Remove netlink_init.c, and move remaining functionality to tun_if.c

Remove openair1/SIMULATION/ETH_TRANSPORT/netlink_init.c, and move TUN
interface creation functionality to tun_if.c.

Remove SIMU_ETH target.

common/utils/tun_if.c

@@ -27,11 +27,106 @@
 #include <netinet/in.h>
 #include <arpa/inet.h>
 #include <linux/ipv6.h>
+#include <linux/if_tun.h>
+#include <linux/netlink.h>
 
 #include "tun_if.h"
+#include "common/platform_constants.h"
 #include "common/utils/LOG/log.h"
 #include "common/utils/system.h"
 
+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)
+{
+  struct ifreq ifr;
+  int fd, err;
+
+  if ((fd = open("/dev/net/tun", O_RDWR)) < 0) {
+    LOG_E(UTIL, "failed to open /dev/net/tun\n");
+    return -1;
+  }
+
+  memset(&ifr, 0, sizeof(ifr));
+  /* Flags: IFF_TUN   - TUN device (no Ethernet headers)
+   *        IFF_TAP   - TAP device
+   *
+   *        IFF_NO_PI - Do not provide packet information
+   */
+  ifr.ifr_flags = IFF_TUN | IFF_NO_PI;
+
+  if (*dev)
+    strncpy(ifr.ifr_name, dev, sizeof(ifr.ifr_name) - 1);
+
+  if ((err = ioctl(fd, TUNSETIFF, (void *)&ifr)) < 0) {
+    close(fd);
+    return err;
+  }
+
+  strcpy(dev, ifr.ifr_name);
+  return fd;
+}
+
+int tun_init_mbms(char *ifprefix, int id)
+{
+  int ret;
+  char ifname[64];
+
+  sprintf(ifname, "%s%d", ifprefix, id);
+  nas_sock_mbms_fd = tun_alloc(ifname);
+
+  if (nas_sock_mbms_fd == -1) {
+    LOG_E(UTIL, "Error opening mbms socket %s (%d:%s)\n", ifname, errno, strerror(errno));
+    exit(1);
+  }
+
+  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));
+
+  return 1;
+}
+
+int tun_init(const char *ifprefix, int num_if, int id)
+{
+  int ret;
+  char ifname[64];
+
+  int begx = (id == 0) ? 0 : id - 1;
+  int endx = (id == 0) ? num_if : id;
+  for (int i = begx; i < endx; i++) {
+    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;
+    }
+  }
+
+  return 1;
+}
+
 /*
  * \brief set a genneric interface parameter
  * \param ifn the name of the interface to modify

common/utils/tun_if.h

@@ -24,6 +24,12 @@
 
 #include <stdbool.h>
 
+/* TODO: doc */
+int tun_init(const char *ifprefix, int num_if, int id);
+
+/* TODO: doc */
+int tun_init_mbms(char *ifsuffix, int id);
+
 /*! \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