Update mud

Required on BSD. Doesn't break anything elsewhere.

src/ip.h

@@ -4,6 +4,7 @@
 
 struct ip_common {
     uint8_t version;
+    uint8_t tc;
     uint8_t proto;
     uint8_t hdr_size;
     uint16_t size;
@@ -24,11 +25,13 @@ static inline int ip_get_common (struct ip_common *ic, const uint8_t *data, size
 
     switch (ic->version) {
     case 4:
+        ic->tc = data[1];
         ic->proto = data[9];
         ic->hdr_size = (data[0]&0xF)<<2;
         ic->size = ((data[2]<<8)|data[3]);
         return 0;
     case 6:
+        ic->tc = ((data[0]&0xF)<<4)|(data[1]>>4);
         ic->proto = data[6];
         ic->hdr_size = 40;
         ic->size = ((data[4]<<8)|data[5])+40;

src/main.c

@@ -252,7 +252,11 @@ int main (int argc, char **argv)
     long time_tolerance = 0;
 
     int v4 = 1;
-    int v6 = 1;
+    int v6 = 0;
+
+#ifdef __linux__
+    v6 = 1;
+#endif
 
     struct option opts[] = {
         { "host",           &host,           option_str    },
@@ -262,7 +266,6 @@ int main (int argc, char **argv)
         { "dev",            &dev,            option_str    },
         { "mtu",            &mtu,            option_long   },
         { "keyfile",        &keyfile,        option_str    },
-        { "multiqueue",     NULL,            option_option },
         { "statefile",      &statefile,      option_str    },
         { "timeout",        &gt.timeout,     option_long   },
         { "time-tolerance", &time_tolerance, option_long   },
@@ -281,13 +284,18 @@ int main (int argc, char **argv)
         return 0;
     }
 
-    if (option_is_set(opts, "v4only"))
+    if (option_is_set(opts, "v4only")) {
+        v4 = 1;
         v6 = 0;
+    }
 
-    if (option_is_set(opts, "v6only"))
+    if (option_is_set(opts, "v6only")) {
         v4 = 0;
+        v6 = 1;
+    }
 
-    if (!v4 && !v6) {
+    if (option_is_set(opts, "v4only") &&
+        option_is_set(opts, "v6only")) {
         gt_log("v4only and v6only are both set\n");
         return 1;
     }
@@ -302,6 +310,15 @@ int main (int argc, char **argv)
         return 1;
     }
 
+    int icmp_fd = -1;
+
+    if (v4) {
+        icmp_fd = socket(AF_INET, SOCK_RAW, IPPROTO_ICMP);
+
+        if (icmp_fd==-1)
+            gt_log("couldn't create ICMP socket\n");
+    }
+
     gt.state_fd = state_create(statefile);
 
     if (statefile && gt.state_fd==-1)
@@ -309,18 +326,23 @@ int main (int argc, char **argv)
 
     char *tun_name = NULL;
 
-    int tun_fd = tun_create(dev, &tun_name, option_is_set(opts, "multiqueue"));
+    int tun_fd = tun_create(dev, &tun_name);
 
     if (tun_fd==-1) {
         gt_log("couldn't create tun device\n");
         return 1;
     }
 
+    if (tun_set_mtu(tun_name, mtu)==-1) {
+        perror("tun_set_mtu");
+        return 1;
+    }
+
     fd_set_nonblock(tun_fd);
 
     int chacha = option_is_set(opts, "chacha20");
 
-    struct mud *mud = mud_create(bind_port, v4, v6, !chacha);
+    struct mud *mud = mud_create(bind_port, v4, v6, !chacha, mtu);
 
     if (!mud) {
         gt_log("couldn't create mud\n");
@@ -375,10 +397,15 @@ int main (int argc, char **argv)
 
     size_t send_size = 0;
     size_t send_limit = 0;
+    int send_tc = 0;
+    int send_next_tc = 0;
 
     while (!gt.quit) {
         FD_SET(tun_fd, &rfds);
 
+        if (icmp_fd!=-1)
+            FD_SET(icmp_fd, &rfds);
+
         if (mud_can_pull(mud)) {
             FD_SET(mud_fd, &rfds);
         } else {
@@ -399,6 +426,26 @@ int main (int argc, char **argv)
             return 1;
         }
 
+        if (icmp_fd!=-1 && FD_ISSET(icmp_fd, &rfds)) {
+            uint8_t buf[1024];
+            struct sockaddr_storage ss;
+            socklen_t sl = sizeof(ss);
+            ssize_t r = recvfrom(icmp_fd, buf, sizeof(buf), 0, (struct sockaddr *)&ss, &sl);
+            if (r>=8) {
+                struct ip_common ic;
+                if (!ip_get_common(&ic, buf, r) && ic.proto==1) {
+                    unsigned char *data = &buf[ic.hdr_size];
+                    if (data[0]==3) {
+                        int new_mtu = (data[6]<<8)|data[7];
+                        if (new_mtu) {
+                            gt_log("received MTU from ICMP: %i\n", new_mtu);
+                            mud_set_mtu(mud, new_mtu-50);
+                        }
+                    }
+                }
+            }
+        }
+
         if (mud_is_up(mud)) {
             if (!started) {
                 state_send(gt.state_fd, "STARTED", tun_name);
@@ -429,28 +476,87 @@ int main (int argc, char **argv)
 
                 send_size += r;
 
-                if (send_size<=mtu)
+                if (send_size<=mtu) {
                     send_limit = send_size;
+                    if ((ic.tc&0xFC)>(send_tc&0xFC))
+                        send_tc = ic.tc;
+                } else {
+                    if ((ic.tc&0xFC)>(send_next_tc&0xFC))
+                        send_next_tc = ic.tc;
+                }
             }
         }
 
-        if (send_limit && mud_send(mud, send.buf, send_limit)==send_limit) {
-            if (send_size>send_limit)
-                memmove(&send.buf[0], &send.buf[send_limit], send_size-send_limit);
-            send_size -= send_limit;
-            send_limit = send_size;
+        if (send_limit) {
+            int r = mud_send(mud, send.buf, send_limit, send_tc);
+
+            if (r==send_limit) {
+                if (send_size>send_limit)
+                    memmove(send.buf, &send.buf[send_limit], send_size-send_limit);
+                send_size -= send_limit;
+                send_limit = send_size;
+                send_tc = send_next_tc;
+                send_next_tc = 0;
+            } else if (r==-1) {
+                if (errno==EMSGSIZE) {
+                    long new_mtu = mud_get_mtu(mud);
+                    if (new_mtu!=mtu) {
+                        size_t total = send_size;
+
+                        if (tun_set_mtu(tun_name, new_mtu)==-1) {
+                            perror("tun_set_mtu");
+                            gt.quit |= 1;
+                            break;
+                        }
+
+                        gt_log("MTU changed: %li\n", new_mtu);
+
+                        mtu = new_mtu;
+                        send_size = 0;
+                        send_limit = 0;
+                        send_tc = 0;
+                        send_next_tc = 0;
+
+                        while (send_size<total) {
+                            struct ip_common ic;
+
+                            if (ip_get_common(&ic, send.buf+send_size, mtu))
+                                break;
+
+                            send_size += ic.size;
+
+                            if (send_size<=mtu) {
+                                send_limit = send_size;
+                                if ((ic.tc&0xFC)>(send_tc&0xFC))
+                                    send_tc = ic.tc;
+                            } else {
+                                if ((ic.tc&0xFC)>(send_next_tc&0xFC))
+                                    send_next_tc = ic.tc;
+                            }
+                        }
+                    }
+                } else if (errno!=EAGAIN) {
+                    perror("mud_send");
+                }
+            }
         }
 
-        mud_push(mud);
+        if (mud_push(mud)==-1 && errno!=EAGAIN)
+            perror("mud_push");
 
-        if (FD_ISSET(mud_fd, &rfds))
-            mud_pull(mud);
+        if (FD_ISSET(mud_fd, &rfds)) {
+            if (mud_pull(mud)==-1 && errno!=EAGAIN)
+                perror("mud_pull");
+        }
 
         while (!gt.quit) {
             const int size = mud_recv(mud, recv.buf, mtu);
 
-            if (size<=0)
+            if (size<=0) {
+                if (size==-1 && errno!=EAGAIN)
+                    perror("mud_recv");
                 break;
+            }
 
             int p = 0;
 

src/tun.c

@@ -11,8 +11,9 @@
 #include <sys/socket.h>
 #include <sys/uio.h>
 
+#include <net/if.h>
+
 #ifdef __linux__
-#include <linux/if.h>
 #include <linux/if_tun.h>
 #endif
 
@@ -28,7 +29,7 @@
 
 #ifdef __APPLE__
 
-static int tun_create_by_id (char *name, size_t size, unsigned id, _unused_ int mq)
+static int tun_create_by_id (char *name, size_t size, unsigned id)
 {
     int fd = socket(PF_SYSTEM, SOCK_DGRAM, SYSPROTO_CONTROL);
 
@@ -63,21 +64,21 @@ static int tun_create_by_id (char *name, size_t size, unsigned id, _unused_ int
     return fd;
 }
 
-static int tun_create_by_name (char *name, size_t size, char *dev_name, int mq)
+static int tun_create_by_name (char *name, size_t size, char *dev_name)
 {
     unsigned id = 0;
 
     if (sscanf(dev_name, "utun%u", &id)!=1)
         return -1;
 
-    return tun_create_by_id(name, size, id, mq);
+    return tun_create_by_id(name, size, id);
 }
 
 #else /* not __APPLE__ */
 
 #ifdef __linux__
 
-static int tun_create_by_name (char *name, size_t size, char *dev_name, int mq)
+static int tun_create_by_name (char *name, size_t size, char *dev_name)
 {
     int fd = open("/dev/net/tun", O_RDWR);
 
@@ -88,12 +89,6 @@ static int tun_create_by_name (char *name, size_t size, char *dev_name, int mq)
         .ifr_flags = IFF_TUN|IFF_NO_PI,
     };
 
-    if (mq) {
-#ifdef IFF_MULTI_QUEUE
-        ifr.ifr_flags |= IFF_MULTI_QUEUE;
-#endif
-    }
-
     str_cpy(ifr.ifr_name, dev_name, IFNAMSIZ-1);
 
     if (ioctl(fd, TUNSETIFF, &ifr)) {
@@ -108,7 +103,7 @@ static int tun_create_by_name (char *name, size_t size, char *dev_name, int mq)
 
 #else /* not __linux__ not __APPLE__ */
 
-static int tun_create_by_name (char *name, size_t size, char *dev_name, _unused_ int mq)
+static int tun_create_by_name (char *name, size_t size, char *dev_name)
 {
     char path[64];
 
@@ -120,32 +115,27 @@ static int tun_create_by_name (char *name, size_t size, char *dev_name, _unused_
 
 #endif /* not __APPLE__ */
 
-static int tun_create_by_id (char *name, size_t size, unsigned id, int mq)
+static int tun_create_by_id (char *name, size_t size, unsigned id)
 {
     char dev_name[64];
 
     snprintf(dev_name, sizeof(dev_name), "tun%u", id);
 
-    return tun_create_by_name(name, size, dev_name, mq);
+    return tun_create_by_name(name, size, dev_name);
 }
 
 #endif
 
-int tun_create (char *dev_name, char **ret_name, int mq)
+int tun_create (char *dev_name, char **ret_name)
 {
     char name[64] = {0};
     int fd = -1;
 
-#ifndef IFF_MULTI_QUEUE
-    if (mq)
-        gt_na("IFF_MULTI_QUEUE");
-#endif
-
     if (str_empty(dev_name)) {
         for (unsigned id=0; id<32 && fd==-1; id++)
-            fd = tun_create_by_id(name, sizeof(name), id, mq);
+            fd = tun_create_by_id(name, sizeof(name), id);
     } else {
-        fd = tun_create_by_name(name, sizeof(name), dev_name, mq);
+        fd = tun_create_by_name(name, sizeof(name), dev_name);
     }
 
     if (fd!=-1 && ret_name)
@@ -240,3 +230,25 @@ ssize_t tun_write (int fd, const void *data, size_t size)
     return ret;
 #endif
 }
+
+int tun_set_mtu (char *dev_name, int mtu)
+{
+    struct ifreq ifr = {
+        .ifr_mtu = mtu,
+    };
+
+    str_cpy(ifr.ifr_name, dev_name, IFNAMSIZ-1);
+
+    int fd = socket(AF_INET, SOCK_DGRAM, 0);
+
+    if (fd==-1)
+        return -1;
+
+    int ret = ioctl(fd, SIOCSIFMTU, &ifr);
+
+    int err = errno;
+    close(fd);
+    errno = err;
+
+    return ret;
+}

src/tun.h

@@ -2,6 +2,7 @@
 
 #include <unistd.h>
 
-int     tun_create (char *, char **, int);
-ssize_t tun_read   (int, void *, size_t);
-ssize_t tun_write  (int, const void *, size_t);
+int     tun_create  (char *, char **);
+ssize_t tun_read    (int, void *, size_t);
+ssize_t tun_write   (int, const void *, size_t);
+int     tun_set_mtu (char *, int);