@ -240,27 +219,25 @@ bool tun_config(int interface_id, const char *ipv4, const char *ipv6, const char
       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);
+    success = success && setInterfaceParameter(sock_fd, ifname, AF_INET6, ipv6, SIOCSIFADDR);
     close(sock_fd);
   }
 
   if (success)
-    success = change_interface_state(sock_fd, interfaceName, INTERFACE_UP);
+    success = change_interface_state(sock_fd, ifname, INTERFACE_UP);
 
   if (success)
-    LOG_I(OIP, "Interface %s successfully configured, IPv4 %s, IPv6 %s\n", interfaceName, ipv4, ipv6);
+    LOG_I(OIP, "Interface %s successfully configured, IPv4 %s, IPv6 %s\n", ifname, ipv4, ipv6);
   else
-    LOG_E(OIP, "Interface %s couldn't be configured (IPv4 %s, IPv6 %s)\n", interfaceName, ipv4, ipv6);
+    LOG_E(OIP, "Interface %s couldn't be configured (IPv4 %s, IPv6 %s)\n", ifname, ipv4, ipv6);
 
   close(sock_fd);
   return success;
 }
 
-void setup_ue_ipv4_route(int interface_id, const char *ipv4, const char *ifpref)
+void setup_ue_ipv4_route(const char* ifname, int instance_id, const char *ipv4)
 {
-  int table_id = interface_id - 1 + 10000;
+  int table_id = instance_id - 1 + 10000;
-  char interfaceName[IFNAMSIZ];
-  snprintf(interfaceName, sizeof(interfaceName), "%s%d", ifpref, interface_id);
 
   char command_line[500];
   int res = sprintf(command_line,
@@ -271,7 +248,7 @@ void setup_ue_ipv4_route(int interface_id, const char *ipv4, const char *ifpref)
                     table_id,
                     ipv4,
                     table_id,
-                    interfaceName,
+                    ifname,
                     table_id);
 
   if (res < 0) {
@@ -281,3 +258,7 @@ void setup_ue_ipv4_route(int interface_id, const char *ipv4, const char *ifpref)
   background_system(command_line);
 }
 
+int tun_generate_ifname(char *ifname, const char *ifprefix, int instance_id)
+{
+  return snprintf(ifname, IFNAMSIZ, "%s%d", ifprefix, instance_id + 1);
+}

common/utils/tun_if.h

@@ -23,28 +23,43 @@
 #define TUN_IF_H_
 
 #include <stdbool.h>
+#include <net/if.h>
 
-/* TODO: doc */
+/*!
-int tun_init(const char *ifprefix, int num_if, int id);
+ * \brief This function generates the name of the interface based on the prefix and
+ * the instance id.
+ *
+ * \param[in,out] ifname name of the interface
+ * \param[in] ifprefix prefix of the interface
+ * \param[in] instance_id unique instance number
+ */
+int tun_generate_ifname(char *ifname, const char *ifprefix, int instance_id);
 
-/* TODO: doc */
+/*!
-int tun_init_mbms(char *ifsuffix, int id);
+ * \brief This function initializes the TUN interface
+ * \param[in] ifname name of the interface
+ * \param[in] instance_id unique instance number, used to save socket file descriptor
+ */
+int tun_init(const char *ifname, int instance_id);
 
-/*! \fn int  tun_config(char*, int, int)
+/*!
+ * \brief This function initializes the TUN interface for MBMS
+ * \param[in] ifname name of the interface
+ */
+int tun_init_mbms(char *ifname);
+
+/*!
  * \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
+ * \param[in] ifname name of the 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);
+bool tun_config(const char* ifname, const char *ipv4, const char *ipv6);
 
 /*!
  * \brief Setup a IPv4 rule in table (interface_id - 1 + 10000) and route to
@@ -52,12 +67,10 @@ bool tun_config(int interface_id, const char *ipv4, const char *ipv6, const char
  * 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
+ * \param[in] ifname name of the interface
- * name
+ * \param[in] instance_id unique instance number, used to create the table
  * \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);
+void setup_ue_ipv4_route(const char* ifname, int instance_id, const char *ipv4);
 
 #endif /*TUN_IF_H_*/

openair2/LAYER2/PDCP_v10.1.0/pdcp.c

@@ -2172,22 +2172,35 @@ uint64_t pdcp_module_init( uint64_t pdcp_optmask, int id) {
 
   if (UE_NAS_USE_TUN) {
     int num_if = (NFAPI_MODE == NFAPI_UE_STUB_PNF || IS_SOFTMODEM_SIML1 || NFAPI_MODE == NFAPI_MODE_STANDALONE_PNF) ? MAX_MOBILES_PER_ENB : 1;
-    tun_init("oaitun_ue", num_if, id);
+    int begx = (id == 0) ? 0 : id - 1;
-    tun_init_mbms("oaitun_uem", id + 1);
+    int endx = (id == 0) ? num_if : id;
-    tun_config(1, "10.0.2.2", NULL, "oaitun_uem");
+    for (int i = begx; i < endx; i++) {
+      char ifname[IFNAMSIZ];
+      tun_generate_ifname(ifname, "oaitun_ue", i);
+      tun_init(ifname, i);
+    }
+    char ifname[IFNAMSIZ];
+    tun_generate_ifname(ifname, "oaitun_uem", id + 1);
+    tun_init_mbms(ifname);
+    tun_config(ifname, "10.0.2.2", NULL);
     LOG_I(PDCP, "UE pdcp will use tun interface\n");
   } else if (ENB_NAS_USE_TUN) {
-    tun_init("oaitun_enb", 1, 0);
+    char ifname[IFNAMSIZ];
-    tun_config(1, "10.0.1.1", NULL, "oaitun_enb");
+    tun_generate_ifname(ifname, "oaitun_enb", 0);
+    tun_init(ifname, 0);
+    tun_config(ifname, "10.0.1.1", NULL);
     if (pdcp_optmask & ENB_NAS_USE_TUN_W_MBMS_BIT) {
-      tun_init_mbms("oaitun_enm", 1);
+      tun_generate_ifname(ifname, "oaitun_enm", 0);
-      tun_config(1, "10.0.2.1", NULL, "oaitun_enm");
+      tun_init_mbms(ifname);
+      tun_config(ifname, "10.0.2.1", NULL);
       LOG_I(PDCP, "ENB pdcp will use mbms tun interface\n");
     }
     LOG_I(PDCP, "ENB pdcp will use tun interface\n");
   } else if (pdcp_optmask & ENB_NAS_USE_TUN_W_MBMS_BIT) {
-    tun_init_mbms("oaitun_enm", 0);
+    char ifname[IFNAMSIZ];
-    tun_config(1, "10.0.2.1", NULL, "oaitun_enm");
+    tun_generate_ifname(ifname, "oaitun_enm", 0);
+    tun_init_mbms(ifname);
+    tun_config(ifname, "10.0.2.1", NULL);
     LOG_I(PDCP, "ENB pdcp will use mbms tun interface\n");
   }
 

openair2/LAYER2/nr_pdcp/nr_pdcp_oai_api.c

@@ -640,18 +640,28 @@ uint64_t nr_pdcp_module_init(uint64_t _pdcp_optmask, int id)
     int num_if = (NFAPI_MODE == NFAPI_UE_STUB_PNF || IS_SOFTMODEM_SIML1 || NFAPI_MODE == NFAPI_MODE_STANDALONE_PNF)
                      ? MAX_MOBILES_PER_ENB
                      : 1;
-    tun_init(ifprefix, num_if, id);
+    int begx = (id == 0) ? 0 : id - 1;
+    int endx = (id == 0) ? num_if : id;
+    for (int i = begx; i < endx; i++) {
+      char ifname[IFNAMSIZ];
+      tun_generate_ifname(ifname, ifprefix, i);
+      tun_init(ifname, i);
+    }
     if (IS_SOFTMODEM_NOS1) {
       const char *ip = !get_softmodem_params()->nsa ? "10.0.1.2" : "10.0.1.3";
-      tun_config(1, ip, NULL, ifprefix);
+      char ifname[IFNAMSIZ];
+      tun_generate_ifname(ifname, ifprefix, id);
+      tun_config(ifname, ip, NULL);
       set_qfi_pduid(7, 10);
     }
     LOG_I(PDCP, "UE pdcp will use tun interface\n");
     start_pdcp_tun_ue();
   } else if (ENB_NAS_USE_TUN) {
     char *ifprefix = get_softmodem_params()->nsa ? "oaitun_gnb" : "oaitun_enb";
-    tun_init(ifprefix, 1, id);
+    char ifname[IFNAMSIZ];
-    tun_config(1, "10.0.1.1", NULL, ifprefix);
+    tun_generate_ifname(ifname, ifprefix, id);
+    tun_init(ifname, id);
+    tun_config(ifname, "10.0.1.1", NULL);
     LOG_I(PDCP, "ENB pdcp will use tun interface\n");
     start_pdcp_tun_enb();
   }

openair2/RRC/LTE/rrc_UE.c

@@ -777,7 +777,9 @@ rrc_ue_establish_drb(
              "10.0.%d.%d",
              UE_NAS_USE_TUN ? 1 : (ip_addr_offset3 + ue_mod_idP + 1),
              ip_addr_offset4 + ue_mod_idP + 1);
-    oip_ifup = tun_config(ip_addr_offset3 + ue_mod_idP + 1, ip, NULL, "oaitun_ue");
+    char ifname[IFNAMSIZ];
+    tun_generate_ifname(ifname, "oaitun_ue", ip_addr_offset3 + ue_mod_idP);
+    oip_ifup = tun_config(ifname, ip, NULL);
 
     if (oip_ifup == 0 && (!UE_NAS_USE_TUN)) { // interface is up --> send a config the DRB
       LOG_I(OIP,"[UE %d] Config the ue net interface %d to send/receive pkt on DRB %ld to/from the protocol stack\n",

openair2/RRC/LTE/rrc_eNB.c

@@ -5250,7 +5250,9 @@ rrc_eNB_process_RRCConnectionReconfigurationComplete(
                   ctxt_pP->module_id);
             char ip[20];
             snprintf(ip, sizeof(ip), "10.0.%d.%d", ctxt_pP->module_id + 1, ctxt_pP->module_id + 1);
-            oip_ifup = tun_config(ctxt_pP->module_id, ip, NULL, "oaitun_oai");
+            char ifname[IFNAMSIZ];
+            tun_generate_ifname(ifname, "oaitun_oai", ctxt_pP->module_id);
+            oip_ifup = tun_config(ifname, ip, NULL);
 
             if (oip_ifup == 0) { // interface is up --> send a config the DRB
               module_id_t ue_module_id;

openair3/NAS/NR_UE/nr_nas_msg.c

@@ -855,14 +855,18 @@ static void process_pdu_session_addr(pdu_session_establishment_accept_msg_t *msg
     case PDU_SESSION_TYPE_IPV4: {
       char ip[20];
       capture_ipv4_addr(&addr[0], ip, sizeof(ip));
-      tun_config(1, ip, NULL, "oaitun_ue");
+      char ifname[IFNAMSIZ];
-      setup_ue_ipv4_route(1, ip, "oaitun_ue");
+      tun_generate_ifname(ifname, "oaitun_ue", 0);
+      tun_config(ifname, ip, NULL);
+      setup_ue_ipv4_route(ifname, 0, ip);
     } break;
 
     case PDU_SESSION_TYPE_IPV6: {
       char ipv6[40];
       capture_ipv6_addr(addr, ipv6, sizeof(ipv6));
-      tun_config(1, NULL, ipv6, "oaitun_ue");
+      char ifname[IFNAMSIZ];
+      tun_generate_ifname(ifname, "oaitun_ue", 0);
+      tun_config(ifname, NULL, ipv6);
     } break;
 
     case PDU_SESSION_TYPE_IPV4V6: {
@@ -870,8 +874,10 @@ static void process_pdu_session_addr(pdu_session_establishment_accept_msg_t *msg
       capture_ipv6_addr(addr, ipv6, sizeof(ipv6));
       char ipv4[20];
       capture_ipv4_addr(&addr[IPv6_INTERFACE_ID_LENGTH], ipv4, sizeof(ipv4));
-      tun_config(1, ipv4, ipv6, "oaitun_ue");
+      char ifname[IFNAMSIZ];
-      setup_ue_ipv4_route(1, ipv4, "oaitun_ue");
+      tun_generate_ifname(ifname, "oaitun_ue", 0);
+      tun_config(ifname, ipv4, ipv6);
+      setup_ue_ipv4_route(ifname, 0, ipv4);
     } break;
 
     default:

openair3/NAS/UE/ESM/esm_ebr_context.c

@@ -207,8 +207,10 @@ int esm_ebr_context_create(
               char *ip_addr = pdn->ip_addr;
               snprintf(ip, sizeof(ip), "%d.%d.%d.%d", ip_addr[0], ip_addr[1], ip_addr[2], ip_addr[3]);
               const char *ifn = get_softmodem_params()->nsa ? "oaitun_nru" : "oaitun_ue";
-              tun_config(1, ip, NULL, ifn);
+              char ifname[IFNAMSIZ];
-              setup_ue_ipv4_route(1, ip, ifn);
+              tun_generate_ifname(ifname, ifn, 0);
+              tun_config(ifname, ip, NULL);
+              setup_ue_ipv4_route(ifname, 0, ip);
             } break;
 
             case NET_PDN_TYPE_IPV6: