Improve tap device initialization

Author: danielinux

src/port/posix/tap_darwin.c

@@ -245,6 +245,42 @@ static int tap_setup_ipv4(const char *ifname, uint32_t host_ip, uint32_t peer_ip
     return 0;
 }
 
+static int tap_wait_ready(const char *ifname, uint32_t host_ip)
+{
+    const int max_tries = 50;
+    const useconds_t delay_us = 100 * 1000;
+
+    for (int i = 0; i < max_tries; i++) {
+        struct ifaddrs *ifas = NULL;
+        int ready = 0;
+
+        if (getifaddrs(&ifas) == 0) {
+            for (struct ifaddrs *ifa = ifas; ifa; ifa = ifa->ifa_next) {
+                struct sockaddr_in *sin;
+                if (!ifa->ifa_addr)
+                    continue;
+                if (strcmp(ifa->ifa_name, ifname) != 0)
+                    continue;
+                if ((ifa->ifa_flags & (IFF_UP | IFF_RUNNING)) != (IFF_UP | IFF_RUNNING))
+                    continue;
+                if (ifa->ifa_addr->sa_family != AF_INET)
+                    continue;
+                sin = (struct sockaddr_in *)ifa->ifa_addr;
+                if (sin->sin_addr.s_addr == host_ip) {
+                    ready = 1;
+                    break;
+                }
+            }
+            freeifaddrs(ifas);
+        }
+
+        if (ready)
+            return 0;
+        usleep(delay_us);
+    }
+    return -1;
+}
+
 int tap_init(struct wolfIP_ll_dev *ll, const char *requested_ifname, uint32_t host_ip)
 {
     struct ctl_info info;
@@ -309,6 +345,13 @@ int tap_init(struct wolfIP_ll_dev *ll, const char *requested_ifname, uint32_t ho
         return -1;
     }
 
+    if (tap_wait_ready(ifname_buf, host_ip) < 0) {
+        fprintf(stderr, "tap_init: interface %s not ready\n", ifname_buf);
+        close(utun_fd);
+        utun_fd = -1;
+        return -1;
+    }
+
     return 0;
 }
 

src/port/posix/tap_freebsd.c

@@ -167,6 +167,42 @@ static void tap_fetch_mac(struct wolfIP_ll_dev *ll)
     freeifaddrs(ifas);
 }
 
+static int tap_wait_ready(const char *ifname, uint32_t host_ip)
+{
+    const int max_tries = 50;
+    const useconds_t delay_us = 100 * 1000;
+
+    for (int i = 0; i < max_tries; i++) {
+        struct ifaddrs *ifas = NULL;
+        int ready = 0;
+
+        if (getifaddrs(&ifas) == 0) {
+            for (struct ifaddrs *ifa = ifas; ifa; ifa = ifa->ifa_next) {
+                struct sockaddr_in *sin;
+                if (!ifa->ifa_addr)
+                    continue;
+                if (strcmp(ifa->ifa_name, ifname) != 0)
+                    continue;
+                if ((ifa->ifa_flags & (IFF_UP | IFF_RUNNING)) != (IFF_UP | IFF_RUNNING))
+                    continue;
+                if (ifa->ifa_addr->sa_family != AF_INET)
+                    continue;
+                sin = (struct sockaddr_in *)ifa->ifa_addr;
+                if (sin->sin_addr.s_addr == host_ip) {
+                    ready = 1;
+                    break;
+                }
+            }
+            freeifaddrs(ifas);
+        }
+
+        if (ready)
+            return 0;
+        usleep(delay_us);
+    }
+    return -1;
+}
+
 int tap_init(struct wolfIP_ll_dev *ll, const char *ifname, uint32_t host_ip)
 {
     char devpath[PATH_MAX];
@@ -232,6 +268,14 @@ int tap_init(struct wolfIP_ll_dev *ll, const char *ifname, uint32_t host_ip)
         return -1;
     }
 
+    if (tap_wait_ready(ll->ifname, host_ip) < 0) {
+        fprintf(stderr, "tap_init: interface %s not ready\n", ll->ifname);
+        close(sock_fd);
+        close(tap_fd);
+        tap_fd = -1;
+        return -1;
+    }
+
     close(sock_fd);
     printf("Successfully initialized tap device %s\n", ll->ifname);
     return 0;

src/port/posix/tap_linux.c

@@ -77,6 +77,44 @@ static int tap_send(struct wolfIP_ll_dev *ll, void *buf, uint32_t len)
     return write(tap_fd, buf, len);
 }
 
+static int tap_wait_ready(const char *ifname, uint32_t host_ip)
+{
+    const int max_tries = 50;
+    const useconds_t delay_us = 100 * 1000;
+
+    for (int i = 0; i < max_tries; i++) {
+        int sock_fd;
+        struct ifreq ifr;
+        struct sockaddr_in *addr;
+        int flags_ready = 0;
+        int addr_ready = 0;
+
+        sock_fd = socket(AF_INET, SOCK_DGRAM, 0);
+        if (sock_fd < 0) {
+            perror("socket");
+            return -1;
+        }
+        memset(&ifr, 0, sizeof(ifr));
+        strncpy(ifr.ifr_name, ifname, IFNAMSIZ);
+        ifr.ifr_name[IFNAMSIZ - 1] = '\0';
+        if (ioctl(sock_fd, SIOCGIFFLAGS, &ifr) == 0) {
+            if ((ifr.ifr_flags & (IFF_UP | IFF_RUNNING)) == (IFF_UP | IFF_RUNNING))
+                flags_ready = 1;
+        }
+        if (ioctl(sock_fd, SIOCGIFADDR, &ifr) == 0) {
+            addr = (struct sockaddr_in *)&ifr.ifr_addr;
+            if (addr->sin_addr.s_addr == host_ip)
+                addr_ready = 1;
+        }
+        close(sock_fd);
+
+        if (flags_ready && addr_ready)
+            return 0;
+        usleep(delay_us);
+    }
+    return -1;
+}
+
 int tap_init(struct wolfIP_ll_dev *ll, const char *ifname, uint32_t host_ip)
 {
     struct ifreq ifr;
@@ -173,6 +211,11 @@ int tap_init(struct wolfIP_ll_dev *ll, const char *ifname, uint32_t host_ip)
         close(sock_fd);
         return -1;
     }
+    if (tap_wait_ready(ifname, host_ip) < 0) {
+        fprintf(stderr, "tap_init: interface %s not ready\n", ifname);
+        close(sock_fd);
+        return -1;
+    }
     printf("Successfully initialized tap device %s\n", ifname);
     return 0;
 }